src/core/timer.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <sys/stat.h>
   4 #include <sys/types.h>
   5 #include <unistd.h>
   6
   7 #include <errno.h>
   8
   9 #include "alloc-util.h"
  10 #include "bus-error.h"
  11 #include "bus-util.h"
  12 #include "dbus-timer.h"
  13 #include "dbus-unit.h"
  14 #include "fs-util.h"
  15 #include "parse-util.h"
  16 #include "random-util.h"
  17 #include "serialize.h"
  18 #include "special.h"
  19 #include "string-table.h"
  20 #include "string-util.h"
  21 #include "timer.h"
  22 #include "unit-name.h"
  23 #include "unit.h"
  24 #include "user-util.h"
  25 #include "virt.h"
  26
  27 static const UnitActiveState state_translation_table[_TIMER_STATE_MAX] = {
  28         [TIMER_DEAD]    = UNIT_INACTIVE,
  29         [TIMER_WAITING] = UNIT_ACTIVE,
  30         [TIMER_RUNNING] = UNIT_ACTIVE,
  31         [TIMER_ELAPSED] = UNIT_ACTIVE,
  32         [TIMER_FAILED]  = UNIT_FAILED,
  33 };
  34
  35 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata);
  36
  37 static void timer_init(Unit *u) {
  38         Timer *t = ASSERT_PTR(TIMER(u));
  39
  40         assert(u->load_state == UNIT_STUB);
  41
  42         t->next_elapse_monotonic_or_boottime = USEC_INFINITY;
  43         t->next_elapse_realtime = USEC_INFINITY;
  44         t->accuracy_usec = u->manager->defaults.timer_accuracy_usec;
  45         t->remain_after_elapse = true;
  46 }
  47
  48 void timer_free_values(Timer *t) {
  49         TimerValue *v;
  50
  51         assert(t);
  52
  53         while ((v = LIST_POP(value, t->values))) {
  54                 calendar_spec_free(v->calendar_spec);
  55                 free(v);
  56         }
  57 }
  58
  59 static void timer_done(Unit *u) {
  60         Timer *t = ASSERT_PTR(TIMER(u));
  61
  62         timer_free_values(t);
  63
  64         t->monotonic_event_source = sd_event_source_disable_unref(t->monotonic_event_source);
  65         t->realtime_event_source = sd_event_source_disable_unref(t->realtime_event_source);
  66
  67         t->stamp_path = mfree(t->stamp_path);
  68 }
  69
  70 static int timer_verify(Timer *t) {
  71         assert(t);
  72         assert(UNIT(t)->load_state == UNIT_LOADED);
  73
  74         if (!t->values && !t->on_clock_change && !t->on_timezone_change)
  75                 return log_unit_error_errno(UNIT(t), SYNTHETIC_ERRNO(ENOEXEC), "Timer unit lacks value setting. Refusing.");
  76
  77         return 0;
  78 }
  79
  80 static int timer_add_default_dependencies(Timer *t) {
  81         int r;
  82
  83         assert(t);
  84
  85         if (!UNIT(t)->default_dependencies)
  86                 return 0;
  87
  88         r = unit_add_dependency_by_name(UNIT(t), UNIT_BEFORE, SPECIAL_TIMERS_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
  89         if (r < 0)
  90                 return r;
  91
  92         if (MANAGER_IS_SYSTEM(UNIT(t)->manager)) {
  93                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
  94                 if (r < 0)
  95                         return r;
  96
  97                 LIST_FOREACH(value, v, t->values) {
  98                         if (v->base != TIMER_CALENDAR)
  99                                 continue;
 100
 101                         FOREACH_STRING(target, SPECIAL_TIME_SYNC_TARGET, SPECIAL_TIME_SET_TARGET) {
 102                                 r = unit_add_dependency_by_name(UNIT(t), UNIT_AFTER, target, true, UNIT_DEPENDENCY_DEFAULT);
 103                                 if (r < 0)
 104                                         return r;
 105                         }
 106
 107                         break;
 108                 }
 109         }
 110
 111         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 112 }
 113
 114 static int timer_add_trigger_dependencies(Timer *t) {
 115         Unit *x;
 116         int r;
 117
 118         assert(t);
 119
 120         if (UNIT_TRIGGER(UNIT(t)))
 121                 return 0;
 122
 123         r = unit_load_related_unit(UNIT(t), ".service", &x);
 124         if (r < 0)
 125                 return r;
 126
 127         return unit_add_two_dependencies(UNIT(t), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
 128 }
 129
 130 static int timer_setup_persistent(Timer *t) {
 131         _cleanup_free_ char *stamp_path = NULL;
 132         int r;
 133
 134         assert(t);
 135
 136         if (!t->persistent)
 137                 return 0;
 138
 139         if (MANAGER_IS_SYSTEM(UNIT(t)->manager)) {
 140
 141                 r = unit_add_mounts_for(UNIT(t), "/var/lib/systemd/timers", UNIT_DEPENDENCY_FILE, UNIT_MOUNT_REQUIRES);
 142                 if (r < 0)
 143                         return r;
 144
 145                 stamp_path = strjoin("/var/lib/systemd/timers/stamp-", UNIT(t)->id);
 146         } else {
 147                 const char *e;
 148
 149                 e = getenv("XDG_DATA_HOME");
 150                 if (e)
 151                         stamp_path = strjoin(e, "/systemd/timers/stamp-", UNIT(t)->id);
 152                 else {
 153
 154                         _cleanup_free_ char *h = NULL;
 155
 156                         r = get_home_dir(&h);
