1/* Kernel module to match MAC address parameters. */
2
3/* (C) 1999-2001 Paul `Rusty' Russell
4 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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/module.h>
12#include <linux/skbuff.h>
13#include <linux/if_arp.h>
14#include <linux/if_ether.h>
15#include <linux/etherdevice.h>
16
17#include <linux/netfilter_ipv4.h>
18#include <linux/netfilter_ipv6.h>
19#include <linux/netfilter/xt_mac.h>
20#include <linux/netfilter/x_tables.h>
21
22MODULE_LICENSE("GPL");
23MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
24MODULE_DESCRIPTION("Xtables: MAC address match");
25MODULE_ALIAS("ipt_mac");
26MODULE_ALIAS("ip6t_mac");
27
28static bool mac_mt(const struct sk_buff *skb, struct xt_action_param *par)
29{
30	const struct xt_mac_info *info = par->matchinfo;
31	bool ret;
32
33	if (skb->dev == NULL || skb->dev->type != ARPHRD_ETHER)
34		return false;
35	if (skb_mac_header(skb) < skb->head)
36		return false;
37	if (skb_mac_header(skb) + ETH_HLEN > skb->data)
38		return false;
39	ret  = ether_addr_equal(eth_hdr(skb)->h_source, info->srcaddr);
40	ret ^= info->invert;
41	return ret;
42}
43
44static struct xt_match mac_mt_reg __read_mostly = {
45	.name      = "mac",
46	.revision  = 0,
47	.family    = NFPROTO_UNSPEC,
48	.match     = mac_mt,
49	.matchsize = sizeof(struct xt_mac_info),
50	.hooks     = (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_IN) |
51	             (1 << NF_INET_FORWARD),
52	.me        = THIS_MODULE,
53};
54
55static int __init mac_mt_init(void)
56{
57	return xt_register_match(&mac_mt_reg);
58}
59
60static void __exit mac_mt_exit(void)
61{
62	xt_unregister_match(&mac_mt_reg);
63}
64
65module_init(mac_mt_init);
66module_exit(mac_mt_exit);
67