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 * Returns: the device major/minor number.
141 _public_ 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 _public_ 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 _public_ 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 _public_ 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 (startswith(udev_device->devpath, "/module/")) {
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 (startswith(udev_device->devpath, "/subsystem/") ||
288 startswith(udev_device->devpath, "/class/") ||
289 startswith(udev_device->devpath, "/bus/")) {
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 (startswith(property, "DEVPATH=")) {
357 char path[UTIL_PATH_SIZE];
359 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys", &property[8], NULL);
360 udev_device_set_syspath(udev_device, path);
361 } else if (startswith(property, "SUBSYSTEM=")) {
362 udev_device_set_subsystem(udev_device, &property[10]);
363 } else if (startswith(property, "DEVTYPE=")) {
364 udev_device_set_devtype(udev_device, &property[8]);
365 } else if (startswith(property, "DEVNAME=")) {
366 udev_device_set_devnode(udev_device, &property[8]);
367 } else if (startswith(property, "DEVLINKS=")) {
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 (startswith(property, "TAGS=")) {
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 (startswith(property, "USEC_INITIALIZED=")) {
404 udev_device_set_usec_initialized(udev_device, strtoull(&property[19], NULL, 10));
405 } else if (startswith(property, "DRIVER=")) {
406 udev_device_set_driver(udev_device, &property[7]);
407 } else if (startswith(property, "ACTION=")) {
408 udev_device_set_action(udev_device, &property[7]);
409 } else if (startswith(property, "MAJOR=")) {
410 udev_device->maj = strtoull(&property[6], NULL, 10);
411 } else if (startswith(property, "MINOR=")) {
412 udev_device->min = strtoull(&property[6], NULL, 10);
413 } else if (startswith(property, "DEVPATH_OLD=")) {
414 udev_device_set_devpath_old(udev_device, &property[12]);
415 } else if (startswith(property, "SEQNUM=")) {
416 udev_device_set_seqnum(udev_device, strtoull(&property[7], NULL, 10));
417 } else if (startswith(property, "IFINDEX=")) {
418 udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10));
419 } else if (startswith(property, "DEVMODE=")) {
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 _public_ 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), TEST_PREFIX "/run/udev/data/", id, NULL);
480 f = fopen(dbfile, "re");
482 dbg(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), TEST_PREFIX "/dev/", 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 dbg(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 (startswith(line, "DEVTYPE=")) {
552 udev_device_set_devtype(udev_device, &line[8]);
555 if (startswith(line, "IFINDEX=")) {
556 udev_device_set_ifindex(udev_device, strtoull(&line[8], NULL, 10));
559 if (startswith(line, "DEVNAME=")) {
560 udev_device_set_devnode(udev_device, &line[8]);
564 if (startswith(line, "MAJOR="))
565 maj = strtoull(&line[6], NULL, 10);
566 else if (startswith(line, "MINOR="))
567 min = strtoull(&line[6], NULL, 10);
568 else if (startswith(line, "DEVMODE="))
569 udev_device->devnode_mode = strtoul(&line[8], NULL, 8);
571 udev_device_add_property_from_string(udev_device, line);
574 udev_device->devnum = makedev(maj, min);
579 void udev_device_set_info_loaded(struct udev_device *device)
581 device->info_loaded = true;
584 struct udev_device *udev_device_new(struct udev *udev)
586 struct udev_device *udev_device;
587 struct udev_list_entry *list_entry;
592 udev_device = calloc(1, sizeof(struct udev_device));
593 if (udev_device == NULL)
595 udev_device->refcount = 1;
596 udev_device->udev = udev;
597 udev_list_init(udev, &udev_device->devlinks_list, true);
598 udev_list_init(udev, &udev_device->properties_list, true);
599 udev_list_init(udev, &udev_device->sysattr_value_list, true);
600 udev_list_init(udev, &udev_device->sysattr_list, false);
601 udev_list_init(udev, &udev_device->tags_list, true);
602 udev_device->watch_handle = -1;
603 /* copy global properties */
604 udev_list_entry_foreach(list_entry, udev_get_properties_list_entry(udev))
605 udev_device_add_property(udev_device,
606 udev_list_entry_get_name(list_entry),
607 udev_list_entry_get_value(list_entry));
612 * udev_device_new_from_syspath:
613 * @udev: udev library context
614 * @syspath: sys device path including sys directory
616 * Create new udev device, and fill in information from the sys
617 * device and the udev database entry. The syspath is the absolute
618 * path to the device, including the sys mount point.
