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.
24 #include <sys/ioctl.h>
25 #include <sys/socket.h>
26 #include <linux/sockios.h>
29 #include "libudev-private.h"
32 * SECTION:libudev-device
33 * @short_description: kernel sys devices
35 * Representation of kernel sys devices. Devices are uniquely identified
36 * by their syspath, every device has exactly one path in the kernel sys
37 * filesystem. Devices usually belong to a kernel subsystem, and and have
38 * a unique name inside that subsystem.
44 * Opaque object representing one kernel sys device.
48 struct udev_device *parent_device;
63 size_t monitor_buf_len;
64 struct udev_list devlinks_list;
65 struct udev_list properties_list;
66 struct udev_list sysattr_value_list;
67 struct udev_list sysattr_list;
68 struct udev_list tags_list;
69 unsigned long long int seqnum;
70 unsigned long long int usec_initialized;
80 bool devlinks_uptodate;
88 bool sysattr_list_read;
93 * udev_device_get_seqnum:
94 * @udev_device: udev device
96 * This is only valid if the device was received through a monitor. Devices read from
97 * sys do not have a sequence number.
99 * Returns: the kernel event sequence number, or 0 if there is no sequence number available.
101 UDEV_EXPORT unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
103 if (udev_device == NULL)
105 return udev_device->seqnum;
108 static int udev_device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
112 udev_device->seqnum = seqnum;
113 snprintf(num, sizeof(num), "%llu", seqnum);
114 udev_device_add_property(udev_device, "SEQNUM", num);
118 int udev_device_get_ifindex(struct udev_device *udev_device)
120 if (!udev_device->info_loaded)
121 udev_device_read_uevent_file(udev_device);
122 return udev_device->ifindex;
125 static int udev_device_set_ifindex(struct udev_device *udev_device, int ifindex)
129 udev_device->ifindex = ifindex;
130 snprintf(num, sizeof(num), "%u", ifindex);
131 udev_device_add_property(udev_device, "IFINDEX", num);
136 * udev_device_get_devnum:
137 * @udev_device: udev device
139 * Returns: the device major/minor number.
141 UDEV_EXPORT dev_t udev_device_get_devnum(struct udev_device *udev_device)
143 if (udev_device == NULL)
144 return makedev(0, 0);
145 if (!udev_device->info_loaded)
146 udev_device_read_uevent_file(udev_device);
147 return udev_device->devnum;
150 static int udev_device_set_devnum(struct udev_device *udev_device, dev_t devnum)
154 udev_device->devnum = devnum;
156 snprintf(num, sizeof(num), "%u", major(devnum));
157 udev_device_add_property(udev_device, "MAJOR", num);
158 snprintf(num, sizeof(num), "%u", minor(devnum));
159 udev_device_add_property(udev_device, "MINOR", num);
163 const char *udev_device_get_devpath_old(struct udev_device *udev_device)
165 return udev_device->devpath_old;
168 static int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
172 free(udev_device->devpath_old);
173 udev_device->devpath_old = strdup(devpath_old);
174 if (udev_device->devpath_old == NULL)
176 udev_device_add_property(udev_device, "DEVPATH_OLD", udev_device->devpath_old);
178 pos = strrchr(udev_device->devpath_old, '/');
185 * udev_device_get_driver:
186 * @udev_device: udev device
188 * Returns: the driver string, or #NULL if there is no driver attached.
190 UDEV_EXPORT const char *udev_device_get_driver(struct udev_device *udev_device)
192 char driver[UTIL_NAME_SIZE];
194 if (udev_device == NULL)
196 if (!udev_device->driver_set) {
197 udev_device->driver_set = true;
198 if (util_get_sys_core_link_value(udev_device->udev, "driver", udev_device->syspath, driver, sizeof(driver)) > 0)
199 udev_device->driver = strdup(driver);
201 return udev_device->driver;
204 static int udev_device_set_driver(struct udev_device *udev_device, const char *driver)
206 free(udev_device->driver);
207 udev_device->driver = strdup(driver);
208 if (udev_device->driver == NULL)
210 udev_device->driver_set = true;
211 udev_device_add_property(udev_device, "DRIVER", udev_device->driver);
216 * udev_device_get_devtype:
217 * @udev_device: udev device
219 * Retrieve the devtype string of the udev device.
