mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2024-08-21 16:32:25 +03:00
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@21952 3c298f89-4303-0410-b956-a3cf2f4a3e73
1367 lines
40 KiB
Diff
1367 lines
40 KiB
Diff
--- /dev/null
|
|
+++ b/include/linux/netfilter/nf_conntrack_rtsp.h
|
|
@@ -0,0 +1,63 @@
|
|
+/*
|
|
+ * RTSP extension for IP connection tracking.
|
|
+ * (C) 2003 by Tom Marshall <tmarshall at real.com>
|
|
+ * based on ip_conntrack_irc.h
|
|
+ *
|
|
+ * This program is free software; you can redistribute it and/or
|
|
+ * modify it under the terms of the GNU General Public License
|
|
+ * as published by the Free Software Foundation; either version
|
|
+ * 2 of the License, or (at your option) any later version.
|
|
+ */
|
|
+#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 (*nf_nat_rtsp_hook)(struct sk_buff *skb,
|
|
+ enum ip_conntrack_info ctinfo,
|
|
+ unsigned int matchoff, unsigned int matchlen,
|
|
+ struct ip_ct_rtsp_expect *prtspexp,
|
|
+ struct nf_conntrack_expect *exp);
|
|
+
|
|
+extern void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
|
|
+
|
|
+#define RTSP_PORT 554
|
|
+
|
|
+#endif /* __KERNEL__ */
|
|
+
|
|
+#endif /* _IP_CONNTRACK_RTSP_H */
|
|
--- /dev/null
|
|
+++ b/include/linux/netfilter_helpers.h
|
|
@@ -0,0 +1,133 @@
|
|
+/*
|
|
+ * Helpers for netfiler modules. This file provides implementations for basic
|
|
+ * functions such as strncasecmp(), etc.
|
|
+ *
|
|
+ * gcc will warn for defined but unused functions, so we only include the
|
|
+ * functions requested. The following macros are used:
|
|
+ * NF_NEED_STRNCASECMP nf_strncasecmp()
|
|
+ * NF_NEED_STRTOU16 nf_strtou16()
|
|
+ * NF_NEED_STRTOU32 nf_strtou32()
|
|
+ */
|
|
+#ifndef _NETFILTER_HELPERS_H
|
|
+#define _NETFILTER_HELPERS_H
|
|
+
|
|
+/* Only include these functions for kernel code. */
|
|
+#ifdef __KERNEL__
|
|
+
|
|
+#include <linux/ctype.h>
|
|
+#define iseol(c) ( (c) == '\r' || (c) == '\n' )
|
|
+
|
|
+/*
|
|
+ * The standard strncasecmp()
|
|
+ */
|
|
+#ifdef NF_NEED_STRNCASECMP
|
|
+static int
|
|
+nf_strncasecmp(const char* s1, const char* s2, u_int32_t len)
|
|
+{
|
|
+ if (s1 == NULL || s2 == NULL)
|
|
+ {
|
|
+ if (s1 == NULL && s2 == NULL)
|
|
+ {
|
|
+ return 0;
|
|
+ }
|
|
+ return (s1 == NULL) ? -1 : 1;
|
|
+ }
|
|
+ while (len > 0 && tolower(*s1) == tolower(*s2))
|
|
+ {
|
|
+ len--;
|
|
+ s1++;
|
|
+ s2++;
|
|
+ }
|
|
+ return ( (len == 0) ? 0 : (tolower(*s1) - tolower(*s2)) );
|
|
+}
|
|
+#endif /* NF_NEED_STRNCASECMP */
|
|
+
|
|
+/*
|
|
+ * Parse a string containing a 16-bit unsigned integer.
|
|
+ * Returns the number of chars used, or zero if no number is found.
|
|
+ */
|
|
+#ifdef NF_NEED_STRTOU16
|
|
+static int
|
|
+nf_strtou16(const char* pbuf, u_int16_t* pval)
|
|
+{
|
|
+ int n = 0;
|
|
+
|
|
+ *pval = 0;
|
|
+ while (isdigit(pbuf[n]))
|
|
+ {
|
|
+ *pval = (*pval * 10) + (pbuf[n] - '0');
|
|
+ n++;
|
|
+ }
|
|
+
|
|
+ return n;
|
|
+}
|
|
+#endif /* NF_NEED_STRTOU16 */
|
|
+
|
|
+/*
|
|
+ * Parse a string containing a 32-bit unsigned integer.
|
|
+ * Returns the number of chars used, or zero if no number is found.
