1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Kernel module to match MAC address parameters. */
3
4 /* (C) 1999-2001 Paul `Rusty' Russell
5 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
6 */
7
8 #include <linux/module.h>
9 #include <linux/skbuff.h>
10 #include <linux/if_arp.h>
11 #include <linux/if_ether.h>
12 #include <linux/etherdevice.h>
13
14 #include <linux/netfilter_ipv4.h>
15 #include <linux/netfilter_ipv6.h>
16 #include <linux/netfilter/xt_mac.h>
17 #include <linux/netfilter/x_tables.h>
18
19 MODULE_LICENSE("GPL");
20 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
21 MODULE_DESCRIPTION("Xtables: MAC address match");
22 MODULE_ALIAS("ipt_mac");
23 MODULE_ALIAS("ip6t_mac");
24
25 static bool mac_mt(const struct sk_buff *skb, struct xt_action_param *par)
26 {
27 const struct xt_mac_info *info = par->matchinfo;
28 bool ret;
29
30 if (skb->dev == NULL || skb->dev->type != ARPHRD_ETHER)
31 return false;
32 if (skb_mac_header(skb) < skb->head)
33 return false;
34 if (skb_mac_header(skb) + ETH_HLEN > skb->data)
35 return false;
36 ret = ether_addr_equal(eth_hdr(skb)->h_source, info->srcaddr);
37 ret ^= info->invert;
38 return ret;
39 }
40
41 static struct xt_match mac_mt_reg __read_mostly = {
42 .name = "mac",
43 .revision = 0,
44 .family = NFPROTO_UNSPEC,
45 .match = mac_mt,
46 .matchsize = sizeof(struct xt_mac_info),
47 .hooks = (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_IN) |
48 (1 << NF_INET_FORWARD),
49 .me = THIS_MODULE,
50 };
51
52 static int __init mac_mt_init(void)
53 {
54 return xt_register_match(&mac_mt_reg);
55 }
56
57 static void __exit mac_mt_exit(void)
58 {
59 xt_unregister_match(&mac_mt_reg);
60 }
61
62 module_init(mac_mt_init);
63 module_exit(mac_mt_exit);
64
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