D-Bus 1.13.18
dbus-sysdeps-util-unix.c
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 <stdio.h>
39#include <stdlib.h>
40#include <string.h>
41#include <signal.h>
42#include <unistd.h>
43#include <stdio.h>
44#include <errno.h>
45#include <fcntl.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_PRCTL_H
56#include <sys/prctl.h>
57#endif
58
59#ifdef HAVE_SYS_SYSLIMITS_H
60#include <sys/syslimits.h>
61#endif
62
63#ifdef HAVE_SYSTEMD
64#include <systemd/sd-daemon.h>
65#endif
66
67#ifndef O_BINARY
68#define O_BINARY 0
69#endif
70
88 DBusPipe *print_pid_pipe,
89 DBusError *error,
90 dbus_bool_t keep_umask)
91{
92 const char *s;
93 pid_t child_pid;
94 DBusEnsureStandardFdsFlags flags;
95
96 _dbus_verbose ("Becoming a daemon...\n");
97
98 _dbus_verbose ("chdir to /\n");
99 if (chdir ("/") < 0)
100 {
102 "Could not chdir() to root directory");
103 return FALSE;
104 }
105
106 _dbus_verbose ("forking...\n");
107
108 /* Make sure our output buffers aren't redundantly printed by both the
109 * parent and the child */
110 fflush (stdout);
111 fflush (stderr);
112
113 switch ((child_pid = fork ()))
114 {
115 case -1:
116 _dbus_verbose ("fork failed\n");
118 "Failed to fork daemon: %s", _dbus_strerror (errno));
119 return FALSE;
120 break;
121
122 case 0:
123 _dbus_verbose ("in child, closing std file descriptors\n");
124
125 flags = DBUS_FORCE_STDIN_NULL | DBUS_FORCE_STDOUT_NULL;
126 s = _dbus_getenv ("DBUS_DEBUG_OUTPUT");
127
128 if (s == NULL || *s == '\0')
129 flags |= DBUS_FORCE_STDERR_NULL;
130 else
131 _dbus_verbose ("keeping stderr open due to DBUS_DEBUG_OUTPUT\n");
132
133 if (!_dbus_ensure_standard_fds (flags, &s))
134 {
135 _dbus_warn ("%s: %s", s, _dbus_strerror (errno));
136 _exit (1);
137 }
138
139 if (!keep_umask)
140 {
141 /* Get a predictable umask */
142 _dbus_verbose ("setting umask\n");
143 umask (022);
144 }
145
146 _dbus_verbose ("calling setsid()\n");
147 if (setsid () == -1)
148 _dbus_assert_not_reached ("setsid() failed");
149
150 break;
151
152 default:
153 if (!_dbus_write_pid_to_file_and_pipe (pidfile, print_pid_pipe,
154 child_pid, error))
155 {
156 _dbus_verbose ("pid file or pipe write failed: %s\n",
157 error->message);
158 kill (child_pid, SIGTERM);
159 return FALSE;
160 }
161
162 _dbus_verbose ("parent exiting\n");
163 _exit (0);
164 break;
165 }
166
167 return TRUE;
168}
169
170
179static dbus_bool_t
180_dbus_write_pid_file (const DBusString *filename,
181 unsigned long pid,
182 DBusError *error)
183{
184 const char *cfilename;
185 int fd;
186 FILE *f;
187
188 cfilename = _dbus_string_get_const_data (filename);
189
190 fd = open (cfilename, O_WRONLY|O_CREAT|O_EXCL|O_BINARY, 0644);
191
192 if (fd < 0)
193 {
195 "Failed to open \"%s\": %s", cfilename,
196 _dbus_strerror (errno));
197 return FALSE;
198 }
199
200 if ((f = fdopen (fd, "w")) == NULL)
201 {
203 "Failed to fdopen fd %d: %s", fd, _dbus_strerror (errno));
204 _dbus_close (fd, NULL);
205 return FALSE;
206 }
207
208 if (fprintf (f, "%lu\n", pid) < 0)
209 {
211 "Failed to write to \"%s\": %s", cfilename,
212 _dbus_strerror (errno));
213
214 fclose (f);
215 return FALSE;
216 }
217
218 if (fclose (f) == EOF)
219 {
221 "Failed to close \"%s\": %s", cfilename,
222 _dbus_strerror (errno));
223 return FALSE;
224 }
225
226 return TRUE;
227}
228
242 DBusPipe *print_pid_pipe,
243 dbus_pid_t pid_to_write,
244 DBusError *error)
245{
246 if (pidfile)
247 {
248 _dbus_verbose ("writing pid file %s\n", _dbus_string_get_const_data (pidfile));
249 if (!_dbus_write_pid_file (pidfile,
250 pid_to_write,
251 error))
252 {
253 _dbus_verbose ("pid file write failed\n");
254 _DBUS_ASSERT_ERROR_IS_SET(error);
255 return FALSE;
256 }
257 }
258 else
259 {
260 _dbus_verbose ("No pid file requested\n");
261 }
262
263 if (print_pid_pipe != NULL && _dbus_pipe_is_valid (print_pid_pipe))
264 {
265 DBusString pid;
266 int bytes;
267
268 _dbus_verbose ("writing our pid to pipe %d\n",
269 print_pid_pipe->fd);
270
271 if (!_dbus_string_init (&pid))
272 {
273 _DBUS_SET_OOM (error);
274 return FALSE;
275 }
276
277 if (!_dbus_string_append_int (&pid, pid_to_write) ||
278 !_dbus_string_append (&pid, "\n"))
279 {
280 _dbus_string_free (&pid);
281 _DBUS_SET_OOM (error);
282 return FALSE;
283 }
284
285 bytes = _dbus_string_get_length (&pid);
286 if (_dbus_pipe_write (print_pid_pipe, &pid, 0, bytes, error) != bytes)
287 {
288 /* _dbus_pipe_write sets error only on failure, not short write */
289 if (error != NULL && !dbus_error_is_set(error))
290 {
292 "Printing message bus PID: did not write enough bytes\n");
293 }
294 _dbus_string_free (&pid);
295 return FALSE;
296 }
297
298 _dbus_string_free (&pid);
299 }
300 else
301 {
302 _dbus_verbose ("No pid pipe to write to\n");
303 }
304
305 return TRUE;
306}
307
315_dbus_verify_daemon_user (const char *user)
316{
317 DBusString u;
318
319 _dbus_string_init_const (&u, user);
320
322}
323
324
325/* The HAVE_LIBAUDIT case lives in selinux.c */
326#ifndef HAVE_LIBAUDIT
336 DBusError *error)
337{
338 dbus_uid_t uid;
339 dbus_gid_t gid;
340 DBusString u;
341
342 _dbus_string_init_const (&u, user);
343
344 if (!_dbus_get_user_id_and_primary_group (&u, &uid, &gid))
345 {
347 "User '%s' does not appear to exist?",
348 user);
349 return FALSE;
350 }
351
352 /* setgroups() only works if we are a privileged process,
353 * so we don't return error on failure; the only possible
354 * failure is that we don't have perms to do it.
