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 _public_ 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 * Get the device major/minor number.
141 * Returns: the dev_t number.
143 _public_ dev_t udev_device_get_devnum(struct udev_device *udev_device)
145 if (udev_device == NULL)
146 return makedev(0, 0);
147 if (!udev_device->info_loaded)
148 udev_device_read_uevent_file(udev_device);
149 return udev_device->devnum;
152 static int udev_device_set_devnum(struct udev_device *udev_device, dev_t devnum)
156 udev_device->devnum = devnum;
158 snprintf(num, sizeof(num), "%u", major(devnum));
159 udev_device_add_property(udev_device, "MAJOR", num);
160 snprintf(num, sizeof(num), "%u", minor(devnum));
161 udev_device_add_property(udev_device, "MINOR", num);
165 const char *udev_device_get_devpath_old(struct udev_device *udev_device)
167 return udev_device->devpath_old;
170 static int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
174 free(udev_device->devpath_old);
175 udev_device->devpath_old = strdup(devpath_old);
176 if (udev_device->devpath_old == NULL)
178 udev_device_add_property(udev_device, "DEVPATH_OLD", udev_device->devpath_old);
180 pos = strrchr(udev_device->devpath_old, '/');
187 * udev_device_get_driver:
188 * @udev_device: udev device
190 * Get the kernel driver name.
192 * Returns: the driver name string, or #NULL if there is no driver attached.
194 _public_ const char *udev_device_get_driver(struct udev_device *udev_device)
196 char driver[UTIL_NAME_SIZE];
198 if (udev_device == NULL)
200 if (!udev_device->driver_set) {
201 udev_device->driver_set = true;
202 if (util_get_sys_core_link_value(udev_device->udev, "driver", udev_device->syspath, driver, sizeof(driver)) > 0)
203 udev_device->driver = strdup(driver);
205 return udev_device->driver;
208 static int udev_device_set_driver(struct udev_device *udev_device, const char *driver)
210 free(udev_device->driver);
211 udev_device->driver = strdup(driver);
212 if (udev_device->driver == NULL)
214 udev_device->driver_set = true;
215 udev_device_add_property(udev_device, "DRIVER", udev_device->driver);
220 * udev_device_get_devtype:
221 * @udev_device: udev device
223 * Retrieve the devtype string of the udev device.
225 * Returns: the devtype name of the udev device, or #NULL if it can not be determined
227 _public_ const char *udev_device_get_devtype(struct udev_device *udev_device)
229 if (udev_device == NULL)
231 if (!udev_device->devtype_set) {
232 udev_device->devtype_set = true;
233 udev_device_read_uevent_file(udev_device);
235 return udev_device->devtype;
238 static int udev_device_set_devtype(struct udev_device *udev_device, const char *devtype)
240 free(udev_device->devtype);
241 udev_device->devtype = strdup(devtype);
242 if (udev_device->devtype == NULL)
244 udev_device->devtype_set = true;
245 udev_device_add_property(udev_device, "DEVTYPE", udev_device->devtype);
249 static int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
251 free(udev_device->subsystem);
252 udev_device->subsystem = strdup(subsystem);
253 if (udev_device->subsystem == NULL)
255 udev_device->subsystem_set = true;
256 udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem);
261 * udev_device_get_subsystem:
262 * @udev_device: udev device
264 * Retrieve the subsystem string of the udev device. The string does not
267 * Returns: the subsystem name of the udev device, or #NULL if it can not be determined
269 _public_ const char *udev_device_get_subsystem(struct udev_device *udev_device)
271 char subsystem[UTIL_NAME_SIZE];
273 if (udev_device == NULL)
275 if (!udev_device->subsystem_set) {
276 udev_device->subsystem_set = true;
277 /* read "subsystem" link */
278 if (util_get_sys_core_link_value(udev_device->udev, "subsystem", udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
279 udev_device_set_subsystem(udev_device, subsystem);
280 return udev_device->subsystem;
283 if (startswith(udev_device->devpath, "/module/")) {
284 udev_device_set_subsystem(udev_device, "module");
285 return udev_device->subsystem;
287 if (strstr(udev_device->devpath, "/drivers/") != NULL) {
288 udev_device_set_subsystem(udev_device, "drivers");
289 return udev_device->subsystem;
291 if (startswith(udev_device->devpath, "/subsystem/") ||
292 startswith(udev_device->devpath, "/class/") ||
293 startswith(udev_device->devpath, "/bus/")) {
294 udev_device_set_subsystem(udev_device, "subsystem");
295 return udev_device->subsystem;
298 return udev_device->subsystem;
301 mode_t udev_device_get_devnode_mode(struct udev_device *udev_device)
303 if (!udev_device->info_loaded)
304 udev_device_read_uevent_file(udev_device);
305 return udev_device->devnode_mode;
308 static int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t mode)
312 udev_device->devnode_mode = mode;
313 snprintf(num, sizeof(num), "%#o", mode);
314 udev_device_add_property(udev_device, "DEVMODE", num);
318 struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value)
320 udev_device->envp_uptodate = false;
322 struct udev_list_entry *list_entry;
324 list_entry = udev_device_get_properties_list_entry(udev_device);
325 list_entry = udev_list_entry_get_by_name(list_entry, key);