221 * Returns: the devtype name of the udev device, or #NULL if it can not be determined
223 UDEV_EXPORT const char *udev_device_get_devtype(struct udev_device *udev_device)
225 if (udev_device == NULL)
227 if (!udev_device->devtype_set) {
228 udev_device->devtype_set = true;
229 udev_device_read_uevent_file(udev_device);
231 return udev_device->devtype;
234 static int udev_device_set_devtype(struct udev_device *udev_device, const char *devtype)
236 free(udev_device->devtype);
237 udev_device->devtype = strdup(devtype);
238 if (udev_device->devtype == NULL)
240 udev_device->devtype_set = true;
241 udev_device_add_property(udev_device, "DEVTYPE", udev_device->devtype);
245 static int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
247 free(udev_device->subsystem);
248 udev_device->subsystem = strdup(subsystem);
249 if (udev_device->subsystem == NULL)
251 udev_device->subsystem_set = true;
252 udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem);
257 * udev_device_get_subsystem:
258 * @udev_device: udev device
260 * Retrieve the subsystem string of the udev device. The string does not
263 * Returns: the subsystem name of the udev device, or #NULL if it can not be determined
265 UDEV_EXPORT const char *udev_device_get_subsystem(struct udev_device *udev_device)
267 char subsystem[UTIL_NAME_SIZE];
269 if (udev_device == NULL)
271 if (!udev_device->subsystem_set) {
272 udev_device->subsystem_set = true;
273 /* read "subsystem" link */
274 if (util_get_sys_core_link_value(udev_device->udev, "subsystem", udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
275 udev_device_set_subsystem(udev_device, subsystem);
276 return udev_device->subsystem;
279 if (strncmp(udev_device->devpath, "/module/", 8) == 0) {
280 udev_device_set_subsystem(udev_device, "module");
281 return udev_device->subsystem;
283 if (strstr(udev_device->devpath, "/drivers/") != NULL) {
284 udev_device_set_subsystem(udev_device, "drivers");
285 return udev_device->subsystem;
287 if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 ||
288 strncmp(udev_device->devpath, "/class/", 7) == 0 ||
289 strncmp(udev_device->devpath, "/bus/", 5) == 0) {
290 udev_device_set_subsystem(udev_device, "subsystem");
291 return udev_device->subsystem;
294 return udev_device->subsystem;
297 mode_t udev_device_get_devnode_mode(struct udev_device *udev_device)
299 if (!udev_device->info_loaded)
300 udev_device_read_uevent_file(udev_device);
301 return udev_device->devnode_mode;
304 static int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t mode)
308 udev_device->devnode_mode = mode;
309 snprintf(num, sizeof(num), "%#o", mode);
310 udev_device_add_property(udev_device, "DEVMODE", num);
314 struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value)
316 udev_device->envp_uptodate = false;
318 struct udev_list_entry *list_entry;
320 list_entry = udev_device_get_properties_list_entry(udev_device);
321 list_entry = udev_list_entry_get_by_name(list_entry, key);
322 if (list_entry != NULL)
323 udev_list_entry_delete(list_entry);
326 return udev_list_entry_add(&udev_device->properties_list, key, value);
329 static struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property)
331 char name[UTIL_LINE_SIZE];
334 util_strscpy(name, sizeof(name), property);
335 val = strchr(name, '=');
342 return udev_device_add_property(udev_device, name, val);
346 * parse property string, and if needed, update internal values accordingly
348 * udev_device_add_property_from_string_parse_finish() needs to be
349 * called after adding properties, and its return value checked
351 * udev_device_set_info_loaded() needs to be set, to avoid trying
352 * to use a device without a DEVPATH set
354 void udev_device_add_property_from_string_parse(struct udev_device *udev_device, const char *property)
356 if (strncmp(property, "DEVPATH=", 8) == 0) {
357 char path[UTIL_PATH_SIZE];
359 util_strscpyl(path, sizeof(path), udev_get_sys_path(udev_device->udev), &property[8], NULL);
360 udev_device_set_syspath(udev_device, path);
361 } else if (strncmp(property, "SUBSYSTEM=", 10) == 0) {
362 udev_device_set_subsystem(udev_device, &property[10]);
363 } else if (strncmp(property, "DEVTYPE=", 8) == 0) {
364 udev_device_set_devtype(udev_device, &property[8]);
365 } else if (strncmp(property, "DEVNAME=", 8) == 0) {
366 udev_device_set_devnode(udev_device, &property[8]);
367 } else if (strncmp(property, "DEVLINKS=", 9) == 0) {
368 char devlinks[UTIL_PATH_SIZE];
372 util_strscpy(devlinks, sizeof(devlinks), &property[9]);
374 next = strchr(slink, ' ');
375 while (next != NULL) {
377 udev_device_add_devlink(udev_device, slink, 0);
379 next = strchr(slink, ' ');
381 if (slink[0] != '\0')
382 udev_device_add_devlink(udev_device, slink, 0);
383 } else if (strncmp(property, "TAGS=", 5) == 0) {
384 char tags[UTIL_PATH_SIZE];
387 util_strscpy(tags, sizeof(tags), &property[5]);
388 next = strchr(tags, ':');
391 while (next[0] != '\0') {
395 next = strchr(tag, ':');
400 udev_device_add_tag(udev_device, tag);
403 } else if (strncmp(property, "USEC_INITIALIZED=", 19) == 0) {
404 udev_device_set_usec_initialized(udev_device, strtoull(&property[19], NULL, 10));
405 } else if (strncmp(property, "DRIVER=", 7) == 0) {
406 udev_device_set_driver(udev_device, &property[7]);
407 } else if (strncmp(property, "ACTION=", 7) == 0) {
408 udev_device_set_action(udev_device, &property[7]);
409 } else if (strncmp(property, "MAJOR=", 6) == 0) {
410 udev_device->maj = strtoull(&property[6], NULL, 10);
411 } else if (strncmp(property, "MINOR=", 6) == 0) {
412 udev_device->min = strtoull(&property[6], NULL, 10);
413 } else if (strncmp(property, "DEVPATH_OLD=", 12) == 0) {
414 udev_device_set_devpath_old(udev_device, &property[12]);
415 } else if (strncmp(property, "SEQNUM=", 7) == 0) {
416 udev_device_set_seqnum(udev_device, strtoull(&property[7], NULL, 10));
417 } else if (strncmp(property, "IFINDEX=", 8) == 0) {
418 udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10));
419 } else if (strncmp(property, "DEVMODE=", 8) == 0) {
420 udev_device_set_devnode_mode(udev_device, strtoul(&property[8], NULL, 8));
422 udev_device_add_property_from_string(udev_device, property);
426 int udev_device_add_property_from_string_parse_finish(struct udev_device *udev_device)
428 if (udev_device->maj > 0)
429 udev_device_set_devnum(udev_device, makedev(udev_device->maj, udev_device->min));
430 udev_device->maj = 0;
431 udev_device->min = 0;
433 if (udev_device->devpath == NULL || udev_device->subsystem == NULL)
439 * udev_device_get_property_value:
440 * @udev_device: udev device
441 * @key: property name
443 * Returns: the value of a device property, or #NULL if there is no such property.