|
|
+ */
|
|
+#ifdef NF_NEED_STRTOU32
|
|
+static int
|
|
+nf_strtou32(const char* pbuf, u_int32_t* pval)
|
|
+{
|
|
+ int n = 0;
|
|
+
|
|
+ *pval = 0;
|
|
+ while (pbuf[n] >= '0' && pbuf[n] <= '9')
|
|
+ {
|
|
+ *pval = (*pval * 10) + (pbuf[n] - '0');
|
|
+ n++;
|
|
+ }
|
|
+
|
|
+ return n;
|
|
+}
|
|
+#endif /* NF_NEED_STRTOU32 */
|
|
+
|
|
+/*
|
|
+ * Given a buffer and length, advance to the next line and mark the current
|
|
+ * line.
|
|
+ */
|
|
+#ifdef NF_NEED_NEXTLINE
|
|
+static int
|
|
+nf_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
|
|
+{
|
|
+ uint off = *poff;
|
|
+ uint physlen = 0;
|
|
+
|
|
+ if (off >= len)
|
|
+ {
|
|
+ return 0;
|
|
+ }
|
|
+
|
|
+ while (p[off] != '\n')
|
|
+ {
|
|
+ if (len-off <= 1)
|
|
+ {
|
|
+ return 0;
|
|
+ }
|
|
+
|
|
+ physlen++;
|
|
+ off++;
|
|
+ }
|
|
+
|
|
+ /* if we saw a crlf, physlen needs adjusted */
|
|
+ if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
|
|
+ {
|
|
+ physlen--;
|
|
+ }
|
|
+
|
|
+ /* advance past the newline */
|
|
+ off++;
|
|
+
|
|
+ *plineoff = *poff;
|
|
+ *plinelen = physlen;
|
|
+ *poff = off;
|
|
+
|
|
+ return 1;
|
|
+}
|
|
+#endif /* NF_NEED_NEXTLINE */
|
|
+
|
|
+#endif /* __KERNEL__ */
|
|
+
|
|
+#endif /* _NETFILTER_HELPERS_H */
|
|
--- /dev/null
|
|
+++ b/include/linux/netfilter_mime.h
|
|
@@ -0,0 +1,89 @@
|
|
+/*
|
|
+ * MIME functions for netfilter modules. This file provides implementations
|
|
+ * for basic MIME parsing. MIME headers are used in many protocols, such as
|
|
+ * HTTP, RTSP, SIP, etc.
|
|
+ *
|
|
+ * gcc will warn for defined but unused functions, so we only include the
|
|
+ * functions requested. The following macros are used:
|
|
+ * NF_NEED_MIME_NEXTLINE nf_mime_nextline()
|
|
+ */
|
|
+#ifndef _NETFILTER_MIME_H
|
|
+#define _NETFILTER_MIME_H
|
|
+
|
|
+/* Only include these functions for kernel code. */
|
|
+#ifdef __KERNEL__
|
|
+
|
|
+#include <linux/ctype.h>
|
|
+
|
|
+/*
|
|
+ * Given a buffer and length, advance to the next line and mark the current
|
|
+ * line. If the current line is empty, *plinelen will be set to zero. If
|
|
+ * not, it will be set to the actual line length (including CRLF).
|
|
+ *
|
|
+ * 'line' in this context means logical line (includes LWS continuations).
|
|
+ * Returns 1 on success, 0 on failure.
|
|
+ */
|
|
+#ifdef NF_NEED_MIME_NEXTLINE
|
|
+static int
|
|
+nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
|
|
+{
|
|
+ uint off = *poff;
|
|
+ uint physlen = 0;
|
|
+ int is_first_line = 1;
|
|
+
|
|
+ if (off >= len)
|
|
+ {
|
|
+ return 0;
|
|
+ }
|
|
+
|
|
+ do
|
|
+ {
|
|
+ while (p[off] != '\n')
|
|
+ {
|
|
+ if (len-off <= 1)
|
|
+ {
|
|
+ return 0;
|
|
+ }
|
|
+
|
|
+ physlen++;
|
|
+ off++;
|
|
+ }
|
|
+
|
|
+ /* if we saw a crlf, physlen needs adjusted */
|
|
+ if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
|
|
+ {
|
|
+ physlen--;
|
|
+ }
|
|
+
|
|
+ /* advance past the newline */
|
|
+ off++;
|
|
+
|
|
+ /* check for an empty line */
|
|
+ if (physlen == 0)
|
|
+ {
|
|
+ break;
