public void CloseConnection()
{
using (EneterTrace.Entering())
{
using (ThreadLock.Lock(myConnectionManipulatorLock))
{
myStopReceivingRequestedFlag = true;
myMessageInSendProgress = EMessageInSendProgress.None;
if (myTcpClient != null)
{
// Try to send the frame closing the communication.
if (myClientStream != null)
{
try
{
// If it was not disconnected by the client then try to send the message the connection was closed.
if (myIsListeningToResponses)
{
// Generate the masking key.
byte[] aCloseFrame = WebSocketFormatter.EncodeCloseFrame(null, 1000);
myClientStream.Write(aCloseFrame, 0, aCloseFrame.Length);
}
}
catch (Exception err)
{
EneterTrace.Warning(TracedObject + ErrorHandler.FailedToCloseConnection, err);
}
myClientStream.Close();
}
try
{
myTcpClient.Close();
}
catch (Exception err)
{
EneterTrace.Warning(TracedObject + "failed to close Tcp connection.", err);
}
myTcpClient = null;
}
myReceivedMessages.UnblockProcessingThreads();
}
}
}
private void ClearConnection(bool sendCloseMessageFlag)
{
using (EneterTrace.Entering())
{
using (ThreadLock.Lock(myConnectionManipulatorLock))
{
myStopReceivingRequestedFlag = true;
myMessageInSendProgress = EMessageInSendProgress.None;
if (myTcpClient != null)
{
// Try to send the frame closing the communication.
if (myClientStream != null)
{
try
{
if (sendCloseMessageFlag)
{
// Generate the masking key.
byte[] aMaskingKey = GetMaskingKey();
byte[] aCloseFrame = WebSocketFormatter.EncodeCloseFrame(aMaskingKey, 1000);
myClientStream.Write(aCloseFrame, 0, aCloseFrame.Length);
}
}
catch (Exception err)
{
EneterTrace.Warning(TracedObject + ErrorHandler.FailedToCloseConnection, err);
}
myClientStream.Close();
}
try
{
myTcpClient.Close();
}
catch (Exception err)
{
EneterTrace.Warning(TracedObject + "failed to close Tcp connection.", err);
}
myTcpClient = null;
}
if (myResponseReceiverThread != null && myResponseReceiverThread.ThreadState != ThreadState.Unstarted)
{
if (!myResponseReceiverThread.Join(3000))
{
EneterTrace.Warning(TracedObject + ErrorHandler.FailedToStopThreadId + myResponseReceiverThread.ManagedThreadId);
try
{
myResponseReceiverThread.Abort();
}
catch (Exception err)
{
EneterTrace.Warning(TracedObject + ErrorHandler.FailedToAbortThread, err);
}
}
}
myResponseReceiverThread = null;
try
{
myMessageProcessingThread.UnregisterMessageHandler();
}
catch (Exception err)
{
EneterTrace.Warning(TracedObject + ErrorHandler.FailedToUnregisterMessageHandler, err);
}
// Reset the responsibility for starting of threads looping for response messages.
myResponsibleForActivatingListening = EResponseListeningResponsible.OpenConnection;
}
}
}
public void DoRequestListening()
{
using (EneterTrace.Entering())
{
myIsListeningToResponses = true;
ushort aCloseCode = 0;
try
{
DynamicStream aContinuousMessageStream = null;
while (!myStopReceivingRequestedFlag)
{
// Decode the incoming message.
WebSocketFrame aFrame = WebSocketFormatter.DecodeFrame(myClientStream);
if (!myStopReceivingRequestedFlag && aFrame != null)
{
// Frames from server must be unmasked.
// According the protocol, If the frame was NOT masked, the server must close connection with the client.
if (aFrame.MaskFlag == false)
{
throw new InvalidOperationException(TracedObject + "received unmasked frame from the client. Frames from client shall be masked.");
}
// Process the frame.
if (aFrame.FrameType == EFrameType.Ping)
{
// Response 'pong'. The response responses same data as received in the 'ping'.
