LXR linux/net/netfilter/xt

   1/* IP tables module for matching the routing realm
   2 *
   3 * (C) 2003 by Sampsa Ranta <sampsa@netsonic.fi>
   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 as
   7 * published by the Free Software Foundation.
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/skbuff.h>
  12#include <linux/netdevice.h>
  13#include <net/route.h>
  14
  15#include <linux/netfilter_ipv4.h>
  16#include <linux/netfilter/xt_realm.h>
  17#include <linux/netfilter/x_tables.h>
  18
  19MODULE_AUTHOR("Sampsa Ranta <sampsa@netsonic.fi>");
  20MODULE_LICENSE("GPL");
  21MODULE_DESCRIPTION("Xtables: Routing realm match");
  22MODULE_ALIAS("ipt_realm");
  23
  24static bool
  25realm_mt(const struct sk_buff *skb, const struct xt_match_param *par)
  26{
  27        const struct xt_realm_info *info = par->matchinfo;
  28        const struct dst_entry *dst = skb_dst(skb);
  29
  30        return (info->id == (dst->tclassid & info->mask)) ^ info->invert;
  31}
  32
  33static struct xt_match realm_mt_reg __read_mostly = {
  34        .name           = "realm",
  35        .match          = realm_mt,
  36        .matchsize      = sizeof(struct xt_realm_info),
  37        .hooks          = (1 << NF_INET_POST_ROUTING) | (1 << NF_INET_FORWARD) |
  38                          (1 << NF_INET_LOCAL_OUT) | (1 << NF_INET_LOCAL_IN),
  39        .family         = NFPROTO_UNSPEC,
  40        .me             = THIS_MODULE
  41};
  42
  43static int __init realm_mt_init(void)
  44{
  45        return xt_register_match(&realm_mt_reg);
  46}
  47
  48static void __exit realm_mt_exit(void)
  49{
  50        xt_unregister_match(&realm_mt_reg);
  51}
  52
  53module_init(realm_mt_init);
  54module_exit(realm_mt_exit);
  55