Merge branch 'bmk/20180918/nififying_inet/OTP-14831' into bmk/20190204/socket_as_nif/OTP-14831

9 files changed, 22737 insertions, 0 deletions

diff --git a/erts/emulator/nifs/common/net_nif.c b/erts/emulator/nifs/common/net_nif.c
new file mode 100644
index 0000000000..d48112133f
--- /dev/null
+++ b/erts/emulator/nifs/common/net_nif.c
@@ -0,0 +1,1683 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : The NIF (C) part of the net interface
+ *            This is a module of miscellaneous functions.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#define STATIC_ERLANG_NIF 1
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* If we HAVE_SCTP_H and Solaris, we need to define the following in
+ * order to get SCTP working:
+ */
+#if (defined(HAVE_SCTP_H) && defined(__sun) && defined(__SVR4))
+#define SOLARIS10    1
+/* WARNING: This is not quite correct, it may also be Solaris 11! */
+#define _XPG4_2
+#define __EXTENSIONS__
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <time.h>
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_SYS_UIO_H
+#include <sys/uio.h>
+#endif
+
+#ifdef HAVE_NET_IF_DL_H
+#include <net/if_dl.h>
+#endif
+
+#ifdef HAVE_IFADDRS_H
+#include <ifaddrs.h>
+#endif
+
+#ifdef HAVE_NETPACKET_PACKET_H
+#include <netpacket/packet.h>
+#endif
+
+#ifdef HAVE_SYS_UN_H
+#include <sys/un.h>
+#endif
+
+/* SENDFILE STUFF HERE IF WE NEED IT... */
+
+#if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__)
+#define __DARWIN__ 1
+#endif
+
+
+#ifdef __WIN32__
+#define STRNCASECMP               strncasecmp
+#define INCL_WINSOCK_API_TYPEDEFS 1
+
+#ifndef WINDOWS_H_INCLUDES_WINSOCK2_H
+#include <winsock2.h>
+#endif
+#include <windows.h>
+#include <Ws2tcpip.h>   /* NEED VC 6.0 or higher */
+
+/* Visual studio 2008+: NTDDI_VERSION needs to be set for iphlpapi.h
+ * to define the right structures. It needs to be set to WINXP (or LONGHORN)
+ * for IPV6 to work and it's set lower by default, so we need to change it.
+ */
+#ifdef HAVE_SDKDDKVER_H
+#  include <sdkddkver.h>
+#  ifdef NTDDI_VERSION
+#    undef NTDDI_VERSION
+#  endif
+#  define NTDDI_VERSION NTDDI_WINXP
+#endif
+#include <iphlpapi.h>
+
+#undef WANT_NONBLOCKING
+#include "sys.h"
+
+#else /* !__WIN32__ */
+
+#include <sys/time.h>
+#ifdef NETDB_H_NEEDS_IN_H
+#include <netinet/in.h>
+#endif
+#include <netdb.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#ifdef DEF_INADDR_LOOPBACK_IN_RPC_TYPES_H
+#include <rpc/types.h>
+#endif
+
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <arpa/inet.h>
+
+#include <sys/param.h>
+#ifdef HAVE_ARPA_NAMESER_H
+#include <arpa/nameser.h>
+#endif
+
+#ifdef HAVE_SYS_SOCKIO_H
+#include <sys/sockio.h>
+#endif
+
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
+#include <net/if.h>
+
+#ifdef HAVE_SCHED_H
+#include <sched.h>
+#endif
+
+#ifdef HAVE_SETNS_H
+#include <setns.h>
+#endif
+
+#define HAVE_UDP
+
+#ifndef WANT_NONBLOCKING
+#define WANT_NONBLOCKING
+#endif
+#include "sys.h"
+
+#endif
+
+#include <erl_nif.h>
+
+#include "socket_dbg.h"
+#include "socket_int.h"
+#include "socket_util.h"
+
+
+/* All platforms fail on malloc errors. */
+#define FATAL_MALLOC
+
+
+#ifdef __WIN32__
+#define net_gethostname(__buf__, __bufSz__) gethostname((__buf__), (__bufSz__))
+#else
+#define net_gethostname(__buf__, __bufSz__) gethostname((__buf__), (__bufSz__))
+#endif // __WIN32__
+
+
+
+/* *** Misc macros and defines *** */
+
+#ifdef __WIN32__
+#define get_errno() WSAGetLastError()
+#else
+#define get_errno() errno
+#endif
+
+
+#define HOSTNAME_LEN 256
+#define SERVICE_LEN  256
+
+
+/* MAXHOSTNAMELEN could be 64 or 255 depending
+ * on the platform. Instead, use INET_MAXHOSTNAMELEN
+ * which is always 255 across all platforms
+ */
+#define NET_MAXHOSTNAMELEN 255
+
+
+/* =================================================================== *
+ *                                                                     *
+ *                        Various enif macros                          *
+ *                                                                     *
+ * =================================================================== */
+
+
+#ifdef HAVE_SOCKLEN_T
+#  define SOCKLEN_T socklen_t
+#else
+#  define SOCKLEN_T size_t
+#endif
+
+/* Debug stuff... */
+#define NET_NIF_DEBUG_DEFAULT FALSE
+
+#define NDBG( proto ) ESOCK_DBG_PRINTF( data.debug , proto )
+
+
+typedef struct {
+    BOOLEAN_T debug;
+} NetData;
+
+
+
+/* =================================================================== *
+ *                                                                     *
+ *                           Static data                               *
+ *                                                                     *
+ * =================================================================== */
+
+
+static NetData data;
+
+
+
+/* ----------------------------------------------------------------------
+ *  F o r w a r d s
+ * ----------------------------------------------------------------------
+ */
+
+/* THIS IS JUST TEMPORARY */
+extern char* erl_errno_id(int error);
+
+
+static ERL_NIF_TERM nif_info(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_command(ErlNifEnv*         env,
+                                int                argc,
+                                const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM nif_gethostname(ErlNifEnv*         env,
+                                    int                argc,
+                                    const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM nif_getnameinfo(ErlNifEnv*         env,
+                                    int                argc,
+                                    const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_getaddrinfo(ErlNifEnv*         env,
+                                    int                argc,
+                                    const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM nif_if_name2index(ErlNifEnv*         env,
+                                      int                argc,
+                                      const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_if_index2name(ErlNifEnv*         env,
+                                      int                argc,
+                                      const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_if_names(ErlNifEnv*         env,
+                                 int                argc,
+                                 const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM ncommand(ErlNifEnv*   env,
+                             ERL_NIF_TERM cmd);
+static ERL_NIF_TERM ngethostname(ErlNifEnv* env);
+static ERL_NIF_TERM ngetnameinfo(ErlNifEnv*           env,
+                                 const SocketAddress* saP,
+                                 SOCKLEN_T            saLen,
+                                 int                  flags);
+static ERL_NIF_TERM ngetaddrinfo(ErlNifEnv* env,
+                                 char*      host,
+                                 char*      serv);
+static ERL_NIF_TERM nif_name2index(ErlNifEnv* env,
+                                   char*      ifn);
+static ERL_NIF_TERM nif_index2name(ErlNifEnv*   env,
+                                   unsigned int id);
+static ERL_NIF_TERM nif_names(ErlNifEnv* env);
+static unsigned int nif_names_length(struct if_nameindex* p);
+
+/*
+static void net_dtor(ErlNifEnv* env, void* obj);
+static void net_stop(ErlNifEnv* env,
+                     void*      obj,
+                     int        fd,
+                     int        is_direct_call);
+static void net_down(ErlNifEnv*           env,
+                     void*                obj,
+                     const ErlNifPid*     pid,
+                     const ErlNifMonitor* mon);
+*/
+
+static BOOLEAN_T decode_nameinfo_flags(ErlNifEnv*         env,
+                                       const ERL_NIF_TERM eflags,
+                                       int*               flags);
+static BOOLEAN_T decode_nameinfo_flags_list(ErlNifEnv*         env,
+                                            const ERL_NIF_TERM eflags,
+                                            int*               flags);
+static
+BOOLEAN_T decode_addrinfo_string(ErlNifEnv*         env,
+                                 const ERL_NIF_TERM eString,
+                                 char**             stringP);
+static ERL_NIF_TERM decode_bool(ErlNifEnv*   env,
+                                ERL_NIF_TERM eBool,
+                                BOOLEAN_T*   bool);
+static ERL_NIF_TERM encode_address_infos(ErlNifEnv*       env,
+                                         struct addrinfo* addrInfo);
+static ERL_NIF_TERM encode_address_info(ErlNifEnv*       env,
+                                        struct addrinfo* addrInfoP);
+static unsigned int address_info_length(struct addrinfo* addrInfoP);
+
+static ERL_NIF_TERM encode_address_info_family(ErlNifEnv* env,
+                                         int        family);
+static ERL_NIF_TERM encode_address_info_type(ErlNifEnv* env,
+                                       int        socktype);
+static ERL_NIF_TERM encode_address_info_proto(ErlNifEnv* env,
+                                        int        proto);
+
+static char* make_address_info(ErlNifEnv*    env,
+                               ERL_NIF_TERM  fam,
+                               ERL_NIF_TERM  sockType,
+                               ERL_NIF_TERM  proto,
+                               ERL_NIF_TERM  addr,
+                               ERL_NIF_TERM* ai);
+
+static BOOLEAN_T extract_debug(ErlNifEnv*   env,
+                               ERL_NIF_TERM map);
+static int on_load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info);
+
+
+#if HAVE_IN6
+#  if ! defined(HAVE_IN6ADDR_ANY) || ! HAVE_IN6ADDR_ANY
+#    if HAVE_DECL_IN6ADDR_ANY_INIT
+static const struct in6_addr in6addr_any = { { IN6ADDR_ANY_INIT } };
+#    else
+static const struct in6_addr in6addr_any =
+    { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } };
+#    endif /* HAVE_IN6ADDR_ANY_INIT */
+#  endif /* ! HAVE_DECL_IN6ADDR_ANY */
+
+#  if ! defined(HAVE_IN6ADDR_LOOPBACK) || ! HAVE_IN6ADDR_LOOPBACK
+#    if HAVE_DECL_IN6ADDR_LOOPBACK_INIT
+static const struct in6_addr in6addr_loopback =
+    { { IN6ADDR_LOOPBACK_INIT } };
+#    else
+static const struct in6_addr in6addr_loopback =
+    { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 } } };
+#    endif /* HAVE_IN6ADDR_LOOPBACk_INIT */
+#  endif /* ! HAVE_DECL_IN6ADDR_LOOPBACK */
+#endif /* HAVE_IN6 */
+
+
+
+/* *** String constants *** */
+static char str_address_info[]              = "address_info";
+static char str_debug[]                     = "debug";
+static char str_idn[]                       = "idn";
+static char str_idna_allow_unassigned[]     = "idna_allow_unassigned";
+static char str_idna_use_std3_ascii_rules[] = "idna_use_std3_ascii_rules";
+static char str_namereqd[]                  = "namereqd";
+static char str_name_info[]                 = "name_info";
+static char str_nofqdn[]                    = "nofqdn";
+static char str_numerichost[]               = "numerichost";
+static char str_numericserv[]               = "numericserv";
+
+/* (special) error string constants */
+static char str_eaddrfamily[]       = "eaddrfamily";
+static char str_ebadflags[]         = "ebadflags";
+static char str_efail[]             = "efail";
+static char str_efamily[]           = "efamily";
+static char str_efault[]            = "efault";
+static char str_emem[]              = "emem";
+static char str_enametoolong[]      = "enametoolong";
+static char str_enodata[]           = "enodata";
+static char str_enoname[]           = "enoname";
+static char str_enxio[]             = "enxio";
+static char str_eoverflow[]         = "eoverflow";
+static char str_eservice[]          = "eservice";
+static char str_esocktype[]         = "esocktype";
+static char str_esystem[]           = "esystem";
+
+
+/* *** Atoms *** */
+
+static ERL_NIF_TERM atom_address_info;
+static ERL_NIF_TERM atom_debug;
+static ERL_NIF_TERM atom_idn;
+static ERL_NIF_TERM atom_idna_allow_unassigned;
+static ERL_NIF_TERM atom_idna_use_std3_ascii_rules;
+static ERL_NIF_TERM atom_namereqd;
+static ERL_NIF_TERM atom_name_info;
+static ERL_NIF_TERM atom_nofqdn;
+static ERL_NIF_TERM atom_numerichost;
+static ERL_NIF_TERM atom_numericserv;
+
+
+static ERL_NIF_TERM atom_eaddrfamily;
+// static ERL_NIF_TERM atom_eagain;
+static ERL_NIF_TERM atom_ebadflags;
+static ERL_NIF_TERM atom_efail;
+static ERL_NIF_TERM atom_efamily;
+static ERL_NIF_TERM atom_efault;
+static ERL_NIF_TERM atom_emem;
+static ERL_NIF_TERM atom_enametoolong;
+static ERL_NIF_TERM atom_enodata;
+static ERL_NIF_TERM atom_enoname;
+static ERL_NIF_TERM atom_enxio;
+static ERL_NIF_TERM atom_eoverflow;
+static ERL_NIF_TERM atom_eservice;
+static ERL_NIF_TERM atom_esocktype;
+static ERL_NIF_TERM atom_esystem;
+
+
+/* *** net *** */
+static ErlNifResourceType*    net;
+static ErlNifResourceTypeInit netInit = {
+    NULL, // net_dtor,
+    NULL, // net_stop,
+    NULL  // (ErlNifResourceDown*) net_down
+};
+
+
+
+/* ----------------------------------------------------------------------
+ *  N I F   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ *
+ * Utility and admin functions:
+ * ----------------------------
+ * nif_info/0
+ * nif_command/1
+ *
+ * The "proper" net functions:
+ * ------------------------------
+ * nif_gethostname/0
+ * nif_getnameinfo/2
+ * nif_getaddrinfo/3
+ * nif_if_name2index/1
+ * nif_if_index2name/1
+ * nif_if_names/0
+ *
+ */
+
+
+/* ----------------------------------------------------------------------
+ * nif_info
+ *
+ * Description:
+ * This is currently just a placeholder...
+ */
+static
+ERL_NIF_TERM nif_info(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    ERL_NIF_TERM info, tmp;
+
+    NDBG( ("NET", "info -> entry\r\n") );
+
+    tmp  = enif_make_new_map(env);
+    if (!enif_make_map_put(env, tmp, atom_debug, BOOL2ATOM(data.debug), &info))
+        info = tmp;
+
+    NDBG( ("NET", "info -> done: %T\r\n", info) );
+
+    return info;
+#endif
+}
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_command
+ *
+ * Description:
+ * This is a general purpose utility function.
+ *
+ * Arguments:
+ * Command - This is a general purpose command, of any type.
+ *           Currently, the only supported command is:
+ *
+ *                  {debug, boolean()}
+ */
+static
+ERL_NIF_TERM nif_command(ErlNifEnv*         env,
+                         int                argc,
+                         const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    ERL_NIF_TERM ecmd, result;
+
+    NDBG( ("NET", "command -> entry (%d)\r\n", argc) );
+
+    if (argc != 1)
+        return enif_make_badarg(env);
+
+    ecmd = argv[0];
+
+    NDBG( ("NET", "command -> ecmd: %T\r\n", ecmd) );
+
+    result = ncommand(env, ecmd);
+
+    NDBG( ("NET", "command -> result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+/*
+ * The command can, in principle, be anything, though currently we only
+ * support a debug command.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ncommand(ErlNifEnv*   env,
+                      ERL_NIF_TERM cmd)
+{
+    const ERL_NIF_TERM* t;
+    int                 tsz;
+
+    if (IS_TUPLE(env, cmd)) {
+        /* Could be the debug tuple */
+        if (!GET_TUPLE(env, cmd, &tsz, &t))
+            return esock_make_error(env, esock_atom_einval);
+
+        if (tsz != 2)
+            return esock_make_error(env, esock_atom_einval);
+
+        /* First element should be the atom 'debug' */
+        if (COMPARE(t[0], atom_debug) != 0)
+            return esock_make_error(env, esock_atom_einval);
+
+        return decode_bool(env, t[1], &data.debug);
+
+    } else {
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_gethostname
+ *
+ * Description:
+ * Access the hostname of the current processor.
+ *
+ */
+static
+ERL_NIF_TERM nif_gethostname(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    ERL_NIF_TERM result;
+    
+    NDBG( ("NET", "nif_gethostname -> entry (%d)\r\n", argc) );
+
+    if (argc != 0)
+        return enif_make_badarg(env);
+
+    result = ngethostname(env);
+
+    NDBG( ("NET", "nif_gethostname -> done when result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ngethostname(ErlNifEnv* env)
+{
+    ERL_NIF_TERM result;
+    char         buf[NET_MAXHOSTNAMELEN + 1];
+    int          res;
+
+    res = net_gethostname(buf, sizeof(buf));
+
+    NDBG( ("NET", "ngethostname -> gethostname res: %d\r\n", res) );
+
+    switch (res) {
+    case 0:
+        result = esock_make_ok2(env, MKS(env, buf));
+        break;
+
+    case EFAULT:
+        result = esock_make_error(env, atom_efault);
+        break;
+
+    case EINVAL:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+
+    case ENAMETOOLONG:
+        result = esock_make_error(env, atom_enametoolong);
+        break;
+
+    default:
+        result = esock_make_error(env, MKI(env, res));
+        break;
+    }
+
+    return result;
+}
+#endif
+
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_getnameinfo
+ *
+ * Description:
+ * Address-to-name translation in protocol-independent manner.
+ *
+ * Arguments:
+ * SockAddr - Socket Address (address and port)
+ * Flags    - The flags argument modifies the behavior of getnameinfo().
+ */
+
+static
+ERL_NIF_TERM nif_getnameinfo(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    ERL_NIF_TERM  result;
+    ERL_NIF_TERM  eSockAddr, eFlags;
+    int           flags = 0; // Just in case...
+    SocketAddress sa;
+    SOCKLEN_T     saLen = 0; // Just in case...
+
+    NDBG( ("NET", "nif_getnameinfo -> entry (%d)\r\n", argc) );
+
+    if (argc != 2)
+        return enif_make_badarg(env);
+    eSockAddr = argv[0];
+    eFlags    = argv[1];
+
+    NDBG( ("NET",
+           "nif_getnameinfo -> "
+           "\r\n   SockAddr: %T"
+           "\r\n   Flags:    %T"
+           "\r\n", eSockAddr, eFlags) );
+
+    if (!esock_decode_sockaddr(env, eSockAddr, &sa, &saLen))
+        return enif_make_badarg(env);
+
+    if (!decode_nameinfo_flags(env, eFlags, &flags))
+        return enif_make_badarg(env);
+
+    result = ngetnameinfo(env, &sa, saLen, flags);
+
+    NDBG( ("NET",
+           "nif_getnameinfo -> done when result: "
+           "\r\n   %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+/* Given the provided sock(et) address (and honts), retreive the host and
+ * service info.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ngetnameinfo(ErlNifEnv*           env,
+                          const SocketAddress* saP,
+                          SOCKLEN_T            saLen,
+                          int                  flags)
+{
+    ERL_NIF_TERM result;
+    char         host[HOSTNAME_LEN];
+    SOCKLEN_T    hostLen = sizeof(host);
+    char         serv[SERVICE_LEN];
+    SOCKLEN_T    servLen = sizeof(serv);
+
+    int res = getnameinfo((struct sockaddr*) saP, saLen,
+                          host, hostLen,
+                          serv, servLen,
+                          flags);
+
+    NDBG( ("NET", "ngetnameinfo -> res: %d\r\n", res) );
+
+    switch (res) {
+    case 0:
+        {
+            ERL_NIF_TERM info = MKT3(env,
+                                     atom_name_info,
+                                     MKS(env, host),
+                                     MKS(env, serv));
+            result = esock_make_ok2(env, info);
+        }
+        break;
+
+#if defined(EAI_AGAIN)
+    case EAI_AGAIN:
+        result = esock_make_error(env, esock_atom_eagain);
+        break;
+#endif
+
+#if defined(EAI_BADFLAGS)
+    case EAI_BADFLAGS:
+        result = esock_make_error(env, atom_ebadflags);
+        break;
+#endif
+
+#if defined(EAI_FAIL)
+    case EAI_FAIL:
+        result = esock_make_error(env, atom_efail);
+        break;
+#endif
+
+#if defined(EAI_FAMILY)
+    case EAI_FAMILY:
+        result = esock_make_error(env, atom_efamily);
+        break;
+#endif
+
+#if defined(EAI_MEMORY)
+    case EAI_MEMORY:
+        result = esock_make_error(env, atom_emem);
+        break;
+#endif
+
+#if defined(EAI_NONAME)
+    case EAI_NONAME:
+        result = esock_make_error(env, atom_enoname);
+        break;
+#endif
+
+#if defined(EAI_OVERFLOW)
+    case EAI_OVERFLOW:
+        result = esock_make_error(env, atom_eoverflow);
+        break;
+#endif
+
+#if defined(EAI_SYSTEM)
+    case EAI_SYSTEM:
+        result = esock_make_error_errno(env, get_errno());
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_getaddrinfo
+ *
+ * Description:
+ * Network address and service translation.
+ *
+ * Arguments:
+ * Host    - Host name (either a string or the atom undefined)
+ * Service - Service name (either a string or the atom undefined)
+ * Hints   - Hints for the lookup (address info record) (currently *ignored*)
+ */
+
+static
+ERL_NIF_TERM nif_getaddrinfo(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    ERL_NIF_TERM     result, eHostName, eServName; //, eHints;
+    char*            hostName;
+    char*            servName;
+    // struct addrinfo* hints;
+
+    NDBG( ("NET", "nif_getaddrinfo -> entry (%d)\r\n", argc) );
+
+    if (argc != 3) {
+        return enif_make_badarg(env);
+    }
+    eHostName = argv[0];
+    eServName = argv[1];
+    // eHints    = argv[2];
+
+    NDBG( ("NET",
+           "nif_getaddrinfo -> "
+           "\r\n   ehost:    %T"
+           "\r\n   eservice: %T"
+           "\r\n   ehints:   %T"
+           "\r\n", argv[0], argv[1], argv[2]) );
+
+    if (!decode_addrinfo_string(env, eHostName, &hostName))
+        return enif_make_badarg(env);
+
+    if (!decode_addrinfo_string(env, eServName, &servName))
+        return enif_make_badarg(env);
+
+    /*
+    if (decode_addrinfo_hints(env, eHints, &hints))
+        return enif_make_badarg(env);
+    */
+
+    if ((hostName == NULL) && (servName == NULL))
+        return enif_make_badarg(env);
+
+    result = ngetaddrinfo(env, hostName, servName);
+
+    if (hostName != NULL)
+        FREE(hostName);
+
+    if (servName != NULL)
+        FREE(servName);
+
+    /*
+    if (hints != NULL)
+        FREE(hints);
+    */
+
+    NDBG( ("NET",
+           "nif_getaddrinfo -> done when result: "
+           "\r\n   %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ngetaddrinfo(ErlNifEnv* env,
+                          char*      host,
+                          char*      serv)
+{
+    ERL_NIF_TERM     result;
+    struct addrinfo* addrInfoP;
+    int              res;
+
+    NDBG( ("NET", "ngetaddrinfo -> entry with"
+           "\r\n   host: %s"
+           "\r\n   serv: %s"
+           "\r\n",
+           ((host == NULL) ? "NULL" : host),
+           ((serv == NULL) ? "NULL" : serv)) );
+    
+    res = getaddrinfo(host, serv, NULL, &addrInfoP);
+
+    NDBG( ("NET", "ngetaddrinfo -> res: %d\r\n", res) );
+    
+    switch (res) {
+    case 0:
+        {
+            ERL_NIF_TERM addrInfo = encode_address_infos(env, addrInfoP);
+            freeaddrinfo(addrInfoP);
+            result = esock_make_ok2(env, addrInfo);
+        }
+        break;
+
+#if defined(EAI_ADDRFAMILY)
+    case EAI_ADDRFAMILY:
+        result = esock_make_error(env, atom_eaddrfamily);
+        break;
+#endif
+
+#if defined(EAI_AGAIN)
+    case EAI_AGAIN:
+        result = esock_make_error(env, esock_atom_eagain);
+        break;
+#endif
+
+#if defined(EAI_BADFLAGS)
+    case EAI_BADFLAGS:
+        result = esock_make_error(env, atom_ebadflags);
+        break;
+#endif
+
+#if defined(EAI_FAIL)
+    case EAI_FAIL:
+        result = esock_make_error(env, atom_efail);
+        break;
+#endif
+
+#if defined(EAI_FAMILY)
+    case EAI_FAMILY:
+        result = esock_make_error(env, atom_efamily);
+        break;
+#endif
+
+#if defined(EAI_MEMORY)
+    case EAI_MEMORY:
+        result = esock_make_error(env, atom_emem);
+        break;
+#endif
+
+#if defined(EAI_NODATA)
+    case EAI_NODATA:
+        result = esock_make_error(env, atom_enodata);
+        break;
+#endif
+
+#if defined(EAI_NONAME)
+    case EAI_NONAME:
+        result = esock_make_error(env, atom_enoname);
+        break;
+#endif
+
+#if defined(EAI_SERVICE)
+    case EAI_SERVICE:
+        result = esock_make_error(env, atom_eservice);
+        break;
+#endif
+
+#if defined(EAI_SOCKTYPE)
+    case EAI_SOCKTYPE:
+        result = esock_make_error(env, atom_esocktype);
+        break;
+#endif
+
+#if defined(EAI_SYSTEM)
+    case EAI_SYSTEM:
+        result = esock_make_error(env, atom_esystem);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_if_name2index
+ *
+ * Description:
+ * Perform a Interface Name to Interface Index translation.
+ *
+ * Arguments:
+ * Ifn - Interface name to be translated.
+ */
+
+static
+ERL_NIF_TERM nif_if_name2index(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    ERL_NIF_TERM eifn, result;
+    char         ifn[IF_NAMESIZE+1];
+
+    NDBG( ("NET", "nif_if_name2index -> entry (%d)\r\n", argc) );
+
+    if (argc != 1) {
+        return enif_make_badarg(env);
+    }
+    eifn = argv[0];
+
+    NDBG( ("NET",
+           "nif_if_name2index -> "
+           "\r\n   Ifn: %T"
+           "\r\n", argv[0]) );
+
+    if (0 >= GET_STR(env, eifn, ifn, sizeof(ifn)))
+        return esock_make_error(env, esock_atom_einval);
+
+    result = nif_name2index(env, ifn);
+
+    NDBG( ("NET", "nif_if_name2index -> done when result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nif_name2index(ErlNifEnv* env,
+                            char*      ifn)
+{
+    unsigned int idx;
+
+    NDBG( ("NET", "nif_name2index -> entry with ifn: %s\r\n", ifn) );
+
+    idx = if_nametoindex(ifn);
+
+    NDBG( ("NET", "nif_name2index -> idx: %d\r\n", idx) );
+
+    if (idx == 0) {
+        int save_errno = get_errno();
+        NDBG( ("NET", "nif_name2index -> failed: %d\r\n", save_errno) );
+        return esock_make_error_errno(env, save_errno);
+    } else {
+         return esock_make_ok2(env, MKI(env, idx));
+    }
+
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_if_index2name
+ *
+ * Description:
+ * Perform a Interface Index to Interface Name translation.
+ *
+ * Arguments:
+ * Idx - Interface index to be translated.
+ */
+
+static
+ERL_NIF_TERM nif_if_index2name(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    ERL_NIF_TERM result;
+    unsigned int idx;
+
+    NDBG( ("NET", "nif_if_index2name -> entry (%d)\r\n", argc) );
+
+    if ((argc != 1) ||
+        !GET_UINT(env, argv[0], &idx)) {
+        return enif_make_badarg(env);
+    }
+
+    NDBG( ("NET", "nif_index2name -> "
+           "\r\n   Idx: %T"
+           "\r\n", argv[0]) );
+
+    result = nif_index2name(env, idx);
+
+    NDBG( ("NET", "nif_if_index2name -> done when result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nif_index2name(ErlNifEnv*   env,
+                            unsigned int idx)
+{
+    ERL_NIF_TERM result;
+    char*        ifn = MALLOC(IF_NAMESIZE+1);
+
+    if (ifn == NULL)
+        return enif_make_badarg(env); // PLACEHOLDER
+
+    if (NULL != if_indextoname(idx, ifn)) {
+        result = esock_make_ok2(env, MKS(env, ifn));
+    } else {
+        result = esock_make_error(env, atom_enxio);
+    }
+
+    FREE(ifn);
+
+    return result;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_if_names
+ *
+ * Description:
+ * Get network interface names and indexes.
+ *
+ */
+
+static
+ERL_NIF_TERM nif_if_names(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    ERL_NIF_TERM result;
+
+    NDBG( ("NET", "nif_if_names -> entry (%d)\r\n", argc) );
+
+    if (argc != 0) {
+        return enif_make_badarg(env);
+    }
+
+    result = nif_names(env);
+
+    NDBG( ("NET", "nif_if_names -> done when result: %T\r\n", result) );
+
+    return result;
+#endif
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nif_names(ErlNifEnv* env)
+{
+    ERL_NIF_TERM         result;
+    struct if_nameindex* ifs = if_nameindex();
+
+    NDBG( ("NET", "nif_names -> ifs: 0x%lX\r\n", ifs) );
+
+    if (ifs == NULL) {
+        result = esock_make_error_errno(env, get_errno());
+    } else {
+        /*
+         * We got some interfaces:
+         * 1) Calculate how many - the only way is to iterate through the list
+         *    until its end (which is indicated by an entry with index = zero
+         *    and if_name = NULL).
+         * 2) Allocate an ERL_NIF_TERM array of the calculated length.
+         * 3) Iterate through the array of interfaces and for each create
+         *    a two tuple: {Idx, If}
+         *
+         * Or shall we instead build a list in reverse order and then when
+         * its done, reverse that? Check
+         */
+        unsigned int len = nif_names_length(ifs);
+
+        NDBG( ("NET", "nif_names -> len: %d\r\n", len) );
+
+        if (len > 0) {
+            ERL_NIF_TERM* array = MALLOC(len * sizeof(ERL_NIF_TERM));
+            unsigned int  i;
+
+            for (i = 0; i < len; i++) {
+                array[i] = MKT2(env,
+                                MKI(env, ifs[i].if_index),
+                                MKS(env, ifs[i].if_name));
+            }
+
+            result = esock_make_ok2(env, MKLA(env, array, len));
+            FREE(array);
+        } else {
+            result = esock_make_ok2(env, enif_make_list(env, 0));
+        }
+    }
+
+    if (ifs != NULL)
+        if_freenameindex(ifs);
+
+    return result;
+}
+
+
+static
+unsigned int nif_names_length(struct if_nameindex* p)
+{
+    unsigned int len = 0;
+    BOOLEAN_T    done =  FALSE;
+
+    while (!done) {
+
+        NDBG( ("NET", "nif_names_length -> %d: "
+               "\r\n   if_index: %d"
+               "\r\n   if_name:  0x%lX"
+               "\r\n", len, p[len].if_index, p[len].if_name) );
+
+        if ((p[len].if_index == 0) && (p[len].if_name == NULL))
+            done = TRUE;
+        else
+            len++;
+    }
+
+    return len;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  U t i l i t y   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* The erlang format for a set of flags is a list of atoms.
+ * A special case is when there is no flags, which is
+ * represented by the atom undefined.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T decode_nameinfo_flags(ErlNifEnv*         env,
+                                const ERL_NIF_TERM eflags,
+                                int*               flags)
+{
+    BOOLEAN_T result;
+
+    if (IS_ATOM(env, eflags)) {
+        if (COMPARE(eflags, esock_atom_undefined) == 0) {
+            *flags = 0;
+            result = TRUE;
+        } else {
+            result = FALSE;
+        }
+    } else if (IS_LIST(env, eflags)) {
+        NDBG( ("NET", "decode_nameinfo_flags -> is atom\r\n") );
+        result = decode_nameinfo_flags_list(env, eflags, flags);
+    } else {
+        result = FALSE;
+    }
+
+    return result;
+}
+
+
+
+static
+BOOLEAN_T decode_nameinfo_flags_list(ErlNifEnv*         env,
+                                     const ERL_NIF_TERM eflags,
+                                     int*               flags)
+{
+    ERL_NIF_TERM elem, tail, list = eflags;
+    int          tmp = 0;
+    BOOLEAN_T    done = FALSE;
+
+    while (!done) {
+        if (GET_LIST_ELEM(env, list, &elem, &tail)) {
+            if (COMPARE(elem, atom_namereqd) == 0) {
+                tmp |= NI_NAMEREQD;
+            } else if (COMPARE(elem, esock_atom_dgram) == 0) {
+                tmp |= NI_DGRAM;
+            } else if (COMPARE(elem, atom_nofqdn) == 0) {
+                tmp |= NI_NOFQDN;
+            } else if (COMPARE(elem, atom_numerichost) == 0) {
+                tmp |= NI_NUMERICHOST;
+            } else if (COMPARE(elem, atom_numericserv) == 0) {
+                tmp |= NI_NUMERICSERV;
+
+                /* Starting with glibc 2.3.4: */
+
+#if defined(NI_IDN)
+            } else if (COMPARE(elem, atom_idn) == 0) {
+                tmp |= NI_IDN;
+#endif
+
+#if defined(NI_IDN_ALLOW_UNASSIGNED)
+            } else if (COMPARE(elem, atom_idna_allow_unassigned) == 0) {
+                tmp |= NI_IDN_ALLOW_UNASSIGNED;
+#endif
+
+#if defined(NI_IDN_USE_STD3_ASCII_RULES)
+            } else if (COMPARE(elem, atom_idna_use_std3_ascii_rules) == 0) {
+                tmp |= NI_IDN_USE_STD3_ASCII_RULES;
+#endif
+
+            } else {
+                return FALSE;
+            }
+
+            list = tail;
+
+        } else {
+            done = TRUE;
+        }
+    }
+
+    *flags = tmp;
+
+    return TRUE;
+}
+
+
+
+/* Decode the address info string (hostname or service name)
+ * The string is either the atom undefined or an actual string.
+ */
+static
+BOOLEAN_T decode_addrinfo_string(ErlNifEnv*         env,
+                                 const ERL_NIF_TERM eString,
+                                 char**             stringP)
+{
+    BOOLEAN_T result;
+
+    if (IS_ATOM(env, eString)) {
+
+        if (COMPARE(eString, esock_atom_undefined) == 0) {
+            *stringP = NULL;
+            result   = TRUE;
+        } else {
+            *stringP = NULL;
+            result   = FALSE;
+        }
+
+    } else {
+
+        result = esock_decode_string(env, eString, stringP);
+
+    }
+
+    return result;
+
+}
+
+
+
+static
+ERL_NIF_TERM decode_bool(ErlNifEnv*   env,
+                         ERL_NIF_TERM eBool,
+                         BOOLEAN_T*   bool)
+{
+    if (COMPARE(eBool, esock_atom_true) == 0) {
+        *bool = TRUE;
+        return esock_atom_ok;
+    } else if (COMPARE(eBool, esock_atom_false) == 0) {
+        *bool = FALSE;
+        return esock_atom_ok;
+    } else {
+        return esock_make_error(env, esock_atom_einval);
+    }
+}
+
+
+
+/* Encode the address info
+ * The address info is a linked list och address info, which
+ * will result in the result being a list of zero or more length.
+ */
+static
+ERL_NIF_TERM encode_address_infos(ErlNifEnv*       env,
+                                  struct addrinfo* addrInfo)
+{
+    ERL_NIF_TERM result;
+    unsigned int len = address_info_length(addrInfo);
+
+    NDBG( ("NET", "encode_address_infos -> len: %d\r\n", len) );
+
+    if (len > 0) {
+        ERL_NIF_TERM*    array = MALLOC(len * sizeof(ERL_NIF_TERM)); // LEAK?
+        unsigned int     i     = 0;
+        struct addrinfo* p     = addrInfo;
+
+        while (i < len) {
+            array[i] = encode_address_info(env, p);
+            p = p->ai_next;
+            i++;
+        }
+
+        result = MKLA(env, array, len);
+    } else {
+        result = MKEL(env);
+    }
+
+    NDBG( ("NET", "encode_address_infos -> result: "
+           "\r\n   %T\r\n", result) );
+
+    return result;
+}
+
+
+
+/* Calculate the length of the adress info linked list
+ * The list is NULL-terminated, so the only way is to
+ * iterate through the list until we find next = NULL.
+ */
+static
+unsigned int address_info_length(struct addrinfo* addrInfoP)
+{
+    unsigned int     len = 1;
+    struct addrinfo* tmp;
+    BOOLEAN_T        done = FALSE;
+
+    tmp = addrInfoP;
+
+    while (!done) {
+        if (tmp->ai_next != NULL) {
+            len++;
+            tmp = tmp->ai_next;
+        } else {
+            done = TRUE;
+        }
+    }
+
+    return len;
+}
+
+
+
+/* Create one (erlang) instance of the address info record
+ * Should we have address info as a record or as a map?
+ *
+ * {address_info, Fam, Type, Proto, Addr}
+ */
+static
+ERL_NIF_TERM encode_address_info(ErlNifEnv*       env,
+                                 struct addrinfo* addrInfoP)
+{
+    ERL_NIF_TERM fam, type, proto, addr, addrInfo;
+
+    fam   = encode_address_info_family(env, addrInfoP->ai_family);
+    type  = encode_address_info_type(env,   addrInfoP->ai_socktype);
+    proto = encode_address_info_proto(env,  addrInfoP->ai_protocol);
+    esock_encode_sockaddr(env,
+                          (SocketAddress*) addrInfoP->ai_addr,
+                          addrInfoP->ai_addrlen,
+                          &addr);
+    
+    if (make_address_info(env, fam, type, proto, addr, &addrInfo) == NULL)
+        return addrInfo;
+    else
+        return esock_atom_undefined; // We should to better...
+
+}
+
+
+/* Convert an "native" family to an erlang family (=domain).
+ * Note that this is not currently exhaustive, but only supports
+ * inet and inet6. Other values will be returned as is, that is
+ * in the form of an integer.
+ */
+static
+ERL_NIF_TERM encode_address_info_family(ErlNifEnv* env,
+                                        int        family)
+{
+    ERL_NIF_TERM efam;
+
+    if (NULL != esock_encode_domain(env, family, &efam))
+        efam = MKI(env, family);
+
+    return efam;
+}
+
+
+
+/* Convert an "native" socket type to an erlang socket type.
+ * Note that this is not currently exhaustive, but only supports
+ * stream and dgram. Other values will be returned as is, that is
+ * in the form of an integer.
+ */
+static
+ERL_NIF_TERM encode_address_info_type(ErlNifEnv* env,
+                                      int        socktype)
+{
+    ERL_NIF_TERM etype;
+
+    if (NULL != esock_encode_type(env, socktype, &etype))
+        etype = MKI(env, socktype);
+
+    return etype;
+}
+
+
+
+/* Convert an "native" protocol to an erlang protocol.
+ * Note that this is not currently exhaustive, but only supports
+ * tcp and udp. Other values will be returned as is, that is
+ * in the form of an integer.
+ */
+static
+ERL_NIF_TERM encode_address_info_proto(ErlNifEnv* env,
+                                       int        proto)
+{
+    ERL_NIF_TERM eproto;
+
+    if (NULL != esock_encode_protocol(env, proto, &eproto))
+        eproto = MKI(env, proto);
+
+    return eproto;
+}
+
+
+
+static
+char* make_address_info(ErlNifEnv*    env,
+                        ERL_NIF_TERM  fam,
+                        ERL_NIF_TERM  sockType,
+                        ERL_NIF_TERM  proto,
+                        ERL_NIF_TERM  addr,
+                        ERL_NIF_TERM* ai)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_family,
+                           esock_atom_type,
+                           esock_atom_protocol,
+                           esock_atom_addr};
+    ERL_NIF_TERM vals[] = {fam, sockType, proto, addr};
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, ai)) {
+        *ai = esock_atom_undefined;
+        return ESOCK_STR_EINVAL;
+    } else {
+        return NULL;
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  C a l l b a c k   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* =========================================================================
+ * net_dtor - Callback function for resource destructor
+ *
+ */
+/*
+static
+void net_dtor(ErlNifEnv* env, void* obj)
+{
+}
+*/
+
+
+/* =========================================================================
+ * net_stop - Callback function for resource stop
+ *
+ */
+/*
+static
+void net_stop(ErlNifEnv* env, void* obj, int fd, int is_direct_call)
+{
+}
+*/
+
+
+
+
+/* =========================================================================
+ * net_down - Callback function for resource down (monitored processes)
+ *
+ */
+/*
+static
+void net_down(ErlNifEnv*           env,
+              void*                obj,
+              const ErlNifPid*     pid,
+              const ErlNifMonitor* mon)
+{
+}
+*/
+
+
+
+/* ----------------------------------------------------------------------
+ *  L o a d / u n l o a d / u p g r a d e   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+static
+ErlNifFunc net_funcs[] =
+{
+    // Some utility functions
+    {"nif_info",      0, nif_info,      0},
+    {"nif_command",   1, nif_command,   0}, // Shall we let this be dirty?
+
+    /* get/set hostname */
+    {"nif_gethostname",         0, nif_gethostname,   0},
+
+    /* address and name translation in protocol-independent manner */
+    {"nif_getnameinfo",         2, nif_getnameinfo,   0},
+    {"nif_getaddrinfo",         3, nif_getaddrinfo,   0},
+
+    /* Network interface (name and/or index) functions */
+    {"nif_if_name2index",       1, nif_if_name2index, 0},
+    {"nif_if_index2name",       1, nif_if_index2name, 0},
+    {"nif_if_names",            0, nif_if_names,      0}
+};
+
+
+#if !defined(__WIN32__)
+static
+BOOLEAN_T extract_debug(ErlNifEnv*   env,
+                        ERL_NIF_TERM map)
+{
+    /*
+     * We need to do this here since the "proper" atom has not been
+     * created when this function is called.
+     */
+    ERL_NIF_TERM debug = MKA(env, "debug");
+    
+    return esock_extract_bool_from_map(env, map, debug, NET_NIF_DEBUG_DEFAULT);
+}
+#endif
+
+
+/* =======================================================================
+ * load_info - A map of misc info (e.g global debug)
+ */
+
+static
+int on_load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info)
+{
+#if !defined(__WIN32__)    
+    // We should make it possible to use load_info to get default values
+    data.debug = extract_debug(env, load_info);
+
+    NDBG( ("NET", "on_load -> entry\r\n") );
+#endif
+
+    /* +++ Misc atoms +++ */
+    atom_address_info              = MKA(env, str_address_info);
+    atom_debug                     = MKA(env, str_debug);
+    atom_idn                       = MKA(env, str_idn);
+    atom_idna_allow_unassigned     = MKA(env, str_idna_allow_unassigned);
+    atom_idna_use_std3_ascii_rules = MKA(env, str_idna_use_std3_ascii_rules);
+    atom_namereqd                  = MKA(env, str_namereqd);
+    atom_name_info                 = MKA(env, str_name_info);
+    atom_nofqdn                    = MKA(env, str_nofqdn);
+    atom_numerichost               = MKA(env, str_numerichost);
+    atom_numericserv               = MKA(env, str_numericserv);
+
+    /* Error codes */
+    atom_eaddrfamily     = MKA(env, str_eaddrfamily);
+    atom_ebadflags       = MKA(env, str_ebadflags);
+    atom_efail           = MKA(env, str_efail);
+    atom_efamily         = MKA(env, str_efamily);
+    atom_efault          = MKA(env, str_efault);
+    atom_emem            = MKA(env, str_emem);
+    atom_enametoolong    = MKA(env, str_enametoolong);
+    atom_enodata         = MKA(env, str_enodata);
+    atom_enoname         = MKA(env, str_enoname);
+    atom_enxio           = MKA(env, str_enxio);
+    atom_eoverflow       = MKA(env, str_eoverflow);
+    atom_eservice        = MKA(env, str_eservice);
+    atom_esocktype       = MKA(env, str_esocktype);
+    atom_esystem         = MKA(env, str_esystem);
+
+    // For storing "global" things...
+    // data.env       = enif_alloc_env(); // We should really check
+    // data.version   = MKA(env, ERTS_VERSION);
+    // data.buildDate = MKA(env, ERTS_BUILD_DATE);
+
+    net = enif_open_resource_type_x(env,
+                                    "net",
+                                    &netInit,
+                                    ERL_NIF_RT_CREATE,
+                                    NULL);
+
+#if !defined(__WIN32__)    
+    NDBG( ("NET", "on_load -> done\r\n") );
+#endif
+
+    return !net;
+}
+
+ERL_NIF_INIT(net, net_funcs, on_load, NULL, NULL, NULL)
diff --git a/erts/emulator/nifs/common/socket_dbg.c b/erts/emulator/nifs/common/socket_dbg.c
new file mode 100644
index 0000000000..fe9135e5a0
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_dbg.c
@@ -0,0 +1,138 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Debug functions for the socket and net NIF(s).
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <time.h>
+
+#include <erl_nif.h>
+#include "socket_dbg.h"
+
+#define TSELF()            enif_thread_self()
+#define TNAME(__T__)       enif_thread_name( __T__ )
+#define TSNAME()           TNAME(TSELF())
+
+static FILE* dbgout = NULL;
+
+static int realtime(struct timespec* tsP);
+static int timespec2str(char *buf, unsigned int len, struct timespec *ts);
+
+
+extern
+void esock_dbg_init(char* filename)
+{
+  if (filename != NULL) {
+    if (strcmp(filename, ESOCK_DBGOUT_DEFAULT) == 0) {
+      dbgout = stdout;
+    } else if (strcmp(filename, ESOCK_DBGOUT_UNIQUE) == 0) {
+      char template[] = "/tmp/esock-dbg-XXXXXX";
+      dbgout = fdopen(mkstemp(template), "w+");
+    } else {
+      dbgout = fopen(filename, "w+");
+    }
+  } else {
+    char template[] = "/tmp/esock-dbg-XXXXXX";
+    dbgout = fdopen(mkstemp(template), "w+");
+  }
+}
+
+
+
+/*
+ * Print a debug format string *with* both a timestamp and the
+ * the name of the *current* thread.
+ */
+extern
+void esock_dbg_printf( const char* prefix, const char* format, ... )
+{
+  va_list         args;
+  char            f[512 + sizeof(format)]; // This has to suffice...
+  char            stamp[30];
+  struct timespec ts;
+  int             res;
+
+  /*
+   * We should really include self in the printout, so we can se which process
+   * are executing the code. But then I must change the API....
+   * ....something for later.
+   */
+
+  if (!realtime(&ts)) {
+    if (timespec2str(stamp, sizeof(stamp), &ts) != 0) {
+        res = enif_snprintf(f, sizeof(f), "%s [%s] %s", prefix, TSNAME(), format);
+        // res = enif_snprintf(f, sizeof(f), "%s [%s]", prefix, format);
+    } else {
+      res = enif_snprintf(f, sizeof(f), "%s [%s] [%s] %s", prefix, stamp, TSNAME(), format);
+      // res = enif_snprintf(f, sizeof(f), "%s [%s] %s", prefix, stamp, format);
+    }
+
+    if (res > 0) {
+      va_start (args, format);
+      enif_vfprintf (dbgout, f, args);
+      va_end (args);
+      fflush(stdout);
+    }
+  }
+
+  return;
+}
+
+
+static
+int realtime(struct timespec* tsP)
+{
+  return clock_gettime(CLOCK_REALTIME, tsP);
+}
+
+
+
+
+/*
+ * Convert a timespec struct into a readable/printable string
+ */
+static
+int timespec2str(char *buf, unsigned int len, struct timespec *ts)
+{
+  int       ret, buflen;
+  struct tm t;
+
+  tzset();
+  if (localtime_r(&(ts->tv_sec), &t) == NULL)
+    return 1;
+
+  ret = strftime(buf, len, "%F %T", &t);
+  if (ret == 0)
+    return 2;
+  len -= ret - 1;
+  buflen = strlen(buf);
+
+  ret = snprintf(&buf[buflen], len, ".%06ld", ts->tv_nsec/1000);
+  if (ret >= len)
+    return 3;
+
+  return 0;
+}
diff --git a/erts/emulator/nifs/common/socket_dbg.h b/erts/emulator/nifs/common/socket_dbg.h
new file mode 100644
index 0000000000..47739b46da
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_dbg.h
@@ -0,0 +1,55 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ * Purpose : Defines and macros for the debug util of the socket and 
+ * net NIF(s).
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#ifndef SOCKET_DBG_H__
+#define SOCKET_DBG_H__
+
+/* Used when calling the init function */
+#define ESOCK_DBGOUT_DEFAULT "stdout"
+#define ESOCK_DBGOUT_UNIQUE  "unique"
+
+
+/* Used in debug printouts */
+#ifdef __WIN32__
+#define LLU "%I64u"
+#else
+#define LLU "%llu"
+#endif
+typedef unsigned long long llu_t;
+
+
+
+#define ESOCK_DBG_PRINTF( ___COND___ , proto ) \
+    if ( ___COND___ ) {                        \
+        esock_dbg_printf proto;                \
+        fflush(stdout);                        \
+    }
+
+
+extern void esock_dbg_init(char* filename);
+extern void esock_dbg_printf( const char* prefix, const char* format, ... );
+
+#endif // SOCKET_DBG_H__
diff --git a/erts/emulator/nifs/common/socket_int.h b/erts/emulator/nifs/common/socket_int.h
new file mode 100644
index 0000000000..0f973855ae
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_int.h
@@ -0,0 +1,387 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Utility "stuff" for socket and net.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#ifndef SOCKET_INT_H__
+#define SOCKET_INT_H__
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef __WIN32__
+
+/* All this just to replace sys/socket.h, netinet/in.h and sys/un.h??? */
+#define INCL_WINSOCK_API_TYPEDEFS 1
+#ifndef WINDOWS_H_INCLUDES_WINSOCK2_H
+#include <winsock2.h>
+#endif
+#include <windows.h>
+#include <Ws2tcpip.h>   /* NEED VC 6.0 or higher */
+/* Visual studio 2008+: NTDDI_VERSION needs to be set for iphlpapi.h
+ * to define the right structures. It needs to be set to WINXP (or LONGHORN)
+ * for IPV6 to work and it's set lower by default, so we need to change it.
+ */
+#ifdef HAVE_SDKDDKVER_H
+#  include <sdkddkver.h>
+#  ifdef NTDDI_VERSION
+#    undef NTDDI_VERSION
+#  endif
+#  define NTDDI_VERSION NTDDI_WINXP
+#endif
+#include <iphlpapi.h>
+
+#else /* !__WIN32__ */
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#ifdef HAVE_SYS_UN_H
+#include <sys/un.h>
+#endif
+
+#endif
+
+#include <erl_nif.h>
+
+/* The general purpose sockaddr */
+typedef union {
+    /* General sockaddr */
+    struct sockaddr     sa;
+
+    /* IPv4 sockaddr */
+    struct sockaddr_in  in4;
+
+    /* IPv6 sockaddr */
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    struct sockaddr_in6 in6;
+#endif
+
+    /* Unix Domain Socket sockaddr */
+#if defined(HAVE_SYS_UN_H)
+    struct sockaddr_un  un;
+#endif
+
+} SocketAddress;
+
+
+/* *** Boolean *type* stuff... *** */
+typedef unsigned int BOOLEAN_T;
+#define TRUE  1
+#define FALSE 0
+
+#define BOOL2ATOM(__B__) ((__B__) ? esock_atom_true : esock_atom_false)
+
+#define B2S(__B__) ((__B__) ? "true" : "false")
+
+/* Misc error strings */
+#define ESOCK_STR_EAFNOSUPPORT "eafnosupport"
+#define ESOCK_STR_EAGAIN       "eagain"
+#define ESOCK_STR_EINVAL       "einval"
+
+
+/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ * "Global" atoms
+ */
+extern ERL_NIF_TERM esock_atom_abort;
+extern ERL_NIF_TERM esock_atom_accept;
+extern ERL_NIF_TERM esock_atom_acceptconn;
+extern ERL_NIF_TERM esock_atom_acceptfilter;
+extern ERL_NIF_TERM esock_atom_adaption_layer;
+extern ERL_NIF_TERM esock_atom_addr;
+extern ERL_NIF_TERM esock_atom_addrform;
+extern ERL_NIF_TERM esock_atom_add_membership;
+extern ERL_NIF_TERM esock_atom_add_source_membership;
+extern ERL_NIF_TERM esock_atom_any;
+extern ERL_NIF_TERM esock_atom_associnfo;
+extern ERL_NIF_TERM esock_atom_authhdr;
+extern ERL_NIF_TERM esock_atom_auth_active_key;
+extern ERL_NIF_TERM esock_atom_auth_asconf;
+extern ERL_NIF_TERM esock_atom_auth_chunk;
+extern ERL_NIF_TERM esock_atom_auth_delete_key;
+extern ERL_NIF_TERM esock_atom_auth_key;
+extern ERL_NIF_TERM esock_atom_auth_level;
+extern ERL_NIF_TERM esock_atom_autoclose;
+extern ERL_NIF_TERM esock_atom_bindtodevice;
+extern ERL_NIF_TERM esock_atom_block_source;
+extern ERL_NIF_TERM esock_atom_broadcast;
+extern ERL_NIF_TERM esock_atom_busy_poll;
+extern ERL_NIF_TERM esock_atom_checksum;
+extern ERL_NIF_TERM esock_atom_close;
+extern ERL_NIF_TERM esock_atom_connect;
+extern ERL_NIF_TERM esock_atom_congestion;
+extern ERL_NIF_TERM esock_atom_context;
+extern ERL_NIF_TERM esock_atom_cork;
+extern ERL_NIF_TERM esock_atom_credentials;
+extern ERL_NIF_TERM esock_atom_ctrl;
+extern ERL_NIF_TERM esock_atom_ctrunc;
+extern ERL_NIF_TERM esock_atom_data;
+extern ERL_NIF_TERM esock_atom_debug;
+extern ERL_NIF_TERM esock_atom_default_send_params;
+extern ERL_NIF_TERM esock_atom_delayed_ack_time;
+extern ERL_NIF_TERM esock_atom_dgram;
+extern ERL_NIF_TERM esock_atom_disable_fragments;
+extern ERL_NIF_TERM esock_atom_domain;
+extern ERL_NIF_TERM esock_atom_dontfrag;
+extern ERL_NIF_TERM esock_atom_dontroute;
+extern ERL_NIF_TERM esock_atom_drop_membership;
+extern ERL_NIF_TERM esock_atom_drop_source_membership;
+extern ERL_NIF_TERM esock_atom_dstopts;
+extern ERL_NIF_TERM esock_atom_eor;
+extern ERL_NIF_TERM esock_atom_error;
+extern ERL_NIF_TERM esock_atom_errqueue;
+extern ERL_NIF_TERM esock_atom_esp_network_level;
+extern ERL_NIF_TERM esock_atom_esp_trans_level;
+extern ERL_NIF_TERM esock_atom_events;
+extern ERL_NIF_TERM esock_atom_explicit_eor;
+extern ERL_NIF_TERM esock_atom_faith;
+extern ERL_NIF_TERM esock_atom_false;
+extern ERL_NIF_TERM esock_atom_family;
+extern ERL_NIF_TERM esock_atom_flags;
+extern ERL_NIF_TERM esock_atom_flowinfo;
+extern ERL_NIF_TERM esock_atom_fragment_interleave;
+extern ERL_NIF_TERM esock_atom_freebind;
+extern ERL_NIF_TERM esock_atom_get_peer_addr_info;
+extern ERL_NIF_TERM esock_atom_hdrincl;
+extern ERL_NIF_TERM esock_atom_hmac_ident;
+extern ERL_NIF_TERM esock_atom_hoplimit;
+extern ERL_NIF_TERM esock_atom_hopopts;
+extern ERL_NIF_TERM esock_atom_ifindex;
+extern ERL_NIF_TERM esock_atom_inet;
+extern ERL_NIF_TERM esock_atom_inet6;
+extern ERL_NIF_TERM esock_atom_info;
+extern ERL_NIF_TERM esock_atom_initmsg;
+extern ERL_NIF_TERM esock_atom_iov;
+extern ERL_NIF_TERM esock_atom_ip;
+extern ERL_NIF_TERM esock_atom_ipcomp_level;
+extern ERL_NIF_TERM esock_atom_ipv6;
+extern ERL_NIF_TERM esock_atom_i_want_mapped_v4_addr;
+extern ERL_NIF_TERM esock_atom_join_group;
+extern ERL_NIF_TERM esock_atom_keepalive;
+extern ERL_NIF_TERM esock_atom_keepcnt;
+extern ERL_NIF_TERM esock_atom_keepidle;
+extern ERL_NIF_TERM esock_atom_keepintvl;
+extern ERL_NIF_TERM esock_atom_leave_group;
+extern ERL_NIF_TERM esock_atom_level;
+extern ERL_NIF_TERM esock_atom_linger;
+extern ERL_NIF_TERM esock_atom_local;
+extern ERL_NIF_TERM esock_atom_local_auth_chunks;
+extern ERL_NIF_TERM esock_atom_loopback;
+extern ERL_NIF_TERM esock_atom_lowdelay;
+extern ERL_NIF_TERM esock_atom_mark;
+extern ERL_NIF_TERM esock_atom_maxburst;
+extern ERL_NIF_TERM esock_atom_maxseg;
+extern ERL_NIF_TERM esock_atom_md5sig;
+extern ERL_NIF_TERM esock_atom_mincost;
+extern ERL_NIF_TERM esock_atom_minttl;
+extern ERL_NIF_TERM esock_atom_msfilter;
+extern ERL_NIF_TERM esock_atom_mtu;
+extern ERL_NIF_TERM esock_atom_mtu_discover;
+extern ERL_NIF_TERM esock_atom_multicast_all;
+extern ERL_NIF_TERM esock_atom_multicast_hops;
+extern ERL_NIF_TERM esock_atom_multicast_if;
+extern ERL_NIF_TERM esock_atom_multicast_loop;
+extern ERL_NIF_TERM esock_atom_multicast_ttl;
+extern ERL_NIF_TERM esock_atom_nodelay;
+extern ERL_NIF_TERM esock_atom_nodefrag;
+extern ERL_NIF_TERM esock_atom_noopt;
+extern ERL_NIF_TERM esock_atom_nopush;
+extern ERL_NIF_TERM esock_atom_not_found;
+extern ERL_NIF_TERM esock_atom_not_owner;
+extern ERL_NIF_TERM esock_atom_ok;
+extern ERL_NIF_TERM esock_atom_oob;
+extern ERL_NIF_TERM esock_atom_oobinline;
+extern ERL_NIF_TERM esock_atom_options;
+extern ERL_NIF_TERM esock_atom_origdstaddr;
+extern ERL_NIF_TERM esock_atom_partial_delivery_point;
+extern ERL_NIF_TERM esock_atom_passcred;
+extern ERL_NIF_TERM esock_atom_path;
+extern ERL_NIF_TERM esock_atom_peekcred;
+extern ERL_NIF_TERM esock_atom_peek_off;
+extern ERL_NIF_TERM esock_atom_peer_addr_params;
+extern ERL_NIF_TERM esock_atom_peer_auth_chunks;
+extern ERL_NIF_TERM esock_atom_pktinfo;
+extern ERL_NIF_TERM esock_atom_pktoptions;
+extern ERL_NIF_TERM esock_atom_port;
+extern ERL_NIF_TERM esock_atom_portrange;
+extern ERL_NIF_TERM esock_atom_primary_addr;
+extern ERL_NIF_TERM esock_atom_priority;
+extern ERL_NIF_TERM esock_atom_protocol;
+extern ERL_NIF_TERM esock_atom_raw;
+extern ERL_NIF_TERM esock_atom_rcvbuf;
+extern ERL_NIF_TERM esock_atom_rcvbufforce;
+extern ERL_NIF_TERM esock_atom_rcvlowat;
+extern ERL_NIF_TERM esock_atom_rcvtimeo;
+extern ERL_NIF_TERM esock_atom_rdm;
+extern ERL_NIF_TERM esock_atom_recv;
+extern ERL_NIF_TERM esock_atom_recvdstaddr;
+extern ERL_NIF_TERM esock_atom_recverr;
+extern ERL_NIF_TERM esock_atom_recvfrom;
+extern ERL_NIF_TERM esock_atom_recvif;
+extern ERL_NIF_TERM esock_atom_recvmsg;
+extern ERL_NIF_TERM esock_atom_recvopts;
+extern ERL_NIF_TERM esock_atom_recvorigdstaddr;
+extern ERL_NIF_TERM esock_atom_recvpktinfo;
+extern ERL_NIF_TERM esock_atom_recvtclass;
+extern ERL_NIF_TERM esock_atom_recvtos;
+extern ERL_NIF_TERM esock_atom_recvttl;
+extern ERL_NIF_TERM esock_atom_reliability;
+extern ERL_NIF_TERM esock_atom_reset_streams;
+extern ERL_NIF_TERM esock_atom_retopts;
+extern ERL_NIF_TERM esock_atom_reuseaddr;
+extern ERL_NIF_TERM esock_atom_reuseport;
+extern ERL_NIF_TERM esock_atom_rights;
+extern ERL_NIF_TERM esock_atom_router_alert;
+extern ERL_NIF_TERM esock_atom_rthdr;
+extern ERL_NIF_TERM esock_atom_rtoinfo;
+extern ERL_NIF_TERM esock_atom_rxq_ovfl;
+extern ERL_NIF_TERM esock_atom_scope_id;
+extern ERL_NIF_TERM esock_atom_sctp;
+extern ERL_NIF_TERM esock_atom_sec;
+extern ERL_NIF_TERM esock_atom_select_sent;
+extern ERL_NIF_TERM esock_atom_send;
+extern ERL_NIF_TERM esock_atom_sendmsg;
+extern ERL_NIF_TERM esock_atom_sendsrcaddr;
+extern ERL_NIF_TERM esock_atom_sendto;
+extern ERL_NIF_TERM esock_atom_seqpacket;
+extern ERL_NIF_TERM esock_atom_setfib;
+extern ERL_NIF_TERM esock_atom_set_peer_primary_addr;
+extern ERL_NIF_TERM esock_atom_sndbuf;
+extern ERL_NIF_TERM esock_atom_sndbufforce;
+extern ERL_NIF_TERM esock_atom_sndlowat;
+extern ERL_NIF_TERM esock_atom_sndtimeo;
+extern ERL_NIF_TERM esock_atom_socket;
+extern ERL_NIF_TERM esock_atom_socket_tag;
+extern ERL_NIF_TERM esock_atom_spec_dst;
+extern ERL_NIF_TERM esock_atom_status;
+extern ERL_NIF_TERM esock_atom_stream;
+extern ERL_NIF_TERM esock_atom_syncnt;
+extern ERL_NIF_TERM esock_atom_tclass;
+extern ERL_NIF_TERM esock_atom_tcp;
+extern ERL_NIF_TERM esock_atom_throughput;
+extern ERL_NIF_TERM esock_atom_timestamp;
+extern ERL_NIF_TERM esock_atom_tos;
+extern ERL_NIF_TERM esock_atom_transparent;
+extern ERL_NIF_TERM esock_atom_true;
+extern ERL_NIF_TERM esock_atom_trunc;
+extern ERL_NIF_TERM esock_atom_ttl;
+extern ERL_NIF_TERM esock_atom_type;
+extern ERL_NIF_TERM esock_atom_udp;
+extern ERL_NIF_TERM esock_atom_unblock_source;
+extern ERL_NIF_TERM esock_atom_undefined;
+extern ERL_NIF_TERM esock_atom_unicast_hops;
+extern ERL_NIF_TERM esock_atom_unknown;
+extern ERL_NIF_TERM esock_atom_usec;
+extern ERL_NIF_TERM esock_atom_user_timeout;
+extern ERL_NIF_TERM esock_atom_use_ext_recvinfo;
+extern ERL_NIF_TERM esock_atom_use_min_mtu;
+extern ERL_NIF_TERM esock_atom_v6only;
+
+
+/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ * Error value (=reason) atoms
+ */
+extern ERL_NIF_TERM esock_atom_eafnosupport;
+extern ERL_NIF_TERM esock_atom_eagain;
+extern ERL_NIF_TERM esock_atom_einval;
+
+
+
+/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ * Various wrapper macros for enif functions
+ */
+#define MALLOC(SZ)          enif_alloc((SZ))
+#define REALLOC(P, SZ)      enif_realloc((P), (SZ))
+#define FREE(P)             enif_free((P))
+
+#define MKA(E,S)            enif_make_atom((E), (S))
+#define MKBIN(E,B)          enif_make_binary((E), (B))
+#define MKI(E,I)            enif_make_int((E), (I))
+#define MKL(E,L)            enif_make_long((E), (L))
+#define MKLA(E,A,L)         enif_make_list_from_array((E), (A), (L))
+#define MKEL(E)             enif_make_list((E), 0)
+#define MKMA(E,KA,VA,L,M)   enif_make_map_from_arrays((E), (KA), (VA), (L), (M))
+#define MKPID(E, P)         enif_make_pid((E), (P))
+#define MKREF(E)            enif_make_ref((E))
+#define MKS(E,S)            enif_make_string((E), (S), ERL_NIF_LATIN1)
+#define MKSL(E,S,L)         enif_make_string_len((E), (S), (L), ERL_NIF_LATIN1)
+#define MKSBIN(E,B,ST,SZ)   enif_make_sub_binary((E), (B), (ST), (SZ))
+#define MKT2(E,E1,E2)       enif_make_tuple2((E), (E1), (E2))
+#define MKT3(E,E1,E2,E3)    enif_make_tuple3((E), (E1), (E2), (E3))
+#define MKT4(E,E1,E2,E3,E4) enif_make_tuple4((E), (E1), (E2), (E3), (E4))
+#define MKT5(E,E1,E2,E3,E4,E5) \
+    enif_make_tuple5((E), (E1), (E2), (E3), (E4), (E5))
+#define MKT8(E,E1,E2,E3,E4,E5,E6,E7,E8) \
+    enif_make_tuple8((E), (E1), (E2), (E3), (E4), (E5), (E6), (E7), (E8))
+#define MKTA(E, A, AL)      enif_make_tuple_from_array((E), (A), (AL))
+#define MKUI(E,UI)          enif_make_uint((E), (UI))
+#define MKUL(E,UL)          enif_make_ulong((E), (UL))
+
+#define MCREATE(N)          enif_mutex_create((N))
+#define MDESTROY(M)         enif_mutex_destroy((M))
+#define MLOCK(M)            enif_mutex_lock((M))
+#define MUNLOCK(M)          enif_mutex_unlock((M))
+
+// #define MONP(S,E,D,P,M)  enif_monitor_process((E), (D), (P), (M))
+// #define DEMONP(S,E,D,M)  enif_demonitor_process((E), (D), (M))
+#define MONP(S,E,D,P,M)     esock_monitor((S), (E), (D), (P), (M))
+#define DEMONP(S,E,D,M)     esock_demonitor((S), (E), (D), (M))
+#define MON_INIT(M)         esock_monitor_init((M))
+// #define MON_COMP(M1, M2)    esock_monitor_compare((M1), (M2))
+
+#define SELECT(E,FD,M,O,P,R)                                    \
+    if (enif_select((E), (FD), (M), (O), (P), (R)) < 0)         \
+        return enif_make_badarg((E));
+
+#define COMPARE(A, B)       enif_compare((A), (B))
+
+#define IS_ATOM(E,  TE) enif_is_atom((E),   (TE))
+#define IS_BIN(E,   TE) enif_is_binary((E), (TE))
+#define IS_LIST(E,  TE) enif_is_list((E),   (TE))
+#define IS_MAP(E,   TE) enif_is_map((E), (TE))
+#define IS_NUM(E,   TE) enif_is_number((E), (TE))
+#define IS_TUPLE(E, TE) enif_is_tuple((E),  (TE))
+
+#define GET_ATOM_LEN(E, TE, LP) \
+    enif_get_atom_length((E), (TE), (LP), ERL_NIF_LATIN1)
+#define GET_ATOM(E, TE, BP, MAX) \
+    enif_get_atom((E), (TE), (BP), (MAX), ERL_NIF_LATIN1)
+#define GET_BIN(E, TE, BP)          enif_inspect_iolist_as_binary((E), (TE), (BP))
+#define GET_INT(E, TE, IP)          enif_get_int((E), (TE), (IP))
+#define GET_LIST_ELEM(E, L, HP, TP) enif_get_list_cell((E), (L), (HP), (TP))
+#define GET_LIST_LEN(E, L, LP)      enif_get_list_length((E), (L), (LP))
+#define GET_LONG(E, TE, LP)         enif_get_long((E), (TE), (LP))
+#define GET_LPID(E, T, P)           enif_get_local_pid((E), (T), (P))
+#define GET_STR(E, L, B, SZ)      \
+    enif_get_string((E), (L), (B), (SZ), ERL_NIF_LATIN1)
+#define GET_UINT(E, TE, UIP)        enif_get_uint((E), (TE), (UIP))
+#define GET_ULONG(E, TE, ULP)       enif_get_long((E), (TE), (ULP))
+#define GET_TUPLE(E, TE, TSZ, TA)   enif_get_tuple((E), (TE), (TSZ), (TA))
+#define GET_MAP_VAL(E, M, K, V)     enif_get_map_value((E), (M), (K), (V))
+
+#define ALLOC_BIN(SZ, BP)         enif_alloc_binary((SZ), (BP))
+#define REALLOC_BIN(SZ, BP)       enif_realloc_binary((SZ), (BP))
+#define FREE_BIN(BP)              enif_release_binary((BP))
+
+
+#endif // SOCKET_INT_H__
diff --git a/erts/emulator/nifs/common/socket_nif.c b/erts/emulator/nifs/common/socket_nif.c
new file mode 100644
index 0000000000..4b8d65ce6a
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_nif.c
@@ -0,0 +1,18421 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : The NIF (C) part of the socket interface
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#define STATIC_ERLANG_NIF 1
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* If we HAVE_SCTP_H and Solaris, we need to define the following in
+ * order to get SCTP working:
+ */
+#if (defined(HAVE_SCTP_H) && defined(__sun) && defined(__SVR4))
+#define SOLARIS10    1
+/* WARNING: This is not quite correct, it may also be Solaris 11! */
+#define _XPG4_2
+#define __EXTENSIONS__
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <time.h>
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_SYS_UIO_H
+#include <sys/uio.h>
+#endif
+
+#ifdef HAVE_NET_IF_DL_H
+#include <net/if_dl.h>
+#endif
+
+#ifdef HAVE_IFADDRS_H
+#include <ifaddrs.h>
+#endif
+
+#ifdef HAVE_NETPACKET_PACKET_H
+#include <netpacket/packet.h>
+#endif
+
+#ifdef HAVE_SYS_UN_H
+#include <sys/un.h>
+#endif
+
+/* SENDFILE STUFF HERE IF WE NEED IT... */
+
+#if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__)
+#define __DARWIN__ 1
+#endif
+
+
+#ifdef __WIN32__
+#define STRNCASECMP               strncasecmp
+#define INCL_WINSOCK_API_TYPEDEFS 1
+
+#ifndef WINDOWS_H_INCLUDES_WINSOCK2_H
+#include <winsock2.h>
+#endif
+#include <windows.h>
+#include <Ws2tcpip.h>   /* NEED VC 6.0 or higher */
+
+/* Visual studio 2008+: NTDDI_VERSION needs to be set for iphlpapi.h
+ * to define the right structures. It needs to be set to WINXP (or LONGHORN)
+ * for IPV6 to work and it's set lower by default, so we need to change it.
+ */
+#ifdef HAVE_SDKDDKVER_H
+#  include <sdkddkver.h>
+#  ifdef NTDDI_VERSION
+#    undef NTDDI_VERSION
+#  endif
+#  define NTDDI_VERSION NTDDI_WINXP
+#endif
+#include <iphlpapi.h>
+
+#undef WANT_NONBLOCKING
+#include "sys.h"
+
+
+
+
+/* AND HERE WE MAY HAVE A BUNCH OF DEFINES....SEE INET DRIVER.... */
+
+
+
+
+#else /* ifdef __WIN32__ */
+
+#include <sys/time.h>
+#ifdef NETDB_H_NEEDS_IN_H
+#include <netinet/in.h>
+#endif
+#include <netdb.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#ifdef DEF_INADDR_LOOPBACK_IN_RPC_TYPES_H
+#include <rpc/types.h>
+#endif
+
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <arpa/inet.h>
+
+#include <sys/param.h>
+#ifdef HAVE_ARPA_NAMESER_H
+#include <arpa/nameser.h>
+#endif
+
+#ifdef HAVE_SYS_SOCKIO_H
+#include <sys/sockio.h>
+#endif
+
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
+#include <net/if.h>
+
+#ifdef HAVE_SCHED_H
+#include <sched.h>
+#endif
+
+#ifdef HAVE_SETNS_H
+#include <setns.h>
+#endif
+
+#define HAVE_UDP
+
+/* SCTP support -- currently for UNIX platforms only: */
+#undef HAVE_SCTP
+#if defined(HAVE_SCTP_H)
+
+#include <netinet/sctp.h>
+
+/* SCTP Socket API Draft from version 11 on specifies that netinet/sctp.h must
+   explicitly define HAVE_SCTP in case when SCTP is supported,  but Solaris 10
+   still apparently uses Draft 10, and does not define that symbol, so we have
+   to define it explicitly:
+*/
+#ifndef     HAVE_SCTP
+#    define HAVE_SCTP
+#endif
+
+/* These changed in draft 11, so SOLARIS10 uses the old MSG_* */
+#if ! HAVE_DECL_SCTP_UNORDERED
+#     define    SCTP_UNORDERED  MSG_UNORDERED
+#endif
+#if ! HAVE_DECL_SCTP_ADDR_OVER
+#     define    SCTP_ADDR_OVER  MSG_ADDR_OVER
+#endif
+#if ! HAVE_DECL_SCTP_ABORT
+#     define    SCTP_ABORT      MSG_ABORT
+#endif
+#if ! HAVE_DECL_SCTP_EOF
+#     define    SCTP_EOF        MSG_EOF
+#endif
+
+/* More Solaris 10 fixes: */
+#if ! HAVE_DECL_SCTP_CLOSED && HAVE_DECL_SCTPS_IDLE
+#    define SCTP_CLOSED SCTPS_IDLE
+#    undef HAVE_DECL_SCTP_CLOSED
+#    define HAVE_DECL_SCTP_CLOSED 1
+#endif
+#if ! HAVE_DECL_SCTP_BOUND && HAVE_DECL_SCTPS_BOUND
+#    define SCTP_BOUND SCTPS_BOUND
+#    undef HAVE_DECL_SCTP_BOUND
+#    define HAVE_DECL_SCTP_BOUND 1
+#endif
+#if ! HAVE_DECL_SCTP_LISTEN && HAVE_DECL_SCTPS_LISTEN
+#    define SCTP_LISTEN SCTPS_LISTEN
+#    undef HAVE_DECL_SCTP_LISTEN
+#    define HAVE_DECL_SCTP_LISTEN 1
+#endif
+#if ! HAVE_DECL_SCTP_COOKIE_WAIT && HAVE_DECL_SCTPS_COOKIE_WAIT
+#    define SCTP_COOKIE_WAIT SCTPS_COOKIE_WAIT
+#    undef HAVE_DECL_SCTP_COOKIE_WAIT
+#    define HAVE_DECL_SCTP_COOKIE_WAIT 1
+#endif
+#if ! HAVE_DECL_SCTP_COOKIE_ECHOED && HAVE_DECL_SCTPS_COOKIE_ECHOED
+#    define SCTP_COOKIE_ECHOED SCTPS_COOKIE_ECHOED
+#    undef HAVE_DECL_SCTP_COOKIE_ECHOED
+#    define HAVE_DECL_SCTP_COOKIE_ECHOED 1
+#endif
+#if ! HAVE_DECL_SCTP_ESTABLISHED && HAVE_DECL_SCTPS_ESTABLISHED
+#    define SCTP_ESTABLISHED SCTPS_ESTABLISHED
+#    undef HAVE_DECL_SCTP_ESTABLISHED
+#    define HAVE_DECL_SCTP_ESTABLISHED 1
+#endif
+#if ! HAVE_DECL_SCTP_SHUTDOWN_PENDING && HAVE_DECL_SCTPS_SHUTDOWN_PENDING
+#    define SCTP_SHUTDOWN_PENDING SCTPS_SHUTDOWN_PENDING
+#    undef HAVE_DECL_SCTP_SHUTDOWN_PENDING
+#    define HAVE_DECL_SCTP_SHUTDOWN_PENDING 1
+#endif
+#if ! HAVE_DECL_SCTP_SHUTDOWN_SENT && HAVE_DECL_SCTPS_SHUTDOWN_SENT
+#    define SCTP_SHUTDOWN_SENT SCTPS_SHUTDOWN_SENT
+#    undef HAVE_DECL_SCTP_SHUTDOWN_SENT
+#    define HAVE_DECL_SCTP_SHUTDOWN_SENT 1
+#endif
+#if ! HAVE_DECL_SCTP_SHUTDOWN_RECEIVED && HAVE_DECL_SCTPS_SHUTDOWN_RECEIVED
+#    define SCTP_SHUTDOWN_RECEIVED SCTPS_SHUTDOWN_RECEIVED
+#    undef HAVE_DECL_SCTP_SHUTDOWN_RECEIVED
+#    define HAVE_DECL_SCTP_SHUTDOWN_RECEIVED 1
+#endif
+#if ! HAVE_DECL_SCTP_SHUTDOWN_ACK_SENT && HAVE_DECL_SCTPS_SHUTDOWN_ACK_SENT
+#    define SCTP_SHUTDOWN_ACK_SENT SCTPS_SHUTDOWN_ACK_SENT
+#    undef HAVE_DECL_SCTP_SHUTDOWN_ACK_SENT
+#    define HAVE_DECL_SCTP_SHUTDOWN_ACK_SENT 1
+#endif
+/* New spelling in lksctp 2.6.22 or maybe even earlier:
+ *  adaption -> adaptation
+ */
+#if !defined(SCTP_ADAPTATION_LAYER) && defined (SCTP_ADAPTION_LAYER)
+#     define SCTP_ADAPTATION_LAYER       SCTP_ADAPTION_LAYER
+#     define SCTP_ADAPTATION_INDICATION  SCTP_ADAPTION_INDICATION
+#     define sctp_adaptation_event       sctp_adaption_event
+#     define sctp_setadaptation          sctp_setadaption
+#     define sn_adaptation_event         sn_adaption_event
+#     define sai_adaptation_ind          sai_adaption_ind
+#     define ssb_adaptation_ind          ssb_adaption_ind
+#     define sctp_adaptation_layer_event sctp_adaption_layer_event
+#endif
+
+/*
+ * We *may* need this stuff later when we *fully* implement support for SCTP 
+ *
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_BINDX)
+static typeof(sctp_bindx) *esock_sctp_bindx = NULL;
+#else
+static int (*esock_sctp_bindx)
+	(int sd, struct sockaddr *addrs, int addrcnt, int flags) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_PEELOFF)
+static typeof(sctp_peeloff) *esock_sctp_peeloff = NULL;
+#else
+static int (*esock_sctp_peeloff)
+        (int sd, sctp_assoc_t assoc_id) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_GETLADDRS)
+static typeof(sctp_getladdrs) *esock_sctp_getladdrs = NULL;
+#else
+static int (*esock_sctp_getladdrs)
+        (int sd, sctp_assoc_t assoc_id, struct sockaddr **ss) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_FREELADDRS)
+static typeof(sctp_freeladdrs) *esock_sctp_freeladdrs = NULL;
+#else
+static void (*esock_sctp_freeladdrs)(struct sockaddr *addrs) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_GETPADDRS)
+static typeof(sctp_getpaddrs) *esock_sctp_getpaddrs = NULL;
+#else
+static int (*esock_sctp_getpaddrs)
+        (int sd, sctp_assoc_t assoc_id, struct sockaddr **ss) = NULL;
+#endif
+
+#if defined(__GNUC__) && defined(HAVE_SCTP_FREEPADDRS)
+static typeof(sctp_freepaddrs) *esock_sctp_freepaddrs = NULL;
+#else
+static void (*esock_sctp_freepaddrs)(struct sockaddr *addrs) = NULL;
+#endif
+
+*/
+
+#endif /* #if defined(HAVE_SCTP_H) */
+
+
+#ifndef WANT_NONBLOCKING
+#define WANT_NONBLOCKING
+#endif
+#include "sys.h"
+
+/* Socket stuff */
+#define INVALID_SOCKET -1
+// #define INVALID_EVENT  -1
+#define SOCKET_ERROR   -1
+
+#endif /* ifdef __WIN32__ */
+
+#include <erl_nif.h>
+
+#include "socket_dbg.h"
+#include "socket_tarray.h"
+#include "socket_int.h"
+#include "socket_util.h"
+
+#if defined(SOL_IPV6) || defined(IPPROTO_IPV6)
+#define HAVE_IPV6
+#endif
+
+/* All platforms fail on malloc errors. */
+#define FATAL_MALLOC
+
+
+/* Debug stuff... */
+#define SOCKET_GLOBAL_DEBUG_DEFAULT FALSE
+#define SOCKET_DEBUG_DEFAULT        FALSE
+
+/* Counters and stuff (Don't know where to sent this stuff anyway) */
+#define SOCKET_NIF_IOW_DEFAULT FALSE
+
+
+
+/* Socket stuff */
+#define INVALID_EVENT  -1
+
+#define SOCKET int
+#define HANDLE long int
+
+
+/* ==============================================================================
+ * The IS_SOCKET_ERROR macro below is used for portability reasons.
