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openwrt/openwrt/target/linux/generic-2.4/patches/614-netfilter_nat_h323.patch

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diff -urN linux-2.4.32/net/ipv4/netfilter/Config.in linux-2.4.32/net/ipv4/netfilter/Config.in
--- linux-2.4.32/net/ipv4/netfilter/Config.in 2005-12-12 11:13:17.000000000 +0100
+++ linux-2.4.32/net/ipv4/netfilter/Config.in 2005-12-12 11:18:47.000000000 +0100
@@ -16,6 +16,7 @@
dep_tristate ' GRE protocol support' CONFIG_IP_NF_CT_PROTO_GRE $CONFIG_IP_NF_CONNTRACK
dep_tristate ' PPTP protocol support' CONFIG_IP_NF_PPTP $CONFIG_IP_NF_CT_PROTO_GRE
dep_tristate ' SIP protocol support' CONFIG_IP_NF_SIP $CONFIG_IP_NF_CONNTRACK
+ dep_tristate ' H.323 (netmeeting) support' CONFIG_IP_NF_H323 $CONFIG_IP_NF_CONNTRACK
fi
if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
@@ -112,6 +113,13 @@
define_tristate CONFIG_IP_NF_NAT_SIP $CONFIG_IP_NF_NAT
fi
fi
+ if [ "$CONFIG_IP_NF_H323" = "m" ]; then
+ define_tristate CONFIG_IP_NF_NAT_H323 m
+ else
+ if [ "$CONFIG_IP_NF_H323" = "y" ]; then
+ define_tristate CONFIG_IP_NF_NAT_H323 $CONFIG_IP_NF_NAT
+ fi
+ fi
if [ "$CONFIG_IP_NF_AMANDA" = "m" ]; then
define_tristate CONFIG_IP_NF_NAT_AMANDA m
else
diff -urN linux-2.4.32/net/ipv4/netfilter/Makefile linux-2.4.32/net/ipv4/netfilter/Makefile
--- linux-2.4.32/net/ipv4/netfilter/Makefile 2005-12-12 11:13:17.000000000 +0100
+++ linux-2.4.32/net/ipv4/netfilter/Makefile 2005-12-12 11:17:37.000000000 +0100
@@ -57,6 +57,10 @@
ifdef CONFIG_IP_NF_NAT_SIP
export-objs += ip_conntrack_sip.o
endif
+obj-$(CONFIG_IP_NF_H323) += ip_conntrack_h323.o
+ifdef CONFIG_IP_NF_NAT_H323
+ export-objs += ip_conntrack_h323.o
+endif
# NAT helpers
@@ -67,6 +71,7 @@
obj-$(CONFIG_IP_NF_NAT_PROTO_GRE) += ip_nat_proto_gre.o
obj-$(CONFIG_IP_NF_NAT_PPTP) += ip_nat_pptp.o
obj-$(CONFIG_IP_NF_NAT_SIP) += ip_nat_sip.o
+obj-$(CONFIG_IP_NF_NAT_H323) += ip_nat_h323.o
# generic IP tables
obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
diff -urN linux-2.4.32/net/ipv4/netfilter/ip_conntrack_h323.c linux-2.4.32/net/ipv4/netfilter/ip_conntrack_h323.c
--- linux-2.4.32/net/ipv4/netfilter/ip_conntrack_h323.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.4.32/net/ipv4/netfilter/ip_conntrack_h323.c 2005-12-12 11:14:54.000000000 +0100
@@ -0,0 +1,302 @@
+/*
+ * H.323 'brute force' extension for H.323 connection tracking.
+ * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
+ *
+ * Based on ip_masq_h323.c for 2.2 kernels from CoRiTel, Sofia project.
+ * (http://www.coritel.it/projects/sofia/nat/)
+ * Uses Sampsa Ranta's excellent idea on using expectfn to 'bind'
+ * the unregistered helpers to the conntrack entries.
+ */
+
+
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+#include <net/tcp.h>
+
+#include <linux/netfilter_ipv4/lockhelp.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ip_conntrack_core.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
+#include <linux/netfilter_ipv4/ip_conntrack_h323.h>
+
+MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
+MODULE_DESCRIPTION("H.323 'brute force' connection tracking module");
+MODULE_LICENSE("GPL");
+
+DECLARE_LOCK(ip_h323_lock);
+struct module *ip_conntrack_h323 = THIS_MODULE;
+
+#define DEBUGP(format, args...)
