2 * libudev - interface to udev device information
4 * Copyright (C) 2008-2010 Kay Sievers <kay.sievers@vrfy.org>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
22 #include <sys/param.h>
25 #include "libudev-private.h"
28 * SECTION:libudev-enumerate
29 * @short_description: lookup and sort sys devices
31 * Lookup devices in the sys filesystem, filter devices by properties,
32 * and return a sorted list of devices.
43 * Opaque object representing one device lookup/sort context.
45 struct udev_enumerate {
48 struct udev_list sysattr_match_list;
49 struct udev_list sysattr_nomatch_list;
50 struct udev_list subsystem_match_list;
51 struct udev_list subsystem_nomatch_list;
52 struct udev_list sysname_match_list;
53 struct udev_list properties_match_list;
54 struct udev_list tags_match_list;
55 struct udev_device *parent_match;
56 struct udev_list devices_list;
57 struct syspath *devices;
58 unsigned int devices_cur;
59 unsigned int devices_max;
60 bool devices_uptodate:1;
61 bool match_is_initialized;
66 * @udev: udev library context
68 * Returns: an enumeration context
70 _public_ struct udev_enumerate *udev_enumerate_new(struct udev *udev)
72 struct udev_enumerate *udev_enumerate;
74 udev_enumerate = calloc(1, sizeof(struct udev_enumerate));
75 if (udev_enumerate == NULL)
77 udev_enumerate->refcount = 1;
78 udev_enumerate->udev = udev;
79 udev_list_init(udev, &udev_enumerate->sysattr_match_list, false);
80 udev_list_init(udev, &udev_enumerate->sysattr_nomatch_list, false);
81 udev_list_init(udev, &udev_enumerate->subsystem_match_list, true);
82 udev_list_init(udev, &udev_enumerate->subsystem_nomatch_list, true);
83 udev_list_init(udev, &udev_enumerate->sysname_match_list, true);
84 udev_list_init(udev, &udev_enumerate->properties_match_list, false);
85 udev_list_init(udev, &udev_enumerate->tags_match_list, true);
86 udev_list_init(udev, &udev_enumerate->devices_list, false);
87 return udev_enumerate;
92 * @udev_enumerate: context
94 * Take a reference of a enumeration context.
96 * Returns: the passed enumeration context
98 _public_ struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
100 if (udev_enumerate == NULL)
102 udev_enumerate->refcount++;
103 return udev_enumerate;
107 * udev_enumerate_unref:
108 * @udev_enumerate: context
110 * Drop a reference of an enumeration context. If the refcount reaches zero,
111 * all resources of the enumeration context will be released.
113 _public_ void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
117 if (udev_enumerate == NULL)
119 udev_enumerate->refcount--;
120 if (udev_enumerate->refcount > 0)
122 udev_list_cleanup(&udev_enumerate->sysattr_match_list);
123 udev_list_cleanup(&udev_enumerate->sysattr_nomatch_list);
124 udev_list_cleanup(&udev_enumerate->subsystem_match_list);
125 udev_list_cleanup(&udev_enumerate->subsystem_nomatch_list);
126 udev_list_cleanup(&udev_enumerate->sysname_match_list);
127 udev_list_cleanup(&udev_enumerate->properties_match_list);
128 udev_list_cleanup(&udev_enumerate->tags_match_list);
129 udev_device_unref(udev_enumerate->parent_match);
130 udev_list_cleanup(&udev_enumerate->devices_list);
131 for (i = 0; i < udev_enumerate->devices_cur; i++)
132 free(udev_enumerate->devices[i].syspath);
133 free(udev_enumerate->devices);
134 free(udev_enumerate);
138 * udev_enumerate_get_udev:
139 * @udev_enumerate: context
141 * Returns: the udev library context.
