[linux-2.6-block.git] / net / bridge / netfilter / ebt_dnat.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  ebt_dnat
 *
 *	Authors:
 *	Bart De Schuymer <bdschuym@pandora.be>
 *
 *  June, 2002
 *
 */
#include <linux/module.h>
#include <net/sock.h>
#include "../br_private.h"
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_nat.h>

static unsigned int
ebt_dnat_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct ebt_nat_info *info = par->targinfo;
	struct net_device *dev;

	if (!skb_make_writable(skb, 0))
		return EBT_DROP;

	ether_addr_copy(eth_hdr(skb)->h_dest, info->mac);

	if (is_multicast_ether_addr(info->mac)) {
		if (is_broadcast_ether_addr(info->mac))
			skb->pkt_type = PACKET_BROADCAST;
		else
			skb->pkt_type = PACKET_MULTICAST;
	} else {
		if (xt_hooknum(par) != NF_BR_BROUTING)
			dev = br_port_get_rcu(xt_in(par))->br->dev;
		else
			dev = xt_in(par);

		if (ether_addr_equal(info->mac, dev->dev_addr))
			skb->pkt_type = PACKET_HOST;
		else
			skb->pkt_type = PACKET_OTHERHOST;
	}

	return info->target;
}

static int ebt_dnat_tg_check(const struct xt_tgchk_param *par)
{
	const struct ebt_nat_info *info = par->targinfo;
	unsigned int hook_mask;

	if (BASE_CHAIN && info->target == EBT_RETURN)
		return -EINVAL;

	hook_mask = par->hook_mask & ~(1 << NF_BR_NUMHOOKS);
	if ((strcmp(par->table, "nat") != 0 ||
	    (hook_mask & ~((1 << NF_BR_PRE_ROUTING) |
	    (1 << NF_BR_LOCAL_OUT)))) &&
	    (strcmp(par->table, "broute") != 0 ||
	    hook_mask & ~(1 << NF_BR_BROUTING)))
		return -EINVAL;
	if (ebt_invalid_target(info->target))
		return -EINVAL;
	return 0;
}

static struct xt_target ebt_dnat_tg_reg __read_mostly = {
	.name		= "dnat",
	.revision	= 0,
	.family		= NFPROTO_BRIDGE,
	.hooks		= (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_PRE_ROUTING) |
			  (1 << NF_BR_LOCAL_OUT) | (1 << NF_BR_BROUTING),
	.target		= ebt_dnat_tg,
	.checkentry	= ebt_dnat_tg_check,
	.targetsize	= sizeof(struct ebt_nat_info),
	.me		= THIS_MODULE,
};

static int __init ebt_dnat_init(void)
{
	return xt_register_target(&ebt_dnat_tg_reg);
}

static void __exit ebt_dnat_fini(void)
{
	xt_unregister_target(&ebt_dnat_tg_reg);
}

