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 UDEV_EXPORT 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 UDEV_EXPORT 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 UDEV_EXPORT 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 UDEV_EXPORT 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) {
213 dbg(udev, "delaying: %s\n", syspath);
220 /* For devices that should just be moved a little bit later, just
221 * before the point where some common path prefix changes. Returns the
222 * number of characters that make up that common prefix */
223 static size_t devices_delay_later(struct udev *udev, const char *syspath)
227 /* For sound cards the control device must be enumerated last
228 * to make sure it's the final device node that gets ACLs
229 * applied. Applications rely on this fact and use ACL changes
230 * on the control node as an indicator that the ACL change of
231 * the entire sound card completed. The kernel makes this
232 * guarantee when creating those devices, and hence we should
233 * too when enumerating them. */
235 if ((c = strstr(syspath, "/sound/card"))) {
237 c += strcspn(c, "/");
239 if (strncmp(c, "/controlC", 9) == 0)
240 return c - syspath + 1;
247 * udev_enumerate_get_list_entry:
248 * @udev_enumerate: context
250 * Returns: the first entry of the sorted list of device paths.
252 UDEV_EXPORT struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
254 if (udev_enumerate == NULL)
256 if (!udev_enumerate->devices_uptodate) {
259 struct syspath *prev = NULL, *move_later = NULL;
260 size_t move_later_prefix = 0;
262 udev_list_cleanup(&udev_enumerate->devices_list);
263 qsort(udev_enumerate->devices, udev_enumerate->devices_cur, sizeof(struct syspath), syspath_cmp);
265 max = udev_enumerate->devices_cur;
266 for (i = 0; i < max; i++) {
267 struct syspath *entry = &udev_enumerate->devices[i];
269 /* skip duplicated entries */
271 entry->len == prev->len &&
272 memcmp(entry->syspath, prev->syspath, entry->len) == 0)
276 /* skip to be delayed devices, and add them to the end of the list */
277 if (devices_delay_end(udev_enumerate->udev, entry->syspath)) {
278 syspath_add(udev_enumerate, entry->syspath);
279 /* need to update prev here for the case realloc() gives a different address */
280 prev = &udev_enumerate->devices[i];
284 /* skip to be delayed devices, and move the to
285 * the point where the prefix changes. We can
286 * only move one item at a time. */
288 move_later_prefix = devices_delay_later(udev_enumerate->udev, entry->syspath);
290 if (move_later_prefix > 0) {
297 strncmp(entry->syspath, move_later->syspath, move_later_prefix) != 0) {
299 udev_list_entry_add(&udev_enumerate->devices_list, move_later->syspath, NULL);
303 udev_list_entry_add(&udev_enumerate->devices_list, entry->syspath, NULL);
307 udev_list_entry_add(&udev_enumerate->devices_list, move_later->syspath, NULL);
309 /* add and cleanup delayed devices from end of list */
310 for (i = max; i < udev_enumerate->devices_cur; i++) {
311 struct syspath *entry = &udev_enumerate->devices[i];
313 udev_list_entry_add(&udev_enumerate->devices_list, entry->syspath, NULL);
314 free(entry->syspath);
316 udev_enumerate->devices_cur = max;
318 udev_enumerate->devices_uptodate = true;
320 return udev_list_get_entry(&udev_enumerate->devices_list);
324 * udev_enumerate_add_match_subsystem:
325 * @udev_enumerate: context
326 * @subsystem: filter for a subsystem of the device to include in the list
328 * Returns: 0 on success, otherwise a negative error value.
330 UDEV_EXPORT int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
332 if (udev_enumerate == NULL)
334 if (subsystem == NULL)
336 if (udev_list_entry_add(&udev_enumerate->subsystem_match_list, subsystem, NULL) == NULL)
342 * udev_enumerate_add_nomatch_subsystem:
343 * @udev_enumerate: context
344 * @subsystem: filter for a subsystem of the device to exclude from the list
346 * Returns: 0 on success, otherwise a negative error value.
348 UDEV_EXPORT int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
350 if (udev_enumerate == NULL)
352 if (subsystem == NULL)
354 if (udev_list_entry_add(&udev_enumerate->subsystem_nomatch_list, subsystem, NULL) == NULL)
360 * udev_enumerate_add_match_sysattr:
361 * @udev_enumerate: context
362 * @sysattr: filter for a sys attribute at the device to include in the list
363 * @value: optional value of the sys attribute
365 * Returns: 0 on success, otherwise a negative error value.
