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 Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser 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"
33 #include "path-util.h"
35 static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
36 [DEVICE_DEAD] = UNIT_INACTIVE,
37 [DEVICE_PLUGGED] = UNIT_ACTIVE
40 static void device_unset_sysfs(Device *d) {
48 /* Remove this unit from the chain of devices which share the
50 first = hashmap_get(UNIT(d)->manager->devices_by_sysfs, d->sysfs);
51 LIST_REMOVE(Device, same_sysfs, first, d);
54 hashmap_remove_and_replace(UNIT(d)->manager->devices_by_sysfs, d->sysfs, first->sysfs, first);
56 hashmap_remove(UNIT(d)->manager->devices_by_sysfs, d->sysfs);
62 static void device_init(Unit *u) {
63 Device *d = DEVICE(u);
66 assert(UNIT(d)->load_state == UNIT_STUB);
68 /* In contrast to all other unit types we timeout jobs waiting
69 * for devices by default. This is because they otherwise wait
70 * indefinitely for plugged in devices, something which cannot
71 * happen for the other units since their operations time out
73 UNIT(d)->job_timeout = DEFAULT_TIMEOUT_USEC;
75 UNIT(d)->ignore_on_isolate = true;
76 UNIT(d)->ignore_on_snapshot = true;
79 static void device_done(Unit *u) {
80 Device *d = DEVICE(u);
84 device_unset_sysfs(d);
87 static void device_set_state(Device *d, DeviceState state) {
88 DeviceState old_state;
94 if (state != old_state)
95 log_debug("%s changed %s -> %s",
97 device_state_to_string(old_state),
98 device_state_to_string(state));
100 unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state], true);
103 static int device_coldplug(Unit *u) {
104 Device *d = DEVICE(u);
107 assert(d->state == DEVICE_DEAD);
110 device_set_state(d, DEVICE_PLUGGED);
115 static void device_dump(Unit *u, FILE *f, const char *prefix) {
116 Device *d = DEVICE(u);
121 "%sDevice State: %s\n"
122 "%sSysfs Path: %s\n",
123 prefix, device_state_to_string(d->state),
124 prefix, strna(d->sysfs));
127 static UnitActiveState device_active_state(Unit *u) {
130 return state_translation_table[DEVICE(u)->state];
133 static const char *device_sub_state_to_string(Unit *u) {
136 return device_state_to_string(DEVICE(u)->state);
139 static int device_add_escaped_name(Unit *u, const char *dn) {
145 assert(dn[0] == '/');
147 e = unit_name_from_path(dn, ".device");
151 r = unit_add_name(u, e);
154 if (r < 0 && r != -EEXIST)
160 static int device_find_escape_name(Manager *m, const char *dn, Unit **_u) {
166 assert(dn[0] == '/');
169 e = unit_name_from_path(dn, ".device");
173 u = manager_get_unit(m, e);
184 static int device_update_unit(Manager *m, struct udev_device *dev, const char *path, bool main) {
185 const char *sysfs, *model;
192 if (!(sysfs = udev_device_get_syspath(dev)))
195 if ((r = device_find_escape_name(m, path, &u)) < 0)
198 if (u && DEVICE(u)->sysfs && !path_equal(DEVICE(u)->sysfs, sysfs))
204 u = unit_new(m, sizeof(Device));
208 r = device_add_escaped_name(u, path);
212 unit_add_to_load_queue(u);
216 /* If this was created via some dependency and has not
217 * actually been seen yet ->sysfs will not be
218 * initialized. Hence initialize it if necessary. */
220 if (!DEVICE(u)->sysfs) {
223 if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
228 if (!m->devices_by_sysfs)
229 if (!(m->devices_by_sysfs = hashmap_new(string_hash_func, string_compare_func))) {
234 first = hashmap_get(m->devices_by_sysfs, sysfs);
235 LIST_PREPEND(Device, same_sysfs, first, DEVICE(u));
237 if ((r = hashmap_replace(m->devices_by_sysfs, DEVICE(u)->sysfs, first)) < 0)
241 if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
