fhandler_serial.cc

cygwin, 著名的在win32下模拟unix操作系统的东东

/* fhandler_serial.cc

   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

This file is part of Cygwin.

This software is a copyrighted work licensed under the terms of the
Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
details. */

#include "winsup.h"
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include "cygerrno.h"
#include "security.h"
#include "fhandler.h"
#include "sigproc.h"
#include "pinfo.h"
#include <sys/termios.h>
#include <ddk/ntddser.h>

/**********************************************************************/
/* fhandler_serial */

fhandler_serial::fhandler_serial (int unit)
  : fhandler_base (FH_SERIAL, unit), vmin_ (0), vtime_ (0), pgrp_ (myself->pgid)
{
  set_need_fork_fixup ();
}

void
fhandler_serial::overlapped_setup ()
{
  memset (&io_status, 0, sizeof (io_status));
  io_status.hEvent = CreateEvent (&sec_none_nih, TRUE, FALSE, NULL);
  ProtectHandle (io_status.hEvent);
  overlapped_armed = 0;
}

int
fhandler_serial::raw_read (void *ptr, size_t ulen)
{
  int tot;
  DWORD n;
  HANDLE w4[2];
  size_t minchars = vmin_ ?: ulen;

  w4[0] = io_status.hEvent;
  w4[1] = signal_arrived;

  debug_printf ("ulen %d, vmin_ %d, vtime_ %d, hEvent %p", ulen, vmin_, vtime_,
		io_status.hEvent);
  if (!overlapped_armed)
    {
      (void) SetCommMask (get_handle (), EV_RXCHAR);
      ResetEvent (io_status.hEvent);
    }

  for (n = 0, tot = 0; ulen; ulen -= n, ptr = (char *) ptr + n)
    {
      COMSTAT st;
      DWORD inq = 1;

      n = 0;

      if (!vtime_ && !vmin_)
	inq = ulen;
      else if (vtime_)
	{
	  inq = ulen;	// non-interruptible -- have to use kernel timeouts
			// also note that this is not strictly correct.
			// if vmin > ulen then things won't work right.
	  overlapped_armed = -1;
	}

      if (!ClearCommError (get_handle (), &ev, &st))
	goto err;
      else if (ev)
	termios_printf ("error detected %x", ev);
      else if (st.cbInQue)
	inq = st.cbInQue;
      else if (!overlapped_armed)
	{
	  if ((size_t) tot >= minchars)
	    break;
	  else if (WaitCommEvent (get_handle (), &ev, &io_status))
	    {
	      debug_printf ("WaitCommEvent succeeded: ev %x", ev);
	      if (!ev)
		continue;
	    }
	  else if (GetLastError () != ERROR_IO_PENDING)
	    goto err;
	  else
	    {
	      overlapped_armed = 1;
	      switch (WaitForMultipleObjects (2, w4, FALSE, INFINITE))
		{
		case WAIT_OBJECT_0:
		  if (!GetOverlappedResult (get_handle (), &io_status, &n, FALSE))
		    goto err;
		  debug_printf ("n %d, ev %x", n, ev);
		  break;
		case WAIT_OBJECT_0 + 1:
		  tot = -1;
		  PurgeComm (get_handle (), PURGE_RXABORT);
		  overlapped_armed = 0;
		  set_sig_errno (EINTR);
		  goto out;
		default:
		  goto err;
		}
	    }
	}

      overlapped_armed = 0;
      ResetEvent (io_status.hEvent);
      if (inq > ulen)
	inq = ulen;
      debug_printf ("inq %d", inq);
      if (ReadFile (get_handle (), ptr, min (inq, ulen), &n, &io_status))
	/* Got something */;
      else if (GetLastError () != ERROR_IO_PENDING)
	goto err;
      else if (!GetOverlappedResult (get_handle (), &io_status, &n, TRUE))
	goto err;

      tot += n;
      debug_printf ("vtime_ %d, vmin_ %d, n %d, tot %d", vtime_, vmin_, n, tot);
      if (vtime_ || !vmin_ || !n)
	break;
      continue;

    err:
      PurgeComm (get_handle (), PURGE_RXABORT);
      debug_printf ("err %E");
      if (GetLastError () == ERROR_OPERATION_ABORTED)
	n = 0;
      else
	{
	  tot = -1;
	  __seterrno ();
	  break;
	}
    }

out:
  return tot;
}

/* Cover function to WriteFile to provide Posix interface and semantics
   (as much as possible).  */
int
fhandler_serial::raw_write (const void *ptr, size_t len)
{
  DWORD bytes_written;
  OVERLAPPED write_status;

  memset (&write_status, 0, sizeof (write_status));
  write_status.hEvent = CreateEvent (&sec_none_nih, TRUE, FALSE, NULL);
  ProtectHandle (write_status.hEvent);

  for (;;)
    {
      if (WriteFile (get_handle (), ptr, len, &bytes_written, &write_status))
	break;

