release/src/router/miniupnpd/getifaddr.c

   1 /* $Id: getifaddr.c,v 1.9 2008/10/15 10:16:28 nanard Exp $ */
   2 /* MiniUPnP project
   3  * http://miniupnp.free.fr/ or http://miniupnp.tuxfamily.org/
   4  * (c) 2006-2008 Thomas Bernard
   5  * This software is subject to the conditions detailed
   6  * in the LICENCE file provided within the distribution */
   7
   8 #include <string.h>
   9 #include <syslog.h>
  10 #include <unistd.h>
  11 #include <sys/ioctl.h>
  12 #include <sys/types.h>
  13 #include <sys/socket.h>
  14 #include <net/if.h>
  15 #include <arpa/inet.h>
  16 #include <netinet/in.h>
  17 #if defined(sun)
  18 #include <sys/sockio.h>
  19 #endif
  20
  21 #include "getifaddr.h"
  22
  23 int
  24 getifaddr(const char * ifname, char * buf, int len)
  25 {
  26         /* SIOCGIFADDR struct ifreq *  */
  27         int s;
  28         struct ifreq ifr;
  29         int ifrlen;
  30         struct sockaddr_in * addr;
  31         ifrlen = sizeof(ifr);
  32         if(!ifname || ifname[0]=='\0')
  33                 return -1;
  34         s = socket(PF_INET, SOCK_DGRAM, 0);
  35         if(s < 0)
  36         {
  37                 syslog(LOG_ERR, "socket(PF_INET, SOCK_DGRAM): %m");
  38                 return -1;
  39         }
  40         strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
  41         if(ioctl(s, SIOCGIFADDR, &ifr, &ifrlen) < 0)
  42         {
  43                 syslog(LOG_ERR, "ioctl(s, SIOCGIFADDR, ...): %m");
  44                 close(s);
  45                 return -1;
  46         }
  47         addr = (struct sockaddr_in *)&ifr.ifr_addr;
  48         if(!inet_ntop(AF_INET, &addr->sin_addr, buf, len))
  49         {
  50                 syslog(LOG_ERR, "inet_ntop(): %m");
  51                 close(s);
  52                 return -1;
  53         }
  54         close(s);
  55         return 0;
  56 }
  57