[deliverable/linux.git] / net / ipv4 / netfilter / nf_nat_h323.c

/*
 * H.323 extension for NAT alteration.
 *
 * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
 *
 * This source code is licensed under General Public License version 2.
 *
 * Based on the 'brute force' H.323 NAT module by
 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/tcp.h>
#include <net/tcp.h>

#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_helper.h>
#include <net/netfilter/nf_nat_rule.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <linux/netfilter/nf_conntrack_h323.h>

/****************************************************************************/
static int set_addr(struct sk_buff *skb,
		    unsigned char **data, int dataoff,
		    unsigned int addroff, __be32 ip, __be16 port)
{
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
	struct {
		__be32 ip;
		__be16 port;
	} __attribute__ ((__packed__)) buf;
	const struct tcphdr *th;
	struct tcphdr _tcph;

	buf.ip = ip;
	buf.port = port;
	addroff += dataoff;

	if (ip_hdr(skb)->protocol == IPPROTO_TCP) {
		if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
					      addroff, sizeof(buf),
					      (char *) &buf, sizeof(buf))) {
			if (net_ratelimit())
				printk("nf_nat_h323: nf_nat_mangle_tcp_packet"
				       " error\n");
			return -1;
		}

		/* Relocate data pointer */
		th = skb_header_pointer(skb, ip_hdrlen(skb),
					sizeof(_tcph), &_tcph);
		if (th == NULL)
			return -1;
		*data = skb->data + ip_hdrlen(skb) + th->doff * 4 + dataoff;
	} else {
		if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
					      addroff, sizeof(buf),
					      (char *) &buf, sizeof(buf))) {
			if (net_ratelimit())
				printk("nf_nat_h323: nf_nat_mangle_udp_packet"
				       " error\n");
			return -1;
		}
		/* nf_nat_mangle_udp_packet uses skb_make_writable() to copy
		 * or pull everything in a linear buffer, so we can safely
		 * use the skb pointers now */
		*data = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
	}

	return 0;
}

/****************************************************************************/
static int set_h225_addr(struct sk_buff *skb,
			 unsigned char **data, int dataoff,
			 TransportAddress *taddr,
			 union nf_inet_addr *addr, __be16 port)
{
	return set_addr(skb, data, dataoff, taddr->ipAddress.ip,
			addr->ip, port);
}

/****************************************************************************/
static int set_h245_addr(struct sk_buff *skb,
			 unsigned char **data, int dataoff,
			 H245_TransportAddress *taddr,
			 union nf_inet_addr *addr, __be16 port)
{
	return set_addr(skb, data, dataoff,
			taddr->unicastAddress.iPAddress.network,
			addr->ip, port);
}

/****************************************************************************/
static int set_sig_addr(struct sk_buff *skb, struct nf_conn *ct,
			enum ip_conntrack_info ctinfo,
			unsigned char **data,
			TransportAddress *taddr, int count)
{
	const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
	int dir = CTINFO2DIR(ctinfo);
	int i;
	__be16 port;
	union nf_inet_addr addr;

	for (i = 0; i < count; i++) {
		if (get_h225_addr(ct, *data, &taddr[i], &addr, &port)) {
			if (addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
			    port == info->sig_port[dir]) {
				/* GW->GK */

				/* Fix for Gnomemeeting */
				if (i > 0 &&
				    get_h225_addr(ct, *data, &taddr[0],
						  &addr, &port) &&
				    (ntohl(addr.ip) & 0xff000000) == 0x7f000000)
					i = 0;

				pr_debug("nf_nat_ras: set signal address "
					 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
					 NIPQUAD(addr.ip), port,
					 NIPQUAD(ct->tuplehash[!dir].tuple.dst.u3.ip),
					 info->sig_port[!dir]);
				return set_h225_addr(skb, data, 0, &taddr[i],
						     &ct->tuplehash[!dir].
						     tuple.dst.u3,
						     info->sig_port[!dir]);
			} else if (addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip &&
				   port == info->sig_port[dir]) {
				/* GK->GW */
				pr_debug("nf_nat_ras: set signal address "
					 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
					 NIPQUAD(addr.ip), port,
					 NIPQUAD(ct->tuplehash[!dir].tuple.src.u3.ip),
					 info->sig_port[!dir]);
				return set_h225_addr(skb, data, 0, &taddr[i],
						     &ct->tuplehash[!dir].
						     tuple.src.u3,
						     info->sig_port[!dir]);
			}
		}
	}

	return 0;
}

/****************************************************************************/
static int set_ras_addr(struct sk_buff *skb, struct nf_conn *ct,
			enum ip_conntrack_info ctinfo,
			unsigned char **data,
			TransportAddress *taddr, int count)
{
	int dir = CTINFO2DIR(ctinfo);
	int i;
	__be16 port;
	union nf_inet_addr addr;

	for (i = 0; i < count; i++) {
		if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
		    addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
		    port == ct->tuplehash[dir].tuple.src.u.udp.port) {
			pr_debug("nf_nat_ras: set rasAddress "
				 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
				 NIPQUAD(addr.ip), ntohs(port),
				 NIPQUAD(ct->tuplehash[!dir].tuple.dst.u3.ip),
				 ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port));
			return set_h225_addr(skb, data, 0, &taddr[i],
					     &ct->tuplehash[!dir].tuple.dst.u3,
					     ct->tuplehash[!dir].tuple.
								dst.u.udp.port);
		}
	}

	return 0;
}

/****************************************************************************/
static int nat_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
			enum ip_conntrack_info ctinfo,
			unsigned char **data, int dataoff,
			H245_TransportAddress *taddr,
			__be16 port, __be16 rtp_port,
			struct nf_conntrack_expect *rtp_exp,
			struct nf_conntrack_expect *rtcp_exp)
{
	struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
	int dir = CTINFO2DIR(ctinfo);
	int i;
	u_int16_t nated_port;

