/* Kernel module to match MAC address parameters. */ /* (C) 1999-2001 Paul `Rusty' Russell * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/module.h>#include <linux/skbuff.h>#include <linux/if_arp.h>#include <linux/if_ether.h>#include <linux/etherdevice.h> #include <linux/netfilter_ipv4.h>#include <linux/netfilter_ipv6.h>#include <linux/netfilter/xt_mac.h>#include <linux/netfilter/x_tables.h> MODULE_LICENSE("GPL");MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");MODULE_DESCRIPTION("Xtables: MAC address match");MODULE_ALIAS("ipt_mac");MODULE_ALIAS("ip6t_mac"); static bool mac_mt(const struct sk_buff *skb, struct xt_action_param *par){	const struct xt_mac_info *info = par->matchinfo;	bool ret; 	if (skb->dev == NULL || skb->dev->type != ARPHRD_ETHER)		return false;	if (skb_mac_header(skb) < skb->head)		return false;	if (skb_mac_header(skb) + ETH_HLEN > skb->data)		return false;	ret  = ether_addr_equal(eth_hdr(skb)->h_source, info->srcaddr);	ret ^= info->invert;	return ret;} static struct xt_match mac_mt_reg __read_mostly = {	.name      = "mac",	.revision  = 0,	.family    = NFPROTO_UNSPEC,	.match     = mac_mt,	.matchsize = sizeof(struct xt_mac_info),	.hooks     = (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_IN) |	             (1 << NF_INET_FORWARD),	.me        = THIS_MODULE,}; static int __init mac_mt_init(void){	return xt_register_match(&mac_mt_reg);} static void __exit mac_mt_exit(void){	xt_unregister_match(&mac_mt_reg);} module_init(mac_mt_init);module_exit(mac_mt_exit);