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 inline int
get_pty_streams (int *fd_tty, char **ttydev)
{
#ifdef NO_SETOWNER_TTYDEV
  int pfd;

# 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
  return -1;
}

static inline int
get_pty_openpty (int *fd_tty, char **ttydev)
{
#ifdef PTYS_ARE_OPENPTY
  int pfd;
  int res;
  char tty_name[sizeof "/dev/pts/????\0"];
  
  res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
  if (res != -1)
    {
      *ttydev = strdup (tty_name);
      return pfd;
    }
#endif
  return -1;
}

static inline int
get_pty__getpty (int *fd_tty, char **ttydev)
{
#ifdef PTYS_ARE__GETPTY
  int pfd;

  *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0);
  if (*ttydev != NULL)
    return pfd;
#endif
  return -1;
}

static inline int
get_pty_ptc (int *fd_tty, char **ttydev)
{
#ifdef PTYS_ARE_PTC
  int pfd;

  if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0)
    {
      *ttydev = strdup (ttyname (pfd));
      return pfd;
    }
#endif
  return -1;
}

static inline int
get_pty_clone (int *fd_tty, char **ttydev)
{
#ifdef PTYS_ARE_CLONE
  int pfd;

  if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0)
    {
      *ttydev = strdup (ptsname (pfd));
      return pfd;
    }
#endif
  return -1;
}

static inline int
get_pty_numeric (int *fd_tty, char **ttydev)
{
#ifdef PTYS_ARE_NUMERIC
    int pfd;
    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
    return -1;
}

static inline int
get_pty_searched (int *fd_tty, char **ttydev)
{
#ifdef PTYS_ARE_SEARCHED
# ifndef PTYCHAR1
#  define PTYCHAR1      "pqrstuvwxyz"
# endif
# ifndef PTYCHAR2
#  define PTYCHAR2      "0123456789abcdef"
# endif
    int pfd;
    const char *c1, *c2;
    char pty_name[] = "/dev/pty??";
    char tty_name[] = "/dev/tty??";

