Here is section 2 :
public void ProcessMessages()
{
UInt16 sendCRC = 0;
DateTime date;
int year = 0;
int month = 0;
int day = 0;
int hour = 0;
int minute = 0;
int second = 0;
KeyValuePair<List<byte>, StateObject> byteState;
KeyValuePair<UNPACK_STATUS, byte[]> status;
byte[] receiveMessage = null;
StateObject state = null;
byte[] serialNumber = null;
byte[] serverFlagBit = null;
byte[] stringArray = null;
string stringMessage = "";
byte lengthOfCommand = 0;
PROTOCOL_NUMBER protocolNumber = PROTOCOL_NUMBER.NONE;
try
{
Boolean firstMessage = true;
acceptDone.Set();
//loop forever
while (true)
{
allDone.WaitOne();
//read fifo until empty
while (true)
{
//read one connection until buffer doesn't contain any more packets
byteState = ReadWrite(PROCESS_STATE.PROCESS, null, null, -1);
if (byteState.Value.fifoCount == -1) break;
state = byteState.Value;
while (true)
{
status = Unpack(byteState);
if (status.Key == UNPACK_STATUS.NOT_ENOUGH_BYTES)
break;
if (status.Key == UNPACK_STATUS.ERROR)
{
Console.WriteLine("Error : Bad Receive Message, Data");
break;
}
//message is 2 start bytes + 1 byte (message length) + 1 byte message length + 2 end bytes
receiveMessage = status.Value;
int messageLength = receiveMessage[2];
Console.WriteLine("Status : '{0}', Receive Message : '{1}'", status.Key == UNPACK_STATUS.GOOD_MESSAGE ? "Good" : "Bad", BytesToString(receiveMessage.Take(messageLength + 5).ToArray()));
if (status.Key != UNPACK_STATUS.GOOD_MESSAGE)
{
break;
}
else
{
if (firstMessage)
{
if (receiveMessage[3] != 0x01)
{
Console.WriteLine("Error : Expected Login Message : '{0}'", BytesToString(receiveMessage));
break;
}
firstMessage = false;
}
//skip start bytes, message length. then go back 4 bytes (CRC and serial number)
serialNumber = receiveMessage.Skip(2 + 1 + messageLength - 4).Take(2).ToArray();
protocolNumber = (PROTOCOL_NUMBER)receiveMessage[3];
Console.WriteLine("Protocol Number : '{0}'",protocolNumber.ToString());
switch (protocolNumber)
{
case PROTOCOL_NUMBER.LOGIN_MESSAGE:
serialNumber.CopyTo(loginResponse, 4);
sendCRC = crc_bytes(loginResponse.Skip(2).Take(loginResponse.Length - 6).ToArray());
loginResponse[loginResponse.Length - 4] = (byte)((sendCRC >> 8) & 0xFF);
loginResponse[loginResponse.Length - 3] = (byte)((sendCRC) & 0xFF);
//
string IMEI = Encoding.ASCII.GetString(receiveMessage.Skip(4).Take(messageLength - 5).ToArray());
byteState.Value.IMEI = IMEI;
Console.WriteLine("Received good login message from Serial Number : '{0}', Terminal ID = '{1}'", "0x" + serialNumber[0].ToString("X2") + serialNumber[1].ToString("X2"), IMEI);
Console.WriteLine("Send Message : '{0}'", BytesToString(loginResponse));
Send(state.workSocket, loginResponse);
WriteDBMessageLogin loginMessage = new WriteDBMessageLogin() { message = DATABASE_MESSAGE_TYPE.LOGIN, IMEI = IMEI, date = DateTime.Now };
WriteDBAsync.ReadWriteFifo(WriteDBAsync.Mode.WRITE, loginMessage);
