--- /dev/null
+/*
+ * 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>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+/****************************************************************************/
+static int set_addr(struct sk_buff **pskb,
+ unsigned char **data, int dataoff,
+ unsigned int addroff, __be32 ip, __be16 port)
+{
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = ip_conntrack_get(*pskb, &ctinfo);
+ struct {
+ __be32 ip;
+ __be16 port;
+ } __attribute__ ((__packed__)) buf;
+ struct tcphdr _tcph, *th;
+
+ buf.ip = ip;
+ buf.port = port;
+ addroff += dataoff;
+
+ if ((*pskb)->nh.iph->protocol == IPPROTO_TCP) {
+ if (!nf_nat_mangle_tcp_packet(pskb, 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(*pskb, (*pskb)->nh.iph->ihl * 4,
+ sizeof(_tcph), &_tcph);
+ if (th == NULL)
+ return -1;
+ *data = (*pskb)->data + (*pskb)->nh.iph->ihl * 4 +
+ th->doff * 4 + dataoff;
+ } else {
+ if (!nf_nat_mangle_udp_packet(pskb, 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 = (*pskb)->data + (*pskb)->nh.iph->ihl * 4 +
+ sizeof(struct udphdr);
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int set_h225_addr(struct sk_buff **pskb,
+ unsigned char **data, int dataoff,
+ TransportAddress *taddr,
+ union nf_conntrack_address *addr, __be16 port)
+{
+ return set_addr(pskb, data, dataoff, taddr->ipAddress.ip,
+ addr->ip, port);
+}
+
+/****************************************************************************/
+static int set_h245_addr(struct sk_buff **pskb,
+ unsigned char **data, int dataoff,
+ H245_TransportAddress *taddr,
+ union nf_conntrack_address *addr, __be16 port)
+{
+ return set_addr(pskb, data, dataoff,
+ taddr->unicastAddress.iPAddress.network,
+ addr->ip, port);
+}
+
+/****************************************************************************/
+static int set_sig_addr(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data,
+ TransportAddress *taddr, int count)
+{
+ struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ int dir = CTINFO2DIR(ctinfo);
+ int i;
+ __be16 port;
+ union nf_conntrack_address 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;
+
+ DEBUGP
+ ("nf_nat_ras: set signal address "
+ "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(ip), port,
+ NIPQUAD(ct->tuplehash[!dir].tuple.dst.
+ ip), info->sig_port[!dir]);
+ return set_h225_addr(pskb, 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 */
+ DEBUGP
+ ("nf_nat_ras: set signal address "
+ "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(ip), port,
+ NIPQUAD(ct->tuplehash[!dir].tuple.src.
+ ip), info->sig_port[!dir]);
+ return set_h225_addr(pskb, data, 0, &taddr[i],
+ &ct->tuplehash[!dir].
+ tuple.src.u3,
+ info->sig_port[!dir]);
+ }
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int set_ras_addr(struct sk_buff **pskb, 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_conntrack_address 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) {
+ DEBUGP("nf_nat_ras: set rasAddress "
+ "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(ip), ntohs(port),
+ NIPQUAD(ct->tuplehash[!dir].tuple.dst.u3.ip),
+ ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.
+ port));
+ return set_h225_addr(pskb, 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 **pskb, 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_conntrack_expect_related(rtp_exp) == 0) {
+ rtcp_exp->tuple.dst.u.udp.port =
+ htons(nated_port + 1);
+ if (nf_conntrack_expect_related(rtcp_exp) == 0)
+ break;
+ nf_conntrack_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(pskb, 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_conntrack_unexpect_related(rtp_exp);
+ nf_conntrack_unexpect_related(rtcp_exp);
+ return -1;
+ }
+
+ /* Success */
+ DEBUGP("nf_nat_h323: expect RTP %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(rtp_exp->tuple.src.ip),
+ ntohs(rtp_exp->tuple.src.u.udp.port),
+ NIPQUAD(rtp_exp->tuple.dst.ip),
+ ntohs(rtp_exp->tuple.dst.u.udp.port));
+ DEBUGP("nf_nat_h323: expect RTCP %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(rtcp_exp->tuple.src.ip),
+ ntohs(rtcp_exp->tuple.src.u.udp.port),
+ NIPQUAD(rtcp_exp->tuple.dst.ip),
+ ntohs(rtcp_exp->tuple.dst.u.udp.port));
+
+ return 0;
+}
+
+/****************************************************************************/
+static int nat_t120(struct sk_buff **pskb, 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_conntrack_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(pskb, data, dataoff, taddr,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ htons(nated_port)) < 0) {
+ nf_conntrack_unexpect_related(exp);
+ return -1;
+ }
+
+ DEBUGP("nf_nat_h323: expect T.120 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(exp->tuple.src.ip), ntohs(exp->tuple.src.u.tcp.port),
+ NIPQUAD(exp->tuple.dst.ip), ntohs(exp->tuple.dst.u.tcp.port));
+
+ return 0;
+}
+
+/****************************************************************************/
+static int nat_h245(struct sk_buff **pskb, 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_conntrack_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(pskb, 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_conntrack_unexpect_related(exp);
+ return -1;
+ }
+
+ DEBUGP("nf_nat_q931: expect H.245 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(exp->tuple.src.ip), ntohs(exp->tuple.src.u.tcp.port),
+ NIPQUAD(exp->tuple.dst.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 ip_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;
+
+ /* hook doesn't matter, but it has to do source manip */
+ nf_nat_setup_info(new, &range, NF_IP_POST_ROUTING);
+
+ /* 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;
+
+ /* hook doesn't matter, but it has to do destination manip */
+ nf_nat_setup_info(new, &range, NF_IP_PRE_ROUTING);
+}
+
+/****************************************************************************/
+static int nat_q931(struct sk_buff **pskb, 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_conntrack_address 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_conntrack_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(pskb, 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_hook(pskb, data, 0, &taddr[0],
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ info->sig_port[!dir]);
+ }
+ } else {
+ nf_conntrack_unexpect_related(exp);
+ return -1;
+ }
+
+ /* Success */
+ DEBUGP("nf_nat_ras: expect Q.931 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(exp->tuple.src.ip), ntohs(exp->tuple.src.u.tcp.port),
+ NIPQUAD(exp->tuple.dst.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;
+
+ /* hook doesn't matter, but it has to do source manip */
+ nf_nat_setup_info(new, &range, NF_IP_POST_ROUTING);
+
+ /* 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;
+
+ /* hook doesn't matter, but it has to do destination manip */
+ nf_nat_setup_info(new, &range, NF_IP_PRE_ROUTING);
+}
+
+/****************************************************************************/
+static int nat_callforwarding(struct sk_buff **pskb, 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_conntrack_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(pskb, data, dataoff, taddr,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ htons(nated_port)) == 0) {
+ nf_conntrack_unexpect_related(exp);
+ return -1;
+ }
+
+ /* Success */
+ DEBUGP("nf_nat_q931: expect Call Forwarding "
+ "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+ NIPQUAD(exp->tuple.src.ip), ntohs(exp->tuple.src.u.tcp.port),
+ NIPQUAD(exp->tuple.dst.ip), ntohs(exp->tuple.dst.u.tcp.port));
+
+ return 0;
+}
+
+/****************************************************************************/
