[socket-nif] CMsgHdr and various doc related changes

Updated the (send) cmsghdr type and the handling of it
(in the nif code). Still not tested!
Removed the is_loaded nif function.
Tried to get fix the doc build problem (socket.erl *i think*),
which causes socket.html generation to fail with:

    "cannot find module exporting type"

To solve this I tried to run dialyzer on preloaded, and ran into
problems with enc_setopt_value. Update various specs and types
to "solve" this (which did not work).
Updated the nif-stub functions to make dialyzer happy.

8 files changed, 430 insertions, 277 deletions

diff --git a/erts/doc/src/socket.xml b/erts/doc/src/socket.xml
index b11b68cba5..35f7e8502d 100644
--- a/erts/doc/src/socket.xml
+++ b/erts/doc/src/socket.xml
@@ -176,11 +176,16 @@
     <datatype>
       <name name="cmsghdr_type"/>
     </datatype>
+    <!--
     <datatype>
       <name name="cmsghdr_data"/>
     </datatype>
+    -->
     <datatype>
-      <name name="cmsghdr"/>
+      <name name="cmsghdr_recv"/>
+    </datatype>
+    <datatype>
+      <name name="cmsghdr_send"/>
     </datatype>
     <datatype>
       <name name="uint8"/>
@@ -427,7 +432,7 @@
 	how much we want to read, it returns when we get a message.</p>
 	<p>The message will be delivered in the form of a <c>msghdr()</c>,
 	which may contain the source address (if socket not connected),
-	a list of <c>cmsghdr()</c> (depends on what socket options have
+	a list of <c>cmsghdr_recv()</c> (depends on what socket options have
 	been set and what the protocol and platform supports) and
 	also a set of flags, providing further info about the read . </p>
 	
@@ -466,11 +471,11 @@
       <name name="sendmsg" arity="4"/>
       <fsummary>Send a message on a socket.</fsummary>
       <desc>
-	<p>Send a message on a socket. The destination, if needed (socket not
-	connected) is provided in the <c>MsgHdr</c>, which also
-	contains the message to send, The <c>MsgHdr</c> may also contain
-	an list of optional <c>cmsghdr()</c> (depends on what the protocol and
-	platform supports).</p>
+	<p>Send a message on a socket. The destination, if needed
+	(socket <em>not</em> connected) is provided in the <c>MsgHdr</c>,
+	which also contains the message to send,
+	The <c>MsgHdr</c> may also contain an list of optional <c>cmsghdr_send()</c>
+	(depends on what the protocol and platform supports).</p>
       </desc>
     </func>
 
@@ -492,6 +497,7 @@
       <name name="setopt" arity="4" clause_i="5"/>
       <name name="setopt" arity="4" clause_i="6"/>
       <name name="setopt" arity="4" clause_i="7"/>
+      <name name="setopt" arity="4" clause_i="8"/>
       <fsummary>Set options on a socket.</fsummary>
       <desc>
         <p>Set options on a socket.</p>
diff --git a/erts/emulator/nifs/common/net_nif.c b/erts/emulator/nifs/common/net_nif.c
index 309ad05a36..9905d99a04 100644
--- a/erts/emulator/nifs/common/net_nif.c
+++ b/erts/emulator/nifs/common/net_nif.c
@@ -241,9 +241,6 @@ static NetData data;
 extern char* erl_errno_id(int error);
 
 
-static ERL_NIF_TERM nif_is_loaded(ErlNifEnv*         env,
-                                  int                argc,
-                                  const ERL_NIF_TERM argv[]);
 static ERL_NIF_TERM nif_info(ErlNifEnv*         env,
                              int                argc,
                              const ERL_NIF_TERM argv[]);
@@ -439,8 +436,8 @@ static ErlNifResourceTypeInit netInit = {
  *
  * Utility and admin functions:
  * ----------------------------
- * nif_is_loaded/0
  * nif_info/0
+ * nif_command/1
  *
  * The "proper" net functions:
  * ------------------------------
@@ -455,27 +452,6 @@ static ErlNifResourceTypeInit netInit = {
 
 
 /* ----------------------------------------------------------------------
- * nif_is_loaded
- *
- * Description:
- * This functions only purpose is to return the atom 'true'.
- * This will happen *if* the (socket) nif library is loaded.
- * If its not, the erlang (nif_is_loaded) will instead return
- * 'false'.
- */
-static
-ERL_NIF_TERM nif_is_loaded(ErlNifEnv*         env,
-                           int                argc,
-                           const ERL_NIF_TERM argv[])
-{
-    if (argc != 0)
-        return enif_make_badarg(env);
-
-    return esock_atom_true;
-}
-
-
-/* ----------------------------------------------------------------------
  * nif_info
  *
  * Description:
@@ -1522,7 +1498,6 @@ static
 ErlNifFunc net_funcs[] =
 {
     // Some utility functions
-    {"nif_is_loaded", 0, nif_is_loaded, 0},
     {"nif_info",      0, nif_info,      0},
     {"nif_command",   1, nif_command,   0}, // Shall we let this be dirty?
 
