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(Manager *m, UserRecord *ur, User **ret) {
  41         _cleanup_(user_freep) User *u = NULL;
  42         char lu[DECIMAL_STR_MAX(uid_t) + 1];
  43         int r;
  44
  45         assert(m);
  46         assert(ur);
  47         assert(ret);
  48
  49         if (!ur->user_name)
  50                 return -EINVAL;
  51
  52         if (!uid_is_valid(ur->uid))
  53                 return -EINVAL;
  54
  55         u = new(User, 1);
  56         if (!u)
  57                 return -ENOMEM;
  58
  59         *u = (User) {
  60                 .manager = m,
  61                 .user_record = user_record_ref(ur),
  62                 .last_session_timestamp = USEC_INFINITY,
  63                 .gc_mode = USER_GC_BY_ANY,
  64         };
  65
  66         if (asprintf(&u->state_file, "/run/systemd/users/" UID_FMT, ur->uid) < 0)
  67                 return -ENOMEM;
  68
  69         if (asprintf(&u->runtime_path, "/run/user/" UID_FMT, ur->uid) < 0)
  70                 return -ENOMEM;
  71
  72         xsprintf(lu, UID_FMT, ur->uid);
  73         r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice);
  74         if (r < 0)
  75                 return r;
  76
  77         r = unit_name_build("user-runtime-dir", lu, ".service", &u->runtime_dir_unit);
  78         if (r < 0)
  79                 return r;
  80
  81         r = unit_name_build("user", lu, ".service", &u->service_manager_unit);
  82         if (r < 0)
  83                 return r;
  84
  85         r = hashmap_put(m->users, UID_TO_PTR(ur->uid), u);
  86         if (r < 0)
  87                 return r;
  88
  89         r = hashmap_put(m->user_units, u->slice, u);
  90         if (r < 0)
  91                 return r;
  92
  93         r = hashmap_put(m->user_units, u->runtime_dir_unit, u);
  94         if (r < 0)
  95                 return r;
  96
  97         r = hashmap_put(m->user_units, u->service_manager_unit, u);
  98         if (r < 0)
  99                 return r;
 100
 101         *ret = TAKE_PTR(u);
 102         return 0;
 103 }
 104
 105 User *user_free(User *u) {
 106         if (!u)
 107                 return NULL;
 108
 109         if (u->in_gc_queue)
 110                 LIST_REMOVE(gc_queue, u->manager->user_gc_queue, u);
 111
 112         while (u->sessions)
 113                 session_free(u->sessions);
 114
 115         sd_event_source_unref(u->timer_event_source);
 116
 117         if (u->service_manager_unit) {
 118                 (void) hashmap_remove_value(u->manager->user_units, u->service_manager_unit, u);
 119                 free(u->service_manager_job);
 120                 free(u->service_manager_unit);
 121         }
 122
 123         if (u->runtime_dir_unit) {
 124                 (void) hashmap_remove_value(u->manager->user_units, u->runtime_dir_unit, u);
 125                 free(u->runtime_dir_job);
 126                 free(u->runtime_dir_unit);
 127         }
 128
 129         if (u->slice) {
 130                 (void) hashmap_remove_value(u->manager->user_units, u->slice, u);
 131                 free(u->slice);
 132         }
 133
 134         (void) hashmap_remove_value(u->manager->users, UID_TO_PTR(u->user_record->uid), u);
 135
 136         free(u->runtime_path);
 137         free(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->runtime_dir_job)
 178                 fprintf(f, "RUNTIME_DIR_JOB=%s\n", u->runtime_dir_job);
 179
 180         if (u->service_manager_job)
 181                 fprintf(f, "SERVICE_JOB=%s\n", u->service_manager_job);
 182
 183         if (u->display)
 184                 fprintf(f, "DISPLAY=%s\n", u->display->id);
 185
 186         if (dual_timestamp_is_set(&u->timestamp))
 187                 fprintf(f,
 188                         "REALTIME="USEC_FMT"\n"
 189                         "MONOTONIC="USEC_FMT"\n",
 190                         u->timestamp.realtime,
 191                         u->timestamp.monotonic);
 192
 193         if (u->last_session_timestamp != USEC_INFINITY)
 194                 fprintf(f, "LAST_SESSION_TIMESTAMP=" USEC_FMT "\n",
 195                         u->last_session_timestamp);
 196
 197         if (u->sessions) {
 198                 bool first;
 199
 200                 fputs("SESSIONS=", f);
 201                 first = true;
 202                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 203                         if (first)
 204                                 first = false;
 205                         else
 206                                 fputc(' ', f);
 207
