1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-sysdeps-util-unix.c Would be in dbus-sysdeps-unix.c, but not used in libdbus
3 *
4 * Copyright (C) 2002, 2003, 2004, 2005 Red Hat, Inc.
5 * Copyright (C) 2003 CodeFactory AB
6 *
7 * Licensed under the Academic Free License version 2.1
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 *
23 */
24
25 #include <config.h>
26 #include "dbus-sysdeps.h"
27 #include "dbus-sysdeps-unix.h"
28 #include "dbus-internals.h"
29 #include "dbus-list.h"
30 #include "dbus-pipe.h"
31 #include "dbus-protocol.h"
32 #include "dbus-string.h"
33 #define DBUS_USERDB_INCLUDES_PRIVATE 1
34 #include "dbus-userdb.h"
35 #include "dbus-test.h"
36
37 #include <sys/types.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <signal.h>
41 #include <unistd.h>
42 #include <stdio.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <syslog.h>
46 #include <sys/stat.h>
47 #ifdef HAVE_SYS_RESOURCE_H
48 #include <sys/resource.h>
49 #endif
50 #include <grp.h>
51 #include <sys/socket.h>
52 #include <dirent.h>
53 #include <sys/un.h>
54
55 #ifdef HAVE_SYS_SYSLIMITS_H
56 #include <sys/syslimits.h>
57 #endif
58
59 #ifdef HAVE_SYSTEMD
60 #include <systemd/sd-daemon.h>
61 #endif
62
63 #ifndef O_BINARY
64 #define O_BINARY 0
65 #endif
66
67 /**
68 * @addtogroup DBusInternalsUtils
69 * @{
70 */
71
72
73 /**
74 * Does the chdir, fork, setsid, etc. to become a daemon process.
75 *
76 * @param pidfile #NULL, or pidfile to create
77 * @param print_pid_pipe pipe to print daemon's pid to, or -1 for none
78 * @param error return location for errors
79 * @param keep_umask #TRUE to keep the original umask
80 * @returns #FALSE on failure
81 */
82 dbus_bool_t
_dbus_become_daemon(const DBusString * pidfile,DBusPipe * print_pid_pipe,DBusError * error,dbus_bool_t keep_umask)83 _dbus_become_daemon (const DBusString *pidfile,
84 DBusPipe *print_pid_pipe,
85 DBusError *error,
86 dbus_bool_t keep_umask)
87 {
88 const char *s;
89 pid_t child_pid;
90 DBusEnsureStandardFdsFlags flags;
91
92 _dbus_verbose ("Becoming a daemon...\n");
93
94 _dbus_verbose ("chdir to /\n");
95 if (chdir ("/") < 0)
96 {
97 dbus_set_error (error, DBUS_ERROR_FAILED,
98 "Could not chdir() to root directory");
99 return FALSE;
100 }
101
102 _dbus_verbose ("forking...\n");
103 switch ((child_pid = fork ()))
104 {
105 case -1:
106 _dbus_verbose ("fork failed\n");
107 dbus_set_error (error, _dbus_error_from_errno (errno),
108 "Failed to fork daemon: %s", _dbus_strerror (errno));
109 return FALSE;
110 break;
111
112 case 0:
113 _dbus_verbose ("in child, closing std file descriptors\n");
114
115 flags = DBUS_FORCE_STDIN_NULL | DBUS_FORCE_STDOUT_NULL;
116 s = _dbus_getenv ("DBUS_DEBUG_OUTPUT");
117
118 if (s == NULL || *s == '\0')
119 flags |= DBUS_FORCE_STDERR_NULL;
120 else
121 _dbus_verbose ("keeping stderr open due to DBUS_DEBUG_OUTPUT\n");
122
123 if (!_dbus_ensure_standard_fds (flags, &s))
124 {
125 _dbus_warn ("%s: %s", s, _dbus_strerror (errno));
126 _exit (1);
127 }
128
129 if (!keep_umask)
130 {
131 /* Get a predictable umask */
132 _dbus_verbose ("setting umask\n");
133 umask (022);
134 }
135
136 _dbus_verbose ("calling setsid()\n");
137 if (setsid () == -1)
138 _dbus_assert_not_reached ("setsid() failed");
139
140 break;
141
142 default:
143 if (!_dbus_write_pid_to_file_and_pipe (pidfile, print_pid_pipe,
144 child_pid, error))
145 {
146 _dbus_verbose ("pid file or pipe write failed: %s\n",
147 error->message);
148 kill (child_pid, SIGTERM);
149 return FALSE;
150 }
151
152 _dbus_verbose ("parent exiting\n");
153 _exit (0);
154 break;
155 }
156
157 return TRUE;
158 }
159
160
161 /**
162 * Creates a file containing the process ID.
163 *
164 * @param filename the filename to write to
165 * @param pid our process ID
166 * @param error return location for errors
167 * @returns #FALSE on failure
168 */
169 static dbus_bool_t
_dbus_write_pid_file(const DBusString * filename,unsigned long pid,DBusError * error)170 _dbus_write_pid_file (const DBusString *filename,
171 unsigned long pid,
172 DBusError *error)
173 {
174 const char *cfilename;
175 int fd;
176 FILE *f;
177
178 cfilename = _dbus_string_get_const_data (filename);
179
180 fd = open (cfilename, O_WRONLY|O_CREAT|O_EXCL|O_BINARY, 0644);
181
182 if (fd < 0)
183 {
184 dbus_set_error (error, _dbus_error_from_errno (errno),
185 "Failed to open \"%s\": %s", cfilename,
186 _dbus_strerror (errno));
187 return FALSE;
188 }
189
190 if ((f = fdopen (fd, "w")) == NULL)
191 {
192 dbus_set_error (error, _dbus_error_from_errno (errno),
193 "Failed to fdopen fd %d: %s", fd, _dbus_strerror (errno));
194 _dbus_close (fd, NULL);
195 return FALSE;
196 }
197
198 if (fprintf (f, "%lu\n", pid) < 0)
199 {
200 dbus_set_error (error, _dbus_error_from_errno (errno),
201 "Failed to write to \"%s\": %s", cfilename,
202 _dbus_strerror (errno));
203
204 fclose (f);
205 return FALSE;
206 }
207
208 if (fclose (f) == EOF)
209 {
210 dbus_set_error (error, _dbus_error_from_errno (errno),
211 "Failed to close \"%s\": %s", cfilename,
212 _dbus_strerror (errno));
213 return FALSE;
214 }
215
216 return TRUE;
217 }
218
219 /**
220 * Writes the given pid_to_write to a pidfile (if non-NULL) and/or to a
221 * pipe (if non-NULL). Does nothing if pidfile and print_pid_pipe are both
222 * NULL.
