src/login/logind-user.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2011 Lennart Poettering
   6 ***/
   7
   8 #include <errno.h>
   9 #include <string.h>
  10 #include <sys/mount.h>
  11 #include <unistd.h>
  12 #include <stdio_ext.h>
  13
  14 #include "alloc-util.h"
  15 #include "bus-common-errors.h"
  16 #include "bus-error.h"
  17 #include "bus-util.h"
  18 #include "cgroup-util.h"
  19 #include "clean-ipc.h"
  20 #include "conf-parser.h"
  21 #include "escape.h"
  22 #include "fd-util.h"
  23 #include "fileio.h"
  24 #include "format-util.h"
  25 #include "fs-util.h"
  26 #include "hashmap.h"
  27 #include "label.h"
  28 #include "logind-user.h"
  29 #include "mkdir.h"
  30 #include "mount-util.h"
  31 #include "parse-util.h"
  32 #include "path-util.h"
  33 #include "rm-rf.h"
  34 #include "smack-util.h"
  35 #include "special.h"
  36 #include "stdio-util.h"
  37 #include "string-table.h"
  38 #include "unit-name.h"
  39 #include "user-util.h"
  40 #include "util.h"
  41
  42 int user_new(User **out, Manager *m, uid_t uid, gid_t gid, const char *name) {
  43         _cleanup_(user_freep) User *u = NULL;
  44         char lu[DECIMAL_STR_MAX(uid_t) + 1];
  45         int r;
  46
  47         assert(out);
  48         assert(m);
  49         assert(name);
  50
  51         u = new0(User, 1);
  52         if (!u)
  53                 return -ENOMEM;
  54
  55         u->manager = m;
  56         u->uid = uid;
  57         u->gid = gid;
  58         xsprintf(lu, UID_FMT, uid);
  59
  60         u->name = strdup(name);
  61         if (!u->name)
  62                 return -ENOMEM;
  63
  64         if (asprintf(&u->state_file, "/run/systemd/users/"UID_FMT, uid) < 0)
  65                 return -ENOMEM;
  66
  67         if (asprintf(&u->runtime_path, "/run/user/"UID_FMT, uid) < 0)
  68                 return -ENOMEM;
  69
  70         r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice);
  71         if (r < 0)
  72                 return r;
  73
  74         r = unit_name_build("user", lu, ".service", &u->service);
  75         if (r < 0)
  76                 return r;
  77
  78         r = hashmap_put(m->users, UID_TO_PTR(uid), u);
  79         if (r < 0)
  80                 return r;
  81
  82         r = hashmap_put(m->user_units, u->slice, u);
  83         if (r < 0)
  84                 return r;
  85
  86         r = hashmap_put(m->user_units, u->service, u);
  87         if (r < 0)
  88                 return r;
  89
  90         *out = TAKE_PTR(u);
  91
  92         return 0;
  93 }
  94
  95 User *user_free(User *u) {
  96         if (!u)
  97                 return NULL;
  98
  99         if (u->in_gc_queue)
 100                 LIST_REMOVE(gc_queue, u->manager->user_gc_queue, u);
 101
 102         while (u->sessions)
 103                 session_free(u->sessions);
 104
 105         if (u->service)
 106                 hashmap_remove_value(u->manager->user_units, u->service, u);
 107
 108         if (u->slice)
 109                 hashmap_remove_value(u->manager->user_units, u->slice, u);
 110
 111         hashmap_remove_value(u->manager->users, UID_TO_PTR(u->uid), u);
 112
 113 #if 0 /// elogind neither supports slice nor service jobs.
