libptytty/src/ptytty.C

// This file is part of libptytty. Do not make local modifications.
// http://software.schmorp.de/pkg/libptytty

/*----------------------------------------------------------------------*
 * File:        ptytty.C
 *----------------------------------------------------------------------*
 *
 * All portions of code are copyright by their respective author/s.
 * Copyright (c) 1999-2001 Geoff Wing <gcw@pobox.com>
 * Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com>
 * Copyright (c) 2006      Emanuele Giaquinta <e.giaquinta@glauco.it>
 *
 * 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 "../config.h"

#include "ptytty.h"

#include <cstdlib>
#include <cstring>
#include <csignal>

#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>

#ifdef HAVE_SYS_IOCTL_H
# include <sys/ioctl.h>
#endif
#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
# include <sys/stropts.h>      /* for I_PUSH */
#endif
#ifdef HAVE_ISASTREAM
# include <stropts.h>
#endif
#if defined(HAVE_PTY_H)
# include <pty.h>
#elif defined(HAVE_LIBUTIL_H)
# include <libutil.h>
#elif defined(HAVE_UTIL_H)
# include <util.h>
#endif
#ifdef TTY_GID_SUPPORT
#include <grp.h>
#endif

#include <cstdio>

/////////////////////////////////////////////////////////////////////////////

/* ------------------------------------------------------------------------- *
 *                  GET PSEUDO TELETYPE - MASTER AND SLAVE                   *
 * ------------------------------------------------------------------------- */
/*
 * Returns pty file descriptor, or -1 on failure
 * If successful, ttydev is set to the name of the slave device.
 * fd_tty _may_ also be set to an open fd to the slave device
 */
#if defined(UNIX98_PTY)

  static int
  get_pty (int *fd_tty, char **ttydev)
  {
    int pfd;

# if defined(HAVE_GETPT)
    pfd = getpt();
# elif defined(HAVE_POSIX_OPENPT)
    pfd = posix_openpt (O_RDWR);
# else
    pfd = open (CLONE_DEVICE, O_RDWR | O_NOCTTY, 0);
# endif

    if (pfd >= 0)
      {
        if (grantpt (pfd) == 0  /* change slave permissions */
            && unlockpt (pfd) == 0)
          {     /* slave now unlocked */
            *ttydev = strdup (ptsname (pfd));   /* get slave's name */
            return pfd;
          }

        close (pfd);
      }

    return -1;
  }

#elif defined(HAVE_OPENPTY)

  static int
  get_pty (int *fd_tty, char **ttydev)
  {
    int pfd;
    int res;

    res = openpty (&pfd, fd_tty, NULL, NULL, NULL);

    if (res != -1)
      {
        *ttydev = strdup (ttyname (*fd_tty));
        return pfd;
      }

    return -1;
  }

#elif defined(HAVE__GETPTY)

  static int
  get_pty (int *fd_tty, char **ttydev)
  {
    int pfd;

    *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0);

    if (*ttydev != NULL)
      return pfd;

    return -1;
  }

#elif defined(HAVE_DEV_PTC)

  static int
  get_pty (int *fd_tty, char **ttydev)
  {
    int pfd;

    if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0)
      {
        *ttydev = strdup (ttyname (pfd));
        return pfd;
      }

    return -1;
  }

#elif defined(HAVE_DEV_CLONE)

  static int
  get_pty (int *fd_tty, char **ttydev)
  {
    int pfd;

    if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0)
      {
        *ttydev = strdup (ptsname (pfd));
        return pfd;
      }

    return -1;
  }

#else

  /* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
  static int
  get_pty (int *fd_tty, char **ttydev)
  {
    int pfd;
    int i;
    char pty_name[32];
    char tty_name[32];
    const char *majors = "pqrstuvwxyzabcde";
    const char *minors = "0123456789abcdef";

    for (i = 0; i < 256; i++)
      {
        snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
        snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);

        if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1)
          {
            snprintf(pty_name, 32, "/dev/ptyp%d", i);
            snprintf(tty_name, 32, "/dev/ttyp%d", i);
            if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1)
              continue;
          }

        if (access (tty_name, R_OK | W_OK) == 0)
          {
            *ttydev = strdup (tty_name);
            return pfd;
          }

        close (pfd);
      }

    return -1;
  }

#endif

/*----------------------------------------------------------------------*/
/*
 * Returns tty file descriptor, or -1 on failure
 */
static int
get_tty (char *ttydev)
{
  return open (ttydev, O_RDWR | O_NOCTTY, 0);
}

