[linux-2.6-block.git] / net / sched / act_nat.c

/*
 * Stateless NAT actions
 *
 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/tc_act/tc_nat.h>
#include <net/act_api.h>
#include <net/icmp.h>
#include <net/ip.h>
#include <net/netlink.h>
#include <net/tc_act/tc_nat.h>
#include <net/tcp.h>
#include <net/udp.h>


static unsigned int nat_net_id;
static struct tc_action_ops act_nat_ops;

static const struct nla_policy nat_policy[TCA_NAT_MAX + 1] = {
	[TCA_NAT_PARMS]	= { .len = sizeof(struct tc_nat) },
};

static int tcf_nat_init(struct net *net, struct nlattr *nla, struct nlattr *est,
			struct tc_action **a, int ovr, int bind,
			bool rtnl_held, struct netlink_ext_ack *extack)
{
	struct tc_action_net *tn = net_generic(net, nat_net_id);
	struct nlattr *tb[TCA_NAT_MAX + 1];
	struct tc_nat *parm;
	int ret = 0, err;
	struct tcf_nat *p;

	if (nla == NULL)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_NAT_MAX, nla, nat_policy, NULL);
	if (err < 0)
		return err;

	if (tb[TCA_NAT_PARMS] == NULL)
		return -EINVAL;
	parm = nla_data(tb[TCA_NAT_PARMS]);

	err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
	if (!err) {
		ret = tcf_idr_create(tn, parm->index, est, a,
				     &act_nat_ops, bind, false);
		if (ret) {
			tcf_idr_cleanup(tn, parm->index);
			return ret;
		}
		ret = ACT_P_CREATED;
	} else if (err > 0) {
		if (bind)
			return 0;
		if (!ovr) {
			tcf_idr_release(*a, bind);
			return -EEXIST;
		}
	} else {
		return err;
	}
	p = to_tcf_nat(*a);

	spin_lock_bh(&p->tcf_lock);
	p->old_addr = parm->old_addr;
	p->new_addr = parm->new_addr;
	p->mask = parm->mask;
	p->flags = parm->flags;

	p->tcf_action = parm->action;
	spin_unlock_bh(&p->tcf_lock);

	if (ret == ACT_P_CREATED)
		tcf_idr_insert(tn, *a);

	return ret;
}

static int tcf_nat_act(struct sk_buff *skb, const struct tc_action *a,
		       struct tcf_result *res)
{
	struct tcf_nat *p = to_tcf_nat(a);
	struct iphdr *iph;
	__be32 old_addr;
	__be32 new_addr;
	__be32 mask;
	__be32 addr;
	int egress;
	int action;
	int ihl;
	int noff;

	spin_lock(&p->tcf_lock);

	tcf_lastuse_update(&p->tcf_tm);
	old_addr = p->old_addr;
	new_addr = p->new_addr;
	mask = p->mask;
	egress = p->flags & TCA_NAT_FLAG_EGRESS;
	action = p->tcf_action;

	bstats_update(&p->tcf_bstats, skb);

	spin_unlock(&p->tcf_lock);

	if (unlikely(action == TC_ACT_SHOT))
		goto drop;

	noff = skb_network_offset(skb);
	if (!pskb_may_pull(skb, sizeof(*iph) + noff))
		goto drop;

	iph = ip_hdr(skb);

	if (egress)
		addr = iph->saddr;
	else
		addr = iph->daddr;

	if (!((old_addr ^ addr) & mask)) {
		if (skb_try_make_writable(skb, sizeof(*iph) + noff))
			goto drop;

		new_addr &= mask;
		new_addr |= addr & ~mask;

		/* Rewrite IP header */
		iph = ip_hdr(skb);
		if (egress)
			iph->saddr = new_addr;
		else
			iph->daddr = new_addr;

		csum_replace4(&iph->check, addr, new_addr);
	} else if ((iph->frag_off & htons(IP_OFFSET)) ||
		   iph->protocol != IPPROTO_ICMP) {
		goto out;
	}

	ihl = iph->ihl * 4;

