net/netfilter/xt_conntrack.c - linux - Git at Google

 /*
  *	xt_conntrack - Netfilter module to match connection tracking
  *	information. (Superset of Rusty's minimalistic state match.)
  *
  *	(C) 2001  Marc Boucher (marc@mbsi.ca).
  *	Copyright © CC Computer Consultants GmbH, 2007 - 2008
  *
  *	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/module.h>
 #include <linux/skbuff.h>
 #include <net/ipv6.h>
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter/xt_conntrack.h>
 #include <net/netfilter/nf_conntrack.h>

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
 MODULE_DESCRIPTION("Xtables: connection tracking state match");
 MODULE_ALIAS("ipt_conntrack");
 MODULE_ALIAS("ip6t_conntrack");

 static bool
 conntrack_addrcmp(const union nf_inet_addr *kaddr,
                   const union nf_inet_addr *uaddr,
                   const union nf_inet_addr *umask, unsigned int l3proto)
 {
 	if (l3proto == NFPROTO_IPV4)
 		return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0;
 	else if (l3proto == NFPROTO_IPV6)
 		return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6,
 		       &uaddr->in6) == 0;
 	else
 		return false;
 }

 static inline bool
 conntrack_mt_origsrc(const struct nf_conn *ct,
                      const struct xt_conntrack_mtinfo2 *info,
 		     u_int8_t family)
 {
 	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3,
 	       &info->origsrc_addr, &info->origsrc_mask, family);
 }

 static inline bool
 conntrack_mt_origdst(const struct nf_conn *ct,
                      const struct xt_conntrack_mtinfo2 *info,
 		     u_int8_t family)
 {
 	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3,
 	       &info->origdst_addr, &info->origdst_mask, family);
 }

 static inline bool
 conntrack_mt_replsrc(const struct nf_conn *ct,
                      const struct xt_conntrack_mtinfo2 *info,
 		     u_int8_t family)
 {
 	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3,
 	       &info->replsrc_addr, &info->replsrc_mask, family);
 }

 static inline bool
 conntrack_mt_repldst(const struct nf_conn *ct,
                      const struct xt_conntrack_mtinfo2 *info,
 		     u_int8_t family)
 {
 	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3,
 	       &info->repldst_addr, &info->repldst_mask, family);
 }

 static inline bool
 ct_proto_port_check(const struct xt_conntrack_mtinfo2 *info,
                     const struct nf_conn *ct)
 {
 	const struct nf_conntrack_tuple *tuple;

 	tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
 	if ((info->match_flags & XT_CONNTRACK_PROTO) &&
 	    (nf_ct_protonum(ct) == info->l4proto) ^
 	    !(info->invert_flags & XT_CONNTRACK_PROTO))
 		return false;

 	/* Shortcut to match all recognized protocols by using ->src.all. */
 	if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) &&
 	    (tuple->src.u.all == info->origsrc_port) ^
 	    !(info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT))
 		return false;

 	if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) &&
 	    (tuple->dst.u.all == info->origdst_port) ^
 	    !(info->invert_flags & XT_CONNTRACK_ORIGDST_PORT))
 		return false;

 	tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;

 	if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) &&
 	    (tuple->src.u.all == info->replsrc_port) ^
 	    !(info->invert_flags & XT_CONNTRACK_REPLSRC_PORT))
 		return false;

 	if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) &&
 	    (tuple->dst.u.all == info->repldst_port) ^
 	    !(info->invert_flags & XT_CONNTRACK_REPLDST_PORT))
 		return false;

 	return true;
 }

 static inline bool
 port_match(u16 min, u16 max, u16 port, bool invert)
 {
 	return (port >= min && port <= max) ^ invert;
 }

 static inline bool
 ct_proto_port_check_v3(const struct xt_conntrack_mtinfo3 *info,
 		       const struct nf_conn *ct)
 {
 	const struct nf_conntrack_tuple *tuple;

 	tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
 	if ((info->match_flags & XT_CONNTRACK_PROTO) &&
 	    (nf_ct_protonum(ct) == info->l4proto) ^
 	    !(info->invert_flags & XT_CONNTRACK_PROTO))
 		return false;