	/* Set expectations for NAT */
	rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port;
	rtp_exp->expectfn = nf_nat_follow_master;
	rtp_exp->dir = !dir;
	rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port;
	rtcp_exp->expectfn = nf_nat_follow_master;
	rtcp_exp->dir = !dir;

	/* Lookup existing expects */
	for (i = 0; i < H323_RTP_CHANNEL_MAX; i++) {
		if (info->rtp_port[i][dir] == rtp_port) {
			/* Expected */

			/* Use allocated ports first. This will refresh
			 * the expects */
			rtp_exp->tuple.dst.u.udp.port = info->rtp_port[i][dir];
			rtcp_exp->tuple.dst.u.udp.port =
			    htons(ntohs(info->rtp_port[i][dir]) + 1);
			break;
		} else if (info->rtp_port[i][dir] == 0) {
			/* Not expected */
			break;
		}
	}

	/* Run out of expectations */
	if (i >= H323_RTP_CHANNEL_MAX) {
		if (net_ratelimit())
			printk("nf_nat_h323: out of expectations\n");
		return 0;
	}

	/* Try to get a pair of ports. */
	for (nated_port = ntohs(rtp_exp->tuple.dst.u.udp.port);
	     nated_port != 0; nated_port += 2) {
		rtp_exp->tuple.dst.u.udp.port = htons(nated_port);
		if (nf_ct_expect_related(rtp_exp) == 0) {
			rtcp_exp->tuple.dst.u.udp.port =
			    htons(nated_port + 1);
			if (nf_ct_expect_related(rtcp_exp) == 0)
				break;
			nf_ct_unexpect_related(rtp_exp);
		}
	}

	if (nated_port == 0) {	/* No port available */
		if (net_ratelimit())
			printk("nf_nat_h323: out of RTP ports\n");
		return 0;
	}

	/* Modify signal */
	if (set_h245_addr(skb, data, dataoff, taddr,
			  &ct->tuplehash[!dir].tuple.dst.u3,
			  htons((port & htons(1)) ? nated_port + 1 :
						    nated_port)) == 0) {
		/* Save ports */
		info->rtp_port[i][dir] = rtp_port;
		info->rtp_port[i][!dir] = htons(nated_port);
	} else {
		nf_ct_unexpect_related(rtp_exp);
		nf_ct_unexpect_related(rtcp_exp);
		return -1;
	}

	/* Success */
	pr_debug("nf_nat_h323: expect RTP %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
		 NIPQUAD(rtp_exp->tuple.src.u3.ip),
		 ntohs(rtp_exp->tuple.src.u.udp.port),
		 NIPQUAD(rtp_exp->tuple.dst.u3.ip),
		 ntohs(rtp_exp->tuple.dst.u.udp.port));
	pr_debug("nf_nat_h323: expect RTCP %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
		 NIPQUAD(rtcp_exp->tuple.src.u3.ip),
		 ntohs(rtcp_exp->tuple.src.u.udp.port),
		 NIPQUAD(rtcp_exp->tuple.dst.u3.ip),
		 ntohs(rtcp_exp->tuple.dst.u.udp.port));

	return 0;
}

/****************************************************************************/
static int nat_t120(struct sk_buff *skb, struct nf_conn *ct,
		    enum ip_conntrack_info ctinfo,
		    unsigned char **data, int dataoff,
		    H245_TransportAddress *taddr, __be16 port,
		    struct nf_conntrack_expect *exp)
{
	int dir = CTINFO2DIR(ctinfo);
	u_int16_t nated_port = ntohs(port);

	/* Set expectations for NAT */
	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
	exp->expectfn = nf_nat_follow_master;
	exp->dir = !dir;

	/* Try to get same port: if not, try to change it. */
	for (; nated_port != 0; nated_port++) {
		exp->tuple.dst.u.tcp.port = htons(nated_port);
		if (nf_ct_expect_related(exp) == 0)
			break;
	}

	if (nated_port == 0) {	/* No port available */
		if (net_ratelimit())
			printk("nf_nat_h323: out of TCP ports\n");
		return 0;
	}

	/* Modify signal */
	if (set_h245_addr(skb, data, dataoff, taddr,
			  &ct->tuplehash[!dir].tuple.dst.u3,
			  htons(nated_port)) < 0) {
		nf_ct_unexpect_related(exp);
		return -1;
	}

	pr_debug("nf_nat_h323: expect T.120 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
		 NIPQUAD(exp->tuple.src.u3.ip),
		 ntohs(exp->tuple.src.u.tcp.port),
		 NIPQUAD(exp->tuple.dst.u3.ip),
		 ntohs(exp->tuple.dst.u.tcp.port));

	return 0;
}

/****************************************************************************/
static int nat_h245(struct sk_buff *skb, struct nf_conn *ct,
		    enum ip_conntrack_info ctinfo,
		    unsigned char **data, int dataoff,
		    TransportAddress *taddr, __be16 port,
		    struct nf_conntrack_expect *exp)
{
	struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
	int dir = CTINFO2DIR(ctinfo);
	u_int16_t nated_port = ntohs(port);

	/* Set expectations for NAT */
	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
	exp->expectfn = nf_nat_follow_master;
	exp->dir = !dir;

	/* Check existing expects */
	if (info->sig_port[dir] == port)
		nated_port = ntohs(info->sig_port[!dir]);

	/* Try to get same port: if not, try to change it. */
	for (; nated_port != 0; nated_port++) {
		exp->tuple.dst.u.tcp.port = htons(nated_port);
		if (nf_ct_expect_related(exp) == 0)
			break;
	}

	if (nated_port == 0) {	/* No port available */
		if (net_ratelimit())
			printk("nf_nat_q931: out of TCP ports\n");
		return 0;
	}

