/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <errno.h> #include <sys/epoll.h> #include <libudev.h> #include "unit.h" #include "device.h" #include "strv.h" #include "log.h" #include "unit-name.h" #include "dbus-device.h" #include "def.h" static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = { [DEVICE_DEAD] = UNIT_INACTIVE, [DEVICE_PLUGGED] = UNIT_ACTIVE }; static void device_unset_sysfs(Device *d) { Device *first; assert(d); if (!d->sysfs) return; /* Remove this unit from the chain of devices which share the * same sysfs path. */ first = hashmap_get(d->meta.manager->devices_by_sysfs, d->sysfs); LIST_REMOVE(Device, same_sysfs, first, d); if (first) hashmap_remove_and_replace(d->meta.manager->devices_by_sysfs, d->sysfs, first->sysfs, first); else hashmap_remove(d->meta.manager->devices_by_sysfs, d->sysfs); free(d->sysfs); d->sysfs = NULL; } static void device_init(Unit *u) { Device *d = DEVICE(u); assert(d); assert(d->meta.load_state == UNIT_STUB); /* In contrast to all other unit types we timeout jobs waiting * for devices by default. This is because they otherwise wait * indefinitely for plugged in devices, something which cannot * happen for the other units since their operations time out * anyway. */ d->meta.job_timeout = DEFAULT_TIMEOUT_USEC; d->meta.ignore_on_isolate = true; d->meta.ignore_on_snapshot = true; } static void device_done(Unit *u) { Device *d = DEVICE(u); assert(d); device_unset_sysfs(d); } static void device_set_state(Device *d, DeviceState state) { DeviceState old_state; assert(d); old_state = d->state; d->state = state; if (state != old_state) log_debug("%s changed %s -> %s", d->meta.id, device_state_to_string(old_state), device_state_to_string(state)); unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state], true); } static int device_coldplug(Unit *u) { Device *d = DEVICE(u); assert(d); assert(d->state == DEVICE_DEAD); if (d->sysfs) device_set_state(d, DEVICE_PLUGGED); return 0; } static void device_dump(Unit *u, FILE *f, const char *prefix) { Device *d = DEVICE(u); assert(d); fprintf(f, "%sDevice State: %s\n" "%sSysfs Path: %s\n", prefix, device_state_to_string(d->state), prefix, strna(d->sysfs)); } static UnitActiveState device_active_state(Unit *u) { assert(u); return state_translation_table[DEVICE(u)->state]; } static const char *device_sub_state_to_string(Unit *u) { assert(u); return device_state_to_string(DEVICE(u)->state); } static int device_add_escaped_name(Unit *u, const char *dn) { char *e; int r; assert(u); assert(dn); assert(dn[0] == '/'); if (!(e = unit_name_from_path(dn, ".device"))) return -ENOMEM; r = unit_add_name(u, e); free(e); if (r < 0 && r != -EEXIST) return r; return 0; } static int device_find_escape_name(Manager *m, const char *dn, Unit **_u) { char *e; Unit *u; assert(m); assert(dn); assert(dn[0] == '/'); assert(_u); if (!(e = unit_name_from_path(dn, ".device"))) return -ENOMEM; u = manager_get_unit(m, e); free(e); if (u) { *_u = u; return 1; } return 0; } static int device_update_unit(Manager *m, struct udev_device *dev, const char *path, bool main) { const char *sysfs, *model; Unit *u = NULL; int r; bool delete; assert(m); if (!(sysfs = udev_device_get_syspath(dev))) return -ENOMEM; if ((r = device_find_escape_name(m, path, &u)) < 0) return r; if (u && DEVICE(u)->sysfs && !path_equal(DEVICE(u)->sysfs, sysfs)) return -EEXIST; if (!u) { delete = true; if (!(u = unit_new(m))) return -ENOMEM; if ((r = device_add_escaped_name(u, path)) < 0) goto fail; unit_add_to_load_queue(u); } else delete = false; /* If this was created via some dependency and has not * actually been seen yet ->sysfs will not be * initialized. Hence initialize it if necessary. */ if (!DEVICE(u)->sysfs) { Device *first; if (!(DEVICE(u)->sysfs = strdup(sysfs))) { r = -ENOMEM; goto fail; } if (!m->devices_by_sysfs) if (!