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00024 #include "dbus-sysdeps.h"
00025 #include "dbus-sysdeps-unix.h"
00026 #include "dbus-internals.h"
00027 #include "dbus-protocol.h"
00028 #include "dbus-string.h"
00029 #define DBUS_USERDB_INCLUDES_PRIVATE 1
00030 #include "dbus-userdb.h"
00031 #include "dbus-test.h"
00032
00033 #include <sys/types.h>
00034 #include <stdlib.h>
00035 #include <string.h>
00036 #include <signal.h>
00037 #include <unistd.h>
00038 #include <stdio.h>
00039 #include <errno.h>
00040 #include <fcntl.h>
00041 #include <sys/stat.h>
00042 #include <grp.h>
00043 #include <sys/socket.h>
00044 #include <dirent.h>
00045 #include <sys/un.h>
00046 #ifdef HAVE_LIBAUDIT
00047 #include <sys/prctl.h>
00048 #include <sys/capability.h>
00049 #include <libaudit.h>
00050 #endif
00051
00052 #ifdef HAVE_SYS_SYSLIMITS_H
00053 #include <sys/syslimits.h>
00054 #endif
00055
00056 #ifndef O_BINARY
00057 #define O_BINARY 0
00058 #endif
00059
00073 dbus_bool_t
00074 _dbus_become_daemon (const DBusString *pidfile,
00075 DBusPipe *print_pid_pipe,
00076 DBusError *error)
00077 {
00078 const char *s;
00079 pid_t child_pid;
00080 int dev_null_fd;
00081
00082 _dbus_verbose ("Becoming a daemon...\n");
00083
00084 _dbus_verbose ("chdir to /\n");
00085 if (chdir ("/") < 0)
00086 {
00087 dbus_set_error (error, DBUS_ERROR_FAILED,
00088 "Could not chdir() to root directory");
00089 return FALSE;
00090 }
00091
00092 _dbus_verbose ("forking...\n");
00093 switch ((child_pid = fork ()))
00094 {
00095 case -1:
00096 _dbus_verbose ("fork failed\n");
00097 dbus_set_error (error, _dbus_error_from_errno (errno),
00098 "Failed to fork daemon: %s", _dbus_strerror (errno));
00099 return FALSE;
00100 break;
00101
00102 case 0:
00103 _dbus_verbose ("in child, closing std file descriptors\n");
00104
00105
00106
00107
00108
00109
00110 dev_null_fd = open ("/dev/null", O_RDWR);
00111 if (dev_null_fd >= 0)
00112 {
00113 dup2 (dev_null_fd, 0);
00114 dup2 (dev_null_fd, 1);
00115
00116 s = _dbus_getenv ("DBUS_DEBUG_OUTPUT");
00117 if (s == NULL || *s == '\0')
00118 dup2 (dev_null_fd, 2);
00119 else
00120 _dbus_verbose ("keeping stderr open due to DBUS_DEBUG_OUTPUT\n");
00121 }
00122
00123
00124 _dbus_verbose ("setting umask\n");
00125 umask (022);
00126 break;
00127
00128 default:
00129 if (pidfile)
00130 {
00131 _dbus_verbose ("parent writing pid file\n");
00132 if (!_dbus_write_pid_file (pidfile,
00133 child_pid,
00134 error))
00135 {
00136 _dbus_verbose ("pid file write failed, killing child\n");
00137 kill (child_pid, SIGTERM);
00138 return FALSE;
00139 }
00140 }
00141
00142
00143 if (print_pid_pipe != NULL && _dbus_pipe_is_valid (print_pid_pipe))
00144 {
00145 DBusString pid;
00146 int bytes;
00147
00148 if (!_dbus_string_init (&pid))
00149 {
00150 _DBUS_SET_OOM (error);
00151 kill (child_pid, SIGTERM);
00152 return FALSE;
00153 }
00154
00155 if (!_dbus_string_append_int (&pid, child_pid) ||
00156 !_dbus_string_append (&pid, "\n"))
00157 {
00158 _dbus_string_free (&pid);
00159 _DBUS_SET_OOM (error);
00160 kill (child_pid, SIGTERM);
00161 return FALSE;
00162 }
00163
00164 bytes = _dbus_string_get_length (&pid);
00165 if (_dbus_pipe_write (print_pid_pipe, &pid, 0, bytes, error) != bytes)
00166 {
00167
00168 if (error != NULL && !dbus_error_is_set(error))
