rxvt-unicode/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 "rxvt.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(PTYS_ARE_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

#include <cstdio>
#include <grp.h>

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

/////////////////////////////////////////////////////////////////////////////

/* ------------------------------------------------------------------------- *
 *                  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
 */
static int
get_pty (int *fd_tty, char **ttydev)
{
  int pfd;

#ifdef PTYS_ARE_OPENPTY
  char tty_name[sizeof "/dev/pts/????\0"];

  int res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);

  if (res != -1)
    {
      *ttydev = strdup (tty_name);
      return pfd;
    }
#endif

#ifdef PTYS_ARE__GETPTY
  *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0);
  if (*ttydev != NULL)
    return pfd;
#endif

#if defined(HAVE_GRANTPT) && defined(HAVE_UNLOCKPT)
# if defined(PTYS_ARE_GETPT) || defined(PTYS_ARE_POSIX) || defined(PTYS_ARE_PTMX)

  {
#  ifdef PTYS_ARE_GETPT
    pfd = getpt();
#  else
#  ifdef PTYS_ARE_POSIX
    pfd = posix_openpt (O_RDWR);
#  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);
      }
  }
# endif
#endif

#ifdef PTYS_ARE_PTC
  if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0)
    {
      *ttydev = strdup (ttyname (pfd));
      return pfd;
    }
#endif

#ifdef PTYS_ARE_CLONE
  if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0)
    {
      *ttydev = strdup (ptsname (pfd));
      return pfd;
    }
#endif

#ifdef PTYS_ARE_NUMERIC
  {
    int idx;
    char *c1, *c2;
    char pty_name[] = "/dev/ptyp???";
    char tty_name[] = "/dev/ttyp???";

    c1 = &(pty_name[sizeof (pty_name) - 4]);
    c2 = &(tty_name[sizeof (tty_name) - 4]);
    for (idx = 0; idx < 256; idx++)
      {
        sprintf (c1, "%d", idx);
        sprintf (c2, "%d", idx);
        if (access (tty_name, F_OK) < 0)
          {
            idx = 256;
            break;
          }

        if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
          {
            if (access (tty_name, R_OK | W_OK) == 0)
              {
                *ttydev = strdup (tty_name);
                return pfd;
              }

            close (pfd);
          }
      }
  }
#endif

#ifdef PTYS_ARE_SEARCHED
  {
    const char *c1, *c2;
    char pty_name[] = "/dev/pty??";
    char tty_name[] = "/dev/tty??";

# ifndef PTYCHAR1
#  define PTYCHAR1      "pqrstuvwxyz"
# endif
# ifndef PTYCHAR2
#  define PTYCHAR2      "0123456789abcdef"
# endif

    for (c1 = PTYCHAR1; *c1; c1++)
      {
        pty_name[ (sizeof (pty_name) - 3)] =
          tty_name[ (sizeof (pty_name) - 3)] = *c1;
        for (c2 = PTYCHAR2; *c2; c2++)
          {
            pty_name[ (sizeof (pty_name) - 2)] =
              tty_name[ (sizeof (pty_name) - 2)] = *c2;
            if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
              {
                if (access (tty_name, R_OK | W_OK) == 0)
                  {
                    *ttydev = strdup (tty_name);
                    return pfd;
                  }

                close (pfd);
              }
          }
      }
  }
#endif

  return -1;
}

/*----------------------------------------------------------------------*/
/*
 * 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 ();

  /* ---------------------------------------- */
# if defined(PTYS_ARE_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
  /* ---------------------------------------- */
  fd = ioctl (fd_tty, TIOCSCTTY, NULL);
  /* ---------------------------------------- */
  fd = open ("/dev/tty", O_WRONLY);
  if (fd < 0)
    return -1;          /* fatal */
  close (fd);
  /* ---------------------------------------- */

  return 0;
}

void
rxvt_ptytty::close_tty ()
{
  if (tty < 0)
    return;

  close (tty);
  tty = -1;
}

bool
rxvt_ptytty::make_controlling_tty ()
{
  return control_tty (tty) >= 0;
}

void
rxvt_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
}

/////////////////////////////////////////////////////////////////////////////

#ifndef NO_SETOWNER_TTYDEV
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 = getgid ();
        }
    }
} ttyconf;