 157                         if (r < 0)
 158                                 return log_unit_error_errno(UNIT(t), r, "Failed to determine home directory: %m");
 159
 160                         stamp_path = strjoin(h, "/.local/share/systemd/timers/stamp-", UNIT(t)->id);
 161                 }
 162         }
 163
 164         if (!stamp_path)
 165                 return log_oom();
 166
 167         return free_and_replace(t->stamp_path, stamp_path);
 168 }
 169
 170 static uint64_t timer_get_fixed_delay_hash(Timer *t) {
 171         static const uint8_t hash_key[] = {
 172                 0x51, 0x0a, 0xdb, 0x76, 0x29, 0x51, 0x42, 0xc2,
 173                 0x80, 0x35, 0xea, 0xe6, 0x8e, 0x3a, 0x37, 0xbd
 174         };
 175
 176         struct siphash state;
 177         sd_id128_t machine_id;
 178         uid_t uid;
 179         int r;
 180
 181         assert(t);
 182
 183         uid = getuid();
 184         r = sd_id128_get_machine(&machine_id);
 185         if (r < 0) {
 186                 log_unit_debug_errno(UNIT(t), r,
 187                                      "Failed to get machine ID for the fixed delay calculation, proceeding with 0: %m");
 188                 machine_id = SD_ID128_NULL;
 189         }
 190
 191         siphash24_init(&state, hash_key);
 192         siphash24_compress_typesafe(machine_id, &state);
 193         siphash24_compress_boolean(MANAGER_IS_SYSTEM(UNIT(t)->manager), &state);
 194         siphash24_compress_typesafe(uid, &state);
 195         siphash24_compress_string(UNIT(t)->id, &state);
 196
 197         return siphash24_finalize(&state);
 198 }
 199
 200 static int timer_load(Unit *u) {
 201         Timer *t = ASSERT_PTR(TIMER(u));
 202         int r;
 203
 204         assert(u->load_state == UNIT_STUB);
 205
 206         r = unit_load_fragment_and_dropin(u, true);
 207         if (r < 0)
 208                 return r;
 209
 210         if (u->load_state != UNIT_LOADED)
 211                 return 0;
 212
 213         /* This is a new unit? Then let's add in some extras */
 214         r = timer_add_trigger_dependencies(t);
 215         if (r < 0)
 216                 return r;
 217
 218         r = timer_setup_persistent(t);
 219         if (r < 0)
 220                 return r;
 221
 222         r = timer_add_default_dependencies(t);
 223         if (r < 0)
 224                 return r;
 225
 226         return timer_verify(t);
 227 }
 228
 229 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
 230         Timer *t = ASSERT_PTR(TIMER(u));
 231         Unit *trigger;
 232
 233         assert(f);
 234         assert(prefix);
 235
 236         trigger = UNIT_TRIGGER(u);
 237
 238         fprintf(f,
 239                 "%sTimer State: %s\n"
 240                 "%sResult: %s\n"
 241                 "%sUnit: %s\n"
 242                 "%sPersistent: %s\n"
 243                 "%sWakeSystem: %s\n"
 244                 "%sAccuracy: %s\n"
 245                 "%sRemainAfterElapse: %s\n"
 246                 "%sFixedRandomDelay: %s\n"
 247                 "%sOnClockChange: %s\n"
 248                 "%sOnTimeZoneChange: %s\n",
 249                 prefix, timer_state_to_string(t->state),
 250                 prefix, timer_result_to_string(t->result),
 251                 prefix, trigger ? trigger->id : "n/a",
 252                 prefix, yes_no(t->persistent),
 253                 prefix, yes_no(t->wake_system),
 254                 prefix, FORMAT_TIMESPAN(t->accuracy_usec, 1),
 255                 prefix, yes_no(t->remain_after_elapse),
 256                 prefix, yes_no(t->fixed_random_delay),
 257                 prefix, yes_no(t->on_clock_change),
 258                 prefix, yes_no(t->on_timezone_change));
 259
 260         LIST_FOREACH(value, v, t->values)
 261                 if (v->base == TIMER_CALENDAR) {
 262                         _cleanup_free_ char *p = NULL;
 263
 264                         (void) calendar_spec_to_string(v->calendar_spec, &p);
 265
 266                         fprintf(f,
 267                                 "%s%s: %s\n",
 268                                 prefix,
 269                                 timer_base_to_string(v->base),
 270                                 strna(p));
 271                 } else
 272                         fprintf(f,
 273                                 "%s%s: %s\n",
 274                                 prefix,
 275                                 timer_base_to_string(v->base),
 276                                 FORMAT_TIMESPAN(v->value, 0));
 277 }
 278
 279 static void timer_set_state(Timer *t, TimerState state) {
 280         TimerState old_state;
 281
 282         assert(t);
 283
 284         if (t->state != state)
 285                 bus_unit_send_pending_change_signal(UNIT(t), false);
 286
 287         old_state = t->state;
 288         t->state = state;
 289
 290         if (state != TIMER_WAITING) {
 291                 t->monotonic_event_source = sd_event_source_disable_unref(t->monotonic_event_source);
 292                 t->realtime_event_source = sd_event_source_disable_unref(t->realtime_event_source);
 293                 t->next_elapse_monotonic_or_boottime = USEC_INFINITY;
