* rtsp-conntrack without needing NAT
@ 2006-09-14 12:51 Steven Van Acker
2006-09-15 4:40 ` Patrick McHardy
0 siblings, 1 reply; 5+ messages in thread
From: Steven Van Acker @ 2006-09-14 12:51 UTC (permalink / raw)
To: Netfilter Development Mailinglist; +Cc: Mickael Marchand, kulnet
[-- Attachment #1: Type: text/plain, Size: 769 bytes --]
Hi,
the rtsp-conntrack patch I found at
http://www.freenux.org/~mm/rtsp/2.6.15-rtsp.patch applies nicely to the
kernels I compile with Full NAT support, but not without.
This is caused by calls to NAT functions from within ip_conntrack_rtsp.c
For the past couple days, I've tried to make sense of connectiontracking
and NAT code and I believe my version of the patch should fix the
problem.
I've compiled it without problems, and the modules load.
But since I've never really messed with kernel code before, I don't know
if I broke anything or introduced bugs anywhere.
Maybe someone with more experience can look over the patch and see if it
makes sense ?
kind regards,
-- Steven Van Acker
--
My amazon wishlist:
http://www.amazon.com/gp/registry/1DB4XNEIEQBPB
[-- Attachment #2: rtsp-conntrack-2.6.17.13.patch --]
[-- Type: text/plain, Size: 41924 bytes --]
diff -urN linux-2.6.15.orig/include/linux/netfilter_helpers.h linux-2.6.15/include/linux/netfilter_helpers.h
--- linux-2.6.15.orig/include/linux/netfilter_helpers.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.15/include/linux/netfilter_helpers.h 2006-02-20 20:55:02.000000000 +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-2.6.15.orig/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h linux-2.6.15/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h
--- linux-2.6.15.orig/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.15/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h 2006-02-20 20:55:36.000000000 +0100
@@ -0,0 +1,63 @@
+/*
+ * 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 1
+#define IP_NF_RTSP_VERSION "0.6.21"
+
+#ifdef __KERNEL__
+/* port block types */
+typedef enum {
+ pb_single, /* client_port=x */
+ pb_range, /* client_port=x-y */
+ pb_discon /* client_port=x/y (rtspbis) */
+} portblock_t;
+
+/* We record seq number and length of rtsp headers here, all in host order. */
+
+/*
+ * This structure is per expected connection. It is a member of struct
+ * ip_conntrack_expect. The TCP SEQ for the conntrack expect is stored
+ * there and we are expected to only store the length of the data which
+ * needs replaced. If a packet contains multiple RTSP messages, we create
+ * one expected connection per message.
+ *
+ * We use these variables to mark the entire header block. This may seem
+ * like overkill, but the nature of RTSP requires it. A header may appear
+ * multiple times in a message. We must treat two Transport headers the
+ * same as one Transport header with two entries.
+ */
+struct ip_ct_rtsp_expect
+{
+ u_int32_t len; /* length of header block */
+ portblock_t pbtype; /* Type of port block that was requested */
+ u_int16_t loport; /* Port that was requested, low or first */
+ u_int16_t hiport; /* Port that was requested, high or second */
+#if 0
+ uint method; /* RTSP method */
+ uint cseq; /* CSeq from request */
+#endif
+};
+
+extern unsigned int (*ip_nat_rtsp_hook)(struct sk_buff **pskb,
+ enum ip_conntrack_info ctinfo,
+ unsigned int matchoff, unsigned int matchlen,
+ struct ip_ct_rtsp_expect *expinfo,
+ struct ip_conntrack_expect *exp);
+
+extern void (*ip_nat_rtsp_hook_expectfn)(struct ip_conntrack *ct, struct ip_conntrack_expect *exp);
+
+#define RTSP_PORT 554
+
+#endif /* __KERNEL__ */
+
+#endif /* _IP_CONNTRACK_RTSP_H */
diff -urN linux-2.6.15.orig/include/linux/netfilter_mime.h linux-2.6.15/include/linux/netfilter_mime.h
--- linux-2.6.15.orig/include/linux/netfilter_mime.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.15/include/linux/netfilter_mime.h 2006-02-20 20:55:02.000000000 +0100
@@ -0,0 +1,89 @@
+/*
+ * MIME functions for netfilter modules. This file provides implementations
+ * for basic MIME parsing. MIME headers are used in many protocols, such as
+ * HTTP, RTSP, SIP, etc.
+ *
+ * gcc will warn for defined but unused functions, so we only include the
+ * functions requested. The following macros are used:
+ * NF_NEED_MIME_NEXTLINE nf_mime_nextline()
+ */
+#ifndef _NETFILTER_MIME_H
+#define _NETFILTER_MIME_H
+
+/* Only include these functions for kernel code. */
+#ifdef __KERNEL__
+
+#include <linux/ctype.h>
+
+/*
+ * Given a buffer and length, advance to the next line and mark the current
+ * line. If the current line is empty, *plinelen will be set to zero. If
+ * not, it will be set to the actual line length (including CRLF).
+ *
+ * 'line' in this context means logical line (includes LWS continuations).
+ * Returns 1 on success, 0 on failure.
+ */
+#ifdef NF_NEED_MIME_NEXTLINE
+static int
+nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
+{
+ uint off = *poff;
+ uint physlen = 0;
+ int is_first_line = 1;
+
+ if (off >= len)
+ {
+ return 0;
+ }
+
+ do
+ {
+ while (p[off] != '\n')
+ {
+ if (len-off <= 1)
+ {
+ return 0;
+ }
+
+ physlen++;
+ off++;
+ }
+
+ /* if we saw a crlf, physlen needs adjusted */
+ if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
+ {
+ physlen--;
+ }
+
+ /* advance past the newline */
+ off++;
+
+ /* check for an empty line */
+ if (physlen == 0)
+ {
+ break;
+ }
+
+ /* check for colon on the first physical line */
+ if (is_first_line)
+ {
+ is_first_line = 0;
+ if (memchr(p+(*poff), ':', physlen) == NULL)
+ {
+ return 0;
+ }
+ }
+ }
+ while (p[off] == ' ' || p[off] == '\t');
+
+ *plineoff = *poff;
+ *plinelen = (physlen == 0) ? 0 : (off - *poff);
+ *poff = off;
+
+ return 1;
+}
+#endif /* NF_NEED_MIME_NEXTLINE */
+
+#endif /* __KERNEL__ */
+
+#endif /* _NETFILTER_MIME_H */
diff -urN linux-2.6.15.orig/net/ipv4/netfilter/Kconfig linux-2.6.15/net/ipv4/netfilter/Kconfig
--- linux-2.6.15.orig/net/ipv4/netfilter/Kconfig 2006-01-03 04:21:10.000000000 +0100
+++ linux-2.6.15/net/ipv4/netfilter/Kconfig 2006-02-20 20:56:41.000000000 +0100
@@ -842,5 +842,21 @@
Allows altering the ARP packet payload: source and destination
hardware and network addresses.
+config IP_NF_NAT_RTSP
+ tristate
+ depends on IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
+ default IP_NF_NAT if IP_NF_RTSP=y
+ default m if IP_NF_RTSP=m
+
+config IP_NF_RTSP
+ tristate ' RTSP protocol support'
+ depends on IP_NF_CONNTRACK
+ help
+ 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'.
+
endmenu
diff -urN linux-2.6.15.orig/net/ipv4/netfilter/Makefile linux-2.6.15/net/ipv4/netfilter/Makefile
--- linux-2.6.15.orig/net/ipv4/netfilter/Makefile 2006-01-03 04:21:10.000000000 +0100
+++ linux-2.6.15/net/ipv4/netfilter/Makefile 2006-02-20 20:56:48.000000000 +0100
@@ -22,3 +22,5 @@
obj-$(CONFIG_IP_NF_PPTP) += ip_conntrack_pptp.o
+obj-$(CONFIG_IP_NF_RTSP) += ip_conntrack_rtsp.o
+obj-$(CONFIG_IP_NF_NAT_RTSP) += ip_nat_rtsp.o
obj-$(CONFIG_IP_NF_AMANDA) += ip_conntrack_amanda.o
obj-$(CONFIG_IP_NF_TFTP) += ip_conntrack_tftp.o
diff -urN linux-2.6.15.orig/net/ipv4/netfilter/ip_conntrack_rtsp.c linux-2.6.15/net/ipv4/netfilter/ip_conntrack_rtsp.c
--- linux-2.6.15.orig/net/ipv4/netfilter/ip_conntrack_rtsp.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.15/net/ipv4/netfilter/ip_conntrack_rtsp.c 2006-02-20 20:57:02.000000000 +0100
@@ -0,0 +1,526 @@
+/*
+ * 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).
