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;
    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
   */
# 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:	1.33
Committed:	Thu Dec 13 14:42:33 2007 UTC (16 years, 7 months ago) by ayin
Content type:	text/plain
Branch:	MAIN
Changes since 1.32:	+5 -4 lines
Log Message:	Fix coding style.
#	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	ayin	1.32	{
92			/* slave now unlocked */
93	root	1.25	ttydev = strdup (ptsname (pfd)); / get slave's name */
94			return pfd;
95			}
96
97			close (pfd);
98			}
99
100			return -1;
101			}
102	root	1.2
103			#elif defined(HAVE_OPENPTY)
104	root	1.1
105	root	1.25	static int
106			get_pty (int fd_tty, char *ttydev)
107			{
108			int pfd;
109			int res;
110	ayin	1.26
111	ayin	1.29	res = openpty (&pfd, fd_tty, NULL, NULL, NULL);
112	root	1.25
113			if (res != -1)
114			{
115	ayin	1.29	ttydev = strdup (ttyname (fd_tty));
116	root	1.25	return pfd;
117			}
118
119			return -1;
120			}
121
122	root	1.2	#elif defined(HAVE__GETPTY)
123
124	root	1.25	static int
125			get_pty (int fd_tty, char *ttydev)
126			{
127			int pfd;
128	ayin	1.30	char *slave;
129	root	1.25
130	ayin	1.30	slave = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
131	root	1.25
132	ayin	1.33	if (slave != NULL)
133			{
134			*ttydev = strdup (slave);
135			return pfd;
136			}
137	root	1.25
138			return -1;
139			}
140	root	1.1
141	root	1.2	#elif defined(HAVE_DEV_PTC)
142	root	1.1
143	root	1.25	static int
144			get_pty (int fd_tty, char *ttydev)
145			{
146			int pfd;
147
148			if ((pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0)) >= 0)
149			{
150			*ttydev = strdup (ttyname (pfd));
151			return pfd;
152			}
153
154			return -1;
155			}
156	root	1.1
157	root	1.2	#elif defined(HAVE_DEV_CLONE)
158
159	root	1.25	static int
160			get_pty (int fd_tty, char *ttydev)
161			{
162			int pfd;
163
164			if ((pfd = open ("/dev/ptym/clone", O_RDWR \| O_NOCTTY, 0)) >= 0)
165			{
166			*ttydev = strdup (ptsname (pfd));
167			return pfd;
168			}
169
170			return -1;
171			}
172	root	1.1
173	root	1.2	#else
174	root	1.1
175	root	1.25	/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
176			static int
177			get_pty (int fd_tty, char *ttydev)
178			{
179			int pfd;
180			int i;
181			char pty_name[32];
182			char tty_name[32];
183			const char *majors = "pqrstuvwxyzabcde";
184			const char *minors = "0123456789abcdef";
185
186			for (i = 0; i < 256; i++)
187			{
188			snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
189			snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
190
191			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
192			{
193			snprintf(pty_name, 32, "/dev/ptyp%d", i);
194			snprintf(tty_name, 32, "/dev/ttyp%d", i);
195			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
196			continue;
197			}
198
199			if (access (tty_name, R_OK \| W_OK) == 0)
200			{
201			*ttydev = strdup (tty_name);
202			return pfd;
203			}
204
205			close (pfd);
206			}
207
208			return -1;
209			}
210	ayin	1.24
211	root	1.1	#endif
212
213			/----------------------------------------------------------------------/
214			/*
215	ayin	1.26	* Returns tty file descriptor, or -1 on failure
216	root	1.1	*/
217			static int
218			get_tty (char *ttydev)
219			{
220			return open (ttydev, O_RDWR \| O_NOCTTY, 0);
221			}
222
223			/----------------------------------------------------------------------/
224			/*
225			* Make our tty a controlling tty so that /dev/tty points to us
226			*/
227			static int
228	root	1.2	control_tty (int fd_tty)
229	root	1.1	{
230	ayin	1.28	int fd;
231
232	root	1.1	setsid ();
233
234	root	1.2	#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
235	root	1.1	/*
236			* Push STREAMS modules:
237			* ptem: pseudo-terminal hardware emulation module.
238			* ldterm: standard terminal line discipline.