+static int __init init(void)
+{
+ BUG_ON(rcu_dereference(set_h245_addr_hook) != NULL);
+ BUG_ON(rcu_dereference(set_h225_addr_hook) != NULL);
+ BUG_ON(rcu_dereference(set_sig_addr_hook) != NULL);
+ BUG_ON(rcu_dereference(set_ras_addr_hook) != NULL);
+ BUG_ON(rcu_dereference(nat_rtp_rtcp_hook) != NULL);
+ BUG_ON(rcu_dereference(nat_t120_hook) != NULL);
+ BUG_ON(rcu_dereference(nat_h245_hook) != NULL);
+ BUG_ON(rcu_dereference(nat_callforwarding_hook) != NULL);
+ BUG_ON(rcu_dereference(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);
+
+ DEBUGP("nf_nat_h323: init success\n");
+ 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");
--- /dev/null
+/*
+ * H.323 connection tracking helper
+ *
+ * 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 connection tracking module by
+ * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
+ *
+ * For more information, please see http://nath323.sourceforge.net/
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/ctype.h>
+#include <linux/inet.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+#include <linux/tcp.h>
+#include <linux/skbuff.h>
+#include <net/route.h>
+#include <net/ip6_route.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_tuple.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <linux/netfilter/nf_conntrack_h323.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+/* Parameters */
+static unsigned int default_rrq_ttl __read_mostly = 300;
+module_param(default_rrq_ttl, uint, 0600);
+MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
+
+static int gkrouted_only __read_mostly = 1;
+module_param(gkrouted_only, int, 0600);
+MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
+
+static int callforward_filter __read_mostly = 1;
+module_param(callforward_filter, bool, 0600);
+MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
+ "if both endpoints are on different sides "
+ "(determined by routing information)");
+
+/* Hooks for NAT */
+int (*set_h245_addr_hook) (struct sk_buff **pskb,
+ unsigned char **data, int dataoff,
+ H245_TransportAddress *taddr,
+ union nf_conntrack_address *addr, __be16 port)
+ __read_mostly;
+int (*set_h225_addr_hook) (struct sk_buff **pskb,
+ unsigned char **data, int dataoff,
+ TransportAddress *taddr,
+ union nf_conntrack_address *addr, __be16 port)
+ __read_mostly;
+int (*set_sig_addr_hook) (struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data,
+ TransportAddress *taddr, int count) __read_mostly;
+int (*set_ras_addr_hook) (struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data,
+ TransportAddress *taddr, int count) __read_mostly;
+int (*nat_rtp_rtcp_hook) (struct sk_buff **pskb,
+ 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) __read_mostly;
+int (*nat_t120_hook) (struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ H245_TransportAddress *taddr, __be16 port,
+ struct nf_conntrack_expect *exp) __read_mostly;
+int (*nat_h245_hook) (struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ TransportAddress *taddr, __be16 port,
+ struct nf_conntrack_expect *exp) __read_mostly;
+int (*nat_callforwarding_hook) (struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ TransportAddress *taddr, __be16 port,
+ struct nf_conntrack_expect *exp) __read_mostly;
+int (*nat_q931_hook) (struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, TransportAddress *taddr, int idx,
+ __be16 port, struct nf_conntrack_expect *exp)
+ __read_mostly;
+
+static DEFINE_SPINLOCK(nf_h323_lock);
+static char *h323_buffer;
+
+static struct nf_conntrack_helper nf_conntrack_helper_h245;
+static struct nf_conntrack_helper nf_conntrack_helper_q931[];
+static struct nf_conntrack_helper nf_conntrack_helper_ras[];
+
+/****************************************************************************/
+static int get_tpkt_data(struct sk_buff **pskb, unsigned int protoff,
+ struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+ unsigned char **data, int *datalen, int *dataoff)
+{
+ struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ int dir = CTINFO2DIR(ctinfo);
+ struct tcphdr _tcph, *th;
+ int tcpdatalen;
+ int tcpdataoff;
+ unsigned char *tpkt;
+ int tpktlen;
+ int tpktoff;
+
+ /* Get TCP header */
+ th = skb_header_pointer(*pskb, protoff, sizeof(_tcph), &_tcph);
+ if (th == NULL)
+ return 0;
+
+ /* Get TCP data offset */
+ tcpdataoff = protoff + th->doff * 4;
+
+ /* Get TCP data length */
+ tcpdatalen = (*pskb)->len - tcpdataoff;
+ if (tcpdatalen <= 0) /* No TCP data */
+ goto clear_out;
+
+ if (*data == NULL) { /* first TPKT */
+ /* Get first TPKT pointer */
+ tpkt = skb_header_pointer(*pskb, tcpdataoff, tcpdatalen,
+ h323_buffer);
+ BUG_ON(tpkt == NULL);
+
+ /* Validate TPKT identifier */
+ if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
+ /* Netmeeting sends TPKT header and data separately */
+ if (info->tpkt_len[dir] > 0) {
+ DEBUGP("nf_ct_h323: previous packet "
+ "indicated separate TPKT data of %hu "
+ "bytes\n", info->tpkt_len[dir]);
+ if (info->tpkt_len[dir] <= tcpdatalen) {
+ /* Yes, there was a TPKT header
+ * received */
+ *data = tpkt;
+ *datalen = info->tpkt_len[dir];
+ *dataoff = 0;
+ goto out;
+ }
+
+ /* Fragmented TPKT */
+ if (net_ratelimit())
+ printk("nf_ct_h323: "
+ "fragmented TPKT\n");
+ goto clear_out;
+ }
+
+ /* It is not even a TPKT */
+ return 0;
+ }
+ tpktoff = 0;
+ } else { /* Next TPKT */
+ tpktoff = *dataoff + *datalen;
+ tcpdatalen -= tpktoff;
+ if (tcpdatalen <= 4) /* No more TPKT */
+ goto clear_out;
+ tpkt = *data + *datalen;
+
+ /* Validate TPKT identifier */
+ if (tpkt[0] != 0x03 || tpkt[1] != 0)
+ goto clear_out;
+ }
+
+ /* Validate TPKT length */
+ tpktlen = tpkt[2] * 256 + tpkt[3];
+ if (tpktlen < 4)
+ goto clear_out;
+ if (tpktlen > tcpdatalen) {
+ if (tcpdatalen == 4) { /* Separate TPKT header */
+ /* Netmeeting sends TPKT header and data separately */
+ DEBUGP("nf_ct_h323: separate TPKT header indicates "
+ "there will be TPKT data of %hu bytes\n",
+ tpktlen - 4);
+ info->tpkt_len[dir] = tpktlen - 4;
+ return 0;
+ }
+
+ if (net_ratelimit())
+ printk("nf_ct_h323: incomplete TPKT (fragmented?)\n");
+ goto clear_out;
+ }
+
+ /* This is the encapsulated data */
+ *data = tpkt + 4;
+ *datalen = tpktlen - 4;
+ *dataoff = tpktoff + 4;
+
+ out:
+ /* Clear TPKT length */
+ info->tpkt_len[dir] = 0;
+ return 1;
+
+ clear_out:
+ info->tpkt_len[dir] = 0;
+ return 0;
+}
+
+/****************************************************************************/
+static int get_h245_addr(struct nf_conn *ct, unsigned char *data,
+ H245_TransportAddress *taddr,
+ union nf_conntrack_address *addr, __be16 *port)
+{
+ unsigned char *p;
+ int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+ int len;
+
+ if (taddr->choice != eH245_TransportAddress_unicastAddress)
+ return 0;
+
+ switch (taddr->unicastAddress.choice) {
+ case eUnicastAddress_iPAddress:
+ if (family != AF_INET)
+ return 0;
+ p = data + taddr->unicastAddress.iPAddress.network;
+ len = 4;
+ break;
+ case eUnicastAddress_iP6Address:
+ if (family != AF_INET6)
+ return 0;
+ p = data + taddr->unicastAddress.iP6Address.network;
+ len = 16;
+ break;
+ default:
+ return 0;
+ }
+
+ memcpy(addr, p, len);
+ memset((void *)addr + len, 0, sizeof(*addr) - len);
+ memcpy(port, p + len, sizeof(__be16));
+
+ return 1;
+}
+
+/****************************************************************************/
+static int expect_rtp_rtcp(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ H245_TransportAddress *taddr)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int ret = 0;
+ __be16 port;
+ __be16 rtp_port, rtcp_port;