242 (model = udev_device_get_property_value(dev, "ID_MODEL"))) {
243 if ((r = unit_set_description(u, model)) < 0)
246 if ((r = unit_set_description(u, path)) < 0)
250 /* The additional systemd udev properties we only
251 * interpret for the main object */
252 const char *wants, *alias;
254 if ((alias = udev_device_get_property_value(dev, "SYSTEMD_ALIAS"))) {
256 log_warning("SYSTEMD_ALIAS for %s is not a path, ignoring: %s", sysfs, alias);
258 if ((r = device_add_escaped_name(u, alias)) < 0)
263 if ((wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS"))) {
267 FOREACH_WORD_QUOTED(w, l, wants, state) {
270 if (!(e = strndup(w, l))) {
275 r = unit_add_dependency_by_name(u, UNIT_WANTS, e, NULL, true);
284 unit_add_to_dbus_queue(u);
288 log_warning("Failed to load device unit: %s", strerror(-r));
296 static int device_process_new_device(Manager *m, struct udev_device *dev, bool update_state) {
297 const char *sysfs, *dn;
298 struct udev_list_entry *item = NULL, *first = NULL;
302 if (!(sysfs = udev_device_get_syspath(dev)))
305 /* Add the main unit named after the sysfs path */
306 device_update_unit(m, dev, sysfs, true);
308 /* Add an additional unit for the device node */
309 if ((dn = udev_device_get_devnode(dev)))
310 device_update_unit(m, dev, dn, false);
312 /* Add additional units for all symlinks */
313 first = udev_device_get_devlinks_list_entry(dev);
314 udev_list_entry_foreach(item, first) {
318 /* Don't bother with the /dev/block links */
319 p = udev_list_entry_get_name(item);
321 if (path_startswith(p, "/dev/block/") ||
322 path_startswith(p, "/dev/char/"))
325 /* Verify that the symlink in the FS actually belongs
326 * to this device. This is useful to deal with
327 * conflicting devices, e.g. when two disks want the
328 * same /dev/disk/by-label/xxx link because they have
329 * the same label. We want to make sure that the same
330 * device that won the symlink wins in systemd, so we
331 * check the device node major/minor*/
332 if (stat(p, &st) >= 0)
333 if ((!S_ISBLK(st.st_mode) && !S_ISCHR(st.st_mode)) ||
334 st.st_rdev != udev_device_get_devnum(dev))
337 device_update_unit(m, dev, p, false);
343 manager_dispatch_load_queue(m);
345 l = hashmap_get(m->devices_by_sysfs, sysfs);
346 LIST_FOREACH(same_sysfs, d, l)
347 device_set_state(d, DEVICE_PLUGGED);
353 static int device_process_path(Manager *m, const char *path, bool update_state) {
355 struct udev_device *dev;
360 if (!(dev = udev_device_new_from_syspath(m->udev, path))) {
361 log_warning("Failed to get udev device object from udev for path %s.", path);
365 r = device_process_new_device(m, dev, update_state);
366 udev_device_unref(dev);
370 static int device_process_removed_device(Manager *m, struct udev_device *dev) {
377 if (!(sysfs = udev_device_get_syspath(dev)))
380 /* Remove all units of this sysfs path */
381 while ((d = hashmap_get(m->devices_by_sysfs, sysfs))) {
382 device_unset_sysfs(d);
383 device_set_state(d, DEVICE_DEAD);
389 static Unit *device_following(Unit *u) {
390 Device *d = DEVICE(u);
391 Device *other, *first = NULL;
395 if (startswith(u->id, "sys-"))
398 /* Make everybody follow the unit that's named after the sysfs path */
399 for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
400 if (startswith(UNIT(other)->id, "sys-"))
403 for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev) {
404 if (startswith(UNIT(other)->id, "sys-"))
413 static int device_following_set(Unit *u, Set **_s) {
414 Device *d = DEVICE(u);
422 if (!d->same_sysfs_prev && !d->same_sysfs_next) {
427 if (!(s = set_new(NULL, NULL)))
