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("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 #if 0 /// elogind neither supports slice nor service jobs.
 124         u->slice_job = mfree(u->slice_job);
 125         u->service_job = mfree(u->service_job);
 126 #endif // 0
 127         u->service = mfree(u->service);
 128         u->slice = mfree(u->slice);
 129         u->runtime_path = mfree(u->runtime_path);
 130         u->state_file = mfree(u->state_file);
 131         u->name = mfree(u->name);
 132
 133         return mfree(u);
 134 }
 135
 136 static int user_save_internal(User *u) {
 137         _cleanup_free_ char *temp_path = NULL;
 138         _cleanup_fclose_ FILE *f = NULL;
 139         int r;
 140
 141         assert(u);
 142         assert(u->state_file);
 143
 144         r = mkdir_safe_label("/run/systemd/users", 0755, 0, 0);
 145         if (r < 0)
 146                 goto fail;
 147
 148         r = fopen_temporary(u->state_file, &f, &temp_path);
 149         if (r < 0)
 150                 goto fail;
 151
 152         fchmod(fileno(f), 0644);
 153
 154         fprintf(f,
 155                 "# This is private data. Do not parse.\n"
 156                 "NAME=%s\n"
 157                 "STATE=%s\n",
 158                 u->name,
 159                 user_state_to_string(user_get_state(u)));
 160
 161         /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */
 162         if (u->runtime_path)
 163                 fprintf(f, "RUNTIME=%s\n", u->runtime_path);
 164
 165 #if 0 /// elogind neither supports service nor slice jobs
 166         if (u->service_job)
 167                 fprintf(f, "SERVICE_JOB=%s\n", u->service_job);
 168
 169         if (u->slice_job)
 170                 fprintf(f, "SLICE_JOB=%s\n", u->slice_job);
 171 #endif // 0
 172
 173         if (u->display)
 174                 fprintf(f, "DISPLAY=%s\n", u->display->id);
 175
 176         if (dual_timestamp_is_set(&u->timestamp))
 177                 fprintf(f,
 178                         "REALTIME="USEC_FMT"\n"
 179                         "MONOTONIC="USEC_FMT"\n",
 180                         u->timestamp.realtime,
 181                         u->timestamp.monotonic);
 182
 183         if (u->sessions) {
 184                 Session *i;
 185                 bool first;
 186
 187                 fputs("SESSIONS=", f);
 188                 first = true;
 189                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 190                         if (first)
 191                                 first = false;
 192                         else
 193                                 fputc(' ', f);
 194
 195                         fputs(i->id, f);
 196                 }
 197
 198                 fputs("\nSEATS=", f);
 199                 first = true;
 200                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 201                         if (!i->seat)
 202                                 continue;
 203
 204                         if (first)
 205                                 first = false;
 206                         else
 207                                 fputc(' ', f);
 208
 209                         fputs(i->seat->id, f);
 210                 }
 211
 212                 fputs("\nACTIVE_SESSIONS=", f);
 213                 first = true;
 214                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 215                         if (!session_is_active(i))
 216                                 continue;
 217
 218                         if (first)
 219                                 first = false;
 220                         else
 221                                 fputc(' ', f);
 222
 223                         fputs(i->id, f);
 224                 }
 225
 226                 fputs("\nONLINE_SESSIONS=", f);
 227                 first = true;
 228                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 229                         if (session_get_state(i) == SESSION_CLOSING)
 230                                 continue;
 231
 232                         if (first)
 233                                 first = false;
 234                         else
 235                                 fputc(' ', f);
 236
 237                         fputs(i->id, f);
 238                 }
 239
 240                 fputs("\nACTIVE_SEATS=", f);
 241                 first = true;
 242                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 243                         if (!session_is_active(i) || !i->seat)
 244                                 continue;
 245
