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