 	/* Shortcut to match all recognized protocols by using ->src.all. */
 	if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) &&
 	    !port_match(info->origsrc_port, info->origsrc_port_high,
 			ntohs(tuple->src.u.all),
 			info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT))
 		return false;

 	if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) &&
 	    !port_match(info->origdst_port, info->origdst_port_high,
 			ntohs(tuple->dst.u.all),
 			info->invert_flags & XT_CONNTRACK_ORIGDST_PORT))
 		return false;

 	tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;

 	if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) &&
 	    !port_match(info->replsrc_port, info->replsrc_port_high,
 			ntohs(tuple->src.u.all),
 			info->invert_flags & XT_CONNTRACK_REPLSRC_PORT))
 		return false;

 	if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) &&
 	    !port_match(info->repldst_port, info->repldst_port_high,
 			ntohs(tuple->dst.u.all),
 			info->invert_flags & XT_CONNTRACK_REPLDST_PORT))
 		return false;

 	return true;
 }

 static bool
 conntrack_mt(const struct sk_buff *skb, struct xt_action_param *par,
              u16 state_mask, u16 status_mask)
 {
 	const struct xt_conntrack_mtinfo2 *info = par->matchinfo;
 	enum ip_conntrack_info ctinfo;
 	const struct nf_conn *ct;
 	unsigned int statebit;

 	ct = nf_ct_get(skb, &ctinfo);

 	if (ct) {
 		if (nf_ct_is_untracked(ct))
 			statebit = XT_CONNTRACK_STATE_UNTRACKED;
 		else
 			statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
 	} else
 		statebit = XT_CONNTRACK_STATE_INVALID;

 	if (info->match_flags & XT_CONNTRACK_STATE) {
 		if (ct != NULL) {
 			if (test_bit(IPS_SRC_NAT_BIT, &ct->status))
 				statebit |= XT_CONNTRACK_STATE_SNAT;
 			if (test_bit(IPS_DST_NAT_BIT, &ct->status))
 				statebit |= XT_CONNTRACK_STATE_DNAT;
 		}
 		if (!!(state_mask & statebit) ^
 		    !(info->invert_flags & XT_CONNTRACK_STATE))
 			return false;
 	}

 	if (ct == NULL)
 		return info->match_flags & XT_CONNTRACK_STATE;
 	if ((info->match_flags & XT_CONNTRACK_DIRECTION) &&
 	    (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^
 	    !(info->invert_flags & XT_CONNTRACK_DIRECTION))
 		return false;

 	if (info->match_flags & XT_CONNTRACK_ORIGSRC)
 		if (conntrack_mt_origsrc(ct, info, par->family) ^
 		    !(info->invert_flags & XT_CONNTRACK_ORIGSRC))
 			return false;

 	if (info->match_flags & XT_CONNTRACK_ORIGDST)
 		if (conntrack_mt_origdst(ct, info, par->family) ^
 		    !(info->invert_flags & XT_CONNTRACK_ORIGDST))
 			return false;

 	if (info->match_flags & XT_CONNTRACK_REPLSRC)
 		if (conntrack_mt_replsrc(ct, info, par->family) ^
 		    !(info->invert_flags & XT_CONNTRACK_REPLSRC))
 			return false;

 	if (info->match_flags & XT_CONNTRACK_REPLDST)
 		if (conntrack_mt_repldst(ct, info, par->family) ^
 		    !(info->invert_flags & XT_CONNTRACK_REPLDST))
 			return false;

 	if (par->match->revision != 3) {
 		if (!ct_proto_port_check(info, ct))
 			return false;
 	} else {
 		if (!ct_proto_port_check_v3(par->matchinfo, ct))
 			return false;
 	}

 	if ((info->match_flags & XT_CONNTRACK_STATUS) &&
 	    (!!(status_mask & ct->status) ^
 	    !(info->invert_flags & XT_CONNTRACK_STATUS)))
 		return false;

 	if (info->match_flags & XT_CONNTRACK_EXPIRES) {
 		unsigned long expires = 0;

 		if (timer_pending(&ct->timeout))
 			expires = (ct->timeout.expires - jiffies) / HZ;
 		if ((expires >= info->expires_min &&
 		    expires <= info->expires_max) ^
 		    !(info->invert_flags & XT_CONNTRACK_EXPIRES))
 			return false;
 	}
 	return true;
 }

 static bool
 conntrack_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
 {
 	const struct xt_conntrack_mtinfo1 *info = par->matchinfo;

 	return conntrack_mt(skb, par, info->state_mask, info->status_mask);
 }

 static bool
 conntrack_mt_v2(const struct sk_buff *skb, struct xt_action_param *par)
 {
 	const struct xt_conntrack_mtinfo2 *info = par->matchinfo;

 	return conntrack_mt(skb, par, info->state_mask, info->status_mask);
 }

 static bool
 conntrack_mt_v3(const struct sk_buff *skb, struct xt_action_param *par)
 {
 	const struct xt_conntrack_mtinfo3 *info = par->matchinfo;