/*----------------------------------------------------------------------*/
/*
 * Make our tty a controlling tty so that /dev/tty points to us
 */
static int
control_tty (int fd_tty)
{
  int fd;

  setsid ();

#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
  /*
   * Push STREAMS modules:
   *    ptem: pseudo-terminal hardware emulation module.
   *    ldterm: standard terminal line discipline.
   *    ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
   *
   * After we push the STREAMS modules, the first open () on the slave side
   * (i.e. the next section between the dashes giving us "tty opened OK")
   * should make the "ptem" (or "ldterm" depending upon either which OS
   * version or which set of manual pages you have) module give us a
   * controlling terminal.  We must already have close ()d the master side
   * fd in this child process before we push STREAMS modules on because the
   * documentation is really unclear about whether it is any close () on
   * the master side or the last close () - i.e. a proper STREAMS dismantling
   * close () - on the master side which causes a hang up to be sent
   * through - Geoff Wing
   */
# ifdef HAVE_ISASTREAM
  if (isastream (fd_tty) == 1)
# endif
    {
      ioctl (fd_tty, I_PUSH, "ptem");
      ioctl (fd_tty, I_PUSH, "ldterm");
      ioctl (fd_tty, I_PUSH, "ttcompat");
    }
#endif

#ifdef TIOCSCTTY
  ioctl (fd_tty, TIOCSCTTY, NULL);
#else
  fd = open (ttyname (fd_tty), O_RDWR);
  if (fd >= 0)
    close (fd);
#endif

  fd = open ("/dev/tty", O_WRONLY);
  if (fd < 0)
    return -1; /* fatal */

  close (fd);

  return 0;
}

void
ptytty::close_tty ()
{
  if (tty < 0)
    return;

  close (tty);
  tty = -1;
}

bool
ptytty::make_controlling_tty ()
{
  return control_tty (tty) >= 0;
}

void
ptytty::set_utf8_mode (bool on)
{
#ifdef IUTF8
  if (pty < 0)
    return;

  struct termios tio;

  if (tcgetattr (pty, &tio) != -1)
    {
      tcflag_t new_cflag = tio.c_iflag;

      if (on)
        new_cflag |= IUTF8;
      else
        new_cflag &= ~IUTF8;

      if (new_cflag != tio.c_iflag)
        {
          tio.c_iflag = new_cflag;
          tcsetattr (pty, TCSANOW, &tio);
        }
    }
#endif
}

static struct ttyconf {
  gid_t gid;
  mode_t mode;

  ttyconf ()
    {
#ifdef TTY_GID_SUPPORT
      struct group *gr = getgrnam ("tty");

      if (gr)
        {           /* change group ownership of tty to "tty" */
          mode = S_IRUSR | S_IWUSR | S_IWGRP;
          gid = gr->gr_gid;
        }
      else
#endif                          /* TTY_GID_SUPPORT */
        {
          mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
          gid = 0;
        }
    }
} ttyconf;

ptytty_unix::ptytty_unix ()
{
  name = 0;
#if UTMP_SUPPORT
  cmd_pid = 0;
#endif
}

ptytty_unix::~ptytty_unix ()
{
#if UTMP_SUPPORT
  logout ();
#endif
  put ();
}

void
ptytty_unix::put ()
{
  if (name)
    {
      chmod (name, RESTORE_TTY_MODE);
      chown (name, 0, ttyconf.gid);
    }

  close_tty ();

  if (pty >= 0)
    close (pty);

  free (name);

  pty = tty = -1;
  name = 0;
}

bool
ptytty_unix::get ()
{
  /* get master (pty) */
  if ((pty = get_pty (&tty, &name)) < 0)
    return false;

  fcntl (pty, F_SETFL, O_NONBLOCK);