+ *
+ * 2005-02-13: Harald Welte <laforge@netfilter.org>
+ * - port to 2.6
+ * - update to recent post-2.6.11 api changes
+ * 2006-09-14: Steven Van Acker <deepstar@singularity.be>
+ * - removed calls to NAT code from conntrack helper: NAT no longer needed to use rtsp-conntrack
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/ip.h>
+#include <linux/inet.h>
+#include <net/checksum.h>
+#include <net/tcp.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 IP_NF_RTSP_DEBUG
+#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");
+module_param_array(ports, int, &num_ports, 0400);
+MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
+module_param(max_outstanding, int, 0400);
+MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
+module_param(setup_timeout, int, 0400);
+MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
+
+static char *rtsp_buffer;
+static DEFINE_SPINLOCK(rtsp_buffer_lock);
+
+unsigned int (*ip_nat_rtsp_hook)(struct sk_buff **pskb,
+ enum ip_conntrack_info ctinfo,
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
+ struct ip_conntrack_expect *exp);
+void (*ip_nat_rtsp_hook_expectfn)(struct ip_conntrack *ct, struct ip_conntrack_expect *exp);
+
+EXPORT_SYMBOL_GPL(ip_nat_rtsp_hook);
+
+/*
+ * Max mappings we will allow for one RTSP connection (for RTP, the number
+ * of allocated ports is twice this value). Note that SMIL burns a lot of
+ * ports so keep this reasonably high. If this is too low, you will see a
+ * lot of "no free client map entries" messages.
+ */
+#define MAX_PORT_MAPS 16
+
+/*** default port list was here in the masq code: 554, 3030, 4040 ***/
+
+#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
+
+/*
+ * Parse an RTSP packet.
+ *
+ * Returns zero if parsing failed.
+ *
+ * Parameters:
+ * IN ptcp tcp data pointer
+ * IN tcplen tcp data len
+ * IN/OUT ptcpoff points to current tcp offset
+ * OUT phdrsoff set to offset of rtsp headers
+ * OUT phdrslen set to length of rtsp headers
+ * OUT pcseqoff set to offset of CSeq header
+ * OUT pcseqlen set to length of CSeq header
+ */
+static int
+rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
+ uint* phdrsoff, uint* phdrslen,
+ uint* pcseqoff, uint* pcseqlen,
+ uint* transoff, uint* translen)
+{
+ uint entitylen = 0;
+ uint lineoff;
+ uint linelen;
+
+ if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
+ return 0;
+
+ *phdrsoff = *ptcpoff;
+ while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen)) {
+ if (linelen == 0) {
+ if (entitylen > 0)
+ *ptcpoff += min(entitylen, tcplen - *ptcpoff);
+ break;
+ }
+ if (lineoff+linelen > tcplen) {
+ INFOP("!! overrun !!\n");
+ break;
+ }
+
+ if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0) {
+ *pcseqoff = lineoff;
+ *pcseqlen = linelen;
+ }
+
+ if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0) {
+ *transoff = lineoff;
+ *translen = linelen;
+ }
+
+ if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0) {
+ uint off = lineoff+15;
+ SKIP_WSPACE(ptcp+lineoff, linelen, off);
+ nf_strtou32(ptcp+off, &entitylen);
+ }
+ }
+ *phdrslen = (*ptcpoff) - (*phdrsoff);
+
+ return 1;
+}
+
+/*
+ * Find lo/hi client ports (if any) in transport header
+ * In:
+ * ptcp, tcplen = packet
+ * tranoff, tranlen = buffer to search
+ *
+ * Out:
+ * pport_lo, pport_hi = lo/hi ports (host endian)
+ *
+ * Returns nonzero if any client ports found
+ *
+ * Note: it is valid (and expected) for the client to request multiple
+ * transports, so we need to parse the entire line.
+ */
+static int
+rtsp_parse_transport(char* ptran, uint tranlen,
+ struct ip_ct_rtsp_expect* prtspexp)
+{
+ int rc = 0;
+ uint off = 0;
+
+ if (tranlen < 10 || !iseol(ptran[tranlen-1]) ||
+ nf_strncasecmp(ptran, "Transport:", 10) != 0) {
+ 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 {
+ DEBUGP("lo port found : %hu\n", port);
+ prtspexp->loport = prtspexp->hiport = port;
+ if (ptran[off] == '-') {
+ off++;
+ numlen = nf_strtou16(ptran+off, &port);
+ off += numlen;
+ prtspexp->pbtype = pb_range;
+ prtspexp->hiport = port;
+
+ // If we have a range, assume rtp:
+ // loport must be even, hiport must be loport+1
+ if ((prtspexp->loport & 0x0001) != 0 ||
+ prtspexp->hiport != prtspexp->loport+1) {
+ 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;
+}
+
+void expected(struct ip_conntrack* ct, struct ip_conntrack_expect *exp)
+{
+ if(ip_nat_rtsp_hook_expectfn) {
+ ip_nat_rtsp_hook_expectfn(ct,exp);
+ }
+}
+
+/*** conntrack functions ***/
+
+/* outbound packet: client->server */
+static inline int
+help_out(struct sk_buff **pskb, unsigned char *rb_ptr, unsigned int datalen,
+ struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
+{
+ struct ip_ct_rtsp_expect expinfo;
+
+ int dir = CTINFO2DIR(ctinfo); /* = IP_CT_DIR_ORIGINAL */
+ //struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
+ //uint tcplen = pktlen - iph->ihl * 4;
+ char* pdata = rb_ptr;
+ //uint datalen = tcplen - tcph->doff * 4;
+ uint dataoff = 0;
+ int ret = NF_ACCEPT;
+
+ struct ip_conntrack_expect *exp;
+
+ memset(&expinfo, 0, sizeof(expinfo));
+
+ while (dataoff < datalen) {
+ uint cmdoff = dataoff;
+ uint hdrsoff = 0;
+ uint hdrslen = 0;
+ uint cseqoff = 0;
+ uint cseqlen = 0;
+ uint transoff = 0;
+ uint translen = 0;
+ uint off;
+
+ if (!rtsp_parse_message(pdata, datalen, &dataoff,
+ &hdrsoff, &hdrslen,
+ &cseqoff, &cseqlen,
+ &transoff, &translen))
+ break; /* not a valid message */
+
+ if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
+ continue; /* not a SETUP message */
+ DEBUGP("found a setup message\n");
+
+ off = 0;
+ if(translen) {
+ rtsp_parse_transport(pdata+transoff, translen, &expinfo);
+ }
+
+ if (expinfo.loport == 0) {
+ DEBUGP("no udp transports found\n");
+ continue; /* no udp transports found */
+ }
+
+ DEBUGP("udp transport found, ports=(%d,%hu,%hu)\n",
+ (int)expinfo.pbtype, expinfo.loport, expinfo.hiport);
+
+ exp = ip_conntrack_expect_alloc(ct);
+ if (!exp) {
+ ret = NF_DROP;
+ goto out;
+ }
+
+ exp->master = ct;
+
+ exp->expectfn = expected;
+ exp->flags = 0;
+
+ exp->tuple = ((struct ip_conntrack_tuple)
+ {
+ { ct->tuplehash[!dir].tuple.src.ip,
+ { 0 }
+ },
+ {
+ ct->tuplehash[!dir].tuple.dst.ip,
+ { .udp = { htons(expinfo.loport) } },
+ IPPROTO_UDP
+ }
+ });
+ exp->mask = ((struct ip_conntrack_tuple)
+ {
+ { 0,
+ { 0 }
+ },
+ {
+ 0xFFFFFFFF,
+ { .udp = { 0xFFFF } }, 0xFF
+ }
+ });
+ if (expinfo.pbtype == pb_range) {
+ DEBUGP("Changing expectation mask to handle multiple ports\n");
+ exp->mask.dst.u.udp.port = 0xfffe;
+ }
+
+ DEBUGP("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
+ NIPQUAD(exp->tuple.src.ip),
+ ntohs(exp->tuple.src.u.udp.port),
+ NIPQUAD(exp->tuple.dst.ip),
+ ntohs(exp->tuple.dst.u.udp.port));
+
+ if (ip_nat_rtsp_hook)
+ /* pass the request off to the nat helper */
+ ret = ip_nat_rtsp_hook(pskb, ctinfo, hdrsoff, hdrslen, &expinfo, exp);
+ else if (ip_conntrack_expect_related(exp) != 0) {
+ INFOP("ip_conntrack_expect_related failed\n");
+ ret = NF_DROP;
+ }
+ ip_conntrack_expect_put(exp);
+ goto out;
+ }
+out:
+
+ return ret;
+}
+
+/* inbound packet: server->client */
+static inline int
+help_in(struct sk_buff **pskb, size_t pktlen,
+ struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
+{
+ return NF_ACCEPT;
+}
+