 246                         if (first)
 247                                 first = false;
 248                         else
 249                                 fputc(' ', f);
 250
 251                         fputs(i->seat->id, f);
 252                 }
 253
 254                 fputs("\nONLINE_SEATS=", f);
 255                 first = true;
 256                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 257                         if (session_get_state(i) == SESSION_CLOSING || !i->seat)
 258                                 continue;
 259
 260                         if (first)
 261                                 first = false;
 262                         else
 263                                 fputc(' ', f);
 264
 265                         fputs(i->seat->id, f);
 266                 }
 267                 fputc('\n', f);
 268         }
 269
 270         r = fflush_and_check(f);
 271         if (r < 0)
 272                 goto fail;
 273
 274         if (rename(temp_path, u->state_file) < 0) {
 275                 r = -errno;
 276                 goto fail;
 277         }
 278
 279         return 0;
 280
 281 fail:
 282         (void) unlink(u->state_file);
 283
 284         if (temp_path)
 285                 (void) unlink(temp_path);
 286
 287         return log_error_errno(r, "Failed to save user data %s: %m", u->state_file);
 288 }
 289
 290 int user_save(User *u) {
 291         assert(u);
 292
 293         if (!u->started)
 294                 return 0;
 295
 296         return user_save_internal (u);
 297 }
 298
 299 int user_load(User *u) {
 300         _cleanup_free_ char *display = NULL, *realtime = NULL, *monotonic = NULL;
 301         Session *s = NULL;
 302         int r;
 303
 304         assert(u);
 305
 306         r = parse_env_file(u->state_file, NEWLINE,
 307 #if 0 /// elogind neither supports service nor slice jobs
 308                            "SERVICE_JOB", &u->service_job,
 309                            "SLICE_JOB",   &u->slice_job,
 310 #endif // 0
 311                            "DISPLAY",     &display,
 312                            "REALTIME",    &realtime,
 313                            "MONOTONIC",   &monotonic,
 314                            NULL);
 315         if (r < 0) {
 316                 if (r == -ENOENT)
 317                         return 0;
 318
 319                 log_error_errno(r, "Failed to read %s: %m", u->state_file);
 320                 return r;
 321         }
 322
 323         if (display)
 324                 s = hashmap_get(u->manager->sessions, display);
 325
 326         if (s && s->display && display_is_local(s->display))
 327                 u->display = s;
 328
 329         deserialize_timestamp_value(realtime, &u->timestamp.realtime);
 330         deserialize_timestamp_value(monotonic, &u->timestamp.monotonic);
 331
 332         return r;
 333 }
 334
 335 static int user_mkdir_runtime_path(User *u) {
 336         int r;
 337
 338         assert(u);
 339
 340         r = mkdir_safe_label("/run/user", 0755, 0, 0);
 341         if (r < 0)
 342                 return log_error_errno(r, "Failed to create /run/user: %m");
 343
 344         if (path_is_mount_point(u->runtime_path, 0) <= 0) {
 345                 _cleanup_free_ char *t = NULL;
 346
 347                 (void) mkdir_label(u->runtime_path, 0700);
 348
 349                 if (mac_smack_use())
 350                         r = asprintf(&t, "mode=0700,smackfsroot=*,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
 351                 else
 352                         r = asprintf(&t, "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
 353                 if (r < 0) {
 354                         r = log_oom();
 355                         goto fail;
 356                 }
 357
 358                 r = mount("tmpfs", u->runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, t);
 359                 if (r < 0) {
 360                         if (errno != EPERM) {
 361                                 r = log_error_errno(errno, "Failed to mount per-user tmpfs directory %s: %m", u->runtime_path);
 362                                 goto fail;
 363                         }
 364
 365                         /* Lacking permissions, maybe
 366                          * CAP_SYS_ADMIN-less container? In this case,
 367                          * just use a normal directory. */
 368
 369                         r = chmod_and_chown(u->runtime_path, 0700, u->uid, u->gid);
 370                         if (r < 0) {
 371                                 log_error_errno(r, "Failed to change runtime directory ownership and mode: %m");
