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;
  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 ()
{
  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:	1.24
Committed:	Sun Sep 10 17:59:21 2006 UTC (17 years, 10 months ago) by ayin
Content type:	text/plain
Branch:	MAIN
Changes since 1.23:	+2 -0 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			#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			* 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	root	1.2	#if defined(UNIX98_PTY)
73	root	1.1	static int
74			get_pty (int fd_tty, char *ttydev)
75			{
76			int pfd;
77
78	root	1.2	# if defined(HAVE_GETPT)
79			pfd = getpt();
80			# elif defined(HAVE_POSIX_OPENPT)
81			pfd = posix_openpt (O_RDWR);
82			# else
83			pfd = open (CLONE_DEVICE, O_RDWR \| O_NOCTTY, 0);
84			# endif
85			if (pfd >= 0)
86			{
87			if (grantpt (pfd) == 0 /* change slave permissions */
88			&& unlockpt (pfd) == 0)
89			{ /* slave now unlocked */
90			ttydev = strdup (ptsname (pfd)); / get slave's name */
91			return pfd;
92			}
93	root	1.1
94	root	1.2	close (pfd);
95			}
96
97			return -1;
98			}
99			#elif defined(HAVE_OPENPTY)
100			static int
101			get_pty (int fd_tty, char *ttydev)
102			{
103			int pfd;
104			int res;
105			char tty_name[32];
106
107			res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
108			if (res != -1)
109	root	1.1	{
110			*ttydev = strdup (tty_name);
111			return pfd;
112			}
113
114	root	1.2	return -1;
115			}
116			#elif defined(HAVE__GETPTY)
117			static int
118			get_pty (int fd_tty, char *ttydev)
119			{
120			int pfd;
121
122	root	1.1	*ttydev = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
123			if (*ttydev != NULL)
124			return pfd;
125
126	root	1.2	return -1;
127			}
128			#elif defined(HAVE_DEV_PTC)
129			static int
130			get_pty (int fd_tty, char *ttydev)
131			{
132			int pfd;
133	root	1.1
134			if ((pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0)) >= 0)
135			{
136			*ttydev = strdup (ttyname (pfd));
137			return pfd;
138			}
139
140	root	1.2	return -1;
141			}
142			#elif defined(HAVE_DEV_CLONE)
143			static int
144			get_pty (int fd_tty, char *ttydev)
145			{
146			int pfd;
147
148	root	1.1	if ((pfd = open ("/dev/ptym/clone", O_RDWR \| O_NOCTTY, 0)) >= 0)
149			{
150			*ttydev = strdup (ptsname (pfd));
151			return pfd;
152			}
153
154	root	1.2	return -1;
155			}
156			#else
157			/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
158			static int
159			get_pty (int fd_tty, char *ttydev)
160			{
161			int pfd;
162			int i;
163			char pty_name[32];
164			char tty_name[32];
165			const char *majors = "pqrstuvwxyzabcde";
166			const char *minors = "0123456789abcdef";
167			for (i = 0; i < 256; i++)
168			{
169			snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
170			snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
171			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
172			{
173			snprintf(pty_name, 32, "/dev/ptyp%d", i);
174			snprintf(tty_name, 32, "/dev/ttyp%d", i);
175			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
176			continue;
177			}
178			if (access (tty_name, R_OK \| W_OK) == 0)
179			{
180			*ttydev = strdup (tty_name);
181			return pfd;
182			}
183	root	1.1
184	root	1.2	close (pfd);
185			}
186	ayin	1.24
187			return -1;
188	root	1.2	}
189	root	1.1	#endif
190
191			/----------------------------------------------------------------------/
192			/*
193			* Returns tty file descriptor, or -1 on failure
194			*/
195			static int
196			get_tty (char *ttydev)
197			{
198			return open (ttydev, O_RDWR \| O_NOCTTY, 0);
199			}
200
201			/----------------------------------------------------------------------/
202			/*
203			* Make our tty a controlling tty so that /dev/tty points to us
204			*/
205			static int
206	root	1.2	control_tty (int fd_tty)
207	root	1.1	{
208			setsid ();
209
210	root	1.2	#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
211	root	1.1	/*
212			* Push STREAMS modules:
213			* ptem: pseudo-terminal hardware emulation module.
214			* ldterm: standard terminal line discipline.
