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>
28 #include "unit-name.h"
29 #include "dbus-device.h"
31 #include "path-util.h"
32 #include "udev-util.h"
37 static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
38 [DEVICE_DEAD] = UNIT_INACTIVE,
39 [DEVICE_PLUGGED] = UNIT_ACTIVE
42 static int device_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
44 static void device_unset_sysfs(Device *d) {
53 /* Remove this unit from the chain of devices which share the
55 devices = UNIT(d)->manager->devices_by_sysfs;
56 first = hashmap_get(devices, d->sysfs);
57 LIST_REMOVE(same_sysfs, first, d);
60 hashmap_remove_and_replace(devices, d->sysfs, first->sysfs, first);
62 hashmap_remove(devices, d->sysfs);
68 static void device_init(Unit *u) {
69 Device *d = DEVICE(u);
72 assert(UNIT(d)->load_state == UNIT_STUB);
74 /* In contrast to all other unit types we timeout jobs waiting
75 * for devices by default. This is because they otherwise wait
76 * indefinitely for plugged in devices, something which cannot
77 * happen for the other units since their operations time out
79 u->job_timeout = u->manager->default_timeout_start_usec;
81 u->ignore_on_isolate = true;
82 u->ignore_on_snapshot = true;
85 static void device_done(Unit *u) {
86 Device *d = DEVICE(u);
90 device_unset_sysfs(d);
93 static void device_set_state(Device *d, DeviceState state) {
94 DeviceState old_state;
100 if (state != old_state)
101 log_debug_unit(UNIT(d)->id,
102 "%s changed %s -> %s", UNIT(d)->id,
103 device_state_to_string(old_state),
104 device_state_to_string(state));
106 unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state], true);
109 static int device_coldplug(Unit *u) {
110 Device *d = DEVICE(u);
113 assert(d->state == DEVICE_DEAD);
116 device_set_state(d, DEVICE_PLUGGED);
121 static void device_dump(Unit *u, FILE *f, const char *prefix) {
122 Device *d = DEVICE(u);
127 "%sDevice State: %s\n"
128 "%sSysfs Path: %s\n",
129 prefix, device_state_to_string(d->state),
130 prefix, strna(d->sysfs));
133 _pure_ static UnitActiveState device_active_state(Unit *u) {
136 return state_translation_table[DEVICE(u)->state];
139 _pure_ static const char *device_sub_state_to_string(Unit *u) {
142 return device_state_to_string(DEVICE(u)->state);
145 static int device_add_escaped_name(Unit *u, const char *dn) {
146 _cleanup_free_ char *e = NULL;
151 assert(dn[0] == '/');
153 e = unit_name_from_path(dn, ".device");
157 r = unit_add_name(u, e);
158 if (r < 0 && r != -EEXIST)
164 static int device_find_escape_name(Manager *m, const char *dn, Unit **_u) {
165 _cleanup_free_ char *e = NULL;
170 assert(dn[0] == '/');
173 e = unit_name_from_path(dn, ".device");
177 u = manager_get_unit(m, e);
186 static int device_update_unit(Manager *m, struct udev_device *dev, const char *path, bool main) {
187 const char *sysfs, *model;
194 sysfs = udev_device_get_syspath(dev);
198 r = device_find_escape_name(m, path, &u);
202 if (u && DEVICE(u)->sysfs && !path_equal(DEVICE(u)->sysfs, sysfs))
208 u = unit_new(m, sizeof(Device));
212 r = device_add_escaped_name(u, path);
216 unit_add_to_load_queue(u);
220 /* If this was created via some dependency and has not
221 * actually been seen yet ->sysfs will not be
222 * initialized. Hence initialize it if necessary. */
224 if (!DEVICE(u)->sysfs) {
227 DEVICE(u)->sysfs = strdup(sysfs);
228 if (!DEVICE(u)->sysfs) {
233 r = hashmap_ensure_allocated(&m->devices_by_sysfs, string_hash_func, string_compare_func);
237 first = hashmap_get(m->devices_by_sysfs, sysfs);
238 LIST_PREPEND(same_sysfs, first, DEVICE(u));
240 r = hashmap_replace(m->devices_by_sysfs, DEVICE(u)->sysfs, first);
245 if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
246 (model = udev_device_get_property_value(dev, "ID_MODEL")))
247 r = unit_set_description(u, model);
