src/login/logind-user.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2011 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <string.h>
  22 #include <sys/mount.h>
  23 #include <unistd.h>
  24
  25 #include "alloc-util.h"
  26 #include "bus-common-errors.h"
  27 #include "bus-error.h"
  28 #include "bus-util.h"
  29 #include "clean-ipc.h"
  30 #include "conf-parser.h"
  31 #include "escape.h"
  32 #include "fd-util.h"
  33 #include "fileio.h"
  34 #include "formats-util.h"
  35 #include "fs-util.h"
  36 #include "hashmap.h"
  37 #include "label.h"
  38 #include "logind-user.h"
  39 #include "mkdir.h"
  40 #include "mount-util.h"
  41 #include "parse-util.h"
  42 #include "path-util.h"
  43 #include "rm-rf.h"
  44 #include "smack-util.h"
  45 #include "special.h"
  46 #include "stdio-util.h"
  47 #include "string-table.h"
  48 #include "unit-name.h"
  49 #include "user-util.h"
  50 #include "util.h"
  51
  52 int user_new(User **out, Manager *m, uid_t uid, gid_t gid, const char *name) {
  53         _cleanup_(user_freep) User *u = NULL;
  54         char lu[DECIMAL_STR_MAX(uid_t) + 1];
  55         int r;
  56
  57         assert(out);
  58         assert(m);
  59         assert(name);
  60
  61         u = new0(User, 1);
  62         if (!u)
  63                 return -ENOMEM;
  64
  65         u->manager = m;
  66         u->uid = uid;
  67         u->gid = gid;
  68         xsprintf(lu, UID_FMT, uid);
  69
  70         u->name = strdup(name);
  71         if (!u->name)
  72                 return -ENOMEM;
  73
  74         if (asprintf(&u->state_file, "/run/systemd/users/"UID_FMT, uid) < 0)
  75                 return -ENOMEM;
  76
  77         if (asprintf(&u->runtime_path, "/run/user/"UID_FMT, uid) < 0)
  78                 return -ENOMEM;
  79
  80         r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice);
  81         if (r < 0)
  82                 return r;
  83
  84         r = unit_name_build("user", lu, ".service", &u->service);
  85         if (r < 0)
  86                 return r;
  87
  88         r = hashmap_put(m->users, UID_TO_PTR(uid), u);
  89         if (r < 0)
  90                 return r;
  91
  92         r = hashmap_put(m->user_units, u->slice, u);
  93         if (r < 0)
  94                 return r;
  95
  96         r = hashmap_put(m->user_units, u->service, u);
  97         if (r < 0)
  98                 return r;
  99
 100         *out = u;
 101         u = NULL;
 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         if (u->service)
 116                 hashmap_remove_value(u->manager->user_units, u->service, u);
 117
 118         if (u->slice)
 119                 hashmap_remove_value(u->manager->user_units, u->slice, u);
 120
 121         hashmap_remove_value(u->manager->users, UID_TO_PTR(u->uid), u);
 122
 123         u->slice_job = mfree(u->slice_job);
 124         u->service_job = mfree(u->service_job);
 125
 126         u->service = mfree(u->service);
 127         u->slice = mfree(u->slice);
 128         u->runtime_path = mfree(u->runtime_path);
 129         u->state_file = mfree(u->state_file);
 130         u->name = mfree(u->name);
 131
 132         return mfree(u);
 133 }
 134
 135 static int user_save_internal(User *u) {
 136         _cleanup_free_ char *temp_path = NULL;
 137         _cleanup_fclose_ FILE *f = NULL;
 138         int r;
 139
 140         assert(u);
 141         assert(u->state_file);
 142
 143         r = mkdir_safe_label("/run/systemd/users", 0755, 0, 0);
 144         if (r < 0)
 145                 goto fail;
 146
 147         r = fopen_temporary(u->state_file, &f, &temp_path);
 148         if (r < 0)
 149                 goto fail;
 150
 151         fchmod(fileno(f), 0644);
 152
 153         fprintf(f,
 154                 "# This is private data. Do not parse.\n"
 155                 "NAME=%s\n"
 156                 "STATE=%s\n",
 157                 u->name,
 158                 user_state_to_string(user_get_state(u)));
 159
 160         /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */
 161         if (u->runtime_path)
 162                 fprintf(f, "RUNTIME=%s\n", u->runtime_path);
 163
 164         if (u->service_job)
 165                 fprintf(f, "SERVICE_JOB=%s\n", u->service_job);
 166
 167         if (u->slice_job)
 168                 fprintf(f, "SLICE_JOB=%s\n", u->slice_job);
 169
 170         if (u->display)
 171                 fprintf(f, "DISPLAY=%s\n", u->display->id);
 172
 173         if (dual_timestamp_is_set(&u->timestamp))
 174                 fprintf(f,
 175                         "REALTIME="USEC_FMT"\n"
 176                         "MONOTONIC="USEC_FMT"\n",
 177                         u->timestamp.realtime,
 178                         u->timestamp.monotonic);
 179
 180         if (u->sessions) {
 181                 Session *i;
 182                 bool first;
 183
 184                 fputs("SESSIONS=", f);
 185                 first = true;
