private async void doRead()
{
while (_ct != null && !_ct.IsCancellationRequested)
{
try
{
byte[] b1 = await ReadExact(2); //options & len (2)
byte[] b2 = null; //extended length
byte[] b3 = null; //mask-key (4)
byte[] b4 = null; //payload (x+y)
if (b1 == null || b1.Length == 0)
{
End(); //tcp connection closed
continue;
}
ulong len = 0;
var fs = _fragStream != null; //fragment started
var ft = b1[0] & 0xF0; //frame type
var rsv = (b1[0] & 0x70) > 0; //reserve bits are set
var op = b1[0] & 0x0F; //opcode
var pl = b1[1] & 0x7F; //payload length
var msk = (b1[1] & 0x80) == 0x80; //masking key set
var cf = (op & 0x08) == 0x08; //control frame
if (pl == 126 || pl == 127)
{
b2 = await ReadExact((ulong)(pl == 126 ? 2 : 8));
b2 = b2.Reverse().ToArray();
len = pl == 126 ? BitConverter.ToUInt16(b2, 0) : BitConverter.ToUInt64(b2, 0);
}
else
{
len = (ulong)pl;
}
if (msk)
{
b3 = await ReadExact(4);
}
b4 = await ReadExact(len);
var wsf = new WebSocketFrame();
wsf.ParsePayload((WebSocketFlags)ft, (WebSocketOpCode)op, msk, len, b3, b4);
//Console.WriteLine(string.Format("Got Frame {0} {1} {2} {3}", wsf.Flags.ToString(), wsf.OpCode.ToString(), wsf.PayloadLength, _sentClose));
if (!_sentClose)
{
if (cf)
{
if (wsf.OpCode == WebSocketOpCode.ConnectionClose) //client is closing the connection
{
if (rsv)
{
await Close(WebsocketCloseCode.ProtocolError, "RSV set and no extension negotiated");
End();
}
else if (wsf.PayloadLength == 0)
{
await Close();
End();
}
else if (wsf.PayloadLength == 1)
{
await Close(WebsocketCloseCode.ProtocolError, "Close frame code invalid");
End();
}
else if (wsf.PayloadLength > 125)
{
await Close(WebsocketCloseCode.ProtocolError, "Close frame too long");
End();
}
else
{
var cc = BitConverter.ToUInt16(new byte[] { wsf.Payload[1], wsf.Payload[0] }, 0);
var cm = wsf.PayloadLength > 2 ? Encoding.UTF8.GetString(wsf.Payload, 2, (int)wsf.PayloadLength - 2) : null;
if (cc >= 0 && cc <= 999)
{
await Close(WebsocketCloseCode.ProtocolError, "Close code invalid");
}
else
{
await Close();
}
End((WebsocketCloseCode)cc, cm);
}
}
else if (wsf.PayloadLength > 125)
{
await Close(WebsocketCloseCode.ProtocolError, "Control frame with payload length > 125 octets");
}
else if (op >= 0xB && op <= 0xF)
{
await Close(WebsocketCloseCode.ProtocolError, "Control frame using reserved opcode");
}
else if (!wsf.Flags.HasFlag(WebSocketFlags.FinalFragment))
{
await Close(WebsocketCloseCode.ProtocolError, "Fragmented control frame");
}
else if (wsf.OpCode == WebSocketOpCode.Ping)
{
await Pong(wsf);
}
}
else
{
if (rsv && Extensions.Count() == 0)
{
await Close(WebsocketCloseCode.ProtocolError, "RSV set and no extension negotiated");
}
else if (op >= 3 && op <= 7)
{
await Close(WebsocketCloseCode.ProtocolError, "Data frame using reserved opcode");
}
else
{
if (!fs && !wsf.Flags.HasFlag(WebSocketFlags.FinalFragment))
{
if (wsf.OpCode == WebSocketOpCode.BinaryFrame || wsf.OpCode == WebSocketOpCode.TextFrame)
{
_fragStream = new MemoryStream();
_fragMessageType = wsf.OpCode;
await _fragStream.WriteAsync(wsf.Payload, 0, (int)wsf.PayloadLength);
}
else
{
await Close(WebsocketCloseCode.ProtocolError, "Cant start fragmented message on continuation frame");
}
}
else if (fs && !wsf.Flags.HasFlag(WebSocketFlags.FinalFragment))
{
if (wsf.OpCode == WebSocketOpCode.ContinuationFrame)
{
await _fragStream.WriteAsync(wsf.Payload, 0, (int)wsf.PayloadLength);
}
else
{
await Close(WebsocketCloseCode.ProtocolError, "Received non-continuation data frame while inside fragmented message");
}
}
else if (fs && wsf.Flags.HasFlag(WebSocketFlags.FinalFragment))
{
if (wsf.OpCode == WebSocketOpCode.ContinuationFrame)
{
await _fragStream.WriteAsync(wsf.Payload, 0, (int)wsf.PayloadLength);
wsf.Payload = _fragStream.ToArray();
wsf.PayloadLength = (ulong)_fragStream.Length;
wsf.OpCode = _fragMessageType;
await ProcessFrame(new FrameEventArgs()
{
Frame = wsf, WebSocket = this
});
}
else
{
await Close(WebsocketCloseCode.ProtocolError, "Received non-continuation data frame while inside fragmented message");
}
_fragStream.Dispose();
_fragStream = null;
}
else if (!fs && wsf.OpCode == WebSocketOpCode.ContinuationFrame)
{
await Close(WebsocketCloseCode.ProtocolError, "Received continuation data frame outside fragmented message");
}
else
{
await ProcessFrame(new FrameEventArgs()
{
Frame = wsf, WebSocket = this
});
}
}
}
}
else if (cf && wsf.OpCode == WebSocketOpCode.ConnectionClose)
{
//Close response from client after we sent close code
End();
}
}
catch (Exception ex)
{
OnError(ex);
}
}
}
public async Task SendDataAsync(string data)
{
await SendFrame(await WebSocketFrame.PackData(data));
}
public async Task Pong(WebSocketFrame f)
{
f.OpCode = WebSocketOpCode.Pong;
await SendFrame(f);
}