143 _public_ struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
145 if (udev_enumerate == NULL)
147 return udev_enumerate->udev;
150 static int syspath_add(struct udev_enumerate *udev_enumerate, const char *syspath)
153 struct syspath *entry;
155 /* double array size if needed */
156 if (udev_enumerate->devices_cur >= udev_enumerate->devices_max) {
160 add = udev_enumerate->devices_max;
163 buf = realloc(udev_enumerate->devices, (udev_enumerate->devices_max + add) * sizeof(struct syspath));
166 udev_enumerate->devices = buf;
167 udev_enumerate->devices_max += add;
170 path = strdup(syspath);
173 entry = &udev_enumerate->devices[udev_enumerate->devices_cur];
174 entry->syspath = path;
175 entry->len = strlen(path);
176 udev_enumerate->devices_cur++;
177 udev_enumerate->devices_uptodate = false;
181 static int syspath_cmp(const void *p1, const void *p2)
183 const struct syspath *path1 = p1;
184 const struct syspath *path2 = p2;
188 len = MIN(path1->len, path2->len);
189 ret = memcmp(path1->syspath, path2->syspath, len);
191 if (path1->len < path2->len)
193 else if (path1->len > path2->len)
199 /* For devices that should be moved to the absolute end of the list */
200 static bool devices_delay_end(struct udev *udev, const char *syspath)
202 static const char *delay_device_list[] = {
210 len = strlen(udev_get_sys_path(udev));
211 for (i = 0; delay_device_list[i] != NULL; i++) {
212 if (strstr(&syspath[len], delay_device_list[i]) != NULL)
218 /* For devices that should just be moved a little bit later, just
219 * before the point where some common path prefix changes. Returns the
220 * number of characters that make up that common prefix */
221 static size_t devices_delay_later(struct udev *udev, const char *syspath)
225 /* For sound cards the control device must be enumerated last
226 * to make sure it's the final device node that gets ACLs
227 * applied. Applications rely on this fact and use ACL changes
228 * on the control node as an indicator that the ACL change of
229 * the entire sound card completed. The kernel makes this
230 * guarantee when creating those devices, and hence we should
231 * too when enumerating them. */
233 if ((c = strstr(syspath, "/sound/card"))) {
235 c += strcspn(c, "/");
237 if (strncmp(c, "/controlC", 9) == 0)
238 return c - syspath + 1;
245 * udev_enumerate_get_list_entry:
246 * @udev_enumerate: context
248 * Returns: the first entry of the sorted list of device paths.
250 _public_ struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
252 if (udev_enumerate == NULL)
254 if (!udev_enumerate->devices_uptodate) {
257 struct syspath *prev = NULL, *move_later = NULL;
258 size_t move_later_prefix = 0;
260 udev_list_cleanup(&udev_enumerate->devices_list);
261 qsort(udev_enumerate->devices, udev_enumerate->devices_cur, sizeof(struct syspath), syspath_cmp);
263 max = udev_enumerate->devices_cur;
264 for (i = 0; i < max; i++) {
265 struct syspath *entry = &udev_enumerate->devices[i];
267 /* skip duplicated entries */
269 entry->len == prev->len &&
270 memcmp(entry->syspath, prev->syspath, entry->len) == 0)
274 /* skip to be delayed devices, and add them to the end of the list */
275 if (devices_delay_end(udev_enumerate->udev, entry->syspath)) {
276 syspath_add(udev_enumerate, entry->syspath);
277 /* need to update prev here for the case realloc() gives a different address */
278 prev = &udev_enumerate->devices[i];
282 /* skip to be delayed devices, and move the to
283 * the point where the prefix changes. We can
284 * only move one item at a time. */
286 move_later_prefix = devices_delay_later(udev_enumerate->udev, entry->syspath);
288 if (move_later_prefix > 0) {
295 strncmp(entry->syspath, move_later->syspath, move_later_prefix) != 0) {
297 udev_list_entry_add(&udev_enumerate->devices_list, move_later->syspath, NULL);
301 udev_list_entry_add(&udev_enumerate->devices_list, entry->syspath, NULL);
305 udev_list_entry_add(&udev_enumerate->devices_list, move_later->syspath, NULL);
307 /* add and cleanup delayed devices from end of list */
308 for (i = max; i < udev_enumerate->devices_cur; i++) {
309 struct syspath *entry = &udev_enumerate->devices[i];
311 udev_list_entry_add(&udev_enumerate->devices_list, entry->syspath, NULL);
312 free(entry->syspath);
314 udev_enumerate->devices_cur = max;
316 udev_enumerate->devices_uptodate = true;
318 return udev_list_get_entry(&udev_enumerate->devices_list);
322 * udev_enumerate_add_match_subsystem:
323 * @udev_enumerate: context
324 * @subsystem: filter for a subsystem of the device to include in the list
326 * Returns: 0 on success, otherwise a negative error value.
328 _public_ int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
330 if (udev_enumerate == NULL)
332 if (subsystem == NULL)
334 if (udev_list_entry_add(&udev_enumerate->subsystem_match_list, subsystem, NULL) == NULL)
340 * udev_enumerate_add_nomatch_subsystem:
341 * @udev_enumerate: context
342 * @subsystem: filter for a subsystem of the device to exclude from the list
344 * Returns: 0 on success, otherwise a negative error value.
