src/login/logind-user.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <unistd.h>
   5
   6 #include "alloc-util.h"
   7 #include "bus-common-errors.h"
   8 #include "bus-error.h"
   9 #include "bus-locator.h"
  10 #include "bus-util.h"
  11 #include "cgroup-util.h"
  12 #include "clean-ipc.h"
  13 #include "env-file.h"
  14 #include "escape.h"
  15 #include "fd-util.h"
  16 #include "fileio.h"
  17 #include "format-util.h"
  18 #include "fs-util.h"
  19 #include "hashmap.h"
  20 #include "label-util.h"
  21 #include "limits-util.h"
  22 #include "logind-dbus.h"
  23 #include "logind-user-dbus.h"
  24 #include "logind-user.h"
  25 #include "mkdir-label.h"
  26 #include "parse-util.h"
  27 #include "path-util.h"
  28 #include "percent-util.h"
  29 #include "rm-rf.h"
  30 #include "serialize.h"
  31 #include "special.h"
  32 #include "stdio-util.h"
  33 #include "string-table.h"
  34 #include "strv.h"
  35 #include "tmpfile-util.h"
  36 #include "uid-classification.h"
  37 #include "unit-name.h"
  38 #include "user-util.h"
  39
  40 int user_new(User **ret,
  41              Manager *m,
  42              UserRecord *ur) {
  43
  44         _cleanup_(user_freep) User *u = NULL;
  45         char lu[DECIMAL_STR_MAX(uid_t) + 1];
  46         int r;
  47
  48         assert(ret);
  49         assert(m);
  50         assert(ur);
  51
  52         if (!ur->user_name)
  53                 return -EINVAL;
  54
  55         if (!uid_is_valid(ur->uid))
  56                 return -EINVAL;
  57
  58         u = new(User, 1);
  59         if (!u)
  60                 return -ENOMEM;
  61
  62         *u = (User) {
  63                 .manager = m,
  64                 .user_record = user_record_ref(ur),
  65                 .last_session_timestamp = USEC_INFINITY,
  66                 .gc_mode = USER_GC_BY_ANY,
  67         };
  68
  69         if (asprintf(&u->state_file, "/run/systemd/users/" UID_FMT, ur->uid) < 0)
  70                 return -ENOMEM;
  71
  72         if (asprintf(&u->runtime_path, "/run/user/" UID_FMT, ur->uid) < 0)
  73                 return -ENOMEM;
  74
  75         xsprintf(lu, UID_FMT, ur->uid);
  76         r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice);
  77         if (r < 0)
  78                 return r;
  79
  80         r = unit_name_build("user", lu, ".service", &u->service);
  81         if (r < 0)
  82                 return r;
  83
  84         r = unit_name_build("user-runtime-dir", lu, ".service", &u->runtime_dir_service);
  85         if (r < 0)
  86                 return r;
  87
  88         r = hashmap_put(m->users, UID_TO_PTR(ur->uid), u);
  89         if (r < 0)
  90                 return r;
  91
  92         r = hashmap_put(m->user_units, u->slice, u);
  93         if (r < 0)
  94                 return r;
  95
  96         r = hashmap_put(m->user_units, u->service, u);
  97         if (r < 0)
  98                 return r;
  99
 100         r = hashmap_put(m->user_units, u->runtime_dir_service, u);
 101         if (r < 0)
 102                 return r;
 103
 104         *ret = TAKE_PTR(u);
 105         return 0;
 106 }
 107
 108 User *user_free(User *u) {
 109         if (!u)
 110                 return NULL;
 111
 112         if (u->in_gc_queue)
 113                 LIST_REMOVE(gc_queue, u->manager->user_gc_queue, u);
 114
 115         while (u->sessions)
 116                 session_free(u->sessions);
 117
 118         if (u->service)
 119                 hashmap_remove_value(u->manager->user_units, u->service, u);
 120
 121         if (u->runtime_dir_service)
 122                 hashmap_remove_value(u->manager->user_units, u->runtime_dir_service, u);
 123
 124         if (u->slice)
 125                 hashmap_remove_value(u->manager->user_units, u->slice, u);
 126
 127         hashmap_remove_value(u->manager->users, UID_TO_PTR(u->user_record->uid), u);
 128
 129         sd_event_source_unref(u->timer_event_source);
 130
 131         u->service_job = mfree(u->service_job);
 132
 133         u->service = mfree(u->service);
 134         u->runtime_dir_service = mfree(u->runtime_dir_service);
 135         u->slice = mfree(u->slice);
 136         u->runtime_path = mfree(u->runtime_path);
 137         u->state_file = mfree(u->state_file);
 138
 139         user_record_unref(u->user_record);
 140
 141         return mfree(u);
 142 }
 143
 144 static int user_save_internal(User *u) {
 145         _cleanup_(unlink_and_freep) char *temp_path = NULL;
 146         _cleanup_fclose_ FILE *f = NULL;
 147         int r;
 148
 149         assert(u);
 150         assert(u->state_file);
 151
