internal void SendData(ClientTelnetStateObject client, string data)
{
try
{
Socket clientSocket = client.ClientSocket;
Log.Default.WriteLine(LogLevels.Debug, "Send data to client at " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address + " : " + data);
// Colorize or strip color
string colorizedData = client.ColorAccepted
? AnsiHelpers.Colorize(data)
: AnsiHelpers.StripColor(data);
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Encoding.ASCII.GetBytes(colorizedData);
// Begin sending the data to the remote device.
clientSocket.BeginSend(byteData, 0, byteData.Length, 0, SendCallback, client);
}
catch (ObjectDisposedException)
{
// If server status is stopping/stopped: ok
// else, throw
if (_status != ServerStatus.Stopping && _status != ServerStatus.Stopped && client.State != ClientStates.Disconnected)
{
throw;
}
}
}
internal void CloseConnection(ClientTelnetStateObject client)
{
// Remove from 'client' collection
_clients.Remove(client);
//
Socket clientSocket = client.ClientSocket;
Log.Default.WriteLine(LogLevels.Info, "Client at " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address + " has disconnected");
// Close socket
clientSocket.Shutdown(SocketShutdown.Both);
clientSocket.Close();
ClientDisconnected?.Invoke(client);
}
internal void SendData(ClientTelnetStateObject client, byte[] byteData)
{
try
{
Socket clientSocket = client.ClientSocket;
Log.Default.WriteLine(LogLevels.Debug, "Send data to client at " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address + " : " + ByteArrayToString(byteData, byteData.Length));
// Begin sending the data to the remote device.
clientSocket.BeginSend(byteData, 0, byteData.Length, 0, SendCallback, client);
}
catch (ObjectDisposedException)
{
// If server status is stopping/stopped: ok
// else, throw
if (_status != ServerStatus.Stopping && _status != ServerStatus.Stopped && client.State != ClientStates.Disconnected)
{
throw;
}
}
}
private void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
ClientTelnetStateObject client = (ClientTelnetStateObject)ar.AsyncState;
Socket clientSocket = client.ClientSocket;
// Complete sending the data to the remote device.
int bytesSent = clientSocket.EndSend(ar);
Log.Default.WriteLine(LogLevels.Debug, "Sent " + bytesSent + " bytes to client at " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address);
}
catch (ObjectDisposedException)
{
// If server status is stopping/stopped: ok
// else, throw
if (_status != ServerStatus.Stopping && _status != ServerStatus.Stopped)
{
throw;
}
}
}
private void AcceptCallback(IAsyncResult ar)
{
try
{
// Signal the ListenTask to continue.
_listenEvent.Set();
// Get the socket that handles the client request.
Socket listener = (Socket)ar.AsyncState;
Socket clientSocket = listener.EndAccept(ar);
Log.Default.WriteLine(LogLevels.Debug, "Client connected from " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address);
// Create the state object.
ClientTelnetStateObject client = new ClientTelnetStateObject(this)
{
ClientSocket = clientSocket,
};
_clients.Add(client);
// TODO: NewClientConnected will be called once protocol handshake is done
//
client.State = ClientStates.Connected;
NewClientConnected?.Invoke(client);
//
clientSocket.BeginReceive(client.Buffer, 0, ClientTelnetStateObject.BufferSize, 0, ReadCallback, client);
}
catch (ObjectDisposedException)
{
// If server status is stopping/stopped: ok
// else, throw
if (_status != ServerStatus.Stopping && _status != ServerStatus.Stopped)
{
throw;
}
}
}
private void ReadCallback(IAsyncResult ar)
{
// Retrieve the state object and the handler socket
// from the asynchronous state object.
ClientTelnetStateObject client = (ClientTelnetStateObject)ar.AsyncState;
try
{
Socket clientSocket = client.ClientSocket;
// Read data from the client socket.
int bytesRead = clientSocket.EndReceive(ar);
Log.Default.WriteLine(LogLevels.Debug, "Received " + bytesRead + " bytes from client at " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address);
if (bytesRead == 0)
{
// Something goes wrong, close connection
CloseConnection(client);
}
else
{
// // Putty handshake is
// //FF FB 1F window size
// //FF FB 20 terminal speed
// //FF FB 18 terminal type
// //FF FB 27 Telnet Environment Option
// //FF FD 01 echo
// //FF FB 03 suppress go ahead
// //FF FD 03 suppress go ahead
// //FF FE 01 received after echo on
//Log.Default.WriteLine(LogLevels.Debug, "Data received from client at " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address + " : " + ByteArrayToString(client.Buffer, bytesRead));
// Remove protocol character
if (bytesRead % 3 == 0 && client.Buffer[0] == 0xFF)// && client.Buffer[1] == 0xFB)
{
Log.Default.WriteLine(LogLevels.Info, "Protocol received from client at " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address + " : " + ByteArrayToString(client.Buffer, bytesRead));
}
else if (client.State == ClientStates.Connected)
{
string dataReceived = Encoding.ASCII.GetString(client.Buffer, 0, bytesRead);
Log.Default.WriteLine(LogLevels.Debug, "Data received from client at " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address + " : " + dataReceived);
// If data ends with CRLF, remove CRLF and consider command as complete
bool commandComplete = false;
if (dataReceived.EndsWith("\n") || dataReceived.EndsWith("\r"))
{
commandComplete = true;
dataReceived = dataReceived.TrimEnd('\r', '\n');
}
// Remove non-ascii char
dataReceived = AsciiRegEx.Replace(dataReceived, string.Empty);
// Append data in command
client.Command.Append(dataReceived);
// Command is complete, send it to command processor and start a new one
if (commandComplete)
{
// Get command
string command = client.Command.ToString();
Log.Default.WriteLine(LogLevels.Info, "Command received from client at " + ((IPEndPoint)clientSocket.RemoteEndPoint).Address + " : " + command);
// Reset command
client.Command.Clear();
// Process command
client.OnDataReceived(command);
}
}
// TODO: other states ?
// Continue reading
clientSocket.BeginReceive(client.Buffer, 0, ClientTelnetStateObject.BufferSize, 0, ReadCallback, client);
}
}
catch (ObjectDisposedException)
{
// If server status is stopping/stopped: ok
// else, throw
if (_status != ServerStatus.Stopping && _status != ServerStatus.Stopped && client.State != ClientStates.Disconnected)
{
throw;
}
}
}
