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openwrt/target/linux/generic-2.4/patches/614-netfilter_nat_rtsp.patch

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--- a/net/ipv4/netfilter/Config.in
+++ b/net/ipv4/netfilter/Config.in
@@ -14,6 +14,7 @@ if [ "$CONFIG_IP_NF_CONNTRACK" != "n" ];
dep_tristate ' Connection tracking flow accounting' CONFIG_IP_NF_CT_ACCT $CONFIG_IP_NF_CONNTRACK
dep_tristate ' Connection byte counter support' CONFIG_IP_NF_MATCH_CONNBYTES $CONFIG_IP_NF_CT_ACCT $CONFIG_IP_NF_CONNTRACK $CONFIG_IP_NF_IPTABLES
dep_tristate ' H.323 (netmeeting) support' CONFIG_IP_NF_H323 $CONFIG_IP_NF_CONNTRACK
+ dep_tristate ' RTSP protocol support' CONFIG_IP_NF_RTSP $CONFIG_IP_NF_CONNTRACK
fi
if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
@@ -88,6 +89,13 @@ if [ "$CONFIG_IP_NF_IPTABLES" != "n" ];
define_tristate CONFIG_IP_NF_NAT_H323 $CONFIG_IP_NF_NAT
fi
fi
+ if [ "$CONFIG_IP_NF_RTSP" = "m" ]; then
+ define_tristate CONFIG_IP_NF_NAT_RTSP m
+ else
+ if [ "$CONFIG_IP_NF_RTSP" = "y" ]; then
+ define_tristate CONFIG_IP_NF_NAT_RTSP $CONFIG_IP_NF_NAT
+ fi
+ fi
if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
dep_tristate ' Basic SNMP-ALG support (EXPERIMENTAL)' CONFIG_IP_NF_NAT_SNMP_BASIC $CONFIG_IP_NF_NAT
fi
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -51,6 +51,11 @@ obj-$(CONFIG_IP_NF_H323) += ip_conntrack
ifdef CONFIG_IP_NF_NAT_H323
export-objs += ip_conntrack_h323.o
endif
+obj-$(CONFIG_IP_NF_RTSP) += ip_conntrack_rtsp.o
+ifdef CONFIG_IP_NF_NAT_RTSP
+ export-objs += ip_conntrack_rtsp.o
+endif
+
# NAT helpers
obj-$(CONFIG_IP_NF_NAT_AMANDA) += ip_nat_amanda.o
@@ -58,6 +63,7 @@ obj-$(CONFIG_IP_NF_NAT_TFTP) += ip_nat_t
obj-$(CONFIG_IP_NF_NAT_FTP) += ip_nat_ftp.o
obj-$(CONFIG_IP_NF_NAT_IRC) += ip_nat_irc.o
obj-$(CONFIG_IP_NF_NAT_H323) += ip_nat_h323.o
+obj-$(CONFIG_IP_NF_NAT_RTSP) += ip_nat_rtsp.o
# generic IP tables
obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
--- /dev/null
+++ b/net/ipv4/netfilter/ip_conntrack_rtsp.c
@@ -0,0 +1,507 @@
+/*
+ * RTSP extension for IP connection tracking
+ * (C) 2003 by Tom Marshall <tmarshall@real.com>
+ * based on ip_conntrack_irc.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Module load syntax:
+ * insmod ip_conntrack_rtsp.o ports=port1,port2,...port<MAX_PORTS>
+ * max_outstanding=n setup_timeout=secs
+ *
+ * If no ports are specified, the default will be port 554.
+ *
+ * With max_outstanding you can define the maximum number of not yet
+ * answered SETUP requests per RTSP session (default 8).
+ * With setup_timeout you can specify how long the system waits for
+ * an expected data channel (default 300 seconds).
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+#include <net/tcp.h>
+
+#include <linux/netfilter_ipv4/lockhelp.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/ip_conntrack_rtsp.h>
+
+#include <linux/ctype.h>
+#define NF_NEED_STRNCASECMP
+#define NF_NEED_STRTOU16
+#define NF_NEED_STRTOU32
+#define NF_NEED_NEXTLINE
+#include <linux/netfilter_helpers.h>
+#define NF_NEED_MIME_NEXTLINE
+#include <linux/netfilter_mime.h>
+
+#define MAX_SIMUL_SETUP 8 /* XXX: use max_outstanding */
+
+#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
+#ifdef IP_NF_RTSP_DEBUG
+#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
+#else
+#define DEBUGP(fmt, args...)
+#endif
+
+#define MAX_PORTS 8
+static int ports[MAX_PORTS];
+static int num_ports = 0;
+static int max_outstanding = 8;
+static unsigned int setup_timeout = 300;
+
+MODULE_AUTHOR("Tom Marshall <tmarshall@real.com>");
+MODULE_DESCRIPTION("RTSP connection tracking module");
+MODULE_LICENSE("GPL");
+#ifdef MODULE_PARM
+MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
+MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
+MODULE_PARM(max_outstanding, "i");
+MODULE_PARM_DESC(max_outstanding, "max number of outstanding SETUP requests per RTSP session");
+MODULE_PARM(setup_timeout, "i");
+MODULE_PARM_DESC(setup_timeout, "timeout on for unestablished data channels");
+#endif
+
+DECLARE_LOCK(ip_rtsp_lock);
+struct module* ip_conntrack_rtsp = THIS_MODULE;
+
+/*
+ * Max mappings we will allow for one RTSP connection (for RTP, the number
+ * of allocated ports is twice this value). Note that SMIL burns a lot of
+ * ports so keep this reasonably high. If this is too low, you will see a
+ * lot of "no free client map entries" messages.
+ */
+#define MAX_PORT_MAPS 16
+
+/*** default port list was here in the masq code: 554, 3030, 4040 ***/
+
+#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
+
+/*
+ * Parse an RTSP packet.
+ *
+ * Returns zero if parsing failed.
