src/network/if_nametoindex.c

   1 #define _GNU_SOURCE
   2 #include <net/if.h>
   3 #include <sys/socket.h>
   4 #include <sys/ioctl.h>
   5 #include <string.h>
   6 #include "syscall.h"
   7
   8 unsigned if_nametoindex(const char *name)
   9 {
  10         struct ifreq ifr;
  11         int fd, r;
  12
  13         if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) return 0;
  14         strncpy(ifr.ifr_name, name, sizeof ifr.ifr_name);
  15         r = ioctl(fd, SIOCGIFINDEX, &ifr);
  16         __syscall(SYS_close, fd);
  17         return r < 0 ? 0 : ifr.ifr_ifindex;
  18 }