355 *
356 * not sure this is right, maybe if setuid()
357 * is going to work then setgroups() should also work.
358 */
359 if (setgroups (0, NULL) < 0)
360 _dbus_warn ("Failed to drop supplementary groups: %s",
361 _dbus_strerror (errno));
362
363 /* Set GID first, or the setuid may remove our permission
364 * to change the GID
365 */
366 if (setgid (gid) < 0)
367 {
369 "Failed to set GID to %lu: %s", gid,
370 _dbus_strerror (errno));
371 return FALSE;
372 }
373
374 if (setuid (uid) < 0)
375 {
377 "Failed to set UID to %lu: %s", uid,
378 _dbus_strerror (errno));
379 return FALSE;
380 }
381
382 return TRUE;
383}
384#endif /* !HAVE_LIBAUDIT */
385
386#ifdef HAVE_SETRLIMIT
387
388/* We assume that if we have setrlimit, we also have getrlimit and
389 * struct rlimit.
390 */
391
392struct DBusRLimit {
393 struct rlimit lim;
394};
395
396DBusRLimit *
397_dbus_rlimit_save_fd_limit (DBusError *error)
398{
399 DBusRLimit *self;
400
401 self = dbus_new0 (DBusRLimit, 1);
402
403 if (self == NULL)
404 {
405 _DBUS_SET_OOM (error);
406 return NULL;
407 }
408
409 if (getrlimit (RLIMIT_NOFILE, &self->lim) < 0)
410 {
412 "Failed to get fd limit: %s", _dbus_strerror (errno));
413 dbus_free (self);
414 return NULL;
415 }
416
417 return self;
418}
419
420/* Enough fds that we shouldn't run out, even if several uids work
421 * together to carry out a denial-of-service attack. This happens to be
422 * the same number that systemd < 234 would normally use. */
423#define ENOUGH_FDS 65536
424
426_dbus_rlimit_raise_fd_limit (DBusError *error)
427{
428 struct rlimit old, lim;
429
430 if (getrlimit (RLIMIT_NOFILE, &lim) < 0)
431 {
433 "Failed to get fd limit: %s", _dbus_strerror (errno));
434 return FALSE;
435 }
436
437 old = lim;
438
439 if (getuid () == 0)
440 {
441 /* We are privileged, so raise the soft limit to at least
442 * ENOUGH_FDS, and the hard limit to at least the desired soft
443 * limit. This assumes we can exercise CAP_SYS_RESOURCE on Linux,
444 * or other OSs' equivalents. */
445 if (lim.rlim_cur != RLIM_INFINITY &&
446 lim.rlim_cur < ENOUGH_FDS)
447 lim.rlim_cur = ENOUGH_FDS;
448
449 if (lim.rlim_max != RLIM_INFINITY &&
450 lim.rlim_max < lim.rlim_cur)
451 lim.rlim_max = lim.rlim_cur;
452 }
453
454 /* Raise the soft limit to match the hard limit, which we can do even
455 * if we are unprivileged. In particular, systemd >= 240 will normally
456 * set rlim_cur to 1024 and rlim_max to 512*1024, recent Debian
457 * versions end up setting rlim_cur to 1024 and rlim_max to 1024*1024,
458 * and older and non-systemd Linux systems would typically set rlim_cur
459 * to 1024 and rlim_max to 4096. */
460 if (lim.rlim_max == RLIM_INFINITY || lim.rlim_cur < lim.rlim_max)
461 lim.rlim_cur = lim.rlim_max;
462
463 /* Early-return if there is nothing to do. */
464 if (lim.rlim_max == old.rlim_max &&
465 lim.rlim_cur == old.rlim_cur)
466 return TRUE;
467
468 if (setrlimit (RLIMIT_NOFILE, &lim) < 0)
469 {
471 "Failed to set fd limit to %lu: %s",
472 (unsigned long) lim.rlim_cur,
473 _dbus_strerror (errno));
474 return FALSE;
475 }
476
477 return TRUE;
478}
479
481_dbus_rlimit_restore_fd_limit (DBusRLimit *saved,
482 DBusError *error)
483{
484 if (setrlimit (RLIMIT_NOFILE, &saved->lim) < 0)
485 {
487 "Failed to restore old fd limit: %s",
488 _dbus_strerror (errno));
489 return FALSE;
490 }
491
492 return TRUE;
493}
494
495#else /* !HAVE_SETRLIMIT */
496
497static void
498fd_limit_not_supported (DBusError *error)
499{
501 "cannot change fd limit on this platform");
502}
503
504DBusRLimit *
505_dbus_rlimit_save_fd_limit (DBusError *error)
506{
507 fd_limit_not_supported (error);
508 return NULL;
509}
510
512_dbus_rlimit_raise_fd_limit (DBusError *error)
513{
514 fd_limit_not_supported (error);
515 return FALSE;
516}
517
519_dbus_rlimit_restore_fd_limit (DBusRLimit *saved,
520 DBusError *error)
521{
522 fd_limit_not_supported (error);
523 return FALSE;
524}
525
526#endif
527
528void
529_dbus_rlimit_free (DBusRLimit *lim)
530{
531 dbus_free (lim);
532}
533
539void
541 DBusSignalHandler handler)
542{
543 struct sigaction act;
544 sigset_t empty_mask;
545
546 sigemptyset (&empty_mask);