367 UDEV_EXPORT int udev_enumerate_add_match_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
369 if (udev_enumerate == NULL)
373 if (udev_list_entry_add(&udev_enumerate->sysattr_match_list, sysattr, value) == NULL)
379 * udev_enumerate_add_nomatch_sysattr:
380 * @udev_enumerate: context
381 * @sysattr: filter for a sys attribute at the device to exclude from the list
382 * @value: optional value of the sys attribute
384 * Returns: 0 on success, otherwise a negative error value.
386 UDEV_EXPORT int udev_enumerate_add_nomatch_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
388 if (udev_enumerate == NULL)
392 if (udev_list_entry_add(&udev_enumerate->sysattr_nomatch_list, sysattr, value) == NULL)
397 static int match_sysattr_value(struct udev_device *dev, const char *sysattr, const char *match_val)
399 const char *val = NULL;
402 val = udev_device_get_sysattr_value(dev, sysattr);
405 if (match_val == NULL) {
409 if (fnmatch(match_val, val, 0) == 0) {
418 * udev_enumerate_add_match_property:
419 * @udev_enumerate: context
420 * @property: filter for a property of the device to include in the list
421 * @value: value of the property
423 * Returns: 0 on success, otherwise a negative error value.
425 UDEV_EXPORT int udev_enumerate_add_match_property(struct udev_enumerate *udev_enumerate, const char *property, const char *value)
427 if (udev_enumerate == NULL)
429 if (property == NULL)
431 if (udev_list_entry_add(&udev_enumerate->properties_match_list, property, value) == NULL)
437 * udev_enumerate_add_match_tag:
438 * @udev_enumerate: context
439 * @tag: filter for a tag of the device to include in the list
441 * Returns: 0 on success, otherwise a negative error value.
443 UDEV_EXPORT int udev_enumerate_add_match_tag(struct udev_enumerate *udev_enumerate, const char *tag)
445 if (udev_enumerate == NULL)
449 if (udev_list_entry_add(&udev_enumerate->tags_match_list, tag, NULL) == NULL)
455 * udev_enumerate_add_match_parent:
456 * @udev_enumerate: context
457 * @parent: parent device where to start searching
459 * Return the devices on the subtree of one given device. The parent
460 * itself is included in the list.
462 * A reference for the device is held until the udev_enumerate context
465 * Returns: 0 on success, otherwise a negative error value.
467 UDEV_EXPORT int udev_enumerate_add_match_parent(struct udev_enumerate *udev_enumerate, struct udev_device *parent)
469 if (udev_enumerate == NULL)
473 if (udev_enumerate->parent_match != NULL)
474 udev_device_unref(udev_enumerate->parent_match);
475 udev_enumerate->parent_match = udev_device_ref(parent);
480 * udev_enumerate_add_match_is_initialized:
481 * @udev_enumerate: context
483 * Match only devices which udev has set up already. This makes
484 * sure, that the device node permissions and context are properly set
485 * and that network devices are fully renamed.
487 * Usually, devices which are found in the kernel but not already
488 * handled by udev, have still pending events. Services should subscribe
489 * to monitor events and wait for these devices to become ready, instead
490 * of using uninitialized devices.
492 * For now, this will not affect devices which do not have a device node
493 * and are not network interfaces.
495 * Returns: 0 on success, otherwise a negative error value.
497 UDEV_EXPORT int udev_enumerate_add_match_is_initialized(struct udev_enumerate *udev_enumerate)
499 if (udev_enumerate == NULL)
501 udev_enumerate->match_is_initialized = true;
506 * udev_enumerate_add_match_sysname:
507 * @udev_enumerate: context
508 * @sysname: filter for the name of the device to include in the list
510 * Returns: 0 on success, otherwise a negative error value.
