2 * libudev - interface to udev device information
4 * Copyright (C) 2008 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_node sysattr_match_list;
49 struct udev_list_node sysattr_nomatch_list;
50 struct udev_list_node subsystem_match_list;
51 struct udev_list_node subsystem_nomatch_list;
52 struct udev_list_node properties_match_list;
53 struct udev_list_node devices_list;
54 struct syspath *devices;
55 unsigned int devices_cur;
56 unsigned int devices_max;
57 bool devices_uptodate:1;
62 * @udev: udev library context
64 * Returns: an enumeration context
66 struct udev_enumerate *udev_enumerate_new(struct udev *udev)
68 struct udev_enumerate *udev_enumerate;
70 udev_enumerate = calloc(1, sizeof(struct udev_enumerate));
71 if (udev_enumerate == NULL)
73 udev_enumerate->refcount = 1;
74 udev_enumerate->udev = udev;
75 udev_list_init(&udev_enumerate->sysattr_match_list);
76 udev_list_init(&udev_enumerate->sysattr_nomatch_list);
77 udev_list_init(&udev_enumerate->subsystem_match_list);
78 udev_list_init(&udev_enumerate->subsystem_nomatch_list);
79 udev_list_init(&udev_enumerate->properties_match_list);
80 udev_list_init(&udev_enumerate->devices_list);
81 return udev_enumerate;
86 * @udev_enumerate: context
88 * Take a reference of a enumeration context.
90 * Returns: the passed enumeration context
92 struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
94 if (udev_enumerate == NULL)
96 udev_enumerate->refcount++;
97 return udev_enumerate;
101 * udev_enumerate_unref:
102 * @udev_enumerate: context
104 * Drop a reference of an enumeration context. If the refcount reaches zero,
105 * all resources of the enumeration context will be released.
107 void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
111 if (udev_enumerate == NULL)
113 udev_enumerate->refcount--;
114 if (udev_enumerate->refcount > 0)
116 udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->sysattr_match_list);
117 udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->sysattr_nomatch_list);
118 udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->subsystem_match_list);
119 udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->subsystem_nomatch_list);
120 udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->properties_match_list);
121 udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->devices_list);
122 for (i = 0; i < udev_enumerate->devices_cur; i++)
123 free(udev_enumerate->devices[i].syspath);
124 free(udev_enumerate->devices);
125 free(udev_enumerate);
129 * udev_enumerate_get_udev:
130 * @udev_enumerate: context
132 * Returns: the udev library context.
134 struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
136 if (udev_enumerate == NULL)
138 return udev_enumerate->udev;
141 static int syspath_add(struct udev_enumerate *udev_enumerate, const char *syspath)
144 struct syspath *entry;
146 /* double array size if needed */
147 if (udev_enumerate->devices_cur >= udev_enumerate->devices_max) {
151 add = udev_enumerate->devices_max;
154 buf = realloc(udev_enumerate->devices, (udev_enumerate->devices_max + add) * sizeof(struct syspath));
157 udev_enumerate->devices = buf;
158 udev_enumerate->devices_max += add;
161 path = strdup(syspath);
164 entry = &udev_enumerate->devices[udev_enumerate->devices_cur];
165 entry->syspath = path;
166 entry->len = strlen(path);
167 udev_enumerate->devices_cur++;
168 udev_enumerate->devices_uptodate = false;
172 static int syspath_cmp(const void *p1, const void *p2)
174 const struct syspath *path1 = p1;
175 const struct syspath *path2 = p2;
179 len = MIN(path1->len, path2->len);
180 ret = memcmp(path1->syspath, path2->syspath, len);
182 if (path1->len < path2->len)
184 else if (path1->len > path2->len)
190 static int devices_delay(struct udev *udev, const char *syspath)
192 static const char *delay_device_list[] = {
200 len = strlen(udev_get_sys_path(udev));
201 for (i = 0; delay_device_list[i] != NULL; i++) {
202 if (strstr(&syspath[len], delay_device_list[i]) != NULL) {
203 dbg(udev, "delaying: %s\n", syspath);
211 * udev_enumerate_get_list_entry:
212 * @udev_enumerate: context
214 * Returns: the first entry of the sorted list of device paths.
