Added support for RTSP connection tracking modules

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@2794 3c298f89-4303-0410-b956-a3cf2f4a3e73

6 files changed, 1549 insertions, 1 deletions

diff --git a/openwrt/target/linux/linux-2.4/config/ar531x b/openwrt/target/linux/linux-2.4/config/ar531x
index 3db1f57c3..5a9137de3 100644
--- a/openwrt/target/linux/linux-2.4/config/ar531x
+++ b/openwrt/target/linux/linux-2.4/config/ar531x
@@ -346,6 +346,7 @@ CONFIG_IP_NF_PPTP=m
 CONFIG_IP_NF_SIP=m
 CONFIG_IP_NF_H323=m
 CONFIG_IP_NF_MMS=m
+CONFIG_IP_NF_RTSP=m
 CONFIG_IP_NF_QUEUE=m
 CONFIG_IP_NF_IPTABLES=y
 CONFIG_IP_NF_MATCH_LIMIT=m
@@ -398,6 +399,7 @@ CONFIG_IP_NF_NAT_PROTO_GRE=m
 CONFIG_IP_NF_NAT_SIP=m
 CONFIG_IP_NF_NAT_H323=m
 CONFIG_IP_NF_NAT_MMS=m
+CONFIG_IP_NF_NAT_RTSP=m
 CONFIG_IP_NF_NAT_AMANDA=m
 CONFIG_IP_NF_NAT_SNMP_BASIC=m
 CONFIG_IP_NF_NAT_IRC=y
diff --git a/openwrt/target/linux/linux-2.4/config/ar7 b/openwrt/target/linux/linux-2.4/config/ar7
index fab2bf32a..829c0551e 100644
--- a/openwrt/target/linux/linux-2.4/config/ar7
+++ b/openwrt/target/linux/linux-2.4/config/ar7
@@ -350,6 +350,7 @@ CONFIG_IP_NF_PPTP=m
 CONFIG_IP_NF_SIP=m
 CONFIG_IP_NF_H323=m
 CONFIG_IP_NF_MMS=m
+CONFIG_IP_NF_RTSP=m
 CONFIG_IP_NF_QUEUE=m
 CONFIG_IP_NF_IPTABLES=y
 CONFIG_IP_NF_MATCH_LIMIT=m
@@ -402,6 +403,7 @@ CONFIG_IP_NF_NAT_PROTO_GRE=m
 CONFIG_IP_NF_NAT_SIP=m
 CONFIG_IP_NF_NAT_H323=m
 CONFIG_IP_NF_NAT_MMS=m
+CONFIG_IP_NF_NAT_RTSP=m
 CONFIG_IP_NF_NAT_AMANDA=m
 CONFIG_IP_NF_NAT_SNMP_BASIC=m
 CONFIG_IP_NF_NAT_IRC=y
diff --git a/openwrt/target/linux/linux-2.4/config/brcm b/openwrt/target/linux/linux-2.4/config/brcm
index 4abc8b1aa..a8636a7ba 100644
--- a/openwrt/target/linux/linux-2.4/config/brcm
+++ b/openwrt/target/linux/linux-2.4/config/brcm
@@ -365,6 +365,7 @@ CONFIG_IP_NF_PPTP=m
 CONFIG_IP_NF_SIP=m
 CONFIG_IP_NF_H323=m
 CONFIG_IP_NF_MMS=m
+CONFIG_IP_NF_NAT_RTSP=m
 CONFIG_IP_NF_QUEUE=m
 CONFIG_IP_NF_IPTABLES=y
 CONFIG_IP_NF_MATCH_LIMIT=m
@@ -416,6 +417,7 @@ CONFIG_IP_NF_NAT_PPTP=m
 CONFIG_IP_NF_NAT_SIP=m
 CONFIG_IP_NF_NAT_H323=m
 CONFIG_IP_NF_NAT_MMS=m
+CONFIG_IP_NF_NAT_RTSP=m
 CONFIG_IP_NF_NAT_PROTO_GRE=m
 CONFIG_IP_NF_NAT_AMANDA=m
 CONFIG_IP_NF_NAT_SNMP_BASIC=m
diff --git a/openwrt/target/linux/linux-2.4/config/x86 b/openwrt/target/linux/linux-2.4/config/x86
index 6da4f94aa..728613c4a 100644
--- a/openwrt/target/linux/linux-2.4/config/x86
+++ b/openwrt/target/linux/linux-2.4/config/x86
@@ -276,7 +276,6 @@ CONFIG_NET_IPGRE=m
 #
 #   IP: Netfilter Configuration
 #
-CONFIG_IP_NF_MMS=m
 CONFIG_IP_NF_CONNTRACK=y
 CONFIG_IP_NF_CONNTRACK_MARK=y
 CONFIG_IP_NF_FTP=y
@@ -289,6 +288,8 @@ CONFIG_IP_NF_CT_PROTO_GRE=m
 CONFIG_IP_NF_PPTP=m
 CONFIG_IP_NF_SIP=m
 CONFIG_IP_NF_H323=m
+CONFIG_IP_NF_MMS=m
+CONFIG_IP_NF_RTSP=m
 CONFIG_IP_NF_QUEUE=m
 CONFIG_IP_NF_IPTABLES=y
 CONFIG_IP_NF_MATCH_LIMIT=m
@@ -341,6 +342,7 @@ CONFIG_IP_NF_NAT_SIP=m
 CONFIG_IP_NF_NAT_H323=m
 CONFIG_IP_NF_NAT_PROTO_GRE=m
 CONFIG_IP_NF_NAT_MMS=m
+CONFIG_IP_NF_NAT_RTSP=m
 CONFIG_IP_NF_NAT_AMANDA=m
 CONFIG_IP_NF_NAT_SNMP_BASIC=m
 CONFIG_IP_NF_NAT_IRC=y
diff --git a/openwrt/target/linux/linux-2.4/patches/generic/617-netfilter_nat_rtsp.patch b/openwrt/target/linux/linux-2.4/patches/generic/617-netfilter_nat_rtsp.patch
new file mode 100644
index 000000000..28bf66442