+ *
+ * Parameters:
+ * IN ptcp tcp data pointer
+ * IN tcplen tcp data len
+ * IN/OUT ptcpoff points to current tcp offset
+ * OUT phdrsoff set to offset of rtsp headers
+ * OUT phdrslen set to length of rtsp headers
+ * OUT pcseqoff set to offset of CSeq header
+ * OUT pcseqlen set to length of CSeq header
+ */
+static int
+rtsp_parse_message(char* ptcp, uint tcplen, uint* ptcpoff,
+ uint* phdrsoff, uint* phdrslen,
+ uint* pcseqoff, uint* pcseqlen)
+{
+ uint entitylen = 0;
+ uint lineoff;
+ uint linelen;
+
+ if (!nf_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
+ {
+ return 0;
+ }
+
+ *phdrsoff = *ptcpoff;
+ while (nf_mime_nextline(ptcp, tcplen, ptcpoff, &lineoff, &linelen))
+ {
+ if (linelen == 0)
+ {
+ if (entitylen > 0)
+ {
+ *ptcpoff += min(entitylen, tcplen - *ptcpoff);
+ }
+ break;
+ }
+ if (lineoff+linelen > tcplen)
+ {
+ INFOP("!! overrun !!\n");
+ break;
+ }
+
+ if (nf_strncasecmp(ptcp+lineoff, "CSeq:", 5) == 0)
+ {
+ *pcseqoff = lineoff;
+ *pcseqlen = linelen;
+ }
+ if (nf_strncasecmp(ptcp+lineoff, "Content-Length:", 15) == 0)
+ {
+ uint off = lineoff+15;
+ SKIP_WSPACE(ptcp+lineoff, linelen, off);
+ nf_strtou32(ptcp+off, &entitylen);
+ }
+ }
+ *phdrslen = (*ptcpoff) - (*phdrsoff);
+
+ return 1;
+}
+
+/*
+ * Find lo/hi client ports (if any) in transport header
+ * In:
+ * ptcp, tcplen = packet
+ * tranoff, tranlen = buffer to search
+ *
+ * Out:
+ * pport_lo, pport_hi = lo/hi ports (host endian)
+ *
+ * Returns nonzero if any client ports found
+ *
+ * Note: it is valid (and expected) for the client to request multiple
+ * transports, so we need to parse the entire line.
+ */
+static int
+rtsp_parse_transport(char* ptran, uint tranlen,
+ struct ip_ct_rtsp_expect* prtspexp)
+{
+ int rc = 0;
+ uint off = 0;
+
+ if (tranlen < 10 || !iseol(ptran[tranlen-1]) ||
+ nf_strncasecmp(ptran, "Transport:", 10) != 0)
+ {
+ INFOP("sanity check failed\n");
+ return 0;
+ }
+ DEBUGP("tran='%.*s'\n", (int)tranlen, ptran);
+ off += 10;
+ SKIP_WSPACE(ptran, tranlen, off);
+
+ /* Transport: tran;field;field=val,tran;field;field=val,... */
+ while (off < tranlen)
+ {
+ const char* pparamend;
+ uint nextparamoff;
+
+ pparamend = memchr(ptran+off, ',', tranlen-off);
+ pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
+ nextparamoff = pparamend-ptran;
+
+ while (off < nextparamoff)
+ {
+ const char* pfieldend;
+ uint nextfieldoff;
+
+ pfieldend = memchr(ptran+off, ';', nextparamoff-off);
+ nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
+
+ if (strncmp(ptran+off, "client_port=", 12) == 0)
+ {
+ u_int16_t port;
+ uint numlen;
+
+ off += 12;
+ numlen = nf_strtou16(ptran+off, &port);
+ off += numlen;
+ if (prtspexp->loport != 0 && prtspexp->loport != port)
+ {
+ DEBUGP("multiple ports found, port %hu ignored\n", port);
+ }
+ else
+ {
+ prtspexp->loport = prtspexp->hiport = port;
+ if (ptran[off] == '-')
+ {
+ off++;
+ numlen = nf_strtou16(ptran+off, &port);
+ off += numlen;
+ prtspexp->pbtype = pb_range;
+ prtspexp->hiport = port;
+
+ // If we have a range, assume rtp:
+ // loport must be even, hiport must be loport+1
+ if ((prtspexp->loport & 0x0001) != 0 ||
+ prtspexp->hiport != prtspexp->loport+1)
+ {
+ DEBUGP("incorrect range: %hu-%hu, correcting\n",
+ prtspexp->loport, prtspexp->hiport);
+ prtspexp->loport &= 0xfffe;
+ prtspexp->hiport = prtspexp->loport+1;
+ }
+ }
+ else if (ptran[off] == '/')
+ {
+ off++;
+ numlen = nf_strtou16(ptran+off, &port);
+ off += numlen;
+ prtspexp->pbtype = pb_discon;
+ prtspexp->hiport = port;
+ }
+ rc = 1;
+ }
+ }
+
+ /*
+ * Note we don't look for the destination parameter here.
+ * If we are using NAT, the NAT module will handle it. If not,
+ * and the client is sending packets elsewhere, the expectation
+ * will quietly time out.