	/* Modify signal */
	if (set_h225_addr(skb, data, dataoff, taddr,
			  &ct->tuplehash[!dir].tuple.dst.u3,
			  htons(nated_port)) == 0) {
		/* Save ports */
		info->sig_port[dir] = port;
		info->sig_port[!dir] = htons(nated_port);
	} else {
		nf_ct_unexpect_related(exp);
		return -1;
	}

	pr_debug("nf_nat_q931: expect H.245 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
		 NIPQUAD(exp->tuple.src.u3.ip),
		 ntohs(exp->tuple.src.u.tcp.port),
		 NIPQUAD(exp->tuple.dst.u3.ip),
		 ntohs(exp->tuple.dst.u.tcp.port));

	return 0;
}

/****************************************************************************
 * This conntrack expect function replaces nf_conntrack_q931_expect()
 * which was set by nf_conntrack_h323.c.
 ****************************************************************************/
static void ip_nat_q931_expect(struct nf_conn *new,
			       struct nf_conntrack_expect *this)
{
	struct nf_nat_range range;

	if (this->tuple.src.u3.ip != 0) {	/* Only accept calls from GK */
		nf_nat_follow_master(new, this);
		return;
	}

	/* This must be a fresh one. */
	BUG_ON(new->status & IPS_NAT_DONE_MASK);

	/* Change src to where master sends to */
	range.flags = IP_NAT_RANGE_MAP_IPS;
	range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.u3.ip;
	nf_nat_setup_info(new, &range, IP_NAT_MANIP_SRC);

	/* For DST manip, map port here to where it's expected. */
	range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED);
	range.min = range.max = this->saved_proto;
	range.min_ip = range.max_ip =
	    new->master->tuplehash[!this->dir].tuple.src.u3.ip;
	nf_nat_setup_info(new, &range, IP_NAT_MANIP_DST);
}

/****************************************************************************/
static int nat_q931(struct sk_buff *skb, struct nf_conn *ct,
		    enum ip_conntrack_info ctinfo,
		    unsigned char **data, TransportAddress *taddr, int idx,
		    __be16 port, struct nf_conntrack_expect *exp)
{
	struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
	int dir = CTINFO2DIR(ctinfo);
	u_int16_t nated_port = ntohs(port);
	union nf_inet_addr addr;

	/* Set expectations for NAT */
	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
	exp->expectfn = ip_nat_q931_expect;
	exp->dir = !dir;

	/* Check existing expects */
	if (info->sig_port[dir] == port)
		nated_port = ntohs(info->sig_port[!dir]);

	/* Try to get same port: if not, try to change it. */
	for (; nated_port != 0; nated_port++) {
		exp->tuple.dst.u.tcp.port = htons(nated_port);
		if (nf_ct_expect_related(exp) == 0)
			break;
	}

	if (nated_port == 0) {	/* No port available */
		if (net_ratelimit())
			printk("nf_nat_ras: out of TCP ports\n");
		return 0;
	}

	/* Modify signal */
	if (set_h225_addr(skb, data, 0, &taddr[idx],
			  &ct->tuplehash[!dir].tuple.dst.u3,
			  htons(nated_port)) == 0) {
		/* Save ports */
		info->sig_port[dir] = port;
		info->sig_port[!dir] = htons(nated_port);

		/* Fix for Gnomemeeting */
		if (idx > 0 &&
		    get_h225_addr(ct, *data, &taddr[0], &addr, &port) &&
		    (ntohl(addr.ip) & 0xff000000) == 0x7f000000) {
			set_h225_addr(skb, data, 0, &taddr[0],
				      &ct->tuplehash[!dir].tuple.dst.u3,
				      info->sig_port[!dir]);
		}
	} else {
		nf_ct_unexpect_related(exp);
		return -1;
	}

	/* Success */
	pr_debug("nf_nat_ras: expect Q.931 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
		 NIPQUAD(exp->tuple.src.u3.ip),
		 ntohs(exp->tuple.src.u.tcp.port),
		 NIPQUAD(exp->tuple.dst.u3.ip),
		 ntohs(exp->tuple.dst.u.tcp.port));

	return 0;
}

/****************************************************************************/
static void ip_nat_callforwarding_expect(struct nf_conn *new,
					 struct nf_conntrack_expect *this)
{
	struct nf_nat_range range;

	/* This must be a fresh one. */
	BUG_ON(new->status & IPS_NAT_DONE_MASK);

	/* Change src to where master sends to */
	range.flags = IP_NAT_RANGE_MAP_IPS;
	range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.u3.ip;
	nf_nat_setup_info(new, &range, IP_NAT_MANIP_SRC);

	/* For DST manip, map port here to where it's expected. */
	range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED);
	range.min = range.max = this->saved_proto;
	range.min_ip = range.max_ip = this->saved_ip;
	nf_nat_setup_info(new, &range, IP_NAT_MANIP_DST);
}

/****************************************************************************/
static int nat_callforwarding(struct sk_buff *skb, struct nf_conn *ct,
			      enum ip_conntrack_info ctinfo,
			      unsigned char **data, int dataoff,
			      TransportAddress *taddr, __be16 port,
			      struct nf_conntrack_expect *exp)
{
	int dir = CTINFO2DIR(ctinfo);
	u_int16_t nated_port;

	/* Set expectations for NAT */
	exp->saved_ip = exp->tuple.dst.u3.ip;
	exp->tuple.dst.u3.ip = ct->tuplehash[!dir].tuple.dst.u3.ip;
	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
	exp->expectfn = ip_nat_callforwarding_expect;
	exp->dir = !dir;

	/* Try to get same port: if not, try to change it. */
	for (nated_port = ntohs(port); nated_port != 0; nated_port++) {
		exp->tuple.dst.u.tcp.port = htons(nated_port);
		if (nf_ct_expect_related(exp) == 0)
			break;
	}

	if (nated_port == 0) {	/* No port available */
		if (net_ratelimit())
			printk("nf_nat_q931: out of TCP ports\n");
		return 0;
	}

