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-rw-r--r--package/network/utils/xtables-addons/patches/100-add-rtsp-conntrack.patch1526
1 files changed, 1526 insertions, 0 deletions
diff --git a/package/network/utils/xtables-addons/patches/100-add-rtsp-conntrack.patch b/package/network/utils/xtables-addons/patches/100-add-rtsp-conntrack.patch
new file mode 100644
index 0000000..6c169ee
--- /dev/null
+++ b/package/network/utils/xtables-addons/patches/100-add-rtsp-conntrack.patch
@@ -0,0 +1,1526 @@
+--- /dev/null
++++ b/extensions/rtsp/Kbuild
+@@ -0,0 +1,4 @@
++# -*- Makefile -*-
++
++obj-m += nf_nat_rtsp.o
++obj-m += nf_conntrack_rtsp.o
+--- /dev/null
++++ b/extensions/rtsp/netfilter_helpers.h
+@@ -0,0 +1,133 @@
++/*
++ * Helpers for netfiler modules. This file provides implementations for basic
++ * functions such as strncasecmp(), etc.
++ *
++ * gcc will warn for defined but unused functions, so we only include the
++ * functions requested. The following macros are used:
++ * NF_NEED_STRNCASECMP nf_strncasecmp()
++ * NF_NEED_STRTOU16 nf_strtou16()
++ * NF_NEED_STRTOU32 nf_strtou32()
++ */
++#ifndef _NETFILTER_HELPERS_H
++#define _NETFILTER_HELPERS_H
++
++/* Only include these functions for kernel code. */
++#ifdef __KERNEL__
++
++#include <linux/ctype.h>
++#define iseol(c) ( (c) == '\r' || (c) == '\n' )
++
++/*
++ * The standard strncasecmp()
++ */
++#ifdef NF_NEED_STRNCASECMP
++static int
++nf_strncasecmp(const char* s1, const char* s2, u_int32_t len)
++{
++ if (s1 == NULL || s2 == NULL)
++ {
++ if (s1 == NULL && s2 == NULL)
++ {
++ return 0;
++ }
++ return (s1 == NULL) ? -1 : 1;
++ }
++ while (len > 0 && tolower(*s1) == tolower(*s2))
++ {
++ len--;
++ s1++;
++ s2++;
++ }
++ return ( (len == 0) ? 0 : (tolower(*s1) - tolower(*s2)) );
++}
++#endif /* NF_NEED_STRNCASECMP */
++
++/*
++ * Parse a string containing a 16-bit unsigned integer.
++ * Returns the number of chars used, or zero if no number is found.
++ */
++#ifdef NF_NEED_STRTOU16
++static int
++nf_strtou16(const char* pbuf, u_int16_t* pval)
++{
++ int n = 0;
++
++ *pval = 0;
++ while (isdigit(pbuf[n]))
++ {
++ *pval = (*pval * 10) + (pbuf[n] - '0');
++ n++;
++ }
++
++ return n;
++}
++#endif /* NF_NEED_STRTOU16 */
++
++/*
++ * Parse a string containing a 32-bit unsigned integer.
++ * Returns the number of chars used, or zero if no number is found.
++ */
++#ifdef NF_NEED_STRTOU32
++static int
++nf_strtou32(const char* pbuf, u_int32_t* pval)
++{
++ int n = 0;
++
++ *pval = 0;
++ while (pbuf[n] >= '0' && pbuf[n] <= '9')
++ {
++ *pval = (*pval * 10) + (pbuf[n] - '0');
++ n++;
++ }
++
++ return n;
++}
++#endif /* NF_NEED_STRTOU32 */
++
++/*
++ * Given a buffer and length, advance to the next line and mark the current
++ * line.
++ */
++#ifdef NF_NEED_NEXTLINE
++static int
++nf_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
++{
++ uint off = *poff;
++ uint physlen = 0;
++
++ if (off >= len)
++ {
++ return 0;
++ }
++
++ while (p[off] != '\n')
++ {
++ if (len-off <= 1)
++ {
++ return 0;
++ }
++
++ physlen++;
++ off++;
++ }
++
++ /* if we saw a crlf, physlen needs adjusted */
++ if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
++ {
++ physlen--;
++ }
++
++ /* advance past the newline */
++ off++;
++
++ *plineoff = *poff;
++ *plinelen = physlen;
++ *poff = off;
++
++ return 1;
++}
++#endif /* NF_NEED_NEXTLINE */
++
++#endif /* __KERNEL__ */
++
++#endif /* _NETFILTER_HELPERS_H */
+--- /dev/null
++++ b/extensions/rtsp/netfilter_mime.h
+@@ -0,0 +1,89 @@
++/*
++ * MIME functions for netfilter modules. This file provides implementations
++ * for basic MIME parsing. MIME headers are used in many protocols, such as
++ * HTTP, RTSP, SIP, etc.
++ *
++ * gcc will warn for defined but unused functions, so we only include the
++ * functions requested. The following macros are used:
++ * NF_NEED_MIME_NEXTLINE nf_mime_nextline()
++ */
++#ifndef _NETFILTER_MIME_H
++#define _NETFILTER_MIME_H
++
++/* Only include these functions for kernel code. */
++#ifdef __KERNEL__
++
++#include <linux/ctype.h>
++
++/*
++ * Given a buffer and length, advance to the next line and mark the current
++ * line. If the current line is empty, *plinelen will be set to zero. If
++ * not, it will be set to the actual line length (including CRLF).
++ *
++ * 'line' in this context means logical line (includes LWS continuations).
++ * Returns 1 on success, 0 on failure.