--- /dev/null
+++ b/openwrt/target/linux/linux-2.4/patches/generic/617-netfilter_nat_rtsp.patch
@@ -0,0 +1,1538 @@
+diff -urN linux-2.4.32.orig/arch/mips/kernel/mips_ksyms.c linux-2.4.32/arch/mips/kernel/mips_ksyms.c
+--- linux-2.4.32.orig/arch/mips/kernel/mips_ksyms.c	2005-12-29 12:17:49.000000000 +0100
++++ linux-2.4.32/arch/mips/kernel/mips_ksyms.c	2005-12-29 12:18:26.000000000 +0100
+@@ -52,6 +52,7 @@
+ /*
+  * String functions
+  */
++EXPORT_SYMBOL_NOVERS(memchr);
+ EXPORT_SYMBOL_NOVERS(memcmp);
+ EXPORT_SYMBOL_NOVERS(memset);
+ EXPORT_SYMBOL_NOVERS(memcpy);
+diff -urN linux-2.4.32.orig/Documentation/Configure.help linux-2.4.32/Documentation/Configure.help
+--- linux-2.4.32.orig/Documentation/Configure.help	2005-12-29 12:17:55.000000000 +0100
++++ linux-2.4.32/Documentation/Configure.help	2005-12-29 12:18:26.000000000 +0100
+@@ -2817,6 +2817,14 @@
+   Documentation/modules.txt.  If unsure, say `N'.
+ 
+ 
++RTSP protocol support
++CONFIG_IP_NF_RTSP
++  Support the RTSP protocol.  This allows UDP transports to be setup
++  properly, including RTP and RDT.
++
++  If you want to compile it as a module, say 'M' here and read
++  Documentation/modules.txt.  If unsure, say 'Y'.
++
+ IRC Send/Chat protocol support
+ CONFIG_IP_NF_IRC
+   There is a commonly-used extension to IRC called
+diff -urN linux-2.4.32.orig/include/linux/netfilter_helpers.h linux-2.4.32/include/linux/netfilter_helpers.h
+--- linux-2.4.32.orig/include/linux/netfilter_helpers.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.32/include/linux/netfilter_helpers.h	2005-12-29 12:18:26.000000000 +0100
+@@ -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 */
+diff -urN linux-2.4.32.orig/include/linux/netfilter_ipv4/ip_conntrack.h linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack.h
+--- linux-2.4.32.orig/include/linux/netfilter_ipv4/ip_conntrack.h	2005-12-29 12:17:55.000000000 +0100
++++ linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack.h	2005-12-29 12:18:26.000000000 +0100
+@@ -66,6 +66,7 @@
+ };
+ 
+ /* Add protocol helper include file here */
++#include <linux/netfilter_ipv4/ip_conntrack_rtsp.h>
+ #include <linux/netfilter_ipv4/ip_conntrack_amanda.h>
+ 
+ #include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
+@@ -78,6 +79,7 @@
+ /* per expectation: application helper private data */
+ union ip_conntrack_expect_help {
+ 	/* insert conntrack helper private data (expect) here */
++	struct ip_ct_rtsp_expect exp_rtsp_info;
+ 	struct ip_ct_amanda_expect exp_amanda_info;
+ 	struct ip_ct_ftp_expect exp_ftp_info;
+ 	struct ip_ct_irc_expect exp_irc_info;
+@@ -96,6 +98,7 @@
+ /* per conntrack: application helper private data */
+ union ip_conntrack_help {
+ 	/* insert conntrack helper private data (master) here */
++	struct ip_ct_rtsp_master ct_rtsp_info;
+ 	struct ip_ct_ftp_master ct_ftp_info;
+ 	struct ip_ct_irc_master ct_irc_info;
+ 	struct ip_ct_pptp_master ct_pptp_info;
+diff -urN linux-2.4.32.orig/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h
+--- linux-2.4.32.orig/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.32/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h	2005-12-29 12:18:26.000000000 +0100
+@@ -0,0 +1,68 @@
++/*
++ * RTSP extension for IP connection tracking.