223 *
224 * @param pidfile the file to write to or #NULL
225 * @param print_pid_pipe the pipe to write to or #NULL
226 * @param pid_to_write the pid to write out
227 * @param error error on failure
228 * @returns FALSE if error is set
229 */
230 dbus_bool_t
_dbus_write_pid_to_file_and_pipe(const DBusString * pidfile,DBusPipe * print_pid_pipe,dbus_pid_t pid_to_write,DBusError * error)231 _dbus_write_pid_to_file_and_pipe (const DBusString *pidfile,
232 DBusPipe *print_pid_pipe,
233 dbus_pid_t pid_to_write,
234 DBusError *error)
235 {
236 if (pidfile)
237 {
238 _dbus_verbose ("writing pid file %s\n", _dbus_string_get_const_data (pidfile));
239 if (!_dbus_write_pid_file (pidfile,
240 pid_to_write,
241 error))
242 {
243 _dbus_verbose ("pid file write failed\n");
244 _DBUS_ASSERT_ERROR_IS_SET(error);
245 return FALSE;
246 }
247 }
248 else
249 {
250 _dbus_verbose ("No pid file requested\n");
251 }
252
253 if (print_pid_pipe != NULL && _dbus_pipe_is_valid (print_pid_pipe))
254 {
255 DBusString pid;
256 int bytes;
257
258 _dbus_verbose ("writing our pid to pipe %d\n",
259 print_pid_pipe->fd);
260
261 if (!_dbus_string_init (&pid))
262 {
263 _DBUS_SET_OOM (error);
264 return FALSE;
265 }
266
267 if (!_dbus_string_append_int (&pid, pid_to_write) ||
268 !_dbus_string_append (&pid, "\n"))
269 {
270 _dbus_string_free (&pid);
271 _DBUS_SET_OOM (error);
272 return FALSE;
273 }
274
275 bytes = _dbus_string_get_length (&pid);
276 if (_dbus_pipe_write (print_pid_pipe, &pid, 0, bytes, error) != bytes)
277 {
278 /* _dbus_pipe_write sets error only on failure, not short write */
279 if (error != NULL && !dbus_error_is_set(error))
280 {
281 dbus_set_error (error, DBUS_ERROR_FAILED,
282 "Printing message bus PID: did not write enough bytes\n");
283 }
284 _dbus_string_free (&pid);
285 return FALSE;
286 }
287
288 _dbus_string_free (&pid);
289 }
290 else
291 {
292 _dbus_verbose ("No pid pipe to write to\n");
293 }
294
295 return TRUE;
296 }
297
298 /**
299 * Verify that after the fork we can successfully change to this user.
300 *
301 * @param user the username given in the daemon configuration
302 * @returns #TRUE if username is valid
303 */
304 dbus_bool_t
_dbus_verify_daemon_user(const char * user)305 _dbus_verify_daemon_user (const char *user)
306 {
307 DBusString u;
308
309 _dbus_string_init_const (&u, user);
310
311 return _dbus_get_user_id_and_primary_group (&u, NULL, NULL);
312 }
313
314
315 /* The HAVE_LIBAUDIT case lives in selinux.c */
316 #ifndef HAVE_LIBAUDIT
317 /**
318 * Changes the user and group the bus is running as.
319 *
320 * @param user the user to become
321 * @param error return location for errors
322 * @returns #FALSE on failure
323 */
324 dbus_bool_t
_dbus_change_to_daemon_user(const char * user,DBusError * error)325 _dbus_change_to_daemon_user (const char *user,
326 DBusError *error)
327 {
328 dbus_uid_t uid;
329 dbus_gid_t gid;
330 DBusString u;
331
332 _dbus_string_init_const (&u, user);
333
334 if (!_dbus_get_user_id_and_primary_group (&u, &uid, &gid))
335 {
336 dbus_set_error (error, DBUS_ERROR_FAILED,
337 "User '%s' does not appear to exist?",
338 user);
339 return FALSE;
340 }
341
342 /* setgroups() only works if we are a privileged process,
343 * so we don't return error on failure; the only possible
344 * failure is that we don't have perms to do it.
345 *
346 * not sure this is right, maybe if setuid()
347 * is going to work then setgroups() should also work.
348 */
349 if (setgroups (0, NULL) < 0)
350 _dbus_warn ("Failed to drop supplementary groups: %s",
351 _dbus_strerror (errno));
352
353 /* Set GID first, or the setuid may remove our permission
354 * to change the GID
355 */
356 if (setgid (gid) < 0)
357 {
358 dbus_set_error (error, _dbus_error_from_errno (errno),
359 "Failed to set GID to %lu: %s", gid,
360 _dbus_strerror (errno));
361 return FALSE;
362 }
363
364 if (setuid (uid) < 0)
365 {
366 dbus_set_error (error, _dbus_error_from_errno (errno),
367 "Failed to set UID to %lu: %s", uid,
368 _dbus_strerror (errno));
369 return FALSE;
370 }
371
372 return TRUE;
373 }
374 #endif /* !HAVE_LIBAUDIT */
375
376 #ifdef HAVE_SETRLIMIT
377
378 /* We assume that if we have setrlimit, we also have getrlimit and
379 * struct rlimit.