 114         u->slice_job = mfree(u->slice_job);
 115         u->service_job = mfree(u->service_job);
 116 #endif // 0
 117
 118         u->service = mfree(u->service);
 119         u->slice = mfree(u->slice);
 120         u->runtime_path = mfree(u->runtime_path);
 121         u->state_file = mfree(u->state_file);
 122         u->name = mfree(u->name);
 123
 124         return mfree(u);
 125 }
 126
 127 static int user_save_internal(User *u) {
 128         _cleanup_free_ char *temp_path = NULL;
 129         _cleanup_fclose_ FILE *f = NULL;
 130         int r;
 131
 132         assert(u);
 133         assert(u->state_file);
 134
 135         r = mkdir_safe_label("/run/systemd/users", 0755, 0, 0, MKDIR_WARN_MODE);
 136         if (r < 0)
 137                 goto fail;
 138
 139         r = fopen_temporary(u->state_file, &f, &temp_path);
 140         if (r < 0)
 141                 goto fail;
 142
 143         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 144         (void) fchmod(fileno(f), 0644);
 145
 146         fprintf(f,
 147                 "# This is private data. Do not parse.\n"
 148                 "NAME=%s\n"
 149                 "STATE=%s\n",
 150                 u->name,
 151                 user_state_to_string(user_get_state(u)));
 152
 153         /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */
 154         if (u->runtime_path)
 155                 fprintf(f, "RUNTIME=%s\n", u->runtime_path);
 156
 157 #if 0 /// elogind neither supports service nor slice jobs
 158         if (u->service_job)
 159                 fprintf(f, "SERVICE_JOB=%s\n", u->service_job);
 160
 161         if (u->slice_job)
 162                 fprintf(f, "SLICE_JOB=%s\n", u->slice_job);
 163 #endif // 0
 164
 165         if (u->display)
 166                 fprintf(f, "DISPLAY=%s\n", u->display->id);
 167
 168         if (dual_timestamp_is_set(&u->timestamp))
 169                 fprintf(f,
 170                         "REALTIME="USEC_FMT"\n"
 171                         "MONOTONIC="USEC_FMT"\n",
 172                         u->timestamp.realtime,
 173                         u->timestamp.monotonic);
 174
 175         if (u->sessions) {
 176                 Session *i;
 177                 bool first;
 178
 179                 fputs("SESSIONS=", f);
 180                 first = true;
 181                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 182                         if (first)
 183                                 first = false;
 184                         else
 185                                 fputc(' ', f);
 186
 187                         fputs(i->id, f);
 188                 }
 189
 190                 fputs("\nSEATS=", f);
 191                 first = true;
 192                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 193                         if (!i->seat)
 194                                 continue;
 195
 196                         if (first)
 197                                 first = false;
 198                         else
 199                                 fputc(' ', f);
 200
 201                         fputs(i->seat->id, f);
 202                 }
 203
 204                 fputs("\nACTIVE_SESSIONS=", f);
 205                 first = true;
 206                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 207                         if (!session_is_active(i))
 208                                 continue;
 209
 210                         if (first)
 211                                 first = false;
 212                         else
 213                                 fputc(' ', f);
 214
 215                         fputs(i->id, f);
 216                 }
 217
 218                 fputs("\nONLINE_SESSIONS=", f);
 219                 first = true;
 220                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 221                         if (session_get_state(i) == SESSION_CLOSING)
 222                                 continue;
 223
 224                         if (first)
 225                                 first = false;
 226                         else
 227                                 fputc(' ', f);
 228
 229                         fputs(i->id, f);
 230                 }
 231
 232                 fputs("\nACTIVE_SEATS=", f);
 233                 first = true;
 234                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 235                         if (!session_is_active(i) || !i->seat)
 236                                 continue;
 237
 238                         if (first)
 239                                 first = false;
 240                         else
 241                                 fputc(' ', f);
 242
 243                         fputs(i->seat->id, f);
 244                 }
 245
 246                 fputs("\nONLINE_SEATS=", f);
 247                 first = true;