|
|
+ }
|
|
+
|
|
+ /* check for colon on the first physical line */
|
|
+ if (is_first_line)
|
|
+ {
|
|
+ is_first_line = 0;
|
|
+ if (memchr(p+(*poff), ':', physlen) == NULL)
|
|
+ {
|
|
+ return 0;
|
|
+ }
|
|
+ }
|
|
+ }
|
|
+ while (p[off] == ' ' || p[off] == '\t');
|
|
+
|
|
+ *plineoff = *poff;
|
|
+ *plinelen = (physlen == 0) ? 0 : (off - *poff);
|
|
+ *poff = off;
|
|
+
|
|
+ return 1;
|
|
+}
|
|
+#endif /* NF_NEED_MIME_NEXTLINE */
|
|
+
|
|
+#endif /* __KERNEL__ */
|
|
+
|
|
+#endif /* _NETFILTER_MIME_H */
|
|
--- a/net/ipv4/netfilter/Makefile
|
|
+++ b/net/ipv4/netfilter/Makefile
|
|
@@ -26,6 +26,7 @@ obj-$(CONFIG_NF_NAT_AMANDA) += nf_nat_am
|
|
obj-$(CONFIG_NF_NAT_FTP) += nf_nat_ftp.o
|
|
obj-$(CONFIG_NF_NAT_H323) += nf_nat_h323.o
|
|
obj-$(CONFIG_NF_NAT_IRC) += nf_nat_irc.o
|
|
+obj-$(CONFIG_NF_NAT_RTSP) += nf_nat_rtsp.o
|
|
obj-$(CONFIG_NF_NAT_PPTP) += nf_nat_pptp.o
|
|
obj-$(CONFIG_NF_NAT_SIP) += nf_nat_sip.o
|
|
obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o
|
|
--- a/net/netfilter/Kconfig
|
|
+++ b/net/netfilter/Kconfig
|
|
@@ -267,6 +267,16 @@ config NF_CONNTRACK_TFTP
|
|
|
|
To compile it as a module, choose M here. If unsure, say N.
|
|
|
|
+config NF_CONNTRACK_RTSP
|
|
+ tristate "RTSP protocol support"
|
|
+ depends on 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'.
|
|
+
|
|
config NF_CT_NETLINK
|
|
tristate 'Connection tracking netlink interface'
|
|
select NETFILTER_NETLINK
|
|
--- a/net/netfilter/Makefile
|
|
+++ b/net/netfilter/Makefile
|
|
@@ -33,6 +33,7 @@ obj-$(CONFIG_NF_CONNTRACK_PPTP) += nf_co
|
|
obj-$(CONFIG_NF_CONNTRACK_SANE) += nf_conntrack_sane.o
|
|
obj-$(CONFIG_NF_CONNTRACK_SIP) += nf_conntrack_sip.o
|
|
obj-$(CONFIG_NF_CONNTRACK_TFTP) += nf_conntrack_tftp.o
|
|
+obj-$(CONFIG_NF_CONNTRACK_RTSP) += nf_conntrack_rtsp.o
|
|
|
|
# transparent proxy support
|
|
obj-$(CONFIG_NETFILTER_TPROXY) += nf_tproxy_core.o
|
|
--- a/net/ipv4/netfilter/Kconfig
|
|
+++ b/net/ipv4/netfilter/Kconfig
|
|
@@ -257,6 +257,11 @@ config NF_NAT_IRC
|
|
depends on NF_CONNTRACK && NF_NAT
|
|
default NF_NAT && NF_CONNTRACK_IRC
|
|
|
|
+config NF_NAT_RTSP
|
|
+ tristate
|
|
+ depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
|
|
+ default NF_NAT && NF_CONNTRACK_RTSP
|
|
+
|
|
config NF_NAT_TFTP
|
|
tristate
|
|
depends on NF_CONNTRACK && NF_NAT
|
|
--- /dev/null
|
|
+++ b/net/netfilter/nf_conntrack_rtsp.c
|
|
@@ -0,0 +1,517 @@
|
|
+/*
|
|
+ * RTSP extension for IP connection tracking
|
|
+ * (C) 2003 by Tom Marshall <tmarshall at 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 nf_conntrack_rtsp.o ports=port1,port2,...port<MAX_PORTS>
|
|
+ * max_outstanding=n setup_timeout=secs
|
|
+ *
|
|
+ * If no ports are specified, the default will be port 554.
|
|
+ *
|
|
+ * With max_outstanding you can define the maximum number of not yet
|
|
+ * answered SETUP requests per RTSP session (default 8).
|
|
+ * With setup_timeout you can specify how long the system waits for
|
|
+ * an expected data channel (default 300 seconds).