326 if (list_entry != NULL)
327 udev_list_entry_delete(list_entry);
330 return udev_list_entry_add(&udev_device->properties_list, key, value);
333 static struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property)
335 char name[UTIL_LINE_SIZE];
338 util_strscpy(name, sizeof(name), property);
339 val = strchr(name, '=');
346 return udev_device_add_property(udev_device, name, val);
350 * parse property string, and if needed, update internal values accordingly
352 * udev_device_add_property_from_string_parse_finish() needs to be
353 * called after adding properties, and its return value checked
355 * udev_device_set_info_loaded() needs to be set, to avoid trying
356 * to use a device without a DEVPATH set
358 void udev_device_add_property_from_string_parse(struct udev_device *udev_device, const char *property)
360 if (startswith(property, "DEVPATH=")) {
361 char path[UTIL_PATH_SIZE];
363 util_strscpyl(path, sizeof(path), "/sys", &property[8], NULL);
364 udev_device_set_syspath(udev_device, path);
365 } else if (startswith(property, "SUBSYSTEM=")) {
366 udev_device_set_subsystem(udev_device, &property[10]);
367 } else if (startswith(property, "DEVTYPE=")) {
368 udev_device_set_devtype(udev_device, &property[8]);
369 } else if (startswith(property, "DEVNAME=")) {
370 udev_device_set_devnode(udev_device, &property[8]);
371 } else if (startswith(property, "DEVLINKS=")) {
372 char devlinks[UTIL_PATH_SIZE];
376 util_strscpy(devlinks, sizeof(devlinks), &property[9]);
378 next = strchr(slink, ' ');
379 while (next != NULL) {
381 udev_device_add_devlink(udev_device, slink, 0);
383 next = strchr(slink, ' ');
385 if (slink[0] != '\0')
386 udev_device_add_devlink(udev_device, slink, 0);
387 } else if (startswith(property, "TAGS=")) {
388 char tags[UTIL_PATH_SIZE];
391 util_strscpy(tags, sizeof(tags), &property[5]);
392 next = strchr(tags, ':');
395 while (next[0] != '\0') {
399 next = strchr(tag, ':');
404 udev_device_add_tag(udev_device, tag);
407 } else if (startswith(property, "USEC_INITIALIZED=")) {
408 udev_device_set_usec_initialized(udev_device, strtoull(&property[19], NULL, 10));
409 } else if (startswith(property, "DRIVER=")) {
410 udev_device_set_driver(udev_device, &property[7]);
411 } else if (startswith(property, "ACTION=")) {
412 udev_device_set_action(udev_device, &property[7]);
413 } else if (startswith(property, "MAJOR=")) {
414 udev_device->maj = strtoull(&property[6], NULL, 10);
415 } else if (startswith(property, "MINOR=")) {
416 udev_device->min = strtoull(&property[6], NULL, 10);
417 } else if (startswith(property, "DEVPATH_OLD=")) {
418 udev_device_set_devpath_old(udev_device, &property[12]);
419 } else if (startswith(property, "SEQNUM=")) {
420 udev_device_set_seqnum(udev_device, strtoull(&property[7], NULL, 10));
421 } else if (startswith(property, "IFINDEX=")) {
422 udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10));
423 } else if (startswith(property, "DEVMODE=")) {
424 udev_device_set_devnode_mode(udev_device, strtoul(&property[8], NULL, 8));
426 udev_device_add_property_from_string(udev_device, property);
430 int udev_device_add_property_from_string_parse_finish(struct udev_device *udev_device)
432 if (udev_device->maj > 0)
433 udev_device_set_devnum(udev_device, makedev(udev_device->maj, udev_device->min));
434 udev_device->maj = 0;
435 udev_device->min = 0;
437 if (udev_device->devpath == NULL || udev_device->subsystem == NULL)
443 * udev_device_get_property_value:
444 * @udev_device: udev device
445 * @key: property name
447 * Get the value of a given property.
449 * Returns: the property string, or #NULL if there is no such property.
451 _public_ const char *udev_device_get_property_value(struct udev_device *udev_device, const char *key)
453 struct udev_list_entry *list_entry;
455 if (udev_device == NULL)
460 list_entry = udev_device_get_properties_list_entry(udev_device);
461 list_entry = udev_list_entry_get_by_name(list_entry, key);
462 return udev_list_entry_get_value(list_entry);
465 int udev_device_read_db(struct udev_device *udev_device, const char *dbfile)
467 char filename[UTIL_PATH_SIZE];
468 char line[UTIL_LINE_SIZE];
471 /* providing a database file will always force-load it */
472 if (dbfile == NULL) {
475 if (udev_device->db_loaded)
477 udev_device->db_loaded = true;
479 id = udev_device_get_id_filename(udev_device);
482 util_strscpyl(filename, sizeof(filename), "/run/udev/data/", id, NULL);
486 f = fopen(dbfile, "re");
488 udev_dbg(udev_device->udev, "no db file to read %s: %m\n", dbfile);
491 udev_device->is_initialized = true;
493 while (fgets(line, sizeof(line), f)) {
496 struct udev_list_entry *entry;
505 util_strscpyl(filename, sizeof(filename), "/dev/", val, NULL);
506 udev_device_add_devlink(udev_device, filename, 0);
509 udev_device_set_devlink_priority(udev_device, atoi(val));
512 entry = udev_device_add_property_from_string(udev_device, val);
513 udev_list_entry_set_num(entry, true);
516 udev_device_add_tag(udev_device, val);
519 udev_device_set_watch_handle(udev_device, atoi(val));
522 udev_device_set_usec_initialized(udev_device, strtoull(val, NULL, 10));
