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
  29         return info->target;
  30 }
  31
  32 static int ebt_target_mark_check(const char *tablename, unsigned int hookmask,
  33    const struct ebt_entry *e, void *data, unsigned int datalen)
  34 {
  35         struct ebt_mark_t_info *info = (struct ebt_mark_t_info *)data;
  36
  37         if (datalen != EBT_ALIGN(sizeof(struct ebt_mark_t_info)))
  38                 return -EINVAL;
  39         if (BASE_CHAIN && info->target == EBT_RETURN)
  40                 return -EINVAL;
  41         CLEAR_BASE_CHAIN_BIT;
  42         if (INVALID_TARGET)
  43                 return -EINVAL;
  44         return 0;
  45 }
  46
  47 static struct ebt_target mark_target =
  48 {
  49         .name           = EBT_MARK_TARGET,
  50         .target         = ebt_target_mark,
  51         .check          = ebt_target_mark_check,
  52         .me             = THIS_MODULE,
  53 };
  54
  55 static int __init ebt_mark_init(void)
  56 {
  57         return ebt_register_target(&mark_target);
  58 }
  59
  60 static void __exit ebt_mark_fini(void)
  61 {
  62         ebt_unregister_target(&mark_target);
  63 }
  64
  65 module_init(ebt_mark_init);
  66 module_exit(ebt_mark_fini);
  67 MODULE_LICENSE("GPL");