src/login/logind-user.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <unistd.h>
   4 #include "sd-bus.h"
   5 #include "sd-event.h"
   6
   7 #include "alloc-util.h"
   8 #include "bus-common-errors.h"
   9 #include "bus-error.h"
  10 #include "bus-locator.h"
  11 #include "bus-util.h"
  12 #include "clean-ipc.h"
  13 #include "env-file.h"
  14 #include "errno-util.h"
  15 #include "escape.h"
  16 #include "fd-util.h"
  17 #include "format-util.h"
  18 #include "fs-util.h"
  19 #include "hashmap.h"
  20 #include "limits-util.h"
  21 #include "logind-session.h"
  22 #include "logind.h"
  23 #include "logind-dbus.h"
  24 #include "logind-seat.h"
  25 #include "logind-user.h"
  26 #include "logind-user-dbus.h"
  27 #include "mkdir-label.h"
  28 #include "parse-util.h"
  29 #include "percent-util.h"
  30 #include "serialize.h"
  31 #include "special.h"
  32 #include "stdio-util.h"
  33 #include "string-table.h"
  34 #include "string-util.h"
  35 #include "strv.h"
  36 #include "tmpfile-util.h"
  37 #include "uid-classification.h"
  38 #include "unit-name.h"
  39 #include "user-record.h"
  40 #include "user-util.h"
  41
  42 int user_new(Manager *m, UserRecord *ur, User **ret) {
  43         _cleanup_(user_freep) User *u = NULL;
  44         char lu[DECIMAL_STR_MAX(uid_t) + 1];
  45         int r;
  46
  47         assert(m);
  48         assert(ur);
  49         assert(ret);
  50
  51         if (!ur->user_name)
  52                 return -EINVAL;
  53
  54         if (!uid_is_valid(ur->uid))
  55                 return -EINVAL;
  56
  57         u = new(User, 1);
  58         if (!u)
  59                 return -ENOMEM;
  60
  61         *u = (User) {
  62                 .manager = m,
  63                 .user_record = user_record_ref(ur),
  64                 .last_session_timestamp = USEC_INFINITY,
  65                 .gc_mode = USER_GC_BY_ANY,
  66         };
  67
  68         if (asprintf(&u->state_file, "/run/systemd/users/" UID_FMT, ur->uid) < 0)
  69                 return -ENOMEM;
  70
  71         if (asprintf(&u->runtime_path, "/run/user/" UID_FMT, ur->uid) < 0)
  72                 return -ENOMEM;
  73
  74         xsprintf(lu, UID_FMT, ur->uid);
  75         r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice);
  76         if (r < 0)
  77                 return r;
  78
  79         r = unit_name_build("user-runtime-dir", lu, ".service", &u->runtime_dir_unit);
  80         if (r < 0)
  81                 return r;
  82
  83         r = unit_name_build("user", lu, ".service", &u->service_manager_unit);
  84         if (r < 0)
  85                 return r;
  86
  87         r = hashmap_put(m->users, UID_TO_PTR(ur->uid), u);
  88         if (r < 0)
  89                 return r;
  90
  91         r = hashmap_put(m->user_units, u->slice, u);
  92         if (r < 0)
  93                 return r;
  94
  95         r = hashmap_put(m->user_units, u->runtime_dir_unit, u);
  96         if (r < 0)
  97                 return r;
  98
  99         r = hashmap_put(m->user_units, u->service_manager_unit, u);
 100         if (r < 0)
 101                 return r;
 102
 103         *ret = TAKE_PTR(u);
 104         return 0;
 105 }
 106
 107 User *user_free(User *u) {
 108         if (!u)
 109                 return NULL;
 110
 111         if (u->in_gc_queue)
 112                 LIST_REMOVE(gc_queue, u->manager->user_gc_queue, u);
 113
 114         while (u->sessions)
 115                 session_free(u->sessions);
 116
 117         sd_event_source_unref(u->timer_event_source);
 118
 119         if (u->service_manager_unit) {
 120                 (void) hashmap_remove_value(u->manager->user_units, u->service_manager_unit, u);
 121                 free(u->service_manager_job);
 122                 free(u->service_manager_unit);
 123         }
 124
 125         if (u->runtime_dir_unit) {
 126                 (void) hashmap_remove_value(u->manager->user_units, u->runtime_dir_unit, u);
 127                 free(u->runtime_dir_job);
 128                 free(u->runtime_dir_unit);
 129         }
 130
 131         if (u->slice) {
 132                 (void) hashmap_remove_value(u->manager->user_units, u->slice, u);
 133                 free(u->slice);
 134         }
 135
 136         (void) hashmap_remove_value(u->manager->users, UID_TO_PTR(u->user_record->uid), u);
 137
 138         free(u->runtime_path);
 139         free(u->state_file);
 140
 141         user_record_unref(u->user_record);
 142
