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(UNIT(d)->manager->devices_by_sysfs, d->sysfs);
50 LIST_REMOVE(Device, same_sysfs, first, d);
53 hashmap_remove_and_replace(UNIT(d)->manager->devices_by_sysfs, d->sysfs, first->sysfs, first);
55 hashmap_remove(UNIT(d)->manager->devices_by_sysfs, d->sysfs);
61 static void device_init(Unit *u) {
62 Device *d = DEVICE(u);
65 assert(UNIT(d)->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 UNIT(d)->job_timeout = DEFAULT_TIMEOUT_USEC;
74 UNIT(d)->ignore_on_isolate = true;
75 UNIT(d)->ignore_on_snapshot = true;
78 static void device_done(Unit *u) {
79 Device *d = DEVICE(u);
83 device_unset_sysfs(d);
86 static void device_set_state(Device *d, DeviceState state) {
87 DeviceState old_state;
93 if (state != old_state)
94 log_debug("%s changed %s -> %s",
96 device_state_to_string(old_state),
97 device_state_to_string(state));
99 unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state], true);
102 static int device_coldplug(Unit *u) {
103 Device *d = DEVICE(u);
106 assert(d->state == DEVICE_DEAD);
109 device_set_state(d, DEVICE_PLUGGED);
114 static void device_dump(Unit *u, FILE *f, const char *prefix) {
115 Device *d = DEVICE(u);
120 "%sDevice State: %s\n"
121 "%sSysfs Path: %s\n",
122 prefix, device_state_to_string(d->state),
123 prefix, strna(d->sysfs));
126 static UnitActiveState device_active_state(Unit *u) {
129 return state_translation_table[DEVICE(u)->state];
132 static const char *device_sub_state_to_string(Unit *u) {
135 return device_state_to_string(DEVICE(u)->state);
138 static int device_add_escaped_name(Unit *u, const char *dn) {
144 assert(dn[0] == '/');
146 if (!(e = unit_name_from_path(dn, ".device")))
149 r = unit_add_name(u, e);
152 if (r < 0 && r != -EEXIST)
158 static int device_find_escape_name(Manager *m, const char *dn, Unit **_u) {
164 assert(dn[0] == '/');
167 if (!(e = unit_name_from_path(dn, ".device")))
170 u = manager_get_unit(m, e);
181 static int device_update_unit(Manager *m, struct udev_device *dev, const char *path, bool main) {
182 const char *sysfs, *model;
189 if (!(sysfs = udev_device_get_syspath(dev)))
192 if ((r = device_find_escape_name(m, path, &u)) < 0)
195 if (u && DEVICE(u)->sysfs && !path_equal(DEVICE(u)->sysfs, sysfs))
201 u = unit_new(m, sizeof(Device));
205 r = device_add_escaped_name(u, path);
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->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(UNIT(other)->id, "sys-"))
400 for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev) {
401 if (startswith(UNIT(other)->id, "sys-"))
410 static int device_following_set(Unit *u, Set **_s) {
411 Device *d = DEVICE(u);
419 if (!d->same_sysfs_prev && !d->same_sysfs_next) {
424 if (!(s = set_new(NULL, NULL)))
427 for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
428 if ((r = set_put(s, other)) < 0)
431 for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev)
432 if ((r = set_put(s, other)) < 0)
443 static void device_shutdown(Manager *m) {
446 if (m->udev_monitor) {
447 udev_monitor_unref(m->udev_monitor);
448 m->udev_monitor = NULL;
456 hashmap_free(m->devices_by_sysfs);
457 m->devices_by_sysfs = NULL;
460 static int device_enumerate(Manager *m) {
461 struct epoll_event ev;
463 struct udev_enumerate *e = NULL;
464 struct udev_list_entry *item = NULL, *first = NULL;
469 if (!(m->udev = udev_new()))
472 if (!(m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev"))) {
477 /* This will fail if we are unprivileged, but that
478 * should not matter much, as user instances won't run
480 udev_monitor_set_receive_buffer_size(m->udev_monitor, 128*1024*1024);
482 if (udev_monitor_filter_add_match_tag(m->udev_monitor, "systemd") < 0) {
487 if (udev_monitor_enable_receiving(m->udev_monitor) < 0) {
492 m->udev_watch.type = WATCH_UDEV;
493 m->udev_watch.fd = udev_monitor_get_fd(m->udev_monitor);
497 ev.data.ptr = &m->udev_watch;
499 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->udev_watch.fd, &ev) < 0)
503 if (!(e = udev_enumerate_new(m->udev))) {
507 if (udev_enumerate_add_match_tag(e, "systemd") < 0) {
512 if (udev_enumerate_scan_devices(e) < 0) {
517 first = udev_enumerate_get_list_entry(e);
518 udev_list_entry_foreach(item, first)
519 device_process_path(m, udev_list_entry_get_name(item), false);
521 udev_enumerate_unref(e);
526 udev_enumerate_unref(e);
532 void device_fd_event(Manager *m, int events) {
533 struct udev_device *dev;
535 const char *action, *ready;
539 if (events != EPOLLIN) {
540 static RATELIMIT_DEFINE(limit, 10*USEC_PER_SEC, 5);
542 if (!ratelimit_test(&limit))
543 log_error("Failed to get udev event: %m");
544 if (!(events & EPOLLIN))
548 if (!(dev = udev_monitor_receive_device(m->udev_monitor))) {
550 * libudev might filter-out devices which pass the bloom filter,
551 * so getting NULL here is not necessarily an error
556 if (!(action = udev_device_get_action(dev))) {
557 log_error("Failed to get udev action string.");
561 ready = udev_device_get_property_value(dev, "SYSTEMD_READY");
563 if (streq(action, "remove") || (ready && parse_boolean(ready) == 0)) {
564 if ((r = device_process_removed_device(m, dev)) < 0) {
565 log_error("Failed to process udev device event: %s", strerror(-r));
569 if ((r = device_process_new_device(m, dev, true)) < 0) {
570 log_error("Failed to process udev device event: %s", strerror(-r));
576 udev_device_unref(dev);
579 static const char* const device_state_table[_DEVICE_STATE_MAX] = {
580 [DEVICE_DEAD] = "dead",
581 [DEVICE_PLUGGED] = "plugged"
584 DEFINE_STRING_TABLE_LOOKUP(device_state, DeviceState);
586 const UnitVTable device_vtable = {
588 .object_size = sizeof(Device),
594 .no_instances = true,
598 .load = unit_load_fragment_and_dropin_optional,
600 .coldplug = device_coldplug,
604 .active_state = device_active_state,
605 .sub_state_to_string = device_sub_state_to_string,
607 .bus_interface = "org.freedesktop.systemd1.Device",
608 .bus_message_handler = bus_device_message_handler,
609 .bus_invalidating_properties = bus_device_invalidating_properties,
611 .following = device_following,
612 .following_set = device_following_set,
614 .enumerate = device_enumerate,
615 .shutdown = device_shutdown