+ * While POSIX specifies that errors from socket-related system calls
+ * should be indicated with a -1 return value, some users have experienced
+ * non-Windows OS kernels that return negative values other than -1.
+ * While one can argue that such kernels are technically broken, comparing
+ * against values less than 0 covers their out-of-spec return values without
+ * imposing incorrect semantics on systems that manage to correctly return -1
+ * for errors, thus increasing Erlang's portability.
+ */
+#ifdef __WIN32__
+#define IS_SOCKET_ERROR(val) ((val) == SOCKET_ERROR)
+#else
+#define IS_SOCKET_ERROR(val) ((val) < 0)
+#endif
+
+
+/* *** Misc macros and defines *** */
+
+/* This macro exist on some (linux) platforms */
+#if !defined(IPTOS_TOS_MASK)
+#define IPTOS_TOS_MASK     0x1E
+#endif
+#if !defined(IPTOS_TOS)
+#define IPTOS_TOS(tos)          ((tos)&IPTOS_TOS_MASK)
+#endif
+
+
+#if defined(TCP_CA_NAME_MAX)
+#define SOCKET_OPT_TCP_CONGESTION_NAME_MAX TCP_CA_NAME_MAX
+#else
+/* This is really excessive, but just in case... */
+#define SOCKET_OPT_TCP_CONGESTION_NAME_MAX 256
+#endif
+
+
+/* *** Socket state defs *** */
+
+#define SOCKET_FLAG_OPEN         0x0001
+#define SOCKET_FLAG_ACTIVE       0x0004
+#define SOCKET_FLAG_LISTEN       0x0008
+#define SOCKET_FLAG_CON          0x0010
+#define SOCKET_FLAG_ACC          0x0020
+#define SOCKET_FLAG_BUSY         0x0040
+#define SOCKET_FLAG_CLOSE        0x0080
+
+#define SOCKET_STATE_CLOSED          (0)
+#define SOCKET_STATE_OPEN            (SOCKET_FLAG_OPEN)
+#define SOCKET_STATE_CONNECTED       (SOCKET_STATE_OPEN      | SOCKET_FLAG_ACTIVE)
+#define SOCKET_STATE_LISTENING       (SOCKET_STATE_OPEN      | SOCKET_FLAG_LISTEN)
+#define SOCKET_STATE_CONNECTING      (SOCKET_STATE_OPEN      | SOCKET_FLAG_CON)
+#define SOCKET_STATE_ACCEPTING       (SOCKET_STATE_LISTENING | SOCKET_FLAG_ACC)
+#define SOCKET_STATE_CLOSING         (SOCKET_FLAG_CLOSE)
+
+#define IS_CLOSED(d)                            \
+    ((d)->state == SOCKET_STATE_CLOSED)
+
+/*
+#define IS_STATE(d, f) \
+    (((d)->state & (f)) == (f))
+*/
+
+#define IS_CLOSING(d)                                                   \
+    (((d)->state & SOCKET_STATE_CLOSING) == SOCKET_STATE_CLOSING)
+
+#define IS_OPEN(d)                                              \
+    (((d)->state & SOCKET_FLAG_OPEN) == SOCKET_FLAG_OPEN)
+
+#define IS_CONNECTED(d)                                                 \
+    (((d)->state & SOCKET_STATE_CONNECTED) == SOCKET_STATE_CONNECTED)
+
+#define IS_CONNECTING(d)                                \
+    (((d)->state & SOCKET_FLAG_CON) == SOCKET_FLAG_CON)
+
+/*
+#define IS_BUSY(d)                                      \
+    (((d)->state & SOCKET_FLAG_BUSY) == SOCKET_FLAG_BUSY)
+*/
+
+#define SOCKET_SEND_FLAG_CONFIRM    0
+#define SOCKET_SEND_FLAG_DONTROUTE  1
+#define SOCKET_SEND_FLAG_EOR        2
+#define SOCKET_SEND_FLAG_MORE       3
+#define SOCKET_SEND_FLAG_NOSIGNAL   4
+#define SOCKET_SEND_FLAG_OOB        5
+#define SOCKET_SEND_FLAG_LOW        SOCKET_SEND_FLAG_CONFIRM
+#define SOCKET_SEND_FLAG_HIGH       SOCKET_SEND_FLAG_OOB
+
+#define SOCKET_RECV_FLAG_CMSG_CLOEXEC 0
+#define SOCKET_RECV_FLAG_ERRQUEUE     1
+#define SOCKET_RECV_FLAG_OOB          2
+#define SOCKET_RECV_FLAG_PEEK         3
+#define SOCKET_RECV_FLAG_TRUNC        4
+#define SOCKET_RECV_FLAG_LOW          SOCKET_RECV_FLAG_CMSG_CLOEXEC
+#define SOCKET_RECV_FLAG_HIGH         SOCKET_RECV_FLAG_TRUNC
+
+#define SOCKET_RECV_BUFFER_SIZE_DEFAULT      8192
+#define SOCKET_RECV_CTRL_BUFFER_SIZE_DEFAULT 1024
+#define SOCKET_SEND_CTRL_BUFFER_SIZE_DEFAULT 1024
+
+#define VT2S(__VT__) (((__VT__) == SOCKET_OPT_VALUE_TYPE_UNSPEC) ? "unspec" : \
+                      (((__VT__) == SOCKET_OPT_VALUE_TYPE_INT) ? "int" : \
+                       ((__VT__) == SOCKET_OPT_VALUE_TYPE_BOOL) ? "bool" : \
+                       "undef"))
+
+#define SOCKET_OPT_VALUE_TYPE_UNSPEC 0
+#define SOCKET_OPT_VALUE_TYPE_INT    1
+#define SOCKET_OPT_VALUE_TYPE_BOOL   2
+
+typedef union {
+    struct {
+        // 0 = not open, 1 = open
+        unsigned int open:1;
+        // 0 = not conn, 1 = connecting, 2 = connected
+        unsigned int connect:2;
+        // unsigned int connecting:1;
+        // unsigned int connected:1;
+        // 0 = not listen, 1 = listening, 2 = accepting
+        unsigned int listen:2;
+        // unsigned int listening:1;
+        // unsigned int accepting:1;
+        /* Room for more... */
+    } flags;
+    unsigned int field; // Make it easy to reset all flags...
+} SocketState;
+
+/*
+#define IS_OPEN(d)       ((d)->state.flags.open)
+#define IS_CONNECTED(d)  ((d)->state.flags.connect == SOCKET_STATE_CONNECTED)
+#define IS_CONNECTING(d) ((d)->state.flags.connect == SOCKET_STATE_CONNECTING)
+*/
+
+
+/*----------------------------------------------------------------------------
+ * Interface constants.
+ *
+ * This section must be "identical" to the corresponding socket.hrl
+ */
+
+/* domain */
+#define SOCKET_DOMAIN_LOCAL       1
+#define SOCKET_DOMAIN_INET        2
+#define SOCKET_DOMAIN_INET6       3
+
+/* type */
+#define SOCKET_TYPE_STREAM        1
+#define SOCKET_TYPE_DGRAM         2
+#define SOCKET_TYPE_RAW           3
+// #define SOCKET_TYPE_RDM           4
+#define SOCKET_TYPE_SEQPACKET     5
+
+/* protocol */
+#define SOCKET_PROTOCOL_IP        1
+#define SOCKET_PROTOCOL_TCP       2
+#define SOCKET_PROTOCOL_UDP       3
+#define SOCKET_PROTOCOL_SCTP      4
+#define SOCKET_PROTOCOL_ICMP      5
+#define SOCKET_PROTOCOL_IGMP      6
+
+/* shutdown how */
+#define SOCKET_SHUTDOWN_HOW_RD    0
+#define SOCKET_SHUTDOWN_HOW_WR    1
+#define SOCKET_SHUTDOWN_HOW_RDWR  2
+
+
+#define SOCKET_OPT_LEVEL_OTP        0
+#define SOCKET_OPT_LEVEL_SOCKET     1
+#define SOCKET_OPT_LEVEL_IP         2
+#define SOCKET_OPT_LEVEL_IPV6       3
+#define SOCKET_OPT_LEVEL_TCP        4
+#define SOCKET_OPT_LEVEL_UDP        5
+#define SOCKET_OPT_LEVEL_SCTP       6
+
+#define SOCKET_OPT_OTP_DEBUG        1
+#define SOCKET_OPT_OTP_IOW          2
+#define SOCKET_OPT_OTP_CTRL_PROC    3
+#define SOCKET_OPT_OTP_RCVBUF       4
+#define SOCKET_OPT_OTP_RCVCTRLBUF   6
+#define SOCKET_OPT_OTP_SNDCTRLBUF   7
+#define SOCKET_OPT_OTP_FD           8
+#define SOCKET_OPT_OTP_DOMAIN       0xFF01 // INTERNAL AND ONLY GET
+#define SOCKET_OPT_OTP_TYPE         0xFF02 // INTERNAL AND ONLY GET
+#define SOCKET_OPT_OTP_PROTOCOL     0xFF03 // INTERNAL AND ONLY GET
+
+#define SOCKET_OPT_SOCK_ACCEPTCONN     1
+#define SOCKET_OPT_SOCK_BINDTODEVICE   3
+#define SOCKET_OPT_SOCK_BROADCAST      4
+#define SOCKET_OPT_SOCK_DEBUG          6
+#define SOCKET_OPT_SOCK_DOMAIN         7
+#define SOCKET_OPT_SOCK_DONTROUTE      8
+#define SOCKET_OPT_SOCK_KEEPALIVE     10
+#define SOCKET_OPT_SOCK_LINGER        11
+#define SOCKET_OPT_SOCK_OOBINLINE     13
+#define SOCKET_OPT_SOCK_PEEK_OFF      15
+#define SOCKET_OPT_SOCK_PRIORITY      17
+#define SOCKET_OPT_SOCK_PROTOCOL      18
+#define SOCKET_OPT_SOCK_RCVBUF        19
+#define SOCKET_OPT_SOCK_RCVLOWAT      21
+#define SOCKET_OPT_SOCK_RCVTIMEO      22
+#define SOCKET_OPT_SOCK_REUSEADDR     23
+#define SOCKET_OPT_SOCK_REUSEPORT     24
+#define SOCKET_OPT_SOCK_SNDBUF        27
+#define SOCKET_OPT_SOCK_SNDLOWAT      29
+#define SOCKET_OPT_SOCK_SNDTIMEO      30
+#define SOCKET_OPT_SOCK_TIMESTAMP     31
+#define SOCKET_OPT_SOCK_TYPE          32
+
+#define SOCKET_OPT_IP_ADD_MEMBERSHIP          1
+#define SOCKET_OPT_IP_ADD_SOURCE_MEMBERSHIP   2
+#define SOCKET_OPT_IP_BLOCK_SOURCE            3
+#define SOCKET_OPT_IP_DROP_MEMBERSHIP         5
+#define SOCKET_OPT_IP_DROP_SOURCE_MEMBERSHIP  6
+#define SOCKET_OPT_IP_FREEBIND                7
+#define SOCKET_OPT_IP_HDRINCL                 8
+#define SOCKET_OPT_IP_MINTTL                  9
+#define SOCKET_OPT_IP_MSFILTER               10
+#define SOCKET_OPT_IP_MTU                    11
+#define SOCKET_OPT_IP_MTU_DISCOVER           12
+#define SOCKET_OPT_IP_MULTICAST_ALL          13
+#define SOCKET_OPT_IP_MULTICAST_IF           14
+#define SOCKET_OPT_IP_MULTICAST_LOOP         15
+#define SOCKET_OPT_IP_MULTICAST_TTL          16
+#define SOCKET_OPT_IP_NODEFRAG               17
+#define SOCKET_OPT_IP_PKTINFO                19
+#define SOCKET_OPT_IP_RECVDSTADDR            20
+#define SOCKET_OPT_IP_RECVERR                21
+#define SOCKET_OPT_IP_RECVIF                 22
+#define SOCKET_OPT_IP_RECVOPTS               23
+#define SOCKET_OPT_IP_RECVORIGDSTADDR        24
+#define SOCKET_OPT_IP_RECVTOS                25
+#define SOCKET_OPT_IP_RECVTTL                26
+#define SOCKET_OPT_IP_RETOPTS                27
+#define SOCKET_OPT_IP_ROUTER_ALERT           28
+#define SOCKET_OPT_IP_SENDSRCADDR            29 // Same as IP_RECVDSTADDR?
+#define SOCKET_OPT_IP_TOS                    30
+#define SOCKET_OPT_IP_TRANSPARENT            31
+#define SOCKET_OPT_IP_TTL                    32
+#define SOCKET_OPT_IP_UNBLOCK_SOURCE         33
+
+#define SOCKET_OPT_IPV6_ADDRFORM              1
+#define SOCKET_OPT_IPV6_ADD_MEMBERSHIP        2
+#define SOCKET_OPT_IPV6_AUTHHDR               3
+#define SOCKET_OPT_IPV6_DROP_MEMBERSHIP       6
+#define SOCKET_OPT_IPV6_DSTOPTS               7
+#define SOCKET_OPT_IPV6_FLOWINFO             11
+#define SOCKET_OPT_IPV6_HOPLIMIT             12
+#define SOCKET_OPT_IPV6_HOPOPTS              13
+#define SOCKET_OPT_IPV6_MTU                  17
+#define SOCKET_OPT_IPV6_MTU_DISCOVER         18
+#define SOCKET_OPT_IPV6_MULTICAST_HOPS       19
+#define SOCKET_OPT_IPV6_MULTICAST_IF         20
+#define SOCKET_OPT_IPV6_MULTICAST_LOOP       21
+#define SOCKET_OPT_IPV6_RECVERR              24
+#define SOCKET_OPT_IPV6_RECVPKTINFO          25 // PKTINFO on FreeBSD
+#define SOCKET_OPT_IPV6_ROUTER_ALERT         27
+#define SOCKET_OPT_IPV6_RTHDR                28
+#define SOCKET_OPT_IPV6_UNICAST_HOPS         30
+#define SOCKET_OPT_IPV6_V6ONLY               32
+
+#define SOCKET_OPT_TCP_CONGESTION   1
+#define SOCKET_OPT_TCP_CORK         2
+#define SOCKET_OPT_TCP_MAXSEG       7
+#define SOCKET_OPT_TCP_NODELAY      9
+
+#define SOCKET_OPT_UDP_CORK         1
+
+#define SOCKET_OPT_SCTP_ASSOCINFO           2
+#define SOCKET_OPT_SCTP_AUTOCLOSE           8
+#define SOCKET_OPT_SCTP_DISABLE_FRAGMENTS  12
+#define SOCKET_OPT_SCTP_EVENTS             14
+#define SOCKET_OPT_SCTP_INITMSG            18
+#define SOCKET_OPT_SCTP_MAXSEG             21
+#define SOCKET_OPT_SCTP_NODELAY            23
+#define SOCKET_OPT_SCTP_RTOINFO            29
+
+/* We should *eventually* use this instead of hard-coding the size (to 1) */
+#define ESOCK_RECVMSG_IOVEC_SZ 1
+
+
+#define SOCKET_SUPPORTS_OPTIONS 0x0001
+#define SOCKET_SUPPORTS_SCTP    0x0002
+#define SOCKET_SUPPORTS_IPV6    0x0003
+
+
+
+/* =================================================================== *
+ *                                                                     *
+ *                        Various enif macros                          *
+ *                                                                     *
+ * =================================================================== */
+
+#define SGDBG( proto )         ESOCK_DBG_PRINTF( data.dbg , proto )
+#define SSDBG( __D__ , proto ) ESOCK_DBG_PRINTF( (__D__)->dbg , proto )
+
+
+
+/* =================================================================== *
+ *                                                                     *
+ *                    Basic socket operations                          *
+ *                                                                     *
+ * =================================================================== */
+
+#ifdef __WIN32__
+
+/* *** Windows macros *** */
+
+#define sock_accept(s, addr, len) \
+    make_noninheritable_handle(accept((s), (addr), (len)))
+#define sock_bind(s, addr, len)        bind((s), (addr), (len))
+#define sock_close(s)                  closesocket((s))
+#define sock_close_event(e)            WSACloseEvent(e)
+#define sock_connect(s, addr, len)     connect((s), (addr), (len))
+#define sock_create_event(s)           WSACreateEvent()
+#define sock_errno()                   WSAGetLastError()
+#define sock_getopt(s,l,o,v,ln)        getsockopt((s),(l),(o),(v),(ln))
+#define sock_htons(x)                  htons((x))
+#define sock_htonl(x)                  htonl((x))
+#define sock_listen(s, b)              listen((s), (b))
+#define sock_name(s, addr, len)        getsockname((s), (addr), (len))
+#define sock_ntohs(x)                  ntohs((x))
+#define sock_open(domain, type, proto)                             \
+    make_noninheritable_handle(socket((domain), (type), (proto)))
+#define sock_peer(s, addr, len)    getpeername((s), (addr), (len))
+#define sock_recv(s,buf,len,flag)  recv((s),(buf),(len),(flag))
+#define sock_recvfrom(s,buf,blen,flag,addr,alen) \
+    recvfrom((s),(buf),(blen),(flag),(addr),(alen))
+#define sock_send(s,buf,len,flag)      send((s),(buf),(len),(flag))
+#define sock_sendto(s,buf,blen,flag,addr,alen) \
+    sendto((s),(buf),(blen),(flag),(addr),(alen))
+#define sock_setopt(s,l,o,v,ln)        setsockopt((s),(l),(o),(v),(ln))
+#define sock_shutdown(s, how)          shutdown((s), (how))
+
+
+#define SET_BLOCKING(s)            ioctlsocket(s, FIONBIO, &zero_value)
+#define SET_NONBLOCKING(s)         ioctlsocket(s, FIONBIO, &one_value)
+static unsigned long zero_value = 0;
+static unsigned long one_value  = 1;
+
+
+#else /* !__WIN32__ */
+
+
+#ifdef HAS_ACCEPT4
+// We have to figure out what the flags are...
+#define sock_accept(s, addr, len)       accept4((s), (addr), (len), (SOCK_CLOEXEC))
+#else
+#define sock_accept(s, addr, len)       accept((s), (addr), (len))
+#endif
+#define sock_bind(s, addr, len)         bind((s), (addr), (len))
+#define sock_close(s)                   close((s))
+#define sock_close_event(e)             /* do nothing */
+#define sock_connect(s, addr, len)      connect((s), (addr), (len))
+#define sock_create_event(s)            (s) /* return file descriptor */
+#define sock_errno()                    errno
+#define sock_getopt(s,t,n,v,l)          getsockopt((s),(t),(n),(v),(l))
+#define sock_htons(x)                   htons((x))
+#define sock_htonl(x)                   htonl((x))
+#define sock_listen(s, b)               listen((s), (b))
+#define sock_name(s, addr, len)         getsockname((s), (addr), (len))
+#define sock_ntohs(x)                   ntohs((x))
+#define sock_open(domain, type, proto)  socket((domain), (type), (proto))
+#define sock_peer(s, addr, len)         getpeername((s), (addr), (len))
+#define sock_recv(s,buf,len,flag)       recv((s),(buf),(len),(flag))
+#define sock_recvfrom(s,buf,blen,flag,addr,alen) \
+    recvfrom((s),(buf),(blen),(flag),(addr),(alen))
+#define sock_recvmsg(s,msghdr,flag)     recvmsg((s),(msghdr),(flag))
+#define sock_send(s,buf,len,flag)       send((s), (buf), (len), (flag))
+#define sock_sendmsg(s,msghdr,flag)     sendmsg((s),(msghdr),(flag))
+#define sock_sendto(s,buf,blen,flag,addr,alen) \
+                sendto((s),(buf),(blen),(flag),(addr),(alen))
+#define sock_setopt(s,l,o,v,ln)         setsockopt((s),(l),(o),(v),(ln))
+#define sock_shutdown(s, how)           shutdown((s), (how))
+
+#endif /* !__WIN32__ */
+
+#ifdef HAVE_SOCKLEN_T
+#  define SOCKLEN_T socklen_t
+#else
+#  define SOCKLEN_T size_t
+#endif
+
+#ifdef __WIN32__
+#define SOCKOPTLEN_T int
+#else
+#define SOCKOPTLEN_T SOCKLEN_T
+#endif
+
+/* We can use the IPv4 def for this since the beginning
+ * is the same for INET and INET6 */
+#define which_address_port(sap)		     \
+  ((((sap)->in4.sin_family == AF_INET) ||  \
+    ((sap)->in4.sin_family == AF_INET6)) ? \
+   ((sap)->in4.sin_port) : -1)
+
+
+typedef union {
+    ErlNifMonitor mon;
+    Uint32        raw[4];
+} ESockMonitor;
+
+
+typedef struct {
+    ErlNifPid     pid; // PID of the requesting process
+    // ErlNifMonitor mon; Monitor to the requesting process
+    ESockMonitor  mon; // Monitor to the requesting process
+    ERL_NIF_TERM  ref; // The (unique) reference (ID) of the request
+} SocketRequestor;
+
+typedef struct socket_request_queue_element {
+    struct socket_request_queue_element* nextP;
+    SocketRequestor                      data;
+} SocketRequestQueueElement;
+
+typedef struct {
+    SocketRequestQueueElement* first;
+    SocketRequestQueueElement* last;
+} SocketRequestQueue;
+
+
+typedef struct {
+    /* +++ The actual socket +++ */
+    SOCKET             sock;
+    HANDLE             event;
+
+    /* +++ Stuff "about" the socket +++ */
+    int                domain;
+    int                type;
+    int                protocol;
+
+    unsigned int       state;
+    SocketAddress      remote;
+    unsigned int       addrLen;
+
+    ErlNifEnv*         env;
+
+    /* +++ Controller (owner) process +++ */
+    ErlNifPid          ctrlPid;
+    // ErlNifMonitor   ctrlMon;
+    ESockMonitor       ctrlMon;
+
+    /* +++ Write stuff +++ */
+    ErlNifMutex*       writeMtx;
+    SocketRequestor    currentWriter;
+    SocketRequestor*   currentWriterP; // NULL or points to currentWriter
+    SocketRequestQueue writersQ;
+    BOOLEAN_T          isWritable;
+    Uint32             writePkgCnt;
+    Uint32             writeByteCnt;
+    Uint32             writeTries;
+    Uint32             writeWaits;
+    Uint32             writeFails;
+
+    /* +++ Read stuff +++ */
+    ErlNifMutex*       readMtx;
+    SocketRequestor    currentReader;
+    SocketRequestor*   currentReaderP; // NULL or points to currentReader
+    SocketRequestQueue readersQ;
+    BOOLEAN_T          isReadable;
+    ErlNifBinary       rbuffer;      // DO WE NEED THIS
+    Uint32             readCapacity; // DO WE NEED THIS
+    Uint32             readPkgCnt;
+    Uint32             readByteCnt;
+    Uint32             readTries;
+    Uint32             readWaits;
+
+    /* +++ Accept stuff +++ */
+    ErlNifMutex*       accMtx;
+    SocketRequestor    currentAcceptor;
+    SocketRequestor*   currentAcceptorP; // NULL or points to currentAcceptor
+    SocketRequestQueue acceptorsQ;
+
+    /* +++ Config & Misc stuff +++ */
+    size_t       rBufSz;  // Read buffer size (when data length = 0)
+    /* rNum and rNumCnt are used (together with rBufSz) when calling the recv 
+     * function with the Length argument set to 0 (zero).
+     * If rNum is 0 (zero), then rNumCnt is not used and only *one* read will
+     * be done. Also, when get'ing the value of the option (rcvbuf) with 
+     * getopt, the value will be reported as an integer. If the rNum has a 
+     * value greater then 0 (zero), then it will instead be reported as {N, BufSz}.
+     */
+    unsigned int rNum;    // recv: Number of reads using rBufSz
+    unsigned int rNumCnt; // recv: Current number of reads (so far)
+    size_t       rCtrlSz; // Read control buffer size
+    size_t       wCtrlSz; // Write control buffer size
+    BOOLEAN_T    iow;     // Inform On (counter) Wrap
+    BOOLEAN_T    dbg;
+
+    /* +++ Close stuff +++ */
+    ErlNifMutex*  closeMtx;
+    ErlNifPid     closerPid;
+    // ErlNifMonitor closerMon;
+    ESockMonitor  closerMon;
+    ERL_NIF_TERM  closeRef;
+    BOOLEAN_T     closeLocal;
+
+} SocketDescriptor;
+
+
+#define SOCKET_OPT_VALUE_UNDEF  0
+#define SOCKET_OPT_VALUE_BOOL   1
+#define SOCKET_OPT_VALUE_INT    2
+#define SOCKET_OPT_VALUE_LINGER 3
+#define SOCKET_OPT_VALUE_BIN    4
+#define SOCKET_OPT_VALUE_STR    5
+
+typedef struct {
+    unsigned int tag;
+    union {
+        BOOLEAN_T     boolVal;
+        int           intVal;
+        struct linger lingerVal;
+        ErlNifBinary  binVal;
+        struct {
+            unsigned int len;
+            char*        str;
+        } strVal;
+    } u;
+    /*
+    void*     optValP;   // Points to the actual data (above)
+    socklen_t optValLen; // The size of the option value
+    */
+} SocketOptValue;
+
+
+/* Global stuff (do we really need to "collect"
+ * these things?)
+ */
+typedef struct {
+    /* These are for debugging, testing and the like */
+    ERL_NIF_TERM version;
+    ERL_NIF_TERM buildDate;
+    BOOLEAN_T    dbg;
+
+    BOOLEAN_T    iow;
+    ErlNifMutex* cntMtx;
+    Uint32       numSockets;
+    Uint32       numTypeStreams;
+    Uint32       numTypeDGrams;
+    Uint32       numTypeSeqPkgs;
+    Uint32       numDomainInet;
+    Uint32       numDomainInet6;
+    Uint32       numDomainLocal;
+    Uint32       numProtoIP;
+    Uint32       numProtoTCP;
+    Uint32       numProtoUDP;
+    Uint32       numProtoSCTP;
+} SocketData;
+
+
+/* ----------------------------------------------------------------------
+ *  F o r w a r d s
+ * ----------------------------------------------------------------------
+ */
+
+
+
+static ERL_NIF_TERM nif_info(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_supports(ErlNifEnv*         env,
+                                 int                argc,
+                                 const ERL_NIF_TERM argv[]);
+/*
+This is a *global* debug function (enable or disable for all
+operations and all sockets.
+static ERL_NIF_TERM nif_debug(ErlNifEnv*         env,
+                              int                argc,
+                              const ERL_NIF_TERM argv[]);
+*/
+static ERL_NIF_TERM nif_open(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_bind(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_connect(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_listen(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_accept(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_send(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_sendto(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_sendmsg(ErlNifEnv*         env,
+                                int                argc,
+                                const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_recv(ErlNifEnv*         env,
+                             int                argc,
+                             const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_recvfrom(ErlNifEnv*         env,
+                                 int                argc,
+                                 const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_recvmsg(ErlNifEnv*         env,
+                                int                argc,
+                                const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_close(ErlNifEnv*         env,
+                              int                argc,
+                              const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_shutdown(ErlNifEnv*         env,
+                                 int                argc,
+                                 const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_setopt(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_getopt(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_sockname(ErlNifEnv*         env,
+                                 int                argc,
+                                 const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_peername(ErlNifEnv*         env,
+                                 int                argc,
+                                 const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_finalize_connection(ErlNifEnv*         env,
+                                            int                argc,
+                                            const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_finalize_close(ErlNifEnv*         env,
+                                       int                argc,
+                                       const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM nif_cancel(ErlNifEnv*         env,
+                               int                argc,
+                               const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM nsupports(ErlNifEnv* env, int key);
+static ERL_NIF_TERM nsupports_options(ErlNifEnv* env);
+static ERL_NIF_TERM nsupports_options_socket(ErlNifEnv* env);
+static ERL_NIF_TERM nsupports_options_ip(ErlNifEnv* env);
+static ERL_NIF_TERM nsupports_options_ipv6(ErlNifEnv* env);
+static ERL_NIF_TERM nsupports_options_tcp(ErlNifEnv* env);
+static ERL_NIF_TERM nsupports_options_udp(ErlNifEnv* env);
+static ERL_NIF_TERM nsupports_options_sctp(ErlNifEnv* env);
+static ERL_NIF_TERM nsupports_sctp(ErlNifEnv* env);
+static ERL_NIF_TERM nsupports_ipv6(ErlNifEnv* env);
+
+static ERL_NIF_TERM nopen(ErlNifEnv* env,
+                          int        domain,
+                          int        type,
+                          int        protocol,
+                          char*      netns);
+static ERL_NIF_TERM nbind(ErlNifEnv*        env,
+                          SocketDescriptor* descP,
+                          SocketAddress*    sockAddrP,
+                          unsigned int      addrLen);
+static ERL_NIF_TERM nconnect(ErlNifEnv*        env,
+                             SocketDescriptor* descP);
+static ERL_NIF_TERM nlisten(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            int               backlog);
+static ERL_NIF_TERM naccept_listening(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      ref);
+static ERL_NIF_TERM naccept_accepting(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      ref);
+static ERL_NIF_TERM naccept(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ERL_NIF_TERM      ref);
+static ERL_NIF_TERM nsend(ErlNifEnv*        env,
+                          SocketDescriptor* descP,
+                          ERL_NIF_TERM      sockRef,
+                          ERL_NIF_TERM      sendRef,
+                          ErlNifBinary*     dataP,
+                          int               flags);
+static ERL_NIF_TERM nsendto(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ERL_NIF_TERM      sockRef,
+                            ERL_NIF_TERM      sendRef,
+                            ErlNifBinary*     dataP,
+                            int               flags,
+                            SocketAddress*    toAddrP,
+                            unsigned int      toAddrLen);
+static ERL_NIF_TERM nsendmsg(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             ERL_NIF_TERM      sockRef,
+                             ERL_NIF_TERM      sendRef,
+                             ERL_NIF_TERM      eMsgHdr,
+                             int               flags);
+static ERL_NIF_TERM nrecv(ErlNifEnv*        env,
+                          SocketDescriptor* descP,
+                          ERL_NIF_TERM      sendRef,
+                          ERL_NIF_TERM      recvRef,
+                          int               len,
+                          int               flags);
+static ERL_NIF_TERM nrecvfrom(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              ERL_NIF_TERM      sockRef,
+                              ERL_NIF_TERM      recvRef,
+                              Uint16            bufSz,
+                              int               flags);
+static ERL_NIF_TERM nrecvmsg(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             ERL_NIF_TERM      sockRef,
+                             ERL_NIF_TERM      recvRef,
+                             Uint16            bufLen,
+                             Uint16            ctrlLen,
+                             int               flags);
+static ERL_NIF_TERM nclose(ErlNifEnv*        env,
+                           SocketDescriptor* descP);
+static ERL_NIF_TERM nshutdown(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              int               how);
+static ERL_NIF_TERM nsetopt(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            BOOLEAN_T         isEncoded,
+                            BOOLEAN_T         isOTP,
+                            int               level,
+                            int               eOpt,
+                            ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_otp(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                int               eOpt,
+                                ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_otp_debug(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_otp_iow(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_otp_ctrl_proc(ErlNifEnv*        env,
+                                          SocketDescriptor* descP,
+                                          ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_otp_rcvbuf(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_otp_rcvctrlbuf(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_otp_sndctrlbuf(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_native(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   int               level,
+                                   int               eOpt,
+                                   ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_level(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  int               level,
+                                  int               eOpt,
+                                  ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_lvl_socket(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       int               eOpt,
+                                       ERL_NIF_TERM      eVal);
+
+
+/* *** Handling set of socket options for level = socket *** */
+
+#if defined(SO_BINDTODEVICE)
+static ERL_NIF_TERM nsetopt_lvl_sock_bindtodevice(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_BROADCAST)
+static ERL_NIF_TERM nsetopt_lvl_sock_broadcast(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_DEBUG)
+static ERL_NIF_TERM nsetopt_lvl_sock_debug(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_DONTROUTE)
+static ERL_NIF_TERM nsetopt_lvl_sock_dontroute(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_KEEPALIVE)
+static ERL_NIF_TERM nsetopt_lvl_sock_keepalive(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_LINGER)
+static ERL_NIF_TERM nsetopt_lvl_sock_linger(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_OOBINLINE)
+static ERL_NIF_TERM nsetopt_lvl_sock_oobinline(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_PEEK_OFF)
+static ERL_NIF_TERM nsetopt_lvl_sock_peek_off(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_PRIORITY)
+static ERL_NIF_TERM nsetopt_lvl_sock_priority(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_RCVBUF)
+static ERL_NIF_TERM nsetopt_lvl_sock_rcvbuf(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_RCVLOWAT)
+static ERL_NIF_TERM nsetopt_lvl_sock_rcvlowat(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_RCVTIMEO)
+static ERL_NIF_TERM nsetopt_lvl_sock_rcvtimeo(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_REUSEADDR)
+static ERL_NIF_TERM nsetopt_lvl_sock_reuseaddr(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_REUSEPORT)
+static ERL_NIF_TERM nsetopt_lvl_sock_reuseport(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_SNDBUF)
+static ERL_NIF_TERM nsetopt_lvl_sock_sndbuf(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_SNDLOWAT)
+static ERL_NIF_TERM nsetopt_lvl_sock_sndlowat(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_SNDTIMEO)
+static ERL_NIF_TERM nsetopt_lvl_sock_sndtimeo(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
+#if defined(SO_TIMESTAMP)
+static ERL_NIF_TERM nsetopt_lvl_sock_timestamp(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+static ERL_NIF_TERM nsetopt_lvl_ip(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   int               eOpt,
+                                   ERL_NIF_TERM      eVal);
+
+/* *** Handling set of socket options for level = ip *** */
+#if defined(IP_ADD_MEMBERSHIP)
+static ERL_NIF_TERM nsetopt_lvl_ip_add_membership(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_ADD_SOURCE_MEMBERSHIP)
+static ERL_NIF_TERM nsetopt_lvl_ip_add_source_membership(ErlNifEnv*        env,
+                                                         SocketDescriptor* descP,
+                                                         ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_BLOCK_SOURCE)
+static ERL_NIF_TERM nsetopt_lvl_ip_block_source(ErlNifEnv*        env,
+                                                SocketDescriptor* descP,
+                                                ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_DROP_MEMBERSHIP)
+static ERL_NIF_TERM nsetopt_lvl_ip_drop_membership(ErlNifEnv*        env,
+                                                   SocketDescriptor* descP,
+                                                   ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_DROP_SOURCE_MEMBERSHIP)
+static ERL_NIF_TERM nsetopt_lvl_ip_drop_source_membership(ErlNifEnv*        env,
+                                                          SocketDescriptor* descP,
+                                                          ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_FREEBIND)
+static ERL_NIF_TERM nsetopt_lvl_ip_freebind(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_HDRINCL)
+static ERL_NIF_TERM nsetopt_lvl_ip_hdrincl(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_MINTTL)
+static ERL_NIF_TERM nsetopt_lvl_ip_minttl(ErlNifEnv*        env,
+                                          SocketDescriptor* descP,
+                                          ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_MSFILTER) && defined(IP_MSFILTER_SIZE)
+static ERL_NIF_TERM nsetopt_lvl_ip_msfilter(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+static BOOLEAN_T decode_ip_msfilter_mode(ErlNifEnv*   env,
+                                         ERL_NIF_TERM eVal,
+                                         Uint32*      mode);
+static ERL_NIF_TERM nsetopt_lvl_ip_msfilter_set(ErlNifEnv*          env,
+                                                SOCKET              sock,
+                                                struct ip_msfilter* msfP,
+                                                SOCKLEN_T           optLen);
+#endif
+#if defined(IP_MTU_DISCOVER)
+static ERL_NIF_TERM nsetopt_lvl_ip_mtu_discover(ErlNifEnv*        env,
+                                                SocketDescriptor* descP,
+                                                ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_MULTICAST_ALL)
+static ERL_NIF_TERM nsetopt_lvl_ip_multicast_all(ErlNifEnv*        env,
+                                                 SocketDescriptor* descP,
+                                                 ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_MULTICAST_IF)
+static ERL_NIF_TERM nsetopt_lvl_ip_multicast_if(ErlNifEnv*        env,
+                                                SocketDescriptor* descP,
+                                                ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_MULTICAST_LOOP)
+static ERL_NIF_TERM nsetopt_lvl_ip_multicast_loop(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_MULTICAST_TTL)
+static ERL_NIF_TERM nsetopt_lvl_ip_multicast_ttl(ErlNifEnv*        env,
+                                                 SocketDescriptor* descP,
+                                                 ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_NODEFRAG)
+static ERL_NIF_TERM nsetopt_lvl_ip_nodefrag(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_PKTINFO)
+static ERL_NIF_TERM nsetopt_lvl_ip_pktinfo(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_RECVDSTADDR)
+static ERL_NIF_TERM nsetopt_lvl_ip_recvdstaddr(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_RECVERR)
+static ERL_NIF_TERM nsetopt_lvl_ip_recverr(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_RECVIF)
+static ERL_NIF_TERM nsetopt_lvl_ip_recvif(ErlNifEnv*        env,
+                                          SocketDescriptor* descP,
+                                          ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_RECVOPTS)
+static ERL_NIF_TERM nsetopt_lvl_ip_recvopts(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_RECVORIGDSTADDR)
+static ERL_NIF_TERM nsetopt_lvl_ip_recvorigdstaddr(ErlNifEnv*        env,
+                                                   SocketDescriptor* descP,
+                                                   ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_RECVTOS)
+static ERL_NIF_TERM nsetopt_lvl_ip_recvtos(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_RECVTTL)
+static ERL_NIF_TERM nsetopt_lvl_ip_recvttl(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_RETOPTS)
+static ERL_NIF_TERM nsetopt_lvl_ip_retopts(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_ROUTER_ALERT)
+static ERL_NIF_TERM nsetopt_lvl_ip_router_alert(ErlNifEnv*        env,
+                                                SocketDescriptor* descP,
+                                                ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_SENDSRCADDR)
+static ERL_NIF_TERM nsetopt_lvl_ip_sendsrcaddr(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_TOS)
+static ERL_NIF_TERM nsetopt_lvl_ip_tos(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_TRANSPARENT)
+static ERL_NIF_TERM nsetopt_lvl_ip_transparent(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_TTL)
+static ERL_NIF_TERM nsetopt_lvl_ip_ttl(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal);
+#endif
+#if defined(IP_UNBLOCK_SOURCE)
+static ERL_NIF_TERM nsetopt_lvl_ip_unblock_source(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal);
+#endif
+
+#if defined(IP_DROP_MEMBERSHIP) || defined(IP_ADD_MEMBERSHIP)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_update_membership(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal,
+                                              int               opt);
+#endif
+#if defined(IP_ADD_SOURCE_MEMBERSHIP) || defined(IP_DROP_SOURCE_MEMBERSHIP) || defined(IP_BLOCK_SOURCE) || defined(IP_UNBLOCK_SOURCE)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_update_source(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal,
+                                              int               opt);
+#endif
+
+
+/* *** Handling set of socket options for level = ipv6 *** */
+#if defined(HAVE_IPV6)
+static ERL_NIF_TERM nsetopt_lvl_ipv6(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     int               eOpt,
+                                     ERL_NIF_TERM      eVal);
+#if defined(IPV6_ADDRFORM)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_addrform(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_ADD_MEMBERSHIP)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_add_membership(ErlNifEnv*        env,
+                                                    SocketDescriptor* descP,
+                                                    ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_AUTHHDR)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_authhdr(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_DROP_MEMBERSHIP)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_drop_membership(ErlNifEnv*        env,
+                                                     SocketDescriptor* descP,
+                                                     ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_DSTOPTS)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_dstopts(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_FLOWINFO)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_flowinfo(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_HOPLIMIT)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_hoplimit(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_HOPOPTS)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_hopopts(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_MTU)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_mtu(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_MTU_DISCOVER)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_mtu_discover(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_MULTICAST_HOPS)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_multicast_hops(ErlNifEnv*        env,
+                                                    SocketDescriptor* descP,
+                                                    ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_MULTICAST_IF)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_multicast_if(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_MULTICAST_LOOP)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_multicast_loop(ErlNifEnv*        env,
+                                                    SocketDescriptor* descP,
+                                                    ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_RECVERR)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_recverr(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_recvpktinfo(ErlNifEnv*        env,
+                                                 SocketDescriptor* descP,
+                                                 ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_ROUTER_ALERT)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_router_alert(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_RTHDR)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_UNICAST_HOPS)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_unicast_hops(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal);
+#endif
+#if defined(IPV6_V6ONLY)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+
+#if defined(IPV6_ADD_MEMBERSHIP) || defined(IPV6_DROP_MEMBERSHIP)
+static ERL_NIF_TERM nsetopt_lvl_ipv6_update_membership(ErlNifEnv*        env,
+                                                       SocketDescriptor* descP,
+                                                       ERL_NIF_TERM      eVal,
+                                                       int               opt);
+#endif
+
+#endif // defined(HAVE_IPV6)
+static ERL_NIF_TERM nsetopt_lvl_tcp(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    int               eOpt,
+                                    ERL_NIF_TERM      eVal);
+#if defined(TCP_CONGESTION)
+static ERL_NIF_TERM nsetopt_lvl_tcp_congestion(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(TCP_MAXSEG)
+static ERL_NIF_TERM nsetopt_lvl_tcp_maxseg(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal);
+#endif
+#if defined(TCP_NODELAY)
+static ERL_NIF_TERM nsetopt_lvl_tcp_nodelay(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+static ERL_NIF_TERM nsetopt_lvl_udp(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    int               eOpt,
+                                    ERL_NIF_TERM      eVal);
+#if defined(UDP_CORK)
+static ERL_NIF_TERM nsetopt_lvl_udp_cork(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         ERL_NIF_TERM      eVal);
+#endif
+#if defined(HAVE_SCTP)
+static ERL_NIF_TERM nsetopt_lvl_sctp(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     int               eOpt,
+                                     ERL_NIF_TERM      eVal);
+#if defined(SCTP_ASSOCINFO)
+static ERL_NIF_TERM nsetopt_lvl_sctp_associnfo(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(SCTP_AUTOCLOSE)
+static ERL_NIF_TERM nsetopt_lvl_sctp_autoclose(ErlNifEnv*        env,
+                                               SocketDescriptor* descP,
+                                               ERL_NIF_TERM      eVal);
+#endif
+#if defined(SCTP_DISABLE_FRAGMENTS)
+static ERL_NIF_TERM nsetopt_lvl_sctp_disable_fragments(ErlNifEnv*        env,
+                                                       SocketDescriptor* descP,
+                                                       ERL_NIF_TERM      eVal);
+#endif
+#if defined(SCTP_EVENTS)
+static ERL_NIF_TERM nsetopt_lvl_sctp_events(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+#if defined(SCTP_INITMSG)
+static ERL_NIF_TERM nsetopt_lvl_sctp_initmsg(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal);
+#endif
+#if defined(SCTP_MAXSEG)
+static ERL_NIF_TERM nsetopt_lvl_sctp_maxseg(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal);
+#endif
+#if defined(SCTP_NODELAY)
+static ERL_NIF_TERM nsetopt_lvl_sctp_nodelay(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal);
+#endif
+#if defined(SCTP_RTOINFO)
+static ERL_NIF_TERM nsetopt_lvl_sctp_rtoinfo(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal);
+#endif
+#endif // defined(HAVE_SCTP)
+
+static ERL_NIF_TERM ngetopt(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            BOOLEAN_T         isEncoded,
+                            BOOLEAN_T         isOTP,
+                            int               level,
+                            ERL_NIF_TERM      eOpt);
+static ERL_NIF_TERM ngetopt_otp(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                int               eOpt);
+static ERL_NIF_TERM ngetopt_otp_debug(ErlNifEnv*        env,
+                                      SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_otp_iow(ErlNifEnv*        env,
+                                    SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_otp_ctrl_proc(ErlNifEnv*        env,
+                                          SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_otp_rcvbuf(ErlNifEnv*        env,
+                                       SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_otp_rcvctrlbuf(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_otp_sndctrlbuf(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_otp_fd(ErlNifEnv*        env,
+                                   SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_otp_domain(ErlNifEnv*        env,
+                                       SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_otp_type(ErlNifEnv*        env,
+                                     SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_otp_protocol(ErlNifEnv*        env,
+                                         SocketDescriptor* descP);
+static ERL_NIF_TERM ngetopt_native(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   int               level,
+                                   ERL_NIF_TERM      eOpt);
+static ERL_NIF_TERM ngetopt_native_unspec(ErlNifEnv*        env,
+                                          SocketDescriptor* descP,
+                                          int               level,
+                                          int               opt,
+                                          SOCKOPTLEN_T      valueSz);
+static ERL_NIF_TERM ngetopt_level(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  int               level,
+                                  int               eOpt);
+static ERL_NIF_TERM ngetopt_lvl_socket(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       int               eOpt);
+#if defined(SO_ACCEPTCONN)
+static ERL_NIF_TERM ngetopt_lvl_sock_acceptconn(ErlNifEnv*        env,
+                                                SocketDescriptor* descP);
+#endif
+#if defined(SO_BINDTODEVICE)
+static ERL_NIF_TERM ngetopt_lvl_sock_bindtodevice(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP);
+#endif
+#if defined(SO_BROADCAST)
+static ERL_NIF_TERM ngetopt_lvl_sock_broadcast(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(SO_DEBUG)
+static ERL_NIF_TERM ngetopt_lvl_sock_debug(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+#endif
+#if defined(SO_DOMAIN)
+static ERL_NIF_TERM ngetopt_lvl_sock_domain(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+#if defined(SO_DONTROUTE)
+static ERL_NIF_TERM ngetopt_lvl_sock_dontroute(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(SO_KEEPALIVE)
+static ERL_NIF_TERM ngetopt_lvl_sock_keepalive(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(SO_LINGER)
+static ERL_NIF_TERM ngetopt_lvl_sock_linger(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+#if defined(SO_OOBINLINE)
+static ERL_NIF_TERM ngetopt_lvl_sock_oobinline(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(SO_PEEK_OFF)
+static ERL_NIF_TERM ngetopt_lvl_sock_peek_off(ErlNifEnv*        env,
+                                              SocketDescriptor* descP);
+#endif
+#if defined(SO_PRIORITY)
+static ERL_NIF_TERM ngetopt_lvl_sock_priority(ErlNifEnv*        env,
+                                              SocketDescriptor* descP);
+#endif
+#if defined(SO_PROTOCOL)
+static ERL_NIF_TERM ngetopt_lvl_sock_protocol(ErlNifEnv*        env,
+                                              SocketDescriptor* descP);
+#endif
+#if defined(SO_RCVBUF)
+static ERL_NIF_TERM ngetopt_lvl_sock_rcvbuf(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+#if defined(SO_RCVLOWAT)
+static ERL_NIF_TERM ngetopt_lvl_sock_rcvlowat(ErlNifEnv*        env,
+                                              SocketDescriptor* descP);
+#endif
+#if defined(SO_RCVTIMEO)
+static ERL_NIF_TERM ngetopt_lvl_sock_rcvtimeo(ErlNifEnv*        env,
+                                              SocketDescriptor* descP);
+#endif
+#if defined(SO_REUSEADDR)
+static ERL_NIF_TERM ngetopt_lvl_sock_reuseaddr(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(SO_REUSEPORT)
+static ERL_NIF_TERM ngetopt_lvl_sock_reuseport(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(SO_SNDBUF)
+static ERL_NIF_TERM ngetopt_lvl_sock_sndbuf(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+#if defined(SO_SNDLOWAT)
+static ERL_NIF_TERM ngetopt_lvl_sock_sndlowat(ErlNifEnv*        env,
+                                              SocketDescriptor* descP);
+#endif
+#if defined(SO_SNDTIMEO)
+static ERL_NIF_TERM ngetopt_lvl_sock_sndtimeo(ErlNifEnv*        env,
+                                              SocketDescriptor* descP);
+#endif
+#if defined(SO_TIMESTAMP)
+static ERL_NIF_TERM ngetopt_lvl_sock_timestamp(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(SO_TYPE)
+static ERL_NIF_TERM ngetopt_lvl_sock_type(ErlNifEnv*        env,
+                                          SocketDescriptor* descP);
+#endif
+static ERL_NIF_TERM ngetopt_lvl_ip(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   int               eOpt);
+#if defined(IP_FREEBIND)
+static ERL_NIF_TERM ngetopt_lvl_ip_freebind(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+#if defined(IP_HDRINCL)
+static ERL_NIF_TERM ngetopt_lvl_ip_hdrincl(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+#endif
+#if defined(IP_MINTTL)
+static ERL_NIF_TERM ngetopt_lvl_ip_minttl(ErlNifEnv*        env,
+                                          SocketDescriptor* descP);
+#endif
+#if defined(IP_MTU)
+static ERL_NIF_TERM ngetopt_lvl_ip_mtu(ErlNifEnv*        env,
+                                       SocketDescriptor* descP);
+#endif
+#if defined(IP_MTU_DISCOVER)
+static ERL_NIF_TERM ngetopt_lvl_ip_mtu_discover(ErlNifEnv*        env,
+                                                SocketDescriptor* descP);
+#endif
+#if defined(IP_MULTICAST_ALL)
+static ERL_NIF_TERM ngetopt_lvl_ip_multicast_all(ErlNifEnv*        env,
+                                                 SocketDescriptor* descP);
+#endif
+#if defined(IP_MULTICAST_IF)
+static ERL_NIF_TERM ngetopt_lvl_ip_multicast_if(ErlNifEnv*        env,
+                                                SocketDescriptor* descP);
+#endif
+#if defined(IP_MULTICAST_LOOP)
+static ERL_NIF_TERM ngetopt_lvl_ip_multicast_loop(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP);
+#endif
+#if defined(IP_MULTICAST_TTL)
+static ERL_NIF_TERM ngetopt_lvl_ip_multicast_ttl(ErlNifEnv*        env,
+                                                 SocketDescriptor* descP);
+#endif
+#if defined(IP_NODEFRAG)
+static ERL_NIF_TERM ngetopt_lvl_ip_nodefrag(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+#if defined(IP_PKTINFO)
+static ERL_NIF_TERM ngetopt_lvl_ip_pktinfo(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+#endif
+#if defined(IP_RECVDSTADDR)
+static ERL_NIF_TERM ngetopt_lvl_ip_recvdstaddr(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(IP_RECVERR)
+static ERL_NIF_TERM ngetopt_lvl_ip_recverr(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+#endif
+#if defined(IP_RECVIF)
+static ERL_NIF_TERM ngetopt_lvl_ip_recvif(ErlNifEnv*        env,
+                                          SocketDescriptor* descP);
+#endif
+#if defined(IP_RECVOPTS)
+static ERL_NIF_TERM ngetopt_lvl_ip_recvopts(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+#if defined(IP_RECVORIGDSTADDR)
+static ERL_NIF_TERM ngetopt_lvl_ip_recvorigdstaddr(ErlNifEnv*        env,
+                                                   SocketDescriptor* descP);
+#endif
+#if defined(IP_RECVTOS)
+static ERL_NIF_TERM ngetopt_lvl_ip_recvtos(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+#endif
+#if defined(IP_RECVTTL)
+static ERL_NIF_TERM ngetopt_lvl_ip_recvttl(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+#endif
+#if defined(IP_RETOPTS)
+static ERL_NIF_TERM ngetopt_lvl_ip_retopts(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+#endif
+#if defined(IP_ROUTER_ALERT)
+static ERL_NIF_TERM ngetopt_lvl_ip_router_alert(ErlNifEnv*        env,
+                                                SocketDescriptor* descP);
+#endif
+#if defined(IP_SENDSRCADDR)
+static ERL_NIF_TERM ngetopt_lvl_ip_sendsrcaddr(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(IP_TOS)
+static ERL_NIF_TERM ngetopt_lvl_ip_tos(ErlNifEnv*        env,
+                                       SocketDescriptor* descP);
+#endif
+#if defined(IP_TRANSPARENT)
+static ERL_NIF_TERM ngetopt_lvl_ip_transparent(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(IP_TTL)
+static ERL_NIF_TERM ngetopt_lvl_ip_ttl(ErlNifEnv*        env,
+                                       SocketDescriptor* descP);
+#endif
+#if defined(HAVE_IPV6)
+static ERL_NIF_TERM ngetopt_lvl_ipv6(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     int               eOpt);
+#if defined(IPV6_AUTHHDR)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_authhdr(ErlNifEnv*        env,
+                                             SocketDescriptor* descP);
+#endif
+#if defined(IPV6_DSTOPTS)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_dstopts(ErlNifEnv*        env,
+                                             SocketDescriptor* descP);
+#endif
+#if defined(IPV6_FLOWINFO)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_flowinfo(ErlNifEnv*        env,
+                                              SocketDescriptor* descP);
+#endif
+#if defined(IPV6_HOPLIMIT)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_hoplimit(ErlNifEnv*        env,
+                                              SocketDescriptor* descP);
+#endif
+#if defined(IPV6_HOPOPTS)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_hopopts(ErlNifEnv*        env,
+                                             SocketDescriptor* descP);
+#endif
+#if defined(IPV6_MTU)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_mtu(ErlNifEnv*        env,
+                                         SocketDescriptor* descP);
+#endif
+#if defined(IPV6_MTU_DISCOVER)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_mtu_discover(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP);
+#endif
+#if defined(IPV6_MULTICAST_HOPS)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_multicast_hops(ErlNifEnv*        env,
+                                                    SocketDescriptor* descP);
+#endif
+#if defined(IPV6_MULTICAST_IF)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_multicast_if(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP);
+#endif
+#if defined(IPV6_MULTICAST_LOOP)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_multicast_loop(ErlNifEnv*        env,
+                                                    SocketDescriptor* descP);
+#endif
+#if defined(IPV6_RECVERR)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_recverr(ErlNifEnv*        env,
+                                             SocketDescriptor* descP);
+#endif
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_recvpktinfo(ErlNifEnv*        env,
+                                                 SocketDescriptor* descP);
+#endif
+#if defined(IPV6_ROUTER_ALERT)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_router_alert(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP);
+#endif
+#if defined(IPV6_RTHDR)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+#endif
+#if defined(IPV6_UNICAST_HOPS)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_unicast_hops(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP);
+#endif
+#if defined(IPV6_V6ONLY)
+static ERL_NIF_TERM ngetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+
+#endif // defined(HAVE_IPV6)
+
+static ERL_NIF_TERM ngetopt_lvl_tcp(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    int               eOpt);
+#if defined(TCP_CONGESTION)
+static ERL_NIF_TERM ngetopt_lvl_tcp_congestion(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(TCP_MAXSEG)
+static ERL_NIF_TERM ngetopt_lvl_tcp_maxseg(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+#endif
+#if defined(TCP_NODELAY)
+static ERL_NIF_TERM ngetopt_lvl_tcp_nodelay(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+static ERL_NIF_TERM ngetopt_lvl_udp(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    int               eOpt);
+#if defined(UDP_CORK)
+static ERL_NIF_TERM ngetopt_lvl_udp_cork(ErlNifEnv*        env,
+                                         SocketDescriptor* descP);
+#endif
+#if defined(HAVE_SCTP)
+static ERL_NIF_TERM ngetopt_lvl_sctp(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     int               eOpt);
+#if defined(SCTP_ASSOCINFO)
+static ERL_NIF_TERM ngetopt_lvl_sctp_associnfo(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(SCTP_AUTOCLOSE)
+static ERL_NIF_TERM ngetopt_lvl_sctp_autoclose(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+#endif
+#if defined(SCTP_DISABLE_FRAGMENTS)
+static ERL_NIF_TERM ngetopt_lvl_sctp_disable_fragments(ErlNifEnv*        env,
+                                                       SocketDescriptor* descP);
+#endif
+#if defined(SCTP_MAXSEG)
+static ERL_NIF_TERM ngetopt_lvl_sctp_maxseg(ErlNifEnv*        env,
+                                            SocketDescriptor* descP);
+#endif
+#if defined(SCTP_INITMSG)
+static ERL_NIF_TERM ngetopt_lvl_sctp_initmsg(ErlNifEnv*        env,
+                                             SocketDescriptor* descP);
+#endif
+#if defined(SCTP_NODELAY)
+static ERL_NIF_TERM ngetopt_lvl_sctp_nodelay(ErlNifEnv*        env,
+                                             SocketDescriptor* descP);
+#endif
+#if defined(SCTP_RTOINFO)
+static ERL_NIF_TERM ngetopt_lvl_sctp_rtoinfo(ErlNifEnv*        env,
+                                             SocketDescriptor* descP);
+#endif
+#endif // defined(HAVE_SCTP)
+static ERL_NIF_TERM nsockname(ErlNifEnv*        env,
+                              SocketDescriptor* descP);
+static ERL_NIF_TERM npeername(ErlNifEnv*        env,
+                              SocketDescriptor* descP);
+static ERL_NIF_TERM ncancel(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ERL_NIF_TERM      op,
+                            ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_connect(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_accept(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_accept_current(ErlNifEnv*        env,
+                                           SocketDescriptor* descP);
+static ERL_NIF_TERM ncancel_accept_waiting(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_send(ErlNifEnv*        env,
+                                 SocketDescriptor* descP,
+                                 ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_send_current(ErlNifEnv*        env,
+                                         SocketDescriptor* descP);
+static ERL_NIF_TERM ncancel_send_waiting(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_recv(ErlNifEnv*        env,
+                                 SocketDescriptor* descP,
+                                 ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_recv_current(ErlNifEnv*        env,
+                                         SocketDescriptor* descP);
+static ERL_NIF_TERM ncancel_recv_waiting(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_read_select(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_write_select(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         ERL_NIF_TERM      opRef);
+static ERL_NIF_TERM ncancel_mode_select(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      opRef,
+                                        int               smode,
+                                        int               rmode);
+
+static ERL_NIF_TERM nsetopt_str_opt(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    int               level,
+                                    int               opt,
+                                    int               max,
+                                    ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_bool_opt(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     int               level,
+                                     int               opt,
+                                     ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_int_opt(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    int               level,
+                                    int               opt,
+                                    ERL_NIF_TERM      eVal);
+static ERL_NIF_TERM nsetopt_timeval_opt(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        int               level,
+                                        int               opt,
+                                        ERL_NIF_TERM      eVal);
+
+static ERL_NIF_TERM ngetopt_str_opt(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    int               level,
+                                    int               opt,
+                                    int               max);
+static ERL_NIF_TERM ngetopt_bool_opt(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     int               level,
+                                     int               opt);
+static ERL_NIF_TERM ngetopt_int_opt(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    int               level,
+                                    int               opt);
+static ERL_NIF_TERM ngetopt_timeval_opt(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        int               level,
+                                        int               opt);
+
+static BOOLEAN_T send_check_writer(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   ERL_NIF_TERM      ref,
+                                   ERL_NIF_TERM*     checkResult);
+static ERL_NIF_TERM send_check_result(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ssize_t           written,
+                                      ssize_t           dataSize,
+                                      int               saveErrno,
+                                      ERL_NIF_TERM      sockRef,
+                                      ERL_NIF_TERM      sendRef);
+static BOOLEAN_T recv_check_reader(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   ERL_NIF_TERM      ref,
+                                   ERL_NIF_TERM*     checkResult);
+static char* recv_init_current_reader(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      ref);
+static ERL_NIF_TERM recv_update_current_reader(ErlNifEnv*        env,
+                                               SocketDescriptor* descP);
+static void recv_error_current_reader(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      sockRef,
+                                      ERL_NIF_TERM      reason);
+static ERL_NIF_TERM recv_check_result(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      int               read,
+                                      int               toRead,
+                                      int               saveErrno,
+                                      ErlNifBinary*     bufP,
+                                      ERL_NIF_TERM      sockRef,
+                                      ERL_NIF_TERM      recvRef);
+static ERL_NIF_TERM recvfrom_check_result(ErlNifEnv*        env,
+                                          SocketDescriptor* descP,
+                                          int               read,
+                                          int               saveErrno,
+                                          ErlNifBinary*     bufP,
+                                          SocketAddress*    fromAddrP,
+                                          unsigned int      fromAddrLen,
+                                          ERL_NIF_TERM      sockRef,
+                                          ERL_NIF_TERM      recvRef);
+static ERL_NIF_TERM recvmsg_check_result(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         int               read,
+                                         int               saveErrno,
+                                         struct msghdr*    msgHdrP,
+                                         ErlNifBinary*     dataBufP,
+                                         ErlNifBinary*     ctrlBufP,
+                                         ERL_NIF_TERM      sockRef,
+                                         ERL_NIF_TERM      recvRef);
+
+static ERL_NIF_TERM nfinalize_connection(ErlNifEnv*        env,
+                                         SocketDescriptor* descP);
+static ERL_NIF_TERM nfinalize_close(ErlNifEnv*        env,
+                                    SocketDescriptor* descP);
+
+extern char* encode_msghdr(ErlNifEnv*        env,
+                           SocketDescriptor* descP,
+                           int               read,
+                           struct msghdr*    msgHdrP,
+                           ErlNifBinary*     dataBufP,
+                           ErlNifBinary*     ctrlBufP,
+                           ERL_NIF_TERM*     eSockAddr);
+extern char* encode_cmsghdrs(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             ErlNifBinary*     cmsgBinP,
+                             struct msghdr*    msgHdrP,
+                             ERL_NIF_TERM*     eCMsgHdr);
+extern char* decode_cmsghdrs(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             ERL_NIF_TERM      eCMsgHdr,
+                             char*             cmsgHdrBufP,
+                             size_t            cmsgHdrBufLen,
+                             size_t*           cmsgHdrBufUsed);
+extern char* decode_cmsghdr(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ERL_NIF_TERM      eCMsgHdr,
+                            char*             bufP,
+                            size_t            rem,
+                            size_t*           used);
+static char* encode_cmsghdr_level(ErlNifEnv*    env,
+                                  int           level,
+                                  ERL_NIF_TERM* eLevel);
+static char* decode_cmsghdr_level(ErlNifEnv*   env,
+                                  ERL_NIF_TERM eLevel,
+                                  int*         level);
+static char* encode_cmsghdr_type(ErlNifEnv*    env,
+                                 int           level,
+                                 int           type,
+                                 ERL_NIF_TERM* eType);
+static char* decode_cmsghdr_type(ErlNifEnv*   env,
+                                 int          level,
+                                 ERL_NIF_TERM eType,
+                                 int*         type);
+static char* encode_cmsghdr_data(ErlNifEnv*     env,
+                                 ERL_NIF_TERM   ctrlBuf,
+                                 int            level,
+                                 int            type,
+                                 unsigned char* dataP,
+                                 size_t         dataPos,
+                                 size_t         dataLen,
+                                 ERL_NIF_TERM*  eCMsgHdrData);
+static char* encode_cmsghdr_data_socket(ErlNifEnv*     env,
+                                        ERL_NIF_TERM   ctrlBuf,
+                                        int            type,
+                                        unsigned char* dataP,
+                                        size_t         dataPos,
+                                        size_t         dataLen,
+                                        ERL_NIF_TERM*  eCMsgHdrData);
+static char* encode_cmsghdr_data_ip(ErlNifEnv*     env,
+                                    ERL_NIF_TERM   ctrlBuf,
+                                    int            type,
+                                    unsigned char* dataP,
+                                    size_t         dataPos,
+                                    size_t         dataLen,
+                                    ERL_NIF_TERM*  eCMsgHdrData);
+#if defined(HAVE_IPV6)
+static char* encode_cmsghdr_data_ipv6(ErlNifEnv*     env,
+                                      ERL_NIF_TERM   ctrlBuf,
+                                      int            type,
+                                      unsigned char* dataP,
+                                      size_t         dataPos,
+                                      size_t         dataLen,
+                                      ERL_NIF_TERM*  eCMsgHdrData);
+#endif
+extern char* encode_msghdr_flags(ErlNifEnv*        env,
+                                 SocketDescriptor* descP,
+                                 int               msgFlags,
+                                 ERL_NIF_TERM*     flags);
+static char* decode_cmsghdr_data(ErlNifEnv*        env,
+                                 SocketDescriptor* descP,
+                                 char*             bufP,
+                                 size_t            rem,
+                                 int               level,
+                                 int               type,
+                                 ERL_NIF_TERM      eData,
+                                 size_t*           used);
+static char* decode_cmsghdr_final(SocketDescriptor* descP,
+                                  char*             bufP,
+                                  size_t            rem,
+                                  int               level,
+                                  int               type,
+                                  char*             data,
+                                  int               sz,
+                                  size_t*           used);
+static BOOLEAN_T decode_sock_linger(ErlNifEnv*     env,
+                                    ERL_NIF_TERM   eVal,
+                                    struct linger* valP);
+#if defined(IP_TOS)
+static BOOLEAN_T decode_ip_tos(ErlNifEnv*   env,
+                               ERL_NIF_TERM eVal,
+                               int*         val);
+#endif
+#if defined(IP_MTU_DISCOVER)
+static char* decode_ip_pmtudisc(ErlNifEnv*   env,
+                                ERL_NIF_TERM eVal,
+                                int*         val);
+#endif
+#if defined(IP_MTU_DISCOVER)
+static void encode_ip_pmtudisc(ErlNifEnv*    env,
+                               int           val,
+                               ERL_NIF_TERM* eVal);
+#endif
+#if defined(IPV6_MTU_DISCOVER)
+static char* decode_ipv6_pmtudisc(ErlNifEnv*   env,
+                                  ERL_NIF_TERM eVal,
+                                  int*         val);
+#endif
+#if defined(IPV6_MTU_DISCOVER)
+static void encode_ipv6_pmtudisc(ErlNifEnv*    env,
+                                 int           val,
+                                 ERL_NIF_TERM* eVal);
+#endif
+
+/*
+static BOOLEAN_T decode_bool(ErlNifEnv*   env,
+                             ERL_NIF_TERM eVal,
+                             BOOLEAN_T*   val);
+*/
+static BOOLEAN_T decode_native_get_opt(ErlNifEnv*   env,
+                                       ERL_NIF_TERM eVal,
+                                       int*         opt,
+                                       Uint16*      valueType,
+                                       int*         valueSz);
+// static void encode_bool(BOOLEAN_T val, ERL_NIF_TERM* eVal);
+static ERL_NIF_TERM encode_ip_tos(ErlNifEnv* env, int val);
+
+static void inform_waiting_procs(ErlNifEnv*          env,
+                                 SocketDescriptor*   descP,
+                                 SocketRequestQueue* q,
+                                 BOOLEAN_T           free,
+                                 ERL_NIF_TERM        reason);
+
+static int socket_setopt(int             sock,
+                         int             level,
+                         int             opt,
+                         const void*     optVal,
+                         const socklen_t optLen);
+
+static BOOLEAN_T verify_is_connected(SocketDescriptor* descP, int* err);
+
+static SocketDescriptor* alloc_descriptor(SOCKET sock, HANDLE event);
+
+static int compare_pids(ErlNifEnv*       env,
+                        const ErlNifPid* pid1,
+                        const ErlNifPid* pid2);
+
+
+
+static BOOLEAN_T edomain2domain(int edomain, int* domain);
+static BOOLEAN_T etype2type(int etype, int* type);
+static BOOLEAN_T eproto2proto(ErlNifEnv*         env,
+                              const ERL_NIF_TERM eproto,
+                              int*               proto);
+static BOOLEAN_T ehow2how(unsigned int ehow, int* how);
+static BOOLEAN_T esendflags2sendflags(unsigned int esendflags, int* sendflags);
+static BOOLEAN_T erecvflags2recvflags(unsigned int erecvflags, int* recvflags);
+static BOOLEAN_T elevel2level(BOOLEAN_T  isEncoded,
+                              int        eLevel,
+                              BOOLEAN_T* isOTP,
+                              int*       level);
+#ifdef HAVE_SETNS
+static BOOLEAN_T emap2netns(ErlNifEnv* env, ERL_NIF_TERM map, char** netns);
+static BOOLEAN_T change_network_namespace(char* netns, int* cns, int* err);
+static BOOLEAN_T restore_network_namespace(int ns, SOCKET sock, int* err);
+#endif
+
+static BOOLEAN_T cnt_inc(Uint32* cnt, Uint32 inc);
+static void      cnt_dec(Uint32* cnt, Uint32 dec);
+
+static void inc_socket(int domain, int type, int protocol);
+static void dec_socket(int domain, int type, int protocol);
+
+
+static BOOLEAN_T acceptor_search4pid(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ErlNifPid*        pid);
+static ERL_NIF_TERM acceptor_push(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  ErlNifPid         pid,
+                                  ERL_NIF_TERM      ref);
+static BOOLEAN_T acceptor_pop(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              ErlNifPid*        pid,
+                              // ErlNifMonitor*    mon,
+                              ESockMonitor*     mon,
+                              ERL_NIF_TERM*     ref);
+static BOOLEAN_T acceptor_unqueue(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  const ErlNifPid*  pid);
+
+static BOOLEAN_T writer_search4pid(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   ErlNifPid*        pid);
+static ERL_NIF_TERM writer_push(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                ErlNifPid         pid,
+                                ERL_NIF_TERM      ref);
+static BOOLEAN_T writer_pop(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ErlNifPid*        pid,
+                            // ErlNifMonitor*    mon,
+                            ESockMonitor*     mon,
+                            ERL_NIF_TERM*     ref);
+static BOOLEAN_T writer_unqueue(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                const ErlNifPid*  pid);
+
+static BOOLEAN_T reader_search4pid(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   ErlNifPid*        pid);
+static ERL_NIF_TERM reader_push(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                ErlNifPid         pid,
+                                ERL_NIF_TERM      ref);
+static BOOLEAN_T reader_pop(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ErlNifPid*        pid,
+                            // ErlNifMonitor*    mon,
+                            ESockMonitor*     mon,
+                            ERL_NIF_TERM*     ref);
+static BOOLEAN_T reader_unqueue(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                const ErlNifPid*  pid);
+
+static BOOLEAN_T qsearch4pid(ErlNifEnv*          env,
+                             SocketRequestQueue* q,
+                             ErlNifPid*          pid);
+static void qpush(SocketRequestQueue*        q,
+                  SocketRequestQueueElement* e);
+static SocketRequestQueueElement* qpop(SocketRequestQueue* q);
+static BOOLEAN_T qunqueue(ErlNifEnv*          env,
+                          SocketDescriptor*   descP,
+                          const char*         slogan,
+                          SocketRequestQueue* q,
+                          const ErlNifPid*    pid);
+
+static int esock_monitor(const char*       slogan,
+                         ErlNifEnv*        env,
+                         SocketDescriptor* descP,
+                         const ErlNifPid*  pid,
+                         ESockMonitor*     mon);
+static int esock_demonitor(const char*       slogan,
+                           ErlNifEnv*        env,
+                           SocketDescriptor* descP,
+                           ESockMonitor*     monP);
+static void esock_monitor_init(ESockMonitor* mon);
+/*
+static int esock_monitor_compare(const ErlNifMonitor* mon1,
+                                 const ESockMonitor*  mon2);
+*/
+
+
+/*
+#if defined(HAVE_SYS_UN_H) || defined(SO_BINDTODEVICE)
+static size_t my_strnlen(const char *s, size_t maxlen);
+#endif
+*/
+
+static void socket_dtor(ErlNifEnv* env, void* obj);
+static void socket_stop(ErlNifEnv* env,
+			void*      obj,
+			int        fd,
+			int        is_direct_call);
+static void socket_down(ErlNifEnv*           env,
+			void*                obj,
+			const ErlNifPid*     pid,
+			const ErlNifMonitor* mon);
+static void socket_down_acceptor(ErlNifEnv*        env,
+                                 SocketDescriptor* descP,
+                                 const ErlNifPid*  pid);
+static void socket_down_writer(ErlNifEnv*        env,
+                               SocketDescriptor* descP,
+                               const ErlNifPid*  pid);
+static void socket_down_reader(ErlNifEnv*        env,
+                               SocketDescriptor* descP,
+                               const ErlNifPid*  pid);
+
+static char* esock_send_close_msg(ErlNifEnv*   env,
+                                  ERL_NIF_TERM closeRef,
+                                  ErlNifPid*   pid);
+static char* esock_send_abort_msg(ErlNifEnv*   env,
+                                  ERL_NIF_TERM sockRef,
+                                  ERL_NIF_TERM recvRef,
+                                  ERL_NIF_TERM reason,
+                                  ErlNifPid*   pid);
+static char* esock_send_socket_msg(ErlNifEnv*   env,
+                                   ERL_NIF_TERM sockRef,
+                                   ERL_NIF_TERM tag,
+                                   ERL_NIF_TERM info,
+                                   ErlNifPid*   pid);
+static char* esock_send_msg(ErlNifEnv*   env,
+                            ERL_NIF_TERM msg,
+                            ErlNifPid*   pid);
+
+static BOOLEAN_T extract_debug(ErlNifEnv*   env,
+                               ERL_NIF_TERM map);
+static BOOLEAN_T extract_iow(ErlNifEnv*   env,
+                             ERL_NIF_TERM map);
+
+static int on_load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info);
+
+
+
+#if HAVE_IN6
+#  if ! defined(HAVE_IN6ADDR_ANY) || ! HAVE_IN6ADDR_ANY
+#    if HAVE_DECL_IN6ADDR_ANY_INIT
+static const struct in6_addr in6addr_any = { { IN6ADDR_ANY_INIT } };
+#    else
+static const struct in6_addr in6addr_any =
+    { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } };
+#    endif /* HAVE_IN6ADDR_ANY_INIT */
+#  endif /* ! HAVE_DECL_IN6ADDR_ANY */
+
+#  if ! defined(HAVE_IN6ADDR_LOOPBACK) || ! HAVE_IN6ADDR_LOOPBACK
+#    if HAVE_DECL_IN6ADDR_LOOPBACK_INIT
+static const struct in6_addr in6addr_loopback =
+    { { IN6ADDR_LOOPBACK_INIT } };
+#    else
+static const struct in6_addr in6addr_loopback =
+    { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 } } };
+#    endif /* HAVE_IN6ADDR_LOOPBACk_INIT */
+#  endif /* ! HAVE_DECL_IN6ADDR_LOOPBACK */
+#endif /* HAVE_IN6 */
+
+
+
+/* *** String constants *** */
+static char str_adaptation_layer[] = "adaptation_layer";
+static char str_address[]          = "address";
+static char str_association[]      = "association";
+static char str_assoc_id[]         = "assoc_id";
+static char str_authentication[]   = "authentication";
+// static char str_any[]              = "any";
+static char str_bool[]             = "bool";
+static char str_close[]            = "close";
+static char str_closed[]           = "closed";
+static char str_closing[]          = "closing";
+static char str_cookie_life[]      = "cookie_life";
+static char str_data_in[]          = "data_in";
+static char str_do[]               = "do";
+static char str_dont[]             = "dont";
+static char str_exclude[]          = "exclude";
+static char str_false[]            = "false";
+static char str_global_counters[]  = "global_counters";
+static char str_in4_sockaddr[]     = "in4_sockaddr";
+static char str_in6_sockaddr[]     = "in6_sockaddr";
+static char str_include[]          = "include";
+static char str_initial[]          = "initial";
+static char str_int[]              = "int";
+static char str_interface[]        = "interface";
+static char str_iow[]              = "iow";
+static char str_local_rwnd[]       = "local_rwnd";
+// static char str_loopback[]         = "loopback";
+static char str_max[]              = "max";
+static char str_max_attempts[]     = "max_attempts";
+static char str_max_init_timeo[]   = "max_init_timeo";
+static char str_max_instreams[]    = "max_instreams";
+static char str_max_rxt[]          = "max_rxt";
+static char str_min[]              = "min";
+static char str_mode[]             = "mode";
+static char str_multiaddr[]        = "multiaddr";
+// static char str_nif_abort[]        = "nif_abort";
+static char str_null[]             = "null";
+static char str_num_dlocal[]       = "num_domain_local";
+static char str_num_dinet[]        = "num_domain_inet";
+static char str_num_dinet6[]       = "num_domain_inet6";
+static char str_num_outstreams[]   = "num_outstreams";
+static char str_num_peer_dests[]   = "num_peer_dests";
+static char str_num_pip[]          = "num_proto_ip";
+static char str_num_psctp[]        = "num_proto_sctp";
+static char str_num_ptcp[]         = "num_proto_tcp";
+static char str_num_pudp[]         = "num_proto_udp";
+static char str_num_sockets[]      = "num_sockets";
+static char str_num_tdgrams[]      = "num_type_dgram";
+static char str_num_tseqpkgs[]     = "num_type_seqpacket";
+static char str_num_tstreams[]     = "num_type_stream";
+static char str_partial_delivery[] = "partial_delivery";
+static char str_peer_error[]       = "peer_error";
+static char str_peer_rwnd[]        = "peer_rwnd";
+static char str_probe[]            = "probe";
+static char str_select[]           = "select";
+static char str_sender_dry[]       = "sender_dry";
+static char str_send_failure[]     = "send_failure";
+static char str_shutdown[]         = "shutdown";
+static char str_slist[]            = "slist";
+static char str_sourceaddr[]       = "sourceaddr";
+static char str_timeout[]          = "timeout";
+static char str_true[]             = "true";
+static char str_want[]             = "want";
+
+/* (special) error string constants */
+static char str_eisconn[]        = "eisconn";
+static char str_enotclosing[]    = "enotclosing";
+static char str_enotconn[]       = "enotconn";
+static char str_exalloc[]        = "exalloc";
+static char str_exbadstate[]     = "exbadstate";
+static char str_exbusy[]         = "exbusy";
+static char str_exmon[]          = "exmonitor";  // failed monitor
+static char str_exself[]         = "exself";     // failed self
+static char str_exsend[]         = "exsend";     // failed send
+
+
+/* *** "Global" Atoms *** */
+ERL_NIF_TERM esock_atom_abort;
+ERL_NIF_TERM esock_atom_accept;
+ERL_NIF_TERM esock_atom_acceptconn;
+ERL_NIF_TERM esock_atom_acceptfilter;
+ERL_NIF_TERM esock_atom_adaption_layer;
+ERL_NIF_TERM esock_atom_addr;
+ERL_NIF_TERM esock_atom_addrform;
+ERL_NIF_TERM esock_atom_add_membership;
+ERL_NIF_TERM esock_atom_add_source_membership;
+ERL_NIF_TERM esock_atom_any;
+ERL_NIF_TERM esock_atom_associnfo;
+ERL_NIF_TERM esock_atom_authhdr;
+ERL_NIF_TERM esock_atom_auth_active_key;
+ERL_NIF_TERM esock_atom_auth_asconf;
+ERL_NIF_TERM esock_atom_auth_chunk;
+ERL_NIF_TERM esock_atom_auth_delete_key;
+ERL_NIF_TERM esock_atom_auth_key;
+ERL_NIF_TERM esock_atom_auth_level;
+ERL_NIF_TERM esock_atom_autoclose;
+ERL_NIF_TERM esock_atom_bindtodevice;
+ERL_NIF_TERM esock_atom_block_source;
+ERL_NIF_TERM esock_atom_broadcast;
+ERL_NIF_TERM esock_atom_busy_poll;
+ERL_NIF_TERM esock_atom_checksum;
+ERL_NIF_TERM esock_atom_close;
+ERL_NIF_TERM esock_atom_connect;
+ERL_NIF_TERM esock_atom_congestion;
+ERL_NIF_TERM esock_atom_context;
+ERL_NIF_TERM esock_atom_cork;
+ERL_NIF_TERM esock_atom_credentials;
+ERL_NIF_TERM esock_atom_ctrl;
+ERL_NIF_TERM esock_atom_ctrunc;
+ERL_NIF_TERM esock_atom_data;
+ERL_NIF_TERM esock_atom_debug;
+ERL_NIF_TERM esock_atom_default_send_params;
+ERL_NIF_TERM esock_atom_delayed_ack_time;
+ERL_NIF_TERM esock_atom_dgram;
+ERL_NIF_TERM esock_atom_disable_fragments;
+ERL_NIF_TERM esock_atom_domain;
+ERL_NIF_TERM esock_atom_dontfrag;
+ERL_NIF_TERM esock_atom_dontroute;
+ERL_NIF_TERM esock_atom_drop_membership;
+ERL_NIF_TERM esock_atom_drop_source_membership;
+ERL_NIF_TERM esock_atom_dstopts;
+ERL_NIF_TERM esock_atom_eor;
+ERL_NIF_TERM esock_atom_error;
+ERL_NIF_TERM esock_atom_errqueue;
+ERL_NIF_TERM esock_atom_esp_network_level;
+ERL_NIF_TERM esock_atom_esp_trans_level;
+ERL_NIF_TERM esock_atom_events;
+ERL_NIF_TERM esock_atom_explicit_eor;
+ERL_NIF_TERM esock_atom_faith;
+ERL_NIF_TERM esock_atom_false;
+ERL_NIF_TERM esock_atom_family;
+ERL_NIF_TERM esock_atom_flags;
+ERL_NIF_TERM esock_atom_flowinfo;
+ERL_NIF_TERM esock_atom_fragment_interleave;
+ERL_NIF_TERM esock_atom_freebind;
+ERL_NIF_TERM esock_atom_get_peer_addr_info;
+ERL_NIF_TERM esock_atom_hdrincl;
+ERL_NIF_TERM esock_atom_hmac_ident;
+ERL_NIF_TERM esock_atom_hoplimit;
+ERL_NIF_TERM esock_atom_hopopts;
+ERL_NIF_TERM esock_atom_ifindex;
+ERL_NIF_TERM esock_atom_inet;
+ERL_NIF_TERM esock_atom_inet6;
+ERL_NIF_TERM esock_atom_info;
+ERL_NIF_TERM esock_atom_initmsg;
+ERL_NIF_TERM esock_atom_iov;
+ERL_NIF_TERM esock_atom_ip;
+ERL_NIF_TERM esock_atom_ipcomp_level;
+ERL_NIF_TERM esock_atom_ipv6;
+ERL_NIF_TERM esock_atom_i_want_mapped_v4_addr;
+ERL_NIF_TERM esock_atom_join_group;
+ERL_NIF_TERM esock_atom_keepalive;
+ERL_NIF_TERM esock_atom_keepcnt;
+ERL_NIF_TERM esock_atom_keepidle;
+ERL_NIF_TERM esock_atom_keepintvl;
+ERL_NIF_TERM esock_atom_leave_group;
+ERL_NIF_TERM esock_atom_level;
+ERL_NIF_TERM esock_atom_linger;
+ERL_NIF_TERM esock_atom_local;
+ERL_NIF_TERM esock_atom_local_auth_chunks;
+ERL_NIF_TERM esock_atom_loopback;
+ERL_NIF_TERM esock_atom_lowdelay;
+ERL_NIF_TERM esock_atom_mark;
+ERL_NIF_TERM esock_atom_maxburst;
+ERL_NIF_TERM esock_atom_maxseg;
+ERL_NIF_TERM esock_atom_md5sig;
+ERL_NIF_TERM esock_atom_mincost;
+ERL_NIF_TERM esock_atom_minttl;
+ERL_NIF_TERM esock_atom_msfilter;
+ERL_NIF_TERM esock_atom_mtu;
+ERL_NIF_TERM esock_atom_mtu_discover;
+ERL_NIF_TERM esock_atom_multicast_all;
+ERL_NIF_TERM esock_atom_multicast_hops;
+ERL_NIF_TERM esock_atom_multicast_if;
+ERL_NIF_TERM esock_atom_multicast_loop;
+ERL_NIF_TERM esock_atom_multicast_ttl;
+ERL_NIF_TERM esock_atom_nodelay;
+ERL_NIF_TERM esock_atom_nodefrag;
+ERL_NIF_TERM esock_atom_noopt;
+ERL_NIF_TERM esock_atom_nopush;
+ERL_NIF_TERM esock_atom_not_found;
+ERL_NIF_TERM esock_atom_not_owner;
+ERL_NIF_TERM esock_atom_ok;
+ERL_NIF_TERM esock_atom_oob;
+ERL_NIF_TERM esock_atom_oobinline;
+ERL_NIF_TERM esock_atom_options;
+ERL_NIF_TERM esock_atom_origdstaddr;
+ERL_NIF_TERM esock_atom_partial_delivery_point;
+ERL_NIF_TERM esock_atom_passcred;
+ERL_NIF_TERM esock_atom_path;
+ERL_NIF_TERM esock_atom_peekcred;
+ERL_NIF_TERM esock_atom_peek_off;
+ERL_NIF_TERM esock_atom_peer_addr_params;
+ERL_NIF_TERM esock_atom_peer_auth_chunks;
+ERL_NIF_TERM esock_atom_pktinfo;
+ERL_NIF_TERM esock_atom_pktoptions;
+ERL_NIF_TERM esock_atom_port;
+ERL_NIF_TERM esock_atom_portrange;
+ERL_NIF_TERM esock_atom_primary_addr;
+ERL_NIF_TERM esock_atom_priority;
+ERL_NIF_TERM esock_atom_protocol;
+ERL_NIF_TERM esock_atom_raw;
+ERL_NIF_TERM esock_atom_rcvbuf;
+ERL_NIF_TERM esock_atom_rcvbufforce;
+ERL_NIF_TERM esock_atom_rcvlowat;
+ERL_NIF_TERM esock_atom_rcvtimeo;
+ERL_NIF_TERM esock_atom_rdm;
+ERL_NIF_TERM esock_atom_recv;
+ERL_NIF_TERM esock_atom_recvdstaddr;
+ERL_NIF_TERM esock_atom_recverr;
+ERL_NIF_TERM esock_atom_recvfrom;
+ERL_NIF_TERM esock_atom_recvif;
+ERL_NIF_TERM esock_atom_recvmsg;
+ERL_NIF_TERM esock_atom_recvopts;
+ERL_NIF_TERM esock_atom_recvorigdstaddr;
+ERL_NIF_TERM esock_atom_recvpktinfo;
+ERL_NIF_TERM esock_atom_recvtclass;
+ERL_NIF_TERM esock_atom_recvtos;
+ERL_NIF_TERM esock_atom_recvttl;
+ERL_NIF_TERM esock_atom_reliability;
+ERL_NIF_TERM esock_atom_reset_streams;
+ERL_NIF_TERM esock_atom_retopts;
+ERL_NIF_TERM esock_atom_reuseaddr;
+ERL_NIF_TERM esock_atom_reuseport;
+ERL_NIF_TERM esock_atom_rights;
+ERL_NIF_TERM esock_atom_router_alert;
+ERL_NIF_TERM esock_atom_rthdr;
+ERL_NIF_TERM esock_atom_rtoinfo;
+ERL_NIF_TERM esock_atom_rxq_ovfl;
+ERL_NIF_TERM esock_atom_scope_id;
+ERL_NIF_TERM esock_atom_sctp;
+ERL_NIF_TERM esock_atom_sec;
+ERL_NIF_TERM esock_atom_select_sent;
+ERL_NIF_TERM esock_atom_send;
+ERL_NIF_TERM esock_atom_sendmsg;
+ERL_NIF_TERM esock_atom_sendsrcaddr;
+ERL_NIF_TERM esock_atom_sendto;
+ERL_NIF_TERM esock_atom_seqpacket;
+ERL_NIF_TERM esock_atom_setfib;
+ERL_NIF_TERM esock_atom_set_peer_primary_addr;
+ERL_NIF_TERM esock_atom_socket;
+ERL_NIF_TERM esock_atom_socket_tag;
+ERL_NIF_TERM esock_atom_sndbuf;
+ERL_NIF_TERM esock_atom_sndbufforce;
+ERL_NIF_TERM esock_atom_sndlowat;
+ERL_NIF_TERM esock_atom_sndtimeo;
+ERL_NIF_TERM esock_atom_spec_dst;
+ERL_NIF_TERM esock_atom_status;
+ERL_NIF_TERM esock_atom_stream;
+ERL_NIF_TERM esock_atom_syncnt;
+ERL_NIF_TERM esock_atom_tclass;
+ERL_NIF_TERM esock_atom_tcp;
+ERL_NIF_TERM esock_atom_throughput;
+ERL_NIF_TERM esock_atom_timestamp;
+ERL_NIF_TERM esock_atom_tos;
+ERL_NIF_TERM esock_atom_transparent;
+ERL_NIF_TERM esock_atom_true;
+ERL_NIF_TERM esock_atom_trunc;
+ERL_NIF_TERM esock_atom_ttl;
+ERL_NIF_TERM esock_atom_type;
+ERL_NIF_TERM esock_atom_udp;
+ERL_NIF_TERM esock_atom_unblock_source;
+ERL_NIF_TERM esock_atom_undefined;
+ERL_NIF_TERM esock_atom_unicast_hops;
+ERL_NIF_TERM esock_atom_unknown;
+ERL_NIF_TERM esock_atom_usec;
+ERL_NIF_TERM esock_atom_user_timeout;
+ERL_NIF_TERM esock_atom_use_ext_recvinfo;
+ERL_NIF_TERM esock_atom_use_min_mtu;
+ERL_NIF_TERM esock_atom_v6only;
+
+/* *** "Global" error (=reason) atoms *** */
+ERL_NIF_TERM esock_atom_eagain;
+ERL_NIF_TERM esock_atom_eafnosupport;
+ERL_NIF_TERM esock_atom_einval;
+
+/* *** Atoms *** */
+static ERL_NIF_TERM atom_adaptation_layer;
+static ERL_NIF_TERM atom_address;
+static ERL_NIF_TERM atom_association;
+static ERL_NIF_TERM atom_assoc_id;
+static ERL_NIF_TERM atom_authentication;
+static ERL_NIF_TERM atom_bool;
+static ERL_NIF_TERM atom_close;
+static ERL_NIF_TERM atom_closed;
+static ERL_NIF_TERM atom_closing;
+static ERL_NIF_TERM atom_cookie_life;
+static ERL_NIF_TERM atom_data_in;
+static ERL_NIF_TERM atom_do;
+static ERL_NIF_TERM atom_dont;
+static ERL_NIF_TERM atom_exclude;
+static ERL_NIF_TERM atom_false;
+static ERL_NIF_TERM atom_global_counters;
+static ERL_NIF_TERM atom_in4_sockaddr;
+static ERL_NIF_TERM atom_in6_sockaddr;
+static ERL_NIF_TERM atom_include;
+static ERL_NIF_TERM atom_initial;
+static ERL_NIF_TERM atom_int;
+static ERL_NIF_TERM atom_interface;
+static ERL_NIF_TERM atom_iow;
+static ERL_NIF_TERM atom_local_rwnd;
+static ERL_NIF_TERM atom_max;
+static ERL_NIF_TERM atom_max_attempts;
+static ERL_NIF_TERM atom_max_init_timeo;
+static ERL_NIF_TERM atom_max_instreams;
+static ERL_NIF_TERM atom_max_rxt;
+static ERL_NIF_TERM atom_min;
+static ERL_NIF_TERM atom_mode;
+static ERL_NIF_TERM atom_multiaddr;
+// static ERL_NIF_TERM atom_nif_abort;
+static ERL_NIF_TERM atom_null;
+static ERL_NIF_TERM atom_num_dinet;
+static ERL_NIF_TERM atom_num_dinet6;
+static ERL_NIF_TERM atom_num_dlocal;
+static ERL_NIF_TERM atom_num_outstreams;
+static ERL_NIF_TERM atom_num_peer_dests;
+static ERL_NIF_TERM atom_num_pip;
+static ERL_NIF_TERM atom_num_psctp;
+static ERL_NIF_TERM atom_num_ptcp;
+static ERL_NIF_TERM atom_num_pudp;
+static ERL_NIF_TERM atom_num_sockets;
+static ERL_NIF_TERM atom_num_tdgrams;
+static ERL_NIF_TERM atom_num_tseqpkgs;
+static ERL_NIF_TERM atom_num_tstreams;
+static ERL_NIF_TERM atom_partial_delivery;
+static ERL_NIF_TERM atom_peer_error;
+static ERL_NIF_TERM atom_peer_rwnd;
+static ERL_NIF_TERM atom_probe;
+static ERL_NIF_TERM atom_select;
+static ERL_NIF_TERM atom_sender_dry;
+static ERL_NIF_TERM atom_send_failure;
+static ERL_NIF_TERM atom_shutdown;
+static ERL_NIF_TERM atom_slist;
+static ERL_NIF_TERM atom_sourceaddr;
+static ERL_NIF_TERM atom_timeout;
+static ERL_NIF_TERM atom_true;
+static ERL_NIF_TERM atom_want;
+
+static ERL_NIF_TERM atom_eisconn;
+static ERL_NIF_TERM atom_enotclosing;
+static ERL_NIF_TERM atom_enotconn;
+static ERL_NIF_TERM atom_exalloc;
+static ERL_NIF_TERM atom_exbadstate;
+static ERL_NIF_TERM atom_exbusy;
+static ERL_NIF_TERM atom_exmon;
+static ERL_NIF_TERM atom_exself;
+static ERL_NIF_TERM atom_exsend;
+
+
+/* *** Sockets *** */
+static ErlNifResourceType*    sockets;
+static ErlNifResourceTypeInit socketInit = {
+   socket_dtor,
+   socket_stop,
+   (ErlNifResourceDown*) socket_down
+};
+
+// Initiated when the nif is loaded
+static SocketData data;
+
+
+/* ----------------------------------------------------------------------
+ *  N I F   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ *
+ * Utility and admin functions:
+ * ----------------------------
+ * nif_info/0
+ * nif_supports/1
+ * (nif_debug/1)
+ *
+ * The "proper" socket functions:
+ * ------------------------------
+ * nif_open(Domain, Type, Protocol, Extra)
+ * nif_bind(Sock, LocalAddr)
+ * nif_connect(Sock, SockAddr)
+ * nif_listen(Sock, Backlog)
+ * nif_accept(LSock, Ref)
+ * nif_send(Sock, SendRef, Data, Flags)
+ * nif_sendto(Sock, SendRef, Data, Dest, Flags)
+ * nif_sendmsg(Sock, SendRef, MsgHdr, Flags)
+ * nif_recv(Sock, RecvRef, Length, Flags)
+ * nif_recvfrom(Sock, RecvRef, BufSz, Flags)
+ * nif_recvmsg(Sock, RecvRef, BufSz, CtrlSz, Flags)
+ * nif_close(Sock)
+ * nif_shutdown(Sock, How)
+ * nif_sockname(Sock)
+ * nif_peername(Sock)
+ *
+ * And some functions to manipulate and retrieve socket options:
+ * -------------------------------------------------------------
+ * nif_setopt/5
+ * nif_getopt/4
+ *
+ * And some utility functions:
+ * -------------------------------------------------------------
+ *
+ * And some socket admin functions:
+ * -------------------------------------------------------------
+ * nif_cancel(Sock, Ref)
+ */
+
+
+/* ----------------------------------------------------------------------
+ * nif_info
+ *
+ * Description:
+ * This is currently just a placeholder...
