libptytty/src/ptytty.C

/*--------------------------------*-C-*---------------------------------*
 * 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>
 *
 * 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"          /* NECESSARY */

#include "fdpass.h"
#include "ptytty.h"

#include <cstdlib>
#include <cstring>

#include <sys/types.h>
#include <sys/socket.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);
    }
}
#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;
}

#if PTYTTY_HELPER

static int sock_fd;
static int pid;

struct command
{
  enum { get, login, destroy } type;

  ptytty *id;

  bool login_shell;
  int cmd_pid;
  char hostname[512]; // arbitrary, but should be plenty
};

struct ptytty_proxy : ptytty
{
  ptytty *id;

  ~ptytty_proxy ()
  : id(0)
  {
  }

  ~ptytty_proxy ();

  bool get ();
  void login (int cmd_pid, bool login_shell, const char *hostname);
};

bool
ptytty_proxy::get ()
{
  command cmd;

  cmd.type = command::get;

  write (sock_fd, &cmd, sizeof (cmd));

  if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
    fatal ("protocol error while creating pty using helper process, aborting.\n");

  if (!id)
    return false;

  if ((pty = ptytty_recv_fd (sock_fd)) < 0
      || (tty = ptytty_recv_fd (sock_fd)) < 0)
    fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");

  return true;
}

void
ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname)
{
  command cmd;

  cmd.type = command::login;
  cmd.id = id;
  cmd.cmd_pid = cmd_pid;
  cmd.login_shell = login_shell;
  strncpy (cmd.hostname, hostname, sizeof (cmd.hostname));

  write (sock_fd, &cmd, sizeof (cmd));
}

ptytty_proxy::~ptytty_proxy ()
{
  if (id)
    {
      command cmd;

      cmd.type = command::destroy;
      cmd.id = id;

      write (sock_fd, &cmd, sizeof (cmd));
    }
}

static
void serve ()
{
  command cmd;
  vector<ptytty *> ptys;

  while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command))
    {
      if (cmd.type == command::get)
        {
          // -> id ptyfd ttyfd
          cmd.id = new ptytty_unix;

          if (cmd.id->get ())
            {
              write (sock_fd, &cmd.id, sizeof (cmd.id));
              ptys.push_back (cmd.id);

              ptytty_send_fd (sock_fd, cmd.id->pty);
              ptytty_send_fd (sock_fd, cmd.id->tty);
            }
          else
            {
              delete cmd.id;
              cmd.id = 0;
              write (sock_fd, &cmd.id, sizeof (cmd.id));
            }
        }
      else if (cmd.type == command::login)
        {
#if UTMP_SUPPORT
          if (find (ptys.begin (), ptys.end (), cmd.id))
            {
              cmd.hostname[sizeof (cmd.hostname) - 1] = 0;
              cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname);
            }
#endif
        }
      else if (cmd.type == command::destroy)
        {
          ptytty **pty = find (ptys.begin (), ptys.end (), cmd.id);

          if (pty)
            {
              delete *pty;
              ptys.erase (pty);
            }
        }
      else
        break;
    }

  // destroy all ptys
  for (ptytty **i = ptys.end (); i-- > ptys.begin (); )
    delete *i;
}

void ptytty_server ()
{
  int sv[2];

  if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
    fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");

  pid = fork ();

  if (pid < 0)
    fatal ("could not create pty/sessiondb helper process, aborting.\n");

  if (pid)
    {
      // client, process
      sock_fd = sv[0];
      close (sv[1]);
      fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
    }
  else
    {
      // server, pty-helper
      sock_fd = sv[1];

      for (int fd = 0; fd < 1023; fd++)
        if (fd != sock_fd)
          close (fd);

      serve ();
      _exit (EXIT_SUCCESS);
    }
}

#endif

// a "factory" *g*
ptytty *
new_ptytty ()
{
#if PTYTTY_HELPER
  if (pid > 0)
    // use helper process
    return new ptytty_proxy;
  else
#endif
    return new ptytty_unix;
}