 372                                 goto fail;
 373                         }
 374                 }
 375
 376                 r = label_fix(u->runtime_path, false, false);
 377                 if (r < 0)
 378                         log_warning_errno(r, "Failed to fix label of '%s', ignoring: %m", u->runtime_path);
 379         }
 380
 381         return 0;
 382
 383 fail:
 384                 /* Try to clean up, but ignore errors */
 385         (void) rmdir(u->runtime_path);
 386         return r;
 387 }
 388
 389 static int user_start_slice(User *u) {
 390 #if 0 /// elogind can not ask systemd via dbus to start user services
 391         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 392         const char *description;
 393         char *job;
 394         int r;
 395
 396         assert(u);
 397
 398         u->slice_job = mfree(u->slice_job);
 399         description = strjoina("User Slice of ", u->name);
 400
 401         r = manager_start_slice(
 402                         u->manager,
 403                         u->slice,
 404                         description,
 405                         "systemd-logind.service",
 406                         "systemd-user-sessions.service",
 407                         u->manager->user_tasks_max,
 408                         &error,
 409                         &job);
 410         if (r >= 0)
 411                 u->slice_job = job;
 412         else if (!sd_bus_error_has_name(&error, BUS_ERROR_UNIT_EXISTS))
 413                 /* we don't fail due to this, let's try to continue */
 414                 log_error_errno(r, "Failed to start user slice %s, ignoring: %s (%s)",
 415                                 u->slice, bus_error_message(&error, r), error.name);
 416 #else
 417         assert(u);
 418
 419         hashmap_put(u->manager->user_units, u->slice, u);
 420 #endif // 0
 421
 422         return 0;
 423 }
 424
 425 static int user_start_service(User *u) {
 426 #if 0 /// elogind can not ask systemd via dbus to start user services
 427         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 428         char *job;
 429         int r;
 430
 431         assert(u);
 432
 433         u->service_job = mfree(u->service_job);
 434
 435         r = manager_start_unit(
 436                         u->manager,
 437                         u->service,
 438                         &error,
 439                         &job);
 440                 if (r < 0) {
 441                 /* we don't fail due to this, let's try to continue */
 442                 log_error_errno(r, "Failed to start user service, ignoring: %s", bus_error_message(&error, r));
 443                 } else {
 444                         u->service_job = job;
 445         }
 446 #else
 447         assert(u);
 448
 449         hashmap_put(u->manager->user_units, u->service, u);
 450 #endif // 0
 451
 452         return 0;
 453 }
 454
 455 int user_start(User *u) {
 456         int r;
 457
 458         assert(u);
 459
 460         if (u->started && !u->stopping)
 461                 return 0;
 462
 463         /*
 464          * If u->stopping is set, the user is marked for removal and the slice
 465          * and service stop-jobs are queued. We have to clear that flag before
 466          * queing the start-jobs again. If they succeed, the user object can be
 467          * re-used just fine (pid1 takes care of job-ordering and proper
 468          * restart), but if they fail, we want to force another user_stop() so
 469          * possibly pending units are stopped.
 470          * Note that we don't clear u->started, as we have no clue what state
 471          * the user is in on failure here. Hence, we pretend the user is
 472          * running so it will be properly taken down by GC. However, we clearly
 473          * return an error from user_start() in that case, so no further
 474          * reference to the user is taken.
 475          */
 476         u->stopping = false;
 477
 478         if (!u->started) {
 479                 log_debug("New user %s logged in.", u->name);
 480
 481                 /* Make XDG_RUNTIME_DIR */
 482                 r = user_mkdir_runtime_path(u);
 483                 if (r < 0)
 484                         return r;
 485         }
 486
 487         /* Create cgroup */
 488         r = user_start_slice(u);
 489         if (r < 0)
 490                 return r;
 491
 492         /* Save the user data so far, because pam_systemd will read the
 493          * XDG_RUNTIME_DIR out of it while starting up systemd --user.
