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
  24 ebt_pkttype_mt_check(const char *table, const void *e,
  25                      const struct xt_match *match, void *data,
  26                      unsigned int hook_mask)
  27 {
  28         const struct ebt_pkttype_info *info = data;
  29
  30         if (info->invert != 0 && info->invert != 1)
  31                 return false;
  32         /* Allow any pkt_type value */
  33         return true;
  34 }
  35
  36 static struct xt_match ebt_pkttype_mt_reg __read_mostly = {
  37         .name           = "pkttype",
  38         .revision       = 0,
  39         .family         = NFPROTO_BRIDGE,
  40         .match          = ebt_pkttype_mt,
  41         .checkentry     = ebt_pkttype_mt_check,
  42         .matchsize      = XT_ALIGN(sizeof(struct ebt_pkttype_info)),
  43         .me             = THIS_MODULE,
  44 };
  45
  46 static int __init ebt_pkttype_init(void)
  47 {
  48         return xt_register_match(&ebt_pkttype_mt_reg);
  49 }
  50
  51 static void __exit ebt_pkttype_fini(void)
  52 {
  53         xt_unregister_match(&ebt_pkttype_mt_reg);
  54 }
  55
  56 module_init(ebt_pkttype_init);
  57 module_exit(ebt_pkttype_fini);
  58 MODULE_DESCRIPTION("Ebtables: Link layer packet type match");
  59 MODULE_LICENSE("GPL");