528 udev_dbg(udev_device->udev, "device %p filled with db file data\n", udev_device);
532 int udev_device_read_uevent_file(struct udev_device *udev_device)
534 char filename[UTIL_PATH_SIZE];
536 char line[UTIL_LINE_SIZE];
540 if (udev_device->uevent_loaded)
543 util_strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL);
544 f = fopen(filename, "re");
547 udev_device->uevent_loaded = true;
549 while (fgets(line, sizeof(line), f)) {
552 pos = strchr(line, '\n');
557 if (startswith(line, "DEVTYPE=")) {
558 udev_device_set_devtype(udev_device, &line[8]);
561 if (startswith(line, "IFINDEX=")) {
562 udev_device_set_ifindex(udev_device, strtoull(&line[8], NULL, 10));
565 if (startswith(line, "DEVNAME=")) {
566 udev_device_set_devnode(udev_device, &line[8]);
570 if (startswith(line, "MAJOR="))
571 maj = strtoull(&line[6], NULL, 10);
572 else if (startswith(line, "MINOR="))
573 min = strtoull(&line[6], NULL, 10);
574 else if (startswith(line, "DEVMODE="))
575 udev_device->devnode_mode = strtoul(&line[8], NULL, 8);
577 udev_device_add_property_from_string(udev_device, line);
580 udev_device->devnum = makedev(maj, min);
585 void udev_device_set_info_loaded(struct udev_device *device)
587 device->info_loaded = true;
590 struct udev_device *udev_device_new(struct udev *udev)
592 struct udev_device *udev_device;
593 struct udev_list_entry *list_entry;
598 udev_device = calloc(1, sizeof(struct udev_device));
599 if (udev_device == NULL)
601 udev_device->refcount = 1;
602 udev_device->udev = udev;
603 udev_list_init(udev, &udev_device->devlinks_list, true);
604 udev_list_init(udev, &udev_device->properties_list, true);
605 udev_list_init(udev, &udev_device->sysattr_value_list, true);
606 udev_list_init(udev, &udev_device->sysattr_list, false);
607 udev_list_init(udev, &udev_device->tags_list, true);
608 udev_device->watch_handle = -1;
609 /* copy global properties */
610 udev_list_entry_foreach(list_entry, udev_get_properties_list_entry(udev))
611 udev_device_add_property(udev_device,
612 udev_list_entry_get_name(list_entry),
613 udev_list_entry_get_value(list_entry));
618 * udev_device_new_from_syspath:
619 * @udev: udev library context
620 * @syspath: sys device path including sys directory
622 * Create new udev device, and fill in information from the sys
623 * device and the udev database entry. The syspath is the absolute
624 * path to the device, including the sys mount point.
626 * The initial refcount is 1, and needs to be decremented to
627 * release the resources of the udev device.
629 * Returns: a new udev device, or #NULL, if it does not exist
631 _public_ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
634 char path[UTIL_PATH_SIZE];
637 struct udev_device *udev_device;
644 /* path starts in sys */
645 if (!startswith(syspath, "/sys")) {
646 udev_dbg(udev, "not in sys :%s\n", syspath);
650 /* path is not a root directory */
651 subdir = syspath + strlen("/sys");
652 pos = strrchr(subdir, '/');
653 if (pos == NULL || pos[1] == '\0' || pos < &subdir[2])
656 /* resolve possible symlink to real path */
657 util_strscpy(path, sizeof(path), syspath);
658 util_resolve_sys_link(udev, path, sizeof(path));
660 if (startswith(path + strlen("/sys"), "/devices/")) {
661 char file[UTIL_PATH_SIZE];
663 /* all "devices" require a "uevent" file */
664 util_strscpyl(file, sizeof(file), path, "/uevent", NULL);
665 if (stat(file, &statbuf) != 0)
668 /* everything else just needs to be a directory */
669 if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode))
673 udev_device = udev_device_new(udev);
674 if (udev_device == NULL)
677 udev_device_set_syspath(udev_device, path);
678 udev_dbg(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
684 * udev_device_new_from_devnum:
685 * @udev: udev library context
686 * @type: char or block device
687 * @devnum: device major/minor number
689 * Create new udev device, and fill in information from the sys
690 * device and the udev database entry. The device is looked-up
691 * by its major/minor number and type. Character and block device
692 * numbers are not unique across the two types.
694 * The initial refcount is 1, and needs to be decremented to
695 * release the resources of the udev device.
697 * Returns: a new udev device, or #NULL, if it does not exist
699 _public_ struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
701 char path[UTIL_PATH_SIZE];
702 const char *type_str;
706 else if (type == 'c')
711 /* use /sys/dev/{block,char}/<maj>:<min> link */
712 snprintf(path, sizeof(path), "/sys/dev/%s/%u:%u",
713 type_str, major(devnum), minor(devnum));
714 return udev_device_new_from_syspath(udev, path);
718 * udev_device_new_from_device_id:
719 * @udev: udev library context
720 * @id: text string identifying a kernel device
722 * Create new udev device, and fill in information from the sys
723 * device and the udev database entry. The device is looked-up
724 * by a special string:
725 * b8:2 - block device major:minor
726 * c128:1 - char device major:minor
727 * n3 - network device ifindex
728 * +sound:card29 - kernel driver core subsystem:device name
730 * The initial refcount is 1, and needs to be decremented to
731 * release the resources of the udev device.
