public void Write(byte[] Bytes, FrameOpCode OpCode = FrameOpCode.BINARY_FRAME)
{
Stream Stream = Client.GetStream();
List <byte[]> Frames = new List <byte[]>();
if (OpCode == FrameOpCode.TEXT_FRAME || OpCode == FrameOpCode.BINARY_FRAME)
{
if (Bytes == null)
{
return;
}
// Arbitrary to us (not specific to spec), since spec could hold a 64bit length
// yet VS array lengths are integers and thus would have an overflow...
int MaxPayloadLength = int.MaxValue - 1;
long FrameCount = Math.Max(Bytes.Length / MaxPayloadLength, 1);
int Offset = 0;
for (int FrameIdx = 0; FrameIdx < FrameCount; FrameIdx++)
{
int PayloadLength;
if (Bytes.Length > MaxPayloadLength)
{
PayloadLength = Math.Min(MaxPayloadLength, Bytes.Length - (FrameIdx * MaxPayloadLength));
}
else
{
PayloadLength = Bytes.Length;
}
// Frame byte size
int FrameSize = PayloadLength;
int OffsetFrameSize = 0;
// Bit 1
bool FinBit = FrameIdx == FrameCount - 1;
FrameOpCode FrameOpCode = FrameIdx > 0 ? FrameOpCode.CONTINUE_FRAME : OpCode;
// Bit 2
// TODO: Support a client WS too?
bool Masked = false; // Only clients send masked data as part of spec 5.1
int Length = PayloadLength; // real length by default (< 126)
byte[] ExtendedLength = null;
if (PayloadLength > Int16.MaxValue)
{
Length = 127; // Set int64 length flag
ExtendedLength = ConvertInt(PayloadLength);
OffsetFrameSize += 8;
}
else if (PayloadLength >= 126)
{
Length = 126; // Set int16 length flag
ExtendedLength = ConvertInt(PayloadLength);
OffsetFrameSize += 2;
} /* else Length = PayloadLength (<126) */
// Frame size is +payload, +2 byte header and +4 byte (32 bit) mask
OffsetFrameSize += 2;
FrameSize += OffsetFrameSize; // + 4;
// Lets start making a frame :)
byte[] FrameBytes = new byte[FrameSize];
FrameBytes[0] = (byte)((FinBit ? 128 : 0) | (int)OpCode);
FrameBytes[1] = (byte)(Masked ? 128 : 0 | Length);
// Add optional extended length
if (ExtendedLength != null)
{
if (ExtendedLength.Length > OffsetFrameSize)
{
// Likely an issue with ConvertInt at this point?
throw new Exception("Payload extended length miscalculation");
}
for (int Idx = 0; Idx < ExtendedLength.Length; Idx++)
{
FrameBytes[2 + Idx] = ExtendedLength[Idx];
}
}
// Add Masks
//byte[] Masks = new byte[4];
//(new Random()).NextBytes(Masks);
//for (int Idx = 0; Idx < 4; Idx++)
//{
// //Masks[Idx] = (byte)(new Random()).Next(255);
// FrameBytes[OffsetFrameSize + Idx] = Masks[Idx];
//}
//OffsetFrameSize += 4;
// Add encoded XOR bytes, only if mask is involved (WS clients senders only)
for (int Idx = 0; Idx < PayloadLength; Idx++)
{
FrameBytes[OffsetFrameSize + Idx] = (byte)(Bytes[Offset + Idx]); // ^ Masks[Idx % 4]);
}
Offset += PayloadLength;
Frames.Add(FrameBytes);
}
}
else
{
if (OpCode.ToString().Contains("RESERVED"))
{
throw new Exception("Unable to send a reserved opcode frame");
}
if (OpCode == FrameOpCode.CONTINUE_FRAME)
{
throw new Exception("Unable to send continue frames outright");
}
Frames.Add(new byte[2] {
(byte)((int)FrameFIN.FINISHED | (int)OpCode),
