/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1997-2011. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved online at http://www.erlang.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* %CopyrightEnd%
*/
/*
* Interface functions to different versions of gethostbyname
*/
#ifdef VXWORKS
#include <vxWorks.h>
#include <stdio.h>
#include <semLib.h>
#include <hostLib.h>
#include <resolvLib.h>
#include <string.h>
#include <sys/socket.h>
#include <errno.h>
#include <symLib.h>
#include <sysSymTbl.h>
#elif __WIN32__
#include <winsock2.h>
#include <windows.h>
#include <winbase.h>
#else /* unix of some kind */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/param.h>
#endif
/* common to all platforms */
#include "eidef.h"
#include "ei_resolve.h"
#include "ei_locking.h"
#ifdef HAVE_GETHOSTBYNAME_R
void ei_init_resolve(void)
{
return; /* Do nothing */
}
#else /* !HAVE_GETHOSTBYNAME_R */
/* we have our own in that case */
/* Make sure this semaphore has been initialized somewhere first. This
* should probably be done from 'erl'_init() but we do it in the first
* call to gethostbyname_r() or gethostbyaddr_r().
*/
/* FIXME we don't want globals here, but maybe ok? */
#ifdef _REENTRANT
static ei_mutex_t *ei_gethost_sem = NULL;
#endif /* _REENTRANT */
static int ei_resolve_initialized = 0;
#ifndef __WIN32__
int h_errno;
#endif
#ifdef DEBUG
#define DEBUGF(X) fprintf X
#else
#define DEBUGF(X) /* Nothing */
#endif
#ifdef VXWORKS
/* FIXME problem for threaded ? */
static struct hostent *(*sens_gethostbyname)(const char *name,
char *, int) = NULL;
static struct hostent *(*sens_gethostbyaddr)(const char *addr,
char *, int) = NULL;
#endif
#ifdef VXWORKS
static int verify_dns_configuration(void);
#endif
/*
* If we find SENS resolver, use the functions found there, i.e.
* resolvGetHostByName() and resolvGetHostByAddr(). Otherwise we use
* our own, which are just wrappers around hostGetByName() and
* hostGetByAddr(). Here we look up the functions.
*/
void ei_init_resolve(void)
{
#ifdef VXWORKS
void *sym;
SYM_TYPE symtype;
if (symFindByName(sysSymTbl,"resolvGetHostByName",
(char **)&sym,&symtype) == OK &&
verify_dns_configuration()) {
sens_gethostbyname = sym;
DEBUGF((stderr,"found SENS resolver - using it for gethostbyname()\n"));
if (symFindByName(sysSymTbl,"resolvGetHostByAddr",
(char **)&sym,&symtype) == OK) {
sens_gethostbyaddr = sym;
DEBUGF((stderr,"found SENS resolver - "
"using it for gethostbyaddr()\n"));
}
else {
DEBUGF((stderr,"SENS resolver not found - "
"using default gethostbyaddr()\n"));
}
}
else {
DEBUGF((stderr,"SENS resolver not found - "
"using default gethostbyname()\n"));
}
#endif /* VXWORKS */
#ifdef _REENTRANT
ei_gethost_sem = ei_mutex_create();
#endif /* _REENTRANT */
ei_resolve_initialized = 1;
}
#ifdef VXWORKS
/*
** Function to verify the DNS configuration on VwXorks SENS.
** Actually configures to a default value if unconfigured...
*/
static int verify_dns_configuration(void)
{
/* FIXME problem for threaded ? */
static char resolv_params[sizeof(RESOLV_PARAMS_S)];
void (*rpg)(char *);
STATUS (*rps)(char *);
SYM_TYPE dummy;
int get_result, set_result;
get_result = symFindByName(sysSymTbl,"resolvParamsGet", (char **) &rpg, &dummy);
set_result = symFindByName(sysSymTbl,"resolvParamsSet", (char **) &rps, &dummy);
if (!(get_result == OK &&
set_result == OK))
return -1;
(*rpg)(resolv_params);
if (*resolv_params == '\0') {
/* It exists, but is not configured, ei_connect would fail
if we left it this way... The best we can do is to configure
it to use the local host database on the card, as a fallback */
*resolv_params = (char) 1;
fprintf(stderr,"Trying to fix up DNS configuration.\n");
if (((*rps)(resolv_params)) != OK)
return -1;
}
return 0;
}
#endif
/*
* Copy the contents of one struct hostent to another, i.e. don't just
* copy the pointers, copy all the data and create new pointers, etc.