 	return conntrack_mt(skb, par, info->state_mask, info->status_mask);
 }

 static int conntrack_mt_check(const struct xt_mtchk_param *par)
 {
 	int ret;

 	if (strcmp(par->table, "raw") == 0) {
 		pr_info("state is undetermined at the time of raw table\n");
 		return -EINVAL;
 	}

 	ret = nf_ct_l3proto_try_module_get(par->family);
 	if (ret < 0)
 		pr_info("cannot load conntrack support for proto=%u\n",
 			par->family);
 	return ret;
 }

 static void conntrack_mt_destroy(const struct xt_mtdtor_param *par)
 {
 	nf_ct_l3proto_module_put(par->family);
 }

 static struct xt_match conntrack_mt_reg[] __read_mostly = {
 	{
 		.name       = "conntrack",
 		.revision   = 1,
 		.family     = NFPROTO_UNSPEC,
 		.matchsize  = sizeof(struct xt_conntrack_mtinfo1),
 		.match      = conntrack_mt_v1,
 		.checkentry = conntrack_mt_check,
 		.destroy    = conntrack_mt_destroy,
 		.me         = THIS_MODULE,
 	},
 	{
 		.name       = "conntrack",
 		.revision   = 2,
 		.family     = NFPROTO_UNSPEC,
 		.matchsize  = sizeof(struct xt_conntrack_mtinfo2),
 		.match      = conntrack_mt_v2,
 		.checkentry = conntrack_mt_check,
 		.destroy    = conntrack_mt_destroy,
 		.me         = THIS_MODULE,
 	},
 	{
 		.name       = "conntrack",
 		.revision   = 3,
 		.family     = NFPROTO_UNSPEC,
 		.matchsize  = sizeof(struct xt_conntrack_mtinfo3),
 		.match      = conntrack_mt_v3,
 		.checkentry = conntrack_mt_check,
 		.destroy    = conntrack_mt_destroy,
 		.me         = THIS_MODULE,
 	},
 };

 static int __init conntrack_mt_init(void)
 {
 	return xt_register_matches(conntrack_mt_reg,
 	       ARRAY_SIZE(conntrack_mt_reg));
 }

 static void __exit conntrack_mt_exit(void)
 {
 	xt_unregister_matches(conntrack_mt_reg, ARRAY_SIZE(conntrack_mt_reg));
 }

 module_init(conntrack_mt_init);
 module_exit(conntrack_mt_exit);
	/*
	* xt_conntrack - Netfilter module to match connection tracking
	* information. (Superset of Rusty's minimalistic state match.)
	*
	* (C) 2001 Marc Boucher (marc@mbsi.ca).
	* Copyright © CC Computer Consultants GmbH, 2007 - 2008
	*
	* 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/module.h>
	#include <linux/skbuff.h>
	#include <net/ipv6.h>
	#include <linux/netfilter/x_tables.h>
	#include <linux/netfilter/xt_conntrack.h>
	#include <net/netfilter/nf_conntrack.h>

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
	MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
	MODULE_DESCRIPTION("Xtables: connection tracking state match");
	MODULE_ALIAS("ipt_conntrack");
	MODULE_ALIAS("ip6t_conntrack");

	static bool
	conntrack_addrcmp(const union nf_inet_addr *kaddr,
	const union nf_inet_addr *uaddr,
	const union nf_inet_addr *umask, unsigned int l3proto)
	{
	if (l3proto == NFPROTO_IPV4)
	return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0;
	else if (l3proto == NFPROTO_IPV6)
	return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6,
	&uaddr->in6) == 0;
	else
	return false;
	}

	static inline bool
	conntrack_mt_origsrc(const struct nf_conn *ct,
	const struct xt_conntrack_mtinfo2 *info,
	u_int8_t family)
	{
	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3,
	&info->origsrc_addr, &info->origsrc_mask, family);
	}

	static inline bool
	conntrack_mt_origdst(const struct nf_conn *ct,
	const struct xt_conntrack_mtinfo2 *info,
	u_int8_t family)
	{
	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3,
	&info->origdst_addr, &info->origdst_mask, family);
	}

	static inline bool
	conntrack_mt_replsrc(const struct nf_conn *ct,
	const struct xt_conntrack_mtinfo2 *info,
	u_int8_t family)
	{
	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3,
	&info->replsrc_addr, &info->replsrc_mask, family);
	}

	static inline bool
	conntrack_mt_repldst(const struct nf_conn *ct,
	const struct xt_conntrack_mtinfo2 *info,
	u_int8_t family)
	{
	return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3,
	&info->repldst_addr, &info->repldst_mask, family);
	}

	static inline bool
	ct_proto_port_check(const struct xt_conntrack_mtinfo2 *info,
	const struct nf_conn *ct)
	{
	const struct nf_conntrack_tuple *tuple;

	tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
	if ((info->match_flags & XT_CONNTRACK_PROTO) &&
	(nf_ct_protonum(ct) == info->l4proto) ^
	!(info->invert_flags & XT_CONNTRACK_PROTO))
	return false;