 186                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 187                         if (first)
 188                                 first = false;
 189                         else
 190                                 fputc(' ', f);
 191
 192                         fputs(i->id, f);
 193                 }
 194
 195                 fputs("\nSEATS=", f);
 196                 first = true;
 197                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 198                         if (!i->seat)
 199                                 continue;
 200
 201                         if (first)
 202                                 first = false;
 203                         else
 204                                 fputc(' ', f);
 205
 206                         fputs(i->seat->id, f);
 207                 }
 208
 209                 fputs("\nACTIVE_SESSIONS=", f);
 210                 first = true;
 211                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 212                         if (!session_is_active(i))
 213                                 continue;
 214
 215                         if (first)
 216                                 first = false;
 217                         else
 218                                 fputc(' ', f);
 219
 220                         fputs(i->id, f);
 221                 }
 222
 223                 fputs("\nONLINE_SESSIONS=", f);
 224                 first = true;
 225                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 226                         if (session_get_state(i) == SESSION_CLOSING)
 227                                 continue;
 228
 229                         if (first)
 230                                 first = false;
 231                         else
 232                                 fputc(' ', f);
 233
 234                         fputs(i->id, f);
 235                 }
 236
 237                 fputs("\nACTIVE_SEATS=", f);
 238                 first = true;
 239                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 240                         if (!session_is_active(i) || !i->seat)
 241                                 continue;
 242
 243                         if (first)
 244                                 first = false;
 245                         else
 246                                 fputc(' ', f);
 247
 248                         fputs(i->seat->id, f);
 249                 }
 250
 251                 fputs("\nONLINE_SEATS=", f);
 252                 first = true;
 253                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 254                         if (session_get_state(i) == SESSION_CLOSING || !i->seat)
 255                                 continue;
 256
 257                         if (first)
 258                                 first = false;
 259                         else
 260                                 fputc(' ', f);
 261
 262                         fputs(i->seat->id, f);
 263                 }
 264                 fputc('\n', f);
 265         }
 266
 267         r = fflush_and_check(f);
 268         if (r < 0)
 269                 goto fail;
 270
 271         if (rename(temp_path, u->state_file) < 0) {
 272                 r = -errno;
 273                 goto fail;
 274         }
 275
 276         return 0;
 277
 278 fail:
 279         (void) unlink(u->state_file);
 280
 281         if (temp_path)
 282                 (void) unlink(temp_path);
 283
 284         return log_error_errno(r, "Failed to save user data %s: %m", u->state_file);
 285 }
 286
 287 int user_save(User *u) {
 288         assert(u);
 289
 290         if (!u->started)
 291                 return 0;
 292
 293         return user_save_internal (u);
 294 }
 295
 296 int user_load(User *u) {
 297         _cleanup_free_ char *display = NULL, *realtime = NULL, *monotonic = NULL;
 298         Session *s = NULL;
 299         int r;
 300
 301         assert(u);
 302
 303         r = parse_env_file(u->state_file, NEWLINE,
 304                            "SERVICE_JOB", &u->service_job,
 305                            "SLICE_JOB",   &u->slice_job,
 306                            "DISPLAY",     &display,
 307                            "REALTIME",    &realtime,
 308                            "MONOTONIC",   &monotonic,
 309                            NULL);
 310         if (r < 0) {
 311                 if (r == -ENOENT)
 312                         return 0;
 313
 314                 log_error_errno(r, "Failed to read %s: %m", u->state_file);
 315                 return r;
 316         }
 317
 318         if (display)
 319                 s = hashmap_get(u->manager->sessions, display);
 320
 321         if (s && s->display && display_is_local(s->display))
 322                 u->display = s;
 323
 324         if (realtime)
 325                 timestamp_deserialize(realtime, &u->timestamp.realtime);
 326         if (monotonic)
 327                 timestamp_deserialize(monotonic, &u->timestamp.monotonic);