+ */
+
+ off = nextfieldoff;
+ }
+
+ off = nextparamoff;
+ }
+
+ return rc;
+}
+
+/*** conntrack functions ***/
+
+/* outbound packet: client->server */
+static int
+help_out(const struct iphdr* iph, size_t pktlen,
+ struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
+{
+ int dir = CTINFO2DIR(ctinfo); /* = IP_CT_DIR_ORIGINAL */
+ struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
+ uint tcplen = pktlen - iph->ihl * 4;
+ char* pdata = (char*)tcph + tcph->doff * 4;
+ uint datalen = tcplen - tcph->doff * 4;
+ uint dataoff = 0;
+
+ struct ip_conntrack_expect exp;
+
+ while (dataoff < datalen)
+ {
+ uint cmdoff = dataoff;
+ uint hdrsoff = 0;
+ uint hdrslen = 0;
+ uint cseqoff = 0;
+ uint cseqlen = 0;
+ uint lineoff = 0;
+ uint linelen = 0;
+ uint off;
+ int rc;
+
+ if (!rtsp_parse_message(pdata, datalen, &dataoff,
+ &hdrsoff, &hdrslen,
+ &cseqoff, &cseqlen))
+ {
+ break; /* not a valid message */
+ }
+
+ if (strncmp(pdata+cmdoff, "SETUP ", 6) != 0)
+ {
+ continue; /* not a SETUP message */
+ }
+ DEBUGP("found a setup message\n");
+
+ memset(&exp, 0, sizeof(exp));
+
+ off = 0;
+ while (nf_mime_nextline(pdata+hdrsoff, hdrslen, &off,
+ &lineoff, &linelen))
+ {
+ if (linelen == 0)
+ {
+ break;
+ }
+ if (off > hdrsoff+hdrslen)
+ {
+ INFOP("!! overrun !!");
+ break;
+ }
+
+ if (nf_strncasecmp(pdata+hdrsoff+lineoff, "Transport:", 10) == 0)
+ {
+ rtsp_parse_transport(pdata+hdrsoff+lineoff, linelen,
+ &exp.help.exp_rtsp_info);
+ }
+ }
+
+ if (exp.help.exp_rtsp_info.loport == 0)
+ {
+ DEBUGP("no udp transports found\n");
+ continue; /* no udp transports found */
+ }
+
+ DEBUGP("udp transport found, ports=(%d,%hu,%hu)\n",
+ (int)exp.help.exp_rtsp_info.pbtype,
+ exp.help.exp_rtsp_info.loport,
+ exp.help.exp_rtsp_info.hiport);
+
+ LOCK_BH(&ip_rtsp_lock);
+ exp.seq = ntohl(tcph->seq) + hdrsoff; /* mark all the headers */
+ exp.help.exp_rtsp_info.len = hdrslen;
+
+ exp.tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
+ exp.mask.src.ip = 0xffffffff;
+ exp.tuple.dst.ip = ct->tuplehash[dir].tuple.src.ip;
+ exp.mask.dst.ip = 0xffffffff;
+ exp.tuple.dst.u.udp.port = exp.help.exp_rtsp_info.loport;
+ exp.mask.dst.u.udp.port = (exp.help.exp_rtsp_info.pbtype == pb_range) ? 0xfffe : 0xffff;
+ exp.tuple.dst.protonum = IPPROTO_UDP;
+ exp.mask.dst.protonum = 0xffff;
+
+ DEBUGP("expect_related %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
+ NIPQUAD(exp.tuple.src.ip),
+ ntohs(exp.tuple.src.u.tcp.port),
+ NIPQUAD(exp.tuple.dst.ip),
+ ntohs(exp.tuple.dst.u.tcp.port));
+
+ /* pass the request off to the nat helper */
+ rc = ip_conntrack_expect_related(ct, &exp);
+ UNLOCK_BH(&ip_rtsp_lock);
+ if (rc == 0)
+ {
+ DEBUGP("ip_conntrack_expect_related succeeded\n");
+ }
+ else
+ {
+ INFOP("ip_conntrack_expect_related failed (%d)\n", rc);
+ }
+ }
+
+ return NF_ACCEPT;
+}
+
+/* inbound packet: server->client */
+static int
+help_in(const struct iphdr* iph, size_t pktlen,
+ struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
+{
+ return NF_ACCEPT;
+}
+
+static int
+help(const struct iphdr* iph, size_t pktlen,
+ struct ip_conntrack* ct, enum ip_conntrack_info ctinfo)
+{
+ /* tcplen not negative guarenteed by ip_conntrack_tcp.c */
+ struct tcphdr* tcph = (void*)iph + iph->ihl * 4;
+ u_int32_t tcplen = pktlen - iph->ihl * 4;
+
+ /* Until there's been traffic both ways, don't look in packets. */
+ if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY)
+ {
+ DEBUGP("conntrackinfo = %u\n", ctinfo);
+ return NF_ACCEPT;
+ }
+
+ /* Not whole TCP header? */
+ if (tcplen < sizeof(struct tcphdr) || tcplen < tcph->doff * 4)
+ {
+ DEBUGP("tcplen = %u\n", (unsigned)tcplen);
+ return NF_ACCEPT;
+ }
+
+ /* Checksum invalid? Ignore. */
+ /* FIXME: Source route IP option packets --RR */
+ if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
+ csum_partial((char*)tcph, tcplen, 0)))
+ {
+ DEBUGP("bad csum: %p %u %u.%u.%u.%u %u.%u.%u.%u\n",
+ tcph, tcplen, NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
+ return NF_ACCEPT;
+ }
+
+ switch (CTINFO2DIR(ctinfo))
+ {
+ case IP_CT_DIR_ORIGINAL:
+ help_out(iph, pktlen, ct, ctinfo);
+ break;
+ case IP_CT_DIR_REPLY:
+ help_in(iph, pktlen, ct, ctinfo);
+ break;
+ }
+
+ return NF_ACCEPT;
+}
+
+static struct ip_conntrack_helper rtsp_helpers[MAX_PORTS];
+static char rtsp_names[MAX_PORTS][10];
+
+/* This function is intentionally _NOT_ defined as __exit */
+static void
+fini(void)
+{
+ int i;
+ for (i = 0; i < num_ports; i++)
+ {
+ DEBUGP("unregistering port %d\n", ports[i]);
+ ip_conntrack_helper_unregister(&rtsp_helpers[i]);
+ }
+}
+
+static int __init
+init(void)
+{
+ int i, ret;
+ struct ip_conntrack_helper *hlpr;
+ char *tmpname;
+
+ printk("ip_conntrack_rtsp v" IP_NF_RTSP_VERSION " loading\n");
+
+ if (max_outstanding < 1)
+ {
+ printk("ip_conntrack_rtsp: max_outstanding must be a positive integer\n");
+ return -EBUSY;
+ }
+ if (setup_timeout < 0)
+ {
+ printk("ip_conntrack_rtsp: setup_timeout must be a positive integer\n");
+ return -EBUSY;
+ }
+
