2 * libudev - interface to udev device information
4 * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
31 #include "libudev-private.h"
36 struct udev_device *parent_device;
42 struct list_node devlink_list;
43 struct list_node properties_list;
51 unsigned long long int seqnum;
52 int num_fake_partitions;
55 struct list_node attr_list;
59 static size_t syspath_to_db_path(struct udev_device *udev_device, char *filename, size_t len)
63 /* translate to location of db file */
64 util_strlcpy(filename, udev_get_dev_path(udev_device->udev), len);
65 start = util_strlcat(filename, "/.udev/db/", len);
66 util_strlcat(filename, udev_device->devpath, len);
67 return util_path_encode(&filename[start], len - start);
70 static int device_read_db(struct udev_device *udev_device)
73 char filename[UTIL_PATH_SIZE];
74 char line[UTIL_LINE_SIZE];
77 syspath_to_db_path(udev_device, filename, sizeof(filename));
79 if (lstat(filename, &stats) != 0) {
80 info(udev_device->udev, "no db file to read %s: %s\n", filename, strerror(errno));
83 if ((stats.st_mode & S_IFMT) == S_IFLNK) {
84 char target[UTIL_PATH_SIZE];
87 target_len = readlink(filename, target, sizeof(target));
89 target[target_len] = '\0';
91 info(udev_device->udev, "error reading db link %s: %s\n", filename, strerror(errno));
94 if (asprintf(&udev_device->devnode, "%s/%s", udev_get_dev_path(udev_device->udev), target) < 0)
96 info(udev_device->udev, "device %p filled with db symlink data '%s'\n", udev_device, udev_device->devnode);
100 f = fopen(filename, "r");
102 info(udev_device->udev, "error reading db file %s: %s\n", filename, strerror(errno));
105 while (fgets(line, sizeof(line), f)) {
117 asprintf(&udev_device->devnode, "%s/%s", udev_get_dev_path(udev_device->udev), val);
120 util_strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
121 util_strlcat(filename, "/", sizeof(filename));
122 util_strlcat(filename, val, sizeof(filename));
123 device_add_devlink(udev_device, filename);
126 device_set_devlink_priority(udev_device, atoi(val));
129 device_set_event_timeout(udev_device, atoi(val));
132 device_set_num_fake_partitions(udev_device, atoi(val));
135 device_set_ignore_remove(udev_device, atoi(val));
138 device_add_property_from_string(udev_device, val);
144 info(udev_device->udev, "device %p filled with db file data\n", udev_device);
148 static int device_read_uevent_file(struct udev_device *udev_device)
150 char filename[UTIL_PATH_SIZE];
152 char line[UTIL_LINE_SIZE];
156 util_strlcpy(filename, udev_device->syspath, sizeof(filename));
157 util_strlcat(filename, "/uevent", sizeof(filename));
158 f = fopen(filename, "r");
162 while (fgets(line, sizeof(line), f)) {
165 pos = strchr(line, '\n');
170 if (strncmp(line, "MAJOR=", 6) == 0)
171 maj = strtoull(&line[6], NULL, 10);
172 else if (strncmp(line, "MINOR=", 6) == 0)
173 min = strtoull(&line[6], NULL, 10);
175 device_add_property_from_string(udev_device, line);
178 udev_device->devnum = makedev(maj, min);
184 static void device_load_info(struct udev_device *device)
186 device_read_uevent_file(device);
187 device_read_db(device);
188 device->info_loaded = 1;
191 void device_set_info_loaded(struct udev_device *device)
193 device->info_loaded = 1;
196 struct udev_device *device_init(struct udev *udev)
198 struct udev_device *udev_device;
203 udev_device = malloc(sizeof(struct udev_device));
204 if (udev_device == NULL)
206 memset(udev_device, 0x00, sizeof(struct udev_device));
207 udev_device->refcount = 1;
208 udev_device->udev = udev;
209 list_init(&udev_device->devlink_list);
210 list_init(&udev_device->properties_list);
211 list_init(&udev_device->attr_list);
212 info(udev_device->udev, "udev_device: %p created\n", udev_device);
217 * udev_device_new_from_syspath:
218 * @udev: udev library context
219 * @syspath: sys device path including sys directory
221 * Create new udev device, and fill in information from the sys
222 * device and the udev database entry. The sypath is the absolute
223 * path to the device, including the sys mount point.
