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-util.h"
  10 #include "cgroup-util.h"
  11 #include "clean-ipc.h"
  12 #include "env-file.h"
  13 #include "escape.h"
  14 #include "fd-util.h"
  15 #include "fileio.h"
  16 #include "format-util.h"
  17 #include "fs-util.h"
  18 #include "hashmap.h"
  19 #include "label.h"
  20 #include "limits-util.h"
  21 #include "logind-dbus.h"
  22 #include "logind-user-dbus.h"
  23 #include "logind-user.h"
  24 #include "mkdir-label.h"
  25 #include "parse-util.h"
  26 #include "path-util.h"
  27 #include "percent-util.h"
  28 #include "rm-rf.h"
  29 #include "serialize.h"
  30 #include "special.h"
  31 #include "stdio-util.h"
  32 #include "string-table.h"
  33 #include "strv.h"
  34 #include "tmpfile-util.h"
  35 #include "uid-alloc-range.h"
  36 #include "unit-name.h"
  37 #include "user-util.h"
  38
  39 int user_new(User **ret,
  40              Manager *m,
  41              UserRecord *ur) {
  42
  43         _cleanup_(user_freep) User *u = NULL;
  44         char lu[DECIMAL_STR_MAX(uid_t) + 1];
  45         int r;
  46
  47         assert(ret);
  48         assert(m);
  49         assert(ur);
  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         };
  66
  67         if (asprintf(&u->state_file, "/run/systemd/users/" UID_FMT, ur->uid) < 0)
  68                 return -ENOMEM;
  69
  70         if (asprintf(&u->runtime_path, "/run/user/" UID_FMT, ur->uid) < 0)
  71                 return -ENOMEM;
  72
  73         xsprintf(lu, UID_FMT, ur->uid);
  74         r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice);
  75         if (r < 0)
  76                 return r;
  77
  78         r = unit_name_build("user", lu, ".service", &u->service);
  79         if (r < 0)
  80                 return r;
  81
  82         r = unit_name_build("user-runtime-dir", lu, ".service", &u->runtime_dir_service);
  83         if (r < 0)
  84                 return r;
  85
  86         r = hashmap_put(m->users, UID_TO_PTR(ur->uid), u);
  87         if (r < 0)
  88                 return r;
  89
  90         r = hashmap_put(m->user_units, u->slice, u);
  91         if (r < 0)
  92                 return r;
  93
  94         r = hashmap_put(m->user_units, u->service, u);
  95         if (r < 0)
  96                 return r;
  97
  98         r = hashmap_put(m->user_units, u->runtime_dir_service, u);
  99         if (r < 0)
 100                 return r;
 101
 102         *ret = TAKE_PTR(u);
 103         return 0;
 104 }
 105
 106 User *user_free(User *u) {
 107         if (!u)
 108                 return NULL;
 109
 110         if (u->in_gc_queue)
 111                 LIST_REMOVE(gc_queue, u->manager->user_gc_queue, u);
 112
 113         while (u->sessions)
 114                 session_free(u->sessions);
 115
 116         if (u->service)
 117                 hashmap_remove_value(u->manager->user_units, u->service, u);
 118
 119         if (u->runtime_dir_service)
 120                 hashmap_remove_value(u->manager->user_units, u->runtime_dir_service, u);
 121
 122         if (u->slice)
 123                 hashmap_remove_value(u->manager->user_units, u->slice, u);
 124
 125         hashmap_remove_value(u->manager->users, UID_TO_PTR(u->user_record->uid), u);
 126
 127         sd_event_source_unref(u->timer_event_source);
 128
 129         u->service_job = mfree(u->service_job);
 130
 131         u->service = mfree(u->service);
 132         u->runtime_dir_service = mfree(u->runtime_dir_service);
 133         u->slice = mfree(u->slice);
 134         u->runtime_path = mfree(u->runtime_path);
 135         u->state_file = mfree(u->state_file);
 136
 137         user_record_unref(u->user_record);
 138
 139         return mfree(u);
 140 }
 141
 142 static int user_save_internal(User *u) {
 143         _cleanup_(unlink_and_freep) char *temp_path = NULL;
 144         _cleanup_fclose_ FILE *f = NULL;
 145         int r;
 146
 147         assert(u);
 148         assert(u->state_file);
 149
 150         r = mkdir_safe_label("/run/systemd/users", 0755, 0, 0, MKDIR_WARN_MODE);
 151         if (r < 0)
 152                 goto fail;
 153
 154         r = fopen_temporary(u->state_file, &f, &temp_path);
 155         if (r < 0)
 156                 goto fail;
 157
 158         (void) fchmod(fileno(f), 0644);
 159
 160         fprintf(f,
 161                 "# This is private data. Do not parse.\n"
 162                 "NAME=%s\n"
 163                 "STATE=%s\n"         /* friendly user-facing state */
 164                 "STOPPING=%s\n",     /* low-level state */
 165                 u->user_record->user_name,
 166                 user_state_to_string(user_get_state(u)),