/*----------------------- end-of-file (C source) -----------------------*/

Revision:	1.6
Committed:	Sun Jan 22 00:04:20 2006 UTC (18 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.5:	+13 -5 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/---------------------------------C----------------------------------
2			* File: ptytty.C
3			----------------------------------------------------------------------
4			*
5			* All portions of code are copyright by their respective author/s.
6			* Copyright (c) 1999-2001 Geoff Wing <gcw@pobox.com>
7	root	1.2	* Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com>
8	root	1.1	*
9			* This program is free software; you can redistribute it and/or modify
10			* it under the terms of the GNU General Public License as published by
11			* the Free Software Foundation; either version 2 of the License, or
12			* (at your option) any later version.
13			*
14			* This program is distributed in the hope that it will be useful,
15			* but WITHOUT ANY WARRANTY; without even the implied warranty of
16			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17			* GNU General Public License for more details.
18			*
19			* You should have received a copy of the GNU General Public License
20			* along with this program; if not, write to the Free Software
21			* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22			---------------------------------------------------------------------/
23
24			#include "../config.h" /* NECESSARY */
25
26	root	1.3	#include "fdpass.h"
27			#include "ptytty.h"
28
29	root	1.2	#include <cstdlib>
30			#include <cstring>
31
32			#include <sys/types.h>
33			#include <sys/socket.h>
34			#include <unistd.h>
35			#include <fcntl.h>
36
37	root	1.1	#ifdef HAVE_SYS_IOCTL_H
38			# include <sys/ioctl.h>
39			#endif
40	root	1.2	#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
41	root	1.1	# include <sys/stropts.h> /* for I_PUSH */
42			#endif
43			#ifdef HAVE_ISASTREAM
44			# include <stropts.h>
45			#endif
46	root	1.2	#if defined(HAVE_PTY_H)
47	root	1.1	# include <pty.h>
48	root	1.2	#elif defined(HAVE_LIBUTIL_H)
49	root	1.1	# include <libutil.h>
50	root	1.2	#elif defined(HAVE_UTIL_H)
51	root	1.1	# include <util.h>
52			#endif
53	root	1.2	#ifdef TTY_GID_SUPPORT
54			#include <grp.h>
55			#endif
56	root	1.1
57			#include <cstdio>
58	root	1.2
59			/////////////////////////////////////////////////////////////////////////////
60	root	1.1
61			/* ------------------------------------------------------------------------- *
62			* GET PSEUDO TELETYPE - MASTER AND SLAVE *
63			* ------------------------------------------------------------------------- */
64			/*
65			* Returns pty file descriptor, or -1 on failure
66			* If successful, ttydev is set to the name of the slave device.
67			* fd_tty _may_ also be set to an open fd to the slave device
68			*/
69	root	1.2	#if defined(UNIX98_PTY)
70	root	1.1	static int
71			get_pty (int fd_tty, char *ttydev)
72			{
73			int pfd;
74
75	root	1.2	# if defined(HAVE_GETPT)
76			pfd = getpt();
77			# elif defined(HAVE_POSIX_OPENPT)
78			pfd = posix_openpt (O_RDWR);
79			# else
80			pfd = open (CLONE_DEVICE, O_RDWR \| O_NOCTTY, 0);
81			# endif
82			if (pfd >= 0)
83			{
84			if (grantpt (pfd) == 0 /* change slave permissions */
85			&& unlockpt (pfd) == 0)
86			{ /* slave now unlocked */
87			ttydev = strdup (ptsname (pfd)); / get slave's name */
88			return pfd;
89			}
90	root	1.1
91	root	1.2	close (pfd);
92			}
93
94			return -1;
95			}
96			#elif defined(HAVE_OPENPTY)
97			static int
98			get_pty (int fd_tty, char *ttydev)
99			{
100			int pfd;
101			int res;
102			char tty_name[32];
103