733 * Returns: a new udev device, or #NULL, if it does not exist
735 _public_ struct udev_device *udev_device_new_from_device_id(struct udev *udev, char *id)
739 char subsys[UTIL_PATH_SIZE];
745 if (sscanf(id, "%c%i:%i", &type, &maj, &min) != 3)
747 return udev_device_new_from_devnum(udev, type, makedev(maj, min));
751 struct udev_device *dev;
754 ifindex = strtoul(&id[1], NULL, 10);
758 sk = socket(PF_INET, SOCK_DGRAM, 0);
761 memset(&ifr, 0x00, sizeof(struct ifreq));
762 ifr.ifr_ifindex = ifindex;
763 if (ioctl(sk, SIOCGIFNAME, &ifr) != 0) {
769 dev = udev_device_new_from_subsystem_sysname(udev, "net", ifr.ifr_name);
772 if (udev_device_get_ifindex(dev) == ifindex)
774 udev_device_unref(dev);
778 util_strscpy(subsys, sizeof(subsys), &id[1]);
779 sysname = strchr(subsys, ':');
783 sysname = &sysname[1];
784 return udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
791 * udev_device_new_from_subsystem_sysname:
792 * @udev: udev library context
793 * @subsystem: the subsystem of the device
794 * @sysname: the name of the device
796 * Create new udev device, and fill in information from the sys device
797 * and the udev database entry. The device is looked up by the subsystem
798 * and name string of the device, like "mem" / "zero", or "block" / "sda".
800 * The initial refcount is 1, and needs to be decremented to
801 * release the resources of the udev device.
803 * Returns: a new udev device, or #NULL, if it does not exist
805 _public_ struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
807 char path[UTIL_PATH_SIZE];
810 if (streq(subsystem, "subsystem")) {
811 util_strscpyl(path, sizeof(path), "/sys/subsystem/", sysname, NULL);
812 if (stat(path, &statbuf) == 0)
815 util_strscpyl(path, sizeof(path), "/sys/bus/", sysname, NULL);
816 if (stat(path, &statbuf) == 0)
819 util_strscpyl(path, sizeof(path), "/sys/class/", sysname, NULL);
820 if (stat(path, &statbuf) == 0)
825 if (streq(subsystem, "module")) {
826 util_strscpyl(path, sizeof(path), "/sys/module/", sysname, NULL);
827 if (stat(path, &statbuf) == 0)
832 if (streq(subsystem, "drivers")) {
833 char subsys[UTIL_NAME_SIZE];
836 util_strscpy(subsys, sizeof(subsys), sysname);
837 driver = strchr(subsys, ':');
838 if (driver != NULL) {
842 util_strscpyl(path, sizeof(path), "/sys/subsystem/", subsys, "/drivers/", driver, NULL);
843 if (stat(path, &statbuf) == 0)
846 util_strscpyl(path, sizeof(path), "/sys/bus/", subsys, "/drivers/", driver, NULL);
847 if (stat(path, &statbuf) == 0)
853 util_strscpyl(path, sizeof(path), "/sys/subsystem/", subsystem, "/devices/", sysname, NULL);
854 if (stat(path, &statbuf) == 0)
857 util_strscpyl(path, sizeof(path), "/sys/bus/", subsystem, "/devices/", sysname, NULL);
858 if (stat(path, &statbuf) == 0)
861 util_strscpyl(path, sizeof(path), "/sys/class/", subsystem, "/", sysname, NULL);
862 if (stat(path, &statbuf) == 0)
867 return udev_device_new_from_syspath(udev, path);
871 * udev_device_new_from_environment
872 * @udev: udev library context
874 * Create new udev device, and fill in information from the
875 * current process environment. This only works reliable if
876 * the process is called from a udev rule. It is usually used
877 * for tools executed from IMPORT= rules.
879 * The initial refcount is 1, and needs to be decremented to
880 * release the resources of the udev device.
882 * Returns: a new udev device, or #NULL, if it does not exist
884 _public_ struct udev_device *udev_device_new_from_environment(struct udev *udev)
887 struct udev_device *udev_device;
889 udev_device = udev_device_new(udev);
890 if (udev_device == NULL)
892 udev_device_set_info_loaded(udev_device);
894 for (i = 0; environ[i] != NULL; i++)
895 udev_device_add_property_from_string_parse(udev_device, environ[i]);
897 if (udev_device_add_property_from_string_parse_finish(udev_device) < 0) {
898 udev_dbg(udev, "missing values, invalid device\n");
899 udev_device_unref(udev_device);
906 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
908 struct udev_device *udev_device_parent = NULL;
909 char path[UTIL_PATH_SIZE];
912 util_strscpy(path, sizeof(path), udev_device->syspath);
913 subdir = path + strlen("/sys/");
917 pos = strrchr(subdir, '/');
918 if (pos == NULL || pos < &subdir[2])
921 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
922 if (udev_device_parent != NULL)
923 return udev_device_parent;
929 * udev_device_get_parent:
930 * @udev_device: the device to start searching from
932 * Find the next parent device, and fill in information from the sys
933 * device and the udev database entry.
935 * The returned the device is not referenced. It is attached to the
936 * child device, and will be cleaned up when the child device
939 * It is not necessarily just the upper level directory, empty or not
940 * recognized sys directories are ignored.
942 * It can be called as many times as needed, without caring about
945 * Returns: a new udev device, or #NULL, if it no parent exist.
