src/core/scope.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2013 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <unistd.h>
  22
  23 #include "alloc-util.h"
  24 #include "dbus-scope.h"
  25 #include "load-dropin.h"
  26 #include "log.h"
  27 #include "scope.h"
  28 #include "special.h"
  29 #include "string-table.h"
  30 #include "string-util.h"
  31 #include "strv.h"
  32 #include "unit-name.h"
  33 #include "unit.h"
  34
  35 static const UnitActiveState state_translation_table[_SCOPE_STATE_MAX] = {
  36         [SCOPE_DEAD] = UNIT_INACTIVE,
  37         [SCOPE_RUNNING] = UNIT_ACTIVE,
  38         [SCOPE_ABANDONED] = UNIT_ACTIVE,
  39         [SCOPE_STOP_SIGTERM] = UNIT_DEACTIVATING,
  40         [SCOPE_STOP_SIGKILL] = UNIT_DEACTIVATING,
  41         [SCOPE_FAILED] = UNIT_FAILED
  42 };
  43
  44 static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
  45
  46 static void scope_init(Unit *u) {
  47         Scope *s = SCOPE(u);
  48
  49         assert(u);
  50         assert(u->load_state == UNIT_STUB);
  51
  52         s->timeout_stop_usec = u->manager->default_timeout_stop_usec;
  53         u->ignore_on_isolate = true;
  54 }
  55
  56 static void scope_done(Unit *u) {
  57         Scope *s = SCOPE(u);
  58
  59         assert(u);
  60
  61         free(s->controller);
  62
  63         s->timer_event_source = sd_event_source_unref(s->timer_event_source);
  64 }
  65
  66 static int scope_arm_timer(Scope *s, usec_t usec) {
  67         int r;
  68
  69         assert(s);
  70
  71         if (s->timer_event_source) {
  72                 r = sd_event_source_set_time(s->timer_event_source, usec);
  73                 if (r < 0)
  74                         return r;
  75
  76                 return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
  77         }
  78
  79         if (usec == USEC_INFINITY)
  80                 return 0;
  81
  82         r = sd_event_add_time(
  83                         UNIT(s)->manager->event,
  84                         &s->timer_event_source,
  85                         CLOCK_MONOTONIC,
  86                         usec, 0,
  87                         scope_dispatch_timer, s);
  88         if (r < 0)
  89                 return r;
  90
  91         (void) sd_event_source_set_description(s->timer_event_source, "scope-timer");
  92
  93         return 0;
  94 }
  95
  96 static void scope_set_state(Scope *s, ScopeState state) {
  97         ScopeState old_state;
  98         assert(s);
  99
 100         old_state = s->state;
 101         s->state = state;
 102
 103         if (!IN_SET(state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 104                 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
 105
 106         if (IN_SET(state, SCOPE_DEAD, SCOPE_FAILED))
 107                 unit_unwatch_all_pids(UNIT(s));
 108
 109         if (state != old_state)
 110                 log_debug("%s changed %s -> %s", UNIT(s)->id, scope_state_to_string(old_state), scope_state_to_string(state));
 111
 112         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 113 }
 114
 115 static int scope_add_default_dependencies(Scope *s) {
 116         int r;
 117
 118         assert(s);
 119
 120         if (!UNIT(s)->default_dependencies)
 121                 return 0;
 122
 123         /* Make sure scopes are unloaded on shutdown */
 124         r = unit_add_two_dependencies_by_name(
 125                         UNIT(s),
 126                         UNIT_BEFORE, UNIT_CONFLICTS,
 127                         SPECIAL_SHUTDOWN_TARGET, NULL, true,
 128                         UNIT_DEPENDENCY_DEFAULT);
 129         if (r < 0)
 130                 return r;
 131
 132         return 0;
 133 }
 134
 135 static int scope_verify(Scope *s) {
 136         assert(s);
 137
 138         if (UNIT(s)->load_state != UNIT_LOADED)
 139                 return 0;
 140
 141         if (set_isempty(UNIT(s)->pids) &&
 142             !MANAGER_IS_RELOADING(UNIT(s)->manager) &&
 143             !unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE)) {
 144                 log_unit_error(UNIT(s), "Scope has no PIDs. Refusing.");
 145                 return -EINVAL;
 146         }
 147
 148         return 0;
 149 }
 150
 151 static int scope_load_init_scope(Unit *u) {
 152         assert(u);
 153
 154         if (!unit_has_name(u, SPECIAL_INIT_SCOPE))
 155                 return 0;
 156
 157         u->transient = true;
 158         u->perpetual = true;
 159
 160         /* init.scope is a bit special, as it has to stick around forever. Because of its special semantics we
 161          * synthesize it here, instead of relying on the unit file on disk. */
 162
 163         u->default_dependencies = false;
 164         u->ignore_on_isolate = true;
 165
 166         SCOPE(u)->kill_context.kill_signal = SIGRTMIN+14;
 167
 168         /* Prettify things, if we can. */