 152         r = mkdir_safe_label("/run/systemd/users", 0755, 0, 0, MKDIR_WARN_MODE);
 153         if (r < 0)
 154                 goto fail;
 155
 156         r = fopen_temporary(u->state_file, &f, &temp_path);
 157         if (r < 0)
 158                 goto fail;
 159
 160         (void) fchmod(fileno(f), 0644);
 161
 162         fprintf(f,
 163                 "# This is private data. Do not parse.\n"
 164                 "NAME=%s\n"
 165                 "STATE=%s\n"         /* friendly user-facing state */
 166                 "STOPPING=%s\n"      /* low-level state */
 167                 "GC_MODE=%s\n",
 168                 u->user_record->user_name,
 169                 user_state_to_string(user_get_state(u)),
 170                 yes_no(u->stopping),
 171                 user_gc_mode_to_string(u->gc_mode));
 172
 173         /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */
 174         if (u->runtime_path)
 175                 fprintf(f, "RUNTIME=%s\n", u->runtime_path);
 176
 177         if (u->service_job)
 178                 fprintf(f, "SERVICE_JOB=%s\n", u->service_job);
 179
 180         if (u->display)
 181                 fprintf(f, "DISPLAY=%s\n", u->display->id);
 182
 183         if (dual_timestamp_is_set(&u->timestamp))
 184                 fprintf(f,
 185                         "REALTIME="USEC_FMT"\n"
 186                         "MONOTONIC="USEC_FMT"\n",
 187                         u->timestamp.realtime,
 188                         u->timestamp.monotonic);
 189
 190         if (u->last_session_timestamp != USEC_INFINITY)
 191                 fprintf(f, "LAST_SESSION_TIMESTAMP=" USEC_FMT "\n",
 192                         u->last_session_timestamp);
 193
 194         if (u->sessions) {
 195                 bool first;
 196
 197                 fputs("SESSIONS=", f);
 198                 first = true;
 199                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 200                         if (first)
 201                                 first = false;
 202                         else
 203                                 fputc(' ', f);
 204
 205                         fputs(i->id, f);
 206                 }
 207
 208                 fputs("\nSEATS=", f);
 209                 first = true;
 210                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 211                         if (!i->seat)
 212                                 continue;
 213
 214                         if (first)
 215                                 first = false;
 216                         else
 217                                 fputc(' ', f);
 218
 219                         fputs(i->seat->id, f);
 220                 }
 221
 222                 fputs("\nACTIVE_SESSIONS=", f);
 223                 first = true;
 224                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 225                         if (!session_is_active(i))
 226                                 continue;
 227
 228                         if (first)
 229                                 first = false;
 230                         else
 231                                 fputc(' ', f);
 232
 233                         fputs(i->id, f);
 234                 }
 235
 236                 fputs("\nONLINE_SESSIONS=", f);
 237                 first = true;
 238                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 239                         if (session_get_state(i) == SESSION_CLOSING)
 240                                 continue;
 241
 242                         if (first)
 243                                 first = false;
 244                         else
 245                                 fputc(' ', f);
 246
 247                         fputs(i->id, f);
 248                 }
 249
 250                 fputs("\nACTIVE_SEATS=", f);
 251                 first = true;
 252                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 253                         if (!session_is_active(i) || !i->seat)
 254                                 continue;
 255
 256                         if (first)
 257                                 first = false;
 258                         else
 259                                 fputc(' ', f);
 260
 261                         fputs(i->seat->id, f);
 262                 }
 263
 264                 fputs("\nONLINE_SEATS=", f);
 265                 first = true;
 266                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 267                         if (session_get_state(i) == SESSION_CLOSING || !i->seat)
 268                                 continue;
 269
 270                         if (first)
 271                                 first = false;
