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

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 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.
 */

/* Everything about the rules for NAT. */
#include <linux/types.h>
#include <linux/ip.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <net/checksum.h>
#include <net/route.h>
#include <linux/bitops.h>

#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ip_nat.h>
#include <linux/netfilter_ipv4/ip_nat_core.h>
#include <linux/netfilter_ipv4/ip_nat_rule.h>

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

#define NAT_VALID_HOOKS ((1<<NF_IP_PRE_ROUTING) | (1<<NF_IP_POST_ROUTING) | (1<<NF_IP_LOCAL_OUT))

static struct
{
	struct ipt_replace repl;
	struct ipt_standard entries[3];
	struct ipt_error term;
} nat_initial_table __initdata
= { { "nat", NAT_VALID_HOOKS, 4,
      sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
      { [NF_IP_PRE_ROUTING] = 0,
	[NF_IP_POST_ROUTING] = sizeof(struct ipt_standard),
	[NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
      { [NF_IP_PRE_ROUTING] = 0,
	[NF_IP_POST_ROUTING] = sizeof(struct ipt_standard),
	[NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
      0, NULL, { } },
    {
	    /* PRE_ROUTING */
	    { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
		0,
		sizeof(struct ipt_entry),
		sizeof(struct ipt_standard),
		0, { 0, 0 }, { } },
	      { { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
		-NF_ACCEPT - 1 } },
	    /* POST_ROUTING */
	    { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
		0,
		sizeof(struct ipt_entry),
		sizeof(struct ipt_standard),
		0, { 0, 0 }, { } },
	      { { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
		-NF_ACCEPT - 1 } },
	    /* LOCAL_OUT */
	    { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
		0,
		sizeof(struct ipt_entry),
		sizeof(struct ipt_standard),
		0, { 0, 0 }, { } },
	      { { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
		-NF_ACCEPT - 1 } }
    },
    /* ERROR */
    { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	0,
	sizeof(struct ipt_entry),
	sizeof(struct ipt_error),
	0, { 0, 0 }, { } },
      { { { { IPT_ALIGN(sizeof(struct ipt_error_target)), IPT_ERROR_TARGET } },
	  { } },
	"ERROR"
      }
    }
};

static struct xt_table nat_table = {
	.name		= "nat",
	.valid_hooks	= NAT_VALID_HOOKS,
	.lock		= RW_LOCK_UNLOCKED,
	.me		= THIS_MODULE,
	.af		= AF_INET,
};

/* Source NAT */
static unsigned int ipt_snat_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;
	const struct ip_nat_multi_range_compat *mr = targinfo;

	IP_NF_ASSERT(hooknum == NF_IP_POST_ROUTING);

	ct = ip_conntrack_get(*pskb, &ctinfo);

	/* Connection must be valid and new. */
	IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED
			    || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY));
	IP_NF_ASSERT(out);

	return ip_nat_setup_info(ct, &mr->range[0], hooknum);
}

/* Before 2.6.11 we did implicit source NAT if required. Warn about change. */
static void warn_if_extra_mangle(__be32 dstip, __be32 srcip)
{
	static int warned = 0;
	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = dstip } } };
	struct rtable *rt;

	if (ip_route_output_key(&rt, &fl) != 0)
		return;

	if (rt->rt_src != srcip && !warned) {
		printk("NAT: no longer support implicit source local NAT\n");
		printk("NAT: packet src %u.%u.%u.%u -> dst %u.%u.%u.%u\n",
		       NIPQUAD(srcip), NIPQUAD(dstip));
		warned = 1;
	}
	ip_rt_put(rt);
}

static unsigned int ipt_dnat_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;
	const struct ip_nat_multi_range_compat *mr = targinfo;

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

	ct = ip_conntrack_get(*pskb, &ctinfo);

	/* Connection must be valid and new. */
	IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));

	if (hooknum == NF_IP_LOCAL_OUT
	    && mr->range[0].flags & IP_NAT_RANGE_MAP_IPS)
		warn_if_extra_mangle((*pskb)->nh.iph->daddr,
				     mr->range[0].min_ip);

	return ip_nat_setup_info(ct, &mr->range[0], hooknum);
}

static int ipt_snat_checkentry(const char *tablename,
			       const void *entry,
			       const struct xt_target *target,
			       void *targinfo,
			       unsigned int hook_mask)
{
	struct ip_nat_multi_range_compat *mr = targinfo;