+static int help(struct sk_buff **pskb, struct ip_conntrack* ct, enum
+ ip_conntrack_info ctinfo)
+{
+ struct tcphdr _tcph, *th;
+ unsigned int dataoff, datalen;
+ char *rb_ptr;
+ int ret = NF_DROP;
+
+ /* Until there's been traffic both ways, don't look in packets. */
+ if (ctinfo != IP_CT_ESTABLISHED &&
+ ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
+ DEBUGP("conntrackinfo = %u\n", ctinfo);
+ return NF_ACCEPT;
+ }
+
+ /* Not whole TCP header? */
+ th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
+ sizeof(_tcph), &_tcph);
+ if (!th)
+ return NF_ACCEPT;
+
+ /* No data ? */
+ dataoff = (*pskb)->nh.iph->ihl*4 + th->doff*4;
+ datalen = (*pskb)->len - dataoff;
+ if (dataoff >= (*pskb)->len)
+ return NF_ACCEPT;
+
+ spin_lock_bh(&rtsp_buffer_lock);
+ rb_ptr = skb_header_pointer(*pskb, dataoff,
+ (*pskb)->len - dataoff, rtsp_buffer);
+ BUG_ON(rb_ptr == NULL);
+
+#if 0
+ /* Checksum invalid? Ignore. */
+ /* FIXME: Source route IP option packets --RR */
+ if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
+ csum_partial((char*)tcph, tcplen, 0)))
+ {
+ DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
+ tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
+ return NF_ACCEPT;
+ }
+#endif
+
+ switch (CTINFO2DIR(ctinfo)) {
+ case IP_CT_DIR_ORIGINAL:
+ ret = help_out(pskb, rb_ptr, datalen, ct, ctinfo);
+ break;
+ case IP_CT_DIR_REPLY:
+ DEBUGP("IP_CT_DIR_REPLY\n");
+ /* inbound packet: server->client */
+ ret = NF_ACCEPT;
+ break;
+ }
+
+ spin_unlock_bh(&rtsp_buffer_lock);
+
+ return ret;
+}
+
+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]);
+ }
+ kfree(rtsp_buffer);
+}
+
+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;
+ }
+
+ rtsp_buffer = kmalloc(65536, GFP_KERNEL);
+ if (!rtsp_buffer)
+ return -ENOMEM;
+
+ /* If no port given, default to standard rtsp port */
+ if (ports[0] == 0) {
+ ports[0] = RTSP_PORT;
+ }
+
+ 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 = 0xFF;
+ hlpr->max_expected = max_outstanding;
+ hlpr->timeout = setup_timeout;
+ hlpr->me = THIS_MODULE;
+ hlpr->help = help;
+
+ tmpname = &rtsp_names[i][0];
+ if (ports[i] == RTSP_PORT) {
+ sprintf(tmpname, "rtsp");
+ } else {
+ sprintf(tmpname, "rtsp-%d", i);
+ }
+ 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;
+}
+
+module_init(init);
+module_exit(fini);
+
+EXPORT_SYMBOL(ip_nat_rtsp_hook_expectfn);
+
diff -urN linux-2.6.15.orig/net/ipv4/netfilter/ip_nat_rtsp.c linux-2.6.15/net/ipv4/netfilter/ip_nat_rtsp.c
--- linux-2.6.15.orig/net/ipv4/netfilter/ip_nat_rtsp.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.15/net/ipv4/netfilter/ip_nat_rtsp.c 2006-02-20 20:57:06.000000000 +0100
@@ -0,0 +1,502 @@
+/*
+ * 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)
+#define IP_NF_RTSP_DEBUG
+#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 char* stunaddr = NULL;
+static char* destaction = NULL;
+
+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");
+module_param(stunaddr, charp, 0644);
+MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
+module_param(destaction, charp, 0644);
+MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
+
+#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
+
+/*** helper functions ***/
+
+static void
+get_skb_tcpdata(struct sk_buff* skb, char** pptcpdata, uint* ptcpdatalen)
+{
+ struct iphdr* iph = (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(enum ip_conntrack_info ctinfo,
+ struct ip_conntrack_expect* exp,
+ struct ip_ct_rtsp_expect* prtspexp,
+ 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_conntrack *ct = exp->master;
+ 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_expect_related(exp) == 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_expect_related(exp) == 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_expect_related(exp) == 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_expect_related(exp) == 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 */
+ ip_conntrack_unexpect_related(exp);
+ 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 */
+ ip_conntrack_unexpect_related(exp);
+ return 0;
+ }
+ get_skb_tcpdata(*pskb, &ptcp, &tcplen);
+ ptran = ptcp+tranoff;
+ tranlen -= diff;
+ nextparamoff -= diff;
+ nextfieldoff -= diff;
+ }
+ }
+
+ off = nextfieldoff;
+ }
+
+ off = nextparamoff;
+ }
+
+ return 1;
+}
+
+static uint
+help_out(struct sk_buff **pskb, enum ip_conntrack_info ctinfo,
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
+ struct ip_conntrack_expect* exp)
+{
+ 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);
+
+ get_skb_tcpdata(*pskb, &ptcp, &tcplen);
+ hdrsoff = matchoff;//exp->seq - ntohl(tcph->seq);
+ hdrslen = matchlen;
+ off = hdrsoff;
+ DEBUGP("NAT rtsp help_out\n");
+
+ 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;
+ DEBUGP("hdr: Transport\n");
+ if (!rtsp_mangle_tran(ctinfo, exp, prtspexp, pskb, lineoff, linelen))
+ {
+ DEBUGP("hdr: Transport mangle failed");
+ 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 unsigned int
+help(struct sk_buff **pskb, enum ip_conntrack_info ctinfo,
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
+ struct ip_conntrack_expect* exp)
+{
+ int dir = CTINFO2DIR(ctinfo);
+ int rc = NF_ACCEPT;
+
+ switch (dir)
+ {
+ case IP_CT_DIR_ORIGINAL:
+ rc = help_out(pskb, ctinfo, matchoff, matchlen, prtspexp, exp);
+ break;
+ case IP_CT_DIR_REPLY:
+ DEBUGP("unmangle ! %u\n", ctinfo);
+ /* XXX: unmangle */
+ rc = NF_ACCEPT;
+ break;
+ }
+ //UNLOCK_BH(&ip_rtsp_lock);
+
+ return rc;
+}
+
+static void expected(struct ip_conntrack* ct, struct ip_conntrack_expect *exp)
+{
+ struct ip_nat_multi_range_compat mr;
+ u_int32_t newdstip, newsrcip, newip;
+
+ struct ip_conntrack *master = master_ct(ct);
+
+ newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ //FIXME (how to port that ?)
+ //code from 2.4 : newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
+ newip = 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;
+
+ ip_nat_setup_info(ct, &mr.range[0], NF_IP_PRE_ROUTING);
+}
+
+
+static void __exit fini(void)
+{
+ ip_nat_rtsp_hook = NULL;
+ ip_nat_rtsp_hook_expectfn = NULL;
+ synchronize_net();
+}
+
+static int __init init(void)
+{
+ printk("ip_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
+
+ BUG_ON(ip_nat_rtsp_hook);
+ ip_nat_rtsp_hook = help;
+ ip_nat_rtsp_hook_expectfn = &expected;
+
+ if (stunaddr != NULL)
+ extip = in_aton(stunaddr);
+
+ if (destaction != NULL) {
+ if (strcmp(destaction, "auto") == 0)
+ dstact = DSTACT_AUTO;
+
+ if (strcmp(destaction, "strip") == 0)
+ dstact = DSTACT_STRIP;
+
+ if (strcmp(destaction, "none") == 0)
+ dstact = DSTACT_NONE;
+ }
+
+ return 0;
+}
+
+module_init(init);
+module_exit(fini);
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: rtsp-conntrack without needing NAT
2006-09-14 12:51 rtsp-conntrack without needing NAT Steven Van Acker
@ 2006-09-15 4:40 ` Patrick McHardy
2006-09-15 8:15 ` Steven Van Acker
0 siblings, 1 reply; 5+ messages in thread
From: Patrick McHardy @ 2006-09-15 4:40 UTC (permalink / raw)
To: Steven Van Acker
Cc: Netfilter Development Mailinglist, Mickael Marchand, kulnet
Steven Van Acker wrote:
> Hi,
>
> the rtsp-conntrack patch I found at
> http://www.freenux.org/~mm/rtsp/2.6.15-rtsp.patch applies nicely to the
> kernels I compile with Full NAT support, but not without.
