src/core/scope.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2013 Lennart Poettering
   6 ***/
   7
   8 #include <errno.h>
   9 #include <unistd.h>
  10
  11 #include "alloc-util.h"
  12 #include "dbus-scope.h"
  13 #include "load-dropin.h"
  14 #include "log.h"
  15 #include "scope.h"
  16 #include "special.h"
  17 #include "string-table.h"
  18 #include "string-util.h"
  19 #include "strv.h"
  20 #include "unit-name.h"
  21 #include "unit.h"
  22
  23 static const UnitActiveState state_translation_table[_SCOPE_STATE_MAX] = {
  24         [SCOPE_DEAD] = UNIT_INACTIVE,
  25         [SCOPE_RUNNING] = UNIT_ACTIVE,
  26         [SCOPE_ABANDONED] = UNIT_ACTIVE,
  27         [SCOPE_STOP_SIGTERM] = UNIT_DEACTIVATING,
  28         [SCOPE_STOP_SIGKILL] = UNIT_DEACTIVATING,
  29         [SCOPE_FAILED] = UNIT_FAILED
  30 };
  31
  32 static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
  33
  34 static void scope_init(Unit *u) {
  35         Scope *s = SCOPE(u);
  36
  37         assert(u);
  38         assert(u->load_state == UNIT_STUB);
  39
  40         s->timeout_stop_usec = u->manager->default_timeout_stop_usec;
  41         u->ignore_on_isolate = true;
  42 }
  43
  44 static void scope_done(Unit *u) {
  45         Scope *s = SCOPE(u);
  46
  47         assert(u);
  48
  49         s->controller = mfree(s->controller);
  50         s->controller_track = sd_bus_track_unref(s->controller_track);
  51
  52         s->timer_event_source = sd_event_source_unref(s->timer_event_source);
  53 }
  54
  55 static int scope_arm_timer(Scope *s, usec_t usec) {
  56         int r;
  57
  58         assert(s);
  59
  60         if (s->timer_event_source) {
  61                 r = sd_event_source_set_time(s->timer_event_source, usec);
  62                 if (r < 0)
  63                         return r;
  64
  65                 return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
  66         }
  67
  68         if (usec == USEC_INFINITY)
  69                 return 0;
  70
  71         r = sd_event_add_time(
  72                         UNIT(s)->manager->event,
  73                         &s->timer_event_source,
  74                         CLOCK_MONOTONIC,
  75                         usec, 0,
  76                         scope_dispatch_timer, s);
  77         if (r < 0)
  78                 return r;
  79
  80         (void) sd_event_source_set_description(s->timer_event_source, "scope-timer");
  81
  82         return 0;
  83 }
  84
  85 static void scope_set_state(Scope *s, ScopeState state) {
  86         ScopeState old_state;
  87         assert(s);
  88
  89         old_state = s->state;
  90         s->state = state;
  91
  92         if (!IN_SET(state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
  93                 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
  94
  95         if (IN_SET(state, SCOPE_DEAD, SCOPE_FAILED))
  96                 unit_unwatch_all_pids(UNIT(s));
  97
  98         if (state != old_state)
  99                 log_debug("%s changed %s -> %s", UNIT(s)->id, scope_state_to_string(old_state), scope_state_to_string(state));
 100
 101         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 102 }
 103
 104 static int scope_add_default_dependencies(Scope *s) {
 105         int r;
 106
 107         assert(s);
 108
 109         if (!UNIT(s)->default_dependencies)
 110                 return 0;
 111
 112         /* Make sure scopes are unloaded on shutdown */
 113         r = unit_add_two_dependencies_by_name(
 114                         UNIT(s),
 115                         UNIT_BEFORE, UNIT_CONFLICTS,
 116                         SPECIAL_SHUTDOWN_TARGET, NULL, true,
 117                         UNIT_DEPENDENCY_DEFAULT);
 118         if (r < 0)
 119                 return r;
 120
 121         return 0;
 122 }
 123
 124 static int scope_verify(Scope *s) {
 125         assert(s);
 126
 127         if (UNIT(s)->load_state != UNIT_LOADED)
 128                 return 0;
 129
 130         if (set_isempty(UNIT(s)->pids) &&
 131             !MANAGER_IS_RELOADING(UNIT(s)->manager) &&
 132             !unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE)) {
 133                 log_unit_error(UNIT(s), "Scope has no PIDs. Refusing.");
 134                 return -EINVAL;
 135         }
 136
 137         return 0;
 138 }
 139
 140 static int scope_load_init_scope(Unit *u) {
 141         assert(u);
 142
 143         if (!unit_has_name(u, SPECIAL_INIT_SCOPE))
 144                 return 0;
 145
 146         u->transient = true;
 147         u->perpetual = true;
 148
 149         /* init.scope is a bit special, as it has to stick around forever. Because of its special semantics we