	/* Must be a valid range */
	if (mr->rangesize != 1) {
		printk("SNAT: multiple ranges no longer supported\n");
		return 0;
	}
	return 1;
}

static int ipt_dnat_checkentry(const char *tablename,
			       const void *entry,
			       const struct xt_target *target,
			       void *targinfo,
			       unsigned int hook_mask)
{
	struct ip_nat_multi_range_compat *mr = targinfo;

	/* Must be a valid range */
	if (mr->rangesize != 1) {
		printk("DNAT: multiple ranges no longer supported\n");
		return 0;
	}
	if (mr->range[0].flags & IP_NAT_RANGE_PROTO_RANDOM) {
		printk("DNAT: port randomization not supported\n");
		return 0;
	}
	return 1;
}

inline unsigned int
alloc_null_binding(struct ip_conntrack *conntrack,
		   struct ip_nat_info *info,
		   unsigned int hooknum)
{
	/* Force range to this IP; let proto decide mapping for
	   per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
	   Use reply in case it's already been mangled (eg local packet).
	*/
	__be32 ip
		= (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
		   ? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip
		   : conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip);
	struct ip_nat_range range
		= { IP_NAT_RANGE_MAP_IPS, ip, ip, { 0 }, { 0 } };

	DEBUGP("Allocating NULL binding for %p (%u.%u.%u.%u)\n", conntrack,
	       NIPQUAD(ip));
	return ip_nat_setup_info(conntrack, &range, hooknum);
}

unsigned int
alloc_null_binding_confirmed(struct ip_conntrack *conntrack,
			     struct ip_nat_info *info,
			     unsigned int hooknum)
{
	__be32 ip
		= (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
		   ? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip
		   : conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip);
	u_int16_t all
		= (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
		   ? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all
		   : conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all);
	struct ip_nat_range range
		= { IP_NAT_RANGE_MAP_IPS, ip, ip, { all }, { all } };

	DEBUGP("Allocating NULL binding for confirmed %p (%u.%u.%u.%u)\n",
	       conntrack, NIPQUAD(ip));
	return ip_nat_setup_info(conntrack, &range, hooknum);
}

int ip_nat_rule_find(struct sk_buff **pskb,
		     unsigned int hooknum,
		     const struct net_device *in,
		     const struct net_device *out,
		     struct ip_conntrack *ct,
		     struct ip_nat_info *info)
{
	int ret;

	ret = ipt_do_table(pskb, hooknum, in, out, &nat_table);

	if (ret == NF_ACCEPT) {
		if (!ip_nat_initialized(ct, HOOK2MANIP(hooknum)))
			/* NUL mapping */
			ret = alloc_null_binding(ct, info, hooknum);
	}
	return ret;
}

static struct xt_target ipt_snat_reg = {
	.name		= "SNAT",
	.family		= AF_INET,
	.target		= ipt_snat_target,
	.targetsize	= sizeof(struct ip_nat_multi_range_compat),
	.table		= "nat",
	.hooks		= 1 << NF_IP_POST_ROUTING,
	.checkentry	= ipt_snat_checkentry,
};

static struct xt_target ipt_dnat_reg = {
	.name		= "DNAT",
	.family		= AF_INET,
	.target		= ipt_dnat_target,
	.targetsize	= sizeof(struct ip_nat_multi_range_compat),
	.table		= "nat",
	.hooks		= (1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT),
	.checkentry	= ipt_dnat_checkentry,
};

int __init ip_nat_rule_init(void)
{
	int ret;

	ret = ipt_register_table(&nat_table, &nat_initial_table.repl);
	if (ret != 0)
		return ret;
	ret = xt_register_target(&ipt_snat_reg);
	if (ret != 0)
		goto unregister_table;

	ret = xt_register_target(&ipt_dnat_reg);
	if (ret != 0)
		goto unregister_snat;

	return ret;

 unregister_snat:
	xt_unregister_target(&ipt_snat_reg);
 unregister_table:
	xt_unregister_table(&nat_table);