 294                 t->next_elapse_realtime = USEC_INFINITY;
 295         }
 296
 297         if (state != old_state)
 298                 log_unit_debug(UNIT(t), "Changed %s -> %s", timer_state_to_string(old_state), timer_state_to_string(state));
 299
 300         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], /* reload_success = */ true);
 301 }
 302
 303 static void timer_enter_waiting(Timer *t, bool time_change);
 304
 305 static int timer_coldplug(Unit *u) {
 306         Timer *t = ASSERT_PTR(TIMER(u));
 307
 308         assert(t->state == TIMER_DEAD);
 309
 310         if (t->deserialized_state == t->state)
 311                 return 0;
 312
 313         if (t->deserialized_state == TIMER_WAITING)
 314                 timer_enter_waiting(t, false);
 315         else
 316                 timer_set_state(t, t->deserialized_state);
 317
 318         return 0;
 319 }
 320
 321 static void timer_enter_dead(Timer *t, TimerResult f) {
 322         assert(t);
 323
 324         if (t->result == TIMER_SUCCESS)
 325                 t->result = f;
 326
 327         unit_log_result(UNIT(t), t->result == TIMER_SUCCESS, timer_result_to_string(t->result));
 328         timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD);
 329 }
 330
 331 static void timer_enter_elapsed(Timer *t, bool leave_around) {
 332         assert(t);
 333
 334         /* If a unit is marked with RemainAfterElapse=yes we leave it
 335          * around even after it elapsed once, so that starting it
 336          * later again does not necessarily mean immediate
 337          * retriggering. We unconditionally leave units with
 338          * TIMER_UNIT_ACTIVE or TIMER_UNIT_INACTIVE triggers around,
 339          * since they might be restarted automatically at any time
 340          * later on. */
 341
 342         if (t->remain_after_elapse || leave_around)
 343                 timer_set_state(t, TIMER_ELAPSED);
 344         else
 345                 timer_enter_dead(t, TIMER_SUCCESS);
 346 }
 347
 348 static void add_random(Timer *t, usec_t *v) {
 349         usec_t add;
 350
 351         assert(t);
 352         assert(v);
 353
 354         if (t->random_usec == 0)
 355                 return;
 356         if (*v == USEC_INFINITY)
 357                 return;
 358
 359         add = (t->fixed_random_delay ? timer_get_fixed_delay_hash(t) : random_u64()) % t->random_usec;
 360
 361         if (*v + add < *v) /* overflow */
 362                 *v = (usec_t) -2; /* Highest possible value, that is not USEC_INFINITY */
 363         else
 364                 *v += add;
 365
 366         log_unit_debug(UNIT(t), "Adding %s random time.", FORMAT_TIMESPAN(add, 0));
 367 }
 368
 369 static void timer_enter_waiting(Timer *t, bool time_change) {
 370         bool found_monotonic = false, found_realtime = false;
 371         bool leave_around = false;
 372         triple_timestamp ts;
 373         Unit *trigger;
 374         int r;
 375
 376         assert(t);
 377
 378         trigger = UNIT_TRIGGER(UNIT(t));
 379         if (!trigger) {
 380                 log_unit_error(UNIT(t), "Unit to trigger vanished.");
 381                 goto fail;
 382         }
 383
 384         triple_timestamp_now(&ts);
 385         t->next_elapse_monotonic_or_boottime = t->next_elapse_realtime = 0;
 386
 387         LIST_FOREACH(value, v, t->values) {
 388                 if (v->disabled)
 389                         continue;
 390
 391                 if (v->base == TIMER_CALENDAR) {
 392                         usec_t b, rebased;
 393
 394                         /* If we know the last time this was
 395                          * triggered, schedule the job based relative
 396                          * to that. If we don't, just start from
 397                          * the activation time. */
 398
 399                         if (dual_timestamp_is_set(&t->last_trigger))
 400                                 b = t->last_trigger.realtime;
 401                         else if (dual_timestamp_is_set(&UNIT(t)->inactive_exit_timestamp))
 402                                 b = UNIT(t)->inactive_exit_timestamp.realtime;
 403                         else
 404                                 b = ts.realtime;
 405
 406                         r = calendar_spec_next_usec(v->calendar_spec, b, &v->next_elapse);
 407                         if (r < 0)
 408                                 continue;
 409
 410                         /* To make the delay due to RandomizedDelaySec= work even at boot, if the scheduled
 411                          * time has already passed, set the time when systemd first started as the scheduled
 412                          * time. Note that we base this on the monotonic timestamp of the boot, not the
 413                          * realtime one, since the wallclock might have been off during boot. */
 414                         rebased = map_clock_usec(UNIT(t)->manager->timestamps[MANAGER_TIMESTAMP_USERSPACE].monotonic,
 415                                                  CLOCK_MONOTONIC, CLOCK_REALTIME);
 416                         if (v->next_elapse < rebased)
 417                                 v->next_elapse = rebased;
 418