547 act.sa_handler = handler;
548 act.sa_mask = empty_mask;
549 act.sa_flags = 0;
550 sigaction (sig, &act, NULL);
551}
552
559_dbus_file_exists (const char *file)
560{
561 return (access (file, F_OK) == 0);
562}
563
571_dbus_user_at_console (const char *username,
572 DBusError *error)
573{
574#ifdef DBUS_CONSOLE_AUTH_DIR
575 DBusString u, f;
576 dbus_bool_t result;
577
578 result = FALSE;
579 if (!_dbus_string_init (&f))
580 {
581 _DBUS_SET_OOM (error);
582 return FALSE;
583 }
584
585 if (!_dbus_string_append (&f, DBUS_CONSOLE_AUTH_DIR))
586 {
587 _DBUS_SET_OOM (error);
588 goto out;
589 }
590
591 _dbus_string_init_const (&u, username);
592
593 if (!_dbus_concat_dir_and_file (&f, &u))
594 {
595 _DBUS_SET_OOM (error);
596 goto out;
597 }
598
599 result = _dbus_file_exists (_dbus_string_get_const_data (&f));
600
601 out:
603
604 return result;
605#else
606 return FALSE;
607#endif
608}
609
610
619{
620 if (_dbus_string_get_length (filename) > 0)
621 return _dbus_string_get_byte (filename, 0) == '/';
622 else
623 return FALSE;
624}
625
635_dbus_stat (const DBusString *filename,
636 DBusStat *statbuf,
637 DBusError *error)
638{
639 const char *filename_c;
640 struct stat sb;
641
642 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
643
644 filename_c = _dbus_string_get_const_data (filename);
645
646 if (stat (filename_c, &sb) < 0)
647 {
649 "%s", _dbus_strerror (errno));
650 return FALSE;
651 }
652
653 statbuf->mode = sb.st_mode;
654 statbuf->nlink = sb.st_nlink;
655 statbuf->uid = sb.st_uid;
656 statbuf->gid = sb.st_gid;
657 statbuf->size = sb.st_size;
658 statbuf->atime = sb.st_atime;
659 statbuf->mtime = sb.st_mtime;
660 statbuf->ctime = sb.st_ctime;
661
662 return TRUE;
663}
664
665
670{
671 DIR *d;
673};
674
684 DBusError *error)
685{
686 DIR *d;
687 DBusDirIter *iter;
688 const char *filename_c;
689
690 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
691
692 filename_c = _dbus_string_get_const_data (filename);
693
694 d = opendir (filename_c);
695 if (d == NULL)
696 {
698 "Failed to read directory \"%s\": %s",
699 filename_c,
700 _dbus_strerror (errno));
701 return NULL;
702 }
703 iter = dbus_new0 (DBusDirIter, 1);
704 if (iter == NULL)
705 {
706 closedir (d);
708 "Could not allocate memory for directory iterator");
709 return NULL;
710 }
711
712 iter->d = d;
713
714 return iter;
715}
716
732 DBusString *filename,
733 DBusError *error)
734{
735 struct dirent *ent;
736 int err;
737
738 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
739
740 again:
741 errno = 0;
742 ent = readdir (iter->d);
743
744 if (!ent)
745 {
746 err = errno;
747
748 if (err != 0)
749 dbus_set_error (error,
751 "%s", _dbus_strerror (err));
752
753 return FALSE;
754 }
755 else if (ent->d_name[0] == '.' &&
756 (ent->d_name[1] == '\0' ||
757 (ent->d_name[1] == '.' && ent->d_name[2] == '\0')))
758 goto again;
759 else
760 {
761 _dbus_string_set_length (filename, 0);
762 if (!_dbus_string_append (filename, ent->d_name))
763 {
765 "No memory to read directory entry");
766 return FALSE;
767 }
768 else
769 {
770 return TRUE;
771 }
772 }
773}
774
778void
780{
781 closedir (iter->d);
782 dbus_free (iter);
783}
784
785static dbus_bool_t
786fill_user_info_from_group (struct group *g,
787 DBusGroupInfo *info,
788 DBusError *error)
789{
790 _dbus_assert (g->gr_name != NULL);
791
792 info->gid = g->gr_gid;
793 info->groupname = _dbus_strdup (g->gr_name);
794
795 /* info->members = dbus_strdupv (g->gr_mem) */
796
797 if (info->groupname == NULL)
798 {
800 return FALSE;
801 }
802
803 return TRUE;
804}
805
806static dbus_bool_t
807fill_group_info (DBusGroupInfo *info,
808 dbus_gid_t gid,
809 const DBusString *groupname,
810 DBusError *error)
811{
812 const char *group_c_str;
813
814 _dbus_assert (groupname != NULL || gid != DBUS_GID_UNSET);
815 _dbus_assert (groupname == NULL || gid == DBUS_GID_UNSET);
816
817 if (groupname)
818 group_c_str = _dbus_string_get_const_data (groupname);
819 else
820 group_c_str = NULL;
821
822 /* For now assuming that the getgrnam() and getgrgid() flavors
823 * always correspond to the pwnam flavors, if not we have
824 * to add more configure checks.