++ */
++#ifdef NF_NEED_MIME_NEXTLINE
++static int
++nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
++{
++ uint off = *poff;
++ uint physlen = 0;
++ int is_first_line = 1;
++
++ if (off >= len)
++ {
++ return 0;
++ }
++
++ do
++ {
++ while (p[off] != '\n')
++ {
++ if (len-off <= 1)
++ {
++ return 0;
++ }
++
++ physlen++;
++ off++;
++ }
++
++ /* if we saw a crlf, physlen needs adjusted */
++ if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
++ {
++ physlen--;
++ }
++
++ /* advance past the newline */
++ off++;
++
++ /* check for an empty line */
++ if (physlen == 0)
++ {
++ break;
++ }
++
++ /* check for colon on the first physical line */
++ if (is_first_line)
++ {
++ is_first_line = 0;
++ if (memchr(p+(*poff), ':', physlen) == NULL)
++ {
++ return 0;
++ }
++ }
++ }
++ while (p[off] == ' ' || p[off] == '\t');
++
++ *plineoff = *poff;
++ *plinelen = (physlen == 0) ? 0 : (off - *poff);
++ *poff = off;
++
++ return 1;
++}
++#endif /* NF_NEED_MIME_NEXTLINE */
++
++#endif /* __KERNEL__ */
++
++#endif /* _NETFILTER_MIME_H */
+--- /dev/null
++++ b/extensions/rtsp/nf_conntrack_rtsp.c
+@@ -0,0 +1,576 @@
++/*
++ * RTSP extension for IP connection tracking
++ * (C) 2003 by Tom Marshall <tmarshall at real.com>
++ *
++ * 2005-02-13: Harald Welte <laforge at netfilter.org>
++ * - port to 2.6
++ * - update to recent post-2.6.11 api changes
++ * 2006-09-14: Steven Van Acker <deepstar at singularity.be>
++ * - removed calls to NAT code from conntrack helper: NAT no longer needed to use rtsp-conntrack
++ * 2007-04-18: Michael Guntsche <mike at it-loops.com>
++ * - Port to new NF API
++ * 2013-03-04: Il'inykh Sergey <sergeyi at inango-sw.com>. Inango Systems Ltd
++ * - fixed rtcp nat mapping and other port mapping fixes
++ * - simple TEARDOWN request handling
++ * - codestyle fixes and other less significant bug fixes
++ *
++ * based on ip_conntrack_irc.c
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ *
++ * Module load syntax:
++ * insmod nf_conntrack_rtsp.o ports=port1,port2,...port<MAX_PORTS>
++ * max_outstanding=n setup_timeout=secs
++ *
++ * If no ports are specified, the default will be port 554.
++ *
++ * With max_outstanding you can define the maximum number of not yet
++ * answered SETUP requests per RTSP session (default 8).
++ * With setup_timeout you can specify how long the system waits for
++ * an expected data channel (default 300 seconds).
++ *
++ */
++
++#include <linux/module.h>
++#include <linux/netfilter.h>
++#include <linux/ip.h>
++#include <linux/inet.h>
++#include <net/tcp.h>
++
++#include <net/netfilter/nf_conntrack.h>
++#include <net/netfilter/nf_conntrack_expect.h>
++#include <net/netfilter/nf_conntrack_helper.h>
++#include "nf_conntrack_rtsp.h"
++
++#define NF_NEED_STRNCASECMP
++#define NF_NEED_STRTOU16
++#define NF_NEED_STRTOU32
++#define NF_NEED_NEXTLINE
++#include "netfilter_helpers.h"
++#define NF_NEED_MIME_NEXTLINE
++#include "netfilter_mime.h"
++
++#include <linux/ctype.h>
++
++#define MAX_PORTS 8
++static int ports[MAX_PORTS];
++static int num_ports = 0;
++static int max_outstanding = 8;
++static unsigned int setup_timeout = 300;
++
++MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
++MODULE_DESCRIPTION("RTSP connection tracking module");
++MODULE_LICENSE("GPL");
++module_param_array(ports, int, &num_ports, 0400);
++MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
++module_param(max_outstanding, int, 0400);
++MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
++module_param(setup_timeout, int, 0400);
++MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
++
++static char *rtsp_buffer;
++static DEFINE_SPINLOCK(rtsp_buffer_lock);
++
++static struct nf_conntrack_expect_policy rtsp_exp_policy;
++
++unsigned int (*nf_nat_rtsp_hook)(struct sk_buff *skb,
++ enum ip_conntrack_info ctinfo,
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ unsigned int protoff,
++#endif
++ unsigned int matchoff, unsigned int matchlen,
++ struct ip_ct_rtsp_expect* prtspexp,
++ struct nf_conntrack_expect *rtp_exp,
++ struct nf_conntrack_expect *rtcp_exp);
++
++EXPORT_SYMBOL_GPL(nf_nat_rtsp_hook);
++
++/*
++ * Max mappings we will allow for one RTSP connection (for RTP, the number
++ * of allocated ports is twice this value). Note that SMIL burns a lot of
++ * ports so keep this reasonably high. If this is too low, you will see a
++ * lot of "no free client map entries" messages.
++ */
++#define MAX_PORT_MAPS 16
++
++/*** default port list was here in the masq code: 554, 3030, 4040 ***/
++
++#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
++
++/*
++ * Parse an RTSP packet.
++ *
++ * Returns zero if parsing failed.
++ *
++ * Parameters:
++ * IN ptcp tcp data pointer
++ * IN tcplen tcp data len
++ * IN/OUT ptcpoff points to current tcp offset
++ * OUT phdrsoff set to offset of rtsp headers
++ * OUT phdrslen set to length of rtsp headers
++ * OUT pcseqoff set to offset of CSeq header
++ * OUT pcseqlen set to length of CSeq header
++ */
++static int
++rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
++ uint* phdrsoff, uint* phdrslen,
++ uint* pcseqoff, uint* pcseqlen,
++ uint* transoff, uint* translen)
++{
++ uint entitylen = 0;
++ uint lineoff;
++ uint linelen;
++
++ if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
++ return 0;
++
++ *phdrsoff = *ptcpoff;
++ while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen)) {
++ if (linelen == 0) {
++ if (entitylen > 0)
++ *ptcpoff += min(entitylen, tcplen - *ptcpoff);
++ break;
++ }
++ if (lineoff+linelen > tcplen) {
++ pr_info("!! overrun !!\n");
++ break;
++ }
++
++ if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0) {
++ *pcseqoff = lineoff;
++ *pcseqlen = linelen;
++ }
++
++ if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0) {
++ *transoff = lineoff;
++ *translen = linelen;
++ }
++
++ if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0) {
++ uint off = lineoff+15;
++ SKIP_WSPACE(ptcp+lineoff, linelen, off);
++ nf_strtou32(ptcp+off, &entitylen);
++ }
++ }
++ *phdrslen = (*ptcpoff) - (*phdrsoff);
++
++ return 1;
++}
++
++/*
++ * Find lo/hi client ports (if any) in transport header
++ * In:
++ * ptcp, tcplen = packet
++ * tranoff, tranlen = buffer to search
++ *
++ * Out:
++ * pport_lo, pport_hi = lo/hi ports (host endian)
++ *
++ * Returns nonzero if any client ports found
++ *
++ * Note: it is valid (and expected) for the client to request multiple
++ * transports, so we need to parse the entire line.
