--- /dev/null
+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 2005-12-11 21:34:32.000000000 +0100
++++ linux-2.4.32/net/ipv4/netfilter/Config.in 2005-12-11 21:38:12.000000000 +0100
+@@ -15,6 +15,7 @@
+ dep_tristate ' Connection byte counter support' CONFIG_IP_NF_MATCH_CONNBYTES $CONFIG_IP_NF_CT_ACCT $CONFIG_IP_NF_CONNTRACK $CONFIG_IP_NF_IPTABLES
+ 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 $CONFIG_IP_NF_CONNTRACK
+ fi
+
+ if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
+@@ -104,6 +105,13 @@
+ define_tristate CONFIG_IP_NF_NAT_PROTO_GRE $CONFIG_IP_NF_NAT
+ fi
+ fi
++ if [ "$CONFIG_IP_NF_SIP" = "m" ]; then
++ define_tristate CONFIG_IP_NF_NAT_SIP m
++ else
++ if [ "$CONFIG_IP_NF_SIP" = "y" ]; then
++ define_tristate CONFIG_IP_NF_NAT_SIP $CONFIG_IP_NF_NAT
++ fi
++ fi
+ if [ "$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 2005-12-11 21:34:32.000000000 +0100
++++ linux-2.4.32/net/ipv4/netfilter/Makefile 2005-12-11 21:39:08.000000000 +0100
+@@ -53,6 +53,10 @@
+ ifdef CONFIG_IP_NF_NAT_PPTP
+ export-objs += ip_conntrack_pptp.o
+ endif
++obj-$(CONFIG_IP_NF_SIP) += ip_conntrack_sip.o
++ifdef CONFIG_IP_NF_NAT_SIP
++ export-objs += ip_conntrack_sip.o
++endif
+
+
+ # NAT helpers
+@@ -62,6 +66,7 @@
+ obj-$(CONFIG_IP_NF_NAT_IRC) += ip_nat_irc.o
+ obj-$(CONFIG_IP_NF_NAT_PROTO_GRE) += ip_nat_proto_gre.o
+ obj-$(CONFIG_IP_NF_NAT_PPTP) += ip_nat_pptp.o
++obj-$(CONFIG_IP_NF_NAT_SIP) += ip_nat_sip.o
+
+ # generic IP tables
+ obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
+diff -urN linux-2.4.32/net/ipv4/netfilter/ip_conntrack_sip.c linux-2.4.32/net/ipv4/netfilter/ip_conntrack_sip.c
+--- linux-2.4.32/net/ipv4/netfilter/ip_conntrack_sip.c 1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.32/net/ipv4/netfilter/ip_conntrack_sip.c 2005-12-11 21:35:51.000000000 +0100
+@@ -0,0 +1,312 @@
++/*
++ * SIP extension for IP connection tracking.
++ *
++ * Copyright (C) 2004, CyberTAN Corporation
++ * All Rights Reserved.
++ *
++ * THIS SOFTWARE IS OFFERED "AS IS", AND CYBERTAN GRANTS NO WARRANTIES OF ANY
++ * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. CYBERTAN
++ * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
++ * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
++ *
++ */
++
++#include <linux/module.h>
++#include <linux/netfilter.h>
++#include <linux/ip.h>
++#include <linux/ctype.h>
++#include <net/checksum.h>
++#include <net/tcp.h>
++
++#include <linux/netfilter_ipv4/lockhelp.h>
++#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
++#include <linux/netfilter_ipv4/ip_conntrack_sip.h>
++#include <linux/netfilter_ipv4/ip_conntrack_core.h>
++
++DECLARE_LOCK(ip_sip_lock);
++
++struct module *ip_conntrack_sip = THIS_MODULE;
++
++#define MAX_PORTS 8
++static int ports[MAX_PORTS];
++static int ports_c;
++#ifdef MODULE_PARM
++MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
++#endif
++
++#if 0
++ #define DEBUGP printk
++#else
++ #define DEBUGP(format, args...)