215			* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
216			*
217			* After we push the STREAMS modules, the first open () on the slave side
218			* (i.e. the next section between the dashes giving us "tty opened OK")
219			* should make the "ptem" (or "ldterm" depending upon either which OS
220			* version or which set of manual pages you have) module give us a
221			* controlling terminal. We must already have close ()d the master side
222			* fd in this child process before we push STREAMS modules on because the
223			* documentation is really unclear about whether it is any close () on
224			* the master side or the last close () - i.e. a proper STREAMS dismantling
225			* close () - on the master side which causes a hang up to be sent
226			* through - Geoff Wing
227			*/
228			# ifdef HAVE_ISASTREAM
229			if (isastream (fd_tty) == 1)
230			# endif
231			{
232			ioctl (fd_tty, I_PUSH, "ptem");
233			ioctl (fd_tty, I_PUSH, "ldterm");
234			ioctl (fd_tty, I_PUSH, "ttcompat");
235			}
236			#endif
237	root	1.2
238			ioctl (fd_tty, TIOCSCTTY, NULL);
239
240			int fd = open ("/dev/tty", O_WRONLY);
241	root	1.1	if (fd < 0)
242	root	1.10	return -1; /* fatal */
243	root	1.2
244	root	1.1	close (fd);
245
246			return 0;
247			}
248
249	root	1.2	void
250	root	1.4	ptytty::close_tty ()
251	root	1.2	{
252			if (tty < 0)
253			return;
254
255			close (tty);
256			tty = -1;
257			}
258
259			bool
260	root	1.4	ptytty::make_controlling_tty ()
261	root	1.2	{
262			return control_tty (tty) >= 0;
263			}
264
265			void
266	root	1.4	ptytty::set_utf8_mode (bool on)
267	root	1.2	{
268			#ifdef IUTF8
269			if (pty < 0)
270			return;
271
272			struct termios tio;
273
274			if (tcgetattr (pty, &tio) != -1)
275			{
276			tcflag_t new_cflag = tio.c_iflag;
277
278			if (on)
279			new_cflag \|= IUTF8;
280			else
281			new_cflag &= ~IUTF8;
282
283			if (new_cflag != tio.c_iflag)
284			{
285			tio.c_iflag = new_cflag;
286			tcsetattr (pty, TCSANOW, &tio);
287			}
288			}
289			#endif
290			}
291
292	root	1.1	static struct ttyconf {
293			gid_t gid;
294			mode_t mode;
295
296			ttyconf ()
297			{
298			#ifdef TTY_GID_SUPPORT
299			struct group *gr = getgrnam ("tty");
300
301			if (gr)
302			{ /* change group ownership of tty to "tty" */
303			mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
304			gid = gr->gr_gid;
305			}
306			else
307			#endif /* TTY_GID_SUPPORT */
308			{
309			mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
310	root	1.2	gid = 0;
311	root	1.1	}
312			}
313			} ttyconf;
314
315	root	1.4	ptytty_unix::ptytty_unix ()
316	root	1.1	{
317			name = 0;
318	root	1.2	#if UTMP_SUPPORT
319			cmd_pid = 0;
320	root	1.1	#endif
321			}
322
323	root	1.4	ptytty_unix::~ptytty_unix ()
324	root	1.1	{
325	root	1.2	#if UTMP_SUPPORT
326			logout ();
327			#endif
328	root	1.1	put ();
329			}
330
331			void
332	root	1.4	ptytty_unix::put ()
333	root	1.2	{
334			chmod (name, RESTORE_TTY_MODE);
335			chown (name, 0, ttyconf.gid);
336	root	1.1
337	root	1.2	close_tty ();
338	root	1.1
339	root	1.2	if (pty >= 0)
340			close (pty);
341	root	1.1
342			free (name);
343
344			pty = tty = -1;
345			name = 0;
346			}
347
348			bool
349	root	1.4	ptytty_unix::get ()
350	root	1.1	{
351			/* get master (pty) */
352			if ((pty = get_pty (&tty, &name)) < 0)
353			return false;
354
355			fcntl (pty, F_SETFL, O_NONBLOCK);
356
357			/* get slave (tty) */
358			if (tty < 0)
359			{
360			#ifndef NO_SETOWNER_TTYDEV
361	root	1.2	chown (name, getuid (), ttyconf.gid); /* fail silently */
362			chmod (name, ttyconf.mode);
363			# ifdef HAVE_REVOKE
364			revoke (name);
365			# endif
366	root	1.1	#endif
367
368			if ((tty = get_tty (name)) < 0)
369			{
370			put ();
371			return false;
372			}
373			}
374
375			return true;
376			}
377