+ union nf_conntrack_address addr;
+ struct nf_conntrack_expect *rtp_exp;
+ struct nf_conntrack_expect *rtcp_exp;
+ typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
+
+ /* Read RTP or RTCP address */
+ if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
+ memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
+ port == 0)
+ return 0;
+
+ /* RTP port is even */
+ port &= htons(~1);
+ rtp_port = port;
+ rtcp_port = htons(ntohs(port) + 1);
+
+ /* Create expect for RTP */
+ if ((rtp_exp = nf_conntrack_expect_alloc(ct)) == NULL)
+ return -1;
+ nf_conntrack_expect_init(rtp_exp, ct->tuplehash[!dir].tuple.src.l3num,
+ &ct->tuplehash[!dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ IPPROTO_UDP, NULL, &rtp_port);
+
+ /* Create expect for RTCP */
+ if ((rtcp_exp = nf_conntrack_expect_alloc(ct)) == NULL) {
+ nf_conntrack_expect_put(rtp_exp);
+ return -1;
+ }
+ nf_conntrack_expect_init(rtcp_exp, ct->tuplehash[!dir].tuple.src.l3num,
+ &ct->tuplehash[!dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ IPPROTO_UDP, NULL, &rtcp_port);
+
+ if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
+ (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
+ ct->status & IPS_NAT_MASK) {
+ /* NAT needed */
+ ret = nat_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
+ taddr, port, rtp_port, rtp_exp, rtcp_exp);
+ } else { /* Conntrack only */
+ if (nf_conntrack_expect_related(rtp_exp) == 0) {
+ if (nf_conntrack_expect_related(rtcp_exp) == 0) {
+ DEBUGP("nf_ct_h323: expect RTP ");
+ NF_CT_DUMP_TUPLE(&rtp_exp->tuple);
+ DEBUGP("nf_ct_h323: expect RTCP ");
+ NF_CT_DUMP_TUPLE(&rtcp_exp->tuple);
+ } else {
+ nf_conntrack_unexpect_related(rtp_exp);
+ ret = -1;
+ }
+ } else
+ ret = -1;
+ }
+
+ nf_conntrack_expect_put(rtp_exp);
+ nf_conntrack_expect_put(rtcp_exp);
+
+ return ret;
+}
+
+/****************************************************************************/
+static int expect_t120(struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ H245_TransportAddress *taddr)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int ret = 0;
+ __be16 port;
+ union nf_conntrack_address addr;
+ struct nf_conntrack_expect *exp;
+ typeof(nat_t120_hook) nat_t120;
+
+ /* Read T.120 address */
+ if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
+ memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
+ port == 0)
+ return 0;
+
+ /* Create expect for T.120 connections */
+ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL)
+ return -1;
+ nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+ &ct->tuplehash[!dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ IPPROTO_TCP, NULL, &port);
+ exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple channels */
+
+ if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
+ (nat_t120 = rcu_dereference(nat_t120_hook)) &&
+ ct->status & IPS_NAT_MASK) {
+ /* NAT needed */
+ ret = nat_t120(pskb, ct, ctinfo, data, dataoff, taddr,
+ port, exp);
+ } else { /* Conntrack only */
+ if (nf_conntrack_expect_related(exp) == 0) {
+ DEBUGP("nf_ct_h323: expect T.120 ");
+ NF_CT_DUMP_TUPLE(&exp->tuple);
+ } else
+ ret = -1;
+ }
+
+ nf_conntrack_expect_put(exp);
+
+ return ret;
+}
+
+/****************************************************************************/
+static int process_h245_channel(struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ H2250LogicalChannelParameters *channel)
+{
+ int ret;
+
+ if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
+ /* RTP */
+ ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
+ &channel->mediaChannel);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (channel->
+ options & eH2250LogicalChannelParameters_mediaControlChannel) {
+ /* RTCP */
+ ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
+ &channel->mediaControlChannel);
+ if (ret < 0)
+ return -1;
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_olc(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ OpenLogicalChannel *olc)
+{
+ int ret;
+
+ DEBUGP("nf_ct_h323: OpenLogicalChannel\n");
+
+ if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
+ eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
+ {
+ ret = process_h245_channel(pskb, ct, ctinfo, data, dataoff,
+ &olc->
+ forwardLogicalChannelParameters.
+ multiplexParameters.
+ h2250LogicalChannelParameters);
+ if (ret < 0)
+ return -1;
+ }
+
+ if ((olc->options &
+ eOpenLogicalChannel_reverseLogicalChannelParameters) &&
+ (olc->reverseLogicalChannelParameters.options &
+ eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
+ && (olc->reverseLogicalChannelParameters.multiplexParameters.
+ choice ==
+ eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
+ {
+ ret =
+ process_h245_channel(pskb, ct, ctinfo, data, dataoff,
+ &olc->
+ reverseLogicalChannelParameters.
+ multiplexParameters.
+ h2250LogicalChannelParameters);
+ if (ret < 0)
+ return -1;
+ }
+
+ if ((olc->options & eOpenLogicalChannel_separateStack) &&
+ olc->forwardLogicalChannelParameters.dataType.choice ==
+ eDataType_data &&
+ olc->forwardLogicalChannelParameters.dataType.data.application.
+ choice == eDataApplicationCapability_application_t120 &&
+ olc->forwardLogicalChannelParameters.dataType.data.application.
+ t120.choice == eDataProtocolCapability_separateLANStack &&
+ olc->separateStack.networkAddress.choice ==
+ eNetworkAccessParameters_networkAddress_localAreaAddress) {
+ ret = expect_t120(pskb, ct, ctinfo, data, dataoff,
+ &olc->separateStack.networkAddress.
+ localAreaAddress);
+ if (ret < 0)
+ return -1;
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_olca(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ OpenLogicalChannelAck *olca)
+{
+ H2250LogicalChannelAckParameters *ack;
+ int ret;
+
+ DEBUGP("nf_ct_h323: OpenLogicalChannelAck\n");
+
+ if ((olca->options &
+ eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
+ (olca->reverseLogicalChannelParameters.options &
+ eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
+ && (olca->reverseLogicalChannelParameters.multiplexParameters.
+ choice ==
+ eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
+ {
+ ret = process_h245_channel(pskb, ct, ctinfo, data, dataoff,
+ &olca->
+ reverseLogicalChannelParameters.
+ multiplexParameters.
+ h2250LogicalChannelParameters);
+ if (ret < 0)
+ return -1;
+ }
+
+ if ((olca->options &
+ eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
+ (olca->forwardMultiplexAckParameters.choice ==
+ eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
+ {
+ ack = &olca->forwardMultiplexAckParameters.
+ h2250LogicalChannelAckParameters;
+ if (ack->options &
+ eH2250LogicalChannelAckParameters_mediaChannel) {
+ /* RTP */
+ ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
+ &ack->mediaChannel);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (ack->options &
+ eH2250LogicalChannelAckParameters_mediaControlChannel) {
+ /* RTCP */
+ ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
+ &ack->mediaControlChannel);
+ if (ret < 0)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_h245(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ MultimediaSystemControlMessage *mscm)
+{
+ switch (mscm->choice) {
+ case eMultimediaSystemControlMessage_request:
+ if (mscm->request.choice ==
+ eRequestMessage_openLogicalChannel) {
+ return process_olc(pskb, ct, ctinfo, data, dataoff,
+ &mscm->request.openLogicalChannel);
+ }
+ DEBUGP("nf_ct_h323: H.245 Request %d\n",
+ mscm->request.choice);
+ break;
+ case eMultimediaSystemControlMessage_response:
+ if (mscm->response.choice ==
+ eResponseMessage_openLogicalChannelAck) {
+ return process_olca(pskb, ct, ctinfo, data, dataoff,
+ &mscm->response.