/////////////////////////////////////////////////////////////////////////////

void
rxvt_ptytty_unix::privileges (rxvt_privaction action)
{
  if (!name || !*name)
    return;

  if (action == SAVE)
    {
# ifndef RESET_TTY_TO_COMMON_DEFAULTS
      /* store original tty status for restoration rxvt_clean_exit () -- rgg 04/12/95 */
      if (lstat (name, &savestat) < 0)       /* you lose out */
        ;
      else
# endif
        {
          saved = true;
          chown (name, getuid (), ttyconf.gid);      /* fail silently */
          chmod (name, ttyconf.mode);
# ifdef HAVE_REVOKE
          revoke (name);
# endif
        }
    }
  else
    {                    /* action == RESTORE */
# ifndef RESET_TTY_TO_COMMON_DEFAULTS
      if (saved)
        {
          chmod (name, savestat.st_mode);
          chown (name, savestat.st_uid, savestat.st_gid);
        }
# else
      chmod (name, (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH));
      chown (name, 0, 0);
# endif

    }
}
#endif

rxvt_ptytty_unix::rxvt_ptytty_unix ()
{
  pty = tty = -1;
  name = 0;
#ifndef NO_SETOWNER_TTYDEV
  saved = false;
#endif
#if UTMP_SUPPORT
  cmd_pid = 0;
#endif
}

rxvt_ptytty_unix::~rxvt_ptytty_unix ()
{
#if UTMP_SUPPORT
  logout ();
#endif
  put ();
}

void
rxvt_ptytty_unix::put ()
{
#ifndef NO_SETOWNER_TTYDEV
  privileges (RESTORE);
#endif

  if (pty >= 0) close (pty);
  close_tty ();
  free (name);

  pty = tty = -1;
  name = 0;
}

bool
rxvt_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
      privileges (SAVE);
#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;

  rxvt_ptytty *id;

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

struct rxvt_ptytty_proxy : zero_initialized, rxvt_ptytty
{
  rxvt_ptytty *id;

  ~rxvt_ptytty_proxy ();

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

bool
rxvt_ptytty_proxy::get ()
{
  command cmd;

  cmd.type = command::get;

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

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

  if (!id)
    return false;

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

  return true;
}

void
rxvt_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));
}

rxvt_ptytty_proxy::~rxvt_ptytty_proxy ()
{
  command cmd;

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

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

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

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

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

              rxvt_send_fd (sock_fd, cmd.id->pty);
              rxvt_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)
        {
          rxvt_ptytty **pty = find (ptys.begin (), ptys.end (), cmd.id);

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

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

void rxvt_ptytty_server ()
{
  int sv[2];

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

  pid = fork ();

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

  if (pid)
    {
      // client, urxvt
      sock_fd = sv[0];
      close (sv[1]);
      fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
    }
  else
    {
      setgid (getegid ());
      setuid (geteuid ());

      // server, pty-helper
      sock_fd = sv[1];

      for (int fd = 0; fd < 1023; fd++)
        if (fd != sock_fd && fd != 1)
          close (fd);

      serve ();
      _exit (EXIT_SUCCESS);
    }
}
#endif

// a "factory" *g*
rxvt_ptytty *
rxvt_new_ptytty ()
{
#if PTYTTY_HELPER
  if (pid > 0)
    // use helper process
    return new rxvt_ptytty_proxy;
  else
#endif
    return new rxvt_ptytty_unix;
}