	/* It would be nice to share code with stateful NAT. */
	switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
	case IPPROTO_TCP:
	{
		struct tcphdr *tcph;

		if (!pskb_may_pull(skb, ihl + sizeof(*tcph) + noff) ||
		    skb_try_make_writable(skb, ihl + sizeof(*tcph) + noff))
			goto drop;

		tcph = (void *)(skb_network_header(skb) + ihl);
		inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr,
					 true);
		break;
	}
	case IPPROTO_UDP:
	{
		struct udphdr *udph;

		if (!pskb_may_pull(skb, ihl + sizeof(*udph) + noff) ||
		    skb_try_make_writable(skb, ihl + sizeof(*udph) + noff))
			goto drop;

		udph = (void *)(skb_network_header(skb) + ihl);
		if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
			inet_proto_csum_replace4(&udph->check, skb, addr,
						 new_addr, true);
			if (!udph->check)
				udph->check = CSUM_MANGLED_0;
		}
		break;
	}
	case IPPROTO_ICMP:
	{
		struct icmphdr *icmph;

		if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + noff))
			goto drop;

		icmph = (void *)(skb_network_header(skb) + ihl);

		if ((icmph->type != ICMP_DEST_UNREACH) &&
		    (icmph->type != ICMP_TIME_EXCEEDED) &&
		    (icmph->type != ICMP_PARAMETERPROB))
			break;

		if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + sizeof(*iph) +
					noff))
			goto drop;

		icmph = (void *)(skb_network_header(skb) + ihl);
		iph = (void *)(icmph + 1);
		if (egress)
			addr = iph->daddr;
		else
			addr = iph->saddr;

		if ((old_addr ^ addr) & mask)
			break;

		if (skb_try_make_writable(skb, ihl + sizeof(*icmph) +
					  sizeof(*iph) + noff))
			goto drop;

		icmph = (void *)(skb_network_header(skb) + ihl);
		iph = (void *)(icmph + 1);

		new_addr &= mask;
		new_addr |= addr & ~mask;

		/* XXX Fix up the inner checksums. */
		if (egress)
			iph->daddr = new_addr;
		else
			iph->saddr = new_addr;

		inet_proto_csum_replace4(&icmph->checksum, skb, addr, new_addr,
					 false);
		break;
	}
	default:
		break;
	}

out:
	return action;

drop:
	spin_lock(&p->tcf_lock);
	p->tcf_qstats.drops++;
	spin_unlock(&p->tcf_lock);
	return TC_ACT_SHOT;
}

static int tcf_nat_dump(struct sk_buff *skb, struct tc_action *a,
			int bind, int ref)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_nat *p = to_tcf_nat(a);
	struct tc_nat opt = {
		.index    = p->tcf_index,
		.refcnt   = refcount_read(&p->tcf_refcnt) - ref,
		.bindcnt  = atomic_read(&p->tcf_bindcnt) - bind,
	};
	struct tcf_t t;

	spin_lock_bh(&p->tcf_lock);
	opt.old_addr = p->old_addr;
	opt.new_addr = p->new_addr;
	opt.mask = p->mask;
	opt.flags = p->flags;
	opt.action = p->tcf_action;

	if (nla_put(skb, TCA_NAT_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;

	tcf_tm_dump(&t, &p->tcf_tm);
	if (nla_put_64bit(skb, TCA_NAT_TM, sizeof(t), &t, TCA_NAT_PAD))
		goto nla_put_failure;
	spin_unlock_bh(&p->tcf_lock);

	return skb->len;

nla_put_failure:
	spin_unlock_bh(&p->tcf_lock);
	nlmsg_trim(skb, b);
	return -1;
}

static int tcf_nat_walker(struct net *net, struct sk_buff *skb,
			  struct netlink_callback *cb, int type,
			  const struct tc_action_ops *ops,
			  struct netlink_ext_ack *extack)
{
	struct tc_action_net *tn = net_generic(net, nat_net_id);