825 */
826
827#ifdef HAVE_GETPWNAM_R
828 {
829 struct group *g;
830 int result;
831 size_t buflen;
832 char *buf;
833 struct group g_str;
834 dbus_bool_t b;
835
836 /* retrieve maximum needed size for buf */
837 buflen = sysconf (_SC_GETGR_R_SIZE_MAX);
838
839 /* sysconf actually returns a long, but everything else expects size_t,
840 * so just recast here.
841 * https://bugs.freedesktop.org/show_bug.cgi?id=17061
842 */
843 if ((long) buflen <= 0)
844 buflen = 1024;
845
846 result = -1;
847 while (1)
848 {
849 buf = dbus_malloc (buflen);
850 if (buf == NULL)
851 {
853 return FALSE;
854 }
855
856 g = NULL;
857 if (group_c_str)
858 result = getgrnam_r (group_c_str, &g_str, buf, buflen,
859 &g);
860 else
861 result = getgrgid_r (gid, &g_str, buf, buflen,
862 &g);
863 /* Try a bigger buffer if ERANGE was returned:
864 https://bugs.freedesktop.org/show_bug.cgi?id=16727
865 */
866 if (result == ERANGE && buflen < 512 * 1024)
867 {
868 dbus_free (buf);
869 buflen *= 2;
870 }
871 else
872 {
873 break;
874 }
875 }
876
877 if (result == 0 && g == &g_str)
878 {
879 b = fill_user_info_from_group (g, info, error);
880 dbus_free (buf);
881 return b;
882 }
883 else
884 {
886 "Group %s unknown or failed to look it up\n",
887 group_c_str ? group_c_str : "???");
888 dbus_free (buf);
889 return FALSE;
890 }
891 }
892#else /* ! HAVE_GETPWNAM_R */
893 {
894 /* I guess we're screwed on thread safety here */
895 struct group *g;
896
897#warning getpwnam_r() not available, please report this to the dbus maintainers with details of your OS
898
899 g = getgrnam (group_c_str);
900
901 if (g != NULL)
902 {
903 return fill_user_info_from_group (g, info, error);
904 }
905 else
906 {
908 "Group %s unknown or failed to look it up\n",
909 group_c_str ? group_c_str : "???");
910 return FALSE;
911 }
912 }
913#endif /* ! HAVE_GETPWNAM_R */
914}
915
927 const DBusString *groupname,
928 DBusError *error)
929{
930 return fill_group_info (info, DBUS_GID_UNSET,
931 groupname, error);
932
933}
934
946 dbus_gid_t gid,
947 DBusError *error)
948{
949 return fill_group_info (info, gid, NULL, error);
950}
951
962 dbus_uid_t *uid_p)
963{
964 return _dbus_get_user_id (username, uid_p);
965
966}
967
978 dbus_gid_t *gid_p)
979{
980 return _dbus_get_group_id (groupname, gid_p);
981}
982
995 dbus_gid_t **group_ids,
996 int *n_group_ids)
997{
998 return _dbus_groups_from_uid (uid, group_ids, n_group_ids);
999}
1000
1012 DBusError *error)
1013{
1014 return _dbus_is_console_user (uid, error);
1015
1016}
1017
1027{
1028 return uid == _dbus_geteuid ();
1029}
1030
1040{
1041 return FALSE;
1042}
1043 /* End of DBusInternalsUtils functions */
1045
1059 DBusString *dirname)
1060{
1061 int sep;
1062
1063 _dbus_assert (filename != dirname);
1064 _dbus_assert (filename != NULL);
1065 _dbus_assert (dirname != NULL);
1066
1067 /* Ignore any separators on the end */
1068 sep = _dbus_string_get_length (filename);
1069 if (sep == 0)
1070 return _dbus_string_append (dirname, "."); /* empty string passed in */
1071
1072 while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
1073 --sep;
1074
1075 _dbus_assert (sep >= 0);
1076
1077 if (sep == 0)
1078 return _dbus_string_append (dirname, "/");
1079
1080 /* Now find the previous separator */
1081 _dbus_string_find_byte_backward (filename, sep, '/', &sep);
1082 if (sep < 0)
1083 return _dbus_string_append (dirname, ".");
1084
1085 /* skip multiple separators */
1086 while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
1087 --sep;
1088
1089 _dbus_assert (sep >= 0);
1090
1091 if (sep == 0 &&
1092 _dbus_string_get_byte (filename, 0) == '/')
1093 return _dbus_string_append (dirname, "/");
1094 else
1095 return _dbus_string_copy_len (filename, 0, sep - 0,
1096 dirname, _dbus_string_get_length (dirname));
1097} /* DBusString stuff */
1099
1100static void
1101string_squash_nonprintable (DBusString *str)
1102{
1103 unsigned char *buf;
1104 int i, len;
1105
1106 buf = _dbus_string_get_udata (str);
1107 len = _dbus_string_get_length (str);
1108
1109 /* /proc/$pid/cmdline is a sequence of \0-terminated words, but we
1110 * want a sequence of space-separated words, with no extra trailing
1111 * space:
1112 * "/bin/sleep" "\0" "60" "\0"
1113 * -> "/bin/sleep" "\0" "60"
1114 * -> "/bin/sleep" " " "60"
1115 *
1116 * so chop off the trailing NUL before cleaning up unprintable
1117 * characters. */
1118 if (len > 0 && buf[len - 1] == '\0')
1119 {
1120 _dbus_string_shorten (str, 1);
1121 len--;
1122 }
1123
1124 for (i = 0; i < len; i++)
1125 {
1126 unsigned char c = (unsigned char) buf[i];
1127 if (c == '\0')
1128 buf[i] = ' ';
1129 else if (c < 0x20 || c > 127)
1130 buf[i] = '?';
1131 }
1132}
1133
1149_dbus_command_for_pid (unsigned long pid,
