/* SPDX-License-Identifier: LGPL-2.1+ */ /*** This file is part of systemd. Copyright 2010 Lennart Poettering ***/ #include #include "alloc-util.h" #include "bus-error.h" #include "bus-util.h" #include "dbus-timer.h" #include "fs-util.h" #include "parse-util.h" #include "random-util.h" #include "special.h" #include "string-table.h" #include "string-util.h" #include "timer.h" #include "unit-name.h" #include "unit.h" #include "user-util.h" #include "virt.h" static const UnitActiveState state_translation_table[_TIMER_STATE_MAX] = { [TIMER_DEAD] = UNIT_INACTIVE, [TIMER_WAITING] = UNIT_ACTIVE, [TIMER_RUNNING] = UNIT_ACTIVE, [TIMER_ELAPSED] = UNIT_ACTIVE, [TIMER_FAILED] = UNIT_FAILED }; static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata); static void timer_init(Unit *u) { Timer *t = TIMER(u); assert(u); assert(u->load_state == UNIT_STUB); t->next_elapse_monotonic_or_boottime = USEC_INFINITY; t->next_elapse_realtime = USEC_INFINITY; t->accuracy_usec = u->manager->default_timer_accuracy_usec; t->remain_after_elapse = true; } void timer_free_values(Timer *t) { TimerValue *v; assert(t); while ((v = t->values)) { LIST_REMOVE(value, t->values, v); calendar_spec_free(v->calendar_spec); free(v); } } static void timer_done(Unit *u) { Timer *t = TIMER(u); assert(t); timer_free_values(t); t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source); t->realtime_event_source = sd_event_source_unref(t->realtime_event_source); free(t->stamp_path); } static int timer_verify(Timer *t) { assert(t); if (UNIT(t)->load_state != UNIT_LOADED) return 0; if (!t->values) { log_unit_error(UNIT(t), "Timer unit lacks value setting. Refusing."); return -ENOEXEC; } return 0; } static int timer_add_default_dependencies(Timer *t) { int r; TimerValue *v; assert(t); if (!UNIT(t)->default_dependencies) return 0; r = unit_add_dependency_by_name(UNIT(t), UNIT_BEFORE, SPECIAL_TIMERS_TARGET, NULL, true, UNIT_DEPENDENCY_DEFAULT); if (r < 0) return r; if (MANAGER_IS_SYSTEM(UNIT(t)->manager)) { r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true, UNIT_DEPENDENCY_DEFAULT); if (r < 0) return r; LIST_FOREACH(value, v, t->values) { if (v->base == TIMER_CALENDAR) { r = unit_add_dependency_by_name(UNIT(t), UNIT_AFTER, SPECIAL_TIME_SYNC_TARGET, NULL, true, UNIT_DEPENDENCY_DEFAULT); if (r < 0) return r; break; } } } return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true, UNIT_DEPENDENCY_DEFAULT); } static int timer_add_trigger_dependencies(Timer *t) { Unit *x; int r; assert(t); if (!hashmap_isempty(UNIT(t)->dependencies[UNIT_TRIGGERS])) return 0; r = unit_load_related_unit(UNIT(t), ".service", &x); if (r < 0) return r; return unit_add_two_dependencies(UNIT(t), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT); } static int timer_setup_persistent(Timer *t) { int r; assert(t); if (!t->persistent) return 0; if (MANAGER_IS_SYSTEM(UNIT(t)->manager)) { r = unit_require_mounts_for(UNIT(t), "/var/lib/systemd/timers", UNIT_DEPENDENCY_FILE); if (r < 0) return r; t->stamp_path = strappend("/var/lib/systemd/timers/stamp-", UNIT(t)->id); } else { const char *e; e = getenv("XDG_DATA_HOME"); if (e) t->stamp_path = strjoin(e, "/systemd/timers/stamp-", UNIT(t)->id); else { _cleanup_free_ char *h = NULL; r = get_home_dir(&h); if (r < 0) return log_unit_error_errno(UNIT(t), r, "Failed to determine home directory: %m"); t->stamp_path = strjoin(h, "/.local/share/systemd/timers/stamp-", UNIT(t)->id); } } if (!t->stamp_path) return log_oom(); return 0; } static int timer_load(Unit *u) { Timer *t = TIMER(u); int r; assert(u); assert(u->load_state == UNIT_STUB); r = unit_load_fragment_and_dropin(u); if (r < 0) return r; if (u->load_state == UNIT_LOADED) { r = timer_add_trigger_dependencies(t); if (r < 0) return r; r = timer_setup_persistent(t); if (r < 0) return r; r = timer_add_default_dependencies(t); if (r < 0) return r; } return timer_verify(t); } static void timer_dump(Unit *u, FILE *f, const char *prefix) { char buf[FORMAT_TIMESPAN_MAX]; Timer *t = TIMER(u); Unit *trigger; TimerValue *v; trigger = UNIT_TRIGGER(u); fprintf(f, "%sTimer State: %s\n" "%sResult: %s\n" "%sUnit: %s\n" "%sPersistent: %s\n" "%sWakeSystem: %s\n" "%sAccuracy: %s\n" "%sRemainAfterElapse: %s\n", prefix, timer_state_to_string(t->state), prefix, timer_result_to_string(t->result), prefix, trigger ? trigger->id : "n/a", prefix, yes_no(t->persistent), prefix, yes_no(t->wake_system), prefix, format_timespan(buf, sizeof(buf), t->accuracy_usec, 1), prefix, yes_no(t->remain_after_elapse)); LIST_FOREACH(value, v, t->values) { if (v->base == TIMER_CALENDAR) { _cleanup_free_ char *p = NULL; (void) calendar_spec_to_string(v->calendar_spec, &p); fprintf(f, "%s%s: %s\n", prefix, timer_base_to_string(v->base), strna(p)); } else { char timespan1[FORMAT_TIMESPAN_MAX]; fprintf(f, "%s%s: %s\n", prefix, timer_base_to_string(v->base), format_timespan(timespan1, sizeof(timespan1), v->value, 0)); } } } static void timer_set_state(Timer *t, TimerState state) { TimerState old_state; assert(t); old_state = t->state; t->state = state; if (state != TIMER_WAITING) { t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source); t->realtime_event_source = sd_event_source_unref(t->realtime_event_source); t->next_elapse_monotonic_or_boottime = USEC_INFINITY; t->next_elapse_realtime = USEC_INFINITY; } if (state != old_state) log_unit_debug(UNIT(t), "Changed %s -> %s", timer_state_to_string(old_state), timer_state_to_string(state)); unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], 0); } static void timer_enter_waiting(Timer *t, bool initial); static int timer_coldplug(Unit *u) { Timer *t = TIMER(u); assert(t); assert(t->state == TIMER_DEAD); if (t->deserialized_state == t->state) return 0; if (t->deserialized_state == TIMER_WAITING) timer_enter_waiting(t, false); else timer_set_state(t, t->deserialized_state); return 0; } static void timer_enter_dead(Timer *t, TimerResult f) { assert(t); if (t->result == TIMER_SUCCESS) t->result = f; if (t->result != TIMER_SUCCESS) log_unit_warning(UNIT(t), "Failed with result '%s'.", timer_result_to_string(t->result)); timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD); } static void timer_enter_elapsed(Timer *t, bool leave_around) { assert(t); /* If a unit is marked with RemainAfterElapse=yes we leave it * around even after it elapsed once, so that starting it * later again does not necessarily mean immediate * retriggering. We unconditionally leave units with * TIMER_UNIT_ACTIVE or TIMER_UNIT_INACTIVE triggers around, * since they might be restarted automatically at any time * later on. */ if (t->remain_after_elapse || leave_around) timer_set_state(t, TIMER_ELAPSED); else timer_enter_dead(t, TIMER_SUCCESS); } static void add_random(Timer *t, usec_t *v) { char s[FORMAT_TIMESPAN_MAX]; usec_t add; assert(t); assert(v); if (t->random_usec == 0) return; if (*v == USEC_INFINITY) return; add = random_u64() % t->random_usec; if (*v + add < *v) /* overflow */ *v = (usec_t) -2; /* Highest possible value, that is not USEC_INFINITY */ else *v += add; log_unit_debug(UNIT(t), "Adding %s random time.", format_timespan(s, sizeof(s), add, 0)); } static void timer_enter_waiting(Timer *t, bool initial) { bool found_monotonic = false, found_realtime = false; bool leave_around = false; triple_timestamp ts; TimerValue *v; Unit *trigger; int r; assert(t); trigger = UNIT_TRIGGER(UNIT(t)); if (!trigger) { log_unit_error(UNIT(t), "Unit to trigger vanished."); timer_enter_dead(t, TIMER_FAILURE_RESOURCES); return; } triple_timestamp_get(&ts); t->next_elapse_monotonic_or_boottime = t->next_elapse_realtime = 0; LIST_FOREACH(value, v, t->values) { if (v->disabled) continue; if (v->base == TIMER_CALENDAR) { usec_t b; /* If we know the last time this was * triggered, schedule the job based relative * to that. If we don't, just start from * the activation time. */ if (t->last_trigger.realtime > 0) b = t->last_trigger.realtime; else { if (state_translation_table[t->state] == UNIT_ACTIVE) b = UNIT(t)->inactive_exit_timestamp.realtime; else b = ts.realtime; } r = calendar_spec_next_usec(v->calendar_spec, b, &v->next_elapse); if (r < 0) continue; if (!found_realtime) t->next_elapse_realtime = v->next_elapse; else t->next_elapse_realtime = MIN(t->next_elapse_realtime, v->next_elapse); found_realtime = true; } else { usec_t base; switch (v->base) { case TIMER_ACTIVE: if (state_translation_table[t->state] == UNIT_ACTIVE) base = UNIT(t)->inactive_exit_timestamp.monotonic; else base = ts.monotonic; break; case TIMER_BOOT: if (detect_container() <= 0) { /* CLOCK_MONOTONIC equals the uptime on Linux */ base = 0; break; } /* In a container we don't want to include the time the host * was already up when the container started, so count from * our own startup. */ _fallthrough_; case TIMER_STARTUP: base = UNIT(t)->manager->timestamps[MANAGER_TIMESTAMP_USERSPACE].monotonic; break; case TIMER_UNIT_ACTIVE: leave_around = true; base = trigger->inactive_exit_timestamp.monotonic; if (base <= 0) base = t->last_trigger.monotonic; if (base <= 0) continue; base = MAX(base, t->last_trigger.monotonic); break; case TIMER_UNIT_INACTIVE: leave_around = true; base = trigger->inactive_enter_timestamp.monotonic; if (base <= 0) base = t->last_trigger.monotonic; if (base <= 0) continue; base = MAX(base, t->last_trigger.monotonic); break; default: assert_not_reached("Unknown timer base"); } v->next_elapse = usec_add(usec_shift_clock(base, CLOCK_MONOTONIC, TIMER_MONOTONIC_CLOCK(t)), v->value); if (!initial && v->next_elapse < triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t)) && IN_SET(v->base, TIMER_ACTIVE, TIMER_BOOT, TIMER_STARTUP)) { /* This is a one time trigger, disable it now */ v->disabled = true; continue; } if (!found_monotonic) t->next_elapse_monotonic_or_boottime = v->next_elapse; else t->next_elapse_monotonic_or_boottime = MIN(t->next_elapse_monotonic_or_boottime, v->next_elapse); found_monotonic = true; } } if (!found_monotonic && !found_realtime) { log_unit_debug(UNIT(t), "Timer is elapsed."); timer_enter_elapsed(t, leave_around); return; } if (found_monotonic) { char buf[FORMAT_TIMESPAN_MAX]; usec_t left; add_random(t, &t->next_elapse_monotonic_or_boottime); left = usec_sub_unsigned(t->next_elapse_monotonic_or_boottime, triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t))); log_unit_debug(UNIT(t), "Monotonic timer elapses in %s.", format_timespan(buf, sizeof(buf), left, 0)); if (t->monotonic_event_source) { r = sd_event_source_set_time(t->monotonic_event_source, t->next_elapse_monotonic_or_boottime); if (r < 0) goto fail; r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_ONESHOT); if (r < 0) goto fail; } else { r = sd_event_add_time( UNIT(t)->manager->event, &t->monotonic_event_source, t->wake_system ? CLOCK_BOOTTIME_ALARM : CLOCK_MONOTONIC, t->next_elapse_monotonic_or_boottime, t->accuracy_usec, timer_dispatch, t); if (r < 0) goto fail; (void) sd_event_source_set_description(t->monotonic_event_source, "timer-monotonic"); } } else if (t->monotonic_event_source) { r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_OFF); if (r < 0) goto fail; } if (found_realtime) { char buf[FORMAT_TIMESTAMP_MAX]; add_random(t, &t->next_elapse_realtime); log_unit_debug(UNIT(t), "Realtime timer elapses at %s.", format_timestamp(buf, sizeof(buf), t->next_elapse_realtime)); if (t->realtime_event_source) { r = sd_event_source_set_time(t->realtime_event_source, t->next_elapse_realtime); if (r < 0) goto fail; r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_ONESHOT); if (r < 0) goto fail; } else { r = sd_event_add_time( UNIT(t)->manager->event, &t->realtime_event_source, t->wake_system ? CLOCK_REALTIME_ALARM : CLOCK_REALTIME, t->next_elapse_realtime, t->accuracy_usec, timer_dispatch, t); if (r < 0) goto