 419                         if (!found_realtime)
 420                                 t->next_elapse_realtime = v->next_elapse;
 421                         else
 422                                 t->next_elapse_realtime = MIN(t->next_elapse_realtime, v->next_elapse);
 423
 424                         found_realtime = true;
 425
 426                 } else {
 427                         usec_t base;
 428
 429                         switch (v->base) {
 430
 431                         case TIMER_ACTIVE:
 432                                 if (state_translation_table[t->state] == UNIT_ACTIVE)
 433                                         base = UNIT(t)->inactive_exit_timestamp.monotonic;
 434                                 else
 435                                         base = ts.monotonic;
 436                                 break;
 437
 438                         case TIMER_BOOT:
 439                                 if (detect_container() <= 0) {
 440                                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 441                                         base = 0;
 442                                         break;
 443                                 }
 444                                 /* In a container we don't want to include the time the host
 445                                  * was already up when the container started, so count from
 446                                  * our own startup. */
 447                                 _fallthrough_;
 448                         case TIMER_STARTUP:
 449                                 base = UNIT(t)->manager->timestamps[MANAGER_TIMESTAMP_USERSPACE].monotonic;
 450                                 break;
 451
 452                         case TIMER_UNIT_ACTIVE:
 453                                 leave_around = true;
 454                                 base = MAX(trigger->inactive_exit_timestamp.monotonic, t->last_trigger.monotonic);
 455                                 if (base <= 0)
 456                                         continue;
 457                                 break;
 458
 459                         case TIMER_UNIT_INACTIVE:
 460                                 leave_around = true;
 461                                 base = MAX(trigger->inactive_enter_timestamp.monotonic, t->last_trigger.monotonic);
 462                                 if (base <= 0)
 463                                         continue;
 464                                 break;
 465
 466                         default:
 467                                 assert_not_reached();
 468                         }
 469
 470                         v->next_elapse = usec_add(usec_shift_clock(base, CLOCK_MONOTONIC, TIMER_MONOTONIC_CLOCK(t)), v->value);
 471
 472                         if (dual_timestamp_is_set(&t->last_trigger) &&
 473                             !time_change &&
 474                             v->next_elapse < triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t)) &&
 475                             IN_SET(v->base, TIMER_ACTIVE, TIMER_BOOT, TIMER_STARTUP)) {
 476                                 /* This is a one time trigger, disable it now */
 477                                 v->disabled = true;
 478                                 continue;
 479                         }
 480
 481                         if (!found_monotonic)
 482                                 t->next_elapse_monotonic_or_boottime = v->next_elapse;
 483                         else
 484                                 t->next_elapse_monotonic_or_boottime = MIN(t->next_elapse_monotonic_or_boottime, v->next_elapse);
 485
 486                         found_monotonic = true;
 487                 }
 488         }
 489
 490         if (!found_monotonic && !found_realtime && !t->on_timezone_change && !t->on_clock_change) {
 491                 log_unit_debug(UNIT(t), "Timer is elapsed.");
 492                 timer_enter_elapsed(t, leave_around);
 493                 return;
 494         }
 495
 496         if (found_monotonic) {
 497                 usec_t left;
 498
 499                 add_random(t, &t->next_elapse_monotonic_or_boottime);
 500
 501                 left = usec_sub_unsigned(t->next_elapse_monotonic_or_boottime, triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t)));
 502                 log_unit_debug(UNIT(t), "Monotonic timer elapses in %s.", FORMAT_TIMESPAN(left, 0));
 503
 504                 if (t->monotonic_event_source) {
 505                         r = sd_event_source_set_time(t->monotonic_event_source, t->next_elapse_monotonic_or_boottime);
 506                         if (r < 0) {
 507                                 log_unit_warning_errno(UNIT(t), r, "Failed to reschedule monotonic event source: %m");
 508                                 goto fail;
 509                         }
 510
 511                         r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_ONESHOT);
 512                         if (r < 0) {
 513                                 log_unit_warning_errno(UNIT(t), r, "Failed to enable monotonic event source: %m");
 514                                 goto fail;
 515                         }
