/******************************************************************************\ * Copyright (c) 2004-2009 * * Author(s): * Volker Fischer * Protocol message definition --------------------------- - All messages received need to be acknowledged by an acknowledge packet MAIN FRAME ---------- +-------------+------------+------------+------------------+ ... | 2 bytes TAG | 2 bytes ID | 1 byte cnt | 2 bytes length n | ... +-------------+------------+------------+------------------+ ... ... --------------+-------------+ ... n bytes data | 2 bytes CRC | ... --------------+-------------+ - TAG is an all zero bit word to identify protocol messages - message ID defined by the defines PROTMESSID_x - cnt: counter which is increment for each message and wraps around at 255 - length n in bytes of the data - actual data, dependent on message type - 16 bits CRC, calculating over the entire message, is transmitted inverted Generator polynom: G_16(x) = x^16 + x^12 + x^5 + 1, initial state: all ones MESSAGES -------- - Acknowledgement message: PROTMESSID_ACKN +-----------------------------------+ | 2 bytes ID of message to be ackn. | +-----------------------------------+ note: the cnt value is the same as of the message to be acknowledged - Jitter buffer size: PROTMESSID_JITT_BUF_SIZE +--------------------------+ | 2 bytes number of blocks | +--------------------------+ - Request jitter buffer size: PROTMESSID_REQ_JITT_BUF_SIZE note: does not have any data -> n = 0 - Server full message: PROTMESSID_SERVER_FULL note: does not have any data -> n = 0 - Network buffer block size factor: PROTMESSID_NET_BLSI_FACTOR note: size, relative to minimum block size +----------------+ | 2 bytes factor | +----------------+ - Gain of channel: PROTMESSID_CHANNEL_GAIN +-------------------+--------------+ | 1 byte channel ID | 2 bytes gain | +-------------------+--------------+ - IP number and name of connected clients: PROTMESSID_CONN_CLIENTS_LIST for each connected client append following data: +-------------------+--------------------+------------------+ ... | 1 byte channel ID | 4 bytes IP address | 2 bytes number n | ... +-------------------+--------------------+------------------+ ... ... ----------------------+ ... n bytes UTF-8 string | ... ----------------------+ - Request connected clients list: PROTMESSID_REQ_CONN_CLIENTS_LIST note: does not have any data -> n = 0 - Name of channel: PROTMESSID_CHANNEL_NAME for each connected client append following data: +------------------+----------------------+ | 2 bytes number n | n bytes UTF-8 string | +------------------+----------------------+ - Chat text: PROTMESSID_CHAT_TEXT +------------------+----------------------+ | 2 bytes number n | n bytes UTF-8 string | +------------------+----------------------+ - Ping message (for measuring the ping time): PROTMESSID_PING_MS +-----------------------------+ | 4 bytes transmit time in ms | +-----------------------------+ - Properties for network transport: PROTMESSID_NETW_TRANSPORT_PROPS +------------------------+-------------------------+-----------------+ ... | 4 bytes base netw size | 2 bytes block size fact | 1 byte num chan | ... +------------------------+-------------------------+-----------------+ ... ... ------------------+-----------------------+ ... ... 4 bytes sam rate | 2 bytes audiocod type | ... ... ------------------+-----------------------+ ... ... -----------------+----------------------+ ... 