 272                         else
 273                                 fputc(' ', f);
 274
 275                         fputs(i->seat->id, f);
 276                 }
 277                 fputc('\n', f);
 278         }
 279
 280         r = fflush_and_check(f);
 281         if (r < 0)
 282                 goto fail;
 283
 284         if (rename(temp_path, u->state_file) < 0) {
 285                 r = -errno;
 286                 goto fail;
 287         }
 288
 289         temp_path = mfree(temp_path);
 290         return 0;
 291
 292 fail:
 293         (void) unlink(u->state_file);
 294
 295         return log_error_errno(r, "Failed to save user data %s: %m", u->state_file);
 296 }
 297
 298 int user_save(User *u) {
 299         assert(u);
 300
 301         if (!u->started)
 302                 return 0;
 303
 304         return user_save_internal(u);
 305 }
 306
 307 int user_load(User *u) {
 308         _cleanup_free_ char *realtime = NULL, *monotonic = NULL, *stopping = NULL, *last_session_timestamp = NULL, *gc_mode = NULL;
 309         int r;
 310
 311         assert(u);
 312
 313         r = parse_env_file(NULL, u->state_file,
 314                            "SERVICE_JOB",            &u->service_job,
 315                            "STOPPING",               &stopping,
 316                            "REALTIME",               &realtime,
 317                            "MONOTONIC",              &monotonic,
 318                            "LAST_SESSION_TIMESTAMP", &last_session_timestamp,
 319                            "GC_MODE",                &gc_mode);
 320         if (r == -ENOENT)
 321                 return 0;
 322         if (r < 0)
 323                 return log_error_errno(r, "Failed to read %s: %m", u->state_file);
 324
 325         if (stopping) {
 326                 r = parse_boolean(stopping);
 327                 if (r < 0)
 328                         log_debug_errno(r, "Failed to parse 'STOPPING' boolean: %s", stopping);
 329                 else
 330                         u->stopping = r;
 331         }
 332
 333         if (realtime)
 334                 (void) deserialize_usec(realtime, &u->timestamp.realtime);
 335         if (monotonic)
 336                 (void) deserialize_usec(monotonic, &u->timestamp.monotonic);
 337         if (last_session_timestamp)
 338                 (void) deserialize_usec(last_session_timestamp, &u->last_session_timestamp);
 339
 340         u->gc_mode = user_gc_mode_from_string(gc_mode);
 341         if (u->gc_mode < 0)
 342                 u->gc_mode = USER_GC_BY_PIN;
 343
 344         return 0;
 345 }
 346
 347 static bool user_wants_service_manager(User *u) {
 348         assert(u);
 349
 350         LIST_FOREACH(sessions_by_user, s, u->sessions)
 351                 if (SESSION_CLASS_WANTS_SERVICE_MANAGER(s->class))
 352                         return true;
 353
 354         return false;
 355 }
 356
 357 void user_start_service_manager(User *u) {
 358         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 359         int r;
 360
 361         assert(u);
 362
 363         /* Start the service containing the "systemd --user" instance (user@.service). Note that we don't explicitly
 364          * start the per-user slice or the systemd-runtime-dir@.service instance, as those are pulled in both by
 365          * user@.service and the session scopes as dependencies. */
 366
 367         if (u->stopping) /* Don't try to start this if the user is going down */
 368                 return;
 369
 370         if (!user_wants_service_manager(u)) /* Only start user service manager if there's at least one session which wants it */
 371                 return;
 372
 373         u->service_job = mfree(u->service_job);
 374
 375         r = manager_start_unit(u->manager, u->service, &error, &u->service_job);
 376         if (r < 0)
 377                 log_full_errno(sd_bus_error_has_name(&error, BUS_ERROR_UNIT_MASKED) ? LOG_DEBUG : LOG_WARNING, r,
 378                                "Failed to start user service '%s', ignoring: %s", u->service, bus_error_message(&error, r));
 379 }
 380
 381 static int update_slice_callback(sd_bus_message *m, void *userdata, sd_bus_error *ret_error) {
 382         _cleanup_(user_record_unrefp) UserRecord *ur = ASSERT_PTR(userdata);
 383         const sd_bus_error *e;
 384         int r;
 385
 386         assert(m);
 387
 388         e = sd_bus_message_get_error(m);
 389         if (e) {
 390                 r = sd_bus_error_get_errno(e);
 391                 log_warning_errno(r,
 392                                   "Failed to update slice of %s, ignoring: %s",
