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         if (realtime) {
 330                 unsigned long long l;
 331                 if (sscanf(realtime, "%llu", &l) > 0)
 332                         u->timestamp.realtime = l;
 333         }
 334
 335         if (monotonic) {
 336                 unsigned long long l;
 337                 if (sscanf(monotonic, "%llu", &l) > 0)
 338                         u->timestamp.monotonic = l;
 339         }
 340
 341         return r;
 342 }
 343
 344 static int user_mkdir_runtime_path(User *u) {
 345         int r;
 346
 347         assert(u);
 348
 349         r = mkdir_safe_label("/run/user", 0755, 0, 0);
 350         if (r < 0)
 351                 return log_error_errno(r, "Failed to create /run/user: %m");
 352
 353         if (path_is_mount_point(u->runtime_path, 0) <= 0) {
 354                 _cleanup_free_ char *t = NULL;
 355
 356                 (void) mkdir_label(u->runtime_path, 0700);
 357
 358                 if (mac_smack_use())
 359                         r = asprintf(&t, "mode=0700,smackfsroot=*,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
 360                 else
 361                         r = asprintf(&t, "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
 362                 if (r < 0) {
 363                         r = log_oom();
 364                         goto fail;
 365                 }
 366
 367                 r = mount("tmpfs", u->runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, t);
 368                 if (r < 0) {
 369                         if (errno != EPERM) {
 370                                 r = log_error_errno(errno, "Failed to mount per-user tmpfs directory %s: %m", u->runtime_path);
 371                                 goto fail;
 372                         }
 373
 374                         /* Lacking permissions, maybe
 375                          * CAP_SYS_ADMIN-less container? In this case,
 376                          * just use a normal directory. */
 377
 378                         r = chmod_and_chown(u->runtime_path, 0700, u->uid, u->gid);
 379                         if (r < 0) {
 380                                 log_error_errno(r, "Failed to change runtime directory ownership and mode: %m");
 381                                 goto fail;
 382                         }
 383                 }
 384
 385                 r = label_fix(u->runtime_path, false, false);
 386                 if (r < 0)
 387                         log_warning_errno(r, "Failed to fix label of '%s', ignoring: %m", u->runtime_path);
 388         }
 389
 390         return 0;
 391
 392 fail:
 393                 /* Try to clean up, but ignore errors */
 394         (void) rmdir(u->runtime_path);
 395         return r;
 396 }
 397
 398 static int user_start_slice(User *u) {
 399 #if 0 /// elogind can not ask systemd via dbus to start user services
 400         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 401         const char *description;
 402         char *job;
 403         int r;
 404
 405         assert(u);
 406
 407         u->slice_job = mfree(u->slice_job);
 408         description = strjoina("User Slice of ", u->name);
 409
 410         r = manager_start_slice(
 411                         u->manager,
 412                         u->slice,
 413                         description,
 414                         "systemd-logind.service",
 415                         "systemd-user-sessions.service",
 416                         u->manager->user_tasks_max,
 417                         &error,
 418                         &job);
 419         if (r >= 0)
 420                 u->slice_job = job;
 421         else if (!sd_bus_error_has_name(&error, BUS_ERROR_UNIT_EXISTS))
 422                 /* we don't fail due to this, let's try to continue */
 423                 log_error_errno(r, "Failed to start user slice %s, ignoring: %s (%s)",
 424                                 u->slice, bus_error_message(&error, r), error.name);
 425 #else
 426         assert(u);
 427
 428         hashmap_put(u->manager->user_units, u->slice, u);
 429 #endif // 0
 430
 431         return 0;
 432 }
 433
 434 static int user_start_service(User *u) {
 435 #if 0 /// elogind can not ask systemd via dbus to start user services
 436         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 437         char *job;
 438         int r;
 439
 440         assert(u);
 441
 442         u->service_job = mfree(u->service_job);
 443
 444         r = manager_start_unit(
 445                         u->manager,
 446                         u->service,
 447                         &error,
 448                         &job);
 449                 if (r < 0) {
 450                 /* we don't fail due to this, let's try to continue */
 451                 log_error_errno(r, "Failed to start user service, ignoring: %s", bus_error_message(&error, r));
 452                 } else {
 453                         u->service_job = job;
 454         }
 455 #else
 456         assert(u);
 457
 458         hashmap_put(u->manager->user_units, u->service, u);
 459 #endif // 0
 460
 461         return 0;
 462 }
 463
 464 int user_start(User *u) {
 465         int r;
 466
 467         assert(u);
 468
 469         if (u->started && !u->stopping)
 470                 return 0;
 471
 472         /*
 473          * If u->stopping is set, the user is marked for removal and the slice
 474          * and service stop-jobs are queued. We have to clear that flag before
 475          * queing the start-jobs again. If they succeed, the user object can be
 476          * re-used just fine (pid1 takes care of job-ordering and proper
 477          * restart), but if they fail, we want to force another user_stop() so
 478          * possibly pending units are stopped.