225 * The initial refcount is 1, and needs to be decremented to
226 * release the ressources of the udev device.
228 * Returns: a new udev device, or #NULL, if it does not exist
230 struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
232 char path[UTIL_PATH_SIZE];
234 struct udev_device *udev_device;
241 util_strlcpy(path, syspath, sizeof(path));
242 util_strlcat(path, "/uevent", sizeof(path));
243 if (stat(path, &statbuf) != 0) {
244 info(udev, "not a device :%s\n", syspath);
248 udev_device = device_init(udev);
249 if (udev_device == NULL)
252 /* resolve possible symlink to real path */
253 util_strlcpy(path, syspath, sizeof(path));
254 util_resolve_sys_link(udev, path, sizeof(path));
255 device_set_syspath(udev_device, path);
256 info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
261 struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
263 char path[UTIL_PATH_SIZE];
264 const char *type_str;
265 struct udev_enumerate *enumerate;
266 struct udev_list *list;
267 struct udev_device *device = NULL;
271 else if (type == 'c')
276 /* /sys/dev/{block,char}/<maj>:<min> links */
277 snprintf(path, sizeof(path), "%s/dev/%s/%u:%u", udev_get_sys_path(udev),
278 type_str, major(devnum), minor(devnum));
279 if (util_resolve_sys_link(udev, path, sizeof(path)) == 0)
280 return udev_device_new_from_syspath(udev, path);
282 /* fallback to search all sys devices for the major/minor */
283 enumerate = udev_enumerate_new_from_subsystems(udev, NULL);
284 if (enumerate == NULL)
286 list = udev_enumerate_get_list(enumerate);
287 while (list != NULL) {
288 struct udev_device *device_loop;
290 device_loop = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list));
291 if (device_loop != NULL) {
292 if (udev_device_get_devnum(device_loop) == devnum) {
293 device = device_loop;
296 udev_device_unref(device_loop);
298 list = udev_list_entry_get_next(list);
300 udev_enumerate_unref(enumerate);
304 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
306 struct udev_device *udev_device_parent = NULL;
307 char path[UTIL_PATH_SIZE];
310 if (udev_device == NULL)
313 util_strlcpy(path, udev_device->syspath, sizeof(path));
315 pos = strrchr(path, '/');
316 if (pos == path || pos == NULL)
319 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
320 if (udev_device_parent != NULL)
321 return udev_device_parent;
324 /* follow "device" link in deprecated sys /sys/class/ layout */
325 if (strncmp(udev_device->devpath, "/class/", 7) == 0) {
326 util_strlcpy(path, udev_device->syspath, sizeof(path));
327 util_strlcat(path, "/device", sizeof(path));
328 if (util_resolve_sys_link(udev_device->udev, path, sizeof(path)) == 0) {
329 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
330 if (udev_device_parent != NULL)
331 return udev_device_parent;
337 struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
339 if (udev_device->parent_device != NULL) {
340 info(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
341 return udev_device->parent_device;
343 udev_device->parent_device = device_new_from_parent(udev_device);
344 return udev_device->parent_device;
348 * udev_device_get_udev:
349 * @udev_device: udev device
351 * Retrieve the udev library context the device was created with.
353 * Returns: the udev library context
355 struct udev *udev_device_get_udev(struct udev_device *udev_device)
357 if (udev_device == NULL)
359 return udev_device->udev;
364 * @udev_device: udev device
366 * Take a reference of a udev device.