00169 {
00170 dbus_set_error (error, DBUS_ERROR_FAILED,
00171 "Printing message bus PID: did not write enough bytes\n");
00172 }
00173 _dbus_string_free (&pid);
00174 kill (child_pid, SIGTERM);
00175 return FALSE;
00176 }
00177
00178 _dbus_string_free (&pid);
00179 }
00180 _dbus_verbose ("parent exiting\n");
00181 _exit (0);
00182 break;
00183 }
00184
00185 _dbus_verbose ("calling setsid()\n");
00186 if (setsid () == -1)
00187 _dbus_assert_not_reached ("setsid() failed");
00188
00189 return TRUE;
00190 }
00191
00192
00201 dbus_bool_t
00202 _dbus_write_pid_file (const DBusString *filename,
00203 unsigned long pid,
00204 DBusError *error)
00205 {
00206 const char *cfilename;
00207 int fd;
00208 FILE *f;
00209
00210 cfilename = _dbus_string_get_const_data (filename);
00211
00212 fd = open (cfilename, O_WRONLY|O_CREAT|O_EXCL|O_BINARY, 0644);
00213
00214 if (fd < 0)
00215 {
00216 dbus_set_error (error, _dbus_error_from_errno (errno),
00217 "Failed to open \"%s\": %s", cfilename,
00218 _dbus_strerror (errno));
00219 return FALSE;
00220 }
00221
00222 if ((f = fdopen (fd, "w")) == NULL)
00223 {
00224 dbus_set_error (error, _dbus_error_from_errno (errno),
00225 "Failed to fdopen fd %d: %s", fd, _dbus_strerror (errno));
00226 _dbus_close (fd, NULL);
00227 return FALSE;
00228 }
00229
00230 if (fprintf (f, "%lu\n", pid) < 0)
00231 {
00232 dbus_set_error (error, _dbus_error_from_errno (errno),
00233 "Failed to write to \"%s\": %s", cfilename,
00234 _dbus_strerror (errno));
00235
00236 fclose (f);
00237 return FALSE;
00238 }
00239
00240 if (fclose (f) == EOF)
00241 {
00242 dbus_set_error (error, _dbus_error_from_errno (errno),
00243 "Failed to close \"%s\": %s", cfilename,
00244 _dbus_strerror (errno));
00245 return FALSE;
00246 }
00247
00248 return TRUE;
00249 }
00250
00257 dbus_bool_t
00258 _dbus_verify_daemon_user (const char *user)
00259 {
00260 DBusString u;
00261
00262 _dbus_string_init_const (&u, user);
00263
00264 return _dbus_get_user_id_and_primary_group (&u, NULL, NULL);
00265 }
00266
00274 dbus_bool_t
00275 _dbus_change_to_daemon_user (const char *user,
00276 DBusError *error)
00277 {
00278 dbus_uid_t uid;
00279 dbus_gid_t gid;
00280 DBusString u;
00281 #ifdef HAVE_LIBAUDIT
00282 dbus_bool_t we_were_root;
00283 cap_t new_caps;
00284 #endif
00285
00286 _dbus_string_init_const (&u, user);
00287
00288 if (!_dbus_get_user_id_and_primary_group (&u, &uid, &gid))
00289 {
00290 dbus_set_error (error, DBUS_ERROR_FAILED,
00291 "User '%s' does not appear to exist?",
00292 user);
00293 return FALSE;
00294 }
00295
00296 #ifdef HAVE_LIBAUDIT
00297 we_were_root = _dbus_getuid () == 0;
00298 new_caps = NULL;
00299
00300
00301
00302
00303 if (we_were_root)
00304 {
00305 cap_value_t new_cap_list[] = { CAP_AUDIT_WRITE };
00306 cap_value_t tmp_cap_list[] = { CAP_AUDIT_WRITE, CAP_SETUID, CAP_SETGID };
00307 cap_t tmp_caps = cap_init();
00308
00309 if (!tmp_caps || !(new_caps = cap_init ()))
00310 {
00311 dbus_set_error (error, DBUS_ERROR_FAILED,
00312 "Failed to initialize drop of capabilities: %s\n",
00313 _dbus_strerror (errno));
00314
00315 if (tmp_caps)
00316 cap_free (tmp_caps);
00317
00318 return FALSE;
00319 }
00320
00321
00322 cap_set_flag (new_caps, CAP_PERMITTED, 1, new_cap_list, CAP_SET);
00323 cap_set_flag (new_caps, CAP_EFFECTIVE, 1, new_cap_list, CAP_SET);