 208                         fputs(i->id, f);
 209                 }
 210
 211                 fputs("\nSEATS=", f);
 212                 first = true;
 213                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 214                         if (!i->seat)
 215                                 continue;
 216
 217                         if (first)
 218                                 first = false;
 219                         else
 220                                 fputc(' ', f);
 221
 222                         fputs(i->seat->id, f);
 223                 }
 224
 225                 fputs("\nACTIVE_SESSIONS=", f);
 226                 first = true;
 227                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 228                         if (!session_is_active(i))
 229                                 continue;
 230
 231                         if (first)
 232                                 first = false;
 233                         else
 234                                 fputc(' ', f);
 235
 236                         fputs(i->id, f);
 237                 }
 238
 239                 fputs("\nONLINE_SESSIONS=", f);
 240                 first = true;
 241                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 242                         if (session_get_state(i) == SESSION_CLOSING)
 243                                 continue;
 244
 245                         if (first)
 246                                 first = false;
 247                         else
 248                                 fputc(' ', f);
 249
 250                         fputs(i->id, f);
 251                 }
 252
 253                 fputs("\nACTIVE_SEATS=", f);
 254                 first = true;
 255                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 256                         if (!session_is_active(i) || !i->seat)
 257                                 continue;
 258
 259                         if (first)
 260                                 first = false;
 261                         else
 262                                 fputc(' ', f);
 263
 264                         fputs(i->seat->id, f);
 265                 }
 266
 267                 fputs("\nONLINE_SEATS=", f);
 268                 first = true;
 269                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 270                         if (session_get_state(i) == SESSION_CLOSING || !i->seat)
 271                                 continue;
 272
 273                         if (first)
 274                                 first = false;
 275                         else
 276                                 fputc(' ', f);
 277
 278                         fputs(i->seat->id, f);
 279                 }
 280                 fputc('\n', f);
 281         }
 282
 283         r = fflush_and_check(f);
 284         if (r < 0)
 285                 goto fail;
 286
 287         if (rename(temp_path, u->state_file) < 0) {
 288                 r = -errno;
 289                 goto fail;
 290         }
 291
 292         temp_path = mfree(temp_path);
 293         return 0;
 294
 295 fail:
 296         (void) unlink(u->state_file);
 297
 298         return log_error_errno(r, "Failed to save user data %s: %m", u->state_file);
 299 }
 300
 301 int user_save(User *u) {
 302         assert(u);
 303
 304         if (!u->started)
 305                 return 0;
 306
 307         return user_save_internal(u);
 308 }
 309
 310 int user_load(User *u) {
 311         _cleanup_free_ char *realtime = NULL, *monotonic = NULL, *stopping = NULL, *last_session_timestamp = NULL, *gc_mode = NULL;
 312         int r;
 313
 314         assert(u);
 315
 316         r = parse_env_file(NULL, u->state_file,
 317                            "RUNTIME_DIR_JOB",        &u->runtime_dir_job,
 318                            "SERVICE_JOB",            &u->service_manager_job,
 319                            "STOPPING",               &stopping,
 320                            "REALTIME",               &realtime,
 321                            "MONOTONIC",              &monotonic,
 322                            "LAST_SESSION_TIMESTAMP", &last_session_timestamp,
 323                            "GC_MODE",                &gc_mode);
 324         if (r == -ENOENT)
 325                 return 0;
 326         if (r < 0)
 327                 return log_error_errno(r, "Failed to read %s: %m", u->state_file);
 328
 329         if (stopping) {
 330                 r = parse_boolean(stopping);
 331                 if (r < 0)
 332                         log_debug_errno(r, "Failed to parse 'STOPPING' boolean: %s", stopping);