 516                 } else {
 517
 518                         r = sd_event_add_time(
 519                                         UNIT(t)->manager->event,
 520                                         &t->monotonic_event_source,
 521                                         t->wake_system ? CLOCK_BOOTTIME_ALARM : CLOCK_MONOTONIC,
 522                                         t->next_elapse_monotonic_or_boottime, t->accuracy_usec,
 523                                         timer_dispatch, t);
 524                         if (r < 0) {
 525                                 log_unit_warning_errno(UNIT(t), r, "Failed to add monotonic event source: %m");
 526                                 goto fail;
 527                         }
 528
 529                         (void) sd_event_source_set_description(t->monotonic_event_source, "timer-monotonic");
 530                 }
 531
 532         } else if (t->monotonic_event_source) {
 533
 534                 r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_OFF);
 535                 if (r < 0) {
 536                         log_unit_warning_errno(UNIT(t), r, "Failed to disable monotonic event source: %m");
 537                         goto fail;
 538                 }
 539         }
 540
 541         if (found_realtime) {
 542                 add_random(t, &t->next_elapse_realtime);
 543
 544                 log_unit_debug(UNIT(t), "Realtime timer elapses at %s.", FORMAT_TIMESTAMP(t->next_elapse_realtime));
 545
 546                 if (t->realtime_event_source) {
 547                         r = sd_event_source_set_time(t->realtime_event_source, t->next_elapse_realtime);
 548                         if (r < 0) {
 549                                 log_unit_warning_errno(UNIT(t), r, "Failed to reschedule realtime event source: %m");
 550                                 goto fail;
 551                         }
 552
 553                         r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_ONESHOT);
 554                         if (r < 0) {
 555                                 log_unit_warning_errno(UNIT(t), r, "Failed to enable realtime event source: %m");
 556                                 goto fail;
 557                         }
 558                 } else {
 559                         r = sd_event_add_time(
 560                                         UNIT(t)->manager->event,
 561                                         &t->realtime_event_source,
 562                                         t->wake_system ? CLOCK_REALTIME_ALARM : CLOCK_REALTIME,
 563                                         t->next_elapse_realtime, t->accuracy_usec,
 564                                         timer_dispatch, t);
 565                         if (r < 0) {
 566                                 log_unit_warning_errno(UNIT(t), r, "Failed to add realtime event source: %m");
 567                                 goto fail;
 568                         }
 569
 570                         (void) sd_event_source_set_description(t->realtime_event_source, "timer-realtime");
 571                 }
 572
 573         } else if (t->realtime_event_source) {
 574
 575                 r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_OFF);
 576                 if (r < 0) {
 577                         log_unit_warning_errno(UNIT(t), r, "Failed to disable realtime event source: %m");
 578                         goto fail;
 579                 }
 580         }
 581
 582         timer_set_state(t, TIMER_WAITING);
 583         return;
 584
 585 fail:
 586         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 587 }
 588
 589 static void timer_enter_running(Timer *t) {
 590         _cleanup_(activation_details_unrefp) ActivationDetails *details = NULL;
 591         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 592         Unit *trigger;
 593         Job *job;
 594         int r;
 595
 596         assert(t);
 597
 598         /* Don't start job if we are supposed to go down */
 599         if (unit_stop_pending(UNIT(t)))
 600                 return;
 601
 602         trigger = UNIT_TRIGGER(UNIT(t));
 603         if (!trigger) {
 604                 log_unit_error(UNIT(t), "Unit to trigger vanished.");
 605                 goto fail;
 606         }
 607
 608         details = activation_details_new(UNIT(t));
 609         if (!details) {
 610                 log_oom();
 611                 goto fail;
 612         }
 613
 614         r = manager_add_job(UNIT(t)->manager, JOB_START, trigger, JOB_REPLACE, NULL, &error, &job);
 615         if (r < 0) {
 616                 log_unit_warning(UNIT(t), "Failed to queue unit startup job: %s", bus_error_message(&error, r));
 617                 goto fail;
 618         }
 619
 620         dual_timestamp_now(&t->last_trigger);
 621         ACTIVATION_DETAILS_TIMER(details)->last_trigger = t->last_trigger;
 622
 623         job_set_activation_details(job, details);
 624
 625         if (t->stamp_path)
 626                 touch_file(t->stamp_path, true, t->last_trigger.realtime, UID_INVALID, GID_INVALID, MODE_INVALID);
 627
 628         timer_set_state(t, TIMER_RUNNING);
 629         return;
 630
 631 fail:
 632         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 633 }
 634
 635 static int timer_start(Unit *u) {
 636         Timer *t = ASSERT_PTR(TIMER(u));
 637         int r;
 638
 639         assert(IN_SET(t->state, TIMER_DEAD, TIMER_FAILED));
 640
 641         r = unit_test_trigger_loaded(u);
 642         if (r < 0)
 643                 return r;
 644
 645         r = unit_acquire_invocation_id(u);
 646         if (r < 0)
 647                 return r;
 648
 649         t->last_trigger = DUAL_TIMESTAMP_NULL;
 650
 651         /* Reenable all timers that depend on unit activation time */
 652         LIST_FOREACH(value, v, t->values)
 653                 if (v->base == TIMER_ACTIVE)
 654                         v->disabled = false;
 655
 656         if (t->stamp_path) {
 657                 struct stat st;
 658
 659                 if (stat(t->stamp_path, &st) >= 0) {
 660                         usec_t ft;
 661
 662                         /* Load the file timestamp, but only if it is actually in the past. If it is in the future,
 663                          * something is wrong with the system clock. */
 664
 665                         ft = timespec_load(&st.st_mtim);
 666                         if (ft < now(CLOCK_REALTIME))
 667                                 t->last_trigger.realtime = ft;
 668                         else
 669                                 log_unit_warning(u, "Not using persistent file timestamp %s as it is in the future.",
 670                                                  FORMAT_TIMESTAMP(ft));
 671
 672                 } else if (errno == ENOENT)
 673                         /* The timer has never run before, make sure a stamp file exists. */
 674                         (void) touch_file(t->stamp_path, true, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
 675         }
 676
 677         t->result = TIMER_SUCCESS;
 678         timer_enter_waiting(t, false);
 679         return 1;
 680 }
 681
 682 static int timer_stop(Unit *u) {
 683         Timer *t = ASSERT_PTR(TIMER(u));
 684
 685         assert(IN_SET(t->state, TIMER_WAITING, TIMER_RUNNING, TIMER_ELAPSED));
 686
 687         timer_enter_dead(t, TIMER_SUCCESS);
 688         return 1;
 689 }
 690
 691 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 692         Timer *t = ASSERT_PTR(TIMER(u));
 693
 694         assert(f);
 695         assert(fds);
 696
 697         (void) serialize_item(f, "state", timer_state_to_string(t->state));
 698         (void) serialize_item(f, "result", timer_result_to_string(t->result));
 699
 700         if (dual_timestamp_is_set(&t->last_trigger))
 701                 (void) serialize_usec(f, "last-trigger-realtime", t->last_trigger.realtime);
 702
 703         if (t->last_trigger.monotonic > 0)
 704                 (void) serialize_usec(f, "last-trigger-monotonic", t->last_trigger.monotonic);
 705
 706         return 0;
 707 }
 708
 709 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 710         Timer *t = ASSERT_PTR(TIMER(u));
 711
 712         assert(key);
 713         assert(value);
 714         assert(fds);
 715
 716         if (streq(key, "state")) {
 717                 TimerState state;
 718
 719                 state = timer_state_from_string(value);
 720                 if (state < 0)
 721                         log_unit_debug(u, "Failed to parse state value: %s", value);
 722                 else
 723                         t->deserialized_state = state;
 724
 725         } else if (streq(key, "result")) {
 726                 TimerResult f;
 727
 728                 f = timer_result_from_string(value);
 729                 if (f < 0)
 730                         log_unit_debug(u, "Failed to parse result value: %s", value);
 731                 else if (f != TIMER_SUCCESS)
 732                         t->result = f;
 733
 734         } else if (streq(key, "last-trigger-realtime"))
 735                 (void) deserialize_usec(value, &t->last_trigger.realtime);
 736         else if (streq(key, "last-trigger-monotonic"))
 737                 (void) deserialize_usec(value, &t->last_trigger.monotonic);
 738         else
 739                 log_unit_debug(u, "Unknown serialization key: %s", key);
 740
 741         return 0;
 742 }
 743
 744 static UnitActiveState timer_active_state(Unit *u) {
 745         Timer *t = ASSERT_PTR(TIMER(u));
 746
 747         return state_translation_table[t->state];
 748 }
 749
 750 static const char *timer_sub_state_to_string(Unit *u) {
 751         Timer *t = ASSERT_PTR(TIMER(u));
 752
 753         return timer_state_to_string(t->state);
 754 }
 755
 756 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata) {
 757         Timer *t = ASSERT_PTR(TIMER(userdata));
 758
 759         if (t->state != TIMER_WAITING)
 760                 return 0;
 761
 762         log_unit_debug(UNIT(t), "Timer elapsed.");
 763         timer_enter_running(t);
 764         return 0;
 765 }
 766
 767 static void timer_trigger_notify(Unit *u, Unit *other) {
 768         Timer *t = ASSERT_PTR(TIMER(u));
 769
 770         assert(other);
 771
 772         /* Filter out invocations with bogus state */
 773         assert(UNIT_IS_LOAD_COMPLETE(other->load_state));
 774