	/* Modify signal */
	if (!set_h225_addr(skb, data, dataoff, taddr,
			   &ct->tuplehash[!dir].tuple.dst.u3,
			   htons(nated_port)) == 0) {
		nf_ct_unexpect_related(exp);
		return -1;
	}

	/* Success */
	pr_debug("nf_nat_q931: expect Call Forwarding "
		 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
		 NIPQUAD(exp->tuple.src.u3.ip),
		 ntohs(exp->tuple.src.u.tcp.port),
		 NIPQUAD(exp->tuple.dst.u3.ip),
		 ntohs(exp->tuple.dst.u.tcp.port));

	return 0;
}

/****************************************************************************/
static int __init init(void)
{
	BUG_ON(set_h245_addr_hook != NULL);
	BUG_ON(set_h225_addr_hook != NULL);
	BUG_ON(set_sig_addr_hook != NULL);
	BUG_ON(set_ras_addr_hook != NULL);
	BUG_ON(nat_rtp_rtcp_hook != NULL);
	BUG_ON(nat_t120_hook != NULL);
	BUG_ON(nat_h245_hook != NULL);
	BUG_ON(nat_callforwarding_hook != NULL);
	BUG_ON(nat_q931_hook != NULL);

	rcu_assign_pointer(set_h245_addr_hook, set_h245_addr);
	rcu_assign_pointer(set_h225_addr_hook, set_h225_addr);
	rcu_assign_pointer(set_sig_addr_hook, set_sig_addr);
	rcu_assign_pointer(set_ras_addr_hook, set_ras_addr);
	rcu_assign_pointer(nat_rtp_rtcp_hook, nat_rtp_rtcp);
	rcu_assign_pointer(nat_t120_hook, nat_t120);
	rcu_assign_pointer(nat_h245_hook, nat_h245);
	rcu_assign_pointer(nat_callforwarding_hook, nat_callforwarding);
	rcu_assign_pointer(nat_q931_hook, nat_q931);
	return 0;
}

/****************************************************************************/
static void __exit fini(void)
{
	rcu_assign_pointer(set_h245_addr_hook, NULL);
	rcu_assign_pointer(set_h225_addr_hook, NULL);
	rcu_assign_pointer(set_sig_addr_hook, NULL);
	rcu_assign_pointer(set_ras_addr_hook, NULL);
	rcu_assign_pointer(nat_rtp_rtcp_hook, NULL);
	rcu_assign_pointer(nat_t120_hook, NULL);
	rcu_assign_pointer(nat_h245_hook, NULL);
	rcu_assign_pointer(nat_callforwarding_hook, NULL);
	rcu_assign_pointer(nat_q931_hook, NULL);
	synchronize_rcu();
}

/****************************************************************************/
module_init(init);
module_exit(fini);

MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
MODULE_DESCRIPTION("H.323 NAT helper");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ip_nat_h323");
Commit	Line	Data
f587de0e PM	1	/*
	2	* H.323 extension for NAT alteration.
	3	*
	4	* Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
	5	*
	6	* This source code is licensed under General Public License version 2.
	7	*
	8	* Based on the 'brute force' H.323 NAT module by
	9	* Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/moduleparam.h>
	14	#include <linux/tcp.h>
	15	#include <net/tcp.h>
	16
	17	#include <net/netfilter/nf_nat.h>
	18	#include <net/netfilter/nf_nat_helper.h>
	19	#include <net/netfilter/nf_nat_rule.h>
	20	#include <net/netfilter/nf_conntrack_helper.h>
	21	#include <net/netfilter/nf_conntrack_expect.h>
	22	#include <linux/netfilter/nf_conntrack_h323.h>
	23
f587de0e	24	/****************************************************************************/
3db05fea	25	static int set_addr(struct sk_buff *skb,
f587de0e PM	26	unsigned char **data, int dataoff,
	27	unsigned int addroff, __be32 ip, __be16 port)
	28	{
	29	enum ip_conntrack_info ctinfo;
3db05fea	30	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
f587de0e PM	31	struct {
	32	__be32 ip;
	33	__be16 port;
	34	} __attribute__ ((__packed__)) buf;
905e3e8e JE	35	const struct tcphdr *th;
905e3e8e JE	36	struct tcphdr _tcph;
f587de0e PM	37
	38	buf.ip = ip;
	39	buf.port = port;
	40	addroff += dataoff;
	41
3db05fea HX	42	if (ip_hdr(skb)->protocol == IPPROTO_TCP) {
3db05fea HX	43	if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
f587de0e PM	44	addroff, sizeof(buf),
	45	(char *) &buf, sizeof(buf))) {
	46	if (net_ratelimit())
	47	printk("nf_nat_h323: nf_nat_mangle_tcp_packet"
	48	" error\n");
	49	return -1;
	50	}
	51
	52	/* Relocate data pointer */
3db05fea	53	th = skb_header_pointer(skb, ip_hdrlen(skb),
f587de0e PM	54	sizeof(_tcph), &_tcph);
	55	if (th == NULL)
	56	return -1;
3db05fea	57	data = skb->data + ip_hdrlen(skb) + th->doff 4 + dataoff;
f587de0e	58	} else {
3db05fea	59	if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
f587de0e PM	60	addroff, sizeof(buf),
	61	(char *) &buf, sizeof(buf))) {
	62	if (net_ratelimit())
	63	printk("nf_nat_h323: nf_nat_mangle_udp_packet"
	64	" error\n");
	65	return -1;
	66	}
	67	/* nf_nat_mangle_udp_packet uses skb_make_writable() to copy
	68	* or pull everything in a linear buffer, so we can safely
	69	* use the skb pointers now */
3db05fea	70	*data = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
f587de0e PM	71	}
	72
	73	return 0;
	74	}
	75
	76	/****************************************************************************/
3db05fea	77	static int set_h225_addr(struct sk_buff *skb,
f587de0e PM	78	unsigned char **data, int dataoff,
f587de0e PM	79	TransportAddress *taddr,
643a2c15	80	union nf_inet_addr *addr, __be16 port)
f587de0e	81	{
3db05fea	82	return set_addr(skb, data, dataoff, taddr->ipAddress.ip,
f587de0e PM	83	addr->ip, port);
	84	}
	85
	86	/****************************************************************************/
3db05fea	87	static int set_h245_addr(struct sk_buff *skb,
f587de0e PM	88	unsigned char **data, int dataoff,
f587de0e PM	89	H245_TransportAddress *taddr,
643a2c15	90	union nf_inet_addr *addr, __be16 port)
f587de0e	91	{
3db05fea	92	return set_addr(skb, data, dataoff,
f587de0e PM	93	taddr->unicastAddress.iPAddress.network,
	94	addr->ip, port);
	95	}
	96
	97	/****************************************************************************/
3db05fea	98	static int set_sig_addr(struct sk_buff skb, struct nf_conn ct,
f587de0e PM	99	enum ip_conntrack_info ctinfo,
	100	unsigned char **data,
	101	TransportAddress *taddr, int count)
	102	{
905e3e8e	103	const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
f587de0e PM	104	int dir = CTINFO2DIR(ctinfo);
	105	int i;
	106	__be16 port;
643a2c15	107	union nf_inet_addr addr;
f587de0e PM	108
	109	for (i = 0; i < count; i++) {
	110	if (get_h225_addr(ct, *data, &taddr[i], &addr, &port)) {
	111	if (addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
	112	port == info->sig_port[dir]) {
	113	/* GW->GK */
	114
	115	/* Fix for Gnomemeeting */
	116	if (i > 0 &&
	117	get_h225_addr(ct, *data, &taddr[0],
	118	&addr, &port) &&
	119	(ntohl(addr.ip) & 0xff000000) == 0x7f000000)
	120	i = 0;
	121
0d53778e PM	122	pr_debug("nf_nat_ras: set signal address "
	123	"%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
	124	NIPQUAD(addr.ip), port,
	125	NIPQUAD(ct->tuplehash[!dir].tuple.dst.u3.ip),
	126	info->sig_port[!dir]);
3db05fea	127	return set_h225_addr(skb, data, 0, &taddr[i],
f587de0e PM	128	&ct->tuplehash[!dir].
	129	tuple.dst.u3,
	130	info->sig_port[!dir]);
	131	} else if (addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip &&
	132	port == info->sig_port[dir]) {
	133	/* GK->GW */
0d53778e PM	134	pr_debug("nf_nat_ras: set signal address "
	135	"%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
	136	NIPQUAD(addr.ip), port,
	137	NIPQUAD(ct->tuplehash[!dir].tuple.src.u3.ip),
	138	info->sig_port[!dir]);
3db05fea	139	return set_h225_addr(skb, data, 0, &taddr[i],
f587de0e PM	140	&ct->tuplehash[!dir].
	141	tuple.src.u3,
	142	info->sig_port[!dir]);
	143	}
	144	}
	145	}
	146
	147	return 0;
	148	}
	149
