src/core/scope.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <unistd.h>
   5
   6 #include "alloc-util.h"
   7 #include "dbus-scope.h"
   8 #include "dbus-unit.h"
   9 #include "load-dropin.h"
  10 #include "log.h"
  11 #include "scope.h"
  12 #include "serialize.h"
  13 #include "special.h"
  14 #include "string-table.h"
  15 #include "string-util.h"
  16 #include "strv.h"
  17 #include "unit-name.h"
  18 #include "unit.h"
  19
  20 static const UnitActiveState state_translation_table[_SCOPE_STATE_MAX] = {
  21         [SCOPE_DEAD] = UNIT_INACTIVE,
  22         [SCOPE_RUNNING] = UNIT_ACTIVE,
  23         [SCOPE_ABANDONED] = UNIT_ACTIVE,
  24         [SCOPE_STOP_SIGTERM] = UNIT_DEACTIVATING,
  25         [SCOPE_STOP_SIGKILL] = UNIT_DEACTIVATING,
  26         [SCOPE_FAILED] = UNIT_FAILED
  27 };
  28
  29 static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
  30
  31 static void scope_init(Unit *u) {
  32         Scope *s = SCOPE(u);
  33
  34         assert(u);
  35         assert(u->load_state == UNIT_STUB);
  36
  37         s->runtime_max_usec = USEC_INFINITY;
  38         s->timeout_stop_usec = u->manager->default_timeout_stop_usec;
  39         u->ignore_on_isolate = true;
  40 }
  41
  42 static void scope_done(Unit *u) {
  43         Scope *s = SCOPE(u);
  44
  45         assert(u);
  46
  47         s->controller = mfree(s->controller);
  48         s->controller_track = sd_bus_track_unref(s->controller_track);
  49
  50         s->timer_event_source = sd_event_source_unref(s->timer_event_source);
  51 }
  52
  53 static int scope_arm_timer(Scope *s, usec_t usec) {
  54         int r;
  55
  56         assert(s);
  57
  58         if (s->timer_event_source) {
  59                 r = sd_event_source_set_time(s->timer_event_source, usec);
  60                 if (r < 0)
  61                         return r;
  62
  63                 return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
  64         }
  65
  66         if (usec == USEC_INFINITY)
  67                 return 0;
  68
  69         r = sd_event_add_time(
  70                         UNIT(s)->manager->event,
  71                         &s->timer_event_source,
  72                         CLOCK_MONOTONIC,
  73                         usec, 0,
  74                         scope_dispatch_timer, s);
  75         if (r < 0)
  76                 return r;
  77
  78         (void) sd_event_source_set_description(s->timer_event_source, "scope-timer");
  79
  80         return 0;
  81 }
  82
  83 static void scope_set_state(Scope *s, ScopeState state) {
  84         ScopeState old_state;
  85         assert(s);
  86
  87         if (s->state != state)
  88                 bus_unit_send_pending_change_signal(UNIT(s), false);
  89
  90         old_state = s->state;
  91         s->state = state;
  92
  93         if (!IN_SET(state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
  94                 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
  95
  96         if (IN_SET(state, SCOPE_DEAD, SCOPE_FAILED)) {
  97                 unit_unwatch_all_pids(UNIT(s));
  98                 unit_dequeue_rewatch_pids(UNIT(s));
  99         }
 100
 101         if (state != old_state)
 102                 log_debug("%s changed %s -> %s", UNIT(s)->id, scope_state_to_string(old_state), scope_state_to_string(state));
 103
 104         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], 0);
 105 }
 106
 107 static int scope_add_default_dependencies(Scope *s) {
 108         int r;
 109
 110         assert(s);
 111
 112         if (!UNIT(s)->default_dependencies)
 113                 return 0;
 114
 115         /* Make sure scopes are unloaded on shutdown */
 116         r = unit_add_two_dependencies_by_name(
 117                         UNIT(s),
 118                         UNIT_BEFORE, UNIT_CONFLICTS,
 119                         SPECIAL_SHUTDOWN_TARGET, true,
 120                         UNIT_DEPENDENCY_DEFAULT);
 121         if (r < 0)
 122                 return r;
 123
 124         return 0;
 125 }
 126
 127 static int scope_verify(Scope *s) {
 128         assert(s);
 129         assert(UNIT(s)->load_state == UNIT_LOADED);
 130
 131         if (set_isempty(UNIT(s)->pids) &&
 132             !MANAGER_IS_RELOADING(UNIT(s)->manager) &&
 133             !unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE)) {
 134                 log_unit_error(UNIT(s), "Scope has no PIDs. Refusing.");
 135                 return -ENOENT;
 136         }
 137