104			res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
105			if (res != -1)
106	root	1.1	{
107			*ttydev = strdup (tty_name);
108			return pfd;
109			}
110
111	root	1.2	return -1;
112			}
113			#elif defined(HAVE__GETPTY)
114			static int
115			get_pty (int fd_tty, char *ttydev)
116			{
117			int pfd;
118
119	root	1.1	*ttydev = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
120			if (*ttydev != NULL)
121			return pfd;
122
123	root	1.2	return -1;
124			}
125			#elif defined(HAVE_DEV_PTC)
126			static int
127			get_pty (int fd_tty, char *ttydev)
128			{
129			int pfd;
130	root	1.1
131			if ((pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0)) >= 0)
132			{
133			*ttydev = strdup (ttyname (pfd));
134			return pfd;
135			}
136
137	root	1.2	return -1;
138			}
139			#elif defined(HAVE_DEV_CLONE)
140			static int
141			get_pty (int fd_tty, char *ttydev)
142			{
143			int pfd;
144
145	root	1.1	if ((pfd = open ("/dev/ptym/clone", O_RDWR \| O_NOCTTY, 0)) >= 0)
146			{
147			*ttydev = strdup (ptsname (pfd));
148			return pfd;
149			}
150
151	root	1.2	return -1;
152			}
153			#else
154			/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
155			static int
156			get_pty (int fd_tty, char *ttydev)
157			{
158			int pfd;
159			int i;
160			char pty_name[32];
161			char tty_name[32];
162			const char *majors = "pqrstuvwxyzabcde";
163			const char *minors = "0123456789abcdef";
164			for (i = 0; i < 256; i++)
165			{
166			snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
167			snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
168			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
169			{
170			snprintf(pty_name, 32, "/dev/ptyp%d", i);
171			snprintf(tty_name, 32, "/dev/ttyp%d", i);
172			if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) == -1)
173			continue;
174			}
175			if (access (tty_name, R_OK \| W_OK) == 0)
176			{
177			*ttydev = strdup (tty_name);
178			return pfd;
179			}
180	root	1.1
181	root	1.2	close (pfd);
182			}
183			}
184	root	1.1	#endif
185
186			/----------------------------------------------------------------------/
187			/*
188			* Returns tty file descriptor, or -1 on failure
189			*/
190			static int
191			get_tty (char *ttydev)
192			{
193			return open (ttydev, O_RDWR \| O_NOCTTY, 0);
194			}
195
196			/----------------------------------------------------------------------/
197			/*
198			* Make our tty a controlling tty so that /dev/tty points to us
199			*/
200			static int
201	root	1.2	control_tty (int fd_tty)
202	root	1.1	{
203			setsid ();
204
205	root	1.2	#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
206	root	1.1	/*
207			* Push STREAMS modules:
208			* ptem: pseudo-terminal hardware emulation module.
209			* ldterm: standard terminal line discipline.
210			* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
211			*
212			* After we push the STREAMS modules, the first open () on the slave side
213			* (i.e. the next section between the dashes giving us "tty opened OK")
214			* should make the "ptem" (or "ldterm" depending upon either which OS
215			* version or which set of manual pages you have) module give us a
216			* controlling terminal. We must already have close ()d the master side
217			* fd in this child process before we push STREAMS modules on because the
218			* documentation is really unclear about whether it is any close () on
219			* the master side or the last close () - i.e. a proper STREAMS dismantling
220			* close () - on the master side which causes a hang up to be sent
221			* through - Geoff Wing
222			*/
223			# ifdef HAVE_ISASTREAM
224			if (isastream (fd_tty) == 1)
225			# endif
226			{
