static void SendMessage(TcpClient client, byte[] payload, int opcode, bool masking, byte[] mask)
{
if (masking && mask == null)
{
throw new ArgumentException(nameof(mask));
}
using (var packet = new MemoryStream())
{
byte firstbyte = 0b0_0_0_0_0000; // fin | rsv1 | rsv2 | rsv3 | [ OPCODE | OPCODE | OPCODE | OPCODE ]
firstbyte |= 0b1_0_0_0_0000; // fin
//firstbyte |= 0b0_1_0_0_0000; // rsv1
//firstbyte |= 0b0_0_1_0_0000; // rsv2
//firstbyte |= 0b0_0_0_1_0000; // rsv3
firstbyte += (byte)opcode; // Text
packet.WriteByte(firstbyte);
// Set bit: bytes[byteIndex] |= mask;
byte secondbyte = 0b0_0000000; // mask | [SIZE | SIZE | SIZE | SIZE | SIZE | SIZE | SIZE]
if (masking)
{
secondbyte |= 0b1_0000000; // mask
}
if (payload.LongLength <= 0b0_1111101) // 125
{
secondbyte |= (byte)payload.Length;
packet.WriteByte(secondbyte);
}
else if (payload.LongLength <= UInt16.MaxValue) // If length takes 2 bytes
{
secondbyte |= 0b0_1111110; // 126
packet.WriteByte(secondbyte);
var len = BitConverter.GetBytes(payload.LongLength);
Array.Reverse(len, 0, 2);
packet.Write(len, 0, 2);
}
else // if (payload.LongLength <= Int64.MaxValue) // If length takes 8 bytes
{
secondbyte |= 0b0_1111111; // 127
packet.WriteByte(secondbyte);
var len = BitConverter.GetBytes(payload.LongLength);
Array.Reverse(len, 0, 8);
packet.Write(len, 0, 8);
}
if (masking)
{
packet.Write(mask, 0, 4);
payload = ApplyMask(payload, mask);
}
// Write all data to the packet
packet.Write(payload, 0, payload.Length);
// Get client's stream
var stream = client.GetStream();
var finalPacket = packet.ToArray();
TcpServer.WriteLogSafe($@"SENT: {BitConverter.ToString(finalPacket)}");
// Send the packet
foreach (var b in finalPacket)
{
stream.WriteByte(b);
}
}
}
public static void Listen(TcpServer server)
{
server.ClientConnected += (_, client) => OnConnected(client);
}
private void MessageLoop()
{
var session = this;
var client = session.Client;
var stream = session.ClientStream;
var packet = new List <byte>();
var messageOpcode = 0x0;
using (var messageBuffer = new MemoryStream())
while (client.Connected)
{
packet.Clear();
var ab = client.Available;
if (ab == 0)
{
MessageProcessQueue();
continue;
}
packet.Add((byte)stream.ReadByte());
var fin = (packet[0] & (1 << 7)) != 0;
var rsv1 = (packet[0] & (1 << 6)) != 0;
var rsv2 = (packet[0] & (1 << 5)) != 0;
var rsv3 = (packet[0] & (1 << 4)) != 0;
// Must error if is set.
//if (rsv1 || rsv2 || rsv3)
// return;
var opcode = packet[0] & ((1 << 4) - 1);
switch (opcode)
{
case 0x0: // Continuation Frame
break;
case 0x1: // Text
case 0x2: // Binary
case 0x8: // Connection Close
messageOpcode = opcode;
break;
case 0x9:
continue; // Ping
case 0xA:
continue; // Pong
default:
continue; // Reserved
}
packet.Add((byte)stream.ReadByte());
var masked = IsMasking = (packet[1] & (1 << 7)) != 0;
var pseudoLength = packet[1] - (masked ? 128 : 0);
ulong actualLength = 0;
if (pseudoLength > 0 && pseudoLength < 125)
{
actualLength = (ulong)pseudoLength;
}
else if (pseudoLength == 126)
{
var length = new byte[2];
stream.Read(length, 0, length.Length);
packet.AddRange(length);
Array.Reverse(length);
actualLength = BitConverter.ToUInt16(length, 0);
}
else if (pseudoLength == 127)
{
var length = new byte[8];
stream.Read(length, 0, length.Length);
packet.AddRange(length);
Array.Reverse(length);
actualLength = BitConverter.ToUInt64(length, 0);
}
var mask = new byte[4];
if (masked)
{
stream.Read(mask, 0, mask.Length);
packet.AddRange(mask);
}
if (actualLength > 0)
{
var data = new byte[actualLength];
stream.Read(data, 0, data.Length);
packet.AddRange(data);
if (masked)
{
data = ApplyMask(data, mask);
}
messageBuffer.Write(data, 0, data.Length);
}
TcpServer.WriteLogSafe($@"RECV: {BitConverter.ToString(packet.ToArray())}");
if (!fin)
{
continue;
}
var message = messageBuffer.ToArray();
switch (messageOpcode)
{
case 0x1:
AnyMessageReceived?.Invoke(session, message);
TextMessageReceived?.Invoke(session, Encoding.UTF8.GetString(message));
break;
case 0x2:
AnyMessageReceived?.Invoke(session, message);
BinaryMessageReceived?.Invoke(session, message);
break;
case 0x8:
Close();
break;
default:
throw new Exception("Invalid opcode: " + messageOpcode);
}
messageBuffer.SetLength(0);
}
}
