Fix transport stack overflow

BACnetClient.cs

@@ -1545,10 +1545,7 @@ public IAsyncResult BeginSubscribeCOVRequest(BacnetAddress adr, BacnetObjectId o
     public void EndSubscribeCOVRequest(IAsyncResult result, out Exception ex)
     {
         var res = (BacnetAsyncResult)result;
-        ex = res.Error;
-        if (ex == null && !res.WaitForDone(Timeout))
-            ex = new Exception("Wait Timeout");
-
+        ex = res.WaitForDone(Timeout) ? res.Error : new Exception("Wait Timeout");
         res.Dispose();
     }
 

Transport/BacnetIpUdpProtocolTransport.cs

@@ -1,34 +1,34 @@
-/**************************************************************************
-*                           MIT License
-* 
-* Copyright (C) 2014 Morten Kvistgaard <mk@pch-engineering.dk>
-*
-* Permission is hereby granted, free of charge, to any person obtaining
-* a copy of this software and associated documentation files (the
-* "Software"), to deal in the Software without restriction, including
-* without limitation the rights to use, copy, modify, merge, publish,
-* distribute, sublicense, and/or sell copies of the Software, and to
-* permit persons to whom the Software is furnished to do so, subject to
-* the following conditions:
-*
-* The above copyright notice and this permission notice shall be included
-* in all copies or substantial portions of the Software.
-*
-* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
-* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
-* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
-* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
-* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-*
-*********************************************************************/
-
+/**************************************************************************
+*                           MIT License
+* 
+* Copyright (C) 2014 Morten Kvistgaard <mk@pch-engineering.dk>
+*
+* Permission is hereby granted, free of charge, to any person obtaining
+* a copy of this software and associated documentation files (the
+* "Software"), to deal in the Software without restriction, including
+* without limitation the rights to use, copy, modify, merge, publish,
+* distribute, sublicense, and/or sell copies of the Software, and to
+* permit persons to whom the Software is furnished to do so, subject to
+* the following conditions:
+*
+* The above copyright notice and this permission notice shall be included
+* in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*
+*********************************************************************/
+
 namespace System.IO.BACnet;
 
-/// <summary>
-/// This is the standard BACNet udp transport
-/// </summary>
+/// <summary>
+/// This is the standard BACNet udp transport
+/// </summary>
 public class BacnetIpUdpProtocolTransport : BacnetTransportBase
 {
     private UdpClient _sharedConn;
@@ -215,15 +215,21 @@ private void OnReceiveData(IAsyncResult asyncResult)
             {
                 if (connection.Client != null && !_disposing)
                 {
-                    try
-                    {
-                        // BeginReceive ASAP to enable parallel processing (e.g. query additional data while processing a notification)
-                        connection.BeginReceive(OnReceiveData, connection);
-                    }
-                    catch (Exception ex)
-                    {
-                        Log.Error($"Failed to restart data receive. {ex}");
-                    }
+					// BeginReceive ASAP to enable parallel processing (e.g. query additional data while processing a notification)
+					ThreadPool.UnsafeQueueUserWorkItem(static state =>
+					{
+						var (transport, udp) = ((BacnetIpUdpProtocolTransport transport, UdpClient udp)) state!;
+						if (udp.Client == null || transport._disposing) return;
+
+						try
+						{
+							udp.BeginReceive(transport.OnReceiveData, udp);
+						}
+						catch (Exception ex)
+						{
+							transport.Log.Error($"Failed to restart data receive. {ex}");
+						}
+					}, (this, connection));
                 }
             }
 
@@ -415,12 +421,12 @@ protected virtual BacnetAddress _GetBroadcastAddress()
         else
         {
             // restricted local broadcast (directed ... routable)
-            foreach (var adapter in NetworkInterface.GetAllNetworkInterfaces())
-                foreach (var ip in adapter.GetIPProperties().UnicastAddresses)
-                    if (LocalEndPoint.Address.Equals(ip.Address))
-                    {
-                        ipAddr = ip;
-                        break;
+            foreach (var adapter in NetworkInterface.GetAllNetworkInterfaces())
+                foreach (var ip in adapter.GetIPProperties().UnicastAddresses)
+                    if (LocalEndPoint.Address.Equals(ip.Address))
+                    {
+                        ipAddr = ip;
+                        break;
                     }
         }
 
@@ -462,4 +468,4 @@ public override void Dispose()
         _sharedConn?.Close();
         _sharedConn = null;
     }
-}
+}