++#endif
++
++#define RTCP_SUPPORT
++
++static int set_expected_rtp(struct ip_conntrack *ct, u_int32_t dstip,
++ u_int16_t dstport, unsigned int conntype)
++{
++ struct ip_conntrack_expect expect, *exp = &expect;
++ struct ip_ct_sip_expect *exp_sip_info = &exp->help.exp_sip_info;
++ int ret = 0;
++
++ memset(&expect, 0, sizeof(expect));
++ LOCK_BH(&ip_sip_lock);
++
++ DEBUGP("conntrack_sip: %s: [%s]: DST=%u.%u.%u.%u:%u\n", __FUNCTION__,
++ conntype == CONN_RTP ? "RTP" : "RTCP", NIPQUAD(dstip), dstport);
++
++ /* exp_sip_info */
++ exp_sip_info->port = dstport;
++ exp_sip_info->type = conntype;
++ exp_sip_info->nated = 0;
++
++ /* new expectation */
++ exp->tuple = ((struct ip_conntrack_tuple)
++ { { 0, { 0 } },
++ { dstip, { htons(dstport) }, IPPROTO_UDP }});
++ exp->mask = ((struct ip_conntrack_tuple)
++ { { 0, { 0 } },
++ { 0xFFFFFFFF, { 0xFFFF }, 0xFFFF }});
++ exp->expectfn = NULL;
++
++ if ((ret=ip_conntrack_expect_related(ct, exp)) != 0) {
++ DEBUGP("Can't add new expectation. \n");
++ }
++
++ UNLOCK_BH(&ip_sip_lock);
++
++ return ret;
++}
++
++/*
++static int unset_expected_rtp(struct ip_conntrack *ct, u_int32_t dstip, u_int16_t dstport)
++{
++ struct ip_conntrack_expect *exp;
++ const struct ip_conntrack_tuple tuple = { { 0, { 0 } },
++ { dstip, { htons(dstport) }, IPPROTO_UDP }};
++
++ LOCK_BH(&ip_sip_lock);
++
++ exp = ip_conntrack_expect_find_get(&tuple);
++ if (exp) {
++ DEBUGP("Find the expectation %p, then delete it.\n", exp);
++ ip_conntrack_unexpect_related(exp);
++ }
++
++ UNLOCK_BH(&ip_sip_lock);
++
++ return 0;
++}*/
++
++/* return:
++ * 0 : Not found
++ * 1 : Found domain name
++ * 2 : Found dotted quads
++ */
++int find_sdp_rtp_addr(const char *data, size_t dlen,
++ unsigned int *numoff, unsigned int *numlen, u_int32_t *addr)
++{
++ char *st, *p = (char *)data;
++ const char *limit = data + dlen;
++ unsigned char p1, p2, p3, p4;
++
++ while (p < limit) {
++ /* find 'c=' line */
++ if (strncmp(p, "\nc=",3) && strncmp(p, "\rc=",3)) {
++ p++;
++ continue;
++ }
++ p += 3;
++
++ if (strncmp(p, "IN IP4 ",7))
++ continue;
++ p += 7;
++
++ /* IP address */
++ st = p;
++
++ /* FQDNs or dotted quads */
++ while (isalpha(*p) || isdigit(*p) || (*p=='.') || (*p=='-')) {
++ p++;
++ if (p == limit)
++ return 0;
++ }
++
++ *numoff = st - data;
++ *numlen = p - st;
++
++ /* Convert the IP address */
++ p1 = simple_strtoul(st, &st ,10);
++ if (*st != '.')
++ return 1;
++ p2 = simple_strtoul(st+1, &st, 10);
++ if (*st != '.')
++ return 1;
++ p3 = simple_strtoul(st+1, &st, 10);
++ if (*st != '.')
++ return 1;
++ p4 = simple_strtoul(st+1, &st, 10);
++
++ *addr = (p1<<24) | (p2<<16) | (p3<<8) | p4;
++
++ return 2;
++ }
++
++ return 0;
++}
++
++u_int16_t find_sdp_audio_port(const char *data, size_t dlen,
++ unsigned int *numoff, unsigned int *numlen)
++{
++ char *st, *p = (char *)data;
++ const char *limit = data + dlen;
++ u_int16_t port = 0;
++
++ while (p < limit) {
++ /* find 'm=' */
++ if (strncmp(p, "\nm=", 3) && strncmp(p, "\rm=", 3)) {
++ p++;
++ continue;
++ }
++ p += 3;
++
++ /* audio stream */
++ if (strncmp(p ,"audio ",6))
++ continue;
++ p += 6;
++
++ st = p;
++ port = simple_strtoul(p, &p, 10);
++
++ *numoff = st - data;
++ *numlen = p - st;
++
++ return port;
++ }
++
++ return 0;
++}
++
++static int help(const struct iphdr *iph, size_t len,
++ struct ip_conntrack *ct,
++ enum ip_conntrack_info ctinfo)
++{
++ int dir = CTINFO2DIR(ctinfo);
++ unsigned int matchlen, matchoff;
++
++ u_int32_t ipaddr=0;
++ u_int16_t port = 0;
++
++ int found = 0;
++ struct udphdr *udph = (void *)iph + iph->ihl * 4;
++ const char *data = (const char *)udph + 8;
++ unsigned int udplen = len - iph->ihl * 4;
++ unsigned int datalen = udplen - 8;
++ struct ip_ct_sip_master *ct_sip_info = &ct->help.ct_sip_info;
++
++ DEBUGP("\nconntrack_sip: help(): DIR=%d, conntrackinfo=%u\n", dir, ctinfo);
++ DEBUGP("conntrack_sip: %u.%u.%u.%u:%u -> %u.%u.%u.%u:%u\n",
++ NIPQUAD(ct->tuplehash[dir].tuple.src.ip),
++ ntohs(ct->tuplehash[dir].tuple.src.u.udp.port),
++ NIPQUAD(ct->tuplehash[dir].tuple.dst.ip),
++ ntohs(ct->tuplehash[dir].tuple.dst.u.udp.port) );
++
++ /* Reset for a new incoming packet */
++ ct_sip_info->mangled = 0;
++
++ /* keep the connection alive */
++ ip_ct_refresh(ct, (SIP_EXPIRES * HZ));
++
++ /* Don't need to set the expectation for upstream direction */