 328
 329         return r;
 330 }
 331
 332 static int user_mkdir_runtime_path(User *u) {
 333         int r;
 334
 335         assert(u);
 336
 337         r = mkdir_safe_label("/run/user", 0755, 0, 0);
 338         if (r < 0)
 339                 return log_error_errno(r, "Failed to create /run/user: %m");
 340
 341         if (path_is_mount_point(u->runtime_path, 0) <= 0) {
 342                 _cleanup_free_ char *t = NULL;
 343
 344                 (void) mkdir_label(u->runtime_path, 0700);
 345
 346                 if (mac_smack_use())
 347                         r = asprintf(&t, "mode=0700,smackfsroot=*,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
 348                 else
 349                         r = asprintf(&t, "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
 350                 if (r < 0) {
 351                         r = log_oom();
 352                         goto fail;
 353                 }
 354
 355                 r = mount("tmpfs", u->runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, t);
 356                 if (r < 0) {
 357                         if (errno != EPERM) {
 358                                 r = log_error_errno(errno, "Failed to mount per-user tmpfs directory %s: %m", u->runtime_path);
 359                                 goto fail;
 360                         }
 361
 362                         /* Lacking permissions, maybe
 363                          * CAP_SYS_ADMIN-less container? In this case,
 364                          * just use a normal directory. */
 365
 366                         r = chmod_and_chown(u->runtime_path, 0700, u->uid, u->gid);
 367                         if (r < 0) {
 368                                 log_error_errno(r, "Failed to change runtime directory ownership and mode: %m");
 369                                 goto fail;
 370                         }
 371                 }
 372
 373                 r = label_fix(u->runtime_path, false, false);
 374                 if (r < 0)
 375                         log_warning_errno(r, "Failed to fix label of '%s', ignoring: %m", u->runtime_path);
 376         }
 377
 378         return 0;
 379
 380 fail:
 381         /* Try to clean up, but ignore errors */
 382         (void) rmdir(u->runtime_path);
 383         return r;
 384 }
 385
 386 static int user_start_slice(User *u) {
 387         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 388         const char *description;
 389         char *job;
 390         int r;
 391
 392         assert(u);
 393
 394         u->slice_job = mfree(u->slice_job);
 395         description = strjoina("User Slice of ", u->name);
 396
 397         r = manager_start_slice(
 398                         u->manager,
 399                         u->slice,
 400                         description,
 401                         "systemd-logind.service",
 402                         "systemd-user-sessions.service",
 403                         u->manager->user_tasks_max,
 404                         &error,
 405                         &job);
 406         if (r >= 0)
 407                 u->slice_job = job;
 408         else if (!sd_bus_error_has_name(&error, BUS_ERROR_UNIT_EXISTS))
 409                 /* we don't fail due to this, let's try to continue */
 410                 log_error_errno(r, "Failed to start user slice %s, ignoring: %s (%s)",
 411                                 u->slice, bus_error_message(&error, r), error.name);
 412
 413         return 0;
 414 }
 415
 416 static int user_start_service(User *u) {
 417         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 418         char *job;
 419         int r;
 420
 421         assert(u);
 422
 423         u->service_job = mfree(u->service_job);
 424
 425         r = manager_start_unit(
 426                         u->manager,
 427                         u->service,
 428                         &error,
 429                         &job);
 430         if (r < 0) {
 431                 /* we don't fail due to this, let's try to continue */
 432                 log_error_errno(r, "Failed to start user service, ignoring: %s", bus_error_message(&error, r));
 433         } else {
 434                 u->service_job = job;
 435         }
 436
 437         return 0;
 438 }
 439
 440 int user_start(User *u) {
 441         int r;
 442
 443         assert(u);
 444
 445         if (u->started && !u->stopping)
 446                 return 0;
 447
 448         /*
 449          * If u->stopping is set, the user is marked for removal and the slice
 450          * and service stop-jobs are queued. We have to clear that flag before
 451          * queing the start-jobs again. If they succeed, the user object can be
 452          * re-used just fine (pid1 takes care of job-ordering and proper
 453          * restart), but if they fail, we want to force another user_stop() so
 454          * possibly pending units are stopped.
