/// <summary>
/// Sends the request to the server.
/// </summary>
protected void SendRequest(DataPacket request)
{
request.Encode();
netStream.Write(request.Buffer, 0, request.BufferLength);
if (CommLog != null)
{
CommLog.WriteAction(FunctionID.GetName(request.FunctionID));
CommLog.WriteAction(BuildWritingText(request.Buffer, 0, request.BufferLength));
}
}
/// <summary>
/// Sends the request to the server.
/// </summary>
protected void SendRequest(DataPacket request)
{
try
{
request.Encode();
netStream.Write(request.Buffer, 0, request.BufferLength);
if (CommLog != null)
{
CommLog.WriteAction(FunctionID.GetName(request.FunctionID));
CommLog.WriteAction(BuildWritingText(request.Buffer, 0, request.BufferLength));
}
}
catch (IOException)
{
ClientState = ClientState.Error;
throw;
}
}
/// <summary>
/// Disconnects from the server.
/// </summary>
protected void Disconnect()
{
if (tcpClient != null)
{
CommLog?.WriteAction("Disconnect");
if (netStream != null)
{
ClearNetStream(netStream, inBuf); // to disconnect correctly
netStream.Close();
netStream = null;
}
tcpClient.Close();
tcpClient = null;
ClientState = ClientState.Disconnected;
SessionID = 0;
ServerName = "";
}
}
/// <summary>
/// Connects and authenticates with the server.
/// </summary>
protected void Connect()
{
// create connection
tcpClient = new TcpClient
{
SendTimeout = ConnectionOptions.Timeout,
ReceiveTimeout = ConnectionOptions.Timeout
};
// connect
CommLog?.WriteAction("Connect to " + ConnectionOptions.Host);
if (IPAddress.TryParse(ConnectionOptions.Host, out IPAddress address))
{
tcpClient.Connect(address, ConnectionOptions.Port);
}
else
{
tcpClient.Connect(ConnectionOptions.Host, ConnectionOptions.Port);
}
netStream = tcpClient.GetStream();
ClientState = ClientState.Connected;
}
/// <summary>
/// Receives a response from the server.
/// </summary>
protected DataPacket ReceiveResponse(DataPacket request)
{
DataPacket response = null;
bool formatError = true;
string errDescr = "";
int bytesToRead = HeaderLength + 2;
int bytesRead;
try
{
bytesRead = netStream.Read(inBuf, 0, bytesToRead);
CommLog?.WriteAction(BuildReadingText(inBuf, 0, bytesToRead, bytesRead));
}
catch (IOException)
{
ClientState = ClientState.Error;
throw;
}
if (bytesRead == bytesToRead)
{
response = new DataPacket
{
TransactionID = BitConverter.ToUInt16(inBuf, 0),
DataLength = BitConverter.ToInt32(inBuf, 2),
SessionID = BitConverter.ToInt64(inBuf, 6),
FunctionID = BitConverter.ToUInt16(inBuf, 14),
Buffer = inBuf
};
if (response.DataLength + 6 > inBuf.Length)
{
errDescr = Locale.IsRussian ?
"длина данных слишком велика" :
"data length is too big";
}
else if (response.TransactionID != request.TransactionID)
{
errDescr = Locale.IsRussian ?
"неверный идентификатор транзакции" :
"incorrect transaction ID";
}
else if (response.SessionID != SessionID && SessionID != 0)
{
errDescr = Locale.IsRussian ?
"неверный идентификатор сессии" :
"incorrect session ID";
}
else if ((response.FunctionID & 0x7FFF) != request.FunctionID)
{
errDescr = Locale.IsRussian ?
"неверный идентификатор функции" :
"incorrect function ID";
}
else
{
// read the rest of the data
bytesToRead = response.DataLength - 10;
bytesRead = ReadData(netStream, tcpClient.ReceiveTimeout, inBuf, HeaderLength + 2, bytesToRead);
CommLog?.WriteAction(BuildReadingText(inBuf, HeaderLength + 2, bytesToRead, bytesRead));
if (bytesRead == bytesToRead)
{
formatError = false;
responseDT = DateTime.UtcNow;
// handle error response
if ((response.FunctionID & 0x8000) > 0)
{
ErrorCode errorCode = (ErrorCode)inBuf[ArgumentIndex];
CommLog?.WriteError(errorCode.ToString());
throw new ProtocolException(errorCode);
}
}
else
{
errDescr = Locale.IsRussian ?
