LXR linux/net/bridge/netfilter/ebt

   1/*
   2 *  ebt_redirect
   3 *
   4 *      Authors:
   5 *      Bart De Schuymer <bdschuym@pandora.be>
   6 *
   7 *  April, 2002
   8 *
   9 */
  10#include <linux/module.h>
  11#include <net/sock.h>
  12#include "../br_private.h"
  13#include <linux/netfilter.h>
  14#include <linux/netfilter/x_tables.h>
  15#include <linux/netfilter_bridge/ebtables.h>
  16#include <linux/netfilter_bridge/ebt_redirect.h>
  17
  18static unsigned int
  19ebt_redirect_tg(struct sk_buff *skb, const struct xt_target_param *par)
  20{
  21        const struct ebt_redirect_info *info = par->targinfo;
  22
  23        if (!skb_make_writable(skb, 0))
  24                return EBT_DROP;
  25
  26        if (par->hooknum != NF_BR_BROUTING)
  27                memcpy(eth_hdr(skb)->h_dest,
  28                       par->in->br_port->br->dev->dev_addr, ETH_ALEN);
  29        else
  30                memcpy(eth_hdr(skb)->h_dest, par->in->dev_addr, ETH_ALEN);
  31        skb->pkt_type = PACKET_HOST;
  32        return info->target;
  33}
  34
  35static bool ebt_redirect_tg_check(const struct xt_tgchk_param *par)
  36{
  37        const struct ebt_redirect_info *info = par->targinfo;
  38        unsigned int hook_mask;
  39
  40        if (BASE_CHAIN && info->target == EBT_RETURN)
  41                return false;
  42
  43        hook_mask = par->hook_mask & ~(1 << NF_BR_NUMHOOKS);
  44        if ((strcmp(par->table, "nat") != 0 ||
  45            hook_mask & ~(1 << NF_BR_PRE_ROUTING)) &&
  46            (strcmp(par->table, "broute") != 0 ||
  47            hook_mask & ~(1 << NF_BR_BROUTING)))
  48                return false;
  49        if (INVALID_TARGET)
  50                return false;
  51        return true;
  52}
  53
  54static struct xt_target ebt_redirect_tg_reg __read_mostly = {
  55        .name           = "redirect",
  56        .revision       = 0,
  57        .family         = NFPROTO_BRIDGE,
  58        .hooks          = (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_PRE_ROUTING) |
  59                          (1 << NF_BR_BROUTING),
  60        .target         = ebt_redirect_tg,
  61        .checkentry     = ebt_redirect_tg_check,
  62        .targetsize     = XT_ALIGN(sizeof(struct ebt_redirect_info)),
  63        .me             = THIS_MODULE,
  64};
  65
  66static int __init ebt_redirect_init(void)
  67{
  68        return xt_register_target(&ebt_redirect_tg_reg);
  69}
  70
  71static void __exit ebt_redirect_fini(void)
  72{
  73        xt_unregister_target(&ebt_redirect_tg_reg);
  74}
  75
  76module_init(ebt_redirect_init);
  77module_exit(ebt_redirect_fini);
  78MODULE_DESCRIPTION("Ebtables: Packet redirection to localhost");
  79MODULE_LICENSE("GPL");
  80