1 /***
2 This file is part of systemd.
3
4 Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
5
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
10
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
18 ***/
19
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <stddef.h>
23 #include <unistd.h>
24 #include <errno.h>
25 #include <string.h>
26 #include <dirent.h>
27 #include <fnmatch.h>
28 #include <stdbool.h>
29 #include <sys/stat.h>
30 #include <sys/param.h>
31 #include <sys/sysmacros.h>
32
33 #include "libudev.h"
34 #include "libudev-private.h"
35
36 /**
37 * SECTION:libudev-enumerate
38 * @short_description: lookup and sort sys devices
39 *
40 * Lookup devices in the sys filesystem, filter devices by properties,
41 * and return a sorted list of devices.
42 */
43
44 struct syspath {
45 char *syspath;
46 size_t len;
47 };
48
49 /**
50 * udev_enumerate:
51 *
52 * Opaque object representing one device lookup/sort context.
53 */
54 struct udev_enumerate {
55 struct udev *udev;
56 int refcount;
57 struct udev_list sysattr_match_list;
58 struct udev_list sysattr_nomatch_list;
59 struct udev_list subsystem_match_list;
60 struct udev_list subsystem_nomatch_list;
61 struct udev_list sysname_match_list;
62 struct udev_list properties_match_list;
63 struct udev_list tags_match_list;
64 struct udev_device *parent_match;
65 struct udev_list devices_list;
66 struct syspath *devices;
67 unsigned int devices_cur;
68 unsigned int devices_max;
69 bool devices_uptodate:1;
70 bool match_is_initialized;
71 };
72
73 /**
74 * udev_enumerate_new:
75 * @udev: udev library context
76 *
77 * Create an enumeration context to scan /sys.
78 *
79 * Returns: an enumeration context.
80 **/
udev_enumerate_new(struct udev * udev)81 _public_ struct udev_enumerate *udev_enumerate_new(struct udev *udev)
82 {
83 struct udev_enumerate *udev_enumerate;
84
85 if (udev == NULL)
86 return NULL;
87 udev_enumerate = new0(struct udev_enumerate, 1);
88 if (udev_enumerate == NULL)
89 return NULL;
90 udev_enumerate->refcount = 1;
91 udev_enumerate->udev = udev;
92 udev_list_init(udev, &udev_enumerate->sysattr_match_list, false);
93 udev_list_init(udev, &udev_enumerate->sysattr_nomatch_list, false);
94 udev_list_init(udev, &udev_enumerate->subsystem_match_list, true);
95 udev_list_init(udev, &udev_enumerate->subsystem_nomatch_list, true);
96 udev_list_init(udev, &udev_enumerate->sysname_match_list, true);
97 udev_list_init(udev, &udev_enumerate->properties_match_list, false);
98 udev_list_init(udev, &udev_enumerate->tags_match_list, true);
99 udev_list_init(udev, &udev_enumerate->devices_list, false);
100 return udev_enumerate;
101 }
102
103 /**
104 * udev_enumerate_ref:
105 * @udev_enumerate: context
106 *
107 * Take a reference of a enumeration context.
108 *
109 * Returns: the passed enumeration context
110 **/
udev_enumerate_ref(struct udev_enumerate * udev_enumerate)111 _public_ struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
112 {
113 if (udev_enumerate == NULL)
114 return NULL;
115 udev_enumerate->refcount++;
116 return udev_enumerate;
117 }
118
119 /**
120 * udev_enumerate_unref:
121 * @udev_enumerate: context
122 *
123 * Drop a reference of an enumeration context. If the refcount reaches zero,
124 * all resources of the enumeration context will be released.