++ */
++static int
++rtsp_parse_transport(char* ptran, uint tranlen,
++ struct ip_ct_rtsp_expect* prtspexp)
++{
++ int rc = 0;
++ uint off = 0;
++
++ if (tranlen < 10 || !iseol(ptran[tranlen-1]) ||
++ nf_strncasecmp(ptran, "Transport:", 10) != 0) {
++ pr_info("sanity check failed\n");
++ return 0;
++ }
++
++ pr_debug("tran='%.*s'\n", (int)tranlen, ptran);
++ off += 10;
++ SKIP_WSPACE(ptran, tranlen, off);
++
++ /* Transport: tran;field;field=val,tran;field;field=val,... */
++ while (off < tranlen) {
++ const char* pparamend;
++ uint nextparamoff;
++
++ pparamend = memchr(ptran+off, ',', tranlen-off);
++ pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
++ nextparamoff = pparamend-ptran;
++
++ while (off < nextparamoff) {
++ const char* pfieldend;
++ uint nextfieldoff;
++
++ pfieldend = memchr(ptran+off, ';', nextparamoff-off);
++ nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
++
++ if (strncmp(ptran+off, "client_port=", 12) == 0) {
++ u_int16_t port;
++ uint numlen;
++
++ off += 12;
++ numlen = nf_strtou16(ptran+off, &port);
++ off += numlen;
++ if (prtspexp->loport != 0 && prtspexp->loport != port)
++ pr_debug("multiple ports found, port %hu ignored\n", port);
++ else {
++ pr_debug("lo port found : %hu\n", port);
++ prtspexp->loport = prtspexp->hiport = port;
++ if (ptran[off] == '-') {
++ off++;
++ numlen = nf_strtou16(ptran+off, &port);
++ off += numlen;
++ prtspexp->pbtype = pb_range;
++ prtspexp->hiport = port;
++
++ // If we have a range, assume rtp:
++ // loport must be even, hiport must be loport+1
++ if ((prtspexp->loport & 0x0001) != 0 ||
++ prtspexp->hiport != prtspexp->loport+1) {
++ pr_debug("incorrect range: %hu-%hu, correcting\n",
++ prtspexp->loport, prtspexp->hiport);
++ prtspexp->loport &= 0xfffe;
++ prtspexp->hiport = prtspexp->loport+1;
++ }
++ } else if (ptran[off] == '/') {
++ off++;
++ numlen = nf_strtou16(ptran+off, &port);
++ off += numlen;
++ prtspexp->pbtype = pb_discon;
++ prtspexp->hiport = port;
++ }
++ rc = 1;
++ }
++ }
++
++ /*
++ * Note we don't look for the destination parameter here.
++ * If we are using NAT, the NAT module will handle it. If not,
++ * and the client is sending packets elsewhere, the expectation
++ * will quietly time out.
++ */
++
++ off = nextfieldoff;
++ }
++
++ off = nextparamoff;
++ }
++
++ return rc;
++}
++
++
++/*** conntrack functions ***/
++
++/* outbound packet: client->server */
++
++static inline int
++help_out(struct sk_buff *skb, unsigned char *rb_ptr, unsigned int datalen,
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ struct nf_conn *ct, enum ip_conntrack_info ctinfo,
++ unsigned int protoff)
++#else
++ struct nf_conn *ct, enum ip_conntrack_info ctinfo)
++#endif
++{
++ struct ip_ct_rtsp_expect expinfo;
++
++ int dir = CTINFO2DIR(ctinfo); /* = IP_CT_DIR_ORIGINAL */
++ //struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
++ //uint tcplen = pktlen - iph->ihl * 4;
++ char* pdata = rb_ptr;
++ //uint datalen = tcplen - tcph->doff * 4;
++ uint dataoff = 0;
++ int ret = NF_ACCEPT;
++
++ struct nf_conntrack_expect *rtp_exp;
++ struct nf_conntrack_expect *rtcp_exp = NULL;
++
++ __be16 be_loport;
++ __be16 be_hiport;
++
++ typeof(nf_nat_rtsp_hook) nf_nat_rtsp;
++
++ memset(&expinfo, 0, sizeof(expinfo));
++
++ while (dataoff < datalen) {
++ uint cmdoff = dataoff;
++ uint hdrsoff = 0;
++ uint hdrslen = 0;
++ uint cseqoff = 0;
++ uint cseqlen = 0;
++ uint transoff = 0;
++ uint translen = 0;
++ uint off;
++
++ if (!rtsp_parse_message(pdata, datalen, &dataoff,
++ &hdrsoff, &hdrslen,
++ &cseqoff, &cseqlen,
++ &transoff, &translen))
++ break; /* not a valid message */
++
++ if (strncmp(pdata+cmdoff, "TEARDOWN ", 9) == 0) {
++ pr_debug("teardown handled\n");
++ nf_ct_remove_expectations(ct); /* FIXME must be session id aware */
++ break;
++ }
++
++ if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
++ continue; /* not a SETUP message */
++
++ pr_debug("found a setup message\n");
++
++ off = 0;
++ if(translen)
++ rtsp_parse_transport(pdata+transoff, translen, &expinfo);
++
++ if (expinfo.loport == 0) {
++ pr_debug("no udp transports found\n");
++ continue; /* no udp transports found */
++ }
++
++ pr_debug("udp transport found, ports=(%d,%hu,%hu)\n",
++ (int)expinfo.pbtype, expinfo.loport, expinfo.hiport);
++
++
++ be_loport = htons(expinfo.loport);
++
++ rtp_exp = nf_ct_expect_alloc(ct);
++ if (rtp_exp == NULL) {
++ ret = NF_DROP;
++ goto out;
++ }
++
++ nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT,
++ nf_ct_l3num(ct),
++ NULL, /* &ct->tuplehash[!dir].tuple.src.u3, */
++ &ct->tuplehash[!dir].tuple.dst.u3,
++ IPPROTO_UDP, NULL, &be_loport);
++
++ rtp_exp->flags = 0;
++
++ if (expinfo.pbtype == pb_range) {
++ pr_debug("setup expectation for rtcp\n");
++
++ be_hiport = htons(expinfo.hiport);
++ rtcp_exp = nf_ct_expect_alloc(ct);
++ if (rtcp_exp == NULL) {
++ ret = NF_DROP;
++ goto out1;
++ }
++
++ nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT,
++ nf_ct_l3num(ct),
++ NULL, /* &ct->tuplehash[!dir].tuple.src.u3, */
++ &ct->tuplehash[!dir].tuple.dst.u3,
++ IPPROTO_UDP, NULL, &be_hiport);
++
++ rtcp_exp->flags = 0;
++
++ pr_debug("expect_related %pI4:%u-%u-%pI4:%u-%u\n",
++ &rtp_exp->tuple.src.u3.ip,
++ ntohs(rtp_exp->tuple.src.u.udp.port),
