1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
23 #include <sys/epoll.h>
30 #include "unit-name.h"
31 #include "dbus-device.h"
34 static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
35 [DEVICE_DEAD] = UNIT_INACTIVE,
36 [DEVICE_PLUGGED] = UNIT_ACTIVE
39 static void device_unset_sysfs(Device *d) {
47 /* Remove this unit from the chain of devices which share the
49 first = hashmap_get(d->meta.manager->devices_by_sysfs, d->sysfs);
50 LIST_REMOVE(Device, same_sysfs, first, d);
53 hashmap_remove_and_replace(d->meta.manager->devices_by_sysfs, d->sysfs, first->sysfs, first);
55 hashmap_remove(d->meta.manager->devices_by_sysfs, d->sysfs);
61 static void device_init(Unit *u) {
62 Device *d = DEVICE(u);
65 assert(d->meta.load_state == UNIT_STUB);
67 /* In contrast to all other unit types we timeout jobs waiting
68 * for devices by default. This is because they otherwise wait
69 * indefinitely for plugged in devices, something which cannot
70 * happen for the other units since their operations time out
72 d->meta.job_timeout = DEFAULT_TIMEOUT_USEC;
75 static void device_done(Unit *u) {
76 Device *d = DEVICE(u);
80 device_unset_sysfs(d);
83 static void device_set_state(Device *d, DeviceState state) {
84 DeviceState old_state;
90 if (state != old_state)
91 log_debug("%s changed %s -> %s",
93 device_state_to_string(old_state),
94 device_state_to_string(state));
96 unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state], true);
99 static int device_coldplug(Unit *u) {
100 Device *d = DEVICE(u);
103 assert(d->state == DEVICE_DEAD);
106 device_set_state(d, DEVICE_PLUGGED);
111 static void device_dump(Unit *u, FILE *f, const char *prefix) {
112 Device *d = DEVICE(u);
117 "%sDevice State: %s\n"
118 "%sSysfs Path: %s\n",
119 prefix, device_state_to_string(d->state),
120 prefix, strna(d->sysfs));
123 static UnitActiveState device_active_state(Unit *u) {
126 return state_translation_table[DEVICE(u)->state];
129 static const char *device_sub_state_to_string(Unit *u) {
132 return device_state_to_string(DEVICE(u)->state);
135 static int device_add_escaped_name(Unit *u, const char *dn) {
141 assert(dn[0] == '/');
143 if (!(e = unit_name_from_path(dn, ".device")))
146 r = unit_add_name(u, e);
149 if (r < 0 && r != -EEXIST)
155 static int device_find_escape_name(Manager *m, const char *dn, Unit **_u) {
161 assert(dn[0] == '/');
164 if (!(e = unit_name_from_path(dn, ".device")))
167 u = manager_get_unit(m, e);
178 static int device_update_unit(Manager *m, struct udev_device *dev, const char *path, bool main) {
179 const char *sysfs, *model;
186 if (!(sysfs = udev_device_get_syspath(dev)))
189 if ((r = device_find_escape_name(m, path, &u)) < 0)
192 if (u && DEVICE(u)->sysfs && !path_equal(DEVICE(u)->sysfs, sysfs))
198 if (!(u = unit_new(m)))
201 if ((r = device_add_escaped_name(u, path)) < 0)
204 unit_add_to_load_queue(u);
208 /* If this was created via some dependency and has not
209 * actually been seen yet ->sysfs will not be
210 * initialized. Hence initialize it if necessary. */
212 if (!DEVICE(u)->sysfs) {
215 if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
220 if (!m->devices_by_sysfs)
221 if (!(m->devices_by_sysfs = hashmap_new(string_hash_func, string_compare_func))) {
226 first = hashmap_get(m->devices_by_sysfs, sysfs);
227 LIST_PREPEND(Device, same_sysfs, first, DEVICE(u));
229 if ((r = hashmap_replace(m->devices_by_sysfs, DEVICE(u)->sysfs, first)) < 0)
233 if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