430 for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
431 if ((r = set_put(s, other)) < 0)
434 for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev)
435 if ((r = set_put(s, other)) < 0)
446 static void device_shutdown(Manager *m) {
449 if (m->udev_monitor) {
450 udev_monitor_unref(m->udev_monitor);
451 m->udev_monitor = NULL;
459 hashmap_free(m->devices_by_sysfs);
460 m->devices_by_sysfs = NULL;
463 static int device_enumerate(Manager *m) {
464 struct epoll_event ev;
466 struct udev_enumerate *e = NULL;
467 struct udev_list_entry *item = NULL, *first = NULL;
472 if (!(m->udev = udev_new()))
475 if (!(m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev"))) {
480 /* This will fail if we are unprivileged, but that
481 * should not matter much, as user instances won't run
483 udev_monitor_set_receive_buffer_size(m->udev_monitor, 128*1024*1024);
485 if (udev_monitor_filter_add_match_tag(m->udev_monitor, "systemd") < 0) {
490 if (udev_monitor_enable_receiving(m->udev_monitor) < 0) {
495 m->udev_watch.type = WATCH_UDEV;
496 m->udev_watch.fd = udev_monitor_get_fd(m->udev_monitor);
500 ev.data.ptr = &m->udev_watch;
502 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->udev_watch.fd, &ev) < 0)
506 if (!(e = udev_enumerate_new(m->udev))) {
510 if (udev_enumerate_add_match_tag(e, "systemd") < 0) {
515 if (udev_enumerate_scan_devices(e) < 0) {
520 first = udev_enumerate_get_list_entry(e);
521 udev_list_entry_foreach(item, first)
522 device_process_path(m, udev_list_entry_get_name(item), false);
524 udev_enumerate_unref(e);
529 udev_enumerate_unref(e);
535 void device_fd_event(Manager *m, int events) {
536 struct udev_device *dev;
538 const char *action, *ready;
542 if (events != EPOLLIN) {
543 static RATELIMIT_DEFINE(limit, 10*USEC_PER_SEC, 5);
545 if (!ratelimit_test(&limit))
546 log_error("Failed to get udev event: %m");
547 if (!(events & EPOLLIN))
551 if (!(dev = udev_monitor_receive_device(m->udev_monitor))) {
553 * libudev might filter-out devices which pass the bloom filter,
554 * so getting NULL here is not necessarily an error
559 if (!(action = udev_device_get_action(dev))) {
560 log_error("Failed to get udev action string.");
564 ready = udev_device_get_property_value(dev, "SYSTEMD_READY");
566 if (streq(action, "remove") || (ready && parse_boolean(ready) == 0)) {
567 if ((r = device_process_removed_device(m, dev)) < 0) {
568 log_error("Failed to process udev device event: %s", strerror(-r));
572 if ((r = device_process_new_device(m, dev, true)) < 0) {
573 log_error("Failed to process udev device event: %s", strerror(-r));
579 udev_device_unref(dev);
582 static const char* const device_state_table[_DEVICE_STATE_MAX] = {
583 [DEVICE_DEAD] = "dead",
584 [DEVICE_PLUGGED] = "plugged"
587 DEFINE_STRING_TABLE_LOOKUP(device_state, DeviceState);
589 const UnitVTable device_vtable = {
590 .object_size = sizeof(Device),
596 .no_instances = true,
600 .load = unit_load_fragment_and_dropin_optional,
602 .coldplug = device_coldplug,
606 .active_state = device_active_state,
607 .sub_state_to_string = device_sub_state_to_string,
609 .bus_interface = "org.freedesktop.systemd1.Device",
610 .bus_message_handler = bus_device_message_handler,
611 .bus_invalidating_properties = bus_device_invalidating_properties,
613 .following = device_following,
614 .following_set = device_following_set,
616 .enumerate = device_enumerate,
617 .shutdown = device_shutdown,
619 .status_message_formats = {
620 .starting_stopping = {
621 [0] = "Expecting device %s...",
623 .finished_start_job = {
624 [JOB_DONE] = "Found device %s.",
625 [JOB_TIMEOUT] = "Timed out waiting for device %s.",