/* Copyright (c) 1993
 *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
 *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
 * Copyright (c) 1987 Oliver Laumann
 *
 * 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, 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 (see the file COPYING); if not, write to the
 * Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 ****************************************************************
 */

#include "rcs.h"
RCS_ID("$Id: pty.c,v 1.1.1.1 1993/08/15 18:32:55 nate Exp $ FAU")

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>

#include "config.h"
#include "screen.h"

#ifndef sun
#include <sys/ioctl.h>
#endif

#if defined(sun) && defined(LOCKPTY) && !defined(TIOCEXCL)
#include <sys/ttold.h>
#endif

#ifdef ISC
# include <sys/tty.h>
# include <sys/sioctl.h>
# include <sys/pty.h>
#endif

#include "extern.h"

/*
 * if no PTYRANGE[01] is in the config file, we pick a default
 */
#ifndef PTYRANGE0
# define PTYRANGE0 "qpr"
#endif
#ifndef PTYRANGE1
# define PTYRANGE1 "0123456789abcdef"
#endif

extern int eff_uid;

/* used for opening a new pty-pair: */
static char PtyName[32], TtyName[32];

#if !(defined(sequent) || defined(_SEQUENT_) || defined(SVR4))
# ifdef hpux
static char PtyProto[] = "/dev/ptym/ptyXY";
static char TtyProto[] = "/dev/pty/ttyXY";
# else
static char PtyProto[] = "/dev/ptyXY";
static char TtyProto[] = "/dev/ttyXY";
# endif /* hpux */
#endif


#if defined(sequent) || defined(_SEQUENT_)

int
OpenPTY(ttyn)
char **ttyn;
{
  char *m, *s;
  register int f;

  if ((f = getpseudotty(&s, &m)) < 0)
    return -1;
#ifdef _SEQUENT_
  fvhangup(s);
#endif
  strncpy(PtyName, m, sizeof(PtyName));
  strncpy(TtyName, s, sizeof(TtyName));
#ifdef POSIX
  tcflush(f, TCIOFLUSH);
#else
# ifdef TIOCFLUSH
  (void) ioctl(f, TIOCFLUSH, (char *) 0);
# endif
#endif
#ifdef LOCKPTY
  (void) ioctl(f, TIOCEXCL, (char *) 0);
#endif
  *ttyn = TtyName;
  return f;
}

#else
# ifdef MIPS
#  ifdef __sgi /* __sgi -> IRIX 4.0 */

int
OpenPTY(ttyn)
char **ttyn;
{
  int f;
  char *name; 
  sig_t (*sigcld)__P(SIGPROTOARG);

  /*
   * SIGCHLD set to SIG_DFL for _getpty() because it may fork() and
   * exec() /usr/adm/mkpts
   */
  sigcld = signal(SIGCHLD, SIG_DFL);
  name = _getpty(&f, O_RDWR | O_NDELAY, 0600, 0);
  signal(SIGCHLD, sigcld);

  if (name == NULL)
    return -1;
#ifdef LOCKPTY
  (void) ioctl(f, TIOCEXCL, (char *) 0);
#endif
  *ttyn = name;
  return f;
}

#  else /* __sgi */

int
OpenPTY(ttyn)
char **ttyn;
{
  register int f;
  register int my_minor;
  struct stat buf;
   
  strcpy(PtyName, "/dev/ptc");
  f = open(PtyName, O_RDWR | O_NDELAY);
  if (f < 0)
    return -1;
  if (fstat(f, &buf) < 0)
    {
      close(f);
      return -1;
    }
  my_minor = minor(buf.st_rdev);
  sprintf(TtyName, "/dev/ttyq%d", my_minor);
#ifdef LOCKPTY
  (void) ioctl(f, TIOCEXCL, (char *) 0);
#endif
  *ttyn = TtyName;
  return f;
}

#  endif /* __sgi */
# else /* MIPS */
#  ifdef SVR4

int
OpenPTY(ttyn)
char **ttyn;
{
  char *m;
  register int f;
  char *ptsname();
  int unlockpt __P((int)), grantpt __P((int));
  sig_t (*sigcld)__P(SIGPROTOARG);

  if ((f = open("/dev/ptmx", O_RDWR)) == -1)
    return -1;

  /*
   * SIGCHLD set to SIG_DFL for grantpt() because it fork()s and
   * exec()s pt_chmod
   */
  sigcld = signal(SIGCHLD, SIG_DFL);
       
  if ((m = ptsname(f)) == NULL || unlockpt(f) || grantpt(f))
    {
      signal(SIGCHLD, sigcld);
      close(f);
      return -1;
    } 
  signal(SIGCHLD, sigcld);
  strncpy(TtyName, m, sizeof(TtyName));
#ifdef POSIX
  tcflush(f, TCIOFLUSH);
#else
# ifdef TIOCFLUSH
  (void) ioctl(f, TIOCFLUSH, (char *) 0);
# endif
#endif
#ifdef LOCKPTY
  (void) ioctl(f, TIOCEXCL, (char *) 0);
#endif
  *ttyn = TtyName;
  return f;
}

#  else /* not SVR4 */
#   ifdef _AIX /* RS6000 */

int
OpenPTY(ttyn)
char **ttyn;
{
  register int f;

  /* a dumb looking loop replaced by mycrofts code: */
  strcpy (PtyName, "/dev/ptc");
  if ((f = open (PtyName, O_RDWR)) < 0)
    return -1;
  strcpy (TtyName, ttyname(f));
  strcpy (PtyName, TtyName);
  PtyName [7] = 'c'; 
  if (eff_uid && access(TtyName, R_OK | W_OK))
    {
      close(f);
      return -1;
    }
#ifdef LOCKPTY
  if (ioctl (f, TIOCEXCL, (char *) 0) == -1)
    return -1;
#endif /* LOCKPTY */
  *ttyn = TtyName;
  return f;
}

#   else /* _AIX, RS6000 */

int
OpenPTY(ttyn)
char **ttyn;
{
  register char *p, *q, *l, *d;
  register int f;

  debug("OpenPTY: Using BSD style ptys.\n");
  strcpy(PtyName, PtyProto);
  strcpy(TtyName, TtyProto);
  for (p = PtyName; *p != 'X'; ++p)
    ;
  for (q = TtyName; *q != 'X'; ++q)
    ;
  for (l = PTYRANGE0; (*p = *l) != '\0'; ++l)
    {
      for (d = PTYRANGE1; (p[1] = *d) != '\0'; ++d)
	{
	  debug1("OpenPTY tries '%s'\n", PtyName);
	  if ((f = open(PtyName, O_RDWR)) == -1)
	    continue;
	  q[0] = *l;
	  q[1] = *d;
	  if (eff_uid && access(TtyName, R_OK | W_OK))
	    {
	      close(f);
	      continue;
	    }
#if defined(sun) && defined(TIOCGPGRP) && !defined(SUNOS3)
	  /* Hack to ensure that the slave side of the pty is
	   * unused. May not work in anything other than SunOS4.1
	   */
	    {
	      int pgrp;

	      /* tcgetpgrp does not work (uses TIOCGETPGRP)! */
	      if (ioctl(f, TIOCGPGRP, (char *)&pgrp) != -1 || errno != EIO)
		{
		  close(f);
		  continue;
		}
	    }
#endif
#ifdef LOCKPTY
	  (void) ioctl(f, TIOCEXCL, (char *) 0);
#endif
	  *ttyn = TtyName;
	  return f;
	}
    }
  return -1;
}

#   endif /* _AIX, RS6000 */
#  endif /* SVR4 */
# endif /* MIPS */
#endif /* sequent || SEQUENT */