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 #if 1 /// elogind uses a static value here
  53 #  define SPECIAL_USER_SLICE "user.slice"
  54 #endif // 1
  55
  56 int user_new(User **out, Manager *m, uid_t uid, gid_t gid, const char *name) {
  57         _cleanup_(user_freep) User *u = NULL;
  58         char lu[DECIMAL_STR_MAX(uid_t) + 1];
  59         int r;
  60
  61         assert(out);
  62         assert(m);
  63         assert(name);
  64
  65         u = new0(User, 1);
  66         if (!u)
  67                 return -ENOMEM;
  68
  69         u->manager = m;
  70         u->uid = uid;
  71         u->gid = gid;
  72         xsprintf(lu, UID_FMT, uid);
  73
  74         u->name = strdup(name);
  75         if (!u->name)
  76                 return -ENOMEM;
  77
  78         if (asprintf(&u->state_file, "/run/systemd/users/"UID_FMT, uid) < 0)
  79                 return -ENOMEM;
  80
  81         if (asprintf(&u->runtime_path, "/run/user/"UID_FMT, uid) < 0)
  82                 return -ENOMEM;
  83
  84         r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice);
  85         if (r < 0)
  86                 return r;
  87
  88         r = unit_name_build("user", lu, ".service", &u->service);
  89         if (r < 0)
  90                 return r;
  91
  92         r = hashmap_put(m->users, UID_TO_PTR(uid), u);
  93         if (r < 0)
  94                 return r;
  95
  96         r = hashmap_put(m->user_units, u->slice, u);
  97         if (r < 0)
  98                 return r;
  99
 100         r = hashmap_put(m->user_units, u->service, u);
 101         if (r < 0)
 102                 return r;
 103
 104         *out = u;
 105         u = NULL;
 106         return 0;
 107 }
 108
 109 User *user_free(User *u) {
 110         if (!u)
 111                 return NULL;
 112
 113         if (u->in_gc_queue)
 114                 LIST_REMOVE(gc_queue, u->manager->user_gc_queue, u);
 115
 116         while (u->sessions)
 117                 session_free(u->sessions);
 118
 119         if (u->service)
 120                 hashmap_remove_value(u->manager->user_units, u->service, u);
 121
 122         if (u->slice)
 123                 hashmap_remove_value(u->manager->user_units, u->slice, u);
 124
 125         hashmap_remove_value(u->manager->users, UID_TO_PTR(u->uid), u);
 126
 127 #if 0 /// elogind neither supports slice nor service jobs.
 128         u->slice_job = mfree(u->slice_job);
 129         u->service_job = mfree(u->service_job);
 130 #endif // 0
 131
 132         u->service = mfree(u->service);
 133         u->slice = mfree(u->slice);
 134         u->runtime_path = mfree(u->runtime_path);
 135         u->state_file = mfree(u->state_file);
 136         u->name = mfree(u->name);
 137
 138         return mfree(u);
 139 }
 140
 141 static int user_save_internal(User *u) {
 142         _cleanup_free_ char *temp_path = NULL;
 143         _cleanup_fclose_ FILE *f = NULL;
 144         int r;
 145
 146         assert(u);
 147         assert(u->state_file);
 148
 149         r = mkdir_safe_label("/run/systemd/users", 0755, 0, 0);
 150         if (r < 0)
 151                 goto fail;
 152
 153         r = fopen_temporary(u->state_file, &f, &temp_path);
 154         if (r < 0)
 155                 goto fail;
 156
 157         fchmod(fileno(f), 0644);
 158
 159         fprintf(f,
 160                 "# This is private data. Do not parse.\n"
 161                 "NAME=%s\n"
 162                 "STATE=%s\n",
 163                 u->name,
 164                 user_state_to_string(user_get_state(u)));
 165
 166         /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */
 167         if (u->runtime_path)
 168                 fprintf(f, "RUNTIME=%s\n", u->runtime_path);
 169
 170 #if 0 /// elogind neither supports service nor slice jobs
 171         if (u->service_job)
 172                 fprintf(f, "SERVICE_JOB=%s\n", u->service_job);
 173
 174         if (u->slice_job)
 175                 fprintf(f, "SLICE_JOB=%s\n", u->slice_job);
 176 #endif // 0
 177
 178         if (u->display)
 179                 fprintf(f, "DISPLAY=%s\n", u->display->id);
 180
 181         if (dual_timestamp_is_set(&u->timestamp))
 182                 fprintf(f,
 183                         "REALTIME="USEC_FMT"\n"
 184                         "MONOTONIC="USEC_FMT"\n",
 185                         u->timestamp.realtime,
 186                         u->timestamp.monotonic);
 187
 188         if (u->sessions) {
 189                 Session *i;
 190                 bool first;
 191
 192                 fputs("SESSIONS=", f);
 193                 first = true;
 194                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 195                         if (first)
 196                                 first = false;
 197                         else
 198                                 fputc(' ', f);
 199
 200                         fputs(i->id, f);
 201                 }
 202
 203                 fputs("\nSEATS=", f);