++ if (dir == IP_CT_DIR_REPLY)
++ return NF_ACCEPT;
++
++ /* Need to set the expected connection for further incoming RTP stream */
++ if (strncmp(data, "INVITE", 6) != 0 && strncmp(data, "SIP/2.0 200", 11) != 0) {
++ DEBUGP("conntrack_sip: Not interesting packet.\n");
++ return NF_ACCEPT;
++ }
++
++ /* Find RTP address */
++ found = find_sdp_rtp_addr(data, datalen, &matchoff, &matchlen, &ipaddr);
++ if (!found)
++ return NF_ACCEPT;
++
++ DEBUGP("conntrack_sip: 'IN IP4' is %s.\n", (found == 1) ? "FQDNs" : "dotted quads");
++
++ /* If it's a null address, then the call is on hold */
++ if (found == 2 && ipaddr == 0) {
++ DEBUGP("conntrack_sip: Null address is found.\n");
++ return NF_ACCEPT;
++ }
++
++ /* Find audio port, and we don't like the well-known ports,
++ * which is less than 1024 */
++ port = find_sdp_audio_port(data, datalen, &matchoff, &matchlen);
++ if (port < 1024)
++ return NF_ACCEPT;
++
++ DEBUGP("conntrack_sip: audio port=%d.\n", port);
++
++ ipaddr = ct->tuplehash[dir].tuple.src.ip;
++ ct_sip_info->rtpport = port;
++
++ /* RFC1889 - RTP uses an even port number and the corresponding RTCP
++ * stream uses the next higher (odd) port number. */
++ if (set_expected_rtp(ct, ipaddr, port, CONN_RTP) == 0) {
++#ifdef RTCP_SUPPORT
++ set_expected_rtp(ct, ipaddr, port + 1, CONN_RTCP);
++#endif
++ }
++
++ return NF_ACCEPT;
++}
++
++static struct ip_conntrack_helper sip[MAX_PORTS];
++
++
++/* Not __exit: called from init() */
++static void fini(void)
++{
++ int i;
++ for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
++ DEBUGP("ip_ct_sip: unregistering helper for port %d\n",
++ ports[i]);
++ ip_conntrack_helper_unregister(&sip[i]);
++ }
++}
++
++static int __init init(void)
++{
++ int i, ret;
++
++ if (ports[0] == 0)
++ ports[0] = SIP_PORT;
++
++ for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
++ memset(&sip[i], 0, sizeof(struct ip_conntrack_helper));
++ sip[i].tuple.dst.u.udp.port = htons(ports[i]);
++ sip[i].tuple.dst.protonum = IPPROTO_UDP;
++ sip[i].mask.dst.u.udp.port = 0xF0FF;
++ sip[i].mask.dst.protonum = 0xFFFF;
++ sip[i].help = help;
++ sip[i].timeout = RTP_TIMEOUT;
++ DEBUGP("ip_ct_sip: registering helper for port %d\n",
++ ports[i]);
++ ret = ip_conntrack_helper_register(&sip[i]);
++
++ if (ret) {
++ fini();
++ return ret;
++ }
++ ports_c++;
++ }
++ return 0;
++}
++
++
++EXPORT_SYMBOL(ip_sip_lock);
++EXPORT_SYMBOL(ip_conntrack_sip);
++
++module_init(init);
++module_exit(fini);
+diff -urN linux-2.4.32/net/ipv4/netfilter/ip_nat_sip.c linux-2.4.32/net/ipv4/netfilter/ip_nat_sip.c
+--- linux-2.4.32/net/ipv4/netfilter/ip_nat_sip.c 1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.32/net/ipv4/netfilter/ip_nat_sip.c 2005-12-11 21:35:51.000000000 +0100
+@@ -0,0 +1,800 @@
++/*
++ * SIP extension for TCP NAT alteration.
++ *
++ * Copyright (C) 2004, CyberTAN Corporation
++ * All Rights Reserved.
++ *
++ * THIS SOFTWARE IS OFFERED "AS IS", AND CYBERTAN GRANTS NO WARRANTIES OF ANY
++ * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. CYBERTAN
++ * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
++ * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
++ *
++ */
++
++#include <linux/module.h>
++#include <linux/netfilter_ipv4.h>
++#include <linux/ip.h>
++#include <linux/tcp.h>
++#include <linux/udp.h>
++#include <linux/ctype.h>
++#include <net/tcp.h>
++#include <net/udp.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_sip.h>
++#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
++
++#if 0
++ #define DEBUGP printk
++#else
++ #define DEBUGP(format, args...)
++#endif
++
++#define MAX_PORTS 8
++static int ports[MAX_PORTS];
++static int ports_c = 0;
++
++#ifdef MODULE_PARM
++MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
++#endif
++
++DECLARE_LOCK_EXTERN(ip_sip_lock);
++
++#define RTCP_SUPPORT
++
++/* down(stream): caller -> callee
++ up(stream): caller <- callee */
++
++
++/* Return 1 for match, 0 for accept, -1 for partial. */
++static int find_pattern(const char *data, size_t dlen,
++ const char *pattern, size_t plen,
++ char skip, char term,
++ unsigned int *numoff,
++ unsigned int *numlen
++ )
++{
++ size_t i, j, k;
++
++// DEBUGP("find_pattern `%s': dlen = %u\n", pattern, dlen);
++ if (dlen == 0)
++ return 0;
++
++ if (dlen <= plen) {
++ /* Short packet: try for partial? */
++ if (strnicmp(data, pattern, dlen) == 0)