SendFrame(maskingKey => WebSocketFormatter.EncodePongFrame(maskingKey, aFrame.Message));
}
else if (aFrame.FrameType == EFrameType.Close)
{
EneterTrace.Debug(TracedObject + "received the close frame.");
break;
}
else if (aFrame.FrameType == EFrameType.Pong)
{
Notify(PongReceived);
}
// If a new message starts.
else if (aFrame.FrameType == EFrameType.Binary || aFrame.FrameType == EFrameType.Text)
{
// If a previous message is not finished then the new message is not expected -> protocol error.
if (aContinuousMessageStream != null)
{
EneterTrace.Warning(TracedObject + "detected unexpected new message. (previous message was not finished)");
// Protocol error close code.
aCloseCode = 1002;
break;
}
WebSocketMessage aReceivedMessage = null;
// If the message does not come in multiple frames then optimize the performance
// and use MemoryStream instead of DynamicStream.
if (aFrame.IsFinal)
{
MemoryStream aMessageStream = new MemoryStream(aFrame.Message);
aReceivedMessage = new WebSocketMessage(aFrame.FrameType == EFrameType.Text, aMessageStream);
}
else
// if the message is split to several frames then use DynamicStream so that writing of incoming
// frames and reading of already received data can run in parallel.
{
// Create stream where the message data will be writen.
aContinuousMessageStream = new DynamicStream();
aContinuousMessageStream.WriteWithoutCopying(aFrame.Message, 0, aFrame.Message.Length);
aReceivedMessage = new WebSocketMessage(aFrame.FrameType == EFrameType.Text, aContinuousMessageStream);
}
// Put received message to the queue.
myReceivedMessages.EnqueueMessage(aReceivedMessage);
}
// If a message continues. (I.e. message is split into more fragments.)
else if (aFrame.FrameType == EFrameType.Continuation)
{
// If the message does not exist then continuing frame does not have any sense -> protocol error.
if (aContinuousMessageStream == null)
{
EneterTrace.Warning(TracedObject + "detected unexpected continuing of a message. (none message was started before)");
// Protocol error close code.
aCloseCode = 1002;
break;
}
aContinuousMessageStream.WriteWithoutCopying(aFrame.Message, 0, aFrame.Message.Length);
// If this is the final frame.
if (aFrame.IsFinal)
{
aContinuousMessageStream.IsBlockingMode = false;
aContinuousMessageStream = null;
}
}
}
// If disconnected
if (aFrame == null)// || !myTcpClient.Client.Poll(0, SelectMode.SelectWrite))
{
//EneterTrace.Warning(TracedObject + "detected the TCP connection is not available. The connection will be closed.");
break;
}
}
}
catch (IOException)
{
// Ignore this exception. It is often thrown when the connection was closed.
// Do not thrace this because the tracing degradates the performance in this case.
}
catch (Exception err)
{
EneterTrace.Error(TracedObject + ErrorHandler.FailedInListeningLoop, err);
}
// If the connection is being closed due to a protocol error.
if (aCloseCode > 1000)
{
// Try to send the close message.
try
{
byte[] aCloseMessage = WebSocketFormatter.EncodeCloseFrame(null, aCloseCode);
myClientStream.Write(aCloseMessage, 0, aCloseMessage.Length);
}
catch
{
}
}
myIsListeningToResponses = false;
myReceivedMessages.UnblockProcessingThreads();
// Notify the listening to messages stoped.
Notify(ConnectionClosed);
}
}
// Handles TCP connection.
// It parses the HTTP request of the websocket to get the requested path.
// Then it searches the matching PathListeners and calls it to handle the connection.
protected override void HandleConnection(TcpClient tcpClient)
{
using (EneterTrace.Entering())
{
try
{
// Get the data stream.
// Note: If SSL then perform the authentication and provide the stream encoding/decoding data.
Stream aDataStream = SecurityFactory.CreateSecurityStreamAndAuthenticate(tcpClient.GetStream());
// Receive open websocket communication request.
