net/bridge/netfilter/ebt_pkttype.c

   1 /*
   2  *  ebt_pkttype
   3  *
   4  *      Authors:
   5  *      Bart De Schuymer <bdschuym@pandora.be>
   6  *
   7  *  April, 2003
   8  *
   9  */
  10 #include <linux/module.h>
  11 #include <linux/netfilter/x_tables.h>
  12 #include <linux/netfilter_bridge/ebtables.h>
  13 #include <linux/netfilter_bridge/ebt_pkttype.h>
  14
  15 static bool
  16 ebt_pkttype_mt(const struct sk_buff *skb, const struct xt_match_param *par)
  17 {
  18         const struct ebt_pkttype_info *info = par->matchinfo;
  19
  20         return (skb->pkt_type == info->pkt_type) ^ info->invert;
  21 }
  22
  23 static bool ebt_pkttype_mt_check(const struct xt_mtchk_param *par)
  24 {
  25         const struct ebt_pkttype_info *info = par->matchinfo;
  26
  27         if (info->invert != 0 && info->invert != 1)
  28                 return false;
  29         /* Allow any pkt_type value */
  30         return true;
  31 }
  32
  33 static struct xt_match ebt_pkttype_mt_reg __read_mostly = {
  34         .name           = "pkttype",
  35         .revision       = 0,
  36         .family         = NFPROTO_BRIDGE,
  37         .match          = ebt_pkttype_mt,
  38         .checkentry     = ebt_pkttype_mt_check,
  39         .matchsize      = XT_ALIGN(sizeof(struct ebt_pkttype_info)),
  40         .me             = THIS_MODULE,
  41 };
  42
  43 static int __init ebt_pkttype_init(void)
  44 {
  45         return xt_register_match(&ebt_pkttype_mt_reg);
  46 }
  47
  48 static void __exit ebt_pkttype_fini(void)
  49 {
  50         xt_unregister_match(&ebt_pkttype_mt_reg);
  51 }
  52
  53 module_init(ebt_pkttype_init);
  54 module_exit(ebt_pkttype_fini);
  55 MODULE_DESCRIPTION("Ebtables: Link layer packet type match");
  56 MODULE_LICENSE("GPL");