380 */
381
382 struct DBusRLimit {
383 struct rlimit lim;
384 };
385
386 DBusRLimit *
_dbus_rlimit_save_fd_limit(DBusError * error)387 _dbus_rlimit_save_fd_limit (DBusError *error)
388 {
389 DBusRLimit *self;
390
391 self = dbus_new0 (DBusRLimit, 1);
392
393 if (self == NULL)
394 {
395 _DBUS_SET_OOM (error);
396 return NULL;
397 }
398
399 if (getrlimit (RLIMIT_NOFILE, &self->lim) < 0)
400 {
401 dbus_set_error (error, _dbus_error_from_errno (errno),
402 "Failed to get fd limit: %s", _dbus_strerror (errno));
403 dbus_free (self);
404 return NULL;
405 }
406
407 return self;
408 }
409
410 /* Enough fds that we shouldn't run out, even if several uids work
411 * together to carry out a denial-of-service attack. This happens to be
412 * the same number that systemd < 234 would normally use. */
413 #define ENOUGH_FDS 65536
414
415 dbus_bool_t
_dbus_rlimit_raise_fd_limit(DBusError * error)416 _dbus_rlimit_raise_fd_limit (DBusError *error)
417 {
418 struct rlimit old, lim;
419
420 if (getrlimit (RLIMIT_NOFILE, &lim) < 0)
421 {
422 dbus_set_error (error, _dbus_error_from_errno (errno),
423 "Failed to get fd limit: %s", _dbus_strerror (errno));
424 return FALSE;
425 }
426
427 old = lim;
428
429 if (getuid () == 0)
430 {
431 /* We are privileged, so raise the soft limit to at least
432 * ENOUGH_FDS, and the hard limit to at least the desired soft
433 * limit. This assumes we can exercise CAP_SYS_RESOURCE on Linux,
434 * or other OSs' equivalents. */
435 if (lim.rlim_cur != RLIM_INFINITY &&
436 lim.rlim_cur < ENOUGH_FDS)
437 lim.rlim_cur = ENOUGH_FDS;
438
439 if (lim.rlim_max != RLIM_INFINITY &&
440 lim.rlim_max < lim.rlim_cur)
441 lim.rlim_max = lim.rlim_cur;
442 }
443
444 /* Raise the soft limit to match the hard limit, which we can do even
445 * if we are unprivileged. In particular, systemd >= 240 will normally
446 * set rlim_cur to 1024 and rlim_max to 512*1024, recent Debian
447 * versions end up setting rlim_cur to 1024 and rlim_max to 1024*1024,
448 * and older and non-systemd Linux systems would typically set rlim_cur
449 * to 1024 and rlim_max to 4096. */
450 if (lim.rlim_max == RLIM_INFINITY || lim.rlim_cur < lim.rlim_max)
451 lim.rlim_cur = lim.rlim_max;
452
453 /* Early-return if there is nothing to do. */
454 if (lim.rlim_max == old.rlim_max &&
455 lim.rlim_cur == old.rlim_cur)
456 return TRUE;
457
458 if (setrlimit (RLIMIT_NOFILE, &lim) < 0)
459 {
460 dbus_set_error (error, _dbus_error_from_errno (errno),
461 "Failed to set fd limit to %lu: %s",
462 (unsigned long) lim.rlim_cur,
463 _dbus_strerror (errno));
464 return FALSE;
465 }
466
467 return TRUE;
468 }
469
470 dbus_bool_t
_dbus_rlimit_restore_fd_limit(DBusRLimit * saved,DBusError * error)471 _dbus_rlimit_restore_fd_limit (DBusRLimit *saved,
472 DBusError *error)
473 {
474 if (setrlimit (RLIMIT_NOFILE, &saved->lim) < 0)
475 {
476 dbus_set_error (error, _dbus_error_from_errno (errno),
477 "Failed to restore old fd limit: %s",
478 _dbus_strerror (errno));
479 return FALSE;
480 }
481
482 return TRUE;
483 }
484
485 #else /* !HAVE_SETRLIMIT */
486
487 static void
fd_limit_not_supported(DBusError * error)488 fd_limit_not_supported (DBusError *error)
489 {
490 dbus_set_error (error, DBUS_ERROR_NOT_SUPPORTED,
491 "cannot change fd limit on this platform");
492 }
493
494 DBusRLimit *
_dbus_rlimit_save_fd_limit(DBusError * error)495 _dbus_rlimit_save_fd_limit (DBusError *error)
496 {
497 fd_limit_not_supported (error);
498 return NULL;
499 }
500
501 dbus_bool_t
_dbus_rlimit_raise_fd_limit(DBusError * error)502 _dbus_rlimit_raise_fd_limit (DBusError *error)
503 {
504 fd_limit_not_supported (error);
505 return FALSE;
506 }
507
508 dbus_bool_t
_dbus_rlimit_restore_fd_limit(DBusRLimit * saved,DBusError * error)509 _dbus_rlimit_restore_fd_limit (DBusRLimit *saved,
510 DBusError *error)
511 {
512 fd_limit_not_supported (error);
513 return FALSE;
514 }
515
516 #endif
517
518 void
_dbus_rlimit_free(DBusRLimit * lim)519 _dbus_rlimit_free (DBusRLimit *lim)
520 {
521 dbus_free (lim);
522 }
523
524 /** Installs a UNIX signal handler
525 *
526 * @param sig the signal to handle
527 * @param handler the handler
528 */
529 void
_dbus_set_signal_handler(int sig,DBusSignalHandler handler)530 _dbus_set_signal_handler (int sig,
531 DBusSignalHandler handler)
532 {
533 struct sigaction act;
534 sigset_t empty_mask;
535
536 sigemptyset (&empty_mask);
537 act.sa_handler = handler;
538 act.sa_mask = empty_mask;
539 act.sa_flags = 0;
540 sigaction (sig, &act, NULL);
541 }
542
543 /** Checks if a file exists
544 *
545 * @param file full path to the file
546 * @returns #TRUE if file exists
547 */
548 dbus_bool_t
_dbus_file_exists(const char * file)549 _dbus_file_exists (const char *file)
550 {
551 return (access (file, F_OK) == 0);
552 }
553
554 /** Checks if user is at the console
555 *
556 * @param username user to check
557 * @param error return location for errors
558 * @returns #TRUE is the user is at the consolei and there are no errors
559 */
560 dbus_bool_t
_dbus_user_at_console(const char * username,DBusError * error)561 _dbus_user_at_console (const char *username,
562 DBusError *error)
563 {
564 #ifdef DBUS_CONSOLE_AUTH_DIR
565 DBusString u, f;
566 dbus_bool_t result;
567
568 result = FALSE;
569 if (!_dbus_string_init (&f))
570 {
571 _DBUS_SET_OOM (error);
572 return FALSE;
573 }
574
575 if (!_dbus_string_append (&f, DBUS_CONSOLE_AUTH_DIR))
576 {
577 _DBUS_SET_OOM (error);
578 goto out;
579 }
580
581 _dbus_string_init_const (&u, username);
582
583 if (!_dbus_concat_dir_and_file (&f, &u))
584 {
585 _DBUS_SET_OOM (error);
586 goto out;
587 }
588
589 result = _dbus_file_exists (_dbus_string_get_const_data (&f));
590
591 out:
592 _dbus_string_free (&f);
593
594 return result;
595 #else
596 return FALSE;
597 #endif
598 }
599
600
601 /**
602 * Checks whether the filename is an absolute path
603 *
604 * @param filename the filename
605 * @returns #TRUE if an absolute path
606 */
607 dbus_bool_t
_dbus_path_is_absolute(const DBusString * filename)608 _dbus_path_is_absolute (const DBusString *filename)
609 {
610 if (_dbus_string_get_length (filename) > 0)
611 return _dbus_string_get_byte (filename, 0) == '/';
612 else
613 return FALSE;
614 }
615
616 /**
617 * stat() wrapper.