fail; (void) sd_event_source_set_description(t->realtime_event_source, "timer-realtime"); } } else if (t->realtime_event_source) { r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_OFF); if (r < 0) goto fail; } timer_set_state(t, TIMER_WAITING); return; fail: log_unit_warning_errno(UNIT(t), r, "Failed to enter waiting state: %m"); timer_enter_dead(t, TIMER_FAILURE_RESOURCES); } static void timer_enter_running(Timer *t) { _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; Unit *trigger; int r; assert(t); /* Don't start job if we are supposed to go down */ if (unit_stop_pending(UNIT(t))) return; trigger = UNIT_TRIGGER(UNIT(t)); if (!trigger) { log_unit_error(UNIT(t), "Unit to trigger vanished."); timer_enter_dead(t, TIMER_FAILURE_RESOURCES); return; } r = manager_add_job(UNIT(t)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL); if (r < 0) goto fail; dual_timestamp_get(&t->last_trigger); if (t->stamp_path) touch_file(t->stamp_path, true, t->last_trigger.realtime, UID_INVALID, GID_INVALID, MODE_INVALID); timer_set_state(t, TIMER_RUNNING); return; fail: log_unit_warning(UNIT(t), "Failed to queue unit startup job: %s", bus_error_message(&error, r)); timer_enter_dead(t, TIMER_FAILURE_RESOURCES); } static int timer_start(Unit *u) { Timer *t = TIMER(u); TimerValue *v; Unit *trigger; int r; assert(t); assert(IN_SET(t->state, TIMER_DEAD, TIMER_FAILED)); trigger = UNIT_TRIGGER(u); if (!trigger || trigger->load_state != UNIT_LOADED) { log_unit_error(u, "Refusing to start, unit to trigger not loaded."); return -ENOENT; } r = unit_start_limit_test(u); if (r < 0) { timer_enter_dead(t, TIMER_FAILURE_START_LIMIT_HIT); return r; } r = unit_acquire_invocation_id(u); if (r < 0) return r; t->last_trigger = DUAL_TIMESTAMP_NULL; /* Reenable all timers that depend on unit activation time */ LIST_FOREACH(value, v, t->values) if (v->base == TIMER_ACTIVE) v->disabled = false; if (t->stamp_path) { struct stat st; if (stat(t->stamp_path, &st) >= 0) { usec_t ft; /* Load the file timestamp, but only if it is actually in the past. If it is in the future, * something is wrong with the system clock. */ ft = timespec_load(&st.st_mtim); if (ft < now(CLOCK_REALTIME)) t->last_trigger.realtime = ft; else { char z[FORMAT_TIMESTAMP_MAX]; log_unit_warning(u, "Not using persistent file timestamp %s as it is in the future.", format_timestamp(z, sizeof(z), ft)); } } else if (errno == ENOENT) /* The timer has never run before, * make sure a stamp file exists. */ (void) touch_file(t->stamp_path, true, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID); } t->result = TIMER_SUCCESS; timer_enter_waiting(t, true); return 1; } static int timer_stop(Unit *u) { Timer *t = TIMER(u); assert(t); assert(IN_SET(t->state, TIMER_WAITING, TIMER_RUNNING, TIMER_ELAPSED)); timer_enter_dead(t, TIMER_SUCCESS); return 1; } static int timer_serialize(Unit *u, FILE *f, FDSet *fds) { Timer *t = TIMER(u); assert(u); assert(f); assert(fds); unit_serialize_item(u, f, "state", timer_state_to_string(t->state)); unit_serialize_item(u, f, "result", timer_result_to_string(t->result)); if (t->last_trigger.realtime > 0) unit_serialize_item_format(u, f, "last-trigger-realtime", "%" PRIu64, t->last_trigger.realtime); if (t->last_trigger.monotonic > 0) unit_serialize_item_format(u, f, "last-trigger-monotonic", "%" PRIu64, t->last_trigger.monotonic); return 0; } static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) { Timer *t = TIMER(u); int r; assert(u); assert(key); assert(value); assert(fds); if (streq(key, "state")) { TimerState state; state = timer_state_from_string(value); if (state < 0) log_unit_debug(u, "Failed to parse state value: %s", value); else t->deserialized_state = state; } else if (streq(key, "result")) { TimerResult f; f = timer_result_from_string(value); if (f < 0) log_unit_debug(u, "Failed to parse result value: %s", value); else if (f != TIMER_SUCCESS) t->result = f; } else if (streq(key, "last-trigger-realtime")) { r = safe_atou64(value, &t->last_trigger.realtime); if (r < 0) log_unit_debug(u, "Failed to parse last-trigger-realtime value: %s", value); } else if (streq(key, "last-trigger-monotonic")) { r = safe_atou64(value, &t->last_trigger.monotonic); if (r < 0) log_unit_debug(u, "Failed to parse last-trigger-monotonic value: %s", value); } else log_unit_debug(u, "Unknown serialization key: %s", key); return 0; } _pure_ static UnitActiveState timer_active_state(Unit *u) { assert(u); return state_translation_table[TIMER(u)->state]; } _pure_ static const char *timer_sub_state_to_string(Unit *u) { assert(u); return timer_state_to_string(TIMER(u)->state); } static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata) { Timer *t = TIMER(userdata); assert(t); if (t->state != TIMER_WAITING) return 0; log_unit_debug(UNIT(t), "Timer elapsed."); timer_enter_running(t); return 0; } static void timer_trigger_notify(Unit *u, Unit *other) { Timer *t = TIMER(u); TimerValue *v; assert(u); assert(other); if (other->load_state != UNIT_LOADED) return; /* Reenable all timers that depend on unit state */ LIST_FOREACH(value, v, t->values) if (IN_SET(v->base, TIMER_UNIT_ACTIVE, TIMER_UNIT_INACTIVE)) v->disabled = false; switch (t->state) { case TIMER_WAITING: case TIMER_ELAPSED: /* Recalculate sleep time */ timer_enter_waiting(t, false); break; case TIMER_RUNNING: if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) { log_unit_debug(UNIT(t), "Got notified about unit deactivation."); timer_enter_waiting(t, false); } break; case TIMER_DEAD: case TIMER_FAILED: break; default: assert_not_reached("Unknown timer state"); } } static void timer_reset_failed(Unit *u) { Timer *t = TIMER(u); assert(t); if (t->state == TIMER_FAILED) timer_set_state(t, TIMER_DEAD); t->result = TIMER_SUCCESS; } static void timer_time_change(Unit *u) { Timer *t = TIMER(u); usec_t ts; assert(u); if (t->state != TIMER_WAITING) return; /* If we appear to have triggered in the future, the system clock must * have been set backwards. So let's rewind our own clock and allow * the future trigger(s) to happen again :). Exactly the same as when * you start a timer unit with Persistent=yes. */ ts = now(CLOCK_REALTIME); if (t->last_trigger.realtime > ts) t->last_trigger.realtime = ts; log_unit_debug(u, "Time change, recalculating next elapse."); timer_enter_waiting(t, false); } static void timer_timezone_change(Unit *u) { Timer *t = TIMER(u); assert(u); if (t->state != TIMER_WAITING) return; log_unit_debug(u, "Timezone change, recalculating next elapse."); timer_enter_waiting(t, false); } static const char* const timer_base_table[_TIMER_BASE_MAX] = { [TIMER_ACTIVE] = "OnActiveSec", [TIMER_BOOT] = "OnBootSec", [TIMER_STARTUP] = "OnStartupSec", [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec", [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec", [TIMER_CALENDAR] = "OnCalendar" }; DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase); static const char* const timer_result_table[_TIMER_RESULT_MAX] = { [TIMER_SUCCESS] = "success", [TIMER_FAILURE_RESOURCES] = "resources", [TIMER_FAILURE_START_LIMIT_HIT] = "start-limit-hit", }; DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult); const UnitVTable timer_vtable = { .object_size = sizeof(Timer), .sections = "Unit\0" "Timer\0" "Install\0", .private_section = "Timer", .init = timer_init, .done = timer_done, .load = timer_load, .coldplug = timer_coldplug, .dump = timer_dump, .start = timer_start, .stop = timer_stop, .serialize = timer_serialize, .deserialize_item = timer_deserialize_item, .active_state = timer_active_state, .sub_state_to_string = timer_sub_state_to_string, .trigger_notify = timer_trigger_notify, .reset_failed = timer_reset_failed, .time_change = timer_time_change, .timezone_change = timer_timezone_change, .bus_vtable = bus_timer_vtable, .bus_set_property = bus_timer_set_property, .can_transient = true, };