512 UDEV_EXPORT int udev_enumerate_add_match_sysname(struct udev_enumerate *udev_enumerate, const char *sysname)
514 if (udev_enumerate == NULL)
518 if (udev_list_entry_add(&udev_enumerate->sysname_match_list, sysname, NULL) == NULL)
523 static bool match_sysattr(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
525 struct udev_list_entry *list_entry;
528 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_nomatch_list)) {
529 if (match_sysattr_value(dev, udev_list_entry_get_name(list_entry),
530 udev_list_entry_get_value(list_entry)))
534 if (udev_list_get_entry(&udev_enumerate->sysattr_match_list) != NULL) {
535 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_match_list)) {
536 /* anything that does not match, will make it FALSE */
537 if (!match_sysattr_value(dev, udev_list_entry_get_name(list_entry),
538 udev_list_entry_get_value(list_entry)))
546 static bool match_property(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
548 struct udev_list_entry *list_entry;
551 /* no match always matches */
552 if (udev_list_get_entry(&udev_enumerate->properties_match_list) == NULL)
555 /* loop over matches */
556 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->properties_match_list)) {
557 const char *match_key = udev_list_entry_get_name(list_entry);
558 const char *match_value = udev_list_entry_get_value(list_entry);
559 struct udev_list_entry *property_entry;
561 /* loop over device properties */
562 udev_list_entry_foreach(property_entry, udev_device_get_properties_list_entry(dev)) {
563 const char *dev_key = udev_list_entry_get_name(property_entry);
564 const char *dev_value = udev_list_entry_get_value(property_entry);
566 if (fnmatch(match_key, dev_key, 0) != 0)
568 if (match_value == NULL && dev_value == NULL) {
572 if (match_value == NULL || dev_value == NULL)
574 if (fnmatch(match_value, dev_value, 0) == 0) {
584 static bool match_tag(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
586 struct udev_list_entry *list_entry;
588 /* no match always matches */
589 if (udev_list_get_entry(&udev_enumerate->tags_match_list) == NULL)
592 /* loop over matches */
593 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->tags_match_list))
594 if (!udev_device_has_tag(dev, udev_list_entry_get_name(list_entry)))
600 static bool match_parent(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
604 if (udev_enumerate->parent_match == NULL)
607 parent = udev_device_get_devpath(udev_enumerate->parent_match);
608 return strncmp(parent, udev_device_get_devpath(dev), strlen(parent)) == 0;
611 static bool match_sysname(struct udev_enumerate *udev_enumerate, const char *sysname)
613 struct udev_list_entry *list_entry;
615 if (udev_list_get_entry(&udev_enumerate->sysname_match_list) == NULL)
618 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysname_match_list)) {
619 if (fnmatch(udev_list_entry_get_name(list_entry), sysname, 0) != 0)
626 static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
627 const char *basedir, const char *subdir1, const char *subdir2)
629 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
630 char path[UTIL_PATH_SIZE];
637 l = util_strpcpyl(&s, sizeof(path), udev_get_sys_path(udev), "/", basedir, NULL);
639 l = util_strpcpyl(&s, l, "/", subdir1, NULL);
641 util_strpcpyl(&s, l, "/", subdir2, NULL);
645 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
646 char syspath[UTIL_PATH_SIZE];
647 struct udev_device *dev;
649 if (dent->d_name[0] == '.')
652 if (!match_sysname(udev_enumerate, dent->d_name))
655 util_strscpyl(syspath, sizeof(syspath), path, "/", dent->d_name, NULL);
656 dev = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
660 if (udev_enumerate->match_is_initialized) {
662 * All devices with a device node or network interfaces
663 * possibly need udev to adjust the device node permission
664 * or context, or rename the interface before it can be
665 * reliably used from other processes.
667 * For now, we can only check these types of devices, we
668 * might not store a database, and have no way to find out
669 * for all other types of devices.
671 if (!udev_device_get_is_initialized(dev) &&
672 (major(udev_device_get_devnum(dev)) > 0 || udev_device_get_ifindex(dev) > 0))
675 if (!match_parent(udev_enumerate, dev))
677 if (!match_tag(udev_enumerate, dev))
679 if (!match_property(udev_enumerate, dev))
681 if (!match_sysattr(udev_enumerate, dev))
684 syspath_add(udev_enumerate, udev_device_get_syspath(dev));
686 udev_device_unref(dev);
692 static bool match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
694 struct udev_list_entry *list_entry;
696 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
697 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
700 if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
701 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
702 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
710 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
712 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
714 char path[UTIL_PATH_SIZE];
718 util_strscpyl(path, sizeof(path), udev_get_sys_path(udev), "/", basedir, NULL);
722 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
723 if (dent->d_name[0] == '.')
725 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
727 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
734 * udev_enumerate_add_syspath:
735 * @udev_enumerate: context
736 * @syspath: path of a device
738 * Add a device to the list of devices, to retrieve it back sorted in dependency order.
740 * Returns: 0 on success, otherwise a negative error value.
742 UDEV_EXPORT int udev_enumerate_add_syspath(struct udev_enumerate *udev_enumerate, const char *syspath)
744 struct udev_device *udev_device;
746 if (udev_enumerate == NULL)
750 /* resolve to real syspath */
751 udev_device = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
752 if (udev_device == NULL)
754 syspath_add(udev_enumerate, udev_device_get_syspath(udev_device));
755 udev_device_unref(udev_device);
759 static int scan_devices_tags(struct udev_enumerate *udev_enumerate)
761 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
762 struct udev_list_entry *list_entry;
764 /* scan only tagged devices, use tags reverse-index, instead of searching all devices in /sys */
765 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->tags_match_list)) {
768 char path[UTIL_PATH_SIZE];
770 util_strscpyl(path, sizeof(path), udev_get_run_path(udev), "/tags/",
771 udev_list_entry_get_name(list_entry), NULL);
775 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
776 struct udev_device *dev;
778 if (dent->d_name[0] == '.')