 248                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 249                         if (session_get_state(i) == SESSION_CLOSING || !i->seat)
 250                                 continue;
 251
 252                         if (first)
 253                                 first = false;
 254                         else
 255                                 fputc(' ', f);
 256
 257                         fputs(i->seat->id, f);
 258                 }
 259                 fputc('\n', f);
 260         }
 261
 262         r = fflush_and_check(f);
 263         if (r < 0)
 264                 goto fail;
 265
 266         if (rename(temp_path, u->state_file) < 0) {
 267                 r = -errno;
 268                 goto fail;
 269         }
 270
 271         return 0;
 272
 273 fail:
 274         (void) unlink(u->state_file);
 275
 276         if (temp_path)
 277                 (void) unlink(temp_path);
 278
 279         return log_error_errno(r, "Failed to save user data %s: %m", u->state_file);
 280 }
 281
 282 int user_save(User *u) {
 283         assert(u);
 284
 285         if (!u->started)
 286                 return 0;
 287
 288         return user_save_internal (u);
 289 }
 290
 291 int user_load(User *u) {
 292         _cleanup_free_ char *display = NULL, *realtime = NULL, *monotonic = NULL;
 293         Session *s = NULL;
 294         int r;
 295
 296         assert(u);
 297
 298         r = parse_env_file(u->state_file, NEWLINE,
 299 #if 0 /// elogind neither supports service nor slice jobs
 300                            "SERVICE_JOB", &u->service_job,
 301                            "SLICE_JOB",   &u->slice_job,
 302 #endif // 0
 303                            "DISPLAY",     &display,
 304                            "REALTIME",    &realtime,
 305                            "MONOTONIC",   &monotonic,
 306                            NULL);
 307         if (r < 0) {
 308                 if (r == -ENOENT)
 309                         return 0;
 310
 311                 return log_error_errno(r, "Failed to read %s: %m", u->state_file);
 312         }
 313
 314         if (display)
 315                 s = hashmap_get(u->manager->sessions, display);
 316
 317         if (s && s->display && display_is_local(s->display))
 318                 u->display = s;
 319
 320         if (realtime)
 321                 timestamp_deserialize(realtime, &u->timestamp.realtime);
 322         if (monotonic)
 323                 timestamp_deserialize(monotonic, &u->timestamp.monotonic);
 324
 325         return r;
 326 }
 327
 328 static int user_mkdir_runtime_path(User *u) {
 329         int r;
 330
 331         assert(u);
 332
 333         r = mkdir_safe_label("/run/user", 0755, 0, 0, MKDIR_WARN_MODE);
 334         if (r < 0)
 335                 return log_error_errno(r, "Failed to create /run/user: %m");
 336
 337         if (path_is_mount_point(u->runtime_path, NULL, 0) <= 0) {
 338                 _cleanup_free_ char *t = NULL;
 339
 340                 r = asprintf(&t, "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu%s",
 341                              u->uid, u->gid, u->manager->runtime_dir_size,
 342                              mac_smack_use() ? ",smackfsroot=*" : "");
 343                 if (r < 0)
 344                         return log_oom();
 345
 346                 (void) mkdir_label(u->runtime_path, 0700);
 347
 348                 r = mount("tmpfs", u->runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, t);
 349                 if (r < 0) {
 350                         if (!IN_SET(errno, EPERM, EACCES)) {
 351                                 r = log_error_errno(errno, "Failed to mount per-user tmpfs directory %s: %m", u->runtime_path);
 352                                 goto fail;
 353                         }
 354
 355                         log_debug_errno(errno, "Failed to mount per-user tmpfs directory %s, assuming containerized execution, ignoring: %m", u->runtime_path);
 356
 357                         r = chmod_and_chown(u->runtime_path, 0700, u->uid, u->gid);
 358                         if (r < 0) {
 359                                 log_error_errno(r, "Failed to change runtime directory ownership and mode: %m");
 360                                 goto fail;
 361                         }
 362                 }
 363
 364                 r = label_fix(u->runtime_path, 0);
 365                 if (r < 0)
 366                         log_warning_errno(r, "Failed to fix label of '%s', ignoring: %m", u->runtime_path);
 367         }
 368
 369         return 0;
 370
 371 fail:
 372         /* Try to clean up, but ignore errors */
 373         (void) rmdir(u->runtime_path);
 374         return r;
 375 }
 376
 377 static int user_start_slice(User *u) {
 378 #if 0 /// elogind can not ask systemd via dbus to start user services