+ /* If no port given, default to standard rtsp port */
+ if (ports[0] == 0)
+ {
+ ports[0] = RTSP_PORT;
+ }
+
+ for (i = 0; (i < MAX_PORTS) && ports[i]; i++)
+ {
+ hlpr = &rtsp_helpers[i];
+ memset(hlpr, 0, sizeof(struct ip_conntrack_helper));
+ hlpr->tuple.src.u.tcp.port = htons(ports[i]);
+ hlpr->tuple.dst.protonum = IPPROTO_TCP;
+ hlpr->mask.src.u.tcp.port = 0xFFFF;
+ hlpr->mask.dst.protonum = 0xFFFF;
+ hlpr->max_expected = max_outstanding;
+ hlpr->timeout = setup_timeout;
+ hlpr->flags = IP_CT_HELPER_F_REUSE_EXPECT;
+ hlpr->me = ip_conntrack_rtsp;
+ hlpr->help = help;
+
+ tmpname = &rtsp_names[i][0];
+ if (ports[i] == RTSP_PORT)
+ {
+ sprintf(tmpname, "rtsp");
+ }
+ else
+ {
+ sprintf(tmpname, "rtsp-%d", i);
+ }
+ hlpr->name = tmpname;
+
+ DEBUGP("port #%d: %d\n", i, ports[i]);
+
+ ret = ip_conntrack_helper_register(hlpr);
+
+ if (ret)
+ {
+ printk("ip_conntrack_rtsp: ERROR registering port %d\n", ports[i]);
+ fini();
+ return -EBUSY;
+ }
+ num_ports++;
+ }
+ return 0;
+}
+
+#ifdef CONFIG_IP_NF_NAT_NEEDED
+EXPORT_SYMBOL(ip_rtsp_lock);
+#endif
+
+module_init(init);
+module_exit(fini);
--- /dev/null
+++ b/net/ipv4/netfilter/ip_nat_rtsp.c
@@ -0,0 +1,621 @@
+/*
+ * RTSP extension for TCP NAT alteration
+ * (C) 2003 by Tom Marshall <tmarshall@real.com>
+ * based on ip_nat_irc.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Module load syntax:
+ * insmod ip_nat_rtsp.o ports=port1,port2,...port<MAX_PORTS>
+ * stunaddr=<address>
+ * destaction=[auto|strip|none]
+ *
+ * If no ports are specified, the default will be port 554 only.
+ *
+ * stunaddr specifies the address used to detect that a client is using STUN.
+ * If this address is seen in the destination parameter, it is assumed that
+ * the client has already punched a UDP hole in the firewall, so we don't
+ * mangle the client_port. If none is specified, it is autodetected. It
+ * only needs to be set if you have multiple levels of NAT. It should be
+ * set to the external address that the STUN clients detect. Note that in
+ * this case, it will not be possible for clients to use UDP with servers
+ * between the NATs.
+ *
+ * If no destaction is specified, auto is used.
+ * destaction=auto: strip destination parameter if it is not stunaddr.
+ * destaction=strip: always strip destination parameter (not recommended).
+ * destaction=none: do not touch destination parameter (not recommended).
+ */
+
+#include <linux/module.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/kernel.h>
+#include <net/tcp.h>
+#include <linux/netfilter_ipv4/ip_nat.h>
+#include <linux/netfilter_ipv4/ip_nat_helper.h>
+#include <linux/netfilter_ipv4/ip_nat_rule.h>
+#include <linux/netfilter_ipv4/ip_conntrack_rtsp.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+
+#include <linux/inet.h>
+#include <linux/ctype.h>
+#define NF_NEED_STRNCASECMP
+#define NF_NEED_STRTOU16
+#include <linux/netfilter_helpers.h>
+#define NF_NEED_MIME_NEXTLINE
+#include <linux/netfilter_mime.h>
+
+#define INFOP(fmt, args...) printk(KERN_INFO "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
+#ifdef IP_NF_RTSP_DEBUG
+#define DEBUGP(fmt, args...) printk(KERN_DEBUG "%s: %s: " fmt, __FILE__, __FUNCTION__ , ## args)
+#else
+#define DEBUGP(fmt, args...)
+#endif
+
+#define MAX_PORTS 8
+#define DSTACT_AUTO 0
+#define DSTACT_STRIP 1
+#define DSTACT_NONE 2
+
+static int ports[MAX_PORTS];
+static char* stunaddr = NULL;
+static char* destaction = NULL;
+
+static int num_ports = 0;
+static u_int32_t extip = 0;
+static int dstact = 0;
+
+MODULE_AUTHOR("Tom Marshall <tmarshall@real.com>");
+MODULE_DESCRIPTION("RTSP network address translation module");
+MODULE_LICENSE("GPL");
+#ifdef MODULE_PARM
+MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
+MODULE_PARM_DESC(ports, "port numbers of RTSP servers");
+MODULE_PARM(stunaddr, "s");
+MODULE_PARM_DESC(stunaddr, "Address for detecting STUN");
+MODULE_PARM(destaction, "s");
+MODULE_PARM_DESC(destaction, "Action for destination parameter (auto/strip/none)");
+#endif
+
+/* protects rtsp part of conntracks */
+DECLARE_LOCK_EXTERN(ip_rtsp_lock);
+
+#define SKIP_WSPACE(ptr,len,off) while(off < len && isspace(*(ptr+off))) { off++; }
+
+/*** helper functions ***/
+
+static void
+get_skb_tcpdata(struct sk_buff* skb, char** pptcpdata, uint* ptcpdatalen)
+{
+ struct iphdr* iph = (struct iphdr*)skb->nh.iph;
+ struct tcphdr* tcph = (struct tcphdr*)((char*)iph + iph->ihl*4);
+
+ *pptcpdata = (char*)tcph + tcph->doff*4;
+ *ptcpdatalen = ((char*)skb->h.raw + skb->len) - *pptcpdata;
+}
+
+/*** nat functions ***/
+
+/*
+ * Mangle the "Transport:" header:
+ * - Replace all occurences of "client_port=<spec>"
+ * - Handle destination parameter
+ *
+ * In:
+ * ct, ctinfo = conntrack context
+ * pskb = packet
+ * tranoff = Transport header offset from TCP data
+ * tranlen = Transport header length (incl. CRLF)
+ * rport_lo = replacement low port (host endian)
+ * rport_hi = replacement high port (host endian)
+ *
+ * Returns packet size difference.