 393                                   ur->user_name,
 394                                   bus_error_message(e, r));
 395
 396                 return 0;
 397         }
 398
 399         log_debug("Successfully set slice parameters of %s.", ur->user_name);
 400         return 0;
 401 }
 402
 403 static int user_update_slice(User *u) {
 404         _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
 405         int r;
 406
 407         assert(u);
 408
 409         if (u->user_record->tasks_max == UINT64_MAX &&
 410             u->user_record->memory_high == UINT64_MAX &&
 411             u->user_record->memory_max == UINT64_MAX &&
 412             u->user_record->cpu_weight == UINT64_MAX &&
 413             u->user_record->io_weight == UINT64_MAX)
 414                 return 0;
 415
 416         r = bus_message_new_method_call(u->manager->bus, &m, bus_systemd_mgr, "SetUnitProperties");
 417         if (r < 0)
 418                 return bus_log_create_error(r);
 419
 420         r = sd_bus_message_append(m, "sb", u->slice, true);
 421         if (r < 0)
 422                 return bus_log_create_error(r);
 423
 424         r = sd_bus_message_open_container(m, 'a', "(sv)");
 425         if (r < 0)
 426                 return bus_log_create_error(r);
 427
 428         const struct {
 429                 const char *name;
 430                 uint64_t value;
 431         } settings[] = {
 432                 { "TasksMax",   u->user_record->tasks_max   },
 433                 { "MemoryMax",  u->user_record->memory_max  },
 434                 { "MemoryHigh", u->user_record->memory_high },
 435                 { "CPUWeight",  u->user_record->cpu_weight  },
 436                 { "IOWeight",   u->user_record->io_weight   },
 437         };
 438
 439         FOREACH_ARRAY(st, settings, ELEMENTSOF(settings)) {
 440                 if (st->value == UINT64_MAX)
 441                         continue;
 442
 443                 r = sd_bus_message_append(m, "(sv)", st->name, "t", st->value);
 444                 if (r < 0)
 445                         return bus_log_create_error(r);
 446         }
 447
 448         r = sd_bus_message_close_container(m);
 449         if (r < 0)
 450                 return bus_log_create_error(r);
 451
 452         r = sd_bus_call_async(u->manager->bus, NULL, m, update_slice_callback, u->user_record, 0);
 453         if (r < 0)
 454                 return log_error_errno(r, "Failed to change user slice properties: %m");
 455
 456         /* Ref the user record pointer, so that the slot keeps it pinned */
 457         user_record_ref(u->user_record);
 458
 459         return 0;
 460 }
 461
 462 int user_start(User *u) {
 463         assert(u);
 464
 465         if (u->started && !u->stopping)
 466                 return 0;
 467
 468         /* If u->stopping is set, the user is marked for removal and service stop-jobs are queued. We have to clear
 469          * that flag before queueing the start-jobs again. If they succeed, the user object can be re-used just fine
 470          * (pid1 takes care of job-ordering and proper restart), but if they fail, we want to force another user_stop()
 471          * so possibly pending units are stopped. */
 472         u->stopping = false;
 473
 474         if (!u->started)
 475                 log_debug("Tracking new user %s.", u->user_record->user_name);
 476
 477         /* Save the user data so far, because pam_systemd will read the XDG_RUNTIME_DIR out of it while starting up
 478          * systemd --user.  We need to do user_save_internal() because we have not "officially" started yet. */
 479         user_save_internal(u);
 480
 481         /* Set slice parameters */
 482         (void) user_update_slice(u);
 483
 484         /* Start user@UID.service */
 485         user_start_service_manager(u);
 486
 487         if (!u->started) {
 488                 if (!dual_timestamp_is_set(&u->timestamp))
 489                         dual_timestamp_now(&u->timestamp);
 490                 user_send_signal(u, true);
 491                 u->started = true;
 492         }
 493
 494         /* Save new user data */
 495         user_save(u);
 496
 497         return 0;
 498 }
 499
 500 static void user_stop_service(User *u, bool force) {
 501         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 502         int r;
 503
 504         assert(u);
 505         assert(u->service);
 506
 507         /* The reverse of user_start_service(). Note that we only stop user@UID.service here, and let StopWhenUnneeded=
 508          * deal with the slice and the user-runtime-dir@.service instance. */
 509