|
|
+ *
|
|
+ * 2005-02-13: Harald Welte <laforge at netfilter.org>
|
|
+ * - port to 2.6
|
|
+ * - update to recent post-2.6.11 api changes
|
|
+ * 2006-09-14: Steven Van Acker <deepstar at singularity.be>
|
|
+ * - removed calls to NAT code from conntrack helper: NAT no longer needed to use rtsp-conntrack
|
|
+ * 2007-04-18: Michael Guntsche <mike at it-loops.com>
|
|
+ * - Port to new NF API
|
|
+ */
|
|
+
|
|
+#include <linux/module.h>
|
|
+#include <linux/netfilter.h>
|
|
+#include <linux/ip.h>
|
|
+#include <linux/inet.h>
|
|
+#include <net/tcp.h>
|
|
+
|
|
+#include <net/netfilter/nf_conntrack.h>
|
|
+#include <net/netfilter/nf_conntrack_expect.h>
|
|
+#include <net/netfilter/nf_conntrack_helper.h>
|
|
+#include <linux/netfilter/nf_conntrack_rtsp.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>
|
|
+
|
|
+#include <linux/ctype.h>
|
|
+#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
|
|
+#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
|
|
+#if 0
|
|
+#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 at real.com>");
|
|
+MODULE_DESCRIPTION("RTSP connection tracking module");
|
|
+MODULE_LICENSE("GPL");
|
|
+module_param_array(ports, int, &num_ports, 0400);
|
|
+MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
|
|
+module_param(max_outstanding, int, 0400);
|
|
+MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
|
|
+module_param(setup_timeout, int, 0400);
|
|
+MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
|
|
+
|
|
+static char *rtsp_buffer;
|
|
+static DEFINE_SPINLOCK(rtsp_buffer_lock);
|
|
+
|
|
+unsigned int (*nf_nat_rtsp_hook)(struct sk_buff *skb,
|
|
+ enum ip_conntrack_info ctinfo,
|
|
+ unsigned int matchoff, unsigned int matchlen,struct ip_ct_rtsp_expect* prtspexp,
|
|
+ struct nf_conntrack_expect *exp);
|
|
+void (*nf_nat_rtsp_hook_expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
|
|
+
|
|
+EXPORT_SYMBOL_GPL(nf_nat_rtsp_hook);
|
|
+
|
|
+/*
|
|
+ * Max mappings we will allow for one RTSP connection (for RTP, the number
|
|
+ * of allocated ports is twice this value). Note that SMIL burns a lot of
|
|
+ * ports so keep this reasonably high. If this is too low, you will see a
|
|
+ * lot of "no free client map entries" messages.
|
|
+ */
|
|
+#define MAX_PORT_MAPS 16
|
|
+
|
|
+/*** default port list was here in the masq code: 554, 3030, 4040 ***/
|
|
+
|
|
+#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
|
|
+
|
|
+/*
|
|
+ * Parse an RTSP packet.
|
|
+ *
|
|
+ * Returns zero if parsing failed.
|
|
+ *
|
|
+ * Parameters:
|
|
+ * IN ptcp tcp data pointer
|
|
+ * IN tcplen tcp data len
|
|
+ * IN/OUT ptcpoff points to current tcp offset
|
|
+ * OUT phdrsoff set to offset of rtsp headers
|
|
+ * OUT phdrslen set to length of rtsp headers
|
|
+ * OUT pcseqoff set to offset of CSeq header
|
|
+ * OUT pcseqlen set to length of CSeq header
|
|
+ */
|
|
+static int
|
|
+rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
|
|
+ uint* phdrsoff, uint* phdrslen,
|
|
+ uint* pcseqoff, uint* pcseqlen,
|
|
+ uint* transoff, uint* translen)
|
|
+{
|
|
+ uint entitylen = 0;
|
|
+ uint lineoff;
|
|
+ uint linelen;
|
|
+
|
|
+ if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
|
|
+ return 0;
|
|
+
|
|
+ *phdrsoff = *ptcpoff;
|
|
+ while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen)) {
|
|
+ if (linelen == 0) {
|
|
+ if (entitylen > 0)
|
|
+ *ptcpoff += min(entitylen, tcplen - *ptcpoff);
|
|
+ break;
|
|
+ }
|
|
+ if (lineoff+linelen > tcplen) {
|
|