++ * (C) 2003 by Tom Marshall <tmarshall@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.
++ */
++#ifndef _IP_CONNTRACK_RTSP_H
++#define _IP_CONNTRACK_RTSP_H
++
++/* #define IP_NF_RTSP_DEBUG */
++#define IP_NF_RTSP_VERSION "0.01"
++
++/* 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
++};
++
++/* This structure exists only once per master */
++struct ip_ct_rtsp_master
++{
++    /* Empty (?) */
++};
++
++
++#ifdef __KERNEL__
++
++#include <linux/netfilter_ipv4/lockhelp.h>
++
++#define RTSP_PORT   554
++
++/* Protects rtsp part of conntracks */
++DECLARE_LOCK_EXTERN(ip_rtsp_lock);
++
++#endif /* __KERNEL__ */
++
++#endif /* _IP_CONNTRACK_RTSP_H */
+diff -urN linux-2.4.32.orig/include/linux/netfilter_mime.h linux-2.4.32/include/linux/netfilter_mime.h
+--- linux-2.4.32.orig/include/linux/netfilter_mime.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.32/include/linux/netfilter_mime.h	2005-12-29 12:18:26.000000000 +0100
+@@ -0,0 +1,90 @@
++/*
++ * 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/kernel.h>
++#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 */
+diff -urN linux-2.4.32.orig/net/ipv4/netfilter/Config.in linux-2.4.32/net/ipv4/netfilter/Config.in
+--- linux-2.4.32.orig/net/ipv4/netfilter/Config.in	2005-12-29 12:17:55.000000000 +0100
++++ linux-2.4.32/net/ipv4/netfilter/Config.in	2005-12-29 12:20:42.000000000 +0100
+@@ -18,6 +18,7 @@
+   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
+   dep_tristate '  MMS protocol support' CONFIG_IP_NF_MMS $CONFIG_IP_NF_CONNTRACK
++  dep_tristate '  RTSP protocol support' CONFIG_IP_NF_RTSP $CONFIG_IP_NF_CONNTRACK
+ fi
+ 
+ if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
+@@ -128,6 +129,13 @@
+ 	  define_tristate CONFIG_IP_NF_NAT_MMS $CONFIG_IP_NF_NAT
+ 	fi
+       fi
++      if [ "$CONFIG_IP_NF_RTSP" = "m" ]; then
++        define_tristate CONFIG_IP_NF_NAT_RTSP m
++      else
++	if [ "$CONFIG_IP_NF_RTSP" = "y" ]; then
++	  define_tristate CONFIG_IP_NF_NAT_RTSP $CONFIG_IP_NF_NAT
++	fi
++      fi
+       if [ "$CONFIG_IP_NF_AMANDA" = "m" ]; then
+         define_tristate CONFIG_IP_NF_NAT_AMANDA m
+       else
+diff -urN linux-2.4.32.orig/net/ipv4/netfilter/ip_conntrack_rtsp.c linux-2.4.32/net/ipv4/netfilter/ip_conntrack_rtsp.c
+--- linux-2.4.32.orig/net/ipv4/netfilter/ip_conntrack_rtsp.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.32/net/ipv4/netfilter/ip_conntrack_rtsp.c	2005-12-29 12:18:26.000000000 +0100
+@@ -0,0 +1,507 @@
++/*
++ * RTSP extension for IP connection tracking
++ * (C) 2003 by Tom Marshall <tmarshall@real.com>
++ * 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 ip_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/config.h>
++#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_helper.h>
++#include <linux/netfilter_ipv4/ip_conntrack_rtsp.h>
++
++#include <linux/ctype.h>
++#define NF_NEED_STRNCASECMP
++#define NF_NEED_STRTOU16
++#define NF_NEED_STRTOU32
++#define NF_NEED_NEXTLINE
++#include <linux/netfilter_helpers.h>
++#define NF_NEED_MIME_NEXTLINE
++#include <linux/netfilter_mime.h>
++
++#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
++
++#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
++#ifdef IP_NF_RTSP_DEBUG
++#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
++#else
++#define DEBUGP(fmt, args...)
