filer.c

通过串口存取HP100LX/HP200LX 掌上型电脑上的文件

   if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
   pPacket->Count = data;

   /* get packet status */
   if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
   pPacket->Status = data;

   /* get data marker */
   if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
   if(data != 0x02) return BAD_PACKET;


   /* server replies */
   switch(pPacket->Function) {

      /* replies */
      case CONNECT_SERVER:
      case DISCONNECT_SERVER:
         /* data end marker */
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         if(data) return BAD_PACKET;
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         if(data) return BAD_PACKET;
         break;

      case MAKE_DIR:
      case DEL_DIR:
      case DEL_FILE:
      case SEND_PATH:
      case SEND_FILENAME:
      case GET_FILENAME:
      case SEND_DATA:
         /* get data marker and size MSB (always 0) */
         for(f=0;f<4;f++) {
            if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
            if(data) return BAD_PACKET;
         }

         /* get data size */
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         sizelo = data;
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         sizehi = data;;
         pPacket->Size = (sizehi * 256) + sizelo;
         break;

      case DATA_END:
      case INIT_GET:
      case ASK_DIR:
         /* get data size & end marker (6 bytes) */
         for(f=0;f<6;f++) {
            if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
            if(data) return BAD_PACKET;
         }
         break;

      /* data retreival */
      case GET_DATA:
         /* get data marker and size MSB (always 0) */
         for(f=0;f<4;f++) {
            if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
            if(data) return BAD_PACKET;
         }

         /* get data size */
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         sizelo = data;
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         sizehi = data;;
         pPacket->Size = (sizehi * 256) + sizelo;

         for(f=0; f<pPacket->Size; f++) {
            if(GetByte(port, &pPacket->pData[f], &Checksum)==TIMEOUT)
               return TIMEOUT;
         }

         break;

      case GET_DIR:
         /* get data marker and size MSB (always 0) */
         for(f=0;f<4;f++) {
            if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
            if(data) return BAD_PACKET;
         }

         /* get data size */
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         sizelo = data;
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         sizehi = data;;
         pPacket->Size = (sizehi * 256) + sizelo;

         for(f=0; f<pPacket->Size; f++) {
            if(GetByte(port, &pPacket->pData[f], &Checksum)==TIMEOUT)
               return TIMEOUT;
         }

         /* special 'dir' data end marker */
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         if(data!=0x01) return BAD_PACKET;
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         if(data) return BAD_PACKET;
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         if(data) return BAD_PACKET;
         if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
         if(data) return BAD_PACKET;

         break;

      default:
         return INVALID_FUNCTION;

   }

   /* get CRC Marker (no CRC on the next byte!) */
   if(GetByte(port, &data, NULL)==TIMEOUT) return TIMEOUT;
   if(data != 0x10) return BAD_PACKET;
   if(GetByte(port, &data, &Checksum)==TIMEOUT) return TIMEOUT;
   if(data != 0x03) return BAD_PACKET;

   /* get received CRC */
   if(GetByte(port, &data, NULL)==TIMEOUT) return TIMEOUT;
   crclo = data;
   if(GetByte(port, &data, NULL)==TIMEOUT) return TIMEOUT;
   crchi = data;
   pPacket->CRC16 = (crchi * 256) + crclo;

   /* check if CRC is good */
   if(pPacket->CRC16 != Checksum) return BAD_CRC;

#ifdef DEBUG_FILER
   printf("\n\nGOT PACKET# : 0x%X\n", pPacket->Count);
   printf("GOT Function: 0x%X\n", pPacket->Function);
   printf("GOT Status  : 0x%X\n", pPacket->Status);
   printf("GOT Size    : 0x%X\n", pPacket->Size);
#endif

   return PACKET_RECVD;
}


/* --------------------------------------------------------------------
                      Talk (handshake) with server
   -------------------------------------------------------------------- */

int FilerRequest(FILERCOM *pFiler, int Request, WORD Size, BYTE *pData)

{
   int attempt = 0, stat;
   WORD Count;

   Count = pFiler->Count;

   /* packet handshake */
   while(attempt<NUM_OF_ATTEMPTS) {
      SendPacket(pFiler, Request, Count, Size, pData);
      stat=GetPacket(pFiler);
      if(stat==PACKET_RECVD) break;
      attempt++;
   }

   if(attempt==NUM_OF_ATTEMPTS) return NO_RESPONSE;
   if(pFiler->Function != (BYTE)Request) return BAD_REQUEST;
   if(pFiler->Count != Count) return BAD_PACKET_COUNT;