1150 DBusString *str,
1151 int max_len,
1152 DBusError *error)
1153{
1154 /* This is all Linux-specific for now */
1155 DBusString path;
1156 DBusString cmdline;
1157 int fd;
1158
1159 if (!_dbus_string_init (&path))
1160 {
1161 _DBUS_SET_OOM (error);
1162 return FALSE;
1163 }
1164
1165 if (!_dbus_string_init (&cmdline))
1166 {
1167 _DBUS_SET_OOM (error);
1168 _dbus_string_free (&path);
1169 return FALSE;
1170 }
1171
1172 if (!_dbus_string_append_printf (&path, "/proc/%ld/cmdline", pid))
1173 goto oom;
1174
1175 fd = open (_dbus_string_get_const_data (&path), O_RDONLY);
1176 if (fd < 0)
1177 {
1178 dbus_set_error (error,
1179 _dbus_error_from_errno (errno),
1180 "Failed to open \"%s\": %s",
1181 _dbus_string_get_const_data (&path),
1182 _dbus_strerror (errno));
1183 goto fail;
1184 }
1185
1186 if (!_dbus_read (fd, &cmdline, max_len))
1187 {
1188 dbus_set_error (error,
1189 _dbus_error_from_errno (errno),
1190 "Failed to read from \"%s\": %s",
1191 _dbus_string_get_const_data (&path),
1192 _dbus_strerror (errno));
1193 _dbus_close (fd, NULL);
1194 goto fail;
1195 }
1196
1197 if (!_dbus_close (fd, error))
1198 goto fail;
1199
1200 string_squash_nonprintable (&cmdline);
1201
1202 if (!_dbus_string_copy (&cmdline, 0, str, _dbus_string_get_length (str)))
1203 goto oom;
1204
1205 _dbus_string_free (&cmdline);
1206 _dbus_string_free (&path);
1207 return TRUE;
1208oom:
1209 _DBUS_SET_OOM (error);
1210fail:
1211 _dbus_string_free (&cmdline);
1212 _dbus_string_free (&path);
1213 return FALSE;
1214}
1215
1226{
1227 return TRUE;
1228}
1229
1230static dbus_bool_t
1231ensure_owned_directory (const char *label,
1232 const DBusString *string,
1233 dbus_bool_t create,
1234 DBusError *error)
1235{
1236 const char *dir = _dbus_string_get_const_data (string);
1237 struct stat buf;
1238
1239 if (create && !_dbus_ensure_directory (string, error))
1240 return FALSE;
1241
1242 /*
1243 * The stat()-based checks in this function are to protect against
1244 * mistakes, not malice. We are working in a directory that is meant
1245 * to be trusted; but if a user has used `su` or similar to escalate
1246 * their privileges without correctly clearing the environment, the
1247 * XDG_RUNTIME_DIR in the environment might still be the user's
1248 * and not root's. We don't want to write root-owned files into that
1249 * directory, so just warn and don't provide support for transient
1250 * services in that case.
1251 *
1252 * In particular, we use stat() and not lstat() so that if we later
1253 * decide to use a different directory name for transient services,
1254 * we can drop in a compatibility symlink without breaking older
1255 * libdbus.
1256 */
1257
1258 if (stat (dir, &buf) != 0)
1259 {
1260 int saved_errno = errno;
1261
1262 dbus_set_error (error, _dbus_error_from_errno (saved_errno),
1263 "%s \"%s\" not available: %s", label, dir,
1264 _dbus_strerror (saved_errno));
1265 return FALSE;
1266 }
1267
1268 if (!S_ISDIR (buf.st_mode))
1269 {
1270 dbus_set_error (error, DBUS_ERROR_FAILED, "%s \"%s\" is not a directory",
1271 label, dir);
1272 return FALSE;
1273 }
1274
1275 if (buf.st_uid != geteuid ())
1276 {
1278 "%s \"%s\" is owned by uid %ld, not our uid %ld",
1279 label, dir, (long) buf.st_uid, (long) geteuid ());
1280 return FALSE;
1281 }
1282
1283 /* This is just because we have the stat() results already, so we might
1284 * as well check opportunistically. */
1285 if ((S_IWOTH | S_IWGRP) & buf.st_mode)
1286 {
1288 "%s \"%s\" can be written by others (mode 0%o)",
1289 label, dir, buf.st_mode);
1290 return FALSE;
1291 }
1292
1293 return TRUE;
1294}
1295
1296#define DBUS_UNIX_STANDARD_SESSION_SERVICEDIR "/dbus-1/services"
1297#define DBUS_UNIX_STANDARD_SYSTEM_SERVICEDIR "/dbus-1/system-services"
1298
1308 DBusError *error)
1309{
1310 const char *xdg_runtime_dir;
1311 DBusString services;
1312 DBusString dbus1;
1313 DBusString xrd;
1314 dbus_bool_t ret = FALSE;
1315 char *data = NULL;
1316
1317 if (!_dbus_string_init (&dbus1))
1318 {
1319 _DBUS_SET_OOM (error);
1320 return FALSE;
1321 }
1322
1323 if (!_dbus_string_init (&services))
1324 {
1325 _dbus_string_free (&dbus1);
1326 _DBUS_SET_OOM (error);
1327 return FALSE;
1328 }
1329
1330 if (!_dbus_string_init (&xrd))
1331 {
1332 _dbus_string_free (&dbus1);
1333 _dbus_string_free (&services);
1334 _DBUS_SET_OOM (error);
1335 return FALSE;
1336 }
1337
1338 xdg_runtime_dir = _dbus_getenv ("XDG_RUNTIME_DIR");
1339
1340 /* Not an error, we just can't have transient session services */
1341 if (xdg_runtime_dir == NULL)
1342 {
1343 _dbus_verbose ("XDG_RUNTIME_DIR is unset: transient session services "
1344 "not available here\n");
1345 ret = TRUE;
1346 goto out;