+
+static int h245_help(const struct iphdr *iph, size_t len,
+ struct ip_conntrack *ct,
+ enum ip_conntrack_info ctinfo)
+{
+ struct tcphdr *tcph = (void *)iph + iph->ihl * 4;
+ unsigned char *data = (unsigned char *) tcph + tcph->doff * 4;
+ unsigned char *data_limit;
+ u_int32_t tcplen = len - iph->ihl * 4;
+ u_int32_t datalen = tcplen - tcph->doff * 4;
+ int dir = CTINFO2DIR(ctinfo);
+ struct ip_ct_h225_master *info = &ct->help.ct_h225_info;
+ struct ip_conntrack_expect expect, *exp = &expect;
+ struct ip_ct_h225_expect *exp_info = &exp->help.exp_h225_info;
+ u_int16_t data_port;
+ u_int32_t data_ip;
+ unsigned int i;
+
+ DEBUGP("ct_h245_help: help entered %u.%u.%u.%u:%u->%u.%u.%u.%u:%u\n",
+ NIPQUAD(iph->saddr), ntohs(tcph->source),
+ NIPQUAD(iph->daddr), ntohs(tcph->dest));
+
+ /* Can't track connections formed before we registered */
+ if (!info)
+ return NF_ACCEPT;
+
+ /* 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) {
+ DEBUGP("ct_h245_help: Conntrackinfo = %u\n", ctinfo);
+ return NF_ACCEPT;
+ }
+
+ /* Not whole TCP header or too short packet? */
+ if (tcplen < sizeof(struct tcphdr) || tcplen < tcph->doff * 4 + 5) {
+ DEBUGP("ct_h245_help: tcplen = %u\n", (unsigned)tcplen);
+ return NF_ACCEPT;
+ }
+
+ /* Checksum invalid? Ignore. */
+ if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
+ csum_partial((char *)tcph, tcplen, 0))) {
+ DEBUGP("ct_h245_help: bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
+ tcph, tcplen, NIPQUAD(iph->saddr),
+ NIPQUAD(iph->daddr));
+ return NF_ACCEPT;
+ }
+
+ data_limit = (unsigned char *) data + datalen;
+ /* bytes: 0123 45
+ ipadrr port */
+ for (i = 0; data < (data_limit - 5); data++, i++) {
+ memcpy(&data_ip, data, sizeof(u_int32_t));
+ if (data_ip == iph->saddr) {
+ memcpy(&data_port, data + 4, sizeof(u_int16_t));
+ memset(&expect, 0, sizeof(expect));
+ /* update the H.225 info */
+ DEBUGP("ct_h245_help: new RTCP/RTP requested %u.%u.%u.%u:->%u.%u.%u.%u:%u\n",
+ NIPQUAD(ct->tuplehash[!dir].tuple.src.ip),
+ NIPQUAD(iph->saddr), ntohs(data_port));
+ LOCK_BH(&ip_h323_lock);
+ info->is_h225 = H225_PORT + 1;
+ exp_info->port = data_port;
+ exp_info->dir = dir;
+ exp_info->offset = i;
+
+ exp->seq = ntohl(tcph->seq) + i;
+
+ exp->tuple = ((struct ip_conntrack_tuple)
+ { { ct->tuplehash[!dir].tuple.src.ip,
+ { 0 } },
+ { data_ip,
+ { data_port },
+ IPPROTO_UDP }});
+ exp->mask = ((struct ip_conntrack_tuple)
+ { { 0xFFFFFFFF, { 0 } },
+ { 0xFFFFFFFF, { 0xFFFF }, 0xFFFF }});
+
+ exp->expectfn = NULL;
+
+ /* Ignore failure; should only happen with NAT */
+ ip_conntrack_expect_related(ct, exp);
+
+ UNLOCK_BH(&ip_h323_lock);
+ }
+ }
+
+ return NF_ACCEPT;
+
+}
+
+/* H.245 helper is not registered! */
+static struct ip_conntrack_helper h245 =
+ { { NULL, NULL },
+ "H.245", /* name */
+ IP_CT_HELPER_F_REUSE_EXPECT, /* flags */
+ NULL, /* module */
+ 8, /* max_ expected */
+ 240, /* timeout */
+ { { 0, { 0 } }, /* tuple */
+ { 0, { 0 }, IPPROTO_TCP } },
+ { { 0, { 0xFFFF } }, /* mask */