249 r = unit_set_description(u, path);
256 /* The additional systemd udev properties we only
257 * interpret for the main object */
259 wants = udev_device_get_property_value(dev, m->running_as == SYSTEMD_USER ? "SYSTEMD_USER_WANTS" : "SYSTEMD_WANTS");
264 FOREACH_WORD_QUOTED(w, l, wants, state) {
265 _cleanup_free_ char *n = NULL;
271 n = unit_name_mangle(e, MANGLE_NOGLOB);
277 r = unit_add_dependency_by_name(u, UNIT_WANTS, n, NULL, true);
284 /* Note that this won't dispatch the load queue, the caller
285 * has to do that if needed and appropriate */
287 unit_add_to_dbus_queue(u);
291 log_warning("Failed to load device unit: %s", strerror(-r));
299 static int device_process_new_device(Manager *m, struct udev_device *dev) {
300 const char *sysfs, *dn, *alias;
301 struct udev_list_entry *item = NULL, *first = NULL;
306 sysfs = udev_device_get_syspath(dev);
310 /* Add the main unit named after the sysfs path */
311 r = device_update_unit(m, dev, sysfs, true);
315 /* Add an additional unit for the device node */
316 dn = udev_device_get_devnode(dev);
318 device_update_unit(m, dev, dn, false);
320 /* Add additional units for all symlinks */
321 first = udev_device_get_devlinks_list_entry(dev);
322 udev_list_entry_foreach(item, first) {
326 /* Don't bother with the /dev/block links */
327 p = udev_list_entry_get_name(item);
329 if (path_startswith(p, "/dev/block/") ||
330 path_startswith(p, "/dev/char/"))
333 /* Verify that the symlink in the FS actually belongs
334 * to this device. This is useful to deal with
335 * conflicting devices, e.g. when two disks want the
336 * same /dev/disk/by-label/xxx link because they have
337 * the same label. We want to make sure that the same
338 * device that won the symlink wins in systemd, so we
339 * check the device node major/minor*/
340 if (stat(p, &st) >= 0)
341 if ((!S_ISBLK(st.st_mode) && !S_ISCHR(st.st_mode)) ||
342 st.st_rdev != udev_device_get_devnum(dev))
345 device_update_unit(m, dev, p, false);
348 /* Add additional units for all explicitly configured
350 alias = udev_device_get_property_value(dev, "SYSTEMD_ALIAS");
355 FOREACH_WORD_QUOTED(w, l, alias, state) {
361 if (path_is_absolute(e))
362 device_update_unit(m, dev, e, false);
364 log_warning("SYSTEMD_ALIAS for %s is not an absolute path, ignoring: %s", sysfs, e);
371 static void device_set_path_plugged(Manager *m, struct udev_device *dev) {
378 sysfs = udev_device_get_syspath(dev);
382 l = hashmap_get(m->devices_by_sysfs, sysfs);
383 LIST_FOREACH(same_sysfs, d, l)
384 device_set_state(d, DEVICE_PLUGGED);
387 static int device_process_removed_device(Manager *m, struct udev_device *dev) {
394 sysfs = udev_device_get_syspath(dev);
398 /* Remove all units of this sysfs path */
399 while ((d = hashmap_get(m->devices_by_sysfs, sysfs))) {
400 device_unset_sysfs(d);
401 device_set_state(d, DEVICE_DEAD);
407 static bool device_is_ready(struct udev_device *dev) {
412 ready = udev_device_get_property_value(dev, "SYSTEMD_READY");
416 return parse_boolean(ready) != 0;
419 static int device_process_new_path(Manager *m, const char *path) {
420 _cleanup_udev_device_unref_ struct udev_device *dev = NULL;
425 dev = udev_device_new_from_syspath(m->udev, path);
429 if (!device_is_ready(dev))
432 return device_process_new_device(m, dev);
435 static Unit *device_following(Unit *u) {
436 Device *d = DEVICE(u);
437 Device *other, *first = NULL;
441 if (startswith(u->id, "sys-"))
444 /* Make everybody follow the unit that's named after the sysfs path */
445 for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
446 if (startswith(UNIT(other)->id, "sys-"))
449 for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev) {
450 if (startswith(UNIT(other)->id, "sys-"))
459 static int device_following_set(Unit *u, Set **_set) {