      switch (GetLastError ())
	{
	  case ERROR_OPERATION_ABORTED:
	    continue;
	  case ERROR_IO_PENDING:
	    break;
	  default:
	    goto err;
	}

      if (!GetOverlappedResult (get_handle (), &write_status, &bytes_written, TRUE))
	goto err;

      break;
    }

  ForceCloseHandle (write_status.hEvent);

  return bytes_written;

err:
  __seterrno ();
  ForceCloseHandle (write_status.hEvent);
  return -1;
}

void
fhandler_serial::dump (void)
{
  paranoid_printf ("here");
}

void
fhandler_serial::init (HANDLE f, DWORD flags, mode_t bin)
{
  (void) open (NULL, flags, bin & (O_BINARY | O_TEXT));
}

int
fhandler_serial::open (path_conv *, int flags, mode_t mode)
{
  int res;
  COMMTIMEOUTS to;
  extern BOOL reset_com;

  syscall_printf ("fhandler_serial::open (%s, %p, %p)",
			get_name (), flags, mode);

  if (!(res = this->fhandler_base::open (NULL, flags, mode)))
    return 0;

  res = 1;

  (void) SetCommMask (get_handle (), EV_RXCHAR);

  set_r_no_interrupt (1);	// Handled explicitly in read code

  overlapped_setup ();

  memset (&to, 0, sizeof (to));
  (void) SetCommTimeouts (get_handle (), &to);

  /* Reset serial port to known state of 9600-8-1-no flow control
     on open for better behavior under Win 95.

     FIXME:  This should only be done when explicitly opening the com
     port.  It should not be reset if an fd is inherited.
     Using __progname in this way, to determine how far along in the
     initialization we are, is really a terrible kludge and should
     be fixed ASAP.
  */
  extern char *__progname;
  if (reset_com && __progname)
    {
      DCB state;
      GetCommState (get_handle (), &state);
      syscall_printf ("setting initial state on %s (reset_com %d)",
		      get_name (), reset_com);
      state.BaudRate = CBR_9600;
      state.ByteSize = 8;
      state.StopBits = ONESTOPBIT;
      state.Parity = NOPARITY; /* FIXME: correct default? */
      state.fBinary = TRUE; /* binary xfer */
      state.EofChar = 0; /* no end-of-data in binary mode */
      state.fNull = FALSE; /* don't discard nulls in binary mode */
      state.fParity = FALSE; /* ignore parity errors */
      state.fErrorChar = FALSE;
      state.fTXContinueOnXoff = TRUE; /* separate TX and RX flow control */
      state.fOutX = FALSE; /* disable transmission flow control */
      state.fInX = FALSE; /* disable reception flow control */
      state.XonChar = 0x11;
      state.XoffChar = 0x13;
      state.fOutxDsrFlow = FALSE; /* disable DSR flow control */
      state.fRtsControl = RTS_CONTROL_ENABLE; /* ignore lead control except
						  DTR */
      state.fOutxCtsFlow = FALSE; /* disable output flow control */
      state.fDtrControl = DTR_CONTROL_ENABLE; /* assert DTR */
      state.fDsrSensitivity = FALSE; /* don't assert DSR */
      state.fAbortOnError = TRUE;
      if (!SetCommState (get_handle (), &state))
	system_printf ("couldn't set initial state for %s, %E", get_name ());
    }

  /* setting rts and dtr to known state so that ioctl() function with
  request TIOCMGET could return correct value of RTS and DTR lines.
  Important only for Win 9x systems */

  if (!wincap.supports_reading_modem_output_lines ())
    {
      if (EscapeCommFunction (get_handle (), SETDTR) == 0)
	system_printf ("couldn't set initial state of DTR for %s, %E", get_name ());
      if (EscapeCommFunction (get_handle (), SETRTS) == 0)
	system_printf ("couldn't set initial state of RTS for %s, %E", get_name ());

      /* even though one of above functions fail I have to set rts and dtr
      variables to initial value. */
      rts = TIOCM_RTS;
      dtr = TIOCM_DTR;
    }

  SetCommMask (get_handle (), EV_RXCHAR);
  set_open_status ();
  syscall_printf ("%p = fhandler_serial::open (%s, %p, %p)",
			res, get_name (), flags, mode);
  return res;
}

int
fhandler_serial::close ()
{
  (void) ForceCloseHandle (io_status.hEvent);
  return fhandler_base::close ();
}

/* tcsendbreak: POSIX 7.2.2.1 */
/* Break for 250-500 milliseconds if duration == 0 */
/* Otherwise, units for duration are undefined */
int
fhandler_serial::tcsendbreak (int duration)
{
  unsigned int sleeptime = 300000;

  if (duration > 0)
    sleeptime *= duration;

  if (SetCommBreak (get_handle ()) == 0)
    return -1;

