/// <summary>
/// Do handshake for client side.
/// </summary>
/// <param name="clientSocket"> Socket from client side to server side</param>
/// <returns>null if handShake fail otherwise return instance of AProtocol</returns>
public async Task <AProtocol> HandShakeClient(NetworkStream clientSocket)
{
HelloCommand hello = new HelloCommand(ClientConfig.SUPPORTED_PROTOCOLS);
await hello.SendAsync(clientSocket);
ACommand shouldBeOLLEH = GetCommand(await clientSocket.ReadLineAsync());
if (shouldBeOLLEH is OllehCommand)
{
OllehCommand olleh = (OllehCommand)shouldBeOLLEH;
AProtocol protocol = ClientConfig.PROTOCOL_FACTORY.GetProtocol(olleh.PROTOCOL);
if (protocol != null)
{
AckCommand ack = new AckCommand();
await ack.SendAsync(clientSocket);
return(protocol);
}
ErrorCommand error = new ErrorCommand($"Unsupported protocols '{olleh.PROTOCOL}'. Handshake failed.");
await error.SendAsync(clientSocket);
}
else
{
printIfErrorElseSendMessage(shouldBeOLLEH, "Handshake error. Expected OllehCommand but receive " + shouldBeOLLEH.GetType().Name, clientSocket);
}
return(null);
}
/// <summary>
/// Do handshake for server side.
/// </summary>
/// <param name="serverSocket"> Socket from client side to server side</param>
/// <returns>null if handShake fail otherwise retur instance of AProtocol</returns>
public async Task <AProtocol> HandShakeServer(SuperNetworkStream serverSocket)
{
ACommand shoudBeHELLO = GetCommand(await serverSocket.ReadLineAsync());
if (shoudBeHELLO is HelloCommand)
{
String selectedProtocolLabel;
HelloCommand hello = (HelloCommand)shoudBeHELLO;
AProtocol protocol = ServerConfig.PROTOCOL_FACTORY.GetProtocol(out selectedProtocolLabel, hello.SUPPORTED_PROTOCOLS);
if (protocol != null)
{
OllehCommand olleh = new OllehCommand(selectedProtocolLabel);
await olleh.SendAsync(serverSocket);
ACommand shoudBeACK = GetCommand(await serverSocket.ReadLineAsync());
if (shoudBeACK is AckCommand)
{
return(protocol);
}
else
{
printIfErrorElseSendMessage(shoudBeACK, "Handshake error. Expected HelloCommand but receive:" + shoudBeACK.GetType().Name, serverSocket);
}
}
await serverSocket.SendCommandAsync(new ErrorCommand(String.Format("Unsupported protocols '{0}'. Handshake failed.", hello.SUPPORTED_PROTOCOLS)));
}
else
{
printIfErrorElseSendMessage(shoudBeHELLO, "Handshake error. Expected HelloCommand but receive:" + shoudBeHELLO.GetType().Name, serverSocket);
}
return(null);
}