  /* get slave (tty) */
  if (tty < 0)
    {
#ifndef NO_SETOWNER_TTYDEV
      chown (name, getuid (), ttyconf.gid);      /* fail silently */
      chmod (name, ttyconf.mode);
# ifdef HAVE_REVOKE
      revoke (name);
# endif
#endif

      if ((tty = get_tty (name)) < 0)
        {
          put ();
          return false;
        }
    }

  return true;
}

Revision:	1.29
Committed:	Thu Jun 28 17:41:01 2007 UTC (17 years ago) by ayin
Content type:	text/plain
Branch:	MAIN
Changes since 1.28:	+2 -3 lines
Log Message:	When using openpty, get the slave name with ttyname rather than with the openpty broken interface.
#	User	Rev	Content
1	root	1.8	// This file is part of libptytty. Do not make local modifications.
2			// http://software.schmorp.de/pkg/libptytty
3
4			/----------------------------------------------------------------------
5	root	1.1	* File: ptytty.C
6			----------------------------------------------------------------------
7			*
8			* All portions of code are copyright by their respective author/s.
9			* Copyright (c) 1999-2001 Geoff Wing <gcw@pobox.com>
10	root	1.2	* Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com>
11	root	1.12	* Copyright (c) 2006 Emanuele Giaquinta <e.giaquinta@glauco.it>
12	root	1.1	*
13			* This program is free software; you can redistribute it and/or modify
14			* it under the terms of the GNU General Public License as published by
15			* the Free Software Foundation; either version 2 of the License, or
16			* (at your option) any later version.
17			*
18			* This program is distributed in the hope that it will be useful,
19			* but WITHOUT ANY WARRANTY; without even the implied warranty of
20			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21			* GNU General Public License for more details.
22			*
23			* You should have received a copy of the GNU General Public License
24			* along with this program; if not, write to the Free Software
25			* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26			---------------------------------------------------------------------/
27
28	root	1.8	#include "../config.h"
29	root	1.1
30	root	1.3	#include "ptytty.h"
31
32	root	1.2	#include <cstdlib>
33			#include <cstring>
34	root	1.19	#include <csignal>
35	root	1.2
36			#include <sys/types.h>
37			#include <unistd.h>
38			#include <fcntl.h>
39
40	root	1.1	#ifdef HAVE_SYS_IOCTL_H
41			# include <sys/ioctl.h>
42			#endif
43	root	1.2	#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
44	root	1.1	# include <sys/stropts.h> /* for I_PUSH */
45			#endif
46			#ifdef HAVE_ISASTREAM
47			# include <stropts.h>
48			#endif
49	root	1.2	#if defined(HAVE_PTY_H)
50	root	1.1	# include <pty.h>
51	root	1.2	#elif defined(HAVE_LIBUTIL_H)
52	root	1.1	# include <libutil.h>
53	root	1.2	#elif defined(HAVE_UTIL_H)
54	root	1.1	# include <util.h>
55			#endif
56	root	1.2	#ifdef TTY_GID_SUPPORT
57			#include <grp.h>
58			#endif
59	root	1.1
60			#include <cstdio>
61	root	1.2
62			/////////////////////////////////////////////////////////////////////////////
63	root	1.1
64			/* ------------------------------------------------------------------------- *
65			* GET PSEUDO TELETYPE - MASTER AND SLAVE *
66			* ------------------------------------------------------------------------- */
67			/*
68	ayin	1.26	* Returns pty file descriptor, or -1 on failure
69	root	1.1	* If successful, ttydev is set to the name of the slave device.
70			* fd_tty _may_ also be set to an open fd to the slave device
71			*/
72	root	1.2	#if defined(UNIX98_PTY)
73	root	1.25
74			static int
75			get_pty (int fd_tty, char *ttydev)
76			{
77			int pfd;
78	root	1.1
79	root	1.2	# if defined(HAVE_GETPT)
80	root	1.25	pfd = getpt();
81	root	1.2	# elif defined(HAVE_POSIX_OPENPT)
82	root	1.25	pfd = posix_openpt (O_RDWR);