1347 }
1348
1349 if (!_dbus_string_append (&xrd, xdg_runtime_dir) ||
1350 !_dbus_string_append_printf (&dbus1, "%s/dbus-1",
1351 xdg_runtime_dir) ||
1352 !_dbus_string_append_printf (&services, "%s/dbus-1/services",
1353 xdg_runtime_dir))
1354 {
1355 _DBUS_SET_OOM (error);
1356 goto out;
1357 }
1358
1359 if (!ensure_owned_directory ("XDG_RUNTIME_DIR", &xrd, FALSE, error) ||
1360 !ensure_owned_directory ("XDG_RUNTIME_DIR subdirectory", &dbus1, TRUE,
1361 error) ||
1362 !ensure_owned_directory ("XDG_RUNTIME_DIR subdirectory", &services,
1363 TRUE, error))
1364 goto out;
1365
1366 if (!_dbus_string_steal_data (&services, &data) ||
1367 !_dbus_list_append (dirs, data))
1368 {
1369 _DBUS_SET_OOM (error);
1370 goto out;
1371 }
1372
1373 _dbus_verbose ("Transient service directory is %s\n", data);
1374 /* Ownership was transferred to @dirs */
1375 data = NULL;
1376 ret = TRUE;
1377
1378out:
1379 _dbus_string_free (&dbus1);
1380 _dbus_string_free (&services);
1381 _dbus_string_free (&xrd);
1382 dbus_free (data);
1383 return ret;
1384}
1385
1405{
1406 const char *xdg_data_home;
1407 const char *xdg_data_dirs;
1408 DBusString servicedir_path;
1409
1410 if (!_dbus_string_init (&servicedir_path))
1411 return FALSE;
1412
1413 xdg_data_home = _dbus_getenv ("XDG_DATA_HOME");
1414 xdg_data_dirs = _dbus_getenv ("XDG_DATA_DIRS");
1415
1416 if (xdg_data_home != NULL)
1417 {
1418 if (!_dbus_string_append (&servicedir_path, xdg_data_home))
1419 goto oom;
1420 }
1421 else
1422 {
1423 const DBusString *homedir;
1424 DBusString local_share;
1425
1426 if (!_dbus_homedir_from_current_process (&homedir))
1427 goto oom;
1428
1429 if (!_dbus_string_append (&servicedir_path, _dbus_string_get_const_data (homedir)))
1430 goto oom;
1431
1432 _dbus_string_init_const (&local_share, "/.local/share");
1433 if (!_dbus_concat_dir_and_file (&servicedir_path, &local_share))
1434 goto oom;
1435 }
1436
1437 if (!_dbus_string_append (&servicedir_path, ":"))
1438 goto oom;
1439
1440 if (xdg_data_dirs != NULL)
1441 {
1442 if (!_dbus_string_append (&servicedir_path, xdg_data_dirs))
1443 goto oom;
1444
1445 if (!_dbus_string_append (&servicedir_path, ":"))
1446 goto oom;
1447 }
1448 else
1449 {
1450 if (!_dbus_string_append (&servicedir_path, "/usr/local/share:/usr/share:"))
1451 goto oom;
1452 }
1453
1454 /*
1455 * add configured datadir to defaults
1456 * this may be the same as an xdg dir
1457 * however the config parser should take
1458 * care of duplicates
1459 */
1460 if (!_dbus_string_append (&servicedir_path, DBUS_DATADIR))
1461 goto oom;
1462
1463 if (!_dbus_split_paths_and_append (&servicedir_path,
1464 DBUS_UNIX_STANDARD_SESSION_SERVICEDIR,
1465 dirs))
1466 goto oom;
1467
1468 _dbus_string_free (&servicedir_path);
1469 return TRUE;
1470
1471 oom:
1472 _dbus_string_free (&servicedir_path);
1473 return FALSE;
1474}
1475
1476
1497{
1498 /*
1499 * DBUS_DATADIR may be the same as one of the standard directories. However,
1500 * the config parser should take care of the duplicates.
1501 *
1502 * Also, append /lib as counterpart of /usr/share on the root
1503 * directory (the root directory does not know /share), in order to
1504 * facilitate early boot system bus activation where /usr might not
1505 * be available.
1506 */
1507 static const char standard_search_path[] =
1508 "/usr/local/share:"
1509 "/usr/share:"
1510 DBUS_DATADIR ":"
1511 "/lib";
1512 DBusString servicedir_path;
1513
1514 _dbus_string_init_const (&servicedir_path, standard_search_path);
1515
1516 return _dbus_split_paths_and_append (&servicedir_path,
1517 DBUS_UNIX_STANDARD_SYSTEM_SERVICEDIR,
1518 dirs);
1519}
1520
1531{
1532 _dbus_assert (_dbus_string_get_length (str) == 0);
1533
1534 return _dbus_string_append (str, DBUS_SYSTEM_CONFIG_FILE);
1535}
1536
1545{
1546 _dbus_assert (_dbus_string_get_length (str) == 0);
1547
1548 return _dbus_string_append (str, DBUS_SESSION_CONFIG_FILE);
1549}
1550
1555void
1557{
1558#ifdef HAVE_SYSTEMD
1559 sd_notify (0, "READY=1");
1560#endif
1561}
1562
1567void
1569{
1570#ifdef HAVE_SYSTEMD
1571 sd_notify (0, "RELOADING=1");
1572#endif
1573}
1574
1579void
1581{
1582#ifdef HAVE_SYSTEMD
1583 /* For systemd, this is the same code */
1585#endif
1586}
1587
1592void
1594{
1595#ifdef HAVE_SYSTEMD
1596 sd_notify (0, "STOPPING=1");
1597#endif
1598}
void dbus_set_error(DBusError *error, const char *name, const char *format,...)
Assigns an error name and message to a DBusError.
Definition: dbus-errors.c:354
dbus_bool_t dbus_error_is_set(const DBusError *error)
Checks whether an error occurred (the error is set).
Definition: dbus-errors.c:329
dbus_bool_t _dbus_stat(const DBusString *filename, DBusStat *statbuf, DBusError *error)
stat() wrapper.