 333                 else {
 334                         u->stopping = r;
 335                         if (u->stopping && !u->runtime_dir_job)
 336                                 log_debug("User '%s' is stopping, but no job is being tracked.", u->user_record->user_name);
 337                 }
 338         }
 339
 340         if (realtime)
 341                 (void) deserialize_usec(realtime, &u->timestamp.realtime);
 342         if (monotonic)
 343                 (void) deserialize_usec(monotonic, &u->timestamp.monotonic);
 344         if (last_session_timestamp)
 345                 (void) deserialize_usec(last_session_timestamp, &u->last_session_timestamp);
 346
 347         u->gc_mode = user_gc_mode_from_string(gc_mode);
 348         if (u->gc_mode < 0)
 349                 u->gc_mode = USER_GC_BY_PIN;
 350
 351         return 0;
 352 }
 353
 354 static int user_start_runtime_dir(User *u) {
 355         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 356         int r;
 357
 358         assert(u);
 359         assert(!u->stopping);
 360         assert(u->manager);
 361         assert(u->runtime_dir_unit);
 362
 363         u->runtime_dir_job = mfree(u->runtime_dir_job);
 364
 365         r = manager_start_unit(u->manager, u->runtime_dir_unit, &error, &u->runtime_dir_job);
 366         if (r < 0)
 367                 return log_full_errno(sd_bus_error_has_name(&error, BUS_ERROR_UNIT_MASKED) ? LOG_DEBUG : LOG_ERR,
 368                                       r, "Failed to start user service '%s': %s",
 369                                       u->runtime_dir_unit, bus_error_message(&error, r));
 370
 371         return 0;
 372 }
 373
 374 static bool user_wants_service_manager(User *u) {
 375         assert(u);
 376
 377         LIST_FOREACH(sessions_by_user, s, u->sessions)
 378                 if (SESSION_CLASS_WANTS_SERVICE_MANAGER(s->class))
 379                         return true;
 380
 381         return false;
 382 }
 383
 384 int user_start_service_manager(User *u) {
 385         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 386         int r;
 387
 388         assert(u);
 389         assert(!u->stopping);
 390         assert(u->manager);
 391         assert(u->service_manager_unit);
 392
 393         if (u->service_manager_started)
 394                 return 1;
 395
 396         /* Only start user service manager if there's at least one session which wants it */
 397         if (!user_wants_service_manager(u))
 398                 return 0;
 399
 400         u->service_manager_job = mfree(u->service_manager_job);
 401
 402         r = manager_start_unit(u->manager, u->service_manager_unit, &error, &u->service_manager_job);
 403         if (r < 0) {
 404                 if (sd_bus_error_has_name(&error, BUS_ERROR_UNIT_MASKED))
 405                         return 0;
 406
 407                 return log_error_errno(r, "Failed to start user service '%s': %s",
 408                                        u->service_manager_unit, bus_error_message(&error, r));
 409         }
 410
 411         return (u->service_manager_started = true);
 412 }
 413
 414 static int update_slice_callback(sd_bus_message *m, void *userdata, sd_bus_error *ret_error) {
 415         _cleanup_(user_record_unrefp) UserRecord *ur = ASSERT_PTR(userdata);
 416         const sd_bus_error *e;
 417         int r;
 418
 419         assert(m);
 420
 421         e = sd_bus_message_get_error(m);
 422         if (e) {
 423                 r = sd_bus_error_get_errno(e);
 424                 log_warning_errno(r,
 425                                   "Failed to update slice of %s, ignoring: %s",
 426                                   ur->user_name,
 427                                   bus_error_message(e, r));
 428
 429                 return 0;
 430         }
 431
 432         log_debug("Successfully set slice parameters of %s.", ur->user_name);
 433         return 0;
 434 }
 435
 436 static int user_update_slice(User *u) {
 437         _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
 438         int r;
 439
 440         assert(u);
 441
 442         if (u->user_record->tasks_max == UINT64_MAX &&
 443             u->user_record->memory_high == UINT64_MAX &&
 444             u->user_record->memory_max == UINT64_MAX &&
 445             u->user_record->cpu_weight == UINT64_MAX &&
 446             u->user_record->io_weight == UINT64_MAX)
 447                 return 0;
 448
 449         r = bus_message_new_method_call(u->manager->bus, &m, bus_systemd_mgr, "SetUnitProperties");
 450         if (r < 0)