 204                 first = true;
 205                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 206                         if (!i->seat)
 207                                 continue;
 208
 209                         if (first)
 210                                 first = false;
 211                         else
 212                                 fputc(' ', f);
 213
 214                         fputs(i->seat->id, f);
 215                 }
 216
 217                 fputs("\nACTIVE_SESSIONS=", f);
 218                 first = true;
 219                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 220                         if (!session_is_active(i))
 221                                 continue;
 222
 223                         if (first)
 224                                 first = false;
 225                         else
 226                                 fputc(' ', f);
 227
 228                         fputs(i->id, f);
 229                 }
 230
 231                 fputs("\nONLINE_SESSIONS=", f);
 232                 first = true;
 233                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 234                         if (session_get_state(i) == SESSION_CLOSING)
 235                                 continue;
 236
 237                         if (first)
 238                                 first = false;
 239                         else
 240                                 fputc(' ', f);
 241
 242                         fputs(i->id, f);
 243                 }
 244
 245                 fputs("\nACTIVE_SEATS=", f);
 246                 first = true;
 247                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 248                         if (!session_is_active(i) || !i->seat)
 249                                 continue;
 250
 251                         if (first)
 252                                 first = false;
 253                         else
 254                                 fputc(' ', f);
 255
 256                         fputs(i->seat->id, f);
 257                 }
 258
 259                 fputs("\nONLINE_SEATS=", f);
 260                 first = true;
 261                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 262                         if (session_get_state(i) == SESSION_CLOSING || !i->seat)
 263                                 continue;
 264
 265                         if (first)
 266                                 first = false;
 267                         else
 268                                 fputc(' ', f);
 269
 270                         fputs(i->seat->id, f);
 271                 }
 272                 fputc('\n', f);
 273         }
 274
 275         r = fflush_and_check(f);
 276         if (r < 0)
 277                 goto fail;
 278
 279         if (rename(temp_path, u->state_file) < 0) {
 280                 r = -errno;
 281                 goto fail;
 282         }
 283
 284         return 0;
 285
 286 fail:
 287         (void) unlink(u->state_file);
 288
 289         if (temp_path)
 290                 (void) unlink(temp_path);
 291
 292         return log_error_errno(r, "Failed to save user data %s: %m", u->state_file);
 293 }
 294
 295 int user_save(User *u) {
 296         assert(u);
 297
 298         if (!u->started)
 299                 return 0;
 300
 301         return user_save_internal (u);
 302 }
 303
 304 int user_load(User *u) {
 305         _cleanup_free_ char *display = NULL, *realtime = NULL, *monotonic = NULL;
 306         Session *s = NULL;
 307         int r;
 308
 309         assert(u);
 310
 311         r = parse_env_file(u->state_file, NEWLINE,
 312 #if 0 /// elogind neither supports service nor slice jobs
 313                            "SERVICE_JOB", &u->service_job,
 314                            "SLICE_JOB",   &u->slice_job,
 315 #endif // 0
 316                            "DISPLAY",     &display,
 317                            "REALTIME",    &realtime,
 318                            "MONOTONIC",   &monotonic,
 319                            NULL);
 320         if (r < 0) {
 321                 if (r == -ENOENT)
 322                         return 0;
 323
 324                 return log_error_errno(r, "Failed to read %s: %m", u->state_file);
 325         }
 326
 327         if (display)
 328                 s = hashmap_get(u->manager->sessions, display);
 329
 330         if (s && s->display && display_is_local(s->display))
 331                 u->display = s;
 332
 333         if (realtime)
 334                 timestamp_deserialize(realtime, &u->timestamp.realtime);
 335         if (monotonic)
 336                 timestamp_deserialize(monotonic, &u->timestamp.monotonic);
 337
 338         return r;
 339 }
 340
 341 static int user_mkdir_runtime_path(User *u) {
 342         int r;
 343
 344         assert(u);
 345
 346         r = mkdir_safe_label("/run/user", 0755, 0, 0);
 347         if (r < 0)
 348                 return log_error_errno(r, "Failed to create /run/user: %m");
 349