620 * The initial refcount is 1, and needs to be decremented to
621 * release the resources of the udev device.
623 * Returns: a new udev device, or #NULL, if it does not exist
625 _public_ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
628 char path[UTIL_PATH_SIZE];
631 struct udev_device *udev_device;
638 /* path starts in sys */
639 if (!startswith(syspath, TEST_PREFIX "/sys")) {
640 dbg(udev, "not in sys :%s\n", syspath);
644 /* path is not a root directory */
645 subdir = syspath + strlen(TEST_PREFIX "/sys");
646 pos = strrchr(subdir, '/');
647 if (pos == NULL || pos[1] == '\0' || pos < &subdir[2])
650 /* resolve possible symlink to real path */
651 util_strscpy(path, sizeof(path), syspath);
652 util_resolve_sys_link(udev, path, sizeof(path));
654 if (startswith(path + strlen(TEST_PREFIX "/sys"), "/devices/")) {
655 char file[UTIL_PATH_SIZE];
657 /* all "devices" require a "uevent" file */
658 util_strscpyl(file, sizeof(file), path, "/uevent", NULL);
659 if (stat(file, &statbuf) != 0)
662 /* everything else just needs to be a directory */
663 if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode))
667 udev_device = udev_device_new(udev);
668 if (udev_device == NULL)
671 udev_device_set_syspath(udev_device, path);
672 dbg(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
678 * udev_device_new_from_devnum:
679 * @udev: udev library context
680 * @type: char or block device
681 * @devnum: device major/minor number
683 * Create new udev device, and fill in information from the sys
684 * device and the udev database entry. The device is looked-up
685 * by its major/minor number and type. Character and block device
686 * numbers are not unique across the two types.
688 * The initial refcount is 1, and needs to be decremented to
689 * release the resources of the udev device.
691 * Returns: a new udev device, or #NULL, if it does not exist
693 _public_ struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
695 char path[UTIL_PATH_SIZE];
696 const char *type_str;
700 else if (type == 'c')
705 /* use /sys/dev/{block,char}/<maj>:<min> link */
706 snprintf(path, sizeof(path), TEST_PREFIX "/sys/dev/%s/%u:%u",
707 type_str, major(devnum), minor(devnum));
708 return udev_device_new_from_syspath(udev, path);
711 struct udev_device *udev_device_new_from_id_filename(struct udev *udev, char *id)
715 char subsys[UTIL_PATH_SIZE];
721 if (sscanf(id, "%c%i:%i", &type, &maj, &min) != 3)
723 return udev_device_new_from_devnum(udev, type, makedev(maj, min));
727 struct udev_device *dev;
730 ifindex = strtoul(&id[1], NULL, 10);
734 sk = socket(PF_INET, SOCK_DGRAM, 0);
737 memset(&ifr, 0x00, sizeof(struct ifreq));
738 ifr.ifr_ifindex = ifindex;
739 if (ioctl(sk, SIOCGIFNAME, &ifr) != 0) {
745 dev = udev_device_new_from_subsystem_sysname(udev, "net", ifr.ifr_name);
748 if (udev_device_get_ifindex(dev) == ifindex)
750 udev_device_unref(dev);
754 util_strscpy(subsys, sizeof(subsys), &id[1]);
755 sysname = strchr(subsys, ':');
759 sysname = &sysname[1];
760 return udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
767 * udev_device_new_from_subsystem_sysname:
768 * @udev: udev library context
769 * @subsystem: the subsystem of the device
770 * @sysname: the name of the device
772 * Create new udev device, and fill in information from the sys device
773 * and the udev database entry. The device is looked up by the subsystem
774 * and name string of the device, like "mem" / "zero", or "block" / "sda".
776 * The initial refcount is 1, and needs to be decremented to
777 * release the resources of the udev device.