 510         u->service_job = mfree(u->service_job);
 511
 512         r = manager_stop_unit(u->manager, u->service, force ? "replace" : "fail", &error, &u->service_job);
 513         if (r < 0)
 514                 log_warning_errno(r, "Failed to stop user service '%s', ignoring: %s", u->service, bus_error_message(&error, r));
 515 }
 516
 517 int user_stop(User *u, bool force) {
 518         int r = 0;
 519
 520         assert(u);
 521
 522         /* This is called whenever we begin with tearing down a user record. It's called in two cases: explicit API
 523          * request to do so via the bus (in which case 'force' is true) and automatically due to GC, if there's no
 524          * session left pinning it (in which case 'force' is false). Note that this just initiates tearing down of the
 525          * user, the User object will remain in memory until user_finalize() is called, see below. */
 526
 527         if (!u->started)
 528                 return 0;
 529
 530         if (u->stopping) { /* Stop jobs have already been queued */
 531                 user_save(u);
 532                 return 0;
 533         }
 534
 535         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 536                 int k;
 537
 538                 k = session_stop(s, force);
 539                 if (k < 0)
 540                         r = k;
 541         }
 542
 543         user_stop_service(u, force);
 544
 545         u->stopping = true;
 546
 547         user_save(u);
 548
 549         return r;
 550 }
 551
 552 int user_finalize(User *u) {
 553         int r = 0, k;
 554
 555         assert(u);
 556
 557         /* Called when the user is really ready to be freed, i.e. when all unit stop jobs and suchlike for it are
 558          * done. This is called as a result of an earlier user_done() when all jobs are completed. */
 559
 560         if (u->started)
 561                 log_debug("User %s logged out.", u->user_record->user_name);
 562
 563         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 564                 k = session_finalize(s);
 565                 if (k < 0)
 566                         r = k;
 567         }
 568
 569         /* Clean SysV + POSIX IPC objects, but only if this is not a system user. Background: in many setups cronjobs
 570          * are run in full PAM and thus logind sessions, even if the code run doesn't belong to actual users but to
 571          * system components. Since enable RemoveIPC= globally for all users, we need to be a bit careful with such
 572          * cases, as we shouldn't accidentally remove a system service's IPC objects while it is running, just because
 573          * a cronjob running as the same user just finished. Hence: exclude system users generally from IPC clean-up,
 574          * and do it only for normal users. */
 575         if (u->manager->remove_ipc && !uid_is_system(u->user_record->uid)) {
 576                 k = clean_ipc_by_uid(u->user_record->uid);
 577                 if (k < 0)
 578                         r = k;
 579         }
 580
 581         (void) unlink(u->state_file);
 582         user_add_to_gc_queue(u);
 583
 584         if (u->started) {
 585                 user_send_signal(u, false);
 586                 u->started = false;
 587         }
 588
 589         return r;
 590 }
 591
 592 int user_get_idle_hint(User *u, dual_timestamp *t) {
 593         bool idle_hint = true;
 594         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 595
 596         assert(u);
 597
 598         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 599                 dual_timestamp k;
 600                 int ih;
 601
 602                 if (!SESSION_CLASS_CAN_IDLE(s->class))
 603                         continue;
 604
 605                 ih = session_get_idle_hint(s, &k);
 606                 if (ih < 0)
 607                         return ih;
 608
 609                 if (!ih) {
 610                         if (!idle_hint) {
 611                                 if (k.monotonic < ts.monotonic)
 612                                         ts = k;
 613                         } else {
 614                                 idle_hint = false;
 615                                 ts = k;
 616                         }
 617                 } else if (idle_hint) {
 618
 619                         if (k.monotonic > ts.monotonic)
 620                                 ts = k;
 621                 }
 622         }
 623
 624         if (t)
 625                 *t = ts;
 626
 627         return idle_hint;
 628 }
 629
 630 int user_check_linger_file(User *u) {
 631         _cleanup_free_ char *cc = NULL;