++#endif
++
++#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@real.com>");
++MODULE_DESCRIPTION("RTSP connection tracking module");
++MODULE_LICENSE("GPL");
++#ifdef MODULE_PARM
++MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
++MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
++MODULE_PARM(max_outstanding, "i");
++MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
++MODULE_PARM(setup_timeout, "i");
++MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
++#endif
++
++DECLARE_LOCK(ip_rtsp_lock);
++struct module* ip_conntrack_rtsp = THIS_MODULE;
++
++/*
++ * 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    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)
++        {
++            INFOP("!! overrun !!\n");
++            break;
++        }
++
++        if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0)
++        {
++            *pcseqoff = lineoff;
++            *pcseqlen = 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)
++    {
++        INFOP("sanity check failed\n");
++        return 0;
++    }
++    DEBUGP("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)
++                {
++                    DEBUGP("multiple ports found, port %hu ignored\n", port);
++                }
++                else
++                {
++                    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)
++                        {
++                            DEBUGP("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 int
++help_out(const struct iphdr* iph, size_t pktlen,
++                struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
++{
++    int dir = CTINFO2DIR(ctinfo);   /* = IP_CT_DIR_ORIGINAL */
++    struct  tcphdr* tcph = (void*)iph + iph->ihl * 4;
++    uint    tcplen = pktlen - iph->ihl * 4;
++    char*   pdata = (char*)tcph + tcph->doff * 4;
++    uint    datalen = tcplen - tcph->doff * 4;
++    uint    dataoff = 0;
++
++    struct ip_conntrack_expect exp;
++
++    while (dataoff < datalen)
++    {
++        uint    cmdoff = dataoff;
++        uint    hdrsoff = 0;
++        uint    hdrslen = 0;
++        uint    cseqoff = 0;
++        uint    cseqlen = 0;
++        uint    lineoff = 0;
++        uint    linelen = 0;
++        uint    off;
++        int     rc;
++
++        if (!rtsp_parse_message(pdata, datalen, &dataoff,
++                                &hdrsoff, &hdrslen,
++                                &cseqoff, &cseqlen))
++        {
++            break;      /* not a valid message */
++        }
++
++        if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
++        {
++            continue;   /* not a SETUP message */
++        }
++        DEBUGP("found a setup message\n");
++
++        memset(&exp, 0, sizeof(exp));
++
++        off = 0;
++        while (nf_mime_nextline(pdata+hdrsoff, hdrslen, &off,
++                                &lineoff, &linelen))
++        {
++            if (linelen == 0)
++            {
++                break;
++            }
++            if (off > hdrsoff+hdrslen)
++            {
++                INFOP("!! overrun !!");
++                break;
++            }
++
++            if (nf_strncasecmp(pdata+hdrsoff+lineoff, "Transport:", 10) == 0)
++            {
++                rtsp_parse_transport(pdata+hdrsoff+lineoff, linelen,
++                                     &exp.help.exp_rtsp_info);
++            }
++        }
++
++        if (exp.help.exp_rtsp_info.loport == 0)
++        {
++            DEBUGP("no udp transports found\n");
++            continue;   /* no udp transports found */
++        }
++
++        DEBUGP("udp transport found, ports=(%d,%hu,%hu)\n",
++              (int)exp.help.exp_rtsp_info.pbtype,
++              exp.help.exp_rtsp_info.loport,
++              exp.help.exp_rtsp_info.hiport);
++
++        LOCK_BH(&ip_rtsp_lock);
++        exp.seq = ntohl(tcph->seq) + hdrsoff; /* mark all the headers */
++        exp.help.exp_rtsp_info.len = hdrslen;
++
++        exp.tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
++        exp.mask.src.ip  = 0xffffffff;
++        exp.tuple.dst.ip = ct->tuplehash[dir].tuple.src.ip;
++        exp.mask.dst.ip  = 0xffffffff;
++        exp.tuple.dst.u.udp.port = exp.help.exp_rtsp_info.loport;
++        exp.mask.dst.u.udp.port  = (exp.help.exp_rtsp_info.pbtype == pb_range) ? 0xfffe : 0xffff;
++        exp.tuple.dst.protonum = IPPROTO_UDP;
++        exp.mask.dst.protonum  = 0xffff;
++
++        DEBUGP("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
++                NIPQUAD(exp.tuple.src.ip),
++                ntohs(exp.tuple.src.u.tcp.port),
++                NIPQUAD(exp.tuple.dst.ip),
++                ntohs(exp.tuple.dst.u.tcp.port));
++
++        /* pass the request off to the nat helper */
++        rc = ip_conntrack_expect_related(ct, &exp);