++ return -1;
++ else return 0;
++ }
++
++ for(i=0; i<= (dlen - plen); i++){
++ if( memcmp(data + i, pattern, plen ) != 0 ) continue;
++
++ /* patten match !! */
++ *numoff=i + plen;
++ for (j=*numoff, k=0; data[j] != term; j++, k++)
++ if( j > dlen ) return -1 ; /* no terminal char */
++
++ *numlen = k;
++ return 1;
++ }
++
++ return 0;
++}
++
++static unsigned int
++sip_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;
++ struct ip_ct_sip_expect *exp_sip_info;
++ struct ip_conntrack *master = master_ct(ct);
++
++ IP_NF_ASSERT(info);
++ IP_NF_ASSERT(master);
++ IP_NF_ASSERT(!(info->initialized & (1<<HOOK2MANIP(hooknum))));
++
++ exp_sip_info = &ct->master->help.exp_sip_info;
++
++ LOCK_BH(&ip_sip_lock);
++
++ /* Outer machine IP */
++ newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
++ /* Client (virtual) IP under NAT */
++ newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
++
++ UNLOCK_BH(&ip_sip_lock);
++
++ if (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC)
++ newip = newsrcip;
++ else
++ newip = newdstip;
++
++ DEBUGP("sip_nat_expected: IP to %u.%u.%u.%u:%u\n", NIPQUAD(newip),
++ htons(exp_sip_info->port));
++
++ 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)
++ { htons(exp_sip_info->port) });
++ }
++
++ return ip_nat_setup_info(ct, &mr, hooknum);
++}
++
++static int _find_sip_via_addrport(const char *data, size_t dlen,
++ unsigned int *numoff, unsigned int *numlen)
++{
++ const char *addr, *p = data;
++ const char *limit = data + dlen;
++
++ while (p < limit) {
++ /* Find the topmost via tag */
++ if (strnicmp(p, "\nvia:",5) && strnicmp(p, "\nv:",3) &&
++ strnicmp(p, "\rvia:",5) && strnicmp(p, "\rv:",3)) {
++ p++;
++ continue;
++ }
++
++ /* Look for UDP */
++ while (*p!='U' && *p!='u') {
++ if (p == limit)
++ return 0;
++ p++;
++ }
++ p+= 3;
++
++ if (p >= limit)
++ return 0;
++
++ /* Skip a space */
++ while (*p == ' '){
++ if (p == limit)
++ return 0;
++ p++;
++ }
++
++ /* IP address */
++ addr = p;
++
++ /* FQDNs or dotted quads */
++ while (isalpha(*p) || isdigit(*p) || (*p=='.') || (*p=='-')) {
++ p++;
++ if (p == limit)
++ return 0;
++ }
++
++ /* If there is a port number, skip it */
++ if (*p == ':') {
++ p++;
++ if (p == limit)
++ return 0;
++
++ while (isdigit(*p)) {
++ p++;
++ if (p == limit)
++ return 0;
++ }
++ }
++
++ *numoff = addr - data;
++ *numlen = p - addr;
++
++ return 1;
++ }
++
++ return 0; /* Not found */
++}
++
++static int _mangle_sip_via(struct ip_conntrack *ct, enum ip_conntrack_info ctinfo,
++ struct sk_buff **pskb, u_int32_t newip, u_int16_t newport,
++ unsigned int numoff, unsigned int numlen)
++{
++ int buflen;
++ char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
++
++ sprintf(buffer, "%u.%u.%u.%u:%u", NIPQUAD(newip), newport);
++ buflen = strlen(buffer);
++
++ MUST_BE_LOCKED(&ip_sip_lock);
++
++ if (!ip_nat_mangle_udp_packet(pskb, ct, ctinfo, numoff,
++ numlen, buffer, buflen) )
++ return 0;
++
++ DEBUGP("(SIP) Via is changed to %s.\n", buffer);
++
++ return buflen - numlen;
++}
++
++static int mangle_sip_via(struct ip_conntrack *ct, enum ip_conntrack_info ctinfo,
++ struct sk_buff **pskb, u_int32_t newip, u_int16_t newport)
++{
++ struct iphdr *iph = (*pskb)->nh.iph;
++ struct udphdr *udph = (void *)iph + iph->ihl * 4;
++ const char *data = (const char *)udph + 8;
++ unsigned int udplen = ntohs(iph->tot_len) - (iph->ihl * 4);
++ unsigned int datalen = udplen - 8;
++ unsigned int matchoff, matchlen;
++
++ /* Find the topmost via tag */
++ _find_sip_via_addrport(data , datalen, &matchoff, &matchlen);
++ return _mangle_sip_via(ct, ctinfo, pskb, newip, newport,
++ matchoff, matchlen);
++}
++
++static int mangle_sip_contact(struct ip_conntrack *ct, enum ip_conntrack_info ctinfo,
++ struct sk_buff **pskb, u_int32_t newip, u_int16_t newport)
++{
++ struct iphdr *iph = (*pskb)->nh.iph;
++ struct udphdr *udph = (void *)iph + iph->ihl * 4;
++ const char *data = (const char *)udph + 8;
++ unsigned int udplen = ntohs(iph->tot_len) - (iph->ihl * 4);
++ unsigned int datalen = udplen - 8;
++
++ int buflen, diff_len = 0;
++ char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
++ const char *uri, *addr, *p = data;
++ const char *limit = data + datalen;
++
++
++ while (p < limit) {
++ if (strnicmp(p, "\ncontact:", 9) && strnicmp(p, "\nm:", 3) &&