"не удалось прочитать все данные" :
"unable to read all data";
}
}
}
else
{
errDescr = Locale.IsRussian ?
"не удалось прочитать заголовок пакета данных" :
"unable to read data packet header";
}
if (formatError)
{
throw new ScadaException(Locale.IsRussian ?
"Некорректный формат данных, полученных от сервера: {0}" :
"Incorrect format of data received from the server: {0}", errDescr);
}
return(response);
}
/// <summary>
/// Restores a connection with the server.
/// </summary>
protected void RestoreConnection()
{
DateTime utcNow = DateTime.UtcNow;
bool connectNeeded = false;
if (ClientState == ClientState.LoggedIn)
{
if (utcNow - responseDT > PingPeriod)
{
try
{
// check connection
DataPacket request = CreateRequest(FunctionID.GetStatus, 10);
SendRequest(request);
ReceiveResponse(request);
}
catch
{
connectNeeded = true;
}
}
}
else if (utcNow - connAttemptDT > ReconnectPeriod)
{
connectNeeded = true;
}
try
{
if (connectNeeded)
{
connAttemptDT = utcNow;
Disconnect();
Connect();
GetSessionInfo(out long sessionID, out string serverName);
SessionID = sessionID;
ServerName = serverName;
Login(ConnectionOptions.Username, ConnectionOptions.Password,
out bool loggedIn, out int userID, out int roleID, out string errMsg);
UserID = userID;
RoleID = roleID;
if (loggedIn)
{
ClientState = ClientState.LoggedIn;
CommLog?.WriteAction("User is logged in");
}
else
{
throw new ScadaException(errMsg);
}
}
else if (ClientState == ClientState.LoggedIn)
{
ClearNetStream(netStream, inBuf);
}
else
{
throw new ScadaException(Locale.IsRussian ?
"Клиент не вошёл в систему. Попробуйте позже." :
"Client is not logged in. Try again later.");
}
}
catch
{
ClientState = ClientState.Error;
throw;
}
}
/// <summary>
/// Restores a connection with the server.
/// </summary>
protected void RestoreConnection()
{
DateTime utcNow = DateTime.UtcNow;
bool connectNeeded = false;
if (ClientState == ClientState.LoggedIn)
{
if (utcNow - responseDT > PingPeriod)
{
try
{
// check connection
DataPacket request = CreateRequest(FunctionID.GetStatus, 10);
SendRequest(request);
ReceiveResponse(request);
}
catch
{
connectNeeded = true;
}
}
}
else if (utcNow - connAttemptDT > ReconnectPeriod)
{
connectNeeded = true;
}
try
{
if (connectNeeded)
{
connAttemptDT = utcNow;
Disconnect();
Connect();
GetSessionInfo(out long sessionID, out ushort protocolVersion, out string serverName);
SessionID = sessionID;
ServerName = serverName;
if (protocolVersion != ProtocolVersion)
{
throw new ScadaException(Locale.IsRussian ?
"Несовместимая версия протокола." :
"Incompatible protocol version.");
}
Login(out bool loggedIn, out _, out _, out string errorMessage);
if (loggedIn)
{
ClientState = ClientState.LoggedIn;
CommLog?.WriteAction("User is logged in");
}
else
{
throw new ScadaException(errorMessage);
}
}
else if (ClientState == ClientState.LoggedIn)
{
ClearNetStream(netStream, inBuf);
}
else
{
throw new ScadaException(Locale.IsRussian ?
"Клиент не вошёл в систему. Попробуйте позже." :
"Client is not logged in. Try again later.");
}
}
catch
{
ClientState = ClientState.Error;
throw;
}
}