Console.WriteLine("Wrote to database");
break;
case PROTOCOL_NUMBER.LOCATION_DATA:
year = receiveMessage[4];
month = receiveMessage[5];
day = receiveMessage[6];
hour = receiveMessage[7];
minute = receiveMessage[8];
second = receiveMessage[9];
date = new DateTime(2000 + year, month, day, hour, minute, second);
WriteDBMessageLocation locationMessage = new WriteDBMessageLocation();
locationMessage.message = DATABASE_MESSAGE_TYPE.LOCATION;
locationMessage.trackTime = date;
locationMessage.currTime = DateTime.Now;
locationMessage.lattitude = new byte[4];
Array.Copy(receiveMessage, 11, locationMessage.lattitude, 0, 4);
locationMessage.longitude = new byte[4];
Array.Copy(receiveMessage, 15, locationMessage.longitude, 0, 4);
locationMessage.speed = receiveMessage[19];
locationMessage.courseStatus = new byte[2];
Array.Copy(receiveMessage, 20, locationMessage.courseStatus, 0, 2);
locationMessage.IMEI = byteState.Value.IMEI;
WriteDBAsync.ReadWriteFifo(WriteDBAsync.Mode.WRITE, locationMessage);
Console.WriteLine("Received good location message from Serial Number '{0}', Time="{1}"", "0x" + serialNumber[0].ToString("X2") + serialNumber[1].ToString("X2"), date.ToLongDateString());
break;
case PROTOCOL_NUMBER.ALARM_DATA:
//first response
int alarmPacketLen = alarmResponse.Length - 5;
alarmResponse[2] = (byte)(alarmPacketLen & 0xFF);
serialNumber.CopyTo(alarmResponse, alarmPacketLen - 1);
sendCRC = crc_bytes(alarmResponse.Skip(2).Take(alarmPacketLen - 1).ToArray());
alarmResponse[alarmPacketLen + 1] = (byte)((sendCRC >> 8) & 0xFF);
alarmResponse[alarmPacketLen + 2] = (byte)((sendCRC) & 0xFF);
Console.WriteLine("Send Alarm Response Message : '{0}'", BytesToString(alarmResponse));
Send(state.workSocket, alarmResponse);
//second response
year = receiveMessage[4];
month = receiveMessage[5];
day = receiveMessage[6];
hour = receiveMessage[7];
minute = receiveMessage[8];
second = receiveMessage[9];
date = new DateTime(2000 + year, month, day, hour, minute, second);
Console.WriteLine("Received good alarm message from Serial Number '{0}', Time="{1}"", "0x" + serialNumber[0].ToString("X2") + serialNumber[1].ToString("X2"), date.ToLongDateString());
int alarmDataAddressPacketLen = alarmDataAddressResponse.Length - 5;
alarmDataAddressResponse[2] = (byte)(alarmDataAddressPacketLen & 0xFF);
serialNumber.CopyTo(alarmDataAddressResponse, alarmDataAddressPacketLen - 1);
sendCRC = crc_bytes(alarmDataAddressResponse.Skip(2).Take(alarmDataAddressPacketLen - 1).ToArray());
alarmDataAddressResponse[alarmDataAddressPacketLen + 1] = (byte)((sendCRC >> 8) & 0xFF);
alarmDataAddressResponse[alarmDataAddressPacketLen + 2] = (byte)((sendCRC) & 0xFF);
Console.WriteLine("Send Alarm Data Address Message : '{0}'", BytesToString(alarmDataAddressResponse));
Send(state.workSocket, alarmDataAddressResponse);
break;
case PROTOCOL_NUMBER.STATUS_INFO:
serialNumber.CopyTo(heartbeatResponse, 4);
