LXR linux/net/bridge/netfilter/ebt

   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/module.h>
  17#include <linux/netfilter/x_tables.h>
  18#include <linux/netfilter_bridge/ebtables.h>
  19#include <linux/netfilter_bridge/ebt_mark_t.h>
  20
  21static unsigned int
  22ebt_mark_tg(struct sk_buff *skb, const struct xt_action_param *par)
  23{
  24        const struct ebt_mark_t_info *info = par->targinfo;
  25        int action = info->target & -16;
  26
  27        if (action == MARK_SET_VALUE)
  28                skb->mark = info->mark;
  29        else if (action == MARK_OR_VALUE)
  30                skb->mark |= info->mark;
  31        else if (action == MARK_AND_VALUE)
  32                skb->mark &= info->mark;
  33        else
  34                skb->mark ^= info->mark;
  35
  36        return info->target | ~EBT_VERDICT_BITS;
  37}
  38
  39static int ebt_mark_tg_check(const struct xt_tgchk_param *par)
  40{
  41        const struct ebt_mark_t_info *info = par->targinfo;
  42        int tmp;
  43
  44        tmp = info->target | ~EBT_VERDICT_BITS;
  45        if (BASE_CHAIN && tmp == EBT_RETURN)
  46                return -EINVAL;
  47        if (tmp < -NUM_STANDARD_TARGETS || tmp >= 0)
  48                return -EINVAL;
  49        tmp = info->target & ~EBT_VERDICT_BITS;
  50        if (tmp != MARK_SET_VALUE && tmp != MARK_OR_VALUE &&
  51            tmp != MARK_AND_VALUE && tmp != MARK_XOR_VALUE)
  52                return -EINVAL;
  53        return 0;
  54}
  55#ifdef CONFIG_COMPAT
  56struct compat_ebt_mark_t_info {
  57        compat_ulong_t mark;
  58        compat_uint_t target;
  59};
  60
  61static void mark_tg_compat_from_user(void *dst, const void *src)
  62{
  63        const struct compat_ebt_mark_t_info *user = src;
  64        struct ebt_mark_t_info *kern = dst;
  65
  66        kern->mark = user->mark;
  67        kern->target = user->target;
  68}
  69
  70static int mark_tg_compat_to_user(void __user *dst, const void *src)
  71{
  72        struct compat_ebt_mark_t_info __user *user = dst;
  73        const struct ebt_mark_t_info *kern = src;
  74
  75        if (put_user(kern->mark, &user->mark) ||
  76            put_user(kern->target, &user->target))
  77                return -EFAULT;
  78        return 0;
  79}
  80#endif
  81
  82static struct xt_target ebt_mark_tg_reg __read_mostly = {
  83        .name           = "mark",
  84        .revision       = 0,
  85        .family         = NFPROTO_BRIDGE,
  86        .target         = ebt_mark_tg,
  87        .checkentry     = ebt_mark_tg_check,
  88        .targetsize     = sizeof(struct ebt_mark_t_info),
  89#ifdef CONFIG_COMPAT
  90        .compatsize     = sizeof(struct compat_ebt_mark_t_info),
  91        .compat_from_user = mark_tg_compat_from_user,
  92        .compat_to_user = mark_tg_compat_to_user,
  93#endif
  94        .me             = THIS_MODULE,
  95};
  96
  97static int __init ebt_mark_init(void)
  98{
  99        return xt_register_target(&ebt_mark_tg_reg);
 100}
 101
 102static void __exit ebt_mark_fini(void)
 103{
 104        xt_unregister_target(&ebt_mark_tg_reg);
 105}
 106
 107module_init(ebt_mark_init);
 108module_exit(ebt_mark_fini);
 109MODULE_DESCRIPTION("Ebtables: Packet mark modification");
 110MODULE_LICENSE("GPL");
 111