rxvt-unicode/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;
    char tty_name[32];
    
    res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);

    if (res != -1)
      {
        *ttydev = strdup (tty_name);
        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)
{
  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

  ioctl (fd_tty, TIOCSCTTY, NULL);

  int 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:	1.63
Committed:	Tue Oct 3 11:21:33 2006 UTC (17 years, 7 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-8_0, rel-8_1, rel-8_2
Changes since 1.62:	+118 -97 lines
Log Message:	libptytty-1.0
#	User	Rev	Content
1	root	1.55	// This file is part of libptytty. Do not make local modifications.
2			// http://software.schmorp.de/pkg/libptytty
3
4			/----------------------------------------------------------------------
5	pcg	1.11	* File: ptytty.C
6	pcg	1.1	----------------------------------------------------------------------
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	1.30	* Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com>
11	root	1.58	* Copyright (c) 2006 Emanuele Giaquinta <e.giaquinta@glauco.it>
12	pcg	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	1.55	#include "../config.h"
29	root	1.54
30			#include "ptytty.h"
31	pcg	1.1
32	root	1.40	#include <cstdlib>
33			#include <cstring>
34	root	1.59	#include <csignal>
35	root	1.40
36			#include <sys/types.h>
37			#include <unistd.h>
38			#include <fcntl.h>
39	root	1.31
40	pcg	1.1	#ifdef HAVE_SYS_IOCTL_H
41			# include <sys/ioctl.h>
42			#endif
43	ayin	1.53	#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
44	pcg	1.1	# include <sys/stropts.h> /* for I_PUSH */
45			#endif
46	pcg	1.10	#ifdef HAVE_ISASTREAM
47			# include <stropts.h>
48			#endif
49	root	1.31	#if defined(HAVE_PTY_H)
50	root	1.22	# include <pty.h>
51	root	1.31	#elif defined(HAVE_LIBUTIL_H)
52	root	1.16	# include <libutil.h>
53	root	1.31	#elif defined(HAVE_UTIL_H)
54	root	1.17	# include <util.h>
55	pcg	1.1	#endif
56	ayin	1.53	#ifdef TTY_GID_SUPPORT
57			#include <grp.h>
58			#endif
59	pcg	1.1
60	root	1.16	#include <cstdio>
61
62	root	1.36	/////////////////////////////////////////////////////////////////////////////
63
64	pcg	1.1	/* ------------------------------------------------------------------------- *
65			* GET PSEUDO TELETYPE - MASTER AND SLAVE *
66			* ------------------------------------------------------------------------- */
67			/*
68			* Returns pty file descriptor, or -1 on failure
69			* 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	ayin	1.53	#if defined(UNIX98_PTY)
73	root	1.63
74			static int
75			get_pty (int fd_tty, char *ttydev)
76			{
77			int pfd;
78	pcg	1.1
79	ayin	1.53	# if defined(HAVE_GETPT)
80	root	1.63	pfd = getpt();
81	ayin	1.53	# elif defined(HAVE_POSIX_OPENPT)
82	root	1.63	pfd = posix_openpt (O_RDWR);
83	ayin	1.44	# else
84	root	1.63	pfd = open (CLONE_DEVICE, O_RDWR \| O_NOCTTY, 0);
85	ayin	1.44	# endif
86	root	1.45
87	root	1.63	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	1.45
102	ayin	1.53	#elif defined(HAVE_OPENPTY)
103	root	1.45