 167                 yes_no(u->stopping));
 168
 169         /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */
 170         if (u->runtime_path)
 171                 fprintf(f, "RUNTIME=%s\n", u->runtime_path);
 172
 173         if (u->service_job)
 174                 fprintf(f, "SERVICE_JOB=%s\n", u->service_job);
 175
 176         if (u->display)
 177                 fprintf(f, "DISPLAY=%s\n", u->display->id);
 178
 179         if (dual_timestamp_is_set(&u->timestamp))
 180                 fprintf(f,
 181                         "REALTIME="USEC_FMT"\n"
 182                         "MONOTONIC="USEC_FMT"\n",
 183                         u->timestamp.realtime,
 184                         u->timestamp.monotonic);
 185
 186         if (u->last_session_timestamp != USEC_INFINITY)
 187                 fprintf(f, "LAST_SESSION_TIMESTAMP=" USEC_FMT "\n",
 188                         u->last_session_timestamp);
 189
 190         if (u->sessions) {
 191                 bool first;
 192
 193                 fputs("SESSIONS=", f);
 194                 first = true;
 195                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 196                         if (first)
 197                                 first = false;
 198                         else
 199                                 fputc(' ', f);
 200
 201                         fputs(i->id, f);
 202                 }
 203
 204                 fputs("\nSEATS=", f);
 205                 first = true;
 206                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 207                         if (!i->seat)
 208                                 continue;
 209
 210                         if (first)
 211                                 first = false;
 212                         else
 213                                 fputc(' ', f);
 214
 215                         fputs(i->seat->id, f);
 216                 }
 217
 218                 fputs("\nACTIVE_SESSIONS=", f);
 219                 first = true;
 220                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 221                         if (!session_is_active(i))
 222                                 continue;
 223
 224                         if (first)
 225                                 first = false;
 226                         else
 227                                 fputc(' ', f);
 228
 229                         fputs(i->id, f);
 230                 }
 231
 232                 fputs("\nONLINE_SESSIONS=", f);
 233                 first = true;
 234                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 235                         if (session_get_state(i) == SESSION_CLOSING)
 236                                 continue;
 237
 238                         if (first)
 239                                 first = false;
 240                         else
 241                                 fputc(' ', f);
 242
 243                         fputs(i->id, f);
 244                 }
 245
 246                 fputs("\nACTIVE_SEATS=", f);
 247                 first = true;
 248                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 249                         if (!session_is_active(i) || !i->seat)
 250                                 continue;
 251
 252                         if (first)
 253                                 first = false;
 254                         else
 255                                 fputc(' ', f);
 256
 257                         fputs(i->seat->id, f);
 258                 }
 259
 260                 fputs("\nONLINE_SEATS=", f);
 261                 first = true;
 262                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 263                         if (session_get_state(i) == SESSION_CLOSING || !i->seat)
 264                                 continue;
 265
 266                         if (first)
 267                                 first = false;
 268                         else
 269                                 fputc(' ', f);
 270
 271                         fputs(i->seat->id, f);
 272                 }
 273                 fputc('\n', f);
 274         }
 275
 276         r = fflush_and_check(f);
 277         if (r < 0)
 278                 goto fail;
 279
 280         if (rename(temp_path, u->state_file) < 0) {
 281                 r = -errno;
 282                 goto fail;
 283         }
 284
 285         temp_path = mfree(temp_path);
 286         return 0;
 287
 288 fail:
 289         (void) unlink(u->state_file);
 290
 291         return log_error_errno(r, "Failed to save user data %s: %m", u->state_file);
 292 }
 293
 294 int user_save(User *u) {
 295         assert(u);
 296
