1 files changed, 631 insertions, 0 deletions

diff --git a/net/ipv4/netfilter/nf_nat_h323.c b/net/ipv4/netfilter/nf_nat_h323.c
new file mode 100644
index 000000000..574f7ebba
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_h323.c
@@ -0,0 +1,631 @@
+/*
+ * H.323 extension for NAT alteration.
+ *
+ * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
+ * Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.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/tcp.h>
+#include <net/tcp.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_helper.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 int protoff,
+		    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,
+					      protoff, addroff, sizeof(buf),
+					      (char *) &buf, sizeof(buf))) {
+			net_notice_ratelimited("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,
+					      protoff, addroff, sizeof(buf),
+					      (char *) &buf, sizeof(buf))) {
+			net_notice_ratelimited("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 int protoff,
+			 unsigned char **data, int dataoff,
+			 TransportAddress *taddr,
+			 union nf_inet_addr *addr, __be16 port)
+{
+	return set_addr(skb, protoff, data, dataoff, taddr->ipAddress.ip,
+			addr->ip, port);
+}
+
+/****************************************************************************/
+static int set_h245_addr(struct sk_buff *skb, unsigned protoff,
+			 unsigned char **data, int dataoff,
+			 H245_TransportAddress *taddr,
+			 union nf_inet_addr *addr, __be16 port)
+{
+	return set_addr(skb, protoff, 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 int protoff, unsigned char **data,
+			TransportAddress *taddr, int count)
+{
+	const struct nf_ct_h323_master *info = nfct_help_data(ct);
+	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 %pI4:%hu->%pI4:%hu\n",
+					 &addr.ip, port,
+					 &ct->tuplehash[!dir].tuple.dst.u3.ip,
+					 info->sig_port[!dir]);
+				return set_h225_addr(skb, protoff, 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 %pI4:%hu->%pI4:%hu\n",
+					 &addr.ip, port,
+					 &ct->tuplehash[!dir].tuple.src.u3.ip,
+					 info->sig_port[!dir]);
+				return set_h225_addr(skb, protoff, 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 int protoff, 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 %pI4:%hu->%pI4:%hu\n",
+				 &addr.ip, ntohs(port),
+				 &ct->tuplehash[!dir].tuple.dst.u3.ip,
+				 ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port));
+			return set_h225_addr(skb, protoff, 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 int protoff, 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_data(ct);
+	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) {
+		net_notice_ratelimited("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) {
+		int ret;
+
+		rtp_exp->tuple.dst.u.udp.port = htons(nated_port);
+		ret = nf_ct_expect_related(rtp_exp);
+		if (ret == 0) {
+			rtcp_exp->tuple.dst.u.udp.port =
+			    htons(nated_port + 1);
+			ret = nf_ct_expect_related(rtcp_exp);
+			if (ret == 0)
+				break;
+			else if (ret == -EBUSY) {
+				nf_ct_unexpect_related(rtp_exp);
+				continue;
+			} else if (ret < 0) {
+				nf_ct_unexpect_related(rtp_exp);
+				nated_port = 0;
+				break;
+			}
+		} else if (ret != -EBUSY) {
+			nated_port = 0;
+			break;
+		}
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		net_notice_ratelimited("nf_nat_h323: out of RTP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (set_h245_addr(skb, protoff, 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 %pI4:%hu->%pI4:%hu\n",
+		 &rtp_exp->tuple.src.u3.ip,
+		 ntohs(rtp_exp->tuple.src.u.udp.port),
+		 &rtp_exp->tuple.dst.u3.ip,
+		 ntohs(rtp_exp->tuple.dst.u.udp.port));
+	pr_debug("nf_nat_h323: expect RTCP %pI4:%hu->%pI4:%hu\n",
+		 &rtcp_exp->tuple.src.u3.ip,
+		 ntohs(rtcp_exp->tuple.src.u.udp.port),
+		 &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 int protoff, 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++) {
+		int ret;
+
+		exp->tuple.dst.u.tcp.port = htons(nated_port);
+		ret = nf_ct_expect_related(exp);
+		if (ret == 0)
+			break;
+		else if (ret != -EBUSY) {
+			nated_port = 0;
+			break;
+		}
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		net_notice_ratelimited("nf_nat_h323: out of TCP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (set_h245_addr(skb, protoff, 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 %pI4:%hu->%pI4:%hu\n",
+		 &exp->tuple.src.u3.ip,
+		 ntohs(exp->tuple.src.u.tcp.port),
+		 &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 int protoff, unsigned char **data, int dataoff,
+		    TransportAddress *taddr, __be16 port,
+		    struct nf_conntrack_expect *exp)
+{
+	struct nf_ct_h323_master *info = nfct_help_data(ct);
+	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++) {
+		int ret;
+
+		exp->tuple.dst.u.tcp.port = htons(nated_port);
+		ret = nf_ct_expect_related(exp);
+		if (ret == 0)
+			break;
+		else if (ret != -EBUSY) {
+			nated_port = 0;
+			break;
+		}
