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>
27 #include "unit-name.h"
28 #include "dbus-device.h"
29 #include "path-util.h"
30 #include "udev-util.h"
35 static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
36 [DEVICE_DEAD] = UNIT_INACTIVE,
37 [DEVICE_TENTATIVE] = UNIT_ACTIVATING,
38 [DEVICE_PLUGGED] = UNIT_ACTIVE,
41 static int device_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
43 static void device_unset_sysfs(Device *d) {
52 /* Remove this unit from the chain of devices which share the
54 devices = UNIT(d)->manager->devices_by_sysfs;
55 first = hashmap_get(devices, d->sysfs);
56 LIST_REMOVE(same_sysfs, first, d);
59 hashmap_remove_and_replace(devices, d->sysfs, first->sysfs, first);
61 hashmap_remove(devices, d->sysfs);
67 static int device_set_sysfs(Device *d, const char *sysfs) {
74 if (streq_ptr(d->sysfs, sysfs))
77 r = hashmap_ensure_allocated(&UNIT(d)->manager->devices_by_sysfs, &string_hash_ops);
85 device_unset_sysfs(d);
87 first = hashmap_get(UNIT(d)->manager->devices_by_sysfs, sysfs);
88 LIST_PREPEND(same_sysfs, first, d);
90 r = hashmap_replace(UNIT(d)->manager->devices_by_sysfs, copy, first);
92 LIST_REMOVE(same_sysfs, first, d);
102 static void device_init(Unit *u) {
103 Device *d = DEVICE(u);
106 assert(UNIT(d)->load_state == UNIT_STUB);
108 /* In contrast to all other unit types we timeout jobs waiting
109 * for devices by default. This is because they otherwise wait
110 * indefinitely for plugged in devices, something which cannot
111 * happen for the other units since their operations time out
113 u->job_timeout = u->manager->default_timeout_start_usec;
115 u->ignore_on_isolate = true;
116 u->ignore_on_snapshot = true;
119 static void device_done(Unit *u) {
120 Device *d = DEVICE(u);
124 device_unset_sysfs(d);
127 static void device_set_state(Device *d, DeviceState state) {
128 DeviceState old_state;
131 old_state = d->state;
134 if (state != old_state)
135 log_unit_debug(UNIT(d)->id,
136 "%s changed %s -> %s", UNIT(d)->id,
137 device_state_to_string(old_state),
138 device_state_to_string(state));
140 unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state], true);
143 static int device_coldplug(Unit *u) {
144 Device *d = DEVICE(u);
147 assert(d->state == DEVICE_DEAD);
149 if (d->found & DEVICE_FOUND_UDEV)
150 /* If udev says the device is around, it's around */
151 device_set_state(d, DEVICE_PLUGGED);
152 else if (d->found != DEVICE_NOT_FOUND)
153 /* If a device is found in /proc/self/mountinfo or
154 * /proc/swaps, it's "tentatively" around. */
155 device_set_state(d, DEVICE_TENTATIVE);
160 static void device_dump(Unit *u, FILE *f, const char *prefix) {
161 Device *d = DEVICE(u);
166 "%sDevice State: %s\n"
167 "%sSysfs Path: %s\n",
168 prefix, device_state_to_string(d->state),
169 prefix, strna(d->sysfs));
172 _pure_ static UnitActiveState device_active_state(Unit *u) {
175 return state_translation_table[DEVICE(u)->state];
178 _pure_ static const char *device_sub_state_to_string(Unit *u) {
181 return device_state_to_string(DEVICE(u)->state);
184 static int device_update_description(Unit *u, struct udev_device *dev, const char *path) {
192 model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE");
194 model = udev_device_get_property_value(dev, "ID_MODEL");
199 /* Try to concatenate the device model string with a label, if there is one */
200 label = udev_device_get_property_value(dev, "ID_FS_LABEL");
202 label = udev_device_get_property_value(dev, "ID_PART_ENTRY_NAME");
204 label = udev_device_get_property_value(dev, "ID_PART_ENTRY_NUMBER");
207 _cleanup_free_ char *j;
209 j = strjoin(model, " ", label, NULL);
211 r = unit_set_description(u, j);
213 r = unit_set_description(u, model);
215 r = unit_set_description(u, path);
218 log_unit_error_errno(u->id, r, "Failed to set device description: %m");