 297         if (!u->started)
 298                 return 0;
 299
 300         return user_save_internal(u);
 301 }
 302
 303 int user_load(User *u) {
 304         _cleanup_free_ char *realtime = NULL, *monotonic = NULL, *stopping = NULL, *last_session_timestamp = NULL;
 305         int r;
 306
 307         assert(u);
 308
 309         r = parse_env_file(NULL, u->state_file,
 310                            "SERVICE_JOB",            &u->service_job,
 311                            "STOPPING",               &stopping,
 312                            "REALTIME",               &realtime,
 313                            "MONOTONIC",              &monotonic,
 314                            "LAST_SESSION_TIMESTAMP", &last_session_timestamp);
 315         if (r == -ENOENT)
 316                 return 0;
 317         if (r < 0)
 318                 return log_error_errno(r, "Failed to read %s: %m", u->state_file);
 319
 320         if (stopping) {
 321                 r = parse_boolean(stopping);
 322                 if (r < 0)
 323                         log_debug_errno(r, "Failed to parse 'STOPPING' boolean: %s", stopping);
 324                 else
 325                         u->stopping = r;
 326         }
 327
 328         if (realtime)
 329                 (void) deserialize_usec(realtime, &u->timestamp.realtime);
 330         if (monotonic)
 331                 (void) deserialize_usec(monotonic, &u->timestamp.monotonic);
 332         if (last_session_timestamp)
 333                 (void) deserialize_usec(last_session_timestamp, &u->last_session_timestamp);
 334
 335         return 0;
 336 }
 337
 338 static void user_start_service(User *u) {
 339         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 340         int r;
 341
 342         assert(u);
 343
 344         /* Start the service containing the "systemd --user" instance (user@.service). Note that we don't explicitly
 345          * start the per-user slice or the systemd-runtime-dir@.service instance, as those are pulled in both by
 346          * user@.service and the session scopes as dependencies. */
 347
 348         u->service_job = mfree(u->service_job);
 349
 350         r = manager_start_unit(u->manager, u->service, &error, &u->service_job);
 351         if (r < 0)
 352                 log_full_errno(sd_bus_error_has_name(&error, BUS_ERROR_UNIT_MASKED) ? LOG_DEBUG : LOG_WARNING, r,
 353                                "Failed to start user service '%s', ignoring: %s", u->service, bus_error_message(&error, r));
 354 }
 355
 356 static int update_slice_callback(sd_bus_message *m, void *userdata, sd_bus_error *ret_error) {
 357         _cleanup_(user_record_unrefp) UserRecord *ur = ASSERT_PTR(userdata);
 358         const sd_bus_error *e;
 359         int r;
 360
 361         assert(m);
 362
 363         e = sd_bus_message_get_error(m);
 364         if (e) {
 365                 r = sd_bus_error_get_errno(e);
 366                 log_warning_errno(r,
 367                                   "Failed to update slice of %s, ignoring: %s",
 368                                   ur->user_name,
 369                                   bus_error_message(e, r));
 370
 371                 return 0;
 372         }
 373
 374         log_debug("Successfully set slice parameters of %s.", ur->user_name);
 375         return 0;
 376 }
 377
 378 static int user_update_slice(User *u) {
 379         _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
 380         int r;
 381
 382         assert(u);
 383
 384         if (u->user_record->tasks_max == UINT64_MAX &&
 385             u->user_record->memory_high == UINT64_MAX &&
 386             u->user_record->memory_max == UINT64_MAX &&
 387             u->user_record->cpu_weight == UINT64_MAX &&
 388             u->user_record->io_weight == UINT64_MAX)
 389                 return 0;
 390
 391         r = sd_bus_message_new_method_call(
 392                         u->manager->bus,
 393                         &m,
 394                         "org.freedesktop.systemd1",
 395                         "/org/freedesktop/systemd1",
 396                         "org.freedesktop.systemd1.Manager",
 397                         "SetUnitProperties");
 398         if (r < 0)
 399                 return bus_log_create_error(r);
 400
 401         r = sd_bus_message_append(m, "sb", u->slice, true);
 402         if (r < 0)
 403                 return bus_log_create_error(r);
 404
 405         r = sd_bus_message_open_container(m, 'a', "(sv)");
 406         if (r < 0)
 407                 return bus_log_create_error(r);
 408
 409         const struct {
 410                 const char *name;
 411                 uint64_t value;