445 UDEV_EXPORT const char *udev_device_get_property_value(struct udev_device *udev_device, const char *key)
447 struct udev_list_entry *list_entry;
449 if (udev_device == NULL)
454 list_entry = udev_device_get_properties_list_entry(udev_device);
455 list_entry = udev_list_entry_get_by_name(list_entry, key);
456 return udev_list_entry_get_value(list_entry);
459 int udev_device_read_db(struct udev_device *udev_device, const char *dbfile)
461 char filename[UTIL_PATH_SIZE];
462 char line[UTIL_LINE_SIZE];
465 /* providing a database file will always force-load it */
466 if (dbfile == NULL) {
469 if (udev_device->db_loaded)
471 udev_device->db_loaded = true;
473 id = udev_device_get_id_filename(udev_device);
476 util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev_device->udev), "/data/", id, NULL);
480 f = fopen(dbfile, "re");
482 info(udev_device->udev, "no db file to read %s: %m\n", dbfile);
485 udev_device->is_initialized = true;
487 while (fgets(line, sizeof(line), f)) {
490 struct udev_list_entry *entry;
499 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_device->udev), "/", val, NULL);
500 udev_device_add_devlink(udev_device, filename, 0);
503 udev_device_set_devlink_priority(udev_device, atoi(val));
506 entry = udev_device_add_property_from_string(udev_device, val);
507 udev_list_entry_set_num(entry, true);
510 udev_device_add_tag(udev_device, val);
513 udev_device_set_watch_handle(udev_device, atoi(val));
516 udev_device_set_usec_initialized(udev_device, strtoull(val, NULL, 10));
522 info(udev_device->udev, "device %p filled with db file data\n", udev_device);
526 int udev_device_read_uevent_file(struct udev_device *udev_device)
528 char filename[UTIL_PATH_SIZE];
530 char line[UTIL_LINE_SIZE];
534 if (udev_device->uevent_loaded)
537 util_strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL);
538 f = fopen(filename, "re");
541 udev_device->uevent_loaded = true;
543 while (fgets(line, sizeof(line), f)) {
546 pos = strchr(line, '\n');
551 if (strncmp(line, "DEVTYPE=", 8) == 0)
552 udev_device_set_devtype(udev_device, &line[8]);
553 else if (strncmp(line, "MAJOR=", 6) == 0)
554 maj = strtoull(&line[6], NULL, 10);
555 else if (strncmp(line, "MINOR=", 6) == 0)
556 min = strtoull(&line[6], NULL, 10);
557 else if (strncmp(line, "IFINDEX=", 8) == 0)
558 udev_device_set_ifindex(udev_device, strtoull(&line[8], NULL, 10));
559 else if (strncmp(line, "DEVNAME=", 8) == 0)
560 udev_device_set_devnode(udev_device, &line[8]);
561 else if (strncmp(line, "DEVMODE=", 8) == 0)
562 udev_device->devnode_mode = strtoul(&line[8], NULL, 8);
564 udev_device_add_property_from_string(udev_device, line);
567 udev_device->devnum = makedev(maj, min);
572 void udev_device_set_info_loaded(struct udev_device *device)
574 device->info_loaded = true;
577 struct udev_device *udev_device_new(struct udev *udev)
579 struct udev_device *udev_device;
580 struct udev_list_entry *list_entry;
585 udev_device = calloc(1, sizeof(struct udev_device));
586 if (udev_device == NULL)
588 udev_device->refcount = 1;
589 udev_device->udev = udev;
590 udev_list_init(udev, &udev_device->devlinks_list, true);
591 udev_list_init(udev, &udev_device->properties_list, true);
592 udev_list_init(udev, &udev_device->sysattr_value_list, true);
593 udev_list_init(udev, &udev_device->sysattr_list, false);
594 udev_list_init(udev, &udev_device->tags_list, true);
595 udev_device->watch_handle = -1;
596 /* copy global properties */
597 udev_list_entry_foreach(list_entry, udev_get_properties_list_entry(udev))
598 udev_device_add_property(udev_device,
599 udev_list_entry_get_name(list_entry),
600 udev_list_entry_get_value(list_entry));
601 dbg(udev_device->udev, "udev_device: %p created\n", udev_device);
606 * udev_device_new_from_syspath:
607 * @udev: udev library context
608 * @syspath: sys device path including sys directory
610 * Create new udev device, and fill in information from the sys
611 * device and the udev database entry. The syspath is the absolute
612 * path to the device, including the sys mount point.
614 * The initial refcount is 1, and needs to be decremented to
615 * release the resources of the udev device.
617 * Returns: a new udev device, or #NULL, if it does not exist
619 UDEV_EXPORT struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
623 char path[UTIL_PATH_SIZE];
626 struct udev_device *udev_device;
633 /* path starts in sys */
634 len = strlen(udev_get_sys_path(udev));
635 if (strncmp(syspath, udev_get_sys_path(udev), len) != 0) {
636 info(udev, "not in sys :%s\n", syspath);
640 /* path is not a root directory */
641 subdir = &syspath[len+1];
642 pos = strrchr(subdir, '/');
643 if (pos == NULL || pos[1] == '\0' || pos < &subdir[2]) {
644 dbg(udev, "not a subdir :%s\n", syspath);
648 /* resolve possible symlink to real path */
649 util_strscpy(path, sizeof(path), syspath);
650 util_resolve_sys_link(udev, path, sizeof(path));
652 if (strncmp(&path[len], "/devices/", 9) == 0) {
653 char file[UTIL_PATH_SIZE];
655 /* all "devices" require a "uevent" file */
656 util_strscpyl(file, sizeof(file), path, "/uevent", NULL);
657 if (stat(file, &statbuf) != 0) {
658 dbg(udev, "not a device: %s\n", syspath);
662 /* everything else just needs to be a directory */
663 if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) {
664 dbg(udev, "directory not found: %s\n", syspath);
669 udev_device = udev_device_new(udev);
670 if (udev_device == NULL)
673 udev_device_set_syspath(udev_device, path);
674 info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
680 * udev_device_new_from_devnum:
681 * @udev: udev library context
682 * @type: char or block device
683 * @devnum: device major/minor number
685 * Create new udev device, and fill in information from the sys
686 * device and the udev database entry. The device is looked-up
687 * by its major/minor number and type. Character and block device
688 * numbers are not unique across the two types.