+ *
+ * Assumes that a complete transport header is present, ending with CR or LF
+ */
+static int
+rtsp_mangle_tran(struct ip_conntrack* ct, enum ip_conntrack_info ctinfo,
+ struct ip_conntrack_expect* exp,
+ struct sk_buff** pskb, uint tranoff, uint tranlen)
+{
+ char* ptcp;
+ uint tcplen;
+ char* ptran;
+ char rbuf1[16]; /* Replacement buffer (one port) */
+ uint rbuf1len; /* Replacement len (one port) */
+ char rbufa[16]; /* Replacement buffer (all ports) */
+ uint rbufalen; /* Replacement len (all ports) */
+ u_int32_t newip;
+ u_int16_t loport, hiport;
+ uint off = 0;
+ uint diff; /* Number of bytes we removed */
+
+ struct ip_ct_rtsp_expect* prtspexp = &exp->help.exp_rtsp_info;
+ struct ip_conntrack_tuple t;
+
+ char szextaddr[15+1];
+ uint extaddrlen;
+ int is_stun;
+
+ get_skb_tcpdata(*pskb, &ptcp, &tcplen);
+ ptran = ptcp+tranoff;
+
+ if (tranoff+tranlen > tcplen || tcplen-tranoff < tranlen ||
+ tranlen < 10 || !iseol(ptran[tranlen-1]) ||
+ nf_strncasecmp(ptran, "Transport:", 10) != 0)
+ {
+ INFOP("sanity check failed\n");
+ return 0;
+ }
+ off += 10;
+ SKIP_WSPACE(ptcp+tranoff, tranlen, off);
+
+ newip = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
+ t = exp->tuple;
+ t.dst.ip = newip;
+
+ extaddrlen = extip ? sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(extip))
+ : sprintf(szextaddr, "%u.%u.%u.%u", NIPQUAD(newip));
+ DEBUGP("stunaddr=%s (%s)\n", szextaddr, (extip?"forced":"auto"));
+
+ rbuf1len = rbufalen = 0;
+ switch (prtspexp->pbtype)
+ {
+ case pb_single:
+ for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
+ {
+ t.dst.u.udp.port = htons(loport);
+ if (ip_conntrack_change_expect(exp, &t) == 0)
+ {
+ DEBUGP("using port %hu\n", loport);
+ break;
+ }
+ }
+ if (loport != 0)
+ {
+ rbuf1len = sprintf(rbuf1, "%hu", loport);
+ rbufalen = sprintf(rbufa, "%hu", loport);
+ }
+ break;
+ case pb_range:
+ for (loport = prtspexp->loport; loport != 0; loport += 2) /* XXX: improper wrap? */
+ {
+ t.dst.u.udp.port = htons(loport);
+ if (ip_conntrack_change_expect(exp, &t) == 0)
+ {
+ hiport = loport + ~exp->mask.dst.u.udp.port;
+ DEBUGP("using ports %hu-%hu\n", loport, hiport);
+ break;
+ }
+ }
+ if (loport != 0)
+ {
+ rbuf1len = sprintf(rbuf1, "%hu", loport);
+ rbufalen = sprintf(rbufa, "%hu-%hu", loport, loport+1);
+ }
+ break;
+ case pb_discon:
+ for (loport = prtspexp->loport; loport != 0; loport++) /* XXX: improper wrap? */
+ {
+ t.dst.u.udp.port = htons(loport);
+ if (ip_conntrack_change_expect(exp, &t) == 0)
+ {
+ DEBUGP("using port %hu (1 of 2)\n", loport);
+ break;
+ }
+ }
+ for (hiport = prtspexp->hiport; hiport != 0; hiport++) /* XXX: improper wrap? */
+ {
+ t.dst.u.udp.port = htons(hiport);
+ if (ip_conntrack_change_expect(exp, &t) == 0)
+ {
+ DEBUGP("using port %hu (2 of 2)\n", hiport);
+ break;
+ }
+ }
+ if (loport != 0 && hiport != 0)
+ {
+ rbuf1len = sprintf(rbuf1, "%hu", loport);
+ if (hiport == loport+1)
+ {
+ rbufalen = sprintf(rbufa, "%hu-%hu", loport, hiport);
+ }
+ else
+ {
+ rbufalen = sprintf(rbufa, "%hu/%hu", loport, hiport);
+ }
+ }
+ break;
+ }
+
+ if (rbuf1len == 0)
+ {
+ return 0; /* cannot get replacement port(s) */
+ }
+
+ /* Transport: tran;field;field=val,tran;field;field=val,... */
+ while (off < tranlen)
+ {
+ uint saveoff;
+ const char* pparamend;
+ uint nextparamoff;
+
+ pparamend = memchr(ptran+off, ',', tranlen-off);
+ pparamend = (pparamend == NULL) ? ptran+tranlen : pparamend+1;
+ nextparamoff = pparamend-ptcp;
+
+ /*
+ * We pass over each param twice. On the first pass, we look for a
+ * destination= field. It is handled by the security policy. If it
+ * is present, allowed, and equal to our external address, we assume
+ * that STUN is being used and we leave the client_port= field alone.
