package/ead/src/pfc.c

   1 /*
   2  * Small pcap precompiler
   3  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <sys/types.h>
  16 #include <sys/time.h>
  17 #include <string.h>
  18 #include <stdlib.h>
  19 #include <pcap.h>
  20
  21 int main (int argc, char ** argv)
  22 {
  23         struct bpf_program filter;
  24         pcap_t *pc;
  25         int i;
  26
  27         if (argc != 2)
  28         {
  29                 printf ("Usage: %s <expression>\n", argv[0]);
  30                 return 1;
  31         }
  32
  33         pc = pcap_open_dead(DLT_EN10MB, 1500);
  34         if (pcap_compile(pc, &filter, argv[1], 1, 0) != 0) {
  35                 printf("error in active-filter expression: %s\n", pcap_geterr(pc));
  36                 return 1;
  37         }
  38
  39         printf("/* precompiled expression: %s */\n\n"
  40                 "static struct bpf_insn pktfilter_insns[] = {\n",
  41                 argv[1]);
  42
  43         for (i = 0; i < filter.bf_len; i++) {
  44                 struct bpf_insn *in = &filter.bf_insns[i];
  45                 printf("\t{ .code = 0x%04x, .jt = 0x%02x, .jf = 0x%02x, .k = 0x%08x },\n", in->code, in->jt, in->jf, in->k);
  46         }
  47         printf("};\n\n"
  48                 "static struct bpf_program pktfilter = {\n"
  49                 "\t.bf_len = %d,\n"
  50                 "\t.bf_insns = pktfilter_insns,\n"
  51                 "};\n", filter.bf_len);
  52         return 0;
  53
  54 }