 412         } settings[] = {
 413                 { "TasksMax",   u->user_record->tasks_max   },
 414                 { "MemoryMax",  u->user_record->memory_max  },
 415                 { "MemoryHigh", u->user_record->memory_high },
 416                 { "CPUWeight",  u->user_record->cpu_weight  },
 417                 { "IOWeight",   u->user_record->io_weight   },
 418         };
 419
 420         for (size_t i = 0; i < ELEMENTSOF(settings); i++)
 421                 if (settings[i].value != UINT64_MAX) {
 422                         r = sd_bus_message_append(m, "(sv)", settings[i].name, "t", settings[i].value);
 423                         if (r < 0)
 424                                 return bus_log_create_error(r);
 425                 }
 426
 427         r = sd_bus_message_close_container(m);
 428         if (r < 0)
 429                 return bus_log_create_error(r);
 430
 431         r = sd_bus_call_async(u->manager->bus, NULL, m, update_slice_callback, u->user_record, 0);
 432         if (r < 0)
 433                 return log_error_errno(r, "Failed to change user slice properties: %m");
 434
 435         /* Ref the user record pointer, so that the slot keeps it pinned */
 436         user_record_ref(u->user_record);
 437
 438         return 0;
 439 }
 440
 441 int user_start(User *u) {
 442         assert(u);
 443
 444         if (u->started && !u->stopping)
 445                 return 0;
 446
 447         /* If u->stopping is set, the user is marked for removal and service stop-jobs are queued. We have to clear
 448          * that flag before queueing the start-jobs again. If they succeed, the user object can be re-used just fine
 449          * (pid1 takes care of job-ordering and proper restart), but if they fail, we want to force another user_stop()
 450          * so possibly pending units are stopped. */
 451         u->stopping = false;
 452
 453         if (!u->started)
 454                 log_debug("Starting services for new user %s.", u->user_record->user_name);
 455
 456         /* Save the user data so far, because pam_systemd will read the XDG_RUNTIME_DIR out of it while starting up
 457          * systemd --user.  We need to do user_save_internal() because we have not "officially" started yet. */
 458         user_save_internal(u);
 459
 460         /* Set slice parameters */
 461         (void) user_update_slice(u);
 462
 463         /* Start user@UID.service */
 464         user_start_service(u);
 465
 466         if (!u->started) {
 467                 if (!dual_timestamp_is_set(&u->timestamp))
 468                         dual_timestamp_get(&u->timestamp);
 469                 user_send_signal(u, true);
 470                 u->started = true;
 471         }
 472
 473         /* Save new user data */
 474         user_save(u);
 475
 476         return 0;
 477 }
 478
 479 static void user_stop_service(User *u, bool force) {
 480         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 481         int r;
 482
 483         assert(u);
 484         assert(u->service);
 485
 486         /* The reverse of user_start_service(). Note that we only stop user@UID.service here, and let StopWhenUnneeded=
 487          * deal with the slice and the user-runtime-dir@.service instance. */
 488
 489         u->service_job = mfree(u->service_job);
 490
 491         r = manager_stop_unit(u->manager, u->service, force ? "replace" : "fail", &error, &u->service_job);
 492         if (r < 0)
 493                 log_warning_errno(r, "Failed to stop user service '%s', ignoring: %s", u->service, bus_error_message(&error, r));
 494 }
 495
 496 int user_stop(User *u, bool force) {
 497         int r = 0;
 498
 499         assert(u);
 500
 501         /* This is called whenever we begin with tearing down a user record. It's called in two cases: explicit API
 502          * request to do so via the bus (in which case 'force' is true) and automatically due to GC, if there's no
 503          * session left pinning it (in which case 'force' is false). Note that this just initiates tearing down of the
 504          * user, the User object will remain in memory until user_finalize() is called, see below. */
 505
 506         if (!u->started)
 507                 return 0;
 508
 509         if (u->stopping) { /* Stop jobs have already been queued */
 510                 user_save(u);
 511                 return 0;
 512         }
 513
 514         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 515                 int k;
 516
 517                 k = session_stop(s, force);
 518                 if (k < 0)
 519                         r = k;
 520         }
 521