+ */
+ is_stun = 0;
+ saveoff = off;
+ while (off < nextparamoff)
+ {
+ const char* pfieldend;
+ uint nextfieldoff;
+
+ pfieldend = memchr(ptran+off, ';', nextparamoff-off);
+ nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
+
+ if (dstact != DSTACT_NONE && strncmp(ptran+off, "destination=", 12) == 0)
+ {
+ if (strncmp(ptran+off+12, szextaddr, extaddrlen) == 0)
+ {
+ is_stun = 1;
+ }
+ if (dstact == DSTACT_STRIP || (dstact == DSTACT_AUTO && !is_stun))
+ {
+ diff = nextfieldoff-off;
+ if (!ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
+ off, diff, NULL, 0))
+ {
+ /* mangle failed, all we can do is bail */
+ return 0;
+ }
+ get_skb_tcpdata(*pskb, &ptcp, &tcplen);
+ ptran = ptcp+tranoff;
+ tranlen -= diff;
+ nextparamoff -= diff;
+ nextfieldoff -= diff;
+ }
+ }
+
+ off = nextfieldoff;
+ }
+ if (is_stun)
+ {
+ continue;
+ }
+ off = saveoff;
+ while (off < nextparamoff)
+ {
+ const char* pfieldend;
+ uint nextfieldoff;
+
+ pfieldend = memchr(ptran+off, ';', nextparamoff-off);
+ nextfieldoff = (pfieldend == NULL) ? nextparamoff : pfieldend-ptran+1;
+
+ if (strncmp(ptran+off, "client_port=", 12) == 0)
+ {
+ u_int16_t port;
+ uint numlen;
+ uint origoff;
+ uint origlen;
+ char* rbuf = rbuf1;
+ uint rbuflen = rbuf1len;
+
+ off += 12;
+ origoff = (ptran-ptcp)+off;
+ origlen = 0;
+ numlen = nf_strtou16(ptran+off, &port);
+ off += numlen;
+ origlen += numlen;
+ if (port != prtspexp->loport)
+ {
+ DEBUGP("multiple ports found, port %hu ignored\n", port);
+ }
+ else
+ {
+ if (ptran[off] == '-' || ptran[off] == '/')
+ {
+ off++;
+ origlen++;
+ numlen = nf_strtou16(ptran+off, &port);
+ off += numlen;
+ origlen += numlen;
+ rbuf = rbufa;
+ rbuflen = rbufalen;
+ }
+
+ /*
+ * note we cannot just memcpy() if the sizes are the same.
+ * the mangle function does skb resizing, checks for a
+ * cloned skb, and updates the checksums.
+ *
+ * parameter 4 below is offset from start of tcp data.
+ */
+ diff = origlen-rbuflen;
+ if (!ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
+ origoff, origlen, rbuf, rbuflen))
+ {
+ /* mangle failed, all we can do is bail */
+ return 0;
+ }
+ get_skb_tcpdata(*pskb, &ptcp, &tcplen);
+ ptran = ptcp+tranoff;
+ tranlen -= diff;
+ nextparamoff -= diff;
+ nextfieldoff -= diff;
+ }
+ }
+
+ off = nextfieldoff;
+ }
+
+ off = nextparamoff;
+ }
+
+ return 1;
+}
+
+static unsigned int
+expected(struct sk_buff **pskb, uint hooknum, struct ip_conntrack* ct, struct ip_nat_info* info)
+{
+ struct ip_nat_multi_range mr;
+ u_int32_t newdstip, newsrcip, newip;
+
+ struct ip_conntrack *master = master_ct(ct);
+
+ IP_NF_ASSERT(info);
+ IP_NF_ASSERT(master);
+
+ IP_NF_ASSERT(!(info->initialized & (1 << HOOK2MANIP(hooknum))));
+
+ newdstip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ newsrcip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
+ newip = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC) ? newsrcip : newdstip;
+
+ DEBUGP("newsrcip=%u.%u.%u.%u, newdstip=%u.%u.%u.%u, newip=%u.%u.%u.%u\n",
+ NIPQUAD(newsrcip), NIPQUAD(newdstip), NIPQUAD(newip));
+
+ mr.rangesize = 1;
+ /* We don't want to manip the per-protocol, just the IPs. */
+ mr.range[0].flags = IP_NAT_RANGE_MAP_IPS;
+ mr.range[0].min_ip = mr.range[0].max_ip = newip;
+
+ return ip_nat_setup_info(ct, &mr, hooknum);
+}
+
+static uint
+help_out(struct ip_conntrack* ct, enum ip_conntrack_info ctinfo,
+ struct ip_conntrack_expect* exp, struct sk_buff** pskb)
+{
+ char* ptcp;
+ uint tcplen;
+ uint hdrsoff;
+ uint hdrslen;
+ uint lineoff;
+ uint linelen;
+ uint off;
+
+ struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
+ struct tcphdr* tcph = (struct tcphdr*)((void*)iph + iph->ihl*4);
+
+ struct ip_ct_rtsp_expect* prtspexp = &exp->help.exp_rtsp_info;
+
+ get_skb_tcpdata(*pskb, &ptcp, &tcplen);
+
+ hdrsoff = exp->seq - ntohl(tcph->seq);
+ hdrslen = prtspexp->len;
+ off = hdrsoff;
+
+ while (nf_mime_nextline(ptcp, hdrsoff+hdrslen, &off, &lineoff, &linelen))
+ {
+ if (linelen == 0)
+ {
+ break;
+ }
+ if (off > hdrsoff+hdrslen)
+ {
+ INFOP("!! overrun !!");
+ break;
+ }
+ DEBUGP("hdr: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
+
+ if (nf_strncasecmp(ptcp+lineoff, "Transport:", 10) == 0)
+ {
+ uint oldtcplen = tcplen;
+ if (!rtsp_mangle_tran(ct, ctinfo, exp, pskb, lineoff, linelen))
+ {
+ break;
+ }
+ get_skb_tcpdata(*pskb, &ptcp, &tcplen);
+ hdrslen -= (oldtcplen-tcplen);
+ off -= (oldtcplen-tcplen);
+ lineoff -= (oldtcplen-tcplen);
+ linelen -= (oldtcplen-tcplen);
+ DEBUGP("rep: len=%u, %.*s", linelen, (int)linelen, ptcp+lineoff);
+ }
+ }
+
+ return NF_ACCEPT;
+}
+
+static uint
+help_in(struct ip_conntrack* ct, enum ip_conntrack_info ctinfo,
+ struct ip_conntrack_expect* exp, struct sk_buff** pskb)
+{
+ /* XXX: unmangle */
+ return NF_ACCEPT;
+}
+
+static uint
+help(struct ip_conntrack* ct,
+ struct ip_conntrack_expect* exp,
+ struct ip_nat_info* info,
+ enum ip_conntrack_info ctinfo,
+ unsigned int hooknum,
+ struct sk_buff** pskb)
+{
+ struct iphdr* iph = (struct iphdr*)(*pskb)->nh.iph;
+ struct tcphdr* tcph = (struct tcphdr*)((char*)iph + iph->ihl * 4);
+ uint datalen;
+ int dir;
+ struct ip_ct_rtsp_expect* ct_rtsp_info;
+ int rc = NF_ACCEPT;
+
+ if (ct == NULL || exp == NULL || info == NULL || pskb == NULL)
+ {
+ DEBUGP("!! null ptr (%p,%p,%p,%p) !!\n", ct, exp, info, pskb);
+ return NF_ACCEPT;
+ }
+
+ ct_rtsp_info = &exp->help.exp_rtsp_info;
+
+ /*
+ * Only mangle things once: original direction in POST_ROUTING
+ * and reply direction on PRE_ROUTING.
