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("X_tables realm match");
22MODULE_ALIAS("ipt_realm");
23
24static int
25match(const struct sk_buff *skb,
26      const struct net_device *in,
27      const struct net_device *out,
28      const struct xt_match *match,
29      const void *matchinfo,
30      int offset,
31      unsigned int protoff,
32      int *hotdrop)
33{
34	const struct xt_realm_info *info = matchinfo;
35	struct dst_entry *dst = skb->dst;
36
37	return (info->id == (dst->tclassid & info->mask)) ^ info->invert;
38}
39
40static struct xt_match realm_match = {
41	.name		= "realm",
42	.match		= match,
43	.matchsize	= sizeof(struct xt_realm_info),
44	.hooks		= (1 << NF_IP_POST_ROUTING) | (1 << NF_IP_FORWARD) |
45			  (1 << NF_IP_LOCAL_OUT) | (1 << NF_IP_LOCAL_IN),
46	.family		= AF_INET,
47	.me		= THIS_MODULE
48};
49
50static int __init xt_realm_init(void)
51{
52	return xt_register_match(&realm_match);
53}
54
55static void __exit xt_realm_fini(void)
56{
57	xt_unregister_match(&realm_match);
58}
59
60module_init(xt_realm_init);
61module_exit(xt_realm_fini);
62