	/* Shortcut to match all recognized protocols by using ->src.all. */
	if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) &&
	(tuple->src.u.all == info->origsrc_port) ^
	!(info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT))
	return false;

	if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) &&
	(tuple->dst.u.all == info->origdst_port) ^
	!(info->invert_flags & XT_CONNTRACK_ORIGDST_PORT))
	return false;

	tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;

	if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) &&
	(tuple->src.u.all == info->replsrc_port) ^
	!(info->invert_flags & XT_CONNTRACK_REPLSRC_PORT))
	return false;

	if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) &&
	(tuple->dst.u.all == info->repldst_port) ^
	!(info->invert_flags & XT_CONNTRACK_REPLDST_PORT))
	return false;

	return true;
	}

	static inline bool
	port_match(u16 min, u16 max, u16 port, bool invert)
	{
	return (port >= min && port <= max) ^ invert;
	}

	static inline bool
	ct_proto_port_check_v3(const struct xt_conntrack_mtinfo3 *info,
	const struct nf_conn *ct)
	{
	const struct nf_conntrack_tuple *tuple;

	tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
	if ((info->match_flags & XT_CONNTRACK_PROTO) &&
	(nf_ct_protonum(ct) == info->l4proto) ^
	!(info->invert_flags & XT_CONNTRACK_PROTO))
	return false;

	/* Shortcut to match all recognized protocols by using ->src.all. */
	if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) &&
	!port_match(info->origsrc_port, info->origsrc_port_high,
	ntohs(tuple->src.u.all),
	info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT))
	return false;

	if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) &&
	!port_match(info->origdst_port, info->origdst_port_high,
	ntohs(tuple->dst.u.all),
	info->invert_flags & XT_CONNTRACK_ORIGDST_PORT))
	return false;

	tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;

	if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) &&
	!port_match(info->replsrc_port, info->replsrc_port_high,
	ntohs(tuple->src.u.all),
	info->invert_flags & XT_CONNTRACK_REPLSRC_PORT))
	return false;

	if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) &&
	!port_match(info->repldst_port, info->repldst_port_high,
	ntohs(tuple->dst.u.all),
	info->invert_flags & XT_CONNTRACK_REPLDST_PORT))
	return false;

	return true;
	}

	static bool
	conntrack_mt(const struct sk_buff skb, struct xt_action_param par,
	u16 state_mask, u16 status_mask)
	{
	const struct xt_conntrack_mtinfo2 *info = par->matchinfo;
	enum ip_conntrack_info ctinfo;
	const struct nf_conn *ct;
	unsigned int statebit;

	ct = nf_ct_get(skb, &ctinfo);

	if (ct) {
	if (nf_ct_is_untracked(ct))
	statebit = XT_CONNTRACK_STATE_UNTRACKED;
	else
	statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
	} else
	statebit = XT_CONNTRACK_STATE_INVALID;

	if (info->match_flags & XT_CONNTRACK_STATE) {
	if (ct != NULL) {
	if (test_bit(IPS_SRC_NAT_BIT, &ct->status))
	statebit \|= XT_CONNTRACK_STATE_SNAT;
	if (test_bit(IPS_DST_NAT_BIT, &ct->status))
	statebit \|= XT_CONNTRACK_STATE_DNAT;
	}
	if (!!(state_mask & statebit) ^
	!(info->invert_flags & XT_CONNTRACK_STATE))
	return false;
	}

	if (ct == NULL)
	return info->match_flags & XT_CONNTRACK_STATE;
	if ((info->match_flags & XT_CONNTRACK_DIRECTION) &&
	(CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^
	!(info->invert_flags & XT_CONNTRACK_DIRECTION))
	return false;

	if (info->match_flags & XT_CONNTRACK_ORIGSRC)
	if (conntrack_mt_origsrc(ct, info, par->family) ^
	!(info->invert_flags & XT_CONNTRACK_ORIGSRC))
	return false;