00324 cap_set_flag (tmp_caps, CAP_PERMITTED, 3, tmp_cap_list, CAP_SET);
00325 cap_set_flag (tmp_caps, CAP_EFFECTIVE, 3, tmp_cap_list, CAP_SET);
00326
00327 if (prctl (PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1)
00328 {
00329 dbus_set_error (error, _dbus_error_from_errno (errno),
00330 "Failed to set keep-capabilities: %s\n",
00331 _dbus_strerror (errno));
00332 cap_free (tmp_caps);
00333 goto fail;
00334 }
00335
00336 if (cap_set_proc (tmp_caps) == -1)
00337 {
00338 dbus_set_error (error, DBUS_ERROR_FAILED,
00339 "Failed to drop capabilities: %s\n",
00340 _dbus_strerror (errno));
00341 cap_free (tmp_caps);
00342 goto fail;
00343 }
00344 cap_free (tmp_caps);
00345 }
00346 #endif
00347
00348
00349
00350
00351
00352
00353
00354
00355 if (setgroups (0, NULL) < 0)
00356 _dbus_warn ("Failed to drop supplementary groups: %s\n",
00357 _dbus_strerror (errno));
00358
00359
00360
00361
00362 if (setgid (gid) < 0)
00363 {
00364 dbus_set_error (error, _dbus_error_from_errno (errno),
00365 "Failed to set GID to %lu: %s", gid,
00366 _dbus_strerror (errno));
00367 goto fail;
00368 }
00369
00370 if (setuid (uid) < 0)
00371 {
00372 dbus_set_error (error, _dbus_error_from_errno (errno),
00373 "Failed to set UID to %lu: %s", uid,
00374 _dbus_strerror (errno));
00375 goto fail;
00376 }
00377
00378 #ifdef HAVE_LIBAUDIT
00379 if (we_were_root)
00380 {
00381 if (cap_set_proc (new_caps))
00382 {
00383 dbus_set_error (error, DBUS_ERROR_FAILED,
00384 "Failed to drop capabilities: %s\n",
00385 _dbus_strerror (errno));
00386 goto fail;
00387 }
00388 cap_free (new_caps);
00389
00390
00391 if (prctl (PR_SET_KEEPCAPS, 0, 0, 0, 0) == -1)
00392 {
00393 dbus_set_error (error, _dbus_error_from_errno (errno),
00394 "Failed to unset keep-capabilities: %s\n",
00395 _dbus_strerror (errno));
00396 return FALSE;
00397 }
00398 audit_init();
00399 }
00400 #endif
00401
00402 return TRUE;
00403
00404 fail:
00405 #ifdef HAVE_LIBAUDIT
00406 if (!we_were_root)
00407 {
00408
00409 prctl (PR_SET_KEEPCAPS, 0, 0, 0, 0);
00410 cap_free (new_caps);
00411 }
00412 #endif
00413
00414 return FALSE;
00415 }
00416
00422 void
00423 _dbus_set_signal_handler (int sig,
00424 DBusSignalHandler handler)
00425 {
00426 struct sigaction act;
00427 sigset_t empty_mask;
00428
00429 sigemptyset (&empty_mask);
00430 act.sa_handler = handler;
00431 act.sa_mask = empty_mask;
00432 act.sa_flags = 0;
00433 sigaction (sig, &act, NULL);
00434 }
00435
00436
00444 dbus_bool_t
00445 _dbus_delete_directory (const DBusString *filename,
00446 DBusError *error)
00447 {
00448 const char *filename_c;
00449
00450 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
00451
00452 filename_c = _dbus_string_get_const_data (filename);
00453
00454 if (rmdir (filename_c) != 0)
00455 {
00456 dbus_set_error (error, DBUS_ERROR_FAILED,
00457 "Failed to remove directory %s: %s\n",
00458 filename_c, _dbus_strerror (errno));
00459 return FALSE;
00460 }
00461
00462 return TRUE;
00463 }
00464
00470 dbus_bool_t
00471 _dbus_file_exists (const char *file)
00472 {
00473 return (access (file, F_OK) == 0);
00474 }
00475
00482 dbus_bool_t
00483 _dbus_user_at_console (const char *username,
00484 DBusError *error)
00485 {
00486
00487 DBusString f;
00488 dbus_bool_t result;
00489
00490 result = FALSE;