 143         return mfree(u);
 144 }
 145
 146 static int user_save_internal(User *u) {
 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                 return log_error_errno(r, "Failed to create /run/systemd/users/: %m");
 155
 156         _cleanup_(unlink_and_freep) char *temp_path = NULL;
 157         _cleanup_fclose_ FILE *f = NULL;
 158         r = fopen_tmpfile_linkable(u->state_file, O_WRONLY|O_CLOEXEC, &temp_path, &f);
 159         if (r < 0)
 160                 return log_error_errno(r, "Failed to create state file '%s': %m", u->state_file);
 161
 162         if (fchmod(fileno(f), 0644) < 0)
 163                 return log_error_errno(errno, "Failed to set access mode for state file '%s' to 0644: %m", u->state_file);
 164
 165         fprintf(f,
 166                 "# This is private data. Do not parse.\n"
 167                 "NAME=%s\n"
 168                 "STATE=%s\n"         /* friendly user-facing state */
 169                 "STOPPING=%s\n"      /* low-level state */
 170                 "GC_MODE=%s\n",
 171                 u->user_record->user_name,
 172                 user_state_to_string(user_get_state(u)),
 173                 yes_no(u->stopping),
 174                 user_gc_mode_to_string(u->gc_mode));
 175
 176         /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */
 177         env_file_fputs_assignment(f, "RUNTIME=", u->runtime_path);
 178         env_file_fputs_assignment(f, "RUNTIME_DIR_JOB=", u->runtime_dir_job);
 179         env_file_fputs_assignment(f, "SERVICE_JOB=", u->service_manager_job);
 180         if (u->display)
 181                 env_file_fputs_assignment(f, "DISPLAY=", 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 = flink_tmpfile(f, temp_path, u->state_file, LINK_TMPFILE_REPLACE);
 281         if (r < 0)
 282                 return log_error_errno(r, "Failed to move '%s' into place: %m", u->state_file);
 283
 284         temp_path = mfree(temp_path); /* disarm auto-destroy: temporary file does not exist anymore */
 285         return 0;
 286 }
 287
 288 int user_save(User *u) {
 289         assert(u);
 290
 291         if (!u->started)
 292                 return 0;
 293
 294         return user_save_internal(u);
 295 }
 296
 297 int user_load(User *u) {
 298         _cleanup_free_ char *realtime = NULL, *monotonic = NULL, *stopping = NULL, *last_session_timestamp = NULL, *gc_mode = NULL;
 299         int r;
 300
 301         assert(u);
 302
 303         r = parse_env_file(NULL, u->state_file,
 304                            "RUNTIME_DIR_JOB",        &u->runtime_dir_job,
 305                            "SERVICE_JOB",            &u->service_manager_job,
 306                            "STOPPING",               &stopping,
 307                            "REALTIME",               &realtime,
 308                            "MONOTONIC",              &monotonic,
 309                            "LAST_SESSION_TIMESTAMP", &last_session_timestamp,
 310                            "GC_MODE",                &gc_mode);
 311         if (r == -ENOENT)
 312                 return 0;
 313         if (r < 0)
 314                 return log_error_errno(r, "Failed to read %s: %m", u->state_file);
 315
 316         if (stopping) {
 317                 r = parse_boolean(stopping);
 318                 if (r < 0)
 319                         log_debug_errno(r, "Failed to parse 'STOPPING' boolean: %s", stopping);
 320                 else {
 321                         u->stopping = r;
 322                         if (u->stopping && !u->runtime_dir_job)
 323                                 log_debug("User '%s' is stopping, but no job is being tracked.", u->user_record->user_name);
 324                 }
 325         }
 326
 327         if (realtime)
 328                 (void) deserialize_usec(realtime, &u->timestamp.realtime);
 329         if (monotonic)
 330                 (void) deserialize_usec(monotonic, &u->timestamp.monotonic);
 331         if (last_session_timestamp)
 332                 (void) deserialize_usec(last_session_timestamp, &u->last_session_timestamp);
 333
 334         u->gc_mode = user_gc_mode_from_string(gc_mode);
 335         if (u->gc_mode < 0)
 336                 u->gc_mode = USER_GC_BY_PIN;
 337
 338         return 0;
 339 }
 340
 341 static int user_start_runtime_dir(User *u) {
 342         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 343         int r;
 344
 345         assert(u);
 346         assert(!u->stopping);