368 * Returns: the passed udev device
370 struct udev_device *udev_device_ref(struct udev_device *udev_device)
372 if (udev_device == NULL)
374 udev_device->refcount++;
380 * @udev_device: udev device
382 * Drop a reference of a udev device. If the refcount reaches zero,
383 * the ressources of the device will be released.
386 void udev_device_unref(struct udev_device *udev_device)
388 if (udev_device == NULL)
390 udev_device->refcount--;
391 if (udev_device->refcount > 0)
393 if (udev_device->parent_device != NULL)
394 udev_device_unref(udev_device->parent_device);
395 free(udev_device->syspath);
396 free(udev_device->devnode);
397 free(udev_device->subsystem);
398 list_cleanup(udev_device->udev, &udev_device->devlink_list);
399 list_cleanup(udev_device->udev, &udev_device->properties_list);
400 free(udev_device->action);
401 free(udev_device->driver);
402 free(udev_device->devpath_old);
403 free(udev_device->physdevpath);
404 list_cleanup(udev_device->udev, &udev_device->attr_list);
405 info(udev_device->udev, "udev_device: %p released\n", udev_device);
410 * udev_device_get_devpath:
411 * @udev_device: udev device
413 * Retrieve the kernel devpath value of the udev device. The path
414 * does not contain the sys mount point, and starts with a '/'.
416 * Returns: the devpath of the udev device
418 const char *udev_device_get_devpath(struct udev_device *udev_device)
420 if (udev_device == NULL)
422 return udev_device->devpath;
426 * udev_device_get_syspath:
427 * @udev_device: udev device
429 * Retrieve the sys path of the udev device. The path is an
430 * absolute path and starts with the sys mount point.
432 * Returns: the sys path of the udev device
434 const char *udev_device_get_syspath(struct udev_device *udev_device)
436 if (udev_device == NULL)
438 return udev_device->syspath;
441 const char *udev_device_get_sysname(struct udev_device *udev_device)
443 if (udev_device == NULL)
445 return udev_device->sysname;
449 * udev_device_get_devnode:
450 * @udev_device: udev device
452 * Retrieve the device node file name belonging to the udev device.
453 * The path is an absolute path, and starts with the device directory.
455 * Returns: the device node file name of the udev device, or #NULL if no device node exists
457 const char *udev_device_get_devnode(struct udev_device *udev_device)
459 if (udev_device == NULL)
461 if (!udev_device->info_loaded)
462 device_load_info(udev_device);
463 return udev_device->devnode;
467 * udev_device_get_subsystem:
468 * @udev_device: udev device
470 * Retrieve the subsystem string of the udev device. The string does not
473 * Returns: the subsystem name of the udev device, or #NULL if it can not be determined
475 const char *udev_device_get_subsystem(struct udev_device *udev_device)
477 char subsystem[UTIL_NAME_SIZE];
479 if (udev_device == NULL)
481 if (udev_device->subsystem != NULL)
482 return udev_device->subsystem;
484 /* read "subsytem" link */
485 if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
486 udev_device->subsystem = strdup(subsystem);
487 return udev_device->subsystem;
491 if (strncmp(udev_device->devpath, "/module/", 8) == 0) {
492 udev_device->subsystem = strdup("module");
493 return udev_device->subsystem;
495 if (strstr(udev_device->devpath, "/drivers/") != NULL) {
496 udev_device->subsystem = strdup("drivers");
497 return udev_device->subsystem;
499 if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 ||
500 strncmp(udev_device->devpath, "/class/", 7) == 0 ||
501 strncmp(udev_device->devpath, "/bus/", 5) == 0) {
502 udev_device->subsystem = strdup("subsystem");
503 return udev_device->subsystem;
509 * udev_device_get_devlinks_list:
510 * @udev_device: udev device
512 * Retrieve the list of device links pointing to the device file of
513 * the udev device. The next list entry can be retrieved with
514 * udev_list_entry_next(), which returns #NULL if no more entries exist.
515 * The devlink path can be retrieved from the list entry by
516 * udev_list_entry_get_name(). The path is an absolute path, and starts with
517 * the device directory.