diff --git a/erts/emulator/nifs/common/socket_nif.c b/erts/emulator/nifs/common/socket_nif.c
index f7e59678bb..68a9730d0c 100644
--- a/erts/emulator/nifs/common/socket_nif.c
+++ b/erts/emulator/nifs/common/socket_nif.c
@@ -848,9 +848,6 @@ typedef struct {
 
 
 
-static ERL_NIF_TERM nif_is_loaded(ErlNifEnv*         env,
-                                  int                argc,
-                                  const ERL_NIF_TERM argv[]);
 static ERL_NIF_TERM nif_info(ErlNifEnv*         env,
                              int                argc,
                              const ERL_NIF_TERM argv[]);
@@ -1973,7 +1970,18 @@ extern char* encode_msghdr_flags(ErlNifEnv*        env,
                                  SocketDescriptor* descP,
                                  int               msgFlags,
                                  ERL_NIF_TERM*     flags);
-
+static char* decode_cmsghdr_data(ErlNifEnv*   env,
+                                 void**       bufP,
+                                 size_t*      rem,
+                                 int          level,
+                                 int          type,
+                                 ERL_NIF_TERM eData);
+static char* decode_cmsghdr_final(void**  bufP,
+                                  size_t* rem,
+                                  int     level,
+                                  int     type,
+                                  char*   data,
+                                  int     sz);
 static BOOLEAN_T decode_sock_linger(ErlNifEnv*     env,
                                     ERL_NIF_TERM   eVal,
                                     struct linger* valP);
@@ -2380,7 +2388,6 @@ static SocketData data;
  *
  * Utility and admin functions:
  * ----------------------------
- * nif_is_loaded/0
  * nif_info/0
  * (nif_debug/1)
  *
@@ -2417,27 +2424,6 @@ static SocketData data;
 
 
 /* ----------------------------------------------------------------------
- * nif_is_loaded
- *
- * Description:
- * This functions only purpose is to return the atom 'true'.
- * This will happen *if* the (socket) nif library is loaded.
- * If its not, the erlang (nif_is_loaded) will instead return
- * 'false'.
- */
-static
-ERL_NIF_TERM nif_is_loaded(ErlNifEnv*         env,
-                           int                argc,
-                           const ERL_NIF_TERM argv[])
-{
-    if (argc != 0)
-        return enif_make_badarg(env);
-
-    return atom_true;
-}
-
-
-/* ----------------------------------------------------------------------
  * nif_info
  *
  * Description:
@@ -11046,7 +11032,7 @@ char* encode_msghdr(ErlNifEnv*        env,
  *
  * 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 tern that into an binary erlang 
+ * 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
@@ -11171,7 +11157,7 @@ char* encode_cmsghdrs(ErlNifEnv*        env,
  *
  * Decode a list of cmsghdr(). There can be 0 or more cmsghdr "blocks".
  *
- * Each element can either be a (erlang) map that needds to be decoded,
+ * 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.
  *
@@ -11267,46 +11253,121 @@ char* decode_cmsghdr(ErlNifEnv*        env,
         /* 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.
-         *
-         * <KOLLA>
-         *
-         * At the moment, the only data we support is a binary...
-         *
-         * </KOLLA>
          */
+
+        return decode_cmsghdr_data(env, bufP, rem, level, type, eData);
+
+    } else {
+        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 (we have already taken care of the binary).
+ */
+static
+char* decode_cmsghdr_data(ErlNifEnv*   env,
+                          void**       bufP,
+                          size_t*      rem,
+                          int          level,
+                          int          type,
+                          ERL_NIF_TERM eData)
+{
+    char* xres = ESOCK_STR_EINVAL;
+
+    if (IS_BIN(env, eData)) {
+        ErlNifBinary bin;
         
-        if (IS_BIN(env, eData)) {
-            ErlNifBinary bin;
-            size_t       currentRem = *rem;
+        if (GET_BIN(env, eData, &bin)) {
+            return decode_cmsghdr_final(bufP, rem, level, type,
+                                        (char*) bin.data, bin.size);
+        }
+    } else {
 