+ 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 nf_conn *ct, struct nf_conntrack_expect *exp)
|
|
+{
|
|
+ if(nf_nat_rtsp_hook_expectfn) {
|
|
+ nf_nat_rtsp_hook_expectfn(ct,exp);
|
|
+ }
|
|
+}
|
|
+
|
|
+/*** conntrack functions ***/
|
|
+
|
|
+/* outbound packet: client->server */
|
|
+
|
|
+static inline int
|
|
+help_out(struct sk_buff *skb, unsigned char *rb_ptr, unsigned int datalen,
|
|
+ struct nf_conn *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 nf_conntrack_expect *exp;
|
|
+
|
|
+ __be16 be_loport;
|
|
+
|
|
+ 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 = nf_ct_expect_alloc(ct);
|
|
+ if (!exp) {
|
|
+ ret = NF_DROP;
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ be_loport = htons(expinfo.loport);
|
|
+
|
|
+ nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
|
|
+ ct->tuplehash[!dir].tuple.src.l3num,
|
|
+ &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3,
|
|
+ IPPROTO_UDP, NULL, &be_loport);
|
|
+
|
|
+ exp->master = ct;
|
|
+
|
|
+ exp->expectfn = expected;
|
|
+ exp->flags = 0;
|
|
+
|
|
+ if (expinfo.pbtype == pb_range) {
|
|
+ DEBUGP("Changing expectation mask to handle multiple ports\n");
|
|
+ exp->mask.src.u.udp.port = 0xfffe;
|
|
+ }
|
|
+
|
|
+ DEBUGP("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
|
|
+ NIPQUAD(exp->tuple.src.u3.ip),
|
|
+ ntohs(exp->tuple.src.u.udp.port),
|
|
+ NIPQUAD(exp->tuple.dst.u3.ip),
|
|
+ ntohs(exp->tuple.dst.u.udp.port));
|
|
+
|
|
+ if (nf_nat_rtsp_hook)
|
|
+ /* pass the request off to the nat helper */
|
|
+ ret = nf_nat_rtsp_hook(skb, ctinfo, hdrsoff, hdrslen, &expinfo, exp);
|
|
+ else if (nf_ct_expect_related(exp) != 0) {
|
|
+ INFOP("nf_ct_expect_related failed\n");
|
|
+ ret = NF_DROP;
|
|
+ }
|
|
+ nf_ct_expect_put(exp);
|
|
+ goto out;
|
|
+ }
|
|
+out:
|
|
+
|
|
+ return ret;
|
|
+}
|
|
+
|
|
+
|
|
+static inline int
|
|
+help_in(struct sk_buff *skb, size_t pktlen,
|
|
+ struct nf_conn* ct, enum ip_conntrack_info ctinfo)
|
|
+{
|
|
+ return NF_ACCEPT;
|
|
+}
|
|
+
|
|
+static int help(struct sk_buff *skb, unsigned int protoff,
|
|
+ struct nf_conn *ct, enum ip_conntrack_info ctinfo)
|
|
+{
|
|
+ struct tcphdr _tcph, *th;
|
|
+ unsigned int dataoff, datalen;
|
|
+ char *rb_ptr;
|
|
+ int ret = NF_DROP;
|
|
+
|
|
+ /* Until there's been traffic both ways, don't look in packets. */
|
|
+ if (ctinfo != IP_CT_ESTABLISHED &&
|
|
+ ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
|
|
+ DEBUGP("conntrackinfo = %u\n", ctinfo);
|
|
+ return NF_ACCEPT;
|
|
+ }
|
|
+
|
|
+ /* Not whole TCP header? */
|
|
+ th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
|
|
+
|
|
+ if (!th)
|
|
+ return NF_ACCEPT;
|
|
+
|
|
+ /* No data ? */
|
|
+ dataoff = protoff + th->doff*4;
|
|
+ datalen = skb->len - dataoff;
|
|
+ if (dataoff >= skb->len)
|
|
+ return NF_ACCEPT;
|
|
+
|
|
+ spin_lock_bh(&rtsp_buffer_lock);
|
|
+ rb_ptr = skb_header_pointer(skb, dataoff,
|
|
+ skb->len - dataoff, rtsp_buffer);
|
|
+ BUG_ON(rb_ptr == NULL);
|
|
+
|
|
+#if 0
|
|
+ /* Checksum invalid? Ignore. */
|
|
+ /* FIXME: Source route IP option packets --RR */
|
|
+ if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
|
|
+ csum_partial((char*)tcph, tcplen, 0)))
|
|
+ {
|
|
+ DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
|
|
+ tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
|
|
+ return NF_ACCEPT;
|
|
+ }
|
|
+#endif
|
|
+
|
|
+ switch (CTINFO2DIR(ctinfo)) {
|
|
+ case IP_CT_DIR_ORIGINAL:
|
|
