package/wprobe/src/filter/pfc.c

   1 #include <arpa/inet.h>
   2 #include <sys/types.h>
   3 #include <sys/time.h>
   4 #include <string.h>
   5 #include <stdint.h>
   6 #include <stdlib.h>
   7
   8 #include <pcap.h>
   9 #include <pcap-bpf.h>
  10
  11 struct wprobe_filter_hdr {
  12         char name[32];
  13         uint32_t len;
  14 } hdr;
  15
  16 int main (int argc, char ** argv)
  17 {
  18     struct  bpf_program filter;
  19     pcap_t  *pc;
  20         int i;
  21
  22     if (argc != 3)
  23     {
  24                 fprintf(stderr, "Usage: %s <name> <expression>\n", argv[0]);
  25                 return 1;
  26     }
  27
  28     pc = pcap_open_dead(DLT_IEEE802_11_RADIO, 256);
  29     if (pcap_compile(pc, &filter, argv[2], 1, 0) != 0)
  30         {
  31                 pcap_perror(pc, argv[0]);
  32                 exit(1);
  33         }
  34
  35         /* fix up for linux */
  36         for (i = 0; i < filter.bf_len; i++) {
  37                 struct bpf_insn *bi = &filter.bf_insns[i];
  38                 switch(BPF_CLASS(bi->code)) {
  39                 case BPF_RET:
  40                         if (BPF_MODE(bi->code) == BPF_K) {
  41                                 if (bi->k != 0)
  42                                         bi->k = 65535;
  43                         }
  44                         break;
  45                 }
  46                 bi->code = ntohs(bi->code);
  47                 bi->k = ntohl(bi->k);
  48         }
  49
  50         memset(&hdr, 0, sizeof(hdr));
  51         strncpy(hdr.name, argv[1], sizeof(hdr.name));
  52         hdr.len = htonl(filter.bf_len);
  53         fwrite(&hdr, sizeof(hdr), 1, stdout);
  54         fwrite(filter.bf_insns, 8, filter.bf_len, stdout);
  55         fflush(stdout);
  56
  57     return 0;
  58 }