>
> This is caused by calls to NAT functions from within ip_conntrack_rtsp.c
>
> For the past couple days, I've tried to make sense of connectiontracking
> and NAT code and I believe my version of the patch should fix the
> problem.
>
> I've compiled it without problems, and the modules load.
> But since I've never really messed with kernel code before, I don't know
> if I broke anything or introduced bugs anywhere.
>
> Maybe someone with more experience can look over the patch and see if it
> makes sense ?
You're more likely to find someone if you post your changes as a patch
to the original version.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: rtsp-conntrack without needing NAT
2006-09-15 4:40 ` Patrick McHardy
@ 2006-09-15 8:15 ` Steven Van Acker
2006-09-15 8:40 ` Steven Van Acker
2006-09-15 8:43 ` Steven Van Acker
0 siblings, 2 replies; 5+ messages in thread
From: Steven Van Acker @ 2006-09-15 8:15 UTC (permalink / raw)
To: Netfilter Development Mailinglist
Cc: Patrick McHardy, Mickael Marchand, kulnet
[-- Attachment #1: Type: text/plain, Size: 301 bytes --]
On Fri, Sep 15, 2006 at 06:40:12AM +0200, Patrick McHardy wrote:
>
> You're more likely to find someone if you post your changes as a patch
> to the original version.
>
Sorry about that. I recreated the patch based on
the latest pom-ng snapshot (patch-o-matic-ng-20060914)
kind regards,
-- Steven
[-- Attachment #2: patch-o-matic-ng-20060914-rtsp.patch --]
[-- Type: text/plain, Size: 31886 bytes --]
diff -Naur patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h patch-o-matic-ng-20060913-patched-rtsp/patchlets/rtsp-conntrack/linux-2.6.11/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h
--- patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h 2005-08-29 22:54:36.000000000 +0200
+++ patch-o-matic-ng-20060913-patched-rtsp/patchlets/rtsp-conntrack/linux-2.6.11/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h 2006-09-15 09:52:21.679949264 +0200
@@ -11,9 +11,10 @@
#ifndef _IP_CONNTRACK_RTSP_H
#define _IP_CONNTRACK_RTSP_H
-/* #define IP_NF_RTSP_DEBUG */
+//#define IP_NF_RTSP_DEBUG 1
#define IP_NF_RTSP_VERSION "0.6.21"
+#ifdef __KERNEL__
/* port block types */
typedef enum {
pb_single, /* client_port=x */
@@ -47,7 +48,13 @@
#endif
};
-#ifdef __KERNEL__
+extern unsigned int (*ip_nat_rtsp_hook)(struct sk_buff **pskb,
+ enum ip_conntrack_info ctinfo,
+ unsigned int matchoff, unsigned int matchlen,
+ struct ip_ct_rtsp_expect *expinfo,
+ struct ip_conntrack_expect *exp);
+
+extern void (*ip_nat_rtsp_hook_expectfn)(struct ip_conntrack *ct, struct ip_conntrack_expect *exp);
#define RTSP_PORT 554
diff -Naur patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_conntrack_rtsp.c patch-o-matic-ng-20060913-patched-rtsp/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_conntrack_rtsp.c
--- patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_conntrack_rtsp.c 2005-09-19 16:53:50.000000000 +0200
+++ patch-o-matic-ng-20060913-patched-rtsp/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_conntrack_rtsp.c 2006-09-15 09:52:55.341831880 +0200
@@ -22,12 +22,15 @@
* 2005-02-13: Harald Welte <laforge@netfilter.org>
* - port to 2.6
* - update to recent post-2.6.11 api changes
+ * 2006-09-14: Steven Van Acker <deepstar@singularity.be>
+ * - removed calls to NAT code from conntrack helper: NAT no longer needed to use rtsp-conntrack
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/ip.h>
+#include <linux/inet.h>
#include <net/checksum.h>
#include <net/tcp.h>
@@ -44,7 +47,7 @@
#include <linux/netfilter_mime.h>
#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
-
+#define IP_NF_RTSP_DEBUG
#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)
@@ -68,13 +71,15 @@
module_param(setup_timeout, int, 0400);
MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
-static char rtsp_buffer[65536];
+static char *rtsp_buffer;
static DEFINE_SPINLOCK(rtsp_buffer_lock);
unsigned int (*ip_nat_rtsp_hook)(struct sk_buff **pskb,
enum ip_conntrack_info ctinfo,
- struct ip_ct_rtsp_expect *expinfo,
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
struct ip_conntrack_expect *exp);
+void (*ip_nat_rtsp_hook_expectfn)(struct ip_conntrack *ct, struct ip_conntrack_expect *exp);
+
EXPORT_SYMBOL_GPL(ip_nat_rtsp_hook);
/*
@@ -106,49 +111,47 @@
static int
rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
uint* phdrsoff, uint* phdrslen,
- uint* pcseqoff, uint* pcseqlen)
+ uint* pcseqoff, uint* pcseqlen,
+ uint* transoff, uint* translen)
{
- uint entitylen = 0;
- uint lineoff;
- uint linelen;
-
- if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
- {
- return 0;
- }
-
- *phdrsoff = *ptcpoff;
- while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
- {
- if (linelen == 0)
- {
- if (entitylen > 0)
- {
- *ptcpoff += min(entitylen, tcplen - *ptcpoff);
- }
- break;
- }
- if (lineoff+linelen > tcplen)
- {
- 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;
+ 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, "Transport:", 10) == 0) {
+ *transoff = lineoff;
+ *translen = linelen;
+ }
+
+ if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0) {
+ uint off = lineoff+15;
+ SKIP_WSPACE(ptcp+lineoff, linelen, off);
+ nf_strtou32(ptcp+off, &entitylen);
+ }
+ }
+ *phdrslen = (*ptcpoff) - (*phdrsoff);
+
+ return 1;
}
/*
@@ -169,97 +172,95 @@
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;
- }
+ 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 {
+ DEBUGP("lo port found : %hu\n", port);
+ prtspexp->loport = prtspexp->hiport = port;
+ if (ptran[off] == '-') {
+ off++;
+ numlen = nf_strtou16(ptran+off, &port);
+ off += numlen;
+ prtspexp->pbtype = pb_range;
+ prtspexp->hiport = port;
+
+ // If we have a range, assume rtp:
+ // loport must be even, hiport must be loport+1
+ if ((prtspexp->loport & 0x0001) != 0 ||
+ prtspexp->hiport != prtspexp->loport+1) {
+ 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;
+}
- off = nextparamoff;
+void expected(struct ip_conntrack* ct, struct ip_conntrack_expect *exp)
+{
+ if(ip_nat_rtsp_hook_expectfn) {
+ ip_nat_rtsp_hook_expectfn(ct,exp);
}
-
- return rc;
}
/*** conntrack functions ***/
@@ -269,182 +270,177 @@
help_out(struct sk_buff **pskb, unsigned char *rb_ptr, unsigned int datalen,
struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
{
- struct ip_ct_rtsp_expect expinfo;
- int dir = CTINFO2DIR(ctinfo); /* = IP_CT_DIR_ORIGINAL */
- //struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
- //uint tcplen = pktlen - iph->ihl * 4;
- char* pdata = rb_ptr;
- //uint datalen = tcplen - tcph->doff * 4;
- uint dataoff = 0;
- int ret = NF_ACCEPT;
-
- struct ip_conntrack_expect *exp;
-
- memset(&expinfo, 0, sizeof(expinfo));
-
- 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;
-
- 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");
-
- 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, &expinfo);
- }
- }
-
- if (expinfo.loport == 0)