 150          * synthesize it here, instead of relying on the unit file on disk. */
 151
 152         u->default_dependencies = false;
 153
 154         /* Prettify things, if we can. */
 155         if (!u->description)
 156                 u->description = strdup("System and Service Manager");
 157         if (!u->documentation)
 158                 (void) strv_extend(&u->documentation, "man:systemd(1)");
 159
 160         return 1;
 161 }
 162
 163 static int scope_load(Unit *u) {
 164         Scope *s = SCOPE(u);
 165         int r;
 166
 167         assert(s);
 168         assert(u->load_state == UNIT_STUB);
 169
 170         if (!u->transient && !MANAGER_IS_RELOADING(u->manager))
 171                 /* Refuse to load non-transient scope units, but allow them while reloading. */
 172                 return -ENOENT;
 173
 174         r = scope_load_init_scope(u);
 175         if (r < 0)
 176                 return r;
 177         r = unit_load_fragment_and_dropin_optional(u);
 178         if (r < 0)
 179                 return r;
 180
 181         if (u->load_state == UNIT_LOADED) {
 182                 r = unit_patch_contexts(u);
 183                 if (r < 0)
 184                         return r;
 185
 186                 r = unit_set_default_slice(u);
 187                 if (r < 0)
 188                         return r;
 189
 190                 r = scope_add_default_dependencies(s);
 191                 if (r < 0)
 192                         return r;
 193         }
 194
 195         return scope_verify(s);
 196 }
 197
 198 static int scope_coldplug(Unit *u) {
 199         Scope *s = SCOPE(u);
 200         int r;
 201
 202         assert(s);
 203         assert(s->state == SCOPE_DEAD);
 204
 205         if (s->deserialized_state == s->state)
 206                 return 0;
 207
 208         if (IN_SET(s->deserialized_state, SCOPE_STOP_SIGKILL, SCOPE_STOP_SIGTERM)) {
 209                 r = scope_arm_timer(s, usec_add(u->state_change_timestamp.monotonic, s->timeout_stop_usec));
 210                 if (r < 0)
 211                         return r;
 212         }
 213
 214         if (!IN_SET(s->deserialized_state, SCOPE_DEAD, SCOPE_FAILED))
 215                 unit_watch_all_pids(UNIT(s));
 216
 217         bus_scope_track_controller(s);
 218
 219         scope_set_state(s, s->deserialized_state);
 220         return 0;
 221 }
 222
 223 static void scope_dump(Unit *u, FILE *f, const char *prefix) {
 224         Scope *s = SCOPE(u);
 225
 226         assert(s);
 227         assert(f);
 228
 229         fprintf(f,
 230                 "%sScope State: %s\n"
 231                 "%sResult: %s\n",
 232                 prefix, scope_state_to_string(s->state),
 233                 prefix, scope_result_to_string(s->result));
 234
 235         cgroup_context_dump(&s->cgroup_context, f, prefix);
 236         kill_context_dump(&s->kill_context, f, prefix);
 237 }
 238
 239 static void scope_enter_dead(Scope *s, ScopeResult f) {
 240         assert(s);
 241
 242         if (s->result == SCOPE_SUCCESS)
 243                 s->result = f;
 244
 245         if (s->result != SCOPE_SUCCESS)
 246                 log_unit_warning(UNIT(s), "Failed with result '%s'.", scope_result_to_string(s->result));
 247
 248         scope_set_state(s, s->result != SCOPE_SUCCESS ? SCOPE_FAILED : SCOPE_DEAD);
 249 }
 250
 251 static void scope_enter_signal(Scope *s, ScopeState state, ScopeResult f) {
 252         bool skip_signal = false;
 253         int r;
 254
 255         assert(s);
 256
 257         if (s->result == SCOPE_SUCCESS)
 258                 s->result = f;
 259
 260         unit_watch_all_pids(UNIT(s));
 261
 262         /* If we have a controller set let's ask the controller nicely to terminate the scope, instead of us going
 263          * directly into SIGTERM berserk mode */
 264         if (state == SCOPE_STOP_SIGTERM)
 265                 skip_signal = bus_scope_send_request_stop(s) > 0;
 266
 267         if (skip_signal)
 268                 r = 1; /* wait */
 269         else {
 270                 r = unit_kill_context(
 271                                 UNIT(s),
 272                                 &s->kill_context,
 273                                 state != SCOPE_STOP_SIGTERM ? KILL_KILL :
 274                                 s->was_abandoned            ? KILL_TERMINATE_AND_LOG :
 275                                                               KILL_TERMINATE,
 276                                 -1, -1, false);
 277                 if (r < 0)
 278                         goto fail;
 279         }
 280
 281         if (r > 0) {
 282                 r = scope_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_stop_usec));
 283                 if (r < 0)
 284                         goto fail;
