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