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 <sys/stat.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
#if defined(HAVE_ISASTREAM) && defined(HAVE_STROPTS_H)
# 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;
    char *slave;

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

    if (slave != NULL)
      {
        *ttydev = strdup (slave);
        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
   */
#if defined(HAVE_ISASTREAM) && defined(HAVE_STROPTS_H)
  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:	1.35
Committed:	Mon May 5 16:51:29 2008 UTC (16 years, 2 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-1_3
Changes since 1.34:	+2 -2 lines
Log Message:	* empty log message *
#	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	ayin	1.34	#include <sys/stat.h>
38	root	1.2	#include <unistd.h>
39			#include <fcntl.h>
40
41	root	1.1	#ifdef HAVE_SYS_IOCTL_H
42			# include <sys/ioctl.h>
43			#endif
44	root	1.2	#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
45	root	1.1	# include <sys/stropts.h> /* for I_PUSH */
46			#endif
47	root	1.35	#if defined(HAVE_ISASTREAM) && defined(HAVE_STROPTS_H)
48	root	1.1	# include <stropts.h>
49			#endif
50	root	1.2	#if defined(HAVE_PTY_H)
51	root	1.1	# include <pty.h>
52	root	1.2	#elif defined(HAVE_LIBUTIL_H)
53	root	1.1	# include <libutil.h>
54	root	1.2	#elif defined(HAVE_UTIL_H)
55	root	1.1	# include <util.h>
56			#endif
57	root	1.2	#ifdef TTY_GID_SUPPORT
58			#include <grp.h>
59			#endif
60	root	1.1
61			#include <cstdio>
62	root	1.2
63			/////////////////////////////////////////////////////////////////////////////
64	root	1.1
65			/* ------------------------------------------------------------------------- *
66			* GET PSEUDO TELETYPE - MASTER AND SLAVE *
67			* ------------------------------------------------------------------------- */
68			/*
69	ayin	1.26	* Returns pty file descriptor, or -1 on failure
70	root	1.1	* If successful, ttydev is set to the name of the slave device.
71			* fd_tty _may_ also be set to an open fd to the slave device
72			*/
73	root	1.2	#if defined(UNIX98_PTY)
74	root	1.25
75			static int
76			get_pty (int fd_tty, char *ttydev)
77			{
78			int pfd;
79	root	1.1
80	root	1.2	# if defined(HAVE_GETPT)
81	root	1.25	pfd = getpt();
82	root	1.2	# elif defined(HAVE_POSIX_OPENPT)
83	root	1.25	pfd = posix_openpt (O_RDWR);
84	root	1.2	# else
85	root	1.25	pfd = open (CLONE_DEVICE, O_RDWR \| O_NOCTTY, 0);
86	root	1.2	# endif
87	root	1.1
88	root	1.25	if (pfd >= 0)
89			{
90			if (grantpt (pfd) == 0 /* change slave permissions */
91			&& unlockpt (pfd) == 0)
92	ayin	1.32	{
93			/* slave now unlocked */
94	root	1.25	ttydev = strdup (ptsname (pfd)); / get slave's name */
95			return pfd;
96			}
97
98			close (pfd);
99			}
100
101			return -1;
102			}
103	root	1.2
104			#elif defined(HAVE_OPENPTY)
105	root	1.1
106	root	1.25	static int
107			get_pty (int fd_tty, char *ttydev)
108			{
109			int pfd;
110			int res;
111	ayin	1.26
112	ayin	1.29	res = openpty (&pfd, fd_tty, NULL, NULL, NULL);