 494          * We need to do user_save_internal() because we have not
 495          * "officially" started yet. */
 496         user_save_internal(u);
 497
 498         /* Spawn user systemd */
 499         r = user_start_service(u);
 500         if (r < 0)
 501                 return r;
 502
 503         if (!u->started) {
 504                 if (!dual_timestamp_is_set(&u->timestamp))
 505                         dual_timestamp_get(&u->timestamp);
 506                 user_send_signal(u, true);
 507                 u->started = true;
 508         }
 509
 510         /* Save new user data */
 511         user_save(u);
 512
 513         return 0;
 514 }
 515
 516 #if 0 /// UNNEEDED by elogind
 517 static int user_stop_slice(User *u) {
 518         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 519         char *job;
 520         int r;
 521
 522         assert(u);
 523
 524         r = manager_stop_unit(u->manager, u->slice, &error, &job);
 525         if (r < 0) {
 526                 log_error("Failed to stop user slice: %s", bus_error_message(&error, r));
 527                 return r;
 528         }
 529
 530         free(u->slice_job);
 531         u->slice_job = job;
 532
 533         return r;
 534 }
 535
 536 static int user_stop_service(User *u) {
 537         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 538         char *job;
 539         int r;
 540
 541         assert(u);
 542
 543         r = manager_stop_unit(u->manager, u->service, &error, &job);
 544         if (r < 0) {
 545                 log_error("Failed to stop user service: %s", bus_error_message(&error, r));
 546                 return r;
 547         }
 548
 549         free(u->service_job);
 550         u->service_job = job;
 551
 552         return r;
 553 }
 554 #endif // 0
 555
 556 static int user_remove_runtime_path(User *u) {
 557         int r;
 558
 559         assert(u);
 560
 561         r = rm_rf(u->runtime_path, 0);
 562         if (r < 0)
 563                 log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
 564
 565         /* Ignore cases where the directory isn't mounted, as that's
 566          * quite possible, if we lacked the permissions to mount
 567          * something */
 568         r = umount2(u->runtime_path, MNT_DETACH);
 569         if (r < 0 && errno != EINVAL && errno != ENOENT)
 570                 log_error_errno(errno, "Failed to unmount user runtime directory %s: %m", u->runtime_path);
 571
 572         r = rm_rf(u->runtime_path, REMOVE_ROOT);
 573         if (r < 0)
 574                 log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
 575
 576         return r;
 577 }
 578
 579 int user_stop(User *u, bool force) {
 580         Session *s;
 581         int r = 0, k;
 582         assert(u);
 583
 584         /* Stop jobs have already been queued */
 585         if (u->stopping) {
 586                 user_save(u);
 587                 return r;
 588         }
 589
 590         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 591                 k = session_stop(s, force);
 592                 if (k < 0)
 593                         r = k;
 594         }
 595
 596         /* Kill systemd */
 597 #if 0 /// elogind does not support service or slice jobs
 598         k = user_stop_service(u);
 599         if (k < 0)
 600                 r = k;
 601
 602         /* Kill cgroup */
 603         k = user_stop_slice(u);
 604         if (k < 0)
 605                 r = k;
 606 #endif // 0
 607
 608         u->stopping = true;
 609
 610         user_save(u);
 611
 612         return r;
 613 }
 614
 615 int user_finalize(User *u) {
 616         Session *s;
 617         int r = 0, k;
 618
 619         assert(u);
 620
 621         if (u->started)
 622                 log_debug("User %s logged out.", u->name);
 623
 624         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 625                 k = session_finalize(s);
 626                 if (k < 0)
 627                         r = k;
 628         }
 629
 630         /* Kill XDG_RUNTIME_DIR */
 631         k = user_remove_runtime_path(u);
 632         if (k < 0)
 633                 r = k;
 634
 635         /* Clean SysV + POSIX IPC objects */
 636         if (u->manager->remove_ipc) {
 637                 k = clean_ipc(u->uid);
 638                 if (k < 0)
 639                         r = k;
 640         }
 641
 642         unlink(u->state_file);
 643         user_add_to_gc_queue(u);
 644
 645         if (u->started) {
 646                 user_send_signal(u, false);
 647                 u->started = false;
 648         }
 649
 650         return r;
 651 }
 652
 653 int user_get_idle_hint(User *u, dual_timestamp *t) {
 654         Session *s;
 655         bool idle_hint = true;
 656         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 657
 658         assert(u);
 659
 660         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 661                 dual_timestamp k;
