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

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  ebt_redirect
 *
 *	Authors:
 *	Bart De Schuymer <bdschuym@pandora.be>
 *
 *  April, 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_redirect.h>

static unsigned int
ebt_redirect_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct ebt_redirect_info *info = par->targinfo;

	if (skb_ensure_writable(skb, ETH_ALEN))
		return EBT_DROP;

	if (xt_hooknum(par) != NF_BR_BROUTING)
		/* rcu_read_lock()ed by nf_hook_thresh */
		ether_addr_copy(eth_hdr(skb)->h_dest,
				br_port_get_rcu(xt_in(par))->br->dev->dev_addr);
	else
		ether_addr_copy(eth_hdr(skb)->h_dest, xt_in(par)->dev_addr);
	skb->pkt_type = PACKET_HOST;
	return info->target;
}

static int ebt_redirect_tg_check(const struct xt_tgchk_param *par)
{
	const struct ebt_redirect_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)) &&
	    (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_redirect_tg_reg __read_mostly = {
	.name		= "redirect",
	.revision	= 0,
	.family		= NFPROTO_BRIDGE,
	.hooks		= (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_PRE_ROUTING) |
			  (1 << NF_BR_BROUTING),
	.target		= ebt_redirect_tg,
	.checkentry	= ebt_redirect_tg_check,
	.targetsize	= sizeof(struct ebt_redirect_info),
	.me		= THIS_MODULE,
};

static int __init ebt_redirect_init(void)
{
	return xt_register_target(&ebt_redirect_tg_reg);
}

static void __exit ebt_redirect_fini(void)
{
	xt_unregister_target(&ebt_redirect_tg_reg);
}

module_init(ebt_redirect_init);
module_exit(ebt_redirect_fini);
MODULE_DESCRIPTION("Ebtables: Packet redirection to localhost");
MODULE_LICENSE("GPL");
Commit	Line	Data
09c434b8	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* ebt_redirect
	4	*
	5	* Authors:
	6	* Bart De Schuymer <bdschuym@pandora.be>
	7	*
	8	* April, 2002
	9	*
	10	*/
1da177e4 LT	11	#include <linux/module.h>
	12	#include <net/sock.h>
	13	#include "../br_private.h"
18219d3f JE	14	#include <linux/netfilter.h>
	15	#include <linux/netfilter/x_tables.h>
	16	#include <linux/netfilter_bridge/ebtables.h>
	17	#include <linux/netfilter_bridge/ebt_redirect.h>
1da177e4	18
2d06d4a5	19	static unsigned int
4b560b44	20	ebt_redirect_tg(struct sk_buff skb, const struct xt_action_param par)
1da177e4	21	{
7eb35586	22	const struct ebt_redirect_info *info = par->targinfo;
1da177e4	23
c1a83116	24	if (skb_ensure_writable(skb, ETH_ALEN))
1b04ab45	25	return EBT_DROP;
1da177e4	26
613dbd95	27	if (xt_hooknum(par) != NF_BR_BROUTING)
e2361cb9	28	/* rcu_read_lock()ed by nf_hook_thresh */
04091142	29	ether_addr_copy(eth_hdr(skb)->h_dest,
613dbd95	30	br_port_get_rcu(xt_in(par))->br->dev->dev_addr);
1da177e4	31	else
613dbd95	32	ether_addr_copy(eth_hdr(skb)->h_dest, xt_in(par)->dev_addr);
3db05fea	33	skb->pkt_type = PACKET_HOST;
1da177e4 LT	34	return info->target;
	35	}
	36
135367b8	37	static int ebt_redirect_tg_check(const struct xt_tgchk_param *par)
1da177e4	38	{
af5d6dc2 JE	39	const struct ebt_redirect_info *info = par->targinfo;
af5d6dc2 JE	40	unsigned int hook_mask;
1da177e4	41
1da177e4	42	if (BASE_CHAIN && info->target == EBT_RETURN)
d6b00a53	43	return -EINVAL;
af5d6dc2 JE	44
	45	hook_mask = par->hook_mask & ~(1 << NF_BR_NUMHOOKS);
	46	if ((strcmp(par->table, "nat") != 0 \|\|
	47	hook_mask & ~(1 << NF_BR_PRE_ROUTING)) &&
	48	(strcmp(par->table, "broute") != 0 \|\|
	49	hook_mask & ~(1 << NF_BR_BROUTING)))
d6b00a53	50	return -EINVAL;
e15b9c50	51	if (ebt_invalid_target(info->target))
d6b00a53 JE	52	return -EINVAL;
d6b00a53 JE	53	return 0;
1da177e4 LT	54	}
1da177e4 LT	55
043ef46c JE	56	static struct xt_target ebt_redirect_tg_reg __read_mostly = {
043ef46c JE	57	.name = "redirect",
001a18d3 JE	58	.revision = 0,
001a18d3 JE	59	.family = NFPROTO_BRIDGE,
f2ff525c JE	60	.hooks = (1 << NF_BR_NUMHOOKS) \| (1 << NF_BR_PRE_ROUTING) \|
f2ff525c JE	61	(1 << NF_BR_BROUTING),
2d06d4a5 JE	62	.target = ebt_redirect_tg,
2d06d4a5 JE	63	.checkentry = ebt_redirect_tg_check,
fc0e3df4	64	.targetsize = sizeof(struct ebt_redirect_info),
1da177e4 LT	65	.me = THIS_MODULE,
	66	};
	67
65b4b4e8	68	static int __init ebt_redirect_init(void)
1da177e4	69	{
043ef46c	70	return xt_register_target(&ebt_redirect_tg_reg);
1da177e4 LT	71	}
1da177e4 LT	72
65b4b4e8	73	static void __exit ebt_redirect_fini(void)
1da177e4	74	{
043ef46c	75	xt_unregister_target(&ebt_redirect_tg_reg);
1da177e4 LT	76	}
1da177e4 LT	77
65b4b4e8 AM	78	module_init(ebt_redirect_init);
65b4b4e8 AM	79	module_exit(ebt_redirect_fini);
f776c4cd	80	MODULE_DESCRIPTION("Ebtables: Packet redirection to localhost");
1da177e4	81	MODULE_LICENSE("GPL");