 632         char *p = NULL;
 633
 634         cc = cescape(u->user_record->user_name);
 635         if (!cc)
 636                 return -ENOMEM;
 637
 638         p = strjoina("/var/lib/systemd/linger/", cc);
 639         if (access(p, F_OK) < 0) {
 640                 if (errno != ENOENT)
 641                         return -errno;
 642
 643                 return false;
 644         }
 645
 646         return true;
 647 }
 648
 649 static bool user_unit_active(User *u) {
 650         int r;
 651
 652         assert(u->service);
 653         assert(u->runtime_dir_service);
 654         assert(u->slice);
 655
 656         FOREACH_STRING(i, u->service, u->runtime_dir_service, u->slice) {
 657                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 658
 659                 r = manager_unit_is_active(u->manager, i, &error);
 660                 if (r < 0)
 661                         log_debug_errno(r, "Failed to determine whether unit '%s' is active, ignoring: %s", i, bus_error_message(&error, r));
 662                 if (r != 0)
 663                         return true;
 664         }
 665
 666         return false;
 667 }
 668
 669 static usec_t user_get_stop_delay(User *u) {
 670         assert(u);
 671
 672         if (u->user_record->stop_delay_usec != UINT64_MAX)
 673                 return u->user_record->stop_delay_usec;
 674
 675         if (user_record_removable(u->user_record) > 0)
 676                 return 0; /* For removable users lower the stop delay to zero */
 677
 678         return u->manager->user_stop_delay;
 679 }
 680
 681 static bool user_pinned_by_sessions(User *u) {
 682         assert(u);
 683
 684         /* Returns true if at least one session exists that shall keep the user tracking alive. That
 685          * generally means one session that isn't the service manager still exists. */
 686
 687         switch (u->gc_mode) {
 688
 689         case USER_GC_BY_ANY:
 690                 return u->sessions;
 691
 692         case USER_GC_BY_PIN:
 693                 LIST_FOREACH(sessions_by_user, i, u->sessions)
 694                         if (SESSION_CLASS_PIN_USER(i->class))
 695                                 return true;
 696
 697                 return false;
 698
 699         default:
 700                 assert_not_reached();
 701         }
 702 }
 703
 704 bool user_may_gc(User *u, bool drop_not_started) {
 705         int r;
 706
 707         assert(u);
 708
 709         if (drop_not_started && !u->started)
 710                 return true;
 711
 712         if (user_pinned_by_sessions(u))
 713                 return false;
 714
 715         if (u->last_session_timestamp != USEC_INFINITY) {
 716                 usec_t user_stop_delay;
 717
 718                 /* All sessions have been closed. Let's see if we shall leave the user record around for a bit */
 719
 720                 user_stop_delay = user_get_stop_delay(u);
 721
 722                 if (user_stop_delay == USEC_INFINITY)
 723                         return false; /* Leave it around forever! */
 724                 if (user_stop_delay > 0 &&
 725                     now(CLOCK_MONOTONIC) < usec_add(u->last_session_timestamp, user_stop_delay))
 726                         return false; /* Leave it around for a bit longer. */
 727         }
 728
 729         /* Is this a user that shall stay around forever ("linger")? Before we say "no" to GC'ing for lingering users, let's check
 730          * if any of the three units that we maintain for this user is still around. If none of them is,
 731          * there's no need to keep this user around even if lingering is enabled. */
 732         if (user_check_linger_file(u) > 0 && user_unit_active(u))
 733                 return false;
 734
 735         /* Check if our job is still pending */
 736         if (u->service_job) {
 737                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 738
 739                 r = manager_job_is_active(u->manager, u->service_job, &error);
 740                 if (r < 0)
 741                         log_debug_errno(r, "Failed to determine whether job '%s' is pending, ignoring: %s", u->service_job, bus_error_message(&error, r));
 742                 if (r != 0)
 743                         return false;
 744         }
 745
 746         /* Note that we don't care if the three units we manage for each user object are up or not, as we are managing
 747          * their state rather than tracking it. */
 748
 749         return true;
 750 }
 751
 752 void user_add_to_gc_queue(User *u) {
 753         assert(u);
 754
 755         if (u->in_gc_queue)
 756                 return;