 451                 return bus_log_create_error(r);
 452
 453         r = sd_bus_message_append(m, "sb", u->slice, true);
 454         if (r < 0)
 455                 return bus_log_create_error(r);
 456
 457         r = sd_bus_message_open_container(m, 'a', "(sv)");
 458         if (r < 0)
 459                 return bus_log_create_error(r);
 460
 461         const struct {
 462                 const char *name;
 463                 uint64_t value;
 464         } settings[] = {
 465                 { "TasksMax",   u->user_record->tasks_max   },
 466                 { "MemoryMax",  u->user_record->memory_max  },
 467                 { "MemoryHigh", u->user_record->memory_high },
 468                 { "CPUWeight",  u->user_record->cpu_weight  },
 469                 { "IOWeight",   u->user_record->io_weight   },
 470         };
 471
 472         FOREACH_ELEMENT(st, settings) {
 473                 if (st->value == UINT64_MAX)
 474                         continue;
 475
 476                 r = sd_bus_message_append(m, "(sv)", st->name, "t", st->value);
 477                 if (r < 0)
 478                         return bus_log_create_error(r);
 479         }
 480
 481         r = sd_bus_message_close_container(m);
 482         if (r < 0)
 483                 return bus_log_create_error(r);
 484
 485         r = sd_bus_call_async(u->manager->bus, NULL, m, update_slice_callback, u->user_record, 0);
 486         if (r < 0)
 487                 return log_error_errno(r, "Failed to change user slice properties: %m");
 488
 489         /* Ref the user record pointer, so that the slot keeps it pinned */
 490         user_record_ref(u->user_record);
 491
 492         return 0;
 493 }
 494
 495 int user_start(User *u) {
 496         int r;
 497
 498         assert(u);
 499
 500         if (u->service_manager_started) {
 501                 /* Everything is up. No action needed. */
 502                 assert(u->started && !u->stopping);
 503                 return 0;
 504         }
 505
 506         if (!u->started || u->stopping) {
 507                 /* If u->stopping is set, the user is marked for removal and service stop-jobs are queued.
 508                  * We have to clear that flag before queueing the start-jobs again. If they succeed, the
 509                  * user object can be re-used just fine (pid1 takes care of job-ordering and proper restart),
 510                  * but if they fail, we want to force another user_stop() so possibly pending units are
 511                  * stopped. */
 512                 u->stopping = false;
 513
 514                 if (!u->started)
 515                         log_debug("Tracking new user %s.", u->user_record->user_name);
 516
 517                 /* Save the user data so far, because pam_systemd will read the XDG_RUNTIME_DIR out of it
 518                  * while starting up systemd --user. We need to do user_save_internal() because we have not
 519                  * "officially" started yet. */
 520                 user_save_internal(u);
 521
 522                 /* Set slice parameters */
 523                 (void) user_update_slice(u);
 524
 525                 (void) user_start_runtime_dir(u);
 526         }
 527
 528         /* Start user@UID.service if needed. */
 529         r = user_start_service_manager(u);
 530         if (r < 0)
 531                 return r;
 532
 533         if (!u->started) {
 534                 if (!dual_timestamp_is_set(&u->timestamp))
 535                         dual_timestamp_now(&u->timestamp);
 536
 537                 user_send_signal(u, true);
 538                 u->started = true;
 539         }
 540
 541         /* Save new user data */
 542         user_save(u);
 543
 544         return 0;
 545 }
 546
 547 static void user_stop_service(User *u, bool force) {
 548         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 549         int r;
 550
 551         assert(u);
 552         assert(u->manager);
 553         assert(u->runtime_dir_unit);
 554
 555         /* Note that we only stop user-runtime-dir@.service here, and let BindsTo= deal with the user@.service
 556          * instance. However, we still need to clear service_manager_job here, so that if the stop is
 557          * interrupted, the new sessions won't be confused by leftovers. */
 558
 559         u->service_manager_job = mfree(u->service_manager_job);
 560         u->service_manager_started = false;
 561
 562         u->runtime_dir_job = mfree(u->runtime_dir_job);
 563
 564         r = manager_stop_unit(u->manager, u->runtime_dir_unit, force ? "replace" : "fail", &error, &u->runtime_dir_job);
