release/src/router/iptables/extensions/libipt_connmark.c

   1 /* Shared library add-on to iptables to add connmark matching support.
   2  *
   3  * (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
   4  * by Henrik Nordstrom <hno@marasystems.com>
   5  *
   6  * Version 1.1
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22 #include <stdio.h>
  23 #include <netdb.h>
  24 #include <string.h>
  25 #include <stdlib.h>
  26 #include <getopt.h>
  27
  28 #include <iptables.h>
  29 #include "../include/linux/netfilter_ipv4/ipt_connmark.h"
  30
  31 /* Function which prints out usage message. */
  32 static void
  33 help(void)
  34 {
  35         printf(
  36 "CONNMARK match v%s options:\n"
  37 "[!] --mark value[/mask]         Match nfmark value with optional mask\n"
  38 "\n",
  39 IPTABLES_VERSION);
  40 }
  41
  42 static struct option opts[] = {
  43         { "mark", 1, 0, '1' },
  44         {0}
  45 };
  46
  47 /* Initialize the match. */
  48 static void
  49 init(struct ipt_entry_match *m, unsigned int *nfcache)
  50 {
  51         /* Can't cache this. */
  52         *nfcache |= NFC_UNKNOWN;
  53 }
  54
  55 /* Function which parses command options; returns true if it
  56    ate an option */
  57 static int
  58 parse(int c, char **argv, int invert, unsigned int *flags,
  59       const struct ipt_entry *entry,
  60       unsigned int *nfcache,
  61       struct ipt_entry_match **match)
  62 {
  63         struct ipt_connmark_info *markinfo = (struct ipt_connmark_info *)(*match)->data;
  64
  65         switch (c) {
  66                 char *end;
  67         case '1':
  68                 check_inverse(optarg, &invert, &optind, 0);
  69
  70                 markinfo->mark = strtoul(optarg, &end, 0);
  71                 markinfo->mask = 0xffffffffUL;
  72
  73                 if (*end == '/')
  74                         markinfo->mask = strtoul(end+1, &end, 0);
  75
  76                 if (*end != '\0' || end == optarg)
  77                         exit_error(PARAMETER_PROBLEM, "Bad MARK value `%s'", optarg);
  78                 if (invert)
  79                         markinfo->invert = 1;
  80                 *flags = 1;
  81                 break;
  82
  83         default:
  84                 return 0;
  85         }
  86         return 1;
  87 }
  88
  89 static void
  90 print_mark(unsigned long mark, unsigned long mask, int numeric)
  91 {
  92         if(mask != 0xffffffffUL)
  93                 printf("0x%lx/0x%lx ", mark, mask);
  94         else
  95                 printf("0x%lx ", mark);
  96 }
  97
  98 /* Final check; must have specified --mark. */
  99 static void
 100 final_check(unsigned int flags)
 101 {
 102         if (!flags)
 103                 exit_error(PARAMETER_PROBLEM,
 104                            "MARK match: You must specify `--mark'");
 105 }
 106
 107 /* Prints out the matchinfo. */
 108 static void
 109 print(const struct ipt_ip *ip,
 110       const struct ipt_entry_match *match,
 111       int numeric)
 112 {
 113         struct ipt_connmark_info *info = (struct ipt_connmark_info *)match->data;
 114
 115         printf("CONNMARK match ");
 116         if (info->invert)
 117                 printf("!");
 118         print_mark(info->mark, info->mask, numeric);
 119 }
 120
 121 /* Saves the matchinfo in parsable form to stdout. */
 122 static void
 123 save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
 124 {
 125         struct ipt_connmark_info *info = (struct ipt_connmark_info *)match->data;
 126
 127         if (info->invert)
 128                 printf("! ");
 129
 130         printf("--mark ");
 131         print_mark(info->mark, info->mask, 0);
 132 }
 133
 134 static struct iptables_match connmark_match = {
 135     .name          = "connmark",
 136     .version       = IPTABLES_VERSION,
 137     .size          = IPT_ALIGN(sizeof(struct ipt_connmark_info)),
 138     .userspacesize = IPT_ALIGN(sizeof(struct ipt_connmark_info)),
 139     .help          = &help,
 140     .init          = &init,
 141     .parse         = &parse,
 142     .final_check   = &final_check,
 143     .print         = &print,
 144     .save          = &save,
 145     .extra_opts    = opts
 146 };
 147
 148 void _init(void)
 149 {
 150         register_match(&connmark_match);
 151 }