path: root/gdb/ser-unix.c

/* Serial interface for local (hardwired) serial ports on Un*x like systems
   Copyright 1992, 1993 Free Software Foundation, Inc.

This file is part of GDB.

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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "serial.h"
#include <fcntl.h>
#include <sys/types.h>

#if !defined (HAVE_TERMIOS) && !defined (HAVE_TERMIO) && !defined (HAVE_SGTTY)
#define HAVE_SGTTY
#endif

#ifdef HAVE_TERMIOS
#include <termios.h>
#include <unistd.h>

struct hardwire_ttystate
{
  struct termios termios;
  pid_t process_group;
};
#endif /* termios */

#ifdef HAVE_TERMIO
#include <termio.h>

/* It is believed that all systems which have added job control to SVR3
   (e.g. sco) have also added termios.  Even if not, trying to figure out
   all the variations (TIOCGPGRP vs. TCGETPGRP, etc.) would be pretty
   bewildering.  So we don't attempt it.  */

struct hardwire_ttystate
{
  struct termio termio;
};
#endif /* termio */

#ifdef HAVE_SGTTY
/* Needed for the code which uses select().  We would include <sys/select.h>
   too if it existed on all systems.  */
#include <sys/time.h>

#include <sgtty.h>

struct hardwire_ttystate
{
  struct sgttyb sgttyb;
  struct tchars tc;
  struct ltchars ltc;
  /* Line discipline flags.  */
  int lmode;

#ifdef SHORT_PGRP
  /* This is only used for the ultra.  Does it have pid_t?  */
  short process_group;
#else
  int process_group;
#endif
};
#endif /* sgtty */

static int hardwire_open PARAMS ((serial_t scb, const char *name));
static void hardwire_raw PARAMS ((serial_t scb));
static int wait_for PARAMS ((serial_t scb, int timeout));
static int hardwire_readchar PARAMS ((serial_t scb, int timeout));
static int rate_to_code PARAMS ((int rate));
static int hardwire_setbaudrate PARAMS ((serial_t scb, int rate));
static int hardwire_write PARAMS ((serial_t scb, const char *str, int len));
/* FIXME: static void hardwire_restore PARAMS ((serial_t scb)); */
static void hardwire_close PARAMS ((serial_t scb));
static int get_tty_state PARAMS ((serial_t scb, struct hardwire_ttystate *state));
static int set_tty_state PARAMS ((serial_t scb, struct hardwire_ttystate *state));
static serial_ttystate hardwire_get_tty_state PARAMS ((serial_t scb));
static int hardwire_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));

/* Open up a real live device for serial I/O */

static int
hardwire_open(scb, name)
     serial_t scb;
     const char *name;
{
  scb->fd = open (name, O_RDWR);
  if (scb->fd < 0)
    return -1;

  return 0;
}

static int
get_tty_state(scb, state)
     serial_t scb;
     struct hardwire_ttystate *state;
{
#ifdef HAVE_TERMIOS
  extern int errno;
  pid_t new_process_group;

  if (tcgetattr(scb->fd, &state->termios) < 0)
    return -1;

  if (!job_control)
    return 0;

  /* Apparently, if a tty has no process group, then tcgetpgrp returns -1 with
     errno == 0.   In this case, set the process group to -1 so that we know to
     omit resetting it later.  */
  new_process_group = tcgetpgrp (scb->fd);
  if ((new_process_group == (pid_t)-1)
      && (errno != ENOTTY))
    return -1;
  errno = 0;
  state->process_group = new_process_group;
  return 0;
#endif

#ifdef HAVE_TERMIO
  if (ioctl (scb->fd, TCGETA, &state->termio) < 0)
    return -1;
  return 0;
#endif

#ifdef HAVE_SGTTY
  if (ioctl (scb->fd, TIOCGETP, &state->sgttyb) < 0)
    return -1;
  if (ioctl (scb->fd, TIOCGETC, &state->tc) < 0)
    return -1;
  if (ioctl (scb->fd, TIOCGLTC, &state->ltc) < 0)
    return -1;
  if (ioctl (scb->fd, TIOCLGET, &state->lmode) < 0)
    return -1;

  if (!job_control)
    return 0;

  return ioctl (scb->fd, TIOCGPGRP, &state->process_group);
#endif
}

static int
set_tty_state(scb, state)
     serial_t scb;
     struct hardwire_ttystate *state;
{
#ifdef HAVE_TERMIOS
  if (tcsetattr(scb->fd, TCSANOW, &state->termios) < 0)
    return -1;

  if (!job_control)
    return 0;