125 *
126 * Returns: #NULL
127 **/
udev_enumerate_unref(struct udev_enumerate * udev_enumerate)128 _public_ struct udev_enumerate *udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
129 {
130 unsigned int i;
131
132 if (udev_enumerate == NULL)
133 return NULL;
134 udev_enumerate->refcount--;
135 if (udev_enumerate->refcount > 0)
136 return NULL;
137 udev_list_cleanup(&udev_enumerate->sysattr_match_list);
138 udev_list_cleanup(&udev_enumerate->sysattr_nomatch_list);
139 udev_list_cleanup(&udev_enumerate->subsystem_match_list);
140 udev_list_cleanup(&udev_enumerate->subsystem_nomatch_list);
141 udev_list_cleanup(&udev_enumerate->sysname_match_list);
142 udev_list_cleanup(&udev_enumerate->properties_match_list);
143 udev_list_cleanup(&udev_enumerate->tags_match_list);
144 udev_device_unref(udev_enumerate->parent_match);
145 udev_list_cleanup(&udev_enumerate->devices_list);
146 for (i = 0; i < udev_enumerate->devices_cur; i++)
147 free(udev_enumerate->devices[i].syspath);
148 free(udev_enumerate->devices);
149 free(udev_enumerate);
150 return NULL;
151 }
152
153 /**
154 * udev_enumerate_get_udev:
155 * @udev_enumerate: context
156 *
157 * Get the udev library context.
158 *
159 * Returns: a pointer to the context.
160 */
udev_enumerate_get_udev(struct udev_enumerate * udev_enumerate)161 _public_ struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
162 {
163 if (udev_enumerate == NULL)
164 return NULL;
165 return udev_enumerate->udev;
166 }
167
syspath_add(struct udev_enumerate * udev_enumerate,const char * syspath)168 static int syspath_add(struct udev_enumerate *udev_enumerate, const char *syspath)
169 {
170 char *path;
171 struct syspath *entry;
172
173 /* double array size if needed */
174 if (udev_enumerate->devices_cur >= udev_enumerate->devices_max) {
175 struct syspath *buf;
176 unsigned int add;
177
178 add = udev_enumerate->devices_max;
179 if (add < 1024)
180 add = 1024;
181 buf = realloc(udev_enumerate->devices, (udev_enumerate->devices_max + add) * sizeof(struct syspath));
182 if (buf == NULL)
183 return -ENOMEM;
184 udev_enumerate->devices = buf;
185 udev_enumerate->devices_max += add;
186 }
187
188 path = strdup(syspath);
189 if (path == NULL)
190 return -ENOMEM;
191 entry = &udev_enumerate->devices[udev_enumerate->devices_cur];
192 entry->syspath = path;
193 entry->len = strlen(path);
194 udev_enumerate->devices_cur++;
195 udev_enumerate->devices_uptodate = false;
196 return 0;
197 }
198
syspath_cmp(const void * p1,const void * p2)199 static int syspath_cmp(const void *p1, const void *p2)
200 {
201 const struct syspath *path1 = p1;
202 const struct syspath *path2 = p2;
203 size_t len;
204 int ret;
205
206 len = MIN(path1->len, path2->len);
207 ret = memcmp(path1->syspath, path2->syspath, len);
208 if (ret == 0) {
209 if (path1->len < path2->len)
210 ret = -1;
211 else if (path1->len > path2->len)
212 ret = 1;
213 }
214 return ret;
215 }
216
217 /* For devices that should be moved to the absolute end of the list */
devices_delay_end(struct udev * udev,const char * syspath)218 static bool devices_delay_end(struct udev *udev, const char *syspath)
219 {
220 static const char *delay_device_list[] = {
221 "/block/md",
222 "/block/dm-",
223 NULL
224 };
225 int i;
226
227 for (i = 0; delay_device_list[i] != NULL; i++) {
228 if (strstr(syspath + strlen("/sys"), delay_device_list[i]) != NULL)
229 return true;
230 }
231 return false;
232 }
233
234 /* For devices that should just be moved a little bit later, just
235 * before the point where some common path prefix changes. Returns the
236 * number of characters that make up that common prefix */
devices_delay_later(struct udev * udev,const char * syspath)237 static size_t devices_delay_later(struct udev *udev, const char *syspath)
238 {
239 const char *c;
240
241 /* For sound cards the control device must be enumerated last
242 * to make sure it's the final device node that gets ACLs
243 * applied. Applications rely on this fact and use ACL changes
244 * on the control node as an indicator that the ACL change of
245 * the entire sound card completed. The kernel makes this
246 * guarantee when creating those devices, and hence we should
247 * too when enumerating them. */
248
249 if ((c = strstr(syspath, "/sound/card"))) {
250 c += 11;
251 c += strcspn(c, "/");
252
253 if (startswith(c, "/controlC"))
254 return c - syspath + 1;
255 }
256
257 return 0;
258 }
259
260 /**
261 * udev_enumerate_get_list_entry:
262 * @udev_enumerate: context
263 *
264 * Get the first entry of the sorted list of device paths.