	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
}

static int tcf_nat_search(struct net *net, struct tc_action **a, u32 index)
{
	struct tc_action_net *tn = net_generic(net, nat_net_id);

	return tcf_idr_search(tn, a, index);
}

static struct tc_action_ops act_nat_ops = {
	.kind		=	"nat",
	.type		=	TCA_ACT_NAT,
	.owner		=	THIS_MODULE,
	.act		=	tcf_nat_act,
	.dump		=	tcf_nat_dump,
	.init		=	tcf_nat_init,
	.walk		=	tcf_nat_walker,
	.lookup		=	tcf_nat_search,
	.size		=	sizeof(struct tcf_nat),
};

static __net_init int nat_init_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, nat_net_id);

	return tc_action_net_init(tn, &act_nat_ops);
}

static void __net_exit nat_exit_net(struct list_head *net_list)
{
	tc_action_net_exit(net_list, nat_net_id);
}

static struct pernet_operations nat_net_ops = {
	.init = nat_init_net,
	.exit_batch = nat_exit_net,
	.id   = &nat_net_id,
	.size = sizeof(struct tc_action_net),
};

MODULE_DESCRIPTION("Stateless NAT actions");
MODULE_LICENSE("GPL");

static int __init nat_init_module(void)
{
	return tcf_register_action(&act_nat_ops, &nat_net_ops);
}

static void __exit nat_cleanup_module(void)
{
	tcf_unregister_action(&act_nat_ops, &nat_net_ops);
}

