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 <cstdio>
#include <cstring>

#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

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

/* ------------------------------------------------------------------------- *
 *                  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 | O_NOCTTY);
# 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_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;

  /* 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

#if UTMP_SUPPORT
# if defined(HAVE_STRUCT_UTMP) && !defined(HAVE_UTMP_PID)
  int fd_stdin = dup (STDIN_FILENO);
  dup2 (tty, STDIN_FILENO);

  utmp_pos = ttyslot ();

  dup2 (fd_stdin, STDIN_FILENO);
  close (fd_stdin);
# endif
#endif

  return true;
}

Revision:	1.46
Committed:	Tue Dec 20 21:03:21 2011 UTC (12 years, 6 months ago) by sf-exg
Content type:	text/plain
Branch:	MAIN
Changes since 1.45:	+1 -3 lines
Log Message:	Includes cleanup.
#	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	sf-exg	1.38	* Copyright (c) 2004-2006 Marc Lehmann <schmorp@schmorp.de>
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	sf-exg	1.36	#include "config.h"
29	root	1.1
30	root	1.3	#include "ptytty.h"
31
32	root	1.2	#include <cstdlib>
33	sf-exg	1.46	#include <cstdio>
34	root	1.2	#include <cstring>
35
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	sf-exg	1.40	#if 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	root	1.2	/////////////////////////////////////////////////////////////////////////////
62	root	1.1
63			/* ------------------------------------------------------------------------- *
64			* GET PSEUDO TELETYPE - MASTER AND SLAVE *
65			* ------------------------------------------------------------------------- */
66			/*
67	ayin	1.26	* Returns pty file descriptor, or -1 on failure
68	root	1.1	* If successful, ttydev is set to the name of the slave device.
69			* fd_tty _may_ also be set to an open fd to the slave device
70			*/
71	root	1.2	#if defined(UNIX98_PTY)
72	root	1.25
73			static int
74			get_pty (int fd_tty, char *ttydev)
75			{
76			int pfd;
77	root	1.1
78	root	1.2	# if defined(HAVE_GETPT)
79	sf-exg	1.43	pfd = getpt ();
80	root	1.2	# elif defined(HAVE_POSIX_OPENPT)
81	sf-exg	1.41	pfd = posix_openpt (O_RDWR \| O_NOCTTY);
82	root	1.2	# else
83	sf-exg	1.40	# ifdef _AIX
84			pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0);
85			# else
86			pfd = open ("/dev/ptmx", O_RDWR \| O_NOCTTY, 0);
87			# endif
88	root	1.2	# endif
89	root	1.1
90	root	1.25	if (pfd >= 0)
91			{
92			if (grantpt (pfd) == 0 /* change slave permissions */
93			&& unlockpt (pfd) == 0)
94	ayin	1.32	{
95			/* slave now unlocked */
96	root	1.25	ttydev = strdup (ptsname (pfd)); / get slave's name */
97			return pfd;
98			}
99
100			close (pfd);
101			}
102
103			return -1;
104			}
105	root	1.2
106			#elif defined(HAVE_OPENPTY)
107	root	1.1
108	root	1.25	static int
109			get_pty (int fd_tty, char *ttydev)
110			{
111			int pfd;
112			int res;
113	ayin	1.26
114	ayin	1.29	res = openpty (&pfd, fd_tty, NULL, NULL, NULL);
115	root	1.25
116			if (res != -1)
117			{
118	ayin	1.29	ttydev = strdup (ttyname (fd_tty));
119	root	1.25	return pfd;
120			}
121
122			return -1;
123			}
124
125	root	1.2	#elif defined(HAVE__GETPTY)
126
127	root	1.25	static int
128			get_pty (int fd_tty, char *ttydev)
129			{
130			int pfd;
131	ayin	1.30	char *slave;
132	root	1.25
133	sf-exg	1.42	slave = _getpty (&pfd, O_RDWR \| O_NOCTTY, 0622, 0);
134	root	1.25
135	ayin	1.33	if (slave != NULL)
136			{
137			*ttydev = strdup (slave);
138			return pfd;
139			}
140	root	1.25
141			return -1;
142			}
143	root	1.1
144	root	1.2	#else
145	root	1.1
146	root	1.25	/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
147			static int
148			get_pty (int fd_tty, char *ttydev)
149			{
150			int pfd;
151			int i;
152			char pty_name[32];
153			char tty_name[32];
154			const char *majors = "pqrstuvwxyzabcde";
155			const char *minors = "0123456789abcdef";
156
157			for (i = 0; i < 256; i++)
158			{
159	sf-exg	1.43	snprintf (pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
160			snprintf (tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
161	root	1.25
162			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
163			{
164	sf-exg	1.43	snprintf (pty_name, 32, "/dev/ptyp%d", i);
165			snprintf (tty_name, 32, "/dev/ttyp%d", i);
166	root	1.25	if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
167			continue;
168			}
169
170			if (access (tty_name, R_OK \| W_OK) == 0)
171			{
172			*ttydev = strdup (tty_name);
173			return pfd;
174			}
175
176			close (pfd);
177			}
178
179			return -1;
180			}
181	ayin	1.24
182	root	1.1	#endif
183
184			/----------------------------------------------------------------------/
185			/*
186	ayin	1.26	* Returns tty file descriptor, or -1 on failure