++ ntohs(rtcp_exp->tuple.src.u.udp.port),
++ &rtp_exp->tuple.dst.u3.ip,
++ ntohs(rtp_exp->tuple.dst.u.udp.port),
++ ntohs(rtcp_exp->tuple.dst.u.udp.port));
++ } else {
++ pr_debug("expect_related %pI4:%u-%pI4:%u\n",
++ &rtp_exp->tuple.src.u3.ip,
++ ntohs(rtp_exp->tuple.src.u.udp.port),
++ &rtp_exp->tuple.dst.u3.ip,
++ ntohs(rtp_exp->tuple.dst.u.udp.port));
++ }
++
++ nf_nat_rtsp = rcu_dereference(nf_nat_rtsp_hook);
++ if (nf_nat_rtsp && ct->status & IPS_NAT_MASK)
++ /* pass the request off to the nat helper */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ ret = nf_nat_rtsp(skb, ctinfo, protoff, hdrsoff, hdrslen,
++ &expinfo, rtp_exp, rtcp_exp);
++#else
++ ret = nf_nat_rtsp(skb, ctinfo, hdrsoff, hdrslen,
++ &expinfo, rtp_exp, rtcp_exp);
++#endif
++ else {
++ if (nf_ct_expect_related(rtp_exp) == 0) {
++ if (rtcp_exp && nf_ct_expect_related(rtcp_exp) != 0) {
++ nf_ct_unexpect_related(rtp_exp);
++ pr_info("nf_conntrack_expect_related failed for rtcp\n");
++ ret = NF_DROP;
++ }
++ } else {
++ pr_info("nf_conntrack_expect_related failed for rtp\n");
++ ret = NF_DROP;
++ }
++ }
++ if (rtcp_exp) {
++ nf_ct_expect_put(rtcp_exp);
++ }
++out1:
++ nf_ct_expect_put(rtp_exp);
++ goto out;
++ }
++out:
++
++ return ret;
++}
++
++
++static inline int
++help_in(struct sk_buff *skb, size_t pktlen,
++ struct nf_conn* ct, enum ip_conntrack_info ctinfo)
++{
++ return NF_ACCEPT;
++}
++
++static int help(struct sk_buff *skb, unsigned int protoff,
++ struct nf_conn *ct, enum ip_conntrack_info ctinfo)
++{
++ struct tcphdr _tcph, *th;
++ unsigned int dataoff, datalen;
++ char *rb_ptr;
++ int ret = NF_DROP;
++
++ /* 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) {
++ pr_debug("conntrackinfo = %u\n", ctinfo);
++ return NF_ACCEPT;
++ }
++
++ /* Not whole TCP header? */
++ th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
++
++ if (!th)
++ return NF_ACCEPT;
++
++ /* No data ? */
++ dataoff = protoff + th->doff*4;
++ datalen = skb->len - dataoff;
++ if (dataoff >= skb->len)
++ return NF_ACCEPT;
++
++ spin_lock_bh(&rtsp_buffer_lock);
++ rb_ptr = skb_header_pointer(skb, dataoff,
++ skb->len - dataoff, rtsp_buffer);
++ BUG_ON(rb_ptr == NULL);
++
++#if 0
++ /* Checksum invalid? Ignore. */
++ /* FIXME: Source route IP option packets --RR */
++ if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
++ csum_partial((char*)tcph, tcplen, 0)))
++ {
++ DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
++ tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
++ return NF_ACCEPT;
++ }
++#endif
++
++ switch (CTINFO2DIR(ctinfo)) {
++ case IP_CT_DIR_ORIGINAL:
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ ret = help_out(skb, rb_ptr, datalen, ct, ctinfo, protoff);
++#else
++ ret = help_out(skb, rb_ptr, datalen, ct, ctinfo);
++#endif
++ break;
++ case IP_CT_DIR_REPLY:
++ pr_debug("IP_CT_DIR_REPLY\n");
++ /* inbound packet: server->client */
++ ret = NF_ACCEPT;
++ break;
++ }
++
++ spin_unlock_bh(&rtsp_buffer_lock);
++
++ return ret;
++}
++
++static struct nf_conntrack_helper rtsp_helpers[MAX_PORTS];
++static char rtsp_names[MAX_PORTS][10];
++
++/* This function is intentionally _NOT_ defined as __exit */
++static void
++fini(void)
++{
++ int i;
++ for (i = 0; i < num_ports; i++) {
++ pr_debug("unregistering port %d\n", ports[i]);
++ nf_conntrack_helper_unregister(&rtsp_helpers[i]);
++ }
++ kfree(rtsp_buffer);
++}
++
++static int __init
++init(void)
++{
++ int i, ret;
++ struct nf_conntrack_helper *hlpr;
++ char *tmpname;
++
++ printk("nf_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
++
++ if (max_outstanding < 1) {
++ printk("nf_conntrack_rtsp: max_outstanding must be a positive integer\n");
++ return -EBUSY;
++ }
++ if (setup_timeout < 0) {
++ printk("nf_conntrack_rtsp: setup_timeout must be a positive integer\n");
++ return -EBUSY;
++ }
++
++ rtsp_exp_policy.max_expected = max_outstanding;
++ rtsp_exp_policy.timeout = setup_timeout;
++
++ rtsp_buffer = kmalloc(65536, GFP_KERNEL);
++ if (!rtsp_buffer)
++ return -ENOMEM;
++
++ /* If no port given, default to standard rtsp port */
++ if (ports[0] == 0) {
++ ports[0] = RTSP_PORT;
++ num_ports = 1;
++ }
++
++ for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
++ hlpr = &rtsp_helpers[i];
++ memset(hlpr, 0, sizeof(struct nf_conntrack_helper));
++ hlpr->tuple.src.l3num = AF_INET;
++ hlpr->tuple.src.u.tcp.port = htons(ports[i]);
++ hlpr->tuple.dst.protonum = IPPROTO_TCP;
++ hlpr->expect_policy = &rtsp_exp_policy;
++ hlpr->me = THIS_MODULE;
++ hlpr->help = help;
++
++ tmpname = &rtsp_names[i][0];
++ if (ports[i] == RTSP_PORT) {
++ sprintf(tmpname, "rtsp");
++ } else {
++ sprintf(tmpname, "rtsp-%d", i);
++ }
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,6,0)
++ strlcpy(hlpr->name, tmpname, sizeof(hlpr->name));
++#else
++ hlpr->name = tmpname;
++#endif
++ pr_debug("port #%d: %d\n", i, ports[i]);
++
++ ret = nf_conntrack_helper_register(hlpr);
++
++ if (ret) {
++ printk("nf_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
++ fini();
++ return -EBUSY;
++ }
++ }
++ return 0;
++}
++
++module_init(init);
++module_exit(fini);
+--- /dev/null
++++ b/extensions/rtsp/nf_conntrack_rtsp.h
+@@ -0,0 +1,72 @@
++/*
++ * RTSP extension for IP connection tracking.