 285
 286                 scope_set_state(s, state);
 287         } else if (state == SCOPE_STOP_SIGTERM)
 288                 scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_SUCCESS);
 289         else
 290                 scope_enter_dead(s, SCOPE_SUCCESS);
 291
 292         return;
 293
 294 fail:
 295         log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m");
 296
 297         scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
 298 }
 299
 300 static int scope_start(Unit *u) {
 301         Scope *s = SCOPE(u);
 302         int r;
 303
 304         assert(s);
 305
 306         if (unit_has_name(u, SPECIAL_INIT_SCOPE))
 307                 return -EPERM;
 308
 309         if (s->state == SCOPE_FAILED)
 310                 return -EPERM;
 311
 312         /* We can't fulfill this right now, please try again later */
 313         if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 314                 return -EAGAIN;
 315
 316         assert(s->state == SCOPE_DEAD);
 317
 318         if (!u->transient && !MANAGER_IS_RELOADING(u->manager))
 319                 return -ENOENT;
 320
 321         (void) bus_scope_track_controller(s);
 322
 323         r = unit_acquire_invocation_id(u);
 324         if (r < 0)
 325                 return r;
 326
 327         (void) unit_realize_cgroup(u);
 328         (void) unit_reset_cpu_accounting(u);
 329         (void) unit_reset_ip_accounting(u);
 330
 331         unit_export_state_files(UNIT(s));
 332
 333         r = unit_attach_pids_to_cgroup(u, UNIT(s)->pids, NULL);
 334         if (r < 0) {
 335                 log_unit_warning_errno(UNIT(s), r, "Failed to add PIDs to scope's control group: %m");
 336                 scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
 337                 return r;
 338         }
 339
 340         s->result = SCOPE_SUCCESS;
 341
 342         scope_set_state(s, SCOPE_RUNNING);
 343         return 1;
 344 }
 345
 346 static int scope_stop(Unit *u) {
 347         Scope *s = SCOPE(u);
 348
 349         assert(s);
 350
 351         if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 352                 return 0;
 353
 354         assert(IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED));
 355
 356         scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_SUCCESS);
 357         return 1;
 358 }
 359
 360 static void scope_reset_failed(Unit *u) {
 361         Scope *s = SCOPE(u);
 362
 363         assert(s);
 364
 365         if (s->state == SCOPE_FAILED)
 366                 scope_set_state(s, SCOPE_DEAD);
 367
 368         s->result = SCOPE_SUCCESS;
 369 }
 370
 371 static int scope_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
 372         return unit_kill_common(u, who, signo, -1, -1, error);
 373 }
 374
 375 static int scope_get_timeout(Unit *u, usec_t *timeout) {
 376         Scope *s = SCOPE(u);
 377         usec_t t;
 378         int r;
 379
 380         if (!s->timer_event_source)
 381                 return 0;
 382
 383         r = sd_event_source_get_time(s->timer_event_source, &t);
 384         if (r < 0)
 385                 return r;
 386         if (t == USEC_INFINITY)
 387                 return 0;
 388
 389         *timeout = t;
 390         return 1;
 391 }
 392
 393 static int scope_serialize(Unit *u, FILE *f, FDSet *fds) {
 394         Scope *s = SCOPE(u);
 395
 396         assert(s);
 397         assert(f);
 398         assert(fds);
 399
 400         unit_serialize_item(u, f, "state", scope_state_to_string(s->state));
 401         unit_serialize_item(u, f, "was-abandoned", yes_no(s->was_abandoned));
 402
 403         if (s->controller)
 404                 unit_serialize_item(u, f, "controller", s->controller);
 405
 406         return 0;
 407 }
 408
 409 static int scope_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 410         Scope *s = SCOPE(u);
 411         int r;
 412
 413         assert(u);
 414         assert(key);
 415         assert(value);
 416         assert(fds);
 417
 418         if (streq(key, "state")) {
 419                 ScopeState state;
 420
 421                 state = scope_state_from_string(value);
 422                 if (state < 0)
 423                         log_unit_debug(u, "Failed to parse state value: %s", value);
 424                 else
 425                         s->deserialized_state = state;
 426
 427         } else if (streq(key, "was-abandoned")) {
 428                 int k;
 429
 430                 k = parse_boolean(value);
 431                 if (k < 0)
 432                         log_unit_debug(u, "Failed to parse boolean value: %s", value);
 433                 else
 434                         s->was_abandoned = k;
 435         } else if (streq(key, "controller")) {
