// получает поле с размером данных из канала связи. Возвращает размер данных или 0xFFFFFFFF в случае ошибки
static uint32 ReceiveLengthField(int Handle, StreamMethod Method, byte *LengthField, byte *LengthFieldSize, uint32 Timeout)
{
uint32 Size = 0xFFFFFFFF;
*LengthFieldSize = 0;
byte b;
if (recvByte(Handle, Method, &b, Timeout) > 0)
{
LengthField[0] = b;
if (b < 0x80)
{
Size = b;
*LengthFieldSize = 1;
}
else
{
byte datasize = b & 0x0F;
uint32 data = 0; // datasize не больше 4 байт
tBuffer buf;
bufInit(&buf, (byte *)&data, datasize);
if (recvBuffer(Handle, Method, buf.ptr, buf.dim, Timeout) > 0)
{
memcpy(LengthField + 1, &data, datasize);
if (IsLittleEndian())
memrev(&data, datasize);
Size = data;
*LengthFieldSize = datasize + 1;
}
}
}
return Size;
}
// Try to read data at serial port & pass anything read to processing function
void Midi::poll(void)
{
int c;
// Just keep sucking data from serial port until it runs out, processing
// MIDI messages as we go
while((c = serial_.read()) != -1) {
recvByte(c);
}
}
static void HandleClientConnection(int Socket)
{
StreamMethod Method = smRecvSend;
if (!Socket) return;
byte Status = 0;
byte cc = 0;
#ifdef TCP_DEBUG
printf("Wait connection\n");
#endif
int ret = recvByte(Socket, Method, &cc, ConnectionTimeoutMSec);
#ifdef TCP_DEBUG
//printf("recvByte: %d. cc = %d \n", ret, cc);
#endif
if (ret > 0 && cc == pccENQ)
{
byte ConnectionBuffer[2];
ret = recvBuffer(Socket, Method, ConnectionBuffer, sizeof(ConnectionBuffer), ConnectionTimeoutMSec); // принимаем данные дл¤ соединени¤
if (ret > 0)
{
PV = ConnectionBuffer[0];
KSN = ConnectionBuffer[1];
if (sendByte(Socket, Method, pccACK) < 0) goto lblKO; // подтверждаем соединение и переходим в режим ожидани¤ сообщени¤
#ifdef TCP_DEBUG
printf("Connected. PV: %d, KSN: %d\n", PV, KSN);
#endif
int time1 = GetTickCount();
uint32 size;
byte *data = NULL;
while (/*Status == 0*/1) // –јЅќ“ј≈ћ ƒќ “ј…ћј”“ј »Ћ» ѕќЋ”„≈Ќ»я —»√ЌјЋј Ќј ќ“—ќ≈ƒ»Ќ≈Ќ»≈
{
data = tcpReceiveMessage(Socket, &size, &cc, ReceiveTimeoutMSec);
#ifdef TCP_DEBUG
if (cc != 0)
printf("drmReceiveMessage. cc = %d, size = %lu\n", cc, size);
#endif
if (cc == pccSTX) // в data у мен¤ лежит data
{
if (data)
{
Status = 3; // хорошее завершение с приЄмом какого-то пакета
ParseClientMessage(Socket, data, size); // в buffer у нас сообщение от клиента
time1 = GetTickCount();
}
else
{
printf("Empty package from client\n");
}
}
else if (cc == pccEOT)
{
Status = 2; // disconnect query
#ifdef TCP_DEBUG
printf("Disconnect query received\n");
#endif
if (sendByte(Socket, Method, pccEOT) < 0) goto lblKO;
break; // exit from the cycle
}
if (data) // очищаем пам¤ть
{
free(data);
data = NULL;
}
// check timeout
if (GetTickCount() - time1 >= ClientTimeoutMSec)
{
#ifdef TCP_DEBUG
printf("Client timeout occurred\n");
#endif
Status = 1; // timeout
//sendByte(Socket, pccEOT);
break;
}
}
if (Status != 1)
{
//printf("Send disconnect byte...");
if (sendByte(Socket, Method, pccEOT) < 0) goto lblKO; // disconnect
//printf("Done\n");
}
}
}
lblKO:
goto lblEnd;
lblEnd:
#ifdef TCP_DEBUG
printf("Closing client socket...");
#endif
close(Socket); // закрываем сокет клиента в конце работы
Socket = 0;
#ifdef TCP_DEBUG
printf("Done\n");
#endif
#ifdef TCP_DEBUG
printf("Client disconnected\n");
#endif
}
/**
@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;
}
/**
@brief Send message to the server (PC or Retail system)
@param size - return size of data
@param decrypt - if TRUE, then decrypt received data by session key
@param control - return control character
@return TRUE if OK, or error code
*/
Bool tcpSendMessage(int Handle, byte *Data, uint32 DataSize, uint32 TimeoutMSec)
{
StreamMethod Method = smRecvSend;
int ret;
Bool result = FALSE;
uint32 size = DataSize;
uint32 AlignedSize = GetAlignedSize(size);
byte LengthField[MAXLENGTHFIELDSIZE];
byte LengthFieldSize;
tlvMakeLengthField(size, LengthField, &LengthFieldSize);
byte MaxAttempsCount = 5;
byte ack;
tBuffer sendbuf;
byte DataToSend[AlignedSize + MAXLENGTHFIELDSIZE + 1 + MAXCRCBUFFERSIZE]; // + max data size buffer, ETX, max CRC buffer
bufInit(&sendbuf, DataToSend, sizeof(DataToSend)); // init buffer for writing (and clear of DataToSend)
bufApp(&sendbuf, LengthField, LengthFieldSize);
memcpy(DataToSend + sendbuf.pos, Data, DataSize); // просто копирование, без шифрования
sendbuf.pos += AlignedSize; // DataToSend уже лежит в буфере на отправку
bufAppByte(&sendbuf, pccETX); // append ETX to buffer
byte CRCBuffer[MAXCRCBUFFERSIZE];
byte CRCBufferSize = crcMakeField(sendbuf.ptr, (word)sendbuf.pos, CRCBuffer);
bufApp(&sendbuf, CRCBuffer, CRCBufferSize);
/*
printf("CRC Buffer: ");
PrintHEX(CRCBuffer, CRCBufferSize);*/
byte AttempsCount = 1;
lblSendAgain:
ret = sendByte(Handle, Method, pccSTX); // send control char "start of packet"
if (ret > 0)
{
ret = sendBuffer(Handle, Method, bufPtr(&sendbuf), bufLen(&sendbuf)); // send packet
if (ret == bufLen(&sendbuf))
{
// and wait for acknowledgment
lblWaitAskAgain:
ack = 0;
ret = recvByte(Handle, Method, &ack, TimeoutMSec);
if (ret > 0)
{
switch (ack)
{
case pccACK: // good
result = TRUE;
break;
case pccBEL: // please, wait
sendByte(Handle, Method, pccBEL);
goto lblWaitAskAgain;
case pccNAK: // send packet again
if (AttempsCount <= MaxAttempsCount)
{
AttempsCount++;
goto lblSendAgain;
}
else
result = FALSE;
break;
default: // unknown state
result = FALSE;
break;
}
}
else
result = FALSE;
}
else
result = FALSE;
}
else
result = FALSE;
//ptarr = memFree(ptarr);
return result;
}