234 (model = udev_device_get_property_value(dev, "ID_MODEL"))) {
235 if ((r = unit_set_description(u, model)) < 0)
238 if ((r = unit_set_description(u, path)) < 0)
242 /* The additional systemd udev properties we only
243 * interpret for the main object */
244 const char *wants, *alias;
246 if ((alias = udev_device_get_property_value(dev, "SYSTEMD_ALIAS"))) {
248 log_warning("SYSTEMD_ALIAS for %s is not a path, ignoring: %s", sysfs, alias);
250 if ((r = device_add_escaped_name(u, alias)) < 0)
255 if ((wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS"))) {
259 FOREACH_WORD_QUOTED(w, l, wants, state) {
262 if (!(e = strndup(w, l))) {
267 r = unit_add_dependency_by_name(u, UNIT_WANTS, e, NULL, true);
276 unit_add_to_dbus_queue(u);
280 log_warning("Failed to load device unit: %s", strerror(-r));
288 static int device_process_new_device(Manager *m, struct udev_device *dev, bool update_state) {
289 const char *sysfs, *dn;
290 struct udev_list_entry *item = NULL, *first = NULL;
294 if (!(sysfs = udev_device_get_syspath(dev)))
297 /* Add the main unit named after the sysfs path */
298 device_update_unit(m, dev, sysfs, true);
300 /* Add an additional unit for the device node */
301 if ((dn = udev_device_get_devnode(dev)))
302 device_update_unit(m, dev, dn, false);
304 /* Add additional units for all symlinks */
305 first = udev_device_get_devlinks_list_entry(dev);
306 udev_list_entry_foreach(item, first) {
310 /* Don't bother with the /dev/block links */
311 p = udev_list_entry_get_name(item);
313 if (path_startswith(p, "/dev/block/") ||
314 path_startswith(p, "/dev/char/"))
317 /* Verify that the symlink in the FS actually belongs
318 * to this device. This is useful to deal with
319 * conflicting devices, e.g. when two disks want the
320 * same /dev/disk/by-label/xxx link because they have
321 * the same label. We want to make sure that the same
322 * device that won the symlink wins in systemd, so we
323 * check the device node major/minor*/
324 if (stat(p, &st) >= 0)
325 if ((!S_ISBLK(st.st_mode) && !S_ISCHR(st.st_mode)) ||
326 st.st_rdev != udev_device_get_devnum(dev))
329 device_update_unit(m, dev, p, false);
335 manager_dispatch_load_queue(m);
337 l = hashmap_get(m->devices_by_sysfs, sysfs);
338 LIST_FOREACH(same_sysfs, d, l)
339 device_set_state(d, DEVICE_PLUGGED);
345 static int device_process_path(Manager *m, const char *path, bool update_state) {
347 struct udev_device *dev;
352 if (!(dev = udev_device_new_from_syspath(m->udev, path))) {
353 log_warning("Failed to get udev device object from udev for path %s.", path);
357 r = device_process_new_device(m, dev, update_state);
358 udev_device_unref(dev);
362 static int device_process_removed_device(Manager *m, struct udev_device *dev) {
369 if (!(sysfs = udev_device_get_syspath(dev)))
372 /* Remove all units of this sysfs path */
373 while ((d = hashmap_get(m->devices_by_sysfs, sysfs))) {
374 device_unset_sysfs(d);
375 device_set_state(d, DEVICE_DEAD);
381 static Unit *device_following(Unit *u) {
382 Device *d = DEVICE(u);
383 Device *other, *first = NULL;
387 if (startswith(u->meta.id, "sys-"))
390 /* Make everybody follow the unit that's named after the sysfs path */
391 for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
392 if (startswith(other->meta.id, "sys-"))
395 for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev) {
396 if (startswith(other->meta.id, "sys-"))
405 static int device_following_set(Unit *u, Set **_s) {
406 Device *d = DEVICE(u);
