| 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); |