	if (info->match_flags & XT_CONNTRACK_ORIGDST)
	if (conntrack_mt_origdst(ct, info, par->family) ^
	!(info->invert_flags & XT_CONNTRACK_ORIGDST))
	return false;

	if (info->match_flags & XT_CONNTRACK_REPLSRC)
	if (conntrack_mt_replsrc(ct, info, par->family) ^
	!(info->invert_flags & XT_CONNTRACK_REPLSRC))
	return false;

	if (info->match_flags & XT_CONNTRACK_REPLDST)
	if (conntrack_mt_repldst(ct, info, par->family) ^
	!(info->invert_flags & XT_CONNTRACK_REPLDST))
	return false;

	if (par->match->revision != 3) {
	if (!ct_proto_port_check(info, ct))
	return false;
	} else {
	if (!ct_proto_port_check_v3(par->matchinfo, ct))
	return false;
	}

	if ((info->match_flags & XT_CONNTRACK_STATUS) &&
	(!!(status_mask & ct->status) ^
	!(info->invert_flags & XT_CONNTRACK_STATUS)))
	return false;

	if (info->match_flags & XT_CONNTRACK_EXPIRES) {
	unsigned long expires = 0;

	if (timer_pending(&ct->timeout))
	expires = (ct->timeout.expires - jiffies) / HZ;
	if ((expires >= info->expires_min &&
	expires <= info->expires_max) ^
	!(info->invert_flags & XT_CONNTRACK_EXPIRES))
	return false;
	}
	return true;
	}

	static bool
	conntrack_mt_v1(const struct sk_buff skb, struct xt_action_param par)
	{
	const struct xt_conntrack_mtinfo1 *info = par->matchinfo;

	return conntrack_mt(skb, par, info->state_mask, info->status_mask);
	}

	static bool
	conntrack_mt_v2(const struct sk_buff skb, struct xt_action_param par)
	{
	const struct xt_conntrack_mtinfo2 *info = par->matchinfo;

	return conntrack_mt(skb, par, info->state_mask, info->status_mask);
	}

	static bool
	conntrack_mt_v3(const struct sk_buff skb, struct xt_action_param par)
	{
	const struct xt_conntrack_mtinfo3 *info = par->matchinfo;

	return conntrack_mt(skb, par, info->state_mask, info->status_mask);
	}

	static int conntrack_mt_check(const struct xt_mtchk_param *par)
	{
	int ret;

	if (strcmp(par->table, "raw") == 0) {
	pr_info("state is undetermined at the time of raw table\n");
	return -EINVAL;
	}

	ret = nf_ct_l3proto_try_module_get(par->family);
	if (ret < 0)
	pr_info("cannot load conntrack support for proto=%u\n",
	par->family);
	return ret;
	}

	static void conntrack_mt_destroy(const struct xt_mtdtor_param *par)
	{
	nf_ct_l3proto_module_put(par->family);
	}

	static struct xt_match conntrack_mt_reg[] __read_mostly = {
	{
	.name = "conntrack",
	.revision = 1,
	.family = NFPROTO_UNSPEC,
	.matchsize = sizeof(struct xt_conntrack_mtinfo1),
	.match = conntrack_mt_v1,
	.checkentry = conntrack_mt_check,
	.destroy = conntrack_mt_destroy,
	.me = THIS_MODULE,
	},
	{
	.name = "conntrack",
	.revision = 2,
	.family = NFPROTO_UNSPEC,
	.matchsize = sizeof(struct xt_conntrack_mtinfo2),
	.match = conntrack_mt_v2,
	.checkentry = conntrack_mt_check,
	.destroy = conntrack_mt_destroy,
	.me = THIS_MODULE,
	},
	{
	.name = "conntrack",
	.revision = 3,
	.family = NFPROTO_UNSPEC,
	.matchsize = sizeof(struct xt_conntrack_mtinfo3),
	.match = conntrack_mt_v3,
	.checkentry = conntrack_mt_check,
	.destroy = conntrack_mt_destroy,
	.me = THIS_MODULE,
	},
	};

	static int __init conntrack_mt_init(void)
	{
	return xt_register_matches(conntrack_mt_reg,
	ARRAY_SIZE(conntrack_mt_reg));
	}

	static void __exit conntrack_mt_exit(void)
	{
	xt_unregister_matches(conntrack_mt_reg, ARRAY_SIZE(conntrack_mt_reg));
	}

	module_init(conntrack_mt_init);
	module_exit(conntrack_mt_exit);