- {
- DEBUGP("no udp transports found\n");
- continue; /* no udp transports found */
- }
-
- DEBUGP("udp transport found, ports=(%d,%hu,%hu)\n",
- (int)expinfo.pbtype,
- expinfo.loport,
- expinfo.hiport);
-
- exp = ip_conntrack_expect_alloc();
- if (!exp) {
- ret = NF_DROP;
+ struct ip_ct_rtsp_expect expinfo;
+
+ int dir = CTINFO2DIR(ctinfo); /* = IP_CT_DIR_ORIGINAL */
+ //struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
+ //uint tcplen = pktlen - iph->ihl * 4;
+ char* pdata = rb_ptr;
+ //uint datalen = tcplen - tcph->doff * 4;
+ uint dataoff = 0;
+ int ret = NF_ACCEPT;
+
+ struct ip_conntrack_expect *exp;
+
+ memset(&expinfo, 0, sizeof(expinfo));
+
+ while (dataoff < datalen) {
+ uint cmdoff = dataoff;
+ uint hdrsoff = 0;
+ uint hdrslen = 0;
+ uint cseqoff = 0;
+ uint cseqlen = 0;
+ uint transoff = 0;
+ uint translen = 0;
+ uint off;
+
+ if (!rtsp_parse_message(pdata, datalen, &dataoff,
+ &hdrsoff, &hdrslen,
+ &cseqoff, &cseqlen,
+ &transoff, &translen))
+ break; /* not a valid message */
+
+ if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
+ continue; /* not a SETUP message */
+ DEBUGP("found a setup message\n");
+
+ off = 0;
+ if(translen) {
+ rtsp_parse_transport(pdata+transoff, translen, &expinfo);
+ }
+
+ if (expinfo.loport == 0) {
+ DEBUGP("no udp transports found\n");
+ continue; /* no udp transports found */
+ }
+
+ DEBUGP("udp transport found, ports=(%d,%hu,%hu)\n",
+ (int)expinfo.pbtype, expinfo.loport, expinfo.hiport);
+
+ exp = ip_conntrack_expect_alloc(ct);
+ if (!exp) {
+ ret = NF_DROP;
+ goto out;
+ }
+
+ exp->master = ct;
+
+ exp->expectfn = expected;
+ exp->flags = 0;
+
+ exp->tuple = ((struct ip_conntrack_tuple)
+ {
+ { ct->tuplehash[!dir].tuple.src.ip,
+ { 0 }
+ },
+ {
+ ct->tuplehash[!dir].tuple.dst.ip,
+ { .udp = { htons(expinfo.loport) } },
+ IPPROTO_UDP
+ }
+ });
+ exp->mask = ((struct ip_conntrack_tuple)
+ {
+ { 0,
+ { 0 }
+ },
+ {
+ 0xFFFFFFFF,
+ { .udp = { 0xFFFF } }, 0xFF
+ }
+ });
+ if (expinfo.pbtype == pb_range) {
+ DEBUGP("Changing expectation mask to handle multiple ports\n");
+ exp->mask.dst.u.udp.port = 0xfffe;
+ }
+
+ DEBUGP("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
+ NIPQUAD(exp->tuple.src.ip),
+ ntohs(exp->tuple.src.u.udp.port),
+ NIPQUAD(exp->tuple.dst.ip),
+ ntohs(exp->tuple.dst.u.udp.port));
+
+ if (ip_nat_rtsp_hook)
+ /* pass the request off to the nat helper */
+ ret = ip_nat_rtsp_hook(pskb, ctinfo, hdrsoff, hdrslen, &expinfo, exp);
+ else if (ip_conntrack_expect_related(exp) != 0) {
+ INFOP("ip_conntrack_expect_related failed\n");
+ ret = NF_DROP;
+ }
+ ip_conntrack_expect_put(exp);
goto out;
}
-
- //exp->seq = ntohl(tcph->seq) + hdrsoff; /* mark all the headers */
- exp->master = ct;
- //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 = expinfo.loport;
- exp->mask.dst.u.udp.port =
- (expinfo.pbtype == pb_range) ? 0xfffe : 0xffff;
- exp->tuple.dst.protonum = IPPROTO_UDP;
- exp->mask.dst.protonum = 0xff;
-
- 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));
-
- if (ip_nat_rtsp_hook)
- /* pass the request off to the nat helper */
- ret = ip_nat_rtsp_hook(pskb, ctinfo, &expinfo, exp);
- else if (ip_conntrack_expect_related(exp) != 0) {
- INFOP("ip_conntrack_expect_related failed\n");
- ip_conntrack_expect_free(exp);
- ret = NF_DROP;
- }
- goto out;
- }
out:
- return ret;
+ return ret;
}
/* inbound packet: server->client */
static inline int
help_in(struct sk_buff **pskb, size_t pktlen,
- struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
+ struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
{
- return NF_ACCEPT;
+ return NF_ACCEPT;
}
static int help(struct sk_buff **pskb, struct ip_conntrack* ct, enum
ip_conntrack_info ctinfo)
{
- struct tcphdr _tcph, *th;
- unsigned int dataoff, datalen;
- char *rb_ptr;
- int ret = NF_DROP;
-
- /* Until there's been traffic both ways, don't look in packets. */
- if (ctinfo != IP_CT_ESTABLISHED &&
- ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY)
- {
- DEBUGP("conntrackinfo = %u\n", ctinfo);
- return NF_ACCEPT;
- }
+ struct tcphdr _tcph, *th;
+ unsigned int dataoff, datalen;
+ char *rb_ptr;
+ int ret = NF_DROP;
+
+ /* Until there's been traffic both ways, don't look in packets. */
+ if (ctinfo != IP_CT_ESTABLISHED &&
+ ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
+ DEBUGP("conntrackinfo = %u\n", ctinfo);
+ return NF_ACCEPT;
+ }
- /* Not whole TCP header? */
- th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
- sizeof(_tcph), &_tcph);
- if (!th)
- return NF_ACCEPT;
+ /* Not whole TCP header? */
+ th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
+ sizeof(_tcph), &_tcph);
+ if (!th)
+ return NF_ACCEPT;
- /* No data ? */
- dataoff = (*pskb)->nh.iph->ihl*4 + th->doff*4;
- datalen = (*pskb)->len - dataoff;
- if (dataoff >= (*pskb)->len)
- return NF_ACCEPT;
-
- spin_lock_bh(&rtsp_buffer_lock);
- rb_ptr = skb_header_pointer(*pskb, dataoff,
- (*pskb)->len - dataoff, rtsp_buffer);
- BUG_ON(rb_ptr == NULL);
+ /* No data ? */
+ dataoff = (*pskb)->nh.iph->ihl*4 + th->doff*4;
+ datalen = (*pskb)->len - dataoff;
+ if (dataoff >= (*pskb)->len)
+ return NF_ACCEPT;
+
+ spin_lock_bh(&rtsp_buffer_lock);
+ rb_ptr = skb_header_pointer(*pskb, dataoff,
+ (*pskb)->len - dataoff, rtsp_buffer);
+ BUG_ON(rb_ptr == NULL);
#if 0
- /* Checksum invalid? Ignore. */
- /* FIXME: Source route IP option packets --RR */
- if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
- csum_partial((char*)tcph, tcplen, 0)))
- {
- DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
- tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
- return NF_ACCEPT;
- }
+ /* Checksum invalid? Ignore. */
+ /* FIXME: Source route IP option packets --RR */
+ if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
+ csum_partial((char*)tcph, tcplen, 0)))
+ {
+ DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
+ tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
+ return NF_ACCEPT;
+ }
#endif
- switch (CTINFO2DIR(ctinfo))
- {
- case IP_CT_DIR_ORIGINAL:
- ret = help_out(pskb, rb_ptr, datalen, ct, ctinfo);
- break;
- case IP_CT_DIR_REPLY:
- /* inbound packet: server->client */
- ret = NF_ACCEPT;
- break;
- }
+ switch (CTINFO2DIR(ctinfo)) {
+ case IP_CT_DIR_ORIGINAL:
+ ret = help_out(pskb, rb_ptr, datalen, ct, ctinfo);
+ break;
+ case IP_CT_DIR_REPLY:
+ DEBUGP("IP_CT_DIR_REPLY\n");
+ /* inbound packet: server->client */
+ ret = NF_ACCEPT;
+ break;
+ }
- spin_unlock_bh(&rtsp_buffer_lock);
+ spin_unlock_bh(&rtsp_buffer_lock);
- return ret;
+ return ret;
}
static struct ip_conntrack_helper rtsp_helpers[MAX_PORTS];
@@ -454,78 +450,77 @@
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]);
- }
+ int i;
+ for (i = 0; i < num_ports; i++) {
+ DEBUGP("unregistering port %d\n", ports[i]);
+ ip_conntrack_helper_unregister(&rtsp_helpers[i]);
+ }
+ kfree(rtsp_buffer);
}
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;
- }