++ * (C) 2003 by Tom Marshall <tmarshall at real.com>
++ * based on ip_conntrack_irc.h
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ *
++ * 2013-03-04: Il'inykh Sergey <sergeyi at inango-sw.com>. Inango Systems Ltd
++ * - conditional compilation for kernel 3.7
++ * - port mapping improvements
++*/
++#ifndef _IP_CONNTRACK_RTSP_H
++#define _IP_CONNTRACK_RTSP_H
++
++#include <linux/version.h>
++
++//#define IP_NF_RTSP_DEBUG 1
++#define IP_NF_RTSP_VERSION "0.7"
++
++#ifdef __KERNEL__
++/* port block types */
++typedef enum {
++ pb_single, /* client_port=x */
++ pb_range, /* client_port=x-y */
++ pb_discon /* client_port=x/y (rtspbis) */
++} portblock_t;
++
++/* We record seq number and length of rtsp headers here, all in host order. */
++
++/*
++ * This structure is per expected connection. It is a member of struct
++ * ip_conntrack_expect. The TCP SEQ for the conntrack expect is stored
++ * there and we are expected to only store the length of the data which
++ * needs replaced. If a packet contains multiple RTSP messages, we create
++ * one expected connection per message.
++ *
++ * We use these variables to mark the entire header block. This may seem
++ * like overkill, but the nature of RTSP requires it. A header may appear
++ * multiple times in a message. We must treat two Transport headers the
++ * same as one Transport header with two entries.
++ */
++struct ip_ct_rtsp_expect
++{
++ u_int32_t len; /* length of header block */
++ portblock_t pbtype; /* Type of port block that was requested */
++ u_int16_t loport; /* Port that was requested, low or first */
++ u_int16_t hiport; /* Port that was requested, high or second */
++#if 0
++ uint method; /* RTSP method */
++ uint cseq; /* CSeq from request */
++#endif
++};
++
++extern unsigned int (*nf_nat_rtsp_hook)(struct sk_buff *skb,
++ enum ip_conntrack_info ctinfo,
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ unsigned int protoff,
++#endif
++ unsigned int matchoff,
++ unsigned int matchlen,
++ struct ip_ct_rtsp_expect *prtspexp,
++ struct nf_conntrack_expect *rtp_exp,
++ struct nf_conntrack_expect *rtcp_exp);
++
++#define RTSP_PORT 554
++
++#endif /* __KERNEL__ */
++
++#endif /* _IP_CONNTRACK_RTSP_H */
+--- /dev/null
++++ b/extensions/rtsp/nf_nat_rtsp.c
+@@ -0,0 +1,617 @@
++/*
++ * RTSP extension for TCP NAT alteration
++ * (C) 2003 by Tom Marshall <tmarshall at real.com>
++ *
++ * 2013-03-04: Il'inykh Sergey <sergeyi at inango-sw.com>. Inango Systems Ltd
++ * - fixed rtcp nat mapping and other port mapping fixes
++ * - fixed system hard lock because of bug in the parser
++ * - codestyle fixes and less significant fixes
++ *
++ * based on ip_nat_irc.c
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public License
++ * as published by the Free Software Foundation; either version
++ * 2 of the License, or (at your option) any later version.
++ *
++ * Module load syntax:
++ * insmod nf_nat_rtsp.o ports=port1,port2,...port<MAX_PORTS>
++ * stunaddr=<address>
++ * destaction=[auto|strip|none]
++ *
++ * If no ports are specified, the default will be port 554 only.
++ *
++ * stunaddr specifies the address used to detect that a client is using STUN.
++ * If this address is seen in the destination parameter, it is assumed that
++ * the client has already punched a UDP hole in the firewall, so we don't
++ * mangle the client_port. If none is specified, it is autodetected. It
++ * only needs to be set if you have multiple levels of NAT. It should be
++ * set to the external address that the STUN clients detect. Note that in
++ * this case, it will not be possible for clients to use UDP with servers
++ * between the NATs.
++ *
++ * If no destaction is specified, auto is used.
++ * destaction=auto: strip destination parameter if it is not stunaddr.
++ * destaction=strip: always strip destination parameter (not recommended).
++ * destaction=none: do not touch destination parameter (not recommended).
++ */
++
++#include <linux/module.h>
++#include <linux/version.h>
++#include <net/tcp.h>
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++# include <net/netfilter/nf_nat.h>
++#else
++# include <net/netfilter/nf_nat_rule.h>
++#endif
++#include <net/netfilter/nf_nat_helper.h>
++#include "nf_conntrack_rtsp.h"
++#include <net/netfilter/nf_conntrack_expect.h>
++
++#include <linux/inet.h>
++#include <linux/ctype.h>
++#define NF_NEED_STRNCASECMP
++#define NF_NEED_STRTOU16
++#include "netfilter_helpers.h"
++#define NF_NEED_MIME_NEXTLINE
++#include "netfilter_mime.h"
++
++#define MAX_PORTS 8
++#define DSTACT_AUTO 0
++#define DSTACT_STRIP 1
++#define DSTACT_NONE 2
++
++static char* stunaddr = NULL;
++static char* destaction = NULL;
++
++static u_int32_t extip = 0;
++static int dstact = 0;
++
++static void nf_nat_rtsp_expected(struct nf_conn* ct, struct nf_conntrack_expect *exp);
++
++MODULE_AUTHOR("Tom Marshall <tmarshall at real.com>");
++MODULE_DESCRIPTION("RTSP network address translation module");
++MODULE_LICENSE("GPL");
++module_param(stunaddr, charp, 0644);
++MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
++module_param(destaction, charp, 0644);
++MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
++
++#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
++
++/*** helper functions ***/
++
++static void
++get_skb_tcpdata(struct sk_buff* skb, char** pptcpdata, uint* ptcpdatalen)
++{
++ struct iphdr* iph = ip_hdr(skb);
++ struct tcphdr* tcph = (void *)iph + ip_hdrlen(skb);
++
++ *pptcpdata = (char*)tcph + tcph->doff*4;
++ *ptcpdatalen = ((char*)skb_transport_header(skb) + skb->len) - *pptcpdata;
++}
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++/* copy of sip_sprintf_addr */
++static int rtsp_sprintf_addr(const struct nf_conn *ct, char *buffer,
++ const union nf_inet_addr *addr, bool delim)
++{
++ if (nf_ct_l3num(ct) == NFPROTO_IPV4) {
++ return sprintf(buffer, "%pI4", &addr->ip);
++ } else {
++ if (delim)
++ return sprintf(buffer, "[%pI6c]", &addr->ip6);
++ else
++ return sprintf(buffer, "%pI6c", &addr->ip6);
++ }
++}
++#endif
++
++/*** nat functions ***/
++
++/*
++ * Mangle the "Transport:" header:
++ * - Replace all occurences of "client_port=<spec>"
++ * - Handle destination parameter
++ *
++ * In:
++ * ct, ctinfo = conntrack context
++ * skb = packet
++ * tranoff = Transport header offset from TCP data
++ * tranlen = Transport header length (incl. CRLF)
++ * rport_lo = replacement low port (host endian)
++ * rport_hi = replacement high port (host endian)
++ *
++ * Returns packet size difference.
