main.c

Gcomm is a serial communications program similar to seyon, but more modern, and easier to use. Works

corrupt(u_char *buffer, int len)
{
	extern double drand48() ;

	while( --len >= 0 ) {
	  if( drand48() < 1./1000. )
	    *buffer ^= 0x81 ;
	  ++buffer ;
	}
}


static	int
doIO(ZModem *info)
{
	fd_set	readfds ;
	struct timeval timeout ;
	int	i ;
	int	len ;
	u_char	buffer[1024] ;
	int	done = 0 ;

	while(!done)
	{
	  FD_ZERO(&readfds) ;
	  FD_SET(info->ifd, &readfds) ;
	  timeout.tv_sec = info->timeout ;
	  timeout.tv_usec = 0 ;
	  i = select(info->ifd+1, &readfds,NULL,NULL, &timeout) ;
	  if( doCancel ) {
	    ZmodemAbort(info) ;
	    fprintf(stderr, "cancelled by user\n") ;
	    resetCom() ;
	    exit(3) ;
	  }
	  if( i<0 )
	    perror("select") ;
	  else if( i==0 )
	    done = ZmodemTimeout(info) ;
	  else {
	    len = read(info->ifd, buffer, sizeof(buffer)) ;
	    if( Corrupt )
	      corrupt(buffer, len) ;
	    if( SerialLogFile != NULL )
	      SerialLog(buffer, len, 1) ;
	    done = ZmodemRcv(buffer, len, info) ;
	  }
	}
	if( SerialLogFile != NULL )
	  SerialLogFlush() ;
	return done ;
}


static	int
InitXmit(ZModem *info)
{
	int	done ;

	if( xmodem )
	  done = XmodemTInit(info) ;
	else if( ymodem )
	  done = YmodemTInit(info) ;
	else
	  done = ZmodemTInit(info) ;
	if( !done )
	  done = doIO(info) ;

	return done != ZmDone ;
}


static	int
XmitFile(char *filename, int f0, int f1, ZModem *info)
{
	int	done ;

	done = ZmodemTFile(filename,filename, f0,f1,0,0,
		0,0, info) ;
	switch( done ) {
	  case 0:
	    if( verbose )
	      fprintf(stderr, "Sending: \"%s\"\n", filename) ;
	    break ;

	  case ZmErrCantOpen:
	    fprintf(stderr, "cannot open file \"%s\": %s\n",
	      filename, strerror(errno)) ;
	    return 0 ;

	  case ZmFileTooLong:
	    fprintf(stderr, "filename \"%s\" too long, skipping...\n",
	      filename) ;
	    return 0 ;

	  case ZmDone:
	    return 0 ;

	  default:
	    return 1 ;
	}

	if( !done )
	  done = doIO(info) ;

	return done != ZmDone ;
}



static	int
FinishXmit(ZModem *info)
{
	int	done ;

	done = ZmodemTFinish(info) ;
	if( !done )
	  done = doIO(info) ;

	return done != ZmDone ;
}



static	int
DoReceive(ZModem *info)
{
	int	done ;

	if( ymodem )
	  done = YmodemRInit(info) ;
	else
	  done = ZmodemRInit(info) ;

	if( !done )
	  done = doIO(info) ;

	return done != ZmDone ;
}


int
ZXmitStr(u_char *buffer, int len, ZModem *info)
{
	u_char	b2[1024] ;

	/* TEST: randomly corrupt every 1000th byte */
	if( Corrupt )
	{
	  bcopy(buffer, b2, len) ;
	  corrupt(b2, len) ;
	  buffer = b2 ;
	}

	if( SerialLogFile != NULL )
	  SerialLog(buffer, len, 0) ;

	if( write(info->ofd, buffer, len) != len )
	  return ZmErrSys ;

	return 0 ;
}


void
ZIFlush(ZModem *info)
{
	if( SerialLogFile != NULL )
	  SerialLogFlush() ;

	if( tcflush(info->ifd, TCIFLUSH) != 0 )
	  perror("TCIFLUSH") ;
}

void
ZOFlush(ZModem *info)
{
	if( SerialLogFile != NULL )
	  SerialLogFlush() ;