+ { 0, { 0 }, 0xFFFF } },
+ h245_help /* helper */
+ };
+
+static int h225_expect(struct ip_conntrack *ct)
+{
+ WRITE_LOCK(&ip_conntrack_lock);
+ ct->helper = &h245;
+ DEBUGP("h225_expect: helper for %p added\n", ct);
+ WRITE_UNLOCK(&ip_conntrack_lock);
+
+ return NF_ACCEPT; /* unused */
+}
+
+static int h225_help(const struct iphdr *iph, size_t len,
+ struct ip_conntrack *ct,
+ enum ip_conntrack_info ctinfo)
+{
+ struct tcphdr *tcph = (void *)iph + iph->ihl * 4;
+ unsigned char *data = (unsigned char *) tcph + tcph->doff * 4;
+ unsigned char *data_limit;
+ u_int32_t tcplen = len - iph->ihl * 4;
+ u_int32_t datalen = tcplen - tcph->doff * 4;
+ int dir = CTINFO2DIR(ctinfo);
+ struct ip_ct_h225_master *info = &ct->help.ct_h225_info;
+ struct ip_conntrack_expect expect, *exp = &expect;
+ struct ip_ct_h225_expect *exp_info = &exp->help.exp_h225_info;
+ u_int16_t data_port;
+ u_int32_t data_ip;
+ unsigned int i;
+
+ DEBUGP("ct_h225_help: help entered %u.%u.%u.%u:%u->%u.%u.%u.%u:%u\n",
+ NIPQUAD(iph->saddr), ntohs(tcph->source),
+ NIPQUAD(iph->daddr), ntohs(tcph->dest));
+
+ /* Can't track connections formed before we registered */
+ if (!info)
+ return NF_ACCEPT;
+
+ /* 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) {
+ DEBUGP("ct_h225_help: Conntrackinfo = %u\n", ctinfo);
+ return NF_ACCEPT;
+ }
+
+ /* Not whole TCP header or too short packet? */
+ if (tcplen < sizeof(struct tcphdr) || tcplen < tcph->doff * 4 + 5) {
+ DEBUGP("ct_h225_help: tcplen = %u\n", (unsigned)tcplen);
+ return NF_ACCEPT;
+ }
+
+ /* Checksum invalid? Ignore. */
+ if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
+ csum_partial((char *)tcph, tcplen, 0))) {
+ DEBUGP("ct_h225_help: bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
+ tcph, tcplen, NIPQUAD(iph->saddr),
+ NIPQUAD(iph->daddr));
+ return NF_ACCEPT;
+ }
+
+ data_limit = (unsigned char *) data + datalen;
+ /* bytes: 0123 45
+ ipadrr port */
+ for (i = 0; data < (data_limit - 5); data++, i++) {
+ memcpy(&data_ip, data, sizeof(u_int32_t));
+ if (data_ip == iph->saddr) {
+ memcpy(&data_port, data + 4, sizeof(u_int16_t));
+ if (data_port == tcph->source) {
+ /* Signal address */
+ DEBUGP("ct_h225_help: sourceCallSignalAddress from %u.%u.%u.%u\n",
+ NIPQUAD(iph->saddr));
+ /* Update the H.225 info so that NAT can mangle the address/port
+ even when we have no expected connection! */
+#ifdef CONFIG_IP_NF_NAT_NEEDED
+ LOCK_BH(&ip_h323_lock);
+ info->dir = dir;
+ info->seq[IP_CT_DIR_ORIGINAL] = ntohl(tcph->seq) + i;
+ info->offset[IP_CT_DIR_ORIGINAL] = i;
+ UNLOCK_BH(&ip_h323_lock);
+#endif
+ } else {
+ memset(&expect, 0, sizeof(expect));
+
+ /* update the H.225 info */
+ LOCK_BH(&ip_h323_lock);
+ info->is_h225 = H225_PORT;
+ exp_info->port = data_port;
+ exp_info->dir = dir;
+ exp_info->offset = i;
+
+ exp->seq = ntohl(tcph->seq) + i;
+
+ exp->tuple = ((struct ip_conntrack_tuple)
+ { { ct->tuplehash[!dir].tuple.src.ip,
+ { 0 } },
+ { data_ip,
+ { data_port },
