LXR linux/net/netfilter/xt

   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_arp.h>
  14#include <linux/if_ether.h>
  15#include <linux/etherdevice.h>
  16
  17#include <linux/netfilter_ipv4.h>
  18#include <linux/netfilter_ipv6.h>
  19#include <linux/netfilter/xt_mac.h>
  20#include <linux/netfilter/x_tables.h>
  21
  22MODULE_LICENSE("GPL");
  23MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  24MODULE_DESCRIPTION("Xtables: MAC address match");
  25MODULE_ALIAS("ipt_mac");
  26MODULE_ALIAS("ip6t_mac");
  27
  28static bool mac_mt(const struct sk_buff *skb, struct xt_action_param *par)
  29{
  30        const struct xt_mac_info *info = par->matchinfo;
  31        bool ret;
  32
  33        if (skb->dev == NULL || skb->dev->type != ARPHRD_ETHER)
  34                return false;
  35        if (skb_mac_header(skb) < skb->head)
  36                return false;
  37        if (skb_mac_header(skb) + ETH_HLEN > skb->data)
  38                return false;
  39        ret  = compare_ether_addr(eth_hdr(skb)->h_source, info->srcaddr) == 0;
  40        ret ^= info->invert;
  41        return ret;
  42}
  43
  44static struct xt_match mac_mt_reg __read_mostly = {
  45        .name      = "mac",
  46        .revision  = 0,
  47        .family    = NFPROTO_UNSPEC,
  48        .match     = mac_mt,
  49        .matchsize = sizeof(struct xt_mac_info),
  50        .hooks     = (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_IN) |
  51                     (1 << NF_INET_FORWARD),
  52        .me        = THIS_MODULE,
  53};
  54
  55static int __init mac_mt_init(void)
  56{
  57        return xt_register_match(&mac_mt_reg);
  58}
  59
  60static void __exit mac_mt_exit(void)
  61{
  62        xt_unregister_match(&mac_mt_reg);
  63}
  64
  65module_init(mac_mt_init);
  66module_exit(mac_mt_exit);
  67