	if( tcflush(info->ifd, TCOFLUSH) != 0 )
	  perror("TCOFLUSH") ;
}

void
ZStatus(int type, int j, char *str)
{
	switch( type ) {
	  case RcvByteCount:
	    if( verbose >= 2 )
	      fprintf(stderr, "received: %6d bytes\n", j) ;
	    break ;
	  case SndByteCount:
	    fileSent = j ;
	    if( verbose >= 2 )
	      fprintf(stderr, "sent: %6d bytes\n", j) ;
	    break ;
	  case RcvTimeout:
	    if( verbose )
	      fprintf(stderr, "receiver timeouts: %2d\n", j) ;
	    break ;
	  case SndTimeout:
	    if( verbose )
	      fprintf(stderr, "sender timeouts: %2d\n", j) ;
	    break ;
	  case RmtCancel:
	    fprintf(stderr, "transfer cancelled by remote\n") ;
	    break ;
	  case ProtocolErr:
	    if( verbose >= 3 )
	      fprintf(stderr, "protocol error: %2.2d\n", j) ;
	    break ;
	  case RemoteMessage:
	    fprintf(stderr, "remote message: %s\n",str) ;
	    break ;
	  case DataErr:
	    if( verbose >= 3 )
	      fprintf(stderr, "data errors: %2d\n", j) ;
#ifdef	COMMENT
	    if( ++fileErrs > 20 )
	    {
	      /* something's wrong */
	      ZmodemAbort(&info) ;
	    }
#endif	/* COMMENT */
	    break ;
	  case FileErr:
	    fprintf(stderr, "cannot write file: %s\n", strerror(errno)) ;
	    break ;
	}
}


int
ZAttn(ZModem *info)
{
	char	*ptr ;

	if( info->attn == NULL )
	  return 0 ;

	for(ptr = info->attn; *ptr != '\0'; ++ptr) {
	  if( *ptr == ATTNBRK )
	    tcsendbreak(info->ifd, 0) ;
	  else if( *ptr == ATTNPSE )
	    sleep(1) ;
	  else
	    write(info->ifd, ptr, 1) ;
	}
	return 0 ;
}


FILE *
ZOpenFile(char *name, u_long crc, ZModem *info)
{
	struct stat	buf ;
	int		exists ;	/* file already exists */
static	int		changeCount = 0 ;
	char		name2[MAXPATHLEN] ;
	int		apnd = 0 ;
	int		f0,f1 ;
	FILE		*rval ;

	/* TODO: if absolute path, do we want to allow it?
	 * if relative path, do we want to prepend something?
	 */

	if( *name == '/' )	/* for now, disallow absolute paths */
	  return NULL ;

	if( stat(name, &buf) == 0 )
	  exists = 1 ;
	else if( errno == ENOENT )
	  exists = 0 ;
	else
	  return NULL ;


	/* if remote end has not specified transfer flags, we can
	 * accept the local definitions
	 */

	if( (f0=info->f0) == 0 ) {
	  if( ascii )
	    f0 = ZCNL ;
	  else if( binary )
	    f0 = ZCBIN ;
	  else if( resume )
	    f0 = ZCRESUM ;
	  else
	    f0 = 0 ;
	}

	if( (f1=info->f1) == 0 )
	  f1 = xferType | noloc ;

	if( f0 == ZCRESUM ) {	/* if exists, and we already have it, return */
	  if( exists  &&  buf.st_size == info->len )
	    return NULL ;
	  apnd = 1 ;
	}

