worked on error handling of network protocols,

updated remote endpoint indication in UI

MultiTerm.Protocols/CommunicationProtocol.cs

@@ -60,7 +60,7 @@ public abstract class CommunicationProtocol : ICommunicationProtocol
     /// <summary>
     /// To be called whenever the protocol detected that it is disconnected, but this is not a known fact.
     /// </summary>
-    protected void OnUnintentionallyDisconnected()
+    protected void OnUnintentionallyDisconnected(bool informUser = true)
     {
         // perform all steps in a task, to prevent deadlock when this method is called from a thread that is joined.
         Task.Run(() =>
@@ -72,7 +72,10 @@ public abstract class CommunicationProtocol : ICommunicationProtocol
             this.State = ProtocolConnectionState.UnintentionallyDisconnected;
 
             // inform user
-            this.messenger.Send<IUserInterfaceMessage>(new GenericUserInterfaceMessage($"'{this.GetProtocolAndInstanceIdentifier()}' unintentionally disconnected.", MessageImportance.High));
+            if (informUser)
+            {
+                this.messenger.Send<IUserInterfaceMessage>(new GenericUserInterfaceMessage($"'{this.GetProtocolAndInstanceIdentifier()}' unintentionally disconnected.", MessageImportance.High));
+            }
         });
     }
 

MultiTerm.Protocols/Tcp/TcpClientProtocol.cs

@@ -47,7 +47,8 @@ public class TcpClientProtocol : CommunicationProtocol
         // check if client is null
         if (this.client != null)
         {
-            throw new Exception($"The TCP client was not null when {nameof(InternalConnect)} was called.");
+            this.client = null;
+            this.logger.LogWarn($"The TCP client was not null when {nameof(InternalConnect)} was called.", nameof(TcpClientProtocol));
         }
 
         /* create client */
@@ -73,7 +74,14 @@ public class TcpClientProtocol : CommunicationProtocol
         // send message to inform about resolved IP address
         if (this.client.Client.RemoteEndPoint is IPEndPoint remoteEndpoint)
         {
-            this.messenger.Send(new TcpConnectedMessage(remoteEndpoint.Address));
+            IPAddress remoteEndpointAddress = remoteEndpoint.Address;
+            // special handling for IPv4MappedToIPv6 addresses
+            if (remoteEndpointAddress.IsIPv4MappedToIPv6)
+            {
+                remoteEndpointAddress = remoteEndpoint.Address.MapToIPv4();
+            }
+
+            this.messenger.Send(new TcpConnectedMessage(remoteEndpointAddress));
         }
 
         return true;
@@ -128,25 +136,30 @@ public class TcpClientProtocol : CommunicationProtocol
             catch (ObjectDisposedException objex)
             {
                 this.logger.LogException(objex, $"ObjectDisposedException while sending data in {nameof(InternalRead)}", nameof(TcpClientProtocol));
-                this.OnUnintentionallyDisconnected();
+                this.OnUnintentionallyDisconnected(informUser: true);
                 break;  // break loop
             }
-            catch (IOException ioEx)
+            catch (IOException ioEx) when (ioEx.InnerException is SocketException sockEx)
             {
-                // socket exception and timeout => normal use case
+                // socket exception timeout => normal use case => do nothing
-                if (ioEx.InnerException is SocketException sockEx && sockEx?.SocketErrorCode == SocketError.TimedOut) { }
+                if (sockEx.SocketErrorCode != SocketError.TimedOut)
-                // other IO Exception
-                else
                 {
-                    this.logger.LogException(ioEx, $"IOException while reading data in {nameof(InternalRead)}", nameof(TcpClientProtocol));
+                    this.logger.LogException(sockEx, $"SocketException with SocketErrorCode={sockEx.SocketErrorCode} while reading data in {nameof(InternalRead)}", nameof(TcpClientProtocol));
-                    this.messenger.Send<IUserInterfaceMessage>(new StoppedReadingUIMessage(this, ioEx.ToString()));
+                    this.messenger.Send<IUserInterfaceMessage>(new StoppedReadingUIMessage(this, $"Socket Error: {sockEx.SocketErrorCode}"));
+                    this.OnUnintentionallyDisconnected(informUser: false);
                     break; // break loop
                 }
             }
+            catch (IOException ioEx)
+            {
+                this.logger.LogException(ioEx, $"IOException while reading data in {nameof(InternalRead)}", nameof(TcpClientProtocol));
+                this.OnUnintentionallyDisconnected(informUser: true);
+                break; // break loop
+            }
             catch (Exception ex)
             {
                 this.logger.LogException(ex, $"Exception while reading data in {nameof(InternalRead)}", nameof(TcpClientProtocol));
-                this.messenger.Send<IUserInterfaceMessage>(new StoppedReadingUIMessage(this, ex.Message));
+                this.OnUnintentionallyDisconnected(informUser: true);
                 break; // break loop
             }
 

MultiTerm.Protocols/Udp/UdpProtocol.cs

@@ -45,8 +45,9 @@ public class UdpProtocol : CommunicationProtocol
         // check if client is null
         if(this.udpClient != null)
         {
-            throw new Exception($"UDP client was not null when {nameof(InternalConnect)} was called: " +
+            this.udpClient = null;
-                $"{nameof(udpClient)} isnull={this.udpClient == null},");
+            this.logger.LogWarn($"UDP client was not null when {nameof(InternalConnect)} was called: " +
+                $"{nameof(udpClient)} isnull={this.udpClient == null}", nameof(UdpProtocol));
         }
 
         /* create udp client */
@@ -135,6 +136,12 @@ public class UdpProtocol : CommunicationProtocol
                     // report received data
                     this.OnReceivedData(new ExtendedByte(b));
                 }
+
+                // after data was processed, send update with latest connected endpoint
+                if(remoteEndPoint != null)
+                {
+                    this.messenger.Send(new UdpConnectedMessage(remoteEndPoint.Address));
+                }
             }
         }
     }

MultiTerm.Wpf/View/SettingsView/NetworkSettingsView.xaml

@@ -50,21 +50,21 @@
             
         </StackPanel>
 
-        <!-- Display for Resolved IP Address (outside of Not changeable range) -->
+        <!-- Display for Remote Endpoint Address (outside of Not changeable range) -->
         <StackPanel Orientation="Horizontal" Margin="20 0 10 0">
             <StackPanel.Style>
                 <Style TargetType="{x:Type StackPanel}">
                     <!-- Defaults to visible -->
                     <Setter Property="Visibility" Value="Visible"/>
                     <Style.Triggers>
-                        <!-- Collapsed when Resolved Address String length is 0 -->
+                        <!-- Collapsed when Remote Endpoint String length is 0 -->
                         <DataTrigger Binding="{Binding Path=ResolvedAddress.Length, FallbackValue=0, TargetNullValue=0}" Value="0">
                             <Setter Property="Visibility" Value="Collapsed"/>
                         </DataTrigger>
                     </Style.Triggers>
                 </Style>
             </StackPanel.Style>
-            <Label Margin="20 0 10 0" VerticalAlignment="Center" HorizontalAlignment="Center" Foreground="DarkGray">Resolved IP Address:</Label>
+            <Label Margin="20 0 10 0" VerticalAlignment="Center" HorizontalAlignment="Center" Foreground="DarkGray">Remote Endpoint:</Label>
             <TextBox IsReadOnly="True" VerticalContentAlignment="Center" Text="{Binding ResolvedAddress}"/>
         </StackPanel>