 522         user_stop_service(u, force);
 523
 524         u->stopping = true;
 525
 526         user_save(u);
 527
 528         return r;
 529 }
 530
 531 int user_finalize(User *u) {
 532         int r = 0, k;
 533
 534         assert(u);
 535
 536         /* Called when the user is really ready to be freed, i.e. when all unit stop jobs and suchlike for it are
 537          * done. This is called as a result of an earlier user_done() when all jobs are completed. */
 538
 539         if (u->started)
 540                 log_debug("User %s logged out.", u->user_record->user_name);
 541
 542         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 543                 k = session_finalize(s);
 544                 if (k < 0)
 545                         r = k;
 546         }
 547
 548         /* Clean SysV + POSIX IPC objects, but only if this is not a system user. Background: in many setups cronjobs
 549          * are run in full PAM and thus logind sessions, even if the code run doesn't belong to actual users but to
 550          * system components. Since enable RemoveIPC= globally for all users, we need to be a bit careful with such
 551          * cases, as we shouldn't accidentally remove a system service's IPC objects while it is running, just because
 552          * a cronjob running as the same user just finished. Hence: exclude system users generally from IPC clean-up,
 553          * and do it only for normal users. */
 554         if (u->manager->remove_ipc && !uid_is_system(u->user_record->uid)) {
 555                 k = clean_ipc_by_uid(u->user_record->uid);
 556                 if (k < 0)
 557                         r = k;
 558         }
 559
 560         (void) unlink(u->state_file);
 561         user_add_to_gc_queue(u);
 562
 563         if (u->started) {
 564                 user_send_signal(u, false);
 565                 u->started = false;
 566         }
 567
 568         return r;
 569 }
 570
 571 int user_get_idle_hint(User *u, dual_timestamp *t) {
 572         bool idle_hint = true;
 573         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 574
 575         assert(u);
 576
 577         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 578                 dual_timestamp k;
 579                 int ih;
 580
 581                 ih = session_get_idle_hint(s, &k);
 582                 if (ih < 0)
 583                         return ih;
 584
 585                 if (!ih) {
 586                         if (!idle_hint) {
 587                                 if (k.monotonic < ts.monotonic)
 588                                         ts = k;
 589                         } else {
 590                                 idle_hint = false;
 591                                 ts = k;
 592                         }
 593                 } else if (idle_hint) {
 594
 595                         if (k.monotonic > ts.monotonic)
 596                                 ts = k;
 597                 }
 598         }
 599
 600         if (t)
 601                 *t = ts;
 602
 603         return idle_hint;
 604 }
 605
 606 int user_check_linger_file(User *u) {
 607         _cleanup_free_ char *cc = NULL;
 608         char *p = NULL;
 609
 610         cc = cescape(u->user_record->user_name);
 611         if (!cc)
 612                 return -ENOMEM;
 613
 614         p = strjoina("/var/lib/systemd/linger/", cc);
 615         if (access(p, F_OK) < 0) {
 616                 if (errno != ENOENT)
 617                         return -errno;
 618
 619                 return false;
 620         }
 621
 622         return true;
 623 }
 624
 625 static bool user_unit_active(User *u) {
 626         int r;
 627
 628         assert(u->service);
 629         assert(u->runtime_dir_service);
 630         assert(u->slice);
 631
 632         FOREACH_STRING(i, u->service, u->runtime_dir_service, u->slice) {
 633                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 634
 635                 r = manager_unit_is_active(u->manager, i, &error);
 636                 if (r < 0)
 637                         log_debug_errno(r, "Failed to determine whether unit '%s' is active, ignoring: %s", i, bus_error_message(&error, r));
 638                 if (r != 0)
 639                         return true;
 640         }
 641
 642         return false;
 643 }
 644
 645 static usec_t user_get_stop_delay(User *u) {
 646         assert(u);
 647
 648         if (u->user_record->stop_delay_usec != UINT64_MAX)
 649                 return u->user_record->stop_delay_usec;
 650
 651         if (user_record_removable(u->user_record) > 0)
 652                 return 0; /* For removable users lower the stop delay to zero */
 653