0 // No mask for clients & no length in control frames
});
}
// Write all frames to client
foreach (byte[] Frame in Frames)
{
if (Client.Connected && Stream.CanWrite)
{
Stream.Write(Frame, 0, Frame.Length);
}
}
}
public void Read()
{
if (OnWebSocketConnected != null)
{
OnWebSocketConnected(this);
}
Stream Stream = Client.GetStream();
MemoryStream Buffer = new MemoryStream();
FrameOpCode LastRecvOpCode = 0;
while (Client.Connected)
{
if (Client.Available == 0)
{
Thread.Sleep(1);
continue;
}
int ReceivedBytesAvailable = Client.Available;
byte[] ReceivedBytes = new byte[ReceivedBytesAvailable];
byte[] DecodedBytes;
byte[] Masks = new byte[4];
ReceivedBytesAvailable = Stream.Read(ReceivedBytes, 0, ReceivedBytesAvailable);
FrameFIN FIN = (FrameFIN)((ReceivedBytes[0] & 0b10000000) != 0 ? FrameFIN.FINISHED : FrameFIN.CONTINUE);
FrameOpCode OpCode = (FrameOpCode)(ReceivedBytes[0] & 0b0001111 /* 15 */);
bool Masked = (ReceivedBytes[1] & 0b10000000) != 0;
long PayloadLength = ReceivedBytes[1] - 0b10000000;
if (!Masked)
{
break; // Must close here (section 5.1 of spec)
}
if (OpCode == FrameOpCode.CONTINUE_FRAME)
{
OpCode = LastRecvOpCode;
}
if (OpCode.ToString().Contains("RESERVED"))
{
break;
}
int Offset = 2;
if (PayloadLength == 127)
{
PayloadLength = ConvertInt(ReceivedBytes, Offset, 8);
Offset += 8; // 2 first bits + 64 bit number (8 bytes)
}
else if (PayloadLength == 126)
{
PayloadLength = ConvertInt(ReceivedBytes, Offset, 2);
Offset += 2; // 2 first bits + 16 bit number (2 bytes)
}
// Masks only used for server reads (client sends masked data)
// Servers should not send masked data
// Mask uses a 32 bit number (4 bytes)
for (int Idx = 0; Idx < 4; Idx++)
{
Masks[Idx] = ReceivedBytes[Offset + Idx];
}
Offset += 4; // Masks used up
DecodedBytes = new byte[PayloadLength];
// Decode bytes
for (int Idx = 0; Idx < PayloadLength; ++Idx)
{
DecodedBytes[Idx] = (byte)(ReceivedBytes[Offset + Idx] ^ Masks[Idx % 4]);
}
// Note: Since we read all available bytes, we may potentially read bytes of the next message,
// so it may be best to append the latest bytes to it. If this happens, this code will
// need to be updated to support this scenario.
if (OpCode == FrameOpCode.CLOSE_FRAME)
{
break;
}
if (OpCode == FrameOpCode.PONG_FRAME)
{
continue;
}
if (OpCode == FrameOpCode.PING_FRAME)
{
this.SendPong();
continue;
}
LastRecvOpCode = OpCode;
// Write message to the buffer;
Offset = 0;
while (Offset < PayloadLength)
{
if (PayloadLength - Offset >= int.MaxValue)
{
Buffer.Write(DecodedBytes, Offset, int.MaxValue);
Offset += int.MaxValue;
}
else
{
int Rest = (int)(PayloadLength - Offset);
Buffer.Write(DecodedBytes, Offset, Rest);
Offset += Rest;
}
}
if (FIN == FrameFIN.FINISHED && MessageReceived != null)
{
MessageReceived(this, new MessageEventArgs(OpCode, Buffer));
Buffer = new MemoryStream();
} /* else FIN == FrameFIN.CONTINUE */
}
Client.Close();
if (OnWebSocketDisconnected != null)
{
OnWebSocketDisconnected(this);
}
}