223 static int device_add_udev_wants(Unit *u, struct udev_device *dev) {
225 const char *word, *state;
228 const char *property;
233 property = u->manager->running_as == SYSTEMD_USER ? "SYSTEMD_USER_WANTS" : "SYSTEMD_WANTS";
234 wants = udev_device_get_property_value(dev, property);
238 FOREACH_WORD_QUOTED(word, l, wants, state) {
239 _cleanup_free_ char *n = NULL;
245 n = unit_name_mangle(e, MANGLE_NOGLOB);
249 r = unit_add_dependency_by_name(u, UNIT_WANTS, n, NULL, true);
251 return log_unit_error_errno(u->id, r, "Failed to add wants dependency: %m");
254 log_unit_warning(u->id, "Property %s on %s has trailing garbage, ignoring.", property, strna(udev_device_get_syspath(dev)));
259 static int device_setup_unit(Manager *m, struct udev_device *dev, const char *path, bool main) {
260 _cleanup_free_ char *e = NULL;
270 sysfs = udev_device_get_syspath(dev);
274 e = unit_name_from_path(path, ".device");
278 u = manager_get_unit(m, e);
282 !path_equal(DEVICE(u)->sysfs, sysfs)) {
283 log_unit_error(u->id, "Device %s appeared twice with different sysfs paths %s and %s", e, DEVICE(u)->sysfs, sysfs);
290 u = unit_new(m, sizeof(Device));
294 r = unit_add_name(u, e);
298 unit_add_to_load_queue(u);
302 /* If this was created via some dependency and has not
303 * actually been seen yet ->sysfs will not be
304 * initialized. Hence initialize it if necessary. */
306 r = device_set_sysfs(DEVICE(u), sysfs);
310 (void) device_update_description(u, dev, path);
312 /* The additional systemd udev properties we only interpret
313 * for the main object */
315 (void) device_add_udev_wants(u, dev);
317 /* Note that this won't dispatch the load queue, the caller
318 * has to do that if needed and appropriate */
320 unit_add_to_dbus_queue(u);
324 log_unit_warning_errno(u->id, r, "Failed to set up device unit: %m");
332 static int device_process_new(Manager *m, struct udev_device *dev) {
333 const char *sysfs, *dn, *alias;
334 struct udev_list_entry *item = NULL, *first = NULL;
339 sysfs = udev_device_get_syspath(dev);
343 /* Add the main unit named after the sysfs path */
344 r = device_setup_unit(m, dev, sysfs, true);
348 /* Add an additional unit for the device node */
349 dn = udev_device_get_devnode(dev);
351 (void) device_setup_unit(m, dev, dn, false);
353 /* Add additional units for all symlinks */
354 first = udev_device_get_devlinks_list_entry(dev);
355 udev_list_entry_foreach(item, first) {
359 /* Don't bother with the /dev/block links */
360 p = udev_list_entry_get_name(item);
362 if (path_startswith(p, "/dev/block/") ||
363 path_startswith(p, "/dev/char/"))
366 /* Verify that the symlink in the FS actually belongs
367 * to this device. This is useful to deal with
368 * conflicting devices, e.g. when two disks want the
369 * same /dev/disk/by-label/xxx link because they have
370 * the same label. We want to make sure that the same
371 * device that won the symlink wins in systemd, so we
372 * check the device node major/minor */
373 if (stat(p, &st) >= 0)
374 if ((!S_ISBLK(st.st_mode) && !S_ISCHR(st.st_mode)) ||
375 st.st_rdev != udev_device_get_devnum(dev))
378 (void) device_setup_unit(m, dev, p, false);
381 /* Add additional units for all explicitly configured
383 alias = udev_device_get_property_value(dev, "SYSTEMD_ALIAS");
385 const char *word, *state;
388 FOREACH_WORD_QUOTED(word, l, alias, state) {
394 if (path_is_absolute(e))
395 (void) device_setup_unit(m, dev, e, false);
397 log_warning("SYSTEMD_ALIAS for %s is not an absolute path, ignoring: %s", sysfs, e);
400 log_warning("SYSTEMD_ALIAS for %s has trailing garbage, ignoring.", sysfs);
406 static void device_update_found_one(Device *d, bool add, DeviceFound found, bool now) {
411 n = add ? (d->found | found) : (d->found & ~found);
418 if (d->found & DEVICE_FOUND_UDEV)