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		net_notice_ratelimited("nf_nat_q931: out of TCP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (set_h225_addr(skb, protoff, 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 %pI4:%hu->%pI4:%hu\n",
+		 &exp->tuple.src.u3.ip,
+		 ntohs(exp->tuple.src.u.tcp.port),
+		 &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 = NF_NAT_RANGE_MAP_IPS;
+	range.min_addr = range.max_addr =
+	    new->tuplehash[!this->dir].tuple.src.u3;
+	nf_nat_setup_info(new, &range, NF_NAT_MANIP_SRC);
+
+	/* For DST manip, map port here to where it's expected. */
+	range.flags = (NF_NAT_RANGE_MAP_IPS | NF_NAT_RANGE_PROTO_SPECIFIED);
+	range.min_proto = range.max_proto = this->saved_proto;
+	range.min_addr = range.max_addr =
+	    new->master->tuplehash[!this->dir].tuple.src.u3;
+	nf_nat_setup_info(new, &range, NF_NAT_MANIP_DST);
+}
+
+/****************************************************************************/
+static int nat_q931(struct sk_buff *skb, struct nf_conn *ct,
+		    enum ip_conntrack_info ctinfo,
+		    unsigned int protoff, unsigned char **data,
+		    TransportAddress *taddr, int idx,
+		    __be16 port, struct nf_conntrack_expect *exp)
+{
+	struct nf_ct_h323_master *info = nfct_help_data(ct);
+	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++) {
+		int ret;
+
+		exp->tuple.dst.u.tcp.port = htons(nated_port);
+		ret = nf_ct_expect_related(exp);
+		if (ret == 0)
+			break;
+		else if (ret != -EBUSY) {
+			nated_port = 0;
+			break;
+		}
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		net_notice_ratelimited("nf_nat_ras: out of TCP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (set_h225_addr(skb, protoff, 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, protoff, 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 %pI4:%hu->%pI4:%hu\n",
+		 &exp->tuple.src.u3.ip,
+		 ntohs(exp->tuple.src.u.tcp.port),
+		 &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 = NF_NAT_RANGE_MAP_IPS;
+	range.min_addr = range.max_addr =
+	    new->tuplehash[!this->dir].tuple.src.u3;
+	nf_nat_setup_info(new, &range, NF_NAT_MANIP_SRC);
+
+	/* For DST manip, map port here to where it's expected. */
+	range.flags = (NF_NAT_RANGE_MAP_IPS | NF_NAT_RANGE_PROTO_SPECIFIED);
+	range.min_proto = range.max_proto = this->saved_proto;
+	range.min_addr = range.max_addr = this->saved_addr;
+	nf_nat_setup_info(new, &range, NF_NAT_MANIP_DST);
+}
+
+/****************************************************************************/
+static int nat_callforwarding(struct sk_buff *skb, struct nf_conn *ct,
+			      enum ip_conntrack_info ctinfo,
+			      unsigned int protoff,
+			      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_addr = exp->tuple.dst.u3;
+	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++) {
+		int ret;
+
+		exp->tuple.dst.u.tcp.port = htons(nated_port);
+		ret = nf_ct_expect_related(exp);
+		if (ret == 0)
+			break;
+		else if (ret != -EBUSY) {
+			nated_port = 0;
+			break;
+		}
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		net_notice_ratelimited("nf_nat_q931: out of TCP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (!set_h225_addr(skb, protoff, 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 %pI4:%hu->%pI4:%hu\n",
+		 &exp->tuple.src.u3.ip,
+		 ntohs(exp->tuple.src.u.tcp.port),
+		 &exp->tuple.dst.u3.ip,
+		 ntohs(exp->tuple.dst.u.tcp.port));
+
+	return 0;
+}
+
+static struct nf_ct_helper_expectfn q931_nat = {
+	.name		= "Q.931",
+	.expectfn	= ip_nat_q931_expect,
+};
+
+static struct nf_ct_helper_expectfn callforwarding_nat = {
+	.name		= "callforwarding",
+	.expectfn	= ip_nat_callforwarding_expect,
+};
+
+/****************************************************************************/
+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_INIT_POINTER(set_h245_addr_hook, set_h245_addr);
+	RCU_INIT_POINTER(set_h225_addr_hook, set_h225_addr);
+	RCU_INIT_POINTER(set_sig_addr_hook, set_sig_addr);
+	RCU_INIT_POINTER(set_ras_addr_hook, set_ras_addr);
+	RCU_INIT_POINTER(nat_rtp_rtcp_hook, nat_rtp_rtcp);
+	RCU_INIT_POINTER(nat_t120_hook, nat_t120);
+	RCU_INIT_POINTER(nat_h245_hook, nat_h245);
+	RCU_INIT_POINTER(nat_callforwarding_hook, nat_callforwarding);
+	RCU_INIT_POINTER(nat_q931_hook, nat_q931);
+	nf_ct_helper_expectfn_register(&q931_nat);
+	nf_ct_helper_expectfn_register(&callforwarding_nat);
+	return 0;
+}
+
+/****************************************************************************/
+static void __exit fini(void)
+{
+	RCU_INIT_POINTER(set_h245_addr_hook, NULL);
+	RCU_INIT_POINTER(set_h225_addr_hook, NULL);
+	RCU_INIT_POINTER(set_sig_addr_hook, NULL);
+	RCU_INIT_POINTER(set_ras_addr_hook, NULL);
+	RCU_INIT_POINTER(nat_rtp_rtcp_hook, NULL);
+	RCU_INIT_POINTER(nat_t120_hook, NULL);
+	RCU_INIT_POINTER(nat_h245_hook, NULL);
+	RCU_INIT_POINTER(nat_callforwarding_hook, NULL);
+	RCU_INIT_POINTER(nat_q931_hook, NULL);
+	nf_ct_helper_expectfn_unregister(&q931_nat);
+	nf_ct_helper_expectfn_unregister(&callforwarding_nat);
+	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");