+ 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;
- }
+ rtsp_buffer = kmalloc(65536, GFP_KERNEL);
+ if (!rtsp_buffer)
+ return -ENOMEM;
+
+ /* If no port given, default to standard rtsp port */
+ if (ports[0] == 0) {
+ ports[0] = RTSP_PORT;
+ }
- 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 = 0xFF;
- hlpr->max_expected = max_outstanding;
- hlpr->timeout = setup_timeout;
- hlpr->me = THIS_MODULE;
- hlpr->help = help;
-
- tmpname = &rtsp_names[i][0];
- if (ports[i] == RTSP_PORT)
- {
- sprintf(tmpname, "rtsp");
- }
- else
- {
- sprintf(tmpname, "rtsp-%d", i);
- }
- 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;
+ 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 = 0xFF;
+ hlpr->max_expected = max_outstanding;
+ hlpr->timeout = setup_timeout;
+ hlpr->me = THIS_MODULE;
+ hlpr->help = help;
+
+ tmpname = &rtsp_names[i][0];
+ if (ports[i] == RTSP_PORT) {
+ sprintf(tmpname, "rtsp");
+ } else {
+ sprintf(tmpname, "rtsp-%d", i);
+ }
+ 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;
}
module_init(init);
module_exit(fini);
+
+EXPORT_SYMBOL(ip_nat_rtsp_hook_expectfn);
+
diff -Naur patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_nat_rtsp.c patch-o-matic-ng-20060913-patched-rtsp/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_nat_rtsp.c
--- patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_nat_rtsp.c 2006-05-10 19:42:57.000000000 +0200
+++ patch-o-matic-ng-20060913-patched-rtsp/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_nat_rtsp.c 2006-09-15 09:52:51.475419664 +0200
@@ -51,6 +51,7 @@
#include <linux/netfilter_mime.h>
#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
+#define IP_NF_RTSP_DEBUG
#ifdef IP_NF_RTSP_DEBUG
#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
#else
@@ -62,11 +63,9 @@
#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;
@@ -164,7 +163,7 @@
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)
+ if (ip_conntrack_expect_related(exp) == 0)
{
DEBUGP("using port %hu\n", loport);
break;
@@ -180,7 +179,7 @@
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)
+ if (ip_conntrack_expect_related(exp) == 0)
{
hiport = loport + ~exp->mask.dst.u.udp.port;
DEBUGP("using ports %hu-%hu\n", loport, hiport);
@@ -197,7 +196,7 @@
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)
+ if (ip_conntrack_expect_related(exp) == 0)
{
DEBUGP("using port %hu (1 of 2)\n", loport);
break;
@@ -206,7 +205,7 @@
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)
+ if (ip_conntrack_expect_related(exp) == 0)
{
DEBUGP("using port %hu (2 of 2)\n", hiport);
break;
@@ -362,37 +361,9 @@
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 sk_buff **pskb, enum ip_conntrack_info ctinfo,
- struct ip_ct_rtsp_expect *prtspexp,
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
struct ip_conntrack_expect* exp)
{
char* ptcp;
@@ -407,10 +378,10 @@
struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
get_skb_tcpdata(*pskb, &ptcp, &tcplen);
-
- hdrsoff = exp->seq - ntohl(tcph->seq);
- hdrslen = prtspexp->len;
+ hdrsoff = matchoff;//exp->seq - ntohl(tcph->seq);
+ hdrslen = matchlen;
off = hdrsoff;
+ DEBUGP("NAT rtsp help_out\n");
while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen))
{
@@ -428,8 +399,10 @@
if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0)
{
uint oldtcplen = tcplen;
- if (!rtsp_mangle_tran(ct, ctinfo, exp, prtspexp, pskb, lineoff, linelen))
+ DEBUGP("hdr: Transport\n");
+ if (!rtsp_mangle_tran(ctinfo, exp, prtspexp, pskb, lineoff, linelen))
{
+ DEBUGP("hdr: Transport mangle failed");
break;
}
get_skb_tcpdata(*pskb, &ptcp, &tcplen);
@@ -444,35 +417,59 @@
return NF_ACCEPT;
}
-static int
-help(struct sk_buff **pskb,
- enum ip_conntrack_info ctinfo,
- struct ip_ct_rtsp_expect *ct_rtsp_info;
+static unsigned int
+help(struct sk_buff **pskb, enum ip_conntrack_info ctinfo,
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
struct ip_conntrack_expect* exp)
{
- struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
- struct tcphdr* tcph = (struct tcphdr*)((char*)iph + iph->ihl * 4);
- uint datalen;
int dir = CTINFO2DIR(ctinfo);
int rc = NF_ACCEPT;
switch (dir)
{
case IP_CT_DIR_ORIGINAL:
- rc = help_out(pskb, ctinfo, ct_rtsp_info, exp, pskb);
+ rc = help_out(pskb, ctinfo, matchoff, matchlen, prtspexp, exp);
break;
case IP_CT_DIR_REPLY:
+ DEBUGP("unmangle ! %u\n", ctinfo);
/* XXX: unmangle */
rc = NF_ACCEPT;
break;
}
+ //UNLOCK_BH(&ip_rtsp_lock);
return rc;
}
+static void expected(struct ip_conntrack* ct, struct ip_conntrack_expect *exp)
+{
+ struct ip_nat_multi_range_compat mr;
+ u_int32_t newdstip, newsrcip, newip;
+
+ struct ip_conntrack *master = master_ct(ct);
+
+ newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ //FIXME (how to port that ?)
+ //code from 2.4 : newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
+ newip = 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;
+
+ ip_nat_setup_info(ct, &mr.range[0], NF_IP_PRE_ROUTING);
+}
+
+
static void __exit fini(void)
{
ip_nat_rtsp_hook = NULL;
+ ip_nat_rtsp_hook_expectfn = NULL;
synchronize_net();
}
@@ -482,6 +479,7 @@
BUG_ON(ip_nat_rtsp_hook);
ip_nat_rtsp_hook = help;
+ ip_nat_rtsp_hook_expectfn = &expected;
if (stunaddr != NULL)
extip = in_aton(stunaddr);
@@ -496,6 +494,7 @@
if (strcmp(destaction, "none") == 0)
dstact = DSTACT_NONE;
}
+
return 0;
}
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: rtsp-conntrack without needing NAT
2006-09-15 8:15 ` Steven Van Acker
@ 2006-09-15 8:40 ` Steven Van Acker
2006-09-15 8:43 ` Steven Van Acker
1 sibling, 0 replies; 5+ messages in thread
From: Steven Van Acker @ 2006-09-15 8:40 UTC (permalink / raw)
To: Netfilter Development Mailinglist
Cc: Patrick McHardy, Mickael Marchand, kulnet
On Fri, Sep 15, 2006 at 10:15:47AM +0200, Steven Van Acker wrote:
> Sorry about that. I recreated the patch based on
> the latest pom-ng snapshot (patch-o-matic-ng-20060914)
Umph, this is getting really embarassing...
Someone complained that I didn't use the --ignore-space-change and
--ignore-tab-expansion options of diff, resulting in a large patchfile.
I recreated the patchfile again.
kinds regards,
-- Steven
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: rtsp-conntrack without needing NAT
2006-09-15 8:15 ` Steven Van Acker
2006-09-15 8:40 ` Steven Van Acker
@ 2006-09-15 8:43 ` Steven Van Acker
1 sibling, 0 replies; 5+ messages in thread
From: Steven Van Acker @ 2006-09-15 8:43 UTC (permalink / raw)
To: Netfilter Development Mailinglist
Cc: Patrick McHardy, Mickael Marchand, kulnet
[-- Attachment #1: Type: text/plain, Size: 475 bytes --]
On Fri, Sep 15, 2006 at 10:15:47AM +0200, Steven Van Acker wrote:
> Sorry about that. I recreated the patch based on
> the latest pom-ng snapshot (patch-o-matic-ng-20060914)
Umph, this is getting really embarassing...
Someone complained that I didn't use the --ignore-space-change and
--ignore-tab-expansion options of diff, resulting in a large patchfile.