947 _public_ struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
949 if (udev_device == NULL)
951 if (!udev_device->parent_set) {
952 udev_device->parent_set = true;
953 udev_device->parent_device = device_new_from_parent(udev_device);
955 return udev_device->parent_device;
959 * udev_device_get_parent_with_subsystem_devtype:
960 * @udev_device: udev device to start searching from
961 * @subsystem: the subsystem of the device
962 * @devtype: the type (DEVTYPE) of the device
964 * Find the next parent device, with a matching subsystem and devtype
965 * value, and fill in information from the sys device and the udev
968 * If devtype is #NULL, only subsystem is checked, and any devtype will
971 * The returned the device is not referenced. It is attached to the
972 * child device, and will be cleaned up when the child device
975 * It can be called as many times as needed, without caring about
978 * Returns: a new udev device, or #NULL if no matching parent exists.
980 _public_ struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype)
982 struct udev_device *parent;
984 if (subsystem == NULL)
987 parent = udev_device_get_parent(udev_device);
988 while (parent != NULL) {
989 const char *parent_subsystem;
990 const char *parent_devtype;
992 parent_subsystem = udev_device_get_subsystem(parent);
993 if (parent_subsystem != NULL && streq(parent_subsystem, subsystem)) {
996 parent_devtype = udev_device_get_devtype(parent);
997 if (parent_devtype != NULL && streq(parent_devtype, devtype))
1000 parent = udev_device_get_parent(parent);
1006 * udev_device_get_udev:
1007 * @udev_device: udev device
1009 * Retrieve the udev library context the device was created with.
1011 * Returns: the udev library context
1013 _public_ struct udev *udev_device_get_udev(struct udev_device *udev_device)
1015 if (udev_device == NULL)
1017 return udev_device->udev;
1022 * @udev_device: udev device
1024 * Take a reference of a udev device.
1026 * Returns: the passed udev device
1028 _public_ struct udev_device *udev_device_ref(struct udev_device *udev_device)
1030 if (udev_device == NULL)
1032 udev_device->refcount++;
1037 * udev_device_unref:
1038 * @udev_device: udev device
1040 * Drop a reference of a udev device. If the refcount reaches zero,
1041 * the resources of the device will be released.
1043 * Returns: the passed udev device if it has still an active reference, or #NULL otherwise.
1045 _public_ struct udev_device *udev_device_unref(struct udev_device *udev_device)
1047 if (udev_device == NULL)
1049 udev_device->refcount--;
1050 if (udev_device->refcount > 0)
1052 if (udev_device->parent_device != NULL)
1053 udev_device_unref(udev_device->parent_device);
1054 free(udev_device->syspath);
1055 free(udev_device->sysname);
1056 free(udev_device->devnode);
1057 free(udev_device->subsystem);
1058 free(udev_device->devtype);
1059 udev_list_cleanup(&udev_device->devlinks_list);
1060 udev_list_cleanup(&udev_device->properties_list);
1061 udev_list_cleanup(&udev_device->sysattr_value_list);
1062 udev_list_cleanup(&udev_device->sysattr_list);
1063 udev_list_cleanup(&udev_device->tags_list);
1064 free(udev_device->action);
1065 free(udev_device->driver);
1066 free(udev_device->devpath_old);
1067 free(udev_device->id_filename);
1068 free(udev_device->envp);
1069 free(udev_device->monitor_buf);
1075 * udev_device_get_devpath:
1076 * @udev_device: udev device
1078 * Retrieve the kernel devpath value of the udev device. The path
1079 * does not contain the sys mount point, and starts with a '/'.
1081 * Returns: the devpath of the udev device
1083 _public_ const char *udev_device_get_devpath(struct udev_device *udev_device)
1085 if (udev_device == NULL)
1087 return udev_device->devpath;
1091 * udev_device_get_syspath:
1092 * @udev_device: udev device
1094 * Retrieve the sys path of the udev device. The path is an
1095 * absolute path and starts with the sys mount point.
1097 * Returns: the sys path of the udev device
1099 _public_ const char *udev_device_get_syspath(struct udev_device *udev_device)
1101 if (udev_device == NULL)
1103 return udev_device->syspath;
1107 * udev_device_get_sysname:
1108 * @udev_device: udev device
1110 * Get the kernel device name in /sys.
1112 * Returns: the name string of the device device
1114 _public_ const char *udev_device_get_sysname(struct udev_device *udev_device)
1116 if (udev_device == NULL)
1118 return udev_device->sysname;
1122 * udev_device_get_sysnum:
1123 * @udev_device: udev device
1125 * Get the instance number of the device.
1127 * Returns: the trailing number string of of the device name
1129 _public_ const char *udev_device_get_sysnum(struct udev_device *udev_device)
1131 if (udev_device == NULL)
1133 return udev_device->sysnum;
1137 * udev_device_get_devnode:
1138 * @udev_device: udev device
1140 * Retrieve the device node file name belonging to the udev device.
1141 * The path is an absolute path, and starts with the device directory.
1143 * Returns: the device node file name of the udev device, or #NULL if no device node exists
1145 _public_ const char *udev_device_get_devnode(struct udev_device *udev_device)
1147 if (udev_device == NULL)
1149 if (udev_device->devnode != NULL)
1150 return udev_device->devnode;
1151 if (!udev_device->info_loaded)
1152 udev_device_read_uevent_file(udev_device);
1153 return udev_device->devnode;
1157 * udev_device_get_devlinks_list_entry:
1158 * @udev_device: udev device
1160 * Retrieve the list of device links pointing to the device file of
1161 * the udev device. The next list entry can be retrieved with
1162 * udev_list_entry_get_next(), which returns #NULL if no more entries exist.