    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;
}

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

  if ((pfd = get_pty_streams (fd_tty, ttydev)) != -1
      || (pfd = get_pty_openpty (fd_tty, ttydev)) != -1
      || (pfd = get_pty__getpty (fd_tty, ttydev)) != -1
      || (pfd = get_pty_ptc (fd_tty, ttydev)) != -1
      || (pfd = get_pty_clone (fd_tty, ttydev)) != -1
      || (pfd = get_pty_numeric (fd_tty, ttydev)) != -1
      || (pfd = get_pty_searched (fd_tty, ttydev)) != -1)
    return pfd;
  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:	1.44
Committed:	Tue Jan 17 17:59:31 2006 UTC (18 years, 4 months ago) by ayin
Content type:	text/plain
Branch:	MAIN
Changes since 1.43:	+84 -41 lines
Log Message:	get_pty refactoring.
#	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 inline int
70	get_pty_streams (int fd_tty, char *ttydev)
71	{
72	#ifdef NO_SETOWNER_TTYDEV
73	int pfd;
74
75	# ifdef PTYS_ARE_GETPT
76	pfd = getpt();
77	# else
78	# ifdef PTYS_ARE_POSIX
79	pfd = posix_openpt (O_RDWR);
80	# else
81	pfd = open ("/dev/ptmx", O_RDWR \| O_NOCTTY, 0);
82	# endif
83	# endif
84	if (pfd >= 0)
85	{
86	if (grantpt (pfd) == 0 /* change slave permissions */
87	&& unlockpt (pfd) == 0)
88	{ /* slave now unlocked */
89	ttydev = strdup (ptsname (pfd)); / get slave's name */
90	return pfd;
91	}
92	close (pfd);
93	}
94	#endif
95	return -1;
96	}
97
98	static inline int
99	get_pty_openpty (int fd_tty, char *ttydev)
100	{
101	#ifdef PTYS_ARE_OPENPTY
102	int pfd;
103	int res;
104	char tty_name[sizeof "/dev/pts/????\0"];
105
106	res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
107	if (res != -1)
108	{
109	*ttydev = strdup (tty_name);
110	return pfd;
111	}
112	#endif
113	return -1;
114	}
115
116	static inline int
117	get_pty__getpty (int fd_tty, char *ttydev)
118	{
119	#ifdef PTYS_ARE__GETPTY
120	int pfd;
121
122	*ttydev = _getpty (&pfd, O_RDWR \| O_NONBLOCK \| O_NOCTTY, 0622, 0);
123	if (*ttydev != NULL)
124	return pfd;
125	#endif
126	return -1;
127	}
128
129	static inline int
130	get_pty_ptc (int fd_tty, char *ttydev)
131	{
132	#ifdef PTYS_ARE_PTC
133	int pfd;
134
135	if ((pfd = open ("/dev/ptc", O_RDWR \| O_NOCTTY, 0)) >= 0)
136	{
137	*ttydev = strdup (ttyname (pfd));
138	return pfd;
139	}
140	#endif
141	return -1;
142	}
143
144	static inline int
145	get_pty_clone (int fd_tty, char *ttydev)
146	{
147	#ifdef PTYS_ARE_CLONE
148	int pfd;
149
150	if ((pfd = open ("/dev/ptym/clone", O_RDWR \| O_NOCTTY, 0)) >= 0)
151	{
152	*ttydev = strdup (ptsname (pfd));
153	return pfd;
154	}
155	#endif
156	return -1;
157	}
158
159	static inline int
160	get_pty_numeric (int fd_tty, char *ttydev)
161	{
162	#ifdef PTYS_ARE_NUMERIC
163	int pfd;
164	int idx;
165	char c1, c2;
166	char pty_name[] = "/dev/ptyp???";
167	char tty_name[] = "/dev/ttyp???";
168
169	c1 = &(pty_name[sizeof (pty_name) - 4]);
170	c2 = &(tty_name[sizeof (tty_name) - 4]);
171	for (idx = 0; idx < 256; idx++)
172	{
173	sprintf (c1, "%d", idx);
174	sprintf (c2, "%d", idx);
175	if (access (tty_name, F_OK) < 0)
176	{
177	idx = 256;
178	break;
179	}
180
181	if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) >= 0)
182	{
183	if (access (tty_name, R_OK \| W_OK) == 0)
184	{
185	*ttydev = strdup (tty_name);
186	return pfd;
187	}
188
189	close (pfd);
190	}
191	}
192	#endif
193	return -1;
194	}
195
196	static inline int
197	get_pty_searched (int fd_tty, char *ttydev)
198	{
199	#ifdef PTYS_ARE_SEARCHED