690 * The initial refcount is 1, and needs to be decremented to
691 * release the resources of the udev device.
693 * Returns: a new udev device, or #NULL, if it does not exist
695 UDEV_EXPORT struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
697 char path[UTIL_PATH_SIZE];
698 const char *type_str;
702 else if (type == 'c')
707 /* use /sys/dev/{block,char}/<maj>:<min> link */
708 snprintf(path, sizeof(path), "%s/dev/%s/%u:%u",
709 udev_get_sys_path(udev), type_str, major(devnum), minor(devnum));
710 return udev_device_new_from_syspath(udev, path);
713 struct udev_device *udev_device_new_from_id_filename(struct udev *udev, char *id)
717 char subsys[UTIL_PATH_SIZE];
723 if (sscanf(id, "%c%i:%i", &type, &maj, &min) != 3)
725 return udev_device_new_from_devnum(udev, type, makedev(maj, min));
729 struct udev_device *dev;
732 ifindex = strtoul(&id[1], NULL, 10);
736 sk = socket(PF_INET, SOCK_DGRAM, 0);
739 memset(&ifr, 0x00, sizeof(struct ifreq));
740 ifr.ifr_ifindex = ifindex;
741 if (ioctl(sk, SIOCGIFNAME, &ifr) != 0) {
747 dev = udev_device_new_from_subsystem_sysname(udev, "net", ifr.ifr_name);
750 if (udev_device_get_ifindex(dev) == ifindex)
752 udev_device_unref(dev);
756 util_strscpy(subsys, sizeof(subsys), &id[1]);
757 sysname = strchr(subsys, ':');
761 sysname = &sysname[1];
762 return udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
769 * udev_device_new_from_subsystem_sysname:
770 * @udev: udev library context
771 * @subsystem: the subsystem of the device
772 * @sysname: the name of the device
774 * Create new udev device, and fill in information from the sys device
775 * and the udev database entry. The device is looked up by the subsystem
776 * and name string of the device, like "mem" / "zero", or "block" / "sda".
778 * The initial refcount is 1, and needs to be decremented to
779 * release the resources of the udev device.
781 * Returns: a new udev device, or #NULL, if it does not exist
783 UDEV_EXPORT struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
785 char path_full[UTIL_PATH_SIZE];
791 l = util_strpcpyl(&path, sizeof(path_full), udev_get_sys_path(udev), NULL);
793 if (strcmp(subsystem, "subsystem") == 0) {
794 util_strscpyl(path, l, "/subsystem/", sysname, NULL);
795 if (stat(path_full, &statbuf) == 0)
798 util_strscpyl(path, l, "/bus/", sysname, NULL);
799 if (stat(path_full, &statbuf) == 0)
802 util_strscpyl(path, l, "/class/", sysname, NULL);
803 if (stat(path_full, &statbuf) == 0)
808 if (strcmp(subsystem, "module") == 0) {
809 util_strscpyl(path, l, "/module/", sysname, NULL);
810 if (stat(path_full, &statbuf) == 0)
815 if (strcmp(subsystem, "drivers") == 0) {
816 char subsys[UTIL_NAME_SIZE];
819 util_strscpy(subsys, sizeof(subsys), sysname);
820 driver = strchr(subsys, ':');
821 if (driver != NULL) {
825 util_strscpyl(path, l, "/subsystem/", subsys, "/drivers/", driver, NULL);
826 if (stat(path_full, &statbuf) == 0)
829 util_strscpyl(path, l, "/bus/", subsys, "/drivers/", driver, NULL);
830 if (stat(path_full, &statbuf) == 0)
836 util_strscpyl(path, l, "/subsystem/", subsystem, "/devices/", sysname, NULL);
837 if (stat(path_full, &statbuf) == 0)
840 util_strscpyl(path, l, "/bus/", subsystem, "/devices/", sysname, NULL);
841 if (stat(path_full, &statbuf) == 0)
844 util_strscpyl(path, l, "/class/", subsystem, "/", sysname, NULL);
845 if (stat(path_full, &statbuf) == 0)
850 return udev_device_new_from_syspath(udev, path_full);
854 * udev_device_new_from_environment
855 * @udev: udev library context
857 * Create new udev device, and fill in information from the
858 * current process environment. This only works reliable if
859 * the process is called from a udev rule. It is usually used
860 * for tools executed from IMPORT= rules.
862 * The initial refcount is 1, and needs to be decremented to
863 * release the resources of the udev device.
865 * Returns: a new udev device, or #NULL, if it does not exist
867 UDEV_EXPORT struct udev_device *udev_device_new_from_environment(struct udev *udev)
870 struct udev_device *udev_device;
872 udev_device = udev_device_new(udev);
873 if (udev_device == NULL)
875 udev_device_set_info_loaded(udev_device);
877 for (i = 0; environ[i] != NULL; i++)
878 udev_device_add_property_from_string_parse(udev_device, environ[i]);
880 if (udev_device_add_property_from_string_parse_finish(udev_device) < 0) {
881 info(udev, "missing values, invalid device\n");
882 udev_device_unref(udev_device);
889 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
891 struct udev_device *udev_device_parent = NULL;
892 char path[UTIL_PATH_SIZE];
895 util_strscpy(path, sizeof(path), udev_device->syspath);
896 subdir = &path[strlen(udev_get_sys_path(udev_device->udev))+1];
900 pos = strrchr(subdir, '/');
901 if (pos == NULL || pos < &subdir[2])
904 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
905 if (udev_device_parent != NULL)
906 return udev_device_parent;
912 * udev_device_get_parent:
913 * @udev_device: the device to start searching from
915 * Find the next parent device, and fill in information from the sys
916 * device and the udev database entry.