+ IPPROTO_TCP }});
+ exp->mask = ((struct ip_conntrack_tuple)
+ { { 0xFFFFFFFF, { 0 } },
+ { 0xFFFFFFFF, { 0xFFFF }, 0xFFFF }});
+
+ exp->expectfn = h225_expect;
+
+ /* Ignore failure */
+ ip_conntrack_expect_related(ct, exp);
+
+ DEBUGP("ct_h225_help: new H.245 requested %u.%u.%u.%u->%u.%u.%u.%u:%u\n",
+ NIPQUAD(ct->tuplehash[!dir].tuple.src.ip),
+ NIPQUAD(iph->saddr), ntohs(data_port));
+
+ UNLOCK_BH(&ip_h323_lock);
+ }
+#ifdef CONFIG_IP_NF_NAT_NEEDED
+ } else if (data_ip == iph->daddr) {
+ memcpy(&data_port, data + 4, sizeof(u_int16_t));
+ if (data_port == tcph->dest) {
+ /* Signal address */
+ DEBUGP("ct_h225_help: destCallSignalAddress %u.%u.%u.%u\n",
+ NIPQUAD(iph->daddr));
+ /* Update the H.225 info so that NAT can mangle the address/port
+ even when we have no expected connection! */
+ LOCK_BH(&ip_h323_lock);
+ info->dir = dir;
+ info->seq[IP_CT_DIR_REPLY] = ntohl(tcph->seq) + i;
+ info->offset[IP_CT_DIR_REPLY] = i;
+ UNLOCK_BH(&ip_h323_lock);
+ }
+#endif
+ }
+ }
+
+ return NF_ACCEPT;
+
+}
+
+static struct ip_conntrack_helper h225 =
+ { { NULL, NULL },
+ "H.225", /* name */
+ IP_CT_HELPER_F_REUSE_EXPECT, /* flags */
+ THIS_MODULE, /* module */
+ 2, /* max_expected */
+ 240, /* timeout */
+ { { 0, { __constant_htons(H225_PORT) } }, /* tuple */
+ { 0, { 0 }, IPPROTO_TCP } },
+ { { 0, { 0xFFFF } }, /* mask */
+ { 0, { 0 }, 0xFFFF } },
+ h225_help /* helper */
+ };
+
+static int __init init(void)
+{
+ return ip_conntrack_helper_register(&h225);
+}
+
+static void __exit fini(void)
+{
+ /* Unregister H.225 helper */
+ ip_conntrack_helper_unregister(&h225);
+}
+
+#ifdef CONFIG_IP_NF_NAT_NEEDED
+EXPORT_SYMBOL(ip_h323_lock);
+#endif
+
+module_init(init);
+module_exit(fini);
diff -urN linux-2.4.32/net/ipv4/netfilter/ip_nat_h323.c /linux-2.4.32/net/ipv4/netfilter/ip_nat_h323.c
--- linux-2.4.32/net/ipv4/netfilter/ip_nat_h323.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.4.32/net/ipv4/netfilter/ip_nat_h323.c 2005-12-12 11:14:54.000000000 +0100
@@ -0,0 +1,403 @@
+/*
+ * H.323 'brute force' extension for NAT alteration.
+ * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
+ *
+ * Based on ip_masq_h323.c for 2.2 kernels from CoRiTel, Sofia project.
+ * (http://www.coritel.it/projects/sofia/nat.html)
+ * Uses Sampsa Ranta's excellent idea on using expectfn to 'bind'
+ * the unregistered helpers to the conntrack entries.
+ */
+
+
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+#include <net/tcp.h>
+
+#include <linux/netfilter_ipv4/lockhelp.h>
+#include <linux/netfilter_ipv4/ip_nat.h>
+#include <linux/netfilter_ipv4/ip_nat_helper.h>
+#include <linux/netfilter_ipv4/ip_nat_rule.h>
+#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/ip_conntrack_h323.h>
+
+MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
+MODULE_DESCRIPTION("H.323 'brute force' connection tracking module");
+MODULE_LICENSE("GPL");
+
+DECLARE_LOCK_EXTERN(ip_h323_lock);
+struct module *ip_nat_h323 = THIS_MODULE;
+
+#define DEBUGP(format, args...)