 347         assert(u->manager);
 348         assert(u->runtime_dir_unit);
 349
 350         u->runtime_dir_job = mfree(u->runtime_dir_job);
 351
 352         r = manager_start_unit(u->manager, u->runtime_dir_unit, &error, &u->runtime_dir_job);
 353         if (r < 0)
 354                 return log_full_errno(sd_bus_error_has_name(&error, BUS_ERROR_UNIT_MASKED) ? LOG_DEBUG : LOG_ERR,
 355                                       r, "Failed to start user service '%s': %s",
 356                                       u->runtime_dir_unit, bus_error_message(&error, r));
 357
 358         return 0;
 359 }
 360
 361 static bool user_wants_service_manager(const User *u) {
 362         assert(u);
 363
 364         LIST_FOREACH(sessions_by_user, s, u->sessions)
 365                 if (SESSION_CLASS_WANTS_SERVICE_MANAGER(s->class))
 366                         return true;
 367
 368         if (user_check_linger_file(u) > 0)
 369                 return true;
 370
 371         return false;
 372 }
 373
 374 int user_start_service_manager(User *u) {
 375         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 376         int r;
 377
 378         assert(u);
 379         assert(!u->stopping);
 380         assert(u->manager);
 381         assert(u->service_manager_unit);
 382
 383         if (u->service_manager_started)
 384                 return 1;
 385
 386         /* Only start user service manager if there's at least one session which wants it */
 387         if (!user_wants_service_manager(u))
 388                 return 0;
 389
 390         u->service_manager_job = mfree(u->service_manager_job);
 391
 392         r = manager_start_unit(u->manager, u->service_manager_unit, &error, &u->service_manager_job);
 393         if (r < 0) {
 394                 if (sd_bus_error_has_name(&error, BUS_ERROR_UNIT_MASKED))
 395                         return 0;
 396
 397                 return log_error_errno(r, "Failed to start user service '%s': %s",
 398                                        u->service_manager_unit, bus_error_message(&error, r));
 399         }
 400
 401         return (u->service_manager_started = true);
 402 }
 403
 404 static int update_slice_callback(sd_bus_message *m, void *userdata, sd_bus_error *ret_error) {
 405         _cleanup_(user_record_unrefp) UserRecord *ur = ASSERT_PTR(userdata);
 406         const sd_bus_error *e;
 407         int r;
 408
 409         assert(m);
 410
 411         e = sd_bus_message_get_error(m);
 412         if (e) {
 413                 r = sd_bus_error_get_errno(e);
 414                 log_warning_errno(r,
 415                                   "Failed to update slice of %s, ignoring: %s",
 416                                   ur->user_name,
 417                                   bus_error_message(e, r));
 418
 419                 return 0;
 420         }
 421
 422         log_debug("Successfully set slice parameters of %s.", ur->user_name);
 423         return 0;
 424 }
 425
 426 static int user_update_slice(User *u) {
 427         _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
 428         int r;
 429
 430         assert(u);
 431
 432         if (u->user_record->tasks_max == UINT64_MAX &&
 433             u->user_record->memory_high == UINT64_MAX &&
 434             u->user_record->memory_max == UINT64_MAX &&
 435             u->user_record->cpu_weight == UINT64_MAX &&
 436             u->user_record->io_weight == UINT64_MAX)
 437                 return 0;
 438
 439         r = bus_message_new_method_call(u->manager->bus, &m, bus_systemd_mgr, "SetUnitProperties");
 440         if (r < 0)
 441                 return bus_log_create_error(r);
 442
 443         r = sd_bus_message_append(m, "sb", u->slice, true);
 444         if (r < 0)
 445                 return bus_log_create_error(r);
 446
 447         r = sd_bus_message_open_container(m, 'a', "(sv)");
 448         if (r < 0)
 449                 return bus_log_create_error(r);
 450
 451         const struct {
 452                 const char *name;
 453                 uint64_t value;
 454         } settings[] = {
 455                 { "TasksMax",   u->user_record->tasks_max   },
 456                 { "MemoryMax",  u->user_record->memory_max  },
 457                 { "MemoryHigh", u->user_record->memory_high },
 458                 { "CPUWeight",  u->user_record->cpu_weight  },
 459                 { "IOWeight",   u->user_record->io_weight   },
 460         };
 461
 462         FOREACH_ELEMENT(st, settings) {