  /* If the tty had no process group before, then do not reset it. */
  if (state->process_group == -1)
    return 0;
  else
    return tcsetpgrp (scb->fd, state->process_group);
#endif

#ifdef HAVE_TERMIO
  if (ioctl (scb->fd, TCSETA, &state->termio) < 0)
    return -1;
  return 0;
#endif

#ifdef HAVE_SGTTY
  if (ioctl (scb->fd, TIOCSETN, &state->sgttyb) < 0)
    return -1;

  if (!job_control)
    return 0;

  return ioctl (scb->fd, TIOCSPGRP, &state->process_group);
#endif
}

static serial_ttystate
hardwire_get_tty_state(scb)
     serial_t scb;
{
  struct hardwire_ttystate *state;

  state = (struct hardwire_ttystate *)xmalloc(sizeof *state);

  if (get_tty_state(scb, state))
    return NULL;

  return (serial_ttystate)state;
}

static int
hardwire_set_tty_state(scb, ttystate)
     serial_t scb;
     serial_ttystate ttystate;
{
  struct hardwire_ttystate *state;

  state = (struct hardwire_ttystate *)ttystate;

  return set_tty_state(scb, state);
}

static int
hardwire_noflush_set_tty_state (scb, new_ttystate, old_ttystate)
     serial_t scb;
     serial_ttystate new_ttystate;
     serial_ttystate old_ttystate;
{
  struct hardwire_ttystate new_state;
  struct hardwire_ttystate *state = (struct hardwire_ttystate *) old_ttystate;

  new_state = *(struct hardwire_ttystate *)new_ttystate;

#ifdef HAVE_TERMIOS
  /* I'm not sure whether this is necessary; the manpage makes no mention
     of discarding input when switching to/from ICANON.  */
  if (state->termios.c_lflag & ICANON)
    new_state.termios.c_lflag |= ICANON;
  else
    new_state.termios.c_lflag &= ~ICANON;
#endif

#ifdef HAVE_TERMIO
  /* I'm not sure whether this is necessary; the manpage makes no mention
     of discarding input when switching to/from ICANON.  */
  if (state->termio.c_lflag & ICANON)
    new_state.termio.c_lflag |= ICANON;
  else
    new_state.termio.c_lflag &= ~ICANON;
#endif

#ifdef HAVE_SGTTY
  if (state->sgttyb.sg_flags & RAW)
    new_state.sgttyb.sg_flags |= RAW;
  else
    new_state.sgttyb.sg_flags &= ~RAW;

  /* I'm not sure whether this is necessary; the manpage just mentions
     RAW not CBREAK.  */
  if (state->sgttyb.sg_flags & CBREAK)
    new_state.sgttyb.sg_flags |= CBREAK;
  else
    new_state.sgttyb.sg_flags &= ~CBREAK;
#endif

  return set_tty_state (scb, &new_state);
}

static void
hardwire_print_tty_state (scb, ttystate)
     serial_t scb;
     serial_ttystate ttystate;
{
  struct hardwire_ttystate *state = (struct hardwire_ttystate *) ttystate;
  int i;

#ifdef HAVE_TERMIOS
  printf_filtered ("Process group = %d\n", state->process_group);

  printf_filtered ("c_iflag = 0x%x, c_oflag = 0x%x,\n",
		   state->termios.c_iflag, state->termios.c_oflag);
  printf_filtered ("c_cflag = 0x%x, c_lflag = 0x%x\n",
		   state->termios.c_cflag, state->termios.c_lflag);
#if 0
  /* This not in POSIX, and is not really documented by those systems
     which have it (at least not Sun).  */
  printf_filtered ("c_line = 0x%x.\n", state->termios.c_line);
#endif
  printf_filtered ("c_cc: ");
  for (i = 0; i < NCCS; i += 1)
    printf_filtered ("0x%x ", state->termios.c_cc[i]);
  printf_filtered ("\n");
#endif