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

Revision:	1.43
Committed:	Tue Jan 17 16:50:42 2006 UTC (18 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.42:	+4 -0 lines
Log Message:	* empty log message *
#	Content
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	* Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com>
8	*
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	#include "rxvt.h"
26
27	#include <cstdlib>
28	#include <cstring>
29
30	#include <sys/types.h>
31	#include <sys/socket.h>
32	#include <unistd.h>
33	#include <fcntl.h>
34
35	#ifdef HAVE_SYS_IOCTL_H
36	# include <sys/ioctl.h>
37	#endif
38	#if defined(PTYS_ARE_PTMX) && defined(HAVE_SYS_STROPTS_H)
39	# include <sys/stropts.h> /* for I_PUSH */
40	#endif
41	#ifdef HAVE_ISASTREAM
42	# include <stropts.h>
43	#endif
44	#if defined(HAVE_PTY_H)
45	# include <pty.h>
46	#elif defined(HAVE_LIBUTIL_H)
47	# include <libutil.h>
48	#elif defined(HAVE_UTIL_H)
49	# include <util.h>
50	#endif
51
52	#include <cstdio>
53	#include <grp.h>
54
55	#include "rxvtutil.h"
56	#include "fdpass.h"
57	#include "ptytty.h"
58
59	/////////////////////////////////////////////////////////////////////////////
60
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	static int
70	get_pty (int fd_tty, char *ttydev)
71	{
72	int pfd;
73
74	#ifdef PTYS_ARE_OPENPTY
75	char tty_name[sizeof "/dev/pts/????\0"];
76
77	int res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
78
79	if (res != -1)
80	{
81	*ttydev = strdup (tty_name);
82	return pfd;
83	}
84	#endif
85
86	#ifdef PTYS_ARE__GETPTY
87	*ttydev = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
88	if (*ttydev != NULL)
89	return pfd;
90	#endif
91
92	#if defined(HAVE_GRANTPT) && defined(HAVE_UNLOCKPT)
93	# if defined(PTYS_ARE_GETPT) \|\| defined(PTYS_ARE_POSIX) \|\| defined(PTYS_ARE_PTMX)
94
95	{
96	# ifdef PTYS_ARE_GETPT
97	pfd = getpt();
98	# else
99	# ifdef PTYS_ARE_POSIX
100	pfd = posix_openpt (O_RDWR);
101	# else
102	pfd = open ("/dev/ptmx", O_RDWR \| O_NOCTTY, 0);
103	# endif
104	# endif
105
106	if (pfd >= 0)
107	{
108	if (grantpt (pfd) == 0 /* change slave permissions */
109	&& unlockpt (pfd) == 0)
110	{ /* slave now unlocked */
111	ttydev = strdup (ptsname (pfd)); / get slave's name */
112	return pfd;
113	}
114	close (pfd);
115	}
116	}
117	# endif
118	#endif
119
120	#ifdef PTYS_ARE_PTC
121	if ((pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0)) >= 0)
122	{
123	*ttydev = strdup (ttyname (pfd));
124	return pfd;
125	}
126	#endif
127
128	#ifdef PTYS_ARE_CLONE
129	if ((pfd = open ("/dev/ptym/clone", O_RDWR \| O_NOCTTY, 0)) >= 0)
130	{
131	*ttydev = strdup (ptsname (pfd));
132	return pfd;
133	}
134	#endif
135
136	#ifdef PTYS_ARE_NUMERIC
137	{
138	int idx;
139	char c1, c2;
140	char pty_name[] = "/dev/ptyp???";
141	char tty_name[] = "/dev/ttyp???";
142
143	c1 = &(pty_name[sizeof (pty_name) - 4]);
144	c2 = &(tty_name[sizeof (tty_name) - 4]);
145	for (idx = 0; idx < 256; idx++)
146	{
147	sprintf (c1, "%d", idx);
148	sprintf (c2, "%d", idx);
149	if (access (tty_name, F_OK) < 0)
150	{
151	idx = 256;
152	break;
153	}
154
155	if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) >= 0)
156	{
157	if (access (tty_name, R_OK \| W_OK) == 0)
158	{
159	*ttydev = strdup (tty_name);
160	return pfd;
161	}
162
163	close (pfd);