++ *
++ * Assumes that a complete transport header is present, ending with CR or LF
++ */
++static int
++rtsp_mangle_tran(enum ip_conntrack_info ctinfo,
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ unsigned int protoff,
++#endif
++ struct nf_conntrack_expect* rtp_exp,
++ struct nf_conntrack_expect* rtcp_exp,
++ struct ip_ct_rtsp_expect* prtspexp,
++ struct sk_buff* skb, uint tranoff, uint tranlen)
++{
++ char* ptcp;
++ uint tcplen;
++ char* ptran;
++ char rbuf1[16]; /* Replacement buffer (one port) */
++ uint rbuf1len; /* Replacement len (one port) */
++ char rbufa[16]; /* Replacement buffer (all ports) */
++ uint rbufalen; /* Replacement len (all ports) */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ union nf_inet_addr newip;
++#else
++ u_int32_t newip;
++#endif
++ u_int16_t loport, hiport;
++ uint off = 0;
++ uint diff; /* Number of bytes we removed */
++
++ struct nf_conn *ct = rtp_exp->master;
++ /* struct nf_conn *ct = nf_ct_get(skb, &ctinfo); */
++ struct nf_conntrack_tuple *rtp_t;
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ char szextaddr[INET6_ADDRSTRLEN];
++#else
++ char szextaddr[INET_ADDRSTRLEN];
++#endif
++ uint extaddrlen;
++ int is_stun;
++
++ get_skb_tcpdata(skb, &ptcp, &tcplen);
++ ptran = ptcp+tranoff;
++
++ if (tranoff+tranlen > tcplen || tcplen-tranoff < tranlen ||
++ tranlen < 10 || !iseol(ptran[tranlen-1]) ||
++ nf_strncasecmp(ptran, "Transport:", 10) != 0) {
++ pr_info("sanity check failed\n");
++ return 0;
++ }
++ off += 10;
++ SKIP_WSPACE(ptcp+tranoff, tranlen, off);
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3;
++ rtp_t = &rtp_exp->tuple;
++ rtp_t->dst.u3 = newip;
++ if (rtcp_exp) {
++ rtcp_exp->tuple.dst.u3 = newip;
++ }
++ extaddrlen = rtsp_sprintf_addr(ct, szextaddr, &newip, true); // FIXME handle extip
++ pr_debug("stunaddr=%s (auto)\n", szextaddr);
++#else
++ newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip;
++ rtp_t = &rtp_exp->tuple;
++ rtp_t->dst.u3.ip = newip;
++ if (rtcp_exp) {
++ rtcp_exp->tuple.dst.u3.ip = newip;
++ }
++ extaddrlen = extip ? sprintf(szextaddr, "%pI4", &extip)
++ : sprintf(szextaddr, "%pI4", &newip);
++ pr_debug("stunaddr=%s (%s)\n", szextaddr, (extip?"forced":"auto"));
++#endif
++ hiport = 0;
++ rbuf1len = rbufalen = 0;
++ switch (prtspexp->pbtype) {
++ case pb_single:
++ for (loport = prtspexp->loport; loport != 0; loport++) { /* XXX: improper wrap? */
++ rtp_t->dst.u.udp.port = htons(loport);
++ if (nf_ct_expect_related(rtp_exp) == 0) {
++ pr_debug("using port %hu\n", loport);
++ break;
++ }
++ }
++ if (loport != 0) {
++ rbuf1len = sprintf(rbuf1, "%hu", loport);
++ rbufalen = sprintf(rbufa, "%hu", loport);
++ }
++ break;
++ case pb_range:
++ for (loport = prtspexp->loport; loport != 0; loport += 2) { /* XXX: improper wrap? */
++ rtp_t->dst.u.udp.port = htons(loport);
++ if (nf_ct_expect_related(rtp_exp) != 0) {
++ continue;
++ }
++ hiport = loport + 1;
++ rtcp_exp->tuple.dst.u.udp.port = htons(hiport);
++ if (nf_ct_expect_related(rtcp_exp) != 0) {
++ nf_ct_unexpect_related(rtp_exp);
++ continue;
++ }
++
++ /* FIXME: invalid print in case of ipv6 */
++ pr_debug("nat expect_related %pI4:%u-%u-%pI4:%u-%u\n",
++ &rtp_exp->tuple.src.u3.ip,
++ ntohs(rtp_exp->tuple.src.u.udp.port),
++ ntohs(rtcp_exp->tuple.src.u.udp.port),
++ &rtp_exp->tuple.dst.u3.ip,
++ ntohs(rtp_exp->tuple.dst.u.udp.port),
++ ntohs(rtcp_exp->tuple.dst.u.udp.port));
++ break;
++ }
++ if (loport != 0) {
++ rbuf1len = sprintf(rbuf1, "%hu", loport);
++ rbufalen = sprintf(rbufa, "%hu-%hu", loport, hiport);
++ }
++ break;
++ case pb_discon:
++ for (loport = prtspexp->loport; loport != 0; loport++) { /* XXX: improper wrap? */
++ rtp_t->dst.u.udp.port = htons(loport);
++ if (nf_ct_expect_related(rtp_exp) == 0) {
++ pr_debug("using port %hu (1 of 2)\n", loport);
++ break;
++ }
++ }
++ for (hiport = prtspexp->hiport; hiport != 0; hiport++) { /* XXX: improper wrap? */
++ rtp_t->dst.u.udp.port = htons(hiport);
++ if (nf_ct_expect_related(rtp_exp) == 0) {
++ pr_debug("using port %hu (2 of 2)\n", hiport);
++ break;
++ }
++ }
++ if (loport != 0 && hiport != 0) {
++ rbuf1len = sprintf(rbuf1, "%hu", loport);
++ rbufalen = sprintf(rbufa, hiport == loport+1 ?