1163 * The devlink path can be retrieved from the list entry by
1164 * udev_list_entry_get_name(). The path is an absolute path, and starts with
1165 * the device directory.
1167 * Returns: the first entry of the device node link list
1169 _public_ struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
1171 if (udev_device == NULL)
1173 if (!udev_device->info_loaded)
1174 udev_device_read_db(udev_device, NULL);
1175 return udev_list_get_entry(&udev_device->devlinks_list);
1178 void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
1180 udev_device->devlinks_uptodate = false;
1181 udev_list_cleanup(&udev_device->devlinks_list);
1185 * udev_device_get_properties_list_entry:
1186 * @udev_device: udev device
1188 * Retrieve the list of key/value device properties of the udev
1189 * device. The next list entry can be retrieved with udev_list_entry_get_next(),
1190 * which returns #NULL if no more entries exist. The property name
1191 * can be retrieved from the list entry by udev_list_entry_get_name(),
1192 * the property value by udev_list_entry_get_value().
1194 * Returns: the first entry of the property list
1196 _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
1198 if (udev_device == NULL)
1200 if (!udev_device->info_loaded) {
1201 udev_device_read_uevent_file(udev_device);
1202 udev_device_read_db(udev_device, NULL);
1204 if (!udev_device->devlinks_uptodate) {
1205 char symlinks[UTIL_PATH_SIZE];
1206 struct udev_list_entry *list_entry;
1208 udev_device->devlinks_uptodate = true;
1209 list_entry = udev_device_get_devlinks_list_entry(udev_device);
1210 if (list_entry != NULL) {
1215 l = util_strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL);
1216 udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
1217 l = util_strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL);
1218 udev_device_add_property(udev_device, "DEVLINKS", symlinks);
1221 if (!udev_device->tags_uptodate) {
1222 udev_device->tags_uptodate = true;
1223 if (udev_device_get_tags_list_entry(udev_device) != NULL) {
1224 char tags[UTIL_PATH_SIZE];
1225 struct udev_list_entry *list_entry;
1230 l = util_strpcpyl(&s, sizeof(tags), ":", NULL);
1231 udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
1232 l = util_strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL);
1233 udev_device_add_property(udev_device, "TAGS", tags);
1236 return udev_list_get_entry(&udev_device->properties_list);
1240 * udev_device_get_action:
1241 * @udev_device: udev device
1243 * This is only valid if the device was received through a monitor. Devices read from
1244 * sys do not have an action string. Usual actions are: add, remove, change, online,
1247 * Returns: the kernel action value, or #NULL if there is no action value available.
1249 _public_ const char *udev_device_get_action(struct udev_device *udev_device)
1251 if (udev_device == NULL)
1253 return udev_device->action;
1257 * udev_device_get_usec_since_initialized:
1258 * @udev_device: udev device
1260 * Return the number of microseconds passed since udev set up the
1261 * device for the first time.
1263 * This is only implemented for devices with need to store properties
1264 * in the udev database. All other devices return 0 here.
1266 * Returns: the number of microseconds since the device was first seen.
1268 _public_ unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device)
1270 unsigned long long now_ts;
1272 if (udev_device == NULL)
1274 if (!udev_device->info_loaded)
1275 udev_device_read_db(udev_device, NULL);
1276 if (udev_device->usec_initialized == 0)
1278 now_ts = now_usec();
1281 return now_ts - udev_device->usec_initialized;
1284 unsigned long long udev_device_get_usec_initialized(struct udev_device *udev_device)
1286 return udev_device->usec_initialized;
1289 void udev_device_set_usec_initialized(struct udev_device *udev_device, unsigned long long usec_initialized)
1293 udev_device->usec_initialized = usec_initialized;
1294 snprintf(num, sizeof(num), "%llu", usec_initialized);
1295 udev_device_add_property(udev_device, "USEC_INITIALIZED", num);
1299 * udev_device_get_sysattr_value:
1300 * @udev_device: udev device
1301 * @sysattr: attribute name
1303 * The retrieved value is cached in the device. Repeated calls will return the same
1304 * value and not open the attribute again.
1306 * Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value.
1308 _public_ const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr)
1310 struct udev_list_entry *list_entry;
1311 char path[UTIL_PATH_SIZE];
1313 struct stat statbuf;
1316 const char *val = NULL;
1318 if (udev_device == NULL)
1320 if (sysattr == NULL)
1323 /* look for possibly already cached result */
1324 list_entry = udev_list_get_entry(&udev_device->sysattr_value_list);
1325 list_entry = udev_list_entry_get_by_name(list_entry, sysattr);
1326 if (list_entry != NULL)
1327 return udev_list_entry_get_value(list_entry);
1329 util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
1330 if (lstat(path, &statbuf) != 0) {
1331 udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, NULL);
1335 if (S_ISLNK(statbuf.st_mode)) {
1336 struct udev_device *dev;
1339 * Some core links return only the last element of the target path,
1340 * these are just values, the paths should not be exposed.