779 * Returns: a new udev device, or #NULL, if it does not exist
781 _public_ struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
783 char path[UTIL_PATH_SIZE];
786 if (streq(subsystem, "subsystem")) {
787 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/subsystem/", sysname, NULL);
788 if (stat(path, &statbuf) == 0)
791 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/bus/", sysname, NULL);
792 if (stat(path, &statbuf) == 0)
795 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/class/", sysname, NULL);
796 if (stat(path, &statbuf) == 0)
801 if (streq(subsystem, "module")) {
802 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/module/", sysname, NULL);
803 if (stat(path, &statbuf) == 0)
808 if (streq(subsystem, "drivers")) {
809 char subsys[UTIL_NAME_SIZE];
812 util_strscpy(subsys, sizeof(subsys), sysname);
813 driver = strchr(subsys, ':');
814 if (driver != NULL) {
818 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/subsystem/", subsys, "/drivers/", driver, NULL);
819 if (stat(path, &statbuf) == 0)
822 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/bus/", subsys, "/drivers/", driver, NULL);
823 if (stat(path, &statbuf) == 0)
829 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/subsystem/", subsystem, "/devices/", sysname, NULL);
830 if (stat(path, &statbuf) == 0)
833 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/bus/", subsystem, "/devices/", sysname, NULL);
834 if (stat(path, &statbuf) == 0)
837 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/class/", subsystem, "/", sysname, NULL);
838 if (stat(path, &statbuf) == 0)
843 return udev_device_new_from_syspath(udev, path);
847 * udev_device_new_from_environment
848 * @udev: udev library context
850 * Create new udev device, and fill in information from the
851 * current process environment. This only works reliable if
852 * the process is called from a udev rule. It is usually used
853 * for tools executed from IMPORT= rules.
855 * The initial refcount is 1, and needs to be decremented to
856 * release the resources of the udev device.
858 * Returns: a new udev device, or #NULL, if it does not exist
860 _public_ struct udev_device *udev_device_new_from_environment(struct udev *udev)
863 struct udev_device *udev_device;
865 udev_device = udev_device_new(udev);
866 if (udev_device == NULL)
868 udev_device_set_info_loaded(udev_device);
870 for (i = 0; environ[i] != NULL; i++)
871 udev_device_add_property_from_string_parse(udev_device, environ[i]);
873 if (udev_device_add_property_from_string_parse_finish(udev_device) < 0) {
874 dbg(udev, "missing values, invalid device\n");
875 udev_device_unref(udev_device);
882 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
884 struct udev_device *udev_device_parent = NULL;
885 char path[UTIL_PATH_SIZE];
888 util_strscpy(path, sizeof(path), udev_device->syspath);
889 subdir = path + strlen(TEST_PREFIX "/sys/");
893 pos = strrchr(subdir, '/');
894 if (pos == NULL || pos < &subdir[2])
897 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
898 if (udev_device_parent != NULL)
899 return udev_device_parent;
905 * udev_device_get_parent:
906 * @udev_device: the device to start searching from
908 * Find the next parent device, and fill in information from the sys
909 * device and the udev database entry.
911 * The returned the device is not referenced. It is attached to the
912 * child device, and will be cleaned up when the child device
915 * It is not necessarily just the upper level directory, empty or not
916 * recognized sys directories are ignored.
918 * It can be called as many times as needed, without caring about
921 * Returns: a new udev device, or #NULL, if it no parent exist.
923 _public_ struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
925 if (udev_device == NULL)
927 if (!udev_device->parent_set) {
928 udev_device->parent_set = true;
929 udev_device->parent_device = device_new_from_parent(udev_device);
931 return udev_device->parent_device;
935 * udev_device_get_parent_with_subsystem_devtype:
936 * @udev_device: udev device to start searching from
937 * @subsystem: the subsystem of the device
938 * @devtype: the type (DEVTYPE) of the device
940 * Find the next parent device, with a matching subsystem and devtype
941 * value, and fill in information from the sys device and the udev
944 * If devtype is #NULL, only subsystem is checked, and any devtype will
947 * The returned the device is not referenced. It is attached to the
948 * child device, and will be cleaned up when the child device
951 * It can be called as many times as needed, without caring about
954 * Returns: a new udev device, or #NULL if no matching parent exists.