-            if (!GET_BIN(env, eData, &bin)) {
-                return ESOCK_STR_EINVAL;
-            } else {
-                int len   = CMSG_LEN(bin.size);   // The cmsghdr
-                int space = CMSG_SPACE(bin.size); // With padding
-                /* Make sure it fits before we copy */
-                if (currentRem >= space) {
-                    struct cmsghdr* cmsgP = (struct cmsghdr*) bufP;
-
-                    /* The header */
-                    cmsgP->cmsg_len   = len;
-                    cmsgP->cmsg_level = level;
-                    cmsgP->cmsg_type  = type;
-
-                    /* And the data */
-                    sys_memcpy(CMSG_DATA(cmsgP), bin.data, bin.size);
-                    *bufP += space;
-                    *rem  -= space;
-                } else {
-                    return ESOCK_STR_EINVAL;
+        /* 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)) {
+                        return decode_cmsghdr_final(bufP, rem, level, type,
+                                                    (char*) &data,
+                                                    sizeof(data));
+                    }
+                }
+                break;
+#endif
+
+#if defined(IP_TTL)
+            case IP_TTL:
+                {
+                    int data;
+                    if (GET_INT(env, eData, &data)) {
+                        return decode_cmsghdr_final(bufP, rem, level, type,
+                                                    (char*) &data,
+                                                    sizeof(data));
+                    }
                 }
+                break;
+#endif
+
             }
-        } else {
+            break;
+
+        default:
+            break;
+        }        
 
-            /* Here is where we should have the proper data decode */
+    }
 
-            return ESOCK_STR_EINVAL;
-        }
+    return xres;
+}
+                              
+
+/* *** decode_cmsghdr_final ***
+ *
+ * This does the final create of the cmsghdr (including the data copy).
+ */
+static
+char* decode_cmsghdr_final(void**  bufP,
+                           size_t* rem,
+                           int     level,
+                           int     type,
+                           char*   data,
+                           int     sz)
+{
+    int currentRem = *rem;
+    int len        = CMSG_LEN(sz);
+    int space      = CMSG_SPACE(sz);
+
+    if (currentRem >= 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);
+        *bufP += space;
+        *rem  -= space;
     } else {
         return ESOCK_STR_EINVAL;
     }
@@ -11334,8 +11395,30 @@ char* encode_cmsghdr_level(ErlNifEnv*    env,
         xres    = NULL;
         break;
 
+#if defined(SOL_IP)
+    case SOL_IP:
+#else
+    case IPPROTO_IP:
+#endif
+        *eLevel = esock_atom_ip;
+        xres    = NULL;
+        break;
+
+#if defined(SOL_IPV6)
+    case SOL_IPV6:
+        *eLevel = esock_atom_ip;
+        xres    = NULL;
+        break;
+#endif
+
+    case IPPROTO_UDP:
+        *eLevel = esock_atom_udp;
+        xres    = NULL;
+        break;
+
     default:
-        xres = esock_encode_protocol(env, level, eLevel);
+        *eLevel = MKI(env, level);
+        xres    = NULL;
         break;
     }
 
@@ -11358,17 +11441,35 @@ char* decode_cmsghdr_level(ErlNifEnv*   env,
     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(SOL_IPV6)
+        } else if (COMPARE(eLevel, esock_atom_ipv6) == 0) {
+            *level = SOL_IPV6;
+            xres   = NULL;
+#endif
+        } else if (COMPARE(eLevel, esock_atom_udp) == 0) {
+            *level = IPPROTO_UDP;
+            xres   = NULL;
         } else {
-            xres = esock_decode_protocol(env, eLevel, level);            
+            *level = -1;
+            xres   = ESOCK_STR_EINVAL;
         }
     } else if (IS_NUM(env, eLevel)) {
         if (!GET_INT(env, eLevel, level))
             xres = ESOCK_STR_EINVAL;
     } else {
-        xres = ESOCK_STR_EINVAL;
+        *level = -1;
+        xres   = ESOCK_STR_EINVAL;
     }
 
     return xres;
@@ -11521,25 +11622,13 @@ char* decode_cmsghdr_type(ErlNifEnv*   env,
 
     switch (level) {
     case SOL_SOCKET:
-        if (COMPARE(eType, esock_atom_timestamp) == 0) {
-#if defined(SO_TIMESTAMP)
-           *type = SO_TIMESTAMP;
-#else
-            xres  = ESOCK_STR_EINVAL;
-#endif
-        } else if (COMPARE(eType, esock_atom_rights) == 0) {
-#if defined(SCM_RIGHTS)
-            *type = SCM_RIGHTS;
-#else
-            xres  = ESOCK_STR_EINVAL;
-#endif
-        } else if (COMPARE(eType, esock_atom_credentials) == 0) {
-#if defined(SCM_CREDENTIALS)
-            *type = SCM_CREDENTIALS;
-#else
-            xres  = ESOCK_STR_EINVAL;
-#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;
@@ -11550,60 +11639,62 @@ char* decode_cmsghdr_type(ErlNifEnv*   env,
 #else
     case IPPROTO_IP:
 #endif
-        if (COMPARE(eType, esock_atom_tos) == 0) {
+        if (IS_ATOM(env, eType)) {
+            if (COMPARE(eType, esock_atom_tos) == 0) {
 #if defined(IP_TOS)
-            *type = IP_TOS;
+                *type = IP_TOS;
 #else
-            xres  = ESOCK_STR_EINVAL;
+                xres  = ESOCK_STR_EINVAL;
 #endif
-        } else if (COMPARE(eType, esock_atom_ttl) == 0) {
+            } else if (COMPARE(eType, esock_atom_ttl) == 0) {
 #if defined(IP_TTL)
-            *type = IP_TTL;
+                *type = IP_TTL;
 #else
-            xres  = ESOCK_STR_EINVAL;
-#endif
-        } else if (COMPARE(eType, esock_atom_pktinfo) == 0) {
-#if defined(IP_PKTINFO)
-            *type = IP_PKTINFO;
-#else
-            xres  = ESOCK_STR_EINVAL;
-#endif
-        } else if (COMPARE(eType, esock_atom_origdstaddr) == 0) {
-#if defined(IP_ORIGDSTADDR)
-            *type = IP_ORIGDSTADDR;
-#else
-            xres  = ESOCK_STR_EINVAL;
+                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 {
-            xres = ESOCK_STR_EINVAL;
+            *type = -1;
+            xres  = ESOCK_STR_EINVAL;
         }
         break;
         