265 *
266 * Returns: a udev_list_entry.
267 */
udev_enumerate_get_list_entry(struct udev_enumerate * udev_enumerate)268 _public_ struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
269 {
270 if (udev_enumerate == NULL)
271 return NULL;
272 if (!udev_enumerate->devices_uptodate) {
273 unsigned int i;
274 int move_later = -1;
275 unsigned int max;
276 struct syspath *prev = NULL;
277 size_t move_later_prefix = 0;
278
279 udev_list_cleanup(&udev_enumerate->devices_list);
280 qsort_safe(udev_enumerate->devices, udev_enumerate->devices_cur, sizeof(struct syspath), syspath_cmp);
281
282 max = udev_enumerate->devices_cur;
283 for (i = 0; i < max; i++) {
284 struct syspath *entry = &udev_enumerate->devices[i];
285
286 /* skip duplicated entries */
287 if (prev != NULL &&
288 entry->len == prev->len &&
289 memcmp(entry->syspath, prev->syspath, entry->len) == 0)
290 continue;
291 prev = entry;
292
293 /* skip to be delayed devices, and add them to the end of the list */
294 if (devices_delay_end(udev_enumerate->udev, entry->syspath)) {
295 syspath_add(udev_enumerate, entry->syspath);
296 /* need to update prev here for the case realloc() gives a different address */
297 prev = &udev_enumerate->devices[i];
298 continue;
299 }
300
301 /* skip to be delayed devices, and move the to
302 * the point where the prefix changes. We can
303 * only move one item at a time. */
304 if (move_later == -1) {
305 move_later_prefix = devices_delay_later(udev_enumerate->udev, entry->syspath);
306
307 if (move_later_prefix > 0) {
308 move_later = i;
309 continue;
310 }
311 }
312
313 if ((move_later >= 0) &&
314 !strneq(entry->syspath, udev_enumerate->devices[move_later].syspath, move_later_prefix)) {
315
316 udev_list_entry_add(&udev_enumerate->devices_list,
317 udev_enumerate->devices[move_later].syspath, NULL);
318 move_later = -1;
319 }
320
321 udev_list_entry_add(&udev_enumerate->devices_list, entry->syspath, NULL);
322 }
323
324 if (move_later >= 0)
325 udev_list_entry_add(&udev_enumerate->devices_list,
326 udev_enumerate->devices[move_later].syspath, NULL);
327
328 /* add and cleanup delayed devices from end of list */
329 for (i = max; i < udev_enumerate->devices_cur; i++) {
330 struct syspath *entry = &udev_enumerate->devices[i];
331
332 udev_list_entry_add(&udev_enumerate->devices_list, entry->syspath, NULL);
333 free(entry->syspath);
334 }
335 udev_enumerate->devices_cur = max;
336
337 udev_enumerate->devices_uptodate = true;
338 }
339 return udev_list_get_entry(&udev_enumerate->devices_list);
340 }
341
342 /**
343 * udev_enumerate_add_match_subsystem:
344 * @udev_enumerate: context
345 * @subsystem: filter for a subsystem of the device to include in the list
346 *
347 * Match only devices belonging to a certain kernel subsystem.
348 *
349 * Returns: 0 on success, otherwise a negative error value.
350 */
udev_enumerate_add_match_subsystem(struct udev_enumerate * udev_enumerate,const char * subsystem)351 _public_ int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
352 {
353 if (udev_enumerate == NULL)
354 return -EINVAL;
355 if (subsystem == NULL)
356 return 0;
357 if (udev_list_entry_add(&udev_enumerate->subsystem_match_list, subsystem, NULL) == NULL)
358 return -ENOMEM;
359 return 0;
360 }
361
362 /**
363 * udev_enumerate_add_nomatch_subsystem:
364 * @udev_enumerate: context
365 * @subsystem: filter for a subsystem of the device to exclude from the list
366 *
367 * Match only devices not belonging to a certain kernel subsystem.
368 *
369 * Returns: 0 on success, otherwise a negative error value.