byte info = receiveMessage[4];
byte voltage = receiveMessage[5];
byte GSMsignalStrength = receiveMessage[6];
UInt16 alarmLanguage = (UInt16)((receiveMessage[7] << 8) | receiveMessage[8]);
ALARM alarm = (ALARM)((info >> 3) & 0x07);
sendCRC = crc_bytes(heartbeatResponse.Skip(2).Take(heartbeatResponse.Length - 6).ToArray());
heartbeatResponse[heartbeatResponse.Length - 4] = (byte)((sendCRC >> 8) & 0xFF);
heartbeatResponse[heartbeatResponse.Length - 3] = (byte)((sendCRC) & 0xFF);
Console.WriteLine("Received good status message from Serial Number : '{0}', INFO : '0x{1}{2}{3}{4}'",
"0x" + serialNumber[0].ToString("X2") + serialNumber[1].ToString("X2"),
info.ToString("X2"), voltage.ToString("X2"), GSMsignalStrength.ToString("X2"),
alarmLanguage.ToString("X4"));
Console.WriteLine("Send Message : '{0}'", BytesToString(heartbeatResponse));
Send(state.workSocket, heartbeatResponse);
switch (alarm)
{
//reset cut off alarm
case ALARM.POWER_CUT_ALARM:
int connectOilAndElectricityPacketLen = connectOilAndEletricity.Length - 5;
serialNumber.CopyTo(connectOilAndEletricity, connectOilAndElectricityPacketLen - 1);
sendCRC = crc_bytes(connectOilAndEletricity.Skip(2).Take(connectOilAndEletricity.Length - 6).ToArray());
connectOilAndEletricity[connectOilAndEletricity.Length - 4] = (byte)((sendCRC >> 8) & 0xFF);
connectOilAndEletricity[connectOilAndEletricity.Length - 3] = (byte)((sendCRC) & 0xFF);
serverFlagBit = new byte[4];
Array.Copy(connectOilAndEletricity, 5, serverFlagBit, 0, 4);
lengthOfCommand = connectOilAndEletricity[4];
stringArray = new byte[lengthOfCommand - 4]; //do not include server flag bit
Array.Copy(connectOilAndEletricity, 9, stringArray, 0, lengthOfCommand - 4);
stringMessage = Encoding.ASCII.GetString(stringArray);
Console.WriteLine("Reset Oil and Electricity, Server Flag Bit : '{0}{1}{2}{3}', Message : '{4}'",
serverFlagBit[0].ToString("X2"),
serverFlagBit[1].ToString("X2"),
serverFlagBit[2].ToString("X2"),
serverFlagBit[3].ToString("X2"),
stringMessage);
Send(state.workSocket, connectOilAndEletricity);
break;
}
break;
case PROTOCOL_NUMBER.STRING_INFO :
lengthOfCommand = receiveMessage[4];
serverFlagBit = new byte[4];
Array.Copy(receiveMessage, 5, serverFlagBit, 0, 4);
stringArray = new byte[lengthOfCommand - 4]; //do not include server flag bit
Array.Copy(receiveMessage, 9, stringArray, 0, lengthOfCommand - 4);
stringMessage = Encoding.ASCII.GetString(stringArray);
Console.WriteLine("String Message, Server Flag Bit : '{0}{1}{2}{3}', Message : '{4}'",
serverFlagBit[0].ToString("X2"),
serverFlagBit[1].ToString("X2"),
serverFlagBit[2].ToString("X2"),
serverFlagBit[3].ToString("X2"),
stringMessage);
break;
} //end switch
}// End if
} //end while
}//end while fifo > 0
allDone.Reset();
}//end while true
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
}
static string BytesToString(byte[] bytes)
{