 455          * Note that we don't clear u->started, as we have no clue what state
 456          * the user is in on failure here. Hence, we pretend the user is
 457          * running so it will be properly taken down by GC. However, we clearly
 458          * return an error from user_start() in that case, so no further
 459          * reference to the user is taken.
 460          */
 461         u->stopping = false;
 462
 463         if (!u->started) {
 464                 log_debug("New user %s logged in.", u->name);
 465
 466                 /* Make XDG_RUNTIME_DIR */
 467                 r = user_mkdir_runtime_path(u);
 468                 if (r < 0)
 469                         return r;
 470         }
 471
 472         /* Create cgroup */
 473         r = user_start_slice(u);
 474         if (r < 0)
 475                 return r;
 476
 477         /* Save the user data so far, because pam_systemd will read the
 478          * XDG_RUNTIME_DIR out of it while starting up systemd --user.
 479          * We need to do user_save_internal() because we have not
 480          * "officially" started yet. */
 481         user_save_internal(u);
 482
 483         /* Spawn user systemd */
 484         r = user_start_service(u);
 485         if (r < 0)
 486                 return r;
 487
 488         if (!u->started) {
 489                 if (!dual_timestamp_is_set(&u->timestamp))
 490                         dual_timestamp_get(&u->timestamp);
 491                 user_send_signal(u, true);
 492                 u->started = true;
 493         }
 494
 495         /* Save new user data */
 496         user_save(u);
 497
 498         return 0;
 499 }
 500
 501 static int user_stop_slice(User *u) {
 502         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 503         char *job;
 504         int r;
 505
 506         assert(u);
 507
 508         r = manager_stop_unit(u->manager, u->slice, &error, &job);
 509         if (r < 0) {
 510                 log_error("Failed to stop user slice: %s", bus_error_message(&error, r));
 511                 return r;
 512         }
 513
 514         free(u->slice_job);
 515         u->slice_job = job;
 516
 517         return r;
 518 }
 519
 520 static int user_stop_service(User *u) {
 521         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 522         char *job;
 523         int r;
 524
 525         assert(u);
 526
 527         r = manager_stop_unit(u->manager, u->service, &error, &job);
 528         if (r < 0) {
 529                 log_error("Failed to stop user service: %s", bus_error_message(&error, r));
 530                 return r;
 531         }
 532
 533         free(u->service_job);
 534         u->service_job = job;
 535
 536         return r;
 537 }
 538
 539 static int user_remove_runtime_path(User *u) {
 540         int r;
 541
 542         assert(u);
 543
 544         r = rm_rf(u->runtime_path, 0);
 545         if (r < 0)
 546                 log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
 547
 548         /* Ignore cases where the directory isn't mounted, as that's
 549          * quite possible, if we lacked the permissions to mount
 550          * something */
 551         r = umount2(u->runtime_path, MNT_DETACH);
 552         if (r < 0 && errno != EINVAL && errno != ENOENT)
 553                 log_error_errno(errno, "Failed to unmount user runtime directory %s: %m", u->runtime_path);
 554
 555         r = rm_rf(u->runtime_path, REMOVE_ROOT);
 556         if (r < 0)
 557                 log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
 558
 559         return r;
 560 }
 561
 562 int user_stop(User *u, bool force) {
 563         Session *s;
 564         int r = 0, k;
 565         assert(u);
 566
 567         /* Stop jobs have already been queued */
 568         if (u->stopping) {
 569                 user_save(u);
 570                 return r;
 571         }
 572
 573         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 574                 k = session_stop(s, force);
 575                 if (k < 0)
 576                         r = k;
 577         }
 578
 579         /* Kill systemd */
 580         k = user_stop_service(u);
 581         if (k < 0)
 582                 r = k;
 583
 584         /* Kill cgroup */
 585         k = user_stop_slice(u);
 586         if (k < 0)
 587                 r = k;
 588
 589         u->stopping = true;
 590
 591         user_save(u);
 592
 593         return r;
 594 }
 595
 596 int user_finalize(User *u) {
 597         Session *s;
 598         int r = 0, k;
 599
 600         assert(u);
 601
 602         if (u->started)
 603                 log_debug("User %s logged out.", u->name);
 604
 605         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 606                 k = session_finalize(s);
 607                 if (k < 0)
 608                         r = k;
 609         }
 610
 611         /* Kill XDG_RUNTIME_DIR */
