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_target_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 bool 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 false;
  47        if (tmp < -NUM_STANDARD_TARGETS || tmp >= 0)
  48                return false;
  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 false;
  53        return true;
  54}
  55
  56static struct xt_target ebt_mark_tg_reg __read_mostly = {
  57        .name           = "mark",
  58        .revision       = 0,
  59        .family         = NFPROTO_BRIDGE,
  60        .target         = ebt_mark_tg,
  61        .checkentry     = ebt_mark_tg_check,
  62        .targetsize     = XT_ALIGN(sizeof(struct ebt_mark_t_info)),
  63        .me             = THIS_MODULE,
  64};
  65
  66static int __init ebt_mark_init(void)
  67{
  68        return xt_register_target(&ebt_mark_tg_reg);
  69}
  70
  71static void __exit ebt_mark_fini(void)
  72{
  73        xt_unregister_target(&ebt_mark_tg_reg);
  74}
  75
  76module_init(ebt_mark_init);
  77module_exit(ebt_mark_fini);
  78MODULE_DESCRIPTION("Ebtables: Packet mark modification");
  79MODULE_LICENSE("GPL");
  80