Added support for drilling a hole through a firewall or NAT by sending

one invalid 4 bytes RTP and RTCP packet.


git-svn-id: http://voip.null.ro/svn/yate@1187 acf43c95-373e-0410-b603-e72c3f656dc1

conf.d/yrtpchan.conf.sample

@@ -23,6 +23,9 @@
 ; rtcp: bool: Allocate socket for the RTCP protocol by default
 ;rtcp=enabled
 
+; drillhole: bool: Attempt to drill a hole through a firewall or NAT
+;drillhole=disabled
+
 ; defsleep: int: Default in-loop sleep time for new RTP sessions in milliseconds
 ;defsleep=5
 

contrib/yrtp/session.cpp

@@ -257,6 +257,7 @@ void RTPReceiver::timerTick(const Time& when)
 {
 }
 
+
 RTPSender::RTPSender(RTPSession* session, bool randomTs)
     : RTPBaseIO(session), m_evTime(0), m_tsLast(0)
 {

contrib/yrtp/transport.cpp

@@ -143,6 +143,7 @@ void RTPGroup::setMinSleep(int msec)
     s_sleep = msec;
 }
 
+
 RTPProcessor::RTPProcessor()
     : m_group(0)
 {
@@ -331,6 +332,19 @@ bool RTPTransport::remoteAddr(SocketAddr& addr, bool sniff)
     return false;
 }
 
+bool RTPTransport::drillHole()
+{
+    if (m_rtpSock.valid() && m_remoteAddr.valid()) {
+	static const char buf[4] = { 0, 0, 0, 0 };
+	if (m_rtpSock.sendTo(buf,sizeof(buf),m_remoteAddr) == sizeof(buf)) {
+	    if (m_rtcpSock.valid() && m_remoteRTCP.valid())
+		m_rtcpSock.sendTo(buf,sizeof(buf),m_remoteRTCP);
+	    return true;
+	}
+    }
+    return false;
+}
+
 
 RTPDejitter::RTPDejitter(RTPReceiver* receiver, unsigned int mindelay, unsigned int maxdelay)
     : m_receiver(receiver), m_mindelay(mindelay), m_maxdelay(maxdelay),

contrib/yrtp/yatertp.h

@@ -254,6 +254,12 @@ public:
     inline Socket* rtpSock()
 	{ return &m_rtpSock; }
 
+    /**
+     * Drill a hole in a firewall or NAT for the RTP and RTCP sockets
+     * @return True if at least a packet was sent for the RTP socket
+     */
+    bool drillHole();
+
 protected:
     /**
      * Method called periodically to read data out of sockets
@@ -922,6 +928,13 @@ public:
     inline Socket* rtpSock()
 	{ return m_transport ? m_transport->rtpSock() : 0; }
 
+    /**
+     * Drill a hole in a firewall or NAT for the RTP and RTCP sockets
+     * @return True if at least a packet was sent for the RTP socket
+     */
+    inline bool drillHole()
+	{ return m_transport && m_transport->drillHole(); }
+
 protected:
     /**
      * Method called periodically to push any asynchronous data or statistics

modules/yrtpchan.cpp

@@ -80,6 +80,7 @@ static String s_tos;
 static bool s_autoaddr = true;
 static bool s_anyssrc = false;
 static bool s_rtcp = true;
+static bool s_drill = false;
 
 static int s_sleep = 5;
 static int s_minjitter = 0;
@@ -432,6 +433,8 @@ bool YRTPWrapper::startRTP(const char* raddr, unsigned int rport, const Message&
     m_rtp->dataPayload(payload);
     m_rtp->eventPayload(evpayload);
     m_rtp->setTOS(tos);
+    if (msg.getBoolValue("drillhole",s_drill))
+	m_rtp->drillHole();
 //    if (maxJitter > 0)
 //	m_rtp->setDejitter(minJitter*1000,maxJitter*1000);
     m_bufsize = s_bufsize;
@@ -842,6 +845,7 @@ void YRTPPlugin::initialize()
     s_autoaddr = cfg.getBoolValue("general","autoaddr",true);
     s_anyssrc = cfg.getBoolValue("general","anyssrc",false);
     s_rtcp = cfg.getBoolValue("general","rtcp",true);
+    s_drill = cfg.getBoolValue("general","drillhole",false);
     s_sleep = cfg.getIntValue("general","defsleep",5);
     RTPGroup::setMinSleep(cfg.getIntValue("general","minsleep"));
     setup();