	150	/****************************************************************************/
3db05fea	151	static int set_ras_addr(struct sk_buff skb, struct nf_conn ct,
f587de0e PM	152	enum ip_conntrack_info ctinfo,
	153	unsigned char **data,
	154	TransportAddress *taddr, int count)
	155	{
	156	int dir = CTINFO2DIR(ctinfo);
	157	int i;
	158	__be16 port;
643a2c15	159	union nf_inet_addr addr;
f587de0e PM	160
	161	for (i = 0; i < count; i++) {
	162	if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
	163	addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
	164	port == ct->tuplehash[dir].tuple.src.u.udp.port) {
0d53778e PM	165	pr_debug("nf_nat_ras: set rasAddress "
	166	"%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
	167	NIPQUAD(addr.ip), ntohs(port),
	168	NIPQUAD(ct->tuplehash[!dir].tuple.dst.u3.ip),
	169	ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port));
3db05fea	170	return set_h225_addr(skb, data, 0, &taddr[i],
f587de0e PM	171	&ct->tuplehash[!dir].tuple.dst.u3,
	172	ct->tuplehash[!dir].tuple.
	173	dst.u.udp.port);
	174	}
	175	}
	176
	177	return 0;
	178	}
	179
	180	/****************************************************************************/
3db05fea	181	static int nat_rtp_rtcp(struct sk_buff skb, struct nf_conn ct,
f587de0e PM	182	enum ip_conntrack_info ctinfo,
	183	unsigned char **data, int dataoff,
	184	H245_TransportAddress *taddr,
	185	__be16 port, __be16 rtp_port,
	186	struct nf_conntrack_expect *rtp_exp,
	187	struct nf_conntrack_expect *rtcp_exp)
	188	{
	189	struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
	190	int dir = CTINFO2DIR(ctinfo);
	191	int i;
	192	u_int16_t nated_port;
	193
	194	/* Set expectations for NAT */
	195	rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port;
	196	rtp_exp->expectfn = nf_nat_follow_master;
	197	rtp_exp->dir = !dir;
	198	rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port;
	199	rtcp_exp->expectfn = nf_nat_follow_master;
	200	rtcp_exp->dir = !dir;
	201
	202	/* Lookup existing expects */
	203	for (i = 0; i < H323_RTP_CHANNEL_MAX; i++) {
	204	if (info->rtp_port[i][dir] == rtp_port) {
	205	/* Expected */
	206
	207	/* Use allocated ports first. This will refresh
	208	* the expects */
	209	rtp_exp->tuple.dst.u.udp.port = info->rtp_port[i][dir];
	210	rtcp_exp->tuple.dst.u.udp.port =
	211	htons(ntohs(info->rtp_port[i][dir]) + 1);
	212	break;
	213	} else if (info->rtp_port[i][dir] == 0) {
	214	/* Not expected */
	215	break;
	216	}
	217	}
	218
	219	/* Run out of expectations */
	220	if (i >= H323_RTP_CHANNEL_MAX) {
	221	if (net_ratelimit())
	222	printk("nf_nat_h323: out of expectations\n");
	223	return 0;
	224	}
	225
	226	/* Try to get a pair of ports. */
	227	for (nated_port = ntohs(rtp_exp->tuple.dst.u.udp.port);
	228	nated_port != 0; nated_port += 2) {
	229	rtp_exp->tuple.dst.u.udp.port = htons(nated_port);
6823645d	230	if (nf_ct_expect_related(rtp_exp) == 0) {
f587de0e PM	231	rtcp_exp->tuple.dst.u.udp.port =
f587de0e PM	232	htons(nated_port + 1);
6823645d	233	if (nf_ct_expect_related(rtcp_exp) == 0)
f587de0e	234	break;
6823645d	235	nf_ct_unexpect_related(rtp_exp);
f587de0e PM	236	}
	237	}
	238
	239	if (nated_port == 0) { /* No port available */
	240	if (net_ratelimit())
	241	printk("nf_nat_h323: out of RTP ports\n");
	242	return 0;
	243	}
	244
	245	/* Modify signal */
3db05fea	246	if (set_h245_addr(skb, data, dataoff, taddr,
f587de0e PM	247	&ct->tuplehash[!dir].tuple.dst.u3,
f587de0e PM	248	htons((port & htons(1)) ? nated_port + 1 :
e905a9ed	249	nated_port)) == 0) {
f587de0e PM	250	/* Save ports */
	251	info->rtp_port[i][dir] = rtp_port;
	252	info->rtp_port[i][!dir] = htons(nated_port);
	253	} else {
6823645d PM	254	nf_ct_unexpect_related(rtp_exp);
6823645d PM	255	nf_ct_unexpect_related(rtcp_exp);
f587de0e PM	256	return -1;
	257	}
	258
	259	/* Success */
0d53778e PM	260	pr_debug("nf_nat_h323: expect RTP %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
	261	NIPQUAD(rtp_exp->tuple.src.u3.ip),
	262	ntohs(rtp_exp->tuple.src.u.udp.port),
	263	NIPQUAD(rtp_exp->tuple.dst.u3.ip),
	264	ntohs(rtp_exp->tuple.dst.u.udp.port));
	265	pr_debug("nf_nat_h323: expect RTCP %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
	266	NIPQUAD(rtcp_exp->tuple.src.u3.ip),
	267	ntohs(rtcp_exp->tuple.src.u.udp.port),
	268	NIPQUAD(rtcp_exp->tuple.dst.u3.ip),
	269	ntohs(rtcp_exp->tuple.dst.u.udp.port));
f587de0e PM	270
	271	return 0;
	272	}
	273
	274	/****************************************************************************/
3db05fea	275	static int nat_t120(struct sk_buff skb, struct nf_conn ct,
f587de0e PM	276	enum ip_conntrack_info ctinfo,
	277	unsigned char **data, int dataoff,
	278	H245_TransportAddress *taddr, __be16 port,
	279	struct nf_conntrack_expect *exp)
	280	{
	281	int dir = CTINFO2DIR(ctinfo);
	282	u_int16_t nated_port = ntohs(port);
	283
	284	/* Set expectations for NAT */
	285	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
	286	exp->expectfn = nf_nat_follow_master;
	287	exp->dir = !dir;
	288
	289	/* Try to get same port: if not, try to change it. */
	290	for (; nated_port != 0; nated_port++) {
	291	exp->tuple.dst.u.tcp.port = htons(nated_port);
6823645d	292	if (nf_ct_expect_related(exp) == 0)
f587de0e PM	293	break;
	294	}
	295
	296	if (nated_port == 0) { /* No port available */
	297	if (net_ratelimit())
