[deliverable/linux.git] / net / ipv4 / netfilter / ipt_MASQUERADE.c

/* Masquerade.  Simple mapping which alters range to a local IP address
   (depending on route). */

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/types.h>
#include <linux/inetdevice.h>
#include <linux/ip.h>
#include <linux/timer.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <net/protocol.h>
#include <net/ip.h>
#include <net/checksum.h>
#include <net/route.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter/x_tables.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/ipv4/nf_nat_masquerade.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("Xtables: automatic-address SNAT");

/* FIXME: Multiple targets. --RR */
static int masquerade_tg_check(const struct xt_tgchk_param *par)
{
	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;

	if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
		pr_debug("bad MAP_IPS.\n");
		return -EINVAL;
	}
	if (mr->rangesize != 1) {
		pr_debug("bad rangesize %u\n", mr->rangesize);
		return -EINVAL;
	}
	return 0;
}

static unsigned int
masquerade_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
	struct nf_nat_range range;
	const struct nf_nat_ipv4_multi_range_compat *mr;

	mr = par->targinfo;
	range.flags = mr->range[0].flags;
	range.min_proto = mr->range[0].min;
	range.max_proto = mr->range[0].max;

	return nf_nat_masquerade_ipv4(skb, par->hooknum, &range, par->out);
}

static struct xt_target masquerade_tg_reg __read_mostly = {
	.name		= "MASQUERADE",
	.family		= NFPROTO_IPV4,
	.target		= masquerade_tg,
	.targetsize	= sizeof(struct nf_nat_ipv4_multi_range_compat),
	.table		= "nat",
	.hooks		= 1 << NF_INET_POST_ROUTING,
	.checkentry	= masquerade_tg_check,
	.me		= THIS_MODULE,
};

static int __init masquerade_tg_init(void)
{
	int ret;

	ret = xt_register_target(&masquerade_tg_reg);

	if (ret == 0)
		nf_nat_masquerade_ipv4_register_notifier();

	return ret;
}

static void __exit masquerade_tg_exit(void)
{
	xt_unregister_target(&masquerade_tg_reg);
	nf_nat_masquerade_ipv4_unregister_notifier();
}

module_init(masquerade_tg_init);
module_exit(masquerade_tg_exit);
Commit	Line	Data
1da177e4 LT	1	/* Masquerade. Simple mapping which alters range to a local IP address
	2	(depending on route). */
	3
	4	/* (C) 1999-2001 Paul `Rusty' Russell
5b1158e9	5	* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
1da177e4 LT	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
ff67e4e4	11	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
1da177e4	12	#include <linux/types.h>
14c85021	13	#include <linux/inetdevice.h>
1da177e4 LT	14	#include <linux/ip.h>
	15	#include <linux/timer.h>
	16	#include <linux/module.h>
	17	#include <linux/netfilter.h>
	18	#include <net/protocol.h>
	19	#include <net/ip.h>
	20	#include <net/checksum.h>
14c85021	21	#include <net/route.h>
587aa641	22	#include <linux/netfilter_ipv4.h>
6709dbbb	23	#include <linux/netfilter/x_tables.h>
c7232c99	24	#include <net/netfilter/nf_nat.h>
8dd33cc9	25	#include <net/netfilter/ipv4/nf_nat_masquerade.h>
1da177e4 LT	26
	27	MODULE_LICENSE("GPL");
	28	MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
2ae15b64	29	MODULE_DESCRIPTION("Xtables: automatic-address SNAT");
1da177e4	30
1da177e4	31	/* FIXME: Multiple targets. --RR */
135367b8	32	static int masquerade_tg_check(const struct xt_tgchk_param *par)
1da177e4	33	{
cbc9f2f4	34	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
1da177e4	35
cbc9f2f4	36	if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
ff67e4e4	37	pr_debug("bad MAP_IPS.\n");
d6b00a53	38	return -EINVAL;
1da177e4 LT	39	}
1da177e4 LT	40	if (mr->rangesize != 1) {
ff67e4e4	41	pr_debug("bad rangesize %u\n", mr->rangesize);
d6b00a53	42	return -EINVAL;
1da177e4	43	}
d6b00a53	44	return 0;
1da177e4 LT	45	}
	46
	47	static unsigned int
4b560b44	48	masquerade_tg(struct sk_buff skb, const struct xt_action_param par)
1da177e4	49	{
8dd33cc9	50	struct nf_nat_range range;
cbc9f2f4	51	const struct nf_nat_ipv4_multi_range_compat *mr;
adcb5ad1	52
7eb35586	53	mr = par->targinfo;
8dd33cc9 AB	54	range.flags = mr->range[0].flags;
	55	range.min_proto = mr->range[0].min;
	56	range.max_proto = mr->range[0].max;
1da177e4	57
8dd33cc9	58	return nf_nat_masquerade_ipv4(skb, par->hooknum, &range, par->out);
1da177e4 LT	59	}
1da177e4 LT	60
d3c5ee6d	61	static struct xt_target masquerade_tg_reg __read_mostly = {
1da177e4	62	.name = "MASQUERADE",
ee999d8b	63	.family = NFPROTO_IPV4,
d3c5ee6d	64	.target = masquerade_tg,
cbc9f2f4	65	.targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
1d5cd909	66	.table = "nat",
6e23ae2a	67	.hooks = 1 << NF_INET_POST_ROUTING,
d3c5ee6d	68	.checkentry = masquerade_tg_check,
1da177e4 LT	69	.me = THIS_MODULE,
	70	};
	71
d3c5ee6d	72	static int __init masquerade_tg_init(void)
1da177e4 LT	73	{
	74	int ret;
	75
d3c5ee6d	76	ret = xt_register_target(&masquerade_tg_reg);
1da177e4	77
8dd33cc9 AB	78	if (ret == 0)
8dd33cc9 AB	79	nf_nat_masquerade_ipv4_register_notifier();
1da177e4 LT	80
	81	return ret;
	82	}
	83
d3c5ee6d	84	static void __exit masquerade_tg_exit(void)
1da177e4	85	{
d3c5ee6d	86	xt_unregister_target(&masquerade_tg_reg);
8dd33cc9	87	nf_nat_masquerade_ipv4_unregister_notifier();
1da177e4 LT	88	}
1da177e4 LT	89
d3c5ee6d JE	90	module_init(masquerade_tg_init);
d3c5ee6d JE	91	module_exit(masquerade_tg_exit);