1342 if (streq(sysattr, "driver") ||
1343 streq(sysattr, "subsystem") ||
1344 streq(sysattr, "module")) {
1345 if (util_get_sys_core_link_value(udev_device->udev, sysattr,
1346 udev_device->syspath, value, sizeof(value)) < 0)
1348 list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1349 val = udev_list_entry_get_value(list_entry);
1353 /* resolve link to a device and return its syspath */
1354 util_strscpyl(path, sizeof(path), udev_device->syspath, "/", sysattr, NULL);
1355 dev = udev_device_new_from_syspath(udev_device->udev, path);
1357 list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr,
1358 udev_device_get_syspath(dev));
1359 val = udev_list_entry_get_value(list_entry);
1360 udev_device_unref(dev);
1366 /* skip directories */
1367 if (S_ISDIR(statbuf.st_mode))
1370 /* skip non-readable files */
1371 if ((statbuf.st_mode & S_IRUSR) == 0)
1374 /* read attribute value */
1375 fd = open(path, O_RDONLY|O_CLOEXEC);
1378 size = read(fd, value, sizeof(value));
1382 if (size == sizeof(value))
1385 /* got a valid value, store it in cache and return it */
1387 util_remove_trailing_chars(value, '\n');
1388 list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1389 val = udev_list_entry_get_value(list_entry);
1394 static int udev_device_sysattr_list_read(struct udev_device *udev_device)
1396 struct dirent *dent;
1400 if (udev_device == NULL)
1402 if (udev_device->sysattr_list_read)
1405 dir = opendir(udev_device_get_syspath(udev_device));
1409 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
1410 char path[UTIL_PATH_SIZE];
1411 struct stat statbuf;
1413 /* only handle symlinks and regular files */
1414 if (dent->d_type != DT_LNK && dent->d_type != DT_REG)
1417 util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL);
1418 if (lstat(path, &statbuf) != 0)
1420 if ((statbuf.st_mode & S_IRUSR) == 0)
1423 udev_list_entry_add(&udev_device->sysattr_list, dent->d_name, NULL);
1428 udev_device->sysattr_list_read = true;
1434 * udev_device_get_sysattr_list_entry:
1435 * @udev_device: udev device
1437 * Retrieve the list of available sysattrs, with value being empty;
1438 * This just return all available sysfs attributes for a particular
1439 * device without reading their values.
1441 * Returns: the first entry of the property list
1443 _public_ struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device)
1445 if (!udev_device->sysattr_list_read) {
1447 ret = udev_device_sysattr_list_read(udev_device);
1452 return udev_list_get_entry(&udev_device->sysattr_list);
1455 int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath)
1460 free(udev_device->syspath);
1461 udev_device->syspath = strdup(syspath);
1462 if (udev_device->syspath == NULL)
1464 udev_device->devpath = udev_device->syspath + strlen("/sys");
1465 udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath);
1467 pos = strrchr(udev_device->syspath, '/');
1470 udev_device->sysname = strdup(&pos[1]);
1471 if (udev_device->sysname == NULL)
1474 /* some devices have '!' in their name, change that to '/' */
1476 while (udev_device->sysname[len] != '\0') {
1477 if (udev_device->sysname[len] == '!')
1478 udev_device->sysname[len] = '/';
1482 /* trailing number */
1483 while (len > 0 && isdigit(udev_device->sysname[--len]))
1484 udev_device->sysnum = &udev_device->sysname[len];
1486 /* sysname is completely numeric */
1488 udev_device->sysnum = NULL;
1493 int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
1495 free(udev_device->devnode);
1496 if (devnode[0] != '/') {
1497 if (asprintf(&udev_device->devnode, "/dev/%s", devnode) < 0)
1498 udev_device->devnode = NULL;
1500 udev_device->devnode = strdup(devnode);
1502 if (udev_device->devnode == NULL)
1504 udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode);
1508 int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink, int unique)
1510 struct udev_list_entry *list_entry;
1512 udev_device->devlinks_uptodate = false;
1513 list_entry = udev_list_entry_add(&udev_device->devlinks_list, devlink, NULL);
1514 if (list_entry == NULL)
1517 udev_list_entry_set_num(list_entry, true);
1521 const char *udev_device_get_id_filename(struct udev_device *udev_device)
1523 if (udev_device->id_filename == NULL) {
1524 if (udev_device_get_subsystem(udev_device) == NULL)
1527 if (major(udev_device_get_devnum(udev_device)) > 0) {
1528 /* use dev_t -- b259:131072, c254:0 */
1529 if (asprintf(&udev_device->id_filename, "%c%u:%u",
1530 streq(udev_device_get_subsystem(udev_device), "block") ? 'b' : 'c',
1531 major(udev_device_get_devnum(udev_device)),
1532 minor(udev_device_get_devnum(udev_device))) < 0)
1533 udev_device->id_filename = NULL;
1534 } else if (udev_device_get_ifindex(udev_device) > 0) {
1535 /* use netdev ifindex -- n3 */
1536 if (asprintf(&udev_device->id_filename, "n%u", udev_device_get_ifindex(udev_device)) < 0)
1537 udev_device->id_filename = NULL;
1540 * use $subsys:$syname -- pci:0000:00:1f.2
1541 * sysname() has '!' translated, get it from devpath
1543 const char *sysname;
1544 sysname = strrchr(udev_device->devpath, '/');
1545 if (sysname == NULL)
1547 sysname = &sysname[1];
1548 if (asprintf(&udev_device->id_filename, "+%s:%s", udev_device_get_subsystem(udev_device), sysname) < 0)
1549 udev_device->id_filename = NULL;
1552 return udev_device->id_filename;
1556 * udev_device_get_is_initialized:
1557 * @udev_device: udev device
1559 * Check if udev has already handled the device and has set up
1560 * device node permissions and context, or has renamed a network
1563 * This is only implemented for devices with a device node
1564 * or network interfaces. All other devices return 1 here.
