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 <schmorp@schmorp.de>
 * 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_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
#  ifdef _AIX
    pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0);
#  else
    pfd = open ("/dev/ptmx", O_RDWR | O_NOCTTY, 0);
#  endif
# 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;
  }

#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 ();

#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;
        }
    }

#if 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
   * 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 (tty) == 1)
# endif
    {
      ioctl (tty, I_PUSH, "ptem");
      ioctl (tty, I_PUSH, "ldterm");
      ioctl (tty, I_PUSH, "ttcompat");
    }
#endif

  return true;
}

Revision:	1.40
Committed:	Thu Nov 10 16:30:16 2011 UTC (12 years, 7 months ago) by sf-exg
Content type:	text/plain
Branch:	MAIN
Changes since 1.39:	+7 -3 lines
Log Message:	Get rid of runtime configure tests to find the multiplexer device. We now assume that if the system provides the unix98 pty api but not posix_openpt then it provides either the ptmx or ptc (aix) device.
#	Content
1	// This file is part of libptytty. Do not make local modifications.
2	// http://software.schmorp.de/pkg/libptytty
3
4	/----------------------------------------------------------------------
5	* 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	* Copyright (c) 2004-2006 Marc Lehmann <schmorp@schmorp.de>
11	* Copyright (c) 2006 Emanuele Giaquinta <e.giaquinta@glauco.it>
12	*
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	#include "config.h"
29
30	#include "ptytty.h"
31
32	#include <cstdlib>
33	#include <cstring>
34	#include <csignal>
35
36	#include <sys/types.h>
37	#include <sys/stat.h>
38	#include <unistd.h>
39	#include <fcntl.h>
40
41	#ifdef HAVE_SYS_IOCTL_H
42	# include <sys/ioctl.h>
43	#endif
44	#if defined(HAVE_SYS_STROPTS_H)
45	# include <sys/stropts.h> /* for I_PUSH */
46	#endif
47	#if defined(HAVE_ISASTREAM) && defined(HAVE_STROPTS_H)
48	# include <stropts.h>
49	#endif
50	#if defined(HAVE_PTY_H)
51	# include <pty.h>
52	#elif defined(HAVE_LIBUTIL_H)
53	# include <libutil.h>
54	#elif defined(HAVE_UTIL_H)
55	# include <util.h>
56	#endif
57	#ifdef TTY_GID_SUPPORT
58	#include <grp.h>
59	#endif
60
61	#include <cstdio>
62
63	/////////////////////////////////////////////////////////////////////////////
64
65	/* ------------------------------------------------------------------------- *
66	* GET PSEUDO TELETYPE - MASTER AND SLAVE *
67	* ------------------------------------------------------------------------- */
68	/*
69	* Returns pty file descriptor, or -1 on failure
70	* 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	#if defined(UNIX98_PTY)
74
75	static int
76	get_pty (int fd_tty, char *ttydev)
77	{
78	int pfd;
79
80	# if defined(HAVE_GETPT)
81	pfd = getpt();
82	# elif defined(HAVE_POSIX_OPENPT)
83	pfd = posix_openpt (O_RDWR);
84	# else
85	# ifdef _AIX
86	pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0);
87	# else
88	pfd = open ("/dev/ptmx", O_RDWR \| O_NOCTTY, 0);
89	# endif
90	# endif
91
92	if (pfd >= 0)
93	{
94	if (grantpt (pfd) == 0 /* change slave permissions */
95	&& unlockpt (pfd) == 0)
96	{
97	/* slave now unlocked */
98	ttydev = strdup (ptsname (pfd)); / get slave's name */
99	return pfd;
100	}
101
102	close (pfd);
103	}
104
105	return -1;
106	}
107
108	#elif defined(HAVE_OPENPTY)
109
110	static int
111	get_pty (int fd_tty, char *ttydev)
112	{
113	int pfd;
114	int res;
115
116	res = openpty (&pfd, fd_tty, NULL, NULL, NULL);
117
118	if (res != -1)
119	{
120	ttydev = strdup (ttyname (fd_tty));
121	return pfd;
122	}
123
124	return -1;
125	}
126
127	#elif defined(HAVE__GETPTY)
128
129	static int
130	get_pty (int fd_tty, char *ttydev)
131	{
132	int pfd;
133	char *slave;
134
135	slave = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
136
137	if (slave != NULL)
138	{
139	*ttydev = strdup (slave);
140	return pfd;
141	}
142
143	return -1;
144	}
145
146	#else
147
148	/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
149	static int
150	get_pty (int fd_tty, char *ttydev)
151	{
152	int pfd;
153	int i;
154	char pty_name[32];
155	char tty_name[32];
156	const char *majors = "pqrstuvwxyzabcde";
157	const char *minors = "0123456789abcdef";
158
159	for (i = 0; i < 256; i++)
160	{
161	snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
