1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dbus-launch.c dbus-launch utility
4 * Copyright (C) 2003 Red Hat, Inc.
6 * Licensed under the Academic Free License version 2.1
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
47 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
50 verbose (const char *format,
54 static int verbose = TRUE;
55 static int verbose_initted = FALSE;
57 /* things are written a bit oddly here so that
58 * in the non-verbose case we just have the one
59 * conditional and return immediately.
66 verbose = getenv ("DBUS_VERBOSE") != NULL;
67 verbose_initted = TRUE;
72 fprintf (stderr, "%lu: ", (unsigned long) getpid ());
74 va_start (args, format);
75 vfprintf (stderr, format, args);
82 fprintf (stderr, "dbus-launch [--version] [--help] [--sh-syntax] [--csh-syntax] [--auto-syntax] [--exit-with-session]\n");
89 printf ("D-BUS Message Bus Launcher %s\n"
90 "Copyright (C) 2003 Red Hat, Inc.\n"
91 "This is free software; see the source for copying conditions.\n"
92 "There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n",
98 xstrdup (const char *str)
108 copy = malloc (len + 1);
112 memcpy (copy, str, len + 1);
119 READ_STATUS_OK, /**< Read succeeded */
120 READ_STATUS_ERROR, /**< Some kind of error */
121 READ_STATUS_EOF /**< EOF returned */
132 memset (buf, '\0', maxlen);
133 maxlen -= 1; /* ensure nul term */
135 retval = READ_STATUS_OK;
143 to_read = maxlen - bytes;
151 if (chunk < 0 && errno == EINTR)
156 retval = READ_STATUS_ERROR;
161 retval = READ_STATUS_EOF;
168 if (retval == READ_STATUS_EOF &&
170 retval = READ_STATUS_OK;
173 if (retval != READ_STATUS_ERROR &&
175 buf[bytes-1] == '\n')
188 retval = READ_STATUS_OK;
196 to_read = sizeof (pid_t) - bytes;
202 ((char*)buf) + bytes,
204 if (chunk < 0 && errno == EINTR)
209 retval = READ_STATUS_ERROR;
214 retval = READ_STATUS_EOF;
225 do_write (int fd, const void *buf, size_t count)
227 size_t bytes_written;
234 ret = write (fd, ((const char*)buf) + bytes_written, count - bytes_written);
242 fprintf (stderr, "Failed to write data to pipe! %s\n",
244 exit (1); /* give up, we suck */
248 bytes_written += ret;
250 if (bytes_written < count)
258 do_write (fd, &pid, sizeof (pid));
262 do_waitpid (pid_t pid)
267 ret = waitpid (pid, NULL, 0);
276 static pid_t bus_pid_to_kill = -1;
279 kill_bus_and_exit (void)
281 verbose ("Killing message bus and exiting babysitter\n");
283 /* in case these point to any NFS mounts, get rid of them immediately */
288 kill (bus_pid_to_kill, SIGTERM);
290 kill (bus_pid_to_kill, SIGKILL);
295 #ifdef DBUS_BUILD_X11
297 x_io_error_handler (Display *xdisplay)
299 verbose ("X IO error\n");
300 kill_bus_and_exit ();
305 static int got_sighup = FALSE;
308 signal_handler (int sig)
319 kill_bus_when_session_ends (void)
326 struct sigaction act;
328 #ifdef DBUS_BUILD_X11
332 /* install SIGHUP handler */
334 sigemptyset (&empty_mask);
335 act.sa_handler = signal_handler;
336 act.sa_mask = empty_mask;
338 sigaction (SIGHUP, &act, 0);
340 #ifdef DBUS_BUILD_X11
341 xdisplay = XOpenDisplay (NULL);
342 if (xdisplay != NULL)
344 verbose ("Successfully opened X display\n");
345 x_fd = ConnectionNumber (xdisplay);
346 XSetIOErrorHandler (x_io_error_handler);
351 verbose ("Compiled without X11 support\n");
361 verbose ("stdin isatty(), monitoring it\n");
363 verbose ("stdin was not a TTY, not monitoring it\n");
365 if (tty_fd < 0 && x_fd < 0)
367 fprintf (stderr, "No terminal on standard input and no X display; cannot attach message bus to session lifetime\n");
378 FD_SET (tty_fd, &read_set);
379 FD_SET (tty_fd, &err_set);
384 FD_SET (x_fd, &read_set);
385 FD_SET (x_fd, &err_set);