++        UNLOCK_BH(&ip_rtsp_lock);
++        if (rc == 0)
++        {
++            DEBUGP("ip_conntrack_expect_related succeeded\n");
++        }
++        else
++        {
++            INFOP("ip_conntrack_expect_related failed (%d)\n", rc);
++        }
++    }
++
++    return NF_ACCEPT;
++}
++
++/* inbound packet: server->client */
++static int
++help_in(const struct iphdr* iph, size_t pktlen,
++                struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
++{
++    return NF_ACCEPT;
++}
++
++static int
++help(const struct iphdr* iph, size_t pktlen,
++                struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
++{
++    /* tcplen not negative guarenteed by ip_conntrack_tcp.c */
++    struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
++    u_int32_t tcplen = pktlen - iph->ihl * 4;
++
++    /* 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("conntrackinfo = %u\n", ctinfo);
++        return NF_ACCEPT;
++    }
++
++    /* Not whole TCP header? */
++    if (tcplen < sizeof(struct tcphdr) || tcplen < tcph->doff * 4)
++    {
++        DEBUGP("tcplen = %u\n", (unsigned)tcplen);
++        return NF_ACCEPT;
++    }
++
++    /* 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;
++    }
++
++    switch (CTINFO2DIR(ctinfo))
++    {
++    case IP_CT_DIR_ORIGINAL:
++        help_out(iph, pktlen, ct, ctinfo);
++        break;
++    case IP_CT_DIR_REPLY:
++        help_in(iph, pktlen, ct, ctinfo);
++        break;
++    }
++
++    return NF_ACCEPT;
++}
++
++static struct ip_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++)
++    {
++        DEBUGP("unregistering port %d\n", ports[i]);
++        ip_conntrack_helper_unregister(&rtsp_helpers[i]);
++    }
++}
++
++static int __init
++init(void)
++{
++    int i, ret;
++    struct ip_conntrack_helper *hlpr;
++    char *tmpname;
++
++    printk("ip_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
++
++    if (max_outstanding < 1)
++    {
++        printk("ip_conntrack_rtsp: max_outstanding must be a positive integer\n");
++        return -EBUSY;
++    }
++    if (setup_timeout < 0)
++    {
++        printk("ip_conntrack_rtsp: setup_timeout must be a positive integer\n");
++        return -EBUSY;
++    }
++
++    /* If no port given, default to standard rtsp port */
++    if (ports[0] == 0)
++    {
++        ports[0] = RTSP_PORT;
++    }
++
++    for (i = 0; (i < MAX_PORTS) && ports[i]; i++)
++    {
++        hlpr = &rtsp_helpers[i];
++        memset(hlpr, 0, sizeof(struct ip_conntrack_helper));
++        hlpr->tuple.src.u.tcp.port = htons(ports[i]);
++        hlpr->tuple.dst.protonum = IPPROTO_TCP;
++        hlpr->mask.src.u.tcp.port = 0xFFFF;
++        hlpr->mask.dst.protonum = 0xFFFF;
++        hlpr->max_expected = max_outstanding;
++        hlpr->timeout = setup_timeout;
++        hlpr->flags = IP_CT_HELPER_F_REUSE_EXPECT;
++        hlpr->me = ip_conntrack_rtsp;
++        hlpr->help = help;
++
++        tmpname = &rtsp_names[i][0];
++        if (ports[i] == RTSP_PORT)
++        {
++            sprintf(tmpname, "rtsp");
++        }
++        else
++        {
++            sprintf(tmpname, "rtsp-%d", i);
++        }
++        hlpr->name = tmpname;
++
++        DEBUGP("port #%d: %d\n", i, ports[i]);
++
++        ret = ip_conntrack_helper_register(hlpr);
++
++        if (ret)
++        {
++            printk("ip_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
++            fini();
++            return -EBUSY;
++        }
++        num_ports++;
++    }
++    return 0;
++}
++
++#ifdef CONFIG_IP_NF_NAT_NEEDED
++EXPORT_SYMBOL(ip_rtsp_lock);
++#endif
++
++module_init(init);
++module_exit(fini);
+diff -urN linux-2.4.32.orig/net/ipv4/netfilter/ip_nat_rtsp.c linux-2.4.32/net/ipv4/netfilter/ip_nat_rtsp.c
+--- linux-2.4.32.orig/net/ipv4/netfilter/ip_nat_rtsp.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.32/net/ipv4/netfilter/ip_nat_rtsp.c	2005-12-29 12:18:26.000000000 +0100
+@@ -0,0 +1,621 @@
++/*
++ * RTSP extension for TCP NAT alteration
++ * (C) 2003 by Tom Marshall <tmarshall@real.com>
++ * 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 ip_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/netfilter_ipv4.h>
++#include <linux/ip.h>
++#include <linux/tcp.h>
++#include <linux/kernel.h>
++#include <net/tcp.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_rtsp.h>
++#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
++
++#include <linux/inet.h>
++#include <linux/ctype.h>
++#define NF_NEED_STRNCASECMP
++#define NF_NEED_STRTOU16
++#include <linux/netfilter_helpers.h>
++#define NF_NEED_MIME_NEXTLINE
++#include <linux/netfilter_mime.h>
++
++#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
++#ifdef IP_NF_RTSP_DEBUG
++#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
++#else
++#define DEBUGP(fmt, args...)
