From 7e58dc4db0838486a90fd8ee718b120ccd99f89b Mon Sep 17 00:00:00 2001
From: Christopher <git@clatza.dev>
Date: Fri, 18 Mar 2022 13:02:10 +0100
Subject: [PATCH] Add checking udp port available and use other port than
 already in use.

---
 OpenSim/Framework/RegionInfo.cs | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/OpenSim/Framework/RegionInfo.cs b/OpenSim/Framework/RegionInfo.cs
index 4282fe06c0..79ca997ee5 100755
--- a/OpenSim/Framework/RegionInfo.cs
+++ b/OpenSim/Framework/RegionInfo.cs
@@ -36,6 +36,7 @@ using log4net;
 using Nini.Config;
 using OpenMetaverse;
 using OpenMetaverse.StructuredData;
+using System.Net.NetworkInformation;
 //using OpenSim.Framework.Console;
 
 namespace OpenSim.Framework
@@ -560,6 +561,15 @@ namespace OpenSim.Framework
                 port = Convert.ToInt32(MainConsole.Instance.Prompt("Internal port", "9000"));
                 config.Set("InternalPort", port);
             }
+
+            if(!CheckAvailableServerPort(port))
+            {
+                while(!CheckAvailableServerPort(port))
+                {
+                    port++;
+                }
+            }
+
             m_internalEndPoint = new IPEndPoint(address, port);
 
             // ResolveAddress
@@ -699,6 +709,29 @@ namespace OpenSim.Framework
             }
         }
 
+        private bool CheckAvailableServerPort(int port)
+        {
+            bool isAvailable = true;
+
+            // Evaluate current system tcp connections. This is the same information provided
+            // by the netstat command line application, just in .Net strongly-typed object
+            // form.  We will look through the list, and if our port we would like to use
+            // in our TcpClient is occupied, we will set isAvailable to false.
+            IPGlobalProperties ipGlobalProperties = IPGlobalProperties.GetIPGlobalProperties();
+            IPEndPoint[] udpConnInfoArray = ipGlobalProperties.GetActiveUdpListeners();
+
+            foreach (IPEndPoint endpoint in udpConnInfoArray)
+            {
+                if (endpoint.Port == port)
+                {
+                    isAvailable = false;
+                    break;
+                }
+            }
+
+            return isAvailable;
+        }
+
         // Make sure DefaultLanding is within region borders with a buffer zone 5 meters from borders
         private void DoDefaultLandingSanityChecks()
         {
-- 
2.30.0.windows.2