388 ret = select (MAX (tty_fd, x_fd) + 1,
389 &read_set, NULL, &err_set, NULL);
393 verbose ("Got SIGHUP, exiting\n");
394 kill_bus_and_exit ();
397 #ifdef DBUS_BUILD_X11
398 /* Dump events on the floor, and let
399 * IO error handler run if we lose
403 verbose ("X fd condition reading = %d error = %d\n",
404 FD_ISSET (x_fd, &read_set),
405 FD_ISSET (x_fd, &err_set));
407 if (xdisplay != NULL)
409 while (XPending (xdisplay))
412 XNextEvent (xdisplay, &ignored);
419 if (FD_ISSET (tty_fd, &read_set))
424 verbose ("TTY ready for reading\n");
426 bytes_read = read (tty_fd, discard, sizeof (discard));
428 verbose ("Read %d bytes from TTY errno = %d\n",
432 kill_bus_and_exit (); /* EOF */
433 else if (bytes_read < 0 && errno != EINTR)
435 /* This shouldn't happen I don't think; to avoid
436 * spinning on the fd forever we exit.
438 fprintf (stderr, "dbus-launch: error reading from stdin: %s\n",
440 kill_bus_and_exit ();
443 else if (FD_ISSET (tty_fd, &err_set))
445 verbose ("TTY has error condition\n");
447 kill_bus_and_exit ();
454 babysit (int exit_with_session,
456 int read_bus_pid_fd, /* read pid from here */
457 int write_bus_pid_fd) /* forward pid to here */
460 #define MAX_PID_LEN 64
461 char buf[MAX_PID_LEN];
467 verbose ("babysitting, exit_with_session = %d, child_pid = %ld, read_bus_pid_fd = %d, write_bus_pid_fd = %d\n",
468 exit_with_session, (long) child_pid, read_bus_pid_fd, write_bus_pid_fd);
470 /* We chdir ("/") since we are persistent and daemon-like, and fork
471 * again so dbus-launch can reap the parent. However, we don't
472 * setsid() or close fd 0 because the idea is to remain attached
473 * to the tty and the X server in order to kill the message bus
474 * when the session ends.
479 fprintf (stderr, "Could not change to root directory: %s\n",
484 /* Close stdout/stderr so we don't block an "eval" or otherwise
485 * lock up. stdout is still chaining through to dbus-launch
486 * and in turn to the parent shell.
488 dev_null_fd = open ("/dev/null", O_RDWR);
489 if (dev_null_fd >= 0)
491 if (!exit_with_session)
492 dup2 (dev_null_fd, 0);
493 dup2 (dev_null_fd, 1);
494 s = getenv ("DBUS_DEBUG_OUTPUT");
495 if (s == NULL || *s == '\0')
496 dup2 (dev_null_fd, 2);
500 fprintf (stderr, "Failed to open /dev/null: %s\n",
502 /* continue, why not */
509 fprintf (stderr, "fork() failed in babysitter: %s\n",
516 /* Parent reaps pre-fork part of bus daemon, then exits and is
517 * reaped so the babysitter isn't a zombie
520 verbose ("=== Babysitter's intermediate parent continues again\n");
522 if (do_waitpid (child_pid) < 0)
524 /* shouldn't happen */
525 fprintf (stderr, "Failed waitpid() waiting for bus daemon's parent\n");
529 verbose ("Babysitter's intermediate parent exiting\n");
534 /* Child continues */
535 verbose ("=== Babysitter process created\n");
537 verbose ("Reading PID from daemon\n");
539 switch (read_line (read_bus_pid_fd, buf, MAX_PID_LEN))
543 case READ_STATUS_EOF:
544 fprintf (stderr, "EOF reading PID from bus daemon\n");
547 case READ_STATUS_ERROR:
548 fprintf (stderr, "Error reading PID from bus daemon: %s\n",
555 val = strtol (buf, &end, 0);
556 if (buf == end || end == NULL)
558 fprintf (stderr, "Failed to parse bus PID \"%s\": %s\n",
559 buf, strerror (errno));
563 bus_pid_to_kill = val;
565 verbose ("Got PID %ld from daemon\n",
566 (long) bus_pid_to_kill);
568 /* Write data to launcher */
569 write_pid (write_bus_pid_fd, bus_pid_to_kill);
570 close (write_bus_pid_fd);
572 if (exit_with_session)
574 /* Bus is now started and launcher has needed info;
575 * we connect to X display and tty and wait to
576 * kill bus if requested.