918 * The returned the device is not referenced. It is attached to the
919 * child device, and will be cleaned up when the child device
922 * It is not necessarily just the upper level directory, empty or not
923 * recognized sys directories are ignored.
925 * It can be called as many times as needed, without caring about
928 * Returns: a new udev device, or #NULL, if it no parent exist.
930 UDEV_EXPORT struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
932 if (udev_device == NULL)
934 if (!udev_device->parent_set) {
935 udev_device->parent_set = true;
936 udev_device->parent_device = device_new_from_parent(udev_device);
938 if (udev_device->parent_device != NULL)
939 dbg(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
940 return udev_device->parent_device;
944 * udev_device_get_parent_with_subsystem_devtype:
945 * @udev_device: udev device to start searching from
946 * @subsystem: the subsystem of the device
947 * @devtype: the type (DEVTYPE) of the device
949 * Find the next parent device, with a matching subsystem and devtype
950 * value, and fill in information from the sys device and the udev
953 * If devtype is #NULL, only subsystem is checked, and any devtype will
956 * The returned the device is not referenced. It is attached to the
957 * child device, and will be cleaned up when the child device
960 * It can be called as many times as needed, without caring about
963 * Returns: a new udev device, or #NULL if no matching parent exists.
965 UDEV_EXPORT struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype)
967 struct udev_device *parent;
969 if (subsystem == NULL)
972 parent = udev_device_get_parent(udev_device);
973 while (parent != NULL) {
974 const char *parent_subsystem;
975 const char *parent_devtype;
977 parent_subsystem = udev_device_get_subsystem(parent);
978 if (parent_subsystem != NULL && strcmp(parent_subsystem, subsystem) == 0) {
981 parent_devtype = udev_device_get_devtype(parent);
982 if (parent_devtype != NULL && strcmp(parent_devtype, devtype) == 0)
985 parent = udev_device_get_parent(parent);
991 * udev_device_get_udev:
992 * @udev_device: udev device
994 * Retrieve the udev library context the device was created with.
996 * Returns: the udev library context
998 UDEV_EXPORT struct udev *udev_device_get_udev(struct udev_device *udev_device)
1000 if (udev_device == NULL)
1002 return udev_device->udev;
1007 * @udev_device: udev device
1009 * Take a reference of a udev device.
1011 * Returns: the passed udev device
1013 UDEV_EXPORT struct udev_device *udev_device_ref(struct udev_device *udev_device)
1015 if (udev_device == NULL)
1017 udev_device->refcount++;
1022 * udev_device_unref:
1023 * @udev_device: udev device
1025 * Drop a reference of a udev device. If the refcount reaches zero,
1026 * the resources of the device will be released.
1029 UDEV_EXPORT void udev_device_unref(struct udev_device *udev_device)
1031 if (udev_device == NULL)
1033 udev_device->refcount--;
1034 if (udev_device->refcount > 0)
1036 if (udev_device->parent_device != NULL)
1037 udev_device_unref(udev_device->parent_device);
1038 free(udev_device->syspath);
1039 free(udev_device->sysname);
1040 free(udev_device->devnode);
1041 free(udev_device->subsystem);
1042 free(udev_device->devtype);
1043 udev_list_cleanup(&udev_device->devlinks_list);
1044 udev_list_cleanup(&udev_device->properties_list);
1045 udev_list_cleanup(&udev_device->sysattr_value_list);
1046 udev_list_cleanup(&udev_device->sysattr_list);
1047 udev_list_cleanup(&udev_device->tags_list);
1048 free(udev_device->action);
1049 free(udev_device->driver);
1050 free(udev_device->devpath_old);
1051 free(udev_device->id_filename);
1052 free(udev_device->envp);
1053 free(udev_device->monitor_buf);
1054 dbg(udev_device->udev, "udev_device: %p released\n", udev_device);
1059 * udev_device_get_devpath:
1060 * @udev_device: udev device
1062 * Retrieve the kernel devpath value of the udev device. The path
1063 * does not contain the sys mount point, and starts with a '/'.
1065 * Returns: the devpath of the udev device
1067 UDEV_EXPORT const char *udev_device_get_devpath(struct udev_device *udev_device)
1069 if (udev_device == NULL)
1071 return udev_device->devpath;
1075 * udev_device_get_syspath:
1076 * @udev_device: udev device
1078 * Retrieve the sys path of the udev device. The path is an
1079 * absolute path and starts with the sys mount point.
1081 * Returns: the sys path of the udev device
1083 UDEV_EXPORT const char *udev_device_get_syspath(struct udev_device *udev_device)
1085 if (udev_device == NULL)
1087 return udev_device->syspath;
1091 * udev_device_get_sysname:
1092 * @udev_device: udev device
1094 * Returns: the sys name of the device device
1096 UDEV_EXPORT const char *udev_device_get_sysname(struct udev_device *udev_device)
1098 if (udev_device == NULL)
1100 return udev_device->sysname;
1104 * udev_device_get_sysnum:
1105 * @udev_device: udev device
1107 * Returns: the trailing number of of the device name
1109 UDEV_EXPORT const char *udev_device_get_sysnum(struct udev_device *udev_device)
1111 if (udev_device == NULL)
1113 return udev_device->sysnum;
1117 * udev_device_get_devnode:
1118 * @udev_device: udev device
1120 * Retrieve the device node file name belonging to the udev device.
1121 * The path is an absolute path, and starts with the device directory.