 379         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 380         const char *description;
 381         char *job;
 382         int r;
 383
 384         assert(u);
 385
 386         u->slice_job = mfree(u->slice_job);
 387         description = strjoina("User Slice of ", u->name);
 388
 389         r = manager_start_slice(
 390                         u->manager,
 391                         u->slice,
 392                         description,
 393                         "systemd-logind.service",
 394                         "systemd-user-sessions.service",
 395                         u->manager->user_tasks_max,
 396                         &error,
 397                         &job);
 398         if (r >= 0)
 399                 u->slice_job = job;
 400         else if (!sd_bus_error_has_name(&error, BUS_ERROR_UNIT_EXISTS))
 401                 /* we don't fail due to this, let's try to continue */
 402                 log_error_errno(r, "Failed to start user slice %s, ignoring: %s (%s)",
 403                                 u->slice, bus_error_message(&error, r), error.name);
 404 #else
 405         assert(u);
 406
 407         hashmap_put(u->manager->user_units, u->slice, u);
 408 #endif // 0
 409
 410         return 0;
 411 }
 412
 413 static int user_start_service(User *u) {
 414 #if 0 /// elogind can not ask systemd via dbus to start user services
 415         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 416         char *job;
 417         int r;
 418
 419         assert(u);
 420
 421         u->service_job = mfree(u->service_job);
 422
 423         r = manager_start_unit(
 424                         u->manager,
 425                         u->service,
 426                         &error,
 427                         &job);
 428         if (r < 0)
 429                 /* we don't fail due to this, let's try to continue */
 430                 log_error_errno(r, "Failed to start user service, ignoring: %s", bus_error_message(&error, r));
 431         else
 432                 u->service_job = job;
 433 #else
 434         assert(u);
 435
 436         hashmap_put(u->manager->user_units, u->service, u);
 437 #endif // 0
 438
 439         return 0;
 440 }
 441
 442 int user_start(User *u) {
 443         int r;
 444
 445         assert(u);
 446
 447         if (u->started && !u->stopping)
 448                 return 0;
 449
 450         /*
 451          * If u->stopping is set, the user is marked for removal and the slice
 452          * and service stop-jobs are queued. We have to clear that flag before
 453          * queing the start-jobs again. If they succeed, the user object can be
 454          * re-used just fine (pid1 takes care of job-ordering and proper
 455          * restart), but if they fail, we want to force another user_stop() so
 456          * possibly pending units are stopped.
 457          * Note that we don't clear u->started, as we have no clue what state
 458          * the user is in on failure here. Hence, we pretend the user is
 459          * running so it will be properly taken down by GC. However, we clearly
 460          * return an error from user_start() in that case, so no further
 461          * reference to the user is taken.
 462          */
 463         u->stopping = false;
 464
 465         if (!u->started) {
 466                 log_debug("Starting services for new user %s.", u->name);
 467
 468                 /* Make XDG_RUNTIME_DIR */
 469                 r = user_mkdir_runtime_path(u);
 470                 if (r < 0)
 471                         return r;
 472         }
 473
 474         /* Create cgroup */
 475         r = user_start_slice(u);
 476         if (r < 0)
 477                 return r;
 478
 479         /* Save the user data so far, because pam_systemd will read the
 480          * XDG_RUNTIME_DIR out of it while starting up systemd --user.
 481          * We need to do user_save_internal() because we have not
 482          * "officially" started yet. */
 483         user_save_internal(u);
 484
 485         /* Spawn user systemd */
 486         r = user_start_service(u);
 487         if (r < 0)
 488                 return r;
 489
 490         if (!u->started) {
 491                 if (!dual_timestamp_is_set(&u->timestamp))
 492                         dual_timestamp_get(&u->timestamp);
 493                 user_send_signal(u, true);
 494                 u->started = true;
 495         }
 496
 497         /* Save new user data */
 498         user_save(u);
 499
 500         return 0;
 501 }
 502
 503 #if 0 /// UNNEEDED by elogind
 504 static int user_stop_slice(User *u) {
 505         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 506         char *job;
 507         int r;
 508
 509         assert(u);
 510
 511         r = manager_stop_unit(u->manager, u->slice, &error, &job);