 138         return 0;
 139 }
 140
 141 static int scope_load_init_scope(Unit *u) {
 142         assert(u);
 143
 144         if (!unit_has_name(u, SPECIAL_INIT_SCOPE))
 145                 return 0;
 146
 147         u->transient = true;
 148         u->perpetual = true;
 149
 150         /* init.scope is a bit special, as it has to stick around forever. Because of its special semantics we
 151          * synthesize it here, instead of relying on the unit file on disk. */
 152
 153         u->default_dependencies = false;
 154
 155         /* Prettify things, if we can. */
 156         if (!u->description)
 157                 u->description = strdup("System and Service Manager");
 158         if (!u->documentation)
 159                 (void) strv_extend(&u->documentation, "man:systemd(1)");
 160
 161         return 1;
 162 }
 163
 164 static int scope_add_extras(Scope *s) {
 165         int r;
 166
 167         r = unit_patch_contexts(UNIT(s));
 168         if (r < 0)
 169                 return r;
 170
 171         r = unit_set_default_slice(UNIT(s));
 172         if (r < 0)
 173                 return r;
 174
 175         return scope_add_default_dependencies(s);
 176 }
 177
 178 static int scope_load(Unit *u) {
 179         Scope *s = SCOPE(u);
 180         int r;
 181
 182         assert(s);
 183         assert(u->load_state == UNIT_STUB);
 184
 185         if (!u->transient && !MANAGER_IS_RELOADING(u->manager))
 186                 /* Refuse to load non-transient scope units, but allow them while reloading. */
 187                 return -ENOENT;
 188
 189         r = scope_load_init_scope(u);
 190         if (r < 0)
 191                 return r;
 192
 193         r = unit_load_fragment_and_dropin(u, false);
 194         if (r < 0)
 195                 return r;
 196
 197         if (u->load_state != UNIT_LOADED)
 198                 return 0;
 199
 200         r = scope_add_extras(s);
 201         if (r < 0)
 202                 return r;
 203
 204         return scope_verify(s);
 205 }
 206
 207 static usec_t scope_coldplug_timeout(Scope *s) {
 208         assert(s);
 209
 210         switch (s->deserialized_state) {
 211
 212         case SCOPE_RUNNING:
 213                 return usec_add(UNIT(s)->active_enter_timestamp.monotonic, s->runtime_max_usec);
 214
 215         case SCOPE_STOP_SIGKILL:
 216         case SCOPE_STOP_SIGTERM:
 217                 return usec_add(UNIT(s)->state_change_timestamp.monotonic, s->timeout_stop_usec);
 218
 219         default:
 220                 return USEC_INFINITY;
 221         }
 222 }
 223
 224 static int scope_coldplug(Unit *u) {
 225         Scope *s = SCOPE(u);
 226         int r;
 227
 228         assert(s);
 229         assert(s->state == SCOPE_DEAD);
 230
 231         if (s->deserialized_state == s->state)
 232                 return 0;
 233
 234         r = scope_arm_timer(s, scope_coldplug_timeout(s));
 235         if (r < 0)
 236                 return r;
 237
 238         if (!IN_SET(s->deserialized_state, SCOPE_DEAD, SCOPE_FAILED))
 239                 (void) unit_enqueue_rewatch_pids(u);
 240
 241         bus_scope_track_controller(s);
 242
 243         scope_set_state(s, s->deserialized_state);
 244         return 0;
 245 }
 246
 247 static void scope_dump(Unit *u, FILE *f, const char *prefix) {
 248         Scope *s = SCOPE(u);
 249         char buf_runtime[FORMAT_TIMESPAN_MAX];
 250
 251         assert(s);
 252         assert(f);
 253
 254         fprintf(f,
 255                 "%sScope State: %s\n"
 256                 "%sResult: %s\n"
 257                 "%sRuntimeMaxSec: %s\n",
 258                 prefix, scope_state_to_string(s->state),
 259                 prefix, scope_result_to_string(s->result),
 260                 prefix, format_timespan(buf_runtime, sizeof(buf_runtime), s->runtime_max_usec, USEC_PER_SEC));
 261
 262         cgroup_context_dump(UNIT(s), f, prefix);
 263         kill_context_dump(&s->kill_context, f, prefix);
 264 }
 265
 266 static void scope_enter_dead(Scope *s, ScopeResult f) {
 267         assert(s);
 268
 269         if (s->result == SCOPE_SUCCESS)
 270                 s->result = f;
 271
 272         unit_log_result(UNIT(s), s->result == SCOPE_SUCCESS, scope_result_to_string(s->result));
 273         scope_set_state(s, s->result != SCOPE_SUCCESS ? SCOPE_FAILED : SCOPE_DEAD);
 274 }
 275
 276 static void scope_enter_signal(Scope *s, ScopeState state, ScopeResult f) {
 277         bool skip_signal = false;
 278         int r;
