[net-next-2.6.git] / net / ipv4 / netfilter / ipt_REDIRECT.c

/* Redirect.  Simple mapping which alters dst to a local IP address. */
/* (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.
 */

#include <linux/types.h>
#include <linux/ip.h>
#include <linux/timer.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/netdevice.h>
#include <linux/if.h>
#include <linux/inetdevice.h>
#include <net/protocol.h>
#include <net/checksum.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter/x_tables.h>
#ifdef CONFIG_NF_NAT_NEEDED
#include <net/netfilter/nf_nat_rule.h>
#else
#include <linux/netfilter_ipv4/ip_nat_rule.h>
#endif

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("iptables REDIRECT target module");

#if 0
#define DEBUGP printk
#else
#define DEBUGP(format, args...)
#endif

/* FIXME: Take multiple ranges --RR */
static int
redirect_check(const char *tablename,
	       const void *e,
	       const struct xt_target *target,
	       void *targinfo,
	       unsigned int hook_mask)
{
	const struct ip_nat_multi_range_compat *mr = targinfo;

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

static unsigned int
redirect_target(struct sk_buff **pskb,
		const struct net_device *in,
		const struct net_device *out,
		unsigned int hooknum,
		const struct xt_target *target,
		const void *targinfo)
{
	struct ip_conntrack *ct;
	enum ip_conntrack_info ctinfo;
	__be32 newdst;
	const struct ip_nat_multi_range_compat *mr = targinfo;
	struct ip_nat_range newrange;

	IP_NF_ASSERT(hooknum == NF_IP_PRE_ROUTING
		     || hooknum == NF_IP_LOCAL_OUT);

	ct = ip_conntrack_get(*pskb, &ctinfo);
	IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));

	/* Local packets: make them go to loopback */
	if (hooknum == NF_IP_LOCAL_OUT)
		newdst = htonl(0x7F000001);
	else {
		struct in_device *indev;
		struct in_ifaddr *ifa;

		newdst = 0;
		
		rcu_read_lock();
		indev = __in_dev_get_rcu((*pskb)->dev);
		if (indev && (ifa = indev->ifa_list))
			newdst = ifa->ifa_local;
		rcu_read_unlock();

		if (!newdst)
			return NF_DROP;
	}

	/* Transfer from original range. */
	newrange = ((struct ip_nat_range)
		{ mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
		  newdst, newdst,
		  mr->range[0].min, mr->range[0].max });

	/* Hand modified range to generic setup. */
	return ip_nat_setup_info(ct, &newrange, hooknum);
}

static struct xt_target redirect_reg = {
	.name		= "REDIRECT",
	.family		= AF_INET,
	.target		= redirect_target,
	.targetsize	= sizeof(struct ip_nat_multi_range_compat),
	.table		= "nat",
	.hooks		= (1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT),
	.checkentry	= redirect_check,
	.me		= THIS_MODULE,
};

static int __init ipt_redirect_init(void)
{
	return xt_register_target(&redirect_reg);
}

static void __exit ipt_redirect_fini(void)
{
	xt_unregister_target(&redirect_reg);
}