 654         return u->manager->user_stop_delay;
 655 }
 656
 657 bool user_may_gc(User *u, bool drop_not_started) {
 658         int r;
 659
 660         assert(u);
 661
 662         if (drop_not_started && !u->started)
 663                 return true;
 664
 665         if (u->sessions)
 666                 return false;
 667
 668         if (u->last_session_timestamp != USEC_INFINITY) {
 669                 usec_t user_stop_delay;
 670
 671                 /* All sessions have been closed. Let's see if we shall leave the user record around for a bit */
 672
 673                 user_stop_delay = user_get_stop_delay(u);
 674
 675                 if (user_stop_delay == USEC_INFINITY)
 676                         return false; /* Leave it around forever! */
 677                 if (user_stop_delay > 0 &&
 678                     now(CLOCK_MONOTONIC) < usec_add(u->last_session_timestamp, user_stop_delay))
 679                         return false; /* Leave it around for a bit longer. */
 680         }
 681
 682         /* Is this a user that shall stay around forever ("linger")? Before we say "no" to GC'ing for lingering users, let's check
 683          * if any of the three units that we maintain for this user is still around. If none of them is,
 684          * there's no need to keep this user around even if lingering is enabled. */
 685         if (user_check_linger_file(u) > 0 && user_unit_active(u))
 686                 return false;
 687
 688         /* Check if our job is still pending */
 689         if (u->service_job) {
 690                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 691
 692                 r = manager_job_is_active(u->manager, u->service_job, &error);
 693                 if (r < 0)
 694                         log_debug_errno(r, "Failed to determine whether job '%s' is pending, ignoring: %s", u->service_job, bus_error_message(&error, r));
 695                 if (r != 0)
 696                         return false;
 697         }
 698
 699         /* Note that we don't care if the three units we manage for each user object are up or not, as we are managing
 700          * their state rather than tracking it. */
 701
 702         return true;
 703 }
 704
 705 void user_add_to_gc_queue(User *u) {
 706         assert(u);
 707
 708         if (u->in_gc_queue)
 709                 return;
 710
 711         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 712         u->in_gc_queue = true;
 713 }
 714
 715 UserState user_get_state(User *u) {
 716         assert(u);
 717
 718         if (u->stopping)
 719                 return USER_CLOSING;
 720
 721         if (!u->started || u->service_job)
 722                 return USER_OPENING;
 723
 724         if (u->sessions) {
 725                 bool all_closing = true;
 726
 727                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 728                         SessionState state;
 729
 730                         state = session_get_state(i);
 731                         if (state == SESSION_ACTIVE)
 732                                 return USER_ACTIVE;
 733                         if (state != SESSION_CLOSING)
 734                                 all_closing = false;
 735                 }
 736
 737                 return all_closing ? USER_CLOSING : USER_ONLINE;
 738         }
 739
 740         if (user_check_linger_file(u) > 0 && user_unit_active(u))
 741                 return USER_LINGERING;
 742
 743         return USER_CLOSING;
 744 }
 745
 746 int user_kill(User *u, int signo) {
 747         assert(u);
 748
 749         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 750 }
 751
 752 static bool elect_display_filter(Session *s) {
 753         /* Return true if the session is a candidate for the user’s ‘primary session’ or ‘display’. */
 754         assert(s);
 755
 756         return IN_SET(s->class, SESSION_USER, SESSION_GREETER) && s->started && !s->stopping;
 757 }
 758
 759 static int elect_display_compare(Session *s1, Session *s2) {
 760         /* Indexed by SessionType. Lower numbers mean more preferred. */
 761         static const int type_ranks[_SESSION_TYPE_MAX] = {
 762                 [SESSION_UNSPECIFIED] = 0,
 763                 [SESSION_TTY] = -2,
 764                 [SESSION_X11] = -3,
 765                 [SESSION_WAYLAND] = -3,
 766                 [SESSION_MIR] = -3,
 767                 [SESSION_WEB] = -1,
 768         };
 769
 770         /* Calculate the partial order relationship between s1 and s2,
 771          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 772          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 773          * is preferred.