 #if defined(SOL_IPV6)
     case SOL_IPV6:
-        xres = ESOCK_STR_EINVAL;
+        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_TCP:
-        xres = ESOCK_STR_EINVAL;
-        break;
-        break;
-
     case IPPROTO_UDP:
-        xres = ESOCK_STR_EINVAL;
-        break;
-        break;
-
-#if defined(HAVE_SCTP)
-    case IPPROTO_SCTP:
-        xres = ESOCK_STR_EINVAL;
-        break;
+        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
 
     default:
-        xres = ESOCK_STR_EINVAL;
+        *type = -1;
+        xres  = ESOCK_STR_EINVAL;
         break;
     }
 
@@ -13481,7 +13572,6 @@ static
 ErlNifFunc socket_funcs[] =
 {
     // Some utility functions
-    {"nif_is_loaded", 0, nif_is_loaded, 0},
     {"nif_info",      0, nif_info, 0},
     // {"nif_debug",      1, nif_debug_, 0},
 
diff --git a/erts/preloaded/ebin/net.beam b/erts/preloaded/ebin/net.beam
index b52fa01b07..e7a393391a 100644
--- a/erts/preloaded/ebin/net.beam
+++ b/erts/preloaded/ebin/net.beam
diff --git a/erts/preloaded/ebin/socket.beam b/erts/preloaded/ebin/socket.beam
index 5b14af3ad8..b3f3e385d2 100644
--- a/erts/preloaded/ebin/socket.beam
+++ b/erts/preloaded/ebin/socket.beam
diff --git a/erts/preloaded/src/Makefile b/erts/preloaded/src/Makefile
index fae60a4491..2a80837719 100644
--- a/erts/preloaded/src/Makefile
+++ b/erts/preloaded/src/Makefile
@@ -78,6 +78,10 @@ STDLIB_INCLUDE=$(ERL_TOP)/lib/stdlib/include
 
 ERL_COMPILE_FLAGS += +debug_info -I$(KERNEL_SRC) -I$(KERNEL_INCLUDE)
 
+DIA_PLT      = erts-preloaded.plt
+DIA_ANALYSIS = $(basename $(DIA_PLT)).dialyzer_analysis
+
+
 debug opt: $(TARGET_FILES) 
 
 clean:
@@ -89,7 +93,6 @@ copy:
 $(APP_TARGET): $(APP_SRC) $(ERL_TOP)/erts/vsn.mk
 	$(vsn_verbose)sed -e 's;%VSN%;$(VSN);' $< > $@
 
-
 include $(ERL_TOP)/make/otp_release_targets.mk
 
 release_spec: $(APP_TARGET)
@@ -104,6 +107,30 @@ release_docs_spec:
 list_preloaded:
 	@echo $(PRE_LOADED_MODULES)
 
+dclean:
+	rm -f $(DIA_PLT)
+	rm -f $(DIA_ANALYSIS)
+
+dialyzer_plt: $(DIA_PLT)
+
+$(DIA_PLT): $(ERL_FILES)
+	@echo "Building ($(basename $(DIA_PLT))) plt file"
+	@dialyzer --build_plt \
+                  --output_plt $@ \
+                  -r ../ebin \
+                     ../../../lib/kernel/ebin \
+                     ../../../lib/stdlib/ebin \
+                     ../../../lib/crypto/ebin \
+                     ../../../lib/compiler/ebin \
+                  --output $(DIA_ANALYSIS) \
+                  --verbose
+
+dialyzer: $(DIA_PLT)
+	@echo "Running dialyzer on $(basename $(DIA_PLT))"
+	@dialyzer --plt $< \
+                  ../ebin \
+                  --verbose
+
 #
 # Combine a BEAM assembly script file a stub Erlang file into a BEAM file.
 # See add_abstract_chunk script.
diff --git a/erts/preloaded/src/net.erl b/erts/preloaded/src/net.erl
index 01b12696e9..0183a69ddb 100644
--- a/erts/preloaded/src/net.erl
+++ b/erts/preloaded/src/net.erl
@@ -20,9 +20,11 @@
 
 -module(net).
 
