1/*
2 *  iptables module to match inet_addr_type() of an ip.
3 *
4 *  Copyright (c) 2004 Patrick McHardy <kaber@trash.net>
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License version 2 as
8 *  published by the Free Software Foundation.
9 */
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/skbuff.h>
14#include <linux/netdevice.h>
15#include <linux/ip.h>
16#include <net/route.h>
17
18#include <linux/netfilter_ipv4/ipt_addrtype.h>
19#include <linux/netfilter/x_tables.h>
20
21MODULE_LICENSE("GPL");
22MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
23MODULE_DESCRIPTION("iptables addrtype match");
24
25static inline int match_type(__be32 addr, u_int16_t mask)
26{
27	return !!(mask & (1 << inet_addr_type(addr)));
28}
29
30static int match(const struct sk_buff *skb,
31		 const struct net_device *in, const struct net_device *out,
32		 const struct xt_match *match, const void *matchinfo,
33		 int offset, unsigned int protoff, int *hotdrop)
34{
35	const struct ipt_addrtype_info *info = matchinfo;
36	const struct iphdr *iph = ip_hdr(skb);
37	int ret = 1;
38
39	if (info->source)
40		ret &= match_type(iph->saddr, info->source)^info->invert_source;
41	if (info->dest)
42		ret &= match_type(iph->daddr, info->dest)^info->invert_dest;
43
44	return ret;
45}
46
47static struct xt_match addrtype_match = {
48	.name		= "addrtype",
49	.family		= AF_INET,
50	.match		= match,
51	.matchsize	= sizeof(struct ipt_addrtype_info),
52	.me		= THIS_MODULE
53};
54
55static int __init ipt_addrtype_init(void)
56{
57	return xt_register_match(&addrtype_match);
58}
59
60static void __exit ipt_addrtype_fini(void)
61{
62	xt_unregister_match(&addrtype_match);
63}
64
65module_init(ipt_addrtype_init);
66module_exit(ipt_addrtype_fini);
67