113	root	1.25
114			if (res != -1)
115			{
116	ayin	1.29	ttydev = strdup (ttyname (fd_tty));
117	root	1.25	return pfd;
118			}
119
120			return -1;
121			}
122
123	root	1.2	#elif defined(HAVE__GETPTY)
124
125	root	1.25	static int
126			get_pty (int fd_tty, char *ttydev)
127			{
128			int pfd;
129	ayin	1.30	char *slave;
130	root	1.25
131	ayin	1.30	slave = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
132	root	1.25
133	ayin	1.33	if (slave != NULL)
134			{
135			*ttydev = strdup (slave);
136			return pfd;
137			}
138	root	1.25
139			return -1;
140			}
141	root	1.1
142	root	1.2	#elif defined(HAVE_DEV_PTC)
143	root	1.1
144	root	1.25	static int
145			get_pty (int fd_tty, char *ttydev)
146			{
147			int pfd;
148
149			if ((pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0)) >= 0)
150			{
151			*ttydev = strdup (ttyname (pfd));
152			return pfd;
153			}
154
155			return -1;
156			}
157	root	1.1
158	root	1.2	#elif defined(HAVE_DEV_CLONE)
159
160	root	1.25	static int
161			get_pty (int fd_tty, char *ttydev)
162			{
163			int pfd;
164
165			if ((pfd = open ("/dev/ptym/clone", O_RDWR \| O_NOCTTY, 0)) >= 0)
166			{
167			*ttydev = strdup (ptsname (pfd));
168			return pfd;
169			}
170
171			return -1;
172			}
173	root	1.1
174	root	1.2	#else
175	root	1.1
176	root	1.25	/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
177			static int
178			get_pty (int fd_tty, char *ttydev)
179			{
180			int pfd;
181			int i;
182			char pty_name[32];
183			char tty_name[32];
184			const char *majors = "pqrstuvwxyzabcde";
185			const char *minors = "0123456789abcdef";
186
187			for (i = 0; i < 256; i++)
188			{
189			snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
190			snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
191
192			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
193			{
194			snprintf(pty_name, 32, "/dev/ptyp%d", i);
195			snprintf(tty_name, 32, "/dev/ttyp%d", i);
196			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
197			continue;
198			}
199
200			if (access (tty_name, R_OK \| W_OK) == 0)
201			{
202			*ttydev = strdup (tty_name);
203			return pfd;
204			}
205
206			close (pfd);
207			}
208
209			return -1;
210			}
211	ayin	1.24
212	root	1.1	#endif
213
214			/----------------------------------------------------------------------/
215			/*
216	ayin	1.26	* Returns tty file descriptor, or -1 on failure
217	root	1.1	*/
218			static int
219			get_tty (char *ttydev)
220			{
221			return open (ttydev, O_RDWR \| O_NOCTTY, 0);
222			}
223
224			/----------------------------------------------------------------------/
225			/*
226			* Make our tty a controlling tty so that /dev/tty points to us
227			*/
228			static int
229	root	1.2	control_tty (int fd_tty)
230	root	1.1	{
231	ayin	1.28	int fd;
232
233	root	1.1	setsid ();
234
235	root	1.2	#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
236	root	1.1	/*
237			* Push STREAMS modules:
238			* ptem: pseudo-terminal hardware emulation module.
239			* ldterm: standard terminal line discipline.