+ */
+#define MKCT(E, T, C) MKT2((E), (T), MKI((E), (C)))
+
+static
+ERL_NIF_TERM nif_info(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    if (argc != 0) {
+        return enif_make_badarg(env);
+    } else {
+        ERL_NIF_TERM numSockets     = MKCT(env, atom_num_sockets,  data.numSockets);
+        ERL_NIF_TERM numTypeDGrams  = MKCT(env, atom_num_tdgrams,  data.numTypeDGrams);
+        ERL_NIF_TERM numTypeStreams = MKCT(env, atom_num_tstreams, data.numTypeStreams);
+        ERL_NIF_TERM numTypeSeqPkgs = MKCT(env, atom_num_tseqpkgs, data.numTypeSeqPkgs);
+        ERL_NIF_TERM numDomLocal    = MKCT(env, atom_num_dlocal,   data.numDomainLocal);
+        ERL_NIF_TERM numDomInet     = MKCT(env, atom_num_dinet,    data.numDomainInet);
+        ERL_NIF_TERM numDomInet6    = MKCT(env, atom_num_dinet6,   data.numDomainInet6);
+        ERL_NIF_TERM numProtoIP     = MKCT(env, atom_num_pip,      data.numProtoIP);
+        ERL_NIF_TERM numProtoTCP    = MKCT(env, atom_num_ptcp,     data.numProtoTCP);
+        ERL_NIF_TERM numProtoUDP    = MKCT(env, atom_num_pudp,     data.numProtoUDP);
+        ERL_NIF_TERM numProtoSCTP   = MKCT(env, atom_num_psctp,    data.numProtoSCTP);
+        ERL_NIF_TERM gcnt[]  = {numSockets,
+                                numTypeDGrams, numTypeStreams, numTypeSeqPkgs,
+                                numDomLocal, numDomInet, numDomInet6,
+                                numProtoIP, numProtoTCP, numProtoUDP, numProtoSCTP};
+        unsigned int lenGCnt = sizeof(gcnt) / sizeof(ERL_NIF_TERM);
+        ERL_NIF_TERM lgcnt   = MKLA(env, gcnt, lenGCnt);
+        ERL_NIF_TERM keys[]  = {esock_atom_debug, atom_iow, atom_global_counters};
+        ERL_NIF_TERM vals[]  = {BOOL2ATOM(data.dbg), BOOL2ATOM(data.iow), lgcnt};
+        ERL_NIF_TERM info;
+        unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+        unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+        ESOCK_ASSERT( (numKeys == numVals) );
+
+        if (!MKMA(env, keys, vals, numKeys, &info))
+            return enif_make_badarg(env);
+    
+        return info;
+    }
+#endif
+}
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_supports
+ *
+ * Description:
+ * This function is intended to answer the question: "Is X supported?"
+ * Currently only one key is "supported": options
+ * That results in a list of all *known options* (known by us) and if
+ * the platform supports (OS) it or not.
+ *
+ * Key
+ * ---
+ * options         [{socket, [{Opt, boolean()}]},
+ *                  {ip,     [{Opt, boolean()}]},
+ *                  {ipv6,   [{Opt, boolean()}]},
+ *                  {tcp,    [{Opt, boolean()}]},
+ *                  {udp,    [{Opt, boolean()}]},
+ *                  {sctp,   [{Opt, boolean()}]}]
+ */
+
+static
+ERL_NIF_TERM nif_supports(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    int key;
+    
+    SGDBG( ("SOCKET", "nif_supports -> entry with %d args\r\n", argc) );
+    
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !GET_INT(env, argv[0], &key)) {
+        return enif_make_badarg(env);
+    }
+
+    return nsupports(env, key);
+#endif
+}
+
+
+
+/* nopen - create an endpoint for communication
+ *
+ * Assumes the input has been validated.
+ *
+ * Normally we want debugging on (individual) sockets to be controlled
+ * by the sockets own debug flag. But since we don't even have a socket
+ * yet, we must use the global debug flag.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports(ErlNifEnv* env, int key)
+{
+    ERL_NIF_TERM result;
+
+    SGDBG( ("SOCKET", "nsupports -> entry with 0x%lX\r\n", key) );
+
+    switch (key) {
+    case SOCKET_SUPPORTS_OPTIONS:
+        result = nsupports_options(env);
+        break;
+
+    case SOCKET_SUPPORTS_SCTP:
+        result = nsupports_sctp(env);
+        break;
+
+    case SOCKET_SUPPORTS_IPV6:
+        result = nsupports_ipv6(env);
+        break;
+
+    default:
+        result = esock_atom_false;
+        break;
+    }
+
+    return result;
+}
+#endif
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_options(ErlNifEnv* env)
+{
+    ERL_NIF_TERM sockOpts  = nsupports_options_socket(env);
+    ERL_NIF_TERM sockOptsT = MKT2(env, esock_atom_socket, sockOpts);
+    ERL_NIF_TERM ipOpts    = nsupports_options_ip(env);
+    ERL_NIF_TERM ipOptsT   = MKT2(env, esock_atom_ip, ipOpts);
+    ERL_NIF_TERM ipv6Opts  = nsupports_options_ipv6(env);
+    ERL_NIF_TERM ipv6OptsT = MKT2(env, esock_atom_ipv6, ipv6Opts);
+    ERL_NIF_TERM tcpOpts   = nsupports_options_tcp(env);
+    ERL_NIF_TERM tcpOptsT  = MKT2(env, esock_atom_tcp, tcpOpts);
+    ERL_NIF_TERM udpOpts   = nsupports_options_udp(env);
+    ERL_NIF_TERM udpOptsT  = MKT2(env, esock_atom_udp, udpOpts);
+    ERL_NIF_TERM sctpOpts  = nsupports_options_sctp(env);
+    ERL_NIF_TERM sctpOptsT = MKT2(env, esock_atom_sctp, sctpOpts);
+    ERL_NIF_TERM optsA[]   = {sockOptsT,
+                              ipOptsT, ipv6OptsT,
+                              tcpOptsT, udpOptsT, sctpOptsT};
+    unsigned int lenOptsA  = sizeof(optsA) / sizeof(ERL_NIF_TERM);
+    ERL_NIF_TERM optsL     = MKLA(env, optsA, lenOptsA);
+
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_options_socket(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(128);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** SOCKET_OPT_SOCK_ACCEPTCONN => SO_ACCEPTCONN *** */
+#if defined(SO_ACCEPTCONN)
+    tmp = MKT2(env, esock_atom_acceptconn, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_acceptconn, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_ACCEPTFILTER => SO_ACCEPTFILTER *** */
+    tmp = MKT2(env, esock_atom_acceptfilter, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_BINDTODEVICE => SO_BINDTODEVICE *** */
+#if defined(SO_BINDTODEVICE)
+    tmp = MKT2(env, esock_atom_bindtodevice, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_bindtodevice, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_BROADCAST => SO_BROADCAST *** */
+#if defined(SO_BROADCAST)
+    tmp = MKT2(env, esock_atom_broadcast, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_broadcast, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_BUSY_POLL => SO_BUSY_POLL *** */
+    tmp = MKT2(env, esock_atom_busy_poll, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_DEBUG => SO_DEBUG *** */
+#if defined(SO_DEBUG)
+    tmp = MKT2(env, esock_atom_debug, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_debug, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_DOMAIN => SO_DOMAIN *** */
+#if defined(SO_DOMAIN)
+    tmp = MKT2(env, esock_atom_domain, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_domain, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_DONTROUTE => SO_DONTROUTE *** */
+#if defined(SO_DONTROUTE)
+    tmp = MKT2(env, esock_atom_dontroute, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_dontroute, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_ERROR => SO_ERROR *** */
+    tmp = MKT2(env, esock_atom_error, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_KEEPALIVE => SO_KEEPALIVE *** */
+#if defined(SO_KEEPALIVE)
+    tmp = MKT2(env, esock_atom_keepalive, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_keepalive, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_LINGER => SO_LINGER *** */
+#if defined(SO_LINGER)
+    tmp = MKT2(env, esock_atom_linger, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_linger, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_MARK => SO_MARK *** */
+    tmp = MKT2(env, esock_atom_mark, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_OOBINLINE => SO_OOBINLINE *** */
+#if defined(SO_OOBINLINE)
+    tmp = MKT2(env, esock_atom_oobinline, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_oobinline, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_PASSCRED => SO_PASSCRED *** */
+    tmp = MKT2(env, esock_atom_passcred, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_PEEK_OFF => SO_PEEK_OFF *** */
+#if defined(SO_PEEK_OFF)
+    tmp = MKT2(env, esock_atom_peek_off, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_peek_off, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_PEEKCRED => SO_PEEKCRED *** */
+    tmp = MKT2(env, esock_atom_peekcred, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_PRIORITY => SO_PRIORITY *** */
+#if defined(SO_PRIORITY)
+    tmp = MKT2(env, esock_atom_priority, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_priority, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_PROTOCOL => SO_PROTOCOL *** */
+#if defined(SO_PROTOCOL)
+    tmp = MKT2(env, esock_atom_protocol, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_protocol, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_RCVBUF => SO_RCVBUF *** */
+#if defined(SO_RCVBUF)
+    tmp = MKT2(env, esock_atom_rcvbuf, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rcvbuf, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_RCVBUFFORCE => SO_RCVBUFFORCE *** */
+    tmp = MKT2(env, esock_atom_rcvbufforce, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_RCVLOWAT => SO_RCVLOWAT *** */
+#if defined(SO_RCVLOWAT)
+    tmp = MKT2(env, esock_atom_rcvlowat, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rcvlowat, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_RCVTIMEO => SO_RCVTIMEO *** */
+#if defined(SO_RCVTIMEO)
+    tmp = MKT2(env, esock_atom_rcvtimeo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rcvtimeo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_REUSEADDR => SO_REUSEADDR *** */
+#if defined(SO_REUSEADDR)
+    tmp = MKT2(env, esock_atom_reuseaddr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_reuseaddr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_REUSEPORT => SO_REUSEPORT *** */
+#if defined(SO_REUSEPORT)
+    tmp = MKT2(env, esock_atom_reuseport, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_reuseport, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_RXQ_OVFL => SO_RXQ_OVFL *** */
+    tmp = MKT2(env, esock_atom_rxq_ovfl, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_SETFIB => SO_SETFIB *** */
+    tmp = MKT2(env, esock_atom_setfib, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_SNDBUF => SO_SNDBUF *** */
+#if defined(SO_SNDBUF)
+    tmp = MKT2(env, esock_atom_sndbuf, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_sndbuf, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_SNDBUFFORCE => SO_SNDBUFFORCE *** */
+    tmp = MKT2(env, esock_atom_sndbufforce, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_SNDLOWAT => SO_SNDLOWAT *** */
+#if defined(SO_SNDLOWAT)
+    tmp = MKT2(env, esock_atom_sndlowat, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_sndlowat, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_SNDTIMEO => SO_SNDTIMEO *** */
+#if defined(SO_SNDTIMEO)
+    tmp = MKT2(env, esock_atom_sndtimeo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_sndtimeo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_TIMESTAMP => SO_TIMESTAMP *** */
+#if defined(SO_TIMESTAMP)
+    tmp = MKT2(env, esock_atom_timestamp, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_timestamp, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SOCK_TYPE => SO_TYPE *** */
+#if defined(SO_TYPE)
+    tmp = MKT2(env, esock_atom_type, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_type, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_options_ip(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(128);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** SOCKET_OPT_IP_ADD_MEMBERSHIP => IP_ADD_MEMBERSHIP *** */
+#if defined(IP_ADD_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_add_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_add_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_ADD_SOURCE_MEMBERSHIP => IP_ADD_SOURCE_MEMBERSHIP *** */
+#if defined(IP_ADD_SOURCE_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_add_source_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_add_source_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_BLOCK_SOURCE => IP_BLOCK_SOURCE *** */
+#if defined(IP_BLOCK_SOURCE)
+    tmp = MKT2(env, esock_atom_block_source, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_block_source, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_DONTFRAG => IP_DONTFRAG *** */
+    tmp = MKT2(env, esock_atom_dontfrag, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_DROP_MEMBERSHIP => IP_DROP_MEMBERSHIP *** */
+#if defined(IP_DROP_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_drop_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_drop_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_DROP_SOURCE_MEMBERSHIP => IP_DROP_SOURCE_MEMBERSHIP *** */
+#if defined(IP_DROP_SOURCE_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_drop_source_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_drop_source_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_FREEBIND => IP_FREEBIND *** */
+#if defined(IP_FREEBIND)
+    tmp = MKT2(env, esock_atom_freebind, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_freebind, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_HDRINCL => IP_HDRINCL *** */
+#if defined(IP_HDRINCL)
+    tmp = MKT2(env, esock_atom_hdrincl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_hdrincl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_MINTTL => IP_MINTTL *** */
+#if defined(IP_MINTTL)
+    tmp = MKT2(env, esock_atom_minttl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_minttl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_MSFILTER => IP_MSFILTER / IP_MSFILTER_SIZE *** */
+#if defined(IP_MSFILTER) && defined(IP_MSFILTER_SIZE)
+    tmp = MKT2(env, esock_atom_msfilter, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_msfilter, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_MTU => IP_MTU *** */
+    tmp = MKT2(env, esock_atom_mtu, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_MTU_DISCOVER => IP_MTU_DISCOVER *** */
+#if defined(IP_MTU_DISCOVER)
+    tmp = MKT2(env, esock_atom_mtu_discover, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_mtu_discover, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_MULTICAST_ALL => IP_MULTICAST_ALL *** */
+#if defined(IP_MULTICAST_ALL)
+    tmp = MKT2(env, esock_atom_multicast_all, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_all, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_MULTICAST_IF => IP_MULTICAST_IF *** */
+#if defined(IP_MULTICAST_IF)
+    tmp = MKT2(env, esock_atom_multicast_if, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_if, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_MULTICAST_LOOP => IP_MULTICAST_LOOP *** */
+#if defined(IP_MULTICAST_LOOP)
+    tmp = MKT2(env, esock_atom_multicast_loop, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_loop, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_MULTICAST_TTL => IP_MULTICAST_TTL *** */
+#if defined(IP_MULTICAST_TTL)
+    tmp = MKT2(env, esock_atom_multicast_ttl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_ttl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_NODEFRAG => IP_NODEFRAG *** */
+#if defined(IP_NODEFRAG)
+    tmp = MKT2(env, esock_atom_nodefrag, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_nodefrag, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_OPTIONS => IP_OPTIONS *** */
+    tmp = MKT2(env, esock_atom_options, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_PKTINFO => IP_PKTINFO *** */
+#if defined(IP_PKTINFO)
+    tmp = MKT2(env, esock_atom_pktinfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_pktinfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_RECVDSTADDR => IP_RECVDSTADDR *** */
+#if defined(IP_RECVDSTADDR)
+    tmp = MKT2(env, esock_atom_recvdstaddr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvdstaddr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_RECVERR => IP_RECVERR *** */
+#if defined(IP_RECVERR)
+    tmp = MKT2(env, esock_atom_recverr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recverr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_RECVIF => IP_RECVIF *** */
+#if defined(IP_RECVIF)
+    tmp = MKT2(env, esock_atom_recvif, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvif, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_RECVOPTS => IP_RECVOPTS *** */
+#if defined(IP_RECVOPTS)
+    tmp = MKT2(env, esock_atom_recvopts, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvopts, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_RECVORIGDSTADDR => IP_RECVORIGDSTADDR *** */
+#if defined(IP_RECVORIGDSTADDR)
+    tmp = MKT2(env, esock_atom_recvorigdstaddr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvorigdstaddr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_RECVTOS => IP_RECVTOS *** */
+#if defined(IP_RECVTOS)
+    tmp = MKT2(env, esock_atom_recvtos, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvtos, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_RECVTTL => IP_RECVTTL *** */
+#if defined(IP_RECVTTL)
+    tmp = MKT2(env, esock_atom_recvttl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvttl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_RETOPTS => IP_RETOPTS *** */
+#if defined(IP_RETOPTS)
+    tmp = MKT2(env, esock_atom_retopts, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_retopts, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_ROUTER_ALERT => IP_ROUTER_ALERT *** */
+#if defined(IP_ROUTER_ALERT)
+    tmp = MKT2(env, esock_atom_router_alert, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_router_alert, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_SENDSRCADDR => IP_SENDSRCADDR *** */
+#if defined(IP_SENDSRCADDR)
+    tmp = MKT2(env, esock_atom_sendsrcaddr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_sendsrcaddr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_TOS => IP_TOS *** */
+#if defined(IP_TOS)
+    tmp = MKT2(env, esock_atom_tos, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_tos, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_TRANSPARENT => IP_TRANSPARENT *** */
+#if defined(IP_TRANSPARENT)
+    tmp = MKT2(env, esock_atom_transparent, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_transparent, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_TTL => IP_TTL *** */
+#if defined(IP_TTL)
+    tmp = MKT2(env, esock_atom_ttl, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_ttl, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IP_UNBLOCK_SOURCE => IP_UNBLOCK_SOURCE *** */
+#if defined(IP_UNBLOCK_SOURCE)
+    tmp = MKT2(env, esock_atom_unblock_source, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_unblock_source, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_options_ipv6(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(128);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** SOCKET_OPT_IPV6_ADDRFORM => IPV6_ADDRFORM *** */
+#if defined(IPV6_ADDRFORM)
+    tmp = MKT2(env, esock_atom_addrform, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_addrform, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_ADD_MEMBERSHIP => IPV6_ADD_MEMBERSHIP *** */
+#if defined(IPV6_ADD_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_add_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_add_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_AUTHHDR => IPV6_AUTHHDR *** */
+#if defined(IPV6_AUTHHDR)
+    tmp = MKT2(env, esock_atom_authhdr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_authhdr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_AUTH_LEVEL => IPV6_AUTH_LEVEL *** */
+    tmp = MKT2(env, esock_atom_auth_level, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_CHECKSUM => IPV6_CHECKSUM *** */
+    tmp = MKT2(env, esock_atom_checksum, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_DROP_MEMBERSHIP => IPV6_DROP_MEMBERSHIP *** */
+#if defined(IPV6_DROP_MEMBERSHIP)
+    tmp = MKT2(env, esock_atom_drop_membership, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_drop_membership, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_DSTOPTS => IPV6_DSTOPTS *** */
+#if defined(IPV6_DSTOPTS)
+    tmp = MKT2(env, esock_atom_dstopts, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_dstopts, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_ESP_NETWORK_LEVEL => IPV6_ESP_NETWORK_LEVEL *** */
+    tmp = MKT2(env, esock_atom_esp_network_level, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_ESP_TRANS_LEVEL => IPV6_ESP_TRANS_LEVEL *** */
+    tmp = MKT2(env, esock_atom_esp_trans_level, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_FAITH => IPV6_FAITH *** */
+    tmp = MKT2(env, esock_atom_faith, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_FLOWINFO => IPV6_FLOWINFO *** */
+#if defined(IPV6_FLOWINFO)
+    tmp = MKT2(env, esock_atom_flowinfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_flowinfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_HOPLIMIT => IPV6_HOPLIMIT *** */
+#if defined(IPV6_HOPLIMIT)
+    tmp = MKT2(env, esock_atom_hoplimit, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_hoplimit, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_HOPOPTS => IPV6_HOPOPTS *** */
+#if defined(IPV6_HOPOPTS)
+    tmp = MKT2(env, esock_atom_hopopts, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_hopopts, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_IPCOMP_LEVEL => IPV6_IPCOMP_LEVEL *** */
+    tmp = MKT2(env, esock_atom_ipcomp_level, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_JOIN_GROUP => IPV6_JOIN_GROUP *** */
+    tmp = MKT2(env, esock_atom_join_group, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_LEAVE_GROUP => IPV6_LEAVE_GROUP *** */
+    tmp = MKT2(env, esock_atom_leave_group, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_MTU => IPV6_MTU *** */
+#if defined(IPV6_MTU)
+    tmp = MKT2(env, esock_atom_mtu, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_mtu, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_MTU_DISCOVER => IPV6_MTU_DISCOVER *** */
+#if defined(IPV6_MTU_DISCOVER)
+    tmp = MKT2(env, esock_atom_mtu_discover, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_mtu_discover, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_MULTICAST_HOPS => IPV6_MULTICAST_HOPS *** */
+#if defined(IPV6_MULTICAST_HOPS)
+    tmp = MKT2(env, esock_atom_multicast_hops, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_hops, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_MULTICAST_IF => IPV6_MULTICAST_IF *** */
+#if defined(IPV6_MULTICAST_IF)
+    tmp = MKT2(env, esock_atom_multicast_if, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_if, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_MULTICAST_LOOP => IPV6_MULTICAST_LOOP *** */
+#if defined(IPV6_MULTICAST_LOOP)
+    tmp = MKT2(env, esock_atom_multicast_loop, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_multicast_loop, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_PORTRANGE => IPV6_PORTRANGE *** */
+    tmp = MKT2(env, esock_atom_portrange, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_PKTOPTIONS => IPV6_PKTOPTIONS *** */
+    tmp = MKT2(env, esock_atom_pktoptions, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_RECVERR => IPV6_RECVERR *** */
+#if defined(IPV6_RECVERR)
+    tmp = MKT2(env, esock_atom_recverr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recverr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_RECVPKTINFO => IPV6_RECVPKTINFO *** */
+#if defined(IPV6_RECVPKTINFO)
+    tmp = MKT2(env, esock_atom_recvpktinfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_recvpktinfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_RECVTCLASS => IPV6_RECVTCLASS *** */
+    tmp = MKT2(env, esock_atom_recvtclass, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_ROUTER_ALERT => IPV6_ROUTER_ALERT *** */
+#if defined(IPV6_ROUTER_ALERT)
+    tmp = MKT2(env, esock_atom_router_alert, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_router_alert, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_RTHDR => IPV6_RTHDR *** */
+#if defined(IPV6_RTHDR)
+    tmp = MKT2(env, esock_atom_rthdr, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rthdr, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_TCLASS => IPV6_TCLASS *** */
+    tmp = MKT2(env, esock_atom_tclass, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_UNICAST_HOPS => IPV6_UNICAST_HOPS *** */
+#if defined(IPV6_UNICAST_HOPS)
+    tmp = MKT2(env, esock_atom_unicast_hops, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_unicast_hops, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_USE_MIN_MTU => IPV6_USE_MIN_MTU *** */
+    tmp = MKT2(env, esock_atom_use_min_mtu, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_IPV6_V6ONLY => IPV6_V6ONLY *** */
+#if defined(IPV6_V6ONLY)
+    tmp = MKT2(env, esock_atom_v6only, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_v6only, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_options_tcp(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(32);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** SOCKET_OPT_TCP_CONGESTION => TCP_CONGESTION *** */
+#if defined(TCP_CONGESTION)
+    tmp = MKT2(env, esock_atom_congestion, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_congestion, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_CORK => TCP_CORK *** */
+#if defined(TCP_CORK)
+    tmp = MKT2(env, esock_atom_cork, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_cork, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_INFO => TCP_INFO *** */
+    tmp = MKT2(env, esock_atom_info, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_KEEPCNT => TCP_KEEPCNT *** */
+    tmp = MKT2(env, esock_atom_keepcnt, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_KEEPIDLE => TCP_KEEPIDLE *** */
+    tmp = MKT2(env, esock_atom_keepidle, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_KEEPINTVL => TCP_KEEPINTVL *** */
+    tmp = MKT2(env, esock_atom_keepintvl, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_MAXSEG => TCP_MAXSEG *** */
+#if defined(TCP_)
+    tmp = MKT2(env, esock_atom_maxseg, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_maxseg, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_MD5SIG => TCP_MD5SIG *** */
+    tmp = MKT2(env, esock_atom_md5sig, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_NODELAY => TCP_NODELAY *** */
+#if defined(TCP_)
+    tmp = MKT2(env, esock_atom_nodelay, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_nodelay, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_NOOPT => TCP_NOOPT *** */
+    tmp = MKT2(env, esock_atom_noopt, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_NOPUSH => TCP_NOPUSH *** */
+    tmp = MKT2(env, esock_atom_nopush, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_SYNCNT => TCP_SYNCNT *** */
+    tmp = MKT2(env, esock_atom_syncnt, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_TCP_USER_TIMEOUT => TCP_USER_TIMEOUT *** */
+    tmp = MKT2(env, esock_atom_user_timeout, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_options_udp(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(8);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** SOCKET_OPT_UDP_CORK => UDP_CORK *** */
+#if defined(UDP_CORK)
+    tmp = MKT2(env, esock_atom_cork, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_cork, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_options_sctp(ErlNifEnv* env)
+{
+    SocketTArray opts = TARRAY_CREATE(64);
+    ERL_NIF_TERM tmp, optsL;
+
+
+    /* *** SOCKET_OPT_SCTP_ADAPTION_LAYER => SCTP_ADAPTION_LAYER *** */
+    tmp = MKT2(env, esock_atom_adaption_layer, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_ASSOCINFO => SCTP_ASSOCINFO *** */
+#if defined(SCTP_ASSOCINFO)
+    tmp = MKT2(env, esock_atom_associnfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_associnfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_AUTH_ACTIVE_KEY => SCTP_AUTH_ACTIVE_KEY *** */
+    tmp = MKT2(env, esock_atom_auth_active_key, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_AUTH_ASCONF => SCTP_AUTH_ASCONF *** */
+    tmp = MKT2(env, esock_atom_auth_asconf, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_AUTH_CHUNK => SCTP_AUTH_CHUNK *** */
+    tmp = MKT2(env, esock_atom_auth_chunk, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_AUTH_DELETE_KEY => SCTP_AUTH_DELETE_KEY *** */
+    tmp = MKT2(env, esock_atom_auth_delete_key, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_AUTH_KEY => SCTP_AUTH_KEY *** */
+    tmp = MKT2(env, esock_atom_auth_key, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_AUTOCLOSE => SCTP_AUTOCLOSE *** */
+#if defined(SCTP_AUTOCLOSE)
+    tmp = MKT2(env, esock_atom_autoclose, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_autoclose, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_CONTEXT => SCTP_CONTEXT *** */
+    tmp = MKT2(env, esock_atom_context, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_DEFAULT_SEND_PARAMS => SCTP_DEFAULT_SEND_PARAMS *** */
+    tmp = MKT2(env, esock_atom_default_send_params, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_DELAYED_ACK_TIME => SCTP_DELAYED_ACK_TIME *** */
+    tmp = MKT2(env, esock_atom_delayed_ack_time, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_DISABLE_FRAGMENTS => SCTP_DISABLE_FRAGMENTS *** */
+#if defined(SCTP_DISABLE_FRAGMENTS)
+    tmp = MKT2(env, esock_atom_disable_fragments, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_disable_fragments, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_HMAC_IDENT => SCTP_HMAC_IDENT *** */
+    tmp = MKT2(env, esock_atom_hmac_ident, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_EVENTS => SCTP_EVENTS *** */
+#if defined(SCTP_EVENTS)
+    tmp = MKT2(env, esock_atom_events, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_events, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_EXPLICIT_EOR => SCTP_EXPLICIT_EOR *** */
+    tmp = MKT2(env, esock_atom_explicit_eor, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_FRAGMENT_INTERLEAVE => SCTP_FRAGMENT_INTERLEAVE *** */
+    tmp = MKT2(env, esock_atom_fragment_interleave, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_GET_PEER_ADDR_INFO => SCTP_GET_PEER_ADDR_INFO *** */
+    tmp = MKT2(env, esock_atom_get_peer_addr_info, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_INITMSG => SCTP_INITMSG *** */
+#if defined(SCTP_INITMSG)
+    tmp = MKT2(env, esock_atom_initmsg, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_initmsg, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_I_WANT_MAPPED_V4_ADDR => SCTP_I_WANT_MAPPED_V4_ADDR *** */
+    tmp = MKT2(env, esock_atom_i_want_mapped_v4_addr, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_LOCAL_AUTH_CHUNKS => SCTP_LOCAL_AUTH_CHUNKS *** */
+    tmp = MKT2(env, esock_atom_local_auth_chunks, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_MAXSEG => SCTP_MAXSEG *** */
+#if defined(SCTP_MAXSEG)
+    tmp = MKT2(env, esock_atom_maxseg, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_maxseg, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_MAXBURST => SCTP_MAXBURST *** */
+    tmp = MKT2(env, esock_atom_maxburst, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_NODELAY => SCTP_NODELAY *** */
+#if defined(SCTP_NODELAY)
+    tmp = MKT2(env, esock_atom_nodelay, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_nodelay, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_PARTIAL_DELIVERY_POINT => SCTP_PARTIAL_DELIVERY_POINT *** */
+    tmp = MKT2(env, esock_atom_partial_delivery_point, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_PEER_ADDR_PARAMS => SCTP_PEER_ADDR_PARAMS *** */
+    tmp = MKT2(env, esock_atom_peer_addr_params, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_PEER_AUTH_CHUNKS => SCTP_PEER_AUTH_CHUNKS *** */
+    tmp = MKT2(env, esock_atom_peer_auth_chunks, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_PRIMARY_ADDR => SCTP_PRIMARY_ADDR *** */
+    tmp = MKT2(env, esock_atom_primary_addr, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_RESET_STREAMS => SCTP_RESET_STREAMS *** */
+    tmp = MKT2(env, esock_atom_reset_streams, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_RTOINFO => SCTP_RTOINFO *** */
+#if defined(SCTP_RTOINFO)
+    tmp = MKT2(env, esock_atom_rtoinfo, esock_atom_true);
+#else
+    tmp = MKT2(env, esock_atom_rtoinfo, esock_atom_false);
+#endif
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_SET_PEER_PRIMARY_ADDR => SCTP_SET_PEER_PRIMARY_ADDR *** */
+    tmp = MKT2(env, esock_atom_set_peer_primary_addr, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_STATUS => SCTP_STATUS *** */
+    tmp = MKT2(env, esock_atom_status, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    /* *** SOCKET_OPT_SCTP_USE_EXT_RECVINFO => SCTP_USE_EXT_RECVINFO *** */
+    tmp = MKT2(env, esock_atom_use_ext_recvinfo, esock_atom_false);
+    TARRAY_ADD(opts, tmp);
+
+
+    TARRAY_TOLIST(opts, env, &optsL);
+    
+    return optsL;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_sctp(ErlNifEnv* env)
+{
+    ERL_NIF_TERM supports;
+
+#if defined(HAVE_SCTP)
+    supports = esock_atom_true;
+#else
+    supports = esock_atom_false;
+#endif
+
+    return supports;
+}
+#endif
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsupports_ipv6(ErlNifEnv* env)
+{
+    ERL_NIF_TERM supports;
+
+    /* Is this (test) really sufficient for testing if we support IPv6? */
+#if defined(HAVE_IPV6)
+    supports = esock_atom_true;
+#else
+    supports = esock_atom_false;
+#endif
+
+    return supports;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_open
+ *
+ * Description:
+ * Create an endpoint for communication.
+ *
+ * Arguments:
+ * Domain   - The domain, for example 'inet'
+ * Type     - Type of socket, for example 'stream'
+ * Protocol - The protocol, for example 'tcp'
+ * Extra    - A map with "obscure" options.
+ *            Currently the only allowed option is netns (network namespace).
+ *            This is *only* allowed on linux!
+ */
+static
+ERL_NIF_TERM nif_open(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    int          edomain, etype, eproto;
+    int          domain, type, proto;
+    char*        netns;
+    ERL_NIF_TERM emap;
+    ERL_NIF_TERM result;
+
+    SGDBG( ("SOCKET", "nif_open -> entry with %d args\r\n", argc) );
+    
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 4) ||
+        !GET_INT(env, argv[0], &edomain) ||
+        !GET_INT(env, argv[1], &etype) ||
+        !IS_MAP(env,  argv[3])) {
+        return enif_make_badarg(env);
+    }
+    eproto = argv[2];
+    emap   = argv[3];
+
+    SGDBG( ("SOCKET", "nif_open -> "
+            "\r\n   edomain: %T"
+            "\r\n   etype:   %T"
+            "\r\n   eproto:  %T"
+            "\r\n   extra:   %T"
+            "\r\n", argv[0], argv[1], eproto, emap) );
+
+    if (!edomain2domain(edomain, &domain)) {
+        SGDBG( ("SOCKET", "nif_open -> domain: %d\r\n", domain) );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if (!etype2type(etype, &type)) {
+        SGDBG( ("SOCKET", "nif_open -> type: %d\r\n", type) );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if (!eproto2proto(env, eproto, &proto)) {
+        SGDBG( ("SOCKET", "nif_open -> protocol: %d\r\n", proto) );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+#ifdef HAVE_SETNS
+    /* We *currently* only support one extra option: netns */
+    if (!emap2netns(env, emap, &netns)) {
+        SGDBG( ("SOCKET", "nif_open -> namespace: %s\r\n", netns) );
+        return enif_make_badarg(env);
+    }
+#else
+    netns = NULL;
+#endif
+
+    result = nopen(env, domain, type, proto, netns);
+
+    SGDBG( ("SOCKET", "nif_open -> done with result: "
+           "\r\n   %T"
+           "\r\n", result) );
+
+    return result;
+#endif // if defined(__WIN32__)
+}
+
+
+/* nopen - create an endpoint for communication
+ *
+ * Assumes the input has been validated.
+ *
+ * Normally we want debugging on (individual) sockets to be controlled
+ * by the sockets own debug flag. But since we don't even have a socket
+ * yet, we must use the global debug flag.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nopen(ErlNifEnv* env,
+                   int domain, int type, int protocol,
+                   char* netns)
+{
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      res;
+    int               save_errno = 0;
+    SOCKET            sock;
+    HANDLE            event;
+#ifdef HAVE_SETNS
+    int               current_ns = 0;
+#endif
+
+    SGDBG( ("SOCKET", "nopen -> entry with"
+            "\r\n   domain:   %d"
+            "\r\n   type:     %d"
+            "\r\n   protocol: %d"
+            "\r\n   netns:    %s"
+            "\r\n", domain, type, protocol, ((netns == NULL) ? "NULL" : netns)) );
+
+#ifdef HAVE_SETNS
+    if ((netns != NULL) &&
+        !change_network_namespace(netns, &current_ns, &save_errno))
+        return esock_make_error_errno(env, save_errno);
+#endif
+
+    if ((sock = sock_open(domain, type, protocol)) == INVALID_SOCKET)
+        return esock_make_error_errno(env, sock_errno());
+
+    SGDBG( ("SOCKET", "nopen -> open success: %d\r\n", sock) );
+
+#ifdef HAVE_SETNS
+    if ((netns != NULL) &&
+        !restore_network_namespace(current_ns, sock, &save_errno))
+        return esock_make_error_errno(env, save_errno);
+
+    if (netns != NULL)
+        FREE(netns);
+#endif
+
+
+    if ((event = sock_create_event(sock)) == INVALID_EVENT) {
+        save_errno = sock_errno();
+        while ((sock_close(sock) == INVALID_SOCKET) && (sock_errno() == EINTR));
+        return esock_make_error_errno(env, save_errno);
+    }
+
+    SGDBG( ("SOCKET", "nopen -> event success: %d\r\n", event) );
+
+    SET_NONBLOCKING(sock);
+
+
+    /* Create and initiate the socket "descriptor" */
+    if ((descP = alloc_descriptor(sock, event)) == NULL) {
+        sock_close(sock);
+        // Not sure if this is really the proper error, but...
+        return enif_make_badarg(env);
+    }
+
+    descP->state    = SOCKET_STATE_OPEN;
+    descP->domain   = domain;
+    descP->type     = type;
+    descP->protocol = protocol;
+
+    /* Does this apply to other types? Such as RAW? */
+    if (type == SOCK_DGRAM) {
+        descP->isReadable = TRUE;
+        descP->isWritable = TRUE;
+    }
+
+    /*
+     * Should we keep track of sockets (resources) in some way?
+     * Doing it here will require mutex to ensure data integrity,
+     * which will be costly. Send it somewhere?
+     */
+    res = enif_make_resource(env, descP);
+    enif_release_resource(descP);
+
+    /* Keep track of the creator
+     * This should not be a problem but just in case
+     * the *open* function is used with the wrong kind
+     * of environment...
+     */
+    if (enif_self(env, &descP->ctrlPid) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    if (MONP("nopen -> ctrl",
+             env, descP,
+             &descP->ctrlPid,
+             &descP->ctrlMon) != 0)
+        return esock_make_error(env, atom_exmon);
+
+
+    inc_socket(domain, type, protocol);
+
+    return esock_make_ok2(env, res);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+#ifdef HAVE_SETNS
+/* We should really have another API, so that we can return errno... */
+
+/* *** change network namespace ***
+ * Retreive the current namespace and set the new.
+ * Return result and previous namespace if successfull.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T change_network_namespace(char* netns, int* cns, int* err)
+{
+    int save_errno;
+    int current_ns = 0;
+    int new_ns     = 0;
+
+    SGDBG( ("SOCKET", "change_network_namespace -> entry with"
+            "\r\n   new ns: %s", netns) );
+
+    if (netns != NULL) {
+        current_ns = open("/proc/self/ns/net", O_RDONLY);
+        if (current_ns == INVALID_SOCKET) {
+            *cns = current_ns;
+            *err = sock_errno();
+            return FALSE;
+        }
+        new_ns = open(netns, O_RDONLY);
+        if (new_ns == INVALID_SOCKET) {
+            save_errno = sock_errno();
+            while (close(current_ns) == INVALID_SOCKET &&
+                   sock_errno() == EINTR);
+            *cns = -1;
+            *err = save_errno;
+            return FALSE;
+        }
+        if (setns(new_ns, CLONE_NEWNET) != 0) {
+            save_errno = sock_errno();
+            while ((close(new_ns) == INVALID_SOCKET) &&
+                   (sock_errno() == EINTR));
+            while ((close(current_ns) == INVALID_SOCKET) &&
+                   (sock_errno() == EINTR));
+            *cns = -1;
+            *err = save_errno;
+            return FALSE;
+        } else {
+            while ((close(new_ns) == INVALID_SOCKET) &&
+                   (sock_errno() == EINTR));
+            *cns = current_ns;
+            *err = 0;
+            return TRUE;
+        }
+    } else {
+        *cns = INVALID_SOCKET;
+        *err = 0;
+        return TRUE;
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+/* *** restore network namespace ***
+ * Restore the previous namespace (see above).
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T restore_network_namespace(int ns, SOCKET sock, int* err)
+{
+    int save_errno;
+
+    SGDBG( ("SOCKET", "restore_network_namespace -> entry with"
+            "\r\n   ns: %d", ns) );
+
+    if (ns != INVALID_SOCKET) {
+        if (setns(ns, CLONE_NEWNET) != 0) {
+            /* XXX Failed to restore network namespace.
+             * What to do? Tidy up and return an error...
+             * Note that the thread now might still be in the namespace.
+             * Can this even happen? Should the emulator be aborted?
+             */
+            if (sock != INVALID_SOCKET)
+                save_errno = sock_errno();
+            while (close(sock) == INVALID_SOCKET &&
+                   sock_errno() == EINTR);
+            sock = INVALID_SOCKET;
+            while (close(ns) == INVALID_SOCKET &&
+                   sock_errno() == EINTR);
+            *err = save_errno;
+            return FALSE;
+        } else {
+            while (close(ns) == INVALID_SOCKET &&
+                   sock_errno() == EINTR);
+            *err = 0;
+            return TRUE;
+        }
+  }
+
+  *err = 0;
+  return TRUE;
+}
+#endif // if !defined(__WIN32__)
+#endif // ifdef HAVE_SETNS
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_bind
+ *
+ * Description:
+ * Bind a name to a socket.
+ *
+ * Arguments:
+ * [0] Socket (ref) - Points to the socket descriptor.
+ * [1] LocalAddr    - Local address is a sockaddr map ( socket:sockaddr() ).
+ */
+static
+ERL_NIF_TERM nif_bind(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      eSockAddr;
+    SocketAddress     sockAddr;
+    unsigned int      addrLen;
+    char*             xres;
+
+    SGDBG( ("SOCKET", "nif_bind -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 2) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    eSockAddr = argv[1];
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_bind -> args when sock = %d (0x%lX)"
+            "\r\n   Socket:   %T"
+            "\r\n   SockAddr: %T"
+            "\r\n", descP->sock, descP->state, argv[0], eSockAddr) );
+
+    /* Make sure we are ready
+     * Not sure how this would even happen, but...
+     */
+    if (descP->state != SOCKET_STATE_OPEN)
+        return esock_make_error(env, atom_exbadstate);
+
+    if ((xres = esock_decode_sockaddr(env, eSockAddr, &sockAddr, &addrLen)) != NULL)
+        return esock_make_error_str(env, xres);
+        
+    return nbind(env, descP, &sockAddr, addrLen);
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nbind(ErlNifEnv*        env,
+                   SocketDescriptor* descP,
+                   SocketAddress*    sockAddrP,
+                   unsigned int      addrLen)
+{
+    int port, ntohs_port;
+
+    SSDBG( descP, ("SOCKET", "nbind -> try bind\r\n") );
+
+    if (IS_SOCKET_ERROR(sock_bind(descP->sock,
+                                  (struct sockaddr*) sockAddrP, addrLen))) {
+        return esock_make_error_errno(env, sock_errno());
+    }
+
+    SSDBG( descP, ("SOCKET", "nbind -> bound - get port\r\n") );
+
+    port = which_address_port(sockAddrP);
+    SSDBG( descP, ("SOCKET", "nbind -> port: %d\r\n", port) );
+    if (port == 0) {
+        SOCKLEN_T len = sizeof(SocketAddress);
+        sys_memzero((char *) sockAddrP, len);
+        sock_name(descP->sock, &sockAddrP->sa, &len);
+        port = which_address_port(sockAddrP);
+    } else if (port == -1) {
+        port = 0;
+    }
+
+    ntohs_port = sock_ntohs(port);
+    
+    SSDBG( descP, ("SOCKET", "nbind -> done with port = %d\r\n", ntohs_port) );
+
+    return esock_make_ok2(env, MKI(env, ntohs_port));
+
+}
+#endif // if !defined(__WIN32__)
+
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_connect
+ *
+ * Description:
+ * Initiate a connection on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SockAddr     - Socket Address of "remote" host.
+ *                This is sockaddr(), which is either
+ *                sockaddr_in4 or sockaddr_in6.
+ */
+static
+ERL_NIF_TERM nif_connect(ErlNifEnv*         env,
+                         int                argc,
+                         const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      eSockAddr;
+    char*             xres;
+
+    SGDBG( ("SOCKET", "nif_connect -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 2) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    eSockAddr = argv[1];
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_connect -> args when sock = %d:"
+            "\r\n   Socket:   %T"
+            "\r\n   SockAddr: %T"
+            "\r\n", descP->sock, argv[0], eSockAddr) );
+    
+    if ((xres = esock_decode_sockaddr(env, eSockAddr,
+                                      &descP->remote, &descP->addrLen)) != NULL) {
+        return esock_make_error_str(env, xres);
+    }
+
+    return nconnect(env, descP);
+#endif // if !defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nconnect(ErlNifEnv*        env,
+                      SocketDescriptor* descP)
+{
+    int code, save_errno = 0;
+
+    /* 
+     * <KOLLA>
+     *
+     * We should look both the read and write mutex:es...
+     *
+     * </KOLLA>
+     *
+     * Verify that we are where in the proper state */
+
+    if (!IS_OPEN(descP)) {
+        SSDBG( descP, ("SOCKET", "nif_connect -> not open\r\n") );
+        return esock_make_error(env, atom_exbadstate);
+    }
+
+    if (IS_CONNECTED(descP)) {
+        SSDBG( descP, ("SOCKET", "nif_connect -> already connected\r\n") );
+        return esock_make_error(env, atom_eisconn);
+    }
+
+    if (IS_CONNECTING(descP)) {
+        SSDBG( descP, ("SOCKET", "nif_connect -> already connecting\r\n") );
+        return esock_make_error(env, esock_atom_einval);
+    }
+    
+    code = sock_connect(descP->sock,
+                        (struct sockaddr*) &descP->remote,
+                        descP->addrLen);
+    save_errno = sock_errno();
+
+    SSDBG( descP, ("SOCKET", "nif_connect -> connect result: %d, %d\r\n",
+                   code, save_errno) );
+
+    if (IS_SOCKET_ERROR(code) &&
+        ((save_errno == ERRNO_BLOCK) ||   /* Winsock2            */
+         (save_errno == EINPROGRESS))) {  /* Unix & OSE!!        */
+        ERL_NIF_TERM ref = MKREF(env);
+        descP->state = SOCKET_STATE_CONNECTING;
+        SELECT(env,
+               descP->sock,
+               (ERL_NIF_SELECT_WRITE),
+               descP, NULL, ref);
+        return esock_make_ok2(env, ref);
+    } else if (code == 0) {                 /* ok we are connected */
+        descP->state      = SOCKET_STATE_CONNECTED;
+        descP->isReadable = TRUE;
+        descP->isWritable = TRUE;
+        /* Do we need to do somthing for "active" mode?
+         * Is there even such a thing *here*?
+         */
+        return esock_atom_ok;
+    } else {
+        return esock_make_error_errno(env, save_errno);
+    }
+
+}
+#endif // if !defined(__WIN32__)
+
+
+/* ----------------------------------------------------------------------
+ * nif_finalize_connection
+ *
+ * Description:
+ * Make socket ready for input and output.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+static
+ERL_NIF_TERM nif_finalize_connection(ErlNifEnv*         env,
+                                     int                argc,
+                                     const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    return nfinalize_connection(env, descP);
+
+#endif
+}
+
+
+/* *** nfinalize_connection ***
+ * Perform the final check to verify a connection.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nfinalize_connection(ErlNifEnv*        env,
+                                  SocketDescriptor* descP)
+{
+    int error;
+
+    if (descP->state != SOCKET_STATE_CONNECTING)
+        return esock_make_error(env, atom_enotconn);
+
+    if (!verify_is_connected(descP, &error)) {
+        descP->state = SOCKET_STATE_OPEN;  /* restore state */
+        return esock_make_error_errno(env, error);
+    }
+
+    descP->state      = SOCKET_STATE_CONNECTED;
+    descP->isReadable = TRUE;
+    descP->isWritable = TRUE;
+
+    return esock_atom_ok;
+}
+#endif
+
+
+/* *** verify_is_connected ***
+ * Check if a connection has been established.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T verify_is_connected(SocketDescriptor* descP, int* err)
+{
+    /*
+     * *** This is strange ***
+     *
+     * This *should* work on Windows NT too, but doesn't.
+     * An bug in Winsock 2.0 for Windows NT?
+     *
+     * See "Unix Netwok Programming", W.R.Stevens, p 412 for a
+     * discussion about Unix portability and non blocking connect.
+     */
+
+#ifndef SO_ERROR
+    
+    int sz, code;
+
+    sz = sizeof(descP->remote);
+    sys_memzero((char *) &descP->remote, sz);
+    code = sock_peer(desc->sock,
+                     (struct sockaddr*) &descP->remote, &sz);
+
+    if (IS_SOCKET_ERROR(code)) {
+        *err = sock_errno();
+        return FALSE;
+    }
+
+#else
+
+    int          error = 0;             /* Has to be initiated, we check it */
+    unsigned int sz    = sizeof(error); /* even if we get -1                */
+    int          code  = sock_getopt(descP->sock,
+                                     SOL_SOCKET, SO_ERROR,
+                                     (void *)&error, &sz);
+
+    if ((code < 0) || error) {
+        *err = error;
+        return FALSE;
+    }
+
+#endif /* SO_ERROR */
+
+    *err = 0;
+
+    return TRUE;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_listen
+ *
+ * Description:
+ * Listen for connections on a socket.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * Backlog      - The maximum length to which the queue of pending
+ *                connections for socket may grow.
+ */
+static
+ERL_NIF_TERM nif_listen(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    int               backlog;
+
+    SGDBG( ("SOCKET", "nif_listen -> entry with argc: %d\r\n", argc) );
+    
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 2) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP) ||
+        !GET_INT(env, argv[1], &backlog)) {
+        return enif_make_badarg(env);
+    }
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_listen -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   backlog: %d"
+            "\r\n", descP->sock, argv[0], backlog) );
+    
+    return nlisten(env, descP, backlog);
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nlisten(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     int               backlog)
+{
+    if (descP->state == SOCKET_STATE_CLOSED)
+        return esock_make_error(env, atom_exbadstate);
+
+    if (!IS_OPEN(descP))
+        return esock_make_error(env, atom_exbadstate);
+
+    if (IS_SOCKET_ERROR(sock_listen(descP->sock, backlog)))
+        return esock_make_error_errno(env, sock_errno());
+
+    descP->state = SOCKET_STATE_LISTENING;
+
+    return esock_atom_ok;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_accept
+ *
+ * Description:
+ * Accept a connection on a socket.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * Request ref  - Unique "id" of this request
+ *                (used for the select, if none is in queue).
+ */
+static
+ERL_NIF_TERM nif_accept(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      ref;
+
+    SGDBG( ("SOCKET", "nif_accept -> entry with argc: %d\r\n", argc) );
+    
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 2) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP)) {
+        return enif_make_badarg(env); 
+   }
+    ref = argv[1];
+    
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_accept -> args when sock = %d:"
+            "\r\n   Socket: %T"
+            "\r\n   ReqRef: %T"
+            "\r\n", descP->sock, argv[0], ref) );
+
+    return naccept(env, descP, ref);
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM naccept(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     ERL_NIF_TERM      ref)
+{
+    ERL_NIF_TERM res;
+
+    switch (descP->state) {
+    case SOCKET_STATE_LISTENING:
+        MLOCK(descP->accMtx);
+        res = naccept_listening(env, descP, ref);
+        MUNLOCK(descP->accMtx);
+        break;
+
+    case SOCKET_STATE_ACCEPTING:
+        MLOCK(descP->accMtx);
+        res = naccept_accepting(env, descP, ref);
+        MUNLOCK(descP->accMtx);
+        break;
+
+    default:
+        res = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return res;
+}
+#endif // if !defined(__WIN32__)
+
+
+/* *** naccept_listening ***
+ * We have no active acceptor and no acceptors in queue.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM naccept_listening(ErlNifEnv*        env,
+                               SocketDescriptor* descP,
+                               ERL_NIF_TERM      ref)
+{
+    SocketAddress remote;
+    unsigned int  n;
+    SOCKET        accSock;
+    HANDLE        accEvent;
+    int           save_errno;
+    ErlNifPid     caller;
+
+    SSDBG( descP, ("SOCKET", "naccept_listening -> get caller\r\n") );
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    n = sizeof(remote);
+    sys_memzero((char *) &remote, n);
+    SSDBG( descP, ("SOCKET", "naccept_listening -> try accept\r\n") );
+    accSock = sock_accept(descP->sock, (struct sockaddr*) &remote, &n);
+    if (accSock == INVALID_SOCKET) {
+
+        save_errno = sock_errno();
+
+        SSDBG( descP,
+               ("SOCKET",
+                "naccept_listening -> accept failed (%d)\r\n", save_errno) );
+
+        if (save_errno == ERRNO_BLOCK) {
+
+            /* *** Try again later *** */
+            SSDBG( descP, ("SOCKET", "naccept_listening -> would block\r\n") );
+
+            descP->currentAcceptor.pid = caller;
+            if (MONP("naccept_listening -> current acceptor",
+                     env, descP,
+                     &descP->currentAcceptor.pid,
+                     &descP->currentAcceptor.mon) != 0)
+                return esock_make_error(env, atom_exmon);
+
+            descP->currentAcceptor.ref = enif_make_copy(descP->env, ref);
+            descP->currentAcceptorP    = &descP->currentAcceptor;
+
+            SELECT(env,
+                   descP->sock,
+                   (ERL_NIF_SELECT_READ),
+                   descP, NULL, ref);
+
+            /* Shall we really change state?
+             * The ready event is sent directly to the calling
+             * process, which simply calls this function again.
+             * Basically, state accepting means that we have
+             * an "outstanding" accept.
+             * Shall we store the pid of the calling process?
+             * And if someone else calls accept, return with ebusy?
+             * Can any process call accept or just the controlling
+             * process?
+             * We also need a monitor it case the calling process is
+             * called before we are done!
+             *
+             * Change state (to accepting) and store pid of the acceptor
+             * (current process). Only accept calls from the acceptor
+             * process (ebusy) and once we have a successful accept,
+             * change state back to listening. If cancel is called instead
+             * (only accepted from the acceptor process), we reset
+             * state to listening and also resets the pid to "null"
+             * (is there such a value?).
+             * Need a mutex to secure that we don't test and change the
+             * pid at the same time.
+             */
+
+            descP->state = SOCKET_STATE_ACCEPTING;
+
+            return esock_make_error(env, esock_atom_eagain);
+
+        } else {
+            SSDBG( descP,
+                   ("SOCKET",
+                    "naccept_listening -> errno: %d\r\n", save_errno) );
+            return esock_make_error_errno(env, save_errno);
+        }
+
+    } else {
+        SocketDescriptor* accDescP;
+        ERL_NIF_TERM      accRef;
+
+        /*
+         * We got one
+         */
+
+        SSDBG( descP, ("SOCKET", "naccept_listening -> accept success\r\n") );
+
+        if ((accEvent = sock_create_event(accSock)) == INVALID_EVENT) {
+            save_errno = sock_errno();
+            while ((sock_close(accSock) == INVALID_SOCKET) &&
+                   (sock_errno() == EINTR));
+            return esock_make_error_errno(env, save_errno);
+        }
+
+        if ((accDescP = alloc_descriptor(accSock, accEvent)) == NULL) {
+            sock_close(accSock);
+            return enif_make_badarg(env);
+        }
+
+        accDescP->domain   = descP->domain;
+        accDescP->type     = descP->type;
+        accDescP->protocol = descP->protocol;
+        accDescP->rBufSz   = descP->rBufSz;  // Inherit buffer size
+        accDescP->rNum     = descP->rNum;    // Inherit buffer uses
+        accDescP->rNumCnt  = 0;
+        accDescP->rCtrlSz  = descP->rCtrlSz; // Inherit buffer siez
+        accDescP->wCtrlSz  = descP->wCtrlSz; // Inherit buffer size
+
+        accRef = enif_make_resource(env, accDescP);
+        enif_release_resource(accDescP);
+
+        accDescP->ctrlPid = caller;
+        if (MONP("naccept_listening -> ctrl",
+                 env, accDescP,
+                 &accDescP->ctrlPid,
+                 &accDescP->ctrlMon) != 0) {
+            sock_close(accSock);
+            return esock_make_error(env, atom_exmon);
+        }
+
+        accDescP->remote = remote;
+        SET_NONBLOCKING(accDescP->sock);
+
+        accDescP->state      = SOCKET_STATE_CONNECTED;
+        accDescP->isReadable = TRUE;
+        accDescP->isWritable = TRUE;
+
+        return esock_make_ok2(env, accRef);
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+/* *** naccept_accepting ***
+ * We have an active acceptor and possibly acceptors waiting in queue.
+ * If the pid of the calling process is not the pid of the "current process",
+ * push the requester onto the queue.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM naccept_accepting(ErlNifEnv*        env,
+                               SocketDescriptor* descP,
+                               ERL_NIF_TERM      ref)
+{
+    SocketAddress remote;
+    unsigned int  n;
+    SOCKET        accSock;
+    HANDLE        accEvent;
+    ErlNifPid     caller;
+    int           save_errno;
+    ERL_NIF_TERM  result;
+
+    SSDBG( descP, ("SOCKET", "naccept_accepting -> get caller\r\n") );
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    SSDBG( descP, ("SOCKET", "naccept_accepting -> check: "
+                   "are caller current acceptor:"
+                   "\r\n   Caller:  %T"
+                   "\r\n   Current: %T"
+                   "\r\n", caller, descP->currentAcceptor.pid) );
+
+    if (!compare_pids(env, &descP->currentAcceptor.pid, &caller)) {
+
+        /* Not the "current acceptor", so (maybe) push onto queue */
+
+        SSDBG( descP, ("SOCKET", "naccept_accepting -> not (active) acceptor\r\n") );
+
+        if (!acceptor_search4pid(env, descP, &caller))
+            result = acceptor_push(env, descP, caller, ref);
+        else
+            result = esock_make_error(env, esock_atom_eagain);
+        
+        SSDBG( descP,
+               ("SOCKET",
+                "naccept_accepting -> queue (push) result: %T\r\n", result) );
+
+        return result;
+    }
+
+    n = sizeof(descP->remote);
+    sys_memzero((char *) &remote, n);
+    SSDBG( descP, ("SOCKET", "naccept_accepting -> try accept\r\n") );
+    accSock = sock_accept(descP->sock, (struct sockaddr*) &remote, &n);
+    if (accSock == INVALID_SOCKET) {
+
+        save_errno = sock_errno();
+
+        SSDBG( descP,
+               ("SOCKET",
+                "naccept_accepting -> accept failed (%d)\r\n", save_errno) );
+
+        if (save_errno == ERRNO_BLOCK) {
+
+            /*
+             * Just try again, no real error, just a ghost trigger from poll,
+             */
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "naccept_accepting -> would block: try again\r\n") );
+
+            SELECT(env,
+                   descP->sock,
+                   (ERL_NIF_SELECT_READ),
+                   descP, NULL, ref);
+
+            return esock_make_error(env, esock_atom_eagain);
+        } else {
+            SSDBG( descP,
+                   ("SOCKET",
+                    "naccept_accepting -> errno: %d\r\n", save_errno) );
+            return esock_make_error_errno(env, save_errno);
+        }
+    } else {
+        SocketDescriptor* accDescP;
+        ERL_NIF_TERM      accRef;
+
+        /*
+         * We got one
+         */
+
+        SSDBG( descP, ("SOCKET", "naccept_accepting -> accept success\r\n") );
+
+        DEMONP("naccept_accepting -> current acceptor",
+               env, descP, &descP->currentAcceptor.mon);
+
+        if ((accEvent = sock_create_event(accSock)) == INVALID_EVENT) {
+            save_errno = sock_errno();
+            while ((sock_close(accSock) == INVALID_SOCKET) &&
+                   (sock_errno() == EINTR));
+            return esock_make_error_errno(env, save_errno);
+        }
+
+        if ((accDescP = alloc_descriptor(accSock, accEvent)) == NULL) {
+            sock_close(accSock);
+            return enif_make_badarg(env);
+        }
+
+        accDescP->domain   = descP->domain;
+        accDescP->type     = descP->type;
+        accDescP->protocol = descP->protocol;
+
+        accRef = enif_make_resource(env, accDescP);
+        enif_release_resource(accDescP); // We should really store a reference ...
+
+        accDescP->ctrlPid = caller;
+        if (MONP("naccept_accepting -> ctrl",
+                 env, accDescP,
+                 &accDescP->ctrlPid,
+                 &accDescP->ctrlMon) != 0) {
+            sock_close(accSock);
+            return esock_make_error(env, atom_exmon);
+        }
+
+        accDescP->remote  = remote;
+        SET_NONBLOCKING(accDescP->sock);
+
+        accDescP->state      = SOCKET_STATE_CONNECTED;
+        accDescP->isReadable = TRUE;
+        accDescP->isWritable = TRUE;
+
+        /* Check if there are waiting acceptors (popping the acceptor queue) */
+
+        if (acceptor_pop(env, descP,
+                         &descP->currentAcceptor.pid,
+                         &descP->currentAcceptor.mon,
+                         &descP->currentAcceptor.ref)) {
+
+            /* There was another one */
+
+            SSDBG( descP, ("SOCKET", "naccept_accepting -> new (active) acceptor: "
+                           "\r\n   pid: %T"
+                           "\r\n   ref: %T"
+                           "\r\n",
+                           descP->currentAcceptor.pid,
+                           descP->currentAcceptor.ref) );
+
+            SELECT(env,
+                   descP->sock,
+                   (ERL_NIF_SELECT_READ),
+                   descP, &descP->currentAcceptor.pid, descP->currentAcceptor.ref);
+        } else {
+            descP->currentAcceptorP = NULL;
+            descP->state            = SOCKET_STATE_LISTENING;
+        }
+        
+        return esock_make_ok2(env, accRef);
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_send
+ *
+ * Description:
+ * Send a message on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SendRef      - A unique id for this (send) request.
+ * Data         - The data to send in the form of a IOVec.
+ * Flags        - Send flags.
+ */
+
+static
+ERL_NIF_TERM nif_send(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      sockRef, sendRef;
+    ErlNifBinary      sndData;
+    unsigned int      eflags;
+    int               flags;
+    ERL_NIF_TERM      res;
+
+    SGDBG( ("SOCKET", "nif_send -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 4) ||
+        !GET_BIN(env, argv[2], &sndData) ||
+        !GET_UINT(env, argv[3], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we send in case we send abort
+    sendRef = argv[1];
+
+    if (!enif_get_resource(env, sockRef, sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nif_send -> args when sock = %d:"
+            "\r\n   Socket:       %T"
+            "\r\n   SendRef:      %T"
+            "\r\n   Size of data: %d"
+            "\r\n   eFlags:       %d"
+            "\r\n", descP->sock, sockRef, sendRef, sndData.size, eflags) );
+
+    if (!esendflags2sendflags(eflags, &flags))
+        return enif_make_badarg(env);
+
+    MLOCK(descP->writeMtx);
+
+    /* We need to handle the case when another process tries
+     * to write at the same time.
+     * If the current write could not write its entire package
+     * this time (resulting in an select). The write of the
+     * other process must be made to wait until current
+     * is done!
+     * Basically, we need a write queue!
+     *
+     * A 'writing' field (boolean), which is set if we did
+     * not manage to write the entire message and reset every
+     * time we do.
+     */
+
+    res = nsend(env, descP, sockRef, sendRef, &sndData, flags);
+
+    MUNLOCK(descP->writeMtx);
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+
+/* *** nsend ***
+ *
+ * Do the actual send.
+ * Do some initial writer checks, do the actual send and then
+ * analyze the result. If we are done, another writer may be
+ * scheduled (if there is one in the writer queue).
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsend(ErlNifEnv*        env,
+                   SocketDescriptor* descP,
+                   ERL_NIF_TERM      sockRef,
+                   ERL_NIF_TERM      sendRef,
+                   ErlNifBinary*     sndDataP,
+                   int               flags)
+{
+    int          save_errno;
+    ssize_t      written;
+    ERL_NIF_TERM writerCheck;
+
+    if (!descP->isWritable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current writer and if its us */
+    if (!send_check_writer(env, descP, sendRef, &writerCheck))
+        return writerCheck;
+    
+    /* We ignore the wrap for the moment.
+     * Maybe we should issue a wrap-message to controlling process...
+     */
+    cnt_inc(&descP->writeTries, 1);
+
+    written = sock_send(descP->sock, sndDataP->data, sndDataP->size, flags);
+    if (IS_SOCKET_ERROR(written))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // The value does not actually matter in this case
+    
+    return send_check_result(env, descP,
+                             written, sndDataP->size, save_errno,
+                             sockRef, sendRef);
+
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_sendto
+ *
+ * Description:
+ * Send a message on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SendRef      - A unique id for this (send) request.
+ * Data         - The data to send in the form of a IOVec.
+ * Dest         - Destination (socket) address.
+ * Flags        - Send flags.