+ openLogicalChannelAck);
+ }
+ DEBUGP("nf_ct_h323: H.245 Response %d\n",
+ mscm->response.choice);
+ break;
+ default:
+ DEBUGP("nf_ct_h323: H.245 signal %d\n", mscm->choice);
+ break;
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int h245_help(struct sk_buff **pskb, unsigned int protoff,
+ struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+ static MultimediaSystemControlMessage mscm;
+ unsigned char *data = NULL;
+ int datalen;
+ int dataoff;
+ int ret;
+
+ /* Until there's been traffic both ways, don't look in packets. */
+ if (ctinfo != IP_CT_ESTABLISHED &&
+ ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
+ return NF_ACCEPT;
+ }
+ DEBUGP("nf_ct_h245: skblen = %u\n", (*pskb)->len);
+
+ spin_lock_bh(&nf_h323_lock);
+
+ /* Process each TPKT */
+ while (get_tpkt_data(pskb, protoff, ct, ctinfo,
+ &data, &datalen, &dataoff)) {
+ DEBUGP("nf_ct_h245: TPKT len=%d ", datalen);
+ NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
+
+ /* Decode H.245 signal */
+ ret = DecodeMultimediaSystemControlMessage(data, datalen,
+ &mscm);
+ if (ret < 0) {
+ if (net_ratelimit())
+ printk("nf_ct_h245: decoding error: %s\n",
+ ret == H323_ERROR_BOUND ?
+ "out of bound" : "out of range");
+ /* We don't drop when decoding error */
+ break;
+ }
+
+ /* Process H.245 signal */
+ if (process_h245(pskb, ct, ctinfo, &data, dataoff, &mscm) < 0)
+ goto drop;
+ }
+
+ spin_unlock_bh(&nf_h323_lock);
+ return NF_ACCEPT;
+
+ drop:
+ spin_unlock_bh(&nf_h323_lock);
+ if (net_ratelimit())
+ printk("nf_ct_h245: packet dropped\n");
+ return NF_DROP;
+}
+
+/****************************************************************************/
+static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
+ .name = "H.245",
+ .me = THIS_MODULE,
+ .max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
+ .timeout = 240,
+ .tuple.dst.protonum = IPPROTO_UDP,
+ .mask.src.u.udp.port = __constant_htons(0xFFFF),
+ .mask.dst.protonum = 0xFF,
+ .help = h245_help
+};
+
+/****************************************************************************/
+int get_h225_addr(struct nf_conn *ct, unsigned char *data,
+ TransportAddress *taddr,
+ union nf_conntrack_address *addr, __be16 *port)
+{
+ unsigned char *p;
+ int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+ int len;
+
+ switch (taddr->choice) {
+ case eTransportAddress_ipAddress:
+ if (family != AF_INET)
+ return 0;
+ p = data + taddr->ipAddress.ip;
+ len = 4;
+ break;
+ case eTransportAddress_ip6Address:
+ if (family != AF_INET6)
+ return 0;
+ p = data + taddr->ip6Address.ip6;
+ len = 16;
+ break;
+ default:
+ return 0;
+ }
+
+ memcpy(addr, p, len);
+ memset((void *)addr + len, 0, sizeof(*addr) - len);
+ memcpy(port, p + len, sizeof(__be16));
+
+ return 1;
+}
+
+/****************************************************************************/
+static int expect_h245(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ TransportAddress *taddr)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int ret = 0;
+ __be16 port;
+ union nf_conntrack_address addr;
+ struct nf_conntrack_expect *exp;
+ typeof(nat_h245_hook) nat_h245;
+
+ /* Read h245Address */
+ if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
+ memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
+ port == 0)
+ return 0;
+
+ /* Create expect for h245 connection */
+ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL)
+ return -1;
+ nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+ &ct->tuplehash[!dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ IPPROTO_TCP, NULL, &port);
+ exp->helper = &nf_conntrack_helper_h245;
+
+ if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
+ (nat_h245 = rcu_dereference(nat_h245_hook)) &&
+ ct->status & IPS_NAT_MASK) {
+ /* NAT needed */
+ ret = nat_h245(pskb, ct, ctinfo, data, dataoff, taddr,
+ port, exp);
+ } else { /* Conntrack only */
+ if (nf_conntrack_expect_related(exp) == 0) {
+ DEBUGP("nf_ct_q931: expect H.245 ");
+ NF_CT_DUMP_TUPLE(&exp->tuple);
+ } else
+ ret = -1;
+ }
+
+ nf_conntrack_expect_put(exp);
+
+ return ret;
+}
+
+/* If the calling party is on the same side of the forward-to party,
+ * we don't need to track the second call */
+static int callforward_do_filter(union nf_conntrack_address *src,
+ union nf_conntrack_address *dst,
+ int family)
+{
+ struct flowi fl1, fl2;
+ int ret = 0;
+
+ memset(&fl1, 0, sizeof(fl1));
+ memset(&fl2, 0, sizeof(fl2));
+
+ switch (family) {
+ case AF_INET: {
+ struct rtable *rt1, *rt2;
+
+ fl1.fl4_dst = src->ip;
+ fl2.fl4_dst = dst->ip;
+ if (ip_route_output_key(&rt1, &fl1) == 0) {
+ if (ip_route_output_key(&rt2, &fl2) == 0) {
+ if (rt1->rt_gateway == rt2->rt_gateway &&
+ rt1->u.dst.dev == rt2->u.dst.dev)
+ ret = 1;
+ dst_release(&rt2->u.dst);
+ }
+ dst_release(&rt1->u.dst);
+ }
+ break;
+ }
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+ case AF_INET6: {
+ struct rt6_info *rt1, *rt2;
+
+ memcpy(&fl1.fl6_dst, src, sizeof(fl1.fl6_dst));
+ memcpy(&fl2.fl6_dst, dst, sizeof(fl2.fl6_dst));
+ rt1 = (struct rt6_info *)ip6_route_output(NULL, &fl1);
+ if (rt1) {
+ rt2 = (struct rt6_info *)ip6_route_output(NULL, &fl2);
+ if (rt2) {
+ if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
+ sizeof(rt1->rt6i_gateway)) &&
+ rt1->u.dst.dev == rt2->u.dst.dev)
+ ret = 1;
+ dst_release(&rt2->u.dst);
+ }
+ dst_release(&rt1->u.dst);
+ }
+ break;
+ }
+#endif
+ }
+ return ret;
+
+}
+
+/****************************************************************************/
+static int expect_callforwarding(struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ TransportAddress *taddr)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int ret = 0;
+ __be16 port;
+ union nf_conntrack_address addr;
+ struct nf_conntrack_expect *exp;
+ typeof(nat_callforwarding_hook) nat_callforwarding;
+
+ /* Read alternativeAddress */
+ if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
+ return 0;
+
+ /* If the calling party is on the same side of the forward-to party,
+ * we don't need to track the second call */
+ if (callforward_filter &&
+ callforward_do_filter(&addr, &ct->tuplehash[!dir].tuple.src.u3,
+ ct->tuplehash[!dir].tuple.src.l3num)) {
+ DEBUGP("nf_ct_q931: Call Forwarding not tracked\n");
+ return 0;
+ }
+
+ /* Create expect for the second call leg */
+ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL)
+ return -1;
+ nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+ &ct->tuplehash[!dir].tuple.src.u3, &addr,
+ IPPROTO_TCP, NULL, &port);
+ exp->helper = nf_conntrack_helper_q931;
+
+ if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
+ (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
+ ct->status & IPS_NAT_MASK) {
+ /* Need NAT */
+ ret = nat_callforwarding(pskb, ct, ctinfo, data, dataoff,
+ taddr, port, exp);
+ } else { /* Conntrack only */
+ if (nf_conntrack_expect_related(exp) == 0) {
+ DEBUGP("nf_ct_q931: expect Call Forwarding ");
+ NF_CT_DUMP_TUPLE(&exp->tuple);
+ } else
+ ret = -1;
+ }
+
+ nf_conntrack_expect_put(exp);
+
+ return ret;
