Allow ForwardClose and UnregisterSession to close the Socket if connection was already closed by Remote Device

rossmann-engineering · rossmann-engineering · commit a9b520a78e31 · 2020-03-14T21:00:29.000+01:00
diff --git a/AllenBradleyPointIO/Program.cs b/AllenBradleyPointIO/Program.cs
@@ -50,7 +50,7 @@ static void Main(string[] args)
 
             while(true)
             {
-
+                
                 //Read the Inputs Transfered form Target -> Originator
                 Console.WriteLine("State of first Input byte: " + eeipClient.T_O_IOData[8]);
                 Console.WriteLine("State of second Input byte: " + eeipClient.T_O_IOData[9]);
@@ -62,6 +62,24 @@ static void Main(string[] args)
                 eeipClient.O_T_IOData[3] = 8;
 
                 System.Threading.Thread.Sleep(500);
+
+                //Detect Timeout (Read last Received Message Property)
+                if (DateTime.Now.Ticks > eeipClient.LastReceivedImplicitMessage.Ticks + (1000 * 10000))
+                    {
+                    try
+                    {
+                        eeipClient.ForwardClose();
+                        eeipClient.UnRegisterSession();
+                    
+                        eeipClient.RegisterSession();
+                        eeipClient.ForwardOpen();
+                    }
+                    catch (Exception)
+                    {
+                        Console.WriteLine("Couldn't reconnect to Point I/O");
+                    }
+                    }
+
             }
 
             //Close the Session
diff --git a/EEIP.NET/EIPClient.cs b/EEIP.NET/EIPClient.cs
@@ -255,7 +255,14 @@ public void UnRegisterSession()
             encapsulation.Length = 0;
             encapsulation.SessionHandle =  sessionHandle;
  
-            stream.Write(encapsulation.toBytes(), 0, encapsulation.toBytes().Length);
+            try
+            {
+                stream.Write(encapsulation.toBytes(), 0, encapsulation.toBytes().Length);
+            }
+            catch (Exception)
+            {
+                //Handle Exception to allow to Close the Stream if the connection was closed by Remote Device
+            }
             byte[] data = new Byte[256];
             client.Close();
             stream.Close();
@@ -727,11 +734,25 @@ public void ForwardClose()
             System.Buffer.BlockCopy(encapsulation.toBytes(), 0, dataToWrite, 0, encapsulation.toBytes().Length);
             System.Buffer.BlockCopy(commonPacketFormat.toBytes(), 0, dataToWrite, encapsulation.toBytes().Length, commonPacketFormat.toBytes().Length);
             encapsulation.toBytes();
-
-            stream.Write(dataToWrite, 0, dataToWrite.Length);
+            try
+            {
+                stream.Write(dataToWrite, 0, dataToWrite.Length);
+            }
+            catch (Exception e)
+            {
+                //Handle Exception  to allow Forward close if the connection was closed by the Remote Device before
+            }
             byte[] data = new Byte[564];
 
-            Int32 bytes = stream.Read(data, 0, data.Length);
+            try
+            {
+                Int32 bytes = stream.Read(data, 0, data.Length);
+            }
+            catch (Exception e)
+            {
+                //Handle Exception  to allow Forward close if the connection was closed by the Remote Device before
+            }
+
 
             //--------------------------BEGIN Error?
             if (data[42] != 0)      //Exception codes see "Table B-1.1 CIP General Status Codes"