+ */
+
+static
+ERL_NIF_TERM nif_sendto(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      sockRef, sendRef;
+    ErlNifBinary      sndData;
+    unsigned int      eflags;
+    int               flags;
+    ERL_NIF_TERM      eSockAddr;
+    SocketAddress     remoteAddr;
+    unsigned int      remoteAddrLen;
+    char*             xres;
+    ERL_NIF_TERM      res;
+
+    SGDBG( ("SOCKET", "nif_sendto -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 5) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP) ||
+        !GET_BIN(env, argv[2], &sndData) ||
+        !GET_UINT(env, argv[4], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef   = argv[0]; // We need this in case we send in case we send abort
+    sendRef   = argv[1];
+    eSockAddr = argv[3];
+
+    if (!enif_get_resource(env, sockRef, sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_sendto -> args when sock = %d:"
+            "\r\n   Socket:       %T"
+            "\r\n   sendRef:      %T"
+            "\r\n   size of data: %d"
+            "\r\n   eSockAddr:    %T"
+            "\r\n   eflags:       %d"
+            "\r\n",
+            descP->sock, sockRef, sendRef, sndData.size, eSockAddr, eflags) );
+
+    if (!esendflags2sendflags(eflags, &flags)) {
+        SSDBG( descP, ("SOCKET", "nif_sendto -> sendflags decode failed\r\n") );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if ((xres = esock_decode_sockaddr(env, eSockAddr,
+                                      &remoteAddr,
+                                      &remoteAddrLen)) != NULL) {
+        SSDBG( descP, ("SOCKET", "nif_sendto -> sockaddr decode: %s\r\n", xres) );
+        return esock_make_error_str(env, xres);
+    }
+
+    MLOCK(descP->writeMtx);
+
+    res = nsendto(env, descP, sockRef, sendRef, &sndData, flags,
+                  &remoteAddr, remoteAddrLen);
+
+    MUNLOCK(descP->writeMtx);
+
+    SGDBG( ("SOCKET", "nif_sendto -> done with result: "
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsendto(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     ERL_NIF_TERM      sockRef,
+                     ERL_NIF_TERM      sendRef,
+                     ErlNifBinary*     dataP,
+                     int               flags,
+                     SocketAddress*    toAddrP,
+                     unsigned int      toAddrLen)
+{
+    int          save_errno;
+    ssize_t      written;
+    ERL_NIF_TERM writerCheck;
+
+    if (!descP->isWritable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current writer and if its us */
+    if (!send_check_writer(env, descP, sendRef, &writerCheck))
+        return writerCheck;
+    
+    /* We ignore the wrap for the moment.
+     * Maybe we should issue a wrap-message to controlling process...
+     */
+    cnt_inc(&descP->writeTries, 1);
+
+    if (toAddrP != NULL) {
+        written = sock_sendto(descP->sock,
+                              dataP->data, dataP->size, flags,
+                              &toAddrP->sa, toAddrLen);
+    } else {
+        written = sock_sendto(descP->sock,
+                              dataP->data, dataP->size, flags,
+                              NULL, 0);
+    }
+    if (IS_SOCKET_ERROR(written))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // The value does not actually matter in this case
+
+    return send_check_result(env, descP, written, dataP->size, save_errno,
+                             sockRef, sendRef);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_sendmsg
+ *
+ * Description:
+ * Send a message on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SendRef      - A unique id for this (send) request.
+ * MsgHdr       - Message Header - data and (maybe) control and dest
+ * Flags        - Send flags.
+ */
+
+static
+ERL_NIF_TERM nif_sendmsg(ErlNifEnv*         env,
+                         int                argc,
+                         const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    ERL_NIF_TERM      res, sockRef, sendRef, eMsgHdr;
+    SocketDescriptor* descP;
+    unsigned int      eflags;
+    int               flags;
+
+    SGDBG( ("SOCKET", "nif_sendmsg -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 4) ||
+        !IS_MAP(env, argv[2]) ||
+        !GET_UINT(env, argv[3], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we send in case we send abort
+    sendRef = argv[1];
+    eMsgHdr = argv[2];
+
+    if (!enif_get_resource(env, sockRef, sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_sendmsg -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   sendRef: %T"
+            "\r\n   eflags:  %d"
+            "\r\n",
+            descP->sock, argv[0], sendRef, eflags) );
+
+    if (!esendflags2sendflags(eflags, &flags))
+        return esock_make_error(env, esock_atom_einval);
+
+    MLOCK(descP->writeMtx);
+
+    res = nsendmsg(env, descP, sockRef, sendRef, eMsgHdr, flags);
+
+    MUNLOCK(descP->writeMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "nif_sendmsg -> done with result: "
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsendmsg(ErlNifEnv*        env,
+                      SocketDescriptor* descP,
+                      ERL_NIF_TERM      sockRef,
+                      ERL_NIF_TERM      sendRef,
+                      ERL_NIF_TERM      eMsgHdr,
+                      int               flags)
+{
+    ERL_NIF_TERM  res, eAddr, eIOV, eCtrl;
+    SocketAddress addr;
+    struct msghdr msgHdr;
+    ErlNifBinary* iovBins;
+    struct iovec* iov;
+    unsigned int  iovLen;
+    char*         ctrlBuf;
+    size_t        ctrlBufLen, ctrlBufUsed;
+    int           save_errno;
+    ssize_t       written, dataSize;
+    ERL_NIF_TERM  writerCheck;
+    char*         xres;
+
+    if (!descP->isWritable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current writer and if its us */
+    if (!send_check_writer(env, descP, sendRef, &writerCheck))
+        return writerCheck;
+    
+    /* Depending on if we are *connected* or not, we require
+     * different things in the msghdr map.
+     */
+    if (IS_CONNECTED(descP)) {
+
+        /* We don't need the address */
+
+        SSDBG( descP, ("SOCKET", "nsendmsg -> connected: no address\r\n") );
+
+        msgHdr.msg_name    = NULL;
+        msgHdr.msg_namelen = 0;
+        
+    } else {
+
+        /* We need the address */
+
+        msgHdr.msg_name    = (void*) &addr;
+        msgHdr.msg_namelen = sizeof(addr);
+        sys_memzero((char *) msgHdr.msg_name, msgHdr.msg_namelen);
+        if (!GET_MAP_VAL(env, eMsgHdr, esock_atom_addr, &eAddr))
+            return esock_make_error(env, esock_atom_einval);
+
+        SSDBG( descP, ("SOCKET", "nsendmsg -> not connected: "
+                       "\r\n   address: %T"
+                       "\r\n", eAddr) );
+
+        if ((xres = esock_decode_sockaddr(env, eAddr,
+                                          msgHdr.msg_name,
+                                          &msgHdr.msg_namelen)) != NULL)
+            return esock_make_error_str(env, xres);
+    }
+
+
+    /* Extract the (other) attributes of the msghdr map: iov and maybe ctrl */
+
+    /* The *mandatory* iov, which must be a list */
+    if (!GET_MAP_VAL(env, eMsgHdr, esock_atom_iov, &eIOV))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_LIST_LEN(env, eIOV, &iovLen) && (iovLen > 0))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP, ("SOCKET", "nsendmsg -> iov length: %d\r\n", iovLen) );
+
+    iovBins = MALLOC(iovLen * sizeof(ErlNifBinary));
+    ESOCK_ASSERT( (iovBins != NULL) );
+
+    iov     = MALLOC(iovLen * sizeof(struct iovec));
+    ESOCK_ASSERT( (iov != NULL) );
+
+    /* The *opional* ctrl */
+    if (GET_MAP_VAL(env, eMsgHdr, esock_atom_ctrl, &eCtrl)) {
+        ctrlBufLen = descP->wCtrlSz;
+        ctrlBuf    = (char*) MALLOC(ctrlBufLen);
+        ESOCK_ASSERT( (ctrlBuf != NULL) );
+    } else {
+        eCtrl      = esock_atom_undefined;
+        ctrlBufLen = 0;
+        ctrlBuf    = NULL;
+    }
+    SSDBG( descP, ("SOCKET", "nsendmsg -> optional ctrl: "
+                   "\r\n   ctrlBuf:    0x%lX"
+                   "\r\n   ctrlBufLen: %d"
+                   "\r\n   eCtrl:      %T\r\n", ctrlBuf, ctrlBufLen, eCtrl) );
+    
+    /* Decode the iov and initiate that part of the msghdr */
+    if ((xres = esock_decode_iov(env, eIOV,
+                                 iovBins, iov, iovLen, &dataSize)) != NULL) {
+        FREE(iovBins);
+        FREE(iov);
+        if (ctrlBuf != NULL) FREE(ctrlBuf);
+        return esock_make_error_str(env, xres);
+    }
+    msgHdr.msg_iov    = iov;
+    msgHdr.msg_iovlen = iovLen;
+    
+
+    SSDBG( descP, ("SOCKET",
+                   "nsendmsg -> total (iov) data size: %d\r\n", dataSize) );
+
+
+    /* Decode the ctrl and initiate that part of the msghdr.
+     */
+    if (ctrlBuf != NULL) {
+        if ((xres = decode_cmsghdrs(env, descP,
+                                    eCtrl,
+                                    ctrlBuf, ctrlBufLen, &ctrlBufUsed)) != NULL) {
+            FREE(iovBins);
+            FREE(iov);
+            if (ctrlBuf != NULL) FREE(ctrlBuf);
+            return esock_make_error_str(env, xres);
+        }
+    } else {
+        ctrlBufUsed = 0;
+    }
+    msgHdr.msg_control    = ctrlBuf;
+    msgHdr.msg_controllen = ctrlBufUsed;
+    
+
+    /* The msg-flags field is not used when sending, but zero it just in case */
+    msgHdr.msg_flags      = 0;
+    
+
+    /* We ignore the wrap for the moment.
+     * Maybe we should issue a wrap-message to controlling process...
+     */
+    cnt_inc(&descP->writeTries, 1);
+
+    /* And now, finally, try to send the message */
+    written = sock_sendmsg(descP->sock, &msgHdr, flags);
+
+    if (IS_SOCKET_ERROR(written))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // OK or not complete: this value should not matter in this case
+
+    res = send_check_result(env, descP, written, dataSize, save_errno,
+                            sockRef, sendRef);
+
+    FREE(iovBins);
+    FREE(iov);
+    if (ctrlBuf != NULL) FREE(ctrlBuf);
+    
+    return res;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_writev / nif_sendv
+ *
+ * Description:
+ * Send a message (vector) on a socket
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * SendRef      - A unique id for this (send) request.
+ * Data         - A vector of binaries
+ * Flags        - Send flags.
+ */
+
+#ifdef FOBAR
+static
+ERL_NIF_TERM nwritev(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     ERL_NIF_TERM      sendRef,
+                     ERL_NIF_TERM      data)
+{
+    ERL_NIF_TERM tail;
+    ErlNifIOVec  vec;
+    ErlNifIOVec* iovec = &vec;
+    SysIOVec*    sysiovec;
+    int          save_errno;
+    int          iovcnt, n;
+
+    if (!enif_inspect_iovec(env, MAX_VSZ, data, &tail, &iovec))
+        return enif_make_badarg(env);
+
+    if (enif_ioq_size(descP->outQ) > 0) {
+        /* If the I/O queue contains data we enqueue the iovec
+         * and then peek the data to write out of the queue.
+         */
+        if (!enif_ioq_enqv(q, iovec, 0))
+            return -3;
+
+        sysiovec = enif_ioq_peek(descP->outQ, &iovcnt);
+
+    } else {
+        /* If the I/O queue is empty we skip the trip through it. */
+        iovcnt   = iovec->iovcnt;
+        sysiovec = iovec->iov;
+    }
+
+    /* Attempt to write the data */
+    n = writev(fd, sysiovec, iovcnt);
+    saved_errno = errno;
+
+    if (enif_ioq_size(descP->outQ) == 0) {
+        /* If the I/O queue was initially empty we enqueue any
+           remaining data into the queue for writing later. */
+        if (n >= 0 && !enif_ioq_enqv(descP->outQ, iovec, n))
+            return -3;
+    } else {
+        /* Dequeue any data that was written from the queue. */
+        if (n > 0 && !enif_ioq_deq(descP->outQ, n, NULL))
+            return -4;
+    }
+    /* return n, which is either number of bytes written or -1 if
+       some error happened */
+    errno = saved_errno;
+    return n;
+}
+#endif
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_recv
+ *
+ * Description:
+ * Receive a message on a socket.
+ * Normally used only on a connected socket!
+ * If we are trying to read > 0 bytes, then that is what we do.
+ * But if we have specified 0 bytes, then we want to read
+ * whatever is in the buffers (everything it got).
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * RecvRef      - A unique id for this (send) request.
+ * Length       - The number of bytes to receive.
+ * Flags        - Receive flags.
+ */
+
+static
+ERL_NIF_TERM nif_recv(ErlNifEnv*         env,
+                      int                argc,
+                      const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      sockRef, recvRef;
+    int               len;
+    unsigned int      eflags;
+    int               flags;
+    ERL_NIF_TERM      res;
+
+    if ((argc != 4) ||
+        !GET_INT(env, argv[2], &len) ||
+        !GET_UINT(env, argv[3], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we case we send abort
+    recvRef = argv[1];
+
+    if (!enif_get_resource(env, sockRef, sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    
+    if (!erecvflags2recvflags(eflags, &flags))
+        return enif_make_badarg(env);
+
+    MLOCK(descP->readMtx);
+
+    /* We need to handle the case when another process tries
+     * to receive at the same time.
+     * If the current recv could not read its entire package
+     * this time (resulting in an select). The read of the
+     * other process must be made to wait until current
+     * is done!
+     * Basically, we need a read queue!
+     *
+     * A 'reading' field (boolean), which is set if we did
+     * not manage to read the entire message and reset every
+     * time we do.
+     */
+
+    res = nrecv(env, descP, sockRef, recvRef, len, flags);
+
+    MUNLOCK(descP->readMtx);
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+/* The (read) buffer handling *must* be optimized!
+ * But for now we make it easy for ourselves by
+ * allocating a binary (of the specified or default
+ * size) and then throwing it away...
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nrecv(ErlNifEnv*        env,
+                   SocketDescriptor* descP,
+                   ERL_NIF_TERM      sockRef,
+                   ERL_NIF_TERM      recvRef,
+                   int               len,
+                   int               flags)
+{
+    ssize_t      read;
+    ErlNifBinary buf;
+    ERL_NIF_TERM readerCheck;
+    int          save_errno;
+    int          bufSz = (len ? len : descP->rBufSz);
+
+    SSDBG( descP, ("SOCKET", "nrecv -> entry with"
+                   "\r\n   len:   %d (%d:%d)"
+                   "\r\n   flags: %d"
+                   "\r\n", len, descP->rNumCnt, bufSz, flags) );
+
+    if (!descP->isReadable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current reader and if its us */
+    if (!recv_check_reader(env, descP, recvRef, &readerCheck))
+        return readerCheck;
+    
+    /* Allocate a buffer:
+     * Either as much as we want to read or (if zero (0)) use the "default"
+     * size (what has been configured).
+     */
+    if (!ALLOC_BIN(bufSz, &buf))
+        return esock_make_error(env, atom_exalloc);
+
+    /* We ignore the wrap for the moment.
+     * Maybe we should issue a wrap-message to controlling process...
+     */
+    cnt_inc(&descP->readTries, 1);
+
+    // If it fails (read = -1), we need errno...
+    SSDBG( descP, ("SOCKET", "nrecv -> try read (%d)\r\n", buf.size) );
+    read = sock_recv(descP->sock, buf.data, buf.size, flags);
+    if (IS_SOCKET_ERROR(read)) {
+        save_errno = sock_errno();
+    } else {
+        save_errno = -1; // The value does not actually matter in this case
+    }
+    
+    SSDBG( descP, ("SOCKET", "nrecv -> read: %d (%d)\r\n", read, save_errno) );
+
+    return recv_check_result(env, descP,
+                             read, len,
+                             save_errno,
+                             &buf,
+                             sockRef,
+                             recvRef);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_recvfrom
+ *
+ * Description:
+ * Receive a message on a socket.
+ * Normally used only on a (un-) connected socket!
+ * If a buffer size = 0 is specified, then the we will use the default
+ * buffer size for this socket (whatever has been configured).
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * RecvRef      - A unique id for this (send) request.
+ * BufSz        - Size of the buffer into which we put the received message.
+ * Flags        - Receive flags.
+ *
+ * <KOLLA>
+ *
+ * How do we handle if the peek flag is set? We need to basically keep
+ * track of if we expect any data from the read. Regardless of the 
+ * number of bytes we try to read.
+ *
+ * </KOLLA>
+ */
+
+static
+ERL_NIF_TERM nif_recvfrom(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      sockRef, recvRef;
+    unsigned int      bufSz;
+    unsigned int      eflags;
+    int               flags;
+    ERL_NIF_TERM      res;
+
+    SGDBG( ("SOCKET", "nif_recvfrom -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 4) ||
+        !GET_UINT(env, argv[2], &bufSz) ||
+        !GET_UINT(env, argv[3], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we send in case we send abort
+    recvRef = argv[1];
+
+    if (!enif_get_resource(env, sockRef, sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nif_recvfrom -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   recvRef: %T"
+            "\r\n   bufSz:   %d"
+            "\r\n   eflags:  %d"
+            "\r\n", descP->sock, argv[0], recvRef, bufSz, eflags) );
+
+    /* if (IS_OPEN(descP)) */
+    /*     return esock_make_error(env, atom_enotconn); */
+
+    if (!erecvflags2recvflags(eflags, &flags)) {
+        SSDBG( descP, ("SOCKET", "nif_recvfrom -> recvflags decode failed\r\n") );
+        return enif_make_badarg(env);
+    }
+
+    MLOCK(descP->readMtx);
+
+    /* <KOLLA>
+     * We need to handle the case when another process tries
+     * to receive at the same time.
+     * If the current recv could not read its entire package
+     * this time (resulting in an select). The read of the
+     * other process must be made to wait until current
+     * is done!
+     * Basically, we need a read queue!
+     *
+     * A 'reading' field (boolean), which is set if we did
+     * not manage to read the entire message and reset every
+     * time we do.
+     * </KOLLA>
+     */
+
+    res = nrecvfrom(env, descP, sockRef, recvRef, bufSz, flags);
+
+    MUNLOCK(descP->readMtx);
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+/* The (read) buffer handling *must* be optimized!
+ * But for now we make it easy for ourselves by
+ * allocating a binary (of the specified or default
+ * size) and then throwing it away...
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nrecvfrom(ErlNifEnv*        env,
+                       SocketDescriptor* descP,
+                       ERL_NIF_TERM      sockRef,
+                       ERL_NIF_TERM      recvRef,
+                       Uint16            len,
+                       int               flags)
+{
+    SocketAddress fromAddr;
+    unsigned int  addrLen;
+    ssize_t       read;
+    int           save_errno;
+    ErlNifBinary  buf;
+    ERL_NIF_TERM  readerCheck;
+    int           bufSz = (len ? len : descP->rBufSz);
+
+    SSDBG( descP, ("SOCKET", "nrecvfrom -> entry with"
+                   "\r\n   len:   %d (%d)"
+                   "\r\n   flags: %d"
+                   "\r\n", len, bufSz, flags) );
+
+    if (!descP->isReadable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current reader and if its us */
+    if (!recv_check_reader(env, descP, recvRef, &readerCheck))
+        return readerCheck;
+    
+    /* Allocate a buffer:
+     * Either as much as we want to read or (if zero (0)) use the "default"
+     * size (what has been configured).
+     */
+    if (!ALLOC_BIN(bufSz, &buf))
+        return esock_make_error(env, atom_exalloc);
+
+    /* We ignore the wrap for the moment.
+     * Maybe we should issue a wrap-message to controlling process...
+     */
+    cnt_inc(&descP->readTries, 1);
+
+    addrLen = sizeof(fromAddr);
+    sys_memzero((char*) &fromAddr, addrLen);
+
+    read = sock_recvfrom(descP->sock, buf.data, buf.size, flags,
+                         &fromAddr.sa, &addrLen);
+    if (IS_SOCKET_ERROR(read))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // The value does not actually matter in this case
+
+    return recvfrom_check_result(env, descP,
+                                 read,
+                                 save_errno,
+                                 &buf,
+                                 &fromAddr, addrLen,
+                                 sockRef,
+                                 recvRef);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_recvmsg
+ *
+ * Description:
+ * Receive a message on a socket.
+ * Normally used only on a (un-) connected socket!
+ * If a buffer size = 0 is specified, then we will use the default
+ * buffer size for this socket (whatever has been configured).
+ * If ctrl (buffer) size = 0 is specified, then the default ctrl
+ * (buffer) size is used (1024). 
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * RecvRef      - A unique id for this (send) request.
+ * BufSz        - Size of the buffer into which we put the received message.
+ * CtrlSz       - Size of the ctrl (buffer) into which we put the received 
+ *                ancillary data.
+ * Flags        - Receive flags.
+ *
+ * <KOLLA>
+ *
+ * How do we handle if the peek flag is set? We need to basically keep
+ * track of if we expect any data from the read. Regardless of the 
+ * number of bytes we try to read.
+ *
+ * </KOLLA>
+ */
+
+static
+ERL_NIF_TERM nif_recvmsg(ErlNifEnv*         env,
+                         int                argc,
+                         const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      sockRef, recvRef;
+    unsigned int      bufSz;
+    unsigned int      ctrlSz;
+    unsigned int      eflags;
+    int               flags;
+    ERL_NIF_TERM      res;
+
+    SGDBG( ("SOCKET", "nif_recvmsg -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 5) ||
+        !GET_UINT(env, argv[2], &bufSz) ||
+        !GET_UINT(env, argv[3], &ctrlSz) ||
+        !GET_UINT(env, argv[4], &eflags)) {
+        return enif_make_badarg(env);
+    }
+    sockRef = argv[0]; // We need this in case we send in case we send abort
+    recvRef = argv[1];
+
+    if (!enif_get_resource(env, sockRef, sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_recvmsg -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   recvRef: %T"
+            "\r\n   bufSz:   %d"
+            "\r\n   ctrlSz:  %d"
+            "\r\n   eflags:  %d"
+            "\r\n", descP->sock, argv[0], recvRef, bufSz, ctrlSz, eflags) );
+
+    /* if (IS_OPEN(descP)) */
+    /*     return esock_make_error(env, atom_enotconn); */
+
+    if (!erecvflags2recvflags(eflags, &flags))
+        return enif_make_badarg(env);
+
+    MLOCK(descP->readMtx);
+
+    /* <KOLLA>
+     *
+     * We need to handle the case when another process tries
+     * to receive at the same time.
+     * If the current recv could not read its entire package
+     * this time (resulting in an select). The read of the
+     * other process must be made to wait until current
+     * is done!
+     * Basically, we need a read queue!
+     *
+     * A 'reading' field (boolean), which is set if we did
+     * not manage to read the entire message and reset every
+     * time we do.
+     *
+     * </KOLLA>
+     */
+
+    res = nrecvmsg(env, descP, sockRef, recvRef, bufSz, ctrlSz, flags);
+
+    MUNLOCK(descP->readMtx);
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+/* The (read) buffer handling *must* be optimized!
+ * But for now we make it easy for ourselves by
+ * allocating a binary (of the specified or default
+ * size) and then throwing it away...
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nrecvmsg(ErlNifEnv*        env,
+                      SocketDescriptor* descP,
+                      ERL_NIF_TERM      sockRef,
+                      ERL_NIF_TERM      recvRef,
+                      Uint16            bufLen,
+                      Uint16            ctrlLen,
+                      int               flags)
+{
+    unsigned int  addrLen;
+    ssize_t       read;
+    int           save_errno;
+    int           bufSz  = (bufLen  ? bufLen  : descP->rBufSz);
+    int           ctrlSz = (ctrlLen ? ctrlLen : descP->rCtrlSz);
+    struct msghdr msgHdr;
+    struct iovec  iov[1];  // Shall we always use 1?
+    ErlNifBinary  data[1]; // Shall we always use 1?
+    ErlNifBinary  ctrl;
+    ERL_NIF_TERM  readerCheck;
+    SocketAddress addr;
+
+    SSDBG( descP, ("SOCKET", "nrecvmsg -> entry with"
+                   "\r\n   bufSz:  %d (%d)"
+                   "\r\n   ctrlSz: %d (%d)"
+                   "\r\n   flags:  %d"
+                   "\r\n", bufSz, bufLen, ctrlSz, ctrlLen, flags) );
+
+    if (!descP->isReadable)
+        return enif_make_badarg(env);
+
+    /* Check if there is already a current reader and if its us */
+    if (!recv_check_reader(env, descP, recvRef, &readerCheck))
+        return readerCheck;
+    
+    /*
+    for (i = 0; i < sizeof(buf); i++) {
+        if (!ALLOC_BIN(bifSz, &buf[i]))
+            return esock_make_error(env, atom_exalloc);
+        iov[i].iov_base = buf[i].data;
+        iov[i].iov_len  = buf[i].size;
+    }
+    */
+    
+    /* Allocate the (msg) data buffer:
+     */
+    if (!ALLOC_BIN(bufSz, &data[0]))
+        return esock_make_error(env, atom_exalloc);
+
+    /* Allocate the ctrl (buffer):
+     */
+    if (!ALLOC_BIN(ctrlSz, &ctrl))
+        return esock_make_error(env, atom_exalloc);
+
+    /* We ignore the wrap for the moment.
+     * Maybe we should issue a wrap-message to controlling process...
+     */
+    cnt_inc(&descP->readTries, 1);
+
+    addrLen = sizeof(addr);
+    sys_memzero((char*) &addr,   addrLen);
+    sys_memzero((char*) &msgHdr, sizeof(msgHdr));
+
+    iov[0].iov_base = data[0].data;
+    iov[0].iov_len  = data[0].size;
+        
+    msgHdr.msg_name       = &addr;
+    msgHdr.msg_namelen    = addrLen;
+    msgHdr.msg_iov        = iov;
+    msgHdr.msg_iovlen     = 1; // Should use a constant or calculate...
+    msgHdr.msg_control    = ctrl.data;
+    msgHdr.msg_controllen = ctrl.size;
+
+    read = sock_recvmsg(descP->sock, &msgHdr, flags);
+    if (IS_SOCKET_ERROR(read))
+        save_errno = sock_errno();
+    else
+        save_errno = -1; // The value does not actually matter in this case
+
+    return recvmsg_check_result(env, descP,
+                                read,
+                                save_errno,
+                                &msgHdr,
+                                data,  // Needed for iov encode
+                                &ctrl, // Needed for ctrl header encode
+                                sockRef,
+                                recvRef);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_close
+ *
+ * Description:
+ * Close a (socket) file descriptor.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+
+static
+ERL_NIF_TERM nif_close(ErlNifEnv*         env,
+                       int                argc,
+                       const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+
+    if ((argc != 1) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    return nclose(env, descP);
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nclose(ErlNifEnv*        env,
+                    SocketDescriptor* descP)
+{
+    ERL_NIF_TERM reply, reason;
+    BOOLEAN_T    doClose;
+    int          selectRes;
+    int          domain   = descP->domain;
+    int          type     = descP->type;
+    int          protocol = descP->protocol;
+
+    SSDBG( descP, ("SOCKET", 
+                   "nclose -> [%d] entry (0x%lX, 0x%lX, 0x%lX, 0x%lX)\r\n",
+                   descP->sock,
+                   descP->state,
+                   descP->currentWriterP,
+                   descP->currentReaderP,
+                   descP->currentAcceptorP) );
+
+    MLOCK(descP->closeMtx);
+
+    if (descP->state == SOCKET_STATE_CLOSED) {
+        reason  = atom_closed;
+        doClose = FALSE;
+    } else if (descP->state == SOCKET_STATE_CLOSING) {
+        reason  = atom_closing;
+        doClose = FALSE;
+    } else {
+
+        /* Store the PID of the caller,
+         * since we need to inform it when we
+         * (that is, the stop callback function)
+         * completes.
+         */
+
+        if (enif_self(env, &descP->closerPid) == NULL) {
+            MUNLOCK(descP->closeMtx);
+            return esock_make_error(env, atom_exself);
+        }
+
+        /* Monitor the caller, since we should complete this operation even if
+         * the caller dies (for whatever reason).
+         *
+         * <KOLLA>
+         *
+         * Can we actiually use this for anything?
+         *
+         * </KOLLA>
+         */
+
+        if (MONP("nclose -> closer",
+                 env, descP,
+                 &descP->closerPid,
+                 &descP->closerMon) != 0) {
+            MUNLOCK(descP->closeMtx);
+            return esock_make_error(env, atom_exmon);
+        }
+
+        descP->closeLocal = TRUE;
+        descP->state      = SOCKET_STATE_CLOSING;
+        descP->isReadable = FALSE;
+        descP->isWritable = FALSE;
+        doClose           = TRUE;
+    }
+
+    MUNLOCK(descP->closeMtx);
+
+    if (doClose) {
+        descP->closeRef = MKREF(env);
+        selectRes       = enif_select(env, descP->sock, (ERL_NIF_SELECT_STOP),
+                                      descP, NULL, descP->closeRef);
+        if (selectRes & ERL_NIF_SELECT_STOP_CALLED) {
+            /* Prep done - inform the caller it can finalize (close) directly */
+            SSDBG( descP,
+                   ("SOCKET", "nclose -> [%d] stop was called\r\n", descP->sock) );
+            dec_socket(domain, type, protocol);
+            reply = esock_atom_ok;
+        } else if (selectRes & ERL_NIF_SELECT_STOP_SCHEDULED) {
+            /* The stop callback function has been *scheduled* which means that we
+             * have to wait for it to complete. */
+            SSDBG( descP,
+                   ("SOCKET", "nclose -> [%d] stop was scheduled\r\n",
+                    descP->sock) );
+            dec_socket(domain, type, protocol); // SHALL WE DO THIS AT finalize?
+            reply = esock_make_ok2(env, descP->closeRef);
+        } else {
+
+            SSDBG( descP,
+                   ("SOCKET", "nclose -> [%d] stop failed: %d\r\n",
+                    descP->sock, selectRes) );
+
+            /* <KOLLA>
+             *
+             * WE SHOULD REALLY HAVE A WAY TO CLOBBER THE SOCKET,
+             * SO WE DON'T LET STUFF LEAK.
+             * NOW, BECAUSE WE FAILED TO SELECT, WE CANNOT FINISH
+             * THE CLOSE, WHAT TO DO? ABORT?
+             *
+             * </KOLLA>
+             */
+
+            // No point in having this?
+            DEMONP("nclose -> closer", env, descP, &descP->closerMon); 
+
+            reason = MKT2(env, atom_select, MKI(env, selectRes));
+            reply  = esock_make_error(env, reason);
+        }
+    } else {
+        reply = esock_make_error(env, reason);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nclose -> [%d] done when: "
+            "\r\n   state: 0x%lX"
+            "\r\n   reply: %T"
+            "\r\n", descP->sock, descP->state, reply) );
+
+    return reply;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_finalize_close
+ *
+ * Description:
+ * Perform the actual socket close!
+ * Note that this function is executed in a dirty scheduler.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+static
+ERL_NIF_TERM nif_finalize_close(ErlNifEnv*         env,
+                                int                argc,
+                                const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    return nfinalize_close(env, descP);
+#endif // if defined(__WIN32__)
+}
+
+
+/* *** nfinalize_close ***
+ * Perform the final step in the socket close.
+ */
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nfinalize_close(ErlNifEnv*        env,
+                             SocketDescriptor* descP)
+{
+    ERL_NIF_TERM reply;
+
+    if (IS_CLOSED(descP))
+        return esock_atom_ok;
+
+    if (!IS_CLOSING(descP))
+        return esock_make_error(env, atom_enotclosing);
+
+    /* This nif is executed in a dirty scheduler just so that
+     * it can "hang" (whith minumum effect on the VM) while the
+     * kernel writes our buffers. IF we have set the linger option
+     * for this ({true, integer() > 0}). For this to work we must
+     * be blocking...
+     */
+    SET_BLOCKING(descP->sock);
+
+    if (sock_close(descP->sock) != 0) {
+        int save_errno = sock_errno();
+
+        if (save_errno != ERRNO_BLOCK) {
+            /* Not all data in the buffers where sent,
+             * make sure the caller gets this.
+             */
+            reply = esock_make_error(env, atom_timeout);
+        } else {
+            reply = esock_make_error_errno(env, save_errno);
+        }
+    } else {
+        reply = esock_atom_ok;
+    }
+    sock_close_event(descP->event);
+
+    descP->sock  = INVALID_SOCKET;
+    descP->event = INVALID_EVENT;
+
+    descP->state = SOCKET_STATE_CLOSED;
+
+    return reply;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_shutdown
+ *
+ * Description:
+ * Disable sends and/or receives on a socket.
+ *
+ * Arguments:
+ * [0] Socket (ref) - Points to the socket descriptor.
+ * [1] How          - What will be shutdown.
+ */
+
+static
+ERL_NIF_TERM nif_shutdown(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    unsigned int      ehow;
+    int               how;
+
+    if ((argc != 2) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP) ||
+        !GET_UINT(env, argv[1], &ehow)) {
+        return enif_make_badarg(env);
+    }
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    if (!ehow2how(ehow, &how))
+        return enif_make_badarg(env);
+
+    return nshutdown(env, descP, how);
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nshutdown(ErlNifEnv*        env,
+                       SocketDescriptor* descP,
+                       int               how)
+{
+    ERL_NIF_TERM reply;
+
+    if (sock_shutdown(descP->sock, how) == 0) {
+        switch (how) {
+        case SHUT_RD:
+            descP->isReadable = FALSE;
+            break;
+        case SHUT_WR:
+            descP->isWritable = FALSE;
+            break;
+        case SHUT_RDWR:
+            descP->isReadable = FALSE;
+            descP->isWritable = FALSE;
+            break;
+        }
+        reply = esock_atom_ok;
+    } else {
+        reply = esock_make_error_errno(env, sock_errno());
+    }
+
+    return reply;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_setopt
+ *
+ * Description:
+ * Set socket option.
+ * Its possible to use a "raw" mode (not encoded). That is, we do not
+ * interpret level, opt and value. They are passed "as is" to the
+ * setsockopt function call (the value arguments is assumed to be a
+ * binary, already encoded).
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * Encoded      - Are the "arguments" encoded or not.
+ * Level        - Level of the socket option.
+ * Opt          - The socket option.
+ * Value        - Value of the socket option (type depend on the option).
+ */
+
+static
+ERL_NIF_TERM nif_setopt(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__) 
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP = NULL;
+    int               eLevel, level = -1;
+    int               eOpt;
+    ERL_NIF_TERM      eIsEncoded;
+    ERL_NIF_TERM      eVal;
+    BOOLEAN_T         isEncoded, isOTP;
+    ERL_NIF_TERM      result;
+
+    SGDBG( ("SOCKET", "nif_setopt -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 5) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP) ||
+        !GET_INT(env, argv[2], &eLevel) ||
+        !GET_INT(env, argv[3], &eOpt)) {
+        SGDBG( ("SOCKET", "nif_setopt -> failed initial arg check\r\n") );
+        return enif_make_badarg(env);
+    }
+    eIsEncoded = argv[1];
+    eVal       = argv[4];
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    isEncoded = esock_decode_bool(eIsEncoded);
+
+    /* SGDBG( ("SOCKET", "nif_setopt -> eIsDecoded (%T) decoded: %d\r\n", */
+    /*         eIsEncoded, isEncoded) ); */
+
+    if (!elevel2level(isEncoded, eLevel, &isOTP, &level)) {
+        SSDBG( descP, ("SOCKET", "nif_seopt -> failed decode level\r\n") );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nif_setopt -> args when sock = %d:"
+            "\r\n   Socket:  %T"
+            "\r\n   Encoded: %d (%T)"
+            "\r\n   Level:   %d (%d)"
+            "\r\n   Opt:     %d"
+            "\r\n   Value:   %T"
+            "\r\n",
+            descP->sock, argv[0],
+            isEncoded, eIsEncoded,
+            level, eLevel,
+            eOpt, eVal) );
+
+    result = nsetopt(env, descP, isEncoded, isOTP, level, eOpt, eVal);
+
+    SSDBG( descP,
+           ("SOCKET", "nif_setopt -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+#endif // if defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsetopt(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     BOOLEAN_T         isEncoded,
+                     BOOLEAN_T         isOTP,
+                     int               level,
+                     int               eOpt,
+                     ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    if (isOTP) {
+        /* These are not actual socket options,
+         * but options for our implementation.
+         */
+        result = nsetopt_otp(env, descP, eOpt, eVal);
+    } else if (!isEncoded) {
+        result = nsetopt_native(env, descP, level, eOpt, eVal);
+    } else {
+        result = nsetopt_level(env, descP, level, eOpt, eVal);
+    }
+
+    return result;
+}
+
+
+
+/* nsetopt_otp - Handle OTP (level) options
+ */
+static
+ERL_NIF_TERM nsetopt_otp(ErlNifEnv*        env,
+                         SocketDescriptor* descP,
+                         int               eOpt,
+                         ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_otp -> entry with"
+            "\r\n   eOpt: %d"
+            "\r\n   eVal: %T"
+            "\r\n", eOpt, eVal) );
+
+    switch (eOpt) {
+    case SOCKET_OPT_OTP_DEBUG:
+        result = nsetopt_otp_debug(env, descP, eVal);
+        break;
+
+    case SOCKET_OPT_OTP_IOW:
+        result = nsetopt_otp_iow(env, descP, eVal);
+        break;
+
+    case SOCKET_OPT_OTP_CTRL_PROC:
+        result = nsetopt_otp_ctrl_proc(env, descP, eVal);
+        break;
+
+    case SOCKET_OPT_OTP_RCVBUF:
+        result = nsetopt_otp_rcvbuf(env, descP, eVal);
+        break;
+
+    case SOCKET_OPT_OTP_RCVCTRLBUF:
+        result = nsetopt_otp_rcvctrlbuf(env, descP, eVal);
+        break;
+
+    case SOCKET_OPT_OTP_SNDCTRLBUF:
+        result = nsetopt_otp_sndctrlbuf(env, descP, eVal);
+        break;
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* nsetopt_otp_debug - Handle the OTP (level) debug options
+ */
+static
+ERL_NIF_TERM nsetopt_otp_debug(ErlNifEnv*        env,
+                               SocketDescriptor* descP,
+                               ERL_NIF_TERM      eVal)
+{
+    descP->dbg = esock_decode_bool(eVal);
+
+    return esock_atom_ok;
+}
+
+
+/* nsetopt_otp_iow - Handle the OTP (level) iow options
+ */
+static
+ERL_NIF_TERM nsetopt_otp_iow(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             ERL_NIF_TERM      eVal)
+{
+    descP->iow = esock_decode_bool(eVal);
+
+    return esock_atom_ok;
+}
+
+
+
+/* nsetopt_otp_ctrl_proc - Handle the OTP (level) controlling_process options
+ */
+static
+ERL_NIF_TERM nsetopt_otp_ctrl_proc(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   ERL_NIF_TERM      eVal)
+{
+    ErlNifPid     caller, newCtrlPid;
+    // ErlNifMonitor newCtrlMon;
+    ESockMonitor  newCtrlMon;
+    int           xres;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_otp_ctrl_proc -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    /* Before we begin, ensure that caller is (current) controlling-process */
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    if (!compare_pids(env, &descP->ctrlPid, &caller)) {
+        SSDBG( descP, ("SOCKET", "nsetopt_otp_ctrl_proc -> not owner (%T)\r\n",
+                       descP->ctrlPid) );
+        return esock_make_error(env, esock_atom_not_owner);
+    }
+    
+    if (!GET_LPID(env, eVal, &newCtrlPid)) {
+        esock_warning_msg("Failed get pid of new controlling process\r\n");
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if ((xres = MONP("nsetopt_otp_ctrl_proc -> (new) ctrl",
+                     env, descP, &newCtrlPid, &newCtrlMon)) != 0) {
+        esock_warning_msg("Failed monitor %d) (new) controlling process\r\n", xres);
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+    if ((xres = DEMONP("nsetopt_otp_ctrl_proc -> (old) ctrl",
+                       env, descP, &descP->ctrlMon)) != 0) {
+        esock_warning_msg("Failed demonitor (%d) "
+                          "old controlling process %T (%T)\r\n",
+                          xres, descP->ctrlPid, descP->ctrlMon);
+    }
+
+    descP->ctrlPid = newCtrlPid;
+    descP->ctrlMon = newCtrlMon;
+    
+    SSDBG( descP, ("SOCKET", "nsetopt_otp_ctrl_proc -> done\r\n") );
+
+    return esock_atom_ok;
+}
+
+
+
+/* nsetopt_otp_rcvbuf - Handle the OTP (level) rcvbuf option
+ * The (otp) rcvbuf option is provided as:
+ *
+ *       BufSz :: integer() | {N :: pos_integer(), BufSz :: pod_integer()}
+ *
+ * Where N is the max number of reads.
+ */
+static
+ERL_NIF_TERM nsetopt_otp_rcvbuf(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                ERL_NIF_TERM      eVal)
+{
+    const ERL_NIF_TERM* t;   // The array of the elements of the tuple
+    int                 tsz; // The size of the tuple - should be 2
+    unsigned int        n;
+    size_t              bufSz;
+    char*               xres;
+
+    if (IS_NUM(env, eVal)) {
+
+        /* This will have the effect that the buffer size will be
+         * reported as an integer (getopt).
+         */
+        n = 0;
+
+        if ((xres = esock_decode_bufsz(env,
+                                       eVal,
+                                       SOCKET_RECV_BUFFER_SIZE_DEFAULT,
+                                       &bufSz)) != NULL)
+            return esock_make_error_str(env, xres);
+
+    } else if (IS_TUPLE(env, eVal)) {
+
+        if (!GET_TUPLE(env, eVal, &tsz, &t))
+            return enif_make_badarg(env); // We should use a "proper" error value...
+
+        if (tsz != 2)
+            return enif_make_badarg(env); // We should use a "proper" error value...
+    
+        if (!GET_UINT(env, t[0], &n))
+            return enif_make_badarg(env); // We should use a "proper" error value...
+
+        if ((xres = esock_decode_bufsz(env,
+                                       t[1],
+                                       SOCKET_RECV_BUFFER_SIZE_DEFAULT,
+                                       &bufSz)) != NULL)
+            return esock_make_error_str(env, xres);
+
+    } else {
+        return enif_make_badarg(env); // We should use a "proper" error value...
+    }
+
+    descP->rNum   = n;
+    descP->rBufSz = bufSz;
+
+    return esock_atom_ok;
+}
+
+
+
+/* nsetopt_otp_rcvctrlbuf - Handle the OTP (level) rcvctrlbuf option
+ */
+static
+ERL_NIF_TERM nsetopt_otp_rcvctrlbuf(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+    size_t val;
+    char*  xres;
+
+    if ((xres = esock_decode_bufsz(env,
+                                   eVal,
+                                   SOCKET_RECV_CTRL_BUFFER_SIZE_DEFAULT,
+                                   &val)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    descP->rCtrlSz = val;
+    
+    return esock_atom_ok;
+}
+
+
+
+/* nsetopt_otp_sndctrlbuf - Handle the OTP (level) sndctrlbuf option
+ */
+static
+ERL_NIF_TERM nsetopt_otp_sndctrlbuf(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+    size_t val;
+    char*  xres;
+
+    if ((xres = esock_decode_bufsz(env,
+                                   eVal,
+                                   SOCKET_SEND_CTRL_BUFFER_SIZE_DEFAULT,
+                                   &val)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    descP->wCtrlSz = val;
+    
+    return esock_atom_ok;
+}
+
+
+
+/* The option has *not* been encoded. Instead it has been provided
+ * in "native mode" (option is provided as is and value as a binary).
+ */
+static
+ERL_NIF_TERM nsetopt_native(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            int               level,
+                            int               opt,
+                            ERL_NIF_TERM      eVal)
+{
+    ErlNifBinary val;
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_native -> entry with"
+            "\r\n   level: %d"
+            "\r\n   opt:   %d"
+            "\r\n   eVal:  %T"
+            "\r\n", level, opt, eVal) );
+
+    if (GET_BIN(env, eVal, &val)) {
+        int res = socket_setopt(descP->sock, level, opt,
+                                val.data, val.size);
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_native -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* nsetopt_level - A "proper" level (option) has been specified
+ */
+static
+ERL_NIF_TERM nsetopt_level(ErlNifEnv*        env,
+                           SocketDescriptor* descP,
+                           int               level,
+                           int               eOpt,
+                           ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_level -> entry with"
+            "\r\n   level: %d"
+            "\r\n", level) );
+
+    switch (level) {
+    case SOL_SOCKET:
+        result = nsetopt_lvl_socket(env, descP, eOpt, eVal);
+        break;
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        result = nsetopt_lvl_ip(env, descP, eOpt, eVal);
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif
+        result = nsetopt_lvl_ipv6(env, descP, eOpt, eVal);
+        break;
+#endif
+
+    case IPPROTO_TCP:
+        result = nsetopt_lvl_tcp(env, descP, eOpt, eVal);
+        break;
+
+    case IPPROTO_UDP:
+        result = nsetopt_lvl_udp(env, descP, eOpt, eVal);
+        break;
+
+#if defined(HAVE_SCTP)
+    case IPPROTO_SCTP:
+        result = nsetopt_lvl_sctp(env, descP, eOpt, eVal);
+        break;
+#endif
+
+    default:
+        SSDBG( descP,
+               ("SOCKET", "nsetopt_level -> unknown level (%d)\r\n", level) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_level -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* nsetopt_lvl_socket - Level *SOCKET* option
+ */
+static
+ERL_NIF_TERM nsetopt_lvl_socket(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                int               eOpt,
+                                ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_socket -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(SO_BINDTODEVICE)
+    case SOCKET_OPT_SOCK_BINDTODEVICE:
+        result = nsetopt_lvl_sock_bindtodevice(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_BROADCAST)
+    case SOCKET_OPT_SOCK_BROADCAST:
+        result = nsetopt_lvl_sock_broadcast(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_DEBUG)
+    case SOCKET_OPT_SOCK_DEBUG:
+        result = nsetopt_lvl_sock_debug(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_DONTROUTE)
+    case SOCKET_OPT_SOCK_DONTROUTE:
+        result = nsetopt_lvl_sock_dontroute(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_KEEPALIVE)
+    case SOCKET_OPT_SOCK_KEEPALIVE:
+        result = nsetopt_lvl_sock_keepalive(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_LINGER)
+    case SOCKET_OPT_SOCK_LINGER:
+        result = nsetopt_lvl_sock_linger(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_PEEK_OFF)
+    case SOCKET_OPT_SOCK_PEEK_OFF:
+        result = nsetopt_lvl_sock_peek_off(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_OOBINLINE)
+    case SOCKET_OPT_SOCK_OOBINLINE:
+        result = nsetopt_lvl_sock_oobinline(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_PRIORITY)
+    case SOCKET_OPT_SOCK_PRIORITY:
+        result = nsetopt_lvl_sock_priority(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_RCVBUF)
+    case SOCKET_OPT_SOCK_RCVBUF:
+        result = nsetopt_lvl_sock_rcvbuf(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_RCVLOWAT)
+    case SOCKET_OPT_SOCK_RCVLOWAT:
+        result = nsetopt_lvl_sock_rcvlowat(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_RCVTIMEO)
+    case SOCKET_OPT_SOCK_RCVTIMEO:
+        result = nsetopt_lvl_sock_rcvtimeo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_REUSEADDR)
+    case SOCKET_OPT_SOCK_REUSEADDR:
+        result = nsetopt_lvl_sock_reuseaddr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_REUSEPORT)
+    case SOCKET_OPT_SOCK_REUSEPORT:
+        result = nsetopt_lvl_sock_reuseport(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_SNDBUF)
+    case SOCKET_OPT_SOCK_SNDBUF:
+        result = nsetopt_lvl_sock_sndbuf(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_SNDLOWAT)
+    case SOCKET_OPT_SOCK_SNDLOWAT:
+        result = nsetopt_lvl_sock_sndlowat(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_SNDTIMEO)
+    case SOCKET_OPT_SOCK_SNDTIMEO:
+        result = nsetopt_lvl_sock_sndtimeo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SO_TIMESTAMP)
+    case SOCKET_OPT_SOCK_TIMESTAMP:
+        result = nsetopt_lvl_sock_timestamp(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        SSDBG( descP,
+               ("SOCKET", "nsetopt_lvl_socket -> unknown opt (%d)\r\n", eOpt) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_socket -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+#if defined(SO_BINDTODEVICE)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_bindtodevice(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal)
+{
+    return nsetopt_str_opt(env, descP,
+                           SOL_SOCKET, SO_BROADCAST,
+                           IFNAMSIZ, eVal);
+}
+#endif
+
+
+#if defined(SO_BROADCAST)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_broadcast(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, SOL_SOCKET, SO_BROADCAST, eVal);
+}
+#endif
+
+
+#if defined(SO_DEBUG)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_debug(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, SOL_SOCKET, SO_DEBUG, eVal);
+}
+#endif
+
+
+#if defined(SO_DONTROUTE)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_dontroute(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, SOL_SOCKET, SO_DONTROUTE, eVal);
+}
+#endif
+
+
+#if defined(SO_KEEPALIVE)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_keepalive(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, SOL_SOCKET, SO_KEEPALIVE, eVal);
+}
+#endif
+
+
+#if defined(SO_LINGER)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_linger(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM  result;
+    struct linger val;
+
+    if (decode_sock_linger(env, eVal, &val)) {
+        int optLen = sizeof(val);
+        int res    = socket_setopt(descP->sock, SOL_SOCKET, SO_LINGER,
+                                   (void*) &val, optLen);
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(SO_OOBINLINE)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_oobinline(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, SOL_SOCKET, SO_OOBINLINE, eVal);
+}
+#endif
+
+
+#if defined(SO_PEEK_OFF)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_peek_off(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, SOL_SOCKET, SO_PEEK_OFF, eVal);
+}
+#endif
+
+
+#if defined(SO_PRIORITY)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_priority(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, SOL_SOCKET, SO_PRIORITY, eVal);
+}
+#endif
+
+
+#if defined(SO_RCVBUF)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_rcvbuf(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, SOL_SOCKET, SO_RCVBUF, eVal);
+}
+#endif
+
+
+#if defined(SO_RCVLOWAT)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_rcvlowat(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, SOL_SOCKET, SO_RCVLOWAT, eVal);
+}
+#endif
+
+
+#if defined(SO_RCVTIMEO)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_rcvtimeo(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal)
+{
+    return nsetopt_timeval_opt(env, descP, SOL_SOCKET, SO_RCVTIMEO, eVal);
+}
+#endif
+
+
+#if defined(SO_REUSEADDR)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_reuseaddr(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, SOL_SOCKET, SO_REUSEADDR, eVal);
+}
+#endif
+
+
+#if defined(SO_REUSEPORT)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_reuseport(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, SOL_SOCKET, SO_REUSEPORT, eVal);
+}
+#endif
+
+
+#if defined(SO_SNDBUF)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_sndbuf(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, SOL_SOCKET, SO_SNDBUF, eVal);
+}
+#endif
+
+
+#if defined(SO_SNDLOWAT)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_sndlowat(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, SOL_SOCKET, SO_SNDLOWAT, eVal);
+}
+#endif
+
+
+#if defined(SO_SNDTIMEO)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_sndtimeo(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal)
+{
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sock_sndtimeo -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    return nsetopt_timeval_opt(env, descP, SOL_SOCKET, SO_SNDTIMEO, eVal);
+}
+#endif
+
+
+#if defined(SO_TIMESTAMP)
+static
+ERL_NIF_TERM nsetopt_lvl_sock_timestamp(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, SOL_SOCKET, SO_TIMESTAMP, eVal);
+}
+#endif
+
+
+
+/* nsetopt_lvl_ip - Level *IP* option(s)
+ */
+static
+ERL_NIF_TERM nsetopt_lvl_ip(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            int               eOpt,
+                            ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ip -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(IP_ADD_MEMBERSHIP)
+    case SOCKET_OPT_IP_ADD_MEMBERSHIP:
+        result = nsetopt_lvl_ip_add_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_ADD_SOURCE_MEMBERSHIP)
+    case SOCKET_OPT_IP_ADD_SOURCE_MEMBERSHIP:
+        result = nsetopt_lvl_ip_add_source_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_BLOCK_SOURCE)
+    case SOCKET_OPT_IP_BLOCK_SOURCE:
+        result = nsetopt_lvl_ip_block_source(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_DROP_MEMBERSHIP)
+    case SOCKET_OPT_IP_DROP_MEMBERSHIP:
+        result = nsetopt_lvl_ip_drop_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_DROP_SOURCE_MEMBERSHIP)
+    case SOCKET_OPT_IP_DROP_SOURCE_MEMBERSHIP:
+        result = nsetopt_lvl_ip_drop_source_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_FREEBIND)
+    case SOCKET_OPT_IP_FREEBIND:
+        result = nsetopt_lvl_ip_freebind(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_HDRINCL)
+    case SOCKET_OPT_IP_HDRINCL:
+        result = nsetopt_lvl_ip_hdrincl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MINTTL)
+    case SOCKET_OPT_IP_MINTTL:
+        result = nsetopt_lvl_ip_minttl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MSFILTER) && defined(IP_MSFILTER_SIZE)
+    case SOCKET_OPT_IP_MSFILTER:
+        result = nsetopt_lvl_ip_msfilter(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MTU_DISCOVER)
+    case SOCKET_OPT_IP_MTU_DISCOVER:
+        result = nsetopt_lvl_ip_mtu_discover(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_ALL)
+    case SOCKET_OPT_IP_MULTICAST_ALL:
+        result = nsetopt_lvl_ip_multicast_all(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_IF)
+    case SOCKET_OPT_IP_MULTICAST_IF:
+        result = nsetopt_lvl_ip_multicast_if(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_LOOP)
+    case SOCKET_OPT_IP_MULTICAST_LOOP:
+        result = nsetopt_lvl_ip_multicast_loop(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_TTL)
+    case SOCKET_OPT_IP_MULTICAST_TTL:
+        result = nsetopt_lvl_ip_multicast_ttl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_NODEFRAG)
+    case SOCKET_OPT_IP_NODEFRAG:
+        result = nsetopt_lvl_ip_nodefrag(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_PKTINFO)
+    case SOCKET_OPT_IP_PKTINFO:
+        result = nsetopt_lvl_ip_pktinfo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVDSTADDR)
+    case SOCKET_OPT_IP_RECVDSTADDR:
+        result = nsetopt_lvl_ip_recvdstaddr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVERR)
+    case SOCKET_OPT_IP_RECVERR:
+        result = nsetopt_lvl_ip_recverr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVIF)
+    case SOCKET_OPT_IP_RECVIF:
+        result = nsetopt_lvl_ip_recvif(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVOPTS)
+    case SOCKET_OPT_IP_RECVOPTS:
+        result = nsetopt_lvl_ip_recvopts(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVORIGDSTADDR)
+    case SOCKET_OPT_IP_RECVORIGDSTADDR:
+        result = nsetopt_lvl_ip_recvorigdstaddr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVTOS)
+    case SOCKET_OPT_IP_RECVTOS:
+        result = nsetopt_lvl_ip_recvtos(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RECVTTL)
+    case SOCKET_OPT_IP_RECVTTL:
+        result = nsetopt_lvl_ip_recvttl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_RETOPTS)
+    case SOCKET_OPT_IP_RETOPTS:
+        result = nsetopt_lvl_ip_retopts(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_ROUTER_ALERT)
+    case SOCKET_OPT_IP_ROUTER_ALERT:
+        result = nsetopt_lvl_ip_router_alert(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_SENDSRCADDR)
+    case SOCKET_OPT_IP_SENDSRCADDR:
+        result = nsetopt_lvl_ip_sendsrcaddr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_TOS)
+    case SOCKET_OPT_IP_TOS:
+        result = nsetopt_lvl_ip_tos(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_TRANSPARENT)
+    case SOCKET_OPT_IP_TRANSPARENT:
+        result = nsetopt_lvl_ip_transparent(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_TTL)
+    case SOCKET_OPT_IP_TTL:
+        result = nsetopt_lvl_ip_ttl(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IP_UNBLOCK_SOURCE)
+    case SOCKET_OPT_IP_UNBLOCK_SOURCE:
+        result = nsetopt_lvl_ip_unblock_source(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        SSDBG( descP, ("SOCKET", "nsetopt_lvl_ip -> unknown opt (%d)\r\n", eOpt) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ip -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* nsetopt_lvl_ip_add_membership - Level IP ADD_MEMBERSHIP option
+ *
+ * The value is a map with two attributes: multiaddr and interface.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is either the atom 'any' or a 4-tuple
+ * (IPv4 address).
+ */
+#if defined(IP_ADD_MEMBERSHIP)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_add_membership(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal)
+{
+    return nsetopt_lvl_ip_update_membership(env, descP, eVal, IP_ADD_MEMBERSHIP);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_add_source_membership - Level IP ADD_SOURCE_MEMBERSHIP option
+ *
+ * The value is a map with three attributes: multiaddr, interface and
+ * sourceaddr.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is always a 4-tuple (IPv4 address).
+ * The attribute 'sourceaddr' is always a 4-tuple (IPv4 address).
+ * (IPv4 address).
+ */
+#if defined(IP_ADD_SOURCE_MEMBERSHIP)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_add_source_membership(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal)
+{
+    return nsetopt_lvl_ip_update_source(env, descP, eVal,
+                                        IP_ADD_SOURCE_MEMBERSHIP);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_block_source - Level IP BLOCK_SOURCE option
+ *
+ * The value is a map with three attributes: multiaddr, interface and
+ * sourceaddr.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is always a 4-tuple (IPv4 address).
+ * The attribute 'sourceaddr' is always a 4-tuple (IPv4 address).
+ * (IPv4 address).
+ */
+#if defined(IP_BLOCK_SOURCE)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_block_source(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         ERL_NIF_TERM      eVal)
+{
+    return nsetopt_lvl_ip_update_source(env, descP, eVal, IP_BLOCK_SOURCE);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_drop_membership - Level IP DROP_MEMBERSHIP option
+ *
+ * The value is a map with two attributes: multiaddr and interface.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is either the atom 'any' or a 4-tuple
+ * (IPv4 address).
+ *
+ * We should really have a common function with add_membership,
+ * since the code is virtually identical (except for the option
+ * value).
+ */
+#if defined(IP_DROP_MEMBERSHIP)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_drop_membership(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal)
+{
+    return nsetopt_lvl_ip_update_membership(env, descP, eVal,
+                                            IP_DROP_MEMBERSHIP);
+}
+#endif
+
+
+
+/* nsetopt_lvl_ip_drop_source_membership - Level IP DROP_SOURCE_MEMBERSHIP option
+ *
+ * The value is a map with three attributes: multiaddr, interface and
+ * sourceaddr.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is always a 4-tuple (IPv4 address).
+ * The attribute 'sourceaddr' is always a 4-tuple (IPv4 address).
+ * (IPv4 address).
+ */
+#if defined(IP_DROP_SOURCE_MEMBERSHIP)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_drop_source_membership(ErlNifEnv*        env,
+                                                  SocketDescriptor* descP,
+                                                  ERL_NIF_TERM      eVal)
+{
+    return nsetopt_lvl_ip_update_source(env, descP, eVal,
+                                        IP_DROP_SOURCE_MEMBERSHIP);
+}
+#endif
+
+
+
+/* nsetopt_lvl_ip_freebind - Level IP FREEBIND option
+ */
+#if defined(IP_FREEBIND)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_freebind(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_FREEBIND, eVal);
+}
+#endif
+
+
+
+/* nsetopt_lvl_ip_hdrincl - Level IP HDRINCL option
+ */
+#if defined(IP_HDRINCL)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_hdrincl(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_HDRINCL, eVal);
+}
+#endif
+
+
+
+/* nsetopt_lvl_ip_minttl - Level IP MINTTL option
+ */
+#if defined(IP_MINTTL)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_minttl(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_int_opt(env, descP, level, IP_MINTTL, eVal);
+}
+#endif
+
+
+
+/* nsetopt_lvl_ip_msfilter - Level IP MSFILTER option
+ *
+ * The value can be *either* the atom 'null' or a map of type ip_msfilter().
+ */
+#if defined(IP_MSFILTER) && defined(IP_MSFILTER_SIZE)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_msfilter(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    if (COMPARE(eVal, atom_null) == 0) {
+        return nsetopt_lvl_ip_msfilter_set(env, descP->sock, NULL, 0);
+    } else {
+        struct ip_msfilter* msfP;
+        Uint32              msfSz;
+        ERL_NIF_TERM        eMultiAddr, eInterface, eFMode, eSList, elem, tail;
+        size_t              sz;
+        unsigned int        slistLen, idx;
+
+        if (!IS_MAP(env, eVal))
+            return esock_make_error(env, esock_atom_einval);
+        
+        // It must have atleast four attributes
+        if (!enif_get_map_size(env, eVal, &sz) || (sz < 4))
+            return esock_make_error(env, esock_atom_einval);
+
+        if (!GET_MAP_VAL(env, eVal, atom_multiaddr, &eMultiAddr))
+            return esock_make_error(env, esock_atom_einval);
+        
+        if (!GET_MAP_VAL(env, eVal, atom_interface, &eInterface))
+            return esock_make_error(env, esock_atom_einval);
+        
+        if (!GET_MAP_VAL(env, eVal, atom_mode, &eFMode))
+            return esock_make_error(env, esock_atom_einval);
+        
+        if (!GET_MAP_VAL(env, eVal, atom_slist, &eSList))
+            return esock_make_error(env, esock_atom_einval);
+
+        /* We start (decoding) with the slist, since without it we don't
+         * really know how much (memory) to allocate.
+         */
+        if (!GET_LIST_LEN(env, eSList, &slistLen))
+            return esock_make_error(env, esock_atom_einval);
+
+        msfSz = IP_MSFILTER_SIZE(slistLen);
+        msfP  = MALLOC(msfSz);
+
+        if (!esock_decode_ip4_address(env, eMultiAddr, &msfP->imsf_multiaddr)) {
+            FREE(msfP);
+            return esock_make_error(env, esock_atom_einval);
+        }
+        
+        if (!esock_decode_ip4_address(env, eInterface, &msfP->imsf_interface)) {
+            FREE(msfP);
+            return esock_make_error(env, esock_atom_einval);
+        }
+        
+        if (!decode_ip_msfilter_mode(env, eFMode, &msfP->imsf_fmode)) {
+            FREE(msfP);
+            return esock_make_error(env, esock_atom_einval);
+        }
+
+        /* And finally, extract the source addresses */
+        msfP->imsf_numsrc = slistLen;
+        for (idx = 0; idx < slistLen; idx++) {
+            if (GET_LIST_ELEM(env, eSList, &elem, &tail)) {
+                if (!esock_decode_ip4_address(env, elem, &msfP->imsf_slist[idx])) {
+                    FREE(msfP);
+                    return esock_make_error(env, esock_atom_einval);
+                } else {
+                    eSList = tail;
+                }
+            }
+        }
+
+        /* And now, finally, set the option */
+        result = nsetopt_lvl_ip_msfilter_set(env, descP->sock, msfP, msfSz);
+        FREE(msfP);
+        return result;
+    }
+
+}
+
+
+static
+BOOLEAN_T decode_ip_msfilter_mode(ErlNifEnv*   env,
+                                  ERL_NIF_TERM eVal,
+                                  Uint32*      mode)
+{
+    BOOLEAN_T result;
+
+    if (COMPARE(eVal, atom_include) == 0) {
+        *mode  = MCAST_INCLUDE;
+        result = TRUE;        
+    } else if (COMPARE(eVal, atom_exclude) == 0) {
+        *mode  = MCAST_EXCLUDE;
+        result = TRUE;        
+    } else {
+        result = FALSE;
+    }
+
+    return result;
+}
+
+
+static
+ERL_NIF_TERM nsetopt_lvl_ip_msfilter_set(ErlNifEnv*          env,
+                                         SOCKET              sock,
+                                         struct ip_msfilter* msfP,
+                                         SOCKLEN_T           optLen)
+{
+    ERL_NIF_TERM result;
+    int          res;
+#if defined(SOL_IP)
+    int          level = SOL_IP;
+#else
+    int          level = IPPROTO_IP;
+#endif
+
+    res = socket_setopt(sock, level, IP_MSFILTER, (void*) msfP, optLen);
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+#endif // IP_MSFILTER
+
+
+
+/* nsetopt_lvl_ip_mtu_discover - Level IP MTU_DISCOVER option
+ *
+ * The value is an atom of the type ip_pmtudisc().
+ */
+#if defined(IP_MTU_DISCOVER)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_mtu_discover(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM   result;
+    int            val;
+    char*          xres;
+    int            res;
+#if defined(SOL_IP)
+    int            level = SOL_IP;
+#else
+    int            level = IPPROTO_IP;
+#endif
+
+    if ((xres = decode_ip_pmtudisc(env, eVal, &val)) != NULL) {
+
+        result = esock_make_error_str(env, xres);
+
+    } else {
+
+        res = socket_setopt(descP->sock, level, IP_MTU_DISCOVER,
+                            &val, sizeof(val));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    }
+
+    return result;
+}
+#endif
+
+
+/* nsetopt_lvl_ip_multicast_all - Level IP MULTICAST_ALL option
+ */
+#if defined(IP_MULTICAST_ALL)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_multicast_all(ErlNifEnv*        env,
+                                          SocketDescriptor* descP,
+                                          ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_MULTICAST_ALL, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_multicast_if - Level IP MULTICAST_IF option
+ *
+ * The value is either the atom 'any' or a 4-tuple.
+ */
+#if defined(IP_MULTICAST_IF)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_multicast_if(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM   result;
+    struct in_addr ifAddr;
+    char*          xres;
+    int            res;
+#if defined(SOL_IP)
+    int            level = SOL_IP;
+#else
+    int            level = IPPROTO_IP;
+#endif
+
+    if ((xres = esock_decode_ip4_address(env, eVal, &ifAddr)) != NULL) {
+        result = esock_make_error_str(env, xres);
+    } else {
+        
+        res = socket_setopt(descP->sock, level, IP_MULTICAST_LOOP,
+                            &ifAddr, sizeof(ifAddr));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    }
+
+    return result;
+}
+#endif
+
+
+/* nsetopt_lvl_ip_multicast_loop - Level IP MULTICAST_LOOP option
+ */
+#if defined(IP_MULTICAST_LOOP)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_multicast_loop(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_MULTICAST_LOOP, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_multicast_ttl - Level IP MULTICAST_TTL option
+ */
+#if defined(IP_MULTICAST_TTL)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_multicast_ttl(ErlNifEnv*        env,
+                                          SocketDescriptor* descP,
+                                          ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_int_opt(env, descP, level, IP_MULTICAST_TTL, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_nodefrag - Level IP NODEFRAG option
+ */
+#if defined(IP_NODEFRAG)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_nodefrag(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_NODEFRAG, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_pktinfo - Level IP PKTINFO option
+ */
+#if defined(IP_PKTINFO)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_pktinfo(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_PKTINFO, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_recvdstaddr - Level IP RECVDSTADDR option
+ */
+#if defined(IP_RECVDSTADDR)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_recvdstaddr(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_RECVDSTADDR, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_recverr - Level IP RECVERR option
+ */
+#if defined(IP_RECVERR)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_recverr(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_RECVERR, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_recvif - Level IP RECVIF option
+ */
+#if defined(IP_RECVIF)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_recvif(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_RECVIF, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_recvopts - Level IP RECVOPTS option
+ */
+#if defined(IP_RECVOPTS)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_recvopts(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_RECVOPTS, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_recvorigdstaddr - Level IP RECVORIGDSTADDR option
+ */
+#if defined(IP_RECVORIGDSTADDR)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_recvorigdstaddr(ErlNifEnv*        env,
+                                            SocketDescriptor* descP,
+                                            ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_RECVORIGDSTADDR, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_recvtos - Level IP RECVTOS option
+ */
+#if defined(IP_RECVTOS)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_recvtos(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_RECVTOS, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_recvttl - Level IP RECVTTL option
+ */
+#if defined(IP_RECVTTL)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_recvttl(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_RECVTTL, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_retopts - Level IP RETOPTS option
+ */
+#if defined(IP_RETOPTS)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_retopts(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_RETOPTS, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_router_alert - Level IP ROUTER_ALERT option
+ */
+#if defined(IP_ROUTER_ALERT)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_router_alert(ErlNifEnv*        env,
+                                         SocketDescriptor* descP,
+                                         ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_int_opt(env, descP, level, IP_ROUTER_ALERT, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_sendsrcaddr - Level IP SENDSRCADDR option
+ */
+#if defined(IP_SENDSRCADDR)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_sendsrcaddr(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_SENDSRCADDR, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ip_tos - Level IP TOS option
+ */
+#if defined(IP_TOS)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_tos(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int          level = SOL_IP;
+#else
+    int          level = IPPROTO_IP;
+#endif
+    ERL_NIF_TERM result;
+    int          val;
+
+    if (decode_ip_tos(env, eVal, &val)) {
+        int res = socket_setopt(descP->sock, level, IP_TOS, &val, sizeof(val));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    return result;
+}
+#endif
+
+
+/* nsetopt_lvl_ip_transparent - Level IP TRANSPARENT option
+ */
+#if defined(IP_TRANSPARENT)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_transparent(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IP_TRANSPARENT, eVal);
+}
+#endif
+
+
+
+/* nsetopt_lvl_ip_ttl - Level IP TTL option
+ */
+#if defined(IP_TTL)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_ttl(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return nsetopt_int_opt(env, descP, level, IP_TTL, eVal);
+}
+#endif
+
+
+
+/* nsetopt_lvl_ip_unblock_source - Level IP UNBLOCK_SOURCE option
+ *
+ * The value is a map with three attributes: multiaddr, interface and
+ * sourceaddr.
+ * The attribute 'multiaddr' is always a 4-tuple (IPv4 address).
+ * The attribute 'interface' is always a 4-tuple (IPv4 address).
+ * The attribute 'sourceaddr' is always a 4-tuple (IPv4 address).
+ * (IPv4 address).
+ */
+#if defined(IP_UNBLOCK_SOURCE)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_unblock_source(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal)
+{
+    return nsetopt_lvl_ip_update_source(env, descP, eVal, IP_UNBLOCK_SOURCE);
+}
+#endif
+
+
+
+#if defined(IP_ADD_MEMBERSHIP) || defined(IP_DROP_MEMBERSHIP)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_update_membership(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal,
+                                              int               opt)
+{
+    ERL_NIF_TERM   result, eMultiAddr, eInterface;
+    struct ip_mreq mreq;
+    char*          xres;
+    int            res;
+    size_t         sz;
+#if defined(SOL_IP)
+    int            level = SOL_IP;
+#else
+    int            level = IPPROTO_IP;
+#endif
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return enif_make_badarg(env);
+
+    // It must have atleast two attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz >= 2))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_multiaddr, &eMultiAddr))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_interface, &eInterface))
+        return enif_make_badarg(env);
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eMultiAddr,
+                                         &mreq.imr_multiaddr)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eInterface,
+                                         &mreq.imr_interface)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    res = socket_setopt(descP->sock, level, opt, &mreq, sizeof(mreq));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+#endif
+
+
+#if defined(IP_ADD_SOURCE_MEMBERSHIP) || defined(IP_DROP_SOURCE_MEMBERSHIP) || defined(IP_BLOCK_SOURCE) || defined(IP_UNBLOCK_SOURCE)
+static
+ERL_NIF_TERM nsetopt_lvl_ip_update_source(ErlNifEnv*        env,
+                                          SocketDescriptor* descP,
+                                          ERL_NIF_TERM      eVal,
+                                          int               opt)
+{
+    ERL_NIF_TERM          result, eMultiAddr, eInterface, eSourceAddr;
+    struct ip_mreq_source mreq;
+    char*                 xres;
+    int                   res;
+    size_t                sz;
+#if defined(SOL_IP)
+    int            level = SOL_IP;
+#else
+    int            level = IPPROTO_IP;
+#endif
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return enif_make_badarg(env);
+
+    // It must have atleast three attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz >= 3))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_multiaddr, &eMultiAddr))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_interface, &eInterface))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_sourceaddr, &eSourceAddr))
+        return enif_make_badarg(env);
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eMultiAddr,
+                                         &mreq.imr_multiaddr)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eInterface,
+                                         &mreq.imr_interface)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    if ((xres = esock_decode_ip4_address(env,
+                                         eSourceAddr,
+                                         &mreq.imr_sourceaddr)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    res = socket_setopt(descP->sock, level, opt, &mreq, sizeof(mreq));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+#endif
+
+
+
+/* *** Handling set of socket options for level = ipv6 *** */
+
+/* nsetopt_lvl_ipv6 - Level *IPv6* option(s)
+ */
+#if defined(HAVE_IPV6)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              int               eOpt,
+                              ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ipv6 -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(IPV6_ADDRFORM)
+    case SOCKET_OPT_IPV6_ADDRFORM:
+        result = nsetopt_lvl_ipv6_addrform(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_ADD_MEMBERSHIP)
+    case SOCKET_OPT_IPV6_ADD_MEMBERSHIP:
+        result = nsetopt_lvl_ipv6_add_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_AUTHHDR)
+    case SOCKET_OPT_IPV6_AUTHHDR:
+        result = nsetopt_lvl_ipv6_authhdr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_DROP_MEMBERSHIP)
+    case SOCKET_OPT_IPV6_DROP_MEMBERSHIP:
+        result = nsetopt_lvl_ipv6_drop_membership(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_DSTOPTS)
+    case SOCKET_OPT_IPV6_DSTOPTS:
+        result = nsetopt_lvl_ipv6_dstopts(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_FLOWINFO)
+    case SOCKET_OPT_IPV6_FLOWINFO:
+        result = nsetopt_lvl_ipv6_flowinfo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_HOPLIMIT)
+    case SOCKET_OPT_IPV6_HOPLIMIT:
+        result = nsetopt_lvl_ipv6_hoplimit(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_HOPOPTS)
+    case SOCKET_OPT_IPV6_HOPOPTS:
+        result = nsetopt_lvl_ipv6_hopopts(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MTU)
+    case SOCKET_OPT_IPV6_MTU:
+        result = nsetopt_lvl_ipv6_mtu(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MTU_DISCOVER)
+    case SOCKET_OPT_IPV6_MTU_DISCOVER:
+        result = nsetopt_lvl_ipv6_mtu_discover(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_HOPS)
+    case SOCKET_OPT_IPV6_MULTICAST_HOPS:
+        result = nsetopt_lvl_ipv6_multicast_hops(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_IF)
+    case SOCKET_OPT_IPV6_MULTICAST_IF:
+        result = nsetopt_lvl_ipv6_multicast_if(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_LOOP)
+    case SOCKET_OPT_IPV6_MULTICAST_LOOP:
+        result = nsetopt_lvl_ipv6_multicast_loop(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_RECVERR)
+    case SOCKET_OPT_IPV6_RECVERR:
+        result = nsetopt_lvl_ipv6_recverr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+    case SOCKET_OPT_IPV6_RECVPKTINFO:
+        result = nsetopt_lvl_ipv6_recvpktinfo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_ROUTER_ALERT)
+    case SOCKET_OPT_IPV6_ROUTER_ALERT:
+        result = nsetopt_lvl_ipv6_router_alert(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_RTHDR)
+    case SOCKET_OPT_IPV6_RTHDR:
+        result = nsetopt_lvl_ipv6_rthdr(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_UNICAST_HOPS)
+    case SOCKET_OPT_IPV6_UNICAST_HOPS:
+        result = nsetopt_lvl_ipv6_unicast_hops(env, descP, eVal);
+        break;
+#endif
+
+#if defined(IPV6_V6ONLY)
+    case SOCKET_OPT_IPV6_V6ONLY:
+        result = nsetopt_lvl_ipv6_v6only(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        SSDBG( descP,
+               ("SOCKET", "nsetopt_lvl_ipv6 -> unknown opt (%d)\r\n", eOpt) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ipv6 -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+#if defined(IPV6_ADDRFORM)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_addrform(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+    int          res, edomain, domain;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ipv6_addrform -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    if (!GET_INT(env, eVal, &edomain))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_ipv6_addrform -> decode"
+            "\r\n   edomain: %d"
+            "\r\n", edomain) );
+
+    if (!edomain2domain(edomain, &domain))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP, ("SOCKET", "nsetopt_lvl_ipv6_addrform -> try set opt to %d\r\n",
+                   domain) );
+    
+    res = socket_setopt(descP->sock,
+                        SOL_IPV6, IPV6_ADDRFORM,
+                        &domain, sizeof(domain));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+#endif
+
+
+#if defined(IPV6_ADD_MEMBERSHIP)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_add_membership(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal)
+{
+    return nsetopt_lvl_ipv6_update_membership(env, descP, eVal,
+                                              IPV6_ADD_MEMBERSHIP);
+}
+#endif
+
+
+#if defined(IPV6_AUTHHDR)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_authhdr(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, SOL_IPV6, IPV6_AUTHHDR, eVal);
+}
+#endif
+
+
+#if defined(IPV6_DROP_MEMBERSHIP)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_drop_membership(ErlNifEnv*        env,
+                                              SocketDescriptor* descP,
+                                              ERL_NIF_TERM      eVal)
+{
+    return nsetopt_lvl_ipv6_update_membership(env, descP, eVal,
+                                              IPV6_DROP_MEMBERSHIP);
+}
+#endif
+
+
+#if defined(IPV6_DSTOPTS)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_dstopts(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IPV6_DSTOPTS, eVal);
+}
+#endif
+
+
+#if defined(IPV6_FLOWINFO)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_flowinfo(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IPV6_FLOWINFO, eVal);
+}
+#endif
+
+
+#if defined(IPV6_HOPLIMIT)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_hoplimit(ErlNifEnv*        env,
+                                       SocketDescriptor* descP,
+                                       ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IPV6_HOPLIMIT, eVal);
+}
+#endif
+
+
+#if defined(IPV6_HOPOPTS)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_hopopts(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IPV6_HOPOPTS, eVal);
+}
+#endif
+
+
+#if defined(IPV6_MTU)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_mtu(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_int_opt(env, descP, level, IPV6_MTU, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_ipv6_mtu_discover - Level IPv6 MTU_DISCOVER option
+ *
+ * The value is an atom of the type ipv6_pmtudisc().