+
+
+static unsigned int
+h225_nat_expected(struct sk_buff **pskb,
+ unsigned int hooknum,
+ struct ip_conntrack *ct,
+ struct ip_nat_info *info);
+
+static unsigned int h225_nat_help(struct ip_conntrack *ct,
+ struct ip_conntrack_expect *exp,
+ struct ip_nat_info *info,
+ enum ip_conntrack_info ctinfo,
+ unsigned int hooknum,
+ struct sk_buff **pskb);
+
+static struct ip_nat_helper h245 =
+ { { NULL, NULL },
+ "H.245", /* name */
+ 0, /* flags */
+ NULL, /* module */
+ { { 0, { 0 } }, /* tuple */
+ { 0, { 0 }, IPPROTO_TCP } },
+ { { 0, { 0xFFFF } }, /* mask */
+ { 0, { 0 }, 0xFFFF } },
+ h225_nat_help, /* helper */
+ h225_nat_expected /* expectfn */
+ };
+
+static unsigned int
+h225_nat_expected(struct sk_buff **pskb,
+ unsigned int hooknum,
+ struct ip_conntrack *ct,
+ struct ip_nat_info *info)
+{
+ struct ip_nat_multi_range mr;
+ u_int32_t newdstip, newsrcip, newip;
+ u_int16_t port;
+ struct ip_ct_h225_expect *exp_info;
+ struct ip_ct_h225_master *master_info;
+ struct ip_conntrack *master = master_ct(ct);
+ unsigned int is_h225, ret;
+
+ IP_NF_ASSERT(info);
+ IP_NF_ASSERT(master);
+
+ IP_NF_ASSERT(!(info->initialized & (1<<HOOK2MANIP(hooknum))));
+
+ DEBUGP("h225_nat_expected: We have a connection!\n");
+ master_info = &ct->master->expectant->help.ct_h225_info;
+ exp_info = &ct->master->help.exp_h225_info;
+
+ LOCK_BH(&ip_h323_lock);
+
+ DEBUGP("master: ");
+ DUMP_TUPLE(&master->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+ DUMP_TUPLE(&master->tuplehash[IP_CT_DIR_REPLY].tuple);
+ DEBUGP("conntrack: ");
+ DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+ if (exp_info->dir == IP_CT_DIR_ORIGINAL) {
+ /* Make connection go to the client. */
+ newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ newsrcip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
+ DEBUGP("h225_nat_expected: %u.%u.%u.%u->%u.%u.%u.%u (to client)\n",
+ NIPQUAD(newsrcip), NIPQUAD(newdstip));
+ } else {
+ /* Make the connection go to the server */
+ newdstip = master->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip;
+ newsrcip = master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
+ DEBUGP("h225_nat_expected: %u.%u.%u.%u->%u.%u.%u.%u (to server)\n",
+ NIPQUAD(newsrcip), NIPQUAD(newdstip));
+ }
+ port = exp_info->port;
+ is_h225 = master_info->is_h225 == H225_PORT;
+ UNLOCK_BH(&ip_h323_lock);
+
+ if (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC)
+ newip = newsrcip;
+ else
+ newip = newdstip;
+
+ DEBUGP("h225_nat_expected: IP to %u.%u.%u.%u\n", NIPQUAD(newip));
+
+ mr.rangesize = 1;
+ /* We don't want to manip the per-protocol, just the IPs... */
+ mr.range[0].flags = IP_NAT_RANGE_MAP_IPS;
+ mr.range[0].min_ip = mr.range[0].max_ip = newip;
+
+ /* ... unless we're doing a MANIP_DST, in which case, make
+ sure we map to the correct port */
+ if (HOOK2MANIP(hooknum) == IP_NAT_MANIP_DST) {
+ mr.range[0].flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
+ mr.range[0].min = mr.range[0].max
+ = ((union ip_conntrack_manip_proto)
+ { port });
+ }
+
+ ret = ip_nat_setup_info(ct, &mr, hooknum);
+
+ if (is_h225) {
+ DEBUGP("h225_nat_expected: H.225, setting NAT helper for %p\n", ct);
+ /* NAT expectfn called with ip_nat_lock write-locked */
+ info->helper = &h245;
+ }
+ return ret;
+}
+
+static int h323_signal_address_fixup(struct ip_conntrack *ct,
+ struct sk_buff **pskb,
+ enum ip_conntrack_info ctinfo)
+{
+ struct iphdr *iph = (*pskb)->nh.iph;