+-compile(no_native).
+
 %% Administrative and "global" utility functions
 -export([
-	 on_load/0, on_load/1, on_load/2,
+	 on_load/0, on_load/1,
 	 info/0,
          command/1
         ]).
@@ -105,23 +107,10 @@ on_load() ->
     on_load(#{}).
 
 -spec on_load(Extra) -> ok when
-      Extra :: maps:map().
-
-on_load(Extra) when is_map(Extra) ->
-    on_load(atom_to_list(?MODULE), Extra).
-
--spec on_load(Path, Extra) -> ok when
-      Path  :: string(),
-      Extra :: maps:map().
-
-on_load(Path, Extra) when is_list(Path) andalso is_map(Extra) ->
-    on_load(nif_is_loaded(), Path, Extra).
-
-on_load(true, _Path, _Extra) ->
-    ok;
-on_load(false, Path, Extra) ->
-    ok = erlang:load_nif(Path, Extra).
+      Extra :: map().
 
+on_load(Extra) ->
+    ok = erlang:load_nif(atom_to_list(?MODULE), Extra).
 
 
 -spec info() -> list().
@@ -315,29 +304,26 @@ if_names() ->
 %%
 %% ===========================================================================
 
-nif_is_loaded() ->
-    false.
-
 nif_info() ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_command(_Cmd) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_gethostname() ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_getnameinfo(_Addr, _Flags) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_getaddrinfo(_Host, _Service, _Hints) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_if_name2index(_Name) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_if_index2name(_Id) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_if_names() ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
diff --git a/erts/preloaded/src/socket.erl b/erts/preloaded/src/socket.erl
index 8af052e149..d1053d88f9 100644
--- a/erts/preloaded/src/socket.erl
+++ b/erts/preloaded/src/socket.erl
@@ -20,11 +20,12 @@
 
 -module(socket).
 
+-compile(no_native).
 -compile({no_auto_import,[error/1]}).
 
 %% Administrative and "global" utility functions
 -export([
-	 on_load/0, on_load/1, on_load/2,
+	 on_load/0, on_load/1,
 	 info/0,
          ensure_sockaddr/1
         ]).
@@ -112,8 +113,8 @@
               msghdr/0,
               cmsghdr_level/0,
               cmsghdr_type/0,
-              cmsghdr_data/0,
-              cmsghdr/0,
+              %% cmsghdr_data/0,
+              cmsghdr_recv/0, cmsghdr_send/0,
 
               uint8/0,
               uint16/0,
@@ -311,7 +312,7 @@
 %% Int    - Raw level, sent down and used "as is".
 -type sockopt_level() :: otp |
                          socket |
-                         ip | ipv6 | tcp | udp | sctp | raw |
+                         ip | ipv6 | tcp | udp | sctp |
                          non_neg_integer().
 
 %% There are some options that are 'read-only'.
@@ -546,7 +547,7 @@
                     %% The maximum size of the control buffer is platform
                     %% specific. It is the users responsibility to ensure 
                     %% that its not exceeded.
-                    ctrl  := [cmsghdr()],
+                    ctrl  := [cmsghdr_recv()] | [cmsghdr_send()],
 
                     %% Only valid with recvmsg
                     flags := msghdr_flags()
@@ -555,7 +556,7 @@
 %% Even if we are able to decode both level and type, we may not be
 %% able to decode the data, in which case it will be a binary.
 