 775         /* Reenable all timers that depend on unit state */
 776         LIST_FOREACH(value, v, t->values)
 777                 if (IN_SET(v->base, TIMER_UNIT_ACTIVE, TIMER_UNIT_INACTIVE))
 778                         v->disabled = false;
 779
 780         switch (t->state) {
 781
 782         case TIMER_WAITING:
 783         case TIMER_ELAPSED:
 784
 785                 /* Recalculate sleep time */
 786                 timer_enter_waiting(t, false);
 787                 break;
 788
 789         case TIMER_RUNNING:
 790
 791                 if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
 792                         log_unit_debug(UNIT(t), "Got notified about unit deactivation.");
 793                         timer_enter_waiting(t, false);
 794                 }
 795                 break;
 796
 797         case TIMER_DEAD:
 798         case TIMER_FAILED:
 799                 break;
 800
 801         default:
 802                 assert_not_reached();
 803         }
 804 }
 805
 806 static void timer_reset_failed(Unit *u) {
 807         Timer *t = ASSERT_PTR(TIMER(u));
 808
 809         if (t->state == TIMER_FAILED)
 810                 timer_set_state(t, TIMER_DEAD);
 811
 812         t->result = TIMER_SUCCESS;
 813 }
 814
 815 static void timer_time_change(Unit *u) {
 816         Timer *t = ASSERT_PTR(TIMER(u));
 817         usec_t ts;
 818
 819         if (t->state != TIMER_WAITING)
 820                 return;
 821
 822         /* If we appear to have triggered in the future, the system clock must
 823          * have been set backwards.  So let's rewind our own clock and allow
 824          * the future triggers to happen again :).  Exactly the same as when
 825          * you start a timer unit with Persistent=yes. */
 826         ts = now(CLOCK_REALTIME);
 827         if (t->last_trigger.realtime > ts)
 828                 t->last_trigger.realtime = ts;
 829
 830         if (t->on_clock_change) {
 831                 log_unit_debug(u, "Time change, triggering activation.");
 832                 timer_enter_running(t);
 833         } else {
 834                 log_unit_debug(u, "Time change, recalculating next elapse.");
 835                 timer_enter_waiting(t, true);
 836         }
 837 }
 838
 839 static void timer_timezone_change(Unit *u) {
 840         Timer *t = ASSERT_PTR(TIMER(u));
 841
 842         if (t->state != TIMER_WAITING)
 843                 return;
 844
 845         if (t->on_timezone_change) {
 846                 log_unit_debug(u, "Timezone change, triggering activation.");
 847                 timer_enter_running(t);
 848         } else {
 849                 log_unit_debug(u, "Timezone change, recalculating next elapse.");
 850                 timer_enter_waiting(t, false);
 851         }
 852 }
 853
 854 static int timer_clean(Unit *u, ExecCleanMask mask) {
 855         Timer *t = ASSERT_PTR(TIMER(u));
 856         int r;
 857
 858         assert(mask != 0);
 859
 860         if (t->state != TIMER_DEAD)
 861                 return -EBUSY;
 862
 863         if (mask != EXEC_CLEAN_STATE)
 864                 return -EUNATCH;
 865
 866         r = timer_setup_persistent(t);
 867         if (r < 0)
 868                 return r;
 869
 870         if (!t->stamp_path)
 871                 return -EUNATCH;
 872
 873         if (unlink(t->stamp_path) && errno != ENOENT)
 874                 return log_unit_error_errno(u, errno, "Failed to clean stamp file of timer: %m");
 875
 876         return 0;
 877 }
 878
 879 static int timer_can_clean(Unit *u, ExecCleanMask *ret) {
 880         Timer *t = ASSERT_PTR(TIMER(u));
 881
 882         assert(ret);
 883
 884         *ret = t->persistent ? EXEC_CLEAN_STATE : 0;
 885         return 0;
 886 }
 887
 888 static int timer_can_start(Unit *u) {
 889         Timer *t = ASSERT_PTR(TIMER(u));
 890         int r;
 891
 892         r = unit_test_start_limit(u);
 893         if (r < 0) {
 894                 timer_enter_dead(t, TIMER_FAILURE_START_LIMIT_HIT);
 895                 return r;
 896         }
 897
 898         return 1;
 899 }
 900
 901 static void activation_details_timer_serialize(ActivationDetails *details, FILE *f) {
 902         ActivationDetailsTimer *t = ASSERT_PTR(ACTIVATION_DETAILS_TIMER(details));
 903
 904         assert(f);
 905         assert(t);
 906
 907         (void) serialize_dual_timestamp(f, "activation-details-timer-last-trigger", &t->last_trigger);
 908 }
 909
 910 static int activation_details_timer_deserialize(const char *key, const char *value, ActivationDetails **details) {
 911         int r;
 912
 913         assert(key);
 914         assert(value);
 915
 916         if (!details || !*details)
 917                 return -EINVAL;
 918
 919         ActivationDetailsTimer *t = ACTIVATION_DETAILS_TIMER(*details);
 920         if (!t)
 921                 return -EINVAL;
 922
 923         if (!streq(key, "activation-details-timer-last-trigger"))
 924                 return -EINVAL;
 925
 926         r = deserialize_dual_timestamp(value, &t->last_trigger);
 927         if (r < 0)
 928                 return r;
 929
 930         return 0;
 931 }
 932