 350         if (path_is_mount_point(u->runtime_path, 0) <= 0) {
 351                 _cleanup_free_ char *t = NULL;
 352
 353                 (void) mkdir_label(u->runtime_path, 0700);
 354
 355                 if (mac_smack_use())
 356                         r = asprintf(&t, "mode=0700,smackfsroot=*,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
 357                 else
 358                         r = asprintf(&t, "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
 359                 if (r < 0) {
 360                         r = log_oom();
 361                         goto fail;
 362                 }
 363
 364                 r = mount("tmpfs", u->runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, t);
 365                 if (r < 0) {
 366                         if (errno != EPERM) {
 367                                 r = log_error_errno(errno, "Failed to mount per-user tmpfs directory %s: %m", u->runtime_path);
 368                                 goto fail;
 369                         }
 370
 371                         /* Lacking permissions, maybe
 372                          * CAP_SYS_ADMIN-less container? In this case,
 373                          * just use a normal directory. */
 374
 375                         r = chmod_and_chown(u->runtime_path, 0700, u->uid, u->gid);
 376                         if (r < 0) {
 377                                 log_error_errno(r, "Failed to change runtime directory ownership and mode: %m");
 378                                 goto fail;
 379                         }
 380                 }
 381
 382                 r = label_fix(u->runtime_path, false, false);
 383                 if (r < 0)
 384                         log_warning_errno(r, "Failed to fix label of '%s', ignoring: %m", u->runtime_path);
 385         }
 386
 387         return 0;
 388
 389 fail:
 390         /* Try to clean up, but ignore errors */
 391         (void) rmdir(u->runtime_path);
 392         return r;
 393 }
 394
 395 static int user_start_slice(User *u) {
 396 #if 0 /// elogind can not ask systemd via dbus to start user services
 397         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 398         const char *description;
 399         char *job;
 400         int r;
 401
 402         assert(u);
 403
 404         u->slice_job = mfree(u->slice_job);
 405         description = strjoina("User Slice of ", u->name);
 406
 407         r = manager_start_slice(
 408                         u->manager,
 409                         u->slice,
 410                         description,
 411                         "systemd-logind.service",
 412                         "systemd-user-sessions.service",
 413                         u->manager->user_tasks_max,
 414                         &error,
 415                         &job);
 416         if (r >= 0)
 417                 u->slice_job = job;
 418         else if (!sd_bus_error_has_name(&error, BUS_ERROR_UNIT_EXISTS))
 419                 /* we don't fail due to this, let's try to continue */
 420                 log_error_errno(r, "Failed to start user slice %s, ignoring: %s (%s)",
 421                                 u->slice, bus_error_message(&error, r), error.name);
 422 #else
 423         assert(u);
 424
 425         hashmap_put(u->manager->user_units, u->slice, u);
 426 #endif // 0
 427
 428         return 0;
 429 }
 430
 431 static int user_start_service(User *u) {
 432 #if 0 /// elogind can not ask systemd via dbus to start user services
 433         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 434         char *job;
 435         int r;
 436
 437         assert(u);
 438
 439         u->service_job = mfree(u->service_job);
 440
 441         r = manager_start_unit(
 442                         u->manager,
 443                         u->service,
 444                         &error,
 445                         &job);
 446         if (r < 0) {
 447                 /* we don't fail due to this, let's try to continue */
 448                 log_error_errno(r, "Failed to start user service, ignoring: %s", bus_error_message(&error, r));
 449         } else {
 450                 u->service_job = job;
 451         }
 452 #else
 453         assert(u);
 454
 455         hashmap_put(u->manager->user_units, u->service, u);
 456 #endif // 0
 457
 458         return 0;
 459 }
 460
 461 int user_start(User *u) {
 462         int r;
 463
 464         assert(u);
 465
 466         if (u->started && !u->stopping)
 467                 return 0;
 468
 469         /*
 470          * If u->stopping is set, the user is marked for removal and the slice
 471          * and service stop-jobs are queued. We have to clear that flag before
 472          * queing the start-jobs again. If they succeed, the user object can be
 473          * re-used just fine (pid1 takes care of job-ordering and proper
 474          * restart), but if they fail, we want to force another user_stop() so
 475          * possibly pending units are stopped.