   /* update packet counter */
   Count++;
   pFiler->Count = Count;

   return SERVER_ACK;    /* client <> server agree */

}

/* --------------------------------------------------------------------
                      Open Filer communications
   -------------------------------------------------------------------- */

FILERCOM *FilerConnect(int PortNumber, unsigned long BaudRate, FLCB *pCb)
{

   int f;
   FILERCOM *pFiler;
   char ttyname[20];

   unsigned static long BaudTable[]= {
      0,115200L,57600L,38400L,19200L,9600L,4800L,2400L,1200L,INV_BAUDRATE
   };
   
   /* check if PortNumber is valid (valid= 1 to 4) */
   if((PortNumber > 4)||(PortNumber ==0))
    {
       close(ttyfd);
       return 0;
    }
   
   /* check for valid baud-rate */
   for(f=0;f<10;f++) {
      if(BaudRate == BaudTable[f]) break;
   }
   if(BaudTable[f]==INV_BAUDRATE)
     {
	close(ttyfd);
	return 0;   /* invalid baudrate */
     }
   
   sprintf(ttyname, "%s%c", SERIAL_NAME, SERIAL_FIRST + PortNumber - 1);
   ttyfd = open(ttyname, O_RDWR);
   if (ttyfd < 0)
   {
      printf("Cannot open %s\n", ttyname);
      return 0;
   }
   
   signal(SIGALRM, alarm_handler);
   


   /* allocate packet storage */
   if(!(pFiler = malloc(sizeof(FILERCOM)))) return 0;

   /* packet structure defaults */
   pFiler->pData=0;
   pFiler->Function=0;
   pFiler->Count=0;
   pFiler->Status=0;
   pFiler->CRC16=0;
   pFiler->Port=0; /* no port address for Unix */
   pFiler->pCb = pCb;

   /* allocate data buffer storage */
   if(!(pFiler->pData = malloc(sizeof(FILERCOM)+PACKET_DATA_SIZE+100)))
   {
      close(ttyfd);
      return 0;
   }
   
   if(!BaudRate) {
      timeout_secs = TIMEOUT_AUTO;
      /* Determine baudrate automatically if given baudrate == 0 */
      for(f=1;f<10;f++) {

         /* no response from server */
         if(BaudTable[f]==INV_BAUDRATE) {
            free(pFiler->pData);
            free(pFiler);
	    close(ttyfd);
            return 0;
         }

         pFiler->Baud = BaudTable[f];
	 close(ttyfd);
         SetBaudRate(ttyname, pFiler->Baud);
	 ttyfd = open(ttyname, O_RDWR);
	 if (ttyfd < 0) return 0;

         /* try 2 attempts */
         SendPacket(pFiler, CONNECT_SERVER, 0,0, NULL);
         if(GetPacket(pFiler)==PACKET_RECVD) break;

         SendPacket(pFiler, CONNECT_SERVER, 0,0, NULL);
         if(GetPacket(pFiler)==PACKET_RECVD) break;
      }
   }

   else {
      pFiler->Baud=BaudRate;
      close(ttyfd);
      SetBaudRate(ttyname, BaudRate);
      ttyfd = open(ttyname, O_RDWR);
      if (ttyfd < 0) return 0;
   }
   timeout_secs = TIMEOUT_NORMAL;

   if(FilerRequest(pFiler, CONNECT_SERVER, 0, NULL) == NO_RESPONSE) {
      free(pFiler->pData);
      free(pFiler);
      close(ttyfd);
      return 0;
   }
   return pFiler;
}


/* --------------------------------------------------------------------
                     CloseServer channel (disconnect)
   -------------------------------------------------------------------- */

int FilerDisconnect(FILERCOM *pFiler)
{

   if(!pFiler) return SERVER_CLOSED;
   pFiler->Count=0;

   if(FilerRequest(pFiler, DISCONNECT_SERVER, 0, NULL) == NO_RESPONSE) {
      return NO_RESPONSE;
   }

   free(pFiler->pData);
   free(pFiler);
   
   close(ttyfd);
   
   return SERVER_CLOSED;

}