I recreated the patchfile again.
kinds regards,
-- Steven
PS: This time with patch attached... I need some coffee
[-- Attachment #2: patch-o-matic-ng-20060914-rtsp.smaller.patch --]
[-- Type: text/plain, Size: 22255 bytes --]
diff -NEbaur patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h patch-o-matic-ng-20060999/patchlets/rtsp-conntrack/linux-2.6.11/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h
--- patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h 2005-08-29 22:54:36.000000000 +0200
+++ patch-o-matic-ng-20060999/patchlets/rtsp-conntrack/linux-2.6.11/include/linux/netfilter_ipv4/ip_conntrack_rtsp.h 2006-09-15 09:56:25.000000000 +0200
@@ -11,9 +11,10 @@
#ifndef _IP_CONNTRACK_RTSP_H
#define _IP_CONNTRACK_RTSP_H
-/* #define IP_NF_RTSP_DEBUG */
+//#define IP_NF_RTSP_DEBUG 1
#define IP_NF_RTSP_VERSION "0.6.21"
+#ifdef __KERNEL__
/* port block types */
typedef enum {
pb_single, /* client_port=x */
@@ -47,7 +48,13 @@
#endif
};
-#ifdef __KERNEL__
+extern unsigned int (*ip_nat_rtsp_hook)(struct sk_buff **pskb,
+ enum ip_conntrack_info ctinfo,
+ unsigned int matchoff, unsigned int matchlen,
+ struct ip_ct_rtsp_expect *expinfo,
+ struct ip_conntrack_expect *exp);
+
+extern void (*ip_nat_rtsp_hook_expectfn)(struct ip_conntrack *ct, struct ip_conntrack_expect *exp);
#define RTSP_PORT 554
diff -NEbaur patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_conntrack_rtsp.c patch-o-matic-ng-20060999/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_conntrack_rtsp.c
--- patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_conntrack_rtsp.c 2005-09-19 16:53:50.000000000 +0200
+++ patch-o-matic-ng-20060999/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_conntrack_rtsp.c 2006-09-15 09:56:25.000000000 +0200
@@ -22,12 +22,15 @@
* 2005-02-13: Harald Welte <laforge@netfilter.org>
* - port to 2.6
* - update to recent post-2.6.11 api changes
+ * 2006-09-14: Steven Van Acker <deepstar@singularity.be>
+ * - removed calls to NAT code from conntrack helper: NAT no longer needed to use rtsp-conntrack
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/ip.h>
+#include <linux/inet.h>
#include <net/checksum.h>
#include <net/tcp.h>
@@ -44,7 +47,7 @@
#include <linux/netfilter_mime.h>
#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
-
+#define IP_NF_RTSP_DEBUG
#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)
@@ -68,13 +71,15 @@
module_param(setup_timeout, int, 0400);
MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
-static char rtsp_buffer[65536];
+static char *rtsp_buffer;
static DEFINE_SPINLOCK(rtsp_buffer_lock);
unsigned int (*ip_nat_rtsp_hook)(struct sk_buff **pskb,
enum ip_conntrack_info ctinfo,
- struct ip_ct_rtsp_expect *expinfo,
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
struct ip_conntrack_expect *exp);
+void (*ip_nat_rtsp_hook_expectfn)(struct ip_conntrack *ct, struct ip_conntrack_expect *exp);
+
EXPORT_SYMBOL_GPL(ip_nat_rtsp_hook);
/*
@@ -106,41 +111,39 @@
static int
rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
uint* phdrsoff, uint* phdrslen,
- uint* pcseqoff, uint* pcseqlen)
+ uint* pcseqoff, uint* pcseqlen,
+ uint* transoff, uint* translen)
{
uint entitylen = 0;
uint lineoff;
uint linelen;
if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
- {
return 0;
- }
*phdrsoff = *ptcpoff;
- while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
- {
- if (linelen == 0)
- {
+ 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)
- {
+ if (lineoff+linelen > tcplen) {
INFOP("!! overrun !!\n");
break;
}
- if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0)
- {
+ if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0) {
*pcseqoff = lineoff;
*pcseqlen = linelen;
}
- if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0)
- {
+
+ if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0) {
+ *transoff = lineoff;
+ *translen = linelen;
+ }
+
+ if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0) {
uint off = lineoff+15;
SKIP_WSPACE(ptcp+lineoff, linelen, off);
nf_strtou32(ptcp+off, &entitylen);
@@ -173,18 +176,17 @@
uint off = 0;
if (tranlen < 10 || !iseol(ptran[tranlen-1]) ||
- nf_strncasecmp(ptran, "Transport:", 10) != 0)
- {
+ 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)
- {
+ while (off < tranlen) {
const char* pparamend;
uint nextparamoff;
@@ -192,16 +194,14 @@
pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
nextparamoff = pparamend-ptran;
- while (off < nextparamoff)
- {
+ 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)
- {
+ if (strncmp(ptran+off, "client_port=", 12) == 0) {
u_int16_t port;
uint numlen;
@@ -209,14 +209,11 @@
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
- {
+ else {
+ DEBUGP("lo port found : %hu\n", port);
prtspexp->loport = prtspexp->hiport = port;
- if (ptran[off] == '-')
- {
+ if (ptran[off] == '-') {
off++;
numlen = nf_strtou16(ptran+off, &port);
off += numlen;
@@ -226,16 +223,13 @@
// 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)
- {
+ 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] == '/')
- {
+ } else if (ptran[off] == '/') {
off++;
numlen = nf_strtou16(ptran+off, &port);
off += numlen;
@@ -262,6 +256,13 @@
return rc;
}
+void expected(struct ip_conntrack* ct, struct ip_conntrack_expect *exp)
+{
+ if(ip_nat_rtsp_hook_expectfn) {
+ ip_nat_rtsp_hook_expectfn(ct,exp);
+ }
+}
+
/*** conntrack functions ***/
/* outbound packet: client->server */
@@ -270,6 +271,7 @@
struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
{
struct ip_ct_rtsp_expect expinfo;
+
int dir = CTINFO2DIR(ctinfo); /* = IP_CT_DIR_ORIGINAL */
//struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
//uint tcplen = pktlen - iph->ihl * 4;
@@ -282,95 +284,90 @@
memset(&expinfo, 0, sizeof(expinfo));
- while (dataoff < datalen)
- {
+ 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 transoff = 0;
+ uint translen = 0;
uint off;
if (!rtsp_parse_message(pdata, datalen, &dataoff,
&hdrsoff, &hdrslen,
- &cseqoff, &cseqlen))
- {
+ &cseqoff, &cseqlen,
+ &transoff, &translen))
break; /* not a valid message */
- }
if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
- {
continue; /* not a SETUP message */
- }
DEBUGP("found a setup message\n");
off = 0;
- while (nf_mime_nextline(pdata+hdrsoff, hdrslen, &off,
- &lineoff, &linelen))
- {
- if (linelen == 0)
- {
- break;
- }
- if (off > hdrsoff+hdrslen)
- {
- INFOP("!! overrun !!");
- break;
+ if(translen) {
+ rtsp_parse_transport(pdata+transoff, translen, &expinfo);
}
- if (nf_strncasecmp(pdata+hdrsoff+lineoff, "Transport:", 10) == 0)
- {
- rtsp_parse_transport(pdata+hdrsoff+lineoff, linelen, &expinfo);
- }
- }
-
- if (expinfo.loport == 0)
- {
+ if (expinfo.loport == 0) {
DEBUGP("no udp transports found\n");
continue; /* no udp transports found */
}
DEBUGP("udp transport found, ports=(%d,%hu,%hu)\n",
- (int)expinfo.pbtype,
- expinfo.loport,
- expinfo.hiport);
+ (int)expinfo.pbtype, expinfo.loport, expinfo.hiport);
- exp = ip_conntrack_expect_alloc();
+ exp = ip_conntrack_expect_alloc(ct);
if (!exp) {
ret = NF_DROP;
goto out;
}
- //exp->seq = ntohl(tcph->seq) + hdrsoff; /* mark all the headers */
exp->master = ct;
- //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 = expinfo.loport;
- exp->mask.dst.u.udp.port =
- (expinfo.pbtype == pb_range) ? 0xfffe : 0xffff;
- exp->tuple.dst.protonum = IPPROTO_UDP;
- exp->mask.dst.protonum = 0xff;
+ exp->expectfn = expected;
+ exp->flags = 0;
+
+ exp->tuple = ((struct ip_conntrack_tuple)
+ {
+ { ct->tuplehash[!dir].tuple.src.ip,
+ { 0 }
+ },
+ {