346 _public_ int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
348 if (udev_enumerate == NULL)
350 if (subsystem == NULL)
352 if (udev_list_entry_add(&udev_enumerate->subsystem_nomatch_list, subsystem, NULL) == NULL)
358 * udev_enumerate_add_match_sysattr:
359 * @udev_enumerate: context
360 * @sysattr: filter for a sys attribute at the device to include in the list
361 * @value: optional value of the sys attribute
363 * Returns: 0 on success, otherwise a negative error value.
365 _public_ int udev_enumerate_add_match_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
367 if (udev_enumerate == NULL)
371 if (udev_list_entry_add(&udev_enumerate->sysattr_match_list, sysattr, value) == NULL)
377 * udev_enumerate_add_nomatch_sysattr:
378 * @udev_enumerate: context
379 * @sysattr: filter for a sys attribute at the device to exclude from the list
380 * @value: optional value of the sys attribute
382 * Returns: 0 on success, otherwise a negative error value.
384 _public_ int udev_enumerate_add_nomatch_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
386 if (udev_enumerate == NULL)
390 if (udev_list_entry_add(&udev_enumerate->sysattr_nomatch_list, sysattr, value) == NULL)
395 static int match_sysattr_value(struct udev_device *dev, const char *sysattr, const char *match_val)
397 const char *val = NULL;
400 val = udev_device_get_sysattr_value(dev, sysattr);
403 if (match_val == NULL) {
407 if (fnmatch(match_val, val, 0) == 0) {
416 * udev_enumerate_add_match_property:
417 * @udev_enumerate: context
418 * @property: filter for a property of the device to include in the list
419 * @value: value of the property
421 * Returns: 0 on success, otherwise a negative error value.
423 _public_ int udev_enumerate_add_match_property(struct udev_enumerate *udev_enumerate, const char *property, const char *value)
425 if (udev_enumerate == NULL)
427 if (property == NULL)
429 if (udev_list_entry_add(&udev_enumerate->properties_match_list, property, value) == NULL)
435 * udev_enumerate_add_match_tag:
436 * @udev_enumerate: context
437 * @tag: filter for a tag of the device to include in the list
439 * Returns: 0 on success, otherwise a negative error value.
441 _public_ int udev_enumerate_add_match_tag(struct udev_enumerate *udev_enumerate, const char *tag)
443 if (udev_enumerate == NULL)
447 if (udev_list_entry_add(&udev_enumerate->tags_match_list, tag, NULL) == NULL)
453 * udev_enumerate_add_match_parent:
454 * @udev_enumerate: context
455 * @parent: parent device where to start searching
457 * Return the devices on the subtree of one given device. The parent
458 * itself is included in the list.
460 * A reference for the device is held until the udev_enumerate context
463 * Returns: 0 on success, otherwise a negative error value.
465 _public_ int udev_enumerate_add_match_parent(struct udev_enumerate *udev_enumerate, struct udev_device *parent)
467 if (udev_enumerate == NULL)
471 if (udev_enumerate->parent_match != NULL)
472 udev_device_unref(udev_enumerate->parent_match);
473 udev_enumerate->parent_match = udev_device_ref(parent);
478 * udev_enumerate_add_match_is_initialized:
479 * @udev_enumerate: context
481 * Match only devices which udev has set up already. This makes
482 * sure, that the device node permissions and context are properly set
483 * and that network devices are fully renamed.
485 * Usually, devices which are found in the kernel but not already
486 * handled by udev, have still pending events. Services should subscribe
487 * to monitor events and wait for these devices to become ready, instead
488 * of using uninitialized devices.
490 * For now, this will not affect devices which do not have a device node
491 * and are not network interfaces.
493 * Returns: 0 on success, otherwise a negative error value.
495 _public_ int udev_enumerate_add_match_is_initialized(struct udev_enumerate *udev_enumerate)
497 if (udev_enumerate == NULL)
499 udev_enumerate->match_is_initialized = true;
504 * udev_enumerate_add_match_sysname:
505 * @udev_enumerate: context
506 * @sysname: filter for the name of the device to include in the list
508 * Returns: 0 on success, otherwise a negative error value.