	return ret;
}

void ip_nat_rule_cleanup(void)
{
	xt_unregister_target(&ipt_dnat_reg);
	xt_unregister_target(&ipt_snat_reg);
	ipt_unregister_table(&nat_table);
}
Commit	Line	Data
1da177e4 LT	1	/* (C) 1999-2001 Paul `Rusty' Russell
	2	* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	/* Everything about the rules for NAT. */
	10	#include <linux/types.h>
	11	#include <linux/ip.h>
	12	#include <linux/netfilter.h>
	13	#include <linux/netfilter_ipv4.h>
	14	#include <linux/module.h>
	15	#include <linux/kmod.h>
	16	#include <linux/skbuff.h>
	17	#include <linux/proc_fs.h>
	18	#include <net/checksum.h>
	19	#include <net/route.h>
	20	#include <linux/bitops.h>
	21
1da177e4 LT	22	#include <linux/netfilter_ipv4/ip_tables.h>
	23	#include <linux/netfilter_ipv4/ip_nat.h>
	24	#include <linux/netfilter_ipv4/ip_nat_core.h>
	25	#include <linux/netfilter_ipv4/ip_nat_rule.h>
1da177e4 LT	26
	27	#if 0
	28	#define DEBUGP printk
	29	#else
	30	#define DEBUGP(format, args...)
	31	#endif
	32
	33	#define NAT_VALID_HOOKS ((1<<NF_IP_PRE_ROUTING) \| (1<<NF_IP_POST_ROUTING) \| (1<<NF_IP_LOCAL_OUT))
	34
	35	static struct
	36	{
	37	struct ipt_replace repl;
	38	struct ipt_standard entries[3];
	39	struct ipt_error term;
	40	} nat_initial_table __initdata
	41	= { { "nat", NAT_VALID_HOOKS, 4,
	42	sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
	43	{ [NF_IP_PRE_ROUTING] = 0,
	44	[NF_IP_POST_ROUTING] = sizeof(struct ipt_standard),
	45	[NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
	46	{ [NF_IP_PRE_ROUTING] = 0,
	47	[NF_IP_POST_ROUTING] = sizeof(struct ipt_standard),
	48	[NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
	49	0, NULL, { } },
	50	{
	51	/* PRE_ROUTING */
	52	{ { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	53	0,
	54	sizeof(struct ipt_entry),
	55	sizeof(struct ipt_standard),
	56	0, { 0, 0 }, { } },
	57	{ { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
	58	-NF_ACCEPT - 1 } },
	59	/* POST_ROUTING */
	60	{ { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	61	0,
	62	sizeof(struct ipt_entry),
	63	sizeof(struct ipt_standard),
	64	0, { 0, 0 }, { } },
	65	{ { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
	66	-NF_ACCEPT - 1 } },
	67	/* LOCAL_OUT */
	68	{ { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	69	0,
	70	sizeof(struct ipt_entry),
	71	sizeof(struct ipt_standard),
	72	0, { 0, 0 }, { } },
	73	{ { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
	74	-NF_ACCEPT - 1 } }
	75	},
	76	/* ERROR */
	77	{ { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
	78	0,
	79	sizeof(struct ipt_entry),
	80	sizeof(struct ipt_error),
	81	0, { 0, 0 }, { } },
	82	{ { { { IPT_ALIGN(sizeof(struct ipt_error_target)), IPT_ERROR_TARGET } },
	83	{ } },
	84	"ERROR"
	85	}
	86	}
	87	};
	88
e60a13e0	89	static struct xt_table nat_table = {
1da177e4 LT	90	.name = "nat",
	91	.valid_hooks = NAT_VALID_HOOKS,
	92	.lock = RW_LOCK_UNLOCKED,
	93	.me = THIS_MODULE,
2e4e6a17	94	.af = AF_INET,
1da177e4 LT	95	};
	96
	97	/* Source NAT */
	98	static unsigned int ipt_snat_target(struct sk_buff **pskb,
	99	const struct net_device *in,
	100	const struct net_device *out,
	101	unsigned int hooknum,
6709dbbb	102	const struct xt_target *target,
fe1cb108	103	const void *targinfo)
1da177e4 LT	104	{
	105	struct ip_conntrack *ct;
	106	enum ip_conntrack_info ctinfo;
	107	const struct ip_nat_multi_range_compat *mr = targinfo;
	108
	109	IP_NF_ASSERT(hooknum == NF_IP_POST_ROUTING);