+ ct->tuplehash[!dir].tuple.dst.ip,
+ { .udp = { htons(expinfo.loport) } },
+ IPPROTO_UDP
+ }
+ });
+ exp->mask = ((struct ip_conntrack_tuple)
+ {
+ { 0,
+ { 0 }
+ },
+ {
+ 0xFFFFFFFF,
+ { .udp = { 0xFFFF } }, 0xFF
+ }
+ });
+ if (expinfo.pbtype == pb_range) {
+ DEBUGP("Changing expectation mask to handle multiple ports\n");
+ exp->mask.dst.u.udp.port = 0xfffe;
+ }
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),
+ ntohs(exp->tuple.src.u.udp.port),
NIPQUAD(exp->tuple.dst.ip),
- ntohs(exp->tuple.dst.u.tcp.port));
+ ntohs(exp->tuple.dst.u.udp.port));
if (ip_nat_rtsp_hook)
/* pass the request off to the nat helper */
- ret = ip_nat_rtsp_hook(pskb, ctinfo, &expinfo, exp);
+ ret = ip_nat_rtsp_hook(pskb, ctinfo, hdrsoff, hdrslen, &expinfo, exp);
else if (ip_conntrack_expect_related(exp) != 0) {
INFOP("ip_conntrack_expect_related failed\n");
- ip_conntrack_expect_free(exp);
ret = NF_DROP;
}
+ ip_conntrack_expect_put(exp);
goto out;
}
out:
@@ -396,8 +393,7 @@
/* 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)
- {
+ ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
DEBUGP("conntrackinfo = %u\n", ctinfo);
return NF_ACCEPT;
}
@@ -431,12 +427,12 @@
}
#endif
- switch (CTINFO2DIR(ctinfo))
- {
+ switch (CTINFO2DIR(ctinfo)) {
case IP_CT_DIR_ORIGINAL:
ret = help_out(pskb, rb_ptr, datalen, ct, ctinfo);
break;
case IP_CT_DIR_REPLY:
+ DEBUGP("IP_CT_DIR_REPLY\n");
/* inbound packet: server->client */
ret = NF_ACCEPT;
break;
@@ -455,11 +451,11 @@
fini(void)
{
int i;
- for (i = 0; i < num_ports; i++)
- {
+ for (i = 0; i < num_ports; i++) {
DEBUGP("unregistering port %d\n", ports[i]);
ip_conntrack_helper_unregister(&rtsp_helpers[i]);
}
+ kfree(rtsp_buffer);
}
static int __init
@@ -471,25 +467,25 @@
printk("ip_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
- if (max_outstanding < 1)
- {
+ if (max_outstanding < 1) {
printk("ip_conntrack_rtsp: max_outstanding must be a positive integer\n");
return -EBUSY;
}
- if (setup_timeout < 0)
- {
+ if (setup_timeout < 0) {
printk("ip_conntrack_rtsp: setup_timeout must be a positive integer\n");
return -EBUSY;
}
+ rtsp_buffer = kmalloc(65536, GFP_KERNEL);
+ if (!rtsp_buffer)
+ return -ENOMEM;
+
/* If no port given, default to standard rtsp port */
- if (ports[0] == 0)
- {
+ if (ports[0] == 0) {
ports[0] = RTSP_PORT;
}
- for (i = 0; (i < MAX_PORTS) && ports[i]; i++)
- {
+ 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]);
@@ -502,12 +498,9 @@
hlpr->help = help;
tmpname = &rtsp_names[i][0];
- if (ports[i] == RTSP_PORT)
- {
+ if (ports[i] == RTSP_PORT) {
sprintf(tmpname, "rtsp");
- }
- else
- {
+ } else {
sprintf(tmpname, "rtsp-%d", i);
}
hlpr->name = tmpname;
@@ -516,8 +509,7 @@
ret = ip_conntrack_helper_register(hlpr);
- if (ret)
- {
+ if (ret) {
printk("ip_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
fini();
return -EBUSY;
@@ -529,3 +521,6 @@
module_init(init);
module_exit(fini);
+
+EXPORT_SYMBOL(ip_nat_rtsp_hook_expectfn);
+
diff -NEbaur patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_nat_rtsp.c patch-o-matic-ng-20060999/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_nat_rtsp.c
--- patch-o-matic-ng-20060913/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_nat_rtsp.c 2006-05-10 19:42:57.000000000 +0200
+++ patch-o-matic-ng-20060999/patchlets/rtsp-conntrack/linux-2.6.11/net/ipv4/netfilter/ip_nat_rtsp.c 2006-09-15 09:56:25.000000000 +0200
@@ -51,6 +51,7 @@
#include <linux/netfilter_mime.h>
#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
+#define IP_NF_RTSP_DEBUG
#ifdef IP_NF_RTSP_DEBUG
#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
#else
@@ -62,11 +63,9 @@
#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;
@@ -164,7 +163,7 @@
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)
+ if (ip_conntrack_expect_related(exp) == 0)
{
DEBUGP("using port %hu\n", loport);
break;
@@ -180,7 +179,7 @@
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)
+ if (ip_conntrack_expect_related(exp) == 0)
{
hiport = loport + ~exp->mask.dst.u.udp.port;
DEBUGP("using ports %hu-%hu\n", loport, hiport);
@@ -197,7 +196,7 @@
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)
+ if (ip_conntrack_expect_related(exp) == 0)
{
DEBUGP("using port %hu (1 of 2)\n", loport);
break;
@@ -206,7 +205,7 @@
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)
+ if (ip_conntrack_expect_related(exp) == 0)
{
DEBUGP("using port %hu (2 of 2)\n", hiport);
break;
@@ -362,37 +361,9 @@
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 sk_buff **pskb, enum ip_conntrack_info ctinfo,
- struct ip_ct_rtsp_expect *prtspexp,
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
struct ip_conntrack_expect* exp)
{
char* ptcp;
@@ -407,10 +378,10 @@
struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
get_skb_tcpdata(*pskb, &ptcp, &tcplen);
-
- hdrsoff = exp->seq - ntohl(tcph->seq);
- hdrslen = prtspexp->len;
+ hdrsoff = matchoff;//exp->seq - ntohl(tcph->seq);
+ hdrslen = matchlen;
off = hdrsoff;
+ DEBUGP("NAT rtsp help_out\n");
while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen))
{
@@ -428,8 +399,10 @@
if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0)
{
uint oldtcplen = tcplen;
- if (!rtsp_mangle_tran(ct, ctinfo, exp, prtspexp, pskb, lineoff, linelen))
+ DEBUGP("hdr: Transport\n");
+ if (!rtsp_mangle_tran(ctinfo, exp, prtspexp, pskb, lineoff, linelen))
{
+ DEBUGP("hdr: Transport mangle failed");
break;
}
get_skb_tcpdata(*pskb, &ptcp, &tcplen);
@@ -444,35 +417,59 @@
return NF_ACCEPT;
}
-static int
-help(struct sk_buff **pskb,
- enum ip_conntrack_info ctinfo,
- struct ip_ct_rtsp_expect *ct_rtsp_info;
+static unsigned int
+help(struct sk_buff **pskb, enum ip_conntrack_info ctinfo,
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
struct ip_conntrack_expect* exp)
{
- struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
- struct tcphdr* tcph = (struct tcphdr*)((char*)iph + iph->ihl * 4);
- uint datalen;
int dir = CTINFO2DIR(ctinfo);
int rc = NF_ACCEPT;
switch (dir)
{
case IP_CT_DIR_ORIGINAL:
- rc = help_out(pskb, ctinfo, ct_rtsp_info, exp, pskb);
+ rc = help_out(pskb, ctinfo, matchoff, matchlen, prtspexp, exp);
break;
case IP_CT_DIR_REPLY:
+ DEBUGP("unmangle ! %u\n", ctinfo);
/* XXX: unmangle */
rc = NF_ACCEPT;
break;
}
+ //UNLOCK_BH(&ip_rtsp_lock);
return rc;
}
+static void expected(struct ip_conntrack* ct, struct ip_conntrack_expect *exp)
+{
+ struct ip_nat_multi_range_compat mr;
+ u_int32_t newdstip, newsrcip, newip;
+
+ struct ip_conntrack *master = master_ct(ct);
+
+ newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ //FIXME (how to port that ?)
+ //code from 2.4 : newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
+ newip = 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;
+
+ ip_nat_setup_info(ct, &mr.range[0], NF_IP_PRE_ROUTING);
+}
+
+
static void __exit fini(void)
{
ip_nat_rtsp_hook = NULL;
+ ip_nat_rtsp_hook_expectfn = NULL;
synchronize_net();
}
@@ -482,6 +479,7 @@
BUG_ON(ip_nat_rtsp_hook);
ip_nat_rtsp_hook = help;
+ ip_nat_rtsp_hook_expectfn = &expected;
if (stunaddr != NULL)
extip = in_aton(stunaddr);
@@ -496,6 +494,7 @@
if (strcmp(destaction, "none") == 0)
dstact = DSTACT_NONE;
}
+
return 0;
}
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2006-09-15 8:43 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2006-09-14 12:51 rtsp-conntrack without needing NAT Steven Van Acker
2006-09-15 4:40 ` Patrick McHardy
2006-09-15 8:15 ` Steven Van Acker
2006-09-15 8:40 ` Steven Van Acker
2006-09-15 8:43 ` Steven Van Acker
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