curl/lib/if2ip.c

/*****************************************************************************
 *                                  _   _ ____  _     
 *  Project                     ___| | | |  _ \| |    
 *                             / __| | | | |_) | |    
 *                            | (__| |_| |  _ <| |___ 
 *                             \___|\___/|_| \_\_____|
 *
 *  The contents of this file are subject to the Mozilla Public License
 *  Version 1.0 (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.mozilla.org/MPL/
 *
 *  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.
 *
 *  The Original Code is Curl.
 *
 *  The Initial Developer of the Original Code is Daniel Stenberg.
 *
 *  Portions created by the Initial Developer are Copyright (C) 1998.
 *  All Rights Reserved.
 *
 * ------------------------------------------------------------
 * Main author:
 * - Daniel Stenberg <Daniel.Stenberg@haxx.nu>
 *
 * 	http://curl.haxx.nu
 *
 * $Source$
 * $Revision$
 * $Date$
 * $Author$
 * $State$
 * $Locker$
 *
 * ------------------------------------------------------------
 ****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "setup.h"

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#if ! defined(WIN32) && ! defined(__BEOS__)

#include <sys/socket.h>
#include <netinet/in.h>
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#include <netinet/in.h>
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#include <sys/ioctl.h>

/* -- if2ip() -- */
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif

#ifdef HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif

#define SYS_ERROR -1

char *if2ip(char *interface)
{
  int dummy;
  char *ip=NULL;
  
  if(!interface)
    return NULL;

  dummy = socket(AF_INET, SOCK_STREAM, 0);
  if (SYS_ERROR == dummy) {
    return NULL;
  }
  else {
    struct ifreq req;
    memset(&req, 0, sizeof(req));
    strcpy(req.ifr_name, interface);
    req.ifr_addr.sa_family = AF_INET;
    if (SYS_ERROR == ioctl(dummy, SIOCGIFADDR, &req, sizeof(req))) {
      return NULL;
    }
    else {
      struct in_addr in;

      struct sockaddr_in *s = (struct sockaddr_in *)&req.ifr_dstaddr;
      memcpy(&in, &(s->sin_addr.s_addr), sizeof(in));
      ip = (char *)strdup(inet_ntoa(in));
    }
    close(dummy);
  }
  return ip;
}

/* -- end of if2ip() -- */
#else
#define if2ip(x) NULL
#endif