 279
 280         assert(s);
 281
 282         if (s->result == SCOPE_SUCCESS)
 283                 s->result = f;
 284
 285         /* Before sending any signal, make sure we track all members of this cgroup */
 286         (void) unit_watch_all_pids(UNIT(s));
 287
 288         /* Also, enqueue a job that we recheck all our PIDs a bit later, given that it's likely some processes have
 289          * died now */
 290         (void) unit_enqueue_rewatch_pids(UNIT(s));
 291
 292         /* If we have a controller set let's ask the controller nicely to terminate the scope, instead of us going
 293          * directly into SIGTERM berserk mode */
 294         if (state == SCOPE_STOP_SIGTERM)
 295                 skip_signal = bus_scope_send_request_stop(s) > 0;
 296
 297         if (skip_signal)
 298                 r = 1; /* wait */
 299         else {
 300                 r = unit_kill_context(
 301                                 UNIT(s),
 302                                 &s->kill_context,
 303                                 state != SCOPE_STOP_SIGTERM ? KILL_KILL :
 304                                 s->was_abandoned            ? KILL_TERMINATE_AND_LOG :
 305                                                               KILL_TERMINATE,
 306                                 -1, -1, false);
 307                 if (r < 0)
 308                         goto fail;
 309         }
 310
 311         if (r > 0) {
 312                 r = scope_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_stop_usec));
 313                 if (r < 0)
 314                         goto fail;
 315
 316                 scope_set_state(s, state);
 317         } else if (state == SCOPE_STOP_SIGTERM)
 318                 scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_SUCCESS);
 319         else
 320                 scope_enter_dead(s, SCOPE_SUCCESS);
 321
 322         return;
 323
 324 fail:
 325         log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m");
 326
 327         scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
 328 }
 329
 330 static int scope_start(Unit *u) {
 331         Scope *s = SCOPE(u);
 332         int r;
 333
 334         assert(s);
 335
 336         if (unit_has_name(u, SPECIAL_INIT_SCOPE))
 337                 return -EPERM;
 338
 339         if (s->state == SCOPE_FAILED)
 340                 return -EPERM;
 341
 342         /* We can't fulfill this right now, please try again later */
 343         if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 344                 return -EAGAIN;
 345
 346         assert(s->state == SCOPE_DEAD);
 347
 348         if (!u->transient && !MANAGER_IS_RELOADING(u->manager))
 349                 return -ENOENT;
 350
 351         (void) bus_scope_track_controller(s);
 352
 353         r = unit_acquire_invocation_id(u);
 354         if (r < 0)
 355                 return r;
 356
 357         (void) unit_realize_cgroup(u);
 358         (void) unit_reset_accounting(u);
 359
 360         unit_export_state_files(u);
 361
 362         r = unit_attach_pids_to_cgroup(u, u->pids, NULL);
 363         if (r < 0) {
 364                 log_unit_warning_errno(u, r, "Failed to add PIDs to scope's control group: %m");
 365                 scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
 366                 return r;
 367         }
 368
 369         s->result = SCOPE_SUCCESS;
 370
 371         scope_set_state(s, SCOPE_RUNNING);
 372
 373         /* Set the maximum runtime timeout. */
 374         scope_arm_timer(s, usec_add(UNIT(s)->active_enter_timestamp.monotonic, s->runtime_max_usec));
 375
 376         /* Start watching the PIDs currently in the scope */
 377         (void) unit_enqueue_rewatch_pids(u);
 378         return 1;
 379 }
 380
 381 static int scope_stop(Unit *u) {
 382         Scope *s = SCOPE(u);
 383
 384         assert(s);
 385
 386         if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 387                 return 0;
 388
 389         assert(IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED));
 390
 391         scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_SUCCESS);
 392         return 1;
 393 }
 394
 395 static void scope_reset_failed(Unit *u) {
 396         Scope *s = SCOPE(u);
 397
 398         assert(s);
 399
 400         if (s->state == SCOPE_FAILED)
 401                 scope_set_state(s, SCOPE_DEAD);
 402
 403         s->result = SCOPE_SUCCESS;
 404 }
 405
 406 static int scope_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