 463                 if (st->value == UINT64_MAX)
 464                         continue;
 465
 466                 r = sd_bus_message_append(m, "(sv)", st->name, "t", st->value);
 467                 if (r < 0)
 468                         return bus_log_create_error(r);
 469         }
 470
 471         r = sd_bus_message_close_container(m);
 472         if (r < 0)
 473                 return bus_log_create_error(r);
 474
 475         r = sd_bus_call_async(u->manager->bus, NULL, m, update_slice_callback, u->user_record, 0);
 476         if (r < 0)
 477                 return log_error_errno(r, "Failed to change user slice properties: %m");
 478
 479         /* Ref the user record pointer, so that the slot keeps it pinned */
 480         user_record_ref(u->user_record);
 481
 482         return 0;
 483 }
 484
 485 int user_start(User *u) {
 486         int r;
 487
 488         assert(u);
 489
 490         if (u->service_manager_started) {
 491                 /* Everything is up. No action needed. */
 492                 assert(u->started && !u->stopping);
 493                 return 0;
 494         }
 495
 496         if (!u->started || u->stopping) {
 497                 /* If u->stopping is set, the user is marked for removal and service stop-jobs are queued.
 498                  * We have to clear that flag before queueing the start-jobs again. If they succeed, the
 499                  * user object can be reused just fine (pid1 takes care of job-ordering and proper restart),
 500                  * but if they fail, we want to force another user_stop() so possibly pending units are
 501                  * stopped. */
 502                 u->stopping = false;
 503
 504                 if (!u->started)
 505                         log_debug("Tracking new user %s.", u->user_record->user_name);
 506
 507                 /* Save the user data so far, because pam_systemd will read the XDG_RUNTIME_DIR out of it
 508                  * while starting up systemd --user. We need to do user_save_internal() because we have not
 509                  * "officially" started yet. */
 510                 user_save_internal(u);
 511
 512                 /* Set slice parameters */
 513                 (void) user_update_slice(u);
 514
 515                 (void) user_start_runtime_dir(u);
 516         }
 517
 518         /* Start user@UID.service if needed. */
 519         r = user_start_service_manager(u);
 520         if (r < 0)
 521                 return r;
 522
 523         if (!u->started) {
 524                 if (!dual_timestamp_is_set(&u->timestamp))
 525                         dual_timestamp_now(&u->timestamp);
 526
 527                 user_send_signal(u, true);
 528                 u->started = true;
 529         }
 530
 531         /* Save new user data */
 532         user_save(u);
 533
 534         return 0;
 535 }
 536
 537 static void user_stop_service(User *u, bool force) {
 538         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 539         int r;
 540
 541         assert(u);
 542         assert(u->manager);
 543         assert(u->runtime_dir_unit);
 544
 545         /* Note that we only stop user-runtime-dir@.service here, and let BindsTo= deal with the user@.service
 546          * instance. However, we still need to clear service_manager_job here, so that if the stop is
 547          * interrupted, the new sessions won't be confused by leftovers. */
 548
 549         u->service_manager_job = mfree(u->service_manager_job);
 550         u->service_manager_started = false;
 551
 552         u->runtime_dir_job = mfree(u->runtime_dir_job);
 553
 554         r = manager_stop_unit(u->manager, u->runtime_dir_unit, force ? "replace" : "fail", &error, &u->runtime_dir_job);
 555         if (r < 0)
 556                 log_warning_errno(r, "Failed to stop user service '%s', ignoring: %s",
 557                                   u->runtime_dir_unit, bus_error_message(&error, r));
 558 }
 559
 560 int user_stop(User *u, bool force) {
 561         int r = 0;
 562
 563         assert(u);
 564
 565         /* This is called whenever we begin with tearing down a user record. It's called in two cases: explicit API
 566          * request to do so via the bus (in which case 'force' is true) and automatically due to GC, if there's no
 567          * session left pinning it (in which case 'force' is false). Note that this just initiates tearing down of the
 568          * user, the User object will remain in memory until user_finalize() is called, see below. */