414 if (!d->same_sysfs_prev && !d->same_sysfs_next) {
419 if (!(s = set_new(NULL, NULL)))
422 for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
423 if ((r = set_put(s, other)) < 0)
426 for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev)
427 if ((r = set_put(s, other)) < 0)
438 static void device_shutdown(Manager *m) {
441 if (m->udev_monitor) {
442 udev_monitor_unref(m->udev_monitor);
443 m->udev_monitor = NULL;
451 hashmap_free(m->devices_by_sysfs);
452 m->devices_by_sysfs = NULL;
455 static int device_enumerate(Manager *m) {
456 struct epoll_event ev;
458 struct udev_enumerate *e = NULL;
459 struct udev_list_entry *item = NULL, *first = NULL;
464 if (!(m->udev = udev_new()))
467 if (!(m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev"))) {
472 /* This will fail if we are unprivileged, but that
473 * should not matter much, as user instances won't run
475 udev_monitor_set_receive_buffer_size(m->udev_monitor, 128*1024*1024);
477 if (udev_monitor_filter_add_match_tag(m->udev_monitor, "systemd") < 0) {
482 if (udev_monitor_enable_receiving(m->udev_monitor) < 0) {
487 m->udev_watch.type = WATCH_UDEV;
488 m->udev_watch.fd = udev_monitor_get_fd(m->udev_monitor);
492 ev.data.ptr = &m->udev_watch;
494 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->udev_watch.fd, &ev) < 0)
498 if (!(e = udev_enumerate_new(m->udev))) {
502 if (udev_enumerate_add_match_tag(e, "systemd") < 0) {
507 if (udev_enumerate_scan_devices(e) < 0) {
512 first = udev_enumerate_get_list_entry(e);
513 udev_list_entry_foreach(item, first)
514 device_process_path(m, udev_list_entry_get_name(item), false);
516 udev_enumerate_unref(e);
521 udev_enumerate_unref(e);
527 void device_fd_event(Manager *m, int events) {
528 struct udev_device *dev;
530 const char *action, *ready;
534 if (events != EPOLLIN) {
535 static RATELIMIT_DEFINE(limit, 10*USEC_PER_SEC, 5);
537 if (!ratelimit_test(&limit))
538 log_error("Failed to get udev event: %m");
539 if (!(events & EPOLLIN))
543 if (!(dev = udev_monitor_receive_device(m->udev_monitor))) {
545 * libudev might filter-out devices which pass the bloom filter,
546 * so getting NULL here is not necessarily an error
551 if (!(action = udev_device_get_action(dev))) {
552 log_error("Failed to get udev action string.");
556 ready = udev_device_get_property_value(dev, "SYSTEMD_READY");
558 if (streq(action, "remove") || (ready && parse_boolean(ready) == 0)) {
559 if ((r = device_process_removed_device(m, dev)) < 0) {
560 log_error("Failed to process udev device event: %s", strerror(-r));
564 if ((r = device_process_new_device(m, dev, true)) < 0) {
565 log_error("Failed to process udev device event: %s", strerror(-r));
571 udev_device_unref(dev);
574 static const char* const device_state_table[_DEVICE_STATE_MAX] = {
575 [DEVICE_DEAD] = "dead",
576 [DEVICE_PLUGGED] = "plugged"
579 DEFINE_STRING_TABLE_LOOKUP(device_state, DeviceState);
581 const UnitVTable device_vtable = {
584 .no_instances = true,
585 .no_snapshots = true,
590 .load = unit_load_fragment_and_dropin_optional,
592 .coldplug = device_coldplug,
596 .active_state = device_active_state,
597 .sub_state_to_string = device_sub_state_to_string,
599 .bus_interface = "org.freedesktop.systemd1.Device",
600 .bus_message_handler = bus_device_message_handler,
601 .bus_invalidating_properties = bus_device_invalidating_properties,
603 .following = device_following,
604 .following_set = device_following_set,
606 .enumerate = device_enumerate,
607 .shutdown = device_shutdown