private async Task HandleTextFrame(Header frameHeader, byte[] payload, int payloadOffset, int payloadCount)
{
if (frameHeader.IsFIN)
{
try
{
var text = Encoding.UTF8.GetString(payload, payloadOffset, payloadCount);
await _module.OnSessionTextReceived(this, text);
}
catch (Exception ex)
{
await HandleUserSideError(ex);
}
}
else
{
try
{
await _module.OnSessionFragmentationStreamOpened(this, payload, payloadOffset, payloadCount);
}
catch (Exception ex)
{
await HandleUserSideError(ex);
}
}
}
private async Task Process()
{
try
{
while (State == WebSocketState.Open || State == WebSocketState.Closing)
{
int receiveCount = await _stream.ReadAsync(_receiveBuffer, _receiveBufferOffset, _receiveBuffer.Length - _receiveBufferOffset);
if (receiveCount == 0)
{
break;
}
_keepAliveTracker.OnDataReceived();
BufferDeflector.ReplaceBuffer(_bufferManager, ref _receiveBuffer, ref _receiveBufferOffset, receiveCount);
while (true)
{
Header frameHeader = null;
if (_frameBuilder.TryDecodeFrameHeader(_receiveBuffer, _receiveBufferOffset, out frameHeader) &&
frameHeader.Length + frameHeader.PayloadLength <= _receiveBufferOffset)
{
try
{
if (!frameHeader.IsMasked)
{
await Close(WebSocketCloseCode.ProtocolError, "A server MUST close the connection upon receiving a frame that is not masked.");
throw new WebSocketException(string.Format(
"Server received unmasked frame [{0}] from remote [{1}].", frameHeader.OpCode, RemoteEndPoint));
}
byte[] payload;
int payloadOffset;
int payloadCount;
_frameBuilder.DecodePayload(_receiveBuffer, frameHeader, out payload, out payloadOffset, out payloadCount);
switch (frameHeader.OpCode)
{
case OpCode.Continuation:
{
if (!frameHeader.IsFIN)
{
try
{
await _module.OnSessionFragmentationStreamContinued(this, payload, payloadOffset, payloadCount);
}
catch (Exception ex)
{
HandleUserSideError(ex);
}
}
else
{
try
{
await _module.OnSessionFragmentationStreamClosed(this, payload, payloadOffset, payloadCount);
}
catch (Exception ex)
{
HandleUserSideError(ex);
}
}
}
break;
case OpCode.Text:
{
if (frameHeader.IsFIN)
{
try
{
var text = Encoding.UTF8.GetString(payload, payloadOffset, payloadCount);
await _module.OnSessionTextReceived(this, text);
}
catch (Exception ex)
{
HandleUserSideError(ex);
}
}
else
{
try
{
await _module.OnSessionFragmentationStreamOpened(this, payload, payloadOffset, payloadCount);
}
catch (Exception ex)
{
HandleUserSideError(ex);
}
}
}
break;
case OpCode.Binary:
{
if (frameHeader.IsFIN)
{
try
{
await _module.OnSessionBinaryReceived(this, payload, payloadOffset, payloadCount);
}
catch (Exception ex)
{
HandleUserSideError(ex);
}
}
else
{
try
{
await _module.OnSessionFragmentationStreamOpened(this, payload, payloadOffset, payloadCount);
}
catch (Exception ex)
{
HandleUserSideError(ex);
}
}
}
break;
case OpCode.Close:
{
if (!frameHeader.IsFIN)
{
throw new WebSocketException(string.Format(
"Server received unfinished frame [{0}] from remote [{1}].", frameHeader.OpCode, RemoteEndPoint));
}
if (payloadCount > 1)
{
var statusCode = payload[0] * 256 + payload[1];
var closeCode = (WebSocketCloseCode)statusCode;
var closeReason = string.Empty;
if (payloadCount > 2)
{
closeReason = Encoding.UTF8.GetString(payload, 2, payloadCount - 2);
}
#if DEBUG
_log.DebugFormat("Session [{0}] received client side close frame [{1}] [{2}].", this, closeCode, closeReason);
#endif
// If an endpoint receives a Close frame and did not previously send a
// Close frame, the endpoint MUST send a Close frame in response. (When
// sending a Close frame in response, the endpoint typically echos the
// status code it received.) It SHOULD do so as soon as practical.
