net/netfilter/xt_pkttype.c

   1 /* (C) 1999-2001 Michal Ludvig <michal@logix.cz>
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 as
   5  * published by the Free Software Foundation.
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/skbuff.h>
  10 #include <linux/if_ether.h>
  11 #include <linux/if_packet.h>
  12
  13 #include <linux/netfilter/xt_pkttype.h>
  14 #include <linux/netfilter/x_tables.h>
  15
  16 MODULE_LICENSE("GPL");
  17 MODULE_AUTHOR("Michal Ludvig <michal@logix.cz>");
  18 MODULE_DESCRIPTION("IP tables match to match on linklayer packet type");
  19 MODULE_ALIAS("ipt_pkttype");
  20 MODULE_ALIAS("ip6t_pkttype");
  21
  22 static int match(const struct sk_buff *skb,
  23       const struct net_device *in,
  24       const struct net_device *out,
  25       const struct xt_match *match,
  26       const void *matchinfo,
  27       int offset,
  28       unsigned int protoff,
  29       int *hotdrop)
  30 {
  31         const struct xt_pkttype_info *info = matchinfo;
  32
  33         return (skb->pkt_type == info->pkttype) ^ info->invert;
  34 }
  35
  36 static struct xt_match pkttype_match = {
  37         .name           = "pkttype",
  38         .match          = match,
  39         .matchsize      = sizeof(struct xt_pkttype_info),
  40         .family         = AF_INET,
  41         .me             = THIS_MODULE,
  42 };
  43
  44 static struct xt_match pkttype6_match = {
  45         .name           = "pkttype",
  46         .match          = match,
  47         .matchsize      = sizeof(struct xt_pkttype_info),
  48         .family         = AF_INET6,
  49         .me             = THIS_MODULE,
  50 };
  51
  52 static int __init xt_pkttype_init(void)
  53 {
  54         int ret;
  55         ret = xt_register_match(&pkttype_match);
  56         if (ret)
  57                 return ret;
  58
  59         ret = xt_register_match(&pkttype6_match);
  60         if (ret)
  61                 xt_unregister_match(&pkttype_match);
  62
  63         return ret;
  64 }
  65
  66 static void __exit xt_pkttype_fini(void)
  67 {
  68         xt_unregister_match(&pkttype_match);
  69         xt_unregister_match(&pkttype6_match);
  70 }
  71
  72 module_init(xt_pkttype_init);
  73 module_exit(xt_pkttype_fini);