370 */
udev_enumerate_add_nomatch_subsystem(struct udev_enumerate * udev_enumerate,const char * subsystem)371 _public_ int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
372 {
373 if (udev_enumerate == NULL)
374 return -EINVAL;
375 if (subsystem == NULL)
376 return 0;
377 if (udev_list_entry_add(&udev_enumerate->subsystem_nomatch_list, subsystem, NULL) == NULL)
378 return -ENOMEM;
379 return 0;
380 }
381
382 /**
383 * udev_enumerate_add_match_sysattr:
384 * @udev_enumerate: context
385 * @sysattr: filter for a sys attribute at the device to include in the list
386 * @value: optional value of the sys attribute
387 *
388 * Match only devices with a certain /sys device attribute.
389 *
390 * Returns: 0 on success, otherwise a negative error value.
391 */
udev_enumerate_add_match_sysattr(struct udev_enumerate * udev_enumerate,const char * sysattr,const char * value)392 _public_ int udev_enumerate_add_match_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
393 {
394 if (udev_enumerate == NULL)
395 return -EINVAL;
396 if (sysattr == NULL)
397 return 0;
398 if (udev_list_entry_add(&udev_enumerate->sysattr_match_list, sysattr, value) == NULL)
399 return -ENOMEM;
400 return 0;
401 }
402
403 /**
404 * udev_enumerate_add_nomatch_sysattr:
405 * @udev_enumerate: context
406 * @sysattr: filter for a sys attribute at the device to exclude from the list
407 * @value: optional value of the sys attribute
408 *
409 * Match only devices not having a certain /sys device attribute.
410 *
411 * Returns: 0 on success, otherwise a negative error value.
412 */
udev_enumerate_add_nomatch_sysattr(struct udev_enumerate * udev_enumerate,const char * sysattr,const char * value)413 _public_ int udev_enumerate_add_nomatch_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
414 {
415 if (udev_enumerate == NULL)
416 return -EINVAL;
417 if (sysattr == NULL)
418 return 0;
419 if (udev_list_entry_add(&udev_enumerate->sysattr_nomatch_list, sysattr, value) == NULL)
420 return -ENOMEM;
421 return 0;
422 }
423
match_sysattr_value(struct udev_device * dev,const char * sysattr,const char * match_val)424 static int match_sysattr_value(struct udev_device *dev, const char *sysattr, const char *match_val)
425 {
426 const char *val = NULL;
427 bool match = false;
428
429 val = udev_device_get_sysattr_value(dev, sysattr);
430 if (val == NULL)
431 goto exit;
432 if (match_val == NULL) {
433 match = true;
434 goto exit;
435 }
436 if (fnmatch(match_val, val, 0) == 0) {
437 match = true;
438 goto exit;
439 }
440 exit:
441 return match;
442 }
443
444 /**
445 * udev_enumerate_add_match_property:
446 * @udev_enumerate: context
447 * @property: filter for a property of the device to include in the list
448 * @value: value of the property
449 *
450 * Match only devices with a certain property.
451 *
452 * Returns: 0 on success, otherwise a negative error value.
453 */
udev_enumerate_add_match_property(struct udev_enumerate * udev_enumerate,const char * property,const char * value)454 _public_ int udev_enumerate_add_match_property(struct udev_enumerate *udev_enumerate, const char *property, const char *value)
455 {
456 if (udev_enumerate == NULL)
457 return -EINVAL;
458 if (property == NULL)
459 return 0;
460 if (udev_list_entry_add(&udev_enumerate->properties_match_list, property, value) == NULL)
461 return -ENOMEM;
462 return 0;
463 }
464
465 /**
466 * udev_enumerate_add_match_tag:
467 * @udev_enumerate: context
468 * @tag: filter for a tag of the device to include in the list
469 *
470 * Match only devices with a certain tag.
471 *
472 * Returns: 0 on success, otherwise a negative error value.
473 */
udev_enumerate_add_match_tag(struct udev_enumerate * udev_enumerate,const char * tag)474 _public_ int udev_enumerate_add_match_tag(struct udev_enumerate *udev_enumerate, const char *tag)
475 {
476 if (udev_enumerate == NULL)
477 return -EINVAL;
478 if (tag == NULL)
479 return 0;
480 if (udev_list_entry_add(&udev_enumerate->tags_match_list, tag, NULL) == NULL)
481 return -ENOMEM;
482 return 0;
483 }
484
485 /**
486 * udev_enumerate_add_match_parent:
487 * @udev_enumerate: context
488 * @parent: parent device where to start searching
489 *
490 * Return the devices on the subtree of one given device. The parent
491 * itself is included in the list.