200	# ifndef PTYCHAR1
201	# define PTYCHAR1 "pqrstuvwxyz"
202	# endif
203	# ifndef PTYCHAR2
204	# define PTYCHAR2 "0123456789abcdef"
205	# endif
206	int pfd;
207	const char c1, c2;
208	char pty_name[] = "/dev/pty??";
209	char tty_name[] = "/dev/tty??";
210
211	for (c1 = PTYCHAR1; *c1; c1++)
212	{
213	pty_name[ (sizeof (pty_name) - 3)] =
214	tty_name[ (sizeof (pty_name) - 3)] = *c1;
215	for (c2 = PTYCHAR2; *c2; c2++)
216	{
217	pty_name[ (sizeof (pty_name) - 2)] =
218	tty_name[ (sizeof (pty_name) - 2)] = *c2;
219	if ((pfd = open (pty_name, O_RDWR \| O_NOCTTY, 0)) >= 0)
220	{
221	if (access (tty_name, R_OK \| W_OK) == 0)
222	{
223	*ttydev = strdup (tty_name);
224	return pfd;
225	}
226
227	close (pfd);
228	}
229	}
230	}
231	#endif
232	return -1;
233	}
234
235	static int
236	get_pty (int fd_tty, char *ttydev)
237	{
238	int pfd;
239
240	if ((pfd = get_pty_streams (fd_tty, ttydev)) != -1
241	\|\| (pfd = get_pty_openpty (fd_tty, ttydev)) != -1
242	\|\| (pfd = get_pty__getpty (fd_tty, ttydev)) != -1
243	\|\| (pfd = get_pty_ptc (fd_tty, ttydev)) != -1
244	\|\| (pfd = get_pty_clone (fd_tty, ttydev)) != -1
245	\|\| (pfd = get_pty_numeric (fd_tty, ttydev)) != -1
246	\|\| (pfd = get_pty_searched (fd_tty, ttydev)) != -1)
247	return pfd;
248	return -1;
249	}
250
251	/----------------------------------------------------------------------/
252	/*
253	* Returns tty file descriptor, or -1 on failure
254	*/
255	static int
256	get_tty (char *ttydev)
257	{
258	return open (ttydev, O_RDWR \| O_NOCTTY, 0);
259	}
260
261	/----------------------------------------------------------------------/
262	/*
263	* Make our tty a controlling tty so that /dev/tty points to us
264	*/
265	static int
266	control_tty (int fd_tty)
267	{
268	int fd;
269
270	/* ---------------------------------------- */
271	setsid ();
272
273	/* ---------------------------------------- */
274	# if defined(PTYS_ARE_PTMX) && defined(I_PUSH)
275	/*
276	* Push STREAMS modules:
277	* ptem: pseudo-terminal hardware emulation module.
278	* ldterm: standard terminal line discipline.
279	* ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
280	*
281	* After we push the STREAMS modules, the first open () on the slave side
282	* (i.e. the next section between the dashes giving us "tty opened OK")
283	* should make the "ptem" (or "ldterm" depending upon either which OS
284	* version or which set of manual pages you have) module give us a
285	* controlling terminal. We must already have close ()d the master side
286	* fd in this child process before we push STREAMS modules on because the
287	* documentation is really unclear about whether it is any close () on
288	* the master side or the last close () - i.e. a proper STREAMS dismantling
289	* close () - on the master side which causes a hang up to be sent
290	* through - Geoff Wing
291	*/
292	# ifdef HAVE_ISASTREAM
293	if (isastream (fd_tty) == 1)
294	# endif
295	{
296	ioctl (fd_tty, I_PUSH, "ptem");
297	ioctl (fd_tty, I_PUSH, "ldterm");
298	ioctl (fd_tty, I_PUSH, "ttcompat");
299	}
300	# endif
301	/* ---------------------------------------- */
302	fd = ioctl (fd_tty, TIOCSCTTY, NULL);
303	/* ---------------------------------------- */
304	fd = open ("/dev/tty", O_WRONLY);
305	if (fd < 0)
306	return -1; /* fatal */
307	close (fd);
308	/* ---------------------------------------- */
309
310	return 0;
311	}
312
313	void
314	rxvt_ptytty::close_tty ()
315	{
316	if (tty < 0)
317	return;
318
