protected override void PreProcessRaw(ArraySegment <byte> data)
{
if (mode == Modes.WebSocket)
{
if (wsWaitHeader == false)
{
if (wsHeader.Mask)
{
wsHeader.UnmaskData(data.Array, data.Offset,
Math.Min(data.Count, wsHeader.PayloadLength - wsMaskIndex), ref wsMaskIndex);
}
}
}
}
// Receive frames, unmask them.
// Should handle pings/pongs internally.
// Should parse out Close frames.
public async Task <WebSocketReceiveTuple> ReceiveAsync(ArraySegment <byte> buffer, CancellationToken cancel)
{
if (currentHeader == null)
{
var header = new WebSocketHeader();
byte headerReadState = 1; // skip initialization
byte[] headerBuffer = new byte[14];
int headerBytesRead = 0;
int headerLength = 2;
while (true)
{
if (headerReadState == 0) // re-initialize
{
// create buffer big enough to hold the complete header
headerBuffer = new byte[14];
headerBytesRead = 0;
headerLength = 2;
headerReadState = 1;
}
var count = await stream.ReadAsync(headerBuffer, headerBytesRead, headerLength - headerBytesRead, cancel);
headerBytesRead += count;
if (headerBytesRead < headerLength)
{
continue;
}
if (headerReadState == 1) // read first 2 bytes
{
header.Fin = ((headerBuffer[0] >> 7) & 0x01) == 1;
header.OpCode = (MessageType)((headerBuffer[0] >> 0) & 0x0f);
header.Mask = ((headerBuffer[1] >> 7) & 0x01) == 1;
headerReadState = 2;
}
if (headerReadState == 2) // read length
{
ulong len = (ulong)(headerBuffer[1] >> 0) & 0x7f;
if (header.PayloadLength == 126)
{
headerLength = 4;
if (headerBytesRead < headerLength)
{
continue;
}
len = (ulong)(headerBuffer[2] * 0x100) + headerBuffer[3];
}
else if (len == 127)
{
headerLength = 10;
if (headerBytesRead < headerLength)
{
continue;
}
len = (ulong)(headerBuffer[6] * 0x1000000) +
(ulong)(headerBuffer[7] * 0x10000) +
(ulong)(headerBuffer[8] * 0x100) + (ulong)headerBuffer[9];
}
header.PayloadLength = len;
headerReadState = 3; // length received
}
if (header.Mask && headerReadState >= 3) // read masking-key
{
if (headerReadState == 3)
{
headerLength += 4;
headerReadState = 4;
}
if (headerBytesRead < headerLength)
{
continue;
}
header.MaskingKey[0] = headerBuffer[headerLength - 4];
header.MaskingKey[1] = headerBuffer[headerLength - 3];
header.MaskingKey[2] = headerBuffer[headerLength - 2];
header.MaskingKey[3] = headerBuffer[headerLength - 1];
}
// received header
Console.WriteLine("fin:{0} opcode:{1} mask:{2} len:{3} controlframe:{4}", header.Fin, header.OpCode, header.Mask, header.PayloadLength, header.IsControlFrame);
if (header.IsControlFrame)
{
// See RFC 6455 section 5.5
// can safely cast to int because control frames have max payload length of 125
int controlFrameLength = (int)header.PayloadLength;
var controlFrameBuffer = new byte[controlFrameLength];
var controlFrameBytesRead = 0;
while (controlFrameBytesRead < controlFrameLength)
{
controlFrameBytesRead += await stream.ReadAsync(controlFrameBuffer, controlFrameBytesRead, controlFrameLength - controlFrameBytesRead, cancel);
}
header.UnmaskData(new ArraySegment <byte>(controlFrameBuffer, 0, controlFrameLength));
// TODO: read data (ping/pong-content)
switch (header.OpCode)
{
case MessageType.Close:
if (controlFrameLength >= 2)
{
this.Environment[OwinConstants.WebSocket.ClientCloseStatus] = (controlFrameBuffer[0] * 0x100) + controlFrameBuffer[1];
if (controlFrameLength > 2)
{
this.Environment[OwinConstants.WebSocket.ClientCloseDescription] = Encoding.UTF8.GetString(controlFrameBuffer, 2, controlFrameLength - 2);
}
}
return(new WebSocketReceiveTuple((int)MessageType.Close, true, 0));
case MessageType.Ping:
case MessageType.Pong:
throw new NotImplementedException(); // TODO
}
headerReadState = 0; // receive next header
}
else
{
currentHeader = header;
break;
}
}
}
// now receive payload
int maxBytes;
if (currentHeader.PayloadLength > int.MaxValue)
{
maxBytes = int.MaxValue;
}
else
{
maxBytes = (int)currentHeader.PayloadLength;
}
if (buffer.Count < maxBytes)
{
maxBytes = buffer.Count;
}
int bytes = await stream.ReadAsync(buffer.Array, buffer.Offset, maxBytes, cancel);
// unmask it
if (currentHeader.Mask)
{
// TODO: handle unaligned offset?
currentHeader.UnmaskData(buffer);
}
currentHeader.PayloadReceived += (ulong)bytes;
bool endOfFrame = currentHeader.PayloadReceived >= currentHeader.PayloadLength;
bool endOfMessage = endOfFrame && currentHeader.Fin;
int messageType = (int)currentHeader.OpCode;
if (endOfFrame)
{
currentHeader = null; // forget last header
}
return(new WebSocketReceiveTuple(messageType, endOfMessage, bytes));
}
// Receive frames, unmask them.