(m->devices_by_sysfs = hashmap_new(string_hash_func, string_compare_func))) { r = -ENOMEM; goto fail; } first = hashmap_get(m->devices_by_sysfs, sysfs); LIST_PREPEND(Device, same_sysfs, first, DEVICE(u)); if ((r = hashmap_replace(m->devices_by_sysfs, DEVICE(u)->sysfs, first)) < 0) goto fail; } if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) || (model = udev_device_get_property_value(dev, "ID_MODEL"))) { if ((r = unit_set_description(u, model)) < 0) goto fail; } else if ((r = unit_set_description(u, path)) < 0) goto fail; if (main) { /* The additional systemd udev properties we only * interpret for the main object */ const char *wants, *alias; if ((alias = udev_device_get_property_value(dev, "SYSTEMD_ALIAS"))) { if (!is_path(alias)) log_warning("SYSTEMD_ALIAS for %s is not a path, ignoring: %s", sysfs, alias); else { if ((r = device_add_escaped_name(u, alias)) < 0) goto fail; } } if ((wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS"))) { char *state, *w; size_t l; FOREACH_WORD_QUOTED(w, l, wants, state) { char *e; if (!(e = strndup(w, l))) { r = -ENOMEM; goto fail; } r = unit_add_dependency_by_name(u, UNIT_WANTS, e, NULL, true); free(e); if (r < 0) goto fail; } } } unit_add_to_dbus_queue(u); return 0; fail: log_warning("Failed to load device unit: %s", strerror(-r)); if (delete && u) unit_free(u); return r; } static int device_process_new_device(Manager *m, struct udev_device *dev, bool update_state) { const char *sysfs, *dn; struct udev_list_entry *item = NULL, *first = NULL; assert(m); if (!(sysfs = udev_device_get_syspath(dev))) return -ENOMEM; /* Add the main unit named after the sysfs path */ device_update_unit(m, dev, sysfs, true); /* Add an additional unit for the device node */ if ((dn = udev_device_get_devnode(dev))) device_update_unit(m, dev, dn, false); /* Add additional units for all symlinks */ first = udev_device_get_devlinks_list_entry(dev); udev_list_entry_foreach(item, first) { const char *p; struct stat st; /* Don't bother with the /dev/block links */ p = udev_list_entry_get_name(item); if (path_startswith(p, "/dev/block/") || path_startswith(p, "/dev/char/")) continue; /* Verify that the symlink in the FS actually belongs * to this device. This is useful to deal with * conflicting devices, e.g. when two disks want the * same /dev/disk/by-label/xxx link because they have * the same label. We want to make sure that the same * device that won the symlink wins in systemd, so we * check the device node major/minor*/ if (stat(p, &st) >= 0) if ((!S_ISBLK(st.st_mode) && !S_ISCHR(st.st_mode)) || st.st_rdev != udev_device_get_devnum(dev)) continue; device_update_unit(m, dev, p, false); } if (update_state) { Device *d, *l; manager_dispatch_load_queue(m); l = hashmap_get(m->devices_by_sysfs, sysfs); LIST_FOREACH(same_sysfs, d, l) device_set_state(d, DEVICE_PLUGGED); } return 0; } static int device_process_path(Manager *m, const char *path, bool update_state) { int r; struct udev_device *dev; assert(m); assert(path); if (!(dev = udev_device_new_from_syspath(m->udev, path))) { log_warning("Failed to get udev device object from udev for path %s.", path); return -ENOMEM; } r = device_process_new_device(m, dev, update_state); udev_device_unref(dev); return r; } static int device_process_removed_device(Manager *m, struct udev_device *dev) { const char *sysfs; Device *d; assert(m); assert(dev); if (!(sysfs = udev_device_get_syspath(dev))) return -ENOMEM; /* Remove all units of this sysfs path */ while ((d = hashmap_get(m->devices_by_sysfs, sysfs))) { device_unset_sysfs(d); device_set_state(d, DEVICE_DEAD); } return 0; } static Unit *device_following(Unit *u) { Device *d = DEVICE(u); Device *other, *first = NULL; assert(d); if (startswith(u->meta.id, "sys-")) return NULL; /* Make everybody follow the unit that's named after the sysfs path */ for (other = d->same_sysfs_next; other; other = other->same_sysfs_next) if (startswith(other->meta.id, "sys-")) return UNIT(other); for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev) { if (startswith(other->meta.id, "sys-")) return UNIT(other); first = other; } return UNIT(first); } static int device_following_set(Unit *u, Set **_s) { Device *d = DEVICE(u); Device *other; Set *s; int r; assert(d); assert(_s); if (!d->same_sysfs_prev && !d->same_sysfs_next) { *_s = NULL; return 0; } if (!