net/bridge/netfilter/ebt_mark_m.c

   1 /*
   2  *  ebt_mark_m
   3  *
   4  *      Authors:
   5  *      Bart De Schuymer <bdschuym@pandora.be>
   6  *
   7  *  July, 2002
   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_mark_m.h>
  14
  15 static bool
  16 ebt_mark_mt(const struct sk_buff *skb, const struct xt_match_param *par)
  17 {
  18         const struct ebt_mark_m_info *info = par->matchinfo;
  19
  20         if (info->bitmask & EBT_MARK_OR)
  21                 return !!(skb->mark & info->mask) ^ info->invert;
  22         return ((skb->mark & info->mask) == info->mark) ^ info->invert;
  23 }
  24
  25 static bool
  26 ebt_mark_mt_check(const char *table, const void *e,
  27                   const struct xt_match *match, void *data,
  28                   unsigned int hook_mask)
  29 {
  30         const struct ebt_mark_m_info *info = data;
  31
  32         if (info->bitmask & ~EBT_MARK_MASK)
  33                 return false;
  34         if ((info->bitmask & EBT_MARK_OR) && (info->bitmask & EBT_MARK_AND))
  35                 return false;
  36         if (!info->bitmask)
  37                 return false;
  38         return true;
  39 }
  40
  41 static struct xt_match ebt_mark_mt_reg __read_mostly = {
  42         .name           = "mark_m",
  43         .revision       = 0,
  44         .family         = NFPROTO_BRIDGE,
  45         .match          = ebt_mark_mt,
  46         .checkentry     = ebt_mark_mt_check,
  47         .matchsize      = XT_ALIGN(sizeof(struct ebt_mark_m_info)),
  48         .me             = THIS_MODULE,
  49 };
  50
  51 static int __init ebt_mark_m_init(void)
  52 {
  53         return xt_register_match(&ebt_mark_mt_reg);
  54 }
  55
  56 static void __exit ebt_mark_m_fini(void)
  57 {
  58         xt_unregister_match(&ebt_mark_mt_reg);
  59 }
  60
  61 module_init(ebt_mark_m_init);
  62 module_exit(ebt_mark_m_fini);
  63 MODULE_DESCRIPTION("Ebtables: Packet mark match");
  64 MODULE_LICENSE("GPL");