240			* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
241			*
242			* After we push the STREAMS modules, the first open () on the slave side
243			* (i.e. the next section between the dashes giving us "tty opened OK")
244			* should make the "ptem" (or "ldterm" depending upon either which OS
245			* version or which set of manual pages you have) module give us a
246			* controlling terminal. We must already have close ()d the master side
247			* fd in this child process before we push STREAMS modules on because the
248			* documentation is really unclear about whether it is any close () on
249			* the master side or the last close () - i.e. a proper STREAMS dismantling
250			* close () - on the master side which causes a hang up to be sent
251			* through - Geoff Wing
252			*/
253	root	1.35	#if defined(HAVE_ISASTREAM) && defined(HAVE_STROPTS_H)
254	root	1.1	if (isastream (fd_tty) == 1)
255			# endif
256			{
257			ioctl (fd_tty, I_PUSH, "ptem");
258			ioctl (fd_tty, I_PUSH, "ldterm");
259			ioctl (fd_tty, I_PUSH, "ttcompat");
260			}
261			#endif
262	root	1.2
263	ayin	1.27	#ifdef TIOCSCTTY
264	root	1.2	ioctl (fd_tty, TIOCSCTTY, NULL);
265	ayin	1.27	#else
266	ayin	1.28	fd = open (ttyname (fd_tty), O_RDWR);
267	ayin	1.27	if (fd >= 0)
268			close (fd);
269			#endif
270	root	1.2
271	ayin	1.28	fd = open ("/dev/tty", O_WRONLY);
272	root	1.1	if (fd < 0)
273	root	1.10	return -1; /* fatal */
274	root	1.2
275	root	1.1	close (fd);
276
277			return 0;
278			}
279
280	root	1.2	void
281	root	1.4	ptytty::close_tty ()
282	root	1.2	{
283			if (tty < 0)
284			return;
285
286			close (tty);
287			tty = -1;
288			}
289
290			bool
291	root	1.4	ptytty::make_controlling_tty ()
292	root	1.2	{
293			return control_tty (tty) >= 0;
294			}
295
296			void
297	root	1.4	ptytty::set_utf8_mode (bool on)
298	root	1.2	{
299			#ifdef IUTF8
300			if (pty < 0)
301			return;
302
303			struct termios tio;
304
305			if (tcgetattr (pty, &tio) != -1)
306			{
307			tcflag_t new_cflag = tio.c_iflag;
308
309			if (on)
310			new_cflag \|= IUTF8;
311			else
312			new_cflag &= ~IUTF8;
313
314			if (new_cflag != tio.c_iflag)
315			{
316			tio.c_iflag = new_cflag;
317			tcsetattr (pty, TCSANOW, &tio);
318			}
319			}
320			#endif
321			}
322
323	root	1.1	static struct ttyconf {
324			gid_t gid;
325			mode_t mode;
326
327			ttyconf ()
328			{
329			#ifdef TTY_GID_SUPPORT
330			struct group *gr = getgrnam ("tty");
331
332			if (gr)
333	ayin	1.32	{
334			/* change group ownership of tty to "tty" */
335	root	1.1	mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
336			gid = gr->gr_gid;
337			}
338			else
339	ayin	1.31	#endif /* TTY_GID_SUPPORT */
340	root	1.1	{
341			mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
342	root	1.2	gid = 0;
343	root	1.1	}
344			}
345			} ttyconf;
346
347	root	1.4	ptytty_unix::ptytty_unix ()
348	root	1.1	{
349			name = 0;
350	root	1.2	#if UTMP_SUPPORT
351			cmd_pid = 0;
352	root	1.1	#endif
353			}
354
355	root	1.4	ptytty_unix::~ptytty_unix ()
356	root	1.1	{
357	root	1.2	#if UTMP_SUPPORT
358			logout ();
359			#endif
360	root	1.1	put ();
361			}
362
363			void
364	root	1.4	ptytty_unix::put ()
365	root	1.2	{
366	root	1.25	if (name)
367			{
368			chmod (name, RESTORE_TTY_MODE);
369			chown (name, 0, ttyconf.gid);
370			}
371	root	1.1
372	root	1.2	close_tty ();
373	root	1.1
374	root	1.2	if (pty >= 0)
375			close (pty);
376	root	1.1
377			free (name);
378
379			pty = tty = -1;
380			name = 0;
381			}
382
383			bool
384	root	1.4	ptytty_unix::get ()
385	root	1.1	{
386			/* get master (pty) */
387			if ((pty = get_pty (&tty, &name)) < 0)
388			return false;
389
390			fcntl (pty, F_SETFL, O_NONBLOCK);
391
392			/* get slave (tty) */
393			if (tty < 0)
394			{
395			#ifndef NO_SETOWNER_TTYDEV
396	root	1.2	chown (name, getuid (), ttyconf.gid); /* fail silently */
397			chmod (name, ttyconf.mode);
398			# ifdef HAVE_REVOKE
399			revoke (name);
400			# endif
401	root	1.1	#endif
402
403			if ((tty = get_tty (name)) < 0)
404			{
405			put ();
406			return false;
407			}
408			}
409
410			return true;
411			}
412