618 *
619 * @param filename the filename to stat
620 * @param statbuf the stat info to fill in
621 * @param error return location for error
622 * @returns #FALSE if error was set
623 */
624 dbus_bool_t
_dbus_stat(const DBusString * filename,DBusStat * statbuf,DBusError * error)625 _dbus_stat (const DBusString *filename,
626 DBusStat *statbuf,
627 DBusError *error)
628 {
629 const char *filename_c;
630 struct stat sb;
631
632 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
633
634 filename_c = _dbus_string_get_const_data (filename);
635
636 if (stat (filename_c, &sb) < 0)
637 {
638 dbus_set_error (error, _dbus_error_from_errno (errno),
639 "%s", _dbus_strerror (errno));
640 return FALSE;
641 }
642
643 statbuf->mode = sb.st_mode;
644 statbuf->nlink = sb.st_nlink;
645 statbuf->uid = sb.st_uid;
646 statbuf->gid = sb.st_gid;
647 statbuf->size = sb.st_size;
648 statbuf->atime = sb.st_atime;
649 statbuf->mtime = sb.st_mtime;
650 statbuf->ctime = sb.st_ctime;
651
652 return TRUE;
653 }
654
655
656 /**
657 * Internals of directory iterator
658 */
659 struct DBusDirIter
660 {
661 DIR *d; /**< The DIR* from opendir() */
662
663 };
664
665 /**
666 * Open a directory to iterate over.
667 *
668 * @param filename the directory name
669 * @param error exception return object or #NULL
670 * @returns new iterator, or #NULL on error
671 */
672 DBusDirIter*
_dbus_directory_open(const DBusString * filename,DBusError * error)673 _dbus_directory_open (const DBusString *filename,
674 DBusError *error)
675 {
676 DIR *d;
677 DBusDirIter *iter;
678 const char *filename_c;
679
680 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
681
682 filename_c = _dbus_string_get_const_data (filename);
683
684 d = opendir (filename_c);
685 if (d == NULL)
686 {
687 dbus_set_error (error, _dbus_error_from_errno (errno),
688 "Failed to read directory \"%s\": %s",
689 filename_c,
690 _dbus_strerror (errno));
691 return NULL;
692 }
693 iter = dbus_new0 (DBusDirIter, 1);
694 if (iter == NULL)
695 {
696 closedir (d);
697 dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
698 "Could not allocate memory for directory iterator");
699 return NULL;
700 }
701
702 iter->d = d;
703
704 return iter;
705 }
706
707 /**
708 * Get next file in the directory. Will not return "." or ".." on
709 * UNIX. If an error occurs, the contents of "filename" are
710 * undefined. The error is never set if the function succeeds.
711 *
712 * This function is not re-entrant, and not necessarily thread-safe.
713 * Only use it for test code or single-threaded utilities.
714 *
715 * @param iter the iterator
716 * @param filename string to be set to the next file in the dir
717 * @param error return location for error
718 * @returns #TRUE if filename was filled in with a new filename
719 */
720 dbus_bool_t
_dbus_directory_get_next_file(DBusDirIter * iter,DBusString * filename,DBusError * error)721 _dbus_directory_get_next_file (DBusDirIter *iter,
722 DBusString *filename,
723 DBusError *error)
724 {
725 struct dirent *ent;
726 int err;
727
728 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
729
730 again:
731 errno = 0;
732 ent = readdir (iter->d);
733
734 if (!ent)
735 {
736 err = errno;
737
738 if (err != 0)
739 dbus_set_error (error,
740 _dbus_error_from_errno (err),
741 "%s", _dbus_strerror (err));
742
743 return FALSE;
744 }
745 else if (ent->d_name[0] == '.' &&
746 (ent->d_name[1] == '\0' ||
747 (ent->d_name[1] == '.' && ent->d_name[2] == '\0')))
748 goto again;
749 else
750 {
751 _dbus_string_set_length (filename, 0);
752 if (!_dbus_string_append (filename, ent->d_name))
753 {
754 dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
755 "No memory to read directory entry");
756 return FALSE;
757 }
758 else
759 {
760 return TRUE;
761 }
762 }
763 }
764
765 /**
766 * Closes a directory iteration.
767 */
768 void
_dbus_directory_close(DBusDirIter * iter)769 _dbus_directory_close (DBusDirIter *iter)
770 {
771 closedir (iter->d);
772 dbus_free (iter);
773 }
774
775 static dbus_bool_t
fill_user_info_from_group(struct group * g,DBusGroupInfo * info,DBusError * error)776 fill_user_info_from_group (struct group *g,
777 DBusGroupInfo *info,
778 DBusError *error)
779 {
780 _dbus_assert (g->gr_name != NULL);
781
782 info->gid = g->gr_gid;
783 info->groupname = _dbus_strdup (g->gr_name);
784
785 /* info->members = dbus_strdupv (g->gr_mem) */
786
787 if (info->groupname == NULL)
788 {
789 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
790 return FALSE;
791 }
792
793 return TRUE;
794 }
795
796 static dbus_bool_t
fill_group_info(DBusGroupInfo * info,dbus_gid_t gid,const DBusString * groupname,DBusError * error)797 fill_group_info (DBusGroupInfo *info,
798 dbus_gid_t gid,
799 const DBusString *groupname,
800 DBusError *error)
801 {
802 const char *group_c_str;
803
804 _dbus_assert (groupname != NULL || gid != DBUS_GID_UNSET);
805 _dbus_assert (groupname == NULL || gid == DBUS_GID_UNSET);
806
807 if (groupname)
808 group_c_str = _dbus_string_get_const_data (groupname);
809 else
810 group_c_str = NULL;
811
812 /* For now assuming that the getgrnam() and getgrgid() flavors
813 * always correspond to the pwnam flavors, if not we have
814 * to add more configure checks.
815 */
816
817 #if defined (HAVE_POSIX_GETPWNAM_R) || defined (HAVE_NONPOSIX_GETPWNAM_R)
818 {
819 struct group *g;
820 int result;
821 size_t buflen;
822 char *buf;
823 struct group g_str;
824 dbus_bool_t b;
825
826 /* retrieve maximum needed size for buf */
827 buflen = sysconf (_SC_GETGR_R_SIZE_MAX);
828
829 /* sysconf actually returns a long, but everything else expects size_t,
830 * so just recast here.