1123 * Returns: the device node file name of the udev device, or #NULL if no device node exists
1125 UDEV_EXPORT const char *udev_device_get_devnode(struct udev_device *udev_device)
1127 if (udev_device == NULL)
1129 if (udev_device->devnode != NULL)
1130 return udev_device->devnode;
1131 if (!udev_device->info_loaded)
1132 udev_device_read_uevent_file(udev_device);
1133 return udev_device->devnode;
1137 * udev_device_get_devlinks_list_entry:
1138 * @udev_device: udev device
1140 * Retrieve the list of device links pointing to the device file of
1141 * the udev device. The next list entry can be retrieved with
1142 * udev_list_entry_next(), which returns #NULL if no more entries exist.
1143 * The devlink path can be retrieved from the list entry by
1144 * udev_list_entry_get_name(). The path is an absolute path, and starts with
1145 * the device directory.
1147 * Returns: the first entry of the device node link list
1149 UDEV_EXPORT struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
1151 if (udev_device == NULL)
1153 if (!udev_device->info_loaded)
1154 udev_device_read_db(udev_device, NULL);
1155 return udev_list_get_entry(&udev_device->devlinks_list);
1158 void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
1160 udev_device->devlinks_uptodate = false;
1161 udev_list_cleanup(&udev_device->devlinks_list);
1165 * udev_device_get_properties_list_entry:
1166 * @udev_device: udev device
1168 * Retrieve the list of key/value device properties of the udev
1169 * device. The next list entry can be retrieved with udev_list_entry_next(),
1170 * which returns #NULL if no more entries exist. The property name
1171 * can be retrieved from the list entry by udev_list_get_name(),
1172 * the property value by udev_list_get_value().
1174 * Returns: the first entry of the property list
1176 UDEV_EXPORT struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
1178 if (udev_device == NULL)
1180 if (!udev_device->info_loaded) {
1181 udev_device_read_uevent_file(udev_device);
1182 udev_device_read_db(udev_device, NULL);
1184 if (!udev_device->devlinks_uptodate) {
1185 char symlinks[UTIL_PATH_SIZE];
1186 struct udev_list_entry *list_entry;
1188 udev_device->devlinks_uptodate = true;
1189 list_entry = udev_device_get_devlinks_list_entry(udev_device);
1190 if (list_entry != NULL) {
1195 l = util_strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL);
1196 udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
1197 l = util_strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL);
1198 udev_device_add_property(udev_device, "DEVLINKS", symlinks);
1201 if (!udev_device->tags_uptodate) {
1202 udev_device->tags_uptodate = true;
1203 if (udev_device_get_tags_list_entry(udev_device) != NULL) {
1204 char tags[UTIL_PATH_SIZE];
1205 struct udev_list_entry *list_entry;
1210 l = util_strpcpyl(&s, sizeof(tags), ":", NULL);
1211 udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
1212 l = util_strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL);
1213 udev_device_add_property(udev_device, "TAGS", tags);
1216 return udev_list_get_entry(&udev_device->properties_list);
1220 * udev_device_get_action:
1221 * @udev_device: udev device
1223 * This is only valid if the device was received through a monitor. Devices read from
1224 * sys do not have an action string. Usual actions are: add, remove, change, online,
1227 * Returns: the kernel action value, or #NULL if there is no action value available.
1229 UDEV_EXPORT const char *udev_device_get_action(struct udev_device *udev_device)
1231 if (udev_device == NULL)
1233 return udev_device->action;
1237 * udev_device_get_usec_since_initialized:
1238 * @udev_device: udev device
1240 * Return the number of microseconds passed since udev set up the
1241 * device for the first time.
1243 * This is only implemented for devices with need to store properties
1244 * in the udev database. All other devices return 0 here.
1246 * Returns: the number of microseconds since the device was first seen.
1248 UDEV_EXPORT unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device)
1250 unsigned long long now;
1252 if (udev_device == NULL)
1254 if (!udev_device->info_loaded)
1255 udev_device_read_db(udev_device, NULL);
1256 if (udev_device->usec_initialized == 0)
1261 return now - udev_device->usec_initialized;
1264 unsigned long long udev_device_get_usec_initialized(struct udev_device *udev_device)
1266 return udev_device->usec_initialized;
1269 void udev_device_set_usec_initialized(struct udev_device *udev_device, unsigned long long usec_initialized)
1273 udev_device->usec_initialized = usec_initialized;
1274 snprintf(num, sizeof(num), "%llu", usec_initialized);
1275 udev_device_add_property(udev_device, "USEC_INITIALIZED", num);
1279 * udev_device_get_sysattr_value:
1280 * @udev_device: udev device
1281 * @sysattr: attribute name
1283 * The retrieved value is cached in the device. Repeated calls will return the same
1284 * value and not open the attribute again.
1286 * Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value.
1288 UDEV_EXPORT const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr)
1290 struct udev_list_entry *list_entry;
1291 char path[UTIL_PATH_SIZE];
1293 struct stat statbuf;
1296 const char *val = NULL;
1298 if (udev_device == NULL)
1300 if (sysattr == NULL)
1303 /* look for possibly already cached result */
1304 list_entry = udev_list_get_entry(&udev_device->sysattr_value_list);
1305 list_entry = udev_list_entry_get_by_name(list_entry, sysattr);
1306 if (list_entry != NULL) {
1307 dbg(udev_device->udev, "got '%s' (%s) from cache\n",
1308 sysattr, udev_list_entry_get_value(list_entry));
1309 return udev_list_entry_get_value(list_entry);
1312 util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
1313 if (lstat(path, &statbuf) != 0) {
1314 dbg(udev_device->udev, "no attribute '%s', keep negative entry\n", path);
1315 udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, NULL);
1319 if (S_ISLNK(statbuf.st_mode)) {
1320 struct udev_device *dev;
1323 * Some core links return only the last element of the target path,
1324 * these are just values, the paths should not be exposed.