+ struct tcphdr *tcph = (void *)iph + iph->ihl*4;
+ unsigned char *data;
+ u_int32_t tcplen = (*pskb)->len - iph->ihl*4;
+ u_int32_t datalen = tcplen - tcph->doff*4;
+ struct ip_ct_h225_master *info = &ct->help.ct_h225_info;
+ u_int32_t newip;
+ u_int16_t port;
+ u_int8_t buffer[6];
+ int i;
+
+ MUST_BE_LOCKED(&ip_h323_lock);
+
+ DEBUGP("h323_signal_address_fixup: %s %s\n",
+ between(info->seq[IP_CT_DIR_ORIGINAL], ntohl(tcph->seq), ntohl(tcph->seq) + datalen)
+ ? "yes" : "no",
+ between(info->seq[IP_CT_DIR_REPLY], ntohl(tcph->seq), ntohl(tcph->seq) + datalen)
+ ? "yes" : "no");
+ if (!(between(info->seq[IP_CT_DIR_ORIGINAL], ntohl(tcph->seq), ntohl(tcph->seq) + datalen)
+ || between(info->seq[IP_CT_DIR_REPLY], ntohl(tcph->seq), ntohl(tcph->seq) + datalen)))
+ return 1;
+
+ DEBUGP("h323_signal_address_fixup: offsets %u + 6 and %u + 6 in %u\n",
+ info->offset[IP_CT_DIR_ORIGINAL],
+ info->offset[IP_CT_DIR_REPLY],
+ tcplen);
+ DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+ DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+ for (i = 0; i < IP_CT_DIR_MAX; i++) {
+ DEBUGP("h323_signal_address_fixup: %s %s\n",
+ info->dir == IP_CT_DIR_ORIGINAL ? "original" : "reply",
+ i == IP_CT_DIR_ORIGINAL ? "caller" : "callee");
+ if (!between(info->seq[i], ntohl(tcph->seq),
+ ntohl(tcph->seq) + datalen))
+ continue;
+ if (!between(info->seq[i] + 6, ntohl(tcph->seq),
+ ntohl(tcph->seq) + datalen)) {
+ /* Partial retransmisison. It's a cracker being funky. */
+ if (net_ratelimit()) {
+ printk("H.323_NAT: partial packet %u/6 in %u/%u\n",
+ info->seq[i],
+ ntohl(tcph->seq),
+ ntohl(tcph->seq) + datalen);
+ }
+ return 0;
+ }
+
+ /* Change address inside packet to match way we're mapping
+ this connection. */
+ if (i == IP_CT_DIR_ORIGINAL) {
+ newip = ct->tuplehash[!info->dir].tuple.dst.ip;
+ port = ct->tuplehash[!info->dir].tuple.dst.u.tcp.port;
+ } else {
+ newip = ct->tuplehash[!info->dir].tuple.src.ip;
+ port = ct->tuplehash[!info->dir].tuple.src.u.tcp.port;
+ }
+
+ data = (char *) tcph + tcph->doff * 4 + info->offset[i];
+
+ DEBUGP("h323_signal_address_fixup: orig %s IP:port %u.%u.%u.%u:%u\n",
+ i == IP_CT_DIR_ORIGINAL ? "source" : "dest ",
+ data[0], data[1], data[2], data[3],
+ (data[4] << 8 | data[5]));
+
+ /* Modify the packet */
+ memcpy(buffer, &newip, 4);
+ memcpy(buffer + 4, &port, 2);
+ if (!ip_nat_mangle_tcp_packet(pskb, ct, ctinfo, info->offset[i],
+ 6, buffer, 6))
+ return 0;
+
+ DEBUGP("h323_signal_address_fixup: new %s IP:port %u.%u.%u.%u:%u\n",
+ i == IP_CT_DIR_ORIGINAL ? "source" : "dest ",
+ data[0], data[1], data[2], data[3],
+ (data[4] << 8 | data[5]));
+ }
+
+ return 1;
+}
+
+static int h323_data_fixup(struct ip_ct_h225_expect *info,
+ struct ip_conntrack *ct,
+ struct sk_buff **pskb,
+ enum ip_conntrack_info ctinfo,
+ struct ip_conntrack_expect *expect)
+{
+ u_int32_t newip;
+ u_int16_t port;
+ u_int8_t buffer[6];
+ struct ip_conntrack_tuple newtuple;
+ struct iphdr *iph = (*pskb)->nh.iph;
+ struct tcphdr *tcph = (void *)iph + iph->ihl*4;
+ unsigned char *data;
+ u_int32_t tcplen = (*pskb)->len - iph->ihl*4;
+ struct ip_ct_h225_master *master_info = &ct->help.ct_h225_info;
+ int is_h225;
+
+ MUST_BE_LOCKED(&ip_h323_lock);
+ DEBUGP("h323_data_fixup: offset %u + 6 in %u\n", info->offset, tcplen);
+ DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+ DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+ if (!between(expect->seq + 6, ntohl(tcph->seq),