 479          * Note that we don't clear u->started, as we have no clue what state
 480          * the user is in on failure here. Hence, we pretend the user is
 481          * running so it will be properly taken down by GC. However, we clearly
 482          * return an error from user_start() in that case, so no further
 483          * reference to the user is taken.
 484          */
 485         u->stopping = false;
 486
 487         if (!u->started) {
 488                 log_debug("New user %s logged in.", u->name);
 489
 490                 /* Make XDG_RUNTIME_DIR */
 491                 r = user_mkdir_runtime_path(u);
 492                 if (r < 0)
 493                         return r;
 494         }
 495
 496         /* Create cgroup */
 497         r = user_start_slice(u);
 498         if (r < 0)
 499                 return r;
 500
 501         /* Save the user data so far, because pam_systemd will read the
 502          * XDG_RUNTIME_DIR out of it while starting up systemd --user.
 503          * We need to do user_save_internal() because we have not
 504          * "officially" started yet. */
 505         user_save_internal(u);
 506
 507         /* Spawn user systemd */
 508         r = user_start_service(u);
 509         if (r < 0)
 510                 return r;
 511
 512         if (!u->started) {
 513                 if (!dual_timestamp_is_set(&u->timestamp))
 514                         dual_timestamp_get(&u->timestamp);
 515                 user_send_signal(u, true);
 516                 u->started = true;
 517         }
 518
 519         /* Save new user data */
 520         user_save(u);
 521
 522         return 0;
 523 }
 524
 525 #if 0 /// UNNEEDED by elogind
 526 static int user_stop_slice(User *u) {
 527         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 528         char *job;
 529         int r;
 530
 531         assert(u);
 532
 533         r = manager_stop_unit(u->manager, u->slice, &error, &job);
 534         if (r < 0) {
 535                 log_error("Failed to stop user slice: %s", bus_error_message(&error, r));
 536                 return r;
 537         }
 538
 539         free(u->slice_job);
 540         u->slice_job = job;
 541
 542         return r;
 543 }
 544
 545 static int user_stop_service(User *u) {
 546         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 547         char *job;
 548         int r;
 549
 550         assert(u);
 551
 552         r = manager_stop_unit(u->manager, u->service, &error, &job);
 553         if (r < 0) {
 554                 log_error("Failed to stop user service: %s", bus_error_message(&error, r));
 555                 return r;
 556         }
 557
 558         free(u->service_job);
 559         u->service_job = job;
 560
 561         return r;
 562 }
 563 #endif // 0
 564
 565 static int user_remove_runtime_path(User *u) {
 566         int r;
 567
 568         assert(u);
 569
 570         r = rm_rf(u->runtime_path, 0);
 571         if (r < 0)
 572                 log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
 573
 574         /* Ignore cases where the directory isn't mounted, as that's
 575          * quite possible, if we lacked the permissions to mount
 576          * something */
 577         r = umount2(u->runtime_path, MNT_DETACH);
 578         if (r < 0 && errno != EINVAL && errno != ENOENT)
 579                 log_error_errno(errno, "Failed to unmount user runtime directory %s: %m", u->runtime_path);
 580
 581         r = rm_rf(u->runtime_path, REMOVE_ROOT);
 582         if (r < 0)
 583                 log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
 584
 585         return r;
 586 }
 587
 588 int user_stop(User *u, bool force) {
 589         Session *s;
 590         int r = 0, k;
 591         assert(u);
 592
 593         /* Stop jobs have already been queued */
 594         if (u->stopping) {
 595                 user_save(u);
 596                 return r;
 597         }
 598
 599         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 600                 k = session_stop(s, force);
 601                 if (k < 0)
 602                         r = k;
 603         }
 604