1326 if (strcmp(sysattr, "driver") == 0 ||
1327 strcmp(sysattr, "subsystem") == 0 ||
1328 strcmp(sysattr, "module") == 0) {
1329 if (util_get_sys_core_link_value(udev_device->udev, sysattr,
1330 udev_device->syspath, value, sizeof(value)) < 0)
1332 dbg(udev_device->udev, "cache '%s' with link value '%s'\n", sysattr, value);
1333 list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1334 val = udev_list_entry_get_value(list_entry);
1338 /* resolve link to a device and return its syspath */
1339 util_strscpyl(path, sizeof(path), udev_device->syspath, "/", sysattr, NULL);
1340 dev = udev_device_new_from_syspath(udev_device->udev, path);
1342 list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr,
1343 udev_device_get_syspath(dev));
1344 val = udev_list_entry_get_value(list_entry);
1345 udev_device_unref(dev);
1351 /* skip directories */
1352 if (S_ISDIR(statbuf.st_mode))
1355 /* skip non-readable files */
1356 if ((statbuf.st_mode & S_IRUSR) == 0)
1359 /* read attribute value */
1360 fd = open(path, O_RDONLY|O_CLOEXEC);
1362 dbg(udev_device->udev, "attribute '%s' can not be opened\n", path);
1365 size = read(fd, value, sizeof(value));
1369 if (size == sizeof(value))
1372 /* got a valid value, store it in cache and return it */
1374 util_remove_trailing_chars(value, '\n');
1375 dbg(udev_device->udev, "'%s' has attribute value '%s'\n", path, value);
1376 list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1377 val = udev_list_entry_get_value(list_entry);
1382 static int udev_device_sysattr_list_read(struct udev_device *udev_device)
1384 struct dirent *dent;
1388 if (udev_device == NULL)
1390 if (udev_device->sysattr_list_read)
1393 dir = opendir(udev_device_get_syspath(udev_device));
1395 dbg(udev_device->udev, "sysfs dir '%s' can not be opened\n",
1396 udev_device_get_syspath(udev_device));
1400 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
1401 char path[UTIL_PATH_SIZE];
1402 struct stat statbuf;
1404 /* only handle symlinks and regular files */
1405 if (dent->d_type != DT_LNK && dent->d_type != DT_REG)
1408 util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL);
1409 if (lstat(path, &statbuf) != 0)
1411 if ((statbuf.st_mode & S_IRUSR) == 0)
1414 udev_list_entry_add(&udev_device->sysattr_list, dent->d_name, NULL);
1419 dbg(udev_device->udev, "found %d sysattrs for '%s'\n", num, udev_device_get_syspath(udev_device));
1420 udev_device->sysattr_list_read = true;
1426 * udev_device_get_sysattr_list_entry:
1427 * @udev_device: udev device
1429 * Retrieve the list of available sysattrs, with value being empty;
1430 * This just return all available sysfs attributes for a particular
1431 * device without reading their values.
1433 * Returns: the first entry of the property list
1435 UDEV_EXPORT struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device)
1437 if (!udev_device->sysattr_list_read) {
1439 ret = udev_device_sysattr_list_read(udev_device);
1444 return udev_list_get_entry(&udev_device->sysattr_list);
1447 int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath)
1452 free(udev_device->syspath);
1453 udev_device->syspath = strdup(syspath);
1454 if (udev_device->syspath == NULL)
1456 udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))];
1457 udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath);
1459 pos = strrchr(udev_device->syspath, '/');
1462 udev_device->sysname = strdup(&pos[1]);
1463 if (udev_device->sysname == NULL)
1466 /* some devices have '!' in their name, change that to '/' */
1468 while (udev_device->sysname[len] != '\0') {
1469 if (udev_device->sysname[len] == '!')
1470 udev_device->sysname[len] = '/';
1474 /* trailing number */
1475 while (len > 0 && isdigit(udev_device->sysname[--len]))
1476 udev_device->sysnum = &udev_device->sysname[len];
1478 /* sysname is completely numeric */
1480 udev_device->sysnum = NULL;
1485 int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
1487 free(udev_device->devnode);
1488 if (devnode[0] != '/') {
1489 if (asprintf(&udev_device->devnode, "%s/%s", udev_get_dev_path(udev_device->udev), devnode) < 0)
1490 udev_device->devnode = NULL;
1492 udev_device->devnode = strdup(devnode);
1494 if (udev_device->devnode == NULL)
1496 udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode);
1500 int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink, int unique)
1502 struct udev_list_entry *list_entry;
1504 udev_device->devlinks_uptodate = false;
1505 list_entry = udev_list_entry_add(&udev_device->devlinks_list, devlink, NULL);
1506 if (list_entry == NULL)
1509 udev_list_entry_set_num(list_entry, true);
1513 const char *udev_device_get_id_filename(struct udev_device *udev_device)
1515 if (udev_device->id_filename == NULL) {
1516 if (udev_device_get_subsystem(udev_device) == NULL)
1519 if (major(udev_device_get_devnum(udev_device)) > 0) {
1520 /* use dev_t -- b259:131072, c254:0 */
1521 if (asprintf(&udev_device->id_filename, "%c%u:%u",
1522 strcmp(udev_device_get_subsystem(udev_device), "block") == 0 ? 'b' : 'c',
1523 major(udev_device_get_devnum(udev_device)),
1524 minor(udev_device_get_devnum(udev_device))) < 0)
1525 udev_device->id_filename = NULL;
1526 } else if (udev_device_get_ifindex(udev_device) > 0) {
1527 /* use netdev ifindex -- n3 */
1528 if (asprintf(&udev_device->id_filename, "n%u", udev_device_get_ifindex(udev_device)) < 0)
1529 udev_device->id_filename = NULL;
1532 * use $subsys:$syname -- pci:0000:00:1f.2
1533 * sysname() has '!' translated, get it from devpath
1535 const char *sysname;
1536 sysname = strrchr(udev_device->devpath, '/');
1537 if (sysname == NULL)
1539 sysname = &sysname[1];
1540 if (asprintf(&udev_device->id_filename, "+%s:%s", udev_device_get_subsystem(udev_device), sysname) < 0)
1541 udev_device->id_filename = NULL;
1544 return udev_device->id_filename;
1548 * udev_device_get_is_initialized:
1549 * @udev_device: udev device
1551 * Check if udev has already handled the device and has set up
1552 * device node permissions and context, or has renamed a network
1555 * This is only implemented for devices with a device node
1556 * or network interfaces. All other devices return 1 here.