#define _dbus_assert_not_reached(explanation)
Aborts with an error message if called.
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)
Writes the given pid_to_write to a pidfile (if non-NULL) and/or to a pipe (if non-NULL).
#define _dbus_assert(condition)
Aborts with an error message if the condition is false.
dbus_bool_t _dbus_file_exists(const char *file)
Checks if a file exists.
dbus_bool_t _dbus_homedir_from_current_process(const DBusString **homedir)
Gets homedir of user owning current process.
Definition: dbus-userdb.c:440
void _dbus_directory_close(DBusDirIter *iter)
Closes a directory iteration.
dbus_bool_t _dbus_group_info_fill(DBusGroupInfo *info, const DBusString *groupname, DBusError *error)
Initializes the given DBusGroupInfo struct with information about the given group name.
dbus_bool_t _dbus_user_at_console(const char *username, DBusError *error)
Checks if user is at the console.
DBusDirIter * _dbus_directory_open(const DBusString *filename, DBusError *error)
Open a directory to iterate over.
dbus_bool_t _dbus_parse_unix_user_from_config(const DBusString *username, dbus_uid_t *uid_p)
Parse a UNIX user from the bus config file.
dbus_bool_t _dbus_verify_daemon_user(const char *user)
Verify that after the fork we can successfully change to this user.
const char * _dbus_error_from_errno(int error_number)
Converts a UNIX errno, or Windows errno or WinSock error value into a DBusError name.
Definition: dbus-sysdeps.c:599
void _dbus_set_signal_handler(int sig, DBusSignalHandler handler)
Installs a UNIX signal handler.
dbus_bool_t _dbus_path_is_absolute(const DBusString *filename)
Checks whether the filename is an absolute path.
char * _dbus_strdup(const char *str)
Duplicates a string.
dbus_bool_t _dbus_unix_groups_from_uid(dbus_uid_t uid, dbus_gid_t **group_ids, int *n_group_ids)
Gets all groups corresponding to the given UNIX user ID.
dbus_bool_t _dbus_change_to_daemon_user(const char *user, DBusError *error)
Changes the user and group the bus is running as.
dbus_bool_t _dbus_unix_user_is_process_owner(dbus_uid_t uid)
Checks to see if the UNIX user ID matches the UID of the process.
dbus_bool_t _dbus_get_group_id(const DBusString *groupname, dbus_gid_t *gid)
Gets group ID given groupname.
dbus_bool_t _dbus_windows_user_is_process_owner(const char *windows_sid)
Checks to see if the Windows user SID matches the owner of the process.
dbus_bool_t _dbus_parse_unix_group_from_config(const DBusString *groupname, dbus_gid_t *gid_p)
Parse a UNIX group from the bus config file.
dbus_bool_t _dbus_is_console_user(dbus_uid_t uid, DBusError *error)
Checks to see if the UID sent in is the console user.
dbus_bool_t _dbus_directory_get_next_file(DBusDirIter *iter, DBusString *filename, DBusError *error)
Get next file in the directory.
void _dbus_warn(const char *format,...)
Prints a warning message to stderr.
dbus_bool_t _dbus_get_user_id_and_primary_group(const DBusString *username, dbus_uid_t *uid_p, dbus_gid_t *gid_p)
Gets user ID and primary group given username.
dbus_bool_t _dbus_become_daemon(const DBusString *pidfile, DBusPipe *print_pid_pipe, DBusError *error, dbus_bool_t keep_umask)
Does the chdir, fork, setsid, etc.
dbus_bool_t _dbus_group_info_fill_gid(DBusGroupInfo *info, dbus_gid_t gid, DBusError *error)
Initializes the given DBusGroupInfo struct with information about the given group ID.
dbus_bool_t _dbus_groups_from_uid(dbus_uid_t uid, dbus_gid_t **group_ids, int *n_group_ids)
Gets all groups corresponding to the given UID.
dbus_bool_t _dbus_unix_user_is_at_console(dbus_uid_t uid, DBusError *error)
Checks to see if the UNIX user ID is at the console.
dbus_bool_t _dbus_get_user_id(const DBusString *username, dbus_uid_t *uid)
Gets user ID given username.
dbus_bool_t _dbus_list_append(DBusList **list, void *data)
Appends a value to the list.
Definition: dbus-list.c:271
#define NULL
A null pointer, defined appropriately for C or C++.
#define TRUE
Expands to "1".
#define FALSE
Expands to "0".
void dbus_free(void *memory)
Frees a block of memory previously allocated by dbus_malloc() or dbus_malloc0().
Definition: dbus-memory.c:704
#define dbus_new0(type, count)
Safe macro for using dbus_malloc0().
Definition: dbus-memory.h:58
void * dbus_malloc(size_t bytes)
Allocates the given number of bytes, as with standard malloc().
Definition: dbus-memory.c:464
#define DBUS_ERROR_NOT_SUPPORTED
Requested operation isn't supported (like ENOSYS on UNIX).
#define DBUS_ERROR_FAILED
A generic error; "something went wrong" - see the error message for more.
#define DBUS_ERROR_NO_MEMORY
There was not enough memory to complete an operation.
dbus_bool_t _dbus_string_set_length(DBusString *str, int length)
Sets the length of a string.
Definition: dbus-string.c:826
dbus_bool_t _dbus_string_append(DBusString *str, const char *buffer)
Appends a nul-terminated C-style string to a DBusString.
Definition: dbus-string.c:959
dbus_bool_t _dbus_string_init(DBusString *str)
Initializes a string.
Definition: dbus-string.c:182
void _dbus_string_init_const(DBusString *str, const char *value)
Initializes a constant string.
Definition: dbus-string.c:197
dbus_bool_t _dbus_string_copy(const DBusString *source, int start, DBusString *dest, int insert_at)
Like _dbus_string_move(), but does not delete the section of the source string that's copied to the d...