 933 static int activation_details_timer_append_env(ActivationDetails *details, char ***strv) {
 934         ActivationDetailsTimer *t = ASSERT_PTR(ACTIVATION_DETAILS_TIMER(details));
 935         int r;
 936
 937         assert(strv);
 938         assert(t);
 939
 940         if (!dual_timestamp_is_set(&t->last_trigger))
 941                 return 0;
 942
 943         r = strv_extendf(strv, "TRIGGER_TIMER_REALTIME_USEC=" USEC_FMT, t->last_trigger.realtime);
 944         if (r < 0)
 945                 return r;
 946
 947         r = strv_extendf(strv, "TRIGGER_TIMER_MONOTONIC_USEC=" USEC_FMT, t->last_trigger.monotonic);
 948         if (r < 0)
 949                 return r;
 950
 951         return 2; /* Return the number of variables added to the env block */
 952 }
 953
 954 static int activation_details_timer_append_pair(ActivationDetails *details, char ***strv) {
 955         ActivationDetailsTimer *t = ASSERT_PTR(ACTIVATION_DETAILS_TIMER(details));
 956         int r;
 957
 958         assert(strv);
 959         assert(t);
 960
 961         if (!dual_timestamp_is_set(&t->last_trigger))
 962                 return 0;
 963
 964         r = strv_extend(strv, "trigger_timer_realtime_usec");
 965         if (r < 0)
 966                 return r;
 967
 968         r = strv_extendf(strv, USEC_FMT, t->last_trigger.realtime);
 969         if (r < 0)
 970                 return r;
 971
 972         r = strv_extend(strv, "trigger_timer_monotonic_usec");
 973         if (r < 0)
 974                 return r;
 975
 976         r = strv_extendf(strv, USEC_FMT, t->last_trigger.monotonic);
 977         if (r < 0)
 978                 return r;
 979
 980         return 2; /* Return the number of pairs added to the env block */
 981 }
 982
 983 uint64_t timer_next_elapse_monotonic(const Timer *t) {
 984         assert(t);
 985
 986         return (uint64_t) usec_shift_clock(t->next_elapse_monotonic_or_boottime,
 987                                            TIMER_MONOTONIC_CLOCK(t), CLOCK_MONOTONIC);
 988 }
 989
 990 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 991         [TIMER_ACTIVE]        = "OnActiveSec",
 992         [TIMER_BOOT]          = "OnBootSec",
 993         [TIMER_STARTUP]       = "OnStartupSec",
 994         [TIMER_UNIT_ACTIVE]   = "OnUnitActiveSec",
 995         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec",
 996         [TIMER_CALENDAR]      = "OnCalendar",
 997 };
 998
 999 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
1000
1001 char* timer_base_to_usec_string(TimerBase i) {
1002         _cleanup_free_ char *buf = NULL;
1003         const char *s;
1004         size_t l;
1005
1006         s = timer_base_to_string(i);
1007
1008         if (endswith(s, "Sec")) {
1009                 /* s/Sec/USec/ */
1010                 l = strlen(s);
1011                 buf = new(char, l+2);
1012                 if (!buf)
1013                         return NULL;
1014
1015                 memcpy(buf, s, l-3);
1016                 memcpy(buf+l-3, "USec", 5);
1017         } else {
1018                 buf = strdup(s);
1019                 if (!buf)
1020                         return NULL;
1021         }
1022
1023         return TAKE_PTR(buf);
1024 }
1025
1026 static const char* const timer_result_table[_TIMER_RESULT_MAX] = {
1027         [TIMER_SUCCESS]                 = "success",
1028         [TIMER_FAILURE_RESOURCES]       = "resources",
1029         [TIMER_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1030 };
1031
1032 DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult);
1033
1034 const UnitVTable timer_vtable = {
1035         .object_size = sizeof(Timer),
1036
1037         .sections =
1038                 "Unit\0"
1039                 "Timer\0"
1040                 "Install\0",
1041         .private_section = "Timer",
1042
1043         .can_transient = true,
1044         .can_fail = true,
1045         .can_trigger = true,
1046
1047         .init = timer_init,
1048         .done = timer_done,
1049         .load = timer_load,
1050
1051         .coldplug = timer_coldplug,
1052
1053         .dump = timer_dump,
1054
1055         .start = timer_start,
1056         .stop = timer_stop,
1057
1058         .clean = timer_clean,
1059         .can_clean = timer_can_clean,
1060
1061         .serialize = timer_serialize,
1062         .deserialize_item = timer_deserialize_item,
1063
1064         .active_state = timer_active_state,
1065         .sub_state_to_string = timer_sub_state_to_string,
1066
1067         .trigger_notify = timer_trigger_notify,
1068
1069         .reset_failed = timer_reset_failed,
1070         .time_change = timer_time_change,
1071         .timezone_change = timer_timezone_change,
1072
1073         .bus_set_property = bus_timer_set_property,
1074
1075         .can_start = timer_can_start,
1076 };
1077
1078 const ActivationDetailsVTable activation_details_timer_vtable = {
1079         .object_size = sizeof(ActivationDetailsTimer),
1080
1081         .serialize = activation_details_timer_serialize,
1082         .deserialize = activation_details_timer_deserialize,
1083         .append_env = activation_details_timer_append_env,
1084         .append_pair = activation_details_timer_append_pair,
1085 };