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"
33 static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
34 [DEVICE_DEAD] = UNIT_INACTIVE,
35 [DEVICE_PLUGGED] = UNIT_ACTIVE
38 static void device_unset_sysfs(Device *d) {
46 /* Remove this unit from the chain of devices which share the
48 first = hashmap_get(d->meta.manager->devices_by_sysfs, d->sysfs);
49 LIST_REMOVE(Device, same_sysfs, first, d);
52 hashmap_remove_and_replace(d->meta.manager->devices_by_sysfs, d->sysfs, first->sysfs, first);
54 hashmap_remove(d->meta.manager->devices_by_sysfs, d->sysfs);
60 static void device_init(Unit *u) {
61 Device *d = DEVICE(u);
64 assert(d->meta.load_state == UNIT_STUB);
66 /* In contrast to all other unit types we timeout jobs waiting
67 * for devices by default. This is because they otherwise wait
68 * indefinetely for plugged in devices, something which cannot
69 * happen for the other units since their operations time out
71 d->meta.job_timeout = DEFAULT_TIMEOUT_USEC;
73 /* We enable recursive stopping by default for all
74 devices. This enables the user to use Requires= to make a
75 service go a way when a device goes away, and Wants=
77 d->meta.recursive_stop = true;
80 static void device_done(Unit *u) {
81 Device *d = DEVICE(u);
85 device_unset_sysfs(d);
88 static void device_set_state(Device *d, DeviceState state) {
89 DeviceState old_state;
95 if (state != old_state)
96 log_debug("%s changed %s -> %s",
98 device_state_to_string(old_state),
99 device_state_to_string(state));
101 unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state]);
104 static int device_coldplug(Unit *u) {
105 Device *d = DEVICE(u);
108 assert(d->state == DEVICE_DEAD);
111 device_set_state(d, DEVICE_PLUGGED);
116 static void device_dump(Unit *u, FILE *f, const char *prefix) {
117 Device *d = DEVICE(u);
122 "%sDevice State: %s\n"
123 "%sSysfs Path: %s\n",
124 prefix, device_state_to_string(d->state),
125 prefix, strna(d->sysfs));
128 static UnitActiveState device_active_state(Unit *u) {
131 return state_translation_table[DEVICE(u)->state];
134 static const char *device_sub_state_to_string(Unit *u) {
137 return device_state_to_string(DEVICE(u)->state);
140 static int device_add_escaped_name(Unit *u, const char *dn) {
146 assert(dn[0] == '/');
148 if (!(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 if (!(e = unit_name_from_path(dn, ".device")))
172 u = manager_get_unit(m, e);
183 static int device_update_unit(Manager *m, struct udev_device *dev, const char *path, bool main) {
184 const char *sysfs, *model;
191 if (!(sysfs = udev_device_get_syspath(dev)))
194 if ((r = device_find_escape_name(m, path, &u)) < 0)
197 if (u && DEVICE(u)->sysfs && !path_equal(DEVICE(u)->sysfs, sysfs))
203 if (!(u = unit_new(m)))
206 if ((r = device_add_escaped_name(u, path)) < 0)
209 unit_add_to_load_queue(u);
213 /* If this was created via some dependency and has not
214 * actually been seen yet ->sysfs will not be
215 * initialized. Hence initialize it if necessary. */
217 if (!DEVICE(u)->sysfs) {
220 if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
225 if (!m->devices_by_sysfs)
226 if (!(m->devices_by_sysfs = hashmap_new(string_hash_func, string_compare_func))) {
231 first = hashmap_get(m->devices_by_sysfs, sysfs);
232 LIST_PREPEND(Device, same_sysfs, first, DEVICE(u));
234 if ((r = hashmap_replace(m->devices_by_sysfs, DEVICE(u)->sysfs, first)) < 0)
238 if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
239 (model = udev_device_get_property_value(dev, "ID_MODEL"))) {
240 if ((r = unit_set_description(u, model)) < 0)
243 if ((r = unit_set_description(u, path)) < 0)
247 /* The additional systemd udev properties we only
248 * interpret for the main object */
249 const char *wants, *alias;
251 if ((alias = udev_device_get_property_value(dev, "SYSTEMD_ALIAS"))) {
253 log_warning("SYSTEMD_ALIAS for %s is not a path, ignoring: %s", sysfs, alias);
255 if ((r = device_add_escaped_name(u, alias)) < 0)
260 if ((wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS"))) {
264 FOREACH_WORD_QUOTED(w, l, wants, state) {
267 if (!(e = strndup(w, l))) {
272 r = unit_add_dependency_by_name(u, UNIT_WANTS, e, NULL, true);
281 unit_add_to_dbus_queue(u);
285 log_warning("Failed to load device unit: %s", strerror(-r));
293 static int device_process_new_device(Manager *m, struct udev_device *dev, bool update_state) {
294 const char *sysfs, *dn;
295 struct udev_list_entry *item = NULL, *first = NULL;
299 if (!(sysfs = udev_device_get_syspath(dev)))
302 /* Add the main unit named after the sysfs path */
303 device_update_unit(m, dev, sysfs, true);
305 /* Add an additional unit for the device node */
306 if ((dn = udev_device_get_devnode(dev)))
307 device_update_unit(m, dev, dn, false);