#ifdef HAVE_TERMIO
  printf_filtered ("c_iflag = 0x%x, c_oflag = 0x%x,\n",
		   state->termio.c_iflag, state->termio.c_oflag);
  printf_filtered ("c_cflag = 0x%x, c_lflag = 0x%x, c_line = 0x%x.\n",
		   state->termio.c_cflag, state->termio.c_lflag,
		   state->termio.c_line);
  printf_filtered ("c_cc: ");
  for (i = 0; i < NCC; i += 1)
    printf_filtered ("0x%x ", state->termio.c_cc[i]);
  printf_filtered ("\n");
#endif

#ifdef HAVE_SGTTY
  printf_filtered ("Process group = %d\n", state->process_group);

  printf_filtered ("sgttyb.sg_flags = 0x%x.\n", state->sgttyb.sg_flags);

  printf_filtered ("tchars: ");
  for (i = 0; i < (int)sizeof (struct tchars); i++)
    printf_filtered ("0x%x ", ((unsigned char *)&state->tc)[i]);
  printf_filtered ("\n");

  printf_filtered ("ltchars: ");
  for (i = 0; i < (int)sizeof (struct ltchars); i++)
    printf_filtered ("0x%x ", ((unsigned char *)&state->ltc)[i]);
  printf_filtered ("\n");

  printf_filtered ("lmode:  0x%x\n", state->lmode);
#endif
}

static int
hardwire_flush_output (scb)
     serial_t scb;
{
#ifdef HAVE_TERMIOS
  return tcflush (scb->fd, TCOFLUSH);
#endif

#ifdef HAVE_TERMIO
  return ioctl (scb->fd, TCFLSH, 1);
#endif

#ifdef HAVE_SGTTY
  /* This flushes both input and output, but we can't do better.  */
  return ioctl (scb->fd, TIOCFLUSH, 0);
#endif  
}

static int
hardwire_flush_input (scb)
     serial_t scb;
{
#ifdef HAVE_TERMIOS
  return tcflush (scb->fd, TCIFLUSH);
#endif

#ifdef HAVE_TERMIO
  return ioctl (scb->fd, TCFLSH, 0);
#endif

#ifdef HAVE_SGTTY
  /* This flushes both input and output, but we can't do better.  */
  return ioctl (scb->fd, TIOCFLUSH, 0);
#endif  
}

static int
hardwire_send_break (scb)
     serial_t scb;
{
#ifdef HAVE_TERMIOS
  return tcsendbreak (scb->fd, 0);
#endif

#ifdef HAVE_TERMIO
  return ioctl (scb->fd, TCSBRK, 0);
#endif

#ifdef HAVE_SGTTY
  {
    int status;
    struct timeval timeout;

    status = ioctl (scb->fd, TIOCSBRK, 0);

    /* Can't use usleep; it doesn't exist in BSD 4.2.  */
    /* Note that if this select() is interrupted by a signal it will not wait
       the full length of time.  I think that is OK.  */
    timeout.tv_sec = 0;
    timeout.tv_usec = 250000;
    select (0, 0, 0, 0, &timeout);
    status = ioctl (scb->fd, TIOCCBRK, 0);
    return status;
  }
#endif  
}

static void
hardwire_raw(scb)
     serial_t scb;
{
  struct hardwire_ttystate state;

  if (get_tty_state(scb, &state))
    fprintf(stderr, "get_tty_state failed: %s\n", safe_strerror(errno));

#ifdef HAVE_TERMIOS
  state.termios.c_iflag = 0;
  state.termios.c_oflag = 0;
  state.termios.c_lflag = 0;
  state.termios.c_cflag &= ~(CSIZE|PARENB);
  state.termios.c_cflag |= CS8;
  state.termios.c_cc[VMIN] = 0;
  state.termios.c_cc[VTIME] = 0;
#endif

#ifdef HAVE_TERMIO
  state.termio.c_iflag = 0;
  state.termio.c_oflag = 0;
  state.termio.c_lflag = 0;
  state.termio.c_cflag &= ~(CSIZE|PARENB);
  state.termio.c_cflag |= CS8;
  state.termio.c_cc[VMIN] = 0;
  state.termio.c_cc[VTIME] = 0;
#endif

#ifdef HAVE_SGTTY
  state.sgttyb.sg_flags |= RAW | ANYP;
  state.sgttyb.sg_flags &= ~(CBREAK | ECHO);
#endif

  scb->current_timeout = 0;

  if (set_tty_state (scb, &state))
    fprintf(stderr, "set_tty_state failed: %s\n", safe_strerror(errno));
}

/* Wait for input on scb, with timeout seconds.  Returns 0 on success,
   otherwise SERIAL_TIMEOUT or SERIAL_ERROR.