Match anHttpOpenConnectionRegEx = WebSocketFormatter.DecodeOpenConnectionHttpRequest(aDataStream);
if (!anHttpOpenConnectionRegEx.Success)
{
EneterTrace.Warning(TracedObject + "failed to receive open websocket connection request. (incorrect http request)");
byte[] aCloseConnectionResponse = WebSocketFormatter.EncodeCloseFrame(null, 400);
aDataStream.Write(aCloseConnectionResponse, 0, aCloseConnectionResponse.Length);
return;
}
// Get http header fields.
IDictionary <string, string> aHeaderFields = WebSocketFormatter.GetHttpHeaderFields(anHttpOpenConnectionRegEx);
string aSecurityKey;
aHeaderFields.TryGetValue("Sec-WebSocket-Key", out aSecurityKey);
// If some required header field is missing or has incorrect value.
if (!aHeaderFields.ContainsKey("Upgrade") ||
!aHeaderFields.ContainsKey("Connection") ||
string.IsNullOrEmpty(aSecurityKey))
{
EneterTrace.Warning(TracedObject + "failed to receive open websocket connection request. (missing or incorrect header field)");
byte[] aCloseConnectionResponse = WebSocketFormatter.EncodeCloseFrame(null, 400);
aDataStream.Write(aCloseConnectionResponse, 0, aCloseConnectionResponse.Length);
return;
}
// Get the path to identify the end-point.
string anIncomingPath = anHttpOpenConnectionRegEx.Groups["path"].Value;
if (string.IsNullOrEmpty(anIncomingPath))
{
EneterTrace.Warning(TracedObject + "failed to process Websocket request because the path is null or empty string.");
byte[] aCloseConnectionResponse = WebSocketFormatter.EncodeCloseFrame(null, 400);
aDataStream.Write(aCloseConnectionResponse, 0, aCloseConnectionResponse.Length);
return;
}
// if the incoming path is the whole uri then extract the absolute path.
Uri anIncomingUri;
Uri.TryCreate(anIncomingPath, UriKind.Absolute, out anIncomingUri);
string anAbsolutePath = (anIncomingUri != null) ? anIncomingUri.AbsolutePath : anIncomingPath;
// Get handler for that path.
Uri aHandlerUri;
Action <IWebSocketClientContext> aPathHandler;
using (ThreadLock.Lock(myHandlers))
{
KeyValuePair <Uri, object> aPair = myHandlers.FirstOrDefault(x => x.Key.AbsolutePath == anAbsolutePath);
aPathHandler = aPair.Value as Action <IWebSocketClientContext>;
aHandlerUri = aPair.Key;
}
// If the listener does not exist.
if (aPathHandler == null)
{
EneterTrace.Warning(TracedObject + "does not listen to " + anIncomingPath);
byte[] aCloseConnectionResponse = WebSocketFormatter.EncodeCloseFrame(null, 404);
aDataStream.Write(aCloseConnectionResponse, 0, aCloseConnectionResponse.Length);
return;
}
// Response that the connection is accepted.
byte[] anOpenConnectionResponse = WebSocketFormatter.EncodeOpenConnectionHttpResponse(aSecurityKey);
aDataStream.Write(anOpenConnectionResponse, 0, anOpenConnectionResponse.Length);
// Create the context for conecting client.
string aRequestUriStr = aHandlerUri.Scheme + "://" + aHandlerUri.Host + ":" + Address.Port + anAbsolutePath + anHttpOpenConnectionRegEx.Groups["query"].Value;
Uri aRequestUri = new Uri(aRequestUriStr);
WebSocketClientContext aClientContext = new WebSocketClientContext(aRequestUri, aHeaderFields, tcpClient, aDataStream);
// Call path handler in a another thread.
EneterThreadPool.QueueUserWorkItem(() =>
{
try
{
aPathHandler(aClientContext);
}
catch (Exception err)
{
EneterTrace.Warning(TracedObject + ErrorHandler.DetectedException, err);
}
});
// Start listening loop in the client context.
// The loop will read websocket messages from the underlying tcp connection.
// Note: User is responsible to call WebSocketClientContext.CloseConnection() to stop this loop
// or the service must close the conneciton.
aClientContext.DoRequestListening();
}
catch (Exception err)
{
EneterTrace.Error(TracedObject + "failed to process TCP connection.", err);
}
}
}