00491 if (!_dbus_string_init (&f))
00492 {
00493 _DBUS_SET_OOM (error);
00494 return FALSE;
00495 }
00496
00497 if (!_dbus_string_append (&f, DBUS_CONSOLE_AUTH_DIR))
00498 {
00499 _DBUS_SET_OOM (error);
00500 goto out;
00501 }
00502
00503
00504 if (!_dbus_string_append (&f, username))
00505 {
00506 _DBUS_SET_OOM (error);
00507 goto out;
00508 }
00509
00510 result = _dbus_file_exists (_dbus_string_get_const_data (&f));
00511
00512 out:
00513 _dbus_string_free (&f);
00514
00515 return result;
00516 }
00517
00518
00525 dbus_bool_t
00526 _dbus_path_is_absolute (const DBusString *filename)
00527 {
00528 if (_dbus_string_get_length (filename) > 0)
00529 return _dbus_string_get_byte (filename, 0) == '/';
00530 else
00531 return FALSE;
00532 }
00533
00542 dbus_bool_t
00543 _dbus_stat (const DBusString *filename,
00544 DBusStat *statbuf,
00545 DBusError *error)
00546 {
00547 const char *filename_c;
00548 struct stat sb;
00549
00550 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
00551
00552 filename_c = _dbus_string_get_const_data (filename);
00553
00554 if (stat (filename_c, &sb) < 0)
00555 {
00556 dbus_set_error (error, _dbus_error_from_errno (errno),
00557 "%s", _dbus_strerror (errno));
00558 return FALSE;
00559 }
00560
00561 statbuf->mode = sb.st_mode;
00562 statbuf->nlink = sb.st_nlink;
00563 statbuf->uid = sb.st_uid;
00564 statbuf->gid = sb.st_gid;
00565 statbuf->size = sb.st_size;
00566 statbuf->atime = sb.st_atime;
00567 statbuf->mtime = sb.st_mtime;
00568 statbuf->ctime = sb.st_ctime;
00569
00570 return TRUE;
00571 }
00572
00573
00577 struct DBusDirIter
00578 {
00579 DIR *d;
00581 };
00582
00590 DBusDirIter*
00591 _dbus_directory_open (const DBusString *filename,
00592 DBusError *error)
00593 {
00594 DIR *d;
00595 DBusDirIter *iter;
00596 const char *filename_c;
00597
00598 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
00599
00600 filename_c = _dbus_string_get_const_data (filename);
00601
00602 d = opendir (filename_c);
00603 if (d == NULL)
00604 {
00605 dbus_set_error (error, _dbus_error_from_errno (errno),
00606 "Failed to read directory \"%s\": %s",
00607 filename_c,
00608 _dbus_strerror (errno));
00609 return NULL;
00610 }
00611 iter = dbus_new0 (DBusDirIter, 1);
00612 if (iter == NULL)
00613 {
00614 closedir (d);
00615 dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
00616 "Could not allocate memory for directory iterator");
00617 return NULL;
00618 }
00619
00620 iter->d = d;
00621
00622 return iter;
00623 }
00624
00625
00626
00627
00628
00629
00630
00631
00632
00633 static dbus_bool_t
00634 dirent_buf_size(DIR * dirp, size_t *size)
00635 {
00636 long name_max;
00637 # if defined(HAVE_FPATHCONF) && defined(_PC_NAME_MAX)
00638 # if defined(HAVE_DIRFD)
00639 name_max = fpathconf(dirfd(dirp), _PC_NAME_MAX);
00640 # elif defined(HAVE_DDFD)
00641 name_max = fpathconf(dirp->dd_fd, _PC_NAME_MAX);
00642 # else
00643 name_max = fpathconf(dirp->__dd_fd, _PC_NAME_MAX);
00644 # endif
00645 if (name_max == -1)
00646 # if defined(NAME_MAX)
00647 name_max = NAME_MAX;
00648 # else
00649 return FALSE;
00650 # endif
00651 # elif defined(MAXNAMELEN)
00652 name_max = MAXNAMELEN;
00653 # else
00654 # if defined(NAME_MAX)
00655 name_max = NAME_MAX;
00656 # else
00657 # error "buffer size for readdir_r cannot be determined"