 569
 570         if (!u->started)
 571                 return 0;
 572
 573         if (u->stopping) { /* Stop jobs have already been queued */
 574                 user_save(u);
 575                 return 0;
 576         }
 577
 578         LIST_FOREACH(sessions_by_user, s, u->sessions)
 579                 RET_GATHER(r, session_stop(s, force));
 580
 581         user_stop_service(u, force);
 582
 583         u->stopping = true;
 584
 585         user_save(u);
 586
 587         return r;
 588 }
 589
 590 int user_finalize(User *u) {
 591         int r = 0;
 592
 593         assert(u);
 594
 595         /* Called when the user is really ready to be freed, i.e. when all unit stop jobs and suchlike for it are
 596          * done. This is called as a result of an earlier user_done() when all jobs are completed. */
 597
 598         if (u->started)
 599                 log_debug("User %s exited.", u->user_record->user_name);
 600
 601         LIST_FOREACH(sessions_by_user, s, u->sessions)
 602                 RET_GATHER(r, session_finalize(s));
 603
 604         /* Clean SysV + POSIX IPC objects, but only if this is not a system user. Background: in many setups cronjobs
 605          * are run in full PAM and thus logind sessions, even if the code run doesn't belong to actual users but to
 606          * system components. Since enable RemoveIPC= globally for all users, we need to be a bit careful with such
 607          * cases, as we shouldn't accidentally remove a system service's IPC objects while it is running, just because
 608          * a cronjob running as the same user just finished. Hence: exclude system users generally from IPC clean-up,
 609          * and do it only for normal users. */
 610         if (u->manager->remove_ipc && !uid_is_system(u->user_record->uid))
 611                 RET_GATHER(r, clean_ipc_by_uid(u->user_record->uid));
 612
 613         (void) unlink(u->state_file);
 614         user_add_to_gc_queue(u);
 615
 616         if (u->started) {
 617                 user_send_signal(u, false);
 618                 u->started = false;
 619         }
 620
 621         return r;
 622 }
 623
 624 int user_get_idle_hint(User *u, dual_timestamp *t) {
 625         bool idle_hint = true;
 626         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 627
 628         assert(u);
 629
 630         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 631                 dual_timestamp k;
 632                 int ih;
 633
 634                 if (!SESSION_CLASS_CAN_IDLE(s->class))
 635                         continue;
 636
 637                 ih = session_get_idle_hint(s, &k);
 638                 if (ih < 0)
 639                         return ih;
 640
 641                 if (!ih) {
 642                         if (!idle_hint) {
 643                                 if (k.monotonic < ts.monotonic)
 644                                         ts = k;
 645                         } else {
 646                                 idle_hint = false;
 647                                 ts = k;
 648                         }
 649                 } else if (idle_hint) {
 650
 651                         if (k.monotonic > ts.monotonic)
 652                                 ts = k;
 653                 }
 654         }
 655
 656         if (t)
 657                 *t = ts;
 658
 659         return idle_hint;
 660 }
 661
 662 int user_check_linger_file(const User *u) {
 663         _cleanup_free_ char *cc = NULL;
 664         const char *p;
 665
 666         assert(u);
 667         assert(u->user_record);
 668
 669         cc = cescape(u->user_record->user_name);
 670         if (!cc)
 671                 return -ENOMEM;
 672
 673         p = strjoina("/var/lib/systemd/linger/", cc);
 674         if (access(p, F_OK) < 0) {
 675                 if (errno != ENOENT)
 676                         return -errno;
 677
 678                 return false;
 679         }
 680
 681         return true;
 682 }
 683
 684 static bool user_unit_active(User *u) {
 685         int r;
 686
 687         assert(u->slice);
 688         assert(u->runtime_dir_unit);
 689         assert(u->service_manager_unit);
 690
 691         FOREACH_STRING(i, u->slice, u->runtime_dir_unit, u->service_manager_unit) {
 692                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 693
 694                 r = manager_unit_is_active(u->manager, i, &error);
 695                 if (r < 0)
