src/core/scope.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2013 Lennart Poettering
   4 ***/
   5
   6 #include <errno.h>
   7 #include <unistd.h>
   8
   9 #include "alloc-util.h"
  10 #include "dbus-scope.h"
  11 #include "load-dropin.h"
  12 #include "log.h"
  13 #include "scope.h"
  14 #include "special.h"
  15 #include "string-table.h"
  16 #include "string-util.h"
  17 #include "strv.h"
  18 #include "unit-name.h"
  19 #include "unit.h"
  20
  21 static const UnitActiveState state_translation_table[_SCOPE_STATE_MAX] = {
  22         [SCOPE_DEAD] = UNIT_INACTIVE,
  23         [SCOPE_RUNNING] = UNIT_ACTIVE,
  24         [SCOPE_ABANDONED] = UNIT_ACTIVE,
  25         [SCOPE_STOP_SIGTERM] = UNIT_DEACTIVATING,
  26         [SCOPE_STOP_SIGKILL] = UNIT_DEACTIVATING,
  27         [SCOPE_FAILED] = UNIT_FAILED
  28 };
  29
  30 static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
  31
  32 static void scope_init(Unit *u) {
  33         Scope *s = SCOPE(u);
  34
  35         assert(u);
  36         assert(u->load_state == UNIT_STUB);
  37
  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         old_state = s->state;
  88         s->state = state;
  89
  90         if (!IN_SET(state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
  91                 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
  92
  93         if (IN_SET(state, SCOPE_DEAD, SCOPE_FAILED)) {
  94                 unit_unwatch_all_pids(UNIT(s));
  95                 unit_dequeue_rewatch_pids(UNIT(s));
  96         }
  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], 0);
 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 -ENOENT;
 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                 (void) unit_enqueue_rewatch_pids(u);
 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         /* Before sending any signal, make sure we track all members of this cgroup */
 261         (void) unit_watch_all_pids(UNIT(s));
 262
 263         /* Also, enqueue a job that we recheck all our PIDs a bit later, given that it's likely some processes have
 264          * died now */
 265         (void) unit_enqueue_rewatch_pids(UNIT(s));
 266
 267         /* If we have a controller set let's ask the controller nicely to terminate the scope, instead of us going
 268          * directly into SIGTERM berserk mode */
 269         if (state == SCOPE_STOP_SIGTERM)
 270                 skip_signal = bus_scope_send_request_stop(s) > 0;
 271
 272         if (skip_signal)
 273                 r = 1; /* wait */
 274         else {
 275                 r = unit_kill_context(
 276                                 UNIT(s),
 277                                 &s->kill_context,
 278                                 state != SCOPE_STOP_SIGTERM ? KILL_KILL :
 279                                 s->was_abandoned            ? KILL_TERMINATE_AND_LOG :
 280                                                               KILL_TERMINATE,
 281                                 -1, -1, false);
 282                 if (r < 0)
 283                         goto fail;
 284         }
 285
 286         if (r > 0) {
 287                 r = scope_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_stop_usec));
 288                 if (r < 0)
 289                         goto fail;
 290
 291                 scope_set_state(s, state);
 292         } else if (state == SCOPE_STOP_SIGTERM)
 293                 scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_SUCCESS);
 294         else
 295                 scope_enter_dead(s, SCOPE_SUCCESS);
 296
 297         return;
 298
 299 fail:
 300         log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m");
 301
 302         scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
 303 }
 304
 305 static int scope_start(Unit *u) {
 306         Scope *s = SCOPE(u);
 307         int r;
 308
 309         assert(s);
 310
 311         if (unit_has_name(u, SPECIAL_INIT_SCOPE))
 312                 return -EPERM;
 313
 314         if (s->state == SCOPE_FAILED)
 315                 return -EPERM;
 316
 317         /* We can't fulfill this right now, please try again later */
 318         if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 319                 return -EAGAIN;
 320
 321         assert(s->state == SCOPE_DEAD);
 322
 323         if (!u->transient && !MANAGER_IS_RELOADING(u->manager))
 324                 return -ENOENT;
 325
 326         (void) bus_scope_track_controller(s);
 327
 328         r = unit_acquire_invocation_id(u);
 329         if (r < 0)
 330                 return r;
 331
 332         (void) unit_realize_cgroup(u);
 333         (void) unit_reset_cpu_accounting(u);
 334         (void) unit_reset_ip_accounting(u);
 335
 336         unit_export_state_files(UNIT(s));
 337
 338         r = unit_attach_pids_to_cgroup(u, UNIT(s)->pids, NULL);
 339         if (r < 0) {
 340                 log_unit_warning_errno(UNIT(s), r, "Failed to add PIDs to scope's control group: %m");
 341                 scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
 342                 return r;
 343         }
 344
 345         s->result = SCOPE_SUCCESS;
 346
 347         scope_set_state(s, SCOPE_RUNNING);
 348
 349         /* Start watching the PIDs currently in the scope */
 350         (void) unit_enqueue_rewatch_pids(UNIT(s));
 351         return 1;
 352 }
 353
 354 static int scope_stop(Unit *u) {
 355         Scope *s = SCOPE(u);
 356
 357         assert(s);
 358
 359         if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 360                 return 0;
 361
 362         assert(IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED));
 363
 364         scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_SUCCESS);
 365         return 1;
 366 }
 367
 368 static void scope_reset_failed(Unit *u) {
 369         Scope *s = SCOPE(u);
 370
 371         assert(s);
 372
 373         if (s->state == SCOPE_FAILED)
 374                 scope_set_state(s, SCOPE_DEAD);
 375
 376         s->result = SCOPE_SUCCESS;
 377 }
 378
 379 static int scope_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
 380         return unit_kill_common(u, who, signo, -1, -1, error);
 381 }
