bpfc.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2011 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,
   4  * Swiss federal institute of technology (ETH Zurich)
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <getopt.h>
  11 #include <ctype.h>
  12 #include <unistd.h>
  13 #include <sys/fsuid.h>
  14
  15 #include "xmalloc.h"
  16 #include "xutils.h"
  17 #include "die.h"
  18 #include "bpf.h"
  19
  20 static const char *short_options = "vhi:VdbD";
  21 static const struct option long_options[] = {
  22         {"input",       required_argument,      NULL, 'i'},
  23         {"verbose",     no_argument,            NULL, 'V'},
  24         {"decimal",     no_argument,            NULL, 'D'},
  25         {"bypass",      no_argument,            NULL, 'b'},
  26         {"dump",        no_argument,            NULL, 'd'},
  27         {"version",     no_argument,            NULL, 'v'},
  28         {"help",        no_argument,            NULL, 'h'},
  29         {NULL, 0, NULL, 0}
  30 };
  31
  32 extern int compile_filter(char *file, int verbose, int bypass, int decimal);
  33
  34 static void help(void)
  35 {
  36         printf("\nbpfc %s, a tiny BPF compiler\n", VERSION_STRING);
  37         puts("http://www.netsniff-ng.org\n\n"
  38              "Usage: bpfc [options] || bpfc <program>\n"
  39              "Options:\n"
  40              "  -i|--input <program/->  Berkeley Packet Filter file/stdin\n"
  41              "  -D|--decimal            Decimal output, e.g. for xt_bpf\n"
  42              "  -V|--verbose            Be more verbose\n"
  43              "  -b|--bypass             Bypass filter validation (e.g. for bug testing)\n"
  44              "  -d|--dump               Dump supported instruction table\n"
  45              "  -v|--version            Print version\n"
  46              "  -h|--help               Print this help\n\n"
  47              "Examples:\n"
  48              "  bpfc fubar\n"
  49              "  bpfc -Dbi fubar\n"
  50              "  bpfc -   (read from stdin)\n\n"
  51              "Please report bugs to <bugs@netsniff-ng.org>\n"
  52              "Copyright (C) 2011-2013 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,\n"
  53              "Swiss federal institute of technology (ETH Zurich)\n"
  54              "License: GNU GPL version 2.0\n"
  55              "This is free software: you are free to change and redistribute it.\n"
  56              "There is NO WARRANTY, to the extent permitted by law.\n");
  57         die();
  58 }
  59
  60 static void version(void)
  61 {
  62         printf("\nbpfc %s, a tiny BPF compiler\n", VERSION_STRING);
  63         puts("http://www.netsniff-ng.org\n\n"
  64              "Please report bugs to <bugs@netsniff-ng.org>\n"
  65              "Copyright (C) 2011-2013 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,\n"
  66              "Swiss federal institute of technology (ETH Zurich)\n"
  67              "License: GNU GPL version 2.0\n"
  68              "This is free software: you are free to change and redistribute it.\n"
  69              "There is NO WARRANTY, to the extent permitted by law.\n");
  70         die();
  71 }
  72
  73 int main(int argc, char **argv)
  74 {
  75         int ret, verbose = 0, c, opt_index, bypass = 0, decimal = 0;
  76         char *file = NULL;
  77
  78         setfsuid(getuid());
  79         setfsgid(getgid());
  80
  81         if (argc == 1)
  82                 help();
  83
  84         while ((c = getopt_long(argc, argv, short_options,
  85                                 long_options, &opt_index)) != EOF) {
  86                 switch (c) {
  87                 case 'h':
  88                         help();
  89                         break;
  90                 case 'v':
  91                         version();
  92                         break;
  93                 case 'V':
  94                         verbose = 1;
  95                         break;
  96                 case 'D':
  97                         decimal = 1;
  98                         break;
  99                 case 'b':
 100                         bypass = 1;
 101                         break;
 102                 case 'd':
 103                         bpf_dump_op_table();
 104                         die();
 105                 case 'i':
 106                         file = xstrdup(optarg);
 107                         break;
 108                 case '?':
 109                         switch (optopt) {
 110                         case 'i':
 111                                 panic("Option -%c requires an argument!\n",
 112                                       optopt);
 113                         default:
 114                                 if (isprint(optopt))
 115                                         printf("Unknown option character `0x%X\'!\n", optopt);
 116                                 die();
 117                         }
 118                 default:
 119                         break;
 120                 }
 121         }
 122
 123         if (argc == 2)
 124                 file = xstrdup(argv[1]);
 125         if (!file)
 126                 panic("No Berkeley Packet Filter program specified!\n");
 127
 128         ret = compile_filter(file, verbose, bypass, decimal);
 129
 130         xfree(file);
 131         return ret;
 132 }