831 * https://bugs.freedesktop.org/show_bug.cgi?id=17061
832 */
833 if ((long) buflen <= 0)
834 buflen = 1024;
835
836 result = -1;
837 while (1)
838 {
839 buf = dbus_malloc (buflen);
840 if (buf == NULL)
841 {
842 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
843 return FALSE;
844 }
845
846 g = NULL;
847 #ifdef HAVE_POSIX_GETPWNAM_R
848 if (group_c_str)
849 result = getgrnam_r (group_c_str, &g_str, buf, buflen,
850 &g);
851 else
852 result = getgrgid_r (gid, &g_str, buf, buflen,
853 &g);
854 #else
855 g = getgrnam_r (group_c_str, &g_str, buf, buflen);
856 result = 0;
857 #endif /* !HAVE_POSIX_GETPWNAM_R */
858 /* Try a bigger buffer if ERANGE was returned:
859 https://bugs.freedesktop.org/show_bug.cgi?id=16727
860 */
861 if (result == ERANGE && buflen < 512 * 1024)
862 {
863 dbus_free (buf);
864 buflen *= 2;
865 }
866 else
867 {
868 break;
869 }
870 }
871
872 if (result == 0 && g == &g_str)
873 {
874 b = fill_user_info_from_group (g, info, error);
875 dbus_free (buf);
876 return b;
877 }
878 else
879 {
880 dbus_set_error (error, _dbus_error_from_errno (errno),
881 "Group %s unknown or failed to look it up\n",
882 group_c_str ? group_c_str : "???");
883 dbus_free (buf);
884 return FALSE;
885 }
886 }
887 #else /* ! HAVE_GETPWNAM_R */
888 {
889 /* I guess we're screwed on thread safety here */
890 struct group *g;
891
892 g = getgrnam (group_c_str);
893
894 if (g != NULL)
895 {
896 return fill_user_info_from_group (g, info, error);
897 }
898 else
899 {
900 dbus_set_error (error, _dbus_error_from_errno (errno),
901 "Group %s unknown or failed to look it up\n",
902 group_c_str ? group_c_str : "???");
903 return FALSE;
904 }
905 }
906 #endif /* ! HAVE_GETPWNAM_R */
907 }
908
909 /**
910 * Initializes the given DBusGroupInfo struct
911 * with information about the given group name.
912 *
913 * @param info the group info struct
914 * @param groupname name of group
915 * @param error the error return
916 * @returns #FALSE if error is set
917 */
918 dbus_bool_t
_dbus_group_info_fill(DBusGroupInfo * info,const DBusString * groupname,DBusError * error)919 _dbus_group_info_fill (DBusGroupInfo *info,
920 const DBusString *groupname,
921 DBusError *error)
922 {
923 return fill_group_info (info, DBUS_GID_UNSET,
924 groupname, error);
925
926 }
927
928 /**
929 * Initializes the given DBusGroupInfo struct
930 * with information about the given group ID.
931 *
932 * @param info the group info struct
933 * @param gid group ID
934 * @param error the error return
935 * @returns #FALSE if error is set
936 */
937 dbus_bool_t
_dbus_group_info_fill_gid(DBusGroupInfo * info,dbus_gid_t gid,DBusError * error)938 _dbus_group_info_fill_gid (DBusGroupInfo *info,
939 dbus_gid_t gid,
940 DBusError *error)
941 {
942 return fill_group_info (info, gid, NULL, error);
943 }
944
945 /**
946 * Parse a UNIX user from the bus config file. On Windows, this should
947 * simply always fail (just return #FALSE).
948 *
949 * @param username the username text
950 * @param uid_p place to return the uid
951 * @returns #TRUE on success
952 */
953 dbus_bool_t
_dbus_parse_unix_user_from_config(const DBusString * username,dbus_uid_t * uid_p)954 _dbus_parse_unix_user_from_config (const DBusString *username,
955 dbus_uid_t *uid_p)
956 {
957 return _dbus_get_user_id (username, uid_p);
958
959 }
960
961 /**
962 * Parse a UNIX group from the bus config file. On Windows, this should
963 * simply always fail (just return #FALSE).
964 *
965 * @param groupname the groupname text
966 * @param gid_p place to return the gid
967 * @returns #TRUE on success
968 */
969 dbus_bool_t
_dbus_parse_unix_group_from_config(const DBusString * groupname,dbus_gid_t * gid_p)970 _dbus_parse_unix_group_from_config (const DBusString *groupname,
971 dbus_gid_t *gid_p)
972 {
973 return _dbus_get_group_id (groupname, gid_p);
974 }
975
976 /**
977 * Gets all groups corresponding to the given UNIX user ID. On UNIX,
978 * just calls _dbus_groups_from_uid(). On Windows, should always
979 * fail since we don't know any UNIX groups.
980 *
981 * @param uid the UID
982 * @param group_ids return location for array of group IDs
983 * @param n_group_ids return location for length of returned array
984 * @returns #TRUE if the UID existed and we got some credentials
985 */
986 dbus_bool_t
_dbus_unix_groups_from_uid(dbus_uid_t uid,dbus_gid_t ** group_ids,int * n_group_ids)987 _dbus_unix_groups_from_uid (dbus_uid_t uid,
988 dbus_gid_t **group_ids,
989 int *n_group_ids)
990 {
991 return _dbus_groups_from_uid (uid, group_ids, n_group_ids);
992 }
993
994 /**
995 * Checks to see if the UNIX user ID is at the console.
996 * Should always fail on Windows (set the error to
997 * #DBUS_ERROR_NOT_SUPPORTED).
998 *
999 * @param uid UID of person to check
1000 * @param error return location for errors
1001 * @returns #TRUE if the UID is the same as the console user and there are no errors
1002 */
1003 dbus_bool_t
_dbus_unix_user_is_at_console(dbus_uid_t uid,DBusError * error)1004 _dbus_unix_user_is_at_console (dbus_uid_t uid,
1005 DBusError *error)
1006 {
1007 return _dbus_is_console_user (uid, error);
1008
1009 }
1010
1011 /**
1012 * Checks to see if the UNIX user ID matches the UID of
1013 * the process. Should always return #FALSE on Windows.
1014 *
1015 * @param uid the UNIX user ID
1016 * @returns #TRUE if this uid owns the process.
