channel-switch.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <sys/socket.h>
   4 #include <net/if.h>
   5 #include <sys/ioctl.h>
   6 #include <unistd.h>
   7 #include "wireless-lite.h"
   8
   9 /* returns 0 on success. */
  10 int set_channel(const char* iface, int channel) {
  11         int s;
  12         if((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
  13                 perror("socket");
  14                 return 1;
  15         }
  16
  17         struct iwreq req = {.u.freq.m = channel, .u.freq.flags = IW_FREQ_FIXED};
  18         snprintf(req.ifr_name, IFNAMSIZ, "%s", iface);
  19
  20         int ret;
  21         if((ret = ioctl(s, SIOCSIWFREQ, &req) < 0)) {
  22 #ifndef LIBRARY_CODE
  23                 perror("ioctl");
  24 #endif
  25         }
  26         close(s);
  27         return ret;
  28 }
  29
  30 #ifndef LIBRARY_CODE
  31 static int usage(char* argv0) {
  32         dprintf(2, "usage: %s interface channel\n", argv0);
  33         return 1;
  34 }
  35
  36 int main(int argc, char** argv) {
  37         if(argc != 3) return usage(argv[0]);
  38         return set_channel(argv[1], atoi(argv[2]));
  39 }
  40 #endif
  41