 612         k = user_remove_runtime_path(u);
 613         if (k < 0)
 614                 r = k;
 615
 616         /* Clean SysV + POSIX IPC objects */
 617         if (u->manager->remove_ipc) {
 618                 k = clean_ipc(u->uid);
 619                 if (k < 0)
 620                         r = k;
 621         }
 622
 623         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         Session *s;
 636         bool idle_hint = true;
 637         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 638
 639         assert(u);
 640
 641         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 642                 dual_timestamp k;
 643                 int ih;
 644
 645                 ih = session_get_idle_hint(s, &k);
 646                 if (ih < 0)
 647                         return ih;
 648
 649                 if (!ih) {
 650                         if (!idle_hint) {
 651                                 if (k.monotonic < ts.monotonic)
 652                                         ts = k;
 653                         } else {
 654                                 idle_hint = false;
 655                                 ts = k;
 656                         }
 657                 } else if (idle_hint) {
 658
 659                         if (k.monotonic > ts.monotonic)
 660                                 ts = k;
 661                 }
 662         }
 663
 664         if (t)
 665                 *t = ts;
 666
 667         return idle_hint;
 668 }
 669
 670 int user_check_linger_file(User *u) {
 671         _cleanup_free_ char *cc = NULL;
 672         char *p = NULL;
 673
 674         cc = cescape(u->name);
 675         if (!cc)
 676                 return -ENOMEM;
 677
 678         p = strjoina("/var/lib/systemd/linger/", cc);
 679
 680         return access(p, F_OK) >= 0;
 681 }
 682
 683 bool user_check_gc(User *u, bool drop_not_started) {
 684         assert(u);
 685
 686         if (drop_not_started && !u->started)
 687                 return false;
 688
 689         if (u->sessions)
 690                 return true;
 691
 692         if (user_check_linger_file(u) > 0)
 693                 return true;
 694
 695         if (u->slice_job && manager_job_is_active(u->manager, u->slice_job))
 696                 return true;
 697
 698         if (u->service_job && manager_job_is_active(u->manager, u->service_job))
 699                 return true;
 700
 701         return false;
 702 }
 703
 704 void user_add_to_gc_queue(User *u) {
 705         assert(u);
 706
 707         if (u->in_gc_queue)
 708                 return;
 709
 710         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 711         u->in_gc_queue = true;
 712 }
 713
 714 UserState user_get_state(User *u) {
 715         Session *i;
 716
 717         assert(u);
 718
 719         if (u->stopping)
 720                 return USER_CLOSING;
 721
 722         if (!u->started || u->slice_job || u->service_job)
 723                 return USER_OPENING;
 724
 725         if (u->sessions) {
 726                 bool all_closing = true;
 727
 728                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 729                         SessionState state;
 730
 731                         state = session_get_state(i);
 732                         if (state == SESSION_ACTIVE)
 733                                 return USER_ACTIVE;
 734                         if (state != SESSION_CLOSING)
 735                                 all_closing = false;
 736                 }
 737
 738                 return all_closing ? USER_CLOSING : USER_ONLINE;
 739         }
 740
 741         if (user_check_linger_file(u) > 0)
 742                 return USER_LINGERING;
 743
 744         return USER_CLOSING;
 745 }
 746
 747 int user_kill(User *u, int signo) {
 748         assert(u);
 749
 750         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 751 }
 752
 753 static bool elect_display_filter(Session *s) {
 754         /* Return true if the session is a candidate for the user’s ‘primary
 755          * session’ or ‘display’. */
 756         assert(s);
 757
 758         return (s->class == SESSION_USER && !s->stopping);
 759 }
 760
 761 static int elect_display_compare(Session *s1, Session *s2) {
 762         /* Indexed by SessionType. Lower numbers mean more preferred. */
 763         const int type_ranks[_SESSION_TYPE_MAX] = {
 764                 [SESSION_UNSPECIFIED] = 0,
 765                 [SESSION_TTY] = -2,
 766                 [SESSION_X11] = -3,
 767                 [SESSION_WAYLAND] = -3,
 768                 [SESSION_MIR] = -3,
 769                 [SESSION_WEB] = -1,
 770         };
 771
 772         /* Calculate the partial order relationship between s1 and s2,
 773          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 774          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 775          * is preferred.