 436
 437                 r = free_and_strdup(&s->controller, value);
 438                 if (r < 0)
 439                         log_oom();
 440
 441         } else
 442                 log_unit_debug(u, "Unknown serialization key: %s", key);
 443
 444         return 0;
 445 }
 446
 447 static void scope_notify_cgroup_empty_event(Unit *u) {
 448         Scope *s = SCOPE(u);
 449         assert(u);
 450
 451         log_unit_debug(u, "cgroup is empty");
 452
 453         if (IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 454                 scope_enter_dead(s, SCOPE_SUCCESS);
 455 }
 456
 457 static void scope_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 458
 459         assert(u);
 460
 461         /* If we get a SIGCHLD event for one of the processes we were interested in, then we look for others to
 462          * watch, under the assumption that we'll sooner or later get a SIGCHLD for them, as the original
 463          * process we watched was probably the parent of them, and they are hence now our children. */
 464         unit_tidy_watch_pids(u, 0, 0);
 465         unit_watch_all_pids(u);
 466
 467         /* If the PID set is empty now, then let's finish this off. */
 468         unit_synthesize_cgroup_empty_event(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,
 519          * so let's step in here, under the assumption that the
 520          * remaining processes will be sooner or later reassigned to
 521          * us as parent. */
 522
 523         unit_tidy_watch_pids(UNIT(s), 0, 0);
 524         unit_watch_all_pids(UNIT(s));
 525
 526         return 0;
 527 }
 528
 529 _pure_ static UnitActiveState scope_active_state(Unit *u) {
 530         assert(u);
 531
 532         return state_translation_table[SCOPE(u)->state];
 533 }
 534
 535 _pure_ static const char *scope_sub_state_to_string(Unit *u) {
 536         assert(u);
 537
 538         return scope_state_to_string(SCOPE(u)->state);
 539 }
 540
 541 static void scope_enumerate(Manager *m) {
 542         Unit *u;
 543         int r;
 544
 545         assert(m);
 546
 547         /* Let's unconditionally add the "init.scope" special unit
 548          * that encapsulates PID 1. Note that PID 1 already is in the
 549          * cgroup for this, we hence just need to allocate the object
 550          * for it and that's it. */
 551
 552         u = manager_get_unit(m, SPECIAL_INIT_SCOPE);
 553         if (!u) {
 554                 r = unit_new_for_name(m, sizeof(Scope), SPECIAL_INIT_SCOPE, &u);
 555                 if (r < 0)  {
 556                         log_error_errno(r, "Failed to allocate the special " SPECIAL_INIT_SCOPE " unit: %m");
 557                         return;
 558                 }
 559         }
 560
 561         u->transient = true;
 562         u->perpetual = true;
 563         SCOPE(u)->deserialized_state = SCOPE_RUNNING;
 564
 565         unit_add_to_load_queue(u);
 566         unit_add_to_dbus_queue(u);
 567 }
 568
 569 static const char* const scope_result_table[_SCOPE_RESULT_MAX] = {
 570         [SCOPE_SUCCESS] = "success",
 571         [SCOPE_FAILURE_RESOURCES] = "resources",
 572         [SCOPE_FAILURE_TIMEOUT] = "timeout",
 573 };
 574
 575 DEFINE_STRING_TABLE_LOOKUP(scope_result, ScopeResult);
 576
 577 const UnitVTable scope_vtable = {
 578         .object_size = sizeof(Scope),
 579         .cgroup_context_offset = offsetof(Scope, cgroup_context),
 580         .kill_context_offset = offsetof(Scope, kill_context),
 581
 582         .sections =
 583                 "Unit\0"
 584                 "Scope\0"
 585                 "Install\0",
 586         .private_section = "Scope",
 587
 588         .can_transient = true,
 589         .can_delegate = true,
 590
 591         .init = scope_init,
 592         .load = scope_load,
 593         .done = scope_done,
 594
 595         .coldplug = scope_coldplug,
 596
 597         .dump = scope_dump,
 598
 599         .start = scope_start,
 600         .stop = scope_stop,
 601
 602         .kill = scope_kill,
 603
 604         .get_timeout = scope_get_timeout,
 605
 606         .serialize = scope_serialize,
 607         .deserialize_item = scope_deserialize_item,
 608
 609         .active_state = scope_active_state,
 610         .sub_state_to_string = scope_sub_state_to_string,
 611
 612         .sigchld_event = scope_sigchld_event,
 613
 614         .reset_failed = scope_reset_failed,
 615
 616         .notify_cgroup_empty = scope_notify_cgroup_empty_event,
 617
 618         .bus_vtable = bus_scope_vtable,
 619         .bus_set_property = bus_scope_set_property,
 620         .bus_commit_properties = bus_scope_commit_properties,
 621
 622         .enumerate = scope_enumerate,
 623 };