 169         if (!u->description)
 170                 u->description = strdup("System and Service Manager");
 171         if (!u->documentation)
 172                 (void) strv_extend(&u->documentation, "man:systemd(1)");
 173
 174         return 1;
 175 }
 176
 177 static int scope_load(Unit *u) {
 178         Scope *s = SCOPE(u);
 179         int r;
 180
 181         assert(s);
 182         assert(u->load_state == UNIT_STUB);
 183
 184         if (!u->transient && !MANAGER_IS_RELOADING(u->manager))
 185                 /* Refuse to load non-transient scope units, but allow them while reloading. */
 186                 return -ENOENT;
 187
 188         r = scope_load_init_scope(u);
 189         if (r < 0)
 190                 return r;
 191         r = unit_load_fragment_and_dropin_optional(u);
 192         if (r < 0)
 193                 return r;
 194
 195         if (u->load_state == UNIT_LOADED) {
 196                 r = unit_patch_contexts(u);
 197                 if (r < 0)
 198                         return r;
 199
 200                 r = unit_set_default_slice(u);
 201                 if (r < 0)
 202                         return r;
 203
 204                 r = scope_add_default_dependencies(s);
 205                 if (r < 0)
 206                         return r;
 207         }
 208
 209         return scope_verify(s);
 210 }
 211
 212 static int scope_coldplug(Unit *u) {
 213         Scope *s = SCOPE(u);
 214         int r;
 215
 216         assert(s);
 217         assert(s->state == SCOPE_DEAD);
 218
 219         if (s->deserialized_state == s->state)
 220                 return 0;
 221
 222         if (IN_SET(s->deserialized_state, SCOPE_STOP_SIGKILL, SCOPE_STOP_SIGTERM)) {
 223                 r = scope_arm_timer(s, usec_add(u->state_change_timestamp.monotonic, s->timeout_stop_usec));
 224                 if (r < 0)
 225                         return r;
 226         }
 227
 228         if (!IN_SET(s->deserialized_state, SCOPE_DEAD, SCOPE_FAILED))
 229                 unit_watch_all_pids(UNIT(s));
 230
 231         scope_set_state(s, s->deserialized_state);
 232         return 0;
 233 }
 234
 235 static void scope_dump(Unit *u, FILE *f, const char *prefix) {
 236         Scope *s = SCOPE(u);
 237
 238         assert(s);
 239         assert(f);
 240
 241         fprintf(f,
 242                 "%sScope State: %s\n"
 243                 "%sResult: %s\n",
 244                 prefix, scope_state_to_string(s->state),
 245                 prefix, scope_result_to_string(s->result));
 246
 247         cgroup_context_dump(&s->cgroup_context, f, prefix);
 248         kill_context_dump(&s->kill_context, f, prefix);
 249 }
 250
 251 static void scope_enter_dead(Scope *s, ScopeResult f) {
 252         assert(s);
 253
 254         if (s->result == SCOPE_SUCCESS)
 255                 s->result = f;
 256
 257         if (s->result != SCOPE_SUCCESS)
 258                 log_unit_warning(UNIT(s), "Failed with result '%s'.", scope_result_to_string(s->result));
 259
 260         scope_set_state(s, s->result != SCOPE_SUCCESS ? SCOPE_FAILED : SCOPE_DEAD);
 261 }
 262
 263 static void scope_enter_signal(Scope *s, ScopeState state, ScopeResult f) {
 264         bool skip_signal = false;
 265         int r;
 266
 267         assert(s);
 268
 269         if (s->result == SCOPE_SUCCESS)
 270                 s->result = f;
 271
 272         unit_watch_all_pids(UNIT(s));
 273
 274         /* If we have a controller set let's ask the controller nicely
 275          * to terminate the scope, instead of us going directly into
 276          * SIGTERM berserk mode */
 277         if (state == SCOPE_STOP_SIGTERM)
 278                 skip_signal = bus_scope_send_request_stop(s) > 0;
 279
 280         if (skip_signal)
 281                 r = 1; /* wait */
 282         else {
 283                 r = unit_kill_context(
 284                                 UNIT(s),
 285                                 &s->kill_context,
 286                                 state != SCOPE_STOP_SIGTERM ? KILL_KILL :
 287                                 s->was_abandoned            ? KILL_TERMINATE_AND_LOG :
 288                                                               KILL_TERMINATE,
 289                                 -1, -1, false);
 290                 if (r < 0)
 291                         goto fail;
 292         }
 293
 294         if (r > 0) {
 295                 r = scope_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_stop_usec));
 296                 if (r < 0)
 297                         goto fail;
 298
 299                 scope_set_state(s, state);
 300         } else if (state == SCOPE_STOP_SIGTERM)
 301                 scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_SUCCESS);
 302         else
 303                 scope_enter_dead(s, SCOPE_SUCCESS);
 304
 305         return;
 306
 307 fail:
 308         log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m");
 309
 310         scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
 311 }
 312
 313 static int scope_start(Unit *u) {
 314         Scope *s = SCOPE(u);
 315         int r;
 316
 317         assert(s);
 318
 319         if (unit_has_name(u, SPECIAL_INIT_SCOPE))
 320                 return -EPERM;
 321
 322         if (s->state == SCOPE_FAILED)
 323                 return -EPERM;
 324
 325         /* We can't fulfill this right now, please try again later */
 326         if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 327                 return -EAGAIN;
 328
 329         assert(s->state == SCOPE_DEAD);
 330
 331         if (!u->transient && !MANAGER_IS_RELOADING(u->manager))
 332                 return -ENOENT;
 333
 334         r = unit_acquire_invocation_id(u);
 335         if (r < 0)
 336                 return r;
 337
 338         (void) unit_realize_cgroup(u);
 339         (void) unit_reset_cpu_accounting(u);
 340         (void) unit_reset_ip_accounting(u);
 341
 342         r = unit_attach_pids_to_cgroup(u);
 343         if (r < 0) {
 344                 log_unit_warning_errno(UNIT(s), r, "Failed to add PIDs to scope's control group: %m");
 345                 scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
 346                 return r;
 347         }
 348
 349         s->result = SCOPE_SUCCESS;
 350
 351         scope_set_state(s, SCOPE_RUNNING);
 352         return 1;
 353 }
 354
 355 static int scope_stop(Unit *u) {
 356         Scope *s = SCOPE(u);
 357
 358         assert(s);
 359
 360         if (IN_SET(s->state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL))
 361                 return 0;
 362
 363         assert(IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED));
 364
 365         scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_SUCCESS);
 366         return 1;
 367 }
 368
 369 static void scope_reset_failed(Unit *u) {
 370         Scope *s = SCOPE(u);
 371
 372         assert(s);
 373
 374         if (s->state == SCOPE_FAILED)
 375                 scope_set_state(s, SCOPE_DEAD);
 376
 377         s->result = SCOPE_SUCCESS;
 378 }
 379
 380 static int scope_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
 381         return unit_kill_common(u, who, signo, -1, -1, error);
 382 }
 383
 384 static int scope_get_timeout(Unit *u, usec_t *timeout) {
 385         Scope *s = SCOPE(u);
 386         usec_t t;
 387         int r;
 388
 389         if (!s->timer_event_source)
 390                 return 0;
 391
 392         r = sd_event_source_get_time(s->timer_event_source, &t);
 393         if (r < 0)
 394                 return r;
 395         if (t == USEC_INFINITY)
 396                 return 0;
 397
 398         *timeout = t;
 399         return 1;
 400 }
 401
 402 static int scope_serialize(Unit *u, FILE *f, FDSet *fds) {
 403         Scope *s = SCOPE(u);
 404
 405         assert(s);
 406         assert(f);
 407         assert(fds);
 408
 409         unit_serialize_item(u, f, "state", scope_state_to_string(s->state));
 410         unit_serialize_item(u, f, "was-abandoned", yes_no(s->was_abandoned));
 411         return 0;
 412 }
 413
 414 static int scope_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 415         Scope *s = SCOPE(u);
 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
 440                 log_unit_debug(u, "Unknown serialization key: %s", key);
 441
 442         return 0;
 443 }
 444
 445 static bool scope_check_gc(Unit *u) {
 446         assert(u);
 447
 448         /* Never clean up scopes that still have a process around,
 449          * even if the scope is formally dead. */
 450
 451         if (!u->cgroup_path)
 452                 return false;
 453
 454         return cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path) <= 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
 469         /* If we get a SIGCHLD event for one of the processes we were
 470            interested in, then we look for others to watch, under the
 471            assumption that we'll sooner or later get a SIGCHLD for
 472            them, as the original process we watched was probably the
 473            parent of them, and they are hence now our children. */
 474
 475         unit_tidy_watch_pids(u, 0, 0);
 476         unit_watch_all_pids(u);
 477
 478         /* If the PID set is empty now, then let's finish this off
 479            (On unified we use proper notifications) */
 480         if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) == 0 && set_isempty(u->pids))
 481                 scope_notify_cgroup_empty_event(u);
 482 }
 483
 484 static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
 485         Scope *s = SCOPE(userdata);
 486
 487         assert(s);
 488         assert(s->timer_event_source == source);
 489
 490         switch (s->state) {