00658 # endif
00659 # endif
00660 if (size)
00661 *size = (size_t)offsetof(struct dirent, d_name) + name_max + 1;
00662 else
00663 return FALSE;
00664
00665 return TRUE;
00666 }
00667
00678 dbus_bool_t
00679 _dbus_directory_get_next_file (DBusDirIter *iter,
00680 DBusString *filename,
00681 DBusError *error)
00682 {
00683 struct dirent *d, *ent;
00684 size_t buf_size;
00685 int err;
00686
00687 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
00688
00689 if (!dirent_buf_size (iter->d, &buf_size))
00690 {
00691 dbus_set_error (error, DBUS_ERROR_FAILED,
00692 "Can't calculate buffer size when reading directory");
00693 return FALSE;
00694 }
00695
00696 d = (struct dirent *)dbus_malloc (buf_size);
00697 if (!d)
00698 {
00699 dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
00700 "No memory to read directory entry");
00701 return FALSE;
00702 }
00703
00704 again:
00705 err = readdir_r (iter->d, d, &ent);
00706 if (err || !ent)
00707 {
00708 if (err != 0)
00709 dbus_set_error (error,
00710 _dbus_error_from_errno (err),
00711 "%s", _dbus_strerror (err));
00712
00713 dbus_free (d);
00714 return FALSE;
00715 }
00716 else if (ent->d_name[0] == '.' &&
00717 (ent->d_name[1] == '\0' ||
00718 (ent->d_name[1] == '.' && ent->d_name[2] == '\0')))
00719 goto again;
00720 else
00721 {
00722 _dbus_string_set_length (filename, 0);
00723 if (!_dbus_string_append (filename, ent->d_name))
00724 {
00725 dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
00726 "No memory to read directory entry");
00727 dbus_free (d);
00728 return FALSE;
00729 }
00730 else
00731 {
00732 dbus_free (d);
00733 return TRUE;
00734 }
00735 }
00736 }
00737
00741 void
00742 _dbus_directory_close (DBusDirIter *iter)
00743 {
00744 closedir (iter->d);
00745 dbus_free (iter);
00746 }
00747
00748 static dbus_bool_t
00749 fill_user_info_from_group (struct group *g,
00750 DBusGroupInfo *info,
00751 DBusError *error)
00752 {
00753 _dbus_assert (g->gr_name != NULL);
00754
00755 info->gid = g->gr_gid;
00756 info->groupname = _dbus_strdup (g->gr_name);
00757
00758
00759
00760 if (info->groupname == NULL)
00761 {
00762 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
00763 return FALSE;
00764 }
00765
00766 return TRUE;
00767 }
00768
00769 static dbus_bool_t
00770 fill_group_info (DBusGroupInfo *info,
00771 dbus_gid_t gid,
00772 const DBusString *groupname,
00773 DBusError *error)
00774 {
00775 const char *group_c_str;
00776
00777 _dbus_assert (groupname != NULL || gid != DBUS_GID_UNSET);
00778 _dbus_assert (groupname == NULL || gid == DBUS_GID_UNSET);
00779
00780 if (groupname)
00781 group_c_str = _dbus_string_get_const_data (groupname);
00782 else
00783 group_c_str = NULL;
00784
00785
00786
00787
00788
00789
00790 #if defined (HAVE_POSIX_GETPWNAM_R) || defined (HAVE_NONPOSIX_GETPWNAM_R)
00791 {
00792 struct group *g;
00793 int result;
00794 char buf[1024];
00795 struct group g_str;
00796
00797 g = NULL;
00798 #ifdef HAVE_POSIX_GETPWNAM_R
00799
00800 if (group_c_str)
00801 result = getgrnam_r (group_c_str, &g_str, buf, sizeof (buf),
00802 &g);
00803 else
00804 result = getgrgid_r (gid, &g_str, buf, sizeof (buf),
00805 &g);
00806 #else
00807 g = getgrnam_r (group_c_str, &g_str, buf, sizeof (buf));
00808 result = 0;
00809 #endif
00810 if (result == 0 && g == &g_str)