187	root	1.1	*/
188			static int
189			get_tty (char *ttydev)
190			{
191			return open (ttydev, O_RDWR \| O_NOCTTY, 0);
192			}
193
194			/----------------------------------------------------------------------/
195			/*
196			* Make our tty a controlling tty so that /dev/tty points to us
197			*/
198			static int
199	root	1.2	control_tty (int fd_tty)
200	root	1.1	{
201	ayin	1.28	int fd;
202
203	root	1.1	setsid ();
204
205	ayin	1.27	#ifdef TIOCSCTTY
206	root	1.2	ioctl (fd_tty, TIOCSCTTY, NULL);
207	ayin	1.27	#else
208	ayin	1.28	fd = open (ttyname (fd_tty), O_RDWR);
209	ayin	1.27	if (fd >= 0)
210			close (fd);
211			#endif
212	root	1.2
213	ayin	1.28	fd = open ("/dev/tty", O_WRONLY);
214	root	1.1	if (fd < 0)
215	root	1.10	return -1; /* fatal */
216	root	1.2
217	root	1.1	close (fd);
218
219			return 0;
220			}
221
222	root	1.2	void
223	root	1.4	ptytty::close_tty ()
224	root	1.2	{
225			if (tty < 0)
226			return;
227
228			close (tty);
229			tty = -1;
230			}
231
232			bool
233	root	1.4	ptytty::make_controlling_tty ()
234	root	1.2	{
235			return control_tty (tty) >= 0;
236			}
237
238			void
239	root	1.4	ptytty::set_utf8_mode (bool on)
240	root	1.2	{
241			#ifdef IUTF8
242			if (pty < 0)
243			return;
244
245			struct termios tio;
246
247			if (tcgetattr (pty, &tio) != -1)
248			{
249			tcflag_t new_cflag = tio.c_iflag;
250
251			if (on)
252			new_cflag \|= IUTF8;
253			else
254			new_cflag &= ~IUTF8;
255
256			if (new_cflag != tio.c_iflag)
257			{
258			tio.c_iflag = new_cflag;
259			tcsetattr (pty, TCSANOW, &tio);
260			}
261			}
262			#endif
263			}
264
265	root	1.1	static struct ttyconf {
266			gid_t gid;
267			mode_t mode;
268
269			ttyconf ()
270			{
271			#ifdef TTY_GID_SUPPORT
272			struct group *gr = getgrnam ("tty");
273
274			if (gr)
275	ayin	1.32	{
276			/* change group ownership of tty to "tty" */
277	root	1.1	mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
278			gid = gr->gr_gid;
279			}
280			else
281	ayin	1.31	#endif /* TTY_GID_SUPPORT */
282	root	1.1	{
283			mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
284	root	1.2	gid = 0;
285	root	1.1	}
286			}
287			} ttyconf;
288
289	root	1.4	ptytty_unix::ptytty_unix ()
290	root	1.1	{
291			name = 0;
292	root	1.2	#if UTMP_SUPPORT
293			cmd_pid = 0;
294	root	1.1	#endif
295			}
296
297	root	1.4	ptytty_unix::~ptytty_unix ()
298	root	1.1	{
299	root	1.2	#if UTMP_SUPPORT
300			logout ();
301			#endif
302	root	1.1	put ();
303			}
304
305			void
306	root	1.4	ptytty_unix::put ()
307	root	1.2	{
308	root	1.25	if (name)
309			{
310			chmod (name, RESTORE_TTY_MODE);
311			chown (name, 0, ttyconf.gid);
312			}
313	root	1.1
314	root	1.2	close_tty ();
315	root	1.1
316	root	1.2	if (pty >= 0)
317			close (pty);
318	root	1.1
319			free (name);
320
321			pty = tty = -1;
322			name = 0;
323			}
324
325			bool
326	root	1.4	ptytty_unix::get ()
327	root	1.1	{
328			/* get master (pty) */
329			if ((pty = get_pty (&tty, &name)) < 0)
330			return false;
331
332			/* get slave (tty) */
333			if (tty < 0)
334			{
335			#ifndef NO_SETOWNER_TTYDEV
336	root	1.2	chown (name, getuid (), ttyconf.gid); /* fail silently */
337			chmod (name, ttyconf.mode);
338			# ifdef HAVE_REVOKE
339			revoke (name);
340			# endif
341	root	1.1	#endif
342
343			if ((tty = get_tty (name)) < 0)
344			{
345			put ();
346			return false;
347			}
348			}
349
350	sf-exg	1.40	#if defined(I_PUSH)
351	sf-exg	1.39	/*
352			* Push STREAMS modules:
353			* ptem: pseudo-terminal hardware emulation module.
354			* ldterm: standard terminal line discipline.
355			* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
356			*
357			* After we push the STREAMS modules, the first open () on the slave side
358			* should make the "ptem" (or "ldterm" depending upon either which OS
359			* version or which set of manual pages you have) module give us a
360			* controlling terminal. We must already have close ()d the master side
361			* fd in this child process before we push STREAMS modules on because the
362			* documentation is really unclear about whether it is any close () on
363			* the master side or the last close () - i.e. a proper STREAMS dismantling
364			* close () - on the master side which causes a hang up to be sent
365			* through - Geoff Wing
366			*/
367			#if defined(HAVE_ISASTREAM) && defined(HAVE_STROPTS_H)
368			if (isastream (tty) == 1)
369			# endif
370			{
371			ioctl (tty, I_PUSH, "ptem");
372			ioctl (tty, I_PUSH, "ldterm");
373			ioctl (tty, I_PUSH, "ttcompat");
374			}
375			#endif
376
377	sf-exg	1.44	#if UTMP_SUPPORT
378			# if defined(HAVE_STRUCT_UTMP) && !defined(HAVE_UTMP_PID)
379			int fd_stdin = dup (STDIN_FILENO);
380			dup2 (tty, STDIN_FILENO);
381
382			utmp_pos = ttyslot ();
383
384			dup2 (fd_stdin, STDIN_FILENO);
385			close (fd_stdin);
386			# endif
387			#endif
388
389	root	1.1	return true;
390			}
391