return string.Join("", bytes.Select(x => x.ToString("X2")));
}
static KeyValuePair<UNPACK_STATUS, byte[]> Unpack(KeyValuePair<List<byte>, StateObject> bitState)
{
List<byte> working_buffer = bitState.Key;
//return null indicates an error
if (working_buffer.Count() < 3) return new KeyValuePair<UNPACK_STATUS, byte[]>(UNPACK_STATUS.NOT_ENOUGH_BYTES, null);
int len = working_buffer[2];
if (working_buffer.Count < len + 5) return new KeyValuePair<UNPACK_STATUS, byte[]>(UNPACK_STATUS.NOT_ENOUGH_BYTES, null);
// check start and end bytes
// remove message fro workig buffer and dictionary
KeyValuePair<List<byte>, StateObject> byteState = ReadWrite(PROCESS_STATE.UNPACK, null, null, bitState.Value.connectionNumber);
if (byteState.Key.Count == 0) return new KeyValuePair<UNPACK_STATUS, byte[]>(UNPACK_STATUS.ERROR, null);
List<byte> packet = byteState.Key;
//crc test
byte[] crc = packet.Skip(len + 1).Take(2).ToArray();
ushort crcShort = (ushort)((crc[0] << 8) | crc[1]);
//skip start bytes, crc, and end bytes
ushort CalculatedCRC = crc_bytes(packet.Skip(2).Take(len - 1).ToArray());
if (CalculatedCRC != crcShort)
{
return new KeyValuePair<UNPACK_STATUS, byte[]>(UNPACK_STATUS.BAD_CRC, packet.ToArray());
}
return new KeyValuePair<UNPACK_STATUS, byte[]>(UNPACK_STATUS.GOOD_MESSAGE, packet.ToArray());
}
static public UInt16 crc_bytes(byte[] data)
{
ushort crc = 0xFFFF;
for (int i = 0; i < data.Length; i++)
{
crc ^= (ushort)(Reflect(data[i], 8) << 8);
for (int j = 0; j < 8; j++)
{
if ((crc & 0x8000) > 0)
crc = (ushort)((crc << 1) ^ 0x1021);
else
crc <<= 1;
}
}
crc = Reflect(crc, 16);
crc = (ushort)~crc;
return crc;
}
static public ushort Reflect(ushort data, int size)
{
ushort output = 0;
for (int i = 0; i < size; i++)
{
int lsb = data & 0x01;
output = (ushort)((output << 1) | lsb);
data >>= 1;
}
return output;
}
static KeyValuePair<List<byte>, StateObject> ReadWrite(PROCESS_STATE ps, Socket handler, IAsyncResult ar, long unpackConnectionNumber)
{
KeyValuePair<List<byte>, StateObject> byteState = new KeyValuePair<List<byte>, StateObject>(); ;
StateObject stateObject = null;
int bytesRead = -1;
int workingBufferLen = 0;
List<byte> working_buffer = null;
byte[] buffer = null;
Object thisLock1 = new Object();
lock (thisLock1)
{
switch (ps)
{
case PROCESS_STATE.ACCEPT:
acceptDone.WaitOne();
acceptDone.Reset();
stateObject = new StateObject();
stateObject.buffer = new byte[BUFFER_SIZE];
connectionDict.Add(connectionNumber, new KeyValuePair<List<byte>, StateObject>(new List<byte>(), stateObject));
stateObject.connectionNumber = connectionNumber++;
stateObject.workSocket = handler;
byteState = new KeyValuePair<List<byte>, StateObject>(null, stateObject);
acceptDone.Set();
break;
case PROCESS_STATE.READ:
//catch when client disconnects
//wait if accept is being called
//acceptDone.WaitOne();
try
{
stateObject = ar.AsyncState as StateObject;
// Read data from the client socket.