83	root	1.2	# else
84	root	1.25	pfd = open (CLONE_DEVICE, O_RDWR \| O_NOCTTY, 0);
85	root	1.2	# endif
86	root	1.1
87	root	1.25	if (pfd >= 0)
88			{
89			if (grantpt (pfd) == 0 /* change slave permissions */
90			&& unlockpt (pfd) == 0)
91			{ /* slave now unlocked */
92			ttydev = strdup (ptsname (pfd)); / get slave's name */
93			return pfd;
94			}
95
96			close (pfd);
97			}
98
99			return -1;
100			}
101	root	1.2
102			#elif defined(HAVE_OPENPTY)
103	root	1.1
104	root	1.25	static int
105			get_pty (int fd_tty, char *ttydev)
106			{
107			int pfd;
108			int res;
109	ayin	1.26
110	ayin	1.29	res = openpty (&pfd, fd_tty, NULL, NULL, NULL);
111	root	1.25
112			if (res != -1)
113			{
114	ayin	1.29	ttydev = strdup (ttyname (fd_tty));
115	root	1.25	return pfd;
116			}
117
118			return -1;
119			}
120
121	root	1.2	#elif defined(HAVE__GETPTY)
122
123	root	1.25	static int
124			get_pty (int fd_tty, char *ttydev)
125			{
126			int pfd;
127
128			*ttydev = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
129
130			if (*ttydev != NULL)
131			return pfd;
132
133			return -1;
134			}
135	root	1.1
136	root	1.2	#elif defined(HAVE_DEV_PTC)
137	root	1.1
138	root	1.25	static int
139			get_pty (int fd_tty, char *ttydev)
140			{
141			int pfd;
142
143			if ((pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0)) >= 0)
144			{
145			*ttydev = strdup (ttyname (pfd));
146			return pfd;
147			}
148
149			return -1;
150			}
151	root	1.1
152	root	1.2	#elif defined(HAVE_DEV_CLONE)
153
154	root	1.25	static int
155			get_pty (int fd_tty, char *ttydev)
156			{
157			int pfd;
158
159			if ((pfd = open ("/dev/ptym/clone", O_RDWR \| O_NOCTTY, 0)) >= 0)
160			{
161			*ttydev = strdup (ptsname (pfd));
162			return pfd;
163			}
164
165			return -1;
166			}
167	root	1.1
168	root	1.2	#else
169	root	1.1
170	root	1.25	/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
171			static int
172			get_pty (int fd_tty, char *ttydev)
173			{
174			int pfd;
175			int i;
176			char pty_name[32];
177			char tty_name[32];
178			const char *majors = "pqrstuvwxyzabcde";
179			const char *minors = "0123456789abcdef";
180
181			for (i = 0; i < 256; i++)
182			{
183			snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
184			snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
185
186			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
187			{
188			snprintf(pty_name, 32, "/dev/ptyp%d", i);
189			snprintf(tty_name, 32, "/dev/ttyp%d", i);
190			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
191			continue;
192			}
193
194			if (access (tty_name, R_OK \| W_OK) == 0)
195			{
196			*ttydev = strdup (tty_name);
197			return pfd;
198			}
199
200			close (pfd);
201			}
202
203			return -1;
204			}
205	ayin	1.24
206	root	1.1	#endif
207
208			/----------------------------------------------------------------------/
209			/*
210	ayin	1.26	* Returns tty file descriptor, or -1 on failure
211	root	1.1	*/
212			static int
213			get_tty (char *ttydev)
214			{
215			return open (ttydev, O_RDWR \| O_NOCTTY, 0);
216			}
217
218			/----------------------------------------------------------------------/
219			/*
220			* Make our tty a controlling tty so that /dev/tty points to us
221			*/
222			static int
223	root	1.2	control_tty (int fd_tty)
224	root	1.1	{
225	ayin	1.28	int fd;
226
227	root	1.1	setsid ();
228
229	root	1.2	#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
230	root	1.1	/*
231			* Push STREAMS modules:
232			* ptem: pseudo-terminal hardware emulation module.
233			* ldterm: standard terminal line discipline.
234			* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
235			*
236			* After we push the STREAMS modules, the first open () on the slave side
237			* (i.e. the next section between the dashes giving us "tty opened OK")