++#endif
++
++#define MAX_PORTS       8
++#define DSTACT_AUTO     0
++#define DSTACT_STRIP    1
++#define DSTACT_NONE     2
++
++static int      ports[MAX_PORTS];
++static char*    stunaddr = NULL;
++static char*    destaction = NULL;
++
++static int       num_ports = 0;
++static u_int32_t extip = 0;
++static int       dstact = 0;
++
++MODULE_AUTHOR("Tom Marshall <tmarshall@real.com>");
++MODULE_DESCRIPTION("RTSP network address translation module");
++MODULE_LICENSE("GPL");
++#ifdef MODULE_PARM
++MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
++MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
++MODULE_PARM(stunaddr, "s");
++MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
++MODULE_PARM(destaction, "s");
++MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
++#endif
++
++/* protects rtsp part of conntracks */
++DECLARE_LOCK_EXTERN(ip_rtsp_lock);
++
++#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  = (struct iphdr*)skb->nh.iph;
++    struct tcphdr*  tcph = (struct tcphdr*)((char*)iph + iph->ihl*4);
++
++    *pptcpdata = (char*)tcph + tcph->doff*4;
++    *ptcpdatalen = ((char*)skb->h.raw + skb->len) - *pptcpdata;
++}
++
++/*** nat functions ***/
++
++/*
++ * Mangle the "Transport:" header:
++ *   - Replace all occurences of "client_port=<spec>"
++ *   - Handle destination parameter
++ *
++ * In:
++ *   ct, ctinfo = conntrack context
++ *   pskb       = 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(struct ip_conntrack* ct, enum ip_conntrack_info ctinfo,
++                 struct ip_conntrack_expect* exp,
++                 struct sk_buff** pskb, 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) */
++    u_int32_t   newip;
++    u_int16_t   loport, hiport;
++    uint        off = 0;
++    uint        diff;           /* Number of bytes we removed */
++
++    struct ip_ct_rtsp_expect* prtspexp = &exp->help.exp_rtsp_info;
++    struct ip_conntrack_tuple t;
++
++    char    szextaddr[15+1];
++    uint    extaddrlen;
++    int     is_stun;
++
++    get_skb_tcpdata(*pskb, &ptcp, &tcplen);
++    ptran = ptcp+tranoff;
++
++    if (tranoff+tranlen > tcplen || tcplen-tranoff < tranlen ||
++        tranlen < 10 || !iseol(ptran[tranlen-1]) ||
++        nf_strncasecmp(ptran, "Transport:", 10) != 0)
++    {
++        INFOP("sanity check failed\n");
++        return 0;
++    }
++    off += 10;
++    SKIP_WSPACE(ptcp+tranoff, tranlen, off);
++
++    newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
++    t = exp->tuple;
++    t.dst.ip = newip;
++
++    extaddrlen = extip ? sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(extip))
++                       : sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(newip));
++    DEBUGP("stunaddr=%s (%s)\n", szextaddr, (extip?"forced":"auto"));
++
++    rbuf1len = rbufalen = 0;
++    switch (prtspexp->pbtype)
++    {
++    case pb_single:
++        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
++        {
++            t.dst.u.udp.port = htons(loport);
++            if (ip_conntrack_change_expect(exp, &t) == 0)
++            {
++                DEBUGP("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? */
++        {
++            t.dst.u.udp.port = htons(loport);
++            if (ip_conntrack_change_expect(exp, &t) == 0)
++            {
++                hiport = loport + ~exp->mask.dst.u.udp.port;
++                DEBUGP("using ports %hu-%hu\n", loport, hiport);
++                break;
++            }
++        }
++        if (loport != 0)
++        {
++            rbuf1len = sprintf(rbuf1, "%hu", loport);
++            rbufalen = sprintf(rbufa, "%hu-%hu", loport, loport+1);
++        }
++        break;
++    case pb_discon:
++        for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
++        {
++            t.dst.u.udp.port = htons(loport);
++            if (ip_conntrack_change_expect(exp, &t) == 0)
++            {
++                DEBUGP("using port %hu (1 of 2)\n", loport);
++                break;
++            }
++        }
++        for (hiport = prtspexp->hiport; hiport != 0; hiport++) /* XXX: improper wrap? */
++        {
++            t.dst.u.udp.port = htons(hiport);
++            if (ip_conntrack_change_expect(exp, &t) == 0)
++            {
++                DEBUGP("using port %hu (2 of 2)\n", hiport);
++                break;
++            }
++        }
++        if (loport != 0 && hiport != 0)
++        {
++            rbuf1len = sprintf(rbuf1, "%hu", loport);
++            if (hiport == loport+1)
++            {
++                rbufalen = sprintf(rbufa, "%hu-%hu", loport, hiport);
++            }