 757
 758         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 759         u->in_gc_queue = true;
 760 }
 761
 762 UserState user_get_state(User *u) {
 763         assert(u);
 764
 765         if (u->stopping)
 766                 return USER_CLOSING;
 767
 768         if (!u->started || u->service_job)
 769                 return USER_OPENING;
 770
 771         bool any = false, all_closing = true;
 772         LIST_FOREACH(sessions_by_user, i, u->sessions) {
 773                 SessionState state;
 774
 775                 /* Ignore sessions that don't pin the user, i.e. are not supposed to have an effect on user state */
 776                 if (!SESSION_CLASS_PIN_USER(i->class))
 777                         continue;
 778
 779                 state = session_get_state(i);
 780                 if (state == SESSION_ACTIVE)
 781                         return USER_ACTIVE;
 782                 if (state != SESSION_CLOSING)
 783                         all_closing = false;
 784
 785                 any = true;
 786         }
 787
 788         if (any)
 789                 return all_closing ? USER_CLOSING : USER_ONLINE;
 790
 791         if (user_check_linger_file(u) > 0 && user_unit_active(u))
 792                 return USER_LINGERING;
 793
 794         return USER_CLOSING;
 795 }
 796
 797 int user_kill(User *u, int signo) {
 798         assert(u);
 799
 800         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 801 }
 802
 803 static bool elect_display_filter(Session *s) {
 804         /* Return true if the session is a candidate for the user’s ‘primary session’ or ‘display’. */
 805         assert(s);
 806
 807         return SESSION_CLASS_CAN_DISPLAY(s->class) && s->started && !s->stopping;
 808 }
 809
 810 static int elect_display_compare(Session *s1, Session *s2) {
 811         /* Indexed by SessionType. Lower numbers mean more preferred. */
 812         static const int type_ranks[_SESSION_TYPE_MAX] = {
 813                 [SESSION_UNSPECIFIED] = 0,
 814                 [SESSION_TTY] = -2,
 815                 [SESSION_X11] = -3,
 816                 [SESSION_WAYLAND] = -3,
 817                 [SESSION_MIR] = -3,
 818                 [SESSION_WEB] = -1,
 819         };
 820
 821         /* Calculate the partial order relationship between s1 and s2,
 822          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 823          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 824          * is preferred.
 825          *
 826          * s1 or s2 may be NULL. */
 827         if (!s1 && !s2)
 828                 return 0;
 829
 830         if ((s1 == NULL) != (s2 == NULL))
 831                 return (s1 == NULL) - (s2 == NULL);
 832
 833         if (s1->stopping != s2->stopping)
 834                 return s1->stopping - s2->stopping;
 835
 836         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 837                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 838
 839         if ((s1->class != SESSION_USER_EARLY) != (s2->class != SESSION_USER_EARLY))
 840                 return (s1->class != SESSION_USER_EARLY) - (s2->class != SESSION_USER_EARLY);
 841
 842         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 843                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 844
 845         if (s1->type != s2->type)
 846                 return type_ranks[s1->type] - type_ranks[s2->type];
 847
 848         return 0;
 849 }
 850
 851 void user_elect_display(User *u) {
 852         assert(u);
 853
 854         /* This elects a primary session for each user, which we call the "display". We try to keep the assignment
 855          * stable, but we "upgrade" to better choices. */
 856         log_debug("Electing new display for user %s", u->user_record->user_name);
 857
 858         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 859                 if (!elect_display_filter(s)) {
 860                         log_debug("Ignoring session %s", s->id);
 861                         continue;
 862                 }
 863
 864                 if (elect_display_compare(s, u->display) < 0) {
 865                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 866                         u->display = s;
 867                 }
 868         }
 869 }
 870
 871 static int user_stop_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
 872         User *u = ASSERT_PTR(userdata);
 873
 874         user_add_to_gc_queue(u);
 875
 876         return 0;
 877 }
 878
 879 void user_update_last_session_timer(User *u) {
 880         usec_t user_stop_delay;
 881         int r;
 882
 883         assert(u);
 884