 476          * Note that we don't clear u->started, as we have no clue what state
 477          * the user is in on failure here. Hence, we pretend the user is
 478          * running so it will be properly taken down by GC. However, we clearly
 479          * return an error from user_start() in that case, so no further
 480          * reference to the user is taken.
 481          */
 482         u->stopping = false;
 483
 484         if (!u->started) {
 485                 log_debug("New user %s logged in.", u->name);
 486
 487                 /* Make XDG_RUNTIME_DIR */
 488                 r = user_mkdir_runtime_path(u);
 489                 if (r < 0)
 490                         return r;
 491         }
 492
 493         /* Create cgroup */
 494         r = user_start_slice(u);
 495         if (r < 0)
 496                 return r;
 497
 498         /* Save the user data so far, because pam_systemd will read the
 499          * XDG_RUNTIME_DIR out of it while starting up systemd --user.
 500          * We need to do user_save_internal() because we have not
 501          * "officially" started yet. */
 502         user_save_internal(u);
 503
 504         /* Spawn user systemd */
 505         r = user_start_service(u);
 506         if (r < 0)
 507                 return r;
 508
 509         if (!u->started) {
 510                 if (!dual_timestamp_is_set(&u->timestamp))
 511                         dual_timestamp_get(&u->timestamp);
 512                 user_send_signal(u, true);
 513                 u->started = true;
 514         }
 515
 516         /* Save new user data */
 517         user_save(u);
 518
 519         return 0;
 520 }
 521
 522 #if 0 /// UNNEEDED by elogind
 523 static int user_stop_slice(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->slice, &error, &job);
 531         if (r < 0) {
 532                 log_error("Failed to stop user slice: %s", bus_error_message(&error, r));
 533                 return r;
 534         }
 535
 536         free(u->slice_job);
 537         u->slice_job = job;
 538
 539         return r;
 540 }
 541
 542 static int user_stop_service(User *u) {
 543         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 544         char *job;
 545         int r;
 546
 547         assert(u);
 548
 549         r = manager_stop_unit(u->manager, u->service, &error, &job);
 550         if (r < 0) {
 551                 log_error("Failed to stop user service: %s", bus_error_message(&error, r));
 552                 return r;
 553         }
 554
 555         free(u->service_job);
 556         u->service_job = job;
 557
 558         return r;
 559 }
 560 #endif // 0
 561
 562 static int user_remove_runtime_path(User *u) {
 563         int r;
 564
 565         assert(u);
 566
 567         r = rm_rf(u->runtime_path, 0);
 568         if (r < 0)
 569                 log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
 570
 571         /* Ignore cases where the directory isn't mounted, as that's
 572          * quite possible, if we lacked the permissions to mount
 573          * something */
 574         r = umount2(u->runtime_path, MNT_DETACH);
 575         if (r < 0 && errno != EINVAL && errno != ENOENT)
 576                 log_error_errno(errno, "Failed to unmount user runtime directory %s: %m", u->runtime_path);
 577
 578         r = rm_rf(u->runtime_path, REMOVE_ROOT);
 579         if (r < 0)
 580                 log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
 581
 582         return r;
 583 }
 584
 585 int user_stop(User *u, bool force) {
 586         Session *s;
 587         int r = 0, k;
 588         assert(u);
 589
 590         /* Stop jobs have already been queued */
 591         if (u->stopping) {
 592                 user_save(u);
 593                 return r;
 594         }
 595
 596         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 597                 k = session_stop(s, force);
 598                 if (k < 0)
 599                         r = k;
 600         }
 601
 602         /* Kill systemd */
 603 #if 0 /// elogind does not support service or slice jobs
 604         k = user_stop_service(u);
 605         if (k < 0)
 606                 r = k;
 607
 608         /* Kill cgroup */
 609         k = user_stop_slice(u);
 610         if (k < 0)
 611                 r = k;
 612 #endif // 0
 613
 614         u->stopping = true;
 615
 616         user_save(u);
 617
 618         return r;
 619 }
 620
 621 int user_finalize(User *u) {
 622         Session *s;
 623         int r = 0, k;
 624
 625         assert(u);
 626
 627         if (u->started)
 628                 log_debug("User %s logged out.", u->name);
 629
 630         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 631                 k = session_finalize(s);
 632                 if (k < 0)
 633                         r = k;
 634         }
 635
 636         /* Kill XDG_RUNTIME_DIR */
 637         k = user_remove_runtime_path(u);
 638         if (k < 0)
 639                 r = k;
 640
 641         /* Clean SysV + POSIX IPC objects */
 642         if (u->manager->remove_ipc) {
 643                 k = clean_ipc(u->uid);
 644                 if (k < 0)
 645                         r = k;
 646         }
 647
 648         unlink(u->state_file);
 649         user_add_to_gc_queue(u);
 650
 651         if (u->started) {