 512         if (r < 0) {
 513                 log_error("Failed to stop user slice: %s", bus_error_message(&error, r));
 514                 return r;
 515         }
 516
 517         free(u->slice_job);
 518         u->slice_job = job;
 519
 520         return r;
 521 }
 522
 523 static int user_stop_service(User *u) {
 524         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 525         char *job;
 526         int r;
 527
 528         assert(u);
 529
 530         r = manager_stop_unit(u->manager, u->service, &error, &job);
 531         if (r < 0) {
 532                 log_error("Failed to stop user service: %s", bus_error_message(&error, r));
 533                 return r;
 534         }
 535
 536         free_and_replace(u->service_job, job);
 537         return r;
 538 }
 539 #endif // 0
 540
 541 static int user_remove_runtime_path(User *u) {
 542         int r;
 543
 544         assert(u);
 545
 546         r = rm_rf(u->runtime_path, 0);
 547         if (r < 0)
 548                 log_error_errno(r, "Failed to remove runtime directory %s (before unmounting): %m", u->runtime_path);
 549
 550         /* Ignore cases where the directory isn't mounted, as that's
 551          * quite possible, if we lacked the permissions to mount
 552          * something */
 553         r = umount2(u->runtime_path, MNT_DETACH);
 554         if (r < 0 && !IN_SET(errno, EINVAL, ENOENT))
 555                 log_error_errno(errno, "Failed to unmount user runtime directory %s: %m", u->runtime_path);
 556
 557         r = rm_rf(u->runtime_path, REMOVE_ROOT);
 558         if (r < 0)
 559                 log_error_errno(r, "Failed to remove runtime directory %s (after unmounting): %m", u->runtime_path);
 560
 561         return r;
 562 }
 563
 564 int user_stop(User *u, bool force) {
 565         Session *s;
 566         int r = 0, k;
 567         assert(u);
 568
 569         /* Stop jobs have already been queued */
 570         if (u->stopping) {
 571                 user_save(u);
 572                 return r;
 573         }
 574
 575         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 576                 k = session_stop(s, force);
 577                 if (k < 0)
 578                         r = k;
 579         }
 580
 581         /* Kill systemd */
 582 #if 0 /// elogind does not support service or slice jobs
 583         k = user_stop_service(u);
 584         if (k < 0)
 585                 r = k;
 586
 587         /* Kill cgroup */
 588         k = user_stop_slice(u);
 589         if (k < 0)
 590                 r = k;
 591 #endif // 0
 592
 593         u->stopping = true;
 594
 595         user_save(u);
 596
 597 #if 1 /// elogind must queue this user again
 598         user_add_to_gc_queue(u);
 599 #endif // 1
 600         return r;
 601 }
 602
 603 int user_finalize(User *u) {
 604         Session *s;
 605         int r = 0, k;
 606
 607         assert(u);
 608
 609         if (u->started)
 610                 log_debug("User %s logged out.", u->name);
 611
 612         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 613                 k = session_finalize(s);
 614                 if (k < 0)
 615                         r = k;
 616         }
 617
 618         /* Kill XDG_RUNTIME_DIR */
 619         k = user_remove_runtime_path(u);
 620         if (k < 0)
 621                 r = k;
 622
 623         /* Clean SysV + POSIX IPC objects, but only if this is not a system user. Background: in many setups cronjobs
 624          * are run in full PAM and thus logind sessions, even if the code run doesn't belong to actual users but to
 625          * system components. Since enable RemoveIPC= globally for all users, we need to be a bit careful with such
 626          * cases, as we shouldn't accidentally remove a system service's IPC objects while it is running, just because
 627          * a cronjob running as the same user just finished. Hence: exclude system users generally from IPC clean-up,
 628          * and do it only for normal users. */
 629         if (u->manager->remove_ipc && !uid_is_system(u->uid)) {
 630                 k = clean_ipc_by_uid(u->uid);
 631                 if (k < 0)
 632                         r = k;
 633         }
 634
 635         unlink(u->state_file);
 636         user_add_to_gc_queue(u);
 637
 638         if (u->started) {
 639                 user_send_signal(u, false);
 640                 u->started = false;
 641         }
 642
 643         return r;
 644 }
 645
 646 int user_get_idle_hint(User *u, dual_timestamp *t) {
 647         Session *s;
 648         bool idle_hint = true;
 649         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 650
 651         assert(u);
 652
 653         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 654                 dual_timestamp k;
 655                 int ih;
 656