519 * Returns: the first entry of the device node link list
521 struct udev_list *udev_device_get_devlinks_list(struct udev_device *udev_device)
523 if (udev_device == NULL)
525 if (!udev_device->info_loaded)
526 device_load_info(udev_device);
527 return list_get_entry(&udev_device->devlink_list);
531 * udev_device_get_properties_list:
532 * @udev_device: udev device
534 * Retrieve the list of key/value device properties of the udev
535 * device. The next list entry can be retrieved with udev_list_entry_next(),
536 * which returns #NULL if no more entries exist. The property name
537 * can be retrieved from the list entry by udev_list_get_name(),
538 * the property value by udev_list_get_value().
540 * Returns: the first entry of the property list
542 struct udev_list *udev_device_get_properties_list(struct udev_device *udev_device)
544 if (udev_device == NULL)
546 if (!udev_device->info_loaded)
547 device_load_info(udev_device);
548 return list_get_entry(&udev_device->properties_list);
551 const char *udev_device_get_driver(struct udev_device *udev_device)
553 char driver[UTIL_NAME_SIZE];
555 if (udev_device == NULL)
557 if (udev_device->driver != NULL)
558 return udev_device->driver;
559 if (util_get_sys_driver(udev_device->udev, udev_device->syspath, driver, sizeof(driver)) < 2)
561 udev_device->driver = strdup(driver);
562 return udev_device->driver;
565 dev_t udev_device_get_devnum(struct udev_device *udev_device)
567 if (udev_device == NULL)
568 return makedev(0, 0);
569 if (!udev_device->info_loaded)
570 device_load_info(udev_device);
571 return udev_device->devnum;
574 const char *udev_device_get_action(struct udev_device *udev_device)
576 if (udev_device == NULL)
578 return udev_device->action;
581 unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
583 if (udev_device == NULL)
585 return udev_device->seqnum;
588 const char *udev_device_get_attr_value(struct udev_device *udev_device, const char *attr)
590 struct udev_list *list;
591 char path[UTIL_PATH_SIZE];
592 char value[UTIL_NAME_SIZE];
596 const char *val = NULL;
598 /* look for possibly already cached result */
599 list = list_get_entry(&udev_device->attr_list);
600 while (list != NULL) {
601 if (strcmp(udev_list_entry_get_name(list), attr) == 0) {
602 info(udev_device->udev, "got '%s' (%s) from cache\n", attr, udev_list_entry_get_value(list));
603 return udev_list_entry_get_value(list);
605 list = udev_list_entry_get_next(list);
608 util_strlcpy(path, udev_device_get_syspath(udev_device), sizeof(path));
609 util_strlcat(path, "/", sizeof(path));
610 util_strlcat(path, attr, sizeof(path));
612 if (lstat(path, &statbuf) != 0) {
613 info(udev_device->udev, "stat '%s' failed: %s\n", path, strerror(errno));
617 if (S_ISLNK(statbuf.st_mode)) {
618 /* links return the last element of the target path */
619 char target[UTIL_NAME_SIZE];
623 len = readlink(path, target, sizeof(target));
626 pos = strrchr(target, '/');
629 info(udev_device->udev, "cache '%s' with link value '%s'\n", attr, pos);
630 list = list_insert_entry(udev_device->udev, &udev_device->attr_list, attr, pos, 0);
631 val = udev_list_entry_get_value(list);
637 /* skip directories */
638 if (S_ISDIR(statbuf.st_mode))
641 /* skip non-readable files */
642 if ((statbuf.st_mode & S_IRUSR) == 0)
645 /* read attribute value */
646 fd = open(path, O_RDONLY);
648 info(udev_device->udev, "attribute '%s' can not be opened\n", path);
651 size = read(fd, value, sizeof(value));
655 if (size == sizeof(value))
658 /* got a valid value, store it in cache and return it */
660 util_remove_trailing_chars(value, '\n');
661 info(udev_device->udev, "'%s' has attribute value '%s'\n", path, value);
662 list = list_insert_entry(udev_device->udev, &udev_device->attr_list, attr, value, 0);