956 _public_ struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype)
958 struct udev_device *parent;
960 if (subsystem == NULL)
963 parent = udev_device_get_parent(udev_device);
964 while (parent != NULL) {
965 const char *parent_subsystem;
966 const char *parent_devtype;
968 parent_subsystem = udev_device_get_subsystem(parent);
969 if (parent_subsystem != NULL && streq(parent_subsystem, subsystem)) {
972 parent_devtype = udev_device_get_devtype(parent);
973 if (parent_devtype != NULL && streq(parent_devtype, devtype))
976 parent = udev_device_get_parent(parent);
982 * udev_device_get_udev:
983 * @udev_device: udev device
985 * Retrieve the udev library context the device was created with.
987 * Returns: the udev library context
989 _public_ struct udev *udev_device_get_udev(struct udev_device *udev_device)
991 if (udev_device == NULL)
993 return udev_device->udev;
998 * @udev_device: udev device
1000 * Take a reference of a udev device.
1002 * Returns: the passed udev device
1004 _public_ struct udev_device *udev_device_ref(struct udev_device *udev_device)
1006 if (udev_device == NULL)
1008 udev_device->refcount++;
1013 * udev_device_unref:
1014 * @udev_device: udev device
1016 * Drop a reference of a udev device. If the refcount reaches zero,
1017 * the resources of the device will be released.
1020 _public_ void udev_device_unref(struct udev_device *udev_device)
1022 if (udev_device == NULL)
1024 udev_device->refcount--;
1025 if (udev_device->refcount > 0)
1027 if (udev_device->parent_device != NULL)
1028 udev_device_unref(udev_device->parent_device);
1029 free(udev_device->syspath);
1030 free(udev_device->sysname);
1031 free(udev_device->devnode);
1032 free(udev_device->subsystem);
1033 free(udev_device->devtype);
1034 udev_list_cleanup(&udev_device->devlinks_list);
1035 udev_list_cleanup(&udev_device->properties_list);
1036 udev_list_cleanup(&udev_device->sysattr_value_list);
1037 udev_list_cleanup(&udev_device->sysattr_list);
1038 udev_list_cleanup(&udev_device->tags_list);
1039 free(udev_device->action);
1040 free(udev_device->driver);
1041 free(udev_device->devpath_old);
1042 free(udev_device->id_filename);
1043 free(udev_device->envp);
1044 free(udev_device->monitor_buf);
1049 * udev_device_get_devpath:
1050 * @udev_device: udev device
1052 * Retrieve the kernel devpath value of the udev device. The path
1053 * does not contain the sys mount point, and starts with a '/'.
1055 * Returns: the devpath of the udev device
1057 _public_ const char *udev_device_get_devpath(struct udev_device *udev_device)
1059 if (udev_device == NULL)
1061 return udev_device->devpath;
1065 * udev_device_get_syspath:
1066 * @udev_device: udev device
1068 * Retrieve the sys path of the udev device. The path is an
1069 * absolute path and starts with the sys mount point.
1071 * Returns: the sys path of the udev device
1073 _public_ const char *udev_device_get_syspath(struct udev_device *udev_device)
1075 if (udev_device == NULL)
1077 return udev_device->syspath;
1081 * udev_device_get_sysname:
1082 * @udev_device: udev device
1084 * Returns: the sys name of the device device
1086 _public_ const char *udev_device_get_sysname(struct udev_device *udev_device)
1088 if (udev_device == NULL)
1090 return udev_device->sysname;
1094 * udev_device_get_sysnum:
1095 * @udev_device: udev device
1097 * Returns: the trailing number of of the device name
1099 _public_ const char *udev_device_get_sysnum(struct udev_device *udev_device)
1101 if (udev_device == NULL)
1103 return udev_device->sysnum;
1107 * udev_device_get_devnode:
1108 * @udev_device: udev device
1110 * Retrieve the device node file name belonging to the udev device.
1111 * The path is an absolute path, and starts with the device directory.