460 Device *d = DEVICE(u), *other;
467 if (LIST_JUST_US(same_sysfs, d)) {
472 set = set_new(NULL, NULL);
476 LIST_FOREACH_AFTER(same_sysfs, other, d) {
477 r = set_put(set, other);
482 LIST_FOREACH_BEFORE(same_sysfs, other, d) {
483 r = set_put(set, other);
496 static void device_shutdown(Manager *m) {
499 m->udev_event_source = sd_event_source_unref(m->udev_event_source);
501 if (m->udev_monitor) {
502 udev_monitor_unref(m->udev_monitor);
503 m->udev_monitor = NULL;
506 hashmap_free(m->devices_by_sysfs);
507 m->devices_by_sysfs = NULL;
510 static int device_enumerate(Manager *m) {
511 _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
512 struct udev_list_entry *item = NULL, *first = NULL;
517 if (!m->udev_monitor) {
518 m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev");
519 if (!m->udev_monitor) {
524 /* This will fail if we are unprivileged, but that
525 * should not matter much, as user instances won't run
527 udev_monitor_set_receive_buffer_size(m->udev_monitor, 128*1024*1024);
529 r = udev_monitor_filter_add_match_tag(m->udev_monitor, "systemd");
533 r = udev_monitor_enable_receiving(m->udev_monitor);
537 r = sd_event_add_io(m->event, &m->udev_event_source, udev_monitor_get_fd(m->udev_monitor), EPOLLIN, device_dispatch_io, m);
542 e = udev_enumerate_new(m->udev);
548 r = udev_enumerate_add_match_tag(e, "systemd");
552 r = udev_enumerate_add_match_is_initialized(e);
556 r = udev_enumerate_scan_devices(e);
560 first = udev_enumerate_get_list_entry(e);
561 udev_list_entry_foreach(item, first)
562 device_process_new_path(m, udev_list_entry_get_name(item));
571 static int device_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
572 _cleanup_udev_device_unref_ struct udev_device *dev = NULL;
573 Manager *m = userdata;
579 if (revents != EPOLLIN) {
580 static RATELIMIT_DEFINE(limit, 10*USEC_PER_SEC, 5);
582 if (!ratelimit_test(&limit))
583 log_error("Failed to get udev event: %m");
584 if (!(revents & EPOLLIN))
589 * libudev might filter-out devices which pass the bloom
590 * filter, so getting NULL here is not necessarily an error.
592 dev = udev_monitor_receive_device(m->udev_monitor);
596 action = udev_device_get_action(dev);
598 log_error("Failed to get udev action string.");
602 if (streq(action, "remove") || !device_is_ready(dev)) {
603 r = device_process_removed_device(m, dev);
605 log_error("Failed to process device remove event: %s", strerror(-r));
607 r = swap_process_removed_device(m, dev);
609 log_error("Failed to process swap device remove event: %s", strerror(-r));
612 r = device_process_new_device(m, dev);
614 log_error("Failed to process device new event: %s", strerror(-r));
616 r = swap_process_new_device(m, dev);
618 log_error("Failed to process swap device new event: %s", strerror(-r));
620 manager_dispatch_load_queue(m);
622 device_set_path_plugged(m, dev);
628 static const char* const device_state_table[_DEVICE_STATE_MAX] = {
629 [DEVICE_DEAD] = "dead",
630 [DEVICE_PLUGGED] = "plugged"
633 DEFINE_STRING_TABLE_LOOKUP(device_state, DeviceState);
635 const UnitVTable device_vtable = {
636 .object_size = sizeof(Device),
642 .no_instances = true,
646 .load = unit_load_fragment_and_dropin_optional,
648 .coldplug = device_coldplug,
652 .active_state = device_active_state,
653 .sub_state_to_string = device_sub_state_to_string,
655 .bus_interface = "org.freedesktop.systemd1.Device",
656 .bus_vtable = bus_device_vtable,
658 .following = device_following,
659 .following_set = device_following_set,
661 .enumerate = device_enumerate,
662 .shutdown = device_shutdown,
664 .status_message_formats = {
665 .starting_stopping = {
666 [0] = "Expecting device %s...",
668 .finished_start_job = {
669 [JOB_DONE] = "Found device %s.",
670 [JOB_TIMEOUT] = "Timed out waiting for device %s.",