1566 * Returns: 1 if the device is set up. 0 otherwise.
1568 _public_ int udev_device_get_is_initialized(struct udev_device *udev_device)
1570 if (!udev_device->info_loaded)
1571 udev_device_read_db(udev_device, NULL);
1572 return udev_device->is_initialized;
1575 void udev_device_set_is_initialized(struct udev_device *udev_device)
1577 udev_device->is_initialized = true;
1580 int udev_device_add_tag(struct udev_device *udev_device, const char *tag)
1582 if (strchr(tag, ':') != NULL || strchr(tag, ' ') != NULL)
1584 udev_device->tags_uptodate = false;
1585 if (udev_list_entry_add(&udev_device->tags_list, tag, NULL) != NULL)
1590 void udev_device_cleanup_tags_list(struct udev_device *udev_device)
1592 udev_device->tags_uptodate = false;
1593 udev_list_cleanup(&udev_device->tags_list);
1597 * udev_device_get_tags_list_entry:
1598 * @udev_device: udev device
1600 * Retrieve the list of tags attached to the udev device. The next
1601 * list entry can be retrieved with udev_list_entry_get_next(),
1602 * which returns #NULL if no more entries exist. The tag string
1603 * can be retrieved from the list entry by udev_list_entry_get_name().
1605 * Returns: the first entry of the tag list
1607 _public_ struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device)
1609 if (udev_device == NULL)
1611 if (!udev_device->info_loaded)
1612 udev_device_read_db(udev_device, NULL);
1613 return udev_list_get_entry(&udev_device->tags_list);
1617 * udev_device_has_tag:
1618 * @udev_device: udev device
1621 * Check if a given device has a certain tag associated.
1623 * Returns: 1 if the tag is found. 0 otherwise.
1625 _public_ int udev_device_has_tag(struct udev_device *udev_device, const char *tag)
1627 struct udev_list_entry *list_entry;
1629 if (udev_device == NULL)
1631 if (!udev_device->info_loaded)
1632 udev_device_read_db(udev_device, NULL);
1633 list_entry = udev_device_get_tags_list_entry(udev_device);
1634 if (udev_list_entry_get_by_name(list_entry, tag) != NULL)
1639 #define ENVP_SIZE 128
1640 #define MONITOR_BUF_SIZE 4096
1641 static int update_envp_monitor_buf(struct udev_device *udev_device)
1643 struct udev_list_entry *list_entry;
1648 /* monitor buffer of property strings */
1649 free(udev_device->monitor_buf);
1650 udev_device->monitor_buf_len = 0;
1651 udev_device->monitor_buf = malloc(MONITOR_BUF_SIZE);
1652 if (udev_device->monitor_buf == NULL)
1655 /* envp array, strings will point into monitor buffer */
1656 if (udev_device->envp == NULL)
1657 udev_device->envp = malloc(sizeof(char *) * ENVP_SIZE);
1658 if (udev_device->envp == NULL)
1662 s = udev_device->monitor_buf;
1663 l = MONITOR_BUF_SIZE;
1664 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
1667 key = udev_list_entry_get_name(list_entry);
1668 /* skip private variables */
1672 /* add string to envp array */
1673 udev_device->envp[i++] = s;
1674 if (i+1 >= ENVP_SIZE)
1677 /* add property string to monitor buffer */
1678 l = util_strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
1681 /* advance past the trailing '\0' that util_strpcpyl() guarantees */
1685 udev_device->envp[i] = NULL;
1686 udev_device->monitor_buf_len = s - udev_device->monitor_buf;
1687 udev_device->envp_uptodate = true;
1691 char **udev_device_get_properties_envp(struct udev_device *udev_device)
1693 if (!udev_device->envp_uptodate)
1694 if (update_envp_monitor_buf(udev_device) != 0)
1696 return udev_device->envp;
1699 ssize_t udev_device_get_properties_monitor_buf(struct udev_device *udev_device, const char **buf)
1701 if (!udev_device->envp_uptodate)
1702 if (update_envp_monitor_buf(udev_device) != 0)
1704 *buf = udev_device->monitor_buf;
1705 return udev_device->monitor_buf_len;
1708 int udev_device_set_action(struct udev_device *udev_device, const char *action)
1710 free(udev_device->action);
1711 udev_device->action = strdup(action);
1712 if (udev_device->action == NULL)
1714 udev_device_add_property(udev_device, "ACTION", udev_device->action);
1718 int udev_device_get_devlink_priority(struct udev_device *udev_device)
1720 if (!udev_device->info_loaded)
1721 udev_device_read_db(udev_device, NULL);
1722 return udev_device->devlink_priority;
1725 int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio)
1727 udev_device->devlink_priority = prio;
1731 int udev_device_get_watch_handle(struct udev_device *udev_device)
1733 if (!udev_device->info_loaded)
1734 udev_device_read_db(udev_device, NULL);
1735 return udev_device->watch_handle;
1738 int udev_device_set_watch_handle(struct udev_device *udev_device, int handle)
1740 udev_device->watch_handle = handle;
1744 bool udev_device_get_db_persist(struct udev_device *udev_device)
1746 return udev_device->db_persist;
1749 void udev_device_set_db_persist(struct udev_device *udev_device)
1751 udev_device->db_persist = true;