164	}
165	}
166	}
167	#endif
168
169	#ifdef PTYS_ARE_SEARCHED
170	{
171	const char c1, c2;
172	char pty_name[] = "/dev/pty??";
173	char tty_name[] = "/dev/tty??";
174
175	# ifndef PTYCHAR1
176	# define PTYCHAR1 "pqrstuvwxyz"
177	# endif
178	# ifndef PTYCHAR2
179	# define PTYCHAR2 "0123456789abcdef"
180	# endif
181
182	for (c1 = PTYCHAR1; *c1; c1++)
183	{
184	pty_name[ (sizeof (pty_name) - 3)] =
185	tty_name[ (sizeof (pty_name) - 3)] = *c1;
186	for (c2 = PTYCHAR2; *c2; c2++)
187	{
188	pty_name[ (sizeof (pty_name) - 2)] =
189	tty_name[ (sizeof (pty_name) - 2)] = *c2;
190	if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) >= 0)
191	{
192	if (access (tty_name, R_OK \| W_OK) == 0)
193	{
194	*ttydev = strdup (tty_name);
195	return pfd;
196	}
197
198	close (pfd);
199	}
200	}
201	}
202	}
203	#endif
204
205	return -1;
206	}
207
208	/----------------------------------------------------------------------/
209	/*
210	* Returns tty file descriptor, or -1 on failure
211	*/
212	static int
213	get_tty (char *ttydev)
214	{
215	return open (ttydev, O_RDWR \| O_NOCTTY, 0);
216	}
217
218	/----------------------------------------------------------------------/
219	/*
220	* Make our tty a controlling tty so that /dev/tty points to us
221	*/
222	static int
223	control_tty (int fd_tty)
224	{
225	int fd;
226
227	/* ---------------------------------------- */
228	setsid ();
229
230	/* ---------------------------------------- */
231	# if defined(PTYS_ARE_PTMX) && defined(I_PUSH)
232	/*
233	* Push STREAMS modules:
234	* ptem: pseudo-terminal hardware emulation module.
235	* ldterm: standard terminal line discipline.
236	* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
237	*
238	* After we push the STREAMS modules, the first open () on the slave side
239	* (i.e. the next section between the dashes giving us "tty opened OK")
240	* should make the "ptem" (or "ldterm" depending upon either which OS
241	* version or which set of manual pages you have) module give us a
242	* controlling terminal. We must already have close ()d the master side
243	* fd in this child process before we push STREAMS modules on because the
244	* documentation is really unclear about whether it is any close () on
245	* the master side or the last close () - i.e. a proper STREAMS dismantling
246	* close () - on the master side which causes a hang up to be sent
247	* through - Geoff Wing
248	*/
249	# ifdef HAVE_ISASTREAM
250	if (isastream (fd_tty) == 1)
251	# endif
252	{
253	ioctl (fd_tty, I_PUSH, "ptem");
254	ioctl (fd_tty, I_PUSH, "ldterm");
255	ioctl (fd_tty, I_PUSH, "ttcompat");
256	}
257	# endif
258	/* ---------------------------------------- */
259	fd = ioctl (fd_tty, TIOCSCTTY, NULL);
260	/* ---------------------------------------- */
261	fd = open ("/dev/tty", O_WRONLY);
262	if (fd < 0)
263	return -1; /* fatal */
264	close (fd);
265	/* ---------------------------------------- */
266
267	return 0;
268	}
269
270	void
271	rxvt_ptytty::close_tty ()
272	{
273	if (tty < 0)
274	return;
275
276	close (tty);
277	tty = -1;
278	}
279
280	bool
281	rxvt_ptytty::make_controlling_tty ()
282	{
283	return control_tty (tty) >= 0;
284	}
285
286	void
287	rxvt_ptytty::set_utf8_mode (bool on)
288	{
289	#ifdef IUTF8
290	if (pty < 0)
291	return;
292
293	struct termios tio;
294
