private WebSocketFrame ReadFrame()
{
WebSocketFrameHeader frameHeader = ReadFrameHeader();
if (frameHeader.PayloadLength > int.MaxValue)
{
throw new HcduServerException("Long messages are not supported.");
}
if (frameHeader.Mask == null)
{
throw new HcduServerException("Client messages should be masked.");
}
byte[] content = HttpUtils.ReadBlock(stream, (int)frameHeader.PayloadLength);
if (frameHeader.Mask != null)
{
for (int i = 0; i < content.Length; i++)
{
content[i] = (byte)(content[i] ^ frameHeader.Mask[i % 4]);
}
}
WebSocketFrame frame = new WebSocketFrame();
frame.Header = frameHeader;
frame.Content = content;
return(frame);
}
private WebSocketFrameHeader ReadFrameHeader()
{
byte[] primaryHeader = HttpUtils.ReadBlock(stream, 2);
WebSocketFrameHeader header = new WebSocketFrameHeader();
header.IsLast = (primaryHeader[0] & 0x80) != 0;
header.OpCode = (byte)(primaryHeader[0] & 0x0F);
header.PayloadLength = (byte)(primaryHeader[1] & 0x7F);
if (header.PayloadLength == 126)
{
byte[] extLengthHeader = HttpUtils.ReadBlock(stream, 2);
header.PayloadLength = BitConverter.ToUInt16(extLengthHeader, 0);
}
if (header.PayloadLength == 127)
{
byte[] extLengthHeader = HttpUtils.ReadBlock(stream, 8);
header.PayloadLength = BitConverter.ToUInt64(extLengthHeader, 0);
}
if ((primaryHeader[0] & 0x80) != 0)
{
header.Mask = HttpUtils.ReadBlock(stream, 4);
}
return(header);
}
private void ListenerLoop()
{
WebSocketFrameHeader messageHeader = null;
MemoryStream messageContent = new MemoryStream();
ulong messageLength = 0;
//todo: stop gracefully
while (!isClosed)
{
WebSocketFrame frame = ReadFrame();
if (WebSocketOpcodes.IsControlFrame(frame.Header.OpCode))
{
//todo: remove magic number
if (!frame.Header.IsLast || frame.Header.PayloadLength > 125)
{
throw new HcduServerException(string.Format("Invalid control frame (Opcode: {0}, FIN: {1}, Length: {2}).", frame.Header.OpCode, frame.Header.IsLast, frame.Header.PayloadLength));
}
HandleControlFrame(frame);
}
if (messageHeader == null)
{
if (frame.Header.OpCode == WebSocketOpcodes.ContinuationFrame)
{
throw new HcduServerException("Continuation frame cannot start message.");
}
messageHeader = frame.Header;
}
messageLength += frame.Header.PayloadLength;
if (messageLength > int.MaxValue)
{
throw new HcduServerException("Long messages are not supported.");
}
messageContent.Write(frame.Content, 0, frame.Content.Length);
if (frame.Header.IsLast)
{
WebSocketMessage message = new WebSocketMessage();
message.OpCode = messageHeader.OpCode;
message.Content = messageContent.ToArray();
messageHeader = null;
messageContent = new MemoryStream();
HandleMessage(message);
}
}
}
private WebSocketFrameHeader ReadFrameHeader()
{
byte[] primaryHeader = HttpUtils.ReadBlock(stream, 2);
WebSocketFrameHeader header = new WebSocketFrameHeader();
header.IsLast = (primaryHeader[0] & 0x80) != 0;
header.OpCode = (byte) (primaryHeader[0] & 0x0F);
header.PayloadLength = (byte) (primaryHeader[1] & 0x7F);
if (header.PayloadLength == 126)
{
byte[] extLengthHeader = HttpUtils.ReadBlock(stream, 2);
header.PayloadLength = BitConverter.ToUInt16(extLengthHeader, 0);
}
if (header.PayloadLength == 127)
{
byte[] extLengthHeader = HttpUtils.ReadBlock(stream, 8);
header.PayloadLength = BitConverter.ToUInt64(extLengthHeader, 0);
}
if ((primaryHeader[0] & 0x80) != 0)
{
header.Mask = HttpUtils.ReadBlock(stream, 4);
}
return header;
}