	/* reject if file not found and it most be there (ZMSKNOLOC) */
	if( !exists && (f1 & ZMSKNOLOC) )
	  return NULL ;

	switch( f1 & ZMMASK ) {
	  case 0:	/* Implementation-dependent.  In this case, we
			 * reject if file exists (and ZMSKNOLOC not set) */
	    if( exists && !(f1 & ZMSKNOLOC) ) {
	      fprintf(stderr, "%s already exists\n", name) ;
	      return NULL ;
	    }
	    break ;

	  case ZMNEWL:	/* take if newer or longer than file on disk */
	    if( exists  &&  info->date <= buf.st_mtime  &&
		info->len <= buf.st_size ) {
	      fprintf(stderr, "%s already exists\n", name) ;
	      return NULL ;
	    }
	    break ;

	  case ZMCRC:		/* take if different CRC or length */
	    if( exists  &&  info->len == buf.st_size && crc == FileCrc(name) )
	    {
	      fprintf(stderr, "%s already exists\n", name) ;
	      return NULL ;
	    }
	    break ;

	  case ZMAPND:	/* append */
	    apnd = 1 ;
	  case ZMCLOB:	/* unconditional replace */
	    break ;

	  case ZMNEW:	/* take if newer than file on disk */
	    if( exists  &&  info->date <= buf.st_mtime ) {
	      fprintf(stderr, "%s already exists and is newer\n", name) ;
	      return NULL ;
	    }
	    break ;

	  case ZMDIFF:	/* take if different date or length */
	    if( exists  &&  info->date == buf.st_mtime  &&
		info->len == buf.st_size )
	    {
	      fprintf(stderr, "%s already exists\n", name) ;
	      return NULL ;
	    }
	    break ;

	  case ZMPROT:	/* only if dest does not exist */
	    if( exists )
	    {
	      fprintf(stderr, "%s already exists\n", name) ;
	      return NULL ;
	    }
	    break ;

	  case ZMCHNG:	/* invent new filename if exists */
	    if( exists ) {
	      while( exists ) {
		sprintf(name2, "%s_%d", name, changeCount++) ;
		exists = stat(name2, &buf) == 0 || errno != ENOENT ;
	      }
	      name = name2 ;
	    }
	    break ;
	}

	/* here if we've decided to accept */
#ifdef	COMMENT
	if( exists && !apnd && unlink(name) != 0 )
	  return NULL ;
#endif	/* COMMENT */

	/* TODO: build directory path if needed */

	if( verbose )
	  fprintf(stderr, "Receiving: \"%s\"\n", name) ;

	rval = fopen(name, apnd ? "a" : "w") ;
	if( rval == NULL )
	  perror(name) ;
	return rval ;
}


int
ZWriteFile(u_char *buffer, int len, FILE *file, ZModem *info)
{
	/* TODO: if ZCNL set in info->f0, convert
	 * newlines to local convention
	 */

	return fwrite(buffer, 1, len, file) == len ? 0 : ZmErrSys ;
}



int
ZCloseFile(ZModem *info)
{
	struct timeval tvp[2] ;
	fclose(info->file) ;
	if( ymodem )
	  truncate(info->filename, info->len) ;
	if( info->date != 0 ) {
	  tvp[0].tv_sec = tvp[1].tv_sec = info->date ;
	  tvp[0].tv_usec = tvp[1].tv_usec = 0 ;
	  utimes(info->filename, tvp) ;
	}
	if( info->mode & 01000000 )
	  chmod(info->filename, info->mode&0777) ;
	return 0 ;
}


void
ZIdleStr(u_char *buffer, int len, ZModem *info)
{
#ifdef	COMMENT
	fwrite(buffer, 1,len, stdout) ;
#endif	/* COMMENT */
}

void
ZFlowControl(int onoff, ZModem *info)
{
	if( onoff ) {
	  new_settings.c_iflag |= IXON|IXANY|IXOFF ;
#ifdef	COMMENT
	  new_settings.c_cflag |= CRTSCTS ;
#endif	/* COMMENT */
	}
	else {
	  new_settings.c_iflag &= ~(IXON|IXANY|IXOFF) ;
	  new_settings.c_cflag &= ~CRTSCTS ;
	}
	tcsetattr(info->ifd,TCSADRAIN, &new_settings) ;
}



static	char *
basename(char *name)
{
	char	*ptr ;

	if( (ptr = strrchr(name, '/')) == NULL )
	  return name ;
	else
	  return ++ptr ;
}