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 ()
{
  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:	1.62
Committed:	Mon Sep 11 08:48:37 2006 UTC (17 years, 8 months ago) by ayin
Content type:	text/plain
Branch:	MAIN
Changes since 1.61:	+2 -0 lines
Log Message:	* empty log message *
#	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	static int
74	get_pty (int fd_tty, char *ttydev)
75	{
76	int pfd;
77
78	# 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
94	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	{
110	*ttydev = strdup (tty_name);
111	return pfd;
112	}
113
114	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	*ttydev = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
123	if (*ttydev != NULL)
124	return pfd;
125
126	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
134	if ((pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0)) >= 0)
135	{
136	*ttydev = strdup (ttyname (pfd));
137	return pfd;
138	}
139
140	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	if ((pfd = open ("/dev/ptym/clone", O_RDWR \| O_NOCTTY, 0)) >= 0)
149	{
150	*ttydev = strdup (ptsname (pfd));
151	return pfd;
152	}
153
154	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
184	close (pfd);
185	}
186
187	return -1;
188	}
189	#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	control_tty (int fd_tty)
207	{
208	setsid ();
209
210	#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
211	/*
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
238	ioctl (fd_tty, TIOCSCTTY, NULL);
239
240	int fd = open ("/dev/tty", O_WRONLY);
241	if (fd < 0)
242	return -1; /* fatal */
243
244	close (fd);
245
246	return 0;
247	}
248
249	void
250	ptytty::close_tty ()
251	{
252	if (tty < 0)
253	return;
254
255	close (tty);
256	tty = -1;
257	}
258
259	bool
260	ptytty::make_controlling_tty ()
261	{
262	return control_tty (tty) >= 0;
263	}
264
265	void
266	ptytty::set_utf8_mode (bool on)
267	{
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	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	gid = 0;
311	}
312	}
313	} ttyconf;
314
315	ptytty_unix::ptytty_unix ()
316	{
317	name = 0;
318	#if UTMP_SUPPORT
319	cmd_pid = 0;
320	#endif
321	}
322
323	ptytty_unix::~ptytty_unix ()
324	{
325	#if UTMP_SUPPORT
326	logout ();
327	#endif
328	put ();
329	}
330
331	void
332	ptytty_unix::put ()
333	{
334	chmod (name, RESTORE_TTY_MODE);
335	chown (name, 0, ttyconf.gid);
336
337	close_tty ();
338
339	if (pty >= 0)
340	close (pty);
341
342	free (name);
343
344	pty = tty = -1;
345	name = 0;
346	}
347
348	bool
349	ptytty_unix::get ()
350	{
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	chown (name, getuid (), ttyconf.gid); /* fail silently */
362	chmod (name, ttyconf.mode);
363	# ifdef HAVE_REVOKE
364	revoke (name);
365	# endif
366	#endif
367
368	if ((tty = get_tty (name)) < 0)
369	{
370	put ();
371	return false;
372	}
373	}
374
375	return true;
376	}
377