 657                 ih = session_get_idle_hint(s, &k);
 658                 if (ih < 0)
 659                         return ih;
 660
 661                 if (!ih) {
 662                         if (!idle_hint) {
 663                                 if (k.monotonic < ts.monotonic)
 664                                         ts = k;
 665                         } else {
 666                                 idle_hint = false;
 667                                 ts = k;
 668                         }
 669                 } else if (idle_hint) {
 670
 671                         if (k.monotonic > ts.monotonic)
 672                                 ts = k;
 673                 }
 674         }
 675
 676         if (t)
 677                 *t = ts;
 678
 679         return idle_hint;
 680 }
 681
 682 int user_check_linger_file(User *u) {
 683         _cleanup_free_ char *cc = NULL;
 684         char *p = NULL;
 685
 686         cc = cescape(u->name);
 687         if (!cc)
 688                 return -ENOMEM;
 689
 690         p = strjoina("/var/lib/elogind/linger/", cc);
 691
 692         return access(p, F_OK) >= 0;
 693 }
 694
 695 bool user_may_gc(User *u, bool drop_not_started) {
 696         assert(u);
 697
 698         if (drop_not_started && !u->started)
 699                 return true;
 700
 701         if (u->sessions)
 702                 return false;
 703
 704         if (user_check_linger_file(u) > 0)
 705                 return false;
 706
 707 #if 0 /// elogind neither supports service nor slice jobs
 708         if (u->slice_job && manager_job_is_active(u->manager, u->slice_job))
 709                 return false;
 710
 711         if (u->service_job && manager_job_is_active(u->manager, u->service_job))
 712                 return false;
 713 #endif // 0
 714
 715         return true;
 716 }
 717
 718 void user_add_to_gc_queue(User *u) {
 719         assert(u);
 720
 721         if (u->in_gc_queue)
 722                 return;
 723
 724         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 725         u->in_gc_queue = true;
 726 }
 727
 728 UserState user_get_state(User *u) {
 729         Session *i;
 730
 731         assert(u);
 732
 733         if (u->stopping)
 734                 return USER_CLOSING;
 735
 736 #if 0 /// elogind neither supports service nor slice jobs.
 737         if (!u->started || u->slice_job || u->service_job)
 738 #else
 739         if (!u->started)
 740 #endif // 0
 741                 return USER_OPENING;
 742
 743         if (u->sessions) {
 744                 bool all_closing = true;
 745
 746                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 747                         SessionState state;
 748
 749                         state = session_get_state(i);
 750                         if (state == SESSION_ACTIVE)
 751                                 return USER_ACTIVE;
 752                         if (state != SESSION_CLOSING)
 753                                 all_closing = false;
 754                 }
 755
 756                 return all_closing ? USER_CLOSING : USER_ONLINE;
 757         }
 758
 759         if (user_check_linger_file(u) > 0)
 760                 return USER_LINGERING;
 761
 762         return USER_CLOSING;
 763 }
 764
 765 int user_kill(User *u, int signo) {
 766 #if 0 /// Without systemd unit support, elogind has to rely on its session system
 767         assert(u);
 768
 769         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 770 #else
 771         Session *s;
 772         int res = 0;
 773
 774         assert(u);
 775
 776         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 777                 int r = session_kill(s, KILL_ALL, signo);
 778                 if (res == 0 && r < 0)
 779                         res = r;
 780         }
 781
 782         return res;
 783 #endif // 0
 784 }
 785
 786 static bool elect_display_filter(Session *s) {
 787         /* Return true if the session is a candidate for the user’s ‘primary
 788          * session’ or ‘display’. */
 789         assert(s);
 790
 791         return (s->class == SESSION_USER && !s->stopping);
 792 }
 793
 794 static int elect_display_compare(Session *s1, Session *s2) {
 795         /* Indexed by SessionType. Lower numbers mean more preferred. */
 796         const int type_ranks[_SESSION_TYPE_MAX] = {
 797                 [SESSION_UNSPECIFIED] = 0,
 798                 [SESSION_TTY] = -2,
 799                 [SESSION_X11] = -3,
 800                 [SESSION_WAYLAND] = -3,
 801                 [SESSION_MIR] = -3,
 802                 [SESSION_WEB] = -1,
 803         };
 804
 805         /* Calculate the partial order relationship between s1 and s2,
 806          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 807          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 808          * is preferred.
