release/src-rt-6.x.4708/linux/linux-2.6.36/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, struct xt_action_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 int ebt_mark_mt_check(const struct xt_mtchk_param *par)
  26 {
  27         const struct ebt_mark_m_info *info = par->matchinfo;
  28
  29         if (info->bitmask & ~EBT_MARK_MASK)
  30                 return -EINVAL;
  31         if ((info->bitmask & EBT_MARK_OR) && (info->bitmask & EBT_MARK_AND))
  32                 return -EINVAL;
  33         if (!info->bitmask)
  34                 return -EINVAL;
  35         return 0;
  36 }
  37
  38
  39 #ifdef CONFIG_COMPAT
  40 struct compat_ebt_mark_m_info {
  41         compat_ulong_t mark, mask;
  42         uint8_t invert, bitmask;
  43 };
  44
  45 static void mark_mt_compat_from_user(void *dst, const void *src)
  46 {
  47         const struct compat_ebt_mark_m_info *user = src;
  48         struct ebt_mark_m_info *kern = dst;
  49
  50         kern->mark = user->mark;
  51         kern->mask = user->mask;
  52         kern->invert = user->invert;
  53         kern->bitmask = user->bitmask;
  54 }
  55
  56 static int mark_mt_compat_to_user(void __user *dst, const void *src)
  57 {
  58         struct compat_ebt_mark_m_info __user *user = dst;
  59         const struct ebt_mark_m_info *kern = src;
  60
  61         if (put_user(kern->mark, &user->mark) ||
  62             put_user(kern->mask, &user->mask) ||
  63             put_user(kern->invert, &user->invert) ||
  64             put_user(kern->bitmask, &user->bitmask))
  65                 return -EFAULT;
  66         return 0;
  67 }
  68 #endif
  69
  70 static struct xt_match ebt_mark_mt_reg __read_mostly = {
  71         .name           = "mark_m",
  72         .revision       = 0,
  73         .family         = NFPROTO_BRIDGE,
  74         .match          = ebt_mark_mt,
  75         .checkentry     = ebt_mark_mt_check,
  76         .matchsize      = sizeof(struct ebt_mark_m_info),
  77 #ifdef CONFIG_COMPAT
  78         .compatsize     = sizeof(struct compat_ebt_mark_m_info),
  79         .compat_from_user = mark_mt_compat_from_user,
  80         .compat_to_user = mark_mt_compat_to_user,
  81 #endif
  82         .me             = THIS_MODULE,
  83 };
  84
  85 static int __init ebt_mark_m_init(void)
  86 {
  87         return xt_register_match(&ebt_mark_mt_reg);
  88 }
  89
  90 static void __exit ebt_mark_m_fini(void)
  91 {
  92         xt_unregister_match(&ebt_mark_mt_reg);
  93 }
  94
  95 module_init(ebt_mark_m_init);
  96 module_exit(ebt_mark_m_fini);
  97 MODULE_DESCRIPTION("Ebtables: Packet mark match");
  98 MODULE_LICENSE("GPL");