module_init(nat_init_module);
module_exit(nat_cleanup_module);
Commit	Line	Data
b4219952 HX	1	/*
	2	* Stateless NAT actions
	3	*
	4	* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the Free
	8	* Software Foundation; either version 2 of the License, or (at your option)
	9	* any later version.
	10	*/
	11
	12	#include <linux/errno.h>
	13	#include <linux/init.h>
	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
	16	#include <linux/netfilter.h>
	17	#include <linux/rtnetlink.h>
	18	#include <linux/skbuff.h>
	19	#include <linux/slab.h>
	20	#include <linux/spinlock.h>
	21	#include <linux/string.h>
	22	#include <linux/tc_act/tc_nat.h>
	23	#include <net/act_api.h>
	24	#include <net/icmp.h>
	25	#include <net/ip.h>
	26	#include <net/netlink.h>
	27	#include <net/tc_act/tc_nat.h>
	28	#include <net/tcp.h>
	29	#include <net/udp.h>
	30
	31
c7d03a00	32	static unsigned int nat_net_id;
a85a970a	33	static struct tc_action_ops act_nat_ops;
ddf97ccd	34
53b2bf3f PM	35	static const struct nla_policy nat_policy[TCA_NAT_MAX + 1] = {
	36	[TCA_NAT_PARMS] = { .len = sizeof(struct tc_nat) },
	37	};
	38
c1b52739	39	static int tcf_nat_init(struct net net, struct nlattr nla, struct nlattr *est,
589dad6d	40	struct tc_action **a, int ovr, int bind,
789871bb	41	bool rtnl_held, struct netlink_ext_ack *extack)
b4219952	42	{
ddf97ccd	43	struct tc_action_net *tn = net_generic(net, nat_net_id);
7ba699c6	44	struct nlattr *tb[TCA_NAT_MAX + 1];
b4219952	45	struct tc_nat *parm;
cee63723	46	int ret = 0, err;
b4219952	47	struct tcf_nat *p;
b4219952	48
cee63723	49	if (nla == NULL)
b4219952 HX	50	return -EINVAL;
b4219952 HX	51
fceb6435	52	err = nla_parse_nested(tb, TCA_NAT_MAX, nla, nat_policy, NULL);
cee63723 PM	53	if (err < 0)
	54	return err;
	55
53b2bf3f	56	if (tb[TCA_NAT_PARMS] == NULL)
b4219952	57	return -EINVAL;
7ba699c6	58	parm = nla_data(tb[TCA_NAT_PARMS]);
b4219952	59
0190c1d4 VB	60	err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
0190c1d4 VB	61	if (!err) {
65a206c0 CM	62	ret = tcf_idr_create(tn, parm->index, est, a,
65a206c0 CM	63	&act_nat_ops, bind, false);
0190c1d4 VB	64	if (ret) {
0190c1d4 VB	65	tcf_idr_cleanup(tn, parm->index);
86062033	66	return ret;
0190c1d4	67	}
b4219952	68	ret = ACT_P_CREATED;
0190c1d4	69	} else if (err > 0) {
1a29321e JHS	70	if (bind)
1a29321e JHS	71	return 0;
4e8ddd7f VB	72	if (!ovr) {
4e8ddd7f VB	73	tcf_idr_release(*a, bind);
b4219952	74	return -EEXIST;
4e8ddd7f	75	}
0190c1d4 VB	76	} else {
0190c1d4 VB	77	return err;
b4219952	78	}
a85a970a	79	p = to_tcf_nat(*a);
b4219952 HX	80
	81	spin_lock_bh(&p->tcf_lock);
	82	p->old_addr = parm->old_addr;
	83	p->new_addr = parm->new_addr;
	84	p->mask = parm->mask;
	85	p->flags = parm->flags;
	86
	87	p->tcf_action = parm->action;
	88	spin_unlock_bh(&p->tcf_lock);
	89
	90	if (ret == ACT_P_CREATED)
65a206c0	91	tcf_idr_insert(tn, *a);
b4219952 HX	92
	93	return ret;
	94	}
	95
0390514f JHS	96	static int tcf_nat_act(struct sk_buff skb, const struct tc_action a,
0390514f JHS	97	struct tcf_result *res)
b4219952	98	{
a85a970a	99	struct tcf_nat *p = to_tcf_nat(a);
b4219952 HX	100	struct iphdr *iph;
	101	__be32 old_addr;
	102	__be32 new_addr;
	103	__be32 mask;
	104	__be32 addr;
	105	int egress;
	106	int action;
	107	int ihl;
36d12690	108	int noff;
b4219952 HX	109
	110	spin_lock(&p->tcf_lock);
	111
9c4a4e48	112	tcf_lastuse_update(&p->tcf_tm);
b4219952 HX	113	old_addr = p->old_addr;
	114	new_addr = p->new_addr;
	115	mask = p->mask;
	116	egress = p->flags & TCA_NAT_FLAG_EGRESS;