1017 */
1018 dbus_bool_t
_dbus_unix_user_is_process_owner(dbus_uid_t uid)1019 _dbus_unix_user_is_process_owner (dbus_uid_t uid)
1020 {
1021 return uid == _dbus_geteuid ();
1022 }
1023
1024 /**
1025 * Checks to see if the Windows user SID matches the owner of
1026 * the process. Should always return #FALSE on UNIX.
1027 *
1028 * @param windows_sid the Windows user SID
1029 * @returns #TRUE if this user owns the process.
1030 */
1031 dbus_bool_t
_dbus_windows_user_is_process_owner(const char * windows_sid)1032 _dbus_windows_user_is_process_owner (const char *windows_sid)
1033 {
1034 return FALSE;
1035 }
1036
1037 /** @} */ /* End of DBusInternalsUtils functions */
1038
1039 /**
1040 * @addtogroup DBusString
1041 *
1042 * @{
1043 */
1044 /**
1045 * Get the directory name from a complete filename
1046 * @param filename the filename
1047 * @param dirname string to append directory name to
1048 * @returns #FALSE if no memory
1049 */
1050 dbus_bool_t
_dbus_string_get_dirname(const DBusString * filename,DBusString * dirname)1051 _dbus_string_get_dirname (const DBusString *filename,
1052 DBusString *dirname)
1053 {
1054 int sep;
1055
1056 _dbus_assert (filename != dirname);
1057 _dbus_assert (filename != NULL);
1058 _dbus_assert (dirname != NULL);
1059
1060 /* Ignore any separators on the end */
1061 sep = _dbus_string_get_length (filename);
1062 if (sep == 0)
1063 return _dbus_string_append (dirname, "."); /* empty string passed in */
1064
1065 while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
1066 --sep;
1067
1068 _dbus_assert (sep >= 0);
1069
1070 if (sep == 0)
1071 return _dbus_string_append (dirname, "/");
1072
1073 /* Now find the previous separator */
1074 _dbus_string_find_byte_backward (filename, sep, '/', &sep);
1075 if (sep < 0)
1076 return _dbus_string_append (dirname, ".");
1077
1078 /* skip multiple separators */
1079 while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
1080 --sep;
1081
1082 _dbus_assert (sep >= 0);
1083
1084 if (sep == 0 &&
1085 _dbus_string_get_byte (filename, 0) == '/')
1086 return _dbus_string_append (dirname, "/");
1087 else
1088 return _dbus_string_copy_len (filename, 0, sep - 0,
1089 dirname, _dbus_string_get_length (dirname));
1090 }
1091 /** @} */ /* DBusString stuff */
1092
1093 static void
string_squash_nonprintable(DBusString * str)1094 string_squash_nonprintable (DBusString *str)
1095 {
1096 unsigned char *buf;
1097 int i, len;
1098
1099 buf = _dbus_string_get_udata (str);
1100 len = _dbus_string_get_length (str);
1101
1102 for (i = 0; i < len; i++)
1103 {
1104 unsigned char c = (unsigned char) buf[i];
1105 if (c == '\0')
1106 buf[i] = ' ';
1107 else if (c < 0x20 || c > 127)
1108 buf[i] = '?';
1109 }
1110 }
1111
1112 /**
1113 * Get a printable string describing the command used to execute
1114 * the process with pid. This string should only be used for
1115 * informative purposes such as logging; it may not be trusted.
1116 *
1117 * The command is guaranteed to be printable ASCII and no longer
1118 * than max_len.
1119 *
1120 * @param pid Process id
1121 * @param str Append command to this string
1122 * @param max_len Maximum length of returned command
1123 * @param error return location for errors
1124 * @returns #FALSE on error
1125 */
1126 dbus_bool_t
_dbus_command_for_pid(unsigned long pid,DBusString * str,int max_len,DBusError * error)1127 _dbus_command_for_pid (unsigned long pid,
1128 DBusString *str,
1129 int max_len,
1130 DBusError *error)
1131 {
1132 /* This is all Linux-specific for now */
1133 DBusString path;
1134 DBusString cmdline;
1135 int fd;
1136
1137 if (!_dbus_string_init (&path))
1138 {
1139 _DBUS_SET_OOM (error);
1140 return FALSE;
1141 }
1142
1143 if (!_dbus_string_init (&cmdline))
1144 {
1145 _DBUS_SET_OOM (error);
1146 _dbus_string_free (&path);
1147 return FALSE;
1148 }
1149
1150 if (!_dbus_string_append_printf (&path, "/proc/%ld/cmdline", pid))
1151 goto oom;
1152
1153 fd = open (_dbus_string_get_const_data (&path), O_RDONLY);
1154 if (fd < 0)
1155 {
1156 dbus_set_error (error,
1157 _dbus_error_from_errno (errno),
1158 "Failed to open \"%s\": %s",
1159 _dbus_string_get_const_data (&path),
1160 _dbus_strerror (errno));
1161 goto fail;
1162 }
1163
1164 if (!_dbus_read (fd, &cmdline, max_len))
1165 {
1166 dbus_set_error (error,
1167 _dbus_error_from_errno (errno),
1168 "Failed to read from \"%s\": %s",
1169 _dbus_string_get_const_data (&path),
1170 _dbus_strerror (errno));
1171 _dbus_close (fd, NULL);
1172 goto fail;
1173 }
1174
1175 if (!_dbus_close (fd, error))
1176 goto fail;
1177
1178 string_squash_nonprintable (&cmdline);
1179
1180 if (!_dbus_string_copy (&cmdline, 0, str, _dbus_string_get_length (str)))
1181 goto oom;
1182
1183 _dbus_string_free (&cmdline);
1184 _dbus_string_free (&path);
1185 return TRUE;
1186 oom:
1187 _DBUS_SET_OOM (error);
1188 fail:
1189 _dbus_string_free (&cmdline);
1190 _dbus_string_free (&path);
1191 return FALSE;
1192 }
1193
1194 /**
1195 * Replace the DBUS_PREFIX in the given path, in-place, by the
1196 * current D-Bus installation directory. On Unix this function
1197 * does nothing, successfully.