  /* FIXME: need to send zero bits during duration */
  usleep (sleeptime);

  if (ClearCommBreak (get_handle ()) == 0)
    return -1;

  syscall_printf ("0 = fhandler_serial:tcsendbreak (%d)", duration);

  return 0;
}

/* tcdrain: POSIX 7.2.2.1 */
int
fhandler_serial::tcdrain (void)
{
  if (FlushFileBuffers (get_handle ()) == 0)
    return -1;

  return 0;
}

/* tcflow: POSIX 7.2.2.1 */
int
fhandler_serial::tcflow (int action)
{
  DWORD win32action = 0;
  DCB dcb;
  char xchar;

  termios_printf ("action %d", action);

  switch (action)
    {
      case TCOOFF:
	win32action = SETXOFF;
	break;
      case TCOON:
	win32action = SETXON;
	break;
      case TCION:
      case TCIOFF:
	if (GetCommState (get_handle (), &dcb) == 0)
	  return -1;
	if (action == TCION)
	  xchar = (dcb.XonChar ? dcb.XonChar : 0x11);
	else
	  xchar = (dcb.XoffChar ? dcb.XoffChar : 0x13);
	if (TransmitCommChar (get_handle (), xchar) == 0)
	  return -1;
	return 0;
	break;
      default:
	return -1;
	break;
    }

  if (EscapeCommFunction (get_handle (), win32action) == 0)
    return -1;

  return 0;
}


/* ioctl: */
int
fhandler_serial::ioctl (unsigned int cmd, void *buffer)
{
  int res = 0;

# define ibuffer ((int) buffer)
# define ipbuffer (*(int *) buffer)

  DWORD ev;
  COMSTAT st;
  if (!ClearCommError (get_handle (), &ev, &st))
    {
      __seterrno ();
      res = -1;
    }
  else
    switch (cmd)
      {
      case TCFLSH:
	res = tcflush (ibuffer);
	break;
      case TIOCMGET:
	DWORD modem_lines;
	if (!GetCommModemStatus (get_handle (), &modem_lines))
	  {
	    __seterrno ();
	    res = -1;
	  }
	else
	  {
	    ipbuffer = 0;
	    if (modem_lines & MS_CTS_ON)
	      ipbuffer |= TIOCM_CTS;
	    if (modem_lines & MS_DSR_ON)
	      ipbuffer |= TIOCM_DSR;
	    if (modem_lines & MS_RING_ON)
	      ipbuffer |= TIOCM_RI;
	    if (modem_lines & MS_RLSD_ON)
	      ipbuffer |= TIOCM_CD;

	    DWORD cb;
	    DWORD mcr;
	    if (!DeviceIoControl (get_handle (), IOCTL_SERIAL_GET_DTRRTS,
				  NULL, 0, &mcr, 4, &cb, 0) || cb != 4)
	      ipbuffer |= rts | dtr;
	    else
	      {
		if (mcr & 2)
		  ipbuffer |= TIOCM_RTS;
		if (mcr & 1)
		  ipbuffer |= TIOCM_DTR;
	      }
	  }
	break;
      case TIOCMSET:
	if (ipbuffer & TIOCM_RTS)
	  {
	    if (EscapeCommFunction (get_handle (), SETRTS))
	      rts = TIOCM_RTS;
	    else
	      {
		__seterrno ();
		res = -1;
	      }
	  }
	else
	  {
	    if (EscapeCommFunction (get_handle (), CLRRTS))
	      rts = 0;
	    else
	      {
		__seterrno ();
		res = -1;
	      }
	  }
	if (ipbuffer & TIOCM_DTR)
	  {
	    if (EscapeCommFunction (get_handle (), SETDTR))
	      dtr = TIOCM_DTR;
	    else
	      {
		__seterrno ();
		res = -1;
	      }
	  }
	else if (EscapeCommFunction (get_handle (), CLRDTR))
	  dtr = 0;
	else
	  {
	    __seterrno ();
	    res = -1;
	  }
	break;
     case TIOCINQ:
       if (ev & CE_FRAME || ev & CE_IOE || ev & CE_OVERRUN || ev & CE_RXOVER
	   || ev & CE_RXPARITY)
	 {
	   set_errno (EINVAL);	/* FIXME: Use correct errno */
	   res = -1;
	 }
       else
	 ipbuffer = st.cbInQue;
       break;
     default:
       set_errno (ENOSYS);
       res = -1;
       break;
     }

  termios_printf ("%d = ioctl (%p, %p)", res, cmd, buffer);
# undef ibuffer
# undef ipbuffer
  return res;
}

/* tcflush: POSIX 7.2.2.1 */
int
fhandler_serial::tcflush (int queue)
{
  if (queue == TCOFLUSH || queue == TCIOFLUSH)
    PurgeComm (get_handle (), PURGE_TXABORT | PURGE_TXCLEAR);

  if (queue == TCIFLUSH || queue == TCIOFLUSH)
    /* Input flushing by polling until nothing turns up
       (we stop after 1000 chars anyway) */
    for (int max = 1000; max > 0; max--)
      {
	COMSTAT st;
	if (!PurgeComm (get_handle (), PURGE_RXABORT | PURGE_RXCLEAR))
	  break;
	low_priority_sleep (100);