2 bytes version | 4 bytes audiocod arg | ... -----------------+----------------------+ - "base netw size": length of the base network packet (frame) in bytes - "block size fact": block size factor - "num chan": number of channels of the audio signal, e.g. "2" is stereo - "sam rate": sample rate of the audio stream - "audiocod type": audio coding type, the following types are supported: - 0: none, no audio coding applied - 1: CELT - "version": version of the audio coder, if not used this value shall be set to 0 - "audiocod arg": argument for the audio coder, if not used this value shall be set to 0 - Request properties for network transport: PROTMESSID_REQ_NETW_TRANSPORT_PROPS note: does not have any data -> n = 0 - Disconnect message: PROTMESSID_DISCONNECTION note: does not have any data -> n = 0 ****************************************************************************** * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License as published by the Free Software * Foundation; either version 2 of the License, or (at your option) any later * version. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * \******************************************************************************/ #include "protocol.h" /* Implementation *************************************************************/ CProtocol::CProtocol() { Reset(); // connections QObject::connect ( &TimerSendMess, SIGNAL ( timeout() ), this, SLOT ( OnTimerSendMess() ) ); } void CProtocol::Reset() { QMutexLocker locker ( &Mutex ); // prepare internal variables for initial protocol transfer iCounter = 0; iOldRecID = PROTMESSID_ILLEGAL; iOldRecCnt = 0; // delete complete "send message queue" SendMessQueue.clear(); } void CProtocol::EnqueueMessage ( CVector& vecMessage, const int iCnt, const int iID ) { bool bListWasEmpty; Mutex.lock(); { // check if list is empty so that we have to initiate a send process bListWasEmpty = SendMessQueue.empty(); // create send message object for the queue CSendMessage SendMessageObj ( vecMessage, iCnt, iID ); // we want to have a FIFO: we add at the end and take from the beginning SendMessQueue.push_back ( SendMessageObj ); } Mutex.unlock(); // if list was empty, initiate send process if ( bListWasEmpty ) { SendMessage(); } } void CProtocol::SendMessage() { CVector vecMessage; bool bSendMess = false; Mutex.lock(); { // we have to check that list is not empty, since in another thread the // last element of the list might have been erased if ( !SendMessQueue.empty() ) { vecMessage.Init ( SendMessQueue.front().vecMessage.Size() ); vecMessage = SendMessQueue.front().vecMessage; bSendMess = true; } } Mutex.unlock(); if ( bSendMess ) { // send message emit MessReadyForSending ( vecMessage ); // start time-out timer if not active if ( !TimerSendMess.isActive() ) { TimerSendMess.start ( SEND_MESS_TIMEOUT_MS ); } } else { // no message to send, stop timer TimerSendMess.stop(); } } void CProtocol::CreateAndSendMessage ( const int iID, const CVector& vecData ) { CVector vecNewMessage; int iCurCounter; Mutex.lock(); { // store current counter value iCurCounter = iCounter; // increase counter (wraps around automatically) iCounter++; } Mutex.unlock(); // build complete message GenMessageFrame ( vecNewMessage, iCurCounter, iID, vecData ); // enqueue message EnqueueMessage ( vecNewMessage, iCurCounter, iID ); } void CProtocol::CreateAndImmSendAcknMess ( const int& iID, const int& iCnt ) { CVector vecAcknMessage; CVector vecData ( 2 ); // 2 bytes of data unsigned int iPos = 0; // init position pointer // build data vector PutValOnStream ( vecData, iPos, static_cast ( iID ), 2 ); // build complete message GenMessageFrame ( vecAcknMessage, iCnt, PROTMESSID_ACKN, vecData ); // immediately send acknowledge message emit MessReadyForSending ( vecAcknMessage ); } bool CProtocol::ParseMessage ( const CVector& vecbyData, const int iNumBytes ) { /* return code: false -> ok; true -> error */ bool bRet = false; bool bSendNextMess; int iRecCounter, iRecID; CVector vecData; if ( !ParseMessageFrame ( vecbyData, iNumBytes, iRecCounter, iRecID, vecData ) ) { // In case we received a message and returned an answer but our answer // did not make it to the receiver, he will resend his message. We check // here if the message is the same as the old one, and if this is the // case, just resend our old answer again if ( ( iOldRecID == iRecID ) && ( iOldRecCnt == iRecCounter ) ) { // acknowledgments are not acknowledged if ( iRecID != PROTMESSID_ACKN ) { // resend acknowledgement CreateAndImmSendAcknMess ( iRecID, iRecCounter ); } } else { // special treatment for acknowledge messages if ( iRecID == PROTMESSID_ACKN ) { // extract data from stream and emit signal for received value unsigned int iPos = 0; const int iData = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); Mutex.lock(); { // check if this is the correct acknowledgment bSendNextMess = false; if ( !SendMessQueue.empty() ) { if ( ( SendMessQueue.front().iCnt == iRecCounter ) && ( SendMessQueue.front().iID == iData ) ) { // message acknowledged, remove from queue SendMessQueue.pop_front(); // send next message in queue bSendNextMess = true; } } } Mutex.unlock(); if ( bSendNextMess ) { SendMessage(); } } else { // check which type of message we received and do action switch ( iRecID ) { case PROTMESSID_JITT_BUF_SIZE: bRet = EvaluateJitBufMes ( vecData ); break; case PROTMESSID_REQ_JITT_BUF_SIZE: bRet = EvaluateReqJitBufMes ( vecData ); break; case PROTMESSID_SERVER_FULL: bRet = EvaluateServerFullMes ( vecData ); break; case PROTMESSID_NET_BLSI_FACTOR: bRet = EvaluateNetwBlSiFactMes ( vecData ); break; case PROTMESSID_CHANNEL_GAIN: bRet = EvaluateChanGainMes ( vecData ); break; case PROTMESSID_CONN_CLIENTS_LIST: bRet = EvaluateConClientListMes ( vecData ); break; case PROTMESSID_REQ_CONN_CLIENTS_LIST: bRet = EvaluateReqConnClientsList ( vecData ); break; case PROTMESSID_CHANNEL_NAME: bRet = EvaluateChanNameMes ( vecData ); break; case PROTMESSID_CHAT_TEXT: bRet = EvaluateChatTextMes ( vecData ); break; case PROTMESSID_PING_MS: bRet = EvaluatePingMes ( vecData ); break; case PROTMESSID_NETW_TRANSPORT_PROPS: bRet = EvaluateNetwTranspPropsMes ( vecData ); break; case PROTMESSID_REQ_NETW_TRANSPORT_PROPS: bRet = EvaluateReqNetwTranspPropsMes ( vecData ); break; case PROTMESSID_DISCONNECTION: bRet = EvaluateDisconnectionMes ( vecData ); break; } // immediately send acknowledge message CreateAndImmSendAcknMess ( iRecID, iRecCounter ); // save current message ID and counter to find out if message // was resent iOldRecID = iRecID; iOldRecCnt = iRecCounter; } } } else { bRet = true; // return error code } return bRet; } // Access-functions for creating and parsing messages -------------------------- void CProtocol::CreateJitBufMes ( const int iJitBufSize ) { CVector vecData ( 2 ); // 2 bytes of data unsigned int iPos = 0; // init position pointer // build data vector PutValOnStream ( vecData, iPos, static_cast ( iJitBufSize ), 2 ); CreateAndSendMessage ( PROTMESSID_JITT_BUF_SIZE, vecData ); } bool CProtocol::EvaluateJitBufMes ( const CVector& vecData ) { unsigned int iPos = 0; // init position pointer // check size if ( vecData.Size() != 2 ) { return true; } // extract jitter buffer size const int iData = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); // invoke message action emit ChangeJittBufSize ( iData ); return false; // no error } void CProtocol::CreateReqJitBufMes() { CreateAndSendMessage ( PROTMESSID_REQ_JITT_BUF_SIZE, CVector ( 0 ) ); } bool CProtocol::EvaluateReqJitBufMes ( const CVector& vecData ) { // invoke message action emit ReqJittBufSize(); return false; // no error } void CProtocol::CreateServerFullMes() { CreateAndSendMessage ( PROTMESSID_SERVER_FULL, CVector ( 0 ) ); } bool CProtocol::EvaluateServerFullMes ( const CVector& vecData ) { // invoke message action emit ServerFull(); return false; // no error } void CProtocol::CreateNetwBlSiFactMes ( const int iNetwBlSiFact ) { CVector vecData ( 2 ); // 2 bytes of data unsigned int iPos = 0; // init position pointer // build data vector PutValOnStream ( vecData, iPos, static_cast ( iNetwBlSiFact ), 2 ); CreateAndSendMessage ( PROTMESSID_NET_BLSI_FACTOR, vecData ); } bool CProtocol::EvaluateNetwBlSiFactMes ( const CVector& vecData ) { unsigned int iPos = 0; // init position pointer // check size if ( vecData.Size() != 2 ) { return true; } const int iData = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); // invoke message action emit ChangeNetwBlSiFact ( iData ); return false; // no error } void CProtocol::CreateChanGainMes ( const int iChanID, const double dGain ) { CVector vecData ( 3 ); // 3 bytes of data unsigned int iPos = 0; // init position pointer // build data vector // channel ID PutValOnStream ( vecData, iPos, static_cast ( iChanID ), 1 ); // actual gain, we convert from double with range 0..1 to integer const int iCurGain = static_cast ( dGain * ( 1 << 15 ) ); PutValOnStream ( vecData, iPos, static_cast ( iCurGain ), 2 ); CreateAndSendMessage ( PROTMESSID_CHANNEL_GAIN, vecData ); } bool CProtocol::EvaluateChanGainMes ( const CVector& vecData ) { unsigned int iPos = 0; // init position pointer // check size if ( vecData.Size() != 3 ) { return true; } // channel ID const int iCurID = static_cast ( GetValFromStream ( vecData, iPos, 1 ) ); // actual gain, we convert from integer to double with range 0..1 const int iData = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); const double dNewGain = static_cast ( iData ) / ( 1 << 15 ); // invoke message action emit ChangeChanGain ( iCurID, dNewGain ); return false; // no error } void CProtocol::CreateConClientListMes ( const CVector& vecChanInfo ) { const int iNumClients = vecChanInfo.Size(); // build data vector CVector vecData ( 0 ); unsigned int iPos = 0; // init position pointer for ( int i = 0; i < iNumClients; i++ ) { // current string size const int iCurStrLen = vecChanInfo[i].strName.size(); // size of current list entry const int iCurListEntrLen = 1 /* chan ID */ + 4 /* IP addr. */ + 2 /* str. size */ + iCurStrLen; // make space for new data vecData.Enlarge ( iCurListEntrLen ); // channel ID PutValOnStream ( vecData, iPos, static_cast ( vecChanInfo[i].iChanID ), 1 ); // IP address (4 bytes) PutValOnStream ( vecData, iPos, static_cast ( vecChanInfo[i].iIpAddr ), 4 ); // number of bytes for name string (2 bytes) PutValOnStream ( vecData, iPos, static_cast ( iCurStrLen ), 2 ); // name string (n bytes) for ( int j = 0; j < iCurStrLen; j++ ) { // byte-by-byte copying of the string data PutValOnStream ( vecData, iPos, static_cast ( vecChanInfo[i].strName[j].toAscii() ), 1 ); } } CreateAndSendMessage ( PROTMESSID_CONN_CLIENTS_LIST, vecData ); } bool CProtocol::EvaluateConClientListMes ( const CVector& vecData ) { unsigned int iPos = 0; // init position pointer int iData; const unsigned int iDataLen = vecData.Size(); CVector vecChanInfo ( 0 ); while ( iPos < iDataLen ) { // check size (the first 7 bytes) if ( iDataLen - iPos < 7 ) { return true; } // channel ID (1 byte) const int iChanID = static_cast ( GetValFromStream ( vecData, iPos, 1 ) ); // IP address (4 bytes) const int iIpAddr = static_cast ( GetValFromStream ( vecData, iPos, 4 ) ); // number of bytes for name string (2 bytes) const unsigned int iStringLen = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); // check size if ( iDataLen - iPos < iStringLen ) { return true; } // name string (n bytes) QString strCurStr = ""; for ( unsigned int j = 0; j < iStringLen; j++ ) { // byte-by-byte copying of the string data iData = static_cast ( GetValFromStream ( vecData, iPos, 1 ) ); strCurStr += QString ( (char*) &iData ); } // add channel information to vector vecChanInfo.Add ( CChannelShortInfo ( iChanID, iIpAddr, strCurStr ) ); } // invoke message action emit ConClientListMesReceived ( vecChanInfo ); return false; // no error } void CProtocol::CreateReqConnClientsList() { CreateAndSendMessage ( PROTMESSID_REQ_CONN_CLIENTS_LIST, CVector ( 0 ) ); } bool CProtocol::EvaluateReqConnClientsList ( const CVector& vecData ) { // invoke message action emit ReqConnClientsList(); return false; // no error } void