419 device_set_state(d, DEVICE_PLUGGED);
420 else if (d->found != DEVICE_NOT_FOUND)
421 device_set_state(d, DEVICE_TENTATIVE);
423 device_set_state(d, DEVICE_DEAD);
427 static int device_update_found_by_sysfs(Manager *m, const char *sysfs, bool add, DeviceFound found, bool now) {
433 if (found == DEVICE_NOT_FOUND)
436 l = hashmap_get(m->devices_by_sysfs, sysfs);
437 LIST_FOREACH(same_sysfs, d, l)
438 device_update_found_one(d, add, found, now);
443 static int device_update_found_by_name(Manager *m, const char *path, bool add, DeviceFound found, bool now) {
444 _cleanup_free_ char *e = NULL;
450 if (found == DEVICE_NOT_FOUND)
453 e = unit_name_from_path(path, ".device");
457 u = manager_get_unit(m, e);
461 device_update_found_one(DEVICE(u), add, found, now);
465 static bool device_is_ready(struct udev_device *dev) {
470 ready = udev_device_get_property_value(dev, "SYSTEMD_READY");
474 return parse_boolean(ready) != 0;
477 static Unit *device_following(Unit *u) {
478 Device *d = DEVICE(u);
479 Device *other, *first = NULL;
483 if (startswith(u->id, "sys-"))
486 /* Make everybody follow the unit that's named after the sysfs path */
487 for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
488 if (startswith(UNIT(other)->id, "sys-"))
491 for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev) {
492 if (startswith(UNIT(other)->id, "sys-"))
501 static int device_following_set(Unit *u, Set **_set) {
502 Device *d = DEVICE(u), *other;
509 if (LIST_JUST_US(same_sysfs, d)) {
518 LIST_FOREACH_AFTER(same_sysfs, other, d) {
519 r = set_put(set, other);
524 LIST_FOREACH_BEFORE(same_sysfs, other, d) {
525 r = set_put(set, other);
538 static void device_shutdown(Manager *m) {
541 m->udev_event_source = sd_event_source_unref(m->udev_event_source);
543 if (m->udev_monitor) {
544 udev_monitor_unref(m->udev_monitor);
545 m->udev_monitor = NULL;
548 hashmap_free(m->devices_by_sysfs);
549 m->devices_by_sysfs = NULL;
552 static int device_enumerate(Manager *m) {
553 _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
554 struct udev_list_entry *item = NULL, *first = NULL;
559 if (!m->udev_monitor) {
560 m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev");
561 if (!m->udev_monitor) {
566 /* This will fail if we are unprivileged, but that
567 * should not matter much, as user instances won't run
569 udev_monitor_set_receive_buffer_size(m->udev_monitor, 128*1024*1024);
571 r = udev_monitor_filter_add_match_tag(m->udev_monitor, "systemd");
575 r = udev_monitor_enable_receiving(m->udev_monitor);
579 r = sd_event_add_io(m->event, &m->udev_event_source, udev_monitor_get_fd(m->udev_monitor), EPOLLIN, device_dispatch_io, m);
584 e = udev_enumerate_new(m->udev);
590 r = udev_enumerate_add_match_tag(e, "systemd");
594 r = udev_enumerate_add_match_is_initialized(e);
598 r = udev_enumerate_scan_devices(e);
602 first = udev_enumerate_get_list_entry(e);
603 udev_list_entry_foreach(item, first) {
604 _cleanup_udev_device_unref_ struct udev_device *dev = NULL;
607 sysfs = udev_list_entry_get_name(item);
609 dev = udev_device_new_from_syspath(m->udev, sysfs);
615 if (!device_is_ready(dev))
618 (void) device_process_new(m, dev);
620 device_update_found_by_sysfs(m, sysfs, true, DEVICE_FOUND_UDEV, false);
626 log_error_errno(r, "Failed to enumerate devices: %m");
632 static int device_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
633 _cleanup_udev_device_unref_ struct udev_device *dev = NULL;
634 Manager *m = userdata;
635 const char *action, *sysfs;
640 if (revents != EPOLLIN) {
641 static RATELIMIT_DEFINE(limit, 10*USEC_PER_SEC, 5);
643 if (!ratelimit_test(&limit))
644 log_error_errno(errno, "Failed to get udev event: %m");
645 if (!(revents & EPOLLIN))
650 * libudev might filter-out devices which pass the bloom
651 * filter, so getting NULL here is not necessarily an error.