1113 * Returns: the device node file name of the udev device, or #NULL if no device node exists
1115 _public_ const char *udev_device_get_devnode(struct udev_device *udev_device)
1117 if (udev_device == NULL)
1119 if (udev_device->devnode != NULL)
1120 return udev_device->devnode;
1121 if (!udev_device->info_loaded)
1122 udev_device_read_uevent_file(udev_device);
1123 return udev_device->devnode;
1127 * udev_device_get_devlinks_list_entry:
1128 * @udev_device: udev device
1130 * Retrieve the list of device links pointing to the device file of
1131 * the udev device. The next list entry can be retrieved with
1132 * udev_list_entry_get_next(), which returns #NULL if no more entries exist.
1133 * The devlink path can be retrieved from the list entry by
1134 * udev_list_entry_get_name(). The path is an absolute path, and starts with
1135 * the device directory.
1137 * Returns: the first entry of the device node link list
1139 _public_ struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
1141 if (udev_device == NULL)
1143 if (!udev_device->info_loaded)
1144 udev_device_read_db(udev_device, NULL);
1145 return udev_list_get_entry(&udev_device->devlinks_list);
1148 void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
1150 udev_device->devlinks_uptodate = false;
1151 udev_list_cleanup(&udev_device->devlinks_list);
1155 * udev_device_get_properties_list_entry:
1156 * @udev_device: udev device
1158 * Retrieve the list of key/value device properties of the udev
1159 * device. The next list entry can be retrieved with udev_list_entry_get_next(),
1160 * which returns #NULL if no more entries exist. The property name
1161 * can be retrieved from the list entry by udev_list_entry_get_name(),
1162 * the property value by udev_list_entry_get_value().
1164 * Returns: the first entry of the property list
1166 _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
1168 if (udev_device == NULL)
1170 if (!udev_device->info_loaded) {
1171 udev_device_read_uevent_file(udev_device);
1172 udev_device_read_db(udev_device, NULL);
1174 if (!udev_device->devlinks_uptodate) {
1175 char symlinks[UTIL_PATH_SIZE];
1176 struct udev_list_entry *list_entry;
1178 udev_device->devlinks_uptodate = true;
1179 list_entry = udev_device_get_devlinks_list_entry(udev_device);
1180 if (list_entry != NULL) {
1185 l = util_strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL);
1186 udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
1187 l = util_strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL);
1188 udev_device_add_property(udev_device, "DEVLINKS", symlinks);
1191 if (!udev_device->tags_uptodate) {
1192 udev_device->tags_uptodate = true;
1193 if (udev_device_get_tags_list_entry(udev_device) != NULL) {
1194 char tags[UTIL_PATH_SIZE];
1195 struct udev_list_entry *list_entry;
1200 l = util_strpcpyl(&s, sizeof(tags), ":", NULL);
1201 udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
1202 l = util_strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL);
1203 udev_device_add_property(udev_device, "TAGS", tags);
1206 return udev_list_get_entry(&udev_device->properties_list);
1210 * udev_device_get_action:
1211 * @udev_device: udev device
1213 * This is only valid if the device was received through a monitor. Devices read from
1214 * sys do not have an action string. Usual actions are: add, remove, change, online,
1217 * Returns: the kernel action value, or #NULL if there is no action value available.
1219 _public_ const char *udev_device_get_action(struct udev_device *udev_device)
1221 if (udev_device == NULL)
1223 return udev_device->action;
1227 * udev_device_get_usec_since_initialized:
1228 * @udev_device: udev device
1230 * Return the number of microseconds passed since udev set up the
1231 * device for the first time.
1233 * This is only implemented for devices with need to store properties
1234 * in the udev database. All other devices return 0 here.
1236 * Returns: the number of microseconds since the device was first seen.
1238 _public_ unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device)
1240 unsigned long long now_ts;
1242 if (udev_device == NULL)
1244 if (!udev_device->info_loaded)
1245 udev_device_read_db(udev_device, NULL);
1246 if (udev_device->usec_initialized == 0)
1248 now_ts = now_usec();
1251 return now_ts - udev_device->usec_initialized;
1254 unsigned long long udev_device_get_usec_initialized(struct udev_device *udev_device)
1256 return udev_device->usec_initialized;
1259 void udev_device_set_usec_initialized(struct udev_device *udev_device, unsigned long long usec_initialized)
1263 udev_device->usec_initialized = usec_initialized;
1264 snprintf(num, sizeof(num), "%llu", usec_initialized);
1265 udev_device_add_property(udev_device, "USEC_INITIALIZED", num);
1269 * udev_device_get_sysattr_value:
1270 * @udev_device: udev device
1271 * @sysattr: attribute name
1273 * The retrieved value is cached in the device. Repeated calls will return the same
1274 * value and not open the attribute again.