239			* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
240			*
241			* After we push the STREAMS modules, the first open () on the slave side
242			* (i.e. the next section between the dashes giving us "tty opened OK")
243			* should make the "ptem" (or "ldterm" depending upon either which OS
244			* version or which set of manual pages you have) module give us a
245			* controlling terminal. We must already have close ()d the master side
246			* fd in this child process before we push STREAMS modules on because the
247			* documentation is really unclear about whether it is any close () on
248			* the master side or the last close () - i.e. a proper STREAMS dismantling
249			* close () - on the master side which causes a hang up to be sent
250			* through - Geoff Wing
251			*/
252			# ifdef HAVE_ISASTREAM
253			if (isastream (fd_tty) == 1)
254			# endif
255			{
256			ioctl (fd_tty, I_PUSH, "ptem");
257			ioctl (fd_tty, I_PUSH, "ldterm");
258			ioctl (fd_tty, I_PUSH, "ttcompat");
259			}
260			#endif
261	root	1.2
262	ayin	1.27	#ifdef TIOCSCTTY
263	root	1.2	ioctl (fd_tty, TIOCSCTTY, NULL);
264	ayin	1.27	#else
265	ayin	1.28	fd = open (ttyname (fd_tty), O_RDWR);
266	ayin	1.27	if (fd >= 0)
267			close (fd);
268			#endif
269	root	1.2
270	ayin	1.28	fd = open ("/dev/tty", O_WRONLY);
271	root	1.1	if (fd < 0)
272	root	1.10	return -1; /* fatal */
273	root	1.2
274	root	1.1	close (fd);
275
276			return 0;
277			}
278
279	root	1.2	void
280	root	1.4	ptytty::close_tty ()
281	root	1.2	{
282			if (tty < 0)
283			return;
284
285			close (tty);
286			tty = -1;
287			}
288
289			bool
290	root	1.4	ptytty::make_controlling_tty ()
291	root	1.2	{
292			return control_tty (tty) >= 0;
293			}
294
295			void
296	root	1.4	ptytty::set_utf8_mode (bool on)
297	root	1.2	{
298			#ifdef IUTF8
299			if (pty < 0)
300			return;
301
302			struct termios tio;
303
304			if (tcgetattr (pty, &tio) != -1)
305			{
306			tcflag_t new_cflag = tio.c_iflag;
307
308			if (on)
309			new_cflag \|= IUTF8;
310			else
311			new_cflag &= ~IUTF8;
312
313			if (new_cflag != tio.c_iflag)
314			{
315			tio.c_iflag = new_cflag;
316			tcsetattr (pty, TCSANOW, &tio);
317			}
318			}
319			#endif
320			}
321
322	root	1.1	static struct ttyconf {
323			gid_t gid;
324			mode_t mode;
325
326			ttyconf ()
327			{
328			#ifdef TTY_GID_SUPPORT
329			struct group *gr = getgrnam ("tty");
330
331			if (gr)
332	ayin	1.32	{
333			/* change group ownership of tty to "tty" */
334	root	1.1	mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
335			gid = gr->gr_gid;
336			}
337			else
338	ayin	1.31	#endif /* TTY_GID_SUPPORT */
339	root	1.1	{
340			mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
341	root	1.2	gid = 0;
342	root	1.1	}
343			}
344			} ttyconf;
345
346	root	1.4	ptytty_unix::ptytty_unix ()
347	root	1.1	{
348			name = 0;
349	root	1.2	#if UTMP_SUPPORT
350			cmd_pid = 0;
351	root	1.1	#endif
352			}
353
354	root	1.4	ptytty_unix::~ptytty_unix ()
355	root	1.1	{
356	root	1.2	#if UTMP_SUPPORT
357			logout ();
358			#endif
359	root	1.1	put ();
360			}
361
362			void
363	root	1.4	ptytty_unix::put ()
364	root	1.2	{
365	root	1.25	if (name)
366			{
367			chmod (name, RESTORE_TTY_MODE);
368			chown (name, 0, ttyconf.gid);
369			}
370	root	1.1
371	root	1.2	close_tty ();
372	root	1.1
373	root	1.2	if (pty >= 0)
374			close (pty);
375	root	1.1
376			free (name);
377
378			pty = tty = -1;
379			name = 0;
380			}
381
382			bool
383	root	1.4	ptytty_unix::get ()
384	root	1.1	{
385			/* get master (pty) */
386			if ((pty = get_pty (&tty, &name)) < 0)
387			return false;
388
389			fcntl (pty, F_SETFL, O_NONBLOCK);
390
391			/* get slave (tty) */
392			if (tty < 0)
393			{
394			#ifndef NO_SETOWNER_TTYDEV
395	root	1.2	chown (name, getuid (), ttyconf.gid); /* fail silently */
396			chmod (name, ttyconf.mode);
397			# ifdef HAVE_REVOKE
398			revoke (name);
399			# endif
400	root	1.1	#endif
401
402			if ((tty = get_tty (name)) < 0)
403			{
404			put ();
405			return false;
406			}
407			}
408
409			return true;
410			}
411