+}
+
+/****************************************************************************/
+static int process_setup(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ Setup_UUIE *setup)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int ret;
+ int i;
+ __be16 port;
+ union nf_conntrack_address addr;
+ typeof(set_h225_addr_hook) set_h225_addr;
+
+ DEBUGP("nf_ct_q931: Setup\n");
+
+ if (setup->options & eSetup_UUIE_h245Address) {
+ ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
+ &setup->h245Address);
+ if (ret < 0)
+ return -1;
+ }
+
+ set_h225_addr = rcu_dereference(set_h225_addr_hook);
+ if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
+ (set_h225_addr) && ct->status && IPS_NAT_MASK &&
+ get_h225_addr(ct, *data, &setup->destCallSignalAddress,
+ &addr, &port) &&
+ memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
+ DEBUGP("nf_ct_q931: set destCallSignalAddress "
+ NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
+ NIP6(*(struct in6_addr *)&addr), ntohs(port),
+ NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.src.u3),
+ ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
+ ret = set_h225_addr(pskb, data, dataoff,
+ &setup->destCallSignalAddress,
+ &ct->tuplehash[!dir].tuple.src.u3,
+ ct->tuplehash[!dir].tuple.src.u.tcp.port);
+ if (ret < 0)
+ return -1;
+ }
+
+ if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
+ (set_h225_addr) && ct->status & IPS_NAT_MASK &&
+ get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
+ &addr, &port) &&
+ memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
+ DEBUGP("nf_ct_q931: set sourceCallSignalAddress "
+ NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
+ NIP6(*(struct in6_addr *)&addr), ntohs(port),
+ NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.dst.u3),
+ ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
+ ret = set_h225_addr(pskb, data, dataoff,
+ &setup->sourceCallSignalAddress,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ ct->tuplehash[!dir].tuple.dst.u.tcp.port);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (setup->options & eSetup_UUIE_fastStart) {
+ for (i = 0; i < setup->fastStart.count; i++) {
+ ret = process_olc(pskb, ct, ctinfo, data, dataoff,
+ &setup->fastStart.item[i]);
+ if (ret < 0)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_callproceeding(struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ CallProceeding_UUIE *callproc)
+{
+ int ret;
+ int i;
+
+ DEBUGP("nf_ct_q931: CallProceeding\n");
+
+ if (callproc->options & eCallProceeding_UUIE_h245Address) {
+ ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
+ &callproc->h245Address);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (callproc->options & eCallProceeding_UUIE_fastStart) {
+ for (i = 0; i < callproc->fastStart.count; i++) {
+ ret = process_olc(pskb, ct, ctinfo, data, dataoff,
+ &callproc->fastStart.item[i]);
+ if (ret < 0)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_connect(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ Connect_UUIE *connect)
+{
+ int ret;
+ int i;
+
+ DEBUGP("nf_ct_q931: Connect\n");
+
+ if (connect->options & eConnect_UUIE_h245Address) {
+ ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
+ &connect->h245Address);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (connect->options & eConnect_UUIE_fastStart) {
+ for (i = 0; i < connect->fastStart.count; i++) {
+ ret = process_olc(pskb, ct, ctinfo, data, dataoff,
+ &connect->fastStart.item[i]);
+ if (ret < 0)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_alerting(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ Alerting_UUIE *alert)
+{
+ int ret;
+ int i;
+
+ DEBUGP("nf_ct_q931: Alerting\n");
+
+ if (alert->options & eAlerting_UUIE_h245Address) {
+ ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
+ &alert->h245Address);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (alert->options & eAlerting_UUIE_fastStart) {
+ for (i = 0; i < alert->fastStart.count; i++) {
+ ret = process_olc(pskb, ct, ctinfo, data, dataoff,
+ &alert->fastStart.item[i]);
+ if (ret < 0)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_information(struct sk_buff **pskb,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ Information_UUIE *info)
+{
+ int ret;
+ int i;
+
+ DEBUGP("nf_ct_q931: Information\n");
+
+ if (info->options & eInformation_UUIE_fastStart) {
+ for (i = 0; i < info->fastStart.count; i++) {
+ ret = process_olc(pskb, ct, ctinfo, data, dataoff,
+ &info->fastStart.item[i]);
+ if (ret < 0)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_facility(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ Facility_UUIE *facility)
+{
+ int ret;
+ int i;
+
+ DEBUGP("nf_ct_q931: Facility\n");
+
+ if (facility->reason.choice == eFacilityReason_callForwarded) {
+ if (facility->options & eFacility_UUIE_alternativeAddress)
+ return expect_callforwarding(pskb, ct, ctinfo, data,
+ dataoff,
+ &facility->
+ alternativeAddress);
+ return 0;
+ }
+
+ if (facility->options & eFacility_UUIE_h245Address) {
+ ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
+ &facility->h245Address);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (facility->options & eFacility_UUIE_fastStart) {
+ for (i = 0; i < facility->fastStart.count; i++) {
+ ret = process_olc(pskb, ct, ctinfo, data, dataoff,
+ &facility->fastStart.item[i]);
+ if (ret < 0)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_progress(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff,
+ Progress_UUIE *progress)
+{
+ int ret;
+ int i;
+
+ DEBUGP("nf_ct_q931: Progress\n");
+
+ if (progress->options & eProgress_UUIE_h245Address) {
+ ret = expect_h245(pskb, ct, ctinfo, data, dataoff,
+ &progress->h245Address);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (progress->options & eProgress_UUIE_fastStart) {
+ for (i = 0; i < progress->fastStart.count; i++) {
+ ret = process_olc(pskb, ct, ctinfo, data, dataoff,
+ &progress->fastStart.item[i]);
+ if (ret < 0)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_q931(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, int dataoff, Q931 *q931)
+{
+ H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
+ int i;
+ int ret = 0;
+
+ switch (pdu->h323_message_body.choice) {
+ case eH323_UU_PDU_h323_message_body_setup:
+ ret = process_setup(pskb, ct, ctinfo, data, dataoff,
+ &pdu->h323_message_body.setup);
+ break;
+ case eH323_UU_PDU_h323_message_body_callProceeding:
+ ret = process_callproceeding(pskb, ct, ctinfo, data, dataoff,
+ &pdu->h323_message_body.
+ callProceeding);
+ break;
+ case eH323_UU_PDU_h323_message_body_connect:
+ ret = process_connect(pskb, ct, ctinfo, data, dataoff,
+ &pdu->h323_message_body.connect);
+ break;
+ case eH323_UU_PDU_h323_message_body_alerting:
+ ret = process_alerting(pskb, ct, ctinfo, data, dataoff,
+ &pdu->h323_message_body.alerting);
+ break;
+ case eH323_UU_PDU_h323_message_body_information:
+ ret = process_information(pskb, ct, ctinfo, data, dataoff,
+ &pdu->h323_message_body.