1276 * Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value.
1278 _public_ const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr)
1280 struct udev_list_entry *list_entry;
1281 char path[UTIL_PATH_SIZE];
1283 struct stat statbuf;
1286 const char *val = NULL;
1288 if (udev_device == NULL)
1290 if (sysattr == NULL)
1293 /* look for possibly already cached result */
1294 list_entry = udev_list_get_entry(&udev_device->sysattr_value_list);
1295 list_entry = udev_list_entry_get_by_name(list_entry, sysattr);
1296 if (list_entry != NULL)
1297 return udev_list_entry_get_value(list_entry);
1299 util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
1300 if (lstat(path, &statbuf) != 0) {
1301 udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, NULL);
1305 if (S_ISLNK(statbuf.st_mode)) {
1306 struct udev_device *dev;
1309 * Some core links return only the last element of the target path,
1310 * these are just values, the paths should not be exposed.
1312 if (streq(sysattr, "driver") ||
1313 streq(sysattr, "subsystem") ||
1314 streq(sysattr, "module")) {
1315 if (util_get_sys_core_link_value(udev_device->udev, sysattr,
1316 udev_device->syspath, value, sizeof(value)) < 0)
1318 list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1319 val = udev_list_entry_get_value(list_entry);
1323 /* resolve link to a device and return its syspath */
1324 util_strscpyl(path, sizeof(path), udev_device->syspath, "/", sysattr, NULL);
1325 dev = udev_device_new_from_syspath(udev_device->udev, path);
1327 list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr,
1328 udev_device_get_syspath(dev));
1329 val = udev_list_entry_get_value(list_entry);
1330 udev_device_unref(dev);
1336 /* skip directories */
1337 if (S_ISDIR(statbuf.st_mode))
1340 /* skip non-readable files */
1341 if ((statbuf.st_mode & S_IRUSR) == 0)
1344 /* read attribute value */
1345 fd = open(path, O_RDONLY|O_CLOEXEC);
1348 size = read(fd, value, sizeof(value));
1352 if (size == sizeof(value))
1355 /* got a valid value, store it in cache and return it */
1357 util_remove_trailing_chars(value, '\n');
1358 list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1359 val = udev_list_entry_get_value(list_entry);
1364 static int udev_device_sysattr_list_read(struct udev_device *udev_device)
1366 struct dirent *dent;
1370 if (udev_device == NULL)
1372 if (udev_device->sysattr_list_read)
1375 dir = opendir(udev_device_get_syspath(udev_device));
1379 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
1380 char path[UTIL_PATH_SIZE];
1381 struct stat statbuf;
1383 /* only handle symlinks and regular files */
1384 if (dent->d_type != DT_LNK && dent->d_type != DT_REG)
1387 util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL);
1388 if (lstat(path, &statbuf) != 0)
1390 if ((statbuf.st_mode & S_IRUSR) == 0)
1393 udev_list_entry_add(&udev_device->sysattr_list, dent->d_name, NULL);
1398 udev_device->sysattr_list_read = true;
1404 * udev_device_get_sysattr_list_entry:
1405 * @udev_device: udev device
1407 * Retrieve the list of available sysattrs, with value being empty;
1408 * This just return all available sysfs attributes for a particular
1409 * device without reading their values.
