/**
* @brief Crea il CRC della frame e lo appende
* @param in frame
* @retval L'esito :
* @arg 0 Fallito
* @arg 1 Successo
*/
CAL_Option_Type frameCRCCreate(uint8_t* data, uint32_t length)
{
if (crcCheckState() != 1)
{
return CAL_NO;
}
uint32_t* data32 = (uint32_t*) data;
uint32_t data32Length = (length - CRC_LENGTH) / 4;
uint32_t crcValue = crcCalculate(data32, data32Length);
data32[data32Length] = crcValue;
return CAL_YES;
}
/**
* @brief Controlla il CRC della frame e lo appende
* @param in frame
* @retval L'esito :
* @arg 0 Fallito
* @arg 1 Successo
*/
CAL_Option_Type frameCRCCheck(uint8_t* data, uint32_t length)
{
if (crcCheckState() != 1)
{
return CAL_NO;
}
uint32_t* data32 = (uint32_t*) data;
uint32_t data32Length = (length - CRC_LENGTH) / 4;
uint32_t crcValue = crcCalculate(data32, data32Length);
uint32_t crcValueToCheck = data32[data32Length];
if (crcValue == crcValueToCheck)
return CAL_YES;
else
return CAL_NO;
}
/**
@brief Receive message from the server
@param size - return size of data
@param decrypt - if TRUE, then decrypt received data by session key
@param control - return control character
@return data (you MUST free memory after use)
*/
byte *tcpReceiveMessage(int Handle, uint32 *size, byte *control, uint32 TimeoutMsec)
{
StreamMethod Method = smRecvSend;
byte *data;
int ret = 0;
byte cc = 0;
byte LengthField[MAXLENGTHFIELDSIZE];
byte LengthFieldSize;
uint32 AlignedSize;
byte AttempsCount = 1;
byte MaxAttempsCount = 5;
lblWaitAgain:
*size = 0;
*control = 0;
data = NULL;
sleepms(100);
ret = recvByte(Handle, Method, &cc, 0/*Timeout*/);
//printf"recvByte: %d. byte %d\n", ret, cc);
if (ret > 0)
{
*control = cc;
switch (cc)
{
case pccSTX:
*size = ReceiveLengthField(Handle, Method, LengthField, &LengthFieldSize, TimeoutMsec); // получаем размер данных
if (*size != 0xFFFFFFFF)
{
AlignedSize = GetAlignedSize(*size);
data = malloc(AlignedSize); // allocate data
ret = recvBuffer(Handle, Method, data, AlignedSize, TimeoutMsec);
#ifdef TCP_DEBUG
// PrintHEX(data, *size);
#endif
//printf"comRecvBufLarge: %d\n", ret);
if (ret > 0)
{
// ok, we have a data - calc CRC
uint32 CRCBufferSize = LengthFieldSize + AlignedSize + 1; // datasize + data + ETX
byte *CRCBuffer = malloc(CRCBufferSize);
memcpy(CRCBuffer, LengthField, LengthFieldSize); // copy length field to checkbuffer
memcpy(CRCBuffer+LengthFieldSize, data, AlignedSize); // copy data from checkbuffer
CRCBuffer[CRCBufferSize - 1] = pccETX; // last character = ETX
uint64 CalculatedCRC = crcCalculate(CRCBuffer, CRCBufferSize);
free(CRCBuffer);
CRCBuffer = NULL;
ret = recvByte(Handle, Method, &cc, TimeoutMsec); // receive ETX character
//printf"comRecv: %d. byte %d\n", ret, cc);
if (ret > 0 && cc == pccETX)
{
byte crcfield[crcGetFieldSize(CRCBufferSize)];
ret = recvBuffer(Handle, Method, crcfield, sizeof(crcfield), TimeoutMsec); // get size
uint64 ReceivedCRC = crcExtract(crcfield, sizeof(crcfield));
//printf"comRecvBuf: %d\n", ret);
if (ret > 0)
{
if (ReceivedCRC == CalculatedCRC) // check the data
ret = sendByte(Handle, Method, pccACK); // good!!!
else
{
if (AttempsCount <= MaxAttempsCount)
{
AttempsCount++;
ret = sendByte(Handle, Method, pccNAK);
// and go to wait this packet again
goto lblWaitAgain;
}
else
{ free(data); data = NULL; }
}
}
else
{ free(data); data = NULL; }
}
else
{ free(data); data = NULL; }
}
else
{ free(data); data = NULL; }
}
break;
case pccEOT: // query close connection
data = NULL;
break;
case pccBEL:
sendByte(Handle, Method, pccBEL);
goto lblWaitAgain;
default:
data = NULL;
break;
}
}
else
{
*control = 0;
data = NULL;
}
/*if (data)
cphDecrypt(data, data, PCSessionKey, AlignedSize, ToServer); // decipher received data*/
return data;
}