216 struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
218 if (udev_enumerate == NULL)
220 if (!udev_enumerate->devices_uptodate) {
223 struct syspath *prev = NULL;
225 udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->devices_list);
226 qsort(udev_enumerate->devices, udev_enumerate->devices_cur, sizeof(struct syspath), syspath_cmp);
228 max = udev_enumerate->devices_cur;
229 for (i = 0; i < max; i++) {
230 struct syspath *entry = &udev_enumerate->devices[i];
232 /* skip duplicated entries */
234 entry->len == prev->len &&
235 memcmp(entry->syspath, prev->syspath, entry->len) == 0)
239 /* skip to be delayed devices, and add them to the end of the list */
240 if (devices_delay(udev_enumerate->udev, entry->syspath)) {
241 syspath_add(udev_enumerate, entry->syspath);
245 udev_list_entry_add(udev_enumerate->udev, &udev_enumerate->devices_list,
246 entry->syspath, NULL, 0, 0);
248 /* add and cleanup delayed devices from end of list */
249 for (i = max; i < udev_enumerate->devices_cur; i++) {
250 struct syspath *entry = &udev_enumerate->devices[i];
252 udev_list_entry_add(udev_enumerate->udev, &udev_enumerate->devices_list,
253 entry->syspath, NULL, 0, 0);
254 free(entry->syspath);
256 udev_enumerate->devices_cur = max;
258 udev_enumerate->devices_uptodate = true;
260 return udev_list_get_entry(&udev_enumerate->devices_list);
264 * udev_enumerate_add_match_subsystem:
265 * @udev_enumerate: context
266 * @subsystem: filter for a subsystem of the device to include in the list
268 * Returns: 0 on success, otherwise a negative error value.
270 int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
272 if (udev_enumerate == NULL)
274 if (subsystem == NULL)
276 if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
277 &udev_enumerate->subsystem_match_list, subsystem, NULL, 1, 0) == NULL)
283 * udev_enumerate_add_nomatch_subsystem:
284 * @udev_enumerate: context
285 * @subsystem: filter for a subsystem of the device to exclude from the list
287 * Returns: 0 on success, otherwise a negative error value.
289 int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
291 if (udev_enumerate == NULL)
293 if (subsystem == NULL)
295 if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
296 &udev_enumerate->subsystem_nomatch_list, subsystem, NULL, 1, 0) == NULL)
302 * udev_enumerate_add_match_sysattr:
303 * @udev_enumerate: context
304 * @sysattr: filter for a sys attribute at the device to include in the list
305 * @value: optional value of the sys attribute
307 * Returns: 0 on success, otherwise a negative error value.
309 int udev_enumerate_add_match_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
311 if (udev_enumerate == NULL)
315 if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
316 &udev_enumerate->sysattr_match_list, sysattr, value, 0, 0) == NULL)
322 * udev_enumerate_add_nomatch_sysattr:
323 * @udev_enumerate: context
324 * @sysattr: filter for a sys attribute at the device to exclude from the list
325 * @value: optional value of the sys attribute
327 * Returns: 0 on success, otherwise a negative error value.
329 int udev_enumerate_add_nomatch_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
331 if (udev_enumerate == NULL)
335 if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
336 &udev_enumerate->sysattr_nomatch_list, sysattr, value, 0, 0) == NULL)
341 static int match_sysattr_value(struct udev *udev, const char *syspath, const char *sysattr, const char *match_val)
343 struct udev_device *device;
344 const char *val = NULL;
347 device = udev_device_new_from_syspath(udev, syspath);
350 val = udev_device_get_sysattr_value(device, sysattr);
353 if (match_val == NULL) {
357 if (fnmatch(match_val, val, 0) == 0) {
362 udev_device_unref(device);
367 * udev_enumerate_add_match_property:
368 * @udev_enumerate: context
369 * @property: filter for a property of the device to include in the list
370 * @value: value of the property
372 * Returns: 0 on success, otherwise a negative error value.
374 int udev_enumerate_add_match_property(struct udev_enumerate *udev_enumerate, const char *property, const char *value)
376 if (udev_enumerate == NULL)
378 if (property == NULL)
380 if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
381 &udev_enumerate->properties_match_list, property, value, 0, 0) == NULL)
386 static int match_sysattr(struct udev_enumerate *udev_enumerate, const char *syspath)
388 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
389 struct udev_list_entry *list_entry;
392 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_nomatch_list)) {
393 if (match_sysattr_value(udev, syspath,
394 udev_list_entry_get_name(list_entry),
395 udev_list_entry_get_value(list_entry)))
399 if (udev_list_get_entry(&udev_enumerate->sysattr_match_list) != NULL) {
400 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_match_list)) {
401 /* anything that does not match, will make it FALSE */
402 if (!match_sysattr_value(udev, syspath,
403 udev_list_entry_get_name(list_entry),
404 udev_list_entry_get_value(list_entry)))
412 static int match_property(struct udev_enumerate *udev_enumerate, const char *syspath)
414 struct udev_device *dev;
415 struct udev_list_entry *list_entry;
418 /* no match always matches */
419 if (udev_list_get_entry(&udev_enumerate->properties_match_list) == NULL)
422 /* no device does not match */
423 dev = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
427 /* loop over matches */
428 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->properties_match_list)) {
429 const char *match_key = udev_list_entry_get_name(list_entry);
430 const char *match_value = udev_list_entry_get_value(list_entry);
431 struct udev_list_entry *property_entry;
433 /* loop over device properties */
434 udev_list_entry_foreach(property_entry, udev_device_get_properties_list_entry(dev)) {
435 const char *dev_key = udev_list_entry_get_name(property_entry);
436 const char *dev_value = udev_list_entry_get_value(property_entry);
438 if (fnmatch(match_key, dev_key, 0) != 0)
440 if (match_value == NULL && dev_value == NULL) {
444 if (match_value == NULL || dev_value == NULL)
446 if (fnmatch(match_value, dev_value, 0) == 0) {
453 udev_device_unref(dev);
457 static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
458 const char *basedir, const char *subdir1, const char *subdir2)
460 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
461 char path[UTIL_PATH_SIZE];
468 l = util_strpcpyl(&s, sizeof(path), udev_get_sys_path(udev), "/", basedir, NULL);
470 l = util_strpcpyl(&s, l, "/", subdir1, NULL);
472 l = util_strpcpyl(&s, l, "/", subdir2, NULL);
476 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
477 char syspath[UTIL_PATH_SIZE];
478 char filename[UTIL_PATH_SIZE];
481 if (dent->d_name[0] == '.')