227			ioctl (fd_tty, I_PUSH, "ptem");
228			ioctl (fd_tty, I_PUSH, "ldterm");
229			ioctl (fd_tty, I_PUSH, "ttcompat");
230			}
231			#endif
232	root	1.2
233			ioctl (fd_tty, TIOCSCTTY, NULL);
234
235			int fd = open ("/dev/tty", O_WRONLY);
236	root	1.1	if (fd < 0)
237			return -1; /* fatal */
238	root	1.2
239	root	1.1	close (fd);
240
241			return 0;
242			}
243
244	root	1.2	void
245	root	1.4	ptytty::close_tty ()
246	root	1.2	{
247			if (tty < 0)
248			return;
249
250			close (tty);
251			tty = -1;
252			}
253
254			bool
255	root	1.4	ptytty::make_controlling_tty ()
256	root	1.2	{
257			return control_tty (tty) >= 0;
258			}
259
260			void
261	root	1.4	ptytty::set_utf8_mode (bool on)
262	root	1.2	{
263			#ifdef IUTF8
264			if (pty < 0)
265			return;
266
267			struct termios tio;
268
269			if (tcgetattr (pty, &tio) != -1)
270			{
271			tcflag_t new_cflag = tio.c_iflag;
272
273			if (on)
274			new_cflag \|= IUTF8;
275			else
276			new_cflag &= ~IUTF8;
277
278			if (new_cflag != tio.c_iflag)
279			{
280			tio.c_iflag = new_cflag;
281			tcsetattr (pty, TCSANOW, &tio);
282			}
283			}
284			#endif
285			}
286
287	root	1.1	static struct ttyconf {
288			gid_t gid;
289			mode_t mode;
290
291			ttyconf ()
292			{
293			#ifdef TTY_GID_SUPPORT
294			struct group *gr = getgrnam ("tty");
295
296			if (gr)
297			{ /* change group ownership of tty to "tty" */
298			mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
299			gid = gr->gr_gid;
300			}
301			else
302			#endif /* TTY_GID_SUPPORT */
303			{
304			mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
305	root	1.2	gid = 0;
306	root	1.1	}
307			}
308			} ttyconf;
309
310	root	1.4	ptytty_unix::ptytty_unix ()
311	root	1.1	{
312			name = 0;
313	root	1.2	#if UTMP_SUPPORT
314			cmd_pid = 0;
315	root	1.1	#endif
316			}
317
318	root	1.4	ptytty_unix::~ptytty_unix ()
319	root	1.1	{
320	root	1.2	#if UTMP_SUPPORT
321			logout ();
322			#endif
323	root	1.1	put ();
324			}
325
326			void
327	root	1.4	ptytty_unix::put ()
328	root	1.2	{
329			chmod (name, RESTORE_TTY_MODE);
330			chown (name, 0, ttyconf.gid);
331	root	1.1
332	root	1.2	close_tty ();
333	root	1.1
334	root	1.2	if (pty >= 0)
335			close (pty);
336	root	1.1
337			free (name);
338
339			pty = tty = -1;
340			name = 0;
341			}
342
343			bool
344	root	1.4	ptytty_unix::get ()
345	root	1.1	{
346			/* get master (pty) */
347			if ((pty = get_pty (&tty, &name)) < 0)
348			return false;
349
350			fcntl (pty, F_SETFL, O_NONBLOCK);
351
352			/* get slave (tty) */
353			if (tty < 0)
354			{
355			#ifndef NO_SETOWNER_TTYDEV
356	root	1.2	chown (name, getuid (), ttyconf.gid); /* fail silently */
357			chmod (name, ttyconf.mode);
358			# ifdef HAVE_REVOKE
359			revoke (name);
360			# endif
361	root	1.1	#endif
362
363			if ((tty = get_tty (name)) < 0)
364			{
365			put ();
366			return false;
367			}
368			}
369
370			return true;
371			}
372
373	root	1.2	#if PTYTTY_HELPER
374
375			static int sock_fd;
376			static int pid;
377
378			struct command
379			{
380			enum { get, login, destroy } type;
381
382	root	1.4	ptytty *id;
383	root	1.2
384			bool login_shell;
385			int cmd_pid;
386			char hostname[512]; // arbitrary, but should be plenty
387			};
388
389	root	1.6	struct ptytty_proxy : ptytty
390	root	1.2	{
391	root	1.4	ptytty *id;
392	root	1.2
393	root	1.6	~ptytty_proxy ()
394			: id(0)
395			{
396			}
397
398	root	1.4	~ptytty_proxy ();
399	root	1.2
400			bool get ();
401			void login (int cmd_pid, bool login_shell, const char *hostname);
402			};
403
404			bool
405	root	1.4	ptytty_proxy::get ()
406	root	1.2	{
407			command cmd;
408
409			cmd.type = command::get;
410
411			write (sock_fd, &cmd, sizeof (cmd));