+ */
+ dir = CTINFO2DIR(ctinfo);
+ if (!((hooknum == NF_IP_POST_ROUTING && dir == IP_CT_DIR_ORIGINAL)
+ || (hooknum == NF_IP_PRE_ROUTING && dir == IP_CT_DIR_REPLY)))
+ {
+ DEBUGP("Not touching dir %s at hook %s\n",
+ dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY",
+ hooknum == NF_IP_POST_ROUTING ? "POSTROUTING"
+ : hooknum == NF_IP_PRE_ROUTING ? "PREROUTING"
+ : hooknum == NF_IP_LOCAL_OUT ? "OUTPUT" : "???");
+ return NF_ACCEPT;
+ }
+ DEBUGP("got beyond not touching\n");
+
+ datalen = (*pskb)->len - iph->ihl * 4 - tcph->doff * 4;
+
+ LOCK_BH(&ip_rtsp_lock);
+ /* Ensure the packet contains all of the marked data */
+ if (!between(exp->seq + ct_rtsp_info->len,
+ ntohl(tcph->seq), ntohl(tcph->seq) + datalen))
+ {
+ /* Partial retransmission? Probably a hacker. */
+ if (net_ratelimit())
+ {
+ INFOP("partial packet %u/%u in %u/%u\n",
+ exp->seq, ct_rtsp_info->len, ntohl(tcph->seq), ntohl(tcph->seq) + datalen);
+ }
+ UNLOCK_BH(&ip_rtsp_lock);
+ return NF_DROP;
+ }
+
+ switch (dir)
+ {
+ case IP_CT_DIR_ORIGINAL:
+ rc = help_out(ct, ctinfo, exp, pskb);
+ break;
+ case IP_CT_DIR_REPLY:
+ rc = help_in(ct, ctinfo, exp, pskb);
+ break;
+ }
+ UNLOCK_BH(&ip_rtsp_lock);
+
+ return rc;
+}
+
+static struct ip_nat_helper ip_nat_rtsp_helpers[MAX_PORTS];
+static char rtsp_names[MAX_PORTS][10];
+
+/* This function is intentionally _NOT_ defined as __exit */
+static void
+fini(void)
+{
+ int i;
+
+ for (i = 0; i < num_ports; i++)
+ {
+ DEBUGP("unregistering helper for port %d\n", ports[i]);
+ ip_nat_helper_unregister(&ip_nat_rtsp_helpers[i]);
+ }
+}
+
+static int __init
+init(void)
+{
+ int ret = 0;
+ int i;
+ struct ip_nat_helper* hlpr;
+ char* tmpname;
+
+ printk("ip_nat_rtsp v" IP_NF_RTSP_VERSION " loading\n");
+
+ if (ports[0] == 0)
+ {
+ ports[0] = RTSP_PORT;
+ }
+
+ for (i = 0; (i < MAX_PORTS) && ports[i] != 0; i++)
+ {
+ hlpr = &ip_nat_rtsp_helpers[i];
+ memset(hlpr, 0, sizeof(struct ip_nat_helper));
+
+ hlpr->tuple.dst.protonum = IPPROTO_TCP;
+ hlpr->tuple.src.u.tcp.port = htons(ports[i]);
+ hlpr->mask.src.u.tcp.port = 0xFFFF;
+ hlpr->mask.dst.protonum = 0xFFFF;
+ hlpr->help = help;
+ hlpr->flags = 0;
+ hlpr->me = THIS_MODULE;
+ hlpr->expect = expected;
+
+ tmpname = &rtsp_names[i][0];
+ if (ports[i] == RTSP_PORT)
+ {
+ sprintf(tmpname, "rtsp");
+ }
+ else
+ {
+ sprintf(tmpname, "rtsp-%d", i);
+ }
+ hlpr->name = tmpname;
+
+ DEBUGP("registering helper for port %d: name %s\n", ports[i], hlpr->name);
+ ret = ip_nat_helper_register(hlpr);
+
+ if (ret)
+ {
+ printk("ip_nat_rtsp: error registering helper for port %d\n", ports[i]);
+ fini();
+ return 1;
+ }
+ num_ports++;
+ }
+ if (stunaddr != NULL)
+ {
+ extip = in_aton(stunaddr);
+ }
+ if (destaction != NULL)
+ {
+ if (strcmp(destaction, "auto") == 0)
+ {
+ dstact = DSTACT_AUTO;
+ }
+ if (strcmp(destaction, "strip") == 0)
+ {
+ dstact = DSTACT_STRIP;
+ }
+ if (strcmp(destaction, "none") == 0)
+ {
+ dstact = DSTACT_NONE;
+ }
+ }
+ return ret;
+}
+
+module_init(init);
+module_exit(fini);
--- a/arch/mips/kernel/mips_ksyms.c
+++ b/arch/mips/kernel/mips_ksyms.c
@@ -52,6 +52,7 @@ EXPORT_SYMBOL(EISA_bus);
/*
* String functions
*/
+EXPORT_SYMBOL_NOVERS(memchr);
EXPORT_SYMBOL_NOVERS(memcmp);
EXPORT_SYMBOL_NOVERS(memset);
EXPORT_SYMBOL_NOVERS(memcpy);
--- /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_ipv4/ip_conntrack_rtsp.h
@@ -0,0 +1,68 @@
+/*
+ * RTSP extension for IP connection tracking.