 407         return unit_kill_common(u, who, signo, -1, -1, error);
 408 }
 409
 410 static int scope_get_timeout(Unit *u, usec_t *timeout) {
 411         Scope *s = SCOPE(u);
 412         usec_t t;
 413         int r;
 414
 415         if (!s->timer_event_source)
 416                 return 0;
 417
 418         r = sd_event_source_get_time(s->timer_event_source, &t);
 419         if (r < 0)
 420                 return r;
 421         if (t == USEC_INFINITY)
 422                 return 0;
 423
 424         *timeout = t;
 425         return 1;
 426 }
 427
 428 static int scope_serialize(Unit *u, FILE *f, FDSet *fds) {
 429         Scope *s = SCOPE(u);
 430
 431         assert(s);
 432         assert(f);
 433         assert(fds);
 434
 435         (void) serialize_item(f, "state", scope_state_to_string(s->state));
 436         (void) serialize_bool(f, "was-abandoned", s->was_abandoned);
 437
 438         if (s->controller)
 439                 (void) serialize_item(f, "controller", s->controller);
 440
 441         return 0;
 442 }
 443
 444 static int scope_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 445         Scope *s = SCOPE(u);
 446         int r;
 447
 448         assert(u);
 449         assert(key);
 450         assert(value);
 451         assert(fds);
 452
 453         if (streq(key, "state")) {
 454                 ScopeState state;
 455
 456                 state = scope_state_from_string(value);
 457                 if (state < 0)
 458                         log_unit_debug(u, "Failed to parse state value: %s", value);
 459                 else
 460                         s->deserialized_state = state;
 461
 462         } else if (streq(key, "was-abandoned")) {
 463                 int k;
 464
 465                 k = parse_boolean(value);
 466                 if (k < 0)
 467                         log_unit_debug(u, "Failed to parse boolean value: %s", value);
 468                 else
 469                         s->was_abandoned = k;
 470         } else if (streq(key, "controller")) {
 471
 472                 r = free_and_strdup(&s->controller, value);
 473                 if (r < 0)
 474                         return log_oom();
 475
 476         } else
 477                 log_unit_debug(u, "Unknown serialization key: %s", key);
 478
 479         return 0;
 480 }
 481
 482 static void scope_notify_cgroup_empty_event(Unit *u) {
 483         Scope *s = SCOPE(u);
 484         assert(u);
 485
 486         log_unit_debug(u, "cgroup is empty");
 487
 488         if (IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 489                 scope_enter_dead(s, SCOPE_SUCCESS);
 490
 491         /* If the cgroup empty notification comes when the unit is not active, we must have failed to clean
 492          * up the cgroup earlier and should do it now. */
 493         if (IN_SET(s->state, SCOPE_DEAD, SCOPE_FAILED))
 494                 unit_prune_cgroup(u);
 495 }
 496
 497 static void scope_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 498         assert(u);
 499
 500         /* If we get a SIGCHLD event for one of the processes we were interested in, then we look for others to
 501          * watch, under the assumption that we'll sooner or later get a SIGCHLD for them, as the original
 502          * process we watched was probably the parent of them, and they are hence now our children. */
 503
 504         (void) unit_enqueue_rewatch_pids(u);
 505 }
 506
 507 static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
 508         Scope *s = SCOPE(userdata);
 509
 510         assert(s);
 511         assert(s->timer_event_source == source);
 512
 513         switch (s->state) {
 514
 515         case SCOPE_RUNNING:
 516                 log_unit_warning(UNIT(s), "Scope reached runtime time limit. Stopping.");
 517                 scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_FAILURE_TIMEOUT);
 518                 break;
 519
 520         case SCOPE_STOP_SIGTERM:
 521                 if (s->kill_context.send_sigkill) {
 522                         log_unit_warning(UNIT(s), "Stopping timed out. Killing.");
 523                         scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_FAILURE_TIMEOUT);
 524                 } else {
 525                         log_unit_warning(UNIT(s), "Stopping timed out. Skipping SIGKILL.");
 526                         scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
 527                 }
 528
 529                 break;
 530