// Should handle pings/pongs internally.
// Should parse out Close frames.
public async Task<WebSocketReceiveTuple> ReceiveAsync(ArraySegment<byte> buffer, CancellationToken cancel)
{
if (currentHeader == null)
{
var header = new WebSocketHeader();
byte headerReadState = 1;// skip initialization
byte[] headerBuffer = new byte[14];
int headerBytesRead = 0;
int headerLength = 2;
while (true)
{
if (headerReadState == 0) // re-initialize
{
// create buffer big enough to hold the complete header
headerBuffer = new byte[14];
headerBytesRead = 0;
headerLength = 2;
headerReadState = 1;
}
var count = await stream.ReadAsync(headerBuffer, headerBytesRead, headerLength - headerBytesRead, cancel);
headerBytesRead += count;
if (headerBytesRead < headerLength)
{
continue;
}
if (headerReadState == 1) // read first 2 bytes
{
header.Fin = ((headerBuffer[0] >> 7) & 0x01) == 1;
header.OpCode = (MessageType)((headerBuffer[0] >> 0) & 0x0f);
header.Mask = ((headerBuffer[1] >> 7) & 0x01) == 1;
headerReadState = 2;
}
if (headerReadState == 2) // read length
{
ulong len = (ulong)(headerBuffer[1] >> 0) & 0x7f;
if (header.PayloadLength == 126)
{
headerLength = 4;
if (headerBytesRead < headerLength)
{
continue;
}
len = (ulong)(headerBuffer[2] * 0x100) + headerBuffer[3];
}
else if (len == 127)
{
headerLength = 10;
if (headerBytesRead < headerLength)
{
continue;
}
len = (ulong)(headerBuffer[6] * 0x1000000) +
(ulong)(headerBuffer[7] * 0x10000) +
(ulong)(headerBuffer[8] * 0x100) + (ulong)headerBuffer[9];
}
header.PayloadLength = len;
headerReadState = 3; // length received
}
if (header.Mask && headerReadState >= 3) // read masking-key
{
if (headerReadState == 3)
{
headerLength += 4;
headerReadState = 4;
}
if (headerBytesRead < headerLength)
{
continue;
}
header.MaskingKey[0] = headerBuffer[headerLength - 4];
header.MaskingKey[1] = headerBuffer[headerLength - 3];
header.MaskingKey[2] = headerBuffer[headerLength - 2];
header.MaskingKey[3] = headerBuffer[headerLength - 1];
}
// received header
Console.WriteLine("fin:{0} opcode:{1} mask:{2} len:{3} controlframe:{4}", header.Fin, header.OpCode, header.Mask, header.PayloadLength, header.IsControlFrame);
if (header.IsControlFrame)
{
// See RFC 6455 section 5.5
// can safely cast to int because control frames have max payload length of 125
int controlFrameLength = (int)header.PayloadLength;
var controlFrameBuffer = new byte[controlFrameLength];
var controlFrameBytesRead = 0;
while (controlFrameBytesRead < controlFrameLength)
{
controlFrameBytesRead += await stream.ReadAsync(controlFrameBuffer, controlFrameBytesRead, controlFrameLength - controlFrameBytesRead, cancel);
}
header.UnmaskData(new ArraySegment<byte>(controlFrameBuffer, 0, controlFrameLength));
// TODO: read data (ping/pong-content)
switch (header.OpCode)
{
case MessageType.Close:
if (controlFrameLength >= 2)
{
this.Environment[OwinConstants.WebSocket.ClientCloseStatus] = (controlFrameBuffer[0] * 0x100) + controlFrameBuffer[1];
if (controlFrameLength > 2)
{
this.Environment[OwinConstants.WebSocket.ClientCloseDescription] = Encoding.UTF8.GetString(controlFrameBuffer, 2, controlFrameLength - 2);
}
}
return new WebSocketReceiveTuple((int)MessageType.Close, true, 0);
case MessageType.Ping:
case MessageType.Pong:
throw new NotImplementedException(); // TODO
}
headerReadState = 0; // receive next header
}
else
{
currentHeader = header;
break;
}
}
}
// now receive payload
int maxBytes;
if (currentHeader.PayloadLength > int.MaxValue)
maxBytes = int.MaxValue;
else
maxBytes = (int)currentHeader.PayloadLength;
if (buffer.Count < maxBytes)
maxBytes = buffer.Count;
int bytes = await stream.ReadAsync(buffer.Array, buffer.Offset, maxBytes, cancel);
// unmask it
if (currentHeader.Mask)
{
// TODO: handle unaligned offset?
currentHeader.UnmaskData(buffer);
}
currentHeader.PayloadReceived += (ulong)bytes;
bool endOfFrame = currentHeader.PayloadReceived >= currentHeader.PayloadLength;
bool endOfMessage = endOfFrame && currentHeader.Fin;
int messageType = (int)currentHeader.OpCode;
if (endOfFrame)
currentHeader = null; // forget last header
return new WebSocketReceiveTuple(messageType, endOfMessage, bytes);
}