+ * (C) 2003 by Tom Marshall <tmarshall@real.com>
+ * based on ip_conntrack_irc.h
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#ifndef _IP_CONNTRACK_RTSP_H
+#define _IP_CONNTRACK_RTSP_H
+
+/* #define IP_NF_RTSP_DEBUG */
+#define IP_NF_RTSP_VERSION "0.01"
+
+/* port block types */
+typedef enum {
+ pb_single, /* client_port=x */
+ pb_range, /* client_port=x-y */
+ pb_discon /* client_port=x/y (rtspbis) */
+} portblock_t;
+
+/* We record seq number and length of rtsp headers here, all in host order. */
+
+/*
+ * This structure is per expected connection. It is a member of struct
+ * ip_conntrack_expect. The TCP SEQ for the conntrack expect is stored
+ * there and we are expected to only store the length of the data which
+ * needs replaced. If a packet contains multiple RTSP messages, we create
+ * one expected connection per message.
+ *
+ * We use these variables to mark the entire header block. This may seem
+ * like overkill, but the nature of RTSP requires it. A header may appear
+ * multiple times in a message. We must treat two Transport headers the
+ * same as one Transport header with two entries.
+ */
+struct ip_ct_rtsp_expect
+{
+ u_int32_t len; /* length of header block */
+ portblock_t pbtype; /* Type of port block that was requested */
+ u_int16_t loport; /* Port that was requested, low or first */
+ u_int16_t hiport; /* Port that was requested, high or second */
+#if 0
+ uint method; /* RTSP method */
+ uint cseq; /* CSeq from request */
+#endif
+};
+
+/* This structure exists only once per master */
+struct ip_ct_rtsp_master
+{
+ /* Empty (?) */
+};
+
+
+#ifdef __KERNEL__
+
+#include <linux/netfilter_ipv4/lockhelp.h>
+
+#define RTSP_PORT 554
+
+/* Protects rtsp part of conntracks */
+DECLARE_LOCK_EXTERN(ip_rtsp_lock);
+
+#endif /* __KERNEL__ */
+
+#endif /* _IP_CONNTRACK_RTSP_H */
--- /dev/null
+++ b/include/linux/netfilter_mime.h
@@ -0,0 +1,90 @@
+/*
+ * MIME functions for netfilter modules. This file provides implementations
+ * for basic MIME parsing. MIME headers are used in many protocols, such as
+ * HTTP, RTSP, SIP, etc.
+ *
+ * gcc will warn for defined but unused functions, so we only include the
+ * functions requested. The following macros are used:
+ * NF_NEED_MIME_NEXTLINE nf_mime_nextline()
+ */
+#ifndef _NETFILTER_MIME_H
+#define _NETFILTER_MIME_H
+
+/* Only include these functions for kernel code. */
+#ifdef __KERNEL__
+
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+
+/*
+ * Given a buffer and length, advance to the next line and mark the current
+ * line. If the current line is empty, *plinelen will be set to zero. If
+ * not, it will be set to the actual line length (including CRLF).
+ *
+ * 'line' in this context means logical line (includes LWS continuations).
+ * Returns 1 on success, 0 on failure.
+ */
+#ifdef NF_NEED_MIME_NEXTLINE
+static int
+nf_mime_nextline(char* p, uint len, uint* poff, uint* plineoff, uint* plinelen)
+{
+ uint off = *poff;
+ uint physlen = 0;
+ int is_first_line = 1;
+
+ if (off >= len)
+ {
+ return 0;
+ }
+
+ do
+ {
+ while (p[off] != '\n')
+ {
+ if (len-off <= 1)
+ {
+ return 0;
+ }
+
+ physlen++;
+ off++;
+ }
+
+ /* if we saw a crlf, physlen needs adjusted */
+ if (physlen > 0 && p[off] == '\n' && p[off-1] == '\r')
+ {
+ physlen--;
+ }
+
+ /* advance past the newline */
+ off++;
+
+ /* check for an empty line */
+ if (physlen == 0)
+ {
+ break;
+ }
+
+ /* check for colon on the first physical line */
+ if (is_first_line)
+ {
+ is_first_line = 0;
+ if (memchr(p+(*poff), ':', physlen) == NULL)
+ {
+ return 0;
+ }
+ }
+ }
+ while (p[off] == ' ' || p[off] == '\t');
+
+ *plineoff = *poff;
+ *plinelen = (physlen == 0) ? 0 : (off - *poff);
+ *poff = off;
+
+ return 1;
+}
+#endif /* NF_NEED_MIME_NEXTLINE */
+
+#endif /* __KERNEL__ */
+
+#endif /* _NETFILTER_MIME_H */
--- a/include/linux/netfilter_ipv4/ip_conntrack.h
+++ b/include/linux/netfilter_ipv4/ip_conntrack.h
@@ -68,6 +68,7 @@ union ip_conntrack_expect_proto {
#include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
#include <linux/netfilter_ipv4/ip_conntrack_irc.h>
#include <linux/netfilter_ipv4/ip_conntrack_h323.h>
+#include <linux/netfilter_ipv4/ip_conntrack_rtsp.h>
/* per expectation: application helper private data */
union ip_conntrack_expect_help {
@@ -76,6 +77,7 @@ union ip_conntrack_expect_help {
struct ip_ct_ftp_expect exp_ftp_info;
struct ip_ct_irc_expect exp_irc_info;
struct ip_ct_h225_expect exp_h225_info;
+ struct ip_ct_rtsp_expect exp_rtsp_info;
#ifdef CONFIG_IP_NF_NAT_NEEDED
union {
@@ -90,6 +92,7 @@ union ip_conntrack_help {
struct ip_ct_ftp_master ct_ftp_info;
struct ip_ct_irc_master ct_irc_info;
struct ip_ct_h225_master ct_h225_info;
+ struct ip_ct_rtsp_master ct_rtsp_info;
};
#ifdef CONFIG_IP_NF_NAT_NEEDED
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