295	if (tcgetattr (pty, &tio) != -1)
296	{
297	tcflag_t new_cflag = tio.c_iflag;
298
299	if (on)
300	new_cflag \|= IUTF8;
301	else
302	new_cflag &= ~IUTF8;
303
304	if (new_cflag != tio.c_iflag)
305	{
306	tio.c_iflag = new_cflag;
307	tcsetattr (pty, TCSANOW, &tio);
308	}
309	}
310	#endif
311	}
312
313	/////////////////////////////////////////////////////////////////////////////
314
315	#ifndef NO_SETOWNER_TTYDEV
316	static struct ttyconf {
317	gid_t gid;
318	mode_t mode;
319
320	ttyconf ()
321	{
322	#ifdef TTY_GID_SUPPORT
323	struct group *gr = getgrnam ("tty");
324
325	if (gr)
326	{ /* change group ownership of tty to "tty" */
327	mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
328	gid = gr->gr_gid;
329	}
330	else
331	#endif /* TTY_GID_SUPPORT */
332	{
333	mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
334	gid = getgid ();
335	}
336	}
337	} ttyconf;
338
339	/////////////////////////////////////////////////////////////////////////////
340
341	void
342	rxvt_ptytty_unix::privileges (rxvt_privaction action)
343	{
344	if (!name \|\| !*name)
345	return;
346
347	if (action == SAVE)
348	{
349	# ifndef RESET_TTY_TO_COMMON_DEFAULTS
350	/* store original tty status for restoration rxvt_clean_exit () -- rgg 04/12/95 */
351	if (lstat (name, &savestat) < 0) /* you lose out */
352	;
353	else
354	# endif
355	{
356	saved = true;
357	chown (name, getuid (), ttyconf.gid); /* fail silently */
358	chmod (name, ttyconf.mode);
359	# ifdef HAVE_REVOKE
360	revoke (name);
361	# endif
362	}
363	}
364	else
365	{ /* action == RESTORE */
366	# ifndef RESET_TTY_TO_COMMON_DEFAULTS
367	if (saved)
368	{
369	chmod (name, savestat.st_mode);
370	chown (name, savestat.st_uid, savestat.st_gid);
371	}
372	# else
373	chmod (name, (S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP \| S_IROTH \| S_IWOTH));
374	chown (name, 0, 0);
375	# endif
376
377	}
378	}
379	#endif
380
381	rxvt_ptytty_unix::rxvt_ptytty_unix ()
382	{
383	pty = tty = -1;
384	name = 0;
385	#ifndef NO_SETOWNER_TTYDEV
386	saved = false;
387	#endif
388	#if UTMP_SUPPORT
389	cmd_pid = 0;
390	#endif
391	}
392
393	rxvt_ptytty_unix::~rxvt_ptytty_unix ()
394	{
395	#if UTMP_SUPPORT
396	logout ();
397	#endif
398	put ();
399	}
400
401	void
402	rxvt_ptytty_unix::put ()
403	{
404	#ifndef NO_SETOWNER_TTYDEV
405	privileges (RESTORE);
406	#endif
407
408	if (pty >= 0) close (pty);
409	close_tty ();
410	free (name);
411
412	pty = tty = -1;
413	name = 0;
414	}
415
416	bool
417	rxvt_ptytty_unix::get ()
418	{
419	/* get master (pty) */
420	if ((pty = get_pty (&tty, &name)) < 0)
421	return false;
422
423	fcntl (pty, F_SETFL, O_NONBLOCK);
424
425	/* get slave (tty) */
426	if (tty < 0)
427	{
428	#ifndef NO_SETOWNER_TTYDEV
429	privileges (SAVE);
430	#endif
431
432	if ((tty = get_tty (name)) < 0)
433	{
434	put ();
435	return false;
436	}
437	}
438
439	return true;
440	}
441
442	#if PTYTTY_HELPER
443
444	static int sock_fd;
445	static int pid;
446
447	struct command
448	{
449	enum { get, login, destroy } type;
450
451	rxvt_ptytty *id;
452
453	bool login_shell;
454	int cmd_pid;
455	char hostname[512]; // arbitrary, but should be plenty
456	};
457
458	struct rxvt_ptytty_proxy : zero_initialized, rxvt_ptytty
459	{
460	rxvt_ptytty *id;
461
462	~rxvt_ptytty_proxy ();
463
464	bool get ();