--type cmsghdr_level() :: socket | protocol() | integer().
+-type cmsghdr_level() :: socket | ip | ipv6 | integer().
 -type cmsghdr_type()  :: timestamp |
                          pktinfo |
                          tos |
@@ -564,18 +565,44 @@
                          credentials |
                          origdstaddr |
                          integer().
--type cmsghdr_data() :: timeval()      | % if level = socket and type = timstamp
-                        ip_pktinfo()   | % if level = ip and type = pktinfo
-                        ipv6_pktinfo() | % if level = ipv6 and type = pktinfo
-                        ip_tos()       | % if level = ip and type = tos
-                        integer()      | % if level = ip and type = ttl
-                        sockaddr_in4() | % if level = ip and type = origdstaddr
-                        binary().
--type cmsghdr() :: #{
-                     level := cmsghdr_level(),
-                     type  := cmsghdr_type(),
-                     data  := cmsghdr_data()
-                    }.
+%% Do we need this? See cmsghdr()
+%% -type cmsghdr_data() :: timeval()      | % if level = socket and type = timstamp
+%%                         ip_pktinfo()   | % if level = ip and type = pktinfo
+%%                         ipv6_pktinfo() | % if level = ipv6 and type = pktinfo
+%%                         ip_tos()       | % if level = ip and type = tos
+%%                         integer()      | % if level = ip and type = ttl
+%%                         sockaddr_in4() | % if level = ip and type = origdstaddr
+%%                         binary().
+%% -type cmsghdr() :: #{
+%%                      level := cmsghdr_level(),
+%%                      type  := cmsghdr_type(),
+%%                      data  := cmsghdr_data()
+%%                     }.
+
+-type cmsghdr_recv() :: 
+        #{level := socket,    type := timestamp,   data := timeval()}      |
+        #{level := socket,    type := rights,      data := binary()}       |
+        #{level := socket,    type := credentials, data := binary()}       |
+        #{level := socket,    type := integer(),   data := binary()}       |
+        #{level := ip,        type := tos,         data := ip_tos()}       |
+        #{level := ip,        type := ttl,         data := integer()}      |
+        #{level := ip,        type := pktinfo,     data := ip_pktinfo()}   |
+        #{level := ip,        type := origdstaddr, data := sockaddr_in4()} |
+        #{level := ip,        type := integer(),   data := binary()}       |
+        #{level := ipv6,      type := pktinfo,     data := ipv6_pktinfo()} |
+        #{level := ipv6,      type := integer(),   data := binary()}       |
+        #{level := integer(), type := integer(),   data := binary()}.
+
+
+-type cmsghdr_send() :: 
+        #{level := socket,    type := integer(), data := binary()} |
+        #{level := ip,        type := tos,       data := ip_tos()  | binary()} |
+        #{level := ip,        type := ttl,       data := integer() | binary()} |
+        #{level := ip,        type := integer(), data := binary()} |
+        #{level := ipv6,      type := integer(), data := binary()} |
+        #{level := udp,       type := integer(), data := binary()} |
+        #{level := integer(), type := integer(), data := binary()}.
+
 
 -define(SOCKET_DOMAIN_LOCAL, 1).
 -define(SOCKET_DOMAIN_UNIX,  ?SOCKET_DOMAIN_LOCAL).
@@ -630,10 +657,12 @@
 -define(SOCKET_OPT_LEVEL_UDP,            5).
 -define(SOCKET_OPT_LEVEL_SCTP,           6).
 
+%% *** OTP (socket) options
 -define(SOCKET_OPT_OTP_DEBUG,            1).
 -define(SOCKET_OPT_OTP_IOW,              2).
 -define(SOCKET_OPT_OTP_CTRL_PROC,        3).
 
+%% *** SOCKET (socket) options
 -define(SOCKET_OPT_SOCK_ACCEPTCONN,      1).
 %% -define(SOCKET_OPT_SOCK_ACCEPTFILTER,    2). % FreeBSD
 -define(SOCKET_OPT_SOCK_BINDTODEVICE,    3).
@@ -667,6 +696,7 @@
 -define(SOCKET_OPT_SOCK_TIMESTAMP,      31).
 -define(SOCKET_OPT_SOCK_TYPE,           32).
 
+%% *** IP (socket) options
 -define(SOCKET_OPT_IP_ADD_MEMBERSHIP,         1).
 -define(SOCKET_OPT_IP_ADD_SOURCE_MEMBERSHIP,  2).
 -define(SOCKET_OPT_IP_BLOCK_SOURCE,           3).
@@ -701,6 +731,7 @@
 -define(SOCKET_OPT_IP_TTL,                   32).
 -define(SOCKET_OPT_IP_UNBLOCK_SOURCE,        33).
 
+%% *** IPv6 (socket) options
 -define(SOCKET_OPT_IPV6_ADDRFORM,           1).
 -define(SOCKET_OPT_IPV6_ADD_MEMBERSHIP,     2).
 -define(SOCKET_OPT_IPV6_AUTHHDR,            3). % Obsolete?
@@ -734,6 +765,7 @@
 %% -define(SOCKET_OPT_IPV6_USE_MIN_MTU,       31). % FreeBSD
 -define(SOCKET_OPT_IPV6_V6ONLY,            32).
 
+%% *** TCP (socket) options
 -define(SOCKET_OPT_TCP_CONGESTION,      1).
 -define(SOCKET_OPT_TCP_CORK,            2).
 %% -define(SOCKET_OPT_TCP_INFO,            3).
@@ -748,8 +780,10 @@
 %% -define(SOCKET_OPT_TCP_SYNCNT,         12).
 %% -define(SOCKET_OPT_TCP_USER_TIMEOUT,   13).
 
+%% *** UDP (socket) options
 -define(SOCKET_OPT_UDP_CORK,            1).
 
+%% *** SCTP (socket) options
 %% -define(SOCKET_OPT_SCTP_ADAPTION_LAYER,          1).
 -define(SOCKET_OPT_SCTP_ASSOCINFO,               2).
 %% -define(SOCKET_OPT_SCTP_AUTH_ACTIVE_KEY,         3).
@@ -802,23 +836,10 @@ on_load() ->
     on_load(#{}).
 
