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