238			* should make the "ptem" (or "ldterm" depending upon either which OS
239			* version or which set of manual pages you have) module give us a
240			* controlling terminal. We must already have close ()d the master side
241			* fd in this child process before we push STREAMS modules on because the
242			* documentation is really unclear about whether it is any close () on
243			* the master side or the last close () - i.e. a proper STREAMS dismantling
244			* close () - on the master side which causes a hang up to be sent
245			* through - Geoff Wing
246			*/
247			# ifdef HAVE_ISASTREAM
248			if (isastream (fd_tty) == 1)
249			# endif
250			{
251			ioctl (fd_tty, I_PUSH, "ptem");
252			ioctl (fd_tty, I_PUSH, "ldterm");
253			ioctl (fd_tty, I_PUSH, "ttcompat");
254			}
255			#endif
256	root	1.2
257	ayin	1.27	#ifdef TIOCSCTTY
258	root	1.2	ioctl (fd_tty, TIOCSCTTY, NULL);
259	ayin	1.27	#else
260	ayin	1.28	fd = open (ttyname (fd_tty), O_RDWR);
261	ayin	1.27	if (fd >= 0)
262			close (fd);
263			#endif
264	root	1.2
265	ayin	1.28	fd = open ("/dev/tty", O_WRONLY);
266	root	1.1	if (fd < 0)
267	root	1.10	return -1; /* fatal */
268	root	1.2
269	root	1.1	close (fd);
270
271			return 0;
272			}
273
274	root	1.2	void
275	root	1.4	ptytty::close_tty ()
276	root	1.2	{
277			if (tty < 0)
278			return;
279
280			close (tty);
281			tty = -1;
282			}
283
284			bool
285	root	1.4	ptytty::make_controlling_tty ()
286	root	1.2	{
287			return control_tty (tty) >= 0;
288			}
289
290			void
291	root	1.4	ptytty::set_utf8_mode (bool on)
292	root	1.2	{
293			#ifdef IUTF8
294			if (pty < 0)
295			return;
296
297			struct termios tio;
298
299			if (tcgetattr (pty, &tio) != -1)
300			{
301			tcflag_t new_cflag = tio.c_iflag;
302
303			if (on)
304			new_cflag \|= IUTF8;
305			else
306			new_cflag &= ~IUTF8;
307
308			if (new_cflag != tio.c_iflag)
309			{
310			tio.c_iflag = new_cflag;
311			tcsetattr (pty, TCSANOW, &tio);
312			}
313			}
314			#endif
315			}
316
317	root	1.1	static struct ttyconf {
318			gid_t gid;
319			mode_t mode;
320
321			ttyconf ()
322			{
323			#ifdef TTY_GID_SUPPORT
324			struct group *gr = getgrnam ("tty");
325
326			if (gr)
327			{ /* change group ownership of tty to "tty" */
328			mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
329			gid = gr->gr_gid;
330			}
331			else
332			#endif /* TTY_GID_SUPPORT */
333			{
334			mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
335	root	1.2	gid = 0;
336	root	1.1	}
337			}
338			} ttyconf;
339
340	root	1.4	ptytty_unix::ptytty_unix ()
341	root	1.1	{
342			name = 0;
343	root	1.2	#if UTMP_SUPPORT
344			cmd_pid = 0;
345	root	1.1	#endif
346			}
347
348	root	1.4	ptytty_unix::~ptytty_unix ()
349	root	1.1	{
350	root	1.2	#if UTMP_SUPPORT
351			logout ();
352			#endif
353	root	1.1	put ();
354			}
355
356			void
357	root	1.4	ptytty_unix::put ()
358	root	1.2	{
359	root	1.25	if (name)
360			{
361			chmod (name, RESTORE_TTY_MODE);
362			chown (name, 0, ttyconf.gid);
363			}
364	root	1.1
365	root	1.2	close_tty ();
366	root	1.1
367	root	1.2	if (pty >= 0)
368			close (pty);
369	root	1.1
370			free (name);
371
372			pty = tty = -1;
373			name = 0;
374			}
375
376			bool
377	root	1.4	ptytty_unix::get ()
378	root	1.1	{
379			/* get master (pty) */
380			if ((pty = get_pty (&tty, &name)) < 0)
381			return false;
382
383			fcntl (pty, F_SETFL, O_NONBLOCK);
384
385			/* get slave (tty) */
386			if (tty < 0)
387			{
388			#ifndef NO_SETOWNER_TTYDEV
389	root	1.2	chown (name, getuid (), ttyconf.gid); /* fail silently */
390			chmod (name, ttyconf.mode);
391			# ifdef HAVE_REVOKE
392			revoke (name);
393			# endif
394	root	1.1	#endif
395
396			if ((tty = get_tty (name)) < 0)
397			{
398			put ();
399			return false;
400			}
401			}
402
403			return true;
404			}
405