412
413			if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
414	root	1.4	fatal ("protocol error while creating pty using helper process, aborting.\n");
415	root	1.2
416			if (!id)
417			return false;
418
419	root	1.4	if ((pty = ptytty_recv_fd (sock_fd)) < 0
420			\|\| (tty = ptytty_recv_fd (sock_fd)) < 0)
421			fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");
422	root	1.2
423			return true;
424			}
425
426	root	1.1	void
427	root	1.4	ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname)
428	root	1.2	{
429			command cmd;
430
431			cmd.type = command::login;
432			cmd.id = id;
433			cmd.cmd_pid = cmd_pid;
434			cmd.login_shell = login_shell;
435			strncpy (cmd.hostname, hostname, sizeof (cmd.hostname));
436
437			write (sock_fd, &cmd, sizeof (cmd));
438			}
439
440	root	1.4	ptytty_proxy::~ptytty_proxy ()
441	root	1.2	{
442	root	1.6	if (id)
443			{
444			command cmd;
445	root	1.2
446	root	1.6	cmd.type = command::destroy;
447			cmd.id = id;
448	root	1.2
449	root	1.6	write (sock_fd, &cmd, sizeof (cmd));
450			}
451	root	1.2	}
452
453			static
454			void serve ()
455	root	1.1	{
456	root	1.2	command cmd;
457	root	1.4	vector<ptytty *> ptys;
458	root	1.2
459			while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command))
460	root	1.1	{
461	root	1.2	if (cmd.type == command::get)
462			{
463			// -> id ptyfd ttyfd
464	root	1.4	cmd.id = new ptytty_unix;
465	root	1.1
466	root	1.2	if (cmd.id->get ())
467			{
468			write (sock_fd, &cmd.id, sizeof (cmd.id));
469			ptys.push_back (cmd.id);
470	root	1.1
471	root	1.4	ptytty_send_fd (sock_fd, cmd.id->pty);
472			ptytty_send_fd (sock_fd, cmd.id->tty);
473	root	1.2	}
474	root	1.1	else
475	root	1.2	{
476			delete cmd.id;
477			cmd.id = 0;
478			write (sock_fd, &cmd.id, sizeof (cmd.id));
479			}
480			}
481			else if (cmd.type == command::login)
482			{
483			#if UTMP_SUPPORT
484			if (find (ptys.begin (), ptys.end (), cmd.id))
485			{
486			cmd.hostname[sizeof (cmd.hostname) - 1] = 0;
487			cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname);
488			}
489			#endif
490			}
491			else if (cmd.type == command::destroy)
492			{
493	root	1.4	ptytty **pty = find (ptys.begin (), ptys.end (), cmd.id);
494	root	1.1
495	root	1.2	if (pty)
496	root	1.1	{
497	root	1.2	delete *pty;
498			ptys.erase (pty);
499	root	1.1	}
500			}
501	root	1.2	else
502			break;
503	root	1.1	}
504	root	1.2
505			// destroy all ptys
506	root	1.4	for (ptytty **i = ptys.end (); i-- > ptys.begin (); )
507	root	1.2	delete *i;
508			}
509
510	root	1.4	void ptytty_server ()
511	root	1.2	{
512			int sv[2];
513
514			if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
515	root	1.4	fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
516	root	1.2
517			pid = fork ();
518
519			if (pid < 0)
520	root	1.4	fatal ("could not create pty/sessiondb helper process, aborting.\n");
521	root	1.2
522			if (pid)
523			{
524	root	1.5	// client, process
525	root	1.2	sock_fd = sv[0];
526			close (sv[1]);
527			fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
528			}
529			else
530			{
531			// server, pty-helper
532			sock_fd = sv[1];
533
534			for (int fd = 0; fd < 1023; fd++)
535			if (fd != sock_fd)
536			close (fd);
537
538			serve ();
539			_exit (EXIT_SUCCESS);
540			}
541			}
542
543			#endif
544
545			// a "factory" g
546	root	1.4	ptytty *
547			new_ptytty ()
548	root	1.2	{
549			#if PTYTTY_HELPER
550			if (pid > 0)
551			// use helper process
552	root	1.4	return new ptytty_proxy;
553	root	1.2	else
554	root	1.1	#endif
555	root	1.4	return new ptytty_unix;
556	root	1.1	}
557
558			/----------------------- end-of-file (C source) -----------------------/
559