579 kill_bus_when_session_ends ();
582 verbose ("Babysitter exiting\n");
591 main (int argc, char **argv)
593 const char *prev_arg;
595 const char *runprog = NULL;
596 int remaining_args = 0;
597 int exit_with_session;
598 int c_shell_syntax = FALSE;
599 int bourne_shell_syntax = FALSE;
600 int auto_shell_syntax = FALSE;
603 int bus_pid_to_launcher_pipe[2];
604 int bus_pid_to_babysitter_pipe[2];
605 int bus_address_to_launcher_pipe[2];
608 exit_with_session = FALSE;
615 const char *arg = argv[i];
617 if (strcmp (arg, "--help") == 0 ||
618 strcmp (arg, "-h") == 0 ||
619 strcmp (arg, "-?") == 0)
621 else if (strcmp (arg, "--auto-syntax") == 0)
622 auto_shell_syntax = TRUE;
623 else if (strcmp (arg, "-c") == 0 ||
624 strcmp (arg, "--csh-syntax") == 0)
625 c_shell_syntax = TRUE;
626 else if (strcmp (arg, "-s") == 0 ||
627 strcmp (arg, "--sh-syntax") == 0)
628 bourne_shell_syntax = TRUE;
629 else if (strcmp (arg, "--version") == 0)
631 else if (strcmp (arg, "--exit-with-session") == 0)
632 exit_with_session = TRUE;
633 else if (strstr (arg, "--config-file=") == arg)
637 if (config_file != NULL)
639 fprintf (stderr, "--config-file given twice\n");
643 file = strchr (arg, '=');
646 config_file = xstrdup (file);
649 strcmp (prev_arg, "--config-file") == 0)
651 if (config_file != NULL)
653 fprintf (stderr, "--config-file given twice\n");
657 config_file = xstrdup (arg);
659 else if (strcmp (arg, "--config-file") == 0)
660 ; /* wait for next arg */
664 remaining_args = i+1;
673 if (exit_with_session)
674 verbose ("--exit-with-session enabled\n");
676 if (auto_shell_syntax)
678 if ((shname = getenv ("SHELL")) != NULL)
680 if (!strncmp (shname + strlen (shname) - 3, "csh", 3))
681 c_shell_syntax = TRUE;
683 bourne_shell_syntax = TRUE;
686 bourne_shell_syntax = TRUE;
689 if (pipe (bus_pid_to_launcher_pipe) < 0 ||
690 pipe (bus_address_to_launcher_pipe) < 0)
693 "Failed to create pipe: %s\n",
698 bus_pid_to_babysitter_pipe[READ_END] = -1;
699 bus_pid_to_babysitter_pipe[WRITE_END] = -1;
704 fprintf (stderr, "Failed to fork: %s\n",
712 #define MAX_FD_LEN 64
713 char write_pid_fd_as_string[MAX_FD_LEN];
714 char write_address_fd_as_string[MAX_FD_LEN];
716 verbose ("=== Babysitter's intermediate parent created\n");
718 /* Fork once more to create babysitter */
720 if (pipe (bus_pid_to_babysitter_pipe) < 0)
723 "Failed to create pipe: %s\n",
731 fprintf (stderr, "Failed to fork: %s\n",
739 verbose ("=== Babysitter's intermediate parent continues\n");
741 close (bus_pid_to_launcher_pipe[READ_END]);
742 close (bus_address_to_launcher_pipe[READ_END]);
743 close (bus_address_to_launcher_pipe[WRITE_END]);
744 close (bus_pid_to_babysitter_pipe[WRITE_END]);
746 /* babysit() will fork *again*
747 * and will also reap the pre-forked bus
750 babysit (exit_with_session, ret,
751 bus_pid_to_babysitter_pipe[READ_END],
752 bus_pid_to_launcher_pipe[WRITE_END]);
756 verbose ("=== Bus exec process created\n");
758 /* Now we are the bus process (well, almost;
759 * dbus-daemon itself forks again)