319	close (tty);
320	tty = -1;
321	}
322
323	bool
324	rxvt_ptytty::make_controlling_tty ()
325	{
326	return control_tty (tty) >= 0;
327	}
328
329	void
330	rxvt_ptytty::set_utf8_mode (bool on)
331	{
332	#ifdef IUTF8
333	if (pty < 0)
334	return;
335
336	struct termios tio;
337
338	if (tcgetattr (pty, &tio) != -1)
339	{
340	tcflag_t new_cflag = tio.c_iflag;
341
342	if (on)
343	new_cflag \|= IUTF8;
344	else
345	new_cflag &= ~IUTF8;
346
347	if (new_cflag != tio.c_iflag)
348	{
349	tio.c_iflag = new_cflag;
350	tcsetattr (pty, TCSANOW, &tio);
351	}
352	}
353	#endif
354	}
355
356	/////////////////////////////////////////////////////////////////////////////
357
358	#ifndef NO_SETOWNER_TTYDEV
359	static struct ttyconf {
360	gid_t gid;
361	mode_t mode;
362
363	ttyconf ()
364	{
365	#ifdef TTY_GID_SUPPORT
366	struct group *gr = getgrnam ("tty");
367
368	if (gr)
369	{ /* change group ownership of tty to "tty" */
370	mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
371	gid = gr->gr_gid;
372	}
373	else
374	#endif /* TTY_GID_SUPPORT */
375	{
376	mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
377	gid = getgid ();
378	}
379	}
380	} ttyconf;
381
382	/////////////////////////////////////////////////////////////////////////////
383
384	void
385	rxvt_ptytty_unix::privileges (rxvt_privaction action)
386	{
387	if (!name \|\| !*name)
388	return;
389
390	if (action == SAVE)
391	{
392	# ifndef RESET_TTY_TO_COMMON_DEFAULTS
393	/* store original tty status for restoration rxvt_clean_exit () -- rgg 04/12/95 */
394	if (lstat (name, &savestat) < 0) /* you lose out */
395	;
396	else
397	# endif
398	{
399	saved = true;
400	chown (name, getuid (), ttyconf.gid); /* fail silently */
401	chmod (name, ttyconf.mode);
402	# ifdef HAVE_REVOKE
403	revoke (name);
404	# endif
405	}
406	}
407	else
408	{ /* action == RESTORE */
409	# ifndef RESET_TTY_TO_COMMON_DEFAULTS
410	if (saved)
411	{
412	chmod (name, savestat.st_mode);
413	chown (name, savestat.st_uid, savestat.st_gid);
414	}
415	# else
416	chmod (name, (S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP \| S_IROTH \| S_IWOTH));
417	chown (name, 0, 0);
418	# endif
419
420	}
421	}
422	#endif
423
424	rxvt_ptytty_unix::rxvt_ptytty_unix ()
425	{
426	pty = tty = -1;
427	name = 0;
428	#ifndef NO_SETOWNER_TTYDEV
429	saved = false;
430	#endif
431	#if UTMP_SUPPORT
432	cmd_pid = 0;
433	#endif
434	}
435
436	rxvt_ptytty_unix::~rxvt_ptytty_unix ()
437	{
438	#if UTMP_SUPPORT
439	logout ();
440	#endif
441	put ();
442	}
443
444	void
445	rxvt_ptytty_unix::put ()
446	{
447	#ifndef NO_SETOWNER_TTYDEV
448	privileges (RESTORE);
449	#endif
450
451	if (pty >= 0) close (pty);
452	close_tty ();
453	free (name);
454
455	pty = tty = -1;
456	name = 0;
457	}
458
459	bool
460	rxvt_ptytty_unix::get ()
461	{
462	/* get master (pty) */
463	if ((pty = get_pty (&tty, &name)) < 0)
464	return false;
465
466	fcntl (pty, F_SETFL, O_NONBLOCK);
467
468	/* get slave (tty) */
469	if (tty < 0)
470	{
471	#ifndef NO_SETOWNER_TTYDEV
472	privileges (SAVE);
473	#endif
474
475	if ((tty = get_tty (name)) < 0)
476	{
477	put ();
478	return false;
479	}
480	}
481
482	return true;
483	}
484
485	#if PTYTTY_HELPER
486
487	static int sock_fd;
488	static int pid;
489
490	struct command
491	{
492	enum { get, login, destroy } type;
493
494	rxvt_ptytty *id;
495
496	bool login_shell;
497	int cmd_pid;
498	char hostname[512]; // arbitrary, but should be plenty
499	};
500