1558 * Returns: 1 if the device is set up. 0 otherwise.
1560 UDEV_EXPORT int udev_device_get_is_initialized(struct udev_device *udev_device)
1562 if (!udev_device->info_loaded)
1563 udev_device_read_db(udev_device, NULL);
1564 return udev_device->is_initialized;
1567 void udev_device_set_is_initialized(struct udev_device *udev_device)
1569 udev_device->is_initialized = true;
1572 int udev_device_add_tag(struct udev_device *udev_device, const char *tag)
1574 if (strchr(tag, ':') != NULL || strchr(tag, ' ') != NULL)
1576 udev_device->tags_uptodate = false;
1577 if (udev_list_entry_add(&udev_device->tags_list, tag, NULL) != NULL)
1582 void udev_device_cleanup_tags_list(struct udev_device *udev_device)
1584 udev_device->tags_uptodate = false;
1585 udev_list_cleanup(&udev_device->tags_list);
1589 * udev_device_get_tags_list_entry:
1590 * @udev_device: udev device
1592 * Retrieve the list of tags attached to the udev device. The next
1593 * list entry can be retrieved with udev_list_entry_next(),
1594 * which returns #NULL if no more entries exist. The tag string
1595 * can be retrieved from the list entry by udev_list_get_name().
1597 * Returns: the first entry of the tag list
1599 UDEV_EXPORT struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device)
1601 if (udev_device == NULL)
1603 if (!udev_device->info_loaded)
1604 udev_device_read_db(udev_device, NULL);
1605 return udev_list_get_entry(&udev_device->tags_list);
1608 UDEV_EXPORT int udev_device_has_tag(struct udev_device *udev_device, const char *tag)
1610 struct udev_list_entry *list_entry;
1612 if (udev_device == NULL)
1614 if (!udev_device->info_loaded)
1615 udev_device_read_db(udev_device, NULL);
1616 list_entry = udev_device_get_tags_list_entry(udev_device);
1617 if (udev_list_entry_get_by_name(list_entry, tag) != NULL)
1622 #define ENVP_SIZE 128
1623 #define MONITOR_BUF_SIZE 4096
1624 static int update_envp_monitor_buf(struct udev_device *udev_device)
1626 struct udev_list_entry *list_entry;
1631 /* monitor buffer of property strings */
1632 free(udev_device->monitor_buf);
1633 udev_device->monitor_buf_len = 0;
1634 udev_device->monitor_buf = malloc(MONITOR_BUF_SIZE);
1635 if (udev_device->monitor_buf == NULL)
1638 /* envp array, strings will point into monitor buffer */
1639 if (udev_device->envp == NULL)
1640 udev_device->envp = malloc(sizeof(char *) * ENVP_SIZE);
1641 if (udev_device->envp == NULL)
1645 s = udev_device->monitor_buf;
1646 l = MONITOR_BUF_SIZE;
1647 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
1650 key = udev_list_entry_get_name(list_entry);
1651 /* skip private variables */
1655 /* add string to envp array */
1656 udev_device->envp[i++] = s;
1657 if (i+1 >= ENVP_SIZE)
1660 /* add property string to monitor buffer */
1661 l = util_strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
1664 /* advance past the trailing '\0' that util_strpcpyl() guarantees */
1668 udev_device->envp[i] = NULL;
1669 udev_device->monitor_buf_len = s - udev_device->monitor_buf;
1670 udev_device->envp_uptodate = true;
1671 dbg(udev_device->udev, "filled envp/monitor buffer, %u properties, %zu bytes\n",
1672 i, udev_device->monitor_buf_len);
1676 char **udev_device_get_properties_envp(struct udev_device *udev_device)
1678 if (!udev_device->envp_uptodate)
1679 if (update_envp_monitor_buf(udev_device) != 0)
1681 return udev_device->envp;
1684 ssize_t udev_device_get_properties_monitor_buf(struct udev_device *udev_device, const char **buf)
1686 if (!udev_device->envp_uptodate)
1687 if (update_envp_monitor_buf(udev_device) != 0)
1689 *buf = udev_device->monitor_buf;
1690 return udev_device->monitor_buf_len;
1693 int udev_device_set_action(struct udev_device *udev_device, const char *action)
1695 free(udev_device->action);
1696 udev_device->action = strdup(action);
1697 if (udev_device->action == NULL)
1699 udev_device_add_property(udev_device, "ACTION", udev_device->action);
1703 int udev_device_get_devlink_priority(struct udev_device *udev_device)
1705 if (!udev_device->info_loaded)
1706 udev_device_read_db(udev_device, NULL);
1707 return udev_device->devlink_priority;
1710 int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio)
1712 udev_device->devlink_priority = prio;
1716 int udev_device_get_watch_handle(struct udev_device *udev_device)
1718 if (!udev_device->info_loaded)
1719 udev_device_read_db(udev_device, NULL);
1720 return udev_device->watch_handle;
1723 int udev_device_set_watch_handle(struct udev_device *udev_device, int handle)
1725 udev_device->watch_handle = handle;
1729 bool udev_device_get_db_persist(struct udev_device *udev_device)
1731 return udev_device->db_persist;
1734 void udev_device_set_db_persist(struct udev_device *udev_device)
1736 udev_device->db_persist = true;