 885         if (user_pinned_by_sessions(u)) {
 886                 /* There are sessions, turn off the timer */
 887                 u->last_session_timestamp = USEC_INFINITY;
 888                 u->timer_event_source = sd_event_source_unref(u->timer_event_source);
 889                 return;
 890         }
 891
 892         if (u->last_session_timestamp != USEC_INFINITY)
 893                 return; /* Timer already started */
 894
 895         u->last_session_timestamp = now(CLOCK_MONOTONIC);
 896
 897         assert(!u->timer_event_source);
 898
 899         user_stop_delay = user_get_stop_delay(u);
 900         if (!timestamp_is_set(user_stop_delay))
 901                 return;
 902
 903         if (sd_event_get_state(u->manager->event) == SD_EVENT_FINISHED) {
 904                 log_debug("Not allocating user stop timeout, since we are already exiting.");
 905                 return;
 906         }
 907
 908         r = sd_event_add_time(u->manager->event,
 909                               &u->timer_event_source,
 910                               CLOCK_MONOTONIC,
 911                               usec_add(u->last_session_timestamp, user_stop_delay), 0,
 912                               user_stop_timeout_callback, u);
 913         if (r < 0)
 914                 log_warning_errno(r, "Failed to enqueue user stop event source, ignoring: %m");
 915
 916         if (DEBUG_LOGGING)
 917                 log_debug("Last session of user '%s' logged out, terminating user context in %s.",
 918                           u->user_record->user_name,
 919                           FORMAT_TIMESPAN(user_stop_delay, USEC_PER_MSEC));
 920 }
 921
 922 static const char* const user_state_table[_USER_STATE_MAX] = {
 923         [USER_OFFLINE]   = "offline",
 924         [USER_OPENING]   = "opening",
 925         [USER_LINGERING] = "lingering",
 926         [USER_ONLINE]    = "online",
 927         [USER_ACTIVE]    = "active",
 928         [USER_CLOSING]   = "closing"
 929 };
 930
 931 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 932
 933 static const char* const user_gc_mode_table[_USER_GC_MODE_MAX] = {
 934         [USER_GC_BY_PIN] = "pin",
 935         [USER_GC_BY_ANY] = "any",
 936 };
 937
 938 DEFINE_STRING_TABLE_LOOKUP(user_gc_mode, UserGCMode);
 939
 940 int config_parse_tmpfs_size(
 941                 const char* unit,
 942                 const char *filename,
 943                 unsigned line,
 944                 const char *section,
 945                 unsigned section_line,
 946                 const char *lvalue,
 947                 int ltype,
 948                 const char *rvalue,
 949                 void *data,
 950                 void *userdata) {
 951
 952         uint64_t *sz = ASSERT_PTR(data);
 953         int r;
 954
 955         assert(filename);
 956         assert(lvalue);
 957         assert(rvalue);
 958
 959         /* First, try to parse as percentage */
 960         r = parse_permyriad(rvalue);
 961         if (r > 0)
 962                 *sz = physical_memory_scale(r, 10000U);
 963         else {
 964                 uint64_t k;
 965
 966                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
 967
 968                 r = parse_size(rvalue, 1024, &k);
 969                 if (r >= 0 && (k <= 0 || (uint64_t) (size_t) k != k))
 970                         r = -ERANGE;
 971                 if (r < 0) {
 972                         log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse size value '%s', ignoring: %m", rvalue);
 973                         return 0;
 974                 }
 975
 976                 *sz = PAGE_ALIGN((size_t) k);
 977         }
 978
 979         return 0;
 980 }
 981
 982 int config_parse_compat_user_tasks_max(
 983                 const char *unit,
 984                 const char *filename,
 985                 unsigned line,
 986                 const char *section,
 987                 unsigned section_line,
 988                 const char *lvalue,
 989                 int ltype,
 990                 const char *rvalue,
 991                 void *data,
 992                 void *userdata) {
 993
 994         assert(filename);
 995         assert(lvalue);
 996         assert(rvalue);
 997
 998         log_syntax(unit, LOG_NOTICE, filename, line, 0,
 999                    "Support for option %s= has been removed.",
1000                    lvalue);
1001         log_info("Hint: try creating /etc/systemd/system/user-.slice.d/50-limits.conf with:\n"
1002                  "        [Slice]\n"
1003                  "        TasksMax=%s",
1004                  rvalue);
1005         return 0;
1006 }