 696                         log_debug_errno(r, "Failed to determine whether unit '%s' is active, ignoring: %s", i, bus_error_message(&error, r));
 697                 if (r != 0)
 698                         return true;
 699         }
 700
 701         return false;
 702 }
 703
 704 static usec_t user_get_stop_delay(User *u) {
 705         assert(u);
 706
 707         if (u->user_record->stop_delay_usec != UINT64_MAX)
 708                 return u->user_record->stop_delay_usec;
 709
 710         if (user_record_removable(u->user_record) > 0)
 711                 return 0; /* For removable users lower the stop delay to zero */
 712
 713         return u->manager->user_stop_delay;
 714 }
 715
 716 static bool user_pinned_by_sessions(User *u) {
 717         assert(u);
 718
 719         /* Returns true if at least one session exists that shall keep the user tracking alive. That
 720          * generally means one session that isn't the service manager still exists. */
 721
 722         switch (u->gc_mode) {
 723
 724         case USER_GC_BY_ANY:
 725                 return u->sessions;
 726
 727         case USER_GC_BY_PIN:
 728                 LIST_FOREACH(sessions_by_user, i, u->sessions)
 729                         if (SESSION_CLASS_PIN_USER(i->class))
 730                                 return true;
 731
 732                 return false;
 733
 734         default:
 735                 assert_not_reached();
 736         }
 737 }
 738
 739 bool user_may_gc(User *u, bool drop_not_started) {
 740         int r;
 741
 742         assert(u);
 743
 744         if (drop_not_started && !u->started)
 745                 return true;
 746
 747         if (user_pinned_by_sessions(u))
 748                 return false;
 749
 750         if (u->last_session_timestamp != USEC_INFINITY) {
 751                 usec_t user_stop_delay;
 752
 753                 /* All sessions have been closed. Let's see if we shall leave the user record around for a bit */
 754
 755                 user_stop_delay = user_get_stop_delay(u);
 756
 757                 if (user_stop_delay == USEC_INFINITY)
 758                         return false; /* Leave it around forever! */
 759                 if (user_stop_delay > 0 &&
 760                     now(CLOCK_MONOTONIC) < usec_add(u->last_session_timestamp, user_stop_delay))
 761                         return false; /* Leave it around for a bit longer. */
 762         }
 763
 764         /* Is this a user that shall stay around forever ("linger")? Before we say "no" to GC'ing for lingering users, let's check
 765          * if any of the three units that we maintain for this user is still around. If none of them is,
 766          * there's no need to keep this user around even if lingering is enabled. */
 767         if (user_check_linger_file(u) > 0 && user_unit_active(u))
 768                 return false;
 769
 770         /* Check if our job is still pending */
 771         const char *j;
 772         FOREACH_ARGUMENT(j, u->runtime_dir_job, u->service_manager_job) {
 773                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 774
 775                 if (!j)
 776                         continue;
 777
 778                 r = manager_job_is_active(u->manager, j, &error);
 779                 if (r < 0)
 780                         log_debug_errno(r, "Failed to determine whether job '%s' is pending, ignoring: %s",
 781                                         j, bus_error_message(&error, r));
 782                 if (r != 0)
 783                         return false;
 784         }
 785
 786         /* Note that we don't care if the three units we manage for each user object are up or not, as we are
 787          * managing their state rather than tracking it. */
 788
 789         return true;
 790 }
 791
 792 void user_add_to_gc_queue(User *u) {
 793         assert(u);
 794
 795         if (u->in_gc_queue)
 796                 return;
 797
 798         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 799         u->in_gc_queue = true;
 800 }
 801
 802 UserState user_get_state(User *u) {
 803         assert(u);
 804
 805         if (u->stopping)
 806                 return USER_CLOSING;
 807
 808         if (!u->started || u->runtime_dir_job)
 809                 return USER_OPENING;
 810
 811         /* USER_GC_BY_PIN: Only pinning sessions count. None -> closing
 812          * USER_GC_BY_ANY: 'manager' sessions also count. However, if lingering is enabled, 'lingering' state