	298	printk("nf_nat_h323: out of TCP ports\n");
	299	return 0;
	300	}
	301
	302	/* Modify signal */
3db05fea	303	if (set_h245_addr(skb, data, dataoff, taddr,
f587de0e PM	304	&ct->tuplehash[!dir].tuple.dst.u3,
f587de0e PM	305	htons(nated_port)) < 0) {
6823645d	306	nf_ct_unexpect_related(exp);
f587de0e PM	307	return -1;
	308	}
	309
0d53778e PM	310	pr_debug("nf_nat_h323: expect T.120 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
	311	NIPQUAD(exp->tuple.src.u3.ip),
	312	ntohs(exp->tuple.src.u.tcp.port),
	313	NIPQUAD(exp->tuple.dst.u3.ip),
	314	ntohs(exp->tuple.dst.u.tcp.port));
f587de0e PM	315
	316	return 0;
	317	}
	318
	319	/****************************************************************************/
3db05fea	320	static int nat_h245(struct sk_buff skb, struct nf_conn ct,
f587de0e PM	321	enum ip_conntrack_info ctinfo,
	322	unsigned char **data, int dataoff,
	323	TransportAddress *taddr, __be16 port,
	324	struct nf_conntrack_expect *exp)
	325	{
	326	struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
	327	int dir = CTINFO2DIR(ctinfo);
	328	u_int16_t nated_port = ntohs(port);
	329
	330	/* Set expectations for NAT */
	331	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
	332	exp->expectfn = nf_nat_follow_master;
	333	exp->dir = !dir;
	334
	335	/* Check existing expects */
	336	if (info->sig_port[dir] == port)
	337	nated_port = ntohs(info->sig_port[!dir]);
	338
	339	/* Try to get same port: if not, try to change it. */
	340	for (; nated_port != 0; nated_port++) {
	341	exp->tuple.dst.u.tcp.port = htons(nated_port);
6823645d	342	if (nf_ct_expect_related(exp) == 0)
f587de0e PM	343	break;
	344	}
	345
	346	if (nated_port == 0) { /* No port available */
	347	if (net_ratelimit())
	348	printk("nf_nat_q931: out of TCP ports\n");
	349	return 0;
	350	}
	351
	352	/* Modify signal */
3db05fea	353	if (set_h225_addr(skb, data, dataoff, taddr,
f587de0e PM	354	&ct->tuplehash[!dir].tuple.dst.u3,
	355	htons(nated_port)) == 0) {
	356	/* Save ports */
	357	info->sig_port[dir] = port;
	358	info->sig_port[!dir] = htons(nated_port);
	359	} else {
6823645d	360	nf_ct_unexpect_related(exp);
f587de0e PM	361	return -1;
	362	}
	363
0d53778e PM	364	pr_debug("nf_nat_q931: expect H.245 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
	365	NIPQUAD(exp->tuple.src.u3.ip),
	366	ntohs(exp->tuple.src.u.tcp.port),
	367	NIPQUAD(exp->tuple.dst.u3.ip),
	368	ntohs(exp->tuple.dst.u.tcp.port));
f587de0e PM	369
	370	return 0;
	371	}
	372
	373	/****************************************************************************
	374	* This conntrack expect function replaces nf_conntrack_q931_expect()
	375	* which was set by nf_conntrack_h323.c.
	376	****************************************************************************/
	377	static void ip_nat_q931_expect(struct nf_conn *new,
	378	struct nf_conntrack_expect *this)
	379	{
587aa641	380	struct nf_nat_range range;
f587de0e PM	381
	382	if (this->tuple.src.u3.ip != 0) { /* Only accept calls from GK */
	383	nf_nat_follow_master(new, this);
	384	return;
	385	}
	386
	387	/* This must be a fresh one. */
	388	BUG_ON(new->status & IPS_NAT_DONE_MASK);
	389
	390	/* Change src to where master sends to */
	391	range.flags = IP_NAT_RANGE_MAP_IPS;
	392	range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.u3.ip;
cc01dcbd	393	nf_nat_setup_info(new, &range, IP_NAT_MANIP_SRC);
f587de0e PM	394
	395	/* For DST manip, map port here to where it's expected. */
	396	range.flags = (IP_NAT_RANGE_MAP_IPS \| IP_NAT_RANGE_PROTO_SPECIFIED);
	397	range.min = range.max = this->saved_proto;
	398	range.min_ip = range.max_ip =
	399	new->master->tuplehash[!this->dir].tuple.src.u3.ip;
cc01dcbd	400	nf_nat_setup_info(new, &range, IP_NAT_MANIP_DST);
f587de0e PM	401	}
	402
	403	/****************************************************************************/
3db05fea	404	static int nat_q931(struct sk_buff skb, struct nf_conn ct,
f587de0e PM	405	enum ip_conntrack_info ctinfo,
	406	unsigned char *data, TransportAddress taddr, int idx,
	407	__be16 port, struct nf_conntrack_expect *exp)
	408	{
	409	struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
	410	int dir = CTINFO2DIR(ctinfo);
	411	u_int16_t nated_port = ntohs(port);
643a2c15	412	union nf_inet_addr addr;
f587de0e PM	413
	414	/* Set expectations for NAT */
	415	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
	416	exp->expectfn = ip_nat_q931_expect;
	417	exp->dir = !dir;
	418
	419	/* Check existing expects */
	420	if (info->sig_port[dir] == port)
	421	nated_port = ntohs(info->sig_port[!dir]);
	422
	423	/* Try to get same port: if not, try to change it. */
	424	for (; nated_port != 0; nated_port++) {
	425	exp->tuple.dst.u.tcp.port = htons(nated_port);
6823645d	426	if (nf_ct_expect_related(exp) == 0)
f587de0e PM	427	break;
	428	}
	429
	430	if (nated_port == 0) { /* No port available */
	431	if (net_ratelimit())
	432	printk("nf_nat_ras: out of TCP ports\n");
	433	return 0;
	434	}
	435
	436	/* Modify signal */
3db05fea	437	if (set_h225_addr(skb, data, 0, &taddr[idx],
f587de0e PM	438	&ct->tuplehash[!dir].tuple.dst.u3,
	439	htons(nated_port)) == 0) {
	440	/* Save ports */
	441	info->sig_port[dir] = port;
	442	info->sig_port[!dir] = htons(nated_port);
	443
	444	/* Fix for Gnomemeeting */
	445	if (idx > 0 &&