781 dev = udev_device_new_from_id_filename(udev_enumerate->udev, dent->d_name);
785 if (!match_subsystem(udev_enumerate, udev_device_get_subsystem(dev)))
787 if (!match_sysname(udev_enumerate, udev_device_get_sysname(dev)))
789 if (!match_parent(udev_enumerate, dev))
791 if (!match_property(udev_enumerate, dev))
793 if (!match_sysattr(udev_enumerate, dev))
796 syspath_add(udev_enumerate, udev_device_get_syspath(dev));
798 udev_device_unref(dev);
805 static int parent_add_child(struct udev_enumerate *enumerate, const char *path)
807 struct udev_device *dev;
809 dev = udev_device_new_from_syspath(enumerate->udev, path);
813 if (!match_subsystem(enumerate, udev_device_get_subsystem(dev)))
815 if (!match_sysname(enumerate, udev_device_get_sysname(dev)))
817 if (!match_property(enumerate, dev))
819 if (!match_sysattr(enumerate, dev))
822 syspath_add(enumerate, udev_device_get_syspath(dev));
823 udev_device_unref(dev);
827 static int parent_crawl_children(struct udev_enumerate *enumerate, const char *path, int maxdepth)
836 for (dent = readdir(d); dent != NULL; dent = readdir(d)) {
839 if (dent->d_name[0] == '.')
841 if (dent->d_type != DT_DIR)
843 if (asprintf(&child, "%s/%s", path, dent->d_name) < 0)
845 parent_add_child(enumerate, child);
847 parent_crawl_children(enumerate, child, maxdepth-1);
855 static int scan_devices_children(struct udev_enumerate *enumerate)
859 path = udev_device_get_syspath(enumerate->parent_match);
860 parent_add_child(enumerate, path);
861 return parent_crawl_children(enumerate, path, 256);
864 static int scan_devices_all(struct udev_enumerate *udev_enumerate)
866 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
867 char base[UTIL_PATH_SIZE];
870 util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/subsystem", NULL);
871 if (stat(base, &statbuf) == 0) {
872 /* we have /subsystem/, forget all the old stuff */
873 dbg(udev, "searching '/subsystem/*/devices/*' dir\n");
874 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
876 dbg(udev, "searching '/bus/*/devices/*' dir\n");
877 scan_dir(udev_enumerate, "bus", "devices", NULL);
878 dbg(udev, "searching '/class/*' dir\n");
879 scan_dir(udev_enumerate, "class", NULL, NULL);
885 * udev_enumerate_scan_devices:
886 * @udev_enumerate: udev enumeration context
888 * Returns: 0 on success, otherwise a negative error value.
890 UDEV_EXPORT int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
892 if (udev_enumerate == NULL)
895 /* efficiently lookup tags only, we maintain a reverse-index */
896 if (udev_list_get_entry(&udev_enumerate->tags_match_list) != NULL)
897 return scan_devices_tags(udev_enumerate);
899 /* walk the subtree of one parent device only */
900 if (udev_enumerate->parent_match != NULL)
901 return scan_devices_children(udev_enumerate);
903 /* scan devices of all subsystems */
904 return scan_devices_all(udev_enumerate);
908 * udev_enumerate_scan_subsystems:
909 * @udev_enumerate: udev enumeration context
911 * Returns: 0 on success, otherwise a negative error value.
913 UDEV_EXPORT int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
915 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
916 char base[UTIL_PATH_SIZE];
918 const char *subsysdir;
920 if (udev_enumerate == NULL)
923 /* all kernel modules */
924 if (match_subsystem(udev_enumerate, "module")) {
925 dbg(udev, "searching '%s/modules/*' dir\n", subsysdir);
926 scan_dir_and_add_devices(udev_enumerate, "module", NULL, NULL);
929 util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/subsystem", NULL);
930 if (stat(base, &statbuf) == 0)
931 subsysdir = "subsystem";
935 /* all subsystems (only buses support coldplug) */
936 if (match_subsystem(udev_enumerate, "subsystem")) {
937 dbg(udev, "searching '%s/*' dir\n", subsysdir);
938 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
941 /* all subsystem drivers */
942 if (match_subsystem(udev_enumerate, "drivers")) {
943 dbg(udev, "searching '%s/*/drivers/*' dir\n", subsysdir);
944 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");