	117	action = p->tcf_action;
	118
bfe0d029	119	bstats_update(&p->tcf_bstats, skb);
b4219952 HX	120
	121	spin_unlock(&p->tcf_lock);
	122
	123	if (unlikely(action == TC_ACT_SHOT))
	124	goto drop;
	125
36d12690 CG	126	noff = skb_network_offset(skb);
36d12690 CG	127	if (!pskb_may_pull(skb, sizeof(*iph) + noff))
b4219952 HX	128	goto drop;
	129
	130	iph = ip_hdr(skb);
	131
	132	if (egress)
	133	addr = iph->saddr;
	134	else
	135	addr = iph->daddr;
	136
	137	if (!((old_addr ^ addr) & mask)) {
3697649f	138	if (skb_try_make_writable(skb, sizeof(*iph) + noff))
b4219952 HX	139	goto drop;
	140
	141	new_addr &= mask;
	142	new_addr \|= addr & ~mask;
	143
	144	/* Rewrite IP header */
	145	iph = ip_hdr(skb);
	146	if (egress)
	147	iph->saddr = new_addr;
	148	else
	149	iph->daddr = new_addr;
	150
be0ea7d5	151	csum_replace4(&iph->check, addr, new_addr);
33c29dde CG	152	} else if ((iph->frag_off & htons(IP_OFFSET)) \|\|
	153	iph->protocol != IPPROTO_ICMP) {
	154	goto out;
b4219952 HX	155	}
	156
	157	ihl = iph->ihl * 4;
	158
	159	/* It would be nice to share code with stateful NAT. */
	160	switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
	161	case IPPROTO_TCP:
	162	{
	163	struct tcphdr *tcph;
	164
36d12690	165	if (!pskb_may_pull(skb, ihl + sizeof(*tcph) + noff) \|\|
3697649f	166	skb_try_make_writable(skb, ihl + sizeof(*tcph) + noff))
b4219952 HX	167	goto drop;
	168
	169	tcph = (void *)(skb_network_header(skb) + ihl);
4b048d6d TH	170	inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr,
4b048d6d TH	171	true);
b4219952 HX	172	break;
	173	}
	174	case IPPROTO_UDP:
	175	{
	176	struct udphdr *udph;
	177
36d12690	178	if (!pskb_may_pull(skb, ihl + sizeof(*udph) + noff) \|\|
3697649f	179	skb_try_make_writable(skb, ihl + sizeof(*udph) + noff))
b4219952 HX	180	goto drop;
	181
	182	udph = (void *)(skb_network_header(skb) + ihl);
	183	if (udph->check \|\| skb->ip_summed == CHECKSUM_PARTIAL) {
be0ea7d5	184	inet_proto_csum_replace4(&udph->check, skb, addr,
4b048d6d	185	new_addr, true);
b4219952 HX	186	if (!udph->check)
	187	udph->check = CSUM_MANGLED_0;
	188	}
	189	break;
	190	}
	191	case IPPROTO_ICMP:
	192	{
	193	struct icmphdr *icmph;
	194
36d12690	195	if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + noff))
b4219952 HX	196	goto drop;
	197
	198	icmph = (void *)(skb_network_header(skb) + ihl);
	199
	200	if ((icmph->type != ICMP_DEST_UNREACH) &&
	201	(icmph->type != ICMP_TIME_EXCEEDED) &&
	202	(icmph->type != ICMP_PARAMETERPROB))
	203	break;
	204
36d12690 CG	205	if (!pskb_may_pull(skb, ihl + sizeof(icmph) + sizeof(iph) +
36d12690 CG	206	noff))
70c2efa5 CG	207	goto drop;
70c2efa5 CG	208
072d79a3	209	icmph = (void *)(skb_network_header(skb) + ihl);
b4219952 HX	210	iph = (void *)(icmph + 1);
	211	if (egress)
	212	addr = iph->daddr;
	213	else
	214	addr = iph->saddr;
	215
	216	if ((old_addr ^ addr) & mask)
	217	break;
	218
3697649f DB	219	if (skb_try_make_writable(skb, ihl + sizeof(*icmph) +
3697649f DB	220	sizeof(*iph) + noff))
b4219952 HX	221	goto drop;
	222
	223	icmph = (void *)(skb_network_header(skb) + ihl);
	224	iph = (void *)(icmph + 1);
	225
	226	new_addr &= mask;
	227	new_addr \|= addr & ~mask;
	228
	229	/* XXX Fix up the inner checksums. */
	230	if (egress)
	231	iph->daddr = new_addr;
	232	else
	233	iph->saddr = new_addr;
	234
be0ea7d5	235	inet_proto_csum_replace4(&icmph->checksum, skb, addr, new_addr,
4b048d6d	236	false);
b4219952 HX	237	break;
	238	}
	239	default:
	240	break;
	241	}
	242
33c29dde	243	out:
b4219952 HX	244	return action;