   For termio{s}, we actually just setup VTIME if necessary, and let the
   timeout occur in the read() in hardwire_read().
 */

static int
wait_for(scb, timeout)
     serial_t scb;
     int timeout;
{
#ifdef HAVE_SGTTY
  struct timeval tv;
  fd_set readfds;

  FD_ZERO (&readfds);

  tv.tv_sec = timeout;
  tv.tv_usec = 0;

  FD_SET(scb->fd, &readfds);

  while (1)
    {
      int numfds;

      if (timeout >= 0)
	numfds = select(scb->fd+1, &readfds, 0, 0, &tv);
      else
	numfds = select(scb->fd+1, &readfds, 0, 0, 0);

      if (numfds <= 0)
	if (numfds == 0)
	  return SERIAL_TIMEOUT;
	else if (errno == EINTR)
	  continue;
	else
	  return SERIAL_ERROR;	/* Got an error from select or poll */

      return 0;
    }

#endif	/* HAVE_SGTTY */

#if defined HAVE_TERMIO || defined HAVE_TERMIOS
  if (timeout == scb->current_timeout)
    return 0;

  {
    struct hardwire_ttystate state;

    if (get_tty_state(scb, &state))
      fprintf(stderr, "get_tty_state failed: %s\n", safe_strerror(errno));

#ifdef HAVE_TERMIOS
    state.termios.c_cc[VTIME] = timeout * 10;
#endif

#ifdef HAVE_TERMIO
    state.termio.c_cc[VTIME] = timeout * 10;
#endif

    scb->current_timeout = timeout;

    if (set_tty_state (scb, &state))
      fprintf(stderr, "set_tty_state failed: %s\n", safe_strerror(errno));

    return 0;
  }
#endif	/* HAVE_TERMIO || HAVE_TERMIOS */
}

/* Read a character with user-specified timeout.  TIMEOUT is number of seconds
   to wait, or -1 to wait forever.  Use timeout of 0 to effect a poll.  Returns
   char if successful.  Returns SERIAL_TIMEOUT if timeout expired, EOF if line
   dropped dead, or SERIAL_ERROR for any other error (see errno in that case).  */

static int
hardwire_readchar(scb, timeout)
     serial_t scb;
     int timeout;
{
  int status;

  if (scb->bufcnt-- > 0)
    return *scb->bufp++;

  status = wait_for(scb, timeout);

  if (status < 0)
    return status;

  scb->bufcnt = read(scb->fd, scb->buf, BUFSIZ);

  if (scb->bufcnt <= 0)
    if (scb->bufcnt == 0)
      return SERIAL_TIMEOUT;	/* 0 chars means timeout [may need to
				   distinguish between EOF & timeouts
				   someday] */
    else
      return SERIAL_ERROR;	/* Got an error from read */

  scb->bufcnt--;
  scb->bufp = scb->buf;
  return *scb->bufp++;
}

#ifndef B19200
#define B19200 EXTA
#endif

#ifndef B38400
#define B38400 EXTB
#endif

/* Translate baud rates from integers to damn B_codes.  Unix should
   have outgrown this crap years ago, but even POSIX wouldn't buck it.  */

static struct
{
  int rate;
  int code;
}
baudtab[] =
{
  {50, B50},
  {75, B75},
  {110, B110},
  {134, B134},
  {150, B150},
  {200, B200},
  {300, B300},
  {600, B600},
  {1200, B1200},
  {1800, B1800},
  {2400, B2400},
  {4800, B4800},
  {9600, B9600},
  {19200, B19200},
  {38400, B38400},
  {-1, -1},
};

static int 
rate_to_code(rate)
     int rate;
{
  int i;

  for (i = 0; baudtab[i].rate != -1; i++)
    if (rate == baudtab[i].rate)  
      return baudtab[i].code;

  return -1;
}

static int
hardwire_setbaudrate(scb, rate)
     serial_t scb;
     int rate;
{
  struct hardwire_ttystate state;

  if (get_tty_state(scb, &state))
    return -1;