+ ntohl(tcph->seq) + tcplen - tcph->doff * 4)) {
+ /* Partial retransmisison. It's a cracker being funky. */
+ if (net_ratelimit()) {
+ printk("H.323_NAT: partial packet %u/6 in %u/%u\n",
+ expect->seq,
+ ntohl(tcph->seq),
+ ntohl(tcph->seq) + tcplen - tcph->doff * 4);
+ }
+ return 0;
+ }
+
+ /* Change address inside packet to match way we're mapping
+ this connection. */
+ if (info->dir == IP_CT_DIR_REPLY) {
+ /* Must be where client thinks server is */
+ newip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
+ /* Expect something from client->server */
+ newtuple.src.ip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ newtuple.dst.ip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
+ } else {
+ /* Must be where server thinks client is */
+ newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
+ /* Expect something from server->client */
+ newtuple.src.ip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip;
+ newtuple.dst.ip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
+ }
+
+ is_h225 = (master_info->is_h225 == H225_PORT);
+
+ if (is_h225) {
+ newtuple.dst.protonum = IPPROTO_TCP;
+ newtuple.src.u.tcp.port = expect->tuple.src.u.tcp.port;
+ } else {
+ newtuple.dst.protonum = IPPROTO_UDP;
+ newtuple.src.u.udp.port = expect->tuple.src.u.udp.port;
+ }
+
+ /* Try to get same port: if not, try to change it. */
+ for (port = ntohs(info->port); port != 0; port++) {
+ if (is_h225)
+ newtuple.dst.u.tcp.port = htons(port);
+ else
+ newtuple.dst.u.udp.port = htons(port);
+
+ if (ip_conntrack_change_expect(expect, &newtuple) == 0)
+ break;
+ }
+ if (port == 0) {
+ DEBUGP("h323_data_fixup: no free port found!\n");
+ return 0;
+ }
+
+ port = htons(port);
+
+ data = (char *) tcph + tcph->doff * 4 + info->offset;
+
+ DEBUGP("h323_data_fixup: orig IP:port %u.%u.%u.%u:%u\n",
+ data[0], data[1], data[2], data[3],
+ (data[4] << 8 | data[5]));
+
+ /* Modify the packet */
+ memcpy(buffer, &newip, 4);
+ memcpy(buffer + 4, &port, 2);
+ if (!ip_nat_mangle_tcp_packet(pskb, ct, ctinfo, info->offset,
+ 6, buffer, 6))
+ return 0;
+
+ DEBUGP("h323_data_fixup: new IP:port %u.%u.%u.%u:%u\n",
+ data[0], data[1], data[2], data[3],
+ (data[4] << 8 | data[5]));
+
+ return 1;
+}
+
+static unsigned int h225_nat_help(struct ip_conntrack *ct,
+ struct ip_conntrack_expect *exp,
+ struct ip_nat_info *info,
+ enum ip_conntrack_info ctinfo,
+ unsigned int hooknum,
+ struct sk_buff **pskb)
+{
+ int dir;
+ struct ip_ct_h225_expect *exp_info;
+
+ /* Only mangle things once: original direction in POST_ROUTING
+ and reply direction on PRE_ROUTING. */
+ dir = CTINFO2DIR(ctinfo);
+ DEBUGP("nat_h323: dir %s at hook %s\n",
+ dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY",
+ hooknum == NF_IP_POST_ROUTING ? "POSTROUTING"
+ : hooknum == NF_IP_PRE_ROUTING ? "PREROUTING"
+ : hooknum == NF_IP_LOCAL_OUT ? "OUTPUT" : "???");
+ if (!((hooknum == NF_IP_POST_ROUTING && dir == IP_CT_DIR_ORIGINAL)
+ || (hooknum == NF_IP_PRE_ROUTING && dir == IP_CT_DIR_REPLY))) {
+ DEBUGP("nat_h323: Not touching dir %s at hook %s\n",
+ dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY",
+ hooknum == NF_IP_POST_ROUTING ? "POSTROUTING"
+ : hooknum == NF_IP_PRE_ROUTING ? "PREROUTING"
+ : hooknum == NF_IP_LOCAL_OUT ? "OUTPUT" : "???");
+ return NF_ACCEPT;
+ }
+
+ if (!exp) {
+ LOCK_BH(&ip_h323_lock);
+ if (!h323_signal_address_fixup(ct, pskb, ctinfo)) {
+ UNLOCK_BH(&ip_h323_lock);