 813          *                 shall be preferred. 'online' if the manager is manually started by user. */
 814
 815         bool has_pinning = false, all_closing = true;
 816         LIST_FOREACH(sessions_by_user, i, u->sessions) {
 817                 bool pinned = SESSION_CLASS_PIN_USER(i->class);
 818
 819                 if (u->gc_mode == USER_GC_BY_PIN && !pinned)
 820                         continue;
 821
 822                 has_pinning = has_pinning || pinned;
 823
 824                 SessionState state = session_get_state(i);
 825                 if (state == SESSION_ACTIVE && pinned)
 826                         return USER_ACTIVE;
 827                 if (state != SESSION_CLOSING)
 828                         all_closing = false;
 829         }
 830
 831         if (!has_pinning && user_check_linger_file(u) > 0 && user_unit_active(u))
 832                 return USER_LINGERING;
 833
 834         return all_closing ? USER_CLOSING : USER_ONLINE;
 835 }
 836
 837 int user_kill(User *u, int signo) {
 838         assert(u);
 839
 840         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 841 }
 842
 843 static bool elect_display_filter(Session *s) {
 844         /* Return true if the session is a candidate for the user’s ‘primary session’ or ‘display’. */
 845         assert(s);
 846
 847         return SESSION_CLASS_CAN_DISPLAY(s->class) && s->started && !s->stopping;
 848 }
 849
 850 static int elect_display_compare(Session *s1, Session *s2) {
 851         /* Indexed by SessionType. Lower numbers mean more preferred. */
 852         static const int type_ranks[_SESSION_TYPE_MAX] = {
 853                 [SESSION_UNSPECIFIED] = 0,
 854                 [SESSION_TTY] = -2,
 855                 [SESSION_X11] = -3,
 856                 [SESSION_WAYLAND] = -3,
 857                 [SESSION_MIR] = -3,
 858                 [SESSION_WEB] = -1,
 859         };
 860
 861         /* Calculate the partial order relationship between s1 and s2,
 862          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 863          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 864          * is preferred.
 865          *
 866          * s1 or s2 may be NULL. */
 867         if (!s1 && !s2)
 868                 return 0;
 869
 870         if ((s1 == NULL) != (s2 == NULL))
 871                 return (s1 == NULL) - (s2 == NULL);
 872
 873         if (s1->stopping != s2->stopping)
 874                 return s1->stopping - s2->stopping;
 875
 876         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 877                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 878
 879         if ((s1->class != SESSION_USER_EARLY) != (s2->class != SESSION_USER_EARLY))
 880                 return (s1->class != SESSION_USER_EARLY) - (s2->class != SESSION_USER_EARLY);
 881
 882         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 883                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 884
 885         if (s1->type != s2->type)
 886                 return type_ranks[s1->type] - type_ranks[s2->type];
 887
 888         return 0;
 889 }
 890
 891 void user_elect_display(User *u) {
 892         assert(u);
 893
 894         /* This elects a primary session for each user, which we call the "display". We try to keep the assignment
 895          * stable, but we "upgrade" to better choices. */
 896         log_debug("Electing new display for user %s", u->user_record->user_name);
 897
 898         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 899                 if (!elect_display_filter(s)) {
 900                         log_debug("Ignoring session %s", s->id);
 901                         continue;
 902                 }
 903
 904                 if (elect_display_compare(s, u->display) < 0) {
 905                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 906                         u->display = s;
 907                 }
 908         }
 909 }
 910
 911 static int user_stop_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
 912         User *u = ASSERT_PTR(userdata);
 913
 914         user_add_to_gc_queue(u);
 915
 916         return 0;
 917 }
 918
 919 void user_update_last_session_timer(User *u) {
 920         usec_t user_stop_delay;
 921         int r;
 922
 923         assert(u);
 924
 925         if (user_pinned_by_sessions(u)) {
 926                 /* There are sessions, turn off the timer */
 927                 u->last_session_timestamp = USEC_INFINITY;