* User must provide a secondary buffer to which the host data can be copied.
*
* Returns 0 on success or -1 if buffer is too small for host data
*/
/* a couple of helpers
* align: increment buf until it is dword-aligned, reduce len by same amount.
* advance: increment buf by n bytes, reduce len by same amount .
*/
#if defined SIZEOF_VOID_P
#define ALIGNBYTES (SIZEOF_VOID_P - 1)
#else
#define ALIGNBYTES (sizeof(void*) - 1)
#endif
#define align_buf(buf,len) for (;(((unsigned)buf) & ALIGNBYTES); (buf)++, len--)
#define advance_buf(buf,len,n) ((buf)+=(n),(len)-=(n))
/* "and now the tricky part..." */
static int copy_hostent(struct hostent *dest, const struct hostent *src, char *buffer, int buflen)
{
char **pptr;
int len;
char **src_aliases = NULL;
char **src_addr_list = NULL;
/* fix initial buffer alignment */
align_buf(buffer, buflen);
/* copy the data into our buffer... */
/* first the easy ones! */
dest->h_length = src->h_length;
dest->h_addrtype = src->h_addrtype;
/* h_name */
dest->h_name = buffer;
len = strlen(src->h_name);
if (buflen < len+1) return -1;
memmove((char *)dest->h_name,src->h_name,len);
buffer[len] = (char)0;
advance_buf(buffer,buflen,len+1);
/* traverse alias list, collecting the pointers */
align_buf(buffer, buflen);
pptr = (char **)buffer;
dest->h_aliases = pptr; /* save head of pointer array */
src_aliases = src->h_aliases;
while(*(src_aliases)) {
if (buflen < sizeof(*pptr)) return -1;
*pptr = src_aliases;
advance_buf(buffer,buflen,sizeof(*pptr));
src_aliases++;
pptr++;
}
if (buflen < sizeof(*pptr)) return -1;
*pptr = NULL;
advance_buf(buffer,buflen,sizeof(*pptr));
/* go back to saved position & transfer the alias data */
pptr = dest->h_aliases;
while (*pptr) {
len = strlen(*pptr);
if (buflen < len+1) return -1;
memmove(buffer,*pptr,len); /* copy data to local buffer */
buffer[len] = (char)0;
*pptr = buffer; /* point to own copy now */
advance_buf(buffer,buflen,len+1);
pptr++;
}
/* traverse address list, collecting the pointers */
align_buf(buffer, buflen);
pptr = (char **)buffer;
dest->h_addr_list = pptr; /* save head of pointer array */
src_addr_list = src->h_addr_list;
while(*(src_addr_list)) {
if (buflen < sizeof(*pptr)) return -1;
*pptr = *src_addr_list;
advance_buf(buffer,buflen,sizeof(*pptr));
src_addr_list++;
pptr++;
}
if (buflen < sizeof(*pptr)) return -1;
*pptr = NULL;
advance_buf(buffer,buflen,sizeof(*pptr));
/* go back to saved position & transfer the addresses */
/* align_buf(buffer, buflen); */
pptr = dest->h_addr_list;
while (*pptr) {
len = src->h_length;
if (buflen < len+1) return -1;
memmove(buffer,*pptr,len); /* copy data to local buffer */
buffer[len]=(char)0; /* not sure if termination is necessary */
*pptr = buffer; /* point to own copy now */
advance_buf(buffer,buflen,len+1);
pptr++;
}
if (buflen < 0) return -1;
return 0;
}
/* This function is a pseudo-reentrant version of gethostbyname(). It
* uses locks to serialize the call to the regular (non-reentrant)
* gethostbyname() and then copies the data into the user-provided
* buffers. It's not pretty but it works.
*
* name - name of host to look up
* hostp - user-supplied structure for returning host entry
* buffer - user-supplied buffer: storage for the copied host data
* buflen - length of user-supplied buffer
* h_errnop - buffer for return status
*
* Returns values as for gethostbyname(). Additionally, sets
* errno=ERANGE and returns NULL if buffer is too small for host data.