510 _public_ int udev_enumerate_add_match_sysname(struct udev_enumerate *udev_enumerate, const char *sysname)
512 if (udev_enumerate == NULL)
516 if (udev_list_entry_add(&udev_enumerate->sysname_match_list, sysname, NULL) == NULL)
521 static bool match_sysattr(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
523 struct udev_list_entry *list_entry;
526 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_nomatch_list)) {
527 if (match_sysattr_value(dev, udev_list_entry_get_name(list_entry),
528 udev_list_entry_get_value(list_entry)))
532 if (udev_list_get_entry(&udev_enumerate->sysattr_match_list) != NULL) {
533 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_match_list)) {
534 /* anything that does not match, will make it FALSE */
535 if (!match_sysattr_value(dev, udev_list_entry_get_name(list_entry),
536 udev_list_entry_get_value(list_entry)))
544 static bool match_property(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
546 struct udev_list_entry *list_entry;
549 /* no match always matches */
550 if (udev_list_get_entry(&udev_enumerate->properties_match_list) == NULL)
553 /* loop over matches */
554 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->properties_match_list)) {
555 const char *match_key = udev_list_entry_get_name(list_entry);
556 const char *match_value = udev_list_entry_get_value(list_entry);
557 struct udev_list_entry *property_entry;
559 /* loop over device properties */
560 udev_list_entry_foreach(property_entry, udev_device_get_properties_list_entry(dev)) {
561 const char *dev_key = udev_list_entry_get_name(property_entry);
562 const char *dev_value = udev_list_entry_get_value(property_entry);
564 if (fnmatch(match_key, dev_key, 0) != 0)
566 if (match_value == NULL && dev_value == NULL) {
570 if (match_value == NULL || dev_value == NULL)
572 if (fnmatch(match_value, dev_value, 0) == 0) {
582 static bool match_tag(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
584 struct udev_list_entry *list_entry;
586 /* no match always matches */
587 if (udev_list_get_entry(&udev_enumerate->tags_match_list) == NULL)
590 /* loop over matches */
591 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->tags_match_list))
592 if (!udev_device_has_tag(dev, udev_list_entry_get_name(list_entry)))
598 static bool match_parent(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
602 if (udev_enumerate->parent_match == NULL)
605 parent = udev_device_get_devpath(udev_enumerate->parent_match);
606 return strncmp(parent, udev_device_get_devpath(dev), strlen(parent)) == 0;
609 static bool match_sysname(struct udev_enumerate *udev_enumerate, const char *sysname)
611 struct udev_list_entry *list_entry;
613 if (udev_list_get_entry(&udev_enumerate->sysname_match_list) == NULL)
616 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysname_match_list)) {
617 if (fnmatch(udev_list_entry_get_name(list_entry), sysname, 0) != 0)
624 static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
625 const char *basedir, const char *subdir1, const char *subdir2)
627 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
628 char path[UTIL_PATH_SIZE];
635 l = util_strpcpyl(&s, sizeof(path), udev_get_sys_path(udev), "/", basedir, NULL);
637 l = util_strpcpyl(&s, l, "/", subdir1, NULL);
639 util_strpcpyl(&s, l, "/", subdir2, NULL);
643 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
644 char syspath[UTIL_PATH_SIZE];
645 struct udev_device *dev;
647 if (dent->d_name[0] == '.')
650 if (!match_sysname(udev_enumerate, dent->d_name))
653 util_strscpyl(syspath, sizeof(syspath), path, "/", dent->d_name, NULL);
654 dev = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
658 if (udev_enumerate->match_is_initialized) {
660 * All devices with a device node or network interfaces
661 * possibly need udev to adjust the device node permission
662 * or context, or rename the interface before it can be
663 * reliably used from other processes.
665 * For now, we can only check these types of devices, we
666 * might not store a database, and have no way to find out
667 * for all other types of devices.
669 if (!udev_device_get_is_initialized(dev) &&
670 (major(udev_device_get_devnum(dev)) > 0 || udev_device_get_ifindex(dev) > 0))
673 if (!match_parent(udev_enumerate, dev))
675 if (!match_tag(udev_enumerate, dev))
677 if (!match_property(udev_enumerate, dev))
679 if (!match_sysattr(udev_enumerate, dev))
682 syspath_add(udev_enumerate, udev_device_get_syspath(dev));
684 udev_device_unref(dev);
690 static bool match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
692 struct udev_list_entry *list_entry;
694 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
695 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
698 if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
699 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
700 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
708 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
710 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
712 char path[UTIL_PATH_SIZE];
716 util_strscpyl(path, sizeof(path), udev_get_sys_path(udev), "/", basedir, NULL);
720 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
721 if (dent->d_name[0] == '.')
723 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
725 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
732 * udev_enumerate_add_syspath:
733 * @udev_enumerate: context
734 * @syspath: path of a device
736 * Add a device to the list of devices, to retrieve it back sorted in dependency order.
738 * Returns: 0 on success, otherwise a negative error value.
