src/core/scope.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2013 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23 #include <signal.h>
  24 #include <unistd.h>
  25
  26 #include "unit.h"
  27 #include "scope.h"
  28 #include "load-fragment.h"
  29 #include "log.h"
  30 #include "dbus-scope.h"
  31 #include "special.h"
  32 #include "unit-name.h"
  33 #include "load-dropin.h"
  34
  35 static const UnitActiveState state_translation_table[_SCOPE_STATE_MAX] = {
  36         [SCOPE_DEAD] = UNIT_INACTIVE,
  37         [SCOPE_RUNNING] = UNIT_ACTIVE,
  38         [SCOPE_STOP_SIGTERM] = UNIT_DEACTIVATING,
  39         [SCOPE_STOP_SIGKILL] = UNIT_DEACTIVATING,
  40         [SCOPE_FAILED] = UNIT_FAILED
  41 };
  42
  43 static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
  44
  45 static void scope_init(Unit *u) {
  46         Scope *s = SCOPE(u);
  47
  48         assert(u);
  49         assert(u->load_state == UNIT_STUB);
  50
  51         s->timeout_stop_usec = u->manager->default_timeout_stop_usec;
  52
  53         cgroup_context_init(&s->cgroup_context);
  54         kill_context_init(&s->kill_context);
  55
  56         UNIT(s)->ignore_on_isolate = true;
  57         UNIT(s)->ignore_on_snapshot = true;
  58 }
  59
  60 static void scope_done(Unit *u) {
  61         Scope *s = SCOPE(u);
  62
  63         assert(u);
  64
  65         cgroup_context_done(&s->cgroup_context);
  66
  67         set_free(s->pids);
  68         s->pids = NULL;
  69
  70         s->timer_event_source = sd_event_source_unref(s->timer_event_source);
  71 }
  72
  73 static int scope_arm_timer(Scope *s) {
  74         int r;
  75
  76         assert(s);
  77
  78         if (s->timeout_stop_usec <= 0) {
  79                 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
  80                 return 0;
  81         }
  82
  83         if (s->timer_event_source) {
  84                 r = sd_event_source_set_time(s->timer_event_source, now(CLOCK_MONOTONIC) + s->timeout_stop_usec);
  85                 if (r < 0)
  86                         return r;
  87
  88                 return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
  89         }
  90
  91         return sd_event_add_monotonic(UNIT(s)->manager->event, now(CLOCK_MONOTONIC) + s->timeout_stop_usec, 0, scope_dispatch_timer, s, &s->timer_event_source);
  92 }
  93
  94 static void scope_set_state(Scope *s, ScopeState state) {
  95         ScopeState old_state;
  96         assert(s);
  97
  98         old_state = s->state;
  99         s->state = state;
 100
 101         if (state != SCOPE_STOP_SIGTERM &&
 102             state != SCOPE_STOP_SIGKILL)
 103                 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
 104
 105         if (state != old_state)
 106                 log_debug("%s changed %s -> %s",
 107                           UNIT(s)->id,
 108                           scope_state_to_string(old_state),
 109                           scope_state_to_string(state));
 110
 111         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 112 }
 113
 114 static int scope_add_default_dependencies(Scope *s) {
 115         int r;
 116
 117         assert(s);
 118
 119         /* Make sure scopes are unloaded on shutdown */
 120         r = unit_add_two_dependencies_by_name(
 121                         UNIT(s),
 122                         UNIT_BEFORE, UNIT_CONFLICTS,
 123                         SPECIAL_SHUTDOWN_TARGET, NULL, true);
 124         if (r < 0)
 125                 return r;
 126
 127         return 0;
 128 }
 129
 130 static int scope_verify(Scope *s) {
 131         assert(s);
 132
 133         if (UNIT(s)->load_state != UNIT_LOADED)
 134                 return 0;
 135
 136         if (set_size(s->pids) <= 0 && UNIT(s)->manager->n_reloading <= 0) {