1198 *
1199 * @param path path to edit
1200 * @return #FALSE on OOM
1201 */
1202 dbus_bool_t
_dbus_replace_install_prefix(DBusString * path)1203 _dbus_replace_install_prefix (DBusString *path)
1204 {
1205 return TRUE;
1206 }
1207
1208 static dbus_bool_t
ensure_owned_directory(const char * label,const DBusString * string,dbus_bool_t create,DBusError * error)1209 ensure_owned_directory (const char *label,
1210 const DBusString *string,
1211 dbus_bool_t create,
1212 DBusError *error)
1213 {
1214 const char *dir = _dbus_string_get_const_data (string);
1215 struct stat buf;
1216
1217 if (create && !_dbus_ensure_directory (string, error))
1218 return FALSE;
1219
1220 /*
1221 * The stat()-based checks in this function are to protect against
1222 * mistakes, not malice. We are working in a directory that is meant
1223 * to be trusted; but if a user has used `su` or similar to escalate
1224 * their privileges without correctly clearing the environment, the
1225 * XDG_RUNTIME_DIR in the environment might still be the user's
1226 * and not root's. We don't want to write root-owned files into that
1227 * directory, so just warn and don't provide support for transient
1228 * services in that case.
1229 *
1230 * In particular, we use stat() and not lstat() so that if we later
1231 * decide to use a different directory name for transient services,
1232 * we can drop in a compatibility symlink without breaking older
1233 * libdbus.
1234 */
1235
1236 if (stat (dir, &buf) != 0)
1237 {
1238 int saved_errno = errno;
1239
1240 dbus_set_error (error, _dbus_error_from_errno (saved_errno),
1241 "%s \"%s\" not available: %s", label, dir,
1242 _dbus_strerror (saved_errno));
1243 return FALSE;
1244 }
1245
1246 if (!S_ISDIR (buf.st_mode))
1247 {
1248 dbus_set_error (error, DBUS_ERROR_FAILED, "%s \"%s\" is not a directory",
1249 label, dir);
1250 return FALSE;
1251 }
1252
1253 if (buf.st_uid != geteuid ())
1254 {
1255 dbus_set_error (error, DBUS_ERROR_FAILED,
1256 "%s \"%s\" is owned by uid %ld, not our uid %ld",
1257 label, dir, (long) buf.st_uid, (long) geteuid ());
1258 return FALSE;
1259 }
1260
1261 /* This is just because we have the stat() results already, so we might
1262 * as well check opportunistically. */
1263 if ((S_IWOTH | S_IWGRP) & buf.st_mode)
1264 {
1265 dbus_set_error (error, DBUS_ERROR_FAILED,
1266 "%s \"%s\" can be written by others (mode 0%o)",
1267 label, dir, buf.st_mode);
1268 return FALSE;
1269 }
1270
1271 return TRUE;
1272 }
1273
1274 #define DBUS_UNIX_STANDARD_SESSION_SERVICEDIR "/dbus-1/services"
1275 #define DBUS_UNIX_STANDARD_SYSTEM_SERVICEDIR "/dbus-1/system-services"
1276
1277 /**
1278 * Returns the standard directories for a session bus to look for
1279 * transient service activation files.
1280 *
1281 * @param dirs the directory list we are returning
1282 * @returns #FALSE on error
1283 */
1284 dbus_bool_t
_dbus_set_up_transient_session_servicedirs(DBusList ** dirs,DBusError * error)1285 _dbus_set_up_transient_session_servicedirs (DBusList **dirs,
1286 DBusError *error)
1287 {
1288 const char *xdg_runtime_dir;
1289 DBusString services;
1290 DBusString dbus1;
1291 DBusString xrd;
1292 dbus_bool_t ret = FALSE;
1293 char *data = NULL;
1294
1295 if (!_dbus_string_init (&dbus1))
1296 {
1297 _DBUS_SET_OOM (error);
1298 return FALSE;
1299 }
1300
1301 if (!_dbus_string_init (&services))
1302 {
1303 _dbus_string_free (&dbus1);
1304 _DBUS_SET_OOM (error);
1305 return FALSE;
1306 }
1307
1308 if (!_dbus_string_init (&xrd))
1309 {
1310 _dbus_string_free (&dbus1);
1311 _dbus_string_free (&services);
1312 _DBUS_SET_OOM (error);
1313 return FALSE;
1314 }
1315
1316 xdg_runtime_dir = _dbus_getenv ("XDG_RUNTIME_DIR");
1317
1318 /* Not an error, we just can't have transient session services */
1319 if (xdg_runtime_dir == NULL)
1320 {
1321 _dbus_verbose ("XDG_RUNTIME_DIR is unset: transient session services "
1322 "not available here\n");
1323 ret = TRUE;
1324 goto out;
1325 }
1326
1327 if (!_dbus_string_append (&xrd, xdg_runtime_dir) ||
1328 !_dbus_string_append_printf (&dbus1, "%s/dbus-1",
1329 xdg_runtime_dir) ||
1330 !_dbus_string_append_printf (&services, "%s/dbus-1/services",
1331 xdg_runtime_dir))
1332 {
1333 _DBUS_SET_OOM (error);
1334 goto out;
1335 }
1336
1337 if (!ensure_owned_directory ("XDG_RUNTIME_DIR", &xrd, FALSE, error) ||
1338 !ensure_owned_directory ("XDG_RUNTIME_DIR subdirectory", &dbus1, TRUE,
1339 error) ||
1340 !ensure_owned_directory ("XDG_RUNTIME_DIR subdirectory", &services,
1341 TRUE, error))
1342 goto out;
1343
1344 if (!_dbus_string_steal_data (&services, &data) ||
1345 !_dbus_list_append (dirs, data))
1346 {
1347 _DBUS_SET_OOM (error);
1348 goto out;
1349 }
1350
1351 _dbus_verbose ("Transient service directory is %s\n", data);
1352 /* Ownership was transferred to @dirs */
1353 data = NULL;
1354 ret = TRUE;
1355
1356 out:
1357 _dbus_string_free (&dbus1);
1358 _dbus_string_free (&services);
1359 _dbus_string_free (&xrd);
1360 dbus_free (data);
1361 return ret;
1362 }
1363
1364 /**
1365 * Returns the standard directories for a session bus to look for service
1366 * activation files
1367 *
1368 * On UNIX this should be the standard xdg freedesktop.org data directories:
1369 *
1370 * XDG_DATA_HOME=${XDG_DATA_HOME-$HOME/.local/share}
1371 * XDG_DATA_DIRS=${XDG_DATA_DIRS-/usr/local/share:/usr/share}
1372 *
1373 * and
1374 *
1375 * DBUS_DATADIR
1376 *
1377 * @param dirs the directory list we are returning
1378 * @returns #FALSE on OOM
1379 */
1380
1381 dbus_bool_t
_dbus_get_standard_session_servicedirs(DBusList ** dirs)1382 _dbus_get_standard_session_servicedirs (DBusList **dirs)