 531         case SCOPE_STOP_SIGKILL:
 532                 log_unit_warning(UNIT(s), "Still around after SIGKILL. Ignoring.");
 533                 scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
 534                 break;
 535
 536         default:
 537                 assert_not_reached("Timeout at wrong time.");
 538         }
 539
 540         return 0;
 541 }
 542
 543 int scope_abandon(Scope *s) {
 544         assert(s);
 545
 546         if (unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE))
 547                 return -EPERM;
 548
 549         if (!IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED))
 550                 return -ESTALE;
 551
 552         s->was_abandoned = true;
 553
 554         s->controller = mfree(s->controller);
 555         s->controller_track = sd_bus_track_unref(s->controller_track);
 556
 557         scope_set_state(s, SCOPE_ABANDONED);
 558
 559         /* The client is no longer watching the remaining processes, so let's step in here, under the assumption that
 560          * the remaining processes will be sooner or later reassigned to us as parent. */
 561         (void) unit_enqueue_rewatch_pids(UNIT(s));
 562
 563         return 0;
 564 }
 565
 566 _pure_ static UnitActiveState scope_active_state(Unit *u) {
 567         assert(u);
 568
 569         return state_translation_table[SCOPE(u)->state];
 570 }
 571
 572 _pure_ static const char *scope_sub_state_to_string(Unit *u) {
 573         assert(u);
 574
 575         return scope_state_to_string(SCOPE(u)->state);
 576 }
 577
 578 static void scope_enumerate_perpetual(Manager *m) {
 579         Unit *u;
 580         int r;
 581
 582         assert(m);
 583
 584         /* Let's unconditionally add the "init.scope" special unit
 585          * that encapsulates PID 1. Note that PID 1 already is in the
 586          * cgroup for this, we hence just need to allocate the object
 587          * for it and that's it. */
 588
 589         u = manager_get_unit(m, SPECIAL_INIT_SCOPE);
 590         if (!u) {
 591                 r = unit_new_for_name(m, sizeof(Scope), SPECIAL_INIT_SCOPE, &u);
 592                 if (r < 0)  {
 593                         log_error_errno(r, "Failed to allocate the special " SPECIAL_INIT_SCOPE " unit: %m");
 594                         return;
 595                 }
 596         }
 597
 598         u->transient = true;
 599         u->perpetual = true;
 600         SCOPE(u)->deserialized_state = SCOPE_RUNNING;
 601
 602         unit_add_to_load_queue(u);
 603         unit_add_to_dbus_queue(u);
 604 }
 605
 606 static const char* const scope_result_table[_SCOPE_RESULT_MAX] = {
 607         [SCOPE_SUCCESS] = "success",
 608         [SCOPE_FAILURE_RESOURCES] = "resources",
 609         [SCOPE_FAILURE_TIMEOUT] = "timeout",
 610 };
 611
 612 DEFINE_STRING_TABLE_LOOKUP(scope_result, ScopeResult);
 613
 614 const UnitVTable scope_vtable = {
 615         .object_size = sizeof(Scope),
 616         .cgroup_context_offset = offsetof(Scope, cgroup_context),
 617         .kill_context_offset = offsetof(Scope, kill_context),
 618
 619         .sections =
 620                 "Unit\0"
 621                 "Scope\0"
 622                 "Install\0",
 623         .private_section = "Scope",
 624
 625         .can_transient = true,
 626         .can_delegate = true,
 627         .can_fail = true,
 628         .once_only = true,
 629         .can_set_managed_oom = true,
 630
 631         .init = scope_init,
 632         .load = scope_load,
 633         .done = scope_done,
 634
 635         .coldplug = scope_coldplug,
 636
 637         .dump = scope_dump,
 638
 639         .start = scope_start,
 640         .stop = scope_stop,
 641
 642         .kill = scope_kill,
 643
 644         .freeze = unit_freeze_vtable_common,
 645         .thaw = unit_thaw_vtable_common,
 646
 647         .get_timeout = scope_get_timeout,
 648
 649         .serialize = scope_serialize,
 650         .deserialize_item = scope_deserialize_item,
 651
 652         .active_state = scope_active_state,
 653         .sub_state_to_string = scope_sub_state_to_string,
 654
 655         .sigchld_event = scope_sigchld_event,
 656
 657         .reset_failed = scope_reset_failed,
 658
 659         .notify_cgroup_empty = scope_notify_cgroup_empty_event,
 660
 661         .bus_set_property = bus_scope_set_property,
 662         .bus_commit_properties = bus_scope_commit_properties,
 663
 664         .enumerate_perpetual = scope_enumerate_perpetual,
 665 };