+ ret = help_out(skb, 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 nf_conntrack_helper rtsp_helpers[MAX_PORTS];
|
|
+static char rtsp_names[MAX_PORTS][10];
|
|
+static struct nf_conntrack_expect_policy rtsp_expect_policy;
|
|
+
|
|
+/* 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]);
|
|
+ nf_conntrack_helper_unregister(&rtsp_helpers[i]);
|
|
+ }
|
|
+ kfree(rtsp_buffer);
|
|
+}
|
|
+
|
|
+static int __init
|
|
+init(void)
|
|
+{
|
|
+ int i, ret;
|
|
+ struct nf_conntrack_helper *hlpr;
|
|
+ char *tmpname;
|
|
+
|
|
+ printk("nf_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
|
|
+
|
|
+ if (max_outstanding < 1) {
|
|
+ printk("nf_conntrack_rtsp: max_outstanding must be a positive integer\n");
|
|
+ return -EBUSY;
|
|
+ }
|
|
+ if (setup_timeout < 0) {
|
|
+ printk("nf_conntrack_rtsp: setup_timeout must be a positive integer\n");
|
|
+ return -EBUSY;
|
|
+ }
|
|
+
|
|
+ rtsp_expect_policy.max_expected = max_outstanding;
|
|
+ rtsp_expect_policy.timeout = setup_timeout;
|
|
+
|
|
+ rtsp_buffer = kmalloc(65536, GFP_KERNEL);
|
|
+ if (!rtsp_buffer)
|
|
+ return -ENOMEM;
|
|
+
|
|
+ /* If no port given, default to standard rtsp port */
|
|
+ if (ports[0] == 0) {
|
|
+ ports[0] = RTSP_PORT;
|
|
+ }
|
|
+
|
|
+ for (i = 0; (i < MAX_PORTS) && ports[i]; i++) {
|
|
+ hlpr = &rtsp_helpers[i];
|
|
+ memset(hlpr, 0, sizeof(struct nf_conntrack_helper));
|
|
+ hlpr->tuple.src.u.tcp.port = htons(ports[i]);
|
|
+ hlpr->tuple.dst.protonum = IPPROTO_TCP;
|
|
+ hlpr->expect_policy = &rtsp_expect_policy;
|
|
+ hlpr->me = THIS_MODULE;
|
|
+ hlpr->help = help;
|
|
+
|
|
+ tmpname = &rtsp_names[i][0];
|
|
+ if (ports[i] == RTSP_PORT) {
|
|
+ sprintf(tmpname, "rtsp");
|
|
+ } else {
|
|
+ sprintf(tmpname, "rtsp-%d", i);
|
|
+ }
|
|
+ hlpr->name = tmpname;
|
|
+
|
|
+ DEBUGP("port #%d: %d\n", i, ports[i]);
|
|
+
|
|
+ ret = nf_conntrack_helper_register(hlpr);
|
|
+
|
|
+ if (ret) {
|
|
+ printk("nf_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
|
|
+ fini();
|
|
+ return -EBUSY;
|
|
+ }
|
|
+ num_ports++;
|
|
+ }
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+module_init(init);
|
|
+module_exit(fini);
|
|
+
|
|
+EXPORT_SYMBOL(nf_nat_rtsp_hook_expectfn);
|
|
+
|
|
--- /dev/null
|
|
+++ b/net/ipv4/netfilter/nf_nat_rtsp.c
|
|
@@ -0,0 +1,496 @@
|
|
+/*
|
|
+ * RTSP extension for TCP NAT alteration
|
|
+ * (C) 2003 by Tom Marshall <tmarshall at 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 nf_nat_rtsp.o ports=port1,port2,...port<MAX_PORTS>
|
|
+ * stunaddr=<address>
|
|
+ * destaction=[auto|strip|none]
|
|
+ *
|
|
+ * If no ports are specified, the default will be port 554 only.
|
|
+ *
|
|
+ * stunaddr specifies the address used to detect that a client is using STUN.
|
|
+ * If this address is seen in the destination parameter, it is assumed that
|
|
+ * the client has already punched a UDP hole in the firewall, so we don't
|
|
+ * mangle the client_port. If none is specified, it is autodetected. It
|
|
+ * only needs to be set if you have multiple levels of NAT. It should be
|
|
+ * set to the external address that the STUN clients detect. Note that in
|
|
+ * this case, it will not be possible for clients to use UDP with servers
|
|
+ * between the NATs.
|
|
+ *
|
|
+ * If no destaction is specified, auto is used.
|
|
+ * destaction=auto: strip destination parameter if it is not stunaddr.
|
|
+ * destaction=strip: always strip destination parameter (not recommended).
|
|
+ * destaction=none: do not touch destination parameter (not recommended).