465	void login (int cmd_pid, bool login_shell, const char *hostname);
466	};
467
468	bool
469	rxvt_ptytty_proxy::get ()
470	{
471	command cmd;
472
473	cmd.type = command::get;
474
475	write (sock_fd, &cmd, sizeof (cmd));
476
477	if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
478	rxvt_fatal ("protocol error while creating pty using helper process, aborting.\n");
479
480	if (!id)
481	return false;
482
483	if ((pty = rxvt_recv_fd (sock_fd)) < 0
484	\|\| (tty = rxvt_recv_fd (sock_fd)) < 0)
485	rxvt_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");
486
487	return true;
488	}
489
490	void
491	rxvt_ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname)
492	{
493	command cmd;
494
495	cmd.type = command::login;
496	cmd.id = id;
497	cmd.cmd_pid = cmd_pid;
498	cmd.login_shell = login_shell;
499	strncpy (cmd.hostname, hostname, sizeof (cmd.hostname));
500
501	write (sock_fd, &cmd, sizeof (cmd));
502	}
503
504	rxvt_ptytty_proxy::~rxvt_ptytty_proxy ()
505	{
506	command cmd;
507
508	cmd.type = command::destroy;
509	cmd.id = id;
510
511	write (sock_fd, &cmd, sizeof (cmd));
512	}
513
514	static
515	void serve ()
516	{
517	command cmd;
518	vector<rxvt_ptytty *> ptys;
519
520	while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command))
521	{
522	if (cmd.type == command::get)
523	{
524	// -> id ptyfd ttyfd
525	cmd.id = new rxvt_ptytty_unix;
526
527	if (cmd.id->get ())
528	{
529	write (sock_fd, &cmd.id, sizeof (cmd.id));
530	ptys.push_back (cmd.id);
531
532	rxvt_send_fd (sock_fd, cmd.id->pty);
533	rxvt_send_fd (sock_fd, cmd.id->tty);
534	}
535	else
536	{
537	delete cmd.id;
538	cmd.id = 0;
539	write (sock_fd, &cmd.id, sizeof (cmd.id));
540	}
541	}
542	else if (cmd.type == command::login)
543	{
544	#if UTMP_SUPPORT
545	if (find (ptys.begin (), ptys.end (), cmd.id))
546	{
547	cmd.hostname[sizeof (cmd.hostname) - 1] = 0;
548	cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname);
549	}
550	#endif
551	}
552	else if (cmd.type == command::destroy)
553	{
554	rxvt_ptytty **pty = find (ptys.begin (), ptys.end (), cmd.id);
555
556	if (pty)
557	{
558	delete *pty;
559	ptys.erase (pty);
560	}
561	}
562	else
563	break;
564	}
565
566	// destroy all ptys
567	for (rxvt_ptytty **i = ptys.end (); i-- > ptys.begin (); )
568	delete *i;
569	}
570
571	void rxvt_ptytty_server ()
572	{
573	int sv[2];
574
575	if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
576	rxvt_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
577
578	pid = fork ();
579
580	if (pid < 0)
581	rxvt_fatal ("could not create pty/sessiondb helper process, aborting.\n");
582
583	if (pid)
584	{
585	// client, urxvt
586	sock_fd = sv[0];
587	close (sv[1]);
588	fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
589	}
590	else
591	{
592	setgid (getegid ());
593	setuid (geteuid ());
594
595	// server, pty-helper
596	sock_fd = sv[1];
597
598	for (int fd = 0; fd < 1023; fd++)
599	if (fd != sock_fd && fd != 1)
600	close (fd);
601
602	serve ();
603	_exit (EXIT_SUCCESS);
604	}
605	}
606	#endif
607
608	// a "factory" g
609	rxvt_ptytty *
610	rxvt_new_ptytty ()
611	{
612	#if PTYTTY_HELPER
613	if (pid > 0)
614	// use helper process
615	return new rxvt_ptytty_proxy;
616	else
617	#endif
618	return new rxvt_ptytty_unix;
619	}
620
621	/----------------------- end-of-file (C source) -----------------------/
622