	245
	246	drop:
	247	spin_lock(&p->tcf_lock);
	248	p->tcf_qstats.drops++;
	249	spin_unlock(&p->tcf_lock);
	250	return TC_ACT_SHOT;
	251	}
	252
	253	static int tcf_nat_dump(struct sk_buff skb, struct tc_action a,
	254	int bind, int ref)
	255	{
	256	unsigned char *b = skb_tail_pointer(skb);
a85a970a	257	struct tcf_nat *p = to_tcf_nat(a);
1c40be12	258	struct tc_nat opt = {
1c40be12	259	.index = p->tcf_index,
036bb443 VB	260	.refcnt = refcount_read(&p->tcf_refcnt) - ref,
036bb443 VB	261	.bindcnt = atomic_read(&p->tcf_bindcnt) - bind,
1c40be12	262	};
b4219952	263	struct tcf_t t;
b4219952	264
f20a4d01 VB	265	spin_lock_bh(&p->tcf_lock);
	266	opt.old_addr = p->old_addr;
	267	opt.new_addr = p->new_addr;
	268	opt.mask = p->mask;
	269	opt.flags = p->flags;
	270	opt.action = p->tcf_action;
	271
1b34ec43 DM	272	if (nla_put(skb, TCA_NAT_PARMS, sizeof(opt), &opt))
1b34ec43 DM	273	goto nla_put_failure;
48d8ee16 JHS	274
48d8ee16 JHS	275	tcf_tm_dump(&t, &p->tcf_tm);
9854518e	276	if (nla_put_64bit(skb, TCA_NAT_TM, sizeof(t), &t, TCA_NAT_PAD))
1b34ec43	277	goto nla_put_failure;
f20a4d01	278	spin_unlock_bh(&p->tcf_lock);
b4219952	279
b4219952 HX	280	return skb->len;
b4219952 HX	281
7ba699c6	282	nla_put_failure:
f20a4d01	283	spin_unlock_bh(&p->tcf_lock);
b4219952	284	nlmsg_trim(skb, b);
b4219952 HX	285	return -1;
	286	}
	287
ddf97ccd WC	288	static int tcf_nat_walker(struct net net, struct sk_buff skb,
ddf97ccd WC	289	struct netlink_callback *cb, int type,
41780105 AA	290	const struct tc_action_ops *ops,
41780105 AA	291	struct netlink_ext_ack *extack)
ddf97ccd WC	292	{
	293	struct tc_action_net *tn = net_generic(net, nat_net_id);
	294
b3620145	295	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
ddf97ccd WC	296	}
ddf97ccd WC	297
f061b48c	298	static int tcf_nat_search(struct net net, struct tc_action *a, u32 index)
ddf97ccd WC	299	{
	300	struct tc_action_net *tn = net_generic(net, nat_net_id);
	301
65a206c0	302	return tcf_idr_search(tn, a, index);
ddf97ccd WC	303	}
ddf97ccd WC	304
b4219952 HX	305	static struct tc_action_ops act_nat_ops = {
b4219952 HX	306	.kind = "nat",
b4219952	307	.type = TCA_ACT_NAT,
b4219952	308	.owner = THIS_MODULE,
0390514f	309	.act = tcf_nat_act,
b4219952	310	.dump = tcf_nat_dump,
b4219952	311	.init = tcf_nat_init,
ddf97ccd WC	312	.walk = tcf_nat_walker,
ddf97ccd WC	313	.lookup = tcf_nat_search,
a85a970a	314	.size = sizeof(struct tcf_nat),
ddf97ccd WC	315	};
	316
	317	static __net_init int nat_init_net(struct net *net)
	318	{
	319	struct tc_action_net *tn = net_generic(net, nat_net_id);
	320
c7e460ce	321	return tc_action_net_init(tn, &act_nat_ops);
ddf97ccd WC	322	}
ddf97ccd WC	323
039af9c6	324	static void __net_exit nat_exit_net(struct list_head *net_list)
ddf97ccd	325	{
039af9c6	326	tc_action_net_exit(net_list, nat_net_id);
ddf97ccd WC	327	}
	328
	329	static struct pernet_operations nat_net_ops = {
	330	.init = nat_init_net,
039af9c6	331	.exit_batch = nat_exit_net,
ddf97ccd WC	332	.id = &nat_net_id,
ddf97ccd WC	333	.size = sizeof(struct tc_action_net),
b4219952 HX	334	};
	335
	336	MODULE_DESCRIPTION("Stateless NAT actions");
	337	MODULE_LICENSE("GPL");
	338
	339	static int __init nat_init_module(void)
	340	{
ddf97ccd	341	return tcf_register_action(&act_nat_ops, &nat_net_ops);
b4219952 HX	342	}
	343
	344	static void __exit nat_cleanup_module(void)
	345	{
ddf97ccd	346	tcf_unregister_action(&act_nat_ops, &nat_net_ops);
b4219952 HX	347	}
	348
	349	module_init(nat_init_module);
	350	module_exit(nat_cleanup_module);