Definition: dbus-string.c:1307
DBUS_PRIVATE_EXPORT dbus_bool_t _dbus_string_append_int(DBusString *str, long value)
Appends an integer to a DBusString.
Definition: dbus-sysdeps.c:363
dbus_bool_t _dbus_string_steal_data(DBusString *str, char **data_return)
Like _dbus_string_get_data(), but removes the gotten data from the original string.
Definition: dbus-string.c:665
void _dbus_string_free(DBusString *str)
Frees a string created by _dbus_string_init(), and fills it with the same contents as #_DBUS_STRING_I...
Definition: dbus-string.c:271
void _dbus_string_shorten(DBusString *str, int length_to_remove)
Makes a string shorter by the given number of bytes.
Definition: dbus-string.c:804
dbus_bool_t _dbus_string_find_byte_backward(const DBusString *str, int start, unsigned char byte, int *found)
Find the given byte scanning backward from the given start.
dbus_bool_t _dbus_string_append_printf(DBusString *str, const char *format,...)
Appends a printf-style formatted string to the DBusString.
Definition: dbus-string.c:1138
dbus_bool_t _dbus_string_copy_len(const DBusString *source, int start, int len, DBusString *dest, int insert_at)
Like _dbus_string_copy(), but can copy a segment from the middle of the source string.
Definition: dbus-string.c:1399
dbus_bool_t _dbus_string_get_dirname(const DBusString *filename, DBusString *dirname)
Get the directory name from a complete filename.
dbus_bool_t _dbus_close(int fd, DBusError *error)
Closes a file descriptor.
void(* DBusSignalHandler)(int sig)
A UNIX signal handler.
int _dbus_read(int fd, DBusString *buffer, int count)
Thin wrapper around the read() system call that appends the data it reads to the DBusString buffer.
dbus_bool_t _dbus_ensure_standard_fds(DBusEnsureStandardFdsFlags flags, const char **error_str_p)
Ensure that the standard file descriptors stdin, stdout and stderr are open, by opening /dev/null if ...
dbus_uid_t _dbus_geteuid(void)
Gets our effective UID.
dbus_bool_t _dbus_get_standard_session_servicedirs(DBusList **dirs)
Returns the standard directories for a session bus to look for service activation files.
void _dbus_daemon_report_ready(void)
Report to a service manager that the daemon calling this function is ready for use.
unsigned long dbus_uid_t
A user ID.
Definition: dbus-sysdeps.h:137
dbus_bool_t _dbus_get_session_config_file(DBusString *str)
Get the absolute path of the session.conf file.
unsigned long dbus_pid_t
A process ID.
Definition: dbus-sysdeps.h:135
void _dbus_daemon_report_reloading(void)
Report to a service manager that the daemon calling this function is reloading configuration.
unsigned long dbus_gid_t
A group ID.
Definition: dbus-sysdeps.h:139
dbus_bool_t _dbus_command_for_pid(unsigned long pid, DBusString *str, int max_len, DBusError *error)
Get a printable string describing the command used to execute the process with pid.
dbus_bool_t _dbus_get_system_config_file(DBusString *str)
Get the absolute path of the system.conf file (there is no system bus on Windows so this can just ret...
dbus_bool_t _dbus_set_up_transient_session_servicedirs(DBusList **dirs, DBusError *error)
Returns the standard directories for a session bus to look for transient service activation files.
const char * _dbus_getenv(const char *varname)
Wrapper for getenv().
Definition: dbus-sysdeps.c:195
dbus_bool_t _dbus_get_standard_system_servicedirs(DBusList **dirs)
Returns the standard directories for a system bus to look for service activation files.
void _dbus_daemon_report_reloaded(void)
Report to a service manager that the daemon calling this function is reloading configuration.
#define DBUS_GID_UNSET
an invalid GID used to represent an uninitialized dbus_gid_t field
Definition: dbus-sysdeps.h:146
void _dbus_daemon_report_stopping(void)
Report to a service manager that the daemon calling this function is shutting down.
dbus_bool_t _dbus_concat_dir_and_file(DBusString *dir, const DBusString *next_component)
Appends the given filename to the given directory.
dbus_bool_t _dbus_split_paths_and_append(DBusString *dirs, const char *suffix, DBusList **dir_list)
Split paths into a list of char strings.
Definition: dbus-sysdeps.c:236
dbus_bool_t _dbus_replace_install_prefix(DBusString *path)
Replace the DBUS_PREFIX in the given path, in-place, by the current D-Bus installation directory.
dbus_bool_t _dbus_ensure_directory(const DBusString *filename, DBusError *error)
Creates a directory; succeeds if the directory is created or already existed.
dbus_uint32_t dbus_bool_t
A boolean, valid values are TRUE and FALSE.
Definition: dbus-types.h:35
Internals of directory iterator.
DIR * d
The DIR* from opendir()
Object representing an exception.
Definition: dbus-errors.h:49
const char * message
public error message field
Definition: dbus-errors.h:51
Information about a UNIX group.
dbus_gid_t gid
GID.
char * groupname
Group name.
A node in a linked list.
Definition: dbus-list.h:35
Portable struct with stat() results.
Definition: dbus-sysdeps.h:554
unsigned long nlink
Number of hard links.
Definition: dbus-sysdeps.h:556
unsigned long size
Size of file.
Definition: dbus-sysdeps.h:559
dbus_uid_t uid
User owning file.
Definition: dbus-sysdeps.h:557
unsigned long mode
File mode.
Definition: dbus-sysdeps.h:555
dbus_gid_t gid
Group owning file.
Definition: dbus-sysdeps.h:558
unsigned long atime
Access time.
Definition: dbus-sysdeps.h:560
unsigned long ctime
Creation time.
Definition: dbus-sysdeps.h:562
unsigned long mtime
Modify time.
Definition: dbus-sysdeps.h:561