492 *
493 * A reference for the device is held until the udev_enumerate context
494 * is cleaned up.
495 *
496 * Returns: 0 on success, otherwise a negative error value.
497 */
udev_enumerate_add_match_parent(struct udev_enumerate * udev_enumerate,struct udev_device * parent)498 _public_ int udev_enumerate_add_match_parent(struct udev_enumerate *udev_enumerate, struct udev_device *parent)
499 {
500 if (udev_enumerate == NULL)
501 return -EINVAL;
502 if (parent == NULL)
503 return 0;
504 if (udev_enumerate->parent_match != NULL)
505 udev_device_unref(udev_enumerate->parent_match);
506 udev_enumerate->parent_match = udev_device_ref(parent);
507 return 0;
508 }
509
510 /**
511 * udev_enumerate_add_match_is_initialized:
512 * @udev_enumerate: context
513 *
514 * Match only devices which udev has set up already. This makes
515 * sure, that the device node permissions and context are properly set
516 * and that network devices are fully renamed.
517 *
518 * Usually, devices which are found in the kernel but not already
519 * handled by udev, have still pending events. Services should subscribe
520 * to monitor events and wait for these devices to become ready, instead
521 * of using uninitialized devices.
522 *
523 * For now, this will not affect devices which do not have a device node
524 * and are not network interfaces.
525 *
526 * Returns: 0 on success, otherwise a negative error value.
527 */
udev_enumerate_add_match_is_initialized(struct udev_enumerate * udev_enumerate)528 _public_ int udev_enumerate_add_match_is_initialized(struct udev_enumerate *udev_enumerate)
529 {
530 if (udev_enumerate == NULL)
531 return -EINVAL;
532 udev_enumerate->match_is_initialized = true;
533 return 0;
534 }
535
536 /**
537 * udev_enumerate_add_match_sysname:
538 * @udev_enumerate: context
539 * @sysname: filter for the name of the device to include in the list
540 *
541 * Match only devices with a given /sys device name.
542 *
543 * Returns: 0 on success, otherwise a negative error value.
544 */
udev_enumerate_add_match_sysname(struct udev_enumerate * udev_enumerate,const char * sysname)545 _public_ int udev_enumerate_add_match_sysname(struct udev_enumerate *udev_enumerate, const char *sysname)
546 {
547 if (udev_enumerate == NULL)
548 return -EINVAL;
549 if (sysname == NULL)
550 return 0;
551 if (udev_list_entry_add(&udev_enumerate->sysname_match_list, sysname, NULL) == NULL)
552 return -ENOMEM;
553 return 0;
554 }
555
match_sysattr(struct udev_enumerate * udev_enumerate,struct udev_device * dev)556 static bool match_sysattr(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
557 {
558 struct udev_list_entry *list_entry;
559
560 /* skip list */
561 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_nomatch_list)) {
562 if (match_sysattr_value(dev, udev_list_entry_get_name(list_entry),
563 udev_list_entry_get_value(list_entry)))
564 return false;
565 }
566 /* include list */
567 if (udev_list_get_entry(&udev_enumerate->sysattr_match_list) != NULL) {
568 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_match_list)) {
569 /* anything that does not match, will make it FALSE */
570 if (!match_sysattr_value(dev, udev_list_entry_get_name(list_entry),
571 udev_list_entry_get_value(list_entry)))
572 return false;
573 }
574 return true;
575 }
576 return true;
577 }
578
match_property(struct udev_enumerate * udev_enumerate,struct udev_device * dev)579 static bool match_property(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
580 {
581 struct udev_list_entry *list_entry;
582 bool match = false;
583
584 /* no match always matches */
585 if (udev_list_get_entry(&udev_enumerate->properties_match_list) == NULL)
586 return true;
587
588 /* loop over matches */
589 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->properties_match_list)) {