 137                 log_error_unit(UNIT(s)->id, "Scope %s has no PIDs. Refusing.", UNIT(s)->id);
 138                 return -EINVAL;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static int scope_load(Unit *u) {
 145         Scope *s = SCOPE(u);
 146         int r;
 147
 148         assert(s);
 149         assert(u->load_state == UNIT_STUB);
 150
 151         if (!u->transient && UNIT(s)->manager->n_reloading <= 0)
 152                 return -ENOENT;
 153
 154         u->load_state = UNIT_LOADED;
 155
 156         r = unit_load_dropin(u);
 157         if (r < 0)
 158                 return r;
 159
 160         r = unit_add_default_slice(u);
 161         if (r < 0)
 162                 return r;
 163
 164         if (u->default_dependencies) {
 165                 r = scope_add_default_dependencies(s);
 166                 if (r < 0)
 167                         return r;
 168         }
 169
 170         return scope_verify(s);
 171 }
 172
 173 static int scope_coldplug(Unit *u) {
 174         Scope *s = SCOPE(u);
 175         int r;
 176
 177         assert(s);
 178         assert(s->state == SCOPE_DEAD);
 179
 180         if (s->deserialized_state != s->state) {
 181
 182                 if (s->deserialized_state == SCOPE_STOP_SIGKILL || s->deserialized_state == SCOPE_STOP_SIGTERM) {
 183                         r = scope_arm_timer(s);
 184                         if (r < 0)
 185                                 return r;
 186                 }
 187
 188                 scope_set_state(s, s->deserialized_state);
 189         }
 190
 191         return 0;
 192 }
 193
 194 static void scope_dump(Unit *u, FILE *f, const char *prefix) {
 195         Scope *s = SCOPE(u);
 196
 197         assert(s);
 198         assert(f);
 199
 200         fprintf(f,
 201                 "%sScope State: %s\n"
 202                 "%sResult: %s\n",
 203                 prefix, scope_state_to_string(s->state),
 204                 prefix, scope_result_to_string(s->result));
 205
 206         cgroup_context_dump(&s->cgroup_context, f, prefix);
 207         kill_context_dump(&s->kill_context, f, prefix);
 208 }
 209
 210 static void scope_enter_dead(Scope *s, ScopeResult f) {
 211         assert(s);
 212
 213         if (f != SCOPE_SUCCESS)
 214                 s->result = f;
 215
 216         scope_set_state(s, s->result != SCOPE_SUCCESS ? SCOPE_FAILED : SCOPE_DEAD);
 217 }
 218
 219 static void scope_enter_signal(Scope *s, ScopeState state, ScopeResult f) {
 220         int r;
 221
 222         assert(s);
 223
 224         if (f != SCOPE_SUCCESS)
 225                 s->result = f;
 226
 227         r = unit_kill_context(
 228                         UNIT(s),
 229                         &s->kill_context,
 230                         state != SCOPE_STOP_SIGTERM,
 231                         -1, -1, false);
 232         if (r < 0)
 233                 goto fail;
 234
 235         if (r > 0) {
 236                 r = scope_arm_timer(s);
 237                 if (r < 0)
 238                         goto fail;
 239
 240                 scope_set_state(s, state);
 241         } else
 242                 scope_enter_dead(s, SCOPE_SUCCESS);
 243
 244         return;
 245
 246 fail:
 247         log_warning_unit(UNIT(s)->id,
 248                          "%s failed to kill processes: %s", UNIT(s)->id, strerror(-r));
 249
 250         scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
 251 }
 252
 253 static int scope_start(Unit *u) {
 254         Scope *s = SCOPE(u);
 255         int r;
 256
 257         assert(s);
 258
 259         if (s->state == SCOPE_FAILED)
 260                 return -EPERM;
 261
 262         if (s->state == SCOPE_STOP_SIGTERM ||
 263             s->state == SCOPE_STOP_SIGKILL)
 264                 return -EAGAIN;
 265
 266         assert(s->state == SCOPE_DEAD);
 267