 662                 int ih;
 663
 664                 ih = session_get_idle_hint(s, &k);
 665                 if (ih < 0)
 666                         return ih;
 667
 668                 if (!ih) {
 669                         if (!idle_hint) {
 670                                 if (k.monotonic < ts.monotonic)
 671                                         ts = k;
 672                         } else {
 673                                 idle_hint = false;
 674                                 ts = k;
 675                         }
 676                 } else if (idle_hint) {
 677
 678                         if (k.monotonic > ts.monotonic)
 679                                 ts = k;
 680                 }
 681         }
 682
 683         if (t)
 684                 *t = ts;
 685
 686         return idle_hint;
 687 }
 688
 689 int user_check_linger_file(User *u) {
 690         _cleanup_free_ char *cc = NULL;
 691         char *p = NULL;
 692
 693         cc = cescape(u->name);
 694         if (!cc)
 695                 return -ENOMEM;
 696
 697         p = strjoina("/var/lib/systemd/linger/", cc);
 698
 699         return access(p, F_OK) >= 0;
 700 }
 701
 702 bool user_check_gc(User *u, bool drop_not_started) {
 703         assert(u);
 704
 705         if (drop_not_started && !u->started)
 706                 return false;
 707
 708         if (u->sessions)
 709                 return true;
 710
 711         if (user_check_linger_file(u) > 0)
 712                 return true;
 713
 714 #if 0 /// elogind neither supports service nor slice jobs
 715         if (u->slice_job && manager_job_is_active(u->manager, u->slice_job))
 716                 return true;
 717
 718         if (u->service_job && manager_job_is_active(u->manager, u->service_job))
 719                 return true;
 720 #endif // 0
 721
 722         return false;
 723 }
 724
 725 void user_add_to_gc_queue(User *u) {
 726         assert(u);
 727
 728         if (u->in_gc_queue)
 729                 return;
 730
 731         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 732         u->in_gc_queue = true;
 733 }
 734
 735 UserState user_get_state(User *u) {
 736         Session *i;
 737
 738         assert(u);
 739
 740         if (u->stopping)
 741                 return USER_CLOSING;
 742
 743 #if 0 /// elogind neither supports service nor slice jobs.
 744         if (!u->started || u->slice_job || u->service_job)
 745 #else
 746         if (!u->started)
 747 #endif // 0
 748                 return USER_OPENING;
 749
 750         if (u->sessions) {
 751                 bool all_closing = true;
 752
 753                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 754                         SessionState state;
 755
 756                         state = session_get_state(i);
 757                         if (state == SESSION_ACTIVE)
 758                                 return USER_ACTIVE;
 759                         if (state != SESSION_CLOSING)
 760                                 all_closing = false;
 761                 }
 762
 763                 return all_closing ? USER_CLOSING : USER_ONLINE;
 764         }
 765
 766         if (user_check_linger_file(u) > 0)
 767                 return USER_LINGERING;
 768
 769         return USER_CLOSING;
 770 }
 771
 772 int user_kill(User *u, int signo) {
 773 #if 0 /// Without systemd unit support, elogind has to rely on its session system
 774         assert(u);
 775
 776         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 777 #else
 778         Session *s;
 779         int res = 0;
 780
 781         assert(u);
 782
 783         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 784                 int r = session_kill(s, KILL_ALL, signo);
 785                 if (res == 0 && r < 0)
 786                         res = r;
 787         }
 788
 789         return res;
 790 #endif // 0
 791 }
 792
 793 static bool elect_display_filter(Session *s) {
 794         /* Return true if the session is a candidate for the user’s ‘primary
 795          * session’ or ‘display’. */
 796         assert(s);
 797
 798         return (s->class == SESSION_USER && !s->stopping);
 799 }
 800
 801 static int elect_display_compare(Session *s1, Session *s2) {
 802         /* Indexed by SessionType. Lower numbers mean more preferred. */
 803         const int type_ranks[_SESSION_TYPE_MAX] = {
 804                 [SESSION_UNSPECIFIED] = 0,
 805                 [SESSION_TTY] = -2,
 806                 [SESSION_X11] = -3,
 807                 [SESSION_WAYLAND] = -3,
 808                 [SESSION_MIR] = -3,
 809                 [SESSION_WEB] = -1,
 810         };
 811
 812         /* Calculate the partial order relationship between s1 and s2,
 813          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 814          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 815          * is preferred.
