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_ether.h>
14#include <linux/etherdevice.h>
15
16#include <linux/netfilter_ipv4.h>
17#include <linux/netfilter_ipv6.h>
18#include <linux/netfilter/xt_mac.h>
19#include <linux/netfilter/x_tables.h>
20
21MODULE_LICENSE("GPL");
22MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
23MODULE_DESCRIPTION("iptables mac matching module");
24MODULE_ALIAS("ipt_mac");
25MODULE_ALIAS("ip6t_mac");
26
27static int
28match(const struct sk_buff *skb,
29      const struct net_device *in,
30      const struct net_device *out,
31      const struct xt_match *match,
32      const void *matchinfo,
33      int offset,
34      unsigned int protoff,
35      int *hotdrop)
36{
37    const struct xt_mac_info *info = matchinfo;
38
39    /* Is mac pointer valid? */
40    return (skb_mac_header(skb) >= skb->head &&
41	    (skb_mac_header(skb) + ETH_HLEN) <= skb->data
42	    /* If so, compare... */
43	    && ((!compare_ether_addr(eth_hdr(skb)->h_source, info->srcaddr))
44		^ info->invert));
45}
46
47static struct xt_match xt_mac_match[] = {
48	{
49		.name		= "mac",
50		.family		= AF_INET,
51		.match		= match,
52		.matchsize	= sizeof(struct xt_mac_info),
53		.hooks		= (1 << NF_IP_PRE_ROUTING) |
54				  (1 << NF_IP_LOCAL_IN) |
55				  (1 << NF_IP_FORWARD),
56		.me		= THIS_MODULE,
57	},
58	{
59		.name		= "mac",
60		.family		= AF_INET6,
61		.match		= match,
62		.matchsize	= sizeof(struct xt_mac_info),
63		.hooks		= (1 << NF_IP6_PRE_ROUTING) |
64				  (1 << NF_IP6_LOCAL_IN) |
65				  (1 << NF_IP6_FORWARD),
66		.me		= THIS_MODULE,
67	},
68};
69
70static int __init xt_mac_init(void)
71{
72	return xt_register_matches(xt_mac_match, ARRAY_SIZE(xt_mac_match));
73}
74
75static void __exit xt_mac_fini(void)
76{
77	xt_unregister_matches(xt_mac_match, ARRAY_SIZE(xt_mac_match));
78}
79
80module_init(xt_mac_init);
81module_exit(xt_mac_fini);
82