+ information);
+ break;
+ case eH323_UU_PDU_h323_message_body_facility:
+ ret = process_facility(pskb, ct, ctinfo, data, dataoff,
+ &pdu->h323_message_body.facility);
+ break;
+ case eH323_UU_PDU_h323_message_body_progress:
+ ret = process_progress(pskb, ct, ctinfo, data, dataoff,
+ &pdu->h323_message_body.progress);
+ break;
+ default:
+ DEBUGP("nf_ct_q931: Q.931 signal %d\n",
+ pdu->h323_message_body.choice);
+ break;
+ }
+
+ if (ret < 0)
+ return -1;
+
+ if (pdu->options & eH323_UU_PDU_h245Control) {
+ for (i = 0; i < pdu->h245Control.count; i++) {
+ ret = process_h245(pskb, ct, ctinfo, data, dataoff,
+ &pdu->h245Control.item[i]);
+ if (ret < 0)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int q931_help(struct sk_buff **pskb, unsigned int protoff,
+ struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+ static Q931 q931;
+ unsigned char *data = NULL;
+ int datalen;
+ int dataoff;
+ int ret;
+
+ /* Until there's been traffic both ways, don't look in packets. */
+ if (ctinfo != IP_CT_ESTABLISHED &&
+ ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
+ return NF_ACCEPT;
+ }
+ DEBUGP("nf_ct_q931: skblen = %u\n", (*pskb)->len);
+
+ spin_lock_bh(&nf_h323_lock);
+
+ /* Process each TPKT */
+ while (get_tpkt_data(pskb, protoff, ct, ctinfo,
+ &data, &datalen, &dataoff)) {
+ DEBUGP("nf_ct_q931: TPKT len=%d ", datalen);
+ NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
+
+ /* Decode Q.931 signal */
+ ret = DecodeQ931(data, datalen, &q931);
+ if (ret < 0) {
+ if (net_ratelimit())
+ printk("nf_ct_q931: decoding error: %s\n",
+ ret == H323_ERROR_BOUND ?
+ "out of bound" : "out of range");
+ /* We don't drop when decoding error */
+ break;
+ }
+
+ /* Process Q.931 signal */
+ if (process_q931(pskb, ct, ctinfo, &data, dataoff, &q931) < 0)
+ goto drop;
+ }
+
+ spin_unlock_bh(&nf_h323_lock);
+ return NF_ACCEPT;
+
+ drop:
+ spin_unlock_bh(&nf_h323_lock);
+ if (net_ratelimit())
+ printk("nf_ct_q931: packet dropped\n");
+ return NF_DROP;
+}
+
+/****************************************************************************/
+static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
+ {
+ .name = "Q.931",
+ .me = THIS_MODULE,
+ /* T.120 and H.245 */
+ .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4,
+ .timeout = 240,
+ .tuple.src.l3num = AF_INET,
+ .tuple.src.u.tcp.port = __constant_htons(Q931_PORT),
+ .tuple.dst.protonum = IPPROTO_TCP,
+ .mask.src.l3num = 0xFFFF,
+ .mask.src.u.tcp.port = __constant_htons(0xFFFF),
+ .mask.dst.protonum = 0xFF,
+ .help = q931_help
+ },
+ {
+ .name = "Q.931",
+ .me = THIS_MODULE,
+ /* T.120 and H.245 */
+ .max_expected = H323_RTP_CHANNEL_MAX * 4 + 4,
+ .timeout = 240,
+ .tuple.src.l3num = AF_INET6,
+ .tuple.src.u.tcp.port = __constant_htons(Q931_PORT),
+ .tuple.dst.protonum = IPPROTO_TCP,
+ .mask.src.l3num = 0xFFFF,
+ .mask.src.u.tcp.port = __constant_htons(0xFFFF),
+ .mask.dst.protonum = 0xFF,
+ .help = q931_help
+ },
+};
+
+/****************************************************************************/
+static unsigned char *get_udp_data(struct sk_buff **pskb, unsigned int protoff,
+ int *datalen)
+{
+ struct udphdr _uh, *uh;
+ int dataoff;
+
+ uh = skb_header_pointer(*pskb, protoff, sizeof(_uh), &_uh);
+ if (uh == NULL)
+ return NULL;
+ dataoff = protoff + sizeof(_uh);
+ if (dataoff >= (*pskb)->len)
+ return NULL;
+ *datalen = (*pskb)->len - dataoff;
+ return skb_header_pointer(*pskb, dataoff, *datalen, h323_buffer);
+}
+
+/****************************************************************************/
+static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
+ union nf_conntrack_address *addr,
+ __be16 port)
+{
+ struct nf_conntrack_expect *exp;
+ struct nf_conntrack_tuple tuple;
+
+ memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
+ tuple.src.u.tcp.port = 0;
+ memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
+ tuple.dst.u.tcp.port = port;
+ tuple.dst.protonum = IPPROTO_TCP;
+
+ exp = __nf_conntrack_expect_find(&tuple);
+ if (exp && exp->master == ct)
+ return exp;
+ return NULL;
+}
+
+/****************************************************************************/
+static int set_expect_timeout(struct nf_conntrack_expect *exp,
+ unsigned timeout)
+{
+ if (!exp || !del_timer(&exp->timeout))
+ return 0;
+
+ exp->timeout.expires = jiffies + timeout * HZ;
+ add_timer(&exp->timeout);
+
+ return 1;
+}
+
+/****************************************************************************/
+static int expect_q931(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data,
+ TransportAddress *taddr, int count)
+{
+ struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ int dir = CTINFO2DIR(ctinfo);
+ int ret = 0;
+ int i;
+ __be16 port;
+ union nf_conntrack_address addr;
+ struct nf_conntrack_expect *exp;
+ typeof(nat_q931_hook) nat_q931;
+
+ /* Look for the first related address */
+ for (i = 0; i < count; i++) {
+ if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
+ memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
+ sizeof(addr)) == 0 && port != 0)
+ break;
+ }
+
+ if (i >= count) /* Not found */
+ return 0;
+
+ /* Create expect for Q.931 */
+ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL)
+ return -1;
+ nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+ gkrouted_only ? /* only accept calls from GK? */
+ &ct->tuplehash[!dir].tuple.src.u3 :
+ NULL,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ IPPROTO_TCP, NULL, &port);
+ exp->helper = nf_conntrack_helper_q931;
+ exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */
+
+ nat_q931 = rcu_dereference(nat_q931_hook);
+ if (nat_q931 && ct->status & IPS_NAT_MASK) { /* Need NAT */
+ ret = nat_q931(pskb, ct, ctinfo, data, taddr, i, port, exp);
+ } else { /* Conntrack only */
+ if (nf_conntrack_expect_related(exp) == 0) {
+ DEBUGP("nf_ct_ras: expect Q.931 ");
+ NF_CT_DUMP_TUPLE(&exp->tuple);
+
+ /* Save port for looking up expect in processing RCF */
+ info->sig_port[dir] = port;
+ } else
+ ret = -1;
+ }
+
+ nf_conntrack_expect_put(exp);
+
+ return ret;
+}
+
+/****************************************************************************/
+static int process_grq(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, GatekeeperRequest *grq)
+{
+ typeof(set_ras_addr_hook) set_ras_addr;
+
+ DEBUGP("nf_ct_ras: GRQ\n");
+
+ set_ras_addr = rcu_dereference(set_ras_addr_hook);
+ if (set_ras_addr && ct->status & IPS_NAT_MASK) /* NATed */
+ return set_ras_addr(pskb, ct, ctinfo, data,
+ &grq->rasAddress, 1);
+ return 0;
+}
+
+/****************************************************************************/
+static int process_gcf(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, GatekeeperConfirm *gcf)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int ret = 0;
+ __be16 port;
+ union nf_conntrack_address addr;
+ struct nf_conntrack_expect *exp;
+
+ DEBUGP("nf_ct_ras: GCF\n");
+
+ if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
+ return 0;
+