1411 * Returns: the first entry of the property list
1413 _public_ struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device)
1415 if (!udev_device->sysattr_list_read) {
1417 ret = udev_device_sysattr_list_read(udev_device);
1422 return udev_list_get_entry(&udev_device->sysattr_list);
1425 int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath)
1430 free(udev_device->syspath);
1431 udev_device->syspath = strdup(syspath);
1432 if (udev_device->syspath == NULL)
1434 udev_device->devpath = udev_device->syspath + strlen(TEST_PREFIX "/sys");
1435 udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath);
1437 pos = strrchr(udev_device->syspath, '/');
1440 udev_device->sysname = strdup(&pos[1]);
1441 if (udev_device->sysname == NULL)
1444 /* some devices have '!' in their name, change that to '/' */
1446 while (udev_device->sysname[len] != '\0') {
1447 if (udev_device->sysname[len] == '!')
1448 udev_device->sysname[len] = '/';
1452 /* trailing number */
1453 while (len > 0 && isdigit(udev_device->sysname[--len]))
1454 udev_device->sysnum = &udev_device->sysname[len];
1456 /* sysname is completely numeric */
1458 udev_device->sysnum = NULL;
1463 int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
1465 free(udev_device->devnode);
1466 if (devnode[0] != '/') {
1467 if (asprintf(&udev_device->devnode, TEST_PREFIX "/dev/%s", devnode) < 0)
1468 udev_device->devnode = NULL;
1470 udev_device->devnode = strdup(devnode);
1472 if (udev_device->devnode == NULL)
1474 udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode);
1478 int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink, int unique)
1480 struct udev_list_entry *list_entry;
1482 udev_device->devlinks_uptodate = false;
1483 list_entry = udev_list_entry_add(&udev_device->devlinks_list, devlink, NULL);
1484 if (list_entry == NULL)
1487 udev_list_entry_set_num(list_entry, true);
1491 const char *udev_device_get_id_filename(struct udev_device *udev_device)
1493 if (udev_device->id_filename == NULL) {
1494 if (udev_device_get_subsystem(udev_device) == NULL)
1497 if (major(udev_device_get_devnum(udev_device)) > 0) {
1498 /* use dev_t -- b259:131072, c254:0 */
1499 if (asprintf(&udev_device->id_filename, "%c%u:%u",
1500 streq(udev_device_get_subsystem(udev_device), "block") ? 'b' : 'c',
1501 major(udev_device_get_devnum(udev_device)),
1502 minor(udev_device_get_devnum(udev_device))) < 0)
1503 udev_device->id_filename = NULL;
1504 } else if (udev_device_get_ifindex(udev_device) > 0) {
1505 /* use netdev ifindex -- n3 */
1506 if (asprintf(&udev_device->id_filename, "n%u", udev_device_get_ifindex(udev_device)) < 0)
1507 udev_device->id_filename = NULL;
1510 * use $subsys:$syname -- pci:0000:00:1f.2
1511 * sysname() has '!' translated, get it from devpath
1513 const char *sysname;
1514 sysname = strrchr(udev_device->devpath, '/');
1515 if (sysname == NULL)
1517 sysname = &sysname[1];
1518 if (asprintf(&udev_device->id_filename, "+%s:%s", udev_device_get_subsystem(udev_device), sysname) < 0)
1519 udev_device->id_filename = NULL;
1522 return udev_device->id_filename;
1526 * udev_device_get_is_initialized:
1527 * @udev_device: udev device
1529 * Check if udev has already handled the device and has set up
1530 * device node permissions and context, or has renamed a network
1533 * This is only implemented for devices with a device node
1534 * or network interfaces. All other devices return 1 here.
1536 * Returns: 1 if the device is set up. 0 otherwise.
1538 _public_ int udev_device_get_is_initialized(struct udev_device *udev_device)
1540 if (!udev_device->info_loaded)
1541 udev_device_read_db(udev_device, NULL);
1542 return udev_device->is_initialized;
1545 void udev_device_set_is_initialized(struct udev_device *udev_device)
1547 udev_device->is_initialized = true;
1550 int udev_device_add_tag(struct udev_device *udev_device, const char *tag)
1552 if (strchr(tag, ':') != NULL || strchr(tag, ' ') != NULL)
1554 udev_device->tags_uptodate = false;
1555 if (udev_list_entry_add(&udev_device->tags_list, tag, NULL) != NULL)
1560 void udev_device_cleanup_tags_list(struct udev_device *udev_device)
1562 udev_device->tags_uptodate = false;
1563 udev_list_cleanup(&udev_device->tags_list);
1567 * udev_device_get_tags_list_entry:
1568 * @udev_device: udev device
1570 * Retrieve the list of tags attached to the udev device. The next
1571 * list entry can be retrieved with udev_list_entry_get_next(),
1572 * which returns #NULL if no more entries exist. The tag string
1573 * can be retrieved from the list entry by udev_list_entry_get_name().