104	root	1.63	static int
105			get_pty (int fd_tty, char *ttydev)
106			{
107			int pfd;
108			int res;
109			char tty_name[32];
110
111			res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
112
113			if (res != -1)
114			{
115			*ttydev = strdup (tty_name);
116			return pfd;
117			}
118
119			return -1;
120			}
121
122	ayin	1.53	#elif defined(HAVE__GETPTY)
123	ayin	1.44
124	root	1.63	static int
125			get_pty (int fd_tty, char *ttydev)
126			{
127			int pfd;
128
129			*ttydev = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
130
131			if (*ttydev != NULL)
132			return pfd;
133
134			return -1;
135			}
136	root	1.45
137	ayin	1.53	#elif defined(HAVE_DEV_PTC)
138	pcg	1.4
139	root	1.63	static int
140			get_pty (int fd_tty, char *ttydev)
141			{
142			int pfd;
143
144			if ((pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0)) >= 0)
145			{
146			*ttydev = strdup (ttyname (pfd));
147			return pfd;
148			}
149
150			return -1;
151			}
152	root	1.45
153	ayin	1.53	#elif defined(HAVE_DEV_CLONE)
154	ayin	1.44
155	root	1.63	static int
156			get_pty (int fd_tty, char *ttydev)
157			{
158			int pfd;
159
160			if ((pfd = open ("/dev/ptym/clone", O_RDWR \| O_NOCTTY, 0)) >= 0)
161			{
162			*ttydev = strdup (ptsname (pfd));
163			return pfd;
164			}
165
166			return -1;
167			}
168	root	1.45
169	ayin	1.53	#else
170	root	1.45
171	root	1.63	/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
172			static int
173			get_pty (int fd_tty, char *ttydev)
174			{
175			int pfd;
176			int i;
177			char pty_name[32];
178			char tty_name[32];
179			const char *majors = "pqrstuvwxyzabcde";
180			const char *minors = "0123456789abcdef";
181
182			for (i = 0; i < 256; i++)
183			{
184			snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
185			snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
186
187			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
188			{
189			snprintf(pty_name, 32, "/dev/ptyp%d", i);
190			snprintf(tty_name, 32, "/dev/ttyp%d", i);
191			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
192			continue;
193			}
194
195			if (access (tty_name, R_OK \| W_OK) == 0)
196			{
197			*ttydev = strdup (tty_name);
198			return pfd;
199			}
200
201			close (pfd);
202			}
203
204			return -1;
205			}
206	ayin	1.62
207	pcg	1.1	#endif
208	root	1.45
209	pcg	1.1	/----------------------------------------------------------------------/
210			/*
211			* Returns tty file descriptor, or -1 on failure
212			*/
213	root	1.16	static int
214			get_tty (char *ttydev)
215	pcg	1.1	{
216	pcg	1.4	return open (ttydev, O_RDWR \| O_NOCTTY, 0);
217	pcg	1.1	}
218
219			/----------------------------------------------------------------------/
220			/*
221			* Make our tty a controlling tty so that /dev/tty points to us
222			*/
223	root	1.16	static int
224	root	1.36	control_tty (int fd_tty)
225	pcg	1.1	{
226	pcg	1.4	setsid ();
227	root	1.16
228	ayin	1.53	#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
229	pcg	1.4	/*
230			* Push STREAMS modules:
231			* ptem: pseudo-terminal hardware emulation module.
232			* ldterm: standard terminal line discipline.