483 util_strscpyl(syspath, sizeof(syspath), path, "/", dent->d_name, NULL);
484 if (lstat(syspath, &statbuf) != 0)
486 if (S_ISREG(statbuf.st_mode))
488 if (S_ISLNK(statbuf.st_mode))
489 util_resolve_sys_link(udev, syspath, sizeof(syspath));
491 util_strscpyl(filename, sizeof(filename), syspath, "/uevent", NULL);
492 if (stat(filename, &statbuf) != 0)
494 if (!match_sysattr(udev_enumerate, syspath))
496 if (!match_property(udev_enumerate, syspath))
498 syspath_add(udev_enumerate, syspath);
504 static int match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
506 struct udev_list_entry *list_entry;
508 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
509 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
512 if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
513 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
514 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
522 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
524 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
526 char path[UTIL_PATH_SIZE];
530 util_strscpyl(path, sizeof(path), udev_get_sys_path(udev), "/", basedir, NULL);
534 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
535 if (dent->d_name[0] == '.')
537 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
539 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
546 * udev_enumerate_add_syspath:
547 * @udev_enumerate: context
548 * @syspath: path of a device
550 * Add a device to the list of devices, to retrieve it back sorted in dependency order.
552 * Returns: 0 on success, otherwise a negative error value.
554 int udev_enumerate_add_syspath(struct udev_enumerate *udev_enumerate, const char *syspath)
556 struct udev_device *udev_device;
558 if (udev_enumerate == NULL)
562 /* resolve to real syspath */
563 udev_device = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
564 if (udev_device == NULL)
566 syspath_add(udev_enumerate, udev_device_get_syspath(udev_device));
567 udev_device_unref(udev_device);
572 * udev_enumerate_scan_devices:
573 * @udev_enumerate: udev enumeration context
575 * Returns: 0 on success, otherwise a negative error value.
577 int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
579 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
580 char base[UTIL_PATH_SIZE];
583 if (udev_enumerate == NULL)
585 util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/subsystem", NULL);
586 if (stat(base, &statbuf) == 0) {
587 /* we have /subsystem/, forget all the old stuff */
588 dbg(udev, "searching '/subsystem/*/devices/*' dir\n");
589 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
591 dbg(udev, "searching '/bus/*/devices/*' dir\n");
592 scan_dir(udev_enumerate, "bus", "devices", NULL);
593 dbg(udev, "searching '/class/*' dir\n");
594 scan_dir(udev_enumerate, "class", NULL, NULL);
595 /* if block isn't a class, scan /block/ */
596 util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/class/block", NULL);
597 if (stat(base, &statbuf) != 0) {
598 if (match_subsystem(udev_enumerate, "block")) {
599 dbg(udev, "searching '/block/*' dir\n");
601 scan_dir_and_add_devices(udev_enumerate, "block", NULL, NULL);
602 /* scan partitions */
603 dbg(udev, "searching '/block/*/*' dir\n");
604 scan_dir(udev_enumerate, "block", NULL, "block");
612 * udev_enumerate_scan_subsystems:
613 * @udev_enumerate: udev enumeration context
615 * Returns: 0 on success, otherwise a negative error value.
617 int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
619 struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
620 char base[UTIL_PATH_SIZE];
622 const char *subsysdir;
624 if (udev_enumerate == NULL)
626 util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/subsystem", NULL);
627 if (stat(base, &statbuf) == 0)
628 subsysdir = "subsystem";
631 if (match_subsystem(udev_enumerate, "subsystem")) {
632 dbg(udev, "searching '%s/*' dir\n", subsysdir);
633 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
635 if (match_subsystem(udev_enumerate, "drivers")) {
636 dbg(udev, "searching '%s/*/drivers/*' dir\n", subsysdir);
637 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");