653 dev = udev_monitor_receive_device(m->udev_monitor);
657 sysfs = udev_device_get_syspath(dev);
659 log_error("Failed to get udev sys path.");
663 action = udev_device_get_action(dev);
665 log_error("Failed to get udev action string.");
669 if (streq(action, "remove")) {
670 r = swap_process_device_remove(m, dev);
672 log_error_errno(r, "Failed to process swap device remove event: %m");
674 /* If we get notified that a device was removed by
675 * udev, then it's completely gone, hence unset all
677 device_update_found_by_sysfs(m, sysfs, false, DEVICE_FOUND_UDEV|DEVICE_FOUND_MOUNT|DEVICE_FOUND_SWAP, true);
679 } else if (device_is_ready(dev)) {
681 (void) device_process_new(m, dev);
683 r = swap_process_device_new(m, dev);
685 log_error_errno(r, "Failed to process swap device new event: %m");
687 manager_dispatch_load_queue(m);
689 /* The device is found now, set the udev found bit */
690 device_update_found_by_sysfs(m, sysfs, true, DEVICE_FOUND_UDEV, true);
693 /* The device is nominally around, but not ready for
694 * us. Hence unset the udev bit, but leave the rest
697 device_update_found_by_sysfs(m, sysfs, false, DEVICE_FOUND_UDEV, true);
703 static bool device_supported(Manager *m) {
704 static int read_only = -1;
707 /* If /sys is read-only we don't support device units, and any
708 * attempts to start one should fail immediately. */
711 read_only = path_is_read_only_fs("/sys");
713 return read_only <= 0;
716 int device_found_node(Manager *m, const char *node, bool add, DeviceFound found, bool now) {
717 _cleanup_udev_device_unref_ struct udev_device *dev = NULL;
723 /* This is called whenever we find a device referenced in
724 * /proc/swaps or /proc/self/mounts. Such a device might be
725 * mounted/enabled at a time where udev has not finished
726 * probing it yet, and we thus haven't learned about it
727 * yet. In this case we will set the device unit to
728 * "tentative" state. */
731 if (!path_startswith(node, "/dev"))
734 if (stat(node, &st) < 0) {
738 return log_error_errno(errno, "Failed to stat device node file %s: %m", node);
741 if (!S_ISBLK(st.st_mode) && !S_ISCHR(st.st_mode))
744 dev = udev_device_new_from_devnum(m->udev, S_ISBLK(st.st_mode) ? 'b' : 'c', st.st_rdev);
752 /* If the device is known in the kernel and newly
753 * appeared, then we'll create a device unit for it,
754 * under the name referenced in /proc/swaps or
755 * /proc/self/mountinfo. */
757 (void) device_setup_unit(m, dev, node, false);
760 /* Update the device unit's state, should it exist */
761 return device_update_found_by_name(m, node, add, found, now);
764 static const char* const device_state_table[_DEVICE_STATE_MAX] = {
765 [DEVICE_DEAD] = "dead",
766 [DEVICE_TENTATIVE] = "tentative",
767 [DEVICE_PLUGGED] = "plugged",
770 DEFINE_STRING_TABLE_LOOKUP(device_state, DeviceState);
772 const UnitVTable device_vtable = {
773 .object_size = sizeof(Device),
779 .no_instances = true,
783 .load = unit_load_fragment_and_dropin_optional,
785 .coldplug = device_coldplug,
789 .active_state = device_active_state,
790 .sub_state_to_string = device_sub_state_to_string,
792 .bus_interface = "org.freedesktop.systemd1.Device",
793 .bus_vtable = bus_device_vtable,
795 .following = device_following,
796 .following_set = device_following_set,
798 .enumerate = device_enumerate,
799 .shutdown = device_shutdown,
800 .supported = device_supported,
802 .status_message_formats = {
803 .starting_stopping = {
804 [0] = "Expecting device %s...",
806 .finished_start_job = {
807 [JOB_DONE] = "Found device %s.",
808 [JOB_TIMEOUT] = "Timed out waiting for device %s.",