 809          *
 810          * s1 or s2 may be NULL. */
 811         if (!s1 && !s2)
 812                 return 0;
 813
 814         if ((s1 == NULL) != (s2 == NULL))
 815                 return (s1 == NULL) - (s2 == NULL);
 816
 817         if (s1->stopping != s2->stopping)
 818                 return s1->stopping - s2->stopping;
 819
 820         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 821                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 822
 823         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 824                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 825
 826         if (s1->type != s2->type)
 827                 return type_ranks[s1->type] - type_ranks[s2->type];
 828
 829         return 0;
 830 }
 831
 832 void user_elect_display(User *u) {
 833         Session *s;
 834
 835         assert(u);
 836
 837         /* This elects a primary session for each user, which we call
 838          * the "display". We try to keep the assignment stable, but we
 839          * "upgrade" to better choices. */
 840         log_debug("Electing new display for user %s", u->name);
 841
 842         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 843                 if (!elect_display_filter(s)) {
 844                         log_debug("Ignoring session %s", s->id);
 845                         continue;
 846                 }
 847
 848                 if (elect_display_compare(s, u->display) < 0) {
 849                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 850                         u->display = s;
 851                 }
 852         }
 853 }
 854
 855 static const char* const user_state_table[_USER_STATE_MAX] = {
 856         [USER_OFFLINE] = "offline",
 857         [USER_OPENING] = "opening",
 858         [USER_LINGERING] = "lingering",
 859         [USER_ONLINE] = "online",
 860         [USER_ACTIVE] = "active",
 861         [USER_CLOSING] = "closing"
 862 };
 863
 864 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 865
 866 int config_parse_tmpfs_size(
 867                 const char* unit,
 868                 const char *filename,
 869                 unsigned line,
 870                 const char *section,
 871                 unsigned section_line,
 872                 const char *lvalue,
 873                 int ltype,
 874                 const char *rvalue,
 875                 void *data,
 876                 void *userdata) {
 877
 878         size_t *sz = data;
 879         int r;
 880
 881         assert(filename);
 882         assert(lvalue);
 883         assert(rvalue);
 884         assert(data);
 885
 886         /* First, try to parse as percentage */
 887         r = parse_percent(rvalue);
 888         if (r > 0 && r < 100)
 889                 *sz = physical_memory_scale(r, 100U);
 890         else {
 891                 uint64_t k;
 892
 893                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
 894
 895                 r = parse_size(rvalue, 1024, &k);
 896                 if (r < 0 || k <= 0 || (uint64_t) (size_t) k != k) {
 897                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse size value, ignoring: %s", rvalue);
 898                         return 0;
 899                 }
 900
 901                 *sz = PAGE_ALIGN((size_t) k);
 902         }
 903
 904         return 0;
 905 }
 906
 907 int config_parse_user_tasks_max(
 908                 const char* unit,
 909                 const char *filename,
 910                 unsigned line,
 911                 const char *section,
 912                 unsigned section_line,
 913                 const char *lvalue,
 914                 int ltype,
 915                 const char *rvalue,
 916                 void *data,
 917                 void *userdata) {
 918
 919         uint64_t *m = data;
 920         uint64_t k;
 921         int r;
 922
 923         assert(filename);
 924         assert(lvalue);
 925         assert(rvalue);
 926         assert(data);
 927
 928         if (isempty(rvalue)) {
 929                 *m = system_tasks_max_scale(DEFAULT_USER_TASKS_MAX_PERCENTAGE, 100U);
 930                 return 0;
 931         }
 932
 933         if (streq(rvalue, "infinity")) {
 934                 *m = CGROUP_LIMIT_MAX;
 935                 return 0;
 936         }
 937
 938         /* Try to parse as percentage */
 939         r = parse_percent(rvalue);
 940         if (r >= 0)
 941                 k = system_tasks_max_scale(r, 100U);
 942         else {
 943
 944                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
 945
 946                 r = safe_atou64(rvalue, &k);
 947                 if (r < 0) {
 948                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse tasks maximum, ignoring: %s", rvalue);
 949                         return 0;
 950                 }
 951         }
 952
 953         if (k <= 0 || k >= UINT64_MAX) {
 954                 log_syntax(unit, LOG_ERR, filename, line, 0, "Tasks maximum out of range, ignoring: %s", rvalue);
 955                 return 0;
 956         }
 957
 958         *m = k;
 959         return 0;
 960 }