 652                 user_send_signal(u, false);
 653                 u->started = false;
 654         }
 655
 656         return r;
 657 }
 658
 659 int user_get_idle_hint(User *u, dual_timestamp *t) {
 660         Session *s;
 661         bool idle_hint = true;
 662         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 663
 664         assert(u);
 665
 666         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 667                 dual_timestamp k;
 668                 int ih;
 669
 670                 ih = session_get_idle_hint(s, &k);
 671                 if (ih < 0)
 672                         return ih;
 673
 674                 if (!ih) {
 675                         if (!idle_hint) {
 676                                 if (k.monotonic < ts.monotonic)
 677                                         ts = k;
 678                         } else {
 679                                 idle_hint = false;
 680                                 ts = k;
 681                         }
 682                 } else if (idle_hint) {
 683
 684                         if (k.monotonic > ts.monotonic)
 685                                 ts = k;
 686                 }
 687         }
 688
 689         if (t)
 690                 *t = ts;
 691
 692         return idle_hint;
 693 }
 694
 695 int user_check_linger_file(User *u) {
 696         _cleanup_free_ char *cc = NULL;
 697         char *p = NULL;
 698
 699         cc = cescape(u->name);
 700         if (!cc)
 701                 return -ENOMEM;
 702
 703         p = strjoina("/var/lib/systemd/linger/", cc);
 704
 705         return access(p, F_OK) >= 0;
 706 }
 707
 708 bool user_check_gc(User *u, bool drop_not_started) {
 709         assert(u);
 710
 711         if (drop_not_started && !u->started)
 712                 return false;
 713
 714         if (u->sessions)
 715                 return true;
 716
 717         if (user_check_linger_file(u) > 0)
 718                 return true;
 719
 720 #if 0 /// elogind neither supports service nor slice jobs
 721         if (u->slice_job && manager_job_is_active(u->manager, u->slice_job))
 722                 return true;
 723
 724         if (u->service_job && manager_job_is_active(u->manager, u->service_job))
 725                 return true;
 726 #endif // 0
 727
 728         return false;
 729 }
 730
 731 void user_add_to_gc_queue(User *u) {
 732         assert(u);
 733
 734         if (u->in_gc_queue)
 735                 return;
 736
 737         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 738         u->in_gc_queue = true;
 739 }
 740
 741 UserState user_get_state(User *u) {
 742         Session *i;
 743
 744         assert(u);
 745
 746         if (u->stopping)
 747                 return USER_CLOSING;
 748
 749 #if 0 /// elogind neither supports service nor slice jobs.
 750         if (!u->started || u->slice_job || u->service_job)
 751 #else
 752         if (!u->started)
 753 #endif // 0
 754                 return USER_OPENING;
 755
 756         if (u->sessions) {
 757                 bool all_closing = true;
 758
 759                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 760                         SessionState state;
 761
 762                         state = session_get_state(i);
 763                         if (state == SESSION_ACTIVE)
 764                                 return USER_ACTIVE;
 765                         if (state != SESSION_CLOSING)
 766                                 all_closing = false;
 767                 }
 768
 769                 return all_closing ? USER_CLOSING : USER_ONLINE;
 770         }
 771
 772         if (user_check_linger_file(u) > 0)
 773                 return USER_LINGERING;
 774
 775         return USER_CLOSING;
 776 }
 777
 778 int user_kill(User *u, int signo) {
 779 #if 0 /// Without systemd unit support, elogind has to rely on its session system
 780         assert(u);
 781
 782         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 783 #else
 784         Session *s;
 785         int res = 0;
 786
 787         assert(u);
 788
 789         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 790                 int r = session_kill(s, KILL_ALL, signo);
 791                 if (res == 0 && r < 0)
 792                         res = r;
 793         }
 794
 795         return res;
 796 #endif // 0
 797 }
 798
 799 static bool elect_display_filter(Session *s) {
 800         /* Return true if the session is a candidate for the user’s ‘primary
 801          * session’ or ‘display’. */
 802         assert(s);
 803
 804         return (s->class == SESSION_USER && !s->stopping);
 805 }
 806
 807 static int elect_display_compare(Session *s1, Session *s2) {
 808         /* Indexed by SessionType. Lower numbers mean more preferred. */
 809         const int type_ranks[_SESSION_TYPE_MAX] = {
 810                 [SESSION_UNSPECIFIED] = 0,
 811                 [SESSION_TTY] = -2,
 812                 [SESSION_X11] = -3,
 813                 [SESSION_WAYLAND] = -3,
 814                 [SESSION_MIR] = -3,
 815                 [SESSION_WEB] = -1,
 816         };
 817
 818         /* Calculate the partial order relationship between s1 and s2,
 819          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 820          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 821          * is preferred.