+ return NF_DROP;
+ }
+ UNLOCK_BH(&ip_h323_lock);
+ return NF_ACCEPT;
+ }
+
+ exp_info = &exp->help.exp_h225_info;
+
+ LOCK_BH(&ip_h323_lock);
+ if (!h323_data_fixup(exp_info, ct, pskb, ctinfo, exp)) {
+ UNLOCK_BH(&ip_h323_lock);
+ return NF_DROP;
+ }
+ UNLOCK_BH(&ip_h323_lock);
+
+ return NF_ACCEPT;
+}
+
+static struct ip_nat_helper h225 =
+ { { NULL, NULL },
+ "H.225", /* name */
+ IP_NAT_HELPER_F_ALWAYS, /* flags */
+ THIS_MODULE, /* module */
+ { { 0, { __constant_htons(H225_PORT) } }, /* tuple */
+ { 0, { 0 }, IPPROTO_TCP } },
+ { { 0, { 0xFFFF } }, /* mask */
+ { 0, { 0 }, 0xFFFF } },
+ h225_nat_help, /* helper */
+ h225_nat_expected /* expectfn */
+ };
+
+static int __init init(void)
+{
+ int ret;
+
+ ret = ip_nat_helper_register(&h225);
+
+ if (ret != 0)
+ printk("ip_nat_h323: cannot initialize the module!\n");
+
+ return ret;
+}
+
+static void __exit fini(void)
+{
+ ip_nat_helper_unregister(&h225);
+}
+
+module_init(init);
+module_exit(fini);
diff -urN linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack.h linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack.h
--- linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack.h 2005-12-12 11:13:17.000000000 +0100
+++ linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack.h 2005-12-12 11:16:13.000000000 +0100
@@ -72,6 +72,7 @@
#include <linux/netfilter_ipv4/ip_conntrack_irc.h>
#include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
#include <linux/netfilter_ipv4/ip_conntrack_sip.h>
+#include <linux/netfilter_ipv4/ip_conntrack_h323.h>
/* per expectation: application helper private data */
union ip_conntrack_expect_help {
@@ -81,6 +82,7 @@
struct ip_ct_irc_expect exp_irc_info;
struct ip_ct_pptp_expect exp_pptp_info;
struct ip_ct_sip_expect exp_sip_info;
+ struct ip_ct_h225_expect exp_h225_info;
#ifdef CONFIG_IP_NF_NAT_NEEDED
union {
@@ -96,6 +98,7 @@
struct ip_ct_irc_master ct_irc_info;
struct ip_ct_pptp_master ct_pptp_info;
struct ip_ct_sip_master ct_sip_info;
+ struct ip_ct_h225_master ct_h225_info;
};
#ifdef CONFIG_IP_NF_NAT_NEEDED
diff -urN linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_h323.h linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_h323.h
--- linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_h323.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_h323.h 2005-12-12 11:14:54.000000000 +0100
@@ -0,0 +1,30 @@
+#ifndef _IP_CONNTRACK_H323_H
+#define _IP_CONNTRACK_H323_H
+/* H.323 connection tracking. */
+
+#ifdef __KERNEL__
+/* Protects H.323 related data */
+DECLARE_LOCK_EXTERN(ip_h323_lock);
+#endif
+
+/* Default H.225 port */
+#define H225_PORT 1720
+
+/* This structure is per expected connection */
+struct ip_ct_h225_expect {
+ u_int16_t port; /* Port of the H.225 helper/RTCP/RTP channel */
+ enum ip_conntrack_dir dir; /* Direction of the original connection */
+ unsigned int offset; /* offset of the address in the payload */
+};
+
+/* This structure exists only once per master */
+struct ip_ct_h225_master {
+ int is_h225; /* H.225 or H.245 connection */
+#ifdef CONFIG_IP_NF_NAT_NEEDED
+ enum ip_conntrack_dir dir; /* Direction of the original connection */
+ u_int32_t seq[IP_CT_DIR_MAX]; /* Exceptional packet mangling for signal addressess... */
+ unsigned int offset[IP_CT_DIR_MAX]; /* ...and the offset of the addresses in the payload */
+#endif
+};
+
+#endif /* _IP_CONNTRACK_H323_H */
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