module_init(ebt_dnat_init);
module_exit(ebt_dnat_fini);
MODULE_DESCRIPTION("Ebtables: Destination MAC address translation");
MODULE_LICENSE("GPL");
Commit	Line	Data
09c434b8	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* ebt_dnat
	4	*
	5	* Authors:
	6	* Bart De Schuymer <bdschuym@pandora.be>
	7	*
	8	* June, 2002
	9	*
	10	*/
18219d3f JE	11	#include <linux/module.h>
18219d3f JE	12	#include <net/sock.h>
cf3cb246	13	#include "../br_private.h"
2ca7b0ac	14	#include <linux/netfilter.h>
18219d3f	15	#include <linux/netfilter/x_tables.h>
1da177e4 LT	16	#include <linux/netfilter_bridge/ebtables.h>
1da177e4 LT	17	#include <linux/netfilter_bridge/ebt_nat.h>
1da177e4	18
2d06d4a5	19	static unsigned int
4b560b44	20	ebt_dnat_tg(struct sk_buff skb, const struct xt_action_param par)
1da177e4	21	{
7eb35586	22	const struct ebt_nat_info *info = par->targinfo;
cf3cb246	23	struct net_device *dev;
1da177e4	24
eb1197bc	25	if (!skb_make_writable(skb, 0))
1b04ab45	26	return EBT_DROP;
1da177e4	27
04091142	28	ether_addr_copy(eth_hdr(skb)->h_dest, info->mac);
cf3cb246 LL	29
	30	if (is_multicast_ether_addr(info->mac)) {
	31	if (is_broadcast_ether_addr(info->mac))
	32	skb->pkt_type = PACKET_BROADCAST;
	33	else
	34	skb->pkt_type = PACKET_MULTICAST;
	35	} else {
	36	if (xt_hooknum(par) != NF_BR_BROUTING)
	37	dev = br_port_get_rcu(xt_in(par))->br->dev;
	38	else
	39	dev = xt_in(par);
	40
	41	if (ether_addr_equal(info->mac, dev->dev_addr))
	42	skb->pkt_type = PACKET_HOST;
	43	else
	44	skb->pkt_type = PACKET_OTHERHOST;
	45	}
	46
1da177e4 LT	47	return info->target;
	48	}
	49
135367b8	50	static int ebt_dnat_tg_check(const struct xt_tgchk_param *par)
1da177e4	51	{
af5d6dc2 JE	52	const struct ebt_nat_info *info = par->targinfo;
af5d6dc2 JE	53	unsigned int hook_mask;
1da177e4 LT	54
1da177e4 LT	55	if (BASE_CHAIN && info->target == EBT_RETURN)
d6b00a53	56	return -EINVAL;
af5d6dc2 JE	57
	58	hook_mask = par->hook_mask & ~(1 << NF_BR_NUMHOOKS);
	59	if ((strcmp(par->table, "nat") != 0 \|\|
	60	(hook_mask & ~((1 << NF_BR_PRE_ROUTING) \|
	61	(1 << NF_BR_LOCAL_OUT)))) &&
	62	(strcmp(par->table, "broute") != 0 \|\|
	63	hook_mask & ~(1 << NF_BR_BROUTING)))
d6b00a53	64	return -EINVAL;
e15b9c50	65	if (ebt_invalid_target(info->target))
d6b00a53 JE	66	return -EINVAL;
d6b00a53 JE	67	return 0;
1da177e4 LT	68	}
1da177e4 LT	69
043ef46c JE	70	static struct xt_target ebt_dnat_tg_reg __read_mostly = {
043ef46c JE	71	.name = "dnat",
001a18d3 JE	72	.revision = 0,
001a18d3 JE	73	.family = NFPROTO_BRIDGE,
f2ff525c JE	74	.hooks = (1 << NF_BR_NUMHOOKS) \| (1 << NF_BR_PRE_ROUTING) \|
f2ff525c JE	75	(1 << NF_BR_LOCAL_OUT) \| (1 << NF_BR_BROUTING),
2d06d4a5 JE	76	.target = ebt_dnat_tg,
2d06d4a5 JE	77	.checkentry = ebt_dnat_tg_check,
fc0e3df4	78	.targetsize = sizeof(struct ebt_nat_info),
1da177e4 LT	79	.me = THIS_MODULE,
	80	};
	81
65b4b4e8	82	static int __init ebt_dnat_init(void)
1da177e4	83	{
043ef46c	84	return xt_register_target(&ebt_dnat_tg_reg);
1da177e4 LT	85	}
1da177e4 LT	86
65b4b4e8	87	static void __exit ebt_dnat_fini(void)
1da177e4	88	{
043ef46c	89	xt_unregister_target(&ebt_dnat_tg_reg);
1da177e4 LT	90	}
1da177e4 LT	91
65b4b4e8 AM	92	module_init(ebt_dnat_init);
65b4b4e8 AM	93	module_exit(ebt_dnat_fini);
f776c4cd	94	MODULE_DESCRIPTION("Ebtables: Destination MAC address translation");
1da177e4	95	MODULE_LICENSE("GPL");