 382
 383 static int scope_get_timeout(Unit *u, usec_t *timeout) {
 384         Scope *s = SCOPE(u);
 385         usec_t t;
 386         int r;
 387
 388         if (!s->timer_event_source)
 389                 return 0;
 390
 391         r = sd_event_source_get_time(s->timer_event_source, &t);
 392         if (r < 0)
 393                 return r;
 394         if (t == USEC_INFINITY)
 395                 return 0;
 396
 397         *timeout = t;
 398         return 1;
 399 }
 400
 401 static int scope_serialize(Unit *u, FILE *f, FDSet *fds) {
 402         Scope *s = SCOPE(u);
 403
 404         assert(s);
 405         assert(f);
 406         assert(fds);
 407
 408         unit_serialize_item(u, f, "state", scope_state_to_string(s->state));
 409         unit_serialize_item(u, f, "was-abandoned", yes_no(s->was_abandoned));
 410
 411         if (s->controller)
 412                 unit_serialize_item(u, f, "controller", s->controller);
 413
 414         return 0;
 415 }
 416
 417 static int scope_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 418         Scope *s = SCOPE(u);
 419         int r;
 420
 421         assert(u);
 422         assert(key);
 423         assert(value);
 424         assert(fds);
 425
 426         if (streq(key, "state")) {
 427                 ScopeState state;
 428
 429                 state = scope_state_from_string(value);
 430                 if (state < 0)
 431                         log_unit_debug(u, "Failed to parse state value: %s", value);
 432                 else
 433                         s->deserialized_state = state;
 434
 435         } else if (streq(key, "was-abandoned")) {
 436                 int k;
 437
 438                 k = parse_boolean(value);
 439                 if (k < 0)
 440                         log_unit_debug(u, "Failed to parse boolean value: %s", value);
 441                 else
 442                         s->was_abandoned = k;
 443         } else if (streq(key, "controller")) {
 444
 445                 r = free_and_strdup(&s->controller, value);
 446                 if (r < 0)
 447                         log_oom();
 448
 449         } else
 450                 log_unit_debug(u, "Unknown serialization key: %s", key);
 451
 452         return 0;
 453 }
 454
 455 static void scope_notify_cgroup_empty_event(Unit *u) {
 456         Scope *s = SCOPE(u);
 457         assert(u);
 458
 459         log_unit_debug(u, "cgroup is empty");
 460
 461         if (IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 462                 scope_enter_dead(s, SCOPE_SUCCESS);
 463 }
 464
 465 static void scope_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 466         assert(u);
 467
 468         /* If we get a SIGCHLD event for one of the processes we were interested in, then we look for others to
 469          * watch, under the assumption that we'll sooner or later get a SIGCHLD for them, as the original
 470          * process we watched was probably the parent of them, and they are hence now our children. */
 471
 472         (void) unit_enqueue_rewatch_pids(u);
 473 }
 474
 475 static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
 476         Scope *s = SCOPE(userdata);
 477
 478         assert(s);
 479         assert(s->timer_event_source == source);
 480
 481         switch (s->state) {
 482
 483         case SCOPE_STOP_SIGTERM:
 484                 if (s->kill_context.send_sigkill) {
 485                         log_unit_warning(UNIT(s), "Stopping timed out. Killing.");
 486                         scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_FAILURE_TIMEOUT);
 487                 } else {
 488                         log_unit_warning(UNIT(s), "Stopping timed out. Skipping SIGKILL.");
 489                         scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
 490                 }
 491
 492                 break;
 493
 494         case SCOPE_STOP_SIGKILL:
 495                 log_unit_warning(UNIT(s), "Still around after SIGKILL. Ignoring.");
 496                 scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
 497                 break;
 498
 499         default:
 500                 assert_not_reached("Timeout at wrong time.");
 501         }
 502
 503         return 0;
 504 }
 505
 506 int scope_abandon(Scope *s) {
 507         assert(s);
 508
 509         if (unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE))
 510                 return -EPERM;
 511
 512         if (!IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED))
 513                 return -ESTALE;
 514
 515         s->was_abandoned = true;
 516
 517         s->controller = mfree(s->controller);
 518         s->controller_track = sd_bus_track_unref(s->controller_track);
 519
 520         scope_set_state(s, SCOPE_ABANDONED);
 521
 522         /* The client is no longer watching the remaining processes, so let's step in here, under the assumption that
 523          * the remaining processes will be sooner or later reassigned to us as parent. */
 524         (void) unit_enqueue_rewatch_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_perpetual(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         .once_only = true,
 591
 592         .init = scope_init,
 593         .load = scope_load,
 594         .done = scope_done,
 595
 596         .coldplug = scope_coldplug,
 597
 598         .dump = scope_dump,
 599
 600         .start = scope_start,
 601         .stop = scope_stop,
 602
 603         .kill = scope_kill,
 604
 605         .get_timeout = scope_get_timeout,
 606
 607         .serialize = scope_serialize,
 608         .deserialize_item = scope_deserialize_item,
 609
 610         .active_state = scope_active_state,
 611         .sub_state_to_string = scope_sub_state_to_string,
 612
 613         .sigchld_event = scope_sigchld_event,
 614
 615         .reset_failed = scope_reset_failed,
 616
 617         .notify_cgroup_empty = scope_notify_cgroup_empty_event,
 618
 619         .bus_vtable = bus_scope_vtable,
 620         .bus_set_property = bus_scope_set_property,
 621         .bus_commit_properties = bus_scope_commit_properties,
 622
 623         .enumerate_perpetual = scope_enumerate_perpetual,
 624 };