	446	get_h225_addr(ct, *data, &taddr[0], &addr, &port) &&
	447	(ntohl(addr.ip) & 0xff000000) == 0x7f000000) {
3db05fea	448	set_h225_addr(skb, data, 0, &taddr[0],
1ff75ed2 JMZ	449	&ct->tuplehash[!dir].tuple.dst.u3,
1ff75ed2 JMZ	450	info->sig_port[!dir]);
f587de0e PM	451	}
f587de0e PM	452	} else {
6823645d	453	nf_ct_unexpect_related(exp);
f587de0e PM	454	return -1;
	455	}
	456
	457	/* Success */
0d53778e PM	458	pr_debug("nf_nat_ras: expect Q.931 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
	459	NIPQUAD(exp->tuple.src.u3.ip),
	460	ntohs(exp->tuple.src.u.tcp.port),
	461	NIPQUAD(exp->tuple.dst.u3.ip),
	462	ntohs(exp->tuple.dst.u.tcp.port));
f587de0e PM	463
	464	return 0;
	465	}
	466
	467	/****************************************************************************/
	468	static void ip_nat_callforwarding_expect(struct nf_conn *new,
	469	struct nf_conntrack_expect *this)
	470	{
	471	struct nf_nat_range range;
	472
	473	/* This must be a fresh one. */
	474	BUG_ON(new->status & IPS_NAT_DONE_MASK);
	475
	476	/* Change src to where master sends to */
	477	range.flags = IP_NAT_RANGE_MAP_IPS;
	478	range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.u3.ip;
cc01dcbd	479	nf_nat_setup_info(new, &range, IP_NAT_MANIP_SRC);
f587de0e PM	480
	481	/* For DST manip, map port here to where it's expected. */
	482	range.flags = (IP_NAT_RANGE_MAP_IPS \| IP_NAT_RANGE_PROTO_SPECIFIED);
	483	range.min = range.max = this->saved_proto;
	484	range.min_ip = range.max_ip = this->saved_ip;
cc01dcbd	485	nf_nat_setup_info(new, &range, IP_NAT_MANIP_DST);
f587de0e PM	486	}
	487
	488	/****************************************************************************/
3db05fea	489	static int nat_callforwarding(struct sk_buff skb, struct nf_conn ct,
f587de0e PM	490	enum ip_conntrack_info ctinfo,
	491	unsigned char **data, int dataoff,
	492	TransportAddress *taddr, __be16 port,
	493	struct nf_conntrack_expect *exp)
	494	{
	495	int dir = CTINFO2DIR(ctinfo);
	496	u_int16_t nated_port;
	497
	498	/* Set expectations for NAT */
	499	exp->saved_ip = exp->tuple.dst.u3.ip;
	500	exp->tuple.dst.u3.ip = ct->tuplehash[!dir].tuple.dst.u3.ip;
	501	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
	502	exp->expectfn = ip_nat_callforwarding_expect;
	503	exp->dir = !dir;
	504
	505	/* Try to get same port: if not, try to change it. */
	506	for (nated_port = ntohs(port); nated_port != 0; nated_port++) {
	507	exp->tuple.dst.u.tcp.port = htons(nated_port);
6823645d	508	if (nf_ct_expect_related(exp) == 0)
f587de0e PM	509	break;
	510	}
	511
	512	if (nated_port == 0) { /* No port available */
	513	if (net_ratelimit())
	514	printk("nf_nat_q931: out of TCP ports\n");
	515	return 0;
	516	}
	517
	518	/* Modify signal */
3db05fea	519	if (!set_h225_addr(skb, data, dataoff, taddr,
f587de0e PM	520	&ct->tuplehash[!dir].tuple.dst.u3,
f587de0e PM	521	htons(nated_port)) == 0) {
6823645d	522	nf_ct_unexpect_related(exp);
f587de0e PM	523	return -1;
	524	}
	525
	526	/* Success */
0d53778e PM	527	pr_debug("nf_nat_q931: expect Call Forwarding "
	528	"%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
	529	NIPQUAD(exp->tuple.src.u3.ip),
	530	ntohs(exp->tuple.src.u.tcp.port),
	531	NIPQUAD(exp->tuple.dst.u3.ip),
	532	ntohs(exp->tuple.dst.u.tcp.port));
f587de0e PM	533
	534	return 0;
	535	}
	536
	537	/****************************************************************************/
	538	static int __init init(void)
	539	{
d1332e0a PM	540	BUG_ON(set_h245_addr_hook != NULL);
	541	BUG_ON(set_h225_addr_hook != NULL);
	542	BUG_ON(set_sig_addr_hook != NULL);
	543	BUG_ON(set_ras_addr_hook != NULL);
	544	BUG_ON(nat_rtp_rtcp_hook != NULL);
	545	BUG_ON(nat_t120_hook != NULL);
	546	BUG_ON(nat_h245_hook != NULL);
	547	BUG_ON(nat_callforwarding_hook != NULL);
	548	BUG_ON(nat_q931_hook != NULL);
f587de0e PM	549
	550	rcu_assign_pointer(set_h245_addr_hook, set_h245_addr);
	551	rcu_assign_pointer(set_h225_addr_hook, set_h225_addr);
	552	rcu_assign_pointer(set_sig_addr_hook, set_sig_addr);
	553	rcu_assign_pointer(set_ras_addr_hook, set_ras_addr);
	554	rcu_assign_pointer(nat_rtp_rtcp_hook, nat_rtp_rtcp);
	555	rcu_assign_pointer(nat_t120_hook, nat_t120);
	556	rcu_assign_pointer(nat_h245_hook, nat_h245);
	557	rcu_assign_pointer(nat_callforwarding_hook, nat_callforwarding);
	558	rcu_assign_pointer(nat_q931_hook, nat_q931);
f587de0e PM	559	return 0;
	560	}
	561
	562	/****************************************************************************/
	563	static void __exit fini(void)
	564	{
	565	rcu_assign_pointer(set_h245_addr_hook, NULL);
	566	rcu_assign_pointer(set_h225_addr_hook, NULL);
	567	rcu_assign_pointer(set_sig_addr_hook, NULL);
	568	rcu_assign_pointer(set_ras_addr_hook, NULL);
	569	rcu_assign_pointer(nat_rtp_rtcp_hook, NULL);
	570	rcu_assign_pointer(nat_t120_hook, NULL);
	571	rcu_assign_pointer(nat_h245_hook, NULL);
	572	rcu_assign_pointer(nat_callforwarding_hook, NULL);
	573	rcu_assign_pointer(nat_q931_hook, NULL);
	574	synchronize_rcu();
	575	}
	576
	577	/****************************************************************************/
	578	module_init(init);
	579	module_exit(fini);
	580
	581	MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
	582	MODULE_DESCRIPTION("H.323 NAT helper");
	583	MODULE_LICENSE("GPL");
	584	MODULE_ALIAS("ip_nat_h323");