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