++            else
++            {
++                rbufalen = sprintf(rbufa, "%hu/%hu", loport, hiport);
++            }
++        }
++        break;
++    }
++
++    if (rbuf1len == 0)
++    {
++        return 0;   /* cannot get replacement port(s) */
++    }
++
++    /* Transport: tran;field;field=val,tran;field;field=val,... */
++    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-ptcp;
++
++        /*
++         * 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))
++                {
++                    diff = nextfieldoff-off;
++                    if (!ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
++                                                         off, diff, NULL, 0))
++                    {
++                        /* mangle failed, all we can do is bail */
++                        return 0;
++                    }
++                    get_skb_tcpdata(*pskb, &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)
++                {
++                    DEBUGP("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 (!ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
++                                              origoff, origlen, rbuf, rbuflen))
++                    {
++                        /* mangle failed, all we can do is bail */
++                        return 0;
++                    }
++                    get_skb_tcpdata(*pskb, &ptcp, &tcplen);
++                    ptran = ptcp+tranoff;
++                    tranlen -= diff;
++                    nextparamoff -= diff;
++                    nextfieldoff -= diff;
++                }
++            }
++
++            off = nextfieldoff;
++        }
++
++        off = nextparamoff;
++    }
++
++    return 1;
++}
++
++static unsigned int
++expected(struct sk_buff **pskb, uint hooknum, struct ip_conntrack* ct, struct ip_nat_info* info)
++{
++    struct ip_nat_multi_range mr;
++    u_int32_t newdstip, newsrcip, newip;
++
++    struct ip_conntrack *master = master_ct(ct);
++
++    IP_NF_ASSERT(info);
++    IP_NF_ASSERT(master);
++
++    IP_NF_ASSERT(!(info->initialized & (1 << HOOK2MANIP(hooknum))));
++
++    newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
++    newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
++    newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
++
++    DEBUGP("newsrcip=%u.%u.%u.%u, newdstip=%u.%u.%u.%u, newip=%u.%u.%u.%u\n",
++           NIPQUAD(newsrcip), NIPQUAD(newdstip), 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;
++
++    return ip_nat_setup_info(ct, &mr, hooknum);
++}
++
++static uint
++help_out(struct ip_conntrack* ct, enum ip_conntrack_info ctinfo,
++         struct ip_conntrack_expect* exp, struct sk_buff** pskb)
++{
++    char*   ptcp;
++    uint    tcplen;
++    uint    hdrsoff;
++    uint    hdrslen;
++    uint    lineoff;
++    uint    linelen;
++    uint    off;
++
++    struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
++    struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
++
++    struct ip_ct_rtsp_expect* prtspexp = &exp->help.exp_rtsp_info;
++
++    get_skb_tcpdata(*pskb, &ptcp, &tcplen);
++
++    hdrsoff = exp->seq - ntohl(tcph->seq);
++    hdrslen = prtspexp->len;
++    off = hdrsoff;
++
++    while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen))
++    {
++        if (linelen == 0)
++        {
++            break;
++        }
++        if (off > hdrsoff+hdrslen)
++        {
++            INFOP("!! overrun !!");
++            break;
++        }
++        DEBUGP("hdr: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
++
++        if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0)
++        {
++            uint oldtcplen = tcplen;
++            if (!rtsp_mangle_tran(ct, ctinfo, exp, pskb, lineoff, linelen))
++            {
++                break;
++            }
++            get_skb_tcpdata(*pskb, &ptcp, &tcplen);
++            hdrslen -= (oldtcplen-tcplen);
++            off -= (oldtcplen-tcplen);
++            lineoff -= (oldtcplen-tcplen);
++            linelen -= (oldtcplen-tcplen);
++            DEBUGP("rep: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
++        }
++    }
++
++    return NF_ACCEPT;
++}
++
++static uint
++help_in(struct ip_conntrack* ct, enum ip_conntrack_info ctinfo,
++         struct ip_conntrack_expect* exp, struct sk_buff** pskb)
++{
++    /* XXX: unmangle */
++    return NF_ACCEPT;
++}
++
++static uint
++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)
++{
++    struct iphdr*  iph  = (struct iphdr*)(*pskb)->nh.iph;
++    struct tcphdr* tcph = (struct tcphdr*)((char*)iph + iph->ihl * 4);