+ */
+#if defined(IPV6_MTU_DISCOVER)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_mtu_discover(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM  result;
+    int           val;
+    char*         xres;
+    int           res;
+
+    if ((xres = decode_ipv6_pmtudisc(env, eVal, &val)) != NULL) {
+
+        result = esock_make_error_str(env, xres);
+
+    } else {
+#if defined(SOL_IPV6)
+        int level = SOL_IPV6;
+#else
+        int level = IPPROTO_IPV6;
+#endif
+
+
+        res = socket_setopt(descP->sock, level, IPV6_MTU_DISCOVER,
+                            &val, sizeof(val));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(IPV6_MULTICAST_HOPS)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_multicast_hops(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_int_opt(env, descP, level, IPV6_MULTICAST_HOPS, eVal);
+}
+#endif
+
+
+
+#if defined(IPV6_MULTICAST_IF)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_multicast_if(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_int_opt(env, descP, level, IPV6_MULTICAST_IF, eVal);
+}
+#endif
+
+
+
+#if defined(IPV6_MULTICAST_LOOP)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_multicast_loop(ErlNifEnv*        env,
+                                             SocketDescriptor* descP,
+                                             ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IPV6_MULTICAST_LOOP, eVal);
+}
+#endif
+
+
+#if defined(IPV6_RECVERR)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_recverr(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IPV6_RECVERR, eVal);
+}
+#endif
+
+
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_recvpktinfo(ErlNifEnv*        env,
+                                          SocketDescriptor* descP,
+                                          ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+#if defined(IPV6_RECVPKTINFO)
+    int opt = IPV6_RECVPKTINFO;
+#else
+    int opt = IPV6_PKTINFO;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, opt, eVal);
+}
+#endif
+
+
+#if defined(IPV6_ROUTER_ALERT)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_router_alert(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_int_opt(env, descP, level, IPV6_ROUTER_ALERT, eVal);
+}
+#endif
+
+
+
+#if defined(IPV6_RTHDR)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IPV6_RTHDR, eVal);
+}
+#endif
+
+
+#if defined(IPV6_UNICAST_HOPS)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_unicast_hops(ErlNifEnv*        env,
+                                           SocketDescriptor* descP,
+                                           ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_int_opt(env, descP, level, IPV6_UNICAST_HOPS, eVal);
+}
+#endif
+
+
+
+#if defined(IPV6_V6ONLY)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return nsetopt_bool_opt(env, descP, level, IPV6_V6ONLY, eVal);
+}
+#endif
+
+
+#if defined(IPV6_ADD_MEMBERSHIP) || defined(IPV6_DROP_MEMBERSHIP)
+static
+ERL_NIF_TERM nsetopt_lvl_ipv6_update_membership(ErlNifEnv*        env,
+                                                SocketDescriptor* descP,
+                                                ERL_NIF_TERM      eVal,
+                                                int               opt)
+{
+    ERL_NIF_TERM     result, eMultiAddr, eInterface;
+    struct ipv6_mreq mreq;
+    char*            xres;
+    int              res;
+    size_t           sz;
+#if defined(SOL_IPV6)
+    int              level = SOL_IPV6;
+#else
+    int              level = IPPROTO_IPV6;
+#endif
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return enif_make_badarg(env);
+
+    // It must have atleast two attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz >= 2))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_multiaddr, &eMultiAddr))
+        return enif_make_badarg(env);
+
+    if (!GET_MAP_VAL(env, eVal, atom_interface, &eInterface))
+        return enif_make_badarg(env);
+
+    if ((xres = esock_decode_ip6_address(env,
+                                         eMultiAddr,
+                                         &mreq.ipv6mr_multiaddr)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    if (!GET_UINT(env, eInterface, &mreq.ipv6mr_interface))
+        return esock_make_error(env, esock_atom_einval);
+
+    res = socket_setopt(descP->sock, level, opt, &mreq, sizeof(mreq));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+#endif
+
+
+
+#endif // defined(HAVE_IPV6)
+
+
+
+/* nsetopt_lvl_tcp - Level *TCP* option(s)
+ */
+static
+ERL_NIF_TERM nsetopt_lvl_tcp(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             int               eOpt,
+                             ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_tcp -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(TCP_CONGESTION)
+    case SOCKET_OPT_TCP_CONGESTION:
+        result = nsetopt_lvl_tcp_congestion(env, descP, eVal);
+        break;
+#endif
+
+#if defined(TCP_MAXSEG)
+    case SOCKET_OPT_TCP_MAXSEG:
+        result = nsetopt_lvl_tcp_maxseg(env, descP, eVal);
+        break;
+#endif
+
+#if defined(TCP_NODELAY)
+    case SOCKET_OPT_TCP_NODELAY:
+        result = nsetopt_lvl_tcp_nodelay(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* nsetopt_lvl_tcp_congestion - Level TCP CONGESTION option
+ */
+#if defined(TCP_CONGESTION)
+static
+ERL_NIF_TERM nsetopt_lvl_tcp_congestion(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    int max = SOCKET_OPT_TCP_CONGESTION_NAME_MAX+1;
+
+    return nsetopt_str_opt(env, descP, IPPROTO_TCP, TCP_CONGESTION, max, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_tcp_maxseg - Level TCP MAXSEG option
+ */
+#if defined(TCP_MAXSEG)
+static
+ERL_NIF_TERM nsetopt_lvl_tcp_maxseg(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, IPPROTO_TCP, TCP_MAXSEG, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_tcp_nodelay - Level TCP NODELAY option
+ */
+#if defined(TCP_NODELAY)
+static
+ERL_NIF_TERM nsetopt_lvl_tcp_nodelay(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, IPPROTO_TCP, TCP_NODELAY, eVal);
+}
+#endif
+
+
+
+/* nsetopt_lvl_udp - Level *UDP* option(s)
+ */
+static
+ERL_NIF_TERM nsetopt_lvl_udp(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             int               eOpt,
+                             ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_udp -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(UDP_CORK)
+    case SOCKET_OPT_UDP_CORK:
+        result = nsetopt_lvl_udp_cork(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* nsetopt_lvl_udp_cork - Level UDP CORK option
+ */
+#if defined(UDP_CORK)
+static
+ERL_NIF_TERM nsetopt_lvl_udp_cork(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, IPPROTO_UDP, UDP_CORK, eVal);
+}
+#endif
+
+
+
+
+/* nsetopt_lvl_sctp - Level *SCTP* option(s)
+ */
+#if defined(HAVE_SCTP)
+static
+ERL_NIF_TERM nsetopt_lvl_sctp(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              int               eOpt,
+                              ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(SCTP_ASSOCINFO)
+    case SOCKET_OPT_SCTP_ASSOCINFO:
+        result = nsetopt_lvl_sctp_associnfo(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_AUTOCLOSE)
+    case SOCKET_OPT_SCTP_AUTOCLOSE:
+        result = nsetopt_lvl_sctp_autoclose(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_DISABLE_FRAGMENTS)
+    case SOCKET_OPT_SCTP_DISABLE_FRAGMENTS:
+        result = nsetopt_lvl_sctp_disable_fragments(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_EVENTS)
+    case SOCKET_OPT_SCTP_EVENTS:
+        result = nsetopt_lvl_sctp_events(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_INITMSG)
+    case SOCKET_OPT_SCTP_INITMSG:
+        result = nsetopt_lvl_sctp_initmsg(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_MAXSEG)
+    case SOCKET_OPT_SCTP_MAXSEG:
+        result = nsetopt_lvl_sctp_maxseg(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_NODELAY)
+    case SOCKET_OPT_SCTP_NODELAY:
+        result = nsetopt_lvl_sctp_nodelay(env, descP, eVal);
+        break;
+#endif
+
+#if defined(SCTP_RTOINFO)
+    case SOCKET_OPT_SCTP_RTOINFO:
+        result = nsetopt_lvl_sctp_rtoinfo(env, descP, eVal);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* nsetopt_lvl_sctp_associnfo - Level SCTP ASSOCINFO option
+ */
+#if defined(SCTP_ASSOCINFO)
+static
+ERL_NIF_TERM nsetopt_lvl_sctp_associnfo(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM            result;
+    ERL_NIF_TERM            eAssocId, eMaxRxt, eNumPeerDests;
+    ERL_NIF_TERM            ePeerRWND, eLocalRWND, eCookieLife;
+    struct sctp_assocparams assocParams;
+    int                     res;
+    size_t                  sz;
+    unsigned int            tmp;
+    Sint32                  tmpAssocId;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_associnfo -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return esock_make_error(env, esock_atom_einval);
+
+    // It must have atleast ten attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 6))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_associnfo -> extract attributes\r\n") );    
+
+    if (!GET_MAP_VAL(env, eVal, atom_assoc_id,          &eAssocId))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max_rxt,        &eMaxRxt))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_num_peer_dests, &eNumPeerDests))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_peer_rwnd,      &ePeerRWND))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_local_rwnd,     &eLocalRWND))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_cookie_life,    &eCookieLife))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_associnfo -> decode attributes\r\n") );
+
+    /* On some platforms the assoc id is typed as an unsigned integer (uint32)
+     * So, to avoid warnings there, we always make an explicit cast... 
+     */
+    if (!GET_INT(env, eAssocId, &tmpAssocId))
+        return esock_make_error(env, esock_atom_einval);
+    assocParams.sasoc_assoc_id = (typeof(assocParams.sasoc_assoc_id)) tmpAssocId;
+    
+    /*
+     * We should really make sure this is ok in erlang (to ensure that 
+     * the values (max-rxt and num-peer-dests) fits in 16-bits).
+     * The value should be a 16-bit unsigned int...
+     * Both sasoc_asocmaxrxt and sasoc_number_peer_destinations.
+     */
+    
+    if (!GET_UINT(env, eMaxRxt, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    assocParams.sasoc_asocmaxrxt = (Uint16) tmp;
+
+    if (!GET_UINT(env, eNumPeerDests, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    assocParams.sasoc_number_peer_destinations = (Uint16) tmp;
+
+    if (!GET_UINT(env, ePeerRWND, &assocParams.sasoc_peer_rwnd))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_UINT(env, eLocalRWND, &assocParams.sasoc_local_rwnd))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_UINT(env, eCookieLife, &assocParams.sasoc_cookie_life))
+        return esock_make_error(env, esock_atom_einval);
+    
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_associnfo -> set associnfo option\r\n") );
+
+    res = socket_setopt(descP->sock, IPPROTO_SCTP, SCTP_ASSOCINFO,
+                        &assocParams, sizeof(assocParams));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_associnfo -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+#endif
+
+
+/* nsetopt_lvl_sctp_autoclose - Level SCTP AUTOCLOSE option
+ */
+#if defined(SCTP_AUTOCLOSE)
+static
+ERL_NIF_TERM nsetopt_lvl_sctp_autoclose(ErlNifEnv*        env,
+                                        SocketDescriptor* descP,
+                                        ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, IPPROTO_SCTP, SCTP_AUTOCLOSE, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_sctp_disable_fragments - Level SCTP DISABLE_FRAGMENTS option
+ */
+#if defined(SCTP_DISABLE_FRAGMENTS)
+static
+ERL_NIF_TERM nsetopt_lvl_sctp_disable_fragments(ErlNifEnv*        env,
+                                                SocketDescriptor* descP,
+                                                ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, IPPROTO_SCTP, SCTP_DISABLE_FRAGMENTS, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_sctp_events - Level SCTP EVENTS option
+ */
+#if defined(SCTP_EVENTS)
+static
+ERL_NIF_TERM nsetopt_lvl_sctp_events(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM                result;
+    ERL_NIF_TERM                eDataIn, eAssoc, eAddr, eSndFailure;
+    ERL_NIF_TERM                ePeerError, eShutdown, ePartialDelivery;
+    ERL_NIF_TERM                eAdaptLayer, eAuth;
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_SENDER_DRY_EVENT)
+    ERL_NIF_TERM                eSndDry;
+#endif
+    struct sctp_event_subscribe events;
+    int                         res;
+    size_t                      sz;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_events -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return esock_make_error(env, esock_atom_einval);
+
+    // It must have atleast ten attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 10))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_events -> extract attributes\r\n") );    
+
+    if (!GET_MAP_VAL(env, eVal, atom_data_in,          &eDataIn))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_association,      &eAssoc))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_address,          &eAddr))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_send_failure,     &eSndFailure))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_peer_error,       &ePeerError))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_shutdown,         &eShutdown))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_partial_delivery, &ePartialDelivery))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_adaptation_layer, &eAdaptLayer))
+        return esock_make_error(env, esock_atom_einval);
+
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_AUTHENTICATION_EVENT)
+    if (!GET_MAP_VAL(env, eVal, atom_authentication,   &eAuth))
+        return esock_make_error(env, esock_atom_einval);
+#endif
+
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_SENDER_DRY_EVENT)
+    if (!GET_MAP_VAL(env, eVal, atom_sender_dry,       &eSndDry))
+        return esock_make_error(env, esock_atom_einval);
+#endif
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_events -> decode attributes\r\n") );
+
+    events.sctp_data_io_event          = esock_decode_bool(eDataIn);
+    events.sctp_association_event      = esock_decode_bool(eAssoc);
+    events.sctp_address_event          = esock_decode_bool(eAddr);
+    events.sctp_send_failure_event     = esock_decode_bool(eSndFailure);
+    events.sctp_peer_error_event       = esock_decode_bool(ePeerError);
+    events.sctp_shutdown_event         = esock_decode_bool(eShutdown);
+    events.sctp_partial_delivery_event = esock_decode_bool(ePartialDelivery);
+    events.sctp_adaptation_layer_event = esock_decode_bool(eAdaptLayer);
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_AUTHENTICATION_EVENT)
+    events.sctp_authentication_event   = esock_decode_bool(eAuth);
+#endif
+#if defined(HAVE_STRUCT_SCTP_EVENT_SUBSCRIBE_SCTP_SENDER_DRY_EVENT)
+    events.sctp_sender_dry_event       = esock_decode_bool(eSndDry);
+#endif
+    
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_events -> set events option\r\n") );
+
+    res = socket_setopt(descP->sock, IPPROTO_SCTP, SCTP_EVENTS,
+                        &events, sizeof(events));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_events -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+#endif
+
+
+/* nsetopt_lvl_sctp_initmsg - Level SCTP INITMSG option
+ */
+#if defined(SCTP_INITMSG)
+static
+ERL_NIF_TERM nsetopt_lvl_sctp_initmsg(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM        result;
+    ERL_NIF_TERM        eNumOut, eMaxIn, eMaxAttempts, eMaxInitTO;
+    struct sctp_initmsg initMsg;
+    int                 res;
+    size_t              sz;
+    unsigned int        tmp;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_initmsg -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return esock_make_error(env, esock_atom_einval);
+
+    // It must have atleast ten attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 4))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_initmsg -> extract attributes\r\n") );    
+
+    if (!GET_MAP_VAL(env, eVal, atom_num_outstreams, &eNumOut))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max_instreams,  &eMaxIn))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max_attempts,   &eMaxAttempts))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max_init_timeo, &eMaxInitTO))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_initmsg -> decode attributes\r\n") );
+
+    if (!GET_UINT(env, eNumOut, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    initMsg.sinit_num_ostreams = (Uint16) tmp;
+    
+    if (!GET_UINT(env, eMaxIn, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    initMsg.sinit_max_instreams = (Uint16) tmp;
+    
+    if (!GET_UINT(env, eMaxAttempts, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    initMsg.sinit_max_attempts = (Uint16) tmp;
+    
+    if (!GET_UINT(env, eMaxInitTO, &tmp))
+        return esock_make_error(env, esock_atom_einval);
+    initMsg.sinit_max_init_timeo = (Uint16) tmp;
+    
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_initmsg -> set initmsg option\r\n") );
+
+    res = socket_setopt(descP->sock, IPPROTO_SCTP, SCTP_INITMSG,
+                        &initMsg, sizeof(initMsg));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_initmsg -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+#endif
+
+
+/* nsetopt_lvl_sctp_maxseg - Level SCTP MAXSEG option
+ */
+#if defined(SCTP_MAXSEG)
+static
+ERL_NIF_TERM nsetopt_lvl_sctp_maxseg(ErlNifEnv*        env,
+                                     SocketDescriptor* descP,
+                                     ERL_NIF_TERM      eVal)
+{
+    return nsetopt_int_opt(env, descP, IPPROTO_SCTP, SCTP_MAXSEG, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_sctp_nodelay - Level SCTP NODELAY option
+ */
+#if defined(SCTP_NODELAY)
+static
+ERL_NIF_TERM nsetopt_lvl_sctp_nodelay(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      eVal)
+{
+    return nsetopt_bool_opt(env, descP, IPPROTO_SCTP, SCTP_NODELAY, eVal);
+}
+#endif
+
+
+/* nsetopt_lvl_sctp_rtoinfo - Level SCTP RTOINFO option
+ */
+#if defined(SCTP_RTOINFO)
+static
+ERL_NIF_TERM nsetopt_lvl_sctp_rtoinfo(ErlNifEnv*        env,
+                                      SocketDescriptor* descP,
+                                      ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM        result;
+    ERL_NIF_TERM        eAssocId, eInitial, eMax, eMin;
+    struct sctp_rtoinfo rtoInfo;
+    int                 res;
+    size_t              sz;
+    Sint32              tmpAssocId;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_rtoinfo -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    // It must be a map
+    if (!IS_MAP(env, eVal))
+        return esock_make_error(env, esock_atom_einval);
+
+    // It must have atleast ten attributes
+    if (!enif_get_map_size(env, eVal, &sz) || (sz < 4))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_rtoinfo -> extract attributes\r\n") );    
+
+    if (!GET_MAP_VAL(env, eVal, atom_assoc_id, &eAssocId))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_initial,  &eInitial))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_max,      &eMax))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_MAP_VAL(env, eVal, atom_min,      &eMin))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_rtoinfo -> decode attributes\r\n") );
+
+    /* On some platforms the assoc id is typed as an unsigned integer (uint32)
+     * So, to avoid warnings there, we always make an explicit cast... 
+     */
+    if (!GET_INT(env, eAssocId, &tmpAssocId))
+        return esock_make_error(env, esock_atom_einval);
+    rtoInfo.srto_assoc_id = (typeof(rtoInfo.srto_assoc_id)) tmpAssocId;
+    
+    if (!GET_UINT(env, eInitial, &rtoInfo.srto_initial))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_UINT(env, eMax, &rtoInfo.srto_max))
+        return esock_make_error(env, esock_atom_einval);
+
+    if (!GET_UINT(env, eMin, &rtoInfo.srto_min))
+        return esock_make_error(env, esock_atom_einval);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_rtoinfo -> set associnfo option\r\n") );
+
+    res = socket_setopt(descP->sock, IPPROTO_SCTP, SCTP_RTOINFO,
+                        &rtoInfo, sizeof(rtoInfo));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_lvl_sctp_rtoinfo -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+#endif
+
+
+
+#endif // defined(HAVE_SCTP)
+
+
+
+
+/* nsetopt_bool_opt - set an option that has an (integer) bool value
+ */
+static
+ERL_NIF_TERM nsetopt_bool_opt(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              int               level,
+                              int               opt,
+                              ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+    BOOLEAN_T    val;
+    int          ival, res;
+
+    val = esock_decode_bool(eVal);
+    
+    ival = (val) ? 1 : 0;
+    res  = socket_setopt(descP->sock, level, opt, &ival, sizeof(ival));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    return result;
+}
+
+
+/* nsetopt_int_opt - set an option that has an integer value
+ */
+static
+ERL_NIF_TERM nsetopt_int_opt(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             int               level,
+                             int               opt,
+                             ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+    int          val;
+
+    if (GET_INT(env, eVal, &val)) {
+        int res;
+
+        /*
+        SSDBG( descP,
+               ("SOCKET", "nsetopt_int_opt -> set option"
+                "\r\n   opt: %d"
+                "\r\n   val: %d"
+                "\r\n", opt, val) );
+        */
+
+        res = socket_setopt(descP->sock, level, opt, &val, sizeof(val));
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    return result;
+}
+
+
+/* nsetopt_str_opt - set an option that has an string value
+ */
+static
+ERL_NIF_TERM nsetopt_str_opt(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             int               level,
+                             int               opt,
+                             int               max,
+                             ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM result;
+    char*        val = MALLOC(max);
+
+    if (GET_STR(env, eVal, val, max) > 0) {
+        int optLen = strlen(val);
+        int res    = socket_setopt(descP->sock, level, opt, &val, optLen);
+
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    FREE(val);
+
+    return result;
+}
+
+
+/* nsetopt_timeval_opt - set an option that has an (timeval) bool value
+ */
+static
+ERL_NIF_TERM nsetopt_timeval_opt(ErlNifEnv*        env,
+                                 SocketDescriptor* descP,
+                                 int               level,
+                                 int               opt,
+                                 ERL_NIF_TERM      eVal)
+{
+    ERL_NIF_TERM   result;
+    struct timeval timeVal;
+    int            res;
+    char*          xres;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_timeval_opt -> entry with"
+            "\r\n   eVal: %T"
+            "\r\n", eVal) );
+
+    if ((xres = esock_decode_timeval(env, eVal, &timeVal)) != NULL)
+        return esock_make_error_str(env, xres);
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_timeval_opt -> set timeval option\r\n") );
+
+    res = socket_setopt(descP->sock, level, opt, &timeVal, sizeof(timeVal));
+
+    if (res != 0)
+        result = esock_make_error_errno(env, sock_errno());
+    else
+        result = esock_atom_ok;
+
+    SSDBG( descP,
+           ("SOCKET", "nsetopt_timeval_opt -> done with"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+    
+}
+
+
+
+static
+BOOLEAN_T elevel2level(BOOLEAN_T  isEncoded,
+                       int        eLevel,
+                       BOOLEAN_T* isOTP,
+                       int*       level)
+{
+    BOOLEAN_T result;
+
+    if (isEncoded) {
+        switch (eLevel) {
+        case SOCKET_OPT_LEVEL_OTP:
+            *isOTP = TRUE;
+            *level = -1;
+            result = TRUE;
+            break;
+
+        case SOCKET_OPT_LEVEL_SOCKET:
+            *isOTP = FALSE;
+            *level = SOL_SOCKET;
+            result = TRUE;
+            break;
+
+        case SOCKET_OPT_LEVEL_IP:
+            *isOTP = FALSE;
+#if defined(SOL_IP)
+            *level = SOL_IP;
+#else
+            *level = IPPROTO_IP;
+#endif
+            result = TRUE;
+            break;
+
+#if defined(HAVE_IPV6)
+        case SOCKET_OPT_LEVEL_IPV6:
+            *isOTP = FALSE;
+#if defined(SOL_IPV6)
+            *level = SOL_IPV6;
+#else
+            *level = IPPROTO_IPV6;
+#endif
+            result = TRUE;
+            break;
+#endif
+
+        case SOCKET_OPT_LEVEL_TCP:
+            *isOTP = FALSE;
+            *level = IPPROTO_TCP;
+            result = TRUE;
+            break;
+
+        case SOCKET_OPT_LEVEL_UDP:
+            *isOTP = FALSE;
+            *level = IPPROTO_UDP;
+            result = TRUE;
+            break;
+
+#ifdef HAVE_SCTP
+        case SOCKET_OPT_LEVEL_SCTP:
+            *isOTP = FALSE;
+            *level = IPPROTO_SCTP;
+            result = TRUE;
+            break;
+#endif
+
+        default:
+            *isOTP = FALSE;
+            *level = -1;
+            result = FALSE;
+            break;
+        }
+    } else {
+        *isOTP = FALSE;
+        *level = eLevel;
+        result = TRUE;
+    }
+
+    return result;
+}
+
+
+
+/* +++ socket_setopt +++
+ *
+ * <Per H @ Tail-f>
+ * The original code here had problems that possibly
+ * only occur if you abuse it for non-INET sockets, but anyway:
+ * a) If the getsockopt for SO_PRIORITY or IP_TOS failed, the actual
+ *    requested setsockopt was never even attempted.
+ * b) If {get,set}sockopt for one of IP_TOS and SO_PRIORITY failed,
+ *    but ditto for the other worked and that was actually the requested
+ *    option, failure was still reported to erlang.
+ * </Per H @ Tail-f>
+ *
+ * <PaN>
+ * The relations between SO_PRIORITY, TOS and other options
+ * is not what you (or at least I) would expect...:
+ * If TOS is set after priority, priority is zeroed.
+ * If any other option is set after tos, tos might be zeroed.
+ * Therefore, save tos and priority. If something else is set,
+ * restore both after setting, if  tos is set, restore only
+ * prio and if prio is set restore none... All to keep the
+ * user feeling socket options are independent.
+ * </PaN>
+ */
+static
+int socket_setopt(int sock, int level, int opt,
+                  const void* optVal, const socklen_t optLen)
+{
+    int res;
+
+#if  defined(IP_TOS) && defined(SOL_IP) && defined(SO_PRIORITY)
+    int          tmpIValPRIO;
+    int          tmpIValTOS;
+    int          resPRIO;
+    int          resTOS;
+    SOCKOPTLEN_T tmpArgSzPRIO = sizeof(tmpIValPRIO);
+    SOCKOPTLEN_T tmpArgSzTOS  = sizeof(tmpIValTOS);
+
+    resPRIO = sock_getopt(sock, SOL_SOCKET, SO_PRIORITY,
+                           &tmpIValPRIO, &tmpArgSzPRIO);
+    resTOS  = sock_getopt(sock, SOL_IP, IP_TOS,
+                          &tmpIValTOS, &tmpArgSzTOS);
+
+    res = sock_setopt(sock, level, opt, optVal, optLen);
+    if (res == 0) {
+
+        /* Ok, now we *maybe* need to "maybe" restore PRIO and TOS...
+         * maybe, possibly, ...
+         */
+
+        if (opt != SO_PRIORITY) {
+	    if ((opt != IP_TOS) && (resTOS == 0)) {
+		resTOS = sock_setopt(sock, SOL_IP, IP_TOS,
+                                     (void *) &tmpIValTOS,
+                                     tmpArgSzTOS);
+                res = resTOS;
+            }
+	    if ((res == 0) && (resPRIO == 0)) {
+		resPRIO = sock_setopt(sock, SOL_SOCKET, SO_PRIORITY,
+                                      &tmpIValPRIO,
+                                      tmpArgSzPRIO);
+
+                /* Some kernels set a SO_PRIORITY by default
+                 * that you are not permitted to reset,
+                 * silently ignore this error condition.
+                 */
+
+                if ((resPRIO != 0) && (sock_errno() == EPERM)) {
+                    res = 0;
+                } else {
+                    res = resPRIO;
+		}
+	    }
+	}
+    }
+
+#else
+
+    res = sock_setopt(sock, level, opt, optVal, optLen);
+
+#endif
+
+    return res;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_getopt
+ *
+ * Description:
+ * Get socket option.
+ * Its possible to use a "raw" mode (not encoded). That is, we do not
+ * interpret level and opt. They are passed "as is" to the
+ * getsockopt function call. The value in this case will "copied" as
+ * is and provided to the user in the form of a binary.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ * IsEncoded    - Are the "arguments" encoded or not.
+ * Level        - Level of the socket option.
+ * Opt          - The socket option.
+ */
+
+static
+ERL_NIF_TERM nif_getopt(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    int               eLevel, level = -1;
+    ERL_NIF_TERM      eIsEncoded, eOpt;
+    BOOLEAN_T         isEncoded, isOTP;
+
+    SGDBG( ("SOCKET", "nif_getopt -> entry with argc: %d\r\n", argc) );
+
+    if ((argc != 4) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP) ||
+        !GET_INT(env, argv[2], &eLevel)) {
+        SGDBG( ("SOCKET", "nif_getopt -> failed processing args\r\n") );
+        return enif_make_badarg(env);
+    }
+    eIsEncoded = argv[1];
+    eOpt       = argv[3]; // Is "normally" an int, but if raw mode: {Int, ValueSz}
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_getopt -> args when sock = %d:"
+            "\r\n   Socket:     %T"
+            "\r\n   eIsEncoded: %T"
+            "\r\n   eLevel:     %d"
+            "\r\n   eOpt:       %T"
+            "\r\n", descP->sock, argv[0], eIsEncoded, eLevel, eOpt) );
+
+    isEncoded = esock_decode_bool(eIsEncoded);
+
+    if (!elevel2level(isEncoded, eLevel, &isOTP, &level))
+        return esock_make_error(env, esock_atom_einval);
+
+    return ngetopt(env, descP, isEncoded, isOTP, level, eOpt);
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ngetopt(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     BOOLEAN_T         isEncoded,
+                     BOOLEAN_T         isOTP,
+                     int               level,
+                     ERL_NIF_TERM      eOpt)
+{
+    ERL_NIF_TERM result;
+    int          opt;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt -> entry with"
+            "\r\n   isEncoded: %s"
+            "\r\n   isOTP:     %s"
+            "\r\n   level:     %d"
+            "\r\n   eOpt:      %T"
+            "\r\n", B2S(isEncoded), B2S(isOTP), level, eOpt) );
+
+    if (isOTP) {
+        /* These are not actual socket options,
+         * but options for our implementation.
+         */
+        if (GET_INT(env, eOpt, &opt))
+            result = ngetopt_otp(env, descP, opt);
+        else
+            result = esock_make_error(env, esock_atom_einval);
+    } else if (!isEncoded) {
+        result = ngetopt_native(env, descP, level, eOpt);
+    } else {
+        if (GET_INT(env, eOpt, &opt))
+            result = ngetopt_level(env, descP, level, opt);
+        else
+            result = esock_make_error(env, esock_atom_einval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* ngetopt_otp - Handle OTP (level) options
+ */
+static
+ERL_NIF_TERM ngetopt_otp(ErlNifEnv*        env,
+                         SocketDescriptor* descP,
+                         int               eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_otp -> entry with"
+            "\r\n   eOpt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+    case SOCKET_OPT_OTP_DEBUG:
+        result = ngetopt_otp_debug(env, descP);
+        break;
+
+    case SOCKET_OPT_OTP_IOW:
+        result = ngetopt_otp_iow(env, descP);
+        break;
+
+    case SOCKET_OPT_OTP_CTRL_PROC:
+        result = ngetopt_otp_ctrl_proc(env, descP);
+        break;
+
+    case SOCKET_OPT_OTP_RCVBUF:
+        result = ngetopt_otp_rcvbuf(env, descP);
+        break;
+
+    case SOCKET_OPT_OTP_RCVCTRLBUF:
+        result = ngetopt_otp_rcvctrlbuf(env, descP);
+        break;
+
+    case SOCKET_OPT_OTP_SNDCTRLBUF:
+        result = ngetopt_otp_sndctrlbuf(env, descP);
+        break;
+
+    case SOCKET_OPT_OTP_FD:
+        result = ngetopt_otp_fd(env, descP);
+        break;
+
+        /* *** INTERNAL *** */
+    case SOCKET_OPT_OTP_DOMAIN:
+        result = ngetopt_otp_domain(env, descP);
+        break;
+
+    case SOCKET_OPT_OTP_TYPE:
+        result = ngetopt_otp_type(env, descP);
+        break;
+
+    case SOCKET_OPT_OTP_PROTOCOL:
+        result = ngetopt_otp_protocol(env, descP);
+        break;
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_otp -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* ngetopt_otp_debug - Handle the OTP (level) debug option
+ */
+static
+ERL_NIF_TERM ngetopt_otp_debug(ErlNifEnv*        env,
+                               SocketDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = esock_encode_bool(descP->dbg);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* ngetopt_otp_iow - Handle the OTP (level) iow option
+ */
+static
+ERL_NIF_TERM ngetopt_otp_iow(ErlNifEnv*        env,
+                             SocketDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = esock_encode_bool(descP->iow);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* ngetopt_otp_ctrl_proc - Handle the OTP (level) controlling_process option
+ */
+static
+ERL_NIF_TERM ngetopt_otp_ctrl_proc(ErlNifEnv*        env,
+                                   SocketDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = MKPID(env, &descP->ctrlPid);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+
+/* ngetopt_otp_rcvbuf - Handle the OTP (level) rcvbuf option
+ */
+static
+ERL_NIF_TERM ngetopt_otp_rcvbuf(ErlNifEnv*        env,
+                                SocketDescriptor* descP)
+{
+    ERL_NIF_TERM eVal;
+
+    if (descP->rNum == 0) {
+        eVal = MKI(env, descP->rBufSz);
+    } else {
+        eVal = MKT2(env, MKI(env, descP->rNum), MKI(env, descP->rBufSz));
+    }
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* ngetopt_otp_rcvctrlbuf - Handle the OTP (level) rcvctrlbuf option
+ */
+static
+ERL_NIF_TERM ngetopt_otp_rcvctrlbuf(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = MKI(env, descP->rCtrlSz);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* ngetopt_otp_sndctrlbuf - Handle the OTP (level) sndctrlbuf option
+ */
+static
+ERL_NIF_TERM ngetopt_otp_sndctrlbuf(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = MKI(env, descP->wCtrlSz);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* ngetopt_otp_fd - Handle the OTP (level) fd option
+ */
+static
+ERL_NIF_TERM ngetopt_otp_fd(ErlNifEnv*        env,
+                            SocketDescriptor* descP)
+{
+    ERL_NIF_TERM eVal = MKI(env, descP->sock);
+
+    return esock_make_ok2(env, eVal);
+}
+
+
+/* ngetopt_otp_domain - Handle the OTP (level) domain option
+ */
+static
+ERL_NIF_TERM ngetopt_otp_domain(ErlNifEnv*        env,
+                                SocketDescriptor* descP)
+{
+    ERL_NIF_TERM result;
+    int          val = descP->domain;
+
+    switch (val) {
+    case AF_INET:
+        result = esock_make_ok2(env, esock_atom_inet);
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case AF_INET6:
+        result = esock_make_ok2(env, esock_atom_inet6);
+        break;
+#endif
+
+#if defined(HAVE_SYS_UN_H)
+    case AF_UNIX:
+        result = esock_make_ok2(env, esock_atom_local);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env,
+                                  MKT2(env,
+                                       esock_atom_unknown,
+                                       MKI(env, val)));
+        break;
+    }
+    
+    return result;
+}
+
+
+/* ngetopt_otp_type - Handle the OTP (level) type options.
+ */
+static
+ERL_NIF_TERM ngetopt_otp_type(ErlNifEnv*        env,
+                              SocketDescriptor* descP)
+{
+    ERL_NIF_TERM result;
+    int          val = descP->type;
+
+    switch (val) {
+    case SOCK_STREAM:
+        result = esock_make_ok2(env, esock_atom_stream);
+        break;
+
+    case SOCK_DGRAM:
+        result = esock_make_ok2(env, esock_atom_dgram);
+        break;
+
+#ifdef HAVE_SCTP
+    case SOCK_SEQPACKET:
+        result = esock_make_ok2(env, esock_atom_seqpacket);
+        break;
+#endif
+    case SOCK_RAW:
+        result = esock_make_ok2(env, esock_atom_raw);
+        break;
+
+    case SOCK_RDM:
+        result = esock_make_ok2(env, esock_atom_rdm);
+        break;
+
+    default:
+        result = esock_make_error(env,
+                                  MKT2(env, esock_atom_unknown, MKI(env, val)));
+        break;
+    }
+
+    return result;
+}
+
+
+/* ngetopt_otp_protocol - Handle the OTP (level) protocol options.
+ */
+static
+ERL_NIF_TERM ngetopt_otp_protocol(ErlNifEnv*        env,
+                                  SocketDescriptor* descP)
+{
+    ERL_NIF_TERM result;
+    int          val = descP->protocol;
+
+        switch (val) {
+        case IPPROTO_IP:
+            result = esock_make_ok2(env, esock_atom_ip);
+            break;
+
+        case IPPROTO_TCP:
+            result = esock_make_ok2(env, esock_atom_tcp);
+            break;
+
+        case IPPROTO_UDP:
+            result = esock_make_ok2(env, esock_atom_udp);
+            break;
+
+#if defined(HAVE_SCTP)
+        case IPPROTO_SCTP:
+            result = esock_make_ok2(env, esock_atom_sctp);
+            break;
+#endif
+
+        default:
+            result = esock_make_error(env,
+                                      MKT2(env, esock_atom_unknown, MKI(env, val)));
+            break;
+    }
+
+    return result;
+}
+
+
+
+/* The option has *not* been encoded. Instead it has been provided
+ * in "native mode" (option is provided as is). In this case it will have the
+ * format: {NativeOpt :: integer(), ValueSize :: non_neg_integer()}
+ */
+static
+ERL_NIF_TERM ngetopt_native(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            int               level,
+                            ERL_NIF_TERM      eOpt)
+{
+    ERL_NIF_TERM result = enif_make_badarg(env);
+    int          opt;
+    Uint16       valueType;
+    SOCKOPTLEN_T valueSz;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_native -> entry with"
+            "\r\n   level: %d"
+            "\r\n   eOpt:  %T"
+            "\r\n", level, eOpt) );
+
+    /* <KOLLA>
+     * We should really make it possible to specify more common specific types,
+     * such as integer or boolean (instead of the size)...
+     * </KOLLA>
+     */
+
+    if (decode_native_get_opt(env, eOpt, &opt, &valueType, (int*) &valueSz)) {
+
+        SSDBG( descP,
+               ("SOCKET", "ngetopt_native -> decoded opt"
+                "\r\n   valueType: %d (%s)"
+                "\r\n   ValueSize: %d"
+                "\r\n", valueType, VT2S(valueType), valueSz) );
+
+        switch (valueType) {
+        case SOCKET_OPT_VALUE_TYPE_UNSPEC:
+            result = ngetopt_native_unspec(env, descP, level, opt, valueSz);
+            break;
+        case SOCKET_OPT_VALUE_TYPE_INT:
+            result = ngetopt_int_opt(env, descP, level, opt);
+            break;
+        case SOCKET_OPT_VALUE_TYPE_BOOL:
+            result = ngetopt_bool_opt(env, descP, level, opt);
+            break;
+        default:
+            result = esock_make_error(env, esock_atom_einval);
+            break;
+        }
+    } else {
+        result = esock_make_error(env, esock_atom_einval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_native -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+static
+ERL_NIF_TERM ngetopt_native_unspec(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   int               level,
+                                   int               opt,
+                                   SOCKOPTLEN_T      valueSz)
+{
+    ERL_NIF_TERM result = esock_make_error(env, esock_atom_einval);
+    int          res;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_native_unspec -> entry with"
+            "\r\n   level:   %d"
+            "\r\n   opt:     %d"
+            "\r\n   valueSz: %d"
+            "\r\n", level, opt, valueSz) );
+
+    if (valueSz == 0) {
+        res = sock_getopt(descP->sock, level, opt, NULL, NULL);
+        if (res != 0)
+            result = esock_make_error_errno(env, sock_errno());
+        else
+            result = esock_atom_ok;
+    } else {
+        SOCKOPTLEN_T vsz = valueSz;
+        ErlNifBinary val;
+
+        SSDBG( descP, ("SOCKET", "ngetopt_native_unspec -> try alloc buffer\r\n") );
+
+        if (ALLOC_BIN(vsz, &val)) {
+            int saveErrno;
+            res = sock_getopt(descP->sock, level, opt, val.data, &vsz);
+            if (res != 0) {
+                saveErrno = sock_errno();
+                
+                result = esock_make_error_errno(env, saveErrno);
+            } else {
+
+                /* Did we use all of the buffer? */
+                if (vsz == val.size) {
+
+                    result = esock_make_ok2(env, MKBIN(env, &val));
+
+                } else {
+
+                    ERL_NIF_TERM tmp;
+
+                    tmp = MKBIN(env, &val);
+                    tmp = MKSBIN(env, tmp, 0, vsz);
+                    
+                    result = esock_make_ok2(env, tmp);
+                }
+            }
+        } else {
+            result = enif_make_badarg(env);
+        }
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_native_unspec -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* ngetopt_level - A "proper" level (option) has been specified
+ */
+static
+ERL_NIF_TERM ngetopt_level(ErlNifEnv*        env,
+                           SocketDescriptor* descP,
+                           int               level,
+                           int               eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_level -> entry with"
+            "\r\n   level: %d"
+            "\r\n   eOpt:  %d"
+            "\r\n", level, eOpt) );
+
+    switch (level) {
+    case SOL_SOCKET:
+        result = ngetopt_lvl_socket(env, descP, eOpt);
+        break;
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        result = ngetopt_lvl_ip(env, descP, eOpt);
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif
+        result = ngetopt_lvl_ipv6(env, descP, eOpt);
+        break;
+#endif
+
+    case IPPROTO_TCP:
+        result = ngetopt_lvl_tcp(env, descP, eOpt);
+        break;
+
+    case IPPROTO_UDP:
+        result = ngetopt_lvl_udp(env, descP, eOpt);
+        break;
+
+#if defined(HAVE_SCTP)
+    case IPPROTO_SCTP:
+        result = ngetopt_lvl_sctp(env, descP, eOpt);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_level -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* ngetopt_lvl_socket - Level *SOCKET* option
+ */
+static
+ERL_NIF_TERM ngetopt_lvl_socket(ErlNifEnv*        env,
+                                SocketDescriptor* descP,
+                                int               eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_socket -> entry with"
+            "\r\n   eOpt:  %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(SO_ACCEPTCONN)
+    case SOCKET_OPT_SOCK_ACCEPTCONN:
+        result = ngetopt_lvl_sock_acceptconn(env, descP);
+        break;
+#endif
+
+#if defined(SO_BINDTODEVICE)
+    case SOCKET_OPT_SOCK_BINDTODEVICE:
+        result = ngetopt_lvl_sock_bindtodevice(env, descP);
+        break;
+#endif
+
+#if defined(SO_BROADCAST)
+    case SOCKET_OPT_SOCK_BROADCAST:
+        result = ngetopt_lvl_sock_broadcast(env, descP);
+        break;
+#endif
+
+#if defined(SO_DEBUG)
+    case SOCKET_OPT_SOCK_DEBUG:
+        result = ngetopt_lvl_sock_debug(env, descP);
+        break;
+#endif
+
+#if defined(SO_DOMAIN)
+    case SOCKET_OPT_SOCK_DOMAIN:
+        result = ngetopt_lvl_sock_domain(env, descP);
+        break;
+#endif
+
+#if defined(SO_DONTROUTE)
+    case SOCKET_OPT_SOCK_DONTROUTE:
+        result = ngetopt_lvl_sock_dontroute(env, descP);
+        break;
+#endif
+
+#if defined(SO_KEEPALIVE)
+    case SOCKET_OPT_SOCK_KEEPALIVE:
+        result = ngetopt_lvl_sock_keepalive(env, descP);
+        break;
+#endif
+
+#if defined(SO_LINGER)
+    case SOCKET_OPT_SOCK_LINGER:
+        result = ngetopt_lvl_sock_linger(env, descP);
+        break;
+#endif
+
+#if defined(SO_OOBINLINE)
+    case SOCKET_OPT_SOCK_OOBINLINE:
+        result = ngetopt_lvl_sock_oobinline(env, descP);
+        break;
+#endif
+
+#if defined(SO_PEEK_OFF)
+    case SOCKET_OPT_SOCK_PEEK_OFF:
+        result = ngetopt_lvl_sock_peek_off(env, descP);
+        break;
+#endif
+
+#if defined(SO_PRIORITY)
+    case SOCKET_OPT_SOCK_PRIORITY:
+        result = ngetopt_lvl_sock_priority(env, descP);
+        break;
+#endif
+
+#if defined(SO_PROTOCOL)
+    case SOCKET_OPT_SOCK_PROTOCOL:
+        result = ngetopt_lvl_sock_protocol(env, descP);
+        break;
+#endif
+
+#if defined(SO_RCVBUF)
+    case SOCKET_OPT_SOCK_RCVBUF:
+        result = ngetopt_lvl_sock_rcvbuf(env, descP);
+        break;
+#endif
+
+#if defined(SO_RCVLOWAT)
+    case SOCKET_OPT_SOCK_RCVLOWAT:
+        result = ngetopt_lvl_sock_rcvlowat(env, descP);
+        break;
+#endif
+
+#if defined(SO_RCVTIMEO)
+    case SOCKET_OPT_SOCK_RCVTIMEO:
+        result = ngetopt_lvl_sock_rcvtimeo(env, descP);
+        break;
+#endif
+
+#if defined(SO_REUSEADDR)
+    case SOCKET_OPT_SOCK_REUSEADDR:
+        result = ngetopt_lvl_sock_reuseaddr(env, descP);
+        break;
+#endif
+
+#if defined(SO_REUSEPORT)
+    case SOCKET_OPT_SOCK_REUSEPORT:
+        result = ngetopt_lvl_sock_reuseport(env, descP);
+        break;
+#endif
+
+#if defined(SO_SNDBUF)
+    case SOCKET_OPT_SOCK_SNDBUF:
+        result = ngetopt_lvl_sock_sndbuf(env, descP);
+        break;
+#endif
+
+#if defined(SO_SNDLOWAT)
+    case SOCKET_OPT_SOCK_SNDLOWAT:
+        result = ngetopt_lvl_sock_sndlowat(env, descP);
+        break;
+#endif
+
+#if defined(SO_SNDTIMEO)
+    case SOCKET_OPT_SOCK_SNDTIMEO:
+        result = ngetopt_lvl_sock_sndtimeo(env, descP);
+        break;
+#endif
+
+#if defined(SO_TIMESTAMP)
+    case SOCKET_OPT_SOCK_TIMESTAMP:
+        result = ngetopt_lvl_sock_timestamp(env, descP);
+        break;
+#endif
+
+#if defined(SO_TYPE)
+    case SOCKET_OPT_SOCK_TYPE:
+        result = ngetopt_lvl_sock_type(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_socket -> done when"
+            "\r\n   result:  %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+#if defined(SO_ACCEPTCONN)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_acceptconn(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_SOCKET, SO_ACCEPTCONN);
+}
+#endif
+
+
+#if defined(SO_BINDTODEVICE)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_bindtodevice(ErlNifEnv*        env,
+                                           SocketDescriptor* descP)
+{
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_sock_bindtodevice -> entry with\r\n") );
+
+    return ngetopt_str_opt(env, descP, SOL_SOCKET, SO_BROADCAST, IFNAMSIZ+1);
+}
+#endif
+
+
+#if defined(SO_BROADCAST)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_broadcast(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_SOCKET, SO_BROADCAST);
+}
+#endif
+
+
+#if defined(SO_DEBUG)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_debug(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, SOL_SOCKET, SO_DEBUG);
+}
+#endif
+
+
+#if defined(SO_DOMAIN)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_domain(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+    ERL_NIF_TERM result;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, SOL_SOCKET, SO_DOMAIN,
+                      &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        switch (val) {
+        case AF_INET:
+            result = esock_make_ok2(env, esock_atom_inet);
+            break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+        case AF_INET6:
+            result = esock_make_ok2(env, esock_atom_inet6);
+            break;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+        case AF_UNIX:
+        result = esock_make_ok2(env, esock_atom_local);
+        break;
+#endif
+
+        default:
+            result = esock_make_error(env,
+                                      MKT2(env,
+                                           esock_atom_unknown,
+                                           MKI(env, val)));
+            break;
+        }
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(SO_DONTROUTE)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_dontroute(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_SOCKET, SO_DONTROUTE);
+}
+#endif
+
+
+#if defined(SO_KEEPALIVE)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_keepalive(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_SOCKET, SO_KEEPALIVE);
+}
+#endif
+
+
+#if defined(SO_LINGER)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_linger(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+    ERL_NIF_TERM  result;
+    struct linger val;
+    SOCKOPTLEN_T  valSz = sizeof(val);
+    int           res;
+
+    sys_memzero((void *) &val, sizeof(val));
+
+    res = sock_getopt(descP->sock, SOL_SOCKET, SO_LINGER,
+                      &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM lOnOff = ((val.l_onoff) ? atom_true : atom_false);
+        ERL_NIF_TERM lSecs  = MKI(env, val.l_linger);
+        ERL_NIF_TERM linger = MKT2(env, lOnOff, lSecs);
+
+        result = esock_make_ok2(env, linger);
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(SO_OOBINLINE)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_oobinline(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_SOCKET, SO_OOBINLINE);
+}
+#endif
+
+
+#if defined(SO_PEEK_OFF)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_peek_off(ErlNifEnv*        env,
+                                       SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, SOL_SOCKET, SO_PEEK_OFF);
+}
+#endif
+
+
+#if defined(SO_PRIORITY)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_priority(ErlNifEnv*        env,
+                                       SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, SOL_SOCKET, SO_PRIORITY);
+}
+#endif
+
+
+#if defined(SO_PROTOCOL)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_protocol(ErlNifEnv*        env,
+                                       SocketDescriptor* descP)
+{
+    ERL_NIF_TERM result;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, SOL_SOCKET, SO_PROTOCOL,
+                      &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        switch (val) {
+        case IPPROTO_IP:
+            result = esock_make_ok2(env, esock_atom_ip);
+            break;
+
+        case IPPROTO_TCP:
+            result = esock_make_ok2(env, esock_atom_tcp);
+            break;
+
+        case IPPROTO_UDP:
+            result = esock_make_ok2(env, esock_atom_udp);
+            break;
+
+#if defined(HAVE_SCTP)
+        case IPPROTO_SCTP:
+            result = esock_make_ok2(env, esock_atom_sctp);
+            break;
+#endif
+
+        default:
+            result = esock_make_error(env,
+                                      MKT2(env, esock_atom_unknown, MKI(env, val)));
+            break;
+        }
+    }
+
+    return result;
+}
+#endif
+
+
+#if defined(SO_RCVBUF)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_rcvbuf(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, SOL_SOCKET, SO_RCVBUF);
+}
+#endif
+
+
+#if defined(SO_RCVLOWAT)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_rcvlowat(ErlNifEnv*        env,
+                                       SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, SOL_SOCKET, SO_RCVLOWAT);
+}
+#endif
+
+
+#if defined(SO_RCVTIMEO)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_rcvtimeo(ErlNifEnv*        env,
+                                       SocketDescriptor* descP)
+{
+    return ngetopt_timeval_opt(env, descP, SOL_SOCKET, SO_RCVTIMEO);
+}
+#endif
+
+
+#if defined(SO_REUSEADDR)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_reuseaddr(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_SOCKET, SO_REUSEADDR);
+}
+#endif
+
+
+#if defined(SO_REUSEPORT)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_reuseport(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_SOCKET, SO_REUSEPORT);
+}
+#endif
+
+
+#if defined(SO_SNDBUF)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_sndbuf(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, SOL_SOCKET, SO_SNDBUF);
+}
+#endif
+
+
+#if defined(SO_SNDLOWAT)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_sndlowat(ErlNifEnv*        env,
+                                       SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, SOL_SOCKET, SO_SNDLOWAT);
+}
+#endif
+
+
+#if defined(SO_SNDTIMEO)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_sndtimeo(ErlNifEnv*        env,
+                                       SocketDescriptor* descP)
+{
+    return ngetopt_timeval_opt(env, descP, SOL_SOCKET, SO_SNDTIMEO);
+}
+#endif
+
+
+#if defined(SO_TIMESTAMP)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_timestamp(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_SOCKET, SO_TIMESTAMP);
+}
+#endif
+
+
+#if defined(SO_TYPE)
+static
+ERL_NIF_TERM ngetopt_lvl_sock_type(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+    ERL_NIF_TERM result;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, SOL_SOCKET, SO_TYPE, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        switch (val) {
+        case SOCK_STREAM:
+            result = esock_make_ok2(env, esock_atom_stream);
+            break;
+        case SOCK_DGRAM:
+            result = esock_make_ok2(env, esock_atom_dgram);
+            break;
+#ifdef HAVE_SCTP
+        case SOCK_SEQPACKET:
+            result = esock_make_ok2(env, esock_atom_seqpacket);
+            break;
+#endif
+        case SOCK_RAW:
+            result = esock_make_ok2(env, esock_atom_raw);
+            break;
+        case SOCK_RDM:
+            result = esock_make_ok2(env, esock_atom_rdm);
+            break;
+        default:
+            result = esock_make_error(env,
+                                      MKT2(env, esock_atom_unknown, MKI(env, val)));
+            break;
+        }
+    }
+
+    return result;
+}
+#endif
+
+
+/* ngetopt_lvl_ip - Level *IP* option(s)
+ */
+static
+ERL_NIF_TERM ngetopt_lvl_ip(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            int               eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_ip -> entry with"
+            "\r\n   eOpt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(IP_FREEBIND)
+    case SOCKET_OPT_IP_FREEBIND:
+        result = ngetopt_lvl_ip_freebind(env, descP);
+        break;
+#endif
+
+#if defined(IP_HDRINCL)
+    case SOCKET_OPT_IP_HDRINCL:
+        result = ngetopt_lvl_ip_hdrincl(env, descP);
+        break;
+#endif
+
+#if defined(IP_MINTTL)
+    case SOCKET_OPT_IP_MINTTL:
+        result = ngetopt_lvl_ip_minttl(env, descP);
+        break;
+#endif
+
+#if defined(IP_MTU)
+    case SOCKET_OPT_IP_MTU:
+        result = ngetopt_lvl_ip_mtu(env, descP);
+        break;
+#endif
+
+#if defined(IP_MTU_DISCOVER)
+    case SOCKET_OPT_IP_MTU_DISCOVER:
+        result = ngetopt_lvl_ip_mtu_discover(env, descP);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_ALL)
+    case SOCKET_OPT_IP_MULTICAST_ALL:
+        result = ngetopt_lvl_ip_multicast_all(env, descP);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_IF)
+    case SOCKET_OPT_IP_MULTICAST_IF:
+        result = ngetopt_lvl_ip_multicast_if(env, descP);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_LOOP)
+    case SOCKET_OPT_IP_MULTICAST_LOOP:
+        result = ngetopt_lvl_ip_multicast_loop(env, descP);
+        break;
+#endif
+
+#if defined(IP_MULTICAST_TTL)
+    case SOCKET_OPT_IP_MULTICAST_TTL:
+        result = ngetopt_lvl_ip_multicast_ttl(env, descP);
+        break;
+#endif
+
+#if defined(IP_NODEFRAG)
+    case SOCKET_OPT_IP_NODEFRAG:
+        result = ngetopt_lvl_ip_nodefrag(env, descP);
+        break;
+#endif
+
+#if defined(IP_PKTINFO)
+    case SOCKET_OPT_IP_PKTINFO:
+        result = ngetopt_lvl_ip_pktinfo(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVDSTADDR)
+    case SOCKET_OPT_IP_RECVDSTADDR:
+        result = ngetopt_lvl_ip_recvdstaddr(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVERR)
+    case SOCKET_OPT_IP_RECVERR:
+        result = ngetopt_lvl_ip_recverr(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVIF)
+    case SOCKET_OPT_IP_RECVIF:
+        result = ngetopt_lvl_ip_recvif(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVOPTS)
+    case SOCKET_OPT_IP_RECVOPTS:
+        result = ngetopt_lvl_ip_recvopts(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVORIGDSTADDR)
+    case SOCKET_OPT_IP_RECVORIGDSTADDR:
+        result = ngetopt_lvl_ip_recvorigdstaddr(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVTOS)
+    case SOCKET_OPT_IP_RECVTOS:
+        result = ngetopt_lvl_ip_recvtos(env, descP);
+        break;
+#endif
+
+#if defined(IP_RECVTTL)
+    case SOCKET_OPT_IP_RECVTTL:
+        result = ngetopt_lvl_ip_recvttl(env, descP);
+        break;
+#endif
+
+#if defined(IP_RETOPTS)
+    case SOCKET_OPT_IP_RETOPTS:
+        result = ngetopt_lvl_ip_retopts(env, descP);
+        break;
+#endif
+
+#if defined(IP_ROUTER_ALERT)
+    case SOCKET_OPT_IP_ROUTER_ALERT:
+        result = ngetopt_lvl_ip_router_alert(env, descP);
+        break;
+#endif
+
+#if defined(IP_SENDSRCADDR)
+    case SOCKET_OPT_IP_SENDSRCADDR:
+        result = ngetopt_lvl_ip_sendsrcaddr(env, descP);
+        break;
+#endif
+
+#if defined(IP_TOS)
+    case SOCKET_OPT_IP_TOS:
+        result = ngetopt_lvl_ip_tos(env, descP);
+        break;
+#endif
+
+#if defined(IP_TRANSPARENT)
+    case SOCKET_OPT_IP_TRANSPARENT:
+        result = ngetopt_lvl_ip_transparent(env, descP);
+        break;
+#endif
+
+#if defined(IP_TTL)
+    case SOCKET_OPT_IP_TTL:
+        result = ngetopt_lvl_ip_ttl(env, descP);
+        break;
+#endif
+
+    default:
+        SSDBG( descP, ("SOCKET", "ngetopt_lvl_ip -> unknown opt %d\r\n", eOpt) );
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_ip -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* ngetopt_lvl_ip_minttl - Level IP MINTTL option
+ */
+#if defined(IP_MINTTL)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_minttl(ErlNifEnv*        env,
+                                   SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IP_MINTTL);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_freebind - Level IP FREEBIND option
+ */
+#if defined(IP_FREEBIND)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_freebind(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_FREEBIND);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_hdrincl - Level IP HDRINCL option
+ */
+#if defined(IP_HDRINCL)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_hdrincl(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_HDRINCL);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_mtu - Level IP MTU option
+ */
+#if defined(IP_MTU)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_mtu(ErlNifEnv*        env,
+                                SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IP_MTU);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_mtu_discover - Level IP MTU_DISCOVER option
+ */
+#if defined(IP_MTU_DISCOVER)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_mtu_discover(ErlNifEnv*        env,
+                                         SocketDescriptor* descP)
+{
+    ERL_NIF_TERM   result;
+    ERL_NIF_TERM   eMtuDisc;
+    int            mtuDisc;
+    SOCKOPTLEN_T   mtuDiscSz = sizeof(mtuDisc);
+    int            res;
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    res = sock_getopt(descP->sock, level, IP_MTU_DISCOVER,
+                      &mtuDisc, &mtuDiscSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        encode_ip_pmtudisc(env, mtuDisc, &eMtuDisc);
+        result = esock_make_ok2(env, eMtuDisc);
+    }
+
+    return result;
+
+}
+#endif
+
+
+/* ngetopt_lvl_ip_multicast_all - Level IP MULTICAST_ALL option
+ */
+#if defined(IP_MULTICAST_ALL)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_multicast_all(ErlNifEnv*        env,
+                                          SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_MULTICAST_ALL);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_multicast_if - Level IP MULTICAST_IF option
+ */
+#if defined(IP_MULTICAST_IF)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_multicast_if(ErlNifEnv*        env,
+                                         SocketDescriptor* descP)
+{
+    ERL_NIF_TERM   result;
+    ERL_NIF_TERM   eAddr;
+    struct in_addr ifAddr;
+    SOCKOPTLEN_T   ifAddrSz = sizeof(ifAddr);
+    char*          xres;
+    int            res;
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    res = sock_getopt(descP->sock, level, IP_MULTICAST_IF, &ifAddr, &ifAddrSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        if ((xres = esock_encode_ip4_address(env, &ifAddr, &eAddr)) != NULL) {
+            result = esock_make_error_str(env, xres);
+        } else {
+            result = esock_make_ok2(env, eAddr);
+        }
+    }
+
+    return result;
+
+}
+#endif
+
+
+/* ngetopt_lvl_ip_multicast_loop - Level IP MULTICAST_LOOP option
+ */
+#if defined(IP_MULTICAST_LOOP)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_multicast_loop(ErlNifEnv*        env,
+                                           SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_MULTICAST_LOOP);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_multicast_ttl - Level IP MULTICAST_TTL option
+ */
+#if defined(IP_MULTICAST_TTL)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_multicast_ttl(ErlNifEnv*        env,
+                                          SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IP_MULTICAST_TTL);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_nodefrag - Level IP NODEFRAG option
+ */
+#if defined(IP_NODEFRAG)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_nodefrag(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_NODEFRAG);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_pktinfo - Level IP PKTINFO option
+ */
+#if defined(IP_PKTINFO)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_pktinfo(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_PKTINFO);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_recvtos - Level IP RECVTOS option
+ */
+#if defined(IP_RECVTOS)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_recvtos(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_RECVTOS);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_recvdstaddr - Level IP RECVDSTADDR option
+ */
+#if defined(IP_RECVDSTADDR)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_recvdstaddr(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_RECVDSTADDR);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_recverr - Level IP RECVERR option
+ */
+#if defined(IP_RECVERR)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_recverr(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_RECVERR);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_recvif - Level IP RECVIF option
+ */
+#if defined(IP_RECVIF)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_recvif(ErlNifEnv*        env,
+                                   SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_RECVIF);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_recvopt - Level IP RECVOPTS option
+ */
+#if defined(IP_RECVOPTS)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_recvopts(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_RECVOPTS);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_recvorigdstaddr - Level IP RECVORIGDSTADDR option
+ */
+#if defined(IP_RECVORIGDSTADDR)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_recvorigdstaddr(ErlNifEnv*        env,
+                                            SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_RECVORIGDSTADDR);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_recvttl - Level IP RECVTTL option
+ */
+#if defined(IP_RECVTTL)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_recvttl(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_RECVTTL);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_retopts - Level IP RETOPTS option
+ */
+#if defined(IP_RETOPTS)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_retopts(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_RETOPTS);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_router_alert - Level IP ROUTER_ALERT option
+ */
+#if defined(IP_ROUTER_ALERT)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_router_alert(ErlNifEnv*        env,
+                                         SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IP_ROUTER_ALERT);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_sendsrcaddr - Level IP SENDSRCADDR option
+ */
+#if defined(IP_SENDSRCADDR)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_sendsrcaddr(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_SENDSRCADDR);
+}
+#endif
+
+
+/* ngetopt_lvl_ip_tos - Level IP TOS option
+ */
+#if defined(IP_TOS)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_tos(ErlNifEnv*        env,
+                                SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int          level = SOL_IP;
+#else
+    int          level = IPPROTO_IP;
+#endif
+    ERL_NIF_TERM result;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, level, IP_TOS, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        result = encode_ip_tos(env, val);
+    }
+
+    return result;
+}
+#endif
+
+
+/* ngetopt_lvl_ip_transparent - Level IP TRANSPARENT option
+ */
+#if defined(IP_TRANSPARENT)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_transparent(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IP_TRANSPARENT);
+}
+#endif
+
+
+
+/* ngetopt_lvl_ip_ttl - Level IP TTL option
+ */
+#if defined(IP_TTL)
+static
+ERL_NIF_TERM ngetopt_lvl_ip_ttl(ErlNifEnv*        env,
+                                SocketDescriptor* descP)
+{
+#if defined(SOL_IP)
+    int level = SOL_IP;
+#else
+    int level = IPPROTO_IP;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IP_TTL);
+}
+#endif
+
+
+
+/* ngetopt_lvl_ipv6 - Level *IPv6* option(s)
+ */
+#if defined(HAVE_IPV6)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              int               eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_ipv6 -> entry with"
+            "\r\n   eOpt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(IPV6_AUTHHDR)
+    case SOCKET_OPT_IPV6_AUTHHDR:
+        result = ngetopt_lvl_ipv6_authhdr(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_DSTOPTS)
+    case SOCKET_OPT_IPV6_DSTOPTS:
+        result = ngetopt_lvl_ipv6_dstopts(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_FLOWINFO)
+    case SOCKET_OPT_IPV6_FLOWINFO:
+        result = ngetopt_lvl_ipv6_flowinfo(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_HOPLIMIT)
+    case SOCKET_OPT_IPV6_HOPLIMIT:
+        result = ngetopt_lvl_ipv6_hoplimit(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_HOPOPTS)
+    case SOCKET_OPT_IPV6_HOPOPTS:
+        result = ngetopt_lvl_ipv6_hopopts(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MTU)
+    case SOCKET_OPT_IPV6_MTU:
+        result = ngetopt_lvl_ipv6_mtu(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MTU_DISCOVER)
+    case SOCKET_OPT_IPV6_MTU_DISCOVER:
+        result = ngetopt_lvl_ipv6_mtu_discover(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_HOPS)
+    case SOCKET_OPT_IPV6_MULTICAST_HOPS:
+        result = ngetopt_lvl_ipv6_multicast_hops(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_IF)
+    case SOCKET_OPT_IPV6_MULTICAST_IF:
+        result = ngetopt_lvl_ipv6_multicast_if(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_MULTICAST_LOOP)
+    case SOCKET_OPT_IPV6_MULTICAST_LOOP:
+        result = ngetopt_lvl_ipv6_multicast_loop(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_RECVERR)
+    case SOCKET_OPT_IPV6_RECVERR:
+        result = ngetopt_lvl_ipv6_recverr(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+    case SOCKET_OPT_IPV6_RECVPKTINFO:
+        result = ngetopt_lvl_ipv6_recvpktinfo(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_ROUTER_ALERT)
+    case SOCKET_OPT_IPV6_ROUTER_ALERT:
+        result = ngetopt_lvl_ipv6_router_alert(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_RTHDR)
+    case SOCKET_OPT_IPV6_RTHDR:
+        result = ngetopt_lvl_ipv6_rthdr(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_UNICAST_HOPS)
+    case SOCKET_OPT_IPV6_UNICAST_HOPS:
+        result = ngetopt_lvl_ipv6_unicast_hops(env, descP);
+        break;
+#endif
+
+#if defined(IPV6_V6ONLY)
+    case SOCKET_OPT_IPV6_V6ONLY:
+        result = ngetopt_lvl_ipv6_v6only(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_ipv6 -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+#if defined(IPV6_AUTHHDR)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_authhdr(ErlNifEnv*        env,
+                                      SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, SOL_IPV6, IPV6_AUTHHDR);
+}
+#endif
+
+
+#if defined(IPV6_DSTOPTS)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_dstopts(ErlNifEnv*        env,
+                                      SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+    return ngetopt_bool_opt(env, descP, level, IPV6_DSTOPTS);
+}
+#endif
+
+
+#if defined(IPV6_FLOWINFO)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_flowinfo(ErlNifEnv*        env,
+                                       SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IPV6_FLOWINFO);
+}
+#endif
+
+
+#if defined(IPV6_HOPLIMIT)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_hoplimit(ErlNifEnv*        env,
+                                       SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IPV6_HOPLIMIT);
+}
+#endif
+
+
+#if defined(IPV6_HOPOPTS)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_hopopts(ErlNifEnv*        env,
+                                      SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IPV6_HOPOPTS);
+}
+#endif
+
+
+#if defined(IPV6_MTU)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_mtu(ErlNifEnv*        env,
+                                  SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IPV6_MTU);
+}
+#endif
+
+
+/* ngetopt_lvl_ipv6_mtu_discover - Level IPv6 MTU_DISCOVER option
+ */
+#if defined(IPV6_MTU_DISCOVER)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_mtu_discover(ErlNifEnv*        env,
+                                           SocketDescriptor* descP)
+{
+    ERL_NIF_TERM  result;
+    ERL_NIF_TERM  eMtuDisc;
+    int           mtuDisc;
+    SOCKOPTLEN_T  mtuDiscSz = sizeof(mtuDisc);
+    int           res;
+#if defined(SOL_IPV6)
+    int           level = SOL_IPV6;
+#else
+    int           level = IPPROTO_IPV6;
+#endif
+
+    res = sock_getopt(descP->sock, level, IPV6_MTU_DISCOVER,
+                      &mtuDisc, &mtuDiscSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        encode_ipv6_pmtudisc(env, mtuDisc, &eMtuDisc);
+        result = esock_make_ok2(env, eMtuDisc);
+    }
+
+    return result;
+
+}
+#endif
+
+
+#if defined(IPV6_MULTICAST_HOPS)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_multicast_hops(ErlNifEnv*        env,
+                                             SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IPV6_MULTICAST_HOPS);
+}
+#endif
+
+
+#if defined(IPV6_MULTICAST_IF)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_multicast_if(ErlNifEnv*        env,
+                                           SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IPV6_MULTICAST_IF);
+}
+#endif
+
+
+#if defined(IPV6_MULTICAST_LOOP)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_multicast_loop(ErlNifEnv*        env,
+                                             SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IPV6_MULTICAST_LOOP);
+}
+#endif
+
+
+#if defined(IPV6_RECVERR)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_recverr(ErlNifEnv*        env,
+                                      SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IPV6_RECVERR);
+}
+#endif
+
+
+#if defined(IPV6_RECVPKTINFO) || defined(IPV6_PKTINFO)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_recvpktinfo(ErlNifEnv*        env,
+                                          SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+#if defined(IPV6_RECVPKTINFO)
+    int opt   = IPV6_RECVPKTINFO;
+#else
+    int opt   = IPV6_PKTINFO;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, opt);
+}
+#endif
+
+
+#if defined(IPV6_ROUTER_ALERT)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_router_alert(ErlNifEnv*        env,
+                                           SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IPV6_ROUTER_ALERT);
+}
+#endif
+
+
+#if defined(IPV6_RTHDR)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_rthdr(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IPV6_RTHDR);
+}
+#endif
+
+
+#if defined(IPV6_UNICAST_HOPS)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_unicast_hops(ErlNifEnv*        env,
+                                           SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_int_opt(env, descP, level, IPV6_UNICAST_HOPS);
+}
+#endif
+
+
+#if defined(IPV6_V6ONLY)
+static
+ERL_NIF_TERM ngetopt_lvl_ipv6_v6only(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+#if defined(SOL_IPV6)
+    int level = SOL_IPV6;
+#else
+    int level = IPPROTO_IPV6;
+#endif
+
+    return ngetopt_bool_opt(env, descP, level, IPV6_V6ONLY);
+}
+#endif
+
+
+#endif // defined(HAVE_IPV6)
+
+
+
+/* ngetopt_lvl_tcp - Level *TCP* option(s)
+ */
+static
+ERL_NIF_TERM ngetopt_lvl_tcp(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             int               eOpt)
+{
+    ERL_NIF_TERM result;
+
+    switch (eOpt) {
+#if defined(TCP_CONGESTION)
+    case SOCKET_OPT_TCP_CONGESTION:
+        result = ngetopt_lvl_tcp_congestion(env, descP);
+        break;
+#endif
+
+#if defined(TCP_MAXSEG)
+    case SOCKET_OPT_TCP_MAXSEG:
+        result = ngetopt_lvl_tcp_maxseg(env, descP);
+        break;
+#endif
+
+#if defined(TCP_NODELAY)
+    case SOCKET_OPT_TCP_NODELAY:
+        result = ngetopt_lvl_tcp_nodelay(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* ngetopt_lvl_tcp_congestion - Level TCP CONGESTION option
+ */
+#if defined(TCP_CONGESTION)
+static
+ERL_NIF_TERM ngetopt_lvl_tcp_congestion(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    int max = SOCKET_OPT_TCP_CONGESTION_NAME_MAX+1;
+
+    return ngetopt_str_opt(env, descP, IPPROTO_TCP, TCP_CONGESTION, max);
+}
+#endif
+
+
+/* ngetopt_lvl_tcp_maxseg - Level TCP MAXSEG option
+ */
+#if defined(TCP_MAXSEG)
+static
+ERL_NIF_TERM ngetopt_lvl_tcp_maxseg(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, IPPROTO_TCP, TCP_MAXSEG);
+}
+#endif
+
+
+/* ngetopt_lvl_tcp_nodelay - Level TCP NODELAY option
+ */
+#if defined(TCP_NODELAY)
+static
+ERL_NIF_TERM ngetopt_lvl_tcp_nodelay(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, IPPROTO_TCP, TCP_NODELAY);
+}
+#endif
+
+
+
+/* ngetopt_lvl_udp - Level *UDP* option(s)
+ */
+static
+ERL_NIF_TERM ngetopt_lvl_udp(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             int               eOpt)
+{
+    ERL_NIF_TERM result;
+
+    switch (eOpt) {
+#if defined(UDP_CORK)
+    case SOCKET_OPT_UDP_CORK:
+        result = ngetopt_lvl_udp_cork(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    return result;
+}
+
+
+/* ngetopt_lvl_udp_cork - Level UDP CORK option
+ */
+#if defined(UDP_CORK)
+static
+ERL_NIF_TERM ngetopt_lvl_udp_cork(ErlNifEnv*        env,
+                                  SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, IPPROTO_UDP, UDP_CORK);
+}
+#endif
+
+
+
+/* ngetopt_lvl_sctp - Level *SCTP* option(s)
+ */
+#if defined(HAVE_SCTP)
+static
+ERL_NIF_TERM ngetopt_lvl_sctp(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              int               eOpt)
+{
+    ERL_NIF_TERM result;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_sctp -> entry with"
+            "\r\n   opt: %d"
+            "\r\n", eOpt) );
+
+    switch (eOpt) {
+#if defined(SCTP_ASSOCINFO)
+    case SOCKET_OPT_SCTP_ASSOCINFO:
+        result = ngetopt_lvl_sctp_associnfo(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_AUTOCLOSE)
+    case SOCKET_OPT_SCTP_AUTOCLOSE:
+        result = ngetopt_lvl_sctp_autoclose(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_DISABLE_FRAGMENTS)
+    case SOCKET_OPT_SCTP_DISABLE_FRAGMENTS:
+        result = ngetopt_lvl_sctp_disable_fragments(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_INITMSG)
+    case SOCKET_OPT_SCTP_INITMSG:
+        result = ngetopt_lvl_sctp_initmsg(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_MAXSEG)
+    case SOCKET_OPT_SCTP_MAXSEG:
+        result = ngetopt_lvl_sctp_maxseg(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_NODELAY)
+    case SOCKET_OPT_SCTP_NODELAY:
+        result = ngetopt_lvl_sctp_nodelay(env, descP);
+        break;
+#endif
+
+#if defined(SCTP_RTOINFO)
+    case SOCKET_OPT_SCTP_RTOINFO:
+        result = ngetopt_lvl_sctp_rtoinfo(env, descP);
+        break;
+#endif
+
+    default:
+        result = esock_make_error(env, esock_atom_einval);
+        break;
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_sctp -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+/* ngetopt_lvl_sctp_associnfo - Level SCTP ASSOCINFO option
+ *
+ * <KOLLA>
+ *
+ * We should really specify which association this relates to,
+ * as it is now we get assoc-id = 0. If this socket is an 
+ * association (and not an endpoint) then it will have an
+ * assoc id. But since the sctp support at present is "limited",
+ * we leave it for now.
+ * What do we do if this is an endpoint? Invalid op?
+ *
+ * </KOLLA>
+ */
+#if defined(SCTP_ASSOCINFO)
+static
+ERL_NIF_TERM ngetopt_lvl_sctp_associnfo(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    ERL_NIF_TERM            result;
+    struct sctp_assocparams val;
+    SOCKOPTLEN_T            valSz = sizeof(val);
+    int                     res;
+
+    SSDBG( descP, ("SOCKET", "ngetopt_lvl_sctp_associnfo -> entry\r\n") );
+    
+    sys_memzero((char*) &val, valSz);
+    res = sock_getopt(descP->sock, IPPROTO_SCTP, SCTP_ASSOCINFO, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM eAssocParams;
+        ERL_NIF_TERM keys[]  = {atom_assoc_id, atom_max_rxt, atom_num_peer_dests,
+                                atom_peer_rwnd, atom_local_rwnd, atom_cookie_life};
+        ERL_NIF_TERM vals[]  = {MKUI(env, val.sasoc_assoc_id),
+                                MKUI(env, val.sasoc_asocmaxrxt),
+                                MKUI(env, val.sasoc_number_peer_destinations),
+                                MKUI(env, val.sasoc_peer_rwnd),
+                                MKUI(env, val.sasoc_local_rwnd),
+                                MKUI(env, val.sasoc_cookie_life)};
+        unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+        unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+        ESOCK_ASSERT( (numKeys == numVals) );
+
+        if (!MKMA(env, keys, vals, numKeys, &eAssocParams))
+            return esock_make_error(env, esock_atom_einval);;
+    
+        result = esock_make_ok2(env, eAssocParams);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_sctp_associnfo -> done with"
+            "\r\n   res:    %d"
+            "\r\n   result: %T"
+            "\r\n", res, result) );
+
+    return result;
+}
+#endif
+
+
+/* ngetopt_lvl_sctp_autoclose - Level SCTP AUTOCLOSE option
+ */
+#if defined(SCTP_AUTOCLOSE)
+static
+ERL_NIF_TERM ngetopt_lvl_sctp_autoclose(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, IPPROTO_SCTP, SCTP_AUTOCLOSE);
+}
+#endif
+
+
+/* ngetopt_lvl_sctp_disable_fragments - Level SCTP DISABLE:FRAGMENTS option
+ */
+#if defined(SCTP_DISABLE_FRAGMENTS)
+static
+ERL_NIF_TERM ngetopt_lvl_sctp_disable_fragments(ErlNifEnv*        env,
+                                                SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, IPPROTO_SCTP, SCTP_DISABLE_FRAGMENTS);
+}
+#endif
+
+
+/* ngetopt_lvl_sctp_initmsg - Level SCTP INITMSG option
+ *
+ */
+#if defined(SCTP_INITMSG)
+static
+ERL_NIF_TERM ngetopt_lvl_sctp_initmsg(ErlNifEnv*        env,
+                                      SocketDescriptor* descP)
+{
+    ERL_NIF_TERM        result;
+    struct sctp_initmsg val;
+    SOCKOPTLEN_T        valSz = sizeof(val);
+    int                 res;
+
+    SSDBG( descP, ("SOCKET", "ngetopt_lvl_sctp_initmsg -> entry\r\n") );
+    
+    sys_memzero((char*) &val, valSz);
+    res = sock_getopt(descP->sock, IPPROTO_SCTP, SCTP_INITMSG, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM eInitMsg;
+        ERL_NIF_TERM keys[]  = {atom_num_outstreams, atom_max_instreams,
+                                atom_max_attempts, atom_max_init_timeo};
+        ERL_NIF_TERM vals[]  = {MKUI(env, val.sinit_num_ostreams),
+                                MKUI(env, val.sinit_max_instreams),
+                                MKUI(env, val.sinit_max_attempts),
+                                MKUI(env, val.sinit_max_init_timeo)};
+        unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+        unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+        ESOCK_ASSERT( (numKeys == numVals) );
+
+        if (!MKMA(env, keys, vals, numKeys, &eInitMsg))
+            return esock_make_error(env, esock_atom_einval);;
+    
+        result = esock_make_ok2(env, eInitMsg);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_sctp_initmsg -> done with"
+            "\r\n   res:    %d"
+            "\r\n   result: %T"
+            "\r\n", res, result) );
+
+    return result;
+}
+#endif
+
+
+/* ngetopt_lvl_sctp_maxseg - Level SCTP MAXSEG option
+ */
+#if defined(SCTP_MAXSEG)
+static
+ERL_NIF_TERM ngetopt_lvl_sctp_maxseg(ErlNifEnv*        env,
+                                     SocketDescriptor* descP)
+{
+    return ngetopt_int_opt(env, descP, IPPROTO_SCTP, SCTP_MAXSEG);
+}
+#endif
+
+
+/* ngetopt_lvl_sctp_nodelay - Level SCTP NODELAY option
+ */
+#if defined(SCTP_NODELAY)
+static
+ERL_NIF_TERM ngetopt_lvl_sctp_nodelay(ErlNifEnv*        env,
+                                      SocketDescriptor* descP)
+{
+    return ngetopt_bool_opt(env, descP, IPPROTO_SCTP, SCTP_NODELAY);
+}
+#endif
+
+
+/* ngetopt_lvl_sctp_associnfo - Level SCTP ASSOCINFO option
+ *
+ * <KOLLA>
+ *
+ * We should really specify which association this relates to,
+ * as it is now we get assoc-id = 0. If this socket is an 
+ * association (and not an endpoint) then it will have an
+ * assoc id (we can assume). But since the sctp support at 
+ * present is "limited", we leave it for now.
+ * What do we do if this is an endpoint? Invalid op?
+ *
+ * </KOLLA>
+ */
+#if defined(SCTP_RTOINFO)
+static
+ERL_NIF_TERM ngetopt_lvl_sctp_rtoinfo(ErlNifEnv*        env,
+                                      SocketDescriptor* descP)
+{
+    ERL_NIF_TERM        result;
+    struct sctp_rtoinfo val;
+    SOCKOPTLEN_T        valSz = sizeof(val);
+    int                 res;
+
+    SSDBG( descP, ("SOCKET", "ngetopt_lvl_sctp_rtoinfo -> entry\r\n") );
+    
+    sys_memzero((char*) &val, valSz);
+    res = sock_getopt(descP->sock, IPPROTO_SCTP, SCTP_RTOINFO, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM eRTOInfo;        
+        ERL_NIF_TERM keys[]  = {atom_assoc_id, atom_initial, atom_max, atom_min};
+        ERL_NIF_TERM vals[]  = {MKUI(env, val.srto_assoc_id),
+                                MKUI(env, val.srto_initial),
+                                MKUI(env, val.srto_max),
+                                MKUI(env, val.srto_min)};
+        unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+        unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+
+        ESOCK_ASSERT( (numKeys == numVals) );
+
+        if (!MKMA(env, keys, vals, numKeys, &eRTOInfo))
+            return esock_make_error(env, esock_atom_einval);;
+    
+        result = esock_make_ok2(env, eRTOInfo);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_lvl_sctp_rtoinfo -> done with"
+            "\r\n   res:    %d"
+            "\r\n   result: %T"
+            "\r\n", res, result) );
+
+    return result;
+}
+#endif
+
+
+
+#endif // defined(HAVE_SCTP)
+
+
+
+/* ngetopt_bool_opt - get an (integer) bool option
+ */
+static
+ERL_NIF_TERM ngetopt_bool_opt(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              int               level,
+                              int               opt)
+{
+    ERL_NIF_TERM result;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    /*
+    SSDBG( descP, ("SOCKET", "ngetopt_bool_opt -> entry with"
+                   "\r\n: level: %d"
+                   "\r\n: opt:   %d"
+                   "\r\n", level, opt) );
+    */
+
+    res = sock_getopt(descP->sock, level, opt, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM bval = ((val) ? atom_true : atom_false);
+
+        result = esock_make_ok2(env, bval);
+    }
+
+    /*
+    SSDBG( descP, ("SOCKET", "ngetopt_bool_opt -> done when"
+                   "\r\n: res:    %d"
+                   "\r\n: result: %T"
+                   "\r\n", res, result) );
+    */
+
+    return result;
+}
+
+
+/* ngetopt_int_opt - get an integer option
+ */
+static
+ERL_NIF_TERM ngetopt_int_opt(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             int               level,
+                             int               opt)
+{
+    ERL_NIF_TERM result;
+    int          val;
+    SOCKOPTLEN_T valSz = sizeof(val);
+    int          res;
+
+    res = sock_getopt(descP->sock, level, opt, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        result = esock_make_ok2(env, MKI(env, val));
+    }
+
+    return result;
+}
+
+
+
+/* ngetopt_timeval_opt - get an timeval option
+ */
+static
+ERL_NIF_TERM ngetopt_timeval_opt(ErlNifEnv*        env,
+                                 SocketDescriptor* descP,
+                                 int               level,
+                                 int               opt)
+{
+    ERL_NIF_TERM   result;
+    struct timeval val;
+    SOCKOPTLEN_T   valSz = sizeof(val);
+    int            res;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_timeval_opt -> entry with"
+            "\r\n   level: %d"
+            "\r\n   opt:   %d"
+            "\r\n", level, opt) );
+
+    sys_memzero((char*) &val, valSz);
+    res = sock_getopt(descP->sock, level, opt, &val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM eTimeVal;
+        char*        xres;
+
+        if ((xres = esock_encode_timeval(env, &val, &eTimeVal)) != NULL)
+            result = esock_make_error_str(env, xres);
+        else
+            result = esock_make_ok2(env, eTimeVal);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_timeval_opt -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    return result;
+}
+
+
+
+/* ngetopt_str_opt - get an string option
+ *
+ * We provide the max size of the string. This is the
+ * size of the buffer we allocate for the value.