162	snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
163
164	if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
165	{
166	snprintf(pty_name, 32, "/dev/ptyp%d", i);
167	snprintf(tty_name, 32, "/dev/ttyp%d", i);
168	if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
169	continue;
170	}
171
172	if (access (tty_name, R_OK \| W_OK) == 0)
173	{
174	*ttydev = strdup (tty_name);
175	return pfd;
176	}
177
178	close (pfd);
179	}
180
181	return -1;
182	}
183
184	#endif
185
186	/----------------------------------------------------------------------/
187	/*
188	* Returns tty file descriptor, or -1 on failure
189	*/
190	static int
191	get_tty (char *ttydev)
192	{
193	return open (ttydev, O_RDWR \| O_NOCTTY, 0);
194	}
195
196	/----------------------------------------------------------------------/
197	/*
198	* Make our tty a controlling tty so that /dev/tty points to us
199	*/
200	static int
201	control_tty (int fd_tty)
202	{
203	int fd;
204
205	setsid ();
206
207	#ifdef TIOCSCTTY
208	ioctl (fd_tty, TIOCSCTTY, NULL);
209	#else
210	fd = open (ttyname (fd_tty), O_RDWR);
211	if (fd >= 0)
212	close (fd);
213	#endif
214
215	fd = open ("/dev/tty", O_WRONLY);
216	if (fd < 0)
217	return -1; /* fatal */
218
219	close (fd);
220
221	return 0;
222	}
223
224	void
225	ptytty::close_tty ()
226	{
227	if (tty < 0)
228	return;
229
230	close (tty);
231	tty = -1;
232	}
233
234	bool
235	ptytty::make_controlling_tty ()
236	{
237	return control_tty (tty) >= 0;
238	}
239
240	void
241	ptytty::set_utf8_mode (bool on)
242	{
243	#ifdef IUTF8
244	if (pty < 0)
245	return;
246
247	struct termios tio;
248
249	if (tcgetattr (pty, &tio) != -1)
250	{
251	tcflag_t new_cflag = tio.c_iflag;
252
253	if (on)
254	new_cflag \|= IUTF8;
255	else
256	new_cflag &= ~IUTF8;
257
258	if (new_cflag != tio.c_iflag)
259	{
260	tio.c_iflag = new_cflag;
261	tcsetattr (pty, TCSANOW, &tio);
262	}
263	}
264	#endif
265	}
266
267	static struct ttyconf {
268	gid_t gid;
269	mode_t mode;
270
271	ttyconf ()
272	{
273	#ifdef TTY_GID_SUPPORT
274	struct group *gr = getgrnam ("tty");
275
276	if (gr)
277	{
278	/* change group ownership of tty to "tty" */
279	mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
280	gid = gr->gr_gid;
281	}
282	else
283	#endif /* TTY_GID_SUPPORT */
284	{
285	mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
286	gid = 0;
287	}
288	}
289	} ttyconf;
290
291	ptytty_unix::ptytty_unix ()
292	{
293	name = 0;
294	#if UTMP_SUPPORT
295	cmd_pid = 0;
296	#endif
297	}
298
299	ptytty_unix::~ptytty_unix ()
300	{
301	#if UTMP_SUPPORT
302	logout ();
303	#endif
304	put ();
305	}
306
307	void
308	ptytty_unix::put ()
309	{
310	if (name)
311	{
312	chmod (name, RESTORE_TTY_MODE);
313	chown (name, 0, ttyconf.gid);
314	}
315
316	close_tty ();
317
318	if (pty >= 0)
319	close (pty);
320
321	free (name);
322
323	pty = tty = -1;
324	name = 0;
325	}
326
327	bool
328	ptytty_unix::get ()
329	{
330	/* get master (pty) */
331	if ((pty = get_pty (&tty, &name)) < 0)
332	return false;
333
334	fcntl (pty, F_SETFL, O_NONBLOCK);
335
336	/* get slave (tty) */
337	if (tty < 0)
338	{
339	#ifndef NO_SETOWNER_TTYDEV
340	chown (name, getuid (), ttyconf.gid); /* fail silently */
341	chmod (name, ttyconf.mode);
342	# ifdef HAVE_REVOKE
343	revoke (name);
344	# endif
345	#endif
346
347	if ((tty = get_tty (name)) < 0)
348	{
349	put ();
350	return false;
351	}
352	}
353
354	#if defined(I_PUSH)
355	/*
356	* Push STREAMS modules:
357	* ptem: pseudo-terminal hardware emulation module.
358	* ldterm: standard terminal line discipline.
359	* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
360	*
361	* After we push the STREAMS modules, the first open () on the slave side
362	* should make the "ptem" (or "ldterm" depending upon either which OS
363	* version or which set of manual pages you have) module give us a
364	* controlling terminal. We must already have close ()d the master side
365	* fd in this child process before we push STREAMS modules on because the
366	* documentation is really unclear about whether it is any close () on
367	* the master side or the last close () - i.e. a proper STREAMS dismantling
368	* close () - on the master side which causes a hang up to be sent
369	* through - Geoff Wing
370	*/
371	#if defined(HAVE_ISASTREAM) && defined(HAVE_STROPTS_H)
372	if (isastream (tty) == 1)
373	# endif
374	{
375	ioctl (tty, I_PUSH, "ptem");
376	ioctl (tty, I_PUSH, "ldterm");
377	ioctl (tty, I_PUSH, "ttcompat");
378	}
379	#endif
380
381	return true;
382	}
383