++    uint datalen;
++    int dir;
++    struct ip_ct_rtsp_expect* ct_rtsp_info;
++    int rc = NF_ACCEPT;
++
++    if (ct == NULL || exp == NULL || info == NULL || pskb == NULL)
++    {
++        DEBUGP("!! null ptr (%p,%p,%p,%p) !!\n", ct, exp, info, pskb);
++        return NF_ACCEPT;
++    }
++
++    ct_rtsp_info = &exp->help.exp_rtsp_info;
++
++    /*
++     * 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("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;
++    }
++    DEBUGP("got beyond not touching\n");
++
++    datalen = (*pskb)->len - iph->ihl * 4 - tcph->doff * 4;
++
++    LOCK_BH(&ip_rtsp_lock);
++    /* Ensure the packet contains all of the marked data */
++    if (!between(exp->seq + ct_rtsp_info->len,
++                 ntohl(tcph->seq), ntohl(tcph->seq) + datalen))
++    {
++        /* Partial retransmission?  Probably a hacker. */
++        if (net_ratelimit())
++        {
++            INFOP("partial packet %u/%u in %u/%u\n",
++                   exp->seq, ct_rtsp_info->len, ntohl(tcph->seq), ntohl(tcph->seq) + datalen);
++        }
++        UNLOCK_BH(&ip_rtsp_lock);
++        return NF_DROP;
++    }
++
++    switch (dir)
++    {
++    case IP_CT_DIR_ORIGINAL:
++        rc = help_out(ct, ctinfo, exp, pskb);
++        break;
++    case IP_CT_DIR_REPLY:
++        rc = help_in(ct, ctinfo, exp, pskb);
++        break;
++    }
++    UNLOCK_BH(&ip_rtsp_lock);
++
++    return rc;
++}
++
++static struct ip_nat_helper ip_nat_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++)
++    {
++        DEBUGP("unregistering helper for port %d\n", ports[i]);
++        ip_nat_helper_unregister(&ip_nat_rtsp_helpers[i]);
++    }
++}
++
++static int __init
++init(void)
++{
++    int ret = 0;
++    int i;
++    struct ip_nat_helper* hlpr;
++    char* tmpname;
++
++    printk("ip_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
++
++    if (ports[0] == 0)
++    {
++        ports[0] = RTSP_PORT;
++    }
++
++    for (i = 0; (i < MAX_PORTS) && ports[i] != 0; i++)
++    {
++        hlpr = &ip_nat_rtsp_helpers[i];
++        memset(hlpr, 0, sizeof(struct ip_nat_helper));
++
++        hlpr->tuple.dst.protonum = IPPROTO_TCP;
++        hlpr->tuple.src.u.tcp.port = htons(ports[i]);
++        hlpr->mask.src.u.tcp.port = 0xFFFF;
++        hlpr->mask.dst.protonum = 0xFFFF;
++        hlpr->help = help;
++        hlpr->flags = 0;
++        hlpr->me = THIS_MODULE;
++        hlpr->expect = expected;
++
++        tmpname = &rtsp_names[i][0];
++        if (ports[i] == RTSP_PORT)
++        {
++                sprintf(tmpname, "rtsp");
++        }
++        else
++        {
++                sprintf(tmpname, "rtsp-%d", i);
++        }
++        hlpr->name = tmpname;
++
++        DEBUGP("registering helper for port %d: name %s\n", ports[i], hlpr->name);
++        ret = ip_nat_helper_register(hlpr);
++
++        if (ret)
++        {
++            printk("ip_nat_rtsp: error registering helper for port %d\n", ports[i]);
++            fini();
++            return 1;
++        }
++        num_ports++;
++    }
++    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 ret;
++}
++
++module_init(init);
++module_exit(fini);
+diff -urN linux-2.4.32.orig/net/ipv4/netfilter/Makefile linux-2.4.32/net/ipv4/netfilter/Makefile
+--- linux-2.4.32.orig/net/ipv4/netfilter/Makefile	2005-12-29 12:17:55.000000000 +0100
++++ linux-2.4.32/net/ipv4/netfilter/Makefile	2005-12-29 12:18:26.000000000 +0100
+@@ -32,6 +32,14 @@
+ obj-$(CONFIG_IP_NF_CONNTRACK) += ip_conntrack.o
+ 
+ # connection tracking helpers
++
++# rtsp protocol support
++obj-$(CONFIG_IP_NF_RTSP) += ip_conntrack_rtsp.o
++ifdef CONFIG_IP_NF_NAT_RTSP
++       export-objs += ip_conntrack_rtsp.o
++endif
++obj-$(CONFIG_IP_NF_NAT_RTSP) += ip_nat_rtsp.o
++
+ obj-$(CONFIG_IP_NF_AMANDA) += ip_conntrack_amanda.o
+ ifdef CONFIG_IP_NF_AMANDA
+ 	export-objs += ip_conntrack_amanda.o
diff --git a/openwrt/target/linux/netfilter.mk b/openwrt/target/linux/netfilter.mk
index 401632033..f272a8548 100644
--- a/openwrt/target/linux/netfilter.mk
+++ b/openwrt/target/linux/netfilter.mk
@@ -62,6 +62,8 @@ IPT_NAT_EXTRA-$(CONFIG_IP_NF_H323) += ip_conntrack_h323
 IPT_NAT_EXTRA-$(CONFIG_IP_NF_NAT_H323) += ip_nat_h323
 IPT_NAT_EXTRA-$(CONFIG_IP_NF_MMS) += ip_conntrack_mms
 IPT_NAT_EXTRA-$(CONFIG_IP_NF_NAT_MMS) += ip_nat_mms
+IPT_NAT_EXTRA-$(CONFIG_IP_NF_RTSP) += ip_conntrack_rtsp
+IPT_NAT_EXTRA-$(CONFIG_IP_NF_NAT_RTSP) += ip_nat_rtsp
 IPT_NAT_EXTRA-$(CONFIG_IP_NF_PPTP) += ip_conntrack_pptp
 IPT_NAT_EXTRA-$(CONFIG_IP_NF_NAT_PPTP) += ip_nat_pptp
 IPT_NAT_EXTRA-$(CONFIG_IP_NF_NAT_SNMP_BASIC) += ip_nat_snmp_basic