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 int ebt_filter_mark(const struct sk_buff *skb,
  16    const struct net_device *in, const struct net_device *out, const void *data,
  17    unsigned int datalen)
  18 {
  19         const struct ebt_mark_m_info *info = data;
  20
  21         if (info->bitmask & EBT_MARK_OR)
  22                 return !(!!(skb->mark & info->mask) ^ info->invert);
  23         return !(((skb->mark & info->mask) == info->mark) ^ info->invert);
  24 }
  25
  26 static int ebt_mark_check(const char *tablename, unsigned int hookmask,
  27    const struct ebt_entry *e, void *data, unsigned int datalen)
  28 {
  29         const struct ebt_mark_m_info *info = data;
  30
  31         if (info->bitmask & ~EBT_MARK_MASK)
  32                 return -EINVAL;
  33         if ((info->bitmask & EBT_MARK_OR) && (info->bitmask & EBT_MARK_AND))
  34                 return -EINVAL;
  35         if (!info->bitmask)
  36                 return -EINVAL;
  37         return 0;
  38 }
  39
  40 static struct ebt_match filter_mark __read_mostly = {
  41         .name           = EBT_MARK_MATCH,
  42         .match          = ebt_filter_mark,
  43         .check          = ebt_mark_check,
  44         .matchsize      = XT_ALIGN(sizeof(struct ebt_mark_m_info)),
  45         .me             = THIS_MODULE,
  46 };
  47
  48 static int __init ebt_mark_m_init(void)
  49 {
  50         return ebt_register_match(&filter_mark);
  51 }
  52
  53 static void __exit ebt_mark_m_fini(void)
  54 {
  55         ebt_unregister_match(&filter_mark);
  56 }
  57
  58 module_init(ebt_mark_m_init);
  59 module_exit(ebt_mark_m_fini);
  60 MODULE_DESCRIPTION("Ebtables: Packet mark match");
  61 MODULE_LICENSE("GPL");