+ * The actual size of the (read) value will be communicated
+ * in the optSz variable.
+ */
+static
+ERL_NIF_TERM ngetopt_str_opt(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             int               level,
+                             int               opt,
+                             int               max)
+{
+    ERL_NIF_TERM result;
+    char*        val   = MALLOC(max);
+    SOCKOPTLEN_T valSz = max;
+    int          res;
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_str_opt -> entry with"
+            "\r\n   level: %d"
+            "\r\n   opt:   %d"
+            "\r\n   max:   %d"
+            "\r\n", level, opt, max) );
+
+    res = sock_getopt(descP->sock, level, opt, val, &valSz);
+
+    if (res != 0) {
+        result = esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM sval = MKSL(env, val, valSz);
+
+        result = esock_make_ok2(env, sval);
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "ngetopt_str_opt -> done when"
+            "\r\n   result: %T"
+            "\r\n", result) );
+
+    FREE(val);
+
+    return result;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_sockname - get socket name
+ *
+ * Description:
+ * Returns the current address to which the socket is bound.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+
+static
+ERL_NIF_TERM nif_sockname(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      res;
+
+    SGDBG( ("SOCKET", "nif_sockname -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_sockname -> args when sock = %d:"
+            "\r\n   Socket: %T"
+            "\r\n", descP->sock, argv[0]) );
+
+    res = nsockname(env, descP);
+
+    SSDBG( descP, ("SOCKET", "nif_sockname -> done with res = %T\r\n", res) );
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM nsockname(ErlNifEnv*        env,
+                       SocketDescriptor* descP)
+{
+    SocketAddress  sa;
+    SocketAddress* saP = &sa;
+    unsigned int   sz  = sizeof(SocketAddress);
+
+    sys_memzero((char*) saP, sz);
+    if (IS_SOCKET_ERROR(sock_name(descP->sock, (struct sockaddr*) saP, &sz))) {
+        return esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM esa;
+        char*        xres;
+
+        if ((xres = esock_encode_sockaddr(env, saP, sz, &esa)) != NULL)
+            return esock_make_error_str(env, xres);
+        else
+            return esock_make_ok2(env, esa);
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_peername - get name of the connected peer socket
+ *
+ * Description:
+ * Returns the address of the peer connected to the socket.
+ *
+ * Arguments:
+ * Socket (ref) - Points to the socket descriptor.
+ */
+
+static
+ERL_NIF_TERM nif_peername(ErlNifEnv*         env,
+                          int                argc,
+                          const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      res;
+
+    SGDBG( ("SOCKET", "nif_peername -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 1) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_peername -> args when sock = %d:"
+            "\r\n   Socket: %T"
+            "\r\n", descP->sock, argv[0]) );
+
+    res = npeername(env, descP);
+
+    SSDBG( descP, ("SOCKET", "nif_peername -> done with res = %T\r\n", res) );
+
+    return res;
+#endif // if defined(__WIN32__)
+}
+
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM npeername(ErlNifEnv*        env,
+                       SocketDescriptor* descP)
+{
+    SocketAddress  sa;
+    SocketAddress* saP = &sa;
+    unsigned int   sz  = sizeof(SocketAddress);
+
+    sys_memzero((char*) saP, sz);
+    if (IS_SOCKET_ERROR(sock_peer(descP->sock, (struct sockaddr*) saP, &sz))) {
+        return esock_make_error_errno(env, sock_errno());
+    } else {
+        ERL_NIF_TERM esa;
+        char*        xres;
+
+        if ((xres = esock_encode_sockaddr(env, saP, sz, &esa)) != NULL)
+            return esock_make_error_str(env, xres);
+        else
+            return esock_make_ok2(env, esa);
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ * nif_cancel
+ *
+ * Description:
+ * Cancel a previous select!
+ *
+ * Arguments:
+ * Socket    (ref)  - Points to the socket descriptor.
+ * Operation (atom) - What kind of operation (accept, send, ...) is to be cancelled
+ * Ref       (ref)  - Unique id for the operation
+ */
+static
+ERL_NIF_TERM nif_cancel(ErlNifEnv*         env,
+                        int                argc,
+                        const ERL_NIF_TERM argv[])
+{
+#if defined(__WIN32__)
+    return enif_raise_exception(env, MKA(env, "nosup"));
+#else
+    SocketDescriptor* descP;
+    ERL_NIF_TERM      op, opRef, result;
+
+    SGDBG( ("SOCKET", "nif_cancel -> entry with argc: %d\r\n", argc) );
+
+    /* Extract arguments and perform preliminary validation */
+
+    if ((argc != 3) ||
+        !enif_get_resource(env, argv[0], sockets, (void**) &descP)) {
+        return enif_make_badarg(env);
+    }
+    op    = argv[1];
+    opRef = argv[2];
+        
+    if (IS_CLOSED(descP) || IS_CLOSING(descP))
+        return esock_make_error(env, atom_closed);
+    
+    SSDBG( descP,
+           ("SOCKET", "nif_cancel -> args when sock = %d:"
+            "\r\n   op:    %T"
+            "\r\n   opRef: %T"
+            "\r\n", descP->sock, op, opRef) );
+    
+    result = ncancel(env, descP, op, opRef);
+
+    SSDBG( descP,
+           ("SOCKET", "nif_cancel -> done with result: "
+           "\r\n   %T"
+           "\r\n", result) );
+
+    return result;
+#endif // if !defined(__WIN32__)
+}
+
+
+#if !defined(__WIN32__)
+static
+ERL_NIF_TERM ncancel(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     ERL_NIF_TERM      op,
+                     ERL_NIF_TERM      opRef)
+{
+    /* <KOLLA>
+     *
+     * Do we really need all these variants? Should it not be enough with: 
+     *
+     *     connect | accept | send | recv
+     *
+     * </KOLLA>
+     */
+    if (COMPARE(op, esock_atom_connect) == 0) {
+        return ncancel_connect(env, descP, opRef);
+    } else if (COMPARE(op, esock_atom_accept) == 0) {
+        return ncancel_accept(env, descP, opRef);
+    } else if (COMPARE(op, esock_atom_send) == 0) {
+        return ncancel_send(env, descP, opRef);
+    } else if (COMPARE(op, esock_atom_sendto) == 0) {
+        return ncancel_send(env, descP, opRef);
+    } else if (COMPARE(op, esock_atom_sendmsg) == 0) {
+        return ncancel_send(env, descP, opRef);
+    } else if (COMPARE(op, esock_atom_recv) == 0) {
+        return ncancel_recv(env, descP, opRef);
+    } else if (COMPARE(op, esock_atom_recvfrom) == 0) {
+        return ncancel_recv(env, descP, opRef);
+    } else if (COMPARE(op, esock_atom_recvmsg) == 0) {
+        return ncancel_recv(env, descP, opRef);
+    } else {
+        return esock_make_error(env, esock_atom_einval);
+    }
+}
+
+
+
+/* *** ncancel_connect ***
+ *
+ *
+ */
+static
+ERL_NIF_TERM ncancel_connect(ErlNifEnv*        env,
+                             SocketDescriptor* descP,
+                             ERL_NIF_TERM      opRef)
+{
+    return ncancel_write_select(env, descP, opRef);
+}
+
+
+/* *** ncancel_accept ***
+ *
+ * We have two different cases:
+ *   *) Its the current acceptor
+ *      Cancel the select!
+ *      We need to activate one of the waiting acceptors.
+ *   *) Its one of the acceptors ("waiting") in the queue
+ *      Simply remove the acceptor from the queue.
+ *
+ */
+static
+ERL_NIF_TERM ncancel_accept(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ERL_NIF_TERM      opRef)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP,
+           ("SOCKET", "ncancel_accept -> entry with"
+            "\r\n   opRef: %T"
+            "\r\n   %s"
+            "\r\n", opRef,
+            ((descP->currentAcceptorP == NULL) ? "without acceptor" : "with acceptor")) );
+
+    MLOCK(descP->accMtx);
+
+    if (descP->currentAcceptorP != NULL) {
+        if (COMPARE(opRef, descP->currentAcceptor.ref) == 0) {
+            res = ncancel_accept_current(env, descP);
+        } else {
+            res = ncancel_accept_waiting(env, descP, opRef);
+        }
+    } else {
+        /* Or badarg? */
+        res =  esock_make_error(env, esock_atom_einval);
+    }
+
+    MUNLOCK(descP->accMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "ncancel_accept -> done with result:"
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+}
+
+
+/* The current acceptor process has an ongoing select we first must
+ * cancel. Then we must re-activate the "first" (the first
+ * in the acceptor queue).
+ */
+static
+ERL_NIF_TERM ncancel_accept_current(ErlNifEnv*        env,
+                                    SocketDescriptor* descP)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP, ("SOCKET", "ncancel_accept_current -> entry\r\n") );
+
+    DEMONP("ncancel_accept_current -> current acceptor",
+           env, descP, &descP->currentAcceptor.mon);
+    res = ncancel_read_select(env, descP, descP->currentAcceptor.ref);
+
+    SSDBG( descP, ("SOCKET", "ncancel_accept_current -> cancel res: %T\r\n", res) );
+
+    if (acceptor_pop(env, descP,
+                     &descP->currentAcceptor.pid,
+                     &descP->currentAcceptor.mon,
+                     &descP->currentAcceptor.ref)) {
+        
+        /* There was another one */
+        
+        SSDBG( descP, ("SOCKET", "ncancel_accept_current -> new (active) acceptor: "
+                       "\r\n   pid: %T"
+                       "\r\n   ref: %T"
+                       "\r\n",
+                       descP->currentAcceptor.pid,
+                       descP->currentAcceptor.ref) );
+        
+        SELECT(env,
+               descP->sock,
+               (ERL_NIF_SELECT_READ),
+               descP, &descP->currentAcceptor.pid, descP->currentAcceptor.ref);
+
+    } else {
+        SSDBG( descP, ("SOCKET", "ncancel_accept_current -> no more acceptors\r\n") );
+        descP->currentAcceptorP = NULL;
+        descP->state            = SOCKET_STATE_LISTENING;
+    }
+    
+    SSDBG( descP, ("SOCKET", "ncancel_accept_current -> done with result:"
+                   "\r\n   %T"
+                   "\r\n", res) );
+
+    return res;
+}
+
+
+/* These processes have not performed a select, so we can simply
+ * remove them from the acceptor queue.
+ */
+static
+ERL_NIF_TERM ncancel_accept_waiting(ErlNifEnv*        env,
+                                    SocketDescriptor* descP,
+                                    ERL_NIF_TERM      opRef)
+{
+    ErlNifPid caller;
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    /* unqueue request from (acceptor) queue */
+
+    if (acceptor_unqueue(env, descP, &caller)) {
+        return esock_atom_ok;
+    } else {
+        /* Race? */
+        return esock_make_error(env, esock_atom_not_found);
+    }
+}
+
+
+
+/* *** ncancel_send ***
+ *
+ * Cancel a send operation.
+ * Its either the current writer or one of the waiting writers.
+ */
+static
+ERL_NIF_TERM ncancel_send(ErlNifEnv*        env,
+                          SocketDescriptor* descP,
+                          ERL_NIF_TERM      opRef)
+{
+    ERL_NIF_TERM res;
+
+    MLOCK(descP->writeMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "ncancel_send -> entry with"
+            "\r\n   opRef: %T"
+            "\r\n   %s"
+            "\r\n", opRef,
+            ((descP->currentWriterP == NULL) ? "without writer" : "with writer")) );
+
+    if (descP->currentWriterP != NULL) {
+        if (COMPARE(opRef, descP->currentWriter.ref) == 0) {
+            res = ncancel_send_current(env, descP);
+        } else {
+            res = ncancel_send_waiting(env, descP, opRef);
+        }
+    } else {
+        /* Or badarg? */
+        res =  esock_make_error(env, esock_atom_einval);
+    }
+
+    MUNLOCK(descP->writeMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "ncancel_send -> done with result:"
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+}
+
+
+
+/* The current writer process has an ongoing select we first must
+ * cancel. Then we must re-activate the "first" (the first
+ * in the writer queue).
+ */
+static
+ERL_NIF_TERM ncancel_send_current(ErlNifEnv*        env,
+                                  SocketDescriptor* descP)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP, ("SOCKET", "ncancel_send_current -> entry\r\n") );
+
+    DEMONP("ncancel_recv_current -> current writer",
+           env, descP, &descP->currentWriter.mon);
+    res = ncancel_write_select(env, descP, descP->currentWriter.ref);
+
+    SSDBG( descP, ("SOCKET", "ncancel_send_current -> cancel res: %T\r\n", res) );
+
+    if (writer_pop(env, descP,
+                   &descP->currentWriter.pid,
+                   &descP->currentWriter.mon,
+                   &descP->currentWriter.ref)) {
+        
+        /* There was another one */
+        
+        SSDBG( descP, ("SOCKET", "ncancel_send_current -> new (active) writer: "
+                       "\r\n   pid: %T"
+                       "\r\n   ref: %T"
+                       "\r\n",
+                       descP->currentWriter.pid,
+                       descP->currentWriter.ref) );
+        
+        SELECT(env,
+               descP->sock,
+               (ERL_NIF_SELECT_WRITE),
+               descP, &descP->currentWriter.pid, descP->currentWriter.ref);
+
+    } else {
+        SSDBG( descP, ("SOCKET", "ncancel_send_current -> no more writers\r\n") );
+        descP->currentWriterP = NULL;
+    }
+    
+    SSDBG( descP, ("SOCKET", "ncancel_send_current -> done with result:"
+                   "\r\n   %T"
+                   "\r\n", res) );
+
+    return res;
+}
+
+
+/* These processes have not performed a select, so we can simply
+ * remove them from the writer queue.
+ */
+static
+ERL_NIF_TERM ncancel_send_waiting(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  ERL_NIF_TERM      opRef)
+{
+    ErlNifPid caller;
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    /* unqueue request from (writer) queue */
+
+    if (writer_unqueue(env, descP, &caller)) {
+        return esock_atom_ok;
+    } else {
+        /* Race? */
+        return esock_make_error(env, esock_atom_not_found);
+    }
+}
+
+
+
+/* *** ncancel_recv ***
+ *
+ * Cancel a read operation.
+ * Its either the current reader or one of the waiting readers.
+ */
+static
+ERL_NIF_TERM ncancel_recv(ErlNifEnv*        env,
+                          SocketDescriptor* descP,
+                          ERL_NIF_TERM      opRef)
+{
+    ERL_NIF_TERM res;
+
+    MLOCK(descP->readMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "ncancel_recv -> entry with"
+            "\r\n   opRef: %T"
+            "\r\n   %s"
+            "\r\n", opRef,
+            ((descP->currentReaderP == NULL) ? "without reader" : "with reader")) );
+
+    if (descP->currentReaderP != NULL) {
+        if (COMPARE(opRef, descP->currentReader.ref) == 0) {
+            res = ncancel_recv_current(env, descP);
+        } else {
+            res = ncancel_recv_waiting(env, descP, opRef);
+        }
+    } else {
+        /* Or badarg? */
+        res =  esock_make_error(env, esock_atom_einval);
+    }
+
+    MUNLOCK(descP->readMtx);
+
+    SSDBG( descP,
+           ("SOCKET", "ncancel_recv -> done with result:"
+            "\r\n   %T"
+            "\r\n", res) );
+
+    return res;
+}
+
+
+/* The current reader process has an ongoing select we first must
+ * cancel. Then we must re-activate the "first" (the first
+ * in the reader queue).
+ */
+static
+ERL_NIF_TERM ncancel_recv_current(ErlNifEnv*        env,
+                                  SocketDescriptor* descP)
+{
+    ERL_NIF_TERM res;
+
+    SSDBG( descP, ("SOCKET", "ncancel_recv_current -> entry\r\n") );
+
+    DEMONP("ncancel_recv_current -> current reader",
+           env, descP, &descP->currentReader.mon);
+    res = ncancel_read_select(env, descP, descP->currentReader.ref);
+
+    SSDBG( descP, ("SOCKET", "ncancel_recv_current -> cancel res: %T\r\n", res) );
+
+    if (reader_pop(env, descP,
+                   &descP->currentReader.pid,
+                   &descP->currentReader.mon,
+                   &descP->currentReader.ref)) {
+        
+        /* There was another one */
+        
+        SSDBG( descP, ("SOCKET", "ncancel_recv_current -> new (active) reader: "
+                       "\r\n   pid: %T"
+                       "\r\n   ref: %T"
+                       "\r\n",
+                       descP->currentReader.pid,
+                       descP->currentReader.ref) );
+        
+        SELECT(env,
+               descP->sock,
+               (ERL_NIF_SELECT_READ),
+               descP, &descP->currentReader.pid, descP->currentReader.ref);
+
+    } else {
+        SSDBG( descP, ("SOCKET", "ncancel_recv_current -> no more readers\r\n") );
+        descP->currentReaderP = NULL;
+    }
+    
+    SSDBG( descP, ("SOCKET", "ncancel_recv_current -> done with result:"
+                   "\r\n   %T"
+                   "\r\n", res) );
+
+    return res;
+}
+
+
+/* These processes have not performed a select, so we can simply
+ * remove them from the reader queue.
+ */
+static
+ERL_NIF_TERM ncancel_recv_waiting(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  ERL_NIF_TERM      opRef)
+{
+    ErlNifPid caller;
+
+    if (enif_self(env, &caller) == NULL)
+        return esock_make_error(env, atom_exself);
+
+    /* unqueue request from (reader) queue */
+
+    if (reader_unqueue(env, descP, &caller)) {
+        return esock_atom_ok;
+    } else {
+        /* Race? */
+        return esock_make_error(env, esock_atom_not_found);
+    }
+}
+
+
+
+static
+ERL_NIF_TERM ncancel_read_select(ErlNifEnv*        env,
+                                 SocketDescriptor* descP,
+                                 ERL_NIF_TERM      opRef)
+{
+    return ncancel_mode_select(env, descP, opRef,
+                               ERL_NIF_SELECT_READ,
+                               ERL_NIF_SELECT_READ_CANCELLED);
+}
+
+
+static
+ERL_NIF_TERM ncancel_write_select(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  ERL_NIF_TERM      opRef)
+{
+    return ncancel_mode_select(env, descP, opRef,
+                               ERL_NIF_SELECT_WRITE,
+                               ERL_NIF_SELECT_WRITE_CANCELLED);
+}
+
+
+static
+ERL_NIF_TERM ncancel_mode_select(ErlNifEnv*        env,
+                                 SocketDescriptor* descP,
+                                 ERL_NIF_TERM      opRef,
+                                 int               smode,
+                                 int               rmode)
+{
+    int selectRes = enif_select(env, descP->sock,
+                                (ERL_NIF_SELECT_CANCEL | smode),
+                                descP, NULL, opRef);
+
+    if (selectRes & rmode) {
+        /* Was cancelled */
+        return esock_atom_ok;
+    } else if (selectRes > 0) {
+        /* Has already sent the message */
+        return esock_make_error(env, esock_atom_select_sent);
+    } else {
+        /* Stopped? */
+        SSDBG( descP, ("SOCKET", "ncancel_mode_select -> failed: %d (0x%lX)"
+                       "\r\n", selectRes, selectRes) );
+        return esock_make_error(env, esock_atom_einval);
+    }
+
+}
+#endif // if !defined(__WIN32__)
+
+
+
+
+/* ----------------------------------------------------------------------
+ *  U t i l i t y   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* *** send_check_writer ***
+ *
+ * Checks if we have a current writer and if that is us. If not, then we must
+ * be made to wait for our turn. This is done by pushing us unto the writer queue.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T send_check_writer(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ERL_NIF_TERM      ref,
+                            ERL_NIF_TERM*     checkResult)
+{
+    if (descP->currentWriterP != NULL) {
+        ErlNifPid caller;
+        
+        if (enif_self(env, &caller) == NULL) {
+            *checkResult = esock_make_error(env, atom_exself);
+            return FALSE;
+        }
+
+        if (!compare_pids(env, &descP->currentWriter.pid, &caller)) {
+            /* Not the "current writer", so (maybe) push onto queue */
+
+            SSDBG( descP,
+                   ("SOCKET", "send_check_writer -> not (current) writer\r\n") );
+
+            if (!writer_search4pid(env, descP, &caller))
+                *checkResult = writer_push(env, descP, caller, ref);
+            else
+                *checkResult = esock_make_error(env, esock_atom_eagain);
+            
+            SSDBG( descP,
+                   ("SOCKET",
+                    "send_check_writer -> queue (push) result: %T\r\n",
+                    checkResult) );
+            
+            return FALSE;
+
+        }
+        
+    }
+
+    *checkResult = esock_atom_ok; // Does not actually matter in this case, but ...
+
+    return TRUE;
+}
+
+
+
+/* *** send_check_result ***
+ *
+ * Check the result of a socket send (send, sendto and sendmsg) call.
+ * If a "complete" send has been made, the next (waiting) writer will be 
+ * scheduled (if there is one).
+ * If we did not manage to send the entire package, make another select,
+ * so that we can be informed when we can make another try (to send the rest),
+ * and return with the amount we actually managed to send (its up to the caller
+ * (that is the erlang code) to figure out hust much is left to send).
+ * If the write fail, we give up and return with the appropriate error code.
+ *
+ * What about the remaining writers!!
+ */
+static
+ERL_NIF_TERM send_check_result(ErlNifEnv*        env,
+                               SocketDescriptor* descP,
+                               ssize_t           written,
+                               ssize_t           dataSize,
+                               int               saveErrno,
+                               ERL_NIF_TERM      sockRef,
+                               ERL_NIF_TERM      sendRef)
+{
+    SSDBG( descP,
+           ("SOCKET", "send_check_result -> entry with"
+            "\r\n   written:   %d"
+            "\r\n   dataSize:  %d"
+            "\r\n   saveErrno: %d"
+            "\r\n", written, dataSize, saveErrno) );
+
+    if (written >= dataSize) {
+
+        cnt_inc(&descP->writePkgCnt,  1);
+        cnt_inc(&descP->writeByteCnt, written);
+        if (descP->currentWriterP != NULL)
+            DEMONP("send_check_result -> current writer",
+                   env, descP, &descP->currentWriter.mon);
+
+        SSDBG( descP,
+               ("SOCKET", "send_check_result -> "
+                "everything written (%d,%d) - done\r\n", dataSize, written) );
+
+        /* Ok, this write is done maybe activate the next (if any) */
+
+        if (writer_pop(env, descP,
+                       &descP->currentWriter.pid,
+                       &descP->currentWriter.mon,
+                       &descP->currentWriter.ref)) {
+
+            /* There was another one */
+
+            SSDBG( descP, ("SOCKET", "send_check_result -> new (active) writer: "
+                           "\r\n   pid: %T"
+                           "\r\n   ref: %T"
+                           "\r\n",
+                           descP->currentWriter.pid,
+                           descP->currentWriter.ref) );
+
+            SELECT(env,
+                   descP->sock,
+                   (ERL_NIF_SELECT_WRITE),
+                   descP, &descP->currentWriter.pid, descP->currentWriter.ref);
+
+        } else {
+            descP->currentWriterP = NULL;
+        }
+
+        return esock_atom_ok;
+
+    } else if (written < 0) {
+
+        /* Some kind of send failure - check what kind */
+
+        if ((saveErrno != EAGAIN) && (saveErrno != EINTR)) {
+            ErlNifPid     pid;
+            // ErlNifMonitor mon;
+            ESockMonitor  mon;
+            ERL_NIF_TERM  ref, res;
+
+            /* 
+             * An actual failure - we (and everyone waiting) give up
+             */
+
+            cnt_inc(&descP->writeFails, 1);
+
+            SSDBG( descP,
+                   ("SOCKET", "send_check_result -> error: %d\r\n", saveErrno) );
+
+            res = esock_make_error_errno(env, saveErrno);
+
+            if (descP->currentWriterP != NULL) {
+                DEMONP("send_check_result -> current writer",
+                       env, descP, &descP->currentWriter.mon);
+
+                while (writer_pop(env, descP, &pid, &mon, &ref)) {
+                    SSDBG( descP,
+                           ("SOCKET", "send_check_result -> abort %T\r\n", pid) );
+                    esock_send_abort_msg(env, sockRef, ref, res, &pid);
+                    DEMONP("send_check_result -> pop'ed writer",
+                           env, descP, &mon);
+                }
+            }
+            
+            return res;
+
+        } else {
+
+            /* Ok, try again later */
+
+            SSDBG( descP, ("SOCKET", "send_check_result -> try again\r\n") );
+
+            SELECT(env, descP->sock, (ERL_NIF_SELECT_WRITE), descP, NULL, sendRef);
+
+            return esock_make_error(env, esock_atom_eagain);
+
+        }
+
+    }
+
+    /* We failed to write the *entire* packet (anything less then size
+     * of the packet, which is 0 <= written < sizeof packet),
+     * so schedule the rest for later.
+     */
+
+    if (descP->currentWriterP == NULL) {
+        ErlNifPid caller;
+
+        if (enif_self(env, &caller) == NULL)
+            return esock_make_error(env, atom_exself);
+        descP->currentWriter.pid = caller;
+        if (MONP("send_check_result -> current writer",
+                 env, descP,
+                 &descP->currentWriter.pid,
+                 &descP->currentWriter.mon) != 0)
+            return esock_make_error(env, atom_exmon);
+        descP->currentWriter.ref = enif_make_copy(descP->env, sendRef);
+        descP->currentWriterP    = &descP->currentWriter;
+    }
+
+    cnt_inc(&descP->writeWaits, 1);
+
+    SELECT(env, descP->sock, (ERL_NIF_SELECT_WRITE), descP, NULL, sendRef);
+
+    SSDBG( descP,
+           ("SOCKET", "send_check_result -> "
+            "not entire package written (%d of %d)\r\n", written, dataSize) );
+
+    return esock_make_ok2(env, MKI(env, written));
+
+}
+
+
+
+/* *** recv_check_reader ***
+ *
+ * Checks if we have a current reader and if that is us. If not, then we must
+ * be made to wait for our turn. This is done by pushing us unto the reader queue.
+ */
+static
+BOOLEAN_T recv_check_reader(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ERL_NIF_TERM      ref,
+                            ERL_NIF_TERM*     checkResult)
+{
+    if (descP->currentReaderP != NULL) {
+        ErlNifPid caller;
+        
+        if (enif_self(env, &caller) == NULL) {
+            *checkResult = esock_make_error(env, atom_exself);
+            return FALSE;
+        }
+
+        if (!compare_pids(env, &descP->currentReader.pid, &caller)) {
+            ERL_NIF_TERM tmp;
+
+            /* Not the "current reader", so (maybe) push onto queue */
+
+            SSDBG( descP,
+                   ("SOCKET", "recv_check_reader -> not (current) reader\r\n") );
+
+            if (!reader_search4pid(env, descP, &caller))
+                tmp = reader_push(env, descP, caller, ref);
+            else
+                tmp = esock_make_error(env, esock_atom_eagain);
+            
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recv_check_reader -> queue (push) result: %T\r\n", tmp) );
+
+            *checkResult = tmp;
+
+            return FALSE;
+
+        }
+        
+    }
+
+    *checkResult = esock_atom_ok; // Does not actually matter in this case, but ...
+
+    return TRUE;
+}
+
+
+
+/* *** recv_init_current_reader ***
+ *
+ * Initiate (maybe) the currentReader structure of the descriptor.
+ * Including monitoring the calling process.
+ */
+static
+char* recv_init_current_reader(ErlNifEnv*        env,
+                               SocketDescriptor* descP,
+                               ERL_NIF_TERM      recvRef)
+{
+    if (descP->currentReaderP == NULL) {
+        ErlNifPid caller;
+
+        if (enif_self(env, &caller) == NULL)
+            return str_exself;
+
+        descP->currentReader.pid = caller;
+        if (MONP("recv_init_current_reader -> current reader",
+                 env, descP,
+                 &descP->currentReader.pid,
+                 &descP->currentReader.mon) != 0) {
+            return str_exmon;
+        }
+        descP->currentReader.ref = enif_make_copy(descP->env, recvRef);
+        descP->currentReaderP    = &descP->currentReader;
+    }
+
+    return NULL;
+}
+
+
+
+/* *** recv_update_current_reader ***
+ *
+ * Demonitors the current reader process and pop's the reader queue.
+ * If there is a waiting (reader) process, then it will be assigned
+ * as the new current reader and a new (read) select will be done.
+ */
+
+static
+ERL_NIF_TERM recv_update_current_reader(ErlNifEnv*        env,
+                                        SocketDescriptor* descP)
+{
+    if (descP->currentReaderP != NULL) {
+        
+        DEMONP("recv_update_current_reader -> current reader",
+               env, descP, &descP->currentReader.mon);
+        
+        if (reader_pop(env, descP,
+                       &descP->currentReader.pid,
+                       &descP->currentReader.mon,
+                       &descP->currentReader.ref)) {
+            
+            /* There was another one */
+            
+            SSDBG( descP,
+                   ("SOCKET", "recv_update_current_reader -> new (active) reader: "
+                    "\r\n   pid: %T"
+                    "\r\n   ref: %T"
+                    "\r\n",
+                    descP->currentReader.pid,
+                    descP->currentReader.ref) );
+            
+            SELECT(env,
+                   descP->sock,
+                   (ERL_NIF_SELECT_READ),
+                   descP,
+                   &descP->currentReader.pid,
+                   descP->currentReader.ref);
+            
+        } else {
+            descP->currentReaderP = NULL;
+        }
+    }
+
+    return esock_atom_ok;
+}
+
+
+
+/* *** recv_error_current_reader ***
+ *
+ * Process the current reader and any waiting readers
+ * when a read (fatal) error has occured.
+ * All waiting readers will be "aborted", that is a 
+ * nif_abort message will be sent (with reaf and reason).
+ */
+static
+void recv_error_current_reader(ErlNifEnv*        env,
+                               SocketDescriptor* descP,
+                               ERL_NIF_TERM      sockRef,
+                               ERL_NIF_TERM      reason)
+{
+    if (descP->currentReaderP != NULL) {
+        ErlNifPid     pid;
+        // ErlNifMonitor mon;
+        ESockMonitor  mon;
+        ERL_NIF_TERM  ref;
+
+        DEMONP("recv_error_current_reader -> current reader",
+               env, descP, &descP->currentReader.mon);
+
+        while (reader_pop(env, descP, &pid, &mon, &ref)) {
+            SSDBG( descP,
+                   ("SOCKET", "recv_error_current_reader -> abort %T\r\n", pid) );
+            esock_send_abort_msg(env, sockRef, ref, reason, &pid);
+            DEMONP("recv_error_current_reader -> pop'ed reader",
+                   env, descP, &mon);
+        }
+    }
+}
+
+
+
+/* *** recv_check_result ***
+ *
+ * Process the result of a call to recv.
+ */
+static
+ERL_NIF_TERM recv_check_result(ErlNifEnv*        env,
+                               SocketDescriptor* descP,
+                               int               read,
+                               int               toRead,
+                               int               saveErrno,
+                               ErlNifBinary*     bufP,
+                               ERL_NIF_TERM      sockRef,
+                               ERL_NIF_TERM      recvRef)
+{
+    char*        xres;
+    ERL_NIF_TERM data;
+
+    SSDBG( descP,
+           ("SOCKET", "recv_check_result -> entry with"
+            "\r\n   read:      %d"
+            "\r\n   toRead:    %d"
+            "\r\n   saveErrno: %d"
+            "\r\n   recvRef:   %T"
+            "\r\n", read, toRead, saveErrno, recvRef) );
+
+
+    /* <KOLLA>
+     *
+     * We need to handle read = 0 for other type(s) (DGRAM) when
+     * its actually valid to read 0 bytes.
+     *
+     * </KOLLA>
+     */
+    
+    if ((read == 0) && (descP->type == SOCK_STREAM)) {
+        ERL_NIF_TERM res = esock_make_error(env, atom_closed);
+        
+        /*
+         * When a stream socket peer has performed an orderly shutdown, the return
+         * value will be 0 (the traditional "end-of-file" return).
+         *
+         * *We* do never actually try to read 0 bytes from a stream socket!
+         *
+         * We must also notify any waiting readers!
+         */
+
+        recv_error_current_reader(env, descP, sockRef, res);
+
+        FREE_BIN(bufP);
+
+        return res;
+
+    }
+    
+    /* There is a special case: If the provided 'to read' value is
+     * zero (0) (only for type =/= stream).
+     * That means that we reads as much as we can, using the default
+     * read buffer size.
+     */
+
+    if (bufP->size == read) {
+
+        /* +++ We filled the buffer +++ */
+
+        SSDBG( descP,
+               ("SOCKET",
+                "recv_check_result -> [%d] filled the buffer\r\n", toRead) );
+
+        if (toRead == 0) {
+
+            /* +++ Give us everything you have got =>     *
+             *     (maybe) needs to continue          +++ */
+
+            /* How do we do this?
+             * Either:
+             * 1) Send up each chunk of data for each of the read
+             *    and let the erlang code assemble it: {ok, false, Bin}
+             *    (when complete it should return {ok, true, Bin}).
+             *    We need to read atleast one more time to be sure if its
+             *    done...
+             * 2) Or put it in a buffer here, and then let the erlang code
+             *    know that it should call again (special return value)
+             *    (continuous binary realloc "here").
+             *
+             * => We choose alt 1 for now.
+             *
+             * Also, we need to check if the rNumCnt has reached its max (rNum),
+             * in which case we will assume the read to be done!
+             */
+
+            cnt_inc(&descP->readByteCnt, read);
+
+            SSDBG( descP,
+                   ("SOCKET", "recv_check_result -> shall we continue reading"
+                    "\r\n   read:    %d"
+                    "\r\n   rNum:    %d"
+                    "\r\n   rNumCnt: %d"
+                    "\r\n", read, descP->rNum, descP->rNumCnt) );
+
+            if (descP->rNum > 0) {
+
+                descP->rNumCnt++;
+                if (descP->rNumCnt >= descP->rNum) {
+
+                    descP->rNumCnt = 0;
+
+                    cnt_inc(&descP->readPkgCnt, 1);
+                    
+                    recv_update_current_reader(env, descP);
+                    
+                    /* This transfers "ownership" of the *allocated* binary to an
+                     * erlang term (no need for an explicit free).
+                     */
+                    data = MKBIN(env, bufP);
+                    
+                    return esock_make_ok3(env, atom_true, data);
+
+                } else {
+
+                    /* Yes, we *do* need to continue reading */
+
+                    if ((xres = recv_init_current_reader(env,
+                                                         descP, recvRef)) != NULL) {
+                        descP->rNumCnt = 0;
+                        return esock_make_error_str(env, xres);
+                    }
+                
+                    /* This transfers "ownership" of the *allocated* binary to an
+                     * erlang term (no need for an explicit free).
+                     */
+                    data = MKBIN(env, bufP);
+                    
+                    return esock_make_ok3(env, atom_false, data);
+
+                }
+
+            } else {
+
+                /* Yes, we *do* need to continue reading */
+
+                if ((xres = recv_init_current_reader(env,
+                                                     descP, recvRef)) != NULL) {
+                    descP->rNumCnt = 0;
+                    return esock_make_error_str(env, xres);
+                }
+                
+                /* This transfers "ownership" of the *allocated* binary to an
+                 * erlang term (no need for an explicit free).
+                 */
+                data = MKBIN(env, bufP);
+                
+                SSDBG( descP,
+                       ("SOCKET",
+                        "recv_check_result -> [%d] "
+                        "we are done for now - read more\r\n", toRead) );
+                
+                return esock_make_ok3(env, atom_false, data);
+            }
+
+        } else {
+
+            /* +++ We got exactly as much as we requested => We are done +++ */
+
+            cnt_inc(&descP->readPkgCnt,  1);
+            cnt_inc(&descP->readByteCnt, read);
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recv_check_result -> [%d] "
+                    "we got exactly what we could fit\r\n", toRead) );
+
+            recv_update_current_reader(env, descP);
+
+            /* This transfers "ownership" of the *allocated* binary to an
+             * erlang term (no need for an explicit free).
+             */
+            data = MKBIN(env, bufP);
+
+            return esock_make_ok3(env, atom_true, data);
+
+        }
+
+    } else if (read < 0) {
+
+        /* +++ Error handling +++ */
+
+        if (saveErrno == ECONNRESET)  {
+            ERL_NIF_TERM res = esock_make_error(env, atom_closed);
+
+            /* +++ Oups - closed +++ */
+
+            SSDBG( descP, ("SOCKET",
+                           "recv_check_result -> [%d] closed\r\n", toRead) );
+
+            /* <KOLLA>
+             *
+             * IF THE CURRENT PROCESS IS *NOT* THE CONTROLLING
+             * PROCESS, WE NEED TO INFORM IT!!!
+             *
+             * ALL WAITING PROCESSES MUST ALSO GET THE ERROR!!
+             * HANDLED BY THE STOP (CALLBACK) FUNCTION?
+             *
+             * SINCE THIS IS A REMOTE CLOSE, WE DON'T NEED TO WAIT
+             * FOR OUTPUT TO BE WRITTEN (NO ONE WILL READ), JUST
+             * ABORT THE SOCKET REGARDLESS OF LINGER???
+             *
+             * </KOLLA>
+             */
+
+            descP->closeLocal = FALSE;
+            descP->state      = SOCKET_STATE_CLOSING;
+
+            recv_error_current_reader(env, descP, sockRef, res);
+
+            SELECT(env,
+                   descP->sock,
+                   (ERL_NIF_SELECT_STOP),
+                   descP, NULL, recvRef);
+
+            FREE_BIN(bufP);
+
+            return res;
+
+        } else if ((saveErrno == ERRNO_BLOCK) ||
+                   (saveErrno == EAGAIN)) {
+            int sres;
+
+            SSDBG( descP, ("SOCKET",
+                           "recv_check_result -> [%d] eagain\r\n", toRead) );
+
+            descP->rNumCnt = 0;
+            if ((xres = recv_init_current_reader(env, descP, recvRef)) != NULL)
+                return esock_make_error_str(env, xres);
+            
+            SSDBG( descP, ("SOCKET", "recv_check_result -> SELECT for more\r\n") );
+
+            sres = enif_select(env, descP->sock, (ERL_NIF_SELECT_READ),
+                               descP, NULL, recvRef);
+
+            SSDBG( descP,
+                   ("SOCKET", "recv_check_result -> SELECT res: %d\r\n", sres) );
+            
+            FREE_BIN(bufP);
+
+            return esock_make_error(env, esock_atom_eagain);
+        } else {
+            ERL_NIF_TERM res = esock_make_error_errno(env, saveErrno);
+
+            SSDBG( descP, ("SOCKET", "recv_check_result -> [%d] errno: %d\r\n",
+                           toRead, saveErrno) );
+
+            recv_error_current_reader(env, descP, sockRef, res);
+
+            FREE_BIN(bufP);
+
+            return res;
+        }
+
+    } else {
+
+        /* +++ We did not fill the buffer +++ */
+
+        SSDBG( descP,
+               ("SOCKET",
+                "recv_check_result -> [%d] "
+                "did not fill the buffer (%d of %d)\r\n",
+                toRead, read, bufP->size) );
+
+        if (toRead == 0) {
+
+            /* +++ We got it all, but since we      +++
+             * +++ did not fill the buffer, we      +++
+             * +++ must split it into a sub-binary. +++
+             */
+
+            SSDBG( descP, ("SOCKET",
+                           "recv_check_result -> [%d] split buffer\r\n", toRead) );
+
+            descP->rNumCnt = 0;
+            cnt_inc(&descP->readPkgCnt,  1);
+            cnt_inc(&descP->readByteCnt, read);
+
+            recv_update_current_reader(env, descP);
+
+            /* This transfers "ownership" of the *allocated* binary to an
+             * erlang term (no need for an explicit free).
+             */
+            data = MKBIN(env, bufP);
+            data = MKSBIN(env, data, 0, read);
+
+            SSDBG( descP,
+                   ("SOCKET", "recv_check_result -> [%d] done\r\n", toRead) );
+
+            return esock_make_ok3(env, atom_true, data);
+
+        } else {
+
+            /* +++ We got only a part of what was expected +++
+             * +++ => select for more more later and       +++
+             * +++    deliver what we got.                 +++ */
+
+            SSDBG( descP, ("SOCKET", "recv_check_result -> [%d] "
+                           "only part of message - expect more\r\n", toRead) );
+
+            /* SELECT for more data */
+
+            SELECT(env, descP->sock, (ERL_NIF_SELECT_READ),
+                   descP, NULL, recvRef);
+            
+            cnt_inc(&descP->readByteCnt, read);
+
+            /* This transfers "ownership" of the *allocated* binary to an
+             * erlang term (no need for an explicit free).
+             */
+            data = MKBIN(env, bufP);
+            data = MKSBIN(env, data, 0, read);
+
+            return esock_make_ok3(env, atom_false, data);
+        }
+    }
+}
+
+
+/* The recvfrom function delivers one (1) message. If our buffer
+ * is to small, the message will be truncated. So, regardless
+ * if we filled the buffer or not, we have got what we are going
+ * to get regarding this message.
+ */
+static
+ERL_NIF_TERM recvfrom_check_result(ErlNifEnv*        env,
+                                   SocketDescriptor* descP,
+                                   int               read,
+                                   int               saveErrno,
+                                   ErlNifBinary*     bufP,
+                                   SocketAddress*    fromAddrP,
+                                   unsigned int      fromAddrLen,
+                                   ERL_NIF_TERM      sockRef,
+                                   ERL_NIF_TERM      recvRef)
+{
+    char*        xres;
+    ERL_NIF_TERM data;
+
+    SSDBG( descP,
+           ("SOCKET", "recvfrom_check_result -> entry with"
+            "\r\n   read:      %d"
+            "\r\n   saveErrno: %d"
+            "\r\n   recvRef:   %T"
+            "\r\n", read, saveErrno, recvRef) );
+
+
+    /* There is a special case: If the provided 'to read' value is
+     * zero (0). That means that we reads as much as we can, using
+     * the default read buffer size.
+     */
+
+    if (read < 0) {
+
+        /* +++ Error handling +++ */
+
+        if (saveErrno == ECONNRESET)  {
+            ERL_NIF_TERM res = esock_make_error(env, atom_closed);
+
+            /* +++ Oups - closed +++ */
+
+            SSDBG( descP, ("SOCKET", "recvfrom_check_result -> closed\r\n") );
+
+            /* <KOLLA>
+             * IF THE CURRENT PROCESS IS *NOT* THE CONTROLLING
+             * PROCESS, WE NEED TO INFORM IT!!!
+             *
+             * ALL WAITING PROCESSES MUST ALSO GET THE ERROR!!
+             *
+             * </KOLLA>
+             */
+
+            descP->closeLocal = FALSE;
+            descP->state      = SOCKET_STATE_CLOSING;
+
+            recv_error_current_reader(env, descP, sockRef, res);
+
+            SELECT(env,
+                   descP->sock,
+                   (ERL_NIF_SELECT_STOP),
+                   descP, NULL, recvRef);
+
+            FREE_BIN(bufP);
+
+            return res;
+
+        } else if ((saveErrno == ERRNO_BLOCK) ||
+                   (saveErrno == EAGAIN)) {
+
+            SSDBG( descP, ("SOCKET", "recvfrom_check_result -> eagain\r\n") );
+            
+            if ((xres = recv_init_current_reader(env, descP, recvRef)) != NULL)
+                return esock_make_error_str(env, xres);
+            
+            SELECT(env, descP->sock, (ERL_NIF_SELECT_READ),
+                   descP, NULL, recvRef);
+
+            FREE_BIN(bufP);
+
+            return esock_make_error(env, esock_atom_eagain);
+
+        } else {
+            ERL_NIF_TERM res = esock_make_error_errno(env, saveErrno);
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recvfrom_check_result -> errno: %d\r\n", saveErrno) );
+            
+            recv_error_current_reader(env, descP, sockRef, res);
+
+            FREE_BIN(bufP);
+
+            return res;
+        }
+
+    } else {
+
+        /* +++ We sucessfully got a message - time to encode the address +++ */
+
+        ERL_NIF_TERM eSockAddr;
+
+        esock_encode_sockaddr(env,
+                              fromAddrP, fromAddrLen,
+                              &eSockAddr);
+
+        if (read == bufP->size) {
+            data = MKBIN(env, bufP);
+        } else {
+
+            /* +++ We got a chunk of data but +++
+             * +++ since we did not fill the  +++
+             * +++ buffer, we must split it   +++
+             * +++ into a sub-binary.         +++
+             */
+
+            data = MKBIN(env, bufP);
+            data = MKSBIN(env, data, 0, read);
+        }
+
+        recv_update_current_reader(env, descP);
+        
+        return esock_make_ok2(env, MKT2(env, eSockAddr, data));
+
+    }
+}
+
+
+
+/* The recvmsg function delivers one (1) message. If our buffer
+ * is to small, the message will be truncated. So, regardless
+ * if we filled the buffer or not, we have got what we are going
+ * to get regarding this message.
+ */
+static
+ERL_NIF_TERM recvmsg_check_result(ErlNifEnv*        env,
+                                  SocketDescriptor* descP,
+                                  int               read,
+                                  int               saveErrno,
+                                  struct msghdr*    msgHdrP,
+                                  ErlNifBinary*     dataBufP,
+                                  ErlNifBinary*     ctrlBufP,
+                                  ERL_NIF_TERM      sockRef,
+                                  ERL_NIF_TERM      recvRef)
+{
+
+    SSDBG( descP,
+           ("SOCKET", "recvmsg_check_result -> entry with"
+            "\r\n   read:      %d"
+            "\r\n   saveErrno: %d"
+            "\r\n   recvRef:   %T"
+            "\r\n", read, saveErrno, recvRef) );
+
+
+    /* <KOLLA>
+     *
+     * We need to handle read = 0 for other type(s) (DGRAM) when
+     * its actually valid to read 0 bytes.
+     *
+     * </KOLLA>
+     */
+    
+    if ((read == 0) && (descP->type == SOCK_STREAM)) {
+        
+        /*
+         * When a stream socket peer has performed an orderly shutdown, the return
+         * value will be 0 (the traditional "end-of-file" return).
+         *
+         * *We* do never actually try to read 0 bytes from a stream socket!
+         */
+
+
+        FREE_BIN(dataBufP); FREE_BIN(ctrlBufP);
+
+        return esock_make_error(env, atom_closed);
+
+    }
+
+
+    /* There is a special case: If the provided 'to read' value is
+     * zero (0). That means that we reads as much as we can, using
+     * the default read buffer size.
+     */
+
+    if (read < 0) {
+
+        /* +++ Error handling +++ */
+
+        if (saveErrno == ECONNRESET)  {
+            ERL_NIF_TERM res = esock_make_error(env, atom_closed);
+
+            /* +++ Oups - closed +++ */
+
+            SSDBG( descP, ("SOCKET", "recvmsg_check_result -> closed\r\n") );
+
+            /* <KOLLA>
+             * IF THE CURRENT PROCESS IS *NOT* THE CONTROLLING
+             * PROCESS, WE NEED TO INFORM IT!!!
+             *
+             * ALL WAITING PROCESSES MUST ALSO GET THE ERROR!!
+             *
+             * </KOLLA>
+             */
+
+            descP->closeLocal = FALSE;
+            descP->state      = SOCKET_STATE_CLOSING;
+
+            recv_error_current_reader(env, descP, sockRef, res);
+
+            SELECT(env,
+                   descP->sock,
+                   (ERL_NIF_SELECT_STOP),
+                   descP, NULL, recvRef);
+
+            FREE_BIN(dataBufP); FREE_BIN(ctrlBufP);
+
+            return res;
+
+        } else if ((saveErrno == ERRNO_BLOCK) ||
+                   (saveErrno == EAGAIN)) {
+            char* xres;
+
+            SSDBG( descP, ("SOCKET", "recvmsg_check_result -> eagain\r\n") );
+            
+            if ((xres = recv_init_current_reader(env, descP, recvRef)) != NULL)
+                return esock_make_error_str(env, xres);
+            
+            SELECT(env, descP->sock, (ERL_NIF_SELECT_READ),
+                   descP, NULL, recvRef);
+
+            FREE_BIN(dataBufP); FREE_BIN(ctrlBufP);
+
+            return esock_make_error(env, esock_atom_eagain);
+
+        } else {
+            ERL_NIF_TERM res = esock_make_error_errno(env, saveErrno);
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recvmsg_check_result -> errno: %d\r\n", saveErrno) );
+            
+            recv_error_current_reader(env, descP, sockRef, res);
+
+            FREE_BIN(dataBufP); FREE_BIN(ctrlBufP);
+
+            return res;
+        }
+
+    } else {
+
+        /* +++ We sucessfully got a message - time to encode it +++ */
+
+        ERL_NIF_TERM eMsgHdr;
+        char*        xres;
+
+        /*
+         * <KOLLA>
+         *
+         * The return value of recvmsg is the *total* number of bytes
+         * that where successfully read. This data has been put into
+         * the *IO vector*.
+         *
+         * </KOLLA>
+         */
+
+        if ((xres = encode_msghdr(env, descP,
+                                  read, msgHdrP, dataBufP, ctrlBufP,
+                                  &eMsgHdr)) != NULL) {
+            
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recvmsg_check_result -> "
+                    "(msghdr) encode failed: %s\r\n", xres) );
+            
+            recv_update_current_reader(env, descP);
+        
+            FREE_BIN(dataBufP); FREE_BIN(ctrlBufP);
+
+            return esock_make_error_str(env, xres);
+        } else {
+
+            SSDBG( descP,
+                   ("SOCKET",
+                    "recvmsg_check_result -> "
+                    "(msghdr) encode ok: %T\r\n", eMsgHdr) );
+            
+            recv_update_current_reader(env, descP);
+
+            return esock_make_ok2(env, eMsgHdr);
+        }
+
+    }
+}
+
+
+
+
+/* +++ encode_msghdr +++
+ *
+ * Encode a msghdr (recvmsg). In erlang its represented as
+ * a map, which has a specific set of attributes:
+ *
+ *     addr (source address) - sockaddr()
+ *     iov                   - [binary()]
+ *     ctrl                  - [cmsghdr()]
+ *     flags                 - msghdr_flags()
+ */
+
+extern
+char* encode_msghdr(ErlNifEnv*        env,
+                    SocketDescriptor* descP,
+                    int               read,
+                    struct msghdr*    msgHdrP,
+                    ErlNifBinary*     dataBufP,
+                    ErlNifBinary*     ctrlBufP,
+                    ERL_NIF_TERM*     eSockAddr)
+{
+    char*        xres;
+    ERL_NIF_TERM addr, iov, ctrl, flags;
+
+    SSDBG( descP,
+           ("SOCKET", "encode_msghdr -> entry with"
+            "\r\n   read: %d"
+            "\r\n", read) );
+
+    /* The address is not used if we are connected,
+     * so check (length = 0) before we try to encodel
+     */
+    if (msgHdrP->msg_namelen != 0) {
+        if ((xres = esock_encode_sockaddr(env,
+                                          (SocketAddress*) msgHdrP->msg_name,
+                                          msgHdrP->msg_namelen,
+                                          &addr)) != NULL)
+            return xres;
+    } else {
+        addr = esock_atom_undefined;
+    }
+
+    SSDBG( descP, ("SOCKET", "encode_msghdr -> try encode iov\r\n") );
+    if ((xres = esock_encode_iov(env,
+                                 read,
+                                 msgHdrP->msg_iov,
+                                 msgHdrP->msg_iovlen,
+                                 dataBufP,
+                                 &iov)) != NULL)
+        return xres;
+
+    SSDBG( descP, ("SOCKET", "encode_msghdr -> try encode cmsghdrs\r\n") );
+    if ((xres = encode_cmsghdrs(env, descP, ctrlBufP, msgHdrP, &ctrl)) != NULL)
+        return xres;
+
+    SSDBG( descP, ("SOCKET", "encode_msghdr -> try encode flags\r\n") );
+    if ((xres = encode_msghdr_flags(env, descP, msgHdrP->msg_flags, &flags)) != NULL)
+        return xres;
+
+    SSDBG( descP,
+           ("SOCKET", "encode_msghdr -> components encoded:"
+            "\r\n   addr:  %T"
+            "\r\n   iov:   %T"
+            "\r\n   ctrl:  %T"
+            "\r\n   flags: %T"
+           "\r\n", addr, iov, ctrl, flags) );
+    {
+        ERL_NIF_TERM keys[]  = {esock_atom_addr,
+                                esock_atom_iov,
+                                esock_atom_ctrl,
+                                esock_atom_flags};
+        ERL_NIF_TERM vals[]  = {addr, iov, ctrl, flags};
+        unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+        unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+        ERL_NIF_TERM tmp;
+        
+        ESOCK_ASSERT( (numKeys == numVals) );
+        
+        SSDBG( descP, ("SOCKET", "encode_msghdr -> create msghdr map\r\n") );
+        if (!MKMA(env, keys, vals, numKeys, &tmp))
+            return ESOCK_STR_EINVAL;
+
+        SSDBG( descP, ("SOCKET", "encode_msghdr -> msghdr: "
+                       "\r\n   %T"
+                       "\r\n", tmp) );
+
+        *eSockAddr = tmp;
+    }
+
+    SSDBG( descP, ("SOCKET", "encode_msghdr -> done\r\n") );
+
+    return NULL;
+}
+
+
+
+
+/* +++ encode_cmsghdrs +++
+ *
+ * Encode a list of cmsghdr(). There can be 0 or more cmsghdr "blocks".
+ *
+ * Our "problem" is that we have no idea how many control messages
+ * we have.
+ *
+ * The cmsgHdrP arguments points to the start of the control data buffer,
+ * an actual binary. Its the only way to create sub-binaries. So, what we
+ * need to continue processing this is to turn that into an binary erlang 
+ * term (which can then in turn be turned into sub-binaries).
+ *
+ * We need the cmsgBufP (even though cmsgHdrP points to it) to be able
+ * to create sub-binaries (one for each cmsg hdr).
+ *
+ * The TArray (term array) is created with the size of 128, which should
+ * be enough. But if its not, then it will be automatically realloc'ed during
+ * add. Once we are done adding hdr's to it, we convert the tarray to a list.
+ */
+
+extern
+char* encode_cmsghdrs(ErlNifEnv*        env,
+                      SocketDescriptor* descP,
+                      ErlNifBinary*     cmsgBinP,
+                      struct msghdr*    msgHdrP,
+                      ERL_NIF_TERM*     eCMsgHdr)
+{
+    ERL_NIF_TERM    ctrlBuf  = MKBIN(env, cmsgBinP); // The *entire* binary
+    SocketTArray    cmsghdrs = TARRAY_CREATE(128);
+    struct cmsghdr* firstP   = CMSG_FIRSTHDR(msgHdrP);
+    struct cmsghdr* currentP;
+    
+    SSDBG( descP, ("SOCKET", "encode_cmsghdrs -> entry\r\n") );
+
+    for (currentP = firstP;
+         currentP != NULL;
+         currentP = CMSG_NXTHDR(msgHdrP, currentP)) {
+
+        SSDBG( descP,
+               ("SOCKET", "encode_cmsghdrs -> process cmsg header when"
+                "\r\n   TArray Size: %d"
+                "\r\n", TARRAY_SZ(cmsghdrs)) );
+
+        /* MUST check this since on Linux the returned "cmsg" may actually
+         * go too far!
+         */
+        if (((CHARP(currentP) + currentP->cmsg_len) - CHARP(firstP)) >
+            msgHdrP->msg_controllen) {
+            /* Ouch, fatal error - give up 
+             * We assume we cannot trust any data if this is wrong.
+             */
+            TARRAY_DELETE(cmsghdrs);
+            return ESOCK_STR_EINVAL;
+        } else {
+            ERL_NIF_TERM   level, type, data;
+            unsigned char* dataP   = (unsigned char*) CMSG_DATA(currentP);
+            size_t         dataPos = dataP - cmsgBinP->data;
+            size_t         dataLen = currentP->cmsg_len - (CHARP(currentP)-CHARP(dataP));
+
+            SSDBG( descP,
+                   ("SOCKET", "encode_cmsghdrs -> cmsg header data: "
+                    "\r\n   dataPos: %d"
+                    "\r\n   dataLen: %d"
+                    "\r\n", dataPos, dataLen) );
+
+            /* We can't give up just because its an unknown protocol,
+             * so if its a protocol we don't know, we return its integer 
+             * value and leave it to the user.
+             */
+            if (encode_cmsghdr_level(env, currentP->cmsg_level, &level) != NULL)
+                level = MKI(env, currentP->cmsg_level);
+
+            if (encode_cmsghdr_type(env,
+                                    currentP->cmsg_level, currentP->cmsg_type,
+                                    &type) != NULL)
+                type = MKI(env, currentP->cmsg_type);
+
+            if (encode_cmsghdr_data(env, ctrlBuf,
+                                    currentP->cmsg_level,
+                                    currentP->cmsg_type,
+                                    dataP, dataPos, dataLen,
+                                    &data) != NULL)
+                data = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+
+            SSDBG( descP,
+                   ("SOCKET", "encode_cmsghdrs -> "
+                    "\r\n   level: %T"
+                    "\r\n   type:  %T"
+                    "\r\n   data:  %T"
+                    "\r\n", level, type, data) );
+
+            /* And finally create the 'cmsghdr' map -
+             * and if successfull add it to the tarray.
+             */
+            {
+                ERL_NIF_TERM keys[]  = {esock_atom_level,
+                                        esock_atom_type,
+                                        esock_atom_data};
+                ERL_NIF_TERM vals[]  = {level, type, data};
+                unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+                unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+                ERL_NIF_TERM cmsgHdr;
+
+                /* Guard agains cut-and-paste errors */
+                ESOCK_ASSERT( (numKeys == numVals) );
+            
+                if (!MKMA(env, keys, vals, numKeys, &cmsgHdr)) {
+                    TARRAY_DELETE(cmsghdrs);
+                    return ESOCK_STR_EINVAL;
+                }
+
+                /* And finally add it to the list... */
+                TARRAY_ADD(cmsghdrs, cmsgHdr);
+            }
+        }
+    }
+
+    SSDBG( descP,
+           ("SOCKET", "encode_cmsghdrs -> cmsg headers processed when"
+            "\r\n   TArray Size: %d"
+            "\r\n", TARRAY_SZ(cmsghdrs)) );
+
+    /* The tarray is populated - convert it to a list */
+    TARRAY_TOLIST(cmsghdrs, env, eCMsgHdr);
+
+    return NULL;
+}
+
+
+
+/* +++ decode_cmsghdrs +++
+ *
+ * Decode a list of cmsghdr(). There can be 0 or more cmsghdr "blocks".
+ *
+ * Each element can either be a (erlang) map that needs to be decoded,
+ * or a (erlang) binary that just needs to be appended to the control
+ * buffer.
+ *
+ * Our "problem" is that we have no idea much memory we actually need.
+ *
+ */
+
+extern
+char* decode_cmsghdrs(ErlNifEnv*        env,
+                      SocketDescriptor* descP,
+                      ERL_NIF_TERM      eCMsgHdr,
+                      char*             cmsgHdrBufP,
+                      size_t            cmsgHdrBufLen,
+                      size_t*           cmsgHdrBufUsed)
+{
+    ERL_NIF_TERM elem, tail, list;
+    char*        bufP;
+    size_t       rem, used, totUsed = 0;
+    unsigned int len;
+    int          i;
+    char*        xres;
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdrs -> entry with"
+                   "\r\n   cmsgHdrBufP:   0x%lX"
+                   "\r\n   cmsgHdrBufLen: %d"
+                   "\r\n", cmsgHdrBufP, cmsgHdrBufLen) );
+
+    if (IS_LIST(env, eCMsgHdr) && GET_LIST_LEN(env, eCMsgHdr, &len)) {
+
+        SSDBG( descP, ("SOCKET", "decode_cmsghdrs -> list length: %d\r\n", len) );
+
+        for (i = 0, list = eCMsgHdr, rem  = cmsgHdrBufLen, bufP = cmsgHdrBufP;
+             i < len; i++) {
+            
+            SSDBG( descP, ("SOCKET", "decode_cmsghdrs -> process elem %d:"
+                           "\r\n   (buffer) rem:     %u"
+                           "\r\n   (buffer) totUsed: %u"
+                           "\r\n", i, rem, totUsed) );
+
+            /* Extract the (current) head of the (cmsg hdr) list */
+            if (!GET_LIST_ELEM(env, list, &elem, &tail))
+                return ESOCK_STR_EINVAL;
+            
+            used = 0; // Just in case...
+            if ((xres = decode_cmsghdr(env, descP, elem, bufP, rem, &used)) != NULL)
+                return xres;
+
+            bufP     = CHARP( ULONG(bufP) + used );
+            rem      = SZT( rem - used );
+            list     = tail;
+            totUsed += used;
+
+        }
+
+        SSDBG( descP, ("SOCKET",
+                       "decode_cmsghdrs -> all %d ctrl headers processed\r\n",
+                       len) );
+
+        xres = NULL;
+    } else {
+        xres = ESOCK_STR_EINVAL;
+    }
+
+    *cmsgHdrBufUsed = totUsed;
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdrs -> done with %s when"
+                   "\r\n   totUsed = %u\r\n",
+                   ((xres != NULL) ? xres : "NULL"), totUsed) );
+
+    return xres;
+}
+
+
+/* +++ decode_cmsghdr +++
+ *
+ * Decode one cmsghdr(). Put the "result" into the buffer and advance the
+ * pointer (of the buffer) afterwards. Also update 'rem' accordingly.
+ * But before the actual decode, make sure that there is enough room in 
+ * the buffer for the cmsg header (sizeof(*hdr) < rem).
+ *
+ * The eCMsgHdr should be a map with three fields: 
+ *
+ *     level :: cmsghdr_level()   (socket | protocol() | integer())
+ *     type  :: cmsghdr_type()    (atom() | integer())
+ *                                What values are valid depend on the level
+ *     data  :: cmsghdr_data()    (term() | binary())
+ *                                The type of the data depends on
+ *                                level and type, but can be a binary,
+ *                                which means that the data is already coded.
+ */
+extern
+char* decode_cmsghdr(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     ERL_NIF_TERM      eCMsgHdr,
+                     char*             bufP,
+                     size_t            rem,
+                     size_t*           used)
+{
+    SSDBG( descP, ("SOCKET", "decode_cmsghdr -> entry with"
+                   "\r\n   eCMsgHdr: %T"
+                   "\r\n", eCMsgHdr) );
+
+    if (IS_MAP(env, eCMsgHdr)) {
+        ERL_NIF_TERM eLevel, eType, eData;
+        int          level, type;
+        char*        xres;
+
+        /* First extract all three attributes (as terms) */
+
+        if (!GET_MAP_VAL(env, eCMsgHdr, esock_atom_level, &eLevel))
+            return ESOCK_STR_EINVAL;
+        
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> eLevel: %T"
+                       "\r\n", eLevel) );
+
+        if (!GET_MAP_VAL(env, eCMsgHdr, esock_atom_type, &eType))
+            return ESOCK_STR_EINVAL;
+        
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> eType:  %T"
+                       "\r\n", eType) );
+
+        if (!GET_MAP_VAL(env, eCMsgHdr, esock_atom_data, &eData))
+            return ESOCK_STR_EINVAL;
+
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> eData:  %T"
+                       "\r\n", eData) );
+
+        /* Second, decode level */
+        if ((xres = decode_cmsghdr_level(env, eLevel, &level)) != NULL)
+            return xres;
+
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> level:  %d\r\n", level) );
+
+        /* third, decode type */
+        if ((xres = decode_cmsghdr_type(env, level, eType, &type)) != NULL)
+            return xres;
+        
+        SSDBG( descP, ("SOCKET", "decode_cmsghdr -> type:   %d\r\n", type) );
+
+        /* And finally data
+         * If its a binary, we are done. Otherwise, we need to check
+         * level and type to know what kind of data to expect.
+         */
+
+        return decode_cmsghdr_data(env, descP, bufP, rem, level, type, eData, used);
+
+    } else {
+        *used = 0;
+        return ESOCK_STR_EINVAL;
+    }
+
+    return NULL;
+}
+
+
+/* *** decode_cmsghdr_data ***
+ *
+ * For all combinations of level and type we accept a binary as data,
+ * so we begin by testing for that. If its not a binary, then we check
+ * level (ip) and type (tos or ttl), in which case the data *must* be
+ * an integer and ip_tos() respectively.
+ */
+static
+char* decode_cmsghdr_data(ErlNifEnv*        env,
+                          SocketDescriptor* descP,
+                          char*             bufP,
+                          size_t            rem,
+                          int               level,
+                          int               type,
+                          ERL_NIF_TERM      eData,
+                          size_t*           used)
+{
+    char* xres;
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> entry with"
+                   "\r\n   eData: %T"
+                   "\r\n", eData) );
+
+    if (IS_BIN(env, eData)) {
+        ErlNifBinary bin;
+        
+        if (GET_BIN(env, eData, &bin)) {
+            SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> "
+                           "do final decode with binary\r\n") );
+            return decode_cmsghdr_final(descP, bufP, rem, level, type,
+                                        (char*) bin.data, bin.size,
+                                        used);
+        } else {
+            *used = 0;
+            xres  = ESOCK_STR_EINVAL;
+        }
+    } else {
+
+        /* Its *not* a binary so we need to look at what level and type 
+         * we have and treat them individually.
+         */
+
+        switch (level) {
+#if defined(SOL_IP)
+        case SOL_IP:
+#else
+        case IPPROTO_IP:
+#endif
+            switch (type) {
+#if defined(IP_TOS)
+            case IP_TOS:
+                {
+                    int data;
+                    if (decode_ip_tos(env, eData, &data)) {
+                        SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> "
+                                       "do final decode with tos\r\n") );
+                        return decode_cmsghdr_final(descP, bufP, rem, level, type,
+                                                    (char*) &data,
+                                                    sizeof(data),
+                                                    used);
+                    } else {
+                        *used = 0;
+                        xres  = ESOCK_STR_EINVAL;
+                    }
+                }
+                break;
+#endif
+
+#if defined(IP_TTL)
+            case IP_TTL:
+                {
+                    int data;
+                    if (GET_INT(env, eData, &data)) {
+                        SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> "
+                                       "do final decode with ttl\r\n") );
+                        return decode_cmsghdr_final(descP, bufP, rem, level, type,
+                                                    (char*) &data,
+                                                    sizeof(data),
+                                                    used);
+                    } else {
+                        *used = 0;
+                        xres  = ESOCK_STR_EINVAL;
+                    }
+                }
+                break;
+#endif
+
+            }
+            break;
+
+        default:
+            *used = 0;
+            xres  = ESOCK_STR_EINVAL;
+            break;
+        }        
+
+    }
+
+    return xres;
+}
+                              
+
+/* *** decode_cmsghdr_final ***
+ *
+ * This does the final create of the cmsghdr (including the data copy).
+ */
+static
+char* decode_cmsghdr_final(SocketDescriptor* descP,
+                           char*             bufP,
+                           size_t            rem,
+                           int               level,
+                           int               type,
+                           char*             data,
+                           int               sz,
+                           size_t*           used)
+{
+    int len   = CMSG_LEN(sz);
+    int space = CMSG_SPACE(sz);
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdr_data -> entry when"
+                   "\r\n   level: %d"
+                   "\r\n   type:  %d"
+                   "\r\n   sz:    %d => %d, %d"
+                   "\r\n", level, type, sz, len, space) );
+
+    if (rem >= space) {
+        struct cmsghdr* cmsgP = (struct cmsghdr*) bufP;
+        
+        /* The header */
+        cmsgP->cmsg_len   = len;
+        cmsgP->cmsg_level = level;
+        cmsgP->cmsg_type  = type;
+
+        sys_memcpy(CMSG_DATA(cmsgP), data, sz);
+        *used = space;
+    } else {
+        *used = 0;
+        return ESOCK_STR_EINVAL;
+    }
+
+    SSDBG( descP, ("SOCKET", "decode_cmsghdr_final -> done\r\n") );
+
+    return NULL;
+}
+
+
+/* +++ encode_cmsghdr_level +++
+ *
+ * Encode the level part of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_level(ErlNifEnv*    env,
+                           int           level,
+                           ERL_NIF_TERM* eLevel)
+{
+    char* xres;
+
+    switch (level) {
+    case SOL_SOCKET:
+        *eLevel = esock_atom_socket;
+        xres    = NULL;
+        break;
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        *eLevel = esock_atom_ip;
+        xres    = NULL;
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif
+        *eLevel = esock_atom_ip;
+        xres    = NULL;
+        break;
+#endif
+
+    case IPPROTO_UDP:
+        *eLevel = esock_atom_udp;
+        xres    = NULL;
+        break;
+
+    default:
+        *eLevel = MKI(env, level);
+        xres    = NULL;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ decode_cmsghdr_level +++
+ *
+ * Decode the level part of the cmsghdr().
+ *
+ */
+
+static
+char* decode_cmsghdr_level(ErlNifEnv*   env,
+                           ERL_NIF_TERM eLevel,
+                           int*         level)
+{
+    char* xres = NULL;
+
+    if (IS_ATOM(env, eLevel)) {
+
+        if (COMPARE(eLevel, esock_atom_socket) == 0) {
+            *level = SOL_SOCKET;
+            xres   = NULL;
+        } else if (COMPARE(eLevel, esock_atom_ip) == 0) {
+#if defined(SOL_IP)
+            *level = SOL_IP;
+#else
+            *level = IPPROTO_IP;
+#endif
+            xres   = NULL;
+#if defined(HAVE_IPV6)
+        } else if (COMPARE(eLevel, esock_atom_ipv6) == 0) {
+#if defined(SOL_IPV6)
+            *level = SOL_IPV6;
+#else
+            *level = IPPROTO_IPV6;
+#endif
+            xres   = NULL;
+#endif
+        } else if (COMPARE(eLevel, esock_atom_udp) == 0) {
+            *level = IPPROTO_UDP;
+            xres   = NULL;
+        } else {
+            *level = -1;
+            xres   = ESOCK_STR_EINVAL;
+        }
+    } else if (IS_NUM(env, eLevel)) {
+        if (!GET_INT(env, eLevel, level))
+            xres = ESOCK_STR_EINVAL;
+    } else {
+        *level = -1;
+        xres   = ESOCK_STR_EINVAL;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ encode_cmsghdr_type +++
+ *
+ * Encode the type part of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_type(ErlNifEnv*    env,
+                          int           level,
+                          int           type,
+                          ERL_NIF_TERM* eType)
+{
+    char* xres = NULL;
+
+    switch (level) {
+    case SOL_SOCKET:
+        switch (type) {
+#if defined(SO_TIMESTAMP)
+        case SO_TIMESTAMP:
+            *eType = esock_atom_timestamp;
+            break;
+#endif
+
+#if defined(SCM_RIGHTS)
+        case SCM_RIGHTS:
+            *eType = esock_atom_rights;
+            break;
+#endif
+
+#if defined(SCM_CREDENTIALS)
+        case SCM_CREDENTIALS:
+            *eType = esock_atom_credentials;
+            break;
+#endif
+
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        switch (type) {
+#if defined(IP_TOS)
+        case IP_TOS:
+            *eType = esock_atom_tos;
+            break;
+#endif
+
+#if defined(IP_TTL)
+        case IP_TTL:
+            *eType = esock_atom_ttl;
+            break;
+#endif
+
+#if defined(IP_PKTINFO)
+        case IP_PKTINFO:
+            *eType = esock_atom_pktinfo;
+            break;
+#endif
+
+#if defined(IP_ORIGDSTADDR)
+        case IP_ORIGDSTADDR:
+            *eType = esock_atom_origdstaddr;
+            break;
+#endif
+
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+        case SOL_IPV6:
+#else
+        case IPPROTO_IPV6:
+#endif
+        switch (type) {
+#if defined(IPV6_PKTINFO)
+        case IPV6_PKTINFO:
+            *eType = esock_atom_pktinfo;
+            break;
+#endif
+
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+#endif
+
+    case IPPROTO_TCP:
+        switch (type) {
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+
+    case IPPROTO_UDP:
+        switch (type) {
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+
+#if defined(HAVE_SCTP)
+    case IPPROTO_SCTP:
+        switch (type) {
+        default:
+            xres = ESOCK_STR_EINVAL;
+            break;
+        }        
+        break;
+#endif
+
+    default:
+        xres = ESOCK_STR_EINVAL;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ decode_cmsghdr_type +++
+ *
+ * Decode the type part of the cmsghdr().
+ *
+ */
+
+static
+char* decode_cmsghdr_type(ErlNifEnv*   env,
+                          int          level,
+                          ERL_NIF_TERM eType,
+                          int*         type)
+{
+    char* xres = NULL;
+
+    switch (level) {
+    case SOL_SOCKET:
+        if (IS_NUM(env, eType)) {
+            if (!GET_INT(env, eType, type)) {
+                *type = -1;
+                xres  = ESOCK_STR_EINVAL;
+            }
+        } else {
+            *type = -1;
+            xres = ESOCK_STR_EINVAL;
+        }
+        break;
+
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        if (IS_ATOM(env, eType)) {
+            if (COMPARE(eType, esock_atom_tos) == 0) {
+#if defined(IP_TOS)
+                *type = IP_TOS;
+#else
+                xres  = ESOCK_STR_EINVAL;
+#endif
+            } else if (COMPARE(eType, esock_atom_ttl) == 0) {
+#if defined(IP_TTL)
+                *type = IP_TTL;
+#else
+                xres  = ESOCK_STR_EINVAL;
+#endif
+            } else {
+                xres = ESOCK_STR_EINVAL;
+            }
+        } else if (IS_NUM(env, eType)) {
+            if (!GET_INT(env, eType, type)) {
+                *type = -1;
+                xres  = ESOCK_STR_EINVAL;
+            }
+        } else {
+            *type = -1;
+            xres  = ESOCK_STR_EINVAL;
+        }
+        break;
+        
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif
+        if (IS_NUM(env, eType)) {
+            if (!GET_INT(env, eType, type)) {
+                *type = -1;
+                xres  = ESOCK_STR_EINVAL;
+            }
+        } else {
+            *type = -1;
+            xres = ESOCK_STR_EINVAL;
+        }
+        break;
+#endif
+        
+    case IPPROTO_UDP:
+        if (IS_NUM(env, eType)) {
+            if (!GET_INT(env, eType, type)) {
+                *type = -1;
+                xres  = ESOCK_STR_EINVAL;
+            }
+        } else {
+            *type = -1;
+            xres = ESOCK_STR_EINVAL;
+        }
+        break;
+
+    default:
+        *type = -1;
+        xres  = ESOCK_STR_EINVAL;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ encode_cmsghdr_data +++
+ *
+ * Encode the data part of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_data(ErlNifEnv*     env,
+                          ERL_NIF_TERM   ctrlBuf,
+                          int            level,
+                          int            type,
+                          unsigned char* dataP,
+                          size_t         dataPos,
+                          size_t         dataLen,
+                          ERL_NIF_TERM*  eCMsgHdrData)
+{
+    char* xres;
+
+    switch (level) {
+#if defined(SOL_SOCKET)
+    case SOL_SOCKET:
+        xres = encode_cmsghdr_data_socket(env, ctrlBuf, type,
+                                          dataP, dataPos, dataLen,
+                                          eCMsgHdrData);
+        break;
+#endif
+
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        xres = encode_cmsghdr_data_ip(env, ctrlBuf, type,
+                                      dataP, dataPos, dataLen,
+                                      eCMsgHdrData);
+        break;
+
+#if defined(HAVE_IPV6)
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+#else
+    case IPPROTO_IPV6:
+#endif        
+        xres = encode_cmsghdr_data_ipv6(env, ctrlBuf, type,
+                                        dataP, dataPos, dataLen,
+                                        eCMsgHdrData);
+        break;
+#endif
+
+        /*
+          case IPPROTO_TCP:
+          xres = encode_cmsghdr_data_tcp(env, type, dataP, eCMsgHdrData);
+          break;
+        */
+
+        /*
+          case IPPROTO_UDP:
+          xres = encode_cmsghdr_data_udp(env, type, dataP, eCMsgHdrData);
+          break;
+        */
+
+        /*
+          #if defined(HAVE_SCTP)
+          case IPPROTO_SCTP:
+          xres = encode_cmsghdr_data_sctp(env, type, dataP, eCMsgHdrData);
+          break;
+          #endif
+        */
+
+    default:
+        *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        xres = NULL;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ encode_cmsghdr_data_socket +++
+ *
+ * Encode the data part when "protocol" = socket of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_data_socket(ErlNifEnv*     env,
+                                 ERL_NIF_TERM   ctrlBuf,
+                                 int            type,
+                                 unsigned char* dataP,
+                                 size_t         dataPos,
+                                 size_t         dataLen,
+                                 ERL_NIF_TERM*  eCMsgHdrData)
+{
+    // char* xres;
+
+    switch (type) {
+#if defined(SO_TIMESTAMP)
+    case SO_TIMESTAMP:
+        {
+            struct timeval* timeP = (struct timeval*) dataP;
+
+            if (esock_encode_timeval(env, timeP, eCMsgHdrData) != NULL)
+                *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        }
+        break;
+#endif
+
+    default:
+        *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        break;
+    }
+
+    return NULL;
+}
+
+
+
+/* +++ encode_cmsghdr_data_ip +++
+ *
+ * Encode the data part when protocol = IP of the cmsghdr().