 565         if (r < 0)
 566                 log_warning_errno(r, "Failed to stop user service '%s', ignoring: %s",
 567                                   u->runtime_dir_unit, bus_error_message(&error, r));
 568 }
 569
 570 int user_stop(User *u, bool force) {
 571         int r = 0;
 572
 573         assert(u);
 574
 575         /* This is called whenever we begin with tearing down a user record. It's called in two cases: explicit API
 576          * request to do so via the bus (in which case 'force' is true) and automatically due to GC, if there's no
 577          * session left pinning it (in which case 'force' is false). Note that this just initiates tearing down of the
 578          * user, the User object will remain in memory until user_finalize() is called, see below. */
 579
 580         if (!u->started)
 581                 return 0;
 582
 583         if (u->stopping) { /* Stop jobs have already been queued */
 584                 user_save(u);
 585                 return 0;
 586         }
 587
 588         LIST_FOREACH(sessions_by_user, s, u->sessions)
 589                 RET_GATHER(r, session_stop(s, force));
 590
 591         user_stop_service(u, force);
 592
 593         u->stopping = true;
 594
 595         user_save(u);
 596
 597         return r;
 598 }
 599
 600 int user_finalize(User *u) {
 601         int r = 0;
 602
 603         assert(u);
 604
 605         /* Called when the user is really ready to be freed, i.e. when all unit stop jobs and suchlike for it are
 606          * done. This is called as a result of an earlier user_done() when all jobs are completed. */
 607
 608         if (u->started)
 609                 log_debug("User %s exited.", u->user_record->user_name);
 610
 611         LIST_FOREACH(sessions_by_user, s, u->sessions)
 612                 RET_GATHER(r, session_finalize(s));
 613
 614         /* Clean SysV + POSIX IPC objects, but only if this is not a system user. Background: in many setups cronjobs
 615          * are run in full PAM and thus logind sessions, even if the code run doesn't belong to actual users but to
 616          * system components. Since enable RemoveIPC= globally for all users, we need to be a bit careful with such
 617          * cases, as we shouldn't accidentally remove a system service's IPC objects while it is running, just because
 618          * a cronjob running as the same user just finished. Hence: exclude system users generally from IPC clean-up,
 619          * and do it only for normal users. */
 620         if (u->manager->remove_ipc && !uid_is_system(u->user_record->uid))
 621                 RET_GATHER(r, clean_ipc_by_uid(u->user_record->uid));
 622
 623         (void) unlink(u->state_file);
 624         user_add_to_gc_queue(u);
 625
 626         if (u->started) {
 627                 user_send_signal(u, false);
 628                 u->started = false;
 629         }
 630
 631         return r;
 632 }
 633
 634 int user_get_idle_hint(User *u, dual_timestamp *t) {
 635         bool idle_hint = true;
 636         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 637
 638         assert(u);
 639
 640         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 641                 dual_timestamp k;
 642                 int ih;
 643
 644                 if (!SESSION_CLASS_CAN_IDLE(s->class))
 645                         continue;
 646
 647                 ih = session_get_idle_hint(s, &k);
 648                 if (ih < 0)
 649                         return ih;
 650
 651                 if (!ih) {
 652                         if (!idle_hint) {
 653                                 if (k.monotonic < ts.monotonic)
 654                                         ts = k;
 655                         } else {
 656                                 idle_hint = false;
 657                                 ts = k;
 658                         }
 659                 } else if (idle_hint) {
 660
 661                         if (k.monotonic > ts.monotonic)
 662                                 ts = k;
 663                 }
 664         }
 665
 666         if (t)
 667                 *t = ts;
 668
 669         return idle_hint;
 670 }
 671
 672 int user_check_linger_file(User *u) {
 673         _cleanup_free_ char *cc = NULL;
 674         char *p = NULL;
 675
 676         cc = cescape(u->user_record->user_name);
 677         if (!cc)
 678                 return -ENOMEM;
 679
 680         p = strjoina("/var/lib/systemd/linger/", cc);
 681         if (access(p, F_OK) < 0) {
 682                 if (errno != ENOENT)
 683                         return -errno;