 928                 u->timer_event_source = sd_event_source_unref(u->timer_event_source);
 929                 return;
 930         }
 931
 932         if (u->last_session_timestamp != USEC_INFINITY)
 933                 return; /* Timer already started */
 934
 935         u->last_session_timestamp = now(CLOCK_MONOTONIC);
 936
 937         assert(!u->timer_event_source);
 938
 939         user_stop_delay = user_get_stop_delay(u);
 940         if (!timestamp_is_set(user_stop_delay))
 941                 return;
 942
 943         if (sd_event_get_state(u->manager->event) == SD_EVENT_FINISHED) {
 944                 log_debug("Not allocating user stop timeout, since we are already exiting.");
 945                 return;
 946         }
 947
 948         r = sd_event_add_time(u->manager->event,
 949                               &u->timer_event_source,
 950                               CLOCK_MONOTONIC,
 951                               usec_add(u->last_session_timestamp, user_stop_delay), 0,
 952                               user_stop_timeout_callback, u);
 953         if (r < 0)
 954                 log_warning_errno(r, "Failed to enqueue user stop event source, ignoring: %m");
 955
 956         if (DEBUG_LOGGING)
 957                 log_debug("Last session of user '%s' logged out, terminating user context in %s.",
 958                           u->user_record->user_name,
 959                           FORMAT_TIMESPAN(user_stop_delay, USEC_PER_MSEC));
 960 }
 961
 962 static const char* const user_state_table[_USER_STATE_MAX] = {
 963         [USER_OFFLINE]   = "offline",
 964         [USER_OPENING]   = "opening",
 965         [USER_LINGERING] = "lingering",
 966         [USER_ONLINE]    = "online",
 967         [USER_ACTIVE]    = "active",
 968         [USER_CLOSING]   = "closing"
 969 };
 970
 971 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 972
 973 static const char* const user_gc_mode_table[_USER_GC_MODE_MAX] = {
 974         [USER_GC_BY_PIN] = "pin",
 975         [USER_GC_BY_ANY] = "any",
 976 };
 977
 978 DEFINE_STRING_TABLE_LOOKUP(user_gc_mode, UserGCMode);
 979
 980 int config_parse_tmpfs_size(
 981                 const char *unit,
 982                 const char *filename,
 983                 unsigned line,
 984                 const char *section,
 985                 unsigned section_line,
 986                 const char *lvalue,
 987                 int ltype,
 988                 const char *rvalue,
 989                 void *data,
 990                 void *userdata) {
 991
 992         uint64_t *sz = ASSERT_PTR(data);
 993         int r;
 994
 995         assert(filename);
 996         assert(lvalue);
 997         assert(rvalue);
 998
 999         /* First, try to parse as percentage */
1000         r = parse_permyriad(rvalue);
1001         if (r > 0)
1002                 *sz = physical_memory_scale(r, 10000U);
1003         else {
1004                 uint64_t k;
1005
1006                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
1007
1008                 r = parse_size(rvalue, 1024, &k);
1009                 if (r >= 0 && (k <= 0 || (uint64_t) (size_t) k != k))
1010                         r = -ERANGE;
1011                 if (r < 0) {
1012                         log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse size value '%s', ignoring: %m", rvalue);
1013                         return 0;
1014                 }
1015
1016                 *sz = PAGE_ALIGN((size_t) k);
1017         }
1018
1019         return 0;
1020 }
1021
1022 int config_parse_compat_user_tasks_max(
1023                 const char *unit,
1024                 const char *filename,
1025                 unsigned line,
1026                 const char *section,
1027                 unsigned section_line,
1028                 const char *lvalue,
1029                 int ltype,
1030                 const char *rvalue,
1031                 void *data,
1032                 void *userdata) {
1033
1034         assert(filename);
1035         assert(lvalue);
1036         assert(rvalue);
1037
1038         log_syntax(unit, LOG_NOTICE, filename, line, 0,
1039                    "Support for option %s= has been removed.",
1040                    lvalue);
1041         log_info("Hint: try creating /etc/systemd/system/user-.slice.d/50-limits.conf with:\n"
1042                  "        [Slice]\n"
1043                  "        TasksMax=%s",
1044                  rvalue);
1045         return 0;
1046 }