+ *
+ */
+
+static
+char* encode_cmsghdr_data_ip(ErlNifEnv*     env,
+                             ERL_NIF_TERM   ctrlBuf,
+                             int            type,
+                             unsigned char* dataP,
+                             size_t         dataPos,
+                             size_t         dataLen,
+                             ERL_NIF_TERM*  eCMsgHdrData)
+{
+    char* xres = NULL;
+
+    switch (type) {
+#if defined(IP_TOS)
+    case IP_TOS:
+        {
+            unsigned char tos = *dataP;
+            switch (IPTOS_TOS(tos)) {
+            case IPTOS_LOWDELAY:
+                *eCMsgHdrData = esock_atom_lowdelay;
+                break;
+            case IPTOS_THROUGHPUT:
+                *eCMsgHdrData = esock_atom_throughput;
+                break;
+            case IPTOS_RELIABILITY:
+                *eCMsgHdrData = esock_atom_reliability;
+                break;
+#if defined(IPTOS_MINCOST)
+            case IPTOS_MINCOST:
+                *eCMsgHdrData = esock_atom_mincost;
+                break;
+#endif
+            default:
+                *eCMsgHdrData = MKUI(env, tos);
+                break;
+            }
+        }
+        break;
+#endif
+
+#if defined(IP_TTL)
+    case IP_TTL:
+        {
+            int ttl = *((int*) dataP);
+            *eCMsgHdrData = MKI(env, ttl);
+        }
+        break;
+#endif
+
+#if defined(IP_PKTINFO)
+    case IP_PKTINFO:
+        {
+            struct in_pktinfo* pktInfoP = (struct in_pktinfo*) dataP;
+            ERL_NIF_TERM       ifIndex  = MKUI(env, pktInfoP->ipi_ifindex);
+            ERL_NIF_TERM       specDst, addr;
+
+            if ((xres = esock_encode_ip4_address(env,
+                                                 &pktInfoP->ipi_spec_dst,
+                                                 &specDst)) != NULL) {
+                *eCMsgHdrData = esock_atom_undefined;
+                return xres;
+            }
+
+            if ((xres = esock_encode_ip4_address(env,
+                                                 &pktInfoP->ipi_addr,
+                                                 &addr)) != NULL) {
+                *eCMsgHdrData = esock_atom_undefined;
+                return xres;
+            }
+
+
+            {
+                ERL_NIF_TERM keys[] = {esock_atom_ifindex,
+                                       esock_atom_spec_dst,
+                                       esock_atom_addr};
+                ERL_NIF_TERM vals[] = {ifIndex, specDst, addr};
+                unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+                unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+                ESOCK_ASSERT( (numKeys == numVals) );
+                
+                if (!MKMA(env, keys, vals, numKeys, eCMsgHdrData)) {
+                    *eCMsgHdrData = esock_atom_undefined;
+                    return ESOCK_STR_EINVAL;
+                }
+            }
+        }
+        break;
+#endif
+
+#if defined(IP_ORIGDSTADDR)
+    case IP_ORIGDSTADDR:
+        if ((xres = esock_encode_sockaddr_in4(env,
+                                              (struct sockaddr_in*) dataP,
+                                              dataLen,
+                                              eCMsgHdrData)) != NULL) {
+            *eCMsgHdrData = esock_atom_undefined;
+            return xres;            
+        }
+        break;
+#endif
+
+    default:
+        *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ encode_cmsghdr_data_ipv6 +++
+ *
+ * Encode the data part when protocol = IPv6 of the cmsghdr().
+ *
+ */
+#if defined(HAVE_IPV6)
+static
+char* encode_cmsghdr_data_ipv6(ErlNifEnv*     env,
+                               ERL_NIF_TERM   ctrlBuf,
+                               int            type,
+                               unsigned char* dataP,
+                               size_t         dataPos,
+                               size_t         dataLen,
+                               ERL_NIF_TERM*  eCMsgHdrData)
+{
+    char* xres;
+
+    switch (type) {
+#if defined(IPV6_PKTINFO)
+    case IPV6_PKTINFO:
+        {
+            struct in6_pktinfo* pktInfoP = (struct in6_pktinfo*) dataP;
+            ERL_NIF_TERM        ifIndex  = MKI(env, pktInfoP->ipi6_ifindex);
+            ERL_NIF_TERM        addr;
+
+            if ((xres = esock_encode_ip6_address(env,
+                                                 &pktInfoP->ipi6_addr,
+                                                 &addr)) != NULL) {
+                *eCMsgHdrData = esock_atom_undefined;
+                return xres;
+            }
+
+            {
+                ERL_NIF_TERM keys[]  = {esock_atom_addr, esock_atom_ifindex};
+                ERL_NIF_TERM vals[]  = {addr, ifIndex};
+                unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+                unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+                ESOCK_ASSERT( (numKeys == numVals) );
+                
+                if (!MKMA(env, keys, vals, numKeys, eCMsgHdrData)) {
+                    *eCMsgHdrData = esock_atom_undefined;
+                    return ESOCK_STR_EINVAL;
+                }
+            }
+        }
+        break;
+#endif
+
+    default:
+        *eCMsgHdrData = MKSBIN(env, ctrlBuf, dataPos, dataLen);
+        break;
+    }
+
+    return NULL;
+}
+#endif
+
+
+
+/* +++ encode_msghdr_flags +++
+ *
+ * Encode a list of msghdr_flag().
+ *
+ * The following flags are handled: eor | trunc | ctrunc | oob | errqueue.
+ */
+
+extern
+char* encode_msghdr_flags(ErlNifEnv*        env,
+                          SocketDescriptor* descP,
+                          int               msgFlags,
+                          ERL_NIF_TERM*     flags)
+{
+    SSDBG( descP,
+           ("SOCKET", "encode_cmsghdrs_flags -> entry with"
+            "\r\n   msgFlags: %d (0x%lX)"
+            "\r\n", msgFlags, msgFlags) );
+
+    if (msgFlags == 0) {
+        *flags = MKEL(env);
+        return NULL;
+    } else {
+        SocketTArray ta = TARRAY_CREATE(10); // Just to be on the safe side
+
+#if defined(MSG_EOR)
+        if ((msgFlags & MSG_EOR) == MSG_EOR)
+            TARRAY_ADD(ta, esock_atom_eor);
+#endif
+
+#if defined(MSG_TRUNC)
+        if ((msgFlags & MSG_TRUNC) == MSG_TRUNC)
+            TARRAY_ADD(ta, esock_atom_trunc);
+#endif
+    
+#if defined(MSG_CTRUNC)
+        if ((msgFlags & MSG_CTRUNC) == MSG_CTRUNC)
+            TARRAY_ADD(ta, esock_atom_ctrunc);
+#endif
+    
+#if defined(MSG_OOB)
+        if ((msgFlags & MSG_OOB) == MSG_OOB)
+            TARRAY_ADD(ta, esock_atom_oob);
+#endif
+    
+#if defined(MSG_ERRQUEUE)
+        if ((msgFlags & MSG_ERRQUEUE) == MSG_ERRQUEUE)
+            TARRAY_ADD(ta, esock_atom_errqueue);
+#endif
+
+        SSDBG( descP,
+               ("SOCKET", "esock_encode_cmsghdrs -> flags processed when"
+                "\r\n   TArray size: %d"
+                "\r\n", TARRAY_SZ(ta)) );
+
+        TARRAY_TOLIST(ta, env, flags);
+
+        return NULL;
+    }
+}
+
+
+
+
+/* +++ decode the linger value +++
+ * The (socket) linger option is provided as a two tuple:
+ *
+ *       {OnOff :: boolean(), Time :: integer()}
+ *
+ */
+static
+BOOLEAN_T decode_sock_linger(ErlNifEnv* env, ERL_NIF_TERM eVal, struct linger* valP)
+{
+    const ERL_NIF_TERM* lt; // The array of the elements of the tuple
+    int                 sz; // The size of the tuple - should be 2
+    BOOLEAN_T           onOff;
+    int                 secs;
+
+    if (!GET_TUPLE(env, eVal, &sz, &lt))
+        return FALSE;
+
+    if (sz != 2)
+        return FALSE;
+
+
+    /* So fas so good - now check the two elements of the tuple. */
+
+    onOff = esock_decode_bool(lt[0]);
+
+    if (!GET_INT(env, lt[1], &secs))
+        return FALSE;
+
+    valP->l_onoff  = (onOff) ? 1 : 0;
+    valP->l_linger = secs;
+
+    return TRUE;
+}
+
+
+
+/* +++ decode the ip socket option TOS +++
+ * The (ip) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * When its an atom it can have the values:
+ *
+ *       lowdelay |  throughput | reliability | mincost
+ *
+ */
+#if defined(IP_TOS)
+static
+BOOLEAN_T decode_ip_tos(ErlNifEnv* env, ERL_NIF_TERM eVal, int* val)
+{
+    BOOLEAN_T result = FALSE;
+
+    if (IS_ATOM(env, eVal)) {
+
+        if (COMPARE(eVal, esock_atom_lowdelay) == 0) {
+            *val   = IPTOS_LOWDELAY;
+            result = TRUE;
+        } else if (COMPARE(eVal, esock_atom_throughput) == 0) {
+            *val   = IPTOS_THROUGHPUT;
+            result = TRUE;
+        } else if (COMPARE(eVal, esock_atom_reliability) == 0) {
+            *val   = IPTOS_RELIABILITY;
+            result = TRUE;
+#if defined(IPTOS_MINCOST)
+        } else if (COMPARE(eVal, esock_atom_mincost) == 0) {
+            *val   = IPTOS_MINCOST;
+            result = TRUE;
+#endif
+        } else {
+            *val   = -1;
+            result = FALSE;
+        }
+            
+    } else if (IS_NUM(env, eVal)) {
+
+        if (GET_INT(env, eVal, val)) {
+            result = TRUE;
+        } else {
+            *val   = -1;
+            result = FALSE;
+        }
+
+    } else {
+        *val   = -1;
+        result = FALSE;
+    }
+
+    return result;
+}
+#endif
+
+
+
+/* +++ decode the ip socket option MTU_DISCOVER +++
+ * The (ip) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * When its an atom it can have the values:
+ *
+ *       want | dont | do | probe
+ *
+ */
+#if defined(IP_MTU_DISCOVER)
+static
+char* decode_ip_pmtudisc(ErlNifEnv* env, ERL_NIF_TERM eVal, int* val)
+{
+    char* res = NULL;
+
+    if (IS_ATOM(env, eVal)) {
+
+        if (COMPARE(eVal, atom_want) == 0) {
+            *val = IP_PMTUDISC_WANT;
+        } else if (COMPARE(eVal, atom_dont) == 0) {
+            *val = IP_PMTUDISC_DONT;
+        } else if (COMPARE(eVal, atom_do) == 0) {
+            *val = IP_PMTUDISC_DO;
+#if defined(IP_PMTUDISC_PROBE)
+        } else if (COMPARE(eVal, atom_probe) == 0) {
+            *val = IP_PMTUDISC_PROBE;
+#endif
+        } else {
+            *val = -1;
+            res  = ESOCK_STR_EINVAL;
+        }
+
+    } else if (IS_NUM(env, eVal)) {
+
+        if (!GET_INT(env, eVal, val)) {
+            *val = -1;
+            res  = ESOCK_STR_EINVAL;
+        }
+
+    } else {
+
+        *val   = -1;
+        res  = ESOCK_STR_EINVAL;
+
+    }
+
+    return res;
+}
+#endif
+
+
+
+/* +++ decode the ipv6 socket option MTU_DISCOVER +++
+ * The (ip) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * When its an atom it can have the values:
+ *
+ *       want | dont | do | probe
+ *
+ */
+#if defined(IPV6_MTU_DISCOVER)
+static
+char* decode_ipv6_pmtudisc(ErlNifEnv* env, ERL_NIF_TERM eVal, int* val)
+{
+    char* res = NULL;
+
+    if (IS_ATOM(env, eVal)) {
+
+        if (COMPARE(eVal, atom_want) == 0) {
+            *val = IPV6_PMTUDISC_WANT;
+        } else if (COMPARE(eVal, atom_dont) == 0) {
+            *val = IPV6_PMTUDISC_DONT;
+        } else if (COMPARE(eVal, atom_do) == 0) {
+            *val = IPV6_PMTUDISC_DO;
+#if defined(IPV6_PMTUDISC_PROBE)
+        } else if (COMPARE(eVal, atom_probe) == 0) {
+            *val = IPV6_PMTUDISC_PROBE;
+#endif
+        } else {
+            *val = -1;
+            res  = ESOCK_STR_EINVAL;
+        }
+
+    } else if (IS_NUM(env, eVal)) {
+
+        if (!GET_INT(env, eVal, val)) {
+            *val = -1;
+            res  = ESOCK_STR_EINVAL;
+        }
+
+    } else {
+
+        *val   = -1;
+        res  = ESOCK_STR_EINVAL;
+
+    }
+
+    return res;
+}
+#endif
+
+
+
+/* +++ encode the ip socket option MTU_DISCOVER +++
+ * The (ip) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * If its one of the "known" values, it will be an atom:
+ *
+ *       want | dont | do | probe
+ *
+ */
+#if defined(IP_MTU_DISCOVER)
+static
+void encode_ip_pmtudisc(ErlNifEnv* env, int val, ERL_NIF_TERM* eVal)
+{
+    switch (val) {
+    case IP_PMTUDISC_WANT:
+        *eVal = atom_want;
+        break;
+
+    case IP_PMTUDISC_DONT:
+        *eVal = atom_dont;
+        break;
+
+    case IP_PMTUDISC_DO:
+        *eVal = atom_do;
+        break;
+
+#if defined(IP_PMTUDISC_PROBE)
+    case IP_PMTUDISC_PROBE:
+        *eVal = atom_probe;
+        break;
+#endif
+
+    default:
+        *eVal = MKI(env, val);
+        break;
+    }
+
+    return;
+}
+#endif
+
+
+
+/* +++ encode the ipv6 socket option MTU_DISCOVER +++
+ * The (ipv6) option can be provide in two ways:
+ *
+ *           atom() | integer()
+ *
+ * If its one of the "known" values, it will be an atom:
+ *
+ *       want | dont | do | probe
+ *
+ */
+#if defined(IPV6_MTU_DISCOVER)
+static
+void encode_ipv6_pmtudisc(ErlNifEnv* env, int val, ERL_NIF_TERM* eVal)
+{
+    switch (val) {
+    case IPV6_PMTUDISC_WANT:
+        *eVal = atom_want;
+        break;
+
+    case IPV6_PMTUDISC_DONT:
+        *eVal = atom_dont;
+        break;
+
+    case IPV6_PMTUDISC_DO:
+        *eVal = atom_do;
+        break;
+
+#if defined(IPV6_PMTUDISC_PROBE)
+    case IPV6_PMTUDISC_PROBE:
+        *eVal = atom_probe;
+        break;
+#endif
+
+    default:
+        *eVal = MKI(env, val);
+        break;
+    }
+
+    return;
+}
+#endif
+
+
+
+/* +++ decocde the native getopt option +++
+ * The option is in this case provide in the form of a two tuple:
+ *
+ *           {NativeOpt, ValueSize}
+ *
+ * NativeOpt :: integer()
+ * ValueSize :: int | bool | non_neg_integer()
+ *
+ */
+static
+BOOLEAN_T decode_native_get_opt(ErlNifEnv* env, ERL_NIF_TERM eVal,
+                                int* opt, Uint16* valueType, int* valueSz)
+{
+    const ERL_NIF_TERM* nativeOptT;
+    int                 nativeOptTSz;
+
+    /* First, get the tuple and verify its size (2) */
+
+    if (!GET_TUPLE(env, eVal, &nativeOptTSz, &nativeOptT))
+        return FALSE;
+
+    if (nativeOptTSz != 2)
+        return FALSE;
+
+    /* So far so good.
+     * First element is an integer.
+     * Second element is an atom or an integer.
+     * The only "types" that we support at the moment are:
+     *
+     *            bool - Which is actually a integer
+     *                   (but will be *returned* as a boolean())
+     *            int  - Just short for integer
+     */
+
+    if (!GET_INT(env, nativeOptT[0], opt))
+        return FALSE;
+
+    if (IS_ATOM(env, nativeOptT[1])) {
+
+        if (COMPARE(nativeOptT[1], atom_int) == 0) {
+            SGDBG( ("SOCKET", "decode_native_get_opt -> int\r\n") );
+            *valueType = SOCKET_OPT_VALUE_TYPE_INT;
+            *valueSz   = sizeof(int); // Just to be sure
+        } else if (COMPARE(nativeOptT[1], atom_bool) == 0) {
+            SGDBG( ("SOCKET", "decode_native_get_opt -> bool\r\n") );
+            *valueType = SOCKET_OPT_VALUE_TYPE_BOOL;
+            *valueSz   = sizeof(int); // Just to be sure
+        } else {
+            return FALSE;
+        }
+    } else if (IS_NUM(env, nativeOptT[1])) {
+        if (GET_INT(env, nativeOptT[1], valueSz)) {
+            SGDBG( ("SOCKET", "decode_native_get_opt -> unspec\r\n") );
+            *valueType = SOCKET_OPT_VALUE_TYPE_UNSPEC;
+        } else {
+            return FALSE;
+        }
+    } else {
+        return FALSE;
+    }
+
+    SGDBG( ("SOCKET", "decode_native_get_opt -> done\r\n") );
+
+    return TRUE;
+}
+
+
+
+/* +++ encode the ip socket option tos +++
+ * The (ip) option can be provide as:
+ *
+ *       lowdelay |  throughput | reliability | mincost | integer()
+ *
+ */
+static
+ERL_NIF_TERM encode_ip_tos(ErlNifEnv* env, int val)
+{
+    ERL_NIF_TERM result;
+
+    switch (IPTOS_TOS(val)) {
+    case IPTOS_LOWDELAY:
+        result = esock_make_ok2(env, esock_atom_lowdelay);
+        break;
+
+    case IPTOS_THROUGHPUT:
+        result = esock_make_ok2(env, esock_atom_throughput);
+        break;
+
+    case IPTOS_RELIABILITY:
+        result = esock_make_ok2(env, esock_atom_reliability);
+        break;
+
+#if defined(IPTOS_MINCOST)
+    case IPTOS_MINCOST:
+        result = esock_make_ok2(env, esock_atom_mincost);
+        break;
+#endif
+
+    default:
+        result = esock_make_ok2(env, MKI(env, val));
+        break;
+    }
+
+    return result;
+}
+
+
+
+
+
+/* *** alloc_descriptor ***
+ * Allocate and perform basic initialization of a socket descriptor.
+ *
+ */
+static
+SocketDescriptor* alloc_descriptor(SOCKET sock, HANDLE event)
+{
+    SocketDescriptor* descP;
+
+    if ((descP = enif_alloc_resource(sockets, sizeof(SocketDescriptor))) != NULL) {
+        char buf[64]; /* Buffer used for building the mutex name */
+
+        // This needs to be released when the socket is closed!
+        descP->env            = enif_alloc_env();
+
+        sprintf(buf, "socket[w,%d]", sock);
+        descP->writeMtx       = MCREATE(buf);
+        descP->currentWriterP = NULL; // currentWriter not used
+        descP->writersQ.first = NULL;
+        descP->writersQ.last  = NULL;
+        descP->isWritable     = FALSE; // TRUE;
+        descP->writePkgCnt    = 0;
+        descP->writeByteCnt   = 0;
+        descP->writeTries     = 0;
+        descP->writeWaits     = 0;
+        descP->writeFails     = 0;
+
+        sprintf(buf, "socket[r,%d]", sock);
+        descP->readMtx        = MCREATE(buf);
+        descP->currentReaderP = NULL; // currentReader not used
+        descP->readersQ.first = NULL;
+        descP->readersQ.last  = NULL;
+        descP->isReadable     = FALSE; // TRUE;
+        descP->readPkgCnt     = 0;
+        descP->readByteCnt    = 0;
+        descP->readTries      = 0;
+        descP->readWaits      = 0;
+
+        sprintf(buf, "socket[acc,%d]", sock);
+        descP->accMtx           = MCREATE(buf);
+        descP->currentAcceptorP = NULL; // currentAcceptor not used
+        descP->acceptorsQ.first = NULL;
+        descP->acceptorsQ.last  = NULL;
+
+        sprintf(buf, "socket[close,%d]", sock);
+        descP->closeMtx         = MCREATE(buf);
+
+        descP->rBufSz           = SOCKET_RECV_BUFFER_SIZE_DEFAULT;
+        descP->rNum             = 0;
+        descP->rNumCnt          = 0;
+        descP->rCtrlSz          = SOCKET_RECV_CTRL_BUFFER_SIZE_DEFAULT;
+        descP->wCtrlSz          = SOCKET_SEND_CTRL_BUFFER_SIZE_DEFAULT;
+        descP->iow              = FALSE;
+        descP->dbg              = SOCKET_DEBUG_DEFAULT;
+
+        descP->sock             = sock;
+        descP->event            = event;
+
+        MON_INIT(&descP->currentWriter.mon);
+        MON_INIT(&descP->currentReader.mon);
+        MON_INIT(&descP->currentAcceptor.mon);
+        MON_INIT(&descP->ctrlMon);
+        MON_INIT(&descP->closerMon);
+    }
+
+    return descP;
+}
+
+
+
+/* decrement counters for when a socket is closed */
+static
+void dec_socket(int domain, int type, int protocol)
+{
+    MLOCK(data.cntMtx);
+
+    cnt_dec(&data.numSockets, 1);
+    
+    if (domain == AF_INET)
+        cnt_dec(&data.numDomainInet, 1);
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    else if (domain == AF_INET6)
+        cnt_dec(&data.numDomainInet6, 1);
+#endif
+#if defined(HAVE_SYS_UN_H)
+    else if (domain == AF_UNIX)
+        cnt_dec(&data.numDomainInet6, 1);
+#endif
+
+    if (type == SOCK_STREAM)
+        cnt_dec(&data.numTypeStreams, 1);
+    else if (type == SOCK_DGRAM)
+        cnt_dec(&data.numTypeDGrams, 1);
+#ifdef HAVE_SCTP
+    else if (type == SOCK_SEQPACKET)
+        cnt_dec(&data.numTypeSeqPkgs, 1);
+#endif
+
+    if (protocol == IPPROTO_IP)
+        cnt_dec(&data.numProtoIP, 1);
+    else if (protocol == IPPROTO_TCP)
+        cnt_dec(&data.numProtoTCP, 1);
+    else if (protocol == IPPROTO_UDP)
+        cnt_dec(&data.numProtoUDP, 1);
+#if defined(HAVE_SCTP)
+    else if (protocol == IPPROTO_SCTP)
+        cnt_dec(&data.numProtoSCTP, 1);
+#endif
+
+    MUNLOCK(data.cntMtx);
+}
+
+
+/* increment counters for when a socket is opened */
+static
+void inc_socket(int domain, int type, int protocol)
+{
+    MLOCK(data.cntMtx);
+
+    cnt_inc(&data.numSockets, 1);
+    
+    if (domain == AF_INET)
+        cnt_inc(&data.numDomainInet, 1);
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    else if (domain == AF_INET6)
+        cnt_inc(&data.numDomainInet6, 1);
+#endif
+#if defined(HAVE_SYS_UN_H)
+    else if (domain == AF_UNIX)
+        cnt_inc(&data.numDomainInet6, 1);
+#endif
+
+    if (type == SOCK_STREAM)
+        cnt_inc(&data.numTypeStreams, 1);
+    else if (type == SOCK_DGRAM)
+        cnt_inc(&data.numTypeDGrams, 1);
+#ifdef HAVE_SCTP
+    else if (type == SOCK_SEQPACKET)
+        cnt_inc(&data.numTypeSeqPkgs, 1);
+#endif
+
+    if (protocol == IPPROTO_IP)
+        cnt_inc(&data.numProtoIP, 1);
+    else if (protocol == IPPROTO_TCP)
+        cnt_inc(&data.numProtoTCP, 1);
+    else if (protocol == IPPROTO_UDP)
+        cnt_inc(&data.numProtoUDP, 1);
+#if defined(HAVE_SCTP)
+    else if (protocol == IPPROTO_SCTP)
+        cnt_inc(&data.numProtoSCTP, 1);
+#endif
+
+    MUNLOCK(data.cntMtx);
+}
+
+
+
+/* compare_pids - Test if two pids are equal
+ *
+ */
+static
+int compare_pids(ErlNifEnv*       env,
+                 const ErlNifPid* pid1,
+                 const ErlNifPid* pid2)
+{
+    ERL_NIF_TERM p1 = enif_make_pid(env, pid1);
+    ERL_NIF_TERM p2 = enif_make_pid(env, pid2);
+
+    return enif_is_identical(p1, p2);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  D e c o d e / E n c o d e   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* edomain2domain - convert internal (erlang) domain to (proper) domain
+ *
+ * Note that only a subset is supported.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T edomain2domain(int edomain, int* domain)
+{
+    switch (edomain) {
+    case SOCKET_DOMAIN_INET:
+        *domain = AF_INET;
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case SOCKET_DOMAIN_INET6:
+        *domain = AF_INET6;
+        break;
+#endif
+#ifdef HAVE_SYS_UN_H
+    case SOCKET_DOMAIN_LOCAL:
+        *domain = AF_UNIX;
+        break;
+#endif
+
+    default:
+        *domain = -1;
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+
+/* etype2type - convert internal (erlang) type to (proper) type
+ *
+ * Note that only a subset is supported.
+ */
+static
+BOOLEAN_T etype2type(int etype, int* type)
+{
+    switch (etype) {
+    case SOCKET_TYPE_STREAM:
+        *type = SOCK_STREAM;
+        break;
+
+    case SOCKET_TYPE_DGRAM:
+        *type = SOCK_DGRAM;
+        break;
+
+    case SOCKET_TYPE_RAW:
+        *type = SOCK_RAW;
+        break;
+
+#ifdef HAVE_SCTP    
+    case SOCKET_TYPE_SEQPACKET:
+        *type = SOCK_SEQPACKET;
+        break;
+#endif
+
+    default:
+        *type = -1;
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+
+/* eproto2proto - convert internal (erlang) protocol to (proper) protocol
+ *
+ * Note that only a subset is supported.
+ */
+static
+BOOLEAN_T eproto2proto(ErlNifEnv*   env,
+                       ERL_NIF_TERM eproto,
+                       int*         proto)
+{
+    if (IS_NUM(env, eproto)) {
+        int ep;
+
+        if (!GET_INT(env, eproto, &ep)) {
+            *proto = -1;
+            return FALSE;
+        }
+
+        switch (ep) {
+        case SOCKET_PROTOCOL_IP:
+            *proto = IPPROTO_IP;
+            break;
+            
+        case SOCKET_PROTOCOL_TCP:
+            *proto = IPPROTO_TCP;
+            break;
+            
+        case SOCKET_PROTOCOL_UDP:
+            *proto = IPPROTO_UDP;
+            break;
+            
+#if defined(HAVE_SCTP)
+        case SOCKET_PROTOCOL_SCTP:
+            *proto = IPPROTO_SCTP;
+            break;
+#endif
+            
+        case SOCKET_PROTOCOL_ICMP:
+            *proto = IPPROTO_ICMP;
+            break;
+            
+        case SOCKET_PROTOCOL_IGMP:
+            *proto = IPPROTO_IGMP;
+            break;
+            
+        default:
+            *proto = -2;
+            return FALSE;
+        }
+    } else {
+        const ERL_NIF_TERM* a;
+        int                 sz;
+
+        if (!GET_TUPLE(env, eproto, &sz, &a)) {
+            *proto = -3;
+            return FALSE;
+        }
+        
+        if (sz != 2) {
+            *proto = -4;
+            return FALSE;
+        }
+
+        if (COMPARE(a[0], esock_atom_raw) != 0) {
+            *proto = -5;
+            return FALSE;
+        }
+
+        if (!GET_INT(env, a[1], proto)) {
+            *proto = -6;
+            return FALSE;
+        }
+    }
+
+    return TRUE;
+}
+
+
+#ifdef HAVE_SETNS
+ /* emap2netns - extract the netns field from the extra map
+ *
+ * Note that currently we only support one extra option, the netns.
+ */
+static
+BOOLEAN_T emap2netns(ErlNifEnv* env, ERL_NIF_TERM map, char** netns)
+{
+    size_t       sz;
+    ERL_NIF_TERM key;
+    ERL_NIF_TERM value;
+    unsigned int len;
+    char*        buf;
+    int          written;
+
+    /* Note that its acceptable that the extra map is empty */
+    if (!enif_get_map_size(env, map, &sz) ||
+        (sz != 1)) {
+        *netns = NULL;
+        return TRUE;
+    }
+
+    /* The currently only supported extra option is:  netns */
+    key = enif_make_atom(env, "netns");
+    if (!GET_MAP_VAL(env, map, key, &value)) {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+
+    /* So far so good. The value should be a string, check. */
+    if (!enif_is_list(env, value)) {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+
+    if (!enif_get_list_length(env, value, &len)) {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+
+    if ((buf = MALLOC(len+1)) == NULL) {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+
+    written = enif_get_string(env, value, buf, len+1, ERL_NIF_LATIN1);
+    if (written == (len+1)) {
+        *netns = buf;
+        return TRUE;
+    } else {
+        *netns = NULL; // Just in case...
+        return FALSE;
+    }
+}
+#endif
+
+
+/* esendflags2sendflags - convert internal (erlang) send flags to (proper)
+ * send flags.
+ */
+static
+BOOLEAN_T esendflags2sendflags(unsigned int eflags, int* flags)
+{
+    unsigned int ef;
+    int          tmp = 0;
+
+    /* First, check if we have any flags at all */
+    if (eflags == 0) {
+        *flags = 0;
+        return TRUE;
+    }
+        
+    for (ef = SOCKET_SEND_FLAG_LOW; ef <= SOCKET_SEND_FLAG_HIGH; ef++) {
+
+        switch (ef) {
+#if defined(MSG_CONFIRM)
+        case SOCKET_SEND_FLAG_CONFIRM:
+            if ((1 << SOCKET_SEND_FLAG_CONFIRM) & eflags)
+                tmp |= MSG_CONFIRM;
+            break;
+#endif
+
+#if defined(MSG_DONTROUTE)
+        case SOCKET_SEND_FLAG_DONTROUTE:
+            if ((1 << SOCKET_SEND_FLAG_DONTROUTE) & eflags)
+                tmp |= MSG_DONTROUTE;
+            break;
+#endif
+
+#if defined(MSG_EOR)
+        case SOCKET_SEND_FLAG_EOR:
+            if ((1 << SOCKET_SEND_FLAG_EOR) & eflags)
+                tmp |= MSG_EOR;
+            break;
+#endif
+
+#if defined(MSG_MORE)
+        case SOCKET_SEND_FLAG_MORE:
+            if ((1 << SOCKET_SEND_FLAG_MORE) & eflags)
+                tmp |= MSG_MORE;
+            break;
+#endif
+
+#if defined(MSG_NOSIGNAL)
+        case SOCKET_SEND_FLAG_NOSIGNAL:
+            if ((1 << SOCKET_SEND_FLAG_NOSIGNAL) & eflags)
+                tmp |= MSG_NOSIGNAL;
+            break;
+#endif
+
+#if defined(MSG_OOB)
+        case SOCKET_SEND_FLAG_OOB:
+            if ((1 << SOCKET_SEND_FLAG_OOB) & eflags)
+                tmp |= MSG_OOB;
+            break;
+#endif
+
+        default:
+            return FALSE;
+        }
+
+    }
+
+    *flags = tmp;
+
+    return TRUE;
+}
+
+
+
+/* erecvflags2recvflags - convert internal (erlang) send flags to (proper)
+ * send flags.
+ */
+static
+BOOLEAN_T erecvflags2recvflags(unsigned int eflags, int* flags)
+{
+    unsigned int ef;
+    int          tmp = 0;
+
+    SGDBG( ("SOCKET", "erecvflags2recvflags -> entry with"
+            "\r\n   eflags: %d"
+            "\r\n", eflags) );
+
+    if (eflags == 0) {
+        *flags = 0;
+        return TRUE;
+    }
+
+    for (ef = SOCKET_RECV_FLAG_LOW; ef <= SOCKET_RECV_FLAG_HIGH; ef++) {
+
+        SGDBG( ("SOCKET", "erecvflags2recvflags -> iteration"
+                "\r\n   ef:  %d"
+                "\r\n   tmp: %d"
+                "\r\n", ef, tmp) );
+
+        switch (ef) {
+#if defined(MSG_CMSG_CLOEXEC)
+        case SOCKET_RECV_FLAG_CMSG_CLOEXEC:
+            if ((1 << SOCKET_RECV_FLAG_CMSG_CLOEXEC) & eflags)
+                tmp |= MSG_CMSG_CLOEXEC;
+            break;
+#endif
+
+#if defined(MSG_ERRQUEUE)
+        case SOCKET_RECV_FLAG_ERRQUEUE:
+            if ((1 << SOCKET_RECV_FLAG_ERRQUEUE) & eflags)
+                tmp |= MSG_ERRQUEUE;
+            break;
+#endif
+
+#if defined(MSG_OOB)
+        case SOCKET_RECV_FLAG_OOB:
+            if ((1 << SOCKET_RECV_FLAG_OOB) & eflags)
+                tmp |= MSG_OOB;
+            break;
+#endif
+
+            /*
+             * <KOLLA>
+             *
+             * We need to handle this, because it may effect the read algorithm
+             *
+             * </KOLLA>
+             */
+#if defined(MSG_PEEK)
+        case SOCKET_RECV_FLAG_PEEK:
+            if ((1 << SOCKET_RECV_FLAG_PEEK) & eflags)
+                tmp |= MSG_PEEK;
+            break;
+#endif
+
+#if defined(MSG_TRUNC)
+        case SOCKET_RECV_FLAG_TRUNC:
+            if ((1 << SOCKET_RECV_FLAG_TRUNC) & eflags)
+                tmp |= MSG_TRUNC;
+            break;
+#endif
+
+        default:
+            return FALSE;
+        }
+
+    }
+
+    *flags = tmp;
+
+    return TRUE;
+}
+
+
+
+/* eproto2proto - convert internal (erlang) protocol to (proper) protocol
+ *
+ * Note that only a subset is supported.
+ */
+static
+BOOLEAN_T ehow2how(unsigned int ehow, int* how)
+{
+     switch (ehow) {
+     case SOCKET_SHUTDOWN_HOW_RD:
+         *how = SHUT_RD;
+         break;
+
+     case SOCKET_SHUTDOWN_HOW_WR:
+         *how = SHUT_WR;
+         break;
+
+     case SOCKET_SHUTDOWN_HOW_RDWR:
+         *how = SHUT_RDWR;
+         break;
+
+     default:
+         return FALSE;
+     }
+
+     return TRUE;
+}
+
+
+
+#if defined(HAVE_SYS_UN_H) || defined(SO_BINDTODEVICE)
+/* strnlen doesn't exist everywhere */
+/*
+static
+size_t my_strnlen(const char *s, size_t maxlen)
+{
+    size_t i = 0;
+    while (i < maxlen && s[i] != '\0')
+        i++;
+    return i;
+}
+*/
+#endif
+
+
+/* Send an error closed message to the specified process:
+ *
+ * This message is for processes that are waiting in the
+ * erlang API functions for a select message.
+ */
+/*
+static
+char* send_msg_error_closed(ErlNifEnv* env,
+                            ErlNifPid* pid)
+{
+  return send_msg_error(env, atom_closed, pid);
+}
+*/
+
+/* Send an error message to the specified process:
+ * A message in the form:
+ *
+ *     {error, Reason}
+ *
+ * This message is for processes that are waiting in the
+ * erlang API functions for a select message.
+ */
+/*
+static
+char* send_msg_error(ErlNifEnv*   env,
+                     ERL_NIF_TERM reason,
+                     ErlNifPid*   pid)
+{
+    ERL_NIF_TERM msg = enif_make_tuple2(env, atom_error, reason);
+
+    return send_msg(env, msg, pid);
+}
+*/
+
+
+/* Send an close message to the specified process:
+ * A message in the form:
+ *
+ *     {'$socket', SockRef, close, CloseRef}
+ *
+ * This message is for processes that is waiting in the
+ * erlang API (close-) function for the socket to be "closed"
+ * (actually that the 'stop' callback function has been called).
+ */
+static
+char* esock_send_close_msg(ErlNifEnv*   env,
+                           ERL_NIF_TERM closeRef,
+                           ErlNifPid*   pid)
+{
+    return esock_send_socket_msg(env,
+                                 esock_atom_undefined,
+                                 esock_atom_close, closeRef, pid);
+}
+
+
+/* Send an abort message to the specified process:
+ * A message in the form:
+ *
+ *     {'$socket', SockRef, abort, {RecvRef, Reason}}
+ *
+ * This message is for processes that is waiting in the
+ * erlang API functions for a select message.
+ */
+static
+char* esock_send_abort_msg(ErlNifEnv*   env,
+                           ERL_NIF_TERM sockRef,
+                           ERL_NIF_TERM recvRef,
+                           ERL_NIF_TERM reason,
+                           ErlNifPid*   pid)
+{
+    ERL_NIF_TERM info = MKT2(env, recvRef, reason);
+
+    /*
+    esock_dbg_printf("SEND MSG",
+                     "try send abort message to %T:\r\n",
+                     "\r\n   sockRef: %T"
+                     "\r\n   recvRef: %T"
+                     "\r\n   reason:  %T"
+                     "\r\n", *pid, sockRef, recvRef, reason);
+    */
+
+    return esock_send_socket_msg(env, sockRef, esock_atom_abort, info, pid);
+}
+
+
+/* *** esock_send_socket_msg ***
+ *
+ * This function sends a general purpose socket message to an erlang
+ * process. A general 'socket' message has the form: 
+ *
+ *      {'$socket', SockRef, Tag, Info}
+ *
+ */
+
+static
+char* esock_send_socket_msg(ErlNifEnv*   env,
+                            ERL_NIF_TERM sockRef,
+                            ERL_NIF_TERM tag,
+                            ERL_NIF_TERM info,
+                            ErlNifPid*   pid)
+{
+    ERL_NIF_TERM msg = MKT4(env, esock_atom_socket_tag, sockRef, tag, info);
+
+    return esock_send_msg(env, msg, pid);
+}
+
+
+/* Send a message to the specified process.
+ */
+static
+char* esock_send_msg(ErlNifEnv*   env,
+                     ERL_NIF_TERM msg,
+                     ErlNifPid*   pid)
+{
+    if (!enif_send(env, pid, NULL, msg))
+        return str_exsend;
+    else
+        return NULL;
+}
+#endif // #if defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  R e q u e s t   Q u e u e   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* *** acceptor search for pid ***
+ *
+ * Search for a pid in the acceptor queue.
+ */
+#if !defined(__WIN32__)
+static
+BOOLEAN_T acceptor_search4pid(ErlNifEnv*        env,
+                              SocketDescriptor* descP,
+                              ErlNifPid*        pid)
+{
+    return qsearch4pid(env, &descP->acceptorsQ, pid);
+}
+
+
+/* *** acceptor push ***
+ *
+ * Push an acceptor onto the acceptor queue.
+ * This happens when we already have atleast one current acceptor.
+ */
+static
+ERL_NIF_TERM acceptor_push(ErlNifEnv*        env,
+                           SocketDescriptor* descP,
+                           ErlNifPid         pid,
+                           ERL_NIF_TERM      ref)
+{
+    SocketRequestQueueElement* e    = MALLOC(sizeof(SocketRequestQueueElement));
+    SocketRequestor*           reqP = &e->data;
+    
+    reqP->pid = pid;
+    reqP->ref = enif_make_copy(descP->env, ref);
+    
+    if (MONP("acceptor_push -> acceptor request",
+             env, descP, &pid, &reqP->mon) != 0) {
+        FREE(reqP);
+        return esock_make_error(env, atom_exmon);
+    }
+    
+    qpush(&descP->acceptorsQ, e);
+    
+    // THIS IS OK => MAKES THE CALLER WAIT FOR ITS TURN
+    return esock_make_error(env, esock_atom_eagain);
+}
+
+
+/* *** acceptor pop ***
+ *
+ * Pop an acceptor from the acceptor queue.
+ */
+static
+BOOLEAN_T acceptor_pop(ErlNifEnv*        env,
+                       SocketDescriptor* descP,
+                       ErlNifPid*        pid,
+                       // ErlNifMonitor*    mon,
+                       ESockMonitor*     mon,
+                       ERL_NIF_TERM*     ref)
+{
+    SocketRequestQueueElement* e = qpop(&descP->acceptorsQ);
+
+    if (e != NULL) {
+        *pid = e->data.pid;
+        *mon = e->data.mon;
+        *ref = e->data.ref;
+        FREE(e);
+        return TRUE;
+    } else {
+        /* (acceptors) Queue was empty */
+        // *pid = NULL; we have no null value for pids
+        // *mon = NULL; we have no null value for monitors
+        *ref = esock_atom_undefined; // Just in case
+        return FALSE;
+    }
+    
+}
+
+
+/* *** acceptor unqueue ***
+ *
+ * Remove an acceptor from the acceptor queue.
+ */
+static
+BOOLEAN_T acceptor_unqueue(ErlNifEnv*        env,
+                           SocketDescriptor* descP,
+                           const ErlNifPid*  pid)
+{
+    return qunqueue(env, descP, "qunqueue -> waiting acceptor",
+                    &descP->acceptorsQ, pid);
+}
+
+
+
+/* *** writer search for pid ***
+ *
+ * Search for a pid in the writer queue.
+ */
+static
+BOOLEAN_T writer_search4pid(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ErlNifPid*        pid)
+{
+    return qsearch4pid(env, &descP->writersQ, pid);
+}
+
+
+/* *** writer push ***
+ *
+ * Push an writer onto the writer queue.
+ * This happens when we already have atleast one current writer.
+ */
+static
+ERL_NIF_TERM writer_push(ErlNifEnv*        env,
+                         SocketDescriptor* descP,
+                         ErlNifPid         pid,
+                         ERL_NIF_TERM      ref)
+{
+    SocketRequestQueueElement* e    = MALLOC(sizeof(SocketRequestQueueElement));
+    SocketRequestor*           reqP = &e->data;
+    
+    reqP->pid = pid;
+    reqP->ref = enif_make_copy(descP->env, ref);
+    
+    if (MONP("writer_push -> writer request",
+             env, descP, &pid, &reqP->mon) != 0) {
+        FREE(reqP);
+        return esock_make_error(env, atom_exmon);
+    }
+    
+    qpush(&descP->writersQ, e);
+    
+    // THIS IS OK => MAKES THE CALLER WAIT FOR ITS TURN
+    return esock_make_error(env, esock_atom_eagain);
+}
+
+
+/* *** writer pop ***
+ *
+ * Pop an writer from the writer queue.
+ */
+static
+BOOLEAN_T writer_pop(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     ErlNifPid*        pid,
+                     // ErlNifMonitor*    mon,
+                     ESockMonitor*     mon,
+                     ERL_NIF_TERM*     ref)
+{
+    SocketRequestQueueElement* e = qpop(&descP->writersQ);
+
+    if (e != NULL) {
+        *pid = e->data.pid;
+        *mon = e->data.mon;
+        *ref = e->data.ref; // At this point the ref has already been copied (env)
+        FREE(e);
+        return TRUE;
+    } else {
+        /* (writers) Queue was empty */
+        // *pid = NULL; we have no null value for pids
+        // *mon = NULL; we have no null value for monitors
+        *ref = esock_atom_undefined; // Just in case
+        return FALSE;
+    }
+    
+}
+
+
+/* *** writer unqueue ***
+ *
+ * Remove an writer from the writer queue.
+ */
+static
+BOOLEAN_T writer_unqueue(ErlNifEnv*        env,
+                         SocketDescriptor* descP,
+                         const ErlNifPid*  pid)
+{
+    return qunqueue(env, descP, "qunqueue -> waiting writer",
+                    &descP->writersQ, pid);
+}
+
+
+
+/* *** reader search for pid ***
+ *
+ * Search for a pid in the reader queue.
+ */
+static
+BOOLEAN_T reader_search4pid(ErlNifEnv*        env,
+                            SocketDescriptor* descP,
+                            ErlNifPid*        pid)
+{
+    return qsearch4pid(env, &descP->readersQ, pid);
+}
+
+
+/* *** reader push ***
+ *
+ * Push an reader onto the raeder queue.
+ * This happens when we already have atleast one current reader.
+ */
+static
+ERL_NIF_TERM reader_push(ErlNifEnv*        env,
+                         SocketDescriptor* descP,
+                         ErlNifPid         pid,
+                         ERL_NIF_TERM      ref)
+{
+    SocketRequestQueueElement* e    = MALLOC(sizeof(SocketRequestQueueElement));
+    SocketRequestor*           reqP = &e->data;
+    
+    reqP->pid = pid;
+    reqP->ref = enif_make_copy(descP->env, ref);
+    
+    if (MONP("reader_push -> reader request",
+             env, descP, &pid, &reqP->mon) != 0) {
+        FREE(reqP);
+        return esock_make_error(env, atom_exmon);
+    }
+    
+    qpush(&descP->readersQ, e);
+    
+    // THIS IS OK => MAKES THE CALLER WAIT FOR ITS TURN
+    return esock_make_error(env, esock_atom_eagain);
+}
+
+
+/* *** reader pop ***
+ *
+ * Pop an writer from the reader queue.
+ */
+static
+BOOLEAN_T reader_pop(ErlNifEnv*        env,
+                     SocketDescriptor* descP,
+                     ErlNifPid*        pid,
+                     // ErlNifMonitor*    mon,
+                     ESockMonitor*    mon,
+                     ERL_NIF_TERM*     ref)
+{
+    SocketRequestQueueElement* e = qpop(&descP->readersQ);
+
+    if (e != NULL) {
+        *pid = e->data.pid;
+        *mon = e->data.mon;
+        *ref = e->data.ref; // At this point the ref has already been copied (env)
+        FREE(e);
+        return TRUE;
+    } else {
+        /* (readers) Queue was empty */
+        // *pid = NULL; we have no null value for pids
+        // *mon = NULL; we have no null value for monitors
+        *ref = esock_atom_undefined; // Just in case
+        return FALSE;
+    }
+    
+}
+
+
+/* *** reader unqueue ***
+ *
+ * Remove an reader from the reader queue.
+ */
+static
+BOOLEAN_T reader_unqueue(ErlNifEnv*        env,
+                         SocketDescriptor* descP,
+                         const ErlNifPid*  pid)
+{
+    return qunqueue(env, descP, "qunqueue -> waiting reader",
+                    &descP->readersQ, pid);
+}
+
+
+
+
+
+static
+BOOLEAN_T qsearch4pid(ErlNifEnv*          env,
+                      SocketRequestQueue* q,
+                      ErlNifPid*          pid)
+{
+    SocketRequestQueueElement* tmp = q->first;
+    
+    while (tmp != NULL) {
+        if (compare_pids(env, &tmp->data.pid, pid))
+            return TRUE;
+        else
+            tmp = tmp->nextP;
+    }
+
+    return FALSE;
+}
+
+
+static
+void qpush(SocketRequestQueue*        q,
+           SocketRequestQueueElement* e)
+{
+    if (q->first != NULL) {
+        q->last->nextP = e;
+        q->last        = e;
+        e->nextP       = NULL;
+    } else {
+        q->first = e;
+        q->last  = e;
+        e->nextP = NULL;
+    }
+}
+ 
+ 
+static
+SocketRequestQueueElement* qpop(SocketRequestQueue* q)
+{
+    SocketRequestQueueElement* e = q->first;
+    
+    if (e != NULL) {
+        /* Atleast one element in the queue */
+        if (e == q->last) {
+            /* Only one element in the queue */
+            q->first = q->last = NULL;
+        } else {
+            /* More than one element in the queue */
+            q->first = e->nextP;
+        }
+    }
+    
+    return e;
+}
+
+
+
+static
+BOOLEAN_T qunqueue(ErlNifEnv*          env,
+                   SocketDescriptor*   descP,
+                   const char*         slogan,
+                   SocketRequestQueue* q,
+                   const ErlNifPid*    pid)
+{
+    SocketRequestQueueElement* e = q->first;
+    SocketRequestQueueElement* p = NULL;
+
+    /* Check if it was one of the waiting acceptor processes */
+    while (e != NULL) {
+        if (compare_pids(env, &e->data.pid, pid)) {
+
+            /* We have a match */
+
+            DEMONP(slogan, env, descP, &e->data.mon);
+            
+            if (p != NULL) {
+                /* Not the first, but could be the last */
+                if (q->last == e) {
+                    q->last  = p;
+                    p->nextP = NULL;                    
+                } else {
+                    p->nextP = e->nextP;
+                }
+                    
+            } else {
+                /* The first and could also be the last */
+                if (q->last == e) {
+                    q->last  = NULL;
+                    q->first = NULL;
+                } else {
+                    q->first = e->nextP;
+                }
+            }
+
+            FREE(e);
+
+            return TRUE;
+        }
+
+        /* Try next */
+        p = e;
+        e = e->nextP;
+    }
+
+    return FALSE;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  C o u n t e r   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+#if !defined(__WIN32__)
+static
+BOOLEAN_T cnt_inc(Uint32* cnt, Uint32 inc)
+{
+    BOOLEAN_T wrap;
+    Uint32    max     = 0xFFFFFFFF;
+    Uint32    current = *cnt;
+
+    if ((max - inc) >= current) {
+        *cnt += inc;
+        wrap  = FALSE;
+    } else {
+        *cnt = inc - (max - current) - 1;
+        wrap = TRUE;
+    }
+
+    return (wrap);
+}
+
+
+static
+void cnt_dec(Uint32* cnt, Uint32 dec)
+{
+    Uint32 current = *cnt;
+
+    if (dec > current)
+        *cnt = 0; // The counter cannot be < 0 so this is the best we can do...
+    else
+        *cnt -= dec;
+
+    return;
+}
+#endif // if !defined(__WIN32__)
+
+
+
+
+/* ----------------------------------------------------------------------
+ *  M o n i t o r   W r a p p e r   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+#if !defined(__WIN32__)
+static
+int esock_monitor(const char*       slogan,
+                  ErlNifEnv*        env,
+                  SocketDescriptor* descP,
+                  const ErlNifPid*  pid,
+                  ESockMonitor*     monP)
+{
+    int res;
+
+    SSDBG( descP, ("SOCKET", "[%d] %s: try monitor\r\n", descP->sock, slogan) );
+    /* esock_dbg_printf("MONP", "[%d] %s\r\n", descP->sock, slogan); */
+    res = enif_monitor_process(env, descP, pid, &monP->mon);
+
+    if (res != 0) {
+        SSDBG( descP, ("SOCKET", "[%d] monitor failed: %d\r\n", descP->sock, res) );
+        // esock_dbg_printf("MONP", "[%d] failed: %d\r\n", descP->sock, res);
+    } /* else {
+        esock_dbg_printf("MONP",
+                         "[%d] success: "
+                         "%u,%u,%u,%u\r\n",
+                         descP->sock,
+                         monP->raw[0], monP->raw[1],
+                         monP->raw[2], monP->raw[3]);
+                         } */
+
+    return res;
+}
+
+
+static
+int esock_demonitor(const char*       slogan,
+                    ErlNifEnv*        env,
+                    SocketDescriptor* descP,
+                    ESockMonitor*     monP)
+{
+    int res;
+
+    SSDBG( descP, ("SOCKET", "[%d] %s: try demonitor\r\n", descP->sock, slogan) );
+
+    /*
+    esock_dbg_printf("DEMONP", "[%d] %s: %u,%u,%u,%u\r\n",
+                     descP->sock, slogan,
+                     monP->raw[0], monP->raw[1],
+                     monP->raw[2], monP->raw[3]);
+    */
+
+    res = enif_demonitor_process(env, descP, &monP->mon);
+
+    if (res == 0) {
+        esock_monitor_init(monP);
+    } else {
+        SSDBG( descP,
+               ("SOCKET", "[%d] demonitor failed: %d\r\n", descP->sock, res) );
+        /*
+        esock_dbg_printf("DEMONP", "[%d] failed: %d\r\n", descP->sock, res);
+        */
+    }
+
+    return res;
+}
+
+
+static
+void esock_monitor_init(ESockMonitor* monP)
+{
+    int i;
+
+    /*
+     * UGLY,
+     * but since we don't have a ERL_NIF_MONITOR_NULL, 
+     * this will have to do for now...
+     */
+    for (i = 0; i < 4; i++) 
+        monP->raw[i] = 0;
+
+}
+#endif // if !defined(__WIN32__)
+
+
+/*
+static
+int esock_monitor_compare(const ErlNifMonitor* mon1,
+                          const ESockMonitor*  mon2)
+{
+    return enif_compare_monitors(mon1, &mon2->mon);
+}
+*/
+
+
+/* ----------------------------------------------------------------------
+ *  C a l l b a c k   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+/* =========================================================================
+ * socket_dtor - Callback function for resource destructor
+ *
+ */
+static
+void socket_dtor(ErlNifEnv* env, void* obj)
+{
+#if !defined(__WIN32__)    
+  SocketDescriptor* descP = (SocketDescriptor*) obj;
+
+  enif_clear_env(descP->env);
+  enif_free_env(descP->env);
+  descP->env = NULL;
+
+  MDESTROY(descP->writeMtx);
+  MDESTROY(descP->readMtx);
+  MDESTROY(descP->accMtx);
+  MDESTROY(descP->closeMtx);
+#endif
+}
+
+
+/* =========================================================================
+ * socket_stop - Callback function for resource stop
+ *
+ * When the socket is stopped, we need to inform:
+ *
+ *     * the controlling process
+ *     * the current writer and any waiting writers
+ *     * the current reader and any waiting readers
+ *     * the current acceptor and any waiting acceptor
+ *
+ * Also, make sure no process gets the message twice
+ * (in case it is, for instance, both controlling process
+ * and a writer).
+ *
+ * <KOLLA>
+ *
+ * We do not handle linger-issues yet! So anything in the out
+ * buffers will be left for the OS to solve...
+ * Do we need a special "close"-thread? Dirty scheduler?
+ *
+ * What happens if we are "stopped" for another reason then 'close'?
+ * For instance, down?
+ *
+ * </KOLLA>
+ */
+static
+void socket_stop(ErlNifEnv* env, void* obj, int fd, int is_direct_call)
+{
+#if !defined(__WIN32__)
+    SocketDescriptor* descP = (SocketDescriptor*) obj;
+
+    /*
+    esock_dbg_printf("STOP", "[%d] begin\r\n", descP->sock);
+    */
+
+    SSDBG( descP,
+           ("SOCKET", "socket_stop -> entry when %s"
+            "\r\n   sock: %d (%d)"
+            "\r\n", ((is_direct_call) ? "called" : "scheduled"), descP->sock, fd) );
+    
+    MLOCK(descP->writeMtx);
+    MLOCK(descP->readMtx);
+    MLOCK(descP->accMtx);
+    MLOCK(descP->closeMtx);
+    
+    SSDBG( descP, ("SOCKET", "socket_stop -> "
+                   "[%d, %T] all mutex(s) locked when counters:"
+                   "\r\n   writePkgCnt:  %u"
+                   "\r\n   writeByteCnt: %u"
+                   "\r\n   writeTries:   %u"
+                   "\r\n   writeWaits:   %u"
+                   "\r\n   writeFails:   %u"
+                   "\r\n   readPkgCnt:   %u"
+                   "\r\n   readByteCnt:  %u"
+                   "\r\n   readTries:    %u"
+                   "\r\n   readWaits:    %u"
+                   "\r\n",
+                   descP->sock, descP->ctrlPid,
+                   descP->writePkgCnt,
+                   descP->writeByteCnt,
+                   descP->writeTries,
+                   descP->writeWaits,
+                   descP->writeFails,
+                   descP->readPkgCnt,
+                   descP->readByteCnt,
+                   descP->readTries,
+                   descP->readWaits) );
+
+    descP->state      = SOCKET_STATE_CLOSING; // Just in case...???
+    descP->isReadable = FALSE;
+    descP->isWritable = FALSE;
+
+    /* We should check that we actually have a monitor.
+     * This *should* be done with a "NULL" monitor value,
+     * which there currently is none...
+     * If we got here because the controlling process died,
+     * its no point in demonitor. Also, we not actually have 
+     * a monitor in that case...
+     */
+    DEMONP("socket_stop -> ctrl", env, descP, &descP->ctrlMon);
+
+    /*
+    esock_dbg_printf("STOP", "[%d] maybe handle current writer (0x%lX)\r\n",
+                     descP->sock, descP->currentReaderP);
+    */
+    if (descP->currentWriterP != NULL) {
+        /* We have a (current) writer and *may* therefor also have
+         * writers waiting.
+         */
+
+        DEMONP("socket_stop -> current writer",
+               env, descP, &descP->currentWriter.mon);
+
+        SSDBG( descP, ("SOCKET", "socket_stop -> handle current writer\r\n") );
+        if (!compare_pids(env,
+                          &descP->closerPid,
+                          &descP->currentWriter.pid)) {
+            SSDBG( descP, ("SOCKET", "socket_stop -> "
+                           "send abort message to current writer %T\r\n",
+                           descP->currentWriter.pid) );
+            if (esock_send_abort_msg(env,
+                                     esock_atom_undefined,
+                                     descP->currentWriter.ref,
+                                     atom_closed,
+                                     &descP->currentWriter.pid) != NULL) {
+                /* Shall we really do this? 
+                 * This happens if the controlling process has been killed!
+                 */
+                esock_warning_msg("Failed sending abort (%T) message to "
+                                  "current writer %T\r\n",
+                                  descP->currentWriter.ref,
+                                  descP->currentWriter.pid);
+            }
+        }
+        
+        /* And also deal with the waiting writers (in the same way) */
+        SSDBG( descP, ("SOCKET", "socket_stop -> handle waiting writer(s)\r\n") );
+        inform_waiting_procs(env, descP, &descP->writersQ, TRUE, atom_closed);
+    }
+
+    /*
+    esock_dbg_printf("STOP", "[%d] maybe handle current reader (0x%lX)\r\n",
+                     descP->sock, descP->currentReaderP);
+    */
+    if (descP->currentReaderP != NULL) {
+        
+        /* We have a (current) reader and *may* therefor also have
+         * readers waiting.
+         */
+        
+        DEMONP("socket_stop -> current reader",
+               env, descP, &descP->currentReader.mon);
+
+        SSDBG( descP, ("SOCKET", "socket_stop -> handle current reader\r\n") );
+        if (!compare_pids(env,
+                          &descP->closerPid,
+                          &descP->currentReader.pid)) {
+            SSDBG( descP, ("SOCKET", "socket_stop -> "
+                           "send abort message to current reader %T\r\n",
+                           descP->currentReader.pid) );
+            if (esock_send_abort_msg(env,
+                                     esock_atom_undefined,
+                                     descP->currentReader.ref,
+                                     atom_closed,
+                                     &descP->currentReader.pid) != NULL) {
+                /* Shall we really do this? 
+                 * This happens if the controlling process has been killed!
+                 */
+                esock_warning_msg("Failed sending abort (%T) message to "
+                                  "current reader %T\r\n",
+                                  descP->currentReader.ref,
+                                  descP->currentReader.pid);
+            }
+        }
+        
+        /* And also deal with the waiting readers (in the same way) */
+        SSDBG( descP, ("SOCKET", "socket_stop -> handle waiting reader(s)\r\n") );
+        inform_waiting_procs(env, descP, &descP->readersQ, TRUE, atom_closed);
+    }
+
+    /*
+    esock_dbg_printf("STOP", "[%d] maybe handle current acceptor (0x%lX)\r\n",
+                     descP->sock, descP->currentReaderP);
+    */
+    if (descP->currentAcceptorP != NULL) {
+        /* We have a (current) acceptor and *may* therefor also have
+         * acceptors waiting.
+         */
+        
+        DEMONP("socket_stop -> current acceptor",
+               env, descP, &descP->currentAcceptor.mon);
+
+        SSDBG( descP, ("SOCKET", "socket_stop -> handle current acceptor\r\n") );
+        if (!compare_pids(env,
+                          &descP->closerPid,
+                          &descP->currentAcceptor.pid)) {
+            SSDBG( descP, ("SOCKET", "socket_stop -> "
+                           "send abort message to current acceptor %T\r\n",
+                           descP->currentWriter.pid) );
+            if (esock_send_abort_msg(env,
+                                     esock_atom_undefined,
+                                     descP->currentAcceptor.ref,
+                                     atom_closed,
+                                     &descP->currentAcceptor.pid) != NULL) {
+                /* Shall we really do this? 
+                 * This happens if the controlling process has been killed!
+                 */
+                esock_warning_msg("Failed sending abort (%T) message to "
+                                  "current acceptor %T\r\n",
+                                  descP->currentAcceptor.ref,
+                                  descP->currentAcceptor.pid);
+            }
+        }
+        
+        /* And also deal with the waiting acceptors (in the same way) */
+        SSDBG( descP, ("SOCKET", "socket_stop -> handle waiting acceptor(s)\r\n") );
+        inform_waiting_procs(env, descP, &descP->acceptorsQ, TRUE, atom_closed);
+    }
+    
+    
+    if (descP->sock != INVALID_SOCKET) {
+        
+        /*
+         * <KOLLA>
+         *
+         * WE NEED TO CHECK IF THIS OPERATION IS TRIGGERED
+         * LOCALLY (VIA A CALL TO CLOSE) OR REMOTELLY
+         * (VIA I.E. ECONSRESET).
+         *
+         * </KOLLA>
+         */
+        
+        if (descP->closeLocal &&
+            !is_direct_call) {
+            
+            /* +++ send close message to the waiting process +++
+             *
+             *           {close, CloseRef}
+             *
+             * <KOLLA>
+             *
+             * WHAT HAPPENS IF THE RECEIVER HAS DIED IN THE MEANTIME????
+             *
+             * Also, we should really *always* use a tag unique to this
+             * (nif-) module. Some like (in this case):
+             *
+             *      {'$socket', undefined, close, CloseRef}
+             *
+             * </KOLLA>
+             */
+
+            esock_send_close_msg(env, descP->closeRef, &descP->closerPid);
+            
+            DEMONP("socket_stop -> closer", env, descP, &descP->closerMon);
+            
+        } else {
+            
+            /*
+             * <KOLLA>
+             *
+             * ABORT?
+             *
+             * </KOLLA>
+             */
+        }
+    }
+    
+
+    if (!is_direct_call) {
+        if (descP->closeLocal) {
+            DEMONP("socket_stop -> closer",
+                   env, descP, &descP->closerMon);
+        }
+        descP->sock  = INVALID_SOCKET;
+        descP->event = INVALID_EVENT;
+        descP->state = SOCKET_STATE_CLOSED;
+    }
+
+    SSDBG( descP, ("SOCKET", "socket_stop -> unlock all mutex(s)\r\n") );
+
+    MUNLOCK(descP->closeMtx);
+    MUNLOCK(descP->accMtx);
+    MUNLOCK(descP->readMtx);
+    MUNLOCK(descP->writeMtx);
+
+    /*
+    esock_dbg_printf("STOP", "[%d] end\r\n", descP->sock);
+    */
+
+    SSDBG( descP,
+           ("SOCKET", "socket_stop -> done (%d, %d)\r\n", descP->sock, fd) );
+#endif // if !defined(__WIN32__)
+}
+
+
+/* This function traverse the queue and sends the specified
+ * nif_abort message with the specified reason to each member,
+ * and if the 'free' argument is TRUE, the queue will be emptied.
+ */
+#if !defined(__WIN32__)
+static
+void inform_waiting_procs(ErlNifEnv*          env,
+                          SocketDescriptor*   descP,
+                          SocketRequestQueue* q,
+                          BOOLEAN_T           free,
+                          ERL_NIF_TERM        reason)
+{
+    SocketRequestQueueElement* currentP = q->first;
+    SocketRequestQueueElement* nextP;
+
+    while (currentP != NULL) {
+
+        /* <KOLLA>
+         *
+         * Should we inform anyone if we fail to demonitor?
+         * NOT SURE WHAT THAT WOULD REPRESENT AND IT IS NOT
+         * IMPORTANT IN *THIS* CASE, BUT ITS A FUNDAMENTAL OP...
+         *
+         * </KOLLA>
+         */
+
+        SSDBG( descP,
+               ("SOCKET", "inform_waiting_procs -> abort request %T (from %T)\r\n",
+                currentP->data.ref, currentP->data.pid) );
+
+        ESOCK_ASSERT( (NULL == esock_send_abort_msg(env,
+                                                    esock_atom_undefined,
+                                                    currentP->data.ref,
+                                                    reason,
+                                                    &currentP->data.pid)) );
+
+        DEMONP("inform_waiting_procs -> current 'request'",
+               env, descP, &currentP->data.mon);
+        nextP = currentP->nextP;
+        if (free) FREE(currentP);
+        currentP = nextP;
+    }
+
+    if (free) {
+        q->first = NULL;
+        q->last  = NULL;
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+/* =========================================================================
+ * socket_down - Callback function for resource down (monitored processes)
+ *
+ */
+static
+void socket_down(ErlNifEnv*           env,
+                 void*                obj,
+                 const ErlNifPid*     pid,
+                 const ErlNifMonitor* mon)
+{
+#if !defined(__WIN32__)
+    SocketDescriptor* descP = (SocketDescriptor*) obj;
+    ESockMonitor*     monP  = (ESockMonitor*) mon;
+
+    SSDBG( descP, ("SOCKET", "socket_down -> entry with"
+                   "\r\n   sock:  %d"
+                   "\r\n   pid:   %T"
+                   "\r\n   Close: %s (%s)"
+                   "\r\n",
+                   descP->sock, *pid,
+                   B2S(IS_CLOSED(descP)),
+                   B2S(IS_CLOSING(descP))) );
+
+    /*
+    esock_dbg_printf("DOWN",
+                     "[%d] begin %u,%u,%u,%d\r\n",
+                     descP->sock,
+                     monP->raw[0], monP->raw[1],
+                     monP->raw[2], monP->raw[3]);
+    */
+
+    /*
+    if (MON_COMP(mon, &descP->ctrlMon) == 0) {
+        SSDBG( descP, ("SOCKET", "socket_down -> controlling process mon\r\n") );
+    } else if (MON_COMP(mon, &descP->closerMon) == 0) {
+        SSDBG( descP, ("SOCKET", "socket_down -> closer mon\r\n") );
+    } else if ((descP->currentWriterP != NULL) &&
+               (MON_COMP(mon, &descP->currentWriter.mon) == 0)) {
+        SSDBG( descP, ("SOCKET", "socket_down -> current writer mon\r\n") );
+    } else if ((descP->currentReaderP != NULL) &&
+               (MON_COMP(mon, &descP->currentReader.mon) == 0)) {
+        SSDBG( descP, ("SOCKET", "socket_down -> current reader mon\r\n") );
+    } else if ((descP->currentAcceptorP != NULL) &&
+               (MON_COMP(mon, &descP->currentAcceptor.mon) == 0)) {
+        SSDBG( descP, ("SOCKET", "socket_down -> current acceptor mon\r\n") );
+    } else {
+        SSDBG( descP, ("SOCKET", "socket_down -> OTHER mon\r\n") );
+    }
+    */
+
+    if (!IS_CLOSED(descP)) {
+        if (compare_pids(env, &descP->ctrlPid, pid)) {
+            int selectRes;
+
+            /* We don't bother with the queue cleanup here - 
+             * we leave it to the stop callback function.
+             */
+
+            SSDBG( descP,
+                   ("SOCKET", "socket_down -> controlling process exit\r\n") );
+
+            descP->state      = SOCKET_STATE_CLOSING;
+            descP->closeLocal = TRUE;
+            descP->closerPid  = *pid;
+            descP->closerMon  = (ESockMonitor) *mon;
+            descP->closeRef   = MKREF(env); // Do we really need this in this case?
+            
+            /*
+              esock_dbg_printf("DOWN",
+              "[%d] select stop %u,%u,%u,%d\r\n",
+              descP->sock,
+              monP->raw[0], monP->raw[1],
+              monP->raw[2], monP->raw[3]);
+            */
+            
+            selectRes = enif_select(env, descP->sock, (ERL_NIF_SELECT_STOP),
+                                    descP, NULL, descP->closeRef);
+
+            if (selectRes & ERL_NIF_SELECT_STOP_CALLED) {
+                /* We are done - we can finalize (socket close) directly */
+                SSDBG( descP,
+                       ("SOCKET", 
+                        "socket_down -> [%d] stop called\r\n", descP->sock) );
+                dec_socket(descP->domain, descP->type, descP->protocol);
+                descP->state = SOCKET_STATE_CLOSED;
+
+                /* And finally close the socket.
+                 * Since we close the socket because of an exiting owner,
+                 * we do not need to wait for buffers to sync (linger).
+                 * If the owner wish to ensure the buffer are written,
+                 * it should have closed the socket explicitly...
+                 */
+                if (sock_close(descP->sock) != 0) {
+                    int save_errno = sock_errno();
+
+                    esock_warning_msg("Failed closing socket for terminating "
+                                      "controlling process: "
+                                      "\r\n   Controlling Process: %T"
+                                      "\r\n   Descriptor:          %d"
+                                      "\r\n   Errno:               %d"
+                                      "\r\n", pid, descP->sock, save_errno);
+                }
+                sock_close_event(descP->event);
+
+                descP->sock  = INVALID_SOCKET;
+                descP->event = INVALID_EVENT;
+
+                descP->state = SOCKET_STATE_CLOSED;
+
+            } else if (selectRes & ERL_NIF_SELECT_STOP_SCHEDULED) {
+                /* The stop callback function has been *scheduled* which means
+                 * that "should" wait for it to complete. But since we are in
+                 * a callback (down) function, we cannot...
+                 * So, we must close the socket
+                 */
+                SSDBG( descP,
+                       ("SOCKET",
+                        "socket_down -> [%d] stop scheduled\r\n",
+                        descP->sock) );
+                dec_socket(descP->domain, descP->type, descP->protocol);
+
+                /* And now what? We can't wait for the stop function here... 
+                 * So, we simply close it here and leave the rest of the "close"
+                 * for later (when the stop function actually gets called...
+                 */
+
+                if (sock_close(descP->sock) != 0) {
+                    int save_errno = sock_errno();
+
+                    esock_warning_msg("Failed closing socket for terminating "
+                                      "controlling process: "
+                                      "\r\n   Controlling Process: %T"
+                                      "\r\n   Descriptor:          %d"
+                                      "\r\n   Errno:               %d"
+                                      "\r\n", pid, descP->sock, save_errno);
+                }
+                sock_close_event(descP->event);
+
+            } else {
+
+                /*
+                 * <KOLLA>
+                 *
+                 * WE SHOULD REALLY HAVE A WAY TO CLOBBER THE SOCKET,
+                 * SO WE DON'T LET STUFF LEAK.
+                 * NOW, BECAUSE WE FAILED TO SELECT, WE CANNOT FINISH
+                 * THE CLOSE, WHAT TO DO? ABORT?
+                 *
+                 * </KOLLA>
+                 */
+                esock_warning_msg("Failed selecting stop when handling down "
+                                  "of controlling process: "
+                                  "\r\n   Select Res:          %d"
+                                  "\r\n   Controlling Process: %T"
+                                  "\r\n   Descriptor:          %d"
+                                  "\r\n   Monitor:             %u.%u.%u.%u"
+                                  "\r\n", selectRes, pid, descP->sock,
+                                  monP->raw[0], monP->raw[1],
+                                  monP->raw[2], monP->raw[3]);
+            }
+
+        } else {
+
+            /* check all operation queue(s): acceptor, writer and reader. 
+             *
+             * Is it really any point in doing this if the socket is closed?
+             *
+             */
+
+            SSDBG( descP, ("SOCKET", "socket_down -> other process term\r\n") );
+
+            MLOCK(descP->accMtx);
+            if (descP->currentAcceptorP != NULL)
+                socket_down_acceptor(env, descP, pid);
+            MUNLOCK(descP->accMtx);
+
+            MLOCK(descP->writeMtx);
+            if (descP->currentWriterP != NULL)
+                socket_down_writer(env, descP, pid);
+            MUNLOCK(descP->writeMtx);
+
+            MLOCK(descP->readMtx);
+            if (descP->currentReaderP != NULL)
+                socket_down_reader(env, descP, pid);
+            MUNLOCK(descP->readMtx);
+
+        }
+    }
+
+    /*
+    esock_dbg_printf("DOWN",
+                     "[%d] end %u,%u,%u,%d\r\n",
+                     descP->sock,
+                     monP->raw[0], monP->raw[1],
+                     monP->raw[2], monP->raw[3]);
+    */
+    
+    SSDBG( descP, ("SOCKET", "socket_down -> done\r\n") );
+
+#endif // if !defined(__WIN32__)
+}
+
+
+
+/* *** socket_down_acceptor ***
+ *
+ * Check and then handle a downed acceptor process.
+ *
+ */
+#if !defined(__WIN32__)
+static
+void socket_down_acceptor(ErlNifEnv*        env,
+                          SocketDescriptor* descP,
+                          const ErlNifPid*  pid)
+{
+    if (compare_pids(env, &descP->currentAcceptor.pid, pid)) {
+        
+        SSDBG( descP, ("SOCKET",
+                       "socket_down_acceptor -> "
+                       "current acceptor - try pop the queue\r\n") );
+        
+        if (acceptor_pop(env, descP,
+                         &descP->currentAcceptor.pid,
+                         &descP->currentAcceptor.mon,
+                         &descP->currentAcceptor.ref)) {
+            int res;
+            
+            /* There was another one, so we will still be in accepting state */
+            
+            SSDBG( descP, ("SOCKET",
+                           "socket_down_acceptor -> new (active) acceptor: "
+                           "\r\n   pid: %T"
+                           "\r\n   ref: %T"
+                           "\r\n",
+                           descP->currentAcceptor.pid,
+                           descP->currentAcceptor.ref) );
+            
+            if ((res = enif_select(env,
+                                   descP->sock,
+                                   (ERL_NIF_SELECT_READ),
+                                   descP,
+                                   &descP->currentAcceptor.pid,
+                                   descP->currentAcceptor.ref) < 0)) {
+                
+                esock_warning_msg("Failed select (%d) for new acceptor "
+                                  "after current (%T) died\r\n",
+                                  res, *pid);
+                
+            }
+            
+        } else {
+            
+            SSDBG( descP, ("SOCKET",
+                           "socket_down_acceptor -> no active acceptor\r\n") );
+            
+            descP->currentAcceptorP = NULL;
+            descP->state            = SOCKET_STATE_LISTENING;
+        }
+        
+    } else {
+        
+        /* Maybe unqueue one of the waiting acceptors */
+        
+        SSDBG( descP, ("SOCKET",
+                       "socket_down_acceptor -> "
+                       "not current acceptor - maybe a waiting acceptor\r\n") );
+        
+        acceptor_unqueue(env, descP, pid);
+    }
+}
+
+
+
+
+/* *** socket_down_writer ***
+ *
+ * Check and then handle a downed writer process.
+ *
+ */
+static
+void socket_down_writer(ErlNifEnv*        env,
+                        SocketDescriptor* descP,
+                        const ErlNifPid*  pid)
+{
+    if (compare_pids(env, &descP->currentWriter.pid, pid)) {
+        
+        SSDBG( descP, ("SOCKET",
+                       "socket_down_writer -> "
+                       "current writer - try pop the queue\r\n") );
+        
+        if (writer_pop(env, descP,
+                       &descP->currentWriter.pid,
+                       &descP->currentWriter.mon,
+                       &descP->currentWriter.ref)) {
+            int res;
+            
+            /* There was another one */
+            
+            SSDBG( descP, ("SOCKET", "socket_down_writer -> new (current) writer: "
+                           "\r\n   pid: %T"
+                           "\r\n   ref: %T"
+                           "\r\n",
+                           descP->currentWriter.pid,
+                           descP->currentWriter.ref) );
+            
+            if ((res = enif_select(env,
+                                   descP->sock,
+                                   (ERL_NIF_SELECT_WRITE),
+                                   descP,
+                                   &descP->currentWriter.pid,
+                                   descP->currentWriter.ref) < 0)) {
+                
+                esock_warning_msg("Failed select (%d) for new writer "
+                                  "after current (%T) died\r\n",
+                                  res, *pid);
+                
+            }
+            
+        } else {
+            
+            SSDBG( descP, ("SOCKET",
+                           "socket_down_writer -> no active writer\r\n") );
+            
+            descP->currentWriterP = NULL;
+        }
+        
+    } else {
+        
+        /* Maybe unqueue one of the waiting writer(s) */
+        
+        SSDBG( descP, ("SOCKET",
+                       "socket_down_writer -> "
+                       "not current writer - maybe a waiting writer\r\n") );
+        
+        writer_unqueue(env, descP, pid);
+    }
+}
+
+
+
+
+/* *** socket_down_reader ***
+ *
+ * Check and then handle a downed reader process.
+ *
+ */
+static
+void socket_down_reader(ErlNifEnv*        env,
+                        SocketDescriptor* descP,
+                        const ErlNifPid*  pid)
+{
+    if (compare_pids(env, &descP->currentReader.pid, pid)) {
+        
+        SSDBG( descP, ("SOCKET",
+                       "socket_down_reader -> "
+                       "current reader - try pop the queue\r\n") );
+        
+        if (reader_pop(env, descP,
+                       &descP->currentReader.pid,
+                       &descP->currentReader.mon,
+                       &descP->currentReader.ref)) {
+            int res;
+            
+            /* There was another one */
+            
+            SSDBG( descP, ("SOCKET", "socket_down_reader -> new (current) reader: "
+                           "\r\n   pid: %T"
+                           "\r\n   ref: %T"
+                           "\r\n",
+                           descP->currentReader.pid,
+                           descP->currentReader.ref) );
+            
+            if ((res = enif_select(env,
+                                   descP->sock,
+                                   (ERL_NIF_SELECT_READ),
+                                   descP,
+                                   &descP->currentReader.pid,
+                                   descP->currentReader.ref) < 0)) {
+                
+                esock_warning_msg("Failed select (%d) for new reader "
+                                  "after current (%T) died\r\n",
+                                  res, *pid);
+                
+            }
+            
+        } else {
+            
+            SSDBG( descP, ("SOCKET",
+                           "socket_down_reader -> no active reader\r\n") );
+            
+            descP->currentReaderP = NULL;
+        }
+        
+    } else {
+        
+        /* Maybe unqueue one of the waiting reader(s) */
+        
+        SSDBG( descP, ("SOCKET",
+                       "socket_down_reader -> "
+                       "not current reader - maybe a waiting reader\r\n") );
+        
+        reader_unqueue(env, descP, pid);
+    }
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* ----------------------------------------------------------------------
+ *  L o a d / u n l o a d / u p g r a d e   F u n c t i o n s
+ * ----------------------------------------------------------------------
+ */
+
+static
+ErlNifFunc socket_funcs[] =
+{
+    // Some utility and support functions
+    {"nif_info",                0, nif_info, 0},
+    {"nif_supports",            1, nif_supports, 0},
+    // {"nif_debug",               1, nif_debug, 0},
+    // {"nif_command",             1, nif_command, 0},
+
+    // The proper "socket" interface
+    // nif_open/1 is used when we already have a file descriptor
+    // {"nif_open",                1, nif_open, 0},
+    {"nif_open",                4, nif_open, 0},
+    {"nif_bind",                2, nif_bind, 0},
+    {"nif_connect",             2, nif_connect, 0},
+    {"nif_listen",              2, nif_listen, 0},
+    {"nif_accept",              2, nif_accept, 0},
+    {"nif_send",                4, nif_send, 0},
+    {"nif_sendto",              5, nif_sendto, 0},
+    {"nif_sendmsg",             4, nif_sendmsg, 0},
+    {"nif_recv",                4, nif_recv, 0},
+    {"nif_recvfrom",            4, nif_recvfrom, 0},
+    {"nif_recvmsg",             5, nif_recvmsg, 0},
+    {"nif_close",               1, nif_close, 0},
+    {"nif_shutdown",            2, nif_shutdown, 0},
+    {"nif_setopt",              5, nif_setopt, 0},
+    {"nif_getopt",              4, nif_getopt, 0},
+    {"nif_sockname",            1, nif_sockname, 0},
+    {"nif_peername",            1, nif_peername, 0},
+
+    /* Misc utility functions */
+
+    /* "Extra" functions to "complete" the socket interface.
+     * For instance, the function nif_finalize_connection
+     * is called after the connect *select* has "completed".