 684
 685                 return false;
 686         }
 687
 688         return true;
 689 }
 690
 691 static bool user_unit_active(User *u) {
 692         int r;
 693
 694         assert(u->slice);
 695         assert(u->runtime_dir_unit);
 696         assert(u->service_manager_unit);
 697
 698         FOREACH_STRING(i, u->slice, u->runtime_dir_unit, u->service_manager_unit) {
 699                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 700
 701                 r = manager_unit_is_active(u->manager, i, &error);
 702                 if (r < 0)
 703                         log_debug_errno(r, "Failed to determine whether unit '%s' is active, ignoring: %s", i, bus_error_message(&error, r));
 704                 if (r != 0)
 705                         return true;
 706         }
 707
 708         return false;
 709 }
 710
 711 static usec_t user_get_stop_delay(User *u) {
 712         assert(u);
 713
 714         if (u->user_record->stop_delay_usec != UINT64_MAX)
 715                 return u->user_record->stop_delay_usec;
 716
 717         if (user_record_removable(u->user_record) > 0)
 718                 return 0; /* For removable users lower the stop delay to zero */
 719
 720         return u->manager->user_stop_delay;
 721 }
 722
 723 static bool user_pinned_by_sessions(User *u) {
 724         assert(u);
 725
 726         /* Returns true if at least one session exists that shall keep the user tracking alive. That
 727          * generally means one session that isn't the service manager still exists. */
 728
 729         switch (u->gc_mode) {
 730
 731         case USER_GC_BY_ANY:
 732                 return u->sessions;
 733
 734         case USER_GC_BY_PIN:
 735                 LIST_FOREACH(sessions_by_user, i, u->sessions)
 736                         if (SESSION_CLASS_PIN_USER(i->class))
 737                                 return true;
 738
 739                 return false;
 740
 741         default:
 742                 assert_not_reached();
 743         }
 744 }
 745
 746 bool user_may_gc(User *u, bool drop_not_started) {
 747         int r;
 748
 749         assert(u);
 750
 751         if (drop_not_started && !u->started)
 752                 return true;
 753
 754         if (user_pinned_by_sessions(u))
 755                 return false;
 756
 757         if (u->last_session_timestamp != USEC_INFINITY) {
 758                 usec_t user_stop_delay;
 759
 760                 /* All sessions have been closed. Let's see if we shall leave the user record around for a bit */
 761
 762                 user_stop_delay = user_get_stop_delay(u);
 763
 764                 if (user_stop_delay == USEC_INFINITY)
 765                         return false; /* Leave it around forever! */
 766                 if (user_stop_delay > 0 &&
 767                     now(CLOCK_MONOTONIC) < usec_add(u->last_session_timestamp, user_stop_delay))
 768                         return false; /* Leave it around for a bit longer. */
 769         }
 770
 771         /* Is this a user that shall stay around forever ("linger")? Before we say "no" to GC'ing for lingering users, let's check
 772          * if any of the three units that we maintain for this user is still around. If none of them is,
 773          * there's no need to keep this user around even if lingering is enabled. */
 774         if (user_check_linger_file(u) > 0 && user_unit_active(u))
 775                 return false;
 776
 777         /* Check if our job is still pending */
 778         const char *j;
 779         FOREACH_ARGUMENT(j, u->runtime_dir_job, u->service_manager_job) {
 780                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 781
 782                 if (!j)
 783                         continue;
 784
 785                 r = manager_job_is_active(u->manager, j, &error);
 786                 if (r < 0)
 787                         log_debug_errno(r, "Failed to determine whether job '%s' is pending, ignoring: %s",
 788                                         j, bus_error_message(&error, r));
 789                 if (r != 0)
 790                         return false;
 791         }
 792
 793         /* Note that we don't care if the three units we manage for each user object are up or not, as we are
 794          * managing their state rather than tracking it. */
 795
 796         return true;
 797 }
 798
 799 void user_add_to_gc_queue(User *u) {
 800         assert(u);
 801
 802         if (u->in_gc_queue)
 803                 return;
 804
 805         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 806         u->in_gc_queue = true;