+ /* Registration port is the same as discovery port */
+ if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
+ port == ct->tuplehash[dir].tuple.src.u.udp.port)
+ return 0;
+
+ /* Avoid RAS expectation loops. A GCF is never expected. */
+ if (test_bit(IPS_EXPECTED_BIT, &ct->status))
+ return 0;
+
+ /* Need new expect */
+ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL)
+ return -1;
+ nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+ &ct->tuplehash[!dir].tuple.src.u3, &addr,
+ IPPROTO_UDP, NULL, &port);
+ exp->helper = nf_conntrack_helper_ras;
+
+ if (nf_conntrack_expect_related(exp) == 0) {
+ DEBUGP("nf_ct_ras: expect RAS ");
+ NF_CT_DUMP_TUPLE(&exp->tuple);
+ } else
+ ret = -1;
+
+ nf_conntrack_expect_put(exp);
+
+ return ret;
+}
+
+/****************************************************************************/
+static int process_rrq(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, RegistrationRequest *rrq)
+{
+ struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ int ret;
+ typeof(set_ras_addr_hook) set_ras_addr;
+
+ DEBUGP("nf_ct_ras: RRQ\n");
+
+ ret = expect_q931(pskb, ct, ctinfo, data,
+ rrq->callSignalAddress.item,
+ rrq->callSignalAddress.count);
+ if (ret < 0)
+ return -1;
+
+ set_ras_addr = rcu_dereference(set_ras_addr_hook);
+ if (set_ras_addr && ct->status & IPS_NAT_MASK) {
+ ret = set_ras_addr(pskb, ct, ctinfo, data,
+ rrq->rasAddress.item,
+ rrq->rasAddress.count);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (rrq->options & eRegistrationRequest_timeToLive) {
+ DEBUGP("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
+ info->timeout = rrq->timeToLive;
+ } else
+ info->timeout = default_rrq_ttl;
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_rcf(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, RegistrationConfirm *rcf)
+{
+ struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ int dir = CTINFO2DIR(ctinfo);
+ int ret;
+ struct nf_conntrack_expect *exp;
+ typeof(set_sig_addr_hook) set_sig_addr;
+
+ DEBUGP("nf_ct_ras: RCF\n");
+
+ set_sig_addr = rcu_dereference(set_sig_addr_hook);
+ if (set_sig_addr && ct->status & IPS_NAT_MASK) {
+ ret = set_sig_addr(pskb, ct, ctinfo, data,
+ rcf->callSignalAddress.item,
+ rcf->callSignalAddress.count);
+ if (ret < 0)
+ return -1;
+ }
+
+ if (rcf->options & eRegistrationConfirm_timeToLive) {
+ DEBUGP("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
+ info->timeout = rcf->timeToLive;
+ }
+
+ if (info->timeout > 0) {
+ DEBUGP
+ ("nf_ct_ras: set RAS connection timeout to %u seconds\n",
+ info->timeout);
+ nf_ct_refresh(ct, *pskb, info->timeout * HZ);
+
+ /* Set expect timeout */
+ read_lock_bh(&nf_conntrack_lock);
+ exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
+ info->sig_port[!dir]);
+ if (exp) {
+ DEBUGP("nf_ct_ras: set Q.931 expect "
+ "timeout to %u seconds for",
+ info->timeout);
+ NF_CT_DUMP_TUPLE(&exp->tuple);
+ set_expect_timeout(exp, info->timeout);
+ }
+ read_unlock_bh(&nf_conntrack_lock);
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_urq(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, UnregistrationRequest *urq)
+{
+ struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ int dir = CTINFO2DIR(ctinfo);
+ int ret;
+ typeof(set_sig_addr_hook) set_sig_addr;
+
+ DEBUGP("nf_ct_ras: URQ\n");
+
+ set_sig_addr = rcu_dereference(set_sig_addr_hook);
+ if (set_sig_addr && ct->status & IPS_NAT_MASK) {
+ ret = set_sig_addr(pskb, ct, ctinfo, data,
+ urq->callSignalAddress.item,
+ urq->callSignalAddress.count);
+ if (ret < 0)
+ return -1;
+ }
+
+ /* Clear old expect */
+ nf_ct_remove_expectations(ct);
+ info->sig_port[dir] = 0;
+ info->sig_port[!dir] = 0;
+
+ /* Give it 30 seconds for UCF or URJ */
+ nf_ct_refresh(ct, *pskb, 30 * HZ);
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_arq(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, AdmissionRequest *arq)
+{
+ struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+ int dir = CTINFO2DIR(ctinfo);
+ __be16 port;
+ union nf_conntrack_address addr;
+ typeof(set_h225_addr_hook) set_h225_addr;
+
+ DEBUGP("nf_ct_ras: ARQ\n");
+
+ set_h225_addr = rcu_dereference(set_h225_addr_hook);
+ if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
+ get_h225_addr(ct, *data, &arq->destCallSignalAddress,
+ &addr, &port) &&
+ !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
+ port == info->sig_port[dir] &&
+ set_h225_addr && ct->status & IPS_NAT_MASK) {
+ /* Answering ARQ */
+ return set_h225_addr(pskb, data, 0,
+ &arq->destCallSignalAddress,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ info->sig_port[!dir]);
+ }
+
+ if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
+ get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
+ &addr, &port) &&
+ !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
+ set_h225_addr && ct->status & IPS_NAT_MASK) {
+ /* Calling ARQ */
+ return set_h225_addr(pskb, data, 0,
+ &arq->srcCallSignalAddress,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ port);
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_acf(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, AdmissionConfirm *acf)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int ret = 0;
+ __be16 port;
+ union nf_conntrack_address addr;
+ struct nf_conntrack_expect *exp;
+ typeof(set_sig_addr_hook) set_sig_addr;
+
+ DEBUGP("nf_ct_ras: ACF\n");
+
+ if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
+ &addr, &port))
+ return 0;
+
+ if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
+ /* Answering ACF */
+ set_sig_addr = rcu_dereference(set_sig_addr_hook);
+ if (set_sig_addr && ct->status & IPS_NAT_MASK)
+ return set_sig_addr(pskb, ct, ctinfo, data,
+ &acf->destCallSignalAddress, 1);
+ return 0;
+ }
+
+ /* Need new expect */
+ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL)
+ return -1;
+ nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+ &ct->tuplehash[!dir].tuple.src.u3, &addr,
+ IPPROTO_TCP, NULL, &port);
+ exp->flags = NF_CT_EXPECT_PERMANENT;
+ exp->helper = nf_conntrack_helper_q931;
+
+ if (nf_conntrack_expect_related(exp) == 0) {
+ DEBUGP("nf_ct_ras: expect Q.931 ");
+ NF_CT_DUMP_TUPLE(&exp->tuple);
+ } else
+ ret = -1;
+
+ nf_conntrack_expect_put(exp);
+
+ return ret;
+}
+
+/****************************************************************************/
+static int process_lrq(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, LocationRequest *lrq)
+{
+ typeof(set_ras_addr_hook) set_ras_addr;
+
+ DEBUGP("nf_ct_ras: LRQ\n");
+
+ set_ras_addr = rcu_dereference(set_ras_addr_hook);
+ if (set_ras_addr && ct->status & IPS_NAT_MASK)
+ return set_ras_addr(pskb, ct, ctinfo, data,
+ &lrq->replyAddress, 1);
+ return 0;
+}
+
+/****************************************************************************/
+static int process_lcf(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, LocationConfirm *lcf)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int ret = 0;
+ __be16 port;