*/
static struct hostent *my_gethostbyname_r(const char *name,
struct hostent *hostp,
char *buffer,
int buflen,
int *h_errnop)
{
struct hostent dest;
struct hostent *src;
struct hostent *rval = NULL;
/* FIXME this should have been done in 'erl'_init()? */
if (!ei_resolve_initialized) ei_init_resolve();
#ifdef _REENTRANT
/* === BEGIN critical section === */
if (ei_mutex_lock(ei_gethost_sem,0) != 0) {
*h_errnop = NO_RECOVERY;
return NULL;
}
#endif /* _REENTRANT */
/* lookup the data */
if ((src = ei_gethostbyname(name))) {
/* copy to caller's buffer */
if (!copy_hostent(&dest,src,buffer,buflen)) {
/* success */
*hostp = dest;
*h_errnop = 0;
rval = hostp;
}
else {
/* failure - buffer size */
#ifdef __WIN32__
SetLastError(ERROR_INSUFFICIENT_BUFFER);
#else
errno = ERANGE;
#endif
*h_errnop = 0;
}
}
else {
/* failure - lookup */
#ifdef __WIN32__
*h_errnop = WSAGetLastError();
#else
*h_errnop = h_errno;
#endif
}
#ifdef _REENTRANT
/* === END critical section === */
ei_mutex_unlock(ei_gethost_sem);
#endif /* _REENTRANT */
return rval;
}
static struct hostent *my_gethostbyaddr_r(const char *addr,
int length,
int type,
struct hostent *hostp,
char *buffer,
int buflen,
int *h_errnop)
{
struct hostent dest;
struct hostent *src;
struct hostent *rval = NULL;
/* FIXME this should have been done in 'erl'_init()? */
if (!ei_resolve_initialized) ei_init_resolve();
#ifdef _REENTRANT
/* === BEGIN critical section === */
if (ei_mutex_lock(ei_gethost_sem,0) != 0) {
*h_errnop = NO_RECOVERY;
return NULL;
}
#endif /* _REENTRANT */
/* lookup the data */
if ((src = ei_gethostbyaddr(addr,length,type))) {
/* copy to caller's buffer */
if (!copy_hostent(&dest,src,buffer,buflen)) {
/* success */
*hostp = dest;
*h_errnop = 0;
rval = hostp;
}
else {
/* failure - buffer size */
#ifdef __WIN32__
SetLastError(ERROR_INSUFFICIENT_BUFFER);
#else
errno = ERANGE;
#endif
*h_errnop = 0;
}
}
else {
/* failure - lookup */
#ifdef __WIN32__
*h_errnop = WSAGetLastError();
#else
*h_errnop = h_errno;
#endif
}
#ifdef _REENTRANT
/* === END critical section === */
ei_mutex_unlock(ei_gethost_sem);
#endif /* _REENTRANT */
return rval;
}
#endif /* !HAVE_GETHOSTBYNAME_R */
#ifdef __WIN32__
struct hostent *ei_gethostbyname(const char *name)
{
return gethostbyname(name);
}
struct hostent *ei_gethostbyaddr(const char *addr, int len, int type)
{
return gethostbyaddr(addr, len, type);
}
#elif VXWORKS
/* these are a couple of substitutes for the real thing when we run on
* stock vxworks (i.e. no sens).