 807 }
 808
 809 UserState user_get_state(User *u) {
 810         assert(u);
 811
 812         if (u->stopping)
 813                 return USER_CLOSING;
 814
 815         if (!u->started || u->runtime_dir_job)
 816                 return USER_OPENING;
 817
 818         bool any = false, all_closing = true;
 819         LIST_FOREACH(sessions_by_user, i, u->sessions) {
 820                 SessionState state;
 821
 822                 /* Ignore sessions that don't pin the user, i.e. are not supposed to have an effect on user state */
 823                 if (!SESSION_CLASS_PIN_USER(i->class))
 824                         continue;
 825
 826                 state = session_get_state(i);
 827                 if (state == SESSION_ACTIVE)
 828                         return USER_ACTIVE;
 829                 if (state != SESSION_CLOSING)
 830                         all_closing = false;
 831
 832                 any = true;
 833         }
 834
 835         if (any)
 836                 return all_closing ? USER_CLOSING : USER_ONLINE;
 837
 838         if (user_check_linger_file(u) > 0 && user_unit_active(u))
 839                 return USER_LINGERING;
 840
 841         return USER_CLOSING;
 842 }
 843
 844 int user_kill(User *u, int signo) {
 845         assert(u);
 846
 847         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 848 }
 849
 850 static bool elect_display_filter(Session *s) {
 851         /* Return true if the session is a candidate for the user’s ‘primary session’ or ‘display’. */
 852         assert(s);
 853
 854         return SESSION_CLASS_CAN_DISPLAY(s->class) && s->started && !s->stopping;
 855 }
 856
 857 static int elect_display_compare(Session *s1, Session *s2) {
 858         /* Indexed by SessionType. Lower numbers mean more preferred. */
 859         static const int type_ranks[_SESSION_TYPE_MAX] = {
 860                 [SESSION_UNSPECIFIED] = 0,
 861                 [SESSION_TTY] = -2,
 862                 [SESSION_X11] = -3,
 863                 [SESSION_WAYLAND] = -3,
 864                 [SESSION_MIR] = -3,
 865                 [SESSION_WEB] = -1,
 866         };
 867
 868         /* Calculate the partial order relationship between s1 and s2,
 869          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 870          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 871          * is preferred.
 872          *
 873          * s1 or s2 may be NULL. */
 874         if (!s1 && !s2)
 875                 return 0;
 876
 877         if ((s1 == NULL) != (s2 == NULL))
 878                 return (s1 == NULL) - (s2 == NULL);
 879
 880         if (s1->stopping != s2->stopping)
 881                 return s1->stopping - s2->stopping;
 882
 883         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 884                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 885
 886         if ((s1->class != SESSION_USER_EARLY) != (s2->class != SESSION_USER_EARLY))
 887                 return (s1->class != SESSION_USER_EARLY) - (s2->class != SESSION_USER_EARLY);
 888
 889         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 890                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 891
 892         if (s1->type != s2->type)
 893                 return type_ranks[s1->type] - type_ranks[s2->type];
 894
 895         return 0;
 896 }
 897
 898 void user_elect_display(User *u) {
 899         assert(u);
 900
 901         /* This elects a primary session for each user, which we call the "display". We try to keep the assignment
 902          * stable, but we "upgrade" to better choices. */
 903         log_debug("Electing new display for user %s", u->user_record->user_name);
 904
 905         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 906                 if (!elect_display_filter(s)) {
 907                         log_debug("Ignoring session %s", s->id);
 908                         continue;
 909                 }
 910
 911                 if (elect_display_compare(s, u->display) < 0) {
 912                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 913                         u->display = s;
 914                 }
 915         }
 916 }
 917
 918 static int user_stop_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
 919         User *u = ASSERT_PTR(userdata);
 920
 921         user_add_to_gc_queue(u);
 922
 923         return 0;
 924 }
 925
 926 void user_update_last_session_timer(User *u) {
 927         usec_t user_stop_delay;
 928         int r;
 929
 930         assert(u);
 931
 932         if (user_pinned_by_sessions(u)) {