761 close (bus_pid_to_launcher_pipe[READ_END]);
762 close (bus_address_to_launcher_pipe[READ_END]);
763 close (bus_pid_to_babysitter_pipe[READ_END]);
764 close (bus_pid_to_launcher_pipe[WRITE_END]);
766 sprintf (write_pid_fd_as_string,
767 "%d", bus_pid_to_babysitter_pipe[WRITE_END]);
769 sprintf (write_address_fd_as_string,
770 "%d", bus_address_to_launcher_pipe[WRITE_END]);
772 verbose ("Calling exec()\n");
774 execlp ("dbus-daemon",
777 "--print-pid", write_pid_fd_as_string,
778 "--print-address", write_address_fd_as_string,
779 config_file ? "--config-file" : "--session",
780 config_file, /* has to be last in this varargs list */
784 "Failed to execute message bus daemon: %s\n",
791 #define MAX_ADDR_LEN 512
793 char bus_address[MAX_ADDR_LEN];
795 verbose ("=== Parent dbus-launch continues\n");
797 close (bus_pid_to_launcher_pipe[WRITE_END]);
798 close (bus_address_to_launcher_pipe[WRITE_END]);
800 verbose ("Waiting for babysitter's intermediate parent\n");
802 /* Immediately reap parent of babysitter
803 * (which was created just for us to reap)
805 if (do_waitpid (ret) < 0)
807 fprintf (stderr, "Failed to waitpid() for babysitter intermediate process: %s\n",
812 verbose ("Reading address from bus\n");
814 /* Read the pipe data, print, and exit */
815 switch (read_line (bus_address_to_launcher_pipe[READ_END],
816 bus_address, MAX_ADDR_LEN))
820 case READ_STATUS_EOF:
821 fprintf (stderr, "EOF in dbus-launch reading address from bus daemon\n");
824 case READ_STATUS_ERROR:
825 fprintf (stderr, "Error in dbus-launch reading address from bus daemon: %s\n",
831 close (bus_address_to_launcher_pipe[READ_END]);
833 verbose ("Reading PID from babysitter\n");
835 switch (read_pid (bus_pid_to_launcher_pipe[READ_END], &bus_pid))
839 case READ_STATUS_EOF:
840 fprintf (stderr, "EOF in dbus-launch reading address from bus daemon\n");
843 case READ_STATUS_ERROR:
844 fprintf (stderr, "Error in dbus-launch reading address from bus daemon: %s\n",
850 close (bus_pid_to_launcher_pipe[READ_END]);
857 envvar = malloc (strlen ("DBUS_SESSION_BUS_ADDRESS=") + strlen (bus_address) + 1);
858 args = malloc (sizeof (char *) * ((argc-remaining_args)+2));
860 if (envvar == NULL || args == NULL)
863 args[0] = xstrdup (runprog);
866 for (i = 1; i <= (argc-remaining_args); i++)
868 size_t len = strlen (argv[remaining_args+i-1])+1;
869 args[i] = malloc (len);
872 strncpy (args[i], argv[remaining_args+i-1], len);
876 strcpy (envvar, "DBUS_SESSION_BUS_ADDRESS=");
877 strcat (envvar, bus_address);
880 execvp (runprog, args);
881 fprintf (stderr, "Couldn't exec %s: %s\n", runprog, strerror (errno));
887 printf ("setenv DBUS_SESSION_BUS_ADDRESS '%s'\n", bus_address);
890 printf ("DBUS_SESSION_BUS_ADDRESS='%s'\n", bus_address);
891 if (bourne_shell_syntax)
892 printf ("export DBUS_SESSION_BUS_ADDRESS\n");
895 printf ("set DBUS_SESSION_BUS_PID=%ld\n", (long) bus_pid);
897 printf ("DBUS_SESSION_BUS_PID=%ld\n", (long) bus_pid);
900 verbose ("dbus-launch exiting\n");
912 fprintf (stderr, "Out of memory!");