	110
	111	ct = ip_conntrack_get(*pskb, &ctinfo);
	112
	113	/* Connection must be valid and new. */
	114	IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW \|\| ctinfo == IP_CT_RELATED
e905a9ed	115	\|\| ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY));
1da177e4 LT	116	IP_NF_ASSERT(out);
	117
	118	return ip_nat_setup_info(ct, &mr->range[0], hooknum);
	119	}
	120
	121	/* Before 2.6.11 we did implicit source NAT if required. Warn about change. */
a76b11dd	122	static void warn_if_extra_mangle(__be32 dstip, __be32 srcip)
1da177e4 LT	123	{
	124	static int warned = 0;
	125	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = dstip } } };
	126	struct rtable *rt;
	127
	128	if (ip_route_output_key(&rt, &fl) != 0)
	129	return;
	130
	131	if (rt->rt_src != srcip && !warned) {
	132	printk("NAT: no longer support implicit source local NAT\n");
	133	printk("NAT: packet src %u.%u.%u.%u -> dst %u.%u.%u.%u\n",
	134	NIPQUAD(srcip), NIPQUAD(dstip));
	135	warned = 1;
	136	}
	137	ip_rt_put(rt);
	138	}
	139
	140	static unsigned int ipt_dnat_target(struct sk_buff **pskb,
	141	const struct net_device *in,
	142	const struct net_device *out,
	143	unsigned int hooknum,
6709dbbb	144	const struct xt_target *target,
fe1cb108	145	const void *targinfo)
1da177e4 LT	146	{
	147	struct ip_conntrack *ct;
	148	enum ip_conntrack_info ctinfo;
	149	const struct ip_nat_multi_range_compat *mr = targinfo;
	150
	151	IP_NF_ASSERT(hooknum == NF_IP_PRE_ROUTING
	152	\|\| hooknum == NF_IP_LOCAL_OUT);
	153
	154	ct = ip_conntrack_get(*pskb, &ctinfo);
	155
	156	/* Connection must be valid and new. */
	157	IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW \|\| ctinfo == IP_CT_RELATED));
	158
	159	if (hooknum == NF_IP_LOCAL_OUT
	160	&& mr->range[0].flags & IP_NAT_RANGE_MAP_IPS)
	161	warn_if_extra_mangle((*pskb)->nh.iph->daddr,
	162	mr->range[0].min_ip);
	163
	164	return ip_nat_setup_info(ct, &mr->range[0], hooknum);
	165	}
	166
	167	static int ipt_snat_checkentry(const char *tablename,
2e4e6a17	168	const void *entry,
6709dbbb	169	const struct xt_target *target,
1da177e4	170	void *targinfo,
1da177e4 LT	171	unsigned int hook_mask)
	172	{
	173	struct ip_nat_multi_range_compat *mr = targinfo;
	174
	175	/* Must be a valid range */
	176	if (mr->rangesize != 1) {
	177	printk("SNAT: multiple ranges no longer supported\n");
	178	return 0;
	179	}
1da177e4 LT	180	return 1;
	181	}
	182
	183	static int ipt_dnat_checkentry(const char *tablename,
2e4e6a17	184	const void *entry,
6709dbbb	185	const struct xt_target *target,
1da177e4	186	void *targinfo,
1da177e4 LT	187	unsigned int hook_mask)
	188	{
	189	struct ip_nat_multi_range_compat *mr = targinfo;
	190
	191	/* Must be a valid range */
	192	if (mr->rangesize != 1) {
	193	printk("DNAT: multiple ranges no longer supported\n");
	194	return 0;
	195	}
41f4689a EL	196	if (mr->range[0].flags & IP_NAT_RANGE_PROTO_RANDOM) {
	197	printk("DNAT: port randomization not supported\n");
	198	return 0;
	199	}
1da177e4 LT	200	return 1;
	201	}
	202
	203	inline unsigned int
	204	alloc_null_binding(struct ip_conntrack *conntrack,
	205	struct ip_nat_info *info,
	206	unsigned int hooknum)
	207	{
	208	/* Force range to this IP; let proto decide mapping for
	209	per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
	210	Use reply in case it's already been mangled (eg local packet).
	211	*/
a76b11dd	212	__be32 ip
1da177e4 LT	213	= (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
