net/bridge/netfilter/ebt_mark.c

   1 /*
   2  *  ebt_mark
   3  *
   4  *      Authors:
   5  *      Bart De Schuymer <bdschuym@pandora.be>
   6  *
   7  *  July, 2002
   8  *
   9  */
  10
  11 /* The mark target can be used in any chain,
  12  * I believe adding a mangle table just for marking is total overkill.
  13  * Marking a frame doesn't really change anything in the frame anyway.
  14  */
  15
  16 #include <linux/netfilter_bridge/ebtables.h>
  17 #include <linux/netfilter_bridge/ebt_mark_t.h>
  18 #include <linux/module.h>
  19
  20 static int ebt_target_mark(struct sk_buff **pskb, unsigned int hooknr,
  21    const struct net_device *in, const struct net_device *out,
  22    const void *data, unsigned int datalen)
  23 {
  24         struct ebt_mark_t_info *info = (struct ebt_mark_t_info *)data;
  25
  26         if ((*pskb)->nfmark != info->mark) {
  27                 (*pskb)->nfmark = info->mark;
  28                 (*pskb)->nfcache |= NFC_ALTERED;
  29         }
  30         return info->target;
  31 }
  32
  33 static int ebt_target_mark_check(const char *tablename, unsigned int hookmask,
  34    const struct ebt_entry *e, void *data, unsigned int datalen)
  35 {
  36         struct ebt_mark_t_info *info = (struct ebt_mark_t_info *)data;
  37
  38         if (datalen != EBT_ALIGN(sizeof(struct ebt_mark_t_info)))
  39                 return -EINVAL;
  40         if (BASE_CHAIN && info->target == EBT_RETURN)
  41                 return -EINVAL;
  42         CLEAR_BASE_CHAIN_BIT;
  43         if (INVALID_TARGET)
  44                 return -EINVAL;
  45         return 0;
  46 }
  47
  48 static struct ebt_target mark_target =
  49 {
  50         .name           = EBT_MARK_TARGET,
  51         .target         = ebt_target_mark,
  52         .check          = ebt_target_mark_check,
  53         .me             = THIS_MODULE,
  54 };
  55
  56 static int __init init(void)
  57 {
  58         return ebt_register_target(&mark_target);
  59 }
  60
  61 static void __exit fini(void)
  62 {
  63         ebt_unregister_target(&mark_target);
  64 }
  65
  66 module_init(init);
  67 module_exit(fini);
  68 MODULE_LICENSE("GPL");