The Tcpdump Group git mirrors - libpcap/blob - testprogs/activatetest.c

   1 #include <stdio.h>
   2 #include <pcap.h>
   3
   4 #define CAPTURE_DEVICE "nosuchdevice"
   5
   6 int main(void)
   7 {
   8         /*
   9          * When trying to use libpcap on a device that does not exist, the
  10          * expected behaviour is that pcap_create() does not return an error,
  11          * and pcap_activate() does return an error, and the error code
  12          * specifically tells that the interface does not exist.  tcpdump
  13          * depends on this semantics to accept integer indices instead of
  14          * device names.  This test provides means to verify the actual
  15          * behaviour, which is specific to each libpcap module.
  16          */
  17         char errbuf[PCAP_ERRBUF_SIZE];
  18         printf("Trying to use capture device \"%s\"...\n", CAPTURE_DEVICE);
  19         pcap_t *p = pcap_create(CAPTURE_DEVICE, errbuf);
  20         if (! p) {
  21                 fprintf(stderr,
  22                         "FAIL: Unexpected error from pcap_create() (%s).\n",
  23                         errbuf);
  24                 return 1;
  25         }
  26         int ret = 1, err = pcap_activate(p);
  27         switch (err) {
  28         case 0:
  29                 fprintf(stderr, "FAIL: No error from pcap_activate().\n");
  30                 break;
  31         case PCAP_ERROR:
  32                 fprintf(stderr, "FAIL: Generic error from pcap_activate().\n");
  33                 break;
  34         case PCAP_ERROR_PERM_DENIED:
  35                 fprintf(stderr, "FAIL: Permission denied from pcap_activate(), "
  36                         "retry with higher privileges.\n");
  37                 break;
  38         case PCAP_ERROR_NO_SUCH_DEVICE:
  39                 printf("PASS: Correct specific error from pcap_activate().\n");
  40                 ret = 0;
  41                 break;
  42         default:
  43                 fprintf(stderr,
  44                         "FAIL: Unexpected error %d from pcap_activate().\n",
  45                         err);
  46         }
  47         pcap_close(p);
  48         return ret;
  49 }