CProtocol::CreateChanNameMes ( const QString strName ) { unsigned int iPos = 0; // init position pointer const int iStrLen = strName.size(); // get string size // size of current list entry const int iEntrLen = 2 /* string size */ + iStrLen; // build data vector CVector vecData ( iEntrLen ); // number of bytes for name string (2 bytes) PutValOnStream ( vecData, iPos, static_cast ( iStrLen ), 2 ); // name string (n bytes) for ( int j = 0; j < iStrLen; j++ ) { // byte-by-byte copying of the string data PutValOnStream ( vecData, iPos, static_cast ( strName[j].toAscii() ), 1 ); } CreateAndSendMessage ( PROTMESSID_CHANNEL_NAME, vecData ); } bool CProtocol::EvaluateChanNameMes ( const CVector& vecData ) { unsigned int iPos = 0; // init position pointer // check size (the first 2 bytes) if ( vecData.Size() < 2 ) { return true; } // number of bytes for name string (2 bytes) const int iStrLen = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); // check size if ( vecData.Size() - 2 != iStrLen ) { return true; } // name string (n bytes) QString strName = ""; for ( int j = 0; j < iStrLen; j++ ) { // byte-by-byte copying of the string data int iData = static_cast ( GetValFromStream ( vecData, iPos, 1 ) ); strName += QString ( (char*) &iData ); } // invoke message action emit ChangeChanName ( strName ); return false; // no error } void CProtocol::CreateChatTextMes ( const QString strChatText ) { unsigned int iPos = 0; // init position pointer const int iStrLen = strChatText.size(); // get string size // size of message body const int iEntrLen = 2 /* string size */ + iStrLen; // build data vector CVector vecData ( iEntrLen ); // number of bytes for name string (2 bytes) PutValOnStream ( vecData, iPos, static_cast ( iStrLen ), 2 ); // name string (n bytes) for ( int j = 0; j < iStrLen; j++ ) { // byte-by-byte copying of the string data PutValOnStream ( vecData, iPos, static_cast ( strChatText[j].toAscii() ), 1 ); } CreateAndSendMessage ( PROTMESSID_CHAT_TEXT, vecData ); } bool CProtocol::EvaluateChatTextMes ( const CVector& vecData ) { unsigned int iPos = 0; // init position pointer // check size (the first 2 bytes) if ( vecData.Size() < 2 ) { return true; } // number of bytes for name string (2 bytes) const int iStrLen = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); // check size if ( vecData.Size() - 2 != iStrLen ) { return true; } // name string (n bytes) QString strChatText = ""; for ( int j = 0; j < iStrLen; j++ ) { // byte-by-byte copying of the string data int iData = static_cast ( GetValFromStream ( vecData, iPos, 1 ) ); strChatText += QString ( (char*) &iData ); } // invoke message action emit ChatTextReceived ( strChatText ); return false; // no error } void CProtocol::CreatePingMes ( const int iMs ) { unsigned int iPos = 0; // init position pointer // build data vector (4 bytes long) CVector vecData ( 4 ); // byte-by-byte copying of the string data PutValOnStream ( vecData, iPos, static_cast ( iMs ), 4 ); CreateAndSendMessage ( PROTMESSID_PING_MS, vecData ); } bool CProtocol::EvaluatePingMes ( const CVector& vecData ) { unsigned int iPos = 0; // init position pointer // check size if ( vecData.Size() != 4 ) { return true; } emit PingReceived ( static_cast ( GetValFromStream ( vecData, iPos, 4 ) ) ); return false; // no error } void CProtocol::CreateNetwTranspPropsMes ( const CNetworkTransportProps& NetTrProps ) { unsigned int iPos = 0; // init position pointer // size of current message body const int iEntrLen = 4 /* netw size */ + 2 /* block size fact */ + 1 /* num chan */ + 4 /* sam rate */ + 2 /* audiocod type */ + 2 /* version */ + 4 /* audiocod arg */; // build data vector CVector vecData ( iEntrLen ); // length of the base network packet (frame) in bytes (4 bytes) PutValOnStream ( vecData, iPos, static_cast ( NetTrProps.iBaseNetworkPacketSize ), 4 ); // block size factor (2 bytes) PutValOnStream ( vecData, iPos, static_cast ( NetTrProps.iBlockSizeFact ), 2 ); // number of channels of the audio signal, e.g. "2" is stereo (1 byte) PutValOnStream ( vecData, iPos, static_cast ( NetTrProps.iNumAudioChannels ), 1 ); // sample rate of the audio stream (4 bytes) PutValOnStream ( vecData, iPos, static_cast ( NetTrProps.iSampleRate ), 4 ); // audio coding type (2 bytes) PutValOnStream ( vecData, iPos, static_cast ( NetTrProps.eAudioCodingType ), 2 ); // version (2 bytes) PutValOnStream ( vecData, iPos, static_cast ( NetTrProps.iVersion ), 2 ); // argument for the audio coder (4 bytes) PutValOnStream ( vecData, iPos, static_cast ( NetTrProps.iAudioCodingArg ), 4 ); CreateAndSendMessage ( PROTMESSID_NETW_TRANSPORT_PROPS, vecData ); } bool CProtocol::EvaluateNetwTranspPropsMes ( const CVector& vecData ) { unsigned int iPos = 0; // init position pointer CNetworkTransportProps ReceivedNetwTranspProps; // size of current message body const int iEntrLen = 4 /* netw size */ + 2 /* block size fact */ + 1 /* num chan */ + 4 /* sam rate */ + 2 /* audiocod type */ + 2 /* version */ + 4 /* audiocod arg */; // check size if ( vecData.Size() != iEntrLen ) { return true; } // length of the base network packet (frame) in bytes (4 bytes) ReceivedNetwTranspProps.iBaseNetworkPacketSize = static_cast ( GetValFromStream ( vecData, iPos, 4 ) ); if ( ( ReceivedNetwTranspProps.iBaseNetworkPacketSize < 1 ) || ( ReceivedNetwTranspProps.iBaseNetworkPacketSize > MAX_SIZE_BYTES_NETW_BUF ) ) { return true; } // block size factor (2 bytes) ReceivedNetwTranspProps.iBlockSizeFact = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); if ( ( ReceivedNetwTranspProps.iBlockSizeFact != FRAME_SIZE_FACTOR_PREFERRED ) && ( ReceivedNetwTranspProps.iBlockSizeFact != FRAME_SIZE_FACTOR_DEFAULT ) && ( ReceivedNetwTranspProps.iBlockSizeFact != FRAME_SIZE_FACTOR_SAFE ) ) { return true; } // number of channels of the audio signal, e.g. "2" is stereo (1 byte) ReceivedNetwTranspProps.iNumAudioChannels = static_cast ( GetValFromStream ( vecData, iPos, 1 ) ); if ( ( ReceivedNetwTranspProps.iNumAudioChannels != 1 ) && ( ReceivedNetwTranspProps.iNumAudioChannels != 2 ) ) { return true; } // sample rate of the audio stream (4 bytes) ReceivedNetwTranspProps.iSampleRate = static_cast ( GetValFromStream ( vecData, iPos, 4 ) ); // audio coding type (2 bytes) with error check const int iRecCodingType = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); if ( ( iRecCodingType != CT_NONE ) && ( iRecCodingType != CT_CELT ) ) { return true; } ReceivedNetwTranspProps.eAudioCodingType = static_cast ( iRecCodingType ); // version (2 bytes) ReceivedNetwTranspProps.iVersion = static_cast ( GetValFromStream ( vecData, iPos, 2 ) ); // argument for the audio coder (4 bytes) ReceivedNetwTranspProps.iAudioCodingArg = static_cast ( GetValFromStream ( vecData, iPos, 4 ) ); // invoke message action emit NetTranspPropsReceived ( ReceivedNetwTranspProps ); return false; // no error } void CProtocol::CreateReqNetwTranspPropsMes() { CreateAndSendMessage ( PROTMESSID_REQ_NETW_TRANSPORT_PROPS, CVector ( 0 ) ); } bool CProtocol::EvaluateReqNetwTranspPropsMes ( const CVector& vecData ) { // invoke message action emit ReqNetTranspProps(); return false; // no error } void CProtocol::CreateAndImmSendDisconnectionMes() { CVector vecDisconMessage; // build complete message (special case, there is not actual data // and we do not use the counter since this is the very last message // of the connection, after that no message will be evaluated) GenMessageFrame ( vecDisconMessage, 0, PROTMESSID_DISCONNECTION, CVector ( 0 ) ); // immediately send acknowledge message emit MessReadyForSending ( vecDisconMessage ); } bool CProtocol::EvaluateDisconnectionMes ( const CVector& vecData ) { // invoke message action emit Disconnection(); return false; // no error } /******************************************************************************\ * Message generation (parsing) * \******************************************************************************/ bool CProtocol::ParseMessageFrame ( const CVector& vecIn, const int iNumBytesIn, int& iCnt, int& iID, CVector& vecData ) { /* return code: true -> ok; false -> error */ int iLenBy, i; unsigned int iCurPos; // vector must be at least "MESS_LEN_WITHOUT_DATA_BYTE" bytes long if ( iNumBytesIn < MESS_LEN_WITHOUT_DATA_BYTE ) { return true; // return error code } // decode header ----- iCurPos = 0; // start from beginning // 2 bytes TAG const int iTag = static_cast ( GetValFromStream ( vecIn, iCurPos, 2 ) ); // check if tag is correct if ( iTag != 0 ) { return true; // return error code } /* 2 bytes ID */ iID = static_cast ( GetValFromStream ( vecIn, iCurPos, 2 ) ); /* 1 byte cnt */ iCnt = static_cast ( GetValFromStream ( vecIn, iCurPos, 1 ) ); /* 2 bytes length */ iLenBy = static_cast ( GetValFromStream ( vecIn, iCurPos, 2 ) ); // make sure the length is correct if ( iLenBy != iNumBytesIn - MESS_LEN_WITHOUT_DATA_BYTE ) { return true; // return error code } // now check CRC ----- CCRC CRCObj; const int iLenCRCCalc = MESS_HEADER_LENGTH_BYTE + iLenBy; iCurPos = 0; // start from beginning for ( i = 0; i < iLenCRCCalc; i++ ) { CRCObj.AddByte ( static_cast ( GetValFromStream ( vecIn, iCurPos, 1 ) ) ); } if ( CRCObj.GetCRC () != GetValFromStream ( vecIn, iCurPos, 2 ) ) { return true; // return error code } // extract actual data ----- vecData.Init ( iLenBy ); iCurPos = MESS_HEADER_LENGTH_BYTE; // start from beginning of data for ( i = 0; i < iLenBy; i++ ) { vecData[i] = static_cast ( GetValFromStream ( vecIn, iCurPos, 1 ) ); } return false; // everything was ok } uint32_t CProtocol::GetValFromStream ( const CVector& vecIn, unsigned int& iPos, const unsigned int iNumOfBytes ) { /* note: iPos is automatically incremented in this function */ // 4 bytes maximum since we return uint32 Q_ASSERT ( ( iNumOfBytes > 0 ) && ( iNumOfBytes <= 4 ) ); Q_ASSERT ( static_cast ( vecIn.Size() ) >= iPos + iNumOfBytes ); uint32_t iRet = 0; for ( unsigned int i = 0; i < iNumOfBytes; i++ ) { iRet |= vecIn[iPos] << ( i * 8 /* size of byte */ ); iPos++; } return iRet; } void CProtocol::GenMessageFrame ( CVector& vecOut, const int iCnt, const int iID, const CVector& vecData ) { int i; // query length of data vector const int iDataLenByte = vecData.Size(); // total length of message const int iTotLenByte = MESS_LEN_WITHOUT_DATA_BYTE + iDataLenByte; // init message vector vecOut.Init ( iTotLenByte ); // encode header ----- unsigned int iCurPos = 0; // init position pointer // 2 bytes TAG (all zero bits) PutValOnStream ( vecOut, iCurPos, static_cast ( 0 ), 2 ); // 2 bytes ID PutValOnStream ( vecOut, iCurPos, static_cast ( iID ), 2 ); // 1 byte cnt PutValOnStream ( vecOut, iCurPos, static_cast ( iCnt ), 1 ); // 2 bytes length PutValOnStream ( vecOut, iCurPos, static_cast ( iDataLenByte ), 2 ); // encode data ----- for ( i = 0; i < iDataLenByte; i++ ) { PutValOnStream ( vecOut, iCurPos, static_cast ( vecData[i] ), 1 ); } // encode CRC ----- CCRC CRCObj; iCurPos = 0; // start from beginning const int iLenCRCCalc = MESS_HEADER_LENGTH_BYTE + iDataLenByte; for ( i = 0; i < iLenCRCCalc; i++ ) { CRCObj.AddByte ( static_cast ( GetValFromStream ( vecOut, iCurPos, 1 ) ) ); } PutValOnStream ( vecOut, iCurPos, static_cast ( CRCObj.GetCRC() ), 2 ); } void CProtocol::PutValOnStream ( CVector& vecIn, unsigned int& iPos, const uint32_t iVal, const unsigned int iNumOfBytes ) { /* note: iPos is automatically incremented in this function */ // 4 bytes maximum since we use uint32 Q_ASSERT ( ( iNumOfBytes > 0 ) && ( iNumOfBytes <= 4 ) ); Q_ASSERT ( static_cast ( vecIn.Size() ) >= iPos + iNumOfBytes ); for ( unsigned int i = 0; i < iNumOfBytes; i++ ) { vecIn[iPos] = ( iVal >> ( i * 8 /* size of byte */ ) ) & 255 /* 11111111 */; iPos++; } }