(s = set_new(NULL, NULL))) return -ENOMEM; for (other = d->same_sysfs_next; other; other = other->same_sysfs_next) if ((r = set_put(s, other)) < 0) goto fail; for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev) if ((r = set_put(s, other)) < 0) goto fail; *_s = s; return 1; fail: set_free(s); return r; } static void device_shutdown(Manager *m) { assert(m); if (m->udev_monitor) { udev_monitor_unref(m->udev_monitor); m->udev_monitor = NULL; } if (m->udev) { udev_unref(m->udev); m->udev = NULL; } hashmap_free(m->devices_by_sysfs); m->devices_by_sysfs = NULL; } static int device_enumerate(Manager *m) { struct epoll_event ev; int r; struct udev_enumerate *e = NULL; struct udev_list_entry *item = NULL, *first = NULL; assert(m); if (!m->udev) { if (!(m->udev = udev_new())) return -ENOMEM; if (!(m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev"))) { r = -ENOMEM; goto fail; } /* This will fail if we are unprivileged, but that * should not matter much, as user instances won't run * during boot. */ udev_monitor_set_receive_buffer_size(m->udev_monitor, 128*1024*1024); if (udev_monitor_filter_add_match_tag(m->udev_monitor, "systemd") < 0) { r = -ENOMEM; goto fail; } if (udev_monitor_enable_receiving(m->udev_monitor) < 0) { r = -EIO; goto fail; } m->udev_watch.type = WATCH_UDEV; m->udev_watch.fd = udev_monitor_get_fd(m->udev_monitor); zero(ev); ev.events = EPOLLIN; ev.data.ptr = &m->udev_watch; if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->udev_watch.fd, &ev) < 0) return -errno; } if (!(e = udev_enumerate_new(m->udev))) { r = -ENOMEM; goto fail; } if (udev_enumerate_add_match_tag(e, "systemd") < 0) { r = -EIO; goto fail; } if (udev_enumerate_scan_devices(e) < 0) { r = -EIO; goto fail; } first = udev_enumerate_get_list_entry(e); udev_list_entry_foreach(item, first) device_process_path(m, udev_list_entry_get_name(item), false); udev_enumerate_unref(e); return 0; fail: if (e) udev_enumerate_unref(e); device_shutdown(m); return r; } void device_fd_event(Manager *m, int events) { struct udev_device *dev; int r; const char *action, *ready; assert(m); if (events != EPOLLIN) { static RATELIMIT_DEFINE(limit, 10*USEC_PER_SEC, 5); if (!ratelimit_test(&limit)) log_error("Failed to get udev event: %m"); if (!(events & EPOLLIN)) return; } if (!(dev = udev_monitor_receive_device(m->udev_monitor))) { /* * libudev might filter-out devices which pass the bloom filter, * so getting NULL here is not necessarily an error */ return; } if (!(action = udev_device_get_action(dev))) { log_error("Failed to get udev action string."); goto fail; } ready = udev_device_get_property_value(dev, "SYSTEMD_READY"); if (streq(action, "remove") || (ready && parse_boolean(ready) == 0)) { if ((r = device_process_removed_device(m, dev)) < 0) { log_error("Failed to process udev device event: %s", strerror(-r)); goto fail; } } else { if ((r = device_process_new_device(m, dev, true)) < 0) { log_error("Failed to process udev device event: %s", strerror(-r)); goto fail; } } fail: udev_device_unref(dev); } static const char* const device_state_table[_DEVICE_STATE_MAX] = { [DEVICE_DEAD] = "dead", [DEVICE_PLUGGED] = "plugged" }; DEFINE_STRING_TABLE_LOOKUP(device_state, DeviceState); const UnitVTable device_vtable = { .suffix = ".device", .no_instances = true, .init = device_init, .load = unit_load_fragment_and_dropin_optional, .done = device_done, .coldplug = device_coldplug, .dump = device_dump, .active_state = device_active_state, .sub_state_to_string = device_sub_state_to_string, .bus_interface = "org.freedesktop.systemd1.Device", .bus_message_handler = bus_device_message_handler, .bus_invalidating_properties = bus_device_invalidating_properties, .following = device_following, .following_set = device_following_set, .enumerate = device_enumerate, .shutdown = device_shutdown };