await Close(closeCode, closeReason);
}
else
{
#if DEBUG
_log.DebugFormat("Session [{0}] received client side close frame but no status code.", this);
#endif
await Close(WebSocketCloseCode.InvalidPayloadData);
}
}
break;
case OpCode.Ping:
{
if (!frameHeader.IsFIN)
{
throw new WebSocketException(string.Format(
"Server received unfinished frame [{0}] from remote [{1}].", frameHeader.OpCode, RemoteEndPoint));
}
// Upon receipt of a Ping frame, an endpoint MUST send a Pong frame in
// response, unless it already received a Close frame. It SHOULD
// respond with Pong frame as soon as is practical. Pong frames are
// discussed in Section 5.5.3.
//
// An endpoint MAY send a Ping frame any time after the connection is
// established and before the connection is closed.
//
// A Ping frame may serve either as a keep-alive or as a means to
// verify that the remote endpoint is still responsive.
var ping = Encoding.UTF8.GetString(payload, payloadOffset, payloadCount);
#if DEBUG
_log.DebugFormat("Session [{0}] received client side ping frame [{1}].", this, ping);
#endif
if (State == WebSocketState.Open)
{
// A Pong frame sent in response to a Ping frame must have identical
// "Application data" as found in the message body of the Ping frame being replied to.
var pong = new PongFrame(ping, false).ToArray(_frameBuilder);
await SendFrame(pong);
#if DEBUG
_log.DebugFormat("Session [{0}] sends server side pong frame [{1}].", this, ping);
#endif
}
}
break;
case OpCode.Pong:
{
if (!frameHeader.IsFIN)
{
throw new WebSocketException(string.Format(
"Server received unfinished frame [{0}] from remote [{1}].", frameHeader.OpCode, RemoteEndPoint));
}
// If an endpoint receives a Ping frame and has not yet sent Pong
// frame(s) in response to previous Ping frame(s), the endpoint MAY
// elect to send a Pong frame for only the most recently processed Ping frame.
//
// A Pong frame MAY be sent unsolicited. This serves as a
// unidirectional heartbeat. A response to an unsolicited Pong frame is not expected.
var pong = Encoding.UTF8.GetString(payload, payloadOffset, payloadCount);
StopKeepAliveTimeoutTimer();
#if DEBUG
_log.DebugFormat("Session [{0}] received client side pong frame [{1}].", this, pong);
#endif
}
break;
default:
{
// Incoming data MUST always be validated by both clients and servers.
// If, at any time, an endpoint is faced with data that it does not
// understand or that violates some criteria by which the endpoint
// determines safety of input, or when the endpoint sees an opening
// handshake that does not correspond to the values it is expecting
// (e.g., incorrect path or origin in the client request), the endpoint
// MAY drop the TCP connection. If the invalid data was received after
// a successful WebSocket handshake, the endpoint SHOULD send a Close
// frame with an appropriate status code (Section 7.4) before proceeding
// to _Close the WebSocket Connection_. Use of a Close frame with an
// appropriate status code can help in diagnosing the problem. If the
// invalid data is sent during the WebSocket handshake, the server
// SHOULD return an appropriate HTTP [RFC2616] status code.
await Close(WebSocketCloseCode.InvalidMessageType);
throw new NotSupportedException(
string.Format("Not support received opcode [{0}].", (byte)frameHeader.OpCode));
}
}
}
catch (Exception ex)
{
_log.Error(string.Format("Session [{0}] exception occurred, [{1}].", this, ex.Message), ex);
throw;
}
finally
{
try
{
BufferDeflector.ShiftBuffer(_bufferManager, frameHeader.Length + frameHeader.PayloadLength, ref _receiveBuffer, ref _receiveBufferOffset);
}
catch (ArgumentOutOfRangeException) { }
}
}
else
{
break;
}
}
}
}
catch (Exception ex) when(!ShouldThrow(ex))
{
}
finally
{
await Abort();
}
}