1383 {
1384 const char *xdg_data_home;
1385 const char *xdg_data_dirs;
1386 DBusString servicedir_path;
1387
1388 if (!_dbus_string_init (&servicedir_path))
1389 return FALSE;
1390
1391 xdg_data_home = _dbus_getenv ("XDG_DATA_HOME");
1392 xdg_data_dirs = _dbus_getenv ("XDG_DATA_DIRS");
1393
1394 if (xdg_data_home != NULL)
1395 {
1396 if (!_dbus_string_append (&servicedir_path, xdg_data_home))
1397 goto oom;
1398 }
1399 else
1400 {
1401 const DBusString *homedir;
1402 DBusString local_share;
1403
1404 if (!_dbus_homedir_from_current_process (&homedir))
1405 goto oom;
1406
1407 if (!_dbus_string_append (&servicedir_path, _dbus_string_get_const_data (homedir)))
1408 goto oom;
1409
1410 _dbus_string_init_const (&local_share, "/.local/share");
1411 if (!_dbus_concat_dir_and_file (&servicedir_path, &local_share))
1412 goto oom;
1413 }
1414
1415 if (!_dbus_string_append (&servicedir_path, ":"))
1416 goto oom;
1417
1418 if (xdg_data_dirs != NULL)
1419 {
1420 if (!_dbus_string_append (&servicedir_path, xdg_data_dirs))
1421 goto oom;
1422
1423 if (!_dbus_string_append (&servicedir_path, ":"))
1424 goto oom;
1425 }
1426 else
1427 {
1428 if (!_dbus_string_append (&servicedir_path, "/usr/local/share:/usr/share:"))
1429 goto oom;
1430 }
1431
1432 /*
1433 * add configured datadir to defaults
1434 * this may be the same as an xdg dir
1435 * however the config parser should take
1436 * care of duplicates
1437 */
1438 if (!_dbus_string_append (&servicedir_path, DBUS_DATADIR))
1439 goto oom;
1440
1441 if (!_dbus_split_paths_and_append (&servicedir_path,
1442 DBUS_UNIX_STANDARD_SESSION_SERVICEDIR,
1443 dirs))
1444 goto oom;
1445
1446 _dbus_string_free (&servicedir_path);
1447 return TRUE;
1448
1449 oom:
1450 _dbus_string_free (&servicedir_path);
1451 return FALSE;
1452 }
1453
1454
1455 /**
1456 * Returns the standard directories for a system bus to look for service
1457 * activation files
1458 *
1459 * On UNIX this should be the standard xdg freedesktop.org data directories:
1460 *
1461 * XDG_DATA_DIRS=${XDG_DATA_DIRS-/usr/local/share:/usr/share}
1462 *
1463 * and
1464 *
1465 * DBUS_DATADIR
1466 *
1467 * On Windows there is no system bus and this function can return nothing.
1468 *
1469 * @param dirs the directory list we are returning
1470 * @returns #FALSE on OOM
1471 */
1472
1473 dbus_bool_t
_dbus_get_standard_system_servicedirs(DBusList ** dirs)1474 _dbus_get_standard_system_servicedirs (DBusList **dirs)
1475 {
1476 /*
1477 * DBUS_DATADIR may be the same as one of the standard directories. However,
1478 * the config parser should take care of the duplicates.
1479 *
1480 * Also, append /lib as counterpart of /usr/share on the root
1481 * directory (the root directory does not know /share), in order to
1482 * facilitate early boot system bus activation where /usr might not
1483 * be available.
1484 */
1485 static const char standard_search_path[] =
1486 "/usr/local/share:"
1487 "/usr/share:"
1488 DBUS_DATADIR ":"
1489 "/lib";
1490 DBusString servicedir_path;
1491
1492 _dbus_string_init_const (&servicedir_path, standard_search_path);
1493
1494 return _dbus_split_paths_and_append (&servicedir_path,
1495 DBUS_UNIX_STANDARD_SYSTEM_SERVICEDIR,
1496 dirs);
1497 }
1498
1499 /**
1500 * Get the absolute path of the system.conf file
1501 * (there is no system bus on Windows so this can just
1502 * return FALSE and print a warning or something)
1503 *
1504 * @param str the string to append to, which must be empty on entry
1505 * @returns #FALSE if no memory
1506 */
1507 dbus_bool_t
_dbus_get_system_config_file(DBusString * str)1508 _dbus_get_system_config_file (DBusString *str)
1509 {
1510 _dbus_assert (_dbus_string_get_length (str) == 0);
1511
1512 return _dbus_string_append (str, DBUS_SYSTEM_CONFIG_FILE);
1513 }
1514
1515 /**
1516 * Get the absolute path of the session.conf file.
1517 *
1518 * @param str the string to append to, which must be empty on entry
1519 * @returns #FALSE if no memory
1520 */
1521 dbus_bool_t
_dbus_get_session_config_file(DBusString * str)1522 _dbus_get_session_config_file (DBusString *str)
1523 {
1524 _dbus_assert (_dbus_string_get_length (str) == 0);
1525
1526 return _dbus_string_append (str, DBUS_SESSION_CONFIG_FILE);
1527 }
1528
1529 #ifdef DBUS_ENABLE_EMBEDDED_TESTS
1530
1531 /*
1532 * Set uid to a machine-readable authentication identity (numeric Unix
1533 * uid or ConvertSidToStringSid-style Windows SID) that is likely to exist,
1534 * and differs from the identity of the current process.
1535 *
1536 * @param uid Populated with a machine-readable authentication identity
1537 * on success
1538 * @returns #FALSE if no memory
1539 */
1540 dbus_bool_t
_dbus_test_append_different_uid(DBusString * uid)1541 _dbus_test_append_different_uid (DBusString *uid)
1542 {
1543 if (geteuid () == 0)
1544 return _dbus_string_append (uid, "65534");
1545 else
1546 return _dbus_string_append (uid, "0");
1547 }
1548
1549 /*
1550 * Set uid to a human-readable authentication identity (login name)
1551 * that is likely to exist, and differs from the identity of the current
1552 * process. This function currently only exists on Unix platforms.
1553 *
1554 * @param uid Populated with a machine-readable authentication identity
1555 * on success
1556 * @returns #FALSE if no memory
1557 */
1558 dbus_bool_t
_dbus_test_append_different_username(DBusString * username)1559 _dbus_test_append_different_username (DBusString *username)
1560 {
1561 if (geteuid () == 0)
1562 return _dbus_string_append (username, "nobody");
1563 else
1564 return _dbus_string_append (username, "root");
1565 }
1566
1567 #endif
1568