1575 * Returns: the first entry of the tag list
1577 _public_ struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device)
1579 if (udev_device == NULL)
1581 if (!udev_device->info_loaded)
1582 udev_device_read_db(udev_device, NULL);
1583 return udev_list_get_entry(&udev_device->tags_list);
1586 _public_ int udev_device_has_tag(struct udev_device *udev_device, const char *tag)
1588 struct udev_list_entry *list_entry;
1590 if (udev_device == NULL)
1592 if (!udev_device->info_loaded)
1593 udev_device_read_db(udev_device, NULL);
1594 list_entry = udev_device_get_tags_list_entry(udev_device);
1595 if (udev_list_entry_get_by_name(list_entry, tag) != NULL)
1600 #define ENVP_SIZE 128
1601 #define MONITOR_BUF_SIZE 4096
1602 static int update_envp_monitor_buf(struct udev_device *udev_device)
1604 struct udev_list_entry *list_entry;
1609 /* monitor buffer of property strings */
1610 free(udev_device->monitor_buf);
1611 udev_device->monitor_buf_len = 0;
1612 udev_device->monitor_buf = malloc(MONITOR_BUF_SIZE);
1613 if (udev_device->monitor_buf == NULL)
1616 /* envp array, strings will point into monitor buffer */
1617 if (udev_device->envp == NULL)
1618 udev_device->envp = malloc(sizeof(char *) * ENVP_SIZE);
1619 if (udev_device->envp == NULL)
1623 s = udev_device->monitor_buf;
1624 l = MONITOR_BUF_SIZE;
1625 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
1628 key = udev_list_entry_get_name(list_entry);
1629 /* skip private variables */
1633 /* add string to envp array */
1634 udev_device->envp[i++] = s;
1635 if (i+1 >= ENVP_SIZE)
1638 /* add property string to monitor buffer */
1639 l = util_strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
1642 /* advance past the trailing '\0' that util_strpcpyl() guarantees */
1646 udev_device->envp[i] = NULL;
1647 udev_device->monitor_buf_len = s - udev_device->monitor_buf;
1648 udev_device->envp_uptodate = true;
1652 char **udev_device_get_properties_envp(struct udev_device *udev_device)
1654 if (!udev_device->envp_uptodate)
1655 if (update_envp_monitor_buf(udev_device) != 0)
1657 return udev_device->envp;
1660 ssize_t udev_device_get_properties_monitor_buf(struct udev_device *udev_device, const char **buf)
1662 if (!udev_device->envp_uptodate)
1663 if (update_envp_monitor_buf(udev_device) != 0)
1665 *buf = udev_device->monitor_buf;
1666 return udev_device->monitor_buf_len;
1669 int udev_device_set_action(struct udev_device *udev_device, const char *action)
1671 free(udev_device->action);
1672 udev_device->action = strdup(action);
1673 if (udev_device->action == NULL)
1675 udev_device_add_property(udev_device, "ACTION", udev_device->action);
1679 int udev_device_get_devlink_priority(struct udev_device *udev_device)
1681 if (!udev_device->info_loaded)
1682 udev_device_read_db(udev_device, NULL);
1683 return udev_device->devlink_priority;
1686 int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio)
1688 udev_device->devlink_priority = prio;
1692 int udev_device_get_watch_handle(struct udev_device *udev_device)
1694 if (!udev_device->info_loaded)
1695 udev_device_read_db(udev_device, NULL);
1696 return udev_device->watch_handle;
1699 int udev_device_set_watch_handle(struct udev_device *udev_device, int handle)
1701 udev_device->watch_handle = handle;
1705 bool udev_device_get_db_persist(struct udev_device *udev_device)
1707 return udev_device->db_persist;
1710 void udev_device_set_db_persist(struct udev_device *udev_device)
1712 udev_device->db_persist = true;