+     */
+    {"nif_finalize_connection", 1, nif_finalize_connection, 0},
+    {"nif_cancel",              3, nif_cancel, 0},
+    {"nif_finalize_close",      1, nif_finalize_close, ERL_NIF_DIRTY_JOB_IO_BOUND}
+};
+
+
+#if !defined(__WIN32__)
+static
+BOOLEAN_T extract_debug(ErlNifEnv*   env,
+                        ERL_NIF_TERM map)
+{
+    /*
+     * We need to do this here since the "proper" atom has not been
+     * created when this function is called.
+     */
+    ERL_NIF_TERM debug = MKA(env, "debug");
+    
+    return esock_extract_bool_from_map(env, map, debug, SOCKET_GLOBAL_DEBUG_DEFAULT);
+}
+
+static
+BOOLEAN_T extract_iow(ErlNifEnv*   env,
+                      ERL_NIF_TERM map)
+{
+    /*
+     * We need to do this here since the "proper" atom has not been
+     * created when this function is called.
+     */
+    ERL_NIF_TERM iow = MKA(env, "iow");
+    
+    return esock_extract_bool_from_map(env, map, iow, SOCKET_NIF_IOW_DEFAULT);
+}
+#endif // if !defined(__WIN32__)
+
+
+
+/* =======================================================================
+ * load_info - A map of misc info (e.g global debug)
+ */
+
+static
+int on_load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info)
+{
+#if !defined(__WIN32__)    
+    esock_dbg_init(ESOCK_DBGOUT_DEFAULT);
+    // esock_dbg_init(ESOCK_DBGOUT_UNIQUE);
+
+    data.dbg = extract_debug(env, load_info);
+    data.iow = extract_iow(env, load_info);
+
+    /* +++ Global Counters +++ */
+    data.cntMtx         = MCREATE("socket[gcnt]");
+    data.numSockets     = 0;
+    data.numTypeDGrams  = 0;
+    data.numTypeStreams = 0;
+    data.numTypeSeqPkgs = 0;
+    data.numDomainLocal = 0;
+    data.numDomainInet  = 0;
+    data.numDomainInet6 = 0;
+    data.numProtoIP     = 0;
+    data.numProtoTCP    = 0;
+    data.numProtoUDP    = 0;
+    data.numProtoSCTP   = 0;
+#endif
+
+    /* +++ Misc atoms +++ */
+    atom_adaptation_layer    = MKA(env, str_adaptation_layer);
+    atom_address             = MKA(env, str_address);
+    atom_association         = MKA(env, str_association);
+    atom_assoc_id            = MKA(env, str_assoc_id);
+    atom_authentication      = MKA(env, str_authentication);
+    atom_bool                = MKA(env, str_bool);
+    atom_close               = MKA(env, str_close);
+    atom_closed              = MKA(env, str_closed);
+    atom_closing             = MKA(env, str_closing);
+    atom_cookie_life         = MKA(env, str_cookie_life);
+    atom_data_in             = MKA(env, str_data_in);
+    atom_do                  = MKA(env, str_do);
+    atom_dont                = MKA(env, str_dont);
+    atom_exclude             = MKA(env, str_exclude);
+    atom_false               = MKA(env, str_false);
+    atom_global_counters     = MKA(env, str_global_counters);
+    atom_in4_sockaddr        = MKA(env, str_in4_sockaddr);
+    atom_in6_sockaddr        = MKA(env, str_in6_sockaddr);
+    atom_include             = MKA(env, str_include);
+    atom_initial             = MKA(env, str_initial);
+    atom_int                 = MKA(env, str_int);
+    atom_interface           = MKA(env, str_interface);
+    atom_iow                 = MKA(env, str_iow);
+    atom_local_rwnd          = MKA(env, str_local_rwnd);
+    atom_max                 = MKA(env, str_max);
+    atom_max_attempts        = MKA(env, str_max_attempts);
+    atom_max_init_timeo      = MKA(env, str_max_init_timeo);
+    atom_max_instreams       = MKA(env, str_max_instreams);
+    atom_max_rxt             = MKA(env, str_max_rxt);
+    atom_min                 = MKA(env, str_min);
+    atom_mode                = MKA(env, str_mode);
+    atom_multiaddr           = MKA(env, str_multiaddr);
+    // atom_nif_abort           = MKA(env, str_nif_abort);
+    atom_null                = MKA(env, str_null);
+    atom_num_dinet           = MKA(env, str_num_dinet);
+    atom_num_dinet6          = MKA(env, str_num_dinet6);
+    atom_num_dlocal          = MKA(env, str_num_dlocal);
+    atom_num_outstreams      = MKA(env, str_num_outstreams);
+    atom_num_peer_dests      = MKA(env, str_num_peer_dests);
+    atom_num_pip             = MKA(env, str_num_pip);
+    atom_num_psctp           = MKA(env, str_num_psctp);
+    atom_num_ptcp            = MKA(env, str_num_ptcp);
+    atom_num_pudp            = MKA(env, str_num_pudp);
+    atom_num_sockets         = MKA(env, str_num_sockets);
+    atom_num_tdgrams         = MKA(env, str_num_tdgrams);
+    atom_num_tseqpkgs        = MKA(env, str_num_tseqpkgs);
+    atom_num_tstreams        = MKA(env, str_num_tstreams);
+    atom_partial_delivery    = MKA(env, str_partial_delivery);
+    atom_peer_rwnd           = MKA(env, str_peer_rwnd);
+    atom_peer_error          = MKA(env, str_peer_error);
+    atom_probe               = MKA(env, str_probe);
+    atom_select              = MKA(env, str_select);
+    atom_sender_dry          = MKA(env, str_sender_dry);
+    atom_send_failure        = MKA(env, str_send_failure);
+    atom_shutdown            = MKA(env, str_shutdown);
+    atom_slist               = MKA(env, str_slist);
+    atom_sourceaddr          = MKA(env, str_sourceaddr);
+    atom_timeout             = MKA(env, str_timeout);
+    atom_true                = MKA(env, str_true);
+    atom_want                = MKA(env, str_want);
+
+    /* Global atom(s) */
+    esock_atom_abort                  = MKA(env, "abort");
+    esock_atom_accept                 = MKA(env, "accept");
+    esock_atom_acceptconn             = MKA(env, "acceptconn");
+    esock_atom_acceptfilter           = MKA(env, "acceptfilter");
+    esock_atom_adaption_layer         = MKA(env, "adaption_layer");
+    esock_atom_addr                   = MKA(env, "addr");
+    esock_atom_addrform               = MKA(env, "addrform");
+    esock_atom_add_membership         = MKA(env, "add_membership");
+    esock_atom_add_source_membership  = MKA(env, "add_source_membership");
+    esock_atom_any                    = MKA(env, "any");
+    esock_atom_associnfo              = MKA(env, "associnfo");
+    esock_atom_authhdr                = MKA(env, "authhdr");
+    esock_atom_auth_active_key        = MKA(env, "auth_active_key");
+    esock_atom_auth_asconf            = MKA(env, "auth_asconf");
+    esock_atom_auth_chunk             = MKA(env, "auth_chunk");
+    esock_atom_auth_delete_key        = MKA(env, "auth_delete_key");
+    esock_atom_auth_key               = MKA(env, "auth_key");
+    esock_atom_auth_level             = MKA(env, "auth_level");
+    esock_atom_autoclose              = MKA(env, "autoclose");
+    esock_atom_bindtodevice           = MKA(env, "bindtodevice");
+    esock_atom_block_source           = MKA(env, "block_source");
+    esock_atom_broadcast              = MKA(env, "broadcast");
+    esock_atom_busy_poll              = MKA(env, "busy_poll");
+    esock_atom_checksum               = MKA(env, "checksum");
+    esock_atom_close                  = MKA(env, "close");
+    esock_atom_connect                = MKA(env, "connect");
+    esock_atom_congestion             = MKA(env, "congestion");
+    esock_atom_context                = MKA(env, "context");
+    esock_atom_cork                   = MKA(env, "cork");
+    esock_atom_credentials            = MKA(env, "credentials");
+    esock_atom_ctrl                   = MKA(env, "ctrl");
+    esock_atom_ctrunc                 = MKA(env, "ctrunc");
+    esock_atom_data                   = MKA(env, "data");
+    esock_atom_debug                  = MKA(env, "debug");
+    esock_atom_default_send_params    = MKA(env, "default_send_params");
+    esock_atom_delayed_ack_time       = MKA(env, "delayed_ack_time");
+    esock_atom_dgram                  = MKA(env, "dgram");
+    esock_atom_disable_fragments      = MKA(env, "disable_fragments");
+    esock_atom_domain                 = MKA(env, "domain");
+    esock_atom_dontfrag               = MKA(env, "dontfrag");
+    esock_atom_dontroute              = MKA(env, "dontroute");
+    esock_atom_drop_membership        = MKA(env, "drop_membership");
+    esock_atom_drop_source_membership = MKA(env, "drop_source_membership");
+    esock_atom_dstopts                = MKA(env, "dstpopts");
+    esock_atom_eor                    = MKA(env, "eor");
+    esock_atom_error                  = MKA(env, "error");
+    esock_atom_errqueue               = MKA(env, "errqueue");
+    esock_atom_esp_network_level      = MKA(env, "esp_network_level");
+    esock_atom_esp_trans_level        = MKA(env, "esp_trans_level");
+    esock_atom_events                 = MKA(env, "events");
+    esock_atom_explicit_eor           = MKA(env, "explicit_eor");
+    esock_atom_faith                  = MKA(env, "faith");
+    esock_atom_false                  = MKA(env, "false");
+    esock_atom_family                 = MKA(env, "family");
+    esock_atom_flags                  = MKA(env, "flags");
+    esock_atom_flowinfo               = MKA(env, "flowinfo");
+    esock_atom_fragment_interleave    = MKA(env, "fragment_interleave");
+    esock_atom_freebind               = MKA(env, "freebind");
+    esock_atom_get_peer_addr_info     = MKA(env, "get_peer_addr_info");
+    esock_atom_hdrincl                = MKA(env, "hdrincl");
+    esock_atom_hmac_ident             = MKA(env, "hmac_ident");
+    esock_atom_hoplimit               = MKA(env, "hoplimit");
+    esock_atom_hopopts                = MKA(env, "hopopts");
+    esock_atom_ifindex                = MKA(env, "ifindex");
+    esock_atom_inet                   = MKA(env, "inet");
+    esock_atom_inet6                  = MKA(env, "inet6");
+    esock_atom_info                   = MKA(env, "info");
+    esock_atom_initmsg                = MKA(env, "initmsg");
+    esock_atom_iov                    = MKA(env, "iov");
+    esock_atom_ip                     = MKA(env, "ip");
+    esock_atom_ipcomp_level           = MKA(env, "ipcomp_level");
+    esock_atom_ipv6                   = MKA(env, "ipv6");
+    esock_atom_i_want_mapped_v4_addr  = MKA(env, "i_want_mapped_v4_addr");
+    esock_atom_join_group             = MKA(env, "join_group");
+    esock_atom_keepalive              = MKA(env, "keepalive");
+    esock_atom_keepcnt                = MKA(env, "keepcnt");
+    esock_atom_keepidle               = MKA(env, "keepidle");
+    esock_atom_keepintvl              = MKA(env, "keepintvl");
+    esock_atom_leave_group            = MKA(env, "leave_group");
+    esock_atom_level                  = MKA(env, "level");
+    esock_atom_linger                 = MKA(env, "linger");
+    esock_atom_local                  = MKA(env, "local");
+    esock_atom_local_auth_chunks      = MKA(env, "local_auth_chunks");
+    esock_atom_loopback               = MKA(env, "loopback");
+    esock_atom_lowdelay               = MKA(env, "lowdelay");
+    esock_atom_mark                   = MKA(env, "mark");
+    esock_atom_maxburst               = MKA(env, "maxburst");
+    esock_atom_maxseg                 = MKA(env, "maxseg");
+    esock_atom_md5sig                 = MKA(env, "md5sig");
+    esock_atom_mincost                = MKA(env, "mincost");
+    esock_atom_minttl                 = MKA(env, "minttl");
+    esock_atom_msfilter               = MKA(env, "msfilter");
+    esock_atom_mtu                    = MKA(env, "mtu");
+    esock_atom_mtu_discover           = MKA(env, "mtu_discover");
+    esock_atom_multicast_all          = MKA(env, "multicast_all");
+    esock_atom_multicast_hops         = MKA(env, "multicast_hops");
+    esock_atom_multicast_if           = MKA(env, "multicast_if");
+    esock_atom_multicast_loop         = MKA(env, "multicast_loop");
+    esock_atom_multicast_ttl          = MKA(env, "multicast_ttl");
+    esock_atom_nodefrag               = MKA(env, "nodefrag");
+    esock_atom_nodelay                = MKA(env, "nodelay");
+    esock_atom_noopt                  = MKA(env, "noopt");
+    esock_atom_nopush                 = MKA(env, "nopush");
+    esock_atom_not_found              = MKA(env, "not_found");
+    esock_atom_not_owner              = MKA(env, "not_owner");
+    esock_atom_ok                     = MKA(env, "ok");
+    esock_atom_oob                    = MKA(env, "oob");
+    esock_atom_oobinline              = MKA(env, "oobinline");
+    esock_atom_options                = MKA(env, "options");
+    esock_atom_origdstaddr            = MKA(env, "origdstaddr");
+    esock_atom_partial_delivery_point = MKA(env, "partial_delivery_point");
+    esock_atom_passcred               = MKA(env, "passcred");
+    esock_atom_path                   = MKA(env, "path");
+    esock_atom_peekcred               = MKA(env, "peekcred");
+    esock_atom_peek_off               = MKA(env, "peek_off");
+    esock_atom_peer_addr_params       = MKA(env, "peer_addr_params");
+    esock_atom_peer_auth_chunks       = MKA(env, "peer_auth_chunks");
+    esock_atom_pktinfo                = MKA(env, "pktinfo");
+    esock_atom_pktoptions             = MKA(env, "pktoptions");
+    esock_atom_port                   = MKA(env, "port");
+    esock_atom_portrange              = MKA(env, "portrange");
+    esock_atom_primary_addr           = MKA(env, "primary_addr");
+    esock_atom_priority               = MKA(env, "priority");
+    esock_atom_protocol               = MKA(env, "protocol");
+    esock_atom_raw                    = MKA(env, "raw");
+    esock_atom_rcvbuf                 = MKA(env, "rcvbuf");
+    esock_atom_rcvbufforce            = MKA(env, "rcvbufforce");
+    esock_atom_rcvlowat               = MKA(env, "rcvlowat");
+    esock_atom_rcvtimeo               = MKA(env, "rcvtimeo");
+    esock_atom_rdm                    = MKA(env, "rdm");
+    esock_atom_recv                   = MKA(env, "recv");
+    esock_atom_recvdstaddr            = MKA(env, "recvdstaddr");
+    esock_atom_recverr                = MKA(env, "recverr");
+    esock_atom_recvfrom               = MKA(env, "recvfrom");
+    esock_atom_recvif                 = MKA(env, "recvif");
+    esock_atom_recvmsg                = MKA(env, "recvmsg");
+    esock_atom_recvopts               = MKA(env, "recvopts");
+    esock_atom_recvorigdstaddr        = MKA(env, "recvorigdstaddr");
+    esock_atom_recvpktinfo            = MKA(env, "recvpktinfo");
+    esock_atom_recvtclass             = MKA(env, "recvtclass");
+    esock_atom_recvtos                = MKA(env, "recvtos");
+    esock_atom_recvttl                = MKA(env, "recvttl");
+    esock_atom_reliability            = MKA(env, "reliability");
+    esock_atom_reset_streams          = MKA(env, "reset_streams");
+    esock_atom_retopts                = MKA(env, "retopts");
+    esock_atom_reuseaddr              = MKA(env, "reuseaddr");
+    esock_atom_reuseport              = MKA(env, "reuseport");
+    esock_atom_rights                 = MKA(env, "rights");
+    esock_atom_router_alert           = MKA(env, "router_alert");
+    esock_atom_rthdr                  = MKA(env, "rthdr");
+    esock_atom_rtoinfo                = MKA(env, "rtoinfo");
+    esock_atom_rxq_ovfl               = MKA(env, "rxq_ovfl");
+    esock_atom_scope_id               = MKA(env, "scope_id");
+    esock_atom_sctp                   = MKA(env, "sctp");
+    esock_atom_sec                    = MKA(env, "sec");
+    esock_atom_select_sent            = MKA(env, "select_sent");
+    esock_atom_send                   = MKA(env, "send");
+    esock_atom_sendmsg                = MKA(env, "sendmsg");
+    esock_atom_sendsrcaddr            = MKA(env, "sendsrcaddr");
+    esock_atom_sendto                 = MKA(env, "sendto");
+    esock_atom_seqpacket              = MKA(env, "seqpacket");
+    esock_atom_setfib                 = MKA(env, "setfib");
+    esock_atom_set_peer_primary_addr  = MKA(env, "set_peer_primary_addr");
+    esock_atom_sndbuf                 = MKA(env, "sndbuf");
+    esock_atom_sndbufforce            = MKA(env, "sndbufforce");
+    esock_atom_sndlowat               = MKA(env, "sndlowat");
+    esock_atom_sndtimeo               = MKA(env, "sndtimeo");
+    esock_atom_socket                 = MKA(env, "socket");
+    esock_atom_socket_tag             = MKA(env, "$socket");
+    esock_atom_spec_dst               = MKA(env, "spec_dst");
+    esock_atom_status                 = MKA(env, "status");
+    esock_atom_stream                 = MKA(env, "stream");
+    esock_atom_syncnt                 = MKA(env, "syncnt");
+    esock_atom_tclass                 = MKA(env, "tclass");
+    esock_atom_tcp                    = MKA(env, "tcp");
+    esock_atom_throughput             = MKA(env, "throughput");
+    esock_atom_timestamp              = MKA(env, "timestamp");
+    esock_atom_tos                    = MKA(env, "tos");
+    esock_atom_transparent            = MKA(env, "transparent");
+    esock_atom_true                   = MKA(env, "true");
+    esock_atom_trunc                  = MKA(env, "trunc");
+    esock_atom_ttl                    = MKA(env, "ttl");
+    esock_atom_type                   = MKA(env, "type");
+    esock_atom_udp                    = MKA(env, "udp");
+    esock_atom_unblock_source         = MKA(env, "unblock_source");
+    esock_atom_undefined              = MKA(env, "undefined");
+    esock_atom_unicast_hops           = MKA(env, "unicast_hops");
+    esock_atom_unknown                = MKA(env, "unknown");
+    esock_atom_usec                   = MKA(env, "usec");
+    esock_atom_user_timeout           = MKA(env, "user_timeout");
+    esock_atom_use_ext_recvinfo       = MKA(env, "use_ext_recvinfo");
+    esock_atom_use_min_mtu            = MKA(env, "use_min_mtu");
+    esock_atom_v6only                 = MKA(env, "v6only");
+
+    /* Global error codes */
+    esock_atom_eafnosupport = MKA(env, ESOCK_STR_EAFNOSUPPORT);
+    esock_atom_eagain       = MKA(env, ESOCK_STR_EAGAIN);
+    esock_atom_einval       = MKA(env, ESOCK_STR_EINVAL);
+
+    /* Error codes */
+    atom_eisconn      = MKA(env, str_eisconn);
+    atom_enotclosing  = MKA(env, str_enotclosing);
+    atom_enotconn     = MKA(env, str_enotconn);
+    atom_exalloc      = MKA(env, str_exalloc);
+    atom_exbadstate   = MKA(env, str_exbadstate);
+    atom_exbusy       = MKA(env, str_exbusy);
+    atom_exmon        = MKA(env, str_exmon);
+    atom_exself       = MKA(env, str_exself);
+    atom_exsend       = MKA(env, str_exsend);
+
+    // For storing "global" things...
+    // data.env       = enif_alloc_env(); // We should really check
+    // data.version   = MKA(env, ERTS_VERSION);
+    // data.buildDate = MKA(env, ERTS_BUILD_DATE);
+
+    sockets = enif_open_resource_type_x(env,
+                                        "sockets",
+                                        &socketInit,
+                                        ERL_NIF_RT_CREATE,
+                                        NULL);
+
+    return !sockets;
+}
+
+ERL_NIF_INIT(socket, socket_funcs, on_load, NULL, NULL, NULL)
diff --git a/erts/emulator/nifs/common/socket_tarray.c b/erts/emulator/nifs/common/socket_tarray.c
new file mode 100644
index 0000000000..def22c4919
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_tarray.c
@@ -0,0 +1,143 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Build and "maintain" a (erlang) term array of 
+ *            variable length.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+/* #ifdef HAVE_CONFIG_H */
+/* #include "config.h" */
+/* #endif */
+
+#include <stdio.h>
+
+#include <erl_nif.h>
+
+#include "socket_int.h"
+#include <sys.h>
+#include "socket_util.h"
+#include "socket_tarray.h"
+
+
+
+/* ----------------------------------------------------------------------
+ * Types 
+ */
+
+typedef struct {
+  Uint32        sz;
+  Uint32        idx;
+  ERL_NIF_TERM* array;
+} SocketTArrayInt;
+
+
+/* ----------------------------------------------------------------------
+ * Forward for internal functions
+ */
+
+static void esock_tarray_add1(SocketTArrayInt* taP, ERL_NIF_TERM t);
+static void esock_tarray_ensure_fits(SocketTArrayInt* taP, Uint32 needs);
+
+
+/* ----------------------------------------------------------------------
+ * API
+ */
+
+extern
+void* esock_tarray_create(Uint32 sz)
+{
+    SocketTArrayInt* tarrayP;
+
+    ESOCK_ASSERT( (sz > 0) );
+
+    tarrayP = MALLOC(sizeof(SocketTArrayInt));
+    ESOCK_ASSERT( (tarrayP != NULL) );
+  
+    tarrayP->array = MALLOC(sz * sizeof(ERL_NIF_TERM));
+    ESOCK_ASSERT( (tarrayP->array != NULL) );
+    tarrayP->sz   = sz;
+    tarrayP->idx  = 0;
+    
+    return ((SocketTArray) tarrayP);
+}
+
+extern
+void esock_tarray_delete(SocketTArray ta)
+{
+    SocketTArrayInt* taP = (SocketTArrayInt*) ta;
+
+    FREE(taP->array);
+    FREE(taP);
+}
+
+
+extern
+Uint32 esock_tarray_sz(SocketTArray a)
+{
+  return ( ((SocketTArrayInt*) a)->idx );
+}
+
+extern
+void esock_tarray_add(SocketTArray ta, ERL_NIF_TERM t)
+{
+    esock_tarray_add1((SocketTArrayInt*) ta, t);
+}
+
+extern
+void esock_tarray_tolist(SocketTArray  ta,
+                         ErlNifEnv*    env,
+                         ERL_NIF_TERM* list)
+{
+    SocketTArrayInt* taP = (SocketTArrayInt*) ta;
+
+    *list = MKLA(env, taP->array, taP->idx);
+
+    esock_tarray_delete(taP);
+}
+
+
+
+/* ----------------------------------------------------------------------
+ * "Internal" functions
+ */
+
+static
+void esock_tarray_add1(SocketTArrayInt* taP, ERL_NIF_TERM t)
+{
+  esock_tarray_ensure_fits(taP, 1);
+
+  taP->array[taP->idx++] = t;
+}
+
+static
+void esock_tarray_ensure_fits(SocketTArrayInt* taP, Uint32 needs)
+{ 
+  if (taP->sz < (taP->idx + needs)) {
+    Uint32 newSz = (needs < taP->sz) ? 2*taP->sz : 2*needs;
+    void*  mem   = REALLOC(taP->array, newSz * sizeof(ERL_NIF_TERM));
+    
+    ESOCK_ASSERT( (mem != NULL) );
+    
+    taP->sz    = newSz;
+    taP->array = (ERL_NIF_TERM*) mem;
+  }
+}
diff --git a/erts/emulator/nifs/common/socket_tarray.h b/erts/emulator/nifs/common/socket_tarray.h
new file mode 100644
index 0000000000..4f1152fb9e
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_tarray.h
@@ -0,0 +1,47 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Build and "maintain" a (erlang) term array of 
+ *            variable length.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#ifndef SOCKET_TARRAY_H__
+#define SOCKET_TARRAY_H__
+
+typedef void* SocketTArray;
+
+extern SocketTArray esock_tarray_create(Uint32 sz);
+extern void         esock_tarray_delete(SocketTArray ta);
+extern Uint32       esock_tarray_sz(SocketTArray ta);
+extern void         esock_tarray_add(SocketTArray ta, ERL_NIF_TERM t);
+extern void         esock_tarray_tolist(SocketTArray  ta,
+                                        ErlNifEnv*    env,
+                                        ERL_NIF_TERM* list);
+
+#define TARRAY_CREATE(SZ)        esock_tarray_create((SZ))
+#define TARRAY_DELETE(TA)        esock_tarray_delete((TA))
+#define TARRAY_SZ(TA)            esock_tarray_sz((TA))
+#define TARRAY_ADD(TA, T)        esock_tarray_add((TA), (T))
+#define TARRAY_TOLIST(TA, E, L)  esock_tarray_tolist((TA), (E), (L))
+
+
+#endif // SOCKET_TARRAY_H__
diff --git a/erts/emulator/nifs/common/socket_util.c b/erts/emulator/nifs/common/socket_util.c
new file mode 100644
index 0000000000..f6e4781977
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_util.c
@@ -0,0 +1,1658 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2019. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Utility functions for the socket and net NIF(s).
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <time.h>
+#include <stddef.h>
+
+#include "socket_int.h"
+#include "sys.h"
+#include "socket_util.h"
+#include "socket_dbg.h"
+
+/* We don't have a "debug flag" to check here, so we 
+ * should use the compile debug flag, whatever that is...
+ */
+
+// #define COMPILE_DEBUG_FLAG_WE_NEED_TO_CHECK 1
+#if defined(COMPILE_DEBUG_FLAG_WE_NEED_TO_CHECK)
+#define UTIL_DEBUG TRUE
+#else
+#define UTIL_DEBUG FALSE
+#endif
+
+#define UDBG( proto ) ESOCK_DBG_PRINTF( UTIL_DEBUG , proto )
+
+
+extern char* erl_errno_id(int error); /* THIS IS JUST TEMPORARY??? */
+
+static int realtime(struct timespec* tsP);
+static int timespec2str(char *buf, unsigned int len, struct timespec *ts);
+
+static char* make_sockaddr_in4(ErlNifEnv*    env,
+                               ERL_NIF_TERM  port,
+                               ERL_NIF_TERM  addr,
+                               ERL_NIF_TERM* sa);
+static char* make_sockaddr_in6(ErlNifEnv*    env,
+                               ERL_NIF_TERM  port,
+                               ERL_NIF_TERM  addr,
+                               ERL_NIF_TERM  flowInfo,
+                               ERL_NIF_TERM  scopeId,
+                               ERL_NIF_TERM* sa);
+static char* make_sockaddr_un(ErlNifEnv*    env,
+                              ERL_NIF_TERM  path,
+                              ERL_NIF_TERM* sa);
+
+
+/* +++ esock_encode_iov +++
+ *
+ * Encode an IO Vector. In erlang we represented this as a list of binaries.
+ *
+ * We iterate through the IO vector, and as long as the remaining (rem)
+ * number of bytes is greater than the size of the current buffer, we
+ * contunue. When we have a buffer that is greater than rem, we have found
+ * the last buffer (it may be empty, and then the previous was last). 
+ * We may need to split this (if 0 < rem < bufferSz).
+ */
+
+extern
+char* esock_encode_iov(ErlNifEnv*    env,
+                       int           read,
+                       struct iovec* iov,
+                       size_t        len,
+                       ErlNifBinary* data,
+                       ERL_NIF_TERM* eIOV)
+{
+    int          rem = read;
+    Uint16       i;
+    BOOLEAN_T    done = FALSE;
+    ERL_NIF_TERM a[len]; // At most this length
+
+    UDBG( ("SUTIL", "esock_encode_iov -> entry with"
+           "\r\n   read:      %d"
+           "\r\n   (IOV) len: %d"
+           "\r\n", read, len) );
+
+    if (len == 0) {
+        *eIOV = MKEL(env);
+        return NULL;
+    }
+
+    for (i = 0; (!done) && (i < len); i++) {
+        UDBG( ("SUTIL", "esock_encode_iov -> process iov:"
+               "\r\n   iov[%d].iov_len: %d"
+               "\r\n   rem:            %d"
+               "\r\n", i, iov[i].iov_len, rem) );
+        if (iov[i].iov_len == rem) {
+            /* We have the exact amount - we are done */
+            UDBG( ("SUTIL", "esock_encode_iov -> exact => done\r\n") );
+            a[i] = MKBIN(env, &data[i]);
+            rem  = 0; // Besserwisser
+            done = TRUE;
+        } else if (iov[i].iov_len < rem) {
+            /* Filled another buffer - continue */
+            UDBG( ("SUTIL", "esock_encode_iov -> filled => continue\r\n") );
+            a[i] = MKBIN(env, &data[i]);
+            rem -= iov[i].iov_len;
+        } else if (iov[i].iov_len > rem) {
+            /* Partly filled buffer (=> split) - we are done */
+            ERL_NIF_TERM tmp;
+            UDBG( ("SUTIL", "esock_encode_iov -> split => done\r\n") );
+            tmp  = MKBIN(env, &data[i]);
+            a[i] = MKSBIN(env, tmp, 0, rem);
+            rem  = 0; // Besserwisser
+            done = TRUE;
+        }
+    }
+
+    UDBG( ("SUTIL", "esock_encode_iov -> create the IOV list (%d)\r\n", i) );
+
+    *eIOV = MKLA(env, a, i);
+
+    UDBG( ("SUTIL", "esock_encode_msghdr -> done\r\n") );
+
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_iov +++
+ *
+ * Decode an IO Vector. In erlang we represented this as a list of binaries.
+ *
+ * We assume that we have already figured out how long the iov (actually
+ * eIOV) is (len), and therefor allocated an array of bins and iov to be
+ * used.
+ */
+
+extern
+char* esock_decode_iov(ErlNifEnv*    env,
+                       ERL_NIF_TERM  eIOV,
+                       ErlNifBinary* bufs,
+                       struct iovec* iov,
+                       size_t        len,
+                       ssize_t*      totSize)
+{
+    Uint16       i;
+    ssize_t      sz;
+    ERL_NIF_TERM elem, tail, list;
+
+    UDBG( ("SUTIL", "esock_decode_iov -> entry with"
+           "\r\n   (IOV) len: %d"
+           "\r\n", read, len) );
+
+    for (i = 0, list = eIOV, sz = 0; (i < len); i++) {
+
+        UDBG( ("SUTIL", "esock_decode_iov -> "
+               "\r\n   iov[%d].iov_len: %d"
+               "\r\n   rem:            %d"
+               "\r\n", i) );
+
+        if (!GET_LIST_ELEM(env, list, &elem, &tail))
+            return ESOCK_STR_EINVAL;
+
+        if (IS_BIN(env, elem) && GET_BIN(env, elem, &bufs[i])) {
+            iov[i].iov_base  = bufs[i].data;
+            iov[i].iov_len   = bufs[i].size;
+            sz              += bufs[i].size;
+        } else {
+            return ESOCK_STR_EINVAL;
+        }
+
+        list = tail;
+    }
+
+    *totSize = sz;
+
+    UDBG( ("SUTIL", "esock_decode_msghdr -> done (%d)\r\n", sz) );
+
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_sockaddr +++
+ *
+ * Decode a socket address - sockaddr. In erlang its represented as
+ * a map, which has a specific set of attributes, depending on one
+ * mandatory attribute; family. So depending on the value of the family
+ * attribute: 
+ *
+ *    local - sockaddr_un:  path
+ *    inet  - sockaddr_in4: port, addr
+ *    inet6 - sockaddr_in6: port, addr, flowinfo, scope_id
+ */
+
+extern
+char* esock_decode_sockaddr(ErlNifEnv*     env,
+                            ERL_NIF_TERM   eSockAddr,
+                            SocketAddress* sockAddrP,
+                            unsigned int*  addrLen)
+{
+    ERL_NIF_TERM efam;
+    int          fam;
+    char*        xres;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr -> entry\r\n") );
+
+    if (!IS_MAP(env, eSockAddr))
+        return ESOCK_STR_EINVAL;
+
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_family, &efam))
+        return ESOCK_STR_EINVAL;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr -> try decode domain (%T)\r\n", efam) );
+    if ((xres = esock_decode_domain(env, efam, &fam)) != NULL)
+        return xres;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr -> fam: %d\r\n", fam) );
+    switch (fam) {
+    case AF_INET:
+        xres = esock_decode_sockaddr_in4(env, eSockAddr,
+                                         &sockAddrP->in4, addrLen);
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case AF_INET6:
+        xres = esock_decode_sockaddr_in6(env, eSockAddr,
+                                         &sockAddrP->in6, addrLen);
+        break;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+    case AF_UNIX:
+        xres = esock_decode_sockaddr_un(env, eSockAddr,
+                                        &sockAddrP->un, addrLen);
+        break;
+#endif
+
+    default:
+        xres = ESOCK_STR_EAFNOSUPPORT;
+        break;
+
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_encode_sockaddr +++
+ *
+ * Encode a socket address - sockaddr. In erlang its represented as
+ * a map, which has a specific set of attributes, depending on one
+ * mandatory attribute; family. So depending on the value of the family
+ * attribute: 
+ *
+ *    local - sockaddr_un:  path
+ *    inet  - sockaddr_in4: port, addr
+ *    inet6 - sockaddr_in6: port, addr, flowinfo, scope_id
+ */
+
+extern
+char* esock_encode_sockaddr(ErlNifEnv*     env,
+                            SocketAddress* sockAddrP,
+                            unsigned int   addrLen,
+                            ERL_NIF_TERM*  eSockAddr)
+{
+    char* xres;
+
+    UDBG( ("SUTIL", "esock_encode_sockaddr -> entry with"
+           "\r\n   family:  %d"
+           "\r\n   addrLen: %d"
+           "\r\n", sockAddrP->sa.sa_family, addrLen) );
+
+    switch (sockAddrP->sa.sa_family) {
+    case AF_INET:
+        xres = esock_encode_sockaddr_in4(env, &sockAddrP->in4, addrLen, eSockAddr);
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case AF_INET6:
+        xres = esock_encode_sockaddr_in6(env, &sockAddrP->in6, addrLen, eSockAddr);
+        break;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+    case AF_UNIX:
+        xres = esock_encode_sockaddr_un(env, &sockAddrP->un, addrLen, eSockAddr);
+        break;
+#endif
+
+    default:
+        *eSockAddr = esock_atom_undefined;
+        xres       = ESOCK_STR_EAFNOSUPPORT;
+        break;
+
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_sockaddr_in4 +++
+ *
+ * Decode a IPv4 socket address - sockaddr_in4. In erlang its represented as
+ * a map, which has a specific set of attributes (beside the mandatory family
+ * attribute, which is "inherited" from the "sockaddr" type): 
+ *
+ *    port :: port_numbber()
+ *    addr :: ip4_address()
+ *
+ * The erlang module ensures that both of these has values exist, so there 
+ * is no need for any elaborate error handling.
+ */
+
+extern
+char* esock_decode_sockaddr_in4(ErlNifEnv*          env,
+                                ERL_NIF_TERM        eSockAddr,
+                                struct sockaddr_in* sockAddrP,
+                                unsigned int*       addrLen)
+{
+    ERL_NIF_TERM eport, eaddr;
+    int          port;
+    char*        xres;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> entry\r\n") );
+
+    /* Basic init */
+    sys_memzero((char*) sockAddrP, sizeof(struct sockaddr_in));
+
+#ifndef NO_SA_LEN
+    sockAddrP->sin_len = sizeof(struct sockaddr_in);
+#endif
+
+    sockAddrP->sin_family = AF_INET;
+
+    /* Extract (e) port number from map */
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> try get port number\r\n") );
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_port, &eport))
+        return ESOCK_STR_EINVAL;
+
+    /* Decode port number */
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> try decode port number\r\n") );
+    if (!GET_INT(env, eport, &port))
+        return ESOCK_STR_EINVAL;
+    
+    sockAddrP->sin_port = htons(port);
+
+    /* Extract (e) address from map */
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> try get (ip) address\r\n") );
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_addr, &eaddr))
+        return ESOCK_STR_EINVAL;
+
+    /* Decode address */
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> try decode (ip) address\r\n") );
+    if ((xres = esock_decode_ip4_address(env,
+                                         eaddr,
+                                         &sockAddrP->sin_addr)) != NULL)
+        return xres;
+
+    *addrLen = sizeof(struct sockaddr_in);
+    
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in4 -> done\r\n") );
+
+    return NULL;
+}
+
+
+
+/* +++ esock_encode_sockaddr_in4 +++
+ *
+ * Encode a IPv4 socket address - sockaddr_in4. In erlang its represented as
+ * a map, which has a specific set of attributes (beside the mandatory family
+ * attribute, which is "inherited" from the "sockaddr" type):
+ *
+ *    port :: port_numbber()
+ *    addr :: ip4_address()
+ *
+ */
+
+extern
+char* esock_encode_sockaddr_in4(ErlNifEnv*          env,
+                                struct sockaddr_in* sockAddrP,
+                                unsigned int        addrLen,
+                                ERL_NIF_TERM*       eSockAddr)
+{
+    ERL_NIF_TERM ePort, eAddr;
+    int          port;
+    char*        xres = NULL;
+
+    UDBG( ("SUTIL", "esock_encode_sockaddr_in4 -> entry\r\n") );
+
+    if (addrLen >= sizeof(struct sockaddr_in)) {
+        /* The port */
+        port  = ntohs(sockAddrP->sin_port);
+        ePort = MKI(env, port);
+
+        /* The address */
+        if ((xres = esock_encode_ip4_address(env, &sockAddrP->sin_addr,
+                                             &eAddr)) == NULL) {
+            /* And finally construct the in4_sockaddr record */
+            xres = make_sockaddr_in4(env, ePort, eAddr, eSockAddr);
+        } else {
+            UDBG( ("SUTIL", "esock_encode_sockaddr_in4 -> "
+                   "failed encoding (ip) address: "
+                   "\r\n   xres: %s"
+                   "\r\n", xres) );
+            *eSockAddr = esock_atom_undefined;
+            xres       = ESOCK_STR_EINVAL;
+        }
+
+    } else {
+        UDBG( ("SUTIL", "esock_encode_sockaddr_in4 -> wrong size: "
+               "\r\n   addrLen:   %d"
+               "\r\n   addr size: %d"
+               "\r\n", addrLen, sizeof(struct sockaddr_in)) );
+        *eSockAddr = esock_atom_undefined;
+        xres       = ESOCK_STR_EINVAL;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_sockaddr_in6 +++
+ *
+ * Decode a IPv6 socket address - sockaddr_in6. In erlang its represented as
+ * a map, which has a specific set of attributes (beside the mandatory family
+ * attribute, which is "inherited" from the "sockaddr" type): 
+ *
+ *    port     :: port_numbber()  (integer)
+ *    addr     :: ip6_address()   (tuple)
+ *    flowinfo :: in6_flow_info() (integer)
+ *    scope_id :: in6_scope_id()  (integer)
+ *
+ * The erlang module ensures that all of these has values exist, so there
+ * is no need for any elaborate error handling here.
+ */
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_decode_sockaddr_in6(ErlNifEnv*           env,
+                                ERL_NIF_TERM         eSockAddr,
+                                struct sockaddr_in6* sockAddrP,
+                                unsigned int*        addrLen)
+{
+    ERL_NIF_TERM eport, eaddr, eflowInfo, escopeId;
+    int          port;
+    unsigned int flowInfo, scopeId;
+    char*        xres;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> entry\r\n") );
+
+    /* Basic init */
+    sys_memzero((char*) sockAddrP, sizeof(struct sockaddr_in6));
+#ifndef NO_SA_LEN
+    sockAddrP->sin6_len = sizeof(struct sockaddr_in);
+#endif
+
+    sockAddrP->sin6_family = AF_INET6;
+
+    /* *** Extract (e) port number from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_port, &eport))
+        return ESOCK_STR_EINVAL;
+
+    /* Decode port number */
+    if (!GET_INT(env, eport, &port))
+        return ESOCK_STR_EINVAL;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> port: %d\r\n", port) );
+
+    sockAddrP->sin6_port = htons(port);
+
+    /* *** Extract (e) flowinfo from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_flowinfo, &eflowInfo))
+        return ESOCK_STR_EINVAL;
+
+    /* 4: Get the flowinfo */
+    if (!GET_UINT(env, eflowInfo, &flowInfo))
+        return ESOCK_STR_EINVAL;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> flowinfo: %d\r\n", flowInfo) );
+
+    sockAddrP->sin6_flowinfo = flowInfo;
+    
+    /* *** Extract (e) scope_id from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_scope_id, &escopeId))
+        return ESOCK_STR_EINVAL;
+
+    /* *** Get the scope_id *** */
+    if (!GET_UINT(env, escopeId, &scopeId))
+        return ESOCK_STR_EINVAL;
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> scopeId: %d\r\n", scopeId) );
+
+    sockAddrP->sin6_scope_id = scopeId;
+
+    /* *** Extract (e) address from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_addr, &eaddr))
+        return ESOCK_STR_EINVAL;
+
+    /* Decode address */
+    if ((xres = esock_decode_ip6_address(env,
+                                         eaddr,
+                                         &sockAddrP->sin6_addr)) != NULL)
+        return xres;
+
+    *addrLen = sizeof(struct sockaddr_in6);
+
+    UDBG( ("SUTIL", "esock_decode_sockaddr_in6 -> done\r\n") );
+
+    return NULL;
+}
+#endif
+
+
+
+/* +++ esock_encode_sockaddr_in6 +++
+ *
+ * Encode a IPv6 socket address - sockaddr_in6. In erlang its represented as
+ * a map, which has a specific set of attributes (beside the mandatory family
+ * attribute, which is "inherited" from the "sockaddr" type): 
+ *
+ *    port     :: port_numbber()  (integer)
+ *    addr     :: ip6_address()   (tuple)
+ *    flowinfo :: in6_flow_info() (integer)
+ *    scope_id :: in6_scope_id()  (integer)
+ *
+ */
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_encode_sockaddr_in6(ErlNifEnv*           env,
+                                struct sockaddr_in6* sockAddrP,
+                                unsigned int         addrLen,
+                                ERL_NIF_TERM*        eSockAddr)
+{
+    ERL_NIF_TERM ePort, eAddr, eFlowInfo, eScopeId;
+    char*        xres;
+
+    if (addrLen >= sizeof(struct sockaddr_in6)) {
+        /* The port */
+        ePort = MKI(env, ntohs(sockAddrP->sin6_port));
+
+        /* The flowInfo */
+        eFlowInfo = MKI(env, sockAddrP->sin6_flowinfo);
+            
+        /* The scopeId */
+        eScopeId = MKI(env, sockAddrP->sin6_scope_id);
+        
+        /* The address */
+        if ((xres = esock_encode_ip6_address(env, &sockAddrP->sin6_addr,
+                                             &eAddr)) == NULL) {
+            /* And finally construct the in6_sockaddr record */
+            xres = make_sockaddr_in6(env,
+                                     ePort, eAddr, eFlowInfo, eScopeId, eSockAddr);
+        } else {
+            *eSockAddr = esock_atom_undefined;
+            xres       = ESOCK_STR_EINVAL;
+        }
+
+    } else {
+        *eSockAddr = esock_atom_undefined;
+        xres       = ESOCK_STR_EINVAL;
+    }
+
+    return xres;
+}
+#endif
+
+
+
+/* +++ esock_decode_sockaddr_un +++
+ *
+ * Decode a Unix Domain socket address - sockaddr_un. In erlang its 
+ * represented as a map, which has a specific set of attributes
+ * (beside the mandatory family attribute, which is "inherited" from
+ * the "sockaddr" type):
+ *
+ *    path :: binary()
+ *
+ * The erlang module ensures that this value exist, so there 
+ * is no need for any elaborate error handling here.
+ */
+
+#ifdef HAVE_SYS_UN_H
+extern
+char* esock_decode_sockaddr_un(ErlNifEnv*          env,
+                               ERL_NIF_TERM        eSockAddr,
+                               struct sockaddr_un* sockAddrP,
+                               unsigned int*       addrLen)
+{
+    ErlNifBinary bin;
+    ERL_NIF_TERM epath;
+    unsigned int len;
+
+    /* *** Extract (e) path (a binary) from map *** */
+    if (!GET_MAP_VAL(env, eSockAddr, esock_atom_path, &epath))
+        return ESOCK_STR_EINVAL;
+
+    /* Get the path */
+    if (!GET_BIN(env, epath, &bin))
+        return ESOCK_STR_EINVAL;
+    
+    if ((bin.size +
+#ifdef __linux__
+         /* Make sure the address gets zero terminated
+          * except when the first byte is \0 because then it is
+          * sort of zero terminated although the zero termination
+          * comes before the address...
+          * This fix handles Linux's nonportable
+          * abstract socket address extension.
+          */
+         (bin.data[0] == '\0' ? 0 : 1)
+#else
+         1
+#endif
+         ) > sizeof(sockAddrP->sun_path))
+        return ESOCK_STR_EINVAL;
+
+
+    sys_memzero((char*) sockAddrP, sizeof(struct sockaddr_un));
+    sockAddrP->sun_family = AF_UNIX;
+
+    sys_memcpy(sockAddrP->sun_path, bin.data, bin.size);
+    len = offsetof(struct sockaddr_un, sun_path) + bin.size;
+
+#ifndef NO_SA_LEN
+    sockAddrP->sun_len = len;
+#endif
+    *addrLen = len;
+
+    return NULL;
+}
+#endif
+
+
+
+/* +++ esock_encode_sockaddr_un +++
+ *
+ * Encode a Unix Domain socket address - sockaddr_un. In erlang its 
+ * represented as a map, which has a specific set of attributes
+ * (beside the mandatory family attribute, which is "inherited" from
+ * the "sockaddr" type):
+ *
+ *    path :: binary()
+ *
+ */
+
+#ifdef HAVE_SYS_UN_H
+extern
+char* esock_encode_sockaddr_un(ErlNifEnv*          env,
+                               struct sockaddr_un* sockAddrP,
+                               unsigned int        addrLen,
+                               ERL_NIF_TERM*       eSockAddr)
+{
+    ERL_NIF_TERM ePath;
+    size_t       n, m;
+    char*        xres;
+
+    if (addrLen >= offsetof(struct sockaddr_un, sun_path)) {
+        n = addrLen - offsetof(struct sockaddr_un, sun_path);
+        if (255 < n) {
+            *eSockAddr = esock_atom_undefined;
+            xres       = ESOCK_STR_EINVAL;
+        } else {
+            m = esock_strnlen(sockAddrP->sun_path, n);
+#ifdef __linux__
+            /* Assume that the address is a zero terminated string,
+             * except when the first byte is \0 i.e the string length is 0,
+             * then use the reported length instead.
+             * This fix handles Linux's nonportable
+             * abstract socket address extension.
+             */
+            if (m == 0) {
+                m = n;
+            }
+#endif
+
+            /* And finally build the 'path' attribute */
+            ePath      = MKSL(env, sockAddrP->sun_path, m);
+
+            /* And the socket address */
+            xres = make_sockaddr_un(env, ePath, eSockAddr);
+        }
+    } else {
+        *eSockAddr = esock_atom_undefined;
+        xres       = ESOCK_STR_EINVAL;
+    }
+
+    return xres;
+}
+#endif
+
+
+
+/* +++ esock_decode_ip4_address +++
+ *
+ * Decode a IPv4 address. This can be three things:
+ *
+ *    + Then atom 'any'
+ *    + Then atom 'loopback'
+ *    + An ip4_address() (4 tuple)
+ *
+ * Note that this *only* decodes the "address" part of a
+ * (IPv4) socket address.
+ */
+
+extern
+char* esock_decode_ip4_address(ErlNifEnv*      env,
+                               ERL_NIF_TERM    eAddr,
+                               struct in_addr* inAddrP)
+{
+    struct in_addr addr;
+
+    UDBG( ("SUTIL", "esock_decode_ip4_address -> entry with"
+           "\r\n   eAddr: %T"
+           "\r\n", eAddr) );
+
+    if (IS_ATOM(env, eAddr)) {
+        /* This is either 'any' or 'loopback' */
+
+        if (COMPARE(esock_atom_loopback, eAddr) == 0) {
+            UDBG( ("SUTIL", "esock_decode_ip4_address -> address: lookback\r\n") );
+            addr.s_addr = htonl(INADDR_LOOPBACK);
+        } else if (COMPARE(esock_atom_any, eAddr) == 0) {
+            UDBG( ("SUTIL", "esock_decode_ip4_address -> address: any\r\n") );
+            addr.s_addr = htonl(INADDR_ANY);
+        } else {
+            UDBG( ("SUTIL", "esock_decode_ip4_address -> address: unknown\r\n") );
+            return ESOCK_STR_EINVAL;
+        }
+
+        inAddrP->s_addr = addr.s_addr;
+
+    } else {
+        /* This is a 4-tuple */
+
+        const ERL_NIF_TERM* addrt;
+        int                 addrtSz;
+        int                 a, v;
+        char                addr[4];
+        
+        if (!GET_TUPLE(env, eAddr, &addrtSz, &addrt))
+            return ESOCK_STR_EINVAL;
+        
+        if (addrtSz != 4)
+            return ESOCK_STR_EINVAL;
+
+        for (a = 0; a < 4; a++) {
+            if (!GET_INT(env, addrt[a], &v))
+                return ESOCK_STR_EINVAL;
+            addr[a] = v;
+        }
+
+        sys_memcpy(inAddrP, &addr, sizeof(addr));
+        
+    }
+
+    return NULL;
+}
+
+
+
+/* +++ esock_encode_ip4_address +++
+ *
+ * Encode a IPv4 address:
+ *
+ *    + An ip4_address() (4 tuple)
+ *
+ * Note that this *only* decodes the "address" part of a
+ * (IPv4) socket address. There are several other things (port).
+ */
+
+extern
+char* esock_encode_ip4_address(ErlNifEnv*      env,
+                               struct in_addr* addrP,
+                               ERL_NIF_TERM*   eAddr)
+{
+    unsigned int   i;
+    ERL_NIF_TERM   at[4];
+    unsigned int   atLen = sizeof(at) / sizeof(ERL_NIF_TERM);
+    unsigned char* a     = (unsigned char*) addrP;
+    ERL_NIF_TERM   addr;
+    
+    /* The address */
+    for (i = 0; i < atLen; i++) {
+        at[i] = MKI(env, a[i]);
+    }
+
+    addr = MKTA(env, at, atLen);
+    UDBG( ("SUTIL", "esock_encode_ip4_address -> addr: %T\r\n", addr) );
+    // *eAddr = MKTA(env, at, atLen);
+    *eAddr = addr;
+    
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_ip6_address +++
+ *
+ * Decode a IPv6 address. This can be three things:
+ *
+ *    + Then atom 'any'
+ *    + Then atom 'loopback'
+ *    + An ip6_address() (8 tuple)
+ *
+ * Note that this *only* decodes the "address" part of a
+ * (IPv6) socket address. There are several other things
+ * (port, flowinfo and scope_id) that are handled elsewhere).
+ */
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_decode_ip6_address(ErlNifEnv*       env,
+                               ERL_NIF_TERM     eAddr,
+                               struct in6_addr* inAddrP)
+{
+    UDBG( ("SUTIL", "esock_decode_ip6_address -> entry with"
+           "\r\n   eAddr: %T"
+           "\r\n", eAddr) );
+
+    if (IS_ATOM(env, eAddr)) {
+        /* This is either 'any' or 'loopback' */
+        const struct in6_addr* addr;
+
+        if (COMPARE(esock_atom_loopback, eAddr) == 0) {
+            addr = &in6addr_loopback;
+        } else if (COMPARE(esock_atom_any, eAddr) == 0) {
+            addr = &in6addr_any;
+        } else {
+            return ESOCK_STR_EINVAL;
+        }
+        
+        *inAddrP = *addr;
+        
+    } else {
+        /* This is a 8-tuple */
+        
+        const ERL_NIF_TERM* addrt;
+        int                 addrtSz;
+        int                 ai, v;
+        unsigned char       addr[16];
+        unsigned char*      a = addr;
+        unsigned int        addrLen = sizeof(addr) / sizeof(unsigned char);
+        
+        if (!GET_TUPLE(env, eAddr, &addrtSz, &addrt))
+            return ESOCK_STR_EINVAL;
+        
+        if (addrtSz != 8)
+            return ESOCK_STR_EINVAL;
+        
+        for (ai = 0; ai < 8; ai++) {
+            if (!GET_INT(env, addrt[ai], &v))
+                return ESOCK_STR_EINVAL;
+            put_int16(v, a);
+            a += 2;
+        }
+        
+        sys_memcpy(inAddrP, &addr, addrLen);
+
+    }
+
+    return NULL;
+}
+#endif
+
+
+
+/* +++ esock_encode_ip6_address +++
+ *
+ * Encode a IPv6 address:
+ *
+ *    + An ip6_address() (8 tuple)
+ *
+ * Note that this *only* encodes the "address" part of a
+ * (IPv6) socket address. There are several other things
+ * (port, flowinfo and scope_id) that are handled elsewhere).
+ */
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_encode_ip6_address(ErlNifEnv*       env,
+                               struct in6_addr* addrP,
+                               ERL_NIF_TERM*    eAddr)
+{
+    unsigned int   i;
+    ERL_NIF_TERM   at[8];
+    unsigned int   atLen = sizeof(at) / sizeof(ERL_NIF_TERM);
+    unsigned char* a     = (unsigned char*) addrP;
+    
+    /* The address */
+    for (i = 0; i < atLen; i++) {
+        at[i] = MKI(env, get_int16(a + i*2));
+    }
+
+    *eAddr = MKTA(env, at, atLen);
+    
+    return NULL;
+}
+#endif
+
+
+
+/* +++ esock_encode_timeval +++
+ *
+ * Encode a timeval struct into its erlang form, a map with two fields:
+ *
+ *    sec
+ *    usec
+ *
+ */
+extern
+char* esock_encode_timeval(ErlNifEnv*      env,
+                           struct timeval* timeP,
+                           ERL_NIF_TERM*   eTime)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_sec, esock_atom_usec};
+    ERL_NIF_TERM vals[] = {MKL(env, timeP->tv_sec), MKL(env, timeP->tv_usec)};
+    
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, eTime))
+        return ESOCK_STR_EINVAL;
+
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_timeval +++
+ *
+ * Decode a timeval in its erlang form (a map) into its native form,
+ * a timeval struct.
+ *
+ */
+extern
+char* esock_decode_timeval(ErlNifEnv*      env,
+                           ERL_NIF_TERM    eTime,
+                           struct timeval* timeP)
+{
+    ERL_NIF_TERM eSec, eUSec;
+    size_t       sz;
+
+    // It must be a map
+    if (!IS_MAP(env, eTime))
+        return ESOCK_STR_EINVAL;
+
+    // It must have atleast two attributes
+    if (!enif_get_map_size(env, eTime, &sz) || (sz < 2))
+        return ESOCK_STR_EINVAL;
+
+    if (!GET_MAP_VAL(env, eTime, esock_atom_sec, &eSec))
+        return ESOCK_STR_EINVAL;
+
+    if (!GET_MAP_VAL(env, eTime, esock_atom_usec, &eUSec))
+        return ESOCK_STR_EINVAL;
+
+    if (!GET_LONG(env, eSec, &timeP->tv_sec))
+        return ESOCK_STR_EINVAL;
+    
+    if (!GET_LONG(env, eUSec, &timeP->tv_usec))
+        return ESOCK_STR_EINVAL;
+
+    return NULL;
+}
+
+
+
+/* +++ esock_decode_domain +++
+ *
+ * Decode the Erlang form of the 'domain' type, that is: 
+ * 
+ *    inet  => AF_INET
+ *    inet6 => AF_INET6
+ *    local => AF_UNIX
+ *
+ */
+extern
+char* esock_decode_domain(ErlNifEnv*   env,
+                          ERL_NIF_TERM eDomain,
+                          int*         domain)
+{
+    char* xres = NULL;
+
+    if (COMPARE(esock_atom_inet, eDomain) == 0) {
+        *domain = AF_INET;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    } else if (COMPARE(esock_atom_inet6, eDomain) == 0) {
+        *domain = AF_INET6;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+    } else if (COMPARE(esock_atom_local, eDomain) == 0) {
+        *domain = AF_UNIX;
+#endif
+
+    } else {
+        *domain = -1;
+        xres    = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_encode_domain +++
+ *
+ * Encode the native domain to the Erlang form, that is: 
+ * 
+ *    AF_INET  => inet
+ *    AF_INET6 => inet6
+ *    AF_UNIX  => local
+ *
+ */
+extern
+char* esock_encode_domain(ErlNifEnv*    env,
+                          int           domain,
+                          ERL_NIF_TERM* eDomain)
+{
+    char* xres = NULL;
+
+    switch (domain) {
+    case AF_INET:
+        *eDomain = esock_atom_inet;
+        break;
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+    case AF_INET6:
+        *eDomain = esock_atom_inet6;
+        break;
+#endif
+
+#ifdef HAVE_SYS_UN_H
+    case AF_UNIX:
+        *eDomain = esock_atom_local;
+        break;
+#endif
+
+    default:
+        *eDomain = esock_atom_undefined; // Just in case
+        xres     = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_type +++
+ *
+ * Decode the Erlang form of the 'type' type, that is: 
+ * 
+ *    stream    => SOCK_STREAM
+ *    dgram     => SOCK_DGRAM
+ *    raw       => SOCK_RAW
+ *    seqpacket => SOCK_SEQPACKET
+ *
+ */
+extern
+char* esock_decode_type(ErlNifEnv*   env,
+                        ERL_NIF_TERM eType,
+                        int*         type)
+{
+    char* xres = NULL;
+
+    if (COMPARE(esock_atom_stream, eType) == 0) {
+        *type = SOCK_STREAM;
+    } else if (COMPARE(esock_atom_dgram, eType) == 0) {
+        *type = SOCK_DGRAM;
+    } else if (COMPARE(esock_atom_raw, eType) == 0) {
+        *type = SOCK_RAW;
+
+#if defined(HAVE_SCTP)
+    } else if (COMPARE(esock_atom_seqpacket, eType) == 0) {
+        *type = SOCK_SEQPACKET;
+#endif
+
+    } else {
+        *type = -1;
+        xres  = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_type +++
+ *
+ * Encode the native type to the Erlang form, that is: 
+ * 
+ *    SOCK_STREAM    => stream
+ *    SOCK_DGRAM     => dgram
+ *    SOCK_RAW       => raw
+ *    SOCK_SEQPACKET => seqpacket
+ *
+ */
+extern
+char* esock_encode_type(ErlNifEnv*    env,
+                        int           type,
+                        ERL_NIF_TERM* eType)
+{
+    char* xres = NULL;
+
+    switch (type) {
+    case SOCK_STREAM:
+        *eType = esock_atom_stream;
+        break;
+
+    case SOCK_DGRAM:
+        *eType = esock_atom_dgram;
+        break;
+
+    case SOCK_RAW:
+        *eType = esock_atom_raw;
+        break;
+
+#if defined(HAVE_SCTP)
+    case SOCK_SEQPACKET:
+        *eType = esock_atom_seqpacket;
+        break;
+#endif
+
+    default:
+        *eType = esock_atom_undefined; // Just in case
+        xres   = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_encode_protocol +++
+ *
+ * Encode the native protocol to the Erlang form, that is: 
+ * 
+ *    SOL_IP | IPPROTO_IP => ip
+ *    SOL_IPV6            => ipv6
+ *    SOL_TCP             => tcp
+ *    SOL_UDP             => udp
+ *    SOL_SCTP            => sctp
+ *
+ */
+extern
+char* esock_encode_protocol(ErlNifEnv*    env,
+                            int           proto,
+                            ERL_NIF_TERM* eProto)
+{
+    char* xres = NULL;
+
+    switch (proto) {
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        *eProto = esock_atom_ip;
+        break;
+
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+        *eProto = esock_atom_ipv6;
+        break;
+#endif
+
+    case IPPROTO_TCP:
+        *eProto = esock_atom_tcp;
+        break;
+
+    case IPPROTO_UDP:
+        *eProto = esock_atom_udp;
+        break;
+
+#if defined(HAVE_SCTP)
+    case IPPROTO_SCTP:
+        *eProto = esock_atom_sctp;
+        break;
+#endif
+
+    default:
+        *eProto = esock_atom_undefined;
+        xres    = ESOCK_STR_EAFNOSUPPORT;
+        break;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_protocol +++
+ *
+ * Decode the Erlang form of the 'protocol' type, that is: 
+ * 
+ *    ip   => SOL_IP | IPPROTO_IP
+ *    ipv6 => SOL_IPV6
+ *    tcp  => SOL_TCP
+ *    udp  => SOL_UDP
+ *    sctp => SOL_SCTP
+ *
+ */
+extern
+char* esock_decode_protocol(ErlNifEnv*   env,
+                            ERL_NIF_TERM eProto,
+                            int*         proto)
+{
+    char* xres = NULL;
+
+    if (COMPARE(esock_atom_ip, eProto) == 0) {
+#if defined(SOL_IP)
+        *proto = SOL_IP;
+#else
+        *proto = IPPROTO_IP;
+#endif
+    } else if (COMPARE(esock_atom_ipv6, eProto) == 0) {
+#if defined(SOL_IPV6)
+        *proto = SOL_IPV6;
+#else
+        *proto = IPPROTO_IPV6;
+#endif
+    } else if (COMPARE(esock_atom_tcp, eProto) == 0) {
+        *proto = IPPROTO_TCP;
+    } else if (COMPARE(esock_atom_udp, eProto) == 0) {
+        *proto = IPPROTO_UDP;
+#if defined(HAVE_SCTP)
+    } else if (COMPARE(esock_atom_sctp, eProto) == 0) {
+        *proto = IPPROTO_SCTP;
+#endif
+    } else {
+        *proto = -1;
+        xres   = ESOCK_STR_EAFNOSUPPORT;
+    }
+
+    return xres;
+}
+
+
+
+/* +++ esock_decode_bufsz +++
+ *
+ * Decode an buffer size. The size of a buffer is: 
+ * 
+ *    Sz > 0 => Use provided value
+ *    Sz     => Use provided default
+ *
+ */
+extern
+char* esock_decode_bufsz(ErlNifEnv*   env,
+                         ERL_NIF_TERM eVal,
+                         size_t       defSz,
+                         size_t*      sz)
+{
+    int val;
+
+    if (!GET_INT(env, eVal, &val))
+        return ESOCK_STR_EINVAL;
+
+    if (val > 0)
+        *sz = (size_t) val;
+    else
+        *sz = defSz;
+
+    return NULL;
+}
+
+
+
+/* *** esock_decode_string ***
+ *
+ * Decode a string value. A successful decode results in an 
+ * allocation of the string, which the caller has to free
+ * once the string has been used.
+ */
+extern
+BOOLEAN_T esock_decode_string(ErlNifEnv*         env,
+                              const ERL_NIF_TERM eString,
+                              char**             stringP)
+{
+    BOOLEAN_T    result;
+    unsigned int len;
+    char*        bufP;
+    
+    if (!GET_LIST_LEN(env, eString, &len) && (len != 0)) {
+        *stringP = NULL;
+        result   = FALSE;
+    } else {
+
+        UDBG( ("SUTIL", "esock_decode_string -> len: %d\r\n", len) );
+
+        bufP = MALLOC(len + 1); // We shall NULL-terminate
+    
+        if (GET_STR(env, eString, bufP, len+1)) {
+            UDBG( ("SUTIL", "esock_decode_string -> buf: %s\r\n", bufP) );
+            // bufP[len] = '\0';
+            *stringP = bufP;
+            result   = TRUE;
+        } else {
+            *stringP = NULL;
+            result   = FALSE;
+            FREE(bufP);
+        }
+    }
+
+    return result;
+}
+
+
+
+/* *** esock_extract_bool_from_map ***
+ *
+ * Extract an boolean item from a map.
+ *
+ */
+extern
+BOOLEAN_T esock_extract_bool_from_map(ErlNifEnv*   env,
+                                      ERL_NIF_TERM map,
+                                      ERL_NIF_TERM key,
+                                      BOOLEAN_T    def)
+{
+    ERL_NIF_TERM val;
+
+    if (!GET_MAP_VAL(env, map, key, &val))
+        return def;
+
+    if (!IS_ATOM(env, val))
+        return def;
+
+    if (COMPARE(val, esock_atom_true) == 0)
+        return TRUE;
+    else
+        return FALSE;
+}
+
+
+
+/* *** esock_decode_bool ***
+ *
+ * Decode a boolean value.
+ *
+ */
+extern
+BOOLEAN_T esock_decode_bool(ERL_NIF_TERM val)
+{
+    if (COMPARE(esock_atom_true, val) == 0) 
+        return TRUE;
+    else
+        return FALSE;
+}
+
+
+/* *** esock_encode_bool ***
+ *
+ * Encode a boolean value.
+ *
+ */
+extern
+ERL_NIF_TERM esock_encode_bool(BOOLEAN_T val)
+{
+    if (val)
+        return esock_atom_true;
+    else
+        return esock_atom_false;
+}
+
+
+/* Create an ok two (2) tuple in the form:
+ *
+ *         {ok, Any}
+ *
+ * The second element (Any) is already in the form of an
+ * ERL_NIF_TERM so all we have to do is create the tuple.
+ */
+extern
+ERL_NIF_TERM esock_make_ok2(ErlNifEnv* env, ERL_NIF_TERM any)
+{
+    return MKT2(env, esock_atom_ok, any);
+}
+
+
+/* Create an ok three (3) tuple in the form:
+ *
+ *         {ok, Val1, Val2}
+ *
+ * The second (Val1) and third (Val2) elements are already in
+ * the form of an ERL_NIF_TERM so all we have to do is create
+ * the tuple.
+ */
+extern
+ERL_NIF_TERM esock_make_ok3(ErlNifEnv* env, ERL_NIF_TERM val1, ERL_NIF_TERM val2)
+{
+  return MKT3(env, esock_atom_ok, val1, val2);
+}
+
+
+
+/* Create an error two (2) tuple in the form:
+ *
+ *          {error, Reason}
+ *
+ * The second element (Reason) is already in the form of an
+ * ERL_NIF_TERM so all we have to do is create the tuple.
+ */
+extern
+ERL_NIF_TERM esock_make_error(ErlNifEnv* env, ERL_NIF_TERM reason)
+{
+    return MKT2(env, esock_atom_error, reason);
+}
+
+
+
+/* Create an error two (2) tuple in the form: {error, Reason}.
+ *
+ *          {error, Reason}
+ *
+ * The second element, Reason, is the reason string that has
+ * converted into an atom.
+ */
+extern
+ERL_NIF_TERM esock_make_error_str(ErlNifEnv* env, char* reason)
+{
+    return esock_make_error(env, MKA(env, reason));
+}
+
+
+/* Create an error two (2) tuple in the form:
+ *
+ *          {error, Reason}
+ *
+ * The second element, Reason, is the errno value in its
+ * basic form (integer) which has been converted into an atom.
+ */
+extern
+ERL_NIF_TERM esock_make_error_errno(ErlNifEnv* env, int err)
+{
+    return esock_make_error_str(env, erl_errno_id(err));
+}
+
+
+
+/* strnlen doesn't exist everywhere */
+extern
+size_t esock_strnlen(const char *s, size_t maxlen)
+{
+    size_t i = 0;
+    while (i < maxlen && s[i] != '\0')
+        i++;
+    return i;
+}
+
+
+
+/* *** esock_abort ***
+ *
+ * Generate an abort with "extra" info. This should be called
+ * via the ESOCK_ABORT macro.
+ * Basically it prints the extra info onto stderr before aborting.
+ *
+ */
+extern
+void esock_abort(const char* expr,
+                 const char* func,
+                 const char* file,
+                 int         line)
+{
+  fflush(stdout);
+  fprintf(stderr, "%s:%d:%s() Assertion failed: %s\n",
+	  file, line, func, expr);
+  fflush(stderr);
+  abort();
+}
+
+
+
+/* *** esock_warning_msg ***
+ *
+ * Temporary function for issuing warning messages.
+ *
+ */
+extern
+void esock_warning_msg( const char* format, ... )
+{
+  va_list         args;
+  char            f[512 + sizeof(format)]; // This has to suffice...
+  char            stamp[64]; // Just in case...
+  struct timespec ts;
+  int             res;
+
+  /*
+   * We should really include self in the printout, so we can se which process
+   * are executing the code. But then I must change the API....
+   * ....something for later.
+   */
+
+  // 2018-06-29 12:13:21.232089
+  // 29-Jun-2018::13:47:25.097097
+  
+  if (!realtime(&ts)) {
+    if (timespec2str(stamp, sizeof(stamp), &ts) != 0) {
+        res = enif_snprintf(f, sizeof(f), "=WARNING MSG==== %s", format);
+    } else {
+        res = enif_snprintf(f, sizeof(f),
+                            "=WARNING MSG==== %s ===\r\n%s" , stamp, format);
+    }
+
+    if (res > 0) {
+      va_start (args, format);
+      enif_vfprintf (stdout, f, args);
+      va_end (args);
+      fflush(stdout);
+    }
+  }
+
+  return;
+}
+
+
+static
+int realtime(struct timespec* tsP)
+{
+  return clock_gettime(CLOCK_REALTIME, tsP);
+}
+
+
+/*
+ * Convert a timespec struct into a readable/printable string.
+ *
+ * "%F::%T"       => 2018-06-29 12:13:21[.232089]
+ * "%d-%b-%Y::%T" => 29-Jun-2018::13:47:25.097097
+ */
+static
+int timespec2str(char *buf, unsigned int len, struct timespec *ts)
+{
+  int       ret, buflen;
+  struct tm t;
+
+  tzset();
+  if (localtime_r(&(ts->tv_sec), &t) == NULL)
+    return 1;
+
+  ret = strftime(buf, len, "%d-%B-%Y::%T", &t);
+  if (ret == 0)
+    return 2;
+  len -= ret - 1;
+  buflen = strlen(buf);
+
+  ret = snprintf(&buf[buflen], len, ".%06ld", ts->tv_nsec/1000);
+  if (ret >= len)
+    return 3;
+
+  return 0;
+}
+
+
+/* =================================================================== *
+ *                                                                     *
+ *              Various (internal) utility functions                   *
+ *                                                                     *
+ * =================================================================== */
+
+/* Construct the IPv4 socket address */
+static
+char* make_sockaddr_in4(ErlNifEnv*    env,
+                        ERL_NIF_TERM  port,
+                        ERL_NIF_TERM  addr,
+                        ERL_NIF_TERM* sa)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_family, esock_atom_port, esock_atom_addr};
+    ERL_NIF_TERM vals[] = {esock_atom_inet, port, addr};
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, sa)) {
+        *sa = esock_atom_undefined;
+        return ESOCK_STR_EINVAL;
+    } else {
+        return NULL;
+    }
+}
+
+
+/* Construct the IPv6 socket address */
+static
+char* make_sockaddr_in6(ErlNifEnv*    env,
+                        ERL_NIF_TERM  port,
+                        ERL_NIF_TERM  addr,
+                        ERL_NIF_TERM  flowInfo,
+                        ERL_NIF_TERM  scopeId,
+                        ERL_NIF_TERM* sa)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_family,
+                           esock_atom_port,
+                           esock_atom_addr,
+                           esock_atom_flowinfo,
+                           esock_atom_scope_id};
+    ERL_NIF_TERM vals[] = {esock_atom_inet6, port, addr, flowInfo, scopeId};
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, sa)) {
+        *sa = esock_atom_undefined;
+        return ESOCK_STR_EINVAL;
+    } else {
+        return NULL;
+    }
+}
+
+
+/* Construct the Unix Domain socket address */
+static
+char* make_sockaddr_un(ErlNifEnv*    env,
+                       ERL_NIF_TERM  path,
+                       ERL_NIF_TERM* sa)
+{
+    ERL_NIF_TERM keys[] = {esock_atom_family, esock_atom_path};
+    ERL_NIF_TERM vals[] = {esock_atom_inet, path};
+    unsigned int numKeys = sizeof(keys) / sizeof(ERL_NIF_TERM);
+    unsigned int numVals = sizeof(vals) / sizeof(ERL_NIF_TERM);
+    
+    ESOCK_ASSERT( (numKeys == numVals) );
+    
+    if (!MKMA(env, keys, vals, numKeys, sa)) {
+        *sa = esock_atom_undefined;
+        return ESOCK_STR_EINVAL;
+    } else {
+        return NULL;
+    }
+}
+
+
diff --git a/erts/emulator/nifs/common/socket_util.h b/erts/emulator/nifs/common/socket_util.h
new file mode 100644
index 0000000000..1b5d003155
--- /dev/null
+++ b/erts/emulator/nifs/common/socket_util.h
@@ -0,0 +1,205 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2018-2018. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ *
+ * ----------------------------------------------------------------------
+ *  Purpose : Utility "stuff" for socket and net.
+ * ----------------------------------------------------------------------
+ *
+ */
+
+#ifndef SOCKET_UTIL_H__
+#define SOCKET_UTIL_H__
+
+#include <erl_nif.h>
+#include "socket_int.h"
+
+#define CHAR(C)  ((char) (C))
+#define UCHAR(C) ((unsigned char) (C))
+#define INT(I)   ((int)   (I))
+#define UINT(U)  ((unsigned int) (U))
+#define LONG(L)  ((long) (L))
+#define ULONG(L) ((unsigned long) (L))
+#define SZT(I)   ((size_t) (I))
+#define VOIDP(P) ((void*) (P))
+#define CHARP(P) ((char*) (P))
+
+#define ESOCK_ABORT(E)  esock_abort(E, __func__, __FILE__, __LINE__)
+#define ESOCK_ASSERT(e) ((void) ((e) ? 1 : (ESOCK_ABORT(#e), 0)))
+
+extern
+char* esock_encode_iov(ErlNifEnv*    env,
+                       int           read,
+                       struct iovec* iov,
+                       size_t        len,
+                       ErlNifBinary* data,
+                       ERL_NIF_TERM* eIOV);
+extern
+char* esock_decode_iov(ErlNifEnv*    env,
+                       ERL_NIF_TERM  eIOV,
+                       ErlNifBinary* bufs,
+                       struct iovec* iov,
+                       size_t        len,
+                       ssize_t*      totSize);
+extern
+char* esock_decode_sockaddr(ErlNifEnv*     env,
+                            ERL_NIF_TERM   eSockAddr,
+                            SocketAddress* sockAddrP,
+                            unsigned int*  addrLen);
+extern
+char* esock_encode_sockaddr(ErlNifEnv*     env,
+                            SocketAddress* sockAddrP,
+                            unsigned int   addrLen,
+                            ERL_NIF_TERM*  eSockAddr);
+
+extern
+char* esock_decode_sockaddr_in4(ErlNifEnv*          env,
+                                ERL_NIF_TERM        eSockAddr,
+                                struct sockaddr_in* sockAddrP,
+                                unsigned int*       addrLen);
+extern
+char* esock_encode_sockaddr_in4(ErlNifEnv*          env,
+                                struct sockaddr_in* sockAddrP,
+                                unsigned int        addrLen,
+                                ERL_NIF_TERM*       eSockAddr);
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_decode_sockaddr_in6(ErlNifEnv*           env,
+                                ERL_NIF_TERM         eSockAddr,
+                                struct sockaddr_in6* sockAddrP,
+                                unsigned int*        addrLen);
+extern
+char* esock_encode_sockaddr_in6(ErlNifEnv*           env,
+                                struct sockaddr_in6* sockAddrP,
+                                unsigned int         addrLen,
+                                ERL_NIF_TERM*        eSockAddr);
+#endif
+
+#ifdef HAVE_SYS_UN_H
+extern
+char* esock_decode_sockaddr_un(ErlNifEnv*          env,
+                               ERL_NIF_TERM        eSockAddr,
+                               struct sockaddr_un* sockAddrP,
+                               unsigned int*       addrLen);
+extern
+char* esock_encode_sockaddr_un(ErlNifEnv*          env,
+                               struct sockaddr_un* sockAddrP,
+                               unsigned int        addrLen,
+                               ERL_NIF_TERM*       eSockAddr);
+#endif
+
+extern
+char* esock_decode_ip4_address(ErlNifEnv*      env,
+                               ERL_NIF_TERM    eAddr,
+                               struct in_addr* inAddrP);
+extern
+char* esock_encode_ip4_address(ErlNifEnv*      env,
+                               struct in_addr* addrP,
+                               ERL_NIF_TERM*   eAddr);
+
+#if defined(HAVE_IN6) && defined(AF_INET6)
+extern
+char* esock_decode_ip6_address(ErlNifEnv*       env,
+                               ERL_NIF_TERM     eAddr,
+                               struct in6_addr* inAddrP);
+extern
+char* esock_encode_ip6_address(ErlNifEnv*       env,
+                               struct in6_addr* addrP,
+                               ERL_NIF_TERM*    eAddr);
+#endif
+
+extern char* esock_encode_timeval(ErlNifEnv*      env,
+                                  struct timeval* timeP,
+                                  ERL_NIF_TERM*   eTime);
+extern char* esock_decode_timeval(ErlNifEnv*      env,
+                                  ERL_NIF_TERM    eTime,
+                                  struct timeval* timeP);
+extern
+char* esock_decode_domain(ErlNifEnv*   env,
+                          ERL_NIF_TERM eDomain,
+                          int*         domain);
+extern
+char* esock_encode_domain(ErlNifEnv*    env,
+                          int           domain,
+                          ERL_NIF_TERM* eDomain);
+
+extern
+char* esock_decode_type(ErlNifEnv*   env,
+                        ERL_NIF_TERM eType,
+                        int*         type);
+extern
+char* esock_encode_type(ErlNifEnv*    env,
+                        int           type,
+                        ERL_NIF_TERM* eType);
+
+extern
+char* esock_decode_protocol(ErlNifEnv*   env,
+                            ERL_NIF_TERM eProtocol,
+                            int*         protocol);
+extern
+char* esock_encode_protocol(ErlNifEnv*    env,
+                            int           type,
+                            ERL_NIF_TERM* eProtocol);
+
+extern
+char* esock_decode_bufsz(ErlNifEnv*   env,
+                         ERL_NIF_TERM eVal,
+                         size_t       defSz,
+                         size_t*      sz);
+
+extern
+BOOLEAN_T esock_decode_string(ErlNifEnv*         env,
+                              const ERL_NIF_TERM eString,
+                              char**             stringP);
+
+extern
+BOOLEAN_T esock_extract_bool_from_map(ErlNifEnv*   env,
+                                      ERL_NIF_TERM map,
+                                      ERL_NIF_TERM key,
+                                      BOOLEAN_T    def);
+extern
+BOOLEAN_T esock_decode_bool(ERL_NIF_TERM val);
+extern
+ERL_NIF_TERM esock_encode_bool(BOOLEAN_T val);
+
+extern
+size_t esock_strnlen(const char *s, size_t maxlen);
+extern
+void esock_abort(const char* expr,
+                 const char* func,
+                 const char* file,
+                 int         line);
+
+extern
+ERL_NIF_TERM esock_make_ok2(ErlNifEnv* env, ERL_NIF_TERM any);
+extern
+ERL_NIF_TERM esock_make_ok3(ErlNifEnv* env, ERL_NIF_TERM val1, ERL_NIF_TERM val2);
+
+extern
+ERL_NIF_TERM esock_make_error(ErlNifEnv* env, ERL_NIF_TERM reason);
+extern
+ERL_NIF_TERM esock_make_error_str(ErlNifEnv* env, char* reason);
+extern
+ERL_NIF_TERM esock_make_error_errno(ErlNifEnv* env, int err);
+
+extern
+void esock_warning_msg(const char* format, ... );
+
+
+#endif // SOCKET_UTIL_H__