 268         if (!u->transient && UNIT(s)->manager->n_reloading <= 0)
 269                 return -ENOENT;
 270
 271         r = unit_realize_cgroup(u);
 272         if (r < 0) {
 273                 log_error("Failed to realize cgroup: %s", strerror(-r));
 274                 return r;
 275         }
 276
 277         r = cg_attach_many_everywhere(u->manager->cgroup_supported, u->cgroup_path, s->pids);
 278         if (r < 0)
 279                 return r;
 280
 281         set_free(s->pids);
 282         s->pids = NULL;
 283
 284         s->result = SCOPE_SUCCESS;
 285
 286         scope_set_state(s, SCOPE_RUNNING);
 287         return 0;
 288 }
 289
 290 static int scope_stop(Unit *u) {
 291         Scope *s = SCOPE(u);
 292
 293         assert(s);
 294         assert(s->state == SCOPE_RUNNING);
 295
 296         if (s->state == SCOPE_STOP_SIGTERM ||
 297             s->state == SCOPE_STOP_SIGKILL)
 298                 return 0;
 299
 300         assert(s->state == SCOPE_RUNNING);
 301
 302         scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_SUCCESS);
 303         return 0;
 304 }
 305
 306 static void scope_reset_failed(Unit *u) {
 307         Scope *s = SCOPE(u);
 308
 309         assert(s);
 310
 311         if (s->state == SCOPE_FAILED)
 312                 scope_set_state(s, SCOPE_DEAD);
 313
 314         s->result = SCOPE_SUCCESS;
 315 }
 316
 317 static int scope_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
 318         return unit_kill_common(u, who, signo, -1, -1, error);
 319 }
 320
 321 static int scope_get_timeout(Unit *u, uint64_t *timeout) {
 322         Scope *s = SCOPE(u);
 323         int r;
 324
 325         if (!s->timer_event_source)
 326                 return 0;
 327
 328         r = sd_event_source_get_time(s->timer_event_source, timeout);
 329         if (r < 0)
 330                 return r;
 331
 332         return 1;
 333 }
 334
 335 static int scope_serialize(Unit *u, FILE *f, FDSet *fds) {
 336         Scope *s = SCOPE(u);
 337
 338         assert(s);
 339         assert(f);
 340         assert(fds);
 341
 342         unit_serialize_item(u, f, "state", scope_state_to_string(s->state));
 343         return 0;
 344 }
 345
 346 static int scope_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 347         Scope *s = SCOPE(u);
 348
 349         assert(u);
 350         assert(key);
 351         assert(value);
 352         assert(fds);
 353
 354         if (streq(key, "state")) {
 355                 ScopeState state;
 356
 357                 state = scope_state_from_string(value);
 358                 if (state < 0)
 359                         log_debug("Failed to parse state value %s", value);
 360                 else
 361                         s->deserialized_state = state;
 362
 363         } else
 364                 log_debug("Unknown serialization key '%s'", key);
 365
 366         return 0;
 367 }
 368
 369 static bool scope_check_gc(Unit *u) {
 370         Scope *s = SCOPE(u);
 371         int r;
 372
 373         assert(s);
 374
 375         /* Never clean up scopes that still have a process around,
 376          * even if the scope is formally dead. */
 377
 378         if (UNIT(s)->cgroup_path) {
 379                 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, UNIT(s)->cgroup_path, true);
 380                 if (r <= 0)
 381                         return true;
 382         }
 383
 384         return false;
 385 }
 386
 387 static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
 388         Scope *s = SCOPE(userdata);
 389
 390         assert(s);
 391         assert(s->timer_event_source == source);
 392
 393         switch (s->state) {
 394
 395         case SCOPE_STOP_SIGTERM:
 396                 if (s->kill_context.send_sigkill) {
 397                         log_warning_unit(UNIT(s)->id, "%s stopping timed out. Killing.", UNIT(s)->id);