 -spec on_load(Extra) -> ok when
-      Extra :: maps:map().
-
-on_load(Extra) when is_map(Extra) ->
-    on_load(atom_to_list(?MODULE), Extra).
-
--spec on_load(Path, Extra) -> ok when
-      Path  :: string(),
-      Extra :: maps:map().
+      Extra :: map().
 
-on_load(Path, Extra) when is_list(Path) andalso is_map(Extra) ->
-    on_load(nif_is_loaded(), Path, Extra).
-
-on_load(true, _Path, _Extra) ->
-    ok;
-on_load(false, Path, Extra) ->
-    %% ok = erlang:load_nif(Path, maps:put(timestamp, formated_timestamp(), Extra)).
-    ok = erlang:load_nif(Path, Extra).
+on_load(Extra) ->
+    ok = erlang:load_nif(atom_to_list(?MODULE), Extra).
 
 
 
@@ -1022,8 +1043,8 @@ bind(#socket{ref = SockRef}, Addrs, Action)
   when is_list(Addrs) andalso ((Action =:= add) orelse (Action =:= remove)) ->
     try
         begin
-            ensure_type(seqpacket, which_type(SockRef)),
-            ensure_proto(sctp, which_protocol(SockRef)),
+            ensure_type(SockRef, seqpacket),
+            ensure_proto(SockRef, sctp),
             validate_addrs(which_domain(SockRef), Addrs),
             nif_bind(SockRef, Addrs, Action)
         end
@@ -1508,38 +1529,6 @@ ensure_msghdr(_) ->
     einval().
 
 
-
-%% send(Sock, #{ctrl = Ctrl} = MsgHdr, Flags) when is_list(Ctrl) ->
-%%     case encode_cmsghdrs(Ctrl) of
-%%         undefined ->
-%%             send(Sock, maps:remove(ctrl, MsgHdr), Flags);
-%%         Ctrl2 ->
-%%             send(Sock, MsgHdr#{ctrl = Ctrl2}, Flags)
-%%     end.
-    
-%% encode_cmsghdrs([]) ->
-%%     undefined;
-%% encode_cmsghdrs(Hdrs) ->
-%%     encode_cmsghdrs(Hdrs, []).
-
-%% encode_cmsghdrs([], Acc) ->
-%%     list_to_binary(lists:reverse(Acc));
-%% encode_cmsghdrs([H|T], Acc) when is_binary(H) ->
-%%     encode_cmsghdrs(T, [H|Acc]);
-%% encode_cmsghdrs([#{level := Level,
-%%                    type  := Type,
-%%                    data  := Data} | T], Acc) ->
-%%     case nif_encode_cmsghdr(Level, Type, Data) of
-%%         {ok, Bin} when is_binary(Bin) ->
-%%             encode_cmsghdrs(T, [Bin | Acc]);
-%%         {error, _} = ERROR ->
-%%             ERROR
-%%     end.
-
-
-    
-    
-
 %% ===========================================================================
 %%
 %% writev - write data into multiple buffers
@@ -1924,7 +1913,8 @@ do_recvfrom(SockRef, BufSz, EFlags, Timeout)  ->
       Reason  :: term().
 
 recvmsg(Socket) ->
-    recvmsg(Socket, 0, 0, ?SOCKET_RECV_FLAGS_DEFAULT, ?SOCKET_RECV_TIMEOUT_DEFAULT).
+    recvmsg(Socket, 0, 0,
+            ?SOCKET_RECV_FLAGS_DEFAULT, ?SOCKET_RECV_TIMEOUT_DEFAULT).
 
 -spec recvmsg(Socket, Flags) -> {ok, MsgHdr} | {error, Reason} when
       Socket  :: socket(),
@@ -2118,6 +2108,12 @@ shutdown(#socket{ref = SockRef}, How) ->
                 ; (Socket, sctp, sctp_socket_option(), Value) -> ok | {error, Reason} when
       Socket :: socket(),
       Value  :: term(),
+      Reason :: term()
+                ; (Socket, Level, Key, Value) -> ok | {error, Reason} when
+      Socket :: socket(),
+      Level  :: non_neg_integer(),
+      Key    :: non_neg_integer(),
+      Value  :: binary(),
       Reason :: term().
 
 setopt(#socket{ref = SockRef}, Level, Key, Value) ->
@@ -2223,6 +2219,11 @@ getopt(#socket{ref = SockRef}, Level, Key) ->
 
 %% These are internal "shortcut" functions for the options
 %% domain, type and protocol.
+
+-spec which_domain(SockRef) -> Domain when
+      SockRef :: reference(),
+      Domain  :: domain().
+
 which_domain(SockRef) ->
     case nif_getopt(SockRef, true,
                     ?SOCKET_OPT_LEVEL_SOCKET, ?SOCKET_OPT_SOCK_DOMAIN) of
@@ -2233,6 +2234,10 @@ which_domain(SockRef) ->
     end.
         