 491
 492         case SCOPE_STOP_SIGTERM:
 493                 if (s->kill_context.send_sigkill) {
 494                         log_unit_warning(UNIT(s), "Stopping timed out. Killing.");
 495                         scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_FAILURE_TIMEOUT);
 496                 } else {
 497                         log_unit_warning(UNIT(s), "Stopping timed out. Skipping SIGKILL.");
 498                         scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
 499                 }
 500
 501                 break;
 502
 503         case SCOPE_STOP_SIGKILL:
 504                 log_unit_warning(UNIT(s), "Still around after SIGKILL. Ignoring.");
 505                 scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
 506                 break;
 507
 508         default:
 509                 assert_not_reached("Timeout at wrong time.");
 510         }
 511
 512         return 0;
 513 }
 514
 515 int scope_abandon(Scope *s) {
 516         assert(s);
 517
 518         if (unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE))
 519                 return -EPERM;
 520
 521         if (!IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED))
 522                 return -ESTALE;
 523
 524         s->was_abandoned = true;
 525         s->controller = mfree(s->controller);
 526         scope_set_state(s, SCOPE_ABANDONED);
 527
 528         /* The client is no longer watching the remaining processes,
 529          * so let's step in here, under the assumption that the
 530          * remaining processes will be sooner or later reassigned to
 531          * us as parent. */
 532
 533         unit_tidy_watch_pids(UNIT(s), 0, 0);
 534         unit_watch_all_pids(UNIT(s));
 535
 536         return 0;
 537 }
 538
 539 _pure_ static UnitActiveState scope_active_state(Unit *u) {
 540         assert(u);
 541
 542         return state_translation_table[SCOPE(u)->state];
 543 }
 544
 545 _pure_ static const char *scope_sub_state_to_string(Unit *u) {
 546         assert(u);
 547
 548         return scope_state_to_string(SCOPE(u)->state);
 549 }
 550
 551 static void scope_enumerate(Manager *m) {
 552         Unit *u;
 553         int r;
 554
 555         assert(m);
 556
 557         /* Let's unconditionally add the "init.scope" special unit
 558          * that encapsulates PID 1. Note that PID 1 already is in the
 559          * cgroup for this, we hence just need to allocate the object
 560          * for it and that's it. */
 561
 562         u = manager_get_unit(m, SPECIAL_INIT_SCOPE);
 563         if (!u) {
 564                 r = unit_new_for_name(m, sizeof(Scope), SPECIAL_INIT_SCOPE, &u);
 565                 if (r < 0)  {
 566                         log_error_errno(r, "Failed to allocate the special " SPECIAL_INIT_SCOPE " unit: %m");
 567                         return;
 568                 }
 569         }
 570
 571         u->transient = true;
 572         u->perpetual = true;
 573         SCOPE(u)->deserialized_state = SCOPE_RUNNING;
 574
 575         unit_add_to_load_queue(u);
 576         unit_add_to_dbus_queue(u);
 577 }
 578
 579 static const char* const scope_result_table[_SCOPE_RESULT_MAX] = {
 580         [SCOPE_SUCCESS] = "success",
 581         [SCOPE_FAILURE_RESOURCES] = "resources",
 582         [SCOPE_FAILURE_TIMEOUT] = "timeout",
 583 };
 584
 585 DEFINE_STRING_TABLE_LOOKUP(scope_result, ScopeResult);
 586
 587 const UnitVTable scope_vtable = {
 588         .object_size = sizeof(Scope),
 589         .cgroup_context_offset = offsetof(Scope, cgroup_context),
 590         .kill_context_offset = offsetof(Scope, kill_context),
 591
 592         .sections =
 593                 "Unit\0"
 594                 "Scope\0"
 595                 "Install\0",
 596         .private_section = "Scope",
 597
 598         .can_transient = true,
 599
 600         .init = scope_init,
 601         .load = scope_load,
 602         .done = scope_done,
 603
 604         .coldplug = scope_coldplug,
 605
 606         .dump = scope_dump,
 607
 608         .start = scope_start,
 609         .stop = scope_stop,
 610
 611         .kill = scope_kill,
 612
 613         .get_timeout = scope_get_timeout,
 614
 615         .serialize = scope_serialize,
 616         .deserialize_item = scope_deserialize_item,
 617
 618         .active_state = scope_active_state,
 619         .sub_state_to_string = scope_sub_state_to_string,
 620
 621         .check_gc = scope_check_gc,
 622
 623         .sigchld_event = scope_sigchld_event,
 624
 625         .reset_failed = scope_reset_failed,
 626
 627         .notify_cgroup_empty = scope_notify_cgroup_empty_event,
 628
 629         .bus_vtable = bus_scope_vtable,
 630         .bus_set_property = bus_scope_set_property,
 631         .bus_commit_properties = bus_scope_commit_properties,
 632
 633         .enumerate = scope_enumerate,
 634 };