1 | // SPDX-License-Identifier: GPL-2.0-only |
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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(addr1: eth_hdr(skb)->h_source, addr2: 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(target: &mac_mt_reg); |
55 | } |
56 | |
57 | static void __exit mac_mt_exit(void) |
58 | { |
59 | xt_unregister_match(target: &mac_mt_reg); |
60 | } |
61 | |
62 | module_init(mac_mt_init); |
63 | module_exit(mac_mt_exit); |
64 |