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
  11 #include <linux/netfilter_bridge/ebtables.h>
  12 #include <linux/netfilter_bridge/ebt_pkttype.h>
  13 #include <linux/module.h>
  14
  15 static int ebt_filter_pkttype(const struct sk_buff *skb,
  16    const struct net_device *in,
  17    const struct net_device *out,
  18    const void *data,
  19    unsigned int datalen)
  20 {
  21         struct ebt_pkttype_info *info = (struct ebt_pkttype_info *)data;
  22
  23         return (skb->pkt_type != info->pkt_type) ^ info->invert;
  24 }
  25
  26 static int ebt_pkttype_check(const char *tablename, unsigned int hookmask,
  27    const struct ebt_entry *e, void *data, unsigned int datalen)
  28 {
  29         struct ebt_pkttype_info *info = (struct ebt_pkttype_info *)data;
  30
  31         if (datalen != EBT_ALIGN(sizeof(struct ebt_pkttype_info)))
  32                 return -EINVAL;
  33         if (info->invert != 0 && info->invert != 1)
  34                 return -EINVAL;
  35         /* Allow any pkt_type value */
  36         return 0;
  37 }
  38
  39 static struct ebt_match filter_pkttype =
  40 {
  41         .name           = EBT_PKTTYPE_MATCH,
  42         .match          = ebt_filter_pkttype,
  43         .check          = ebt_pkttype_check,
  44         .me             = THIS_MODULE,
  45 };
  46
  47 static int __init init(void)
  48 {
  49         return ebt_register_match(&filter_pkttype);
  50 }
  51
  52 static void __exit fini(void)
  53 {
  54         ebt_unregister_match(&filter_pkttype);
  55 }
  56
  57 module_init(init);
  58 module_exit(fini);
  59 MODULE_LICENSE("GPL");