++ strnicmp(p, "\rcontact:", 9) && strnicmp(p, "\rm:", 3)) {
++ p++;
++ continue;
++ }
++
++ while (strnicmp(p, "sip:", 4)) {
++ if (p == limit)
++ return 0;
++ p++;
++ }
++ p += 4;
++
++ /* If there is user info in the contact */
++ uri = p;
++
++ while (*p!='@' && *p!='>' && *p!=';' && *p!='\n' && *p!='\r' && *p!='?' && *p!=',') {
++ if (p == limit)
++ return 0;
++ p++;
++ }
++
++ if (*p=='@')
++ p++;
++ else
++ p = uri; /* back to previous URI pointer */
++
++ /* IP address */
++ addr = p;
++
++ /* FQDNs or dotted quads */
++ while (isalpha(*p) || isdigit(*p) || (*p=='.') || (*p=='-')) {
++ p++;
++ if (p == limit)
++ return 0;
++ }
++
++ /* If there is a port number, skip it */
++ if (*p==':') {
++ p++;
++ while (isdigit(*p))
++ p++;
++ }
++
++ sprintf(buffer, "%u.%u.%u.%u:%u", NIPQUAD(newip), newport);
++ buflen = strlen(buffer);
++
++ MUST_BE_LOCKED(&ip_sip_lock);
++
++ if (!ip_nat_mangle_udp_packet(pskb, ct, ctinfo, addr - data,
++ p - addr, buffer, buflen) )
++ return 0;
++
++ diff_len = buflen - (p - addr);
++ DEBUGP("(SIP) Contact is changed to %s.\n", buffer);
++ break;
++ }
++
++ return diff_len;
++}
++
++static int _find_sip_content_length_size(const char *data, size_t dlen,
++ unsigned int *numoff, unsigned int *numlen)
++{
++ char *st, *p = (char *)data;
++ const char *limit = data + dlen;
++ int size = 0;
++
++ while (p < limit) {
++ if (strnicmp(p, "\nContent-Length:", 16) && strnicmp(p, "\nl:", 3) &&
++ strnicmp(p, "\rContent-Length:", 16) && strnicmp(p, "\rm:", 3)) {
++ p++;
++ continue;
++ }
++
++ /* Go through the string above */
++ while (*p != ':') {
++ if (p == limit)
++ return 0;
++ p++;
++ }
++ p++;
++
++ while (*p == ' ') {
++ if (p == limit)
++ return 0;
++ p++;
++ }
++
++ st = p;
++ size = simple_strtoul(p, &p, 10);
++
++ *numoff = st - data;
++ *numlen = p - st;
++
++ return size;
++ }
++
++ return 0;
++}
++
++static int mangle_sip_content_length(struct ip_conntrack *ct, enum ip_conntrack_info ctinfo,
++ struct sk_buff **pskb, int diff_len)
++{
++ struct iphdr *iph = (*pskb)->nh.iph;
++ struct udphdr *udph = (void *)iph + iph->ihl * 4;
++ const char *data = (const char *)udph + 8;
++ unsigned int udplen = ntohs(iph->tot_len) - (iph->ihl * 4);
++ unsigned int datalen = udplen - 8;
++
++ unsigned int matchlen, matchoff;
++ int size, buflen;
++ char buffer[sizeof("nnnnn")];
++
++ /* original legth */
++ size = _find_sip_content_length_size(data, datalen, &matchoff, &matchlen);
++
++ /* new legth */
++ sprintf(buffer, "%u", size + diff_len);
++ buflen = strlen(buffer);
++
++ if (!ip_nat_mangle_udp_packet(pskb, ct, ctinfo, matchoff,
++ matchlen, buffer, buflen) )
++ return 0;
++
++ DEBUGP("(SDP) Content-Length is changed %d->%s.\n", size, buffer);
++ return buflen - matchlen;
++
++}
++
++static int mangle_sip_sdp_content(struct ip_conntrack *ct, enum ip_conntrack_info ctinfo,
++ struct sk_buff **pskb, u_int32_t newip, u_int16_t newport)
++{
++ struct iphdr *iph = (*pskb)->nh.iph;
++ struct udphdr *udph = (void *)iph + iph->ihl * 4;
++ const char *data = (const char *)udph + 8;
++ unsigned int udplen = ntohs(iph->tot_len) - (iph->ihl * 4);
++ unsigned int datalen = udplen - 8;
++
++ unsigned int matchlen, matchoff;
++ int found, buflen, diff_len = 0;
++ char buffer[sizeof("nnn.nnn.nnn.nnn")];
++ char *addr, *p;
++ char *limit = (char *)data + datalen;
++ u_int32_t ipaddr = 0;
++ u_int16_t getport;
++ int dir;
++
++ /* Find RTP address */
++ found = find_sdp_rtp_addr(data, datalen, &matchoff, &matchlen, &ipaddr);
++ if (found) {
++ /* If it's a null address, then the call is on hold */
++ if (found == 2 && ipaddr == 0)
++ return 0;
++
++ sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(newip));
++ buflen = strlen(buffer);
++
++ MUST_BE_LOCKED(&ip_sip_lock);
++
++ if (!ip_nat_mangle_udp_packet(pskb, ct, ctinfo, matchoff,
++ matchlen, buffer, buflen) )
++ return 0;
++
++ diff_len += (buflen - matchlen);
++ DEBUGP("(SDP) RTP address is changed to %s.\n", buffer);
++ }
++
++ /* Find audio port */
++ getport = find_sdp_audio_port(data, datalen, &matchoff, &matchlen);
++ if (getport != newport) {
++ sprintf(buffer, "%d", newport);
++ buflen = strlen(buffer);
++
++ MUST_BE_LOCKED(&ip_sip_lock);
++
++ if (!ip_nat_mangle_udp_packet(pskb, ct, ctinfo, matchoff,
++ matchlen, buffer, buflen) )
++ return 0;
++
++ diff_len += (buflen - matchlen);