 776          *
 777          * s1 or s2 may be NULL. */
 778         if (!s1 && !s2)
 779                 return 0;
 780
 781         if ((s1 == NULL) != (s2 == NULL))
 782                 return (s1 == NULL) - (s2 == NULL);
 783
 784         if (s1->stopping != s2->stopping)
 785                 return s1->stopping - s2->stopping;
 786
 787         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 788                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 789
 790         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 791                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 792
 793         if (s1->type != s2->type)
 794                 return type_ranks[s1->type] - type_ranks[s2->type];
 795
 796         return 0;
 797 }
 798
 799 void user_elect_display(User *u) {
 800         Session *s;
 801
 802         assert(u);
 803
 804         /* This elects a primary session for each user, which we call
 805          * the "display". We try to keep the assignment stable, but we
 806          * "upgrade" to better choices. */
 807         log_debug("Electing new display for user %s", u->name);
 808
 809         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 810                 if (!elect_display_filter(s)) {
 811                         log_debug("Ignoring session %s", s->id);
 812                         continue;
 813                 }
 814
 815                 if (elect_display_compare(s, u->display) < 0) {
 816                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 817                         u->display = s;
 818                 }
 819         }
 820 }
 821
 822 static const char* const user_state_table[_USER_STATE_MAX] = {
 823         [USER_OFFLINE] = "offline",
 824         [USER_OPENING] = "opening",
 825         [USER_LINGERING] = "lingering",
 826         [USER_ONLINE] = "online",
 827         [USER_ACTIVE] = "active",
 828         [USER_CLOSING] = "closing"
 829 };
 830
 831 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 832
 833 int config_parse_tmpfs_size(
 834                 const char* unit,
 835                 const char *filename,
 836                 unsigned line,
 837                 const char *section,
 838                 unsigned section_line,
 839                 const char *lvalue,
 840                 int ltype,
 841                 const char *rvalue,
 842                 void *data,
 843                 void *userdata) {
 844
 845         size_t *sz = data;
 846         int r;
 847
 848         assert(filename);
 849         assert(lvalue);
 850         assert(rvalue);
 851         assert(data);
 852
 853         /* First, try to parse as percentage */
 854         r = parse_percent(rvalue);
 855         if (r > 0 && r < 100)
 856                 *sz = physical_memory_scale(r, 100U);
 857         else {
 858                 uint64_t k;
 859
 860                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
 861
 862                 r = parse_size(rvalue, 1024, &k);
 863                 if (r < 0 || k <= 0 || (uint64_t) (size_t) k != k) {
 864                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse size value, ignoring: %s", rvalue);
 865                         return 0;
 866                 }
 867
 868                 *sz = PAGE_ALIGN((size_t) k);
 869         }
 870
 871         return 0;
 872 }
 873
 874 int config_parse_user_tasks_max(
 875                 const char* unit,
 876                 const char *filename,
 877                 unsigned line,
 878                 const char *section,
 879                 unsigned section_line,
 880                 const char *lvalue,
 881                 int ltype,
 882                 const char *rvalue,
 883                 void *data,
 884                 void *userdata) {
 885
 886         uint64_t *m = data;
 887         uint64_t k;
 888         int r;
 889
 890         assert(filename);
 891         assert(lvalue);
 892         assert(rvalue);
 893         assert(data);
 894
 895         /* First, try to parse as percentage */
 896         r = parse_percent(rvalue);
 897         if (r > 0 && r < 100)
 898                 k = system_tasks_max_scale(r, 100U);
 899         else {
 900
 901                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
 902
 903                 r = safe_atou64(rvalue, &k);
 904                 if (r < 0) {
 905                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse tasks maximum, ignoring: %s", rvalue);
 906                         return 0;
 907                 }
 908         }
 909
 910         if (k <= 0 || k >= UINT64_MAX) {
 911                 log_syntax(unit, LOG_ERR, filename, line, 0, "Tasks maximum out of range, ignoring: %s", rvalue);
 912                 return 0;
 913         }
 914
 915         *m = k;
 916         return 0;
 917 }