00811 {
00812 return fill_user_info_from_group (g, info, error);
00813 }
00814 else
00815 {
00816 dbus_set_error (error, _dbus_error_from_errno (errno),
00817 "Group %s unknown or failed to look it up\n",
00818 group_c_str ? group_c_str : "???");
00819 return FALSE;
00820 }
00821 }
00822 #else
00823 {
00824
00825 struct group *g;
00826
00827 g = getgrnam (group_c_str);
00828
00829 if (g != NULL)
00830 {
00831 return fill_user_info_from_group (g, info, error);
00832 }
00833 else
00834 {
00835 dbus_set_error (error, _dbus_error_from_errno (errno),
00836 "Group %s unknown or failed to look it up\n",
00837 group_c_str ? group_c_str : "???");
00838 return FALSE;
00839 }
00840 }
00841 #endif
00842 }
00843
00853 dbus_bool_t
00854 _dbus_group_info_fill (DBusGroupInfo *info,
00855 const DBusString *groupname,
00856 DBusError *error)
00857 {
00858 return fill_group_info (info, DBUS_GID_UNSET,
00859 groupname, error);
00860
00861 }
00862
00872 dbus_bool_t
00873 _dbus_group_info_fill_gid (DBusGroupInfo *info,
00874 dbus_gid_t gid,
00875 DBusError *error)
00876 {
00877 return fill_group_info (info, gid, NULL, error);
00878 }
00879
00888 dbus_bool_t
00889 _dbus_parse_unix_user_from_config (const DBusString *username,
00890 dbus_uid_t *uid_p)
00891 {
00892 return _dbus_get_user_id (username, uid_p);
00893
00894 }
00895
00904 dbus_bool_t
00905 _dbus_parse_unix_group_from_config (const DBusString *groupname,
00906 dbus_gid_t *gid_p)
00907 {
00908 return _dbus_get_group_id (groupname, gid_p);
00909 }
00910
00921 dbus_bool_t
00922 _dbus_unix_groups_from_uid (dbus_uid_t uid,
00923 dbus_gid_t **group_ids,
00924 int *n_group_ids)
00925 {
00926 return _dbus_groups_from_uid (uid, group_ids, n_group_ids);
00927 }
00928
00938 dbus_bool_t
00939 _dbus_unix_user_is_at_console (dbus_uid_t uid,
00940 DBusError *error)
00941 {
00942 return _dbus_is_console_user (uid, error);
00943
00944 }
00945
00953 dbus_bool_t
00954 _dbus_unix_user_is_process_owner (dbus_uid_t uid)
00955 {
00956 return uid == _dbus_getuid ();
00957 }
00958
00966 dbus_bool_t
00967 _dbus_windows_user_is_process_owner (const char *windows_sid)
00968 {
00969 return FALSE;
00970 }
00971
00973
00985 dbus_bool_t
00986 _dbus_string_get_dirname (const DBusString *filename,
00987 DBusString *dirname)
00988 {
00989 int sep;
00990
00991 _dbus_assert (filename != dirname);
00992 _dbus_assert (filename != NULL);
00993 _dbus_assert (dirname != NULL);
00994
00995
00996 sep = _dbus_string_get_length (filename);
00997 if (sep == 0)
00998 return _dbus_string_append (dirname, ".");
00999
01000 while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
01001 --sep;
01002
01003 _dbus_assert (sep >= 0);
01004
01005 if (sep == 0)
01006 return _dbus_string_append (dirname, "/");
01007
01008
01009 _dbus_string_find_byte_backward (filename, sep, '/', &sep);
01010 if (sep < 0)
01011 return _dbus_string_append (dirname, ".");
01012
01013
01014 while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
01015 --sep;
01016
01017 _dbus_assert (sep >= 0);
01018
01019 if (sep == 0 &&
01020 _dbus_string_get_byte (filename, 0) == '/')
01021 return _dbus_string_append (dirname, "/");
01022 else
01023 return _dbus_string_copy_len (filename, 0, sep - 0,
01024 dirname, _dbus_string_get_length (dirname));
01025 }
01027