++ DEBUGP("(SDP) audio port is changed to %d.\n", newport);
++ }
++
++ dir = CTINFO2DIR(ctinfo);
++ if (dir == IP_CT_DIR_ORIGINAL)
++ return diff_len;
++
++ /* Find Session ID address */
++ found = find_pattern(data, datalen, " IN IP4 ", 8, ' ', '\r',
++ &matchoff, &matchlen);
++ if (found) {
++ p = addr = (char *)data + matchoff;
++
++ /* FQDNs or dotted quads */
++ while (isalpha(*p) || isdigit(*p) || (*p=='.') || (*p=='-')) {
++ p++;
++ if (p == limit)
++ return 0;
++ }
++
++ sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(newip));
++ buflen = strlen(buffer);
++
++ MUST_BE_LOCKED(&ip_sip_lock);
++
++ if (!ip_nat_mangle_udp_packet(pskb, ct, ctinfo, addr - data,
++ p - addr, buffer, buflen) )
++ return 0;
++
++ diff_len += (buflen - (p - addr));
++ DEBUGP("(SDP) Session ID is changed to %s.\n", buffer);
++ }
++
++ return diff_len;
++}
++
++static int mangle_sip_packet(struct ip_conntrack *ct, enum ip_conntrack_info ctinfo,
++ struct sk_buff **pskb, u_int32_t newip)
++{
++ struct iphdr *iph = (*pskb)->nh.iph;
++ struct udphdr *udph = (void *)iph + iph->ihl * 4;
++ const char *data = (const char *)udph + 8;
++ int diff_len = 0;
++ struct ip_ct_sip_master *ct_sip_info = &ct->help.ct_sip_info;
++ u_int16_t natport = ntohs(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.udp.port);
++
++ DEBUGP("nat_sip: %s:(%d)\n", __FUNCTION__, __LINE__);
++
++ ct_sip_info->mangled = 1;
++
++ /* Changes the via, if this is a request */
++ if (strnicmp(data,"SIP/2.0",7) != 0) {
++ mangle_sip_via(ct, ctinfo, pskb, newip, natport);
++ }
++
++ mangle_sip_contact(ct, ctinfo, pskb, newip, natport);
++
++ if ((diff_len = mangle_sip_sdp_content(ct, ctinfo, pskb, newip, ct_sip_info->rtpport)) != 0)
++ mangle_sip_content_length(ct, ctinfo, pskb, diff_len);
++
++ return 1;
++}
++
++static struct ip_conntrack_expect *
++expect_find(struct ip_conntrack *ct, u_int32_t dstip, u_int16_t dstport)
++{
++ const struct ip_conntrack_tuple tuple = { { 0, { 0 } },
++ { dstip, { htons(dstport) }, IPPROTO_UDP }};
++
++ return ip_conntrack_expect_find_get(&tuple);
++
++}
++
++static int sip_out_data_fixup(struct ip_conntrack *ct,
++ struct sk_buff **pskb,
++ enum ip_conntrack_info ctinfo,
++ struct ip_conntrack_expect *expect)
++{
++ struct ip_conntrack_tuple newtuple;
++ struct ip_ct_sip_master *ct_sip_info = &ct->help.ct_sip_info;
++ struct ip_ct_sip_expect *exp_sip_info;
++ u_int32_t wanip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip; // NAT wan ip
++ u_int16_t port = 0;
++#ifdef RTCP_SUPPORT
++ struct ip_conntrack_expect *rtcp_exp;
++#endif
++
++ MUST_BE_LOCKED(&ip_sip_lock);
++
++ if (expect) {
++ DEBUGP("nat_sip: %s: There is a exp %p.\n", __FUNCTION__, expect);
++
++ exp_sip_info = &expect->help.exp_sip_info;
++ if (exp_sip_info->nated) {
++ DEBUGP("nat_sip: %s: The exp %p had been changed.\n", __FUNCTION__, expect);
++ goto mangle;
++ }
++
++ /* RTP expect */
++ if (exp_sip_info->type == CONN_RTP) {
++ port = ntohs(expect->tuple.dst.u.udp.port);
++#ifdef RTCP_SUPPORT
++ rtcp_exp = expect_find(ct, expect->tuple.dst.ip, port + 1);
++#endif
++ /* RFC1889 - If an application is supplied with an odd number
++ * for use as the RTP port, it should replace this number with
++ * the next lower (even) number. */
++ if (port % 2)
++ port++;
++
++ /* fullfill newtuple */
++ newtuple.dst.ip = wanip;
++ newtuple.src.ip = expect->tuple.src.ip;
++ newtuple.dst.protonum = expect->tuple.dst.protonum;
++
++ /* Try to get same port: if not, try to change it. */
++ for (; port != 0; port += 2) {
++ newtuple.dst.u.udp.port = htons(port);
++ if (ip_conntrack_change_expect(expect, &newtuple) == 0) {
++#ifdef RTCP_SUPPORT
++ /* Change RTCP */
++ if (rtcp_exp) {
++ DEBUGP("nat_sip: %s: RTCP exp %p found.\n",
++ __FUNCTION__, rtcp_exp);
++ newtuple.dst.u.udp.port = htons(port + 1);
++ if (ip_conntrack_change_expect(rtcp_exp, &newtuple) != 0) {
++ DEBUGP("nat_sip: %s: Can't change RTCP exp %p.\n",
++ __FUNCTION__, rtcp_exp);
++ continue;
++ }
++ rtcp_exp->help.exp_sip_info.nated = 1;
++ }
++#endif
++ break;
++ }
++ }
++ if (port == 0)
++ return 0;
++
++ exp_sip_info->nated = 1;
++ ct_sip_info->rtpport = port;
++ DEBUGP("nat_sip: %s: RTP exp %p, masq port=%d\n", __FUNCTION__, expect, port);
++ }
++#ifdef RTCP_SUPPORT
++ else {
++ /* We ignore the RTCP expect, and will adjust it later
++ * during RTP expect */