#ifdef HAVE_TERMIOS
  cfsetospeed (&state.termios, rate_to_code (rate));
  cfsetispeed (&state.termios, rate_to_code (rate));
#endif

#ifdef HAVE_TERMIO
#ifndef CIBAUD
#define CIBAUD CBAUD
#endif

  state.termio.c_cflag &= ~(CBAUD | CIBAUD);
  state.termio.c_cflag |= rate_to_code (rate);
#endif

#ifdef HAVE_SGTTY
  state.sgttyb.sg_ispeed = rate_to_code (rate);
  state.sgttyb.sg_ospeed = rate_to_code (rate);
#endif

  return set_tty_state (scb, &state);
}

static int
hardwire_set_process_group (scb, ttystate, group)
     serial_t scb;
     serial_ttystate ttystate;
     int group;
{
#if defined (HAVE_SGTTY) || defined (HAVE_TERMIOS)
  ((struct hardwire_ttystate *)ttystate)->process_group = group;
#endif
  return 0;
}

static int
hardwire_write(scb, str, len)
     serial_t scb;
     const char *str;
     int len;
{
  int cc;

  while (len > 0)
    {
      cc = write(scb->fd, str, len);

      if (cc < 0)
	return 1;
      len -= cc;
      str += cc;
    }
  return 0;
}

static void
hardwire_close(scb)
     serial_t scb;
{
  if (scb->fd < 0)
    return;

  close(scb->fd);
  scb->fd = -1;
}

static struct serial_ops hardwire_ops =
{
  "hardwire",
  0,
  hardwire_open,
  hardwire_close,
  hardwire_readchar,
  hardwire_write,
  hardwire_flush_output,
  hardwire_flush_input,
  hardwire_send_break,
  hardwire_raw,
  hardwire_get_tty_state,
  hardwire_set_tty_state,
  hardwire_print_tty_state,
  hardwire_noflush_set_tty_state,
  hardwire_setbaudrate,
  hardwire_set_process_group
};

int job_control;
#if defined (HAVE_TERMIOS)
#include <unistd.h>
#endif

/* This is here because this is where we figure out whether we (probably)
   have job control.  Just using job_control only does part of it because
   setpgid or setpgrp might not exist on a system without job control.
   It might be considered misplaced (on the other hand, process groups and
   job control are closely related to ttys).

   For a more clean implementation, in libiberty, put a setpgid which merely
   calls setpgrp and a setpgrp which does nothing (any system with job control
   will have one or the other).  */
int
gdb_setpgid ()
{
  int retval = 0;
  if (job_control)
    {
#if defined (NEED_POSIX_SETPGID) || defined (HAVE_TERMIOS)
      /* Do all systems with termios have setpgid?  I hope so.  */
      /* setpgid (0, 0) is supposed to work and mean the same thing as
	 this, but on Ultrix 4.2A it fails with EPERM (and
	 setpgid (getpid (), getpid ()) succeeds).  */
      retval = setpgid (getpid (), getpid ());
#else
#if defined (TIOCGPGRP)
#if defined(USG) && !defined(SETPGRP_ARGS)
      retval = setpgrp ();
#else
      retval = setpgrp (getpid (), getpid ());
#endif /* USG */
#endif /* TIOCGPGRP.  */
#endif /* NEED_POSIX_SETPGID */
    }
  return retval;
}

void
_initialize_ser_hardwire ()
{
  serial_add_interface (&hardwire_ops);

  /* OK, figure out whether we have job control.  */

#if defined (HAVE_TERMIOS)
  /* Do all systems with termios have the POSIX way of identifying job
     control?  I hope so.  */
#ifdef _POSIX_JOB_CONTROL
  job_control = 1;
#else
  job_control = sysconf (_SC_JOB_CONTROL);
#endif
#endif /* termios */

#ifdef HAVE_TERMIO
  /* See comment at top of file about trying to support process groups
     with termio.  */
  job_control = 0;
#endif /* termio */

#ifdef HAVE_SGTTY
#ifdef TIOCGPGRP
  job_control = 1;
#else
  job_control = 0;
#endif /* TIOCGPGRP */
#endif /* sgtty */

}