From 8f7386e7351ec5b5e4559fc95a23833ab4d574fb Mon Sep 17 00:00:00 2001
From: Jan Willamowius <jan@willamowius.de>
Date: Wed, 23 Jun 2021 11:21:03 +0200
Subject: [PATCH] fix media loop on half port-detected channel when media is
 very early

---
 ProxyChannel.cxx | 19 ++++++++++++++++++-
 changes.txt      |  1 +
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/ProxyChannel.cxx b/ProxyChannel.cxx
index f73ff7d3..0aa5b9b8 100644
--- a/ProxyChannel.cxx
+++ b/ProxyChannel.cxx
@@ -35,6 +35,7 @@
 #include "GkStatus.h"
 #include <queue>
 #include <math.h> // needed for ceil() on Solaris 11, OpenBSD
+#include <algorithm>
 
 #ifdef HAS_AVAYA_SUPPORT
 #include "avaya.h"
@@ -13837,6 +13838,14 @@ void UDPProxySocket::SetForwardDestination(const Address & srcIP, WORD srcPort,
         PTRACE(7, "JW RTP skip overwriting due to completed port detection");
         return;
     }
+
+    // doing port detection and forward source is already set (probably by port detection) and set to same as forward dest -> swap the directions (OR skip the setting ?)
+    H245_UnicastAddress fSrc = SocketToH245UnicastAddr(fSrcIP, fSrcPort); // for easy comparison
+    if (m_ignoreSignaledIPs && fSrc == *dstAddr) {
+        PTRACE(7, "JW RTP swap directions before SetForwardDestination to avoid loop");
+        swap(fSrcIP, rSrcIP); swap(fSrcPort, rSrcPort);
+        swap(fDestIP, rDestIP); swap(fDestPort, rDestPort);
+    }
 #endif
 
     if (!onlySetDest) {
@@ -13894,6 +13903,14 @@ void UDPProxySocket::SetReverseDestination(const Address & srcIP, WORD srcPort,
         PTRACE(7, "JW RTP skip overwriting due to completed port detection");
         return;
     }
+
+    // doing port detection and reverse source is already set (probably by port detection) and set to same as reverse dest -> swap the directions (OR skip the setting ?)
+    H245_UnicastAddress rSrc = SocketToH245UnicastAddr(rSrcIP, rSrcPort); // for easy comparison
+    if (m_ignoreSignaledIPs && rSrc == *dstAddr) {
+        PTRACE(7, "JW RTP swap directions before SetReverseDestination to avoid loop");
+        swap(fSrcIP, rSrcIP); swap(fSrcPort, rSrcPort);
+        swap(fDestIP, rDestIP); swap(fDestPort, rDestPort);
+    }
 #endif
 
     if (!onlySetDest) {
@@ -14151,7 +14168,7 @@ ProxySocket::Result UDPProxySocket::ReceiveData()
     }
 
     if (m_ignoreSignaledIPs && !m_portDetectionDone) {
-        //// learn from data we already have (eg. from H.239 signaling)
+        //// learn from data we already have (eg. from signaling)
         // set known destination as assumed source
         if (fSrcIP == 0 && rSrcIP == 0 && fDestIP != 0) {
             rSrcIP = fDestIP, rSrcPort = fDestPort;
diff --git a/changes.txt b/changes.txt
index 666e402e..a966a735 100644
--- a/changes.txt
+++ b/changes.txt
@@ -1,5 +1,6 @@
 Changes from 5.7 to 5.8
 =======================
+- BUGFIX(ProxyChannel.cxx) fix media loop on half port-detected channel when media is very early
 - new switches to set the HTTP Content-Type header: [HttpAcct] ContentType=, [HttpPasswordAuth] ContentType=
   and [Routing::Http] ContentType=
 - new switch [Proxy] AllowAnyRTPSourcePortForH239From= to handle incorrect RTCP addresses in H.239 OLC (EdgeProtect interop)