bytesRead = stateObject.workSocket.EndReceive(ar);
if (bytesRead > 0)
{
byteState = connectionDict[stateObject.connectionNumber];
buffer = new byte[bytesRead];
Array.Copy(byteState.Value.buffer, buffer, bytesRead);
byteState.Key.AddRange(buffer);
}
//only put one instance of connection number into fifo
if (!fifo.Contains(byteState.Value.connectionNumber)) {
fifo.Add(byteState.Value.connectionNumber);
}
}
catch (Exception ex)
{
//will get here if client disconnects
fifo.RemoveAll(x => x == byteState.Value.connectionNumber);
connectionDict.Remove(byteState.Value.connectionNumber);
byteState = new KeyValuePair<List<byte>, StateObject>(new List<byte>(), null);
}
break;
case PROCESS_STATE.PROCESS:
if (fifo.Count > 0)
{
//get message from working buffer
//unpack will later delete message
//remove connection number from fifo
// the list in the key in known as the working buffer
byteState = new KeyValuePair<List<byte>, StateObject>(connectionDict[fifo[0]].Key, connectionDict[fifo[0]].Value);
fifo.RemoveAt(0);
//put a valid value in fifoCount so -1 below can be detected.
byteState.Value.fifoCount = fifo.Count;
}
else
{
//getting here is normal when there is no more work to be performed
//set fifocount to zero so rest of code know fifo was empty so code waits for next receive message
byteState = new KeyValuePair<List<byte>, StateObject>(null, new StateObject() { fifoCount = -1 });
}
break;
case PROCESS_STATE.UNPACK:
try
{
working_buffer = connectionDict[unpackConnectionNumber].Key;
workingBufferLen = working_buffer[2];
if ((working_buffer[0] != 0x78) && (working_buffer[1] != 0x78) && (working_buffer[workingBufferLen + 3] != 0x0D) && (working_buffer[workingBufferLen + 4] != 0x0A))
{
working_buffer.Clear();
return new KeyValuePair<List<byte>, StateObject>(new List<byte>(), null);
}
List<byte> packet = working_buffer.GetRange(0, workingBufferLen + 5);
working_buffer.RemoveRange(0, workingBufferLen + 5);
byteState = new KeyValuePair<List<byte>, StateObject>(packet, null);
}
catch(Exception ex)
{
int testPoint = 0;
}
break;
}// end switch
}
return byteState;
}
static void Send(Socket handler, String data)
{
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Encoding.ASCII.GetBytes(data);
// Begin sending the data to the remote device.
handler.BeginSend(byteData, 0, byteData.Length, 0,
new AsyncCallback(SendCallback), handler);
}
static void Send(Socket socket, byte[] data)
{
// Convert the string data to byte data using ASCII encoding.
// byte[] byteData = Encoding.ASCII.GetBytes(data);
// Begin sending the data to the remote device.
socket.BeginSend(data, 0, data.Length, 0,
new AsyncCallback(SendCallback), socket);
}
static void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket handler = ar.AsyncState as Socket;
// Complete sending the data to the remote device.
int bytesSent = handler.EndSend(ar);
// Console.WriteLine("Sent {0} bytes to client.", bytesSent);
}
catch (Exception e)
{
// Console.WriteLine(e.ToString());
int myerror = -1;
}
}
public static void AcceptCallback(IAsyncResult ar)
{
try
{
// Get the socket that handles the client request.
// Retrieve the state object and the handler socket
// from the asynchronous state object.
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
// Create the state object.
StateObject state = ReadWrite(PROCESS_STATE.ACCEPT, handler, ar, - 1).Value;
handler.BeginReceive(state.buffer, 0, BUFFER_SIZE, 0,
new AsyncCallback(ReadCallback), state);
}
catch (Exception ex)
{
int myerror = -1;
}
}
public static void ReadCallback(IAsyncResult ar)
{
try
{
StateObject state = ar.AsyncState as StateObject;
Socket handler = state.workSocket;
// Read data from the client socket.
KeyValuePair<List<byte>, StateObject> byteState = ReadWrite(PROCESS_STATE.READ, handler, ar, -1);
if (byteState.Value != null)
{
allDone.Set();
handler.BeginReceive(state.buffer, 0, BUFFER_SIZE, 0,
new AsyncCallback(ReadCallback), state);
}
else
{
int testPoint = 0;
}
}
catch (Exception ex)
{
int myerror = -1;
}
// Signal the main thread to continue.
allDone.Set();
}
}
}