 816          *
 817          * s1 or s2 may be NULL. */
 818         if (!s1 && !s2)
 819                 return 0;
 820
 821         if ((s1 == NULL) != (s2 == NULL))
 822                 return (s1 == NULL) - (s2 == NULL);
 823
 824         if (s1->stopping != s2->stopping)
 825                 return s1->stopping - s2->stopping;
 826
 827         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 828                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 829
 830         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 831                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 832
 833         if (s1->type != s2->type)
 834                 return type_ranks[s1->type] - type_ranks[s2->type];
 835
 836         return 0;
 837 }
 838
 839 void user_elect_display(User *u) {
 840         Session *s;
 841
 842         assert(u);
 843
 844         /* This elects a primary session for each user, which we call
 845          * the "display". We try to keep the assignment stable, but we
 846          * "upgrade" to better choices. */
 847         log_debug("Electing new display for user %s", u->name);
 848
 849         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 850                 if (!elect_display_filter(s)) {
 851                         log_debug("Ignoring session %s", s->id);
 852                         continue;
 853                 }
 854
 855                 if (elect_display_compare(s, u->display) < 0) {
 856                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 857                         u->display = s;
 858                 }
 859         }
 860 }
 861
 862 static const char* const user_state_table[_USER_STATE_MAX] = {
 863         [USER_OFFLINE] = "offline",
 864         [USER_OPENING] = "opening",
 865         [USER_LINGERING] = "lingering",
 866         [USER_ONLINE] = "online",
 867         [USER_ACTIVE] = "active",
 868         [USER_CLOSING] = "closing"
 869 };
 870
 871 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 872
 873 int config_parse_tmpfs_size(
 874                 const char* unit,
 875                 const char *filename,
 876                 unsigned line,
 877                 const char *section,
 878                 unsigned section_line,
 879                 const char *lvalue,
 880                 int ltype,
 881                 const char *rvalue,
 882                 void *data,
 883                 void *userdata) {
 884
 885         size_t *sz = data;
 886         const char *e;
 887         int r;
 888
 889         assert(filename);
 890         assert(lvalue);
 891         assert(rvalue);
 892         assert(data);
 893
 894         e = endswith(rvalue, "%");
 895         if (e) {
 896                 unsigned long ul;
 897                 char *f;
 898
 899                 errno = 0;
 900                 ul = strtoul(rvalue, &f, 10);
 901                 if (errno > 0 || f != e) {
 902                         log_syntax(unit, LOG_ERR, filename, line, errno, "Failed to parse percentage value, ignoring: %s", rvalue);
 903                         return 0;
 904                 }
 905
 906                 if (ul <= 0 || ul >= 100) {
 907                         log_syntax(unit, LOG_ERR, filename, line, 0, "Percentage value out of range, ignoring: %s", rvalue);
 908                         return 0;
 909                 }
 910
 911                 *sz = PAGE_ALIGN((size_t) ((physical_memory() * (uint64_t) ul) / (uint64_t) 100));
 912         } else {
 913                 uint64_t k;
 914
 915                 r = parse_size(rvalue, 1024, &k);
 916                 if (r < 0 || (uint64_t) (size_t) k != k) {
 917                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse size value, ignoring: %s", rvalue);
 918                         return 0;
 919                 }
 920
 921                 *sz = PAGE_ALIGN((size_t) k);
 922         }
 923
 924         return 0;
 925 }