*
* len and type are ignored, but we make up some reasonable values and
* insert them
*/
static struct hostent *my_gethostbyname(const char *name)
{
/* FIXME problem for threaded ? */
static struct hostent h;
static char hostname[EI_MAXHOSTNAMELEN+1];
static char *aliases[1] = {NULL};
static char *addrp[2] = {NULL,NULL};
static unsigned long addr = 0;
strcpy(hostname,name);
if ((addr = (unsigned long)hostGetByName(hostname)) == ERROR) {
h_errno = HOST_NOT_FOUND;
return NULL;
}
h_errno = 0;
h.h_name = hostname;
h.h_aliases = aliases;
h.h_length = 4;
h.h_addrtype = AF_INET;
addrp[0] = (char *)&addr;
h.h_addr_list = addrp;
return &h;
}
static struct hostent *my_gethostbyaddr(const char *addr, int len, int type)
{
/* FIXME problem for threaded ? */
static struct hostent h;
static char hostname[EI_MAXHOSTNAMELEN+1];
static char *aliases[1] = { NULL };
static unsigned long inaddr;
static char *addrp[2] = {(char *)&inaddr, NULL};
memmove(&inaddr,addr,sizeof(inaddr));
if ((hostGetByAddr(inaddr,hostname)) == ERROR) {
h_errno = HOST_NOT_FOUND;
return NULL;
}
h_errno = 0;
h.h_name = hostname;
h.h_aliases = aliases;
h.h_length = 4;
h.h_addrtype = AF_INET;
h.h_addr_list = addrp;
return &h;
}
/* use sens functions for these, if found. */
struct hostent *ei_gethostbyname(const char *name)
{
struct hostent *h = NULL;
if (!sens_gethostbyname) {
h = my_gethostbyname(name);
}
else {
/* FIXME problem for threaded ? */
static char buf[1024];
h = sens_gethostbyname(name,buf,1024);
}
return h;
}
struct hostent *ei_gethostbyaddr(const char *addr, int len, int type)
{
struct hostent *h = NULL;
if (!sens_gethostbyaddr) {
h = my_gethostbyaddr(addr,len,type);
}
else {
/* FIXME problem for threaded ? */
static char buf[1024];
h = sens_gethostbyaddr(addr,buf,1024);
}
return h;
}
struct hostent *ei_gethostbyaddr_r(const char *addr,
int length,
int type,
struct hostent *hostp,
char *buffer,
int buflen,
int *h_errnop)
{
struct hostent *h = NULL;
/* use own func if sens function not available */
if (!sens_gethostbyaddr) {
h = my_gethostbyaddr_r(addr,length,type,hostp,buffer,buflen,h_errnop);
}
else {
if (!(h = sens_gethostbyaddr(addr,buffer,buflen))) {
/* sens returns status via errno */
*h_errnop = errno;
}
else {
*hostp = *h;
*h_errnop = 0;
}
}
return h;
}
struct hostent *ei_gethostbyname_r(const char *name,
struct hostent *hostp,
char *buffer,
int buflen,
int *h_errnop)
{
struct hostent *h = NULL;
/* use own func if sens function not available */
if (!sens_gethostbyname) {
h = my_gethostbyname_r(name,hostp,buffer,buflen,h_errnop);
}
else {
if (!(h = sens_gethostbyname(name,buffer,buflen))) {
/* sens returns status via errno */
*h_errnop = errno;
}
else {
*hostp = *h;
*h_errnop = 0;
}
}
return h;
}
#else /* unix of some kind */
struct hostent *ei_gethostbyname(const char *name)
{
return gethostbyname(name);
}
struct hostent *ei_gethostbyaddr(const char *addr, int len, int type)
{
return gethostbyaddr(addr, len, type);
}
struct hostent *ei_gethostbyaddr_r(const char *addr,
int length,
int type,
struct hostent *hostp,
char *buffer,
int buflen,
int *h_errnop)
{
#if (EI_THREADS == false)
/* threads disabled, no need to call reentrant function */
return gethostbyaddr(addr, length, type);
#else
#ifndef HAVE_GETHOSTBYNAME_R
return my_gethostbyaddr_r(addr,length,type,hostp,buffer,buflen,h_errnop);
#else
#if (defined(__GLIBC__) || (__FreeBSD_version >= 602000) || defined(__DragonFly__))
struct hostent *result;
gethostbyaddr_r(addr, length, type, hostp, buffer, buflen, &result,
h_errnop);
return result;
#else
return gethostbyaddr_r(addr,length,type,hostp,buffer,buflen,h_errnop);
#endif
#endif
#endif
}
struct hostent *ei_gethostbyname_r(const char *name,
struct hostent *hostp,
char *buffer,
int buflen,
int *h_errnop)
{
#ifndef _REENTRANT
/* threads disabled, no need to call reentrant function */
return gethostbyname(name);
#else
#ifndef HAVE_GETHOSTBYNAME_R
return my_gethostbyname_r(name,hostp,buffer,buflen,h_errnop);
#else
#if (defined(__GLIBC__) || (__FreeBSD_version >= 602000) || defined(__DragonFly__))
struct hostent *result;
gethostbyname_r(name, hostp, buffer, buflen, &result, h_errnop);
return result;
#else
return gethostbyname_r(name,hostp,buffer,buflen,h_errnop);
#endif
#endif
#endif
}
#endif /* vxworks, win, unix */
