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.
#	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 <schmorp@schmorp.de>
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 <cstdio>
34	#include <cstring>
35
36	#include <sys/types.h>
37	#include <sys/stat.h>
38	#include <unistd.h>
39	#include <fcntl.h>
40
41	#ifdef HAVE_SYS_IOCTL_H
42	# include <sys/ioctl.h>
43	#endif
44	#if defined(HAVE_SYS_STROPTS_H)
45	# include <sys/stropts.h> /* for I_PUSH */
46	#endif
47	#if defined(HAVE_ISASTREAM) && defined(HAVE_STROPTS_H)
48	# include <stropts.h>
49	#endif
50	#if defined(HAVE_PTY_H)
51	# include <pty.h>
52	#elif defined(HAVE_LIBUTIL_H)
53	# include <libutil.h>
54	#elif defined(HAVE_UTIL_H)
55	# include <util.h>
56	#endif
57	#ifdef TTY_GID_SUPPORT
58	#include <grp.h>
59	#endif
60
61	/////////////////////////////////////////////////////////////////////////////
62
63	/* ------------------------------------------------------------------------- *
64	* GET PSEUDO TELETYPE - MASTER AND SLAVE *
65	* ------------------------------------------------------------------------- */
66	/*
67	* Returns pty file descriptor, or -1 on failure
68	* 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	#if defined(UNIX98_PTY)
72
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 \| O_NOCTTY);
82	# else
83	# 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	# endif
89
90	if (pfd >= 0)
91	{
92	if (grantpt (pfd) == 0 /* change slave permissions */
93	&& unlockpt (pfd) == 0)
94	{
95	/* slave now unlocked */
96	ttydev = strdup (ptsname (pfd)); / get slave's name */
97	return pfd;
98	}
99
100	close (pfd);
101	}
102
103	return -1;
104	}
105
106	#elif defined(HAVE_OPENPTY)
107
108	static int
109	get_pty (int fd_tty, char *ttydev)
110	{
111	int pfd;
112	int res;
113
114	res = openpty (&pfd, fd_tty, NULL, NULL, NULL);
115
116	if (res != -1)
117	{
118	ttydev = strdup (ttyname (fd_tty));
119	return pfd;
120	}
121
122	return -1;
123	}
124
125	#elif defined(HAVE__GETPTY)
126
127	static int
128	get_pty (int fd_tty, char *ttydev)
129	{
130	int pfd;
131	char *slave;
132
133	slave = _getpty (&pfd, O_RDWR \| O_NOCTTY, 0622, 0);
134
135	if (slave != NULL)
136	{
137	*ttydev = strdup (slave);
138	return pfd;
139	}
140
141	return -1;
142	}
143
144	#else
145
146	/* 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	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
162	if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
163	{
164	snprintf (pty_name, 32, "/dev/ptyp%d", i);
165	snprintf (tty_name, 32, "/dev/ttyp%d", i);
166	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
182	#endif
183
184	/----------------------------------------------------------------------/
185	/*
186	* Returns tty file descriptor, or -1 on failure
187	*/
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	control_tty (int fd_tty)
200	{
201	int fd;
202
203	setsid ();
204
205	#ifdef TIOCSCTTY
206	ioctl (fd_tty, TIOCSCTTY, NULL);
207	#else
208	fd = open (ttyname (fd_tty), O_RDWR);
209	if (fd >= 0)
210	close (fd);
211	#endif
212
213	fd = open ("/dev/tty", O_WRONLY);
214	if (fd < 0)
215	return -1; /* fatal */
216
217	close (fd);
218
219	return 0;
220	}
221
222	void
223	ptytty::close_tty ()
224	{
225	if (tty < 0)
226	return;
227
228	close (tty);
229	tty = -1;
230	}
231
232	bool
233	ptytty::make_controlling_tty ()
234	{
235	return control_tty (tty) >= 0;
236	}
237
238	void
239	ptytty::set_utf8_mode (bool on)
240	{
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	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	{
276	/* change group ownership of tty to "tty" */
277	mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
278	gid = gr->gr_gid;
279	}
280	else
281	#endif /* TTY_GID_SUPPORT */
282	{
283	mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
284	gid = 0;
285	}
286	}
287	} ttyconf;
288
289	ptytty_unix::ptytty_unix ()
290	{
291	name = 0;
292	#if UTMP_SUPPORT
293	cmd_pid = 0;
294	#endif
295	}
296
297	ptytty_unix::~ptytty_unix ()
298	{
299	#if UTMP_SUPPORT
300	logout ();
301	#endif
302	put ();
303	}
304
305	void
306	ptytty_unix::put ()
307	{
308	if (name)
309	{
310	chmod (name, RESTORE_TTY_MODE);
311	chown (name, 0, ttyconf.gid);
312	}
313
314	close_tty ();
315
316	if (pty >= 0)
317	close (pty);
318
319	free (name);
320
321	pty = tty = -1;
322	name = 0;
323	}
324
325	bool
326	ptytty_unix::get ()
327	{
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	chown (name, getuid (), ttyconf.gid); /* fail silently */
337	chmod (name, ttyconf.mode);
338	# ifdef HAVE_REVOKE
339	revoke (name);
340	# endif
341	#endif
342
343	if ((tty = get_tty (name)) < 0)
344	{
345	put ();
346	return false;
347	}
348	}
349
350	#if defined(I_PUSH)
351	/*
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	#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	return true;
390	}
391