From 815e1cfba0c1f7a9adda5070a2c1e7a63b796cb0 Mon Sep 17 00:00:00 2001 From: florian Date: Thu, 29 Dec 2005 11:57:06 +0000 Subject: Added support for RTSP connection tracking modules git-svn-id: svn://svn.openwrt.org/openwrt/trunk@2794 3c298f89-4303-0410-b956-a3cf2f4a3e73 --- .../patches/generic/617-netfilter_nat_rtsp.patch | 1538 ++++++++++++++++++++ 1 file changed, 1538 insertions(+) create mode 100644 openwrt/target/linux/linux-2.4/patches/generic/617-netfilter_nat_rtsp.patch (limited to 'openwrt/target/linux/linux-2.4/patches/generic') 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 0000000000..28bf664423 --- /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 ++#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 + #include + + #include +@@ -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 ++ * 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 ++ ++#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 ++#include ++ ++/* ++ * 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 ++ * 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_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 ++#include ++#include ++#include ++#include ++#include ++ ++#include ++#include ++#include ++ ++#include ++#define NF_NEED_STRNCASECMP ++#define NF_NEED_STRTOU16 ++#define NF_NEED_STRTOU32 ++#define NF_NEED_NEXTLINE ++#include ++#define NF_NEED_MIME_NEXTLINE ++#include ++ ++#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 "); ++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 ++ * 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 ++ * stunaddr=
++ * 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 ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#include ++#include ++#define NF_NEED_STRNCASECMP ++#define NF_NEED_STRTOU16 ++#include ++#define NF_NEED_MIME_NEXTLINE ++#include ++ ++#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 "); ++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=" ++ * - 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 -- cgit v1.2.3