++ "%hu-%hu":"%hu/%hu", loport, hiport);
++ }
++ break;
++ }
++
++ if (rbuf1len == 0)
++ return 0; /* cannot get replacement port(s) */
++
++ /* Transport: tran;field;field=val,tran;field;field=val,...
++ `off` is set to the start of Transport value from start of line
++ */
++ while (off < tranlen) {
++ uint saveoff;
++ const char* pparamend;
++ uint nextparamoff;
++
++ pparamend = memchr(ptran+off, ',', tranlen-off);
++ pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
++ nextparamoff = pparamend-ptran;
++
++ /*
++ * We pass over each param twice. On the first pass, we look for a
++ * destination= field. It is handled by the security policy. If it
++ * is present, allowed, and equal to our external address, we assume
++ * that STUN is being used and we leave the client_port= field alone.
++ */
++ is_stun = 0;
++ saveoff = off;
++ while (off < nextparamoff) {
++ const char* pfieldend;
++ uint nextfieldoff;
++
++ pfieldend = memchr(ptran+off, ';', nextparamoff-off);
++ nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
++
++ if (dstact != DSTACT_NONE && strncmp(ptran+off, "destination=", 12) == 0) {
++ if (strncmp(ptran+off+12, szextaddr, extaddrlen) == 0)
++ is_stun = 1;
++
++ if (dstact == DSTACT_STRIP || (dstact == DSTACT_AUTO && !is_stun)) {
++ uint dstoff = (ptran-ptcp)+off;
++ uint dstlen = nextfieldoff-off;
++ char* pdstrep = NULL;
++ uint dstreplen = 0;
++ diff = dstlen;
++ if (dstact == DSTACT_AUTO && !is_stun) {
++ pr_debug("RTSP: replace dst addr\n");
++ dstoff += 12;
++ dstlen -= 13;
++ pdstrep = szextaddr;
++ dstreplen = extaddrlen;
++ diff = nextfieldoff-off-13-extaddrlen;
++ }
++
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff,
++ dstoff, dstlen, pdstrep, dstreplen)) {
++#else
++ if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
++ dstoff, dstlen, pdstrep, dstreplen)) {
++#endif
++ /* mangle failed, all we can do is bail */
++ nf_ct_unexpect_related(rtp_exp);
++ if (rtcp_exp)
++ nf_ct_unexpect_related(rtcp_exp);
++ return 0;
++ }
++ get_skb_tcpdata(skb, &ptcp, &tcplen);
++ ptran = ptcp+tranoff;
++ tranlen -= diff;
++ nextparamoff -= diff;
++ nextfieldoff -= diff;
++ }
++ }
++
++ off = nextfieldoff;
++ }
++
++ if (is_stun)
++ continue;
++
++ off = saveoff;
++ while (off < nextparamoff) {
++ const char* pfieldend;
++ uint nextfieldoff;
++
++ pfieldend = memchr(ptran+off, ';', nextparamoff-off);
++ nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
++
++ if (strncmp(ptran+off, "client_port=", 12) == 0) {
++ u_int16_t port;
++ uint numlen;
++ uint origoff;
++ uint origlen;
++ char* rbuf = rbuf1;
++ uint rbuflen = rbuf1len;
++
++ off += 12;
++ origoff = (ptran-ptcp)+off;
++ origlen = 0;
++ numlen = nf_strtou16(ptran+off, &port);
++ off += numlen;
++ origlen += numlen;
++ if (port != prtspexp->loport) {
++ pr_debug("multiple ports found, port %hu ignored\n", port);
++ } else {
++ if (ptran[off] == '-' || ptran[off] == '/') {
++ off++;
++ origlen++;
++ numlen = nf_strtou16(ptran+off, &port);
++ off += numlen;
++ origlen += numlen;
++ rbuf = rbufa;
++ rbuflen = rbufalen;
++ }
++
++ /*
++ * note we cannot just memcpy() if the sizes are the same.
++ * the mangle function does skb resizing, checks for a
++ * cloned skb, and updates the checksums.
++ *
++ * parameter 4 below is offset from start of tcp data.
++ */
++ diff = origlen-rbuflen;
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, protoff,
++ origoff, origlen, rbuf, rbuflen)) {
++#else
++ if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
++ origoff, origlen, rbuf, rbuflen)) {
++#endif
++ /* mangle failed, all we can do is bail */
++ nf_ct_unexpect_related(rtp_exp);
++ if (rtcp_exp)
++ nf_ct_unexpect_related(rtcp_exp);
++ return 0;
++ }
++ get_skb_tcpdata(skb, &ptcp, &tcplen);
++ ptran = ptcp+tranoff;
++ tranlen -= diff;
++ nextparamoff -= diff;
++ nextfieldoff -= diff;
++ }
++ }
++
++ off = nextfieldoff;
++ }
++
++ off = nextparamoff;
++ }
++
++ return 1;
++}
++
++static uint
++help_out(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ unsigned int protoff,
++#endif
++ unsigned int matchoff, unsigned int matchlen,
++ struct ip_ct_rtsp_expect* prtspexp,
++ struct nf_conntrack_expect* rtp_exp,
++ struct nf_conntrack_expect* rtcp_exp)
++{
++ char* ptcp;
++ uint tcplen;
++ uint hdrsoff;
++ uint hdrslen;
++ uint lineoff;
++ uint linelen;
++ uint off;
++ int dir = CTINFO2DIR(ctinfo);
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ union nf_inet_addr saddr = rtp_exp->master->tuplehash[dir].tuple.src.u3;
++#else
++ __be32 saddr = rtp_exp->master->tuplehash[dir].tuple.src.u3.ip;
++#endif
++
++ //struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
++ //struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
++
++ get_skb_tcpdata(skb, &ptcp, &tcplen);
++ hdrsoff = matchoff;//exp->seq - ntohl(tcph->seq);
++ hdrslen = matchlen;
++ off = hdrsoff;
++ pr_debug("NAT rtsp help_out\n");
++
++ while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen)) {
++ if (linelen == 0)
++ break;
++
++ if (off > hdrsoff+hdrslen) {
++ pr_info("!! overrun !!");
++ break;
++ }
++ pr_debug("hdr: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
++