590 const char *match_key = udev_list_entry_get_name(list_entry);
591 const char *match_value = udev_list_entry_get_value(list_entry);
592 struct udev_list_entry *property_entry;
593
594 /* loop over device properties */
595 udev_list_entry_foreach(property_entry, udev_device_get_properties_list_entry(dev)) {
596 const char *dev_key = udev_list_entry_get_name(property_entry);
597 const char *dev_value = udev_list_entry_get_value(property_entry);
598
599 if (fnmatch(match_key, dev_key, 0) != 0)
600 continue;
601 if (match_value == NULL && dev_value == NULL) {
602 match = true;
603 goto out;
604 }
605 if (match_value == NULL || dev_value == NULL)
606 continue;
607 if (fnmatch(match_value, dev_value, 0) == 0) {
608 match = true;
609 goto out;
610 }
611 }
612 }
613 out:
614 return match;
615 }
616
match_tag(struct udev_enumerate * udev_enumerate,struct udev_device * dev)617 static bool match_tag(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
618 {
619 struct udev_list_entry *list_entry;
620
621 /* no match always matches */
622 if (udev_list_get_entry(&udev_enumerate->tags_match_list) == NULL)
623 return true;
624
625 /* loop over matches */
626 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->tags_match_list))
627 if (!udev_device_has_tag(dev, udev_list_entry_get_name(list_entry)))
628 return false;
629
630 return true;
631 }
632
match_parent(struct udev_enumerate * udev_enumerate,struct udev_device * dev)633 static bool match_parent(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
634 {
635 if (udev_enumerate->parent_match == NULL)
636 return true;
637
638 return startswith(udev_device_get_devpath(dev), udev_device_get_devpath(udev_enumerate->parent_match));
639 }
640
match_sysname(struct udev_enumerate * udev_enumerate,const char * sysname)641 static bool match_sysname(struct udev_enumerate *udev_enumerate, const char *sysname)
642 {
643 struct udev_list_entry *list_entry;
644
645 if (udev_list_get_entry(&udev_enumerate->sysname_match_list) == NULL)
646 return true;
647
648 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysname_match_list)) {
649 if (fnmatch(udev_list_entry_get_name(list_entry), sysname, 0) != 0)
650 continue;
651 return true;
652 }
653 return false;
654 }
655
scan_dir_and_add_devices(struct udev_enumerate * udev_enumerate,const char * basedir,const char * subdir1,const char * subdir2)656 static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
657 const char *basedir, const char *subdir1, const char *subdir2)
658 {
659 char path[UTIL_PATH_SIZE];
660 size_t l;
661 char *s;
662 DIR *dir;
663 struct dirent *dent;
664
665 s = path;
666 l = strpcpyl(&s, sizeof(path), "/sys/", basedir, NULL);
667 if (subdir1 != NULL)
668 l = strpcpyl(&s, l, "/", subdir1, NULL);
669 if (subdir2 != NULL)
670 strpcpyl(&s, l, "/", subdir2, NULL);
671 dir = opendir(path);
672 if (dir == NULL)
673 return -ENOENT;
674 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
675 char syspath[UTIL_PATH_SIZE];
676 struct udev_device *dev;
677
678 if (dent->d_name[0] == '.')
679 continue;
680
681 if (!match_sysname(udev_enumerate, dent->d_name))
682 continue;
683
684 strscpyl(syspath, sizeof(syspath), path, "/", dent->d_name, NULL);
685 dev = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
686 if (dev == NULL)
687 continue;
688
689 if (udev_enumerate->match_is_initialized) {
690 /*
691 * All devices with a device node or network interfaces
692 * possibly need udev to adjust the device node permission
693 * or context, or rename the interface before it can be
694 * reliably used from other processes.
695 *
696 * For now, we can only check these types of devices, we
697 * might not store a database, and have no way to find out
698 * for all other types of devices.