 774          *
 775          * s1 or s2 may be NULL. */
 776         if (!s1 && !s2)
 777                 return 0;
 778
 779         if ((s1 == NULL) != (s2 == NULL))
 780                 return (s1 == NULL) - (s2 == NULL);
 781
 782         if (s1->stopping != s2->stopping)
 783                 return s1->stopping - s2->stopping;
 784
 785         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 786                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 787
 788         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 789                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 790
 791         if (s1->type != s2->type)
 792                 return type_ranks[s1->type] - type_ranks[s2->type];
 793
 794         return 0;
 795 }
 796
 797 void user_elect_display(User *u) {
 798         assert(u);
 799
 800         /* This elects a primary session for each user, which we call the "display". We try to keep the assignment
 801          * stable, but we "upgrade" to better choices. */
 802         log_debug("Electing new display for user %s", u->user_record->user_name);
 803
 804         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 805                 if (!elect_display_filter(s)) {
 806                         log_debug("Ignoring session %s", s->id);
 807                         continue;
 808                 }
 809
 810                 if (elect_display_compare(s, u->display) < 0) {
 811                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 812                         u->display = s;
 813                 }
 814         }
 815 }
 816
 817 static int user_stop_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
 818         User *u = ASSERT_PTR(userdata);
 819
 820         user_add_to_gc_queue(u);
 821
 822         return 0;
 823 }
 824
 825 void user_update_last_session_timer(User *u) {
 826         usec_t user_stop_delay;
 827         int r;
 828
 829         assert(u);
 830
 831         if (u->sessions) {
 832                 /* There are sessions, turn off the timer */
 833                 u->last_session_timestamp = USEC_INFINITY;
 834                 u->timer_event_source = sd_event_source_unref(u->timer_event_source);
 835                 return;
 836         }
 837
 838         if (u->last_session_timestamp != USEC_INFINITY)
 839                 return; /* Timer already started */
 840
 841         u->last_session_timestamp = now(CLOCK_MONOTONIC);
 842
 843         assert(!u->timer_event_source);
 844
 845         user_stop_delay = user_get_stop_delay(u);
 846         if (!timestamp_is_set(user_stop_delay))
 847                 return;
 848
 849         if (sd_event_get_state(u->manager->event) == SD_EVENT_FINISHED) {
 850                 log_debug("Not allocating user stop timeout, since we are already exiting.");
 851                 return;
 852         }
 853
 854         r = sd_event_add_time(u->manager->event,
 855                               &u->timer_event_source,
 856                               CLOCK_MONOTONIC,
 857                               usec_add(u->last_session_timestamp, user_stop_delay), 0,
 858                               user_stop_timeout_callback, u);
 859         if (r < 0)
 860                 log_warning_errno(r, "Failed to enqueue user stop event source, ignoring: %m");
 861
 862         if (DEBUG_LOGGING)
 863                 log_debug("Last session of user '%s' logged out, terminating user context in %s.",
 864                           u->user_record->user_name,
 865                           FORMAT_TIMESPAN(user_stop_delay, USEC_PER_MSEC));
 866 }
 867
 868 static const char* const user_state_table[_USER_STATE_MAX] = {
 869         [USER_OFFLINE] = "offline",
 870         [USER_OPENING] = "opening",
 871         [USER_LINGERING] = "lingering",
 872         [USER_ONLINE] = "online",
 873         [USER_ACTIVE] = "active",
 874         [USER_CLOSING] = "closing"
 875 };
 876
 877 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 878
 879 int config_parse_tmpfs_size(
 880                 const char* unit,
 881                 const char *filename,
 882                 unsigned line,
 883                 const char *section,
 884                 unsigned section_line,
 885                 const char *lvalue,
 886                 int ltype,
 887                 const char *rvalue,
 888                 void *data,
 889                 void *userdata) {
 890
 891         uint64_t *sz = ASSERT_PTR(data);
 892         int r;
 893
 894         assert(filename);
 895         assert(lvalue);
 896         assert(rvalue);
 897
 898         /* First, try to parse as percentage */
 899         r = parse_permyriad(rvalue);
 900         if (r > 0)
 901                 *sz = physical_memory_scale(r, 10000U);
 902         else {
 903                 uint64_t k;
 904
 905                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
 906
 907                 r = parse_size(rvalue, 1024, &k);
 908                 if (r >= 0 && (k <= 0 || (uint64_t) (size_t) k != k))
 909                         r = -ERANGE;
 910                 if (r < 0) {
 911                         log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse size value '%s', ignoring: %m", rvalue);
 912                         return 0;
 913                 }
 914
 915                 *sz = PAGE_ALIGN((size_t) k);
 916         }
 917
 918         return 0;
 919 }
 920
 921 int config_parse_compat_user_tasks_max(
 922                 const char *unit,
 923                 const char *filename,
 924                 unsigned line,
 925                 const char *section,
 926                 unsigned section_line,
 927                 const char *lvalue,
 928                 int ltype,
 929                 const char *rvalue,
 930                 void *data,
 931                 void *userdata) {
 932
 933         assert(filename);
 934         assert(lvalue);
 935         assert(rvalue);
 936
 937         log_syntax(unit, LOG_NOTICE, filename, line, 0,
 938                    "Support for option %s= has been removed.",
 939                    lvalue);
 940         log_info("Hint: try creating /etc/systemd/system/user-.slice.d/50-limits.conf with:\n"
 941                  "        [Slice]\n"
 942                  "        TasksMax=%s",
 943                  rvalue);
 944         return 0;
 945 }