 605         /* Kill systemd */
 606 #if 0 /// elogind does not support service or slice jobs
 607         k = user_stop_service(u);
 608         if (k < 0)
 609                 r = k;
 610
 611         /* Kill cgroup */
 612         k = user_stop_slice(u);
 613         if (k < 0)
 614                 r = k;
 615 #endif // 0
 616
 617         u->stopping = true;
 618
 619         user_save(u);
 620
 621         return r;
 622 }
 623
 624 int user_finalize(User *u) {
 625         Session *s;
 626         int r = 0, k;
 627
 628         assert(u);
 629
 630         if (u->started)
 631                 log_debug("User %s logged out.", u->name);
 632
 633         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 634                 k = session_finalize(s);
 635                 if (k < 0)
 636                         r = k;
 637         }
 638
 639         /* Kill XDG_RUNTIME_DIR */
 640         k = user_remove_runtime_path(u);
 641         if (k < 0)
 642                 r = k;
 643
 644         /* Clean SysV + POSIX IPC objects */
 645         if (u->manager->remove_ipc) {
 646                 k = clean_ipc(u->uid);
 647                 if (k < 0)
 648                         r = k;
 649         }
 650
 651         unlink(u->state_file);
 652         user_add_to_gc_queue(u);
 653
 654         if (u->started) {
 655                 user_send_signal(u, false);
 656                 u->started = false;
 657         }
 658
 659         return r;
 660 }
 661
 662 int user_get_idle_hint(User *u, dual_timestamp *t) {
 663         Session *s;
 664         bool idle_hint = true;
 665         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 666
 667         assert(u);
 668
 669         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 670                 dual_timestamp k;
 671                 int ih;
 672
 673                 ih = session_get_idle_hint(s, &k);
 674                 if (ih < 0)
 675                         return ih;
 676
 677                 if (!ih) {
 678                         if (!idle_hint) {
 679                                 if (k.monotonic < ts.monotonic)
 680                                         ts = k;
 681                         } else {
 682                                 idle_hint = false;
 683                                 ts = k;
 684                         }
 685                 } else if (idle_hint) {
 686
 687                         if (k.monotonic > ts.monotonic)
 688                                 ts = k;
 689                 }
 690         }
 691
 692         if (t)
 693                 *t = ts;
 694
 695         return idle_hint;
 696 }
 697
 698 int user_check_linger_file(User *u) {
 699         _cleanup_free_ char *cc = NULL;
 700         char *p = NULL;
 701
 702         cc = cescape(u->name);
 703         if (!cc)
 704                 return -ENOMEM;
 705
 706         p = strjoina("/var/lib/systemd/linger/", cc);
 707
 708         return access(p, F_OK) >= 0;
 709 }
 710
 711 bool user_check_gc(User *u, bool drop_not_started) {
 712         assert(u);
 713
 714         if (drop_not_started && !u->started)
 715                 return false;
 716
 717         if (u->sessions)
 718                 return true;
 719
 720         if (user_check_linger_file(u) > 0)
 721                 return true;
 722
 723 #if 0 /// elogind neither supports service nor slice jobs
 724         if (u->slice_job && manager_job_is_active(u->manager, u->slice_job))
 725                 return true;
 726
 727         if (u->service_job && manager_job_is_active(u->manager, u->service_job))
 728                 return true;
 729 #endif // 0
 730
 731         return false;
 732 }
 733
 734 void user_add_to_gc_queue(User *u) {
 735         assert(u);
 736
 737         if (u->in_gc_queue)
 738                 return;
 739
 740         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 741         u->in_gc_queue = true;
 742 }
 743
 744 UserState user_get_state(User *u) {
 745         Session *i;
 746
 747         assert(u);
 748
 749         if (u->stopping)
 750                 return USER_CLOSING;
 751
 752 #if 0 /// elogind neither supports service nor slice jobs.