699 */
700 if (!udev_device_get_is_initialized(dev) &&
701 (major(udev_device_get_devnum(dev)) > 0 || udev_device_get_ifindex(dev) > 0))
702 goto nomatch;
703 }
704 if (!match_parent(udev_enumerate, dev))
705 goto nomatch;
706 if (!match_tag(udev_enumerate, dev))
707 goto nomatch;
708 if (!match_property(udev_enumerate, dev))
709 goto nomatch;
710 if (!match_sysattr(udev_enumerate, dev))
711 goto nomatch;
712
713 syspath_add(udev_enumerate, udev_device_get_syspath(dev));
714 nomatch:
715 udev_device_unref(dev);
716 }
717 closedir(dir);
718 return 0;
719 }
720
match_subsystem(struct udev_enumerate * udev_enumerate,const char * subsystem)721 static bool match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
722 {
723 struct udev_list_entry *list_entry;
724
725 if (!subsystem)
726 return false;
727
728 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
729 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
730 return false;
731 }
732
733 if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
734 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
735 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
736 return true;
737 }
738 return false;
739 }
740
741 return true;
742 }
743
scan_dir(struct udev_enumerate * udev_enumerate,const char * basedir,const char * subdir,const char * subsystem)744 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
745 {
746 char path[UTIL_PATH_SIZE];
747 DIR *dir;
748 struct dirent *dent;
749
750 strscpyl(path, sizeof(path), "/sys/", basedir, NULL);
751 dir = opendir(path);
752 if (dir == NULL)
753 return -1;
754 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
755 if (dent->d_name[0] == '.')
756 continue;
757 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
758 continue;
759 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
760 }
761 closedir(dir);
762 return 0;
763 }
764
765 /**
766 * udev_enumerate_add_syspath:
767 * @udev_enumerate: context
768 * @syspath: path of a device
769 *
770 * Add a device to the list of devices, to retrieve it back sorted in dependency order.
771 *
772 * Returns: 0 on success, otherwise a negative error value.
773 */
udev_enumerate_add_syspath(struct udev_enumerate * udev_enumerate,const char * syspath)774 _public_ int udev_enumerate_add_syspath(struct udev_enumerate *udev_enumerate, const char *syspath)
775 {
776 struct udev_device *udev_device;
777
778 if (udev_enumerate == NULL)
779 return -EINVAL;
780 if (syspath == NULL)
781 return 0;
782 /* resolve to real syspath */
783 udev_device = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
784 if (udev_device == NULL)
785 return -EINVAL;
786 syspath_add(udev_enumerate, udev_device_get_syspath(udev_device));
787 udev_device_unref(udev_device);
788 return 0;
789 }
790
scan_devices_tags(struct udev_enumerate * udev_enumerate)791 static int scan_devices_tags(struct udev_enumerate *udev_enumerate)
792 {
793 struct udev_list_entry *list_entry;
794
795 /* scan only tagged devices, use tags reverse-index, instead of searching all devices in /sys */
796 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->tags_match_list)) {
797 DIR *dir;
798 struct dirent *dent;
799 char path[UTIL_PATH_SIZE];
800
801 strscpyl(path, sizeof(path), UDEV_ROOT_RUN "/udev/tags/", udev_list_entry_get_name(list_entry), NULL);
802 dir = opendir(path);
803 if (dir == NULL)
804 continue;
805 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
806 struct udev_device *dev;
807
808 if (dent->d_name[0] == '.')
809 continue;
810
811 dev = udev_device_new_from_device_id(udev_enumerate->udev, dent->d_name);
812 if (dev == NULL)
813 continue;
814
815 if (!match_subsystem(udev_enumerate, udev_device_get_subsystem(dev)))
816 goto nomatch;
817 if (!match_sysname(udev_enumerate, udev_device_get_sysname(dev)))
818 goto nomatch;
819 if (!match_parent(udev_enumerate, dev))
820 goto nomatch;
821 if (!match_property(udev_enumerate, dev))
822 goto nomatch;
823 if (!match_sysattr(udev_enumerate, dev))
824 goto nomatch;
825
826 syspath_add(udev_enumerate, udev_device_get_syspath(dev));
827 nomatch:
828 udev_device_unref(dev);
829 }
830 closedir(dir);
831 }
832 return 0;
833 }
834
parent_add_child(struct udev_enumerate * enumerate,const char * path)835 static int parent_add_child(struct udev_enumerate *enumerate, const char *path)
836 {
837 struct udev_device *dev;
838 int r = 0;
839
840 dev = udev_device_new_from_syspath(enumerate->udev, path);
841 if (dev == NULL)
842 return -ENODEV;
843
844 if (!match_subsystem(enumerate, udev_device_get_subsystem(dev)))
845 goto nomatch;
846 if (!match_sysname(enumerate, udev_device_get_sysname(dev)))
847 goto nomatch;
848 if (!match_property(enumerate, dev))
849 goto nomatch;
850 if (!match_sysattr(enumerate, dev))
851 goto nomatch;
852
853 syspath_add(enumerate, udev_device_get_syspath(dev));
854 r = 1;
855
856 nomatch:
857 udev_device_unref(dev);
858 return r;
859 }
860
parent_crawl_children(struct udev_enumerate * enumerate,const char * path,int maxdepth)861 static int parent_crawl_children(struct udev_enumerate *enumerate, const char *path, int maxdepth)
862 {
863 DIR *d;
864 struct dirent *dent;
865
866 d = opendir(path);
867 if (d == NULL)
868 return -errno;
869
870 for (dent = readdir(d); dent != NULL; dent = readdir(d)) {
871 char *child;
872
873 if (dent->d_name[0] == '.')