 
+-spec which_type(SockRef) -> Type when
+      SockRef :: reference(),
+      Type    :: type().
+
 which_type(SockRef) ->
     case nif_getopt(SockRef, true,
                     ?SOCKET_OPT_LEVEL_SOCKET, ?SOCKET_OPT_SOCK_TYPE) of
@@ -2242,6 +2247,10 @@ which_type(SockRef) ->
             throw(ERROR)
     end.
 
+-spec which_protocol(SockRef) -> Protocol when
+      SockRef  :: reference(),
+      Protocol :: protocol().
+
 which_protocol(SockRef) ->
     case nif_getopt(SockRef, true,
                     ?SOCKET_OPT_LEVEL_SOCKET, ?SOCKET_OPT_SOCK_PROTOCOL) of
@@ -2409,6 +2418,57 @@ enc_setopt_key(Level, Opt, Domain, Type, Protocol) ->
 %% encode the value into an more "manageable" type.
 %% It also handles "aliases" (see linger).
 
+-spec enc_setopt_value(otp, otp_socket_option(),
+                       Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+                  ; (socket, socket_option(),
+                     Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (ip, ip_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (ipv6, ipv6_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (tcp, tcp_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (udp, udp_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (sctp, sctp_socket_option(),
+              Value, Domain, Type, Protocol) -> term() when
+      Value    :: term(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol()
+           ; (Level, Opt,
+              Value, Domain, Type, Protocol) -> term() when
+      Level    :: integer(),
+      Opt      :: integer(),
+      Value    :: binary(),
+      Domain   :: domain(),
+      Type     :: type(),
+      Protocol :: protocol().
+      
 enc_setopt_value(otp, debug, V, _, _, _) when is_boolean(V) ->
     V;
 enc_setopt_value(otp, iow, V, _, _, _) when is_boolean(V) ->
@@ -2762,8 +2822,8 @@ enc_setopt_value(sctp, rtoinfo, #{assoc_id := AssocId,
 enc_setopt_value(sctp = L, Opt, V, _D, _T, _P) ->
     not_supported({L, Opt, V});
 
-enc_setopt_value(raw = L, Opt, _V, _D, _T, _P) ->
-    not_supported({L, Opt});
+%% enc_setopt_value(raw = L, Opt, _V, _D, _T, _P) ->
+%%     not_supported({L, Opt});
 
 %% Is this correct? What about getopt?
 enc_setopt_value(L, Opt, V, _, _, _)
@@ -2788,10 +2848,10 @@ enc_getopt_key(Level, Opt, Domain, Type, Protocol) ->
 %% +++ Decode getopt value +++
 %%
 %% For the most part, we simply let the value pass through, but for some
-%% values we do an actual decode.
+%% values we may need to do an actual decode.
 %%
 
-%% Let the user deal with this...
+%% Let the user deal with this for now...
 dec_getopt_value(_L, _Opt, V, _D, _T, _P) ->
     V.
 
@@ -3361,15 +3421,26 @@ tdiff(T1, T2) ->
 %%
 %% ===========================================================================
 
+-spec not_supported(What) -> no_return() when
+      What :: term().
+
 not_supported(What) ->
     error({not_supported, What}).
 
+-spec unknown(What) -> no_return() when
+      What :: term().
+
 unknown(What) ->
     error({unknown, What}).
 
+-spec einval() -> no_return().
+
 einval() ->
     error(einval).
 
+-spec error(Reason) -> no_return() when
+      Reason :: term().
+
 error(Reason) ->
     throw({error, Reason}).
 
@@ -3380,71 +3451,69 @@ error(Reason) ->
 %%
 %% ===========================================================================
 
-nif_is_loaded() -> false.
-
 nif_info() ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_open(_Domain, _Type, _Protocol, _Extra) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_bind(_SRef, _SockAddr) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_bind(_SRef, _SockAddrs, _Action) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_connect(_SRef, _SockAddr) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_finalize_connection(_SRef) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_listen(_SRef, _Backlog) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_accept(_SRef, _Ref) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_send(_SockRef, _SendRef, _Data, _Flags) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_sendto(_SRef, _SendRef, _Data, _Dest, _Flags) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_sendmsg(_SRef, _SendRef, _MsgHdr, _Flags) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_recv(_SRef, _RecvRef, _Length, _Flags) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_recvfrom(_SRef, _RecvRef, _Length, _Flags) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_recvmsg(_SRef, _RecvRef, _BufSz, _CtrlSz, _Flags) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_cancel(_SRef, _Op, _Ref) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_close(_SRef) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_shutdown(_SRef, _How) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_finalize_close(_SRef) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_setopt(_Ref, _IsEnc, _Lev, _Key, _Val) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_getopt(_Ref, _IsEnc, _Lev, _Key) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_sockname(_Ref) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).
 
 nif_peername(_Ref) ->
-    erlang:error(badarg).
+    erlang:nif_error(undef).