|
|
+ */
|
|
+
|
|
+#include <linux/module.h>
|
|
+#include <net/tcp.h>
|
|
+#include <net/netfilter/nf_nat_helper.h>
|
|
+#include <net/netfilter/nf_nat_rule.h>
|
|
+#include <linux/netfilter/nf_conntrack_rtsp.h>
|
|
+#include <net/netfilter/nf_conntrack_expect.h>
|
|
+
|
|
+#include <linux/inet.h>
|
|
+#include <linux/ctype.h>
|
|
+#define NF_NEED_STRNCASECMP
|
|
+#define NF_NEED_STRTOU16
|
|
+#include <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)
|
|
+#if 0
|
|
+#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 at real.com>");
|
|
+MODULE_DESCRIPTION("RTSP network address translation module");
|
|
+MODULE_LICENSE("GPL");
|
|
+module_param(stunaddr, charp, 0644);
|
|
+MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
|
|
+module_param(destaction, charp, 0644);
|
|
+MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
|
|
+
|
|
+#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
|
|
+
|
|
+/*** helper functions ***/
|
|
+
|
|
+static void
|
|
+get_skb_tcpdata(struct sk_buff* skb, char** pptcpdata, uint* ptcpdatalen)
|
|
+{
|
|
+ struct iphdr* iph = ip_hdr(skb);
|
|
+ struct tcphdr* tcph = (void *)iph + ip_hdrlen(skb);
|
|
+
|
|
+ *pptcpdata = (char*)tcph + tcph->doff*4;
|
|
+ *ptcpdatalen = ((char*)skb_transport_header(skb) + skb->len) - *pptcpdata;
|
|
+}
|
|
+
|
|
+/*** nat functions ***/
|
|
+
|
|
+/*
|
|
+ * Mangle the "Transport:" header:
|
|
+ * - Replace all occurences of "client_port=<spec>"
|
|
+ * - Handle destination parameter
|
|
+ *
|
|
+ * In:
|
|
+ * ct, ctinfo = conntrack context
|
|
+ * skb = packet
|
|
+ * tranoff = Transport header offset from TCP data
|
|
+ * tranlen = Transport header length (incl. CRLF)
|
|
+ * rport_lo = replacement low port (host endian)
|
|
+ * rport_hi = replacement high port (host endian)
|
|
+ *
|
|
+ * Returns packet size difference.
|
|
+ *
|
|
+ * Assumes that a complete transport header is present, ending with CR or LF
|
|
+ */
|
|
+static int
|
|
+rtsp_mangle_tran(enum ip_conntrack_info ctinfo,
|
|
+ struct nf_conntrack_expect* exp,
|
|
+ struct ip_ct_rtsp_expect* prtspexp,
|
|
+ struct sk_buff* skb, uint tranoff, uint tranlen)
|
|
+{
|
|
+ char* ptcp;
|
|
+ uint tcplen;
|
|
+ char* ptran;
|
|
+ char rbuf1[16]; /* Replacement buffer (one port) */
|
|
+ uint rbuf1len; /* Replacement len (one port) */
|
|
+ char rbufa[16]; /* Replacement buffer (all ports) */
|
|
+ uint rbufalen; /* Replacement len (all ports) */
|
|
+ u_int32_t newip;
|
|
+ u_int16_t loport, hiport;
|
|
+ uint off = 0;
|
|
+ uint diff; /* Number of bytes we removed */
|
|
+
|
|
+ struct nf_conn *ct = exp->master;
|
|
+ struct nf_conntrack_tuple *t;
|
|
+
|
|
+ char szextaddr[15+1];
|
|
+ uint extaddrlen;
|
|
+ int is_stun;
|
|
+
|
|
+ get_skb_tcpdata(skb, &ptcp, &tcplen);
|
|
+ ptran = ptcp+tranoff;
|
|
+
|
|
+ if (tranoff+tranlen > tcplen || tcplen-tranoff < tranlen ||
|
|
+ tranlen < 10 || !iseol(ptran[tranlen-1]) ||
|
|
+ nf_strncasecmp(ptran, "Transport:", 10) != 0)
|
|
+ {
|
|
+ INFOP("sanity check failed\n");
|
|
+ return 0;
|
|
+ }
|
|
+ off += 10;
|
|
+ SKIP_WSPACE(ptcp+tranoff, tranlen, off);
|
|
+
|
|
+ newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip;
|
|
+ t = &exp->tuple;
|
|
+ t->dst.u3.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 (nf_ct_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 (nf_ct_expect_related(exp) == 0)
|
|
+ {
|
|
+ hiport = loport + ~exp->mask.src.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 (nf_ct_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 (nf_ct_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 (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
|
|
+ off, diff, NULL, 0))
|
|
+ {
|
|