+ union nf_conntrack_address addr;
+ struct nf_conntrack_expect *exp;
+
+ DEBUGP("nf_ct_ras: LCF\n");
+
+ if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
+ &addr, &port))
+ return 0;
+
+ /* Need new expect for call signal */
+ if ((exp = nf_conntrack_expect_alloc(ct)) == NULL)
+ return -1;
+ nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+ &ct->tuplehash[!dir].tuple.src.u3, &addr,
+ IPPROTO_TCP, NULL, &port);
+ exp->flags = NF_CT_EXPECT_PERMANENT;
+ exp->helper = nf_conntrack_helper_q931;
+
+ if (nf_conntrack_expect_related(exp) == 0) {
+ DEBUGP("nf_ct_ras: expect Q.931 ");
+ NF_CT_DUMP_TUPLE(&exp->tuple);
+ } else
+ ret = -1;
+
+ nf_conntrack_expect_put(exp);
+
+ /* Ignore rasAddress */
+
+ return ret;
+}
+
+/****************************************************************************/
+static int process_irr(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, InfoRequestResponse *irr)
+{
+ int ret;
+ typeof(set_ras_addr_hook) set_ras_addr;
+ typeof(set_sig_addr_hook) set_sig_addr;
+
+ DEBUGP("nf_ct_ras: IRR\n");
+
+ set_ras_addr = rcu_dereference(set_ras_addr_hook);
+ if (set_ras_addr && ct->status & IPS_NAT_MASK) {
+ ret = set_ras_addr(pskb, ct, ctinfo, data,
+ &irr->rasAddress, 1);
+ if (ret < 0)
+ return -1;
+ }
+
+ set_sig_addr = rcu_dereference(set_sig_addr_hook);
+ if (set_sig_addr && ct->status & IPS_NAT_MASK) {
+ ret = set_sig_addr(pskb, ct, ctinfo, data,
+ irr->callSignalAddress.item,
+ irr->callSignalAddress.count);
+ if (ret < 0)
+ return -1;
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int process_ras(struct sk_buff **pskb, struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo,
+ unsigned char **data, RasMessage *ras)
+{
+ switch (ras->choice) {
+ case eRasMessage_gatekeeperRequest:
+ return process_grq(pskb, ct, ctinfo, data,
+ &ras->gatekeeperRequest);
+ case eRasMessage_gatekeeperConfirm:
+ return process_gcf(pskb, ct, ctinfo, data,
+ &ras->gatekeeperConfirm);
+ case eRasMessage_registrationRequest:
+ return process_rrq(pskb, ct, ctinfo, data,
+ &ras->registrationRequest);
+ case eRasMessage_registrationConfirm:
+ return process_rcf(pskb, ct, ctinfo, data,
+ &ras->registrationConfirm);
+ case eRasMessage_unregistrationRequest:
+ return process_urq(pskb, ct, ctinfo, data,
+ &ras->unregistrationRequest);
+ case eRasMessage_admissionRequest:
+ return process_arq(pskb, ct, ctinfo, data,
+ &ras->admissionRequest);
+ case eRasMessage_admissionConfirm:
+ return process_acf(pskb, ct, ctinfo, data,
+ &ras->admissionConfirm);
+ case eRasMessage_locationRequest:
+ return process_lrq(pskb, ct, ctinfo, data,
+ &ras->locationRequest);
+ case eRasMessage_locationConfirm:
+ return process_lcf(pskb, ct, ctinfo, data,
+ &ras->locationConfirm);
+ case eRasMessage_infoRequestResponse:
+ return process_irr(pskb, ct, ctinfo, data,
+ &ras->infoRequestResponse);
+ default:
+ DEBUGP("nf_ct_ras: RAS message %d\n", ras->choice);
+ break;
+ }
+
+ return 0;
+}
+
+/****************************************************************************/
+static int ras_help(struct sk_buff **pskb, unsigned int protoff,
+ struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+ static RasMessage ras;
+ unsigned char *data;
+ int datalen = 0;
+ int ret;
+
+ DEBUGP("nf_ct_ras: skblen = %u\n", (*pskb)->len);
+
+ spin_lock_bh(&nf_h323_lock);
+
+ /* Get UDP data */
+ data = get_udp_data(pskb, protoff, &datalen);
+ if (data == NULL)
+ goto accept;
+ DEBUGP("nf_ct_ras: RAS message len=%d ", datalen);
+ NF_CT_DUMP_TUPLE(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
+
+ /* Decode RAS message */
+ ret = DecodeRasMessage(data, datalen, &ras);
+ if (ret < 0) {
+ if (net_ratelimit())
+ printk("nf_ct_ras: decoding error: %s\n",
+ ret == H323_ERROR_BOUND ?
+ "out of bound" : "out of range");
+ goto accept;
+ }
+
+ /* Process RAS message */
+ if (process_ras(pskb, ct, ctinfo, &data, &ras) < 0)
+ goto drop;
+
+ accept:
+ spin_unlock_bh(&nf_h323_lock);
+ return NF_ACCEPT;
+
+ drop:
+ spin_unlock_bh(&nf_h323_lock);
+ if (net_ratelimit())
+ printk("nf_ct_ras: packet dropped\n");
+ return NF_DROP;
+}
+
+/****************************************************************************/
+static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
+ {
+ .name = "RAS",
+ .me = THIS_MODULE,
+ .max_expected = 32,
+ .timeout = 240,
+ .tuple.src.l3num = AF_INET,
+ .tuple.src.u.udp.port = __constant_htons(RAS_PORT),
+ .tuple.dst.protonum = IPPROTO_UDP,
+ .mask.src.l3num = 0xFFFF,
+ .mask.src.u.udp.port = __constant_htons(0xFFFF),
+ .mask.dst.protonum = 0xFF,
+ .help = ras_help,
+ },
+ {
+ .name = "RAS",
+ .me = THIS_MODULE,
+ .max_expected = 32,
+ .timeout = 240,
+ .tuple.src.l3num = AF_INET6,
+ .tuple.src.u.udp.port = __constant_htons(RAS_PORT),
+ .tuple.dst.protonum = IPPROTO_UDP,
+ .mask.src.l3num = 0xFFFF,
+ .mask.src.u.udp.port = __constant_htons(0xFFFF),
+ .mask.dst.protonum = 0xFF,
+ .help = ras_help,
+ },
+};
+
+/****************************************************************************/
+static void __exit nf_conntrack_h323_fini(void)
+{
+ nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
+ nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
+ nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
+ nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
+ kfree(h323_buffer);
+ DEBUGP("nf_ct_h323: fini\n");
+}
+
+/****************************************************************************/
+static int __init nf_conntrack_h323_init(void)
+{
+ int ret;
+
+ h323_buffer = kmalloc(65536, GFP_KERNEL);
+ if (!h323_buffer)
+ return -ENOMEM;
+ ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
+ if (ret < 0)
+ goto err1;
+ ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
+ if (ret < 0)
+ goto err2;
+ ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
+ if (ret < 0)
+ goto err3;
+ ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
+ if (ret < 0)
+ goto err4;
+ DEBUGP("nf_ct_h323: init success\n");
+ return 0;
+
+err4:
+ nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
+err3:
+ nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
+err2:
+ nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
+err1:
+ return ret;
+}
+
+/****************************************************************************/
+module_init(nf_conntrack_h323_init);
+module_exit(nf_conntrack_h323_fini);
+
+EXPORT_SYMBOL_GPL(get_h225_addr);
+EXPORT_SYMBOL_GPL(set_h245_addr_hook);
+EXPORT_SYMBOL_GPL(set_h225_addr_hook);
+EXPORT_SYMBOL_GPL(set_sig_addr_hook);
+EXPORT_SYMBOL_GPL(set_ras_addr_hook);
+EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
+EXPORT_SYMBOL_GPL(nat_t120_hook);
+EXPORT_SYMBOL_GPL(nat_h245_hook);
+EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
+EXPORT_SYMBOL_GPL(nat_q931_hook);
+
+MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
+MODULE_DESCRIPTION("H.323 connection tracking helper");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_conntrack_h323");
projects / linux-2.6 / commitdiff