module_init(ipt_redirect_init);
module_exit(ipt_redirect_fini);
Commit	Line	Data
1da177e4 LT	1	/* Redirect. Simple mapping which alters dst to a local IP address. */
1da177e4 LT	2	/* (C) 1999-2001 Paul `Rusty' Russell
5b1158e9	3	* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
1da177e4 LT	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*/
	9
	10	#include <linux/types.h>
	11	#include <linux/ip.h>
	12	#include <linux/timer.h>
	13	#include <linux/module.h>
	14	#include <linux/netfilter.h>
	15	#include <linux/netdevice.h>
	16	#include <linux/if.h>
	17	#include <linux/inetdevice.h>
	18	#include <net/protocol.h>
	19	#include <net/checksum.h>
	20	#include <linux/netfilter_ipv4.h>
6709dbbb	21	#include <linux/netfilter/x_tables.h>
5b1158e9 JK	22	#ifdef CONFIG_NF_NAT_NEEDED
	23	#include <net/netfilter/nf_nat_rule.h>
	24	#else
1da177e4	25	#include <linux/netfilter_ipv4/ip_nat_rule.h>
5b1158e9	26	#endif
1da177e4 LT	27
	28	MODULE_LICENSE("GPL");
	29	MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
	30	MODULE_DESCRIPTION("iptables REDIRECT target module");
	31
	32	#if 0
	33	#define DEBUGP printk
	34	#else
	35	#define DEBUGP(format, args...)
	36	#endif
	37
	38	/* FIXME: Take multiple ranges --RR */
	39	static int
	40	redirect_check(const char *tablename,
2e4e6a17	41	const void *e,
c4986734	42	const struct xt_target *target,
1da177e4	43	void *targinfo,
1da177e4 LT	44	unsigned int hook_mask)
	45	{
	46	const struct ip_nat_multi_range_compat *mr = targinfo;
	47
1da177e4 LT	48	if (mr->range[0].flags & IP_NAT_RANGE_MAP_IPS) {
	49	DEBUGP("redirect_check: bad MAP_IPS.\n");
	50	return 0;
	51	}
	52	if (mr->rangesize != 1) {
	53	DEBUGP("redirect_check: bad rangesize %u.\n", mr->rangesize);
	54	return 0;
	55	}
	56	return 1;
	57	}
	58
	59	static unsigned int
	60	redirect_target(struct sk_buff **pskb,
	61	const struct net_device *in,
	62	const struct net_device *out,
	63	unsigned int hooknum,
c4986734	64	const struct xt_target *target,
fe1cb108	65	const void *targinfo)
1da177e4 LT	66	{
	67	struct ip_conntrack *ct;
	68	enum ip_conntrack_info ctinfo;
a144ea4b	69	__be32 newdst;
1da177e4 LT	70	const struct ip_nat_multi_range_compat *mr = targinfo;
	71	struct ip_nat_range newrange;
	72
	73	IP_NF_ASSERT(hooknum == NF_IP_PRE_ROUTING
	74	\|\| hooknum == NF_IP_LOCAL_OUT);
	75
	76	ct = ip_conntrack_get(*pskb, &ctinfo);
	77	IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW \|\| ctinfo == IP_CT_RELATED));
	78
	79	/* Local packets: make them go to loopback */
	80	if (hooknum == NF_IP_LOCAL_OUT)
	81	newdst = htonl(0x7F000001);
	82	else {
	83	struct in_device *indev;
cd0bf2d7	84	struct in_ifaddr *ifa;
1da177e4	85
cd0bf2d7 PM	86	newdst = 0;
	87
	88	rcu_read_lock();
e5ed6399	89	indev = __in_dev_get_rcu((*pskb)->dev);
cd0bf2d7 PM	90	if (indev && (ifa = indev->ifa_list))
	91	newdst = ifa->ifa_local;
	92	rcu_read_unlock();
1da177e4	93
cd0bf2d7 PM	94	if (!newdst)
cd0bf2d7 PM	95	return NF_DROP;
1da177e4 LT	96	}
	97
	98	/* Transfer from original range. */
	99	newrange = ((struct ip_nat_range)
	100	{ mr->range[0].flags \| IP_NAT_RANGE_MAP_IPS,
	101	newdst, newdst,
	102	mr->range[0].min, mr->range[0].max });
	103
	104	/* Hand modified range to generic setup. */
	105	return ip_nat_setup_info(ct, &newrange, hooknum);
	106	}
	107
6709dbbb	108	static struct xt_target redirect_reg = {
1da177e4	109	.name = "REDIRECT",
6709dbbb	110	.family = AF_INET,
1da177e4	111	.target = redirect_target,
1d5cd909 PM	112	.targetsize = sizeof(struct ip_nat_multi_range_compat),
	113	.table = "nat",
	114	.hooks = (1 << NF_IP_PRE_ROUTING) \| (1 << NF_IP_LOCAL_OUT),
1da177e4 LT	115	.checkentry = redirect_check,
	116	.me = THIS_MODULE,
	117	};
	118
65b4b4e8	119	static int __init ipt_redirect_init(void)
1da177e4	120	{
6709dbbb	121	return xt_register_target(&redirect_reg);
1da177e4 LT	122	}
1da177e4 LT	123
65b4b4e8	124	static void __exit ipt_redirect_fini(void)
1da177e4	125	{
6709dbbb	126	xt_unregister_target(&redirect_reg);
1da177e4 LT	127	}
1da177e4 LT	128
65b4b4e8 AM	129	module_init(ipt_redirect_init);
65b4b4e8 AM	130	module_exit(ipt_redirect_fini);