+ /* mangle failed, all we can do is bail */
|
|
+ nf_ct_unexpect_related(exp);
|
|
+ return 0;
|
|
+ }
|
|
+ get_skb_tcpdata(skb, &ptcp, &tcplen);
|
|
+ ptran = ptcp+tranoff;
|
|
+ tranlen -= diff;
|
|
+ nextparamoff -= diff;
|
|
+ nextfieldoff -= diff;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ off = nextfieldoff;
|
|
+ }
|
|
+ if (is_stun)
|
|
+ {
|
|
+ continue;
|
|
+ }
|
|
+ off = saveoff;
|
|
+ while (off < nextparamoff)
|
|
+ {
|
|
+ const char* pfieldend;
|
|
+ uint nextfieldoff;
|
|
+
|
|
+ pfieldend = memchr(ptran+off, ';', nextparamoff-off);
|
|
+ nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
|
|
+
|
|
+ if (strncmp(ptran+off, "client_port=", 12) == 0)
|
|
+ {
|
|
+ u_int16_t port;
|
|
+ uint numlen;
|
|
+ uint origoff;
|
|
+ uint origlen;
|
|
+ char* rbuf = rbuf1;
|
|
+ uint rbuflen = rbuf1len;
|
|
+
|
|
+ off += 12;
|
|
+ origoff = (ptran-ptcp)+off;
|
|
+ origlen = 0;
|
|
+ numlen = nf_strtou16(ptran+off, &port);
|
|
+ off += numlen;
|
|
+ origlen += numlen;
|
|
+ if (port != prtspexp->loport)
|
|
+ {
|
|
+ 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 (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
|
|
+ origoff, origlen, rbuf, rbuflen))
|
|
+ {
|
|
+ /* mangle failed, all we can do is bail */
|
|
+ nf_ct_unexpect_related(exp);
|
|
+ return 0;
|
|
+ }
|
|
+ get_skb_tcpdata(skb, &ptcp, &tcplen);
|
|
+ ptran = ptcp+tranoff;
|
|
+ tranlen -= diff;
|
|
+ nextparamoff -= diff;
|
|
+ nextfieldoff -= diff;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ off = nextfieldoff;
|
|
+ }
|
|
+
|
|
+ off = nextparamoff;
|
|
+ }
|
|
+
|
|
+ return 1;
|
|
+}
|
|
+
|
|
+static uint
|
|
+help_out(struct sk_buff *skb, enum ip_conntrack_info ctinfo,
|
|
+ unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
|
|
+ struct nf_conntrack_expect* exp)
|
|
+{
|
|
+ char* ptcp;
|
|
+ uint tcplen;
|
|
+ uint hdrsoff;
|
|
+ uint hdrslen;
|
|
+ uint lineoff;
|
|
+ uint linelen;
|
|
+ uint off;
|
|
+
|
|
+ //struct iphdr* iph = (struct iphdr*)skb->nh.iph;
|
|
+ //struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
|
|
+
|
|
+ get_skb_tcpdata(skb, &ptcp, &tcplen);
|
|
+ hdrsoff = matchoff;//exp->seq - ntohl(tcph->seq);
|
|
+ hdrslen = matchlen;
|
|
+ off = hdrsoff;
|
|
+ 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, skb, lineoff, linelen))
|
|
+ {
|
|
+ DEBUGP("hdr: Transport mangle failed");
|
|
+ break;
|
|
+ }
|
|
+ get_skb_tcpdata(skb, &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 *skb, enum ip_conntrack_info ctinfo,
|
|
+ unsigned int matchoff, unsigned int matchlen, struct ip_ct_rtsp_expect* prtspexp,
|
|
+ struct nf_conntrack_expect* exp)
|
|
+{
|
|
+ int dir = CTINFO2DIR(ctinfo);
|
|
+ int rc = NF_ACCEPT;
|
|
+
|
|
+ switch (dir)
|
|
+ {
|
|
+ case IP_CT_DIR_ORIGINAL:
|
|
+ rc = help_out(skb, 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 nf_conn* ct, struct nf_conntrack_expect *exp)
|
|
+{
|
|
+ struct nf_nat_multi_range_compat mr;
|
|
+ u_int32_t newdstip, newsrcip, newip;
|
|
+
|
|
+ struct nf_conn *master = ct->master;
|
|
+
|
|
+ newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
|
|
+ newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.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;
|
|
+
|
|
+ nf_nat_setup_info(ct, &mr.range[0], IP_NAT_MANIP_DST);
|
|
+}
|
|
+
|
|
+
|
|
+static void __exit fini(void)
|
|
+{
|
|
+ nf_nat_rtsp_hook = NULL;
|
|
+ nf_nat_rtsp_hook_expectfn = NULL;
|
|
+ synchronize_net();
|
|
+}
|
|
+
|
|
+static int __init init(void)
|
|
+{
|
|
+ printk("nf_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
|
|
+
|
|
+ BUG_ON(nf_nat_rtsp_hook);
|
|
+ nf_nat_rtsp_hook = help;
|
|
+ nf_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);
|