 398                         scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_FAILURE_TIMEOUT);
 399                 } else {
 400                         log_warning_unit(UNIT(s)->id, "%s stopping timed out. Skipping SIGKILL.", UNIT(s)->id);
 401                         scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
 402                 }
 403
 404                 break;
 405
 406         case SCOPE_STOP_SIGKILL:
 407                 log_warning_unit(UNIT(s)->id, "%s still around after SIGKILL. Ignoring.", UNIT(s)->id);
 408                 scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT);
 409                 break;
 410
 411         default:
 412                 assert_not_reached("Timeout at wrong time.");
 413         }
 414
 415         return 0;
 416 }
 417
 418 static void scope_notify_cgroup_empty_event(Unit *u) {
 419         Scope *s = SCOPE(u);
 420         assert(u);
 421
 422         log_debug_unit(u->id, "%s: cgroup is empty", u->id);
 423
 424         switch (s->state) {
 425
 426         case SCOPE_RUNNING:
 427         case SCOPE_STOP_SIGTERM:
 428         case SCOPE_STOP_SIGKILL:
 429                 scope_enter_dead(s, SCOPE_SUCCESS);
 430
 431                 break;
 432
 433         default:
 434                 ;
 435         }
 436 }
 437
 438 _pure_ static UnitActiveState scope_active_state(Unit *u) {
 439         assert(u);
 440
 441         return state_translation_table[SCOPE(u)->state];
 442 }
 443
 444 _pure_ static const char *scope_sub_state_to_string(Unit *u) {
 445         assert(u);
 446
 447         return scope_state_to_string(SCOPE(u)->state);
 448 }
 449
 450 static const char* const scope_state_table[_SCOPE_STATE_MAX] = {
 451         [SCOPE_DEAD] = "dead",
 452         [SCOPE_RUNNING] = "running",
 453         [SCOPE_STOP_SIGTERM] = "stop-sigterm",
 454         [SCOPE_STOP_SIGKILL] = "stop-sigkill",
 455         [SCOPE_FAILED] = "failed",
 456 };
 457
 458 DEFINE_STRING_TABLE_LOOKUP(scope_state, ScopeState);
 459
 460 static const char* const scope_result_table[_SCOPE_RESULT_MAX] = {
 461         [SCOPE_SUCCESS] = "success",
 462         [SCOPE_FAILURE_RESOURCES] = "resources",
 463         [SCOPE_FAILURE_TIMEOUT] = "timeout",
 464 };
 465
 466 DEFINE_STRING_TABLE_LOOKUP(scope_result, ScopeResult);
 467
 468 const UnitVTable scope_vtable = {
 469         .object_size = sizeof(Scope),
 470         .cgroup_context_offset = offsetof(Scope, cgroup_context),
 471         .kill_context_offset = offsetof(Scope, kill_context),
 472
 473         .sections =
 474                 "Unit\0"
 475                 "Scope\0"
 476                 "Install\0",
 477         .private_section = "Scope",
 478
 479         .no_alias = true,
 480         .no_instances = true,
 481
 482         .init = scope_init,
 483         .load = scope_load,
 484         .done = scope_done,
 485
 486         .coldplug = scope_coldplug,
 487
 488         .dump = scope_dump,
 489
 490         .start = scope_start,
 491         .stop = scope_stop,
 492
 493         .kill = scope_kill,
 494
 495         .get_timeout = scope_get_timeout,
 496
 497         .serialize = scope_serialize,
 498         .deserialize_item = scope_deserialize_item,
 499
 500         .active_state = scope_active_state,
 501         .sub_state_to_string = scope_sub_state_to_string,
 502
 503         .check_gc = scope_check_gc,
 504
 505         .reset_failed = scope_reset_failed,
 506
 507         .notify_cgroup_empty = scope_notify_cgroup_empty_event,
 508
 509         .bus_interface = "org.freedesktop.systemd1.Scope",
 510         .bus_vtable = bus_scope_vtable,
 511         .bus_set_property = bus_scope_set_property,
 512         .bus_commit_properties = bus_scope_commit_properties,
 513
 514         .can_transient = true
 515 };