 822          *
 823          * s1 or s2 may be NULL. */
 824         if (!s1 && !s2)
 825                 return 0;
 826
 827         if ((s1 == NULL) != (s2 == NULL))
 828                 return (s1 == NULL) - (s2 == NULL);
 829
 830         if (s1->stopping != s2->stopping)
 831                 return s1->stopping - s2->stopping;
 832
 833         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 834                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 835
 836         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 837                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 838
 839         if (s1->type != s2->type)
 840                 return type_ranks[s1->type] - type_ranks[s2->type];
 841
 842         return 0;
 843 }
 844
 845 void user_elect_display(User *u) {
 846         Session *s;
 847
 848         assert(u);
 849
 850         /* This elects a primary session for each user, which we call
 851          * the "display". We try to keep the assignment stable, but we
 852          * "upgrade" to better choices. */
 853         log_debug("Electing new display for user %s", u->name);
 854
 855         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 856                 if (!elect_display_filter(s)) {
 857                         log_debug("Ignoring session %s", s->id);
 858                         continue;
 859                 }
 860
 861                 if (elect_display_compare(s, u->display) < 0) {
 862                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 863                         u->display = s;
 864                 }
 865         }
 866 }
 867
 868 static const char* const user_state_table[_USER_STATE_MAX] = {
 869         [USER_OFFLINE] = "offline",
 870         [USER_OPENING] = "opening",
 871         [USER_LINGERING] = "lingering",
 872         [USER_ONLINE] = "online",
 873         [USER_ACTIVE] = "active",
 874         [USER_CLOSING] = "closing"
 875 };
 876
 877 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 878
 879 int config_parse_tmpfs_size(
 880                 const char* unit,
 881                 const char *filename,
 882                 unsigned line,
 883                 const char *section,
 884                 unsigned section_line,
 885                 const char *lvalue,
 886                 int ltype,
 887                 const char *rvalue,
 888                 void *data,
 889                 void *userdata) {
 890
 891         size_t *sz = data;
 892         int r;
 893
 894         assert(filename);
 895         assert(lvalue);
 896         assert(rvalue);
 897         assert(data);
 898
 899         /* First, try to parse as percentage */
 900         r = parse_percent(rvalue);
 901         if (r > 0 && r < 100)
 902                 *sz = physical_memory_scale(r, 100U);
 903         else {
 904                 uint64_t k;
 905
 906                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
 907
 908                 r = parse_size(rvalue, 1024, &k);
 909                 if (r < 0 || k <= 0 || (uint64_t) (size_t) k != k) {
 910                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse size value, ignoring: %s", rvalue);
 911                         return 0;
 912                 }
 913
 914                 *sz = PAGE_ALIGN((size_t) k);
 915         }
 916
 917         return 0;
 918 }
 919
 920 int config_parse_user_tasks_max(
 921                 const char* unit,
 922                 const char *filename,
 923                 unsigned line,
 924                 const char *section,
 925                 unsigned section_line,
 926                 const char *lvalue,
 927                 int ltype,
 928                 const char *rvalue,
 929                 void *data,
 930                 void *userdata) {
 931
 932         uint64_t *m = data;
 933         uint64_t k;
 934         int r;
 935
 936         assert(filename);
 937         assert(lvalue);
 938         assert(rvalue);
 939         assert(data);
 940
 941         /* First, try to parse as percentage */
 942         r = parse_percent(rvalue);
 943         if (r >= 0)
 944                 k = system_tasks_max_scale(r, 100U);
 945         else {
 946
 947                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
 948
 949                 r = safe_atou64(rvalue, &k);
 950                 if (r < 0) {
 951                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse tasks maximum, ignoring: %s", rvalue);
 952                         return 0;
 953                 }
 954         }
 955
 956         if (k <= 0 || k >= UINT64_MAX) {
 957                 log_syntax(unit, LOG_ERR, filename, line, 0, "Tasks maximum out of range, ignoring: %s", rvalue);
 958                 return 0;
 959         }
 960
 961         *m = k;
 962         return 0;
 963 }