309 /* Add additional units for all symlinks */
310 first = udev_device_get_devlinks_list_entry(dev);
311 udev_list_entry_foreach(item, first) {
315 /* Don't bother with the /dev/block links */
316 p = udev_list_entry_get_name(item);
318 if (path_startswith(p, "/dev/block/") ||
319 path_startswith(p, "/dev/char/"))
322 /* Verify that the symlink in the FS actually belongs
323 * to this device. This is useful to deal with
324 * conflicting devices, e.g. when two disks want the
325 * same /dev/disk/by-label/xxx link because they have
326 * the same label. We want to make sure that the same
327 * device that won the symlink wins in systemd, so we
328 * check the device node major/minor*/
329 if (stat(p, &st) >= 0)
330 if ((!S_ISBLK(st.st_mode) && !S_ISCHR(st.st_mode)) ||
331 st.st_rdev != udev_device_get_devnum(dev))
334 device_update_unit(m, dev, p, false);
340 manager_dispatch_load_queue(m);
342 l = hashmap_get(m->devices_by_sysfs, sysfs);
343 LIST_FOREACH(same_sysfs, d, l)
344 device_set_state(d, DEVICE_PLUGGED);
350 static int device_process_path(Manager *m, const char *path, bool update_state) {
352 struct udev_device *dev;
357 if (!(dev = udev_device_new_from_syspath(m->udev, path))) {
358 log_warning("Failed to get udev device object from udev for path %s.", path);
362 r = device_process_new_device(m, dev, update_state);
363 udev_device_unref(dev);
367 static int device_process_removed_device(Manager *m, struct udev_device *dev) {
374 if (!(sysfs = udev_device_get_syspath(dev)))
377 /* Remove all units of this sysfs path */
378 while ((d = hashmap_get(m->devices_by_sysfs, sysfs))) {
379 device_unset_sysfs(d);
380 device_set_state(d, DEVICE_DEAD);
386 static Unit *device_following(Unit *u) {
387 Device *d = DEVICE(u);
388 Device *other, *first = NULL;
392 if (startswith(u->meta.id, "sys-"))
395 /* Make everybody follow the unit that's named after the sysfs path */
396 for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
397 if (startswith(other->meta.id, "sys-"))
400 for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev) {
401 if (startswith(other->meta.id, "sys-"))
410 static void device_shutdown(Manager *m) {
413 if (m->udev_monitor) {
414 udev_monitor_unref(m->udev_monitor);
415 m->udev_monitor = NULL;
423 hashmap_free(m->devices_by_sysfs);
424 m->devices_by_sysfs = NULL;
427 static int device_enumerate(Manager *m) {
428 struct epoll_event ev;
430 struct udev_enumerate *e = NULL;
431 struct udev_list_entry *item = NULL, *first = NULL;
436 if (!(m->udev = udev_new()))
439 if (!(m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev"))) {
444 if (udev_monitor_filter_add_match_tag(m->udev_monitor, "systemd") < 0) {
449 if (udev_monitor_enable_receiving(m->udev_monitor) < 0) {
454 m->udev_watch.type = WATCH_UDEV;
455 m->udev_watch.fd = udev_monitor_get_fd(m->udev_monitor);
459 ev.data.ptr = &m->udev_watch;
461 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->udev_watch.fd, &ev) < 0)
465 if (!(e = udev_enumerate_new(m->udev))) {
469 if (udev_enumerate_add_match_tag(e, "systemd") < 0) {
474 if (udev_enumerate_scan_devices(e) < 0) {
479 first = udev_enumerate_get_list_entry(e);
480 udev_list_entry_foreach(item, first)
481 device_process_path(m, udev_list_entry_get_name(item), false);
483 udev_enumerate_unref(e);
488 udev_enumerate_unref(e);
494 void device_fd_event(Manager *m, int events) {
495 struct udev_device *dev;
500 assert(events == EPOLLIN);
502 if (!(dev = udev_monitor_receive_device(m->udev_monitor))) {
503 log_error("Failed to receive device.");
507 if (!(action = udev_device_get_action(dev))) {
508 log_error("Failed to get udev action string.");
512 if (streq(action, "remove")) {
513 if ((r = device_process_removed_device(m, dev)) < 0) {
514 log_error("Failed to process udev device event: %s", strerror(-r));
518 if ((r = device_process_new_device(m, dev, true)) < 0) {
519 log_error("Failed to process udev device event: %s", strerror(-r));
525 udev_device_unref(dev);
528 static const char* const device_state_table[_DEVICE_STATE_MAX] = {
529 [DEVICE_DEAD] = "dead",
530 [DEVICE_PLUGGED] = "plugged"
533 DEFINE_STRING_TABLE_LOOKUP(device_state, DeviceState);
535 const UnitVTable device_vtable = {
539 .no_instances = true,
540 .no_snapshots = true,
545 .load = unit_load_fragment_and_dropin_optional,
547 .coldplug = device_coldplug,
551 .active_state = device_active_state,
552 .sub_state_to_string = device_sub_state_to_string,
554 .bus_interface = "org.freedesktop.systemd1.Device",
555 .bus_message_handler = bus_device_message_handler,
556 .bus_invalidating_properties = bus_device_invalidating_properties,
558 .following = device_following,
560 .enumerate = device_enumerate,
561 .shutdown = device_shutdown