233			* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
234			*
235	pcg	1.6	* After we push the STREAMS modules, the first open () on the slave side
236	pcg	1.4	* (i.e. the next section between the dashes giving us "tty opened OK")
237			* should make the "ptem" (or "ldterm" depending upon either which OS
238			* version or which set of manual pages you have) module give us a
239	pcg	1.6	* controlling terminal. We must already have close ()d the master side
240	pcg	1.4	* fd in this child process before we push STREAMS modules on because the
241	pcg	1.6	* documentation is really unclear about whether it is any close () on
242			* the master side or the last close () - i.e. a proper STREAMS dismantling
243			* close () - on the master side which causes a hang up to be sent
244	pcg	1.4	* through - Geoff Wing
245			*/
246	root	1.47	# ifdef HAVE_ISASTREAM
247	pcg	1.4	if (isastream (fd_tty) == 1)
248	root	1.47	# endif
249	pcg	1.1	{
250	pcg	1.4	ioctl (fd_tty, I_PUSH, "ptem");
251			ioctl (fd_tty, I_PUSH, "ldterm");
252			ioctl (fd_tty, I_PUSH, "ttcompat");
253	pcg	1.1	}
254	root	1.47	#endif
255	root	1.45
256			ioctl (fd_tty, TIOCSCTTY, NULL);
257
258			int fd = open ("/dev/tty", O_WRONLY);
259	pcg	1.4	if (fd < 0)
260	root	1.56	return -1; /* fatal */
261	root	1.45
262	pcg	1.4	close (fd);
263
264			return 0;
265	pcg	1.1	}
266	root	1.16
267	root	1.36	void
268	root	1.54	ptytty::close_tty ()
269	root	1.36	{
270			if (tty < 0)
271			return;
272
273			close (tty);
274			tty = -1;
275			}
276
277			bool
278	root	1.54	ptytty::make_controlling_tty ()
279	root	1.36	{
280			return control_tty (tty) >= 0;
281			}
282
283			void
284	root	1.54	ptytty::set_utf8_mode (bool on)
285	root	1.36	{
286			#ifdef IUTF8
287			if (pty < 0)
288			return;
289
290			struct termios tio;
291
292			if (tcgetattr (pty, &tio) != -1)
293			{
294			tcflag_t new_cflag = tio.c_iflag;
295
296			if (on)
297			new_cflag \|= IUTF8;
298			else
299			new_cflag &= ~IUTF8;
300
301			if (new_cflag != tio.c_iflag)
302			{
303			tio.c_iflag = new_cflag;
304			tcsetattr (pty, TCSANOW, &tio);
305			}
306			}
307			#endif
308			}
309
310	root	1.16	static struct ttyconf {
311			gid_t gid;
312			mode_t mode;
313
314			ttyconf ()
315			{
316			#ifdef TTY_GID_SUPPORT
317			struct group *gr = getgrnam ("tty");
318
319			if (gr)
320			{ /* change group ownership of tty to "tty" */
321			mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
322			gid = gr->gr_gid;
323			}
324			else
325			#endif /* TTY_GID_SUPPORT */
326			{
327			mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
328	ayin	1.48	gid = 0;
329	root	1.16	}
330			}
331			} ttyconf;
332
333	root	1.54	ptytty_unix::ptytty_unix ()
334	root	1.16	{
335			name = 0;
336	root	1.35	#if UTMP_SUPPORT
337			cmd_pid = 0;
338			#endif
339	root	1.16	}
340
341	root	1.54	ptytty_unix::~ptytty_unix ()
342	root	1.16	{
343	root	1.43	#if UTMP_SUPPORT
344	root	1.35	logout ();
345	root	1.43	#endif
346	root	1.16	put ();
347			}
348
349			void
350	root	1.54	ptytty_unix::put ()
351	root	1.16	{
352	root	1.63	if (name)
353			{
354			chmod (name, RESTORE_TTY_MODE);
355			chown (name, 0, ttyconf.gid);
356			}
357	root	1.16
358			close_tty ();
359	root	1.50
360			if (pty >= 0)
361			close (pty);
362
363	root	1.16	free (name);
364
365			pty = tty = -1;
366			name = 0;
367			}
368
369			bool
370	root	1.54	ptytty_unix::get ()
371	root	1.16	{
372			/* get master (pty) */
373			if ((pty = get_pty (&tty, &name)) < 0)
374			return false;
375
376			fcntl (pty, F_SETFL, O_NONBLOCK);
377
378			/* get slave (tty) */
379			if (tty < 0)
380			{
381			#ifndef NO_SETOWNER_TTYDEV
382	ayin	1.49	chown (name, getuid (), ttyconf.gid); /* fail silently */
383			chmod (name, ttyconf.mode);
384			# ifdef HAVE_REVOKE
385			revoke (name);
386			# endif
387	root	1.16	#endif
388
389			if ((tty = get_tty (name)) < 0)
390			{
391			put ();
392			return false;
393			}
394			}
395
396			return true;
397			}
398