extensions/libxt_NFQUEUE.c

   1 /* Shared library add-on to iptables for NFQ
   2  *
   3  * (C) 2005 by Harald Welte <laforge@netfilter.org>
   4  *
   5  * This program is distributed under the terms of GNU GPL v2, 1991
   6  *
   7  */
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <stdlib.h>
  11 #include <getopt.h>
  12
  13 #include <xtables.h>
  14 #include <linux/netfilter/x_tables.h>
  15 #include <linux/netfilter/xt_NFQUEUE.h>
  16
  17 static void NFQUEUE_help(void)
  18 {
  19         printf(
  20 "NFQUEUE target options\n"
  21 "  --queue-num value            Send packet to QUEUE number <value>.\n"
  22 "                               Valid queue numbers are 0-65535\n"
  23 );
  24 }
  25
  26 static const struct option NFQUEUE_opts[] = {
  27         { "queue-num", 1, NULL, 'F' },
  28         { .name = NULL }
  29 };
  30
  31 static void
  32 parse_num(const char *s, struct xt_NFQ_info *tinfo)
  33 {
  34         unsigned int num;
  35
  36         if (string_to_number(s, 0, 65535, &num) == -1)
  37                 exit_error(PARAMETER_PROBLEM,
  38                            "Invalid queue number `%s'\n", s);
  39
  40         tinfo->queuenum = num & 0xffff;
  41         return;
  42 }
  43
  44 static int
  45 NFQUEUE_parse(int c, char **argv, int invert, unsigned int *flags,
  46               const void *entry, struct xt_entry_target **target)
  47 {
  48         struct xt_NFQ_info *tinfo
  49                 = (struct xt_NFQ_info *)(*target)->data;
  50
  51         switch (c) {
  52         case 'F':
  53                 if (*flags)
  54                         exit_error(PARAMETER_PROBLEM, "NFQUEUE target: "
  55                                    "Only use --queue-num ONCE!");
  56                 parse_num(optarg, tinfo);
  57                 break;
  58         default:
  59                 return 0;
  60         }
  61
  62         return 1;
  63 }
  64
  65 /* Prints out the targinfo. */
  66 static void NFQUEUE_print(const void *ip,
  67                           const struct xt_entry_target *target, int numeric)
  68 {
  69         const struct xt_NFQ_info *tinfo =
  70                 (const struct xt_NFQ_info *)target->data;
  71         printf("NFQUEUE num %u", tinfo->queuenum);
  72 }
  73
  74 /* Saves the union ipt_targinfo in parsable form to stdout. */
  75 static void NFQUEUE_save(const void *ip, const struct xt_entry_target *target)
  76 {
  77         const struct xt_NFQ_info *tinfo =
  78                 (const struct xt_NFQ_info *)target->data;
  79
  80         printf("--queue-num %u ", tinfo->queuenum);
  81 }
  82
  83 static struct xtables_target nfqueue_target = {
  84         .family         = AF_INET,
  85         .name           = "NFQUEUE",
  86         .version        = XTABLES_VERSION,
  87         .size           = XT_ALIGN(sizeof(struct xt_NFQ_info)),
  88         .userspacesize  = XT_ALIGN(sizeof(struct xt_NFQ_info)),
  89         .help           = NFQUEUE_help,
  90         .parse          = NFQUEUE_parse,
  91         .print          = NFQUEUE_print,
  92         .save           = NFQUEUE_save,
  93         .extra_opts     = NFQUEUE_opts
  94 };
  95
  96 static struct xtables_target nfqueue_target6 = {
  97         .family         = AF_INET6,
  98         .name           = "NFQUEUE",
  99         .version        = XTABLES_VERSION,
 100         .size           = XT_ALIGN(sizeof(struct xt_NFQ_info)),
 101         .userspacesize  = XT_ALIGN(sizeof(struct xt_NFQ_info)),
 102         .help           = NFQUEUE_help,
 103         .parse          = NFQUEUE_parse,
 104         .print          = NFQUEUE_print,
 105         .save           = NFQUEUE_save,
 106         .extra_opts     = NFQUEUE_opts,
 107 };
 108
 109 void _init(void)
 110 {
 111         xtables_register_target(&nfqueue_target);
 112         xtables_register_target(&nfqueue_target6);
 113 }