663 val = udev_list_entry_get_value(list);
667 int device_set_syspath(struct udev_device *udev_device, const char *syspath)
671 udev_device->syspath = strdup(syspath);
672 if (udev_device->syspath == NULL)
674 udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))];
675 pos = strrchr(udev_device->syspath, '/');
678 udev_device->sysname = &pos[1];
682 int device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
684 udev_device->subsystem = strdup(subsystem);
685 if (udev_device->subsystem == NULL)
690 int device_set_devnode(struct udev_device *udev_device, const char *devnode)
692 udev_device->devnode = strdup(devnode);
693 if (udev_device->devnode == NULL)
698 int device_add_devlink(struct udev_device *udev_device, const char *devlink)
700 if (list_insert_entry(udev_device->udev, &udev_device->devlink_list, devlink, NULL, 0) == NULL)
705 int device_add_property(struct udev_device *udev_device, const char *key, const char *value)
707 if (list_insert_entry(udev_device->udev, &udev_device->properties_list, key, value, 0) == NULL)
712 int device_add_property_from_string(struct udev_device *udev_device, const char *property)
714 char name[UTIL_PATH_SIZE];
717 strncpy(name, property, sizeof(name));
718 val = strchr(name, '=');
725 device_add_property(udev_device, name, val);
729 int device_set_action(struct udev_device *udev_device, const char *action)
731 udev_device->action = strdup(action);
732 if (udev_device->action == NULL)
737 int device_set_driver(struct udev_device *udev_device, const char *driver)
739 udev_device->driver = strdup(driver);
740 if (udev_device->driver == NULL)
745 const char *device_get_devpath_old(struct udev_device *udev_device)
747 return udev_device->devpath_old;
750 int device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
752 udev_device->devpath_old = strdup(devpath_old);
753 if (udev_device->devpath_old == NULL)
758 const char *device_get_physdevpath(struct udev_device *udev_device)
760 return udev_device->physdevpath;
763 int device_set_physdevpath(struct udev_device *udev_device, const char *physdevpath)
765 udev_device->physdevpath = strdup(physdevpath);
766 if (udev_device->physdevpath == NULL)
771 int device_get_timeout(struct udev_device *udev_device)
773 return udev_device->timeout;
776 int device_set_timeout(struct udev_device *udev_device, int timeout)
778 udev_device->timeout = timeout;
781 int device_get_event_timeout(struct udev_device *udev_device)
783 if (!udev_device->info_loaded)
784 device_load_info(udev_device);
785 return udev_device->event_timeout;
788 int device_set_event_timeout(struct udev_device *udev_device, int event_timeout)
790 udev_device->event_timeout = event_timeout;
794 int device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
796 udev_device->seqnum = seqnum;
800 int device_set_devnum(struct udev_device *udev_device, dev_t devnum)
802 udev_device->devnum = devnum;
806 int device_get_num_fake_partitions(struct udev_device *udev_device)
808 if (!udev_device->info_loaded)
809 device_load_info(udev_device);
810 return udev_device->num_fake_partitions;
813 int device_set_num_fake_partitions(struct udev_device *udev_device, int num)
815 udev_device->num_fake_partitions = num;
819 int device_get_devlink_priority(struct udev_device *udev_device)
821 if (!udev_device->info_loaded)
822 device_load_info(udev_device);
823 return udev_device->devlink_priority;
826 int device_set_devlink_priority(struct udev_device *udev_device, int prio)
828 udev_device->devlink_priority = prio;
832 int device_get_ignore_remove(struct udev_device *udev_device)
834 if (!udev_device->info_loaded)
835 device_load_info(udev_device);
836 return udev_device->ignore_remove;
839 int device_set_ignore_remove(struct udev_device *udev_device, int ignore)
841 udev_device->ignore_remove = ignore;