740 _public_ int udev_enumerate_add_syspath(struct udev_enumerate *udev_enumerate, const char *syspath)
742 struct udev_device *udev_device;
744 if (udev_enumerate == NULL)
748 /* resolve to real syspath */
749 udev_device = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
750 if (udev_device == NULL)
752 syspath_add(udev_enumerate, udev_device_get_syspath(udev_device));
753 udev_device_unref(udev_device);
757 static int scan_devices_tags(struct udev_enumerate *udev_enumerate)
759 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
760 struct udev_list_entry *list_entry;
762 /* scan only tagged devices, use tags reverse-index, instead of searching all devices in /sys */
763 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->tags_match_list)) {
766 char path[UTIL_PATH_SIZE];
768 util_strscpyl(path, sizeof(path), udev_get_run_path(udev), "/tags/",
769 udev_list_entry_get_name(list_entry), NULL);
773 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
774 struct udev_device *dev;
776 if (dent->d_name[0] == '.')
779 dev = udev_device_new_from_id_filename(udev_enumerate->udev, dent->d_name);
783 if (!match_subsystem(udev_enumerate, udev_device_get_subsystem(dev)))
785 if (!match_sysname(udev_enumerate, udev_device_get_sysname(dev)))
787 if (!match_parent(udev_enumerate, dev))
789 if (!match_property(udev_enumerate, dev))
791 if (!match_sysattr(udev_enumerate, dev))
794 syspath_add(udev_enumerate, udev_device_get_syspath(dev));
796 udev_device_unref(dev);
803 static int parent_add_child(struct udev_enumerate *enumerate, const char *path)
805 struct udev_device *dev;
807 dev = udev_device_new_from_syspath(enumerate->udev, path);
811 if (!match_subsystem(enumerate, udev_device_get_subsystem(dev)))
813 if (!match_sysname(enumerate, udev_device_get_sysname(dev)))
815 if (!match_property(enumerate, dev))
817 if (!match_sysattr(enumerate, dev))
820 syspath_add(enumerate, udev_device_get_syspath(dev));
821 udev_device_unref(dev);
825 static int parent_crawl_children(struct udev_enumerate *enumerate, const char *path, int maxdepth)
834 for (dent = readdir(d); dent != NULL; dent = readdir(d)) {
837 if (dent->d_name[0] == '.')
839 if (dent->d_type != DT_DIR)
841 if (asprintf(&child, "%s/%s", path, dent->d_name) < 0)
843 parent_add_child(enumerate, child);
845 parent_crawl_children(enumerate, child, maxdepth-1);
853 static int scan_devices_children(struct udev_enumerate *enumerate)
857 path = udev_device_get_syspath(enumerate->parent_match);
858 parent_add_child(enumerate, path);
859 return parent_crawl_children(enumerate, path, 256);
862 static int scan_devices_all(struct udev_enumerate *udev_enumerate)
864 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
865 char base[UTIL_PATH_SIZE];
868 util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/subsystem", NULL);
869 if (stat(base, &statbuf) == 0) {
870 /* we have /subsystem/, forget all the old stuff */
871 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
873 scan_dir(udev_enumerate, "bus", "devices", NULL);
874 scan_dir(udev_enumerate, "class", NULL, NULL);
880 * udev_enumerate_scan_devices:
881 * @udev_enumerate: udev enumeration context
883 * Returns: 0 on success, otherwise a negative error value.
885 _public_ int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
887 if (udev_enumerate == NULL)
890 /* efficiently lookup tags only, we maintain a reverse-index */
891 if (udev_list_get_entry(&udev_enumerate->tags_match_list) != NULL)
892 return scan_devices_tags(udev_enumerate);
894 /* walk the subtree of one parent device only */
895 if (udev_enumerate->parent_match != NULL)
896 return scan_devices_children(udev_enumerate);
898 /* scan devices of all subsystems */
899 return scan_devices_all(udev_enumerate);
903 * udev_enumerate_scan_subsystems:
904 * @udev_enumerate: udev enumeration context
906 * Returns: 0 on success, otherwise a negative error value.
908 _public_ int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
910 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
911 char base[UTIL_PATH_SIZE];
913 const char *subsysdir;
915 if (udev_enumerate == NULL)
918 /* all kernel modules */
919 if (match_subsystem(udev_enumerate, "module"))
920 scan_dir_and_add_devices(udev_enumerate, "module", NULL, NULL);
922 util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/subsystem", NULL);
923 if (stat(base, &statbuf) == 0)
924 subsysdir = "subsystem";
928 /* all subsystems (only buses support coldplug) */
929 if (match_subsystem(udev_enumerate, "subsystem"))
930 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
932 /* all subsystem drivers */
933 if (match_subsystem(udev_enumerate, "drivers"))
934 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");