874 continue;
875 if (dent->d_type != DT_DIR)
876 continue;
877 if (asprintf(&child, "%s/%s", path, dent->d_name) < 0)
878 continue;
879 parent_add_child(enumerate, child);
880 if (maxdepth > 0)
881 parent_crawl_children(enumerate, child, maxdepth-1);
882 free(child);
883 }
884
885 closedir(d);
886 return 0;
887 }
888
scan_devices_children(struct udev_enumerate * enumerate)889 static int scan_devices_children(struct udev_enumerate *enumerate)
890 {
891 const char *path;
892
893 path = udev_device_get_syspath(enumerate->parent_match);
894 parent_add_child(enumerate, path);
895 return parent_crawl_children(enumerate, path, 256);
896 }
897
scan_devices_all(struct udev_enumerate * udev_enumerate)898 static int scan_devices_all(struct udev_enumerate *udev_enumerate)
899 {
900 struct stat statbuf;
901
902 if (stat("/sys/subsystem", &statbuf) == 0) {
903 /* we have /subsystem/, forget all the old stuff */
904 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
905 } else {
906 scan_dir(udev_enumerate, "bus", "devices", NULL);
907 scan_dir(udev_enumerate, "class", NULL, NULL);
908 }
909 return 0;
910 }
911
912 /**
913 * udev_enumerate_scan_devices:
914 * @udev_enumerate: udev enumeration context
915 *
916 * Scan /sys for all devices which match the given filters. No matches
917 * will return all currently available devices.
918 *
919 * Returns: 0 on success, otherwise a negative error value.
920 **/
udev_enumerate_scan_devices(struct udev_enumerate * udev_enumerate)921 _public_ int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
922 {
923 if (udev_enumerate == NULL)
924 return -EINVAL;
925
926 /* efficiently lookup tags only, we maintain a reverse-index */
927 if (udev_list_get_entry(&udev_enumerate->tags_match_list) != NULL)
928 return scan_devices_tags(udev_enumerate);
929
930 /* walk the subtree of one parent device only */
931 if (udev_enumerate->parent_match != NULL)
932 return scan_devices_children(udev_enumerate);
933
934 /* scan devices of all subsystems */
935 return scan_devices_all(udev_enumerate);
936 }
937
938 /**
939 * udev_enumerate_scan_subsystems:
940 * @udev_enumerate: udev enumeration context
941 *
942 * Scan /sys for all kernel subsystems, including buses, classes, drivers.
943 *
944 * Returns: 0 on success, otherwise a negative error value.
945 **/
udev_enumerate_scan_subsystems(struct udev_enumerate * udev_enumerate)946 _public_ int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
947 {
948 struct stat statbuf;
949 const char *subsysdir;
950
951 if (udev_enumerate == NULL)
952 return -EINVAL;
953
954 /* all kernel modules */
955 if (match_subsystem(udev_enumerate, "module"))
956 scan_dir_and_add_devices(udev_enumerate, "module", NULL, NULL);
957
958 if (stat("/sys/subsystem", &statbuf) == 0)
959 subsysdir = "subsystem";
960 else
961 subsysdir = "bus";
962
963 /* all subsystems (only buses support coldplug) */
964 if (match_subsystem(udev_enumerate, "subsystem"))
965 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
966
967 /* all subsystem drivers */
968 if (match_subsystem(udev_enumerate, "drivers"))
969 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");
970 return 0;
971 }
972