1/*
2 *  ebt_dnat
3 *
4 *	Authors:
5 *	Bart De Schuymer <bdschuym@pandora.be>
6 *
7 *  June, 2002
8 *
9 */
10#include <linux/module.h>
11#include <net/sock.h>
12#include <linux/netfilter.h>
13#include <linux/netfilter/x_tables.h>
14#include <linux/netfilter_bridge/ebtables.h>
15#include <linux/netfilter_bridge/ebt_nat.h>
16
17static unsigned int
18ebt_dnat_tg(struct sk_buff *skb, const struct xt_action_param *par)
19{
20	const struct ebt_nat_info *info = par->targinfo;
21
22	if (!skb_make_writable(skb, 0))
23		return EBT_DROP;
24
25	ether_addr_copy(eth_hdr(skb)->h_dest, info->mac);
26	return info->target;
27}
28
29static int ebt_dnat_tg_check(const struct xt_tgchk_param *par)
30{
31	const struct ebt_nat_info *info = par->targinfo;
32	unsigned int hook_mask;
33
34	if (BASE_CHAIN && info->target == EBT_RETURN)
35		return -EINVAL;
36
37	hook_mask = par->hook_mask & ~(1 << NF_BR_NUMHOOKS);
38	if ((strcmp(par->table, "nat") != 0 ||
39	    (hook_mask & ~((1 << NF_BR_PRE_ROUTING) |
40	    (1 << NF_BR_LOCAL_OUT)))) &&
41	    (strcmp(par->table, "broute") != 0 ||
42	    hook_mask & ~(1 << NF_BR_BROUTING)))
43		return -EINVAL;
44	if (INVALID_TARGET)
45		return -EINVAL;
46	return 0;
47}
48
49static struct xt_target ebt_dnat_tg_reg __read_mostly = {
50	.name		= "dnat",
51	.revision	= 0,
52	.family		= NFPROTO_BRIDGE,
53	.hooks		= (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_PRE_ROUTING) |
54			  (1 << NF_BR_LOCAL_OUT) | (1 << NF_BR_BROUTING),
55	.target		= ebt_dnat_tg,
56	.checkentry	= ebt_dnat_tg_check,
57	.targetsize	= sizeof(struct ebt_nat_info),
58	.me		= THIS_MODULE,
59};
60
61static int __init ebt_dnat_init(void)
62{
63	return xt_register_target(&ebt_dnat_tg_reg);
64}
65
66static void __exit ebt_dnat_fini(void)
67{
68	xt_unregister_target(&ebt_dnat_tg_reg);
69}
70
71module_init(ebt_dnat_init);
72module_exit(ebt_dnat_fini);
73MODULE_DESCRIPTION("Ebtables: Destination MAC address translation");
74MODULE_LICENSE("GPL");
75