501	struct rxvt_ptytty_proxy : zero_initialized, rxvt_ptytty
502	{
503	rxvt_ptytty *id;
504
505	~rxvt_ptytty_proxy ();
506
507	bool get ();
508	void login (int cmd_pid, bool login_shell, const char *hostname);
509	};
510
511	bool
512	rxvt_ptytty_proxy::get ()
513	{
514	command cmd;
515
516	cmd.type = command::get;
517
518	write (sock_fd, &cmd, sizeof (cmd));
519
520	if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
521	rxvt_fatal ("protocol error while creating pty using helper process, aborting.\n");
522
523	if (!id)
524	return false;
525
526	if ((pty = rxvt_recv_fd (sock_fd)) < 0
527	\|\| (tty = rxvt_recv_fd (sock_fd)) < 0)
528	rxvt_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");
529
530	return true;
531	}
532
533	void
534	rxvt_ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname)
535	{
536	command cmd;
537
538	cmd.type = command::login;
539	cmd.id = id;
540	cmd.cmd_pid = cmd_pid;
541	cmd.login_shell = login_shell;
542	strncpy (cmd.hostname, hostname, sizeof (cmd.hostname));
543
544	write (sock_fd, &cmd, sizeof (cmd));
545	}
546
547	rxvt_ptytty_proxy::~rxvt_ptytty_proxy ()
548	{
549	command cmd;
550
551	cmd.type = command::destroy;
552	cmd.id = id;
553
554	write (sock_fd, &cmd, sizeof (cmd));
555	}
556
557	static
558	void serve ()
559	{
560	command cmd;
561	vector<rxvt_ptytty *> ptys;
562
563	while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command))
564	{
565	if (cmd.type == command::get)
566	{
567	// -> id ptyfd ttyfd
568	cmd.id = new rxvt_ptytty_unix;
569
570	if (cmd.id->get ())
571	{
572	write (sock_fd, &cmd.id, sizeof (cmd.id));
573	ptys.push_back (cmd.id);
574
575	rxvt_send_fd (sock_fd, cmd.id->pty);
576	rxvt_send_fd (sock_fd, cmd.id->tty);
577	}
578	else
579	{
580	delete cmd.id;
581	cmd.id = 0;
582	write (sock_fd, &cmd.id, sizeof (cmd.id));
583	}
584	}
585	else if (cmd.type == command::login)
586	{
587	#if UTMP_SUPPORT
588	if (find (ptys.begin (), ptys.end (), cmd.id))
589	{
590	cmd.hostname[sizeof (cmd.hostname) - 1] = 0;
591	cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname);
592	}
593	#endif
594	}
595	else if (cmd.type == command::destroy)
596	{
597	rxvt_ptytty **pty = find (ptys.begin (), ptys.end (), cmd.id);
598
599	if (pty)
600	{
601	delete *pty;
602	ptys.erase (pty);
603	}
604	}
605	else
606	break;
607	}
608
609	// destroy all ptys
610	for (rxvt_ptytty **i = ptys.end (); i-- > ptys.begin (); )
611	delete *i;
612	}
613
614	void rxvt_ptytty_server ()
615	{
616	int sv[2];
617
618	if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
619	rxvt_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
620
621	pid = fork ();
622
623	if (pid < 0)
624	rxvt_fatal ("could not create pty/sessiondb helper process, aborting.\n");
625
626	if (pid)
627	{
628	// client, urxvt
629	sock_fd = sv[0];
630	close (sv[1]);
631	fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
632	}
633	else
634	{
635	setgid (getegid ());
636	setuid (geteuid ());
637
638	// server, pty-helper
639	sock_fd = sv[1];
640
641	for (int fd = 0; fd < 1023; fd++)
642	if (fd != sock_fd && fd != 1)
643	close (fd);
644
645	serve ();
646	_exit (EXIT_SUCCESS);
647	}
648	}
649	#endif
650
651	// a "factory" g
652	rxvt_ptytty *
653	rxvt_new_ptytty ()
654	{
655	#if PTYTTY_HELPER
656	if (pid > 0)
657	// use helper process
658	return new rxvt_ptytty_proxy;
659	else
660	#endif
661	return new rxvt_ptytty_unix;
662	}
663
664	/----------------------- end-of-file (C source) -----------------------/
665