	214	? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip
	215	: conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip);
	216	struct ip_nat_range range
	217	= { IP_NAT_RANGE_MAP_IPS, ip, ip, { 0 }, { 0 } };
	218
	219	DEBUGP("Allocating NULL binding for %p (%u.%u.%u.%u)\n", conntrack,
	220	NIPQUAD(ip));
	221	return ip_nat_setup_info(conntrack, &range, hooknum);
	222	}
	223
03486a4f PM	224	unsigned int
03486a4f PM	225	alloc_null_binding_confirmed(struct ip_conntrack *conntrack,
e905a9ed YH	226	struct ip_nat_info *info,
e905a9ed YH	227	unsigned int hooknum)
03486a4f	228	{
a76b11dd	229	__be32 ip
03486a4f PM	230	= (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
	231	? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip
	232	: conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip);
	233	u_int16_t all
	234	= (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
	235	? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all
	236	: conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all);
	237	struct ip_nat_range range
	238	= { IP_NAT_RANGE_MAP_IPS, ip, ip, { all }, { all } };
	239
	240	DEBUGP("Allocating NULL binding for confirmed %p (%u.%u.%u.%u)\n",
	241	conntrack, NIPQUAD(ip));
	242	return ip_nat_setup_info(conntrack, &range, hooknum);
	243	}
	244
1da177e4 LT	245	int ip_nat_rule_find(struct sk_buff **pskb,
	246	unsigned int hooknum,
	247	const struct net_device *in,
	248	const struct net_device *out,
	249	struct ip_conntrack *ct,
	250	struct ip_nat_info *info)
	251	{
	252	int ret;
	253
fe1cb108	254	ret = ipt_do_table(pskb, hooknum, in, out, &nat_table);
1da177e4 LT	255
	256	if (ret == NF_ACCEPT) {
	257	if (!ip_nat_initialized(ct, HOOK2MANIP(hooknum)))
	258	/* NUL mapping */
	259	ret = alloc_null_binding(ct, info, hooknum);
	260	}
	261	return ret;
	262	}
	263
6709dbbb	264	static struct xt_target ipt_snat_reg = {
1da177e4	265	.name = "SNAT",
6709dbbb	266	.family = AF_INET,
1da177e4	267	.target = ipt_snat_target,
1d5cd909 PM	268	.targetsize = sizeof(struct ip_nat_multi_range_compat),
	269	.table = "nat",
	270	.hooks = 1 << NF_IP_POST_ROUTING,
1da177e4 LT	271	.checkentry = ipt_snat_checkentry,
	272	};
	273
6709dbbb	274	static struct xt_target ipt_dnat_reg = {
1da177e4	275	.name = "DNAT",
6709dbbb	276	.family = AF_INET,
1da177e4	277	.target = ipt_dnat_target,
1d5cd909 PM	278	.targetsize = sizeof(struct ip_nat_multi_range_compat),
1d5cd909 PM	279	.table = "nat",
19910d1a	280	.hooks = (1 << NF_IP_PRE_ROUTING) \| (1 << NF_IP_LOCAL_OUT),
1da177e4 LT	281	.checkentry = ipt_dnat_checkentry,
	282	};
	283
	284	int __init ip_nat_rule_init(void)
	285	{
	286	int ret;
	287
	288	ret = ipt_register_table(&nat_table, &nat_initial_table.repl);
	289	if (ret != 0)
	290	return ret;
6709dbbb	291	ret = xt_register_target(&ipt_snat_reg);
1da177e4 LT	292	if (ret != 0)
	293	goto unregister_table;
	294
6709dbbb	295	ret = xt_register_target(&ipt_dnat_reg);
1da177e4 LT	296	if (ret != 0)
	297	goto unregister_snat;
	298
	299	return ret;
	300
	301	unregister_snat:
6709dbbb	302	xt_unregister_target(&ipt_snat_reg);
1da177e4	303	unregister_table:
6709dbbb	304	xt_unregister_table(&nat_table);
1da177e4 LT	305
	306	return ret;
	307	}
	308
	309	void ip_nat_rule_cleanup(void)
	310	{
6709dbbb JE	311	xt_unregister_target(&ipt_dnat_reg);
6709dbbb JE	312	xt_unregister_target(&ipt_snat_reg);
1da177e4 LT	313	ipt_unregister_table(&nat_table);
1da177e4 LT	314	}