++ if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0) {
++ uint oldtcplen = tcplen;
++ pr_debug("hdr: Transport\n");
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ if (!rtsp_mangle_tran(ctinfo, protoff, rtp_exp, rtcp_exp,
++ prtspexp, skb, lineoff, linelen)) {
++#else
++ if (!rtsp_mangle_tran(ctinfo, rtp_exp, rtcp_exp, prtspexp,
++ skb, lineoff, linelen)) {
++#endif
++ pr_debug("hdr: Transport mangle failed");
++ break;
++ }
++ rtp_exp->expectfn = nf_nat_rtsp_expected;
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ rtp_exp->saved_addr = saddr;
++#else
++ rtp_exp->saved_ip = saddr;
++#endif
++ rtp_exp->saved_proto.udp.port = htons(prtspexp->loport);
++ rtp_exp->dir = !dir;
++ if (rtcp_exp) {
++ rtcp_exp->expectfn = nf_nat_rtsp_expected;
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ rtcp_exp->saved_addr = saddr;
++#else
++ rtcp_exp->saved_ip = saddr;
++#endif
++ rtcp_exp->saved_proto.udp.port = htons(prtspexp->hiport);
++ rtcp_exp->dir = !dir;
++ }
++ get_skb_tcpdata(skb, &ptcp, &tcplen);
++ hdrslen -= (oldtcplen-tcplen);
++ off -= (oldtcplen-tcplen);
++ lineoff -= (oldtcplen-tcplen);
++ linelen -= (oldtcplen-tcplen);
++ pr_debug("rep: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
++ }
++ }
++
++ return NF_ACCEPT;
++}
++
++static unsigned int
++nf_nat_rtsp(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ unsigned int protoff,
++#endif
++ unsigned int matchoff, unsigned int matchlen,
++ struct ip_ct_rtsp_expect* prtspexp,
++ struct nf_conntrack_expect* rtp_exp,
++ struct nf_conntrack_expect* rtcp_exp)
++{
++ int dir = CTINFO2DIR(ctinfo);
++ int rc = NF_ACCEPT;
++
++ switch (dir) {
++ case IP_CT_DIR_ORIGINAL:
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ rc = help_out(skb, ctinfo, protoff, matchoff, matchlen, prtspexp,
++ rtp_exp, rtcp_exp);
++#else
++ rc = help_out(skb, ctinfo, matchoff, matchlen, prtspexp,
++ rtp_exp, rtcp_exp);
++#endif
++ break;
++ case IP_CT_DIR_REPLY:
++ pr_debug("unmangle ! %u\n", ctinfo);
++ /* XXX: unmangle */
++ rc = NF_ACCEPT;
++ break;
++ }
++ //UNLOCK_BH(&ip_rtsp_lock);
++
++ return rc;
++}
++
++static void nf_nat_rtsp_expected(struct nf_conn* ct, struct nf_conntrack_expect *exp)
++{
++#if LINUX_VERSION_CODE < KERNEL_VERSION(3,3,0) || LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ struct nf_nat_range range;
++#else
++ struct nf_nat_ipv4_range range;
++#endif
++
++ /* This must be a fresh one. */
++ BUG_ON(ct->status & IPS_NAT_DONE_MASK);
++
++ /* For DST manip, map port here to where it's expected. */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ range.min_proto = range.max_proto = exp->saved_proto;
++ range.min_addr = range.max_addr = exp->saved_addr;
++#else
++ range.min = range.max = exp->saved_proto;
++ range.min_ip = range.max_ip = exp->saved_ip;
++#endif
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,3,0)
++ range.flags = (NF_NAT_RANGE_MAP_IPS | NF_NAT_RANGE_PROTO_SPECIFIED);
++ nf_nat_setup_info(ct, &range, NF_NAT_MANIP_DST);
++#else
++ range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED);
++ nf_nat_setup_info(ct, &range, IP_NAT_MANIP_DST);
++#endif
++
++ /* Change src to where master sends to, but only if the connection
++ * actually came from the same source. */
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
++ if (nf_inet_addr_cmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3,
++ &ct->master->tuplehash[exp->dir].tuple.src.u3)) {
++ range.min_addr = range.max_addr
++ = ct->master->tuplehash[!exp->dir].tuple.dst.u3;
++#else
++ if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip ==
++ ct->master->tuplehash[exp->dir].tuple.src.u3.ip) {
++ range.min_ip = range.max_ip
++ = ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip;
++#endif
++#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,3,0)
++ range.flags = NF_NAT_RANGE_MAP_IPS;
++ nf_nat_setup_info(ct, &range, NF_NAT_MANIP_SRC);
++#else
++ range.flags = IP_NAT_RANGE_MAP_IPS;
++ nf_nat_setup_info(ct, &range, IP_NAT_MANIP_SRC);
++#endif
++ }
++}
++
++
++static void __exit fini(void)
++{
++ rcu_assign_pointer(nf_nat_rtsp_hook, NULL);
++ synchronize_net();
++}
++
++static int __init init(void)
++{
++ printk("nf_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
++
++ BUG_ON(nf_nat_rtsp_hook);
++ rcu_assign_pointer(nf_nat_rtsp_hook, nf_nat_rtsp);
++
++ if (stunaddr != NULL)
++ extip = in_aton(stunaddr);
++
++ if (destaction != NULL) {
++ if (strcmp(destaction, "auto") == 0)
++ dstact = DSTACT_AUTO;
++
++ if (strcmp(destaction, "strip") == 0)
++ dstact = DSTACT_STRIP;
++
++ if (strcmp(destaction, "none") == 0)
++ dstact = DSTACT_NONE;
++ }
++
++ return 0;
++}
++
++module_init(init);
++module_exit(fini);
+--- a/extensions/Kbuild
++++ b/extensions/Kbuild
+@@ -28,6 +28,7 @@ obj-${build_lscan} += xt_lscan.o
+ obj-${build_pknock} += pknock/
+ obj-${build_psd} += xt_psd.o
+ obj-${build_quota2} += xt_quota2.o
++obj-${build_rtsp} += rtsp/
+
+ -include ${M}/*.Kbuild
+ -include ${M}/Kbuild.*
+--- a/mconfig
++++ b/mconfig
+@@ -22,3 +22,4 @@ build_lscan=m
+ build_pknock=m
+ build_psd=m
+ build_quota2=m
++build_rtsp=m
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-19 08:10:43 +0000