 753         if (!u->started || u->slice_job || u->service_job)
 754 #else
 755         if (!u->started)
 756 #endif // 0
 757                 return USER_OPENING;
 758
 759         if (u->sessions) {
 760                 bool all_closing = true;
 761
 762                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 763                         SessionState state;
 764
 765                         state = session_get_state(i);
 766                         if (state == SESSION_ACTIVE)
 767                                 return USER_ACTIVE;
 768                         if (state != SESSION_CLOSING)
 769                                 all_closing = false;
 770                 }
 771
 772                 return all_closing ? USER_CLOSING : USER_ONLINE;
 773         }
 774
 775         if (user_check_linger_file(u) > 0)
 776                 return USER_LINGERING;
 777
 778         return USER_CLOSING;
 779 }
 780
 781 int user_kill(User *u, int signo) {
 782 #if 0 /// Without systemd unit support, elogind has to rely on its session system
 783         assert(u);
 784
 785         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 786 #else
 787         Session *s;
 788         int res = 0;
 789
 790         assert(u);
 791
 792         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 793                 int r = session_kill(s, KILL_ALL, signo);
 794                 if (res == 0 && r < 0)
 795                         res = r;
 796         }
 797
 798         return res;
 799 #endif // 0
 800 }
 801
 802 static bool elect_display_filter(Session *s) {
 803         /* Return true if the session is a candidate for the user’s ‘primary
 804          * session’ or ‘display’. */
 805         assert(s);
 806
 807         return (s->class == SESSION_USER && !s->stopping);
 808 }
 809
 810 static int elect_display_compare(Session *s1, Session *s2) {
 811         /* Indexed by SessionType. Lower numbers mean more preferred. */
 812         const int type_ranks[_SESSION_TYPE_MAX] = {
 813                 [SESSION_UNSPECIFIED] = 0,
 814                 [SESSION_TTY] = -2,
 815                 [SESSION_X11] = -3,
 816                 [SESSION_WAYLAND] = -3,
 817                 [SESSION_MIR] = -3,
 818                 [SESSION_WEB] = -1,
 819         };
 820
 821         /* Calculate the partial order relationship between s1 and s2,
 822          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 823          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 824          * is preferred.
 825          *
 826          * s1 or s2 may be NULL. */
 827         if (!s1 && !s2)
 828                 return 0;
 829
 830         if ((s1 == NULL) != (s2 == NULL))
 831                 return (s1 == NULL) - (s2 == NULL);
 832
 833         if (s1->stopping != s2->stopping)
 834                 return s1->stopping - s2->stopping;
 835
 836         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 837                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 838
 839         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 840                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 841
 842         if (s1->type != s2->type)
 843                 return type_ranks[s1->type] - type_ranks[s2->type];
 844
 845         return 0;
 846 }
 847
 848 void user_elect_display(User *u) {
 849         Session *s;
 850
 851         assert(u);
 852
 853         /* This elects a primary session for each user, which we call
 854          * the "display". We try to keep the assignment stable, but we
 855          * "upgrade" to better choices. */
 856         log_debug("Electing new display for user %s", u->name);
 857
 858         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 859                 if (!elect_display_filter(s)) {
 860                         log_debug("Ignoring session %s", s->id);
 861                         continue;
 862                 }
 863
 864                 if (elect_display_compare(s, u->display) < 0) {
 865                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 866                         u->display = s;
 867                 }
 868         }
 869 }
 870
 871 static const char* const user_state_table[_USER_STATE_MAX] = {
 872         [USER_OFFLINE] = "offline",
 873         [USER_OPENING] = "opening",
 874         [USER_LINGERING] = "lingering",
 875         [USER_ONLINE] = "online",
 876         [USER_ACTIVE] = "active",
 877         [USER_CLOSING] = "closing"
 878 };
 879
 880 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 881
 882 int config_parse_tmpfs_size(
 883                 const char* unit,
 884                 const char *filename,
 885                 unsigned line,
 886                 const char *section,
 887                 unsigned section_line,
 888                 const char *lvalue,
 889                 int ltype,
 890                 const char *rvalue,
 891                 void *data,
 892                 void *userdata) {
 893
 894         size_t *sz = data;
 895         const char *e;
 896         int r;
 897
 898         assert(filename);
 899         assert(lvalue);
 900         assert(rvalue);
 901         assert(data);
 902
 903         e = endswith(rvalue, "%");
 904         if (e) {
 905                 unsigned long ul;
 906                 char *f;
 907
 908                 errno = 0;
 909                 ul = strtoul(rvalue, &f, 10);
 910                 if (errno > 0 || f != e) {
 911                         log_syntax(unit, LOG_ERR, filename, line, errno, "Failed to parse percentage value, ignoring: %s", rvalue);
 912                         return 0;
 913                 }
 914
 915                 if (ul <= 0 || ul >= 100) {
 916                         log_syntax(unit, LOG_ERR, filename, line, 0, "Percentage value out of range, ignoring: %s", rvalue);
 917                         return 0;
 918                 }
 919
 920                 *sz = PAGE_ALIGN((size_t) ((physical_memory() * (uint64_t) ul) / (uint64_t) 100));
 921         } else {
 922                 uint64_t k;
 923
 924                 r = parse_size(rvalue, 1024, &k);
 925                 if (r < 0 || (uint64_t) (size_t) k != k) {
 926                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse size value, ignoring: %s", rvalue);
 927                         return 0;
 928                 }
 929
 930                 *sz = PAGE_ALIGN((size_t) k);
 931         }
 932
 933         return 0;
 934 }