++ DEBUGP("nat_sip: %s: RTCP exp %p, by-pass.\n", __FUNCTION__, expect);
++ return 1;
++ }
++#endif
++ }
++
++mangle:
++ /* Change address inside packet to match way we're mapping
++ this connection. */
++ if (!ct_sip_info->mangled)
++ if (!mangle_sip_packet(ct, ctinfo, pskb, wanip))
++ return 0;
++
++ return 1;
++}
++
++static int sip_in_data_fixup(struct ip_conntrack *ct,
++ struct sk_buff **pskb,
++ enum ip_conntrack_info ctinfo,
++ struct ip_conntrack_expect *expect)
++{
++ struct iphdr *iph = (*pskb)->nh.iph;
++ struct udphdr *udph = (void *)iph + iph->ihl * 4;
++ const char *data = (const char *)udph + 8;
++ unsigned int udplen = ntohs(iph->tot_len) - (iph->ihl * 4);
++ unsigned int datalen = udplen - 8;
++ struct ip_ct_sip_master *ct_sip_info = &ct->help.ct_sip_info;
++ u_int32_t wanip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip; // NAT wan ip
++ unsigned int matchlen, matchoff;
++ int found, diff_len = 0;
++ u_int32_t ipaddr = 0, vip = 0;
++ u_int16_t port = 0, vport = 0, aport = 0;
++ struct ip_conntrack_expect *exp;
++#ifdef RTCP_SUPPORT
++ struct ip_conntrack_expect *rtcpexp;
++#endif
++
++ if (expect)
++ DEBUGP("nat_sip: %s: There is a exp %p.\n", __FUNCTION__, expect);
++
++ /* Prevent from mangling the packet or expect twice */
++ if (ct_sip_info->mangled)
++ return 1;
++
++ ct_sip_info->mangled = 1;
++
++ if (strnicmp(data, "SIP/2.0 200", 11) == 0) {
++ /* Find CSeq field */
++ found = find_pattern(data, datalen, "CSeq: ", 6, ' ', '\r',
++ &matchoff, &matchlen);
++ if (found) {
++ char *p = (char *)data + matchoff;
++
++ simple_strtoul(p, &p, 10);
++ if (strnicmp(p, " REGISTER", 9) == 0) {
++ DEBUGP("nat_sip: 200 OK - REGISTER\n");
++ vip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
++ vport = ntohs(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port);
++ mangle_sip_via(ct, ctinfo, pskb, vip, vport);
++ mangle_sip_contact(ct, ctinfo, pskb, vip, vport);
++ return 1;
++ }
++ }
++ }
++
++ /* Only interesting the SDP content. */
++ if (strnicmp(data, "INVITE", 6) != 0 && strnicmp(data, "SIP/2.0 200", 11) != 0)
++ return 1;
++
++ /* Find RTP address */
++ found = find_sdp_rtp_addr(data, datalen, &matchoff, &matchlen, &ipaddr);
++
++ DEBUGP("nat_sip: sdp address found = %d, ipaddr = %u.\n", found, ipaddr);
++ if (found < 2)
++ return 1;
++
++ /* Is it a null address or our WAN address? */
++ if (ipaddr == 0 || (htonl(ipaddr) != wanip))
++ return 1;
++
++ DEBUGP("nat_sip: %s: This is a lookback RTP connection.\n", __FUNCTION__);
++
++ /* Find audio port, and we don't like the well-known ports,
++ * which is less than 1024 */
++ port = find_sdp_audio_port(data, datalen, &matchoff, &matchlen);
++ if (port < 1024)
++ return 0;
++
++ exp = expect_find(ct, wanip, port);
++ if (exp) {
++ DEBUGP("nat_sip: %s: Found exp %p, tuple.dst=%u.%u.%u.%u:%u.\n",
++ __FUNCTION__, exp, NIPQUAD(ipaddr), port);
++
++ /* Restore masq-ed SDP */
++ vip = exp->expectant->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
++ aport = exp->help.exp_sip_info.port;
++ if ((diff_len = mangle_sip_sdp_content(ct, ctinfo, pskb, vip, aport)) != 0)
++ mangle_sip_content_length(ct, ctinfo, pskb, diff_len);
++
++ /* Unset RTP, RTCP expect, respectively */
++ ip_conntrack_unexpect_related(exp);
++#ifdef RTCP_SUPPORT
++ rtcpexp = expect_find(ct, wanip, port + 1);
++ if (rtcpexp)
++ ip_conntrack_unexpect_related(rtcpexp);
++#endif
++ }
++
++ return 1;
++}
++
++static unsigned int 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 iphdr *iph = (*pskb)->nh.iph;
++ struct udphdr *udph = (void *)iph + iph->ihl * 4;
++ const char *data = (const char *)udph + 8;
++
++ /* Only mangle things once: original direction in POST_ROUTING
++ and reply direction on PRE_ROUTING. */
++ dir = CTINFO2DIR(ctinfo);
++ if (!((hooknum == NF_IP_POST_ROUTING && dir == IP_CT_DIR_ORIGINAL)
++ || (hooknum == NF_IP_PRE_ROUTING && dir == IP_CT_DIR_REPLY))) {
++ DEBUGP("nat_sip: 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 (strnicmp(data, "REGISTER" , 8) == 0)
++ DEBUGP("nat_sip: REGISTER\n");
++ else if (strnicmp(data, "INVITE" , 6) == 0)
++ DEBUGP("nat_sip: INVITE\n");
++ else if (strnicmp(data, "ACK" , 3) == 0)
++ DEBUGP("nat_sip: ACK\n");
++ else if (strnicmp(data, "BYE", 3) == 0)
++ DEBUGP("nat_sip: BYE\n");
++ else if (strnicmp(data, "SIP/2.0 200", 11) == 0)