 933                 /* There are sessions, turn off the timer */
 934                 u->last_session_timestamp = USEC_INFINITY;
 935                 u->timer_event_source = sd_event_source_unref(u->timer_event_source);
 936                 return;
 937         }
 938
 939         if (u->last_session_timestamp != USEC_INFINITY)
 940                 return; /* Timer already started */
 941
 942         u->last_session_timestamp = now(CLOCK_MONOTONIC);
 943
 944         assert(!u->timer_event_source);
 945
 946         user_stop_delay = user_get_stop_delay(u);
 947         if (!timestamp_is_set(user_stop_delay))
 948                 return;
 949
 950         if (sd_event_get_state(u->manager->event) == SD_EVENT_FINISHED) {
 951                 log_debug("Not allocating user stop timeout, since we are already exiting.");
 952                 return;
 953         }
 954
 955         r = sd_event_add_time(u->manager->event,
 956                               &u->timer_event_source,
 957                               CLOCK_MONOTONIC,
 958                               usec_add(u->last_session_timestamp, user_stop_delay), 0,
 959                               user_stop_timeout_callback, u);
 960         if (r < 0)
 961                 log_warning_errno(r, "Failed to enqueue user stop event source, ignoring: %m");
 962
 963         if (DEBUG_LOGGING)
 964                 log_debug("Last session of user '%s' logged out, terminating user context in %s.",
 965                           u->user_record->user_name,
 966                           FORMAT_TIMESPAN(user_stop_delay, USEC_PER_MSEC));
 967 }
 968
 969 static const char* const user_state_table[_USER_STATE_MAX] = {
 970         [USER_OFFLINE]   = "offline",
 971         [USER_OPENING]   = "opening",
 972         [USER_LINGERING] = "lingering",
 973         [USER_ONLINE]    = "online",
 974         [USER_ACTIVE]    = "active",
 975         [USER_CLOSING]   = "closing"
 976 };
 977
 978 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 979
 980 static const char* const user_gc_mode_table[_USER_GC_MODE_MAX] = {
 981         [USER_GC_BY_PIN] = "pin",
 982         [USER_GC_BY_ANY] = "any",
 983 };
 984
 985 DEFINE_STRING_TABLE_LOOKUP(user_gc_mode, UserGCMode);
 986
 987 int config_parse_tmpfs_size(
 988                 const char* unit,
 989                 const char *filename,
 990                 unsigned line,
 991                 const char *section,
 992                 unsigned section_line,
 993                 const char *lvalue,
 994                 int ltype,
 995                 const char *rvalue,
 996                 void *data,
 997                 void *userdata) {
 998
 999         uint64_t *sz = ASSERT_PTR(data);
1000         int r;
1001
1002         assert(filename);
1003         assert(lvalue);
1004         assert(rvalue);
1005
1006         /* First, try to parse as percentage */
1007         r = parse_permyriad(rvalue);
1008         if (r > 0)
1009                 *sz = physical_memory_scale(r, 10000U);
1010         else {
1011                 uint64_t k;
1012
1013                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
1014
1015                 r = parse_size(rvalue, 1024, &k);
1016                 if (r >= 0 && (k <= 0 || (uint64_t) (size_t) k != k))
1017                         r = -ERANGE;
1018                 if (r < 0) {
1019                         log_syntax(unit, LOG_WARNING, filename, line, r, "Failed to parse size value '%s', ignoring: %m", rvalue);
1020                         return 0;
1021                 }
1022
1023                 *sz = PAGE_ALIGN((size_t) k);
1024         }
1025
1026         return 0;
1027 }
1028
1029 int config_parse_compat_user_tasks_max(
1030                 const char *unit,
1031                 const char *filename,
1032                 unsigned line,
1033                 const char *section,
1034                 unsigned section_line,
1035                 const char *lvalue,
1036                 int ltype,
1037                 const char *rvalue,
1038                 void *data,
1039                 void *userdata) {
1040
1041         assert(filename);
1042         assert(lvalue);
1043         assert(rvalue);
1044
1045         log_syntax(unit, LOG_NOTICE, filename, line, 0,
1046                    "Support for option %s= has been removed.",
1047                    lvalue);
1048         log_info("Hint: try creating /etc/systemd/system/user-.slice.d/50-limits.conf with:\n"
1049                  "        [Slice]\n"
1050                  "        TasksMax=%s",
1051                  rvalue);
1052         return 0;
1053 }