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, 8 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
#	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 <pcg@goof.com>
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 <unistd.h>
38	#include <fcntl.h>
39
40	#ifdef HAVE_SYS_IOCTL_H
41	# include <sys/ioctl.h>
42	#endif
43	#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
44	# include <sys/stropts.h> /* for I_PUSH */
45	#endif
46	#ifdef HAVE_ISASTREAM
47	# include <stropts.h>
48	#endif
49	#if defined(HAVE_PTY_H)
50	# include <pty.h>
51	#elif defined(HAVE_LIBUTIL_H)
52	# include <libutil.h>
53	#elif defined(HAVE_UTIL_H)
54	# include <util.h>
55	#endif
56	#ifdef TTY_GID_SUPPORT
57	#include <grp.h>
58	#endif
59
60	#include <cstdio>
61
62	/////////////////////////////////////////////////////////////////////////////
63
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	#if defined(UNIX98_PTY)
73
74	static int
75	get_pty (int fd_tty, char *ttydev)
76	{
77	int pfd;
78
79	# if defined(HAVE_GETPT)
80	pfd = getpt();
81	# elif defined(HAVE_POSIX_OPENPT)
82	pfd = posix_openpt (O_RDWR);
83	# else
84	pfd = open (CLONE_DEVICE, O_RDWR \| O_NOCTTY, 0);
85	# endif
86
87	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
102	#elif defined(HAVE_OPENPTY)
103
104	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	#elif defined(HAVE__GETPTY)
123
124	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
137	#elif defined(HAVE_DEV_PTC)
138
139	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
153	#elif defined(HAVE_DEV_CLONE)
154
155	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
169	#else
170
171	/* 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
207	#endif
208
209	/----------------------------------------------------------------------/
210	/*
211	* Returns tty file descriptor, or -1 on failure
212	*/
213	static int
214	get_tty (char *ttydev)
215	{
216	return open (ttydev, O_RDWR \| O_NOCTTY, 0);
217	}
218
219	/----------------------------------------------------------------------/
220	/*
221	* Make our tty a controlling tty so that /dev/tty points to us
222	*/
223	static int
224	control_tty (int fd_tty)
225	{
226	setsid ();
227
228	#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
229	/*
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	* After we push the STREAMS modules, the first open () on the slave side
236	* (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	* controlling terminal. We must already have close ()d the master side
240	* fd in this child process before we push STREAMS modules on because the
241	* 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	* through - Geoff Wing
245	*/
246	# ifdef HAVE_ISASTREAM
247	if (isastream (fd_tty) == 1)
248	# endif
249	{
250	ioctl (fd_tty, I_PUSH, "ptem");
251	ioctl (fd_tty, I_PUSH, "ldterm");
252	ioctl (fd_tty, I_PUSH, "ttcompat");
253	}
254	#endif
255
256	ioctl (fd_tty, TIOCSCTTY, NULL);
257
258	int fd = open ("/dev/tty", O_WRONLY);
259	if (fd < 0)
260	return -1; /* fatal */
261
262	close (fd);
263
264	return 0;
265	}
266
267	void
268	ptytty::close_tty ()
269	{
270	if (tty < 0)
271	return;
272
273	close (tty);
274	tty = -1;
275	}
276
277	bool
278	ptytty::make_controlling_tty ()
279	{
280	return control_tty (tty) >= 0;
281	}
282
283	void
284	ptytty::set_utf8_mode (bool on)
285	{
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	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	gid = 0;
329	}
330	}
331	} ttyconf;
332
333	ptytty_unix::ptytty_unix ()
334	{
335	name = 0;
336	#if UTMP_SUPPORT
337	cmd_pid = 0;
338	#endif
339	}
340
341	ptytty_unix::~ptytty_unix ()
342	{
343	#if UTMP_SUPPORT
344	logout ();
345	#endif
346	put ();
347	}
348
349	void
350	ptytty_unix::put ()
351	{
352	if (name)
353	{
354	chmod (name, RESTORE_TTY_MODE);
355	chown (name, 0, ttyconf.gid);
356	}
357
358	close_tty ();
359
360	if (pty >= 0)
361	close (pty);
362
363	free (name);
364
365	pty = tty = -1;
366	name = 0;
367	}
368
369	bool
370	ptytty_unix::get ()
371	{
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	chown (name, getuid (), ttyconf.gid); /* fail silently */
383	chmod (name, ttyconf.mode);
384	# ifdef HAVE_REVOKE
385	revoke (name);
386	# endif
387	#endif
388
389	if ((tty = get_tty (name)) < 0)
390	{
391	put ();
392	return false;
393	}
394	}
395
396	return true;
397	}
398