++ DEBUGP("nat_sip: 200 OK\n");
++ else if (strnicmp(data, "SIP/2.0 100", 11) == 0)
++ DEBUGP("nat_sip: 100 Trying\n");
++ else if (strnicmp(data, "SIP/2.0 180", 11) == 0)
++ DEBUGP("nat_sip: 180 Ringing\n");
++
++ LOCK_BH(&ip_sip_lock);
++
++ if (dir == IP_CT_DIR_ORIGINAL)
++ sip_out_data_fixup(ct, pskb, ctinfo, exp);
++ else
++ sip_in_data_fixup(ct, pskb, ctinfo, exp);
++
++ UNLOCK_BH(&ip_sip_lock);
++
++ return NF_ACCEPT;
++}
++
++static struct ip_nat_helper sip[MAX_PORTS];
++static char sip_names[MAX_PORTS][6];
++
++/* Not __exit: called from init() */
++static void fini(void)
++{
++ int i;
++
++ for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
++ DEBUGP("ip_nat_sip: unregistering port %d\n", ports[i]);
++ ip_nat_helper_unregister(&sip[i]);
++ }
++}
++
++static int __init init(void)
++{
++ int i, ret=0;
++ char *tmpname;
++
++ if (ports[0] == 0)
++ ports[0] = SIP_PORT;
++
++ for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
++
++ memset(&sip[i], 0, sizeof(struct ip_nat_helper));
++
++ sip[i].tuple.dst.u.udp.port = htons(ports[i]);
++ sip[i].tuple.dst.protonum = IPPROTO_UDP;
++ sip[i].mask.dst.u.udp.port = 0xF0FF;
++ sip[i].mask.dst.protonum = 0xFFFF;
++ sip[i].help = nat_help;
++ sip[i].expect = sip_nat_expected;
++ sip[i].flags = IP_NAT_HELPER_F_ALWAYS;
++
++ tmpname = &sip_names[i][0];
++ sprintf(tmpname, "sip%2.2d", i);
++ sip[i].name = tmpname;
++
++ DEBUGP("ip_nat_sip: Trying to register for port %d\n",
++ ports[i]);
++ ret = ip_nat_helper_register(&sip[i]);
++
++ if (ret) {
++ printk("ip_nat_sip: error registering "
++ "helper for port %d\n", ports[i]);
++ fini();
++ return ret;
++ }
++ ports_c++;
++ }
++
++ return ret;
++}
++
++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 2005-12-11 21:34:32.000000000 +0100
++++ linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack.h 2005-12-11 22:06:57.000000000 +0100
+@@ -71,6 +71,7 @@
+ #include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
+ #include <linux/netfilter_ipv4/ip_conntrack_irc.h>
+ #include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
++#include <linux/netfilter_ipv4/ip_conntrack_sip.h>
+
+ /* per expectation: application helper private data */
+ union ip_conntrack_expect_help {
+@@ -79,6 +80,7 @@
+ struct ip_ct_ftp_expect exp_ftp_info;
+ struct ip_ct_irc_expect exp_irc_info;
+ struct ip_ct_pptp_expect exp_pptp_info;
++ struct ip_ct_sip_expect exp_sip_info;
+
+ #ifdef CONFIG_IP_NF_NAT_NEEDED
+ union {
+@@ -93,6 +95,7 @@
+ struct ip_ct_ftp_master ct_ftp_info;
+ struct ip_ct_irc_master ct_irc_info;
+ struct ip_ct_pptp_master ct_pptp_info;
++ struct ip_ct_sip_master ct_sip_info;
+ };
+
+ #ifdef CONFIG_IP_NF_NAT_NEEDED
+diff -urN linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_sip.h linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_sip.h
+--- linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_sip.h 1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_sip.h 2005-12-11 21:35:51.000000000 +0100
+@@ -0,0 +1,56 @@
++#ifndef _IP_CONNTRACK_SIP_H
++#define _IP_CONNTRACK_SIP_H
++/* SIP tracking. */
++
++#ifdef __KERNEL__
++
++#include <linux/netfilter_ipv4/lockhelp.h>
++
++/* Protects sip part of conntracks */
++DECLARE_LOCK_EXTERN(ip_sip_lock);
++
++#define SIP_PORT 5060 /* UDP */
++#define SIP_EXPIRES 3600 /* seconds */
++#define RTP_TIMEOUT 180 /* seconds */
++
++#endif /* __KERNEL__ */
++
++/* SIP Request */
++#define SIP_INVITE 0x01
++#define SIP_ACK 0x02
++#define SIP_BYE 0x04
++/* SIP Response */
++#define SIP_100 0x10
++#define SIP_200 0x20
++#define SIP_200_BYE 0x40
++/* SIP session direction */
++#define SIP_OUTGOING 0
++#define SIP_INCOMING 1
++
++enum ip_ct_conntype
++{
++ CONN_SIP,
++ CONN_RTP,
++ CONN_RTCP,
++};
++
++/* This structure is per expected connection */
++struct ip_ct_sip_expect
++{
++ u_int16_t port; /* TCP port that was to be used */
++
++ enum ip_ct_conntype type;
++ int nated;
++};
++
++/* This structure exists only once per master */
++struct ip_ct_sip_master {
++ int mangled;
++ u_int16_t rtpport;
++};
++
++extern u_int16_t find_sdp_audio_port(const char *data, size_t dlen,
++ unsigned int *numoff, unsigned int *numlen);
++extern int find_sdp_rtp_addr(const char *data, size_t dlen,
++ unsigned int *numoff, unsigned int *numlen, u_int32_t *addr);
++#endif /* _IP_CONNTRACK_SIP_H */
projects / openwrt.git / commitdiff