src/login/logind.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7
   8 #include "sd-daemon.h"
   9 #include "sd-device.h"
  10
  11 #include "alloc-util.h"
  12 #include "bus-error.h"
  13 #include "bus-util.h"
  14 #include "cgroup-util.h"
  15 #include "def.h"
  16 #include "device-util.h"
  17 #include "dirent-util.h"
  18 #include "fd-util.h"
  19 #include "format-util.h"
  20 #include "fs-util.h"
  21 #include "logind.h"
  22 #include "main-func.h"
  23 #include "parse-util.h"
  24 #include "process-util.h"
  25 #include "selinux-util.h"
  26 #include "signal-util.h"
  27 #include "strv.h"
  28 #include "terminal-util.h"
  29
  30 static Manager* manager_unref(Manager *m);
  31 DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_unref);
  32
  33 static int manager_new(Manager **ret) {
  34         _cleanup_(manager_unrefp) Manager *m = NULL;
  35         int r;
  36
  37         assert(ret);
  38
  39         m = new(Manager, 1);
  40         if (!m)
  41                 return -ENOMEM;
  42
  43         *m = (Manager) {
  44                 .console_active_fd = -1,
  45                 .reserve_vt_fd = -1,
  46         };
  47
  48         m->idle_action_not_before_usec = now(CLOCK_MONOTONIC);
  49
  50         m->devices = hashmap_new(&string_hash_ops);
  51         m->seats = hashmap_new(&string_hash_ops);
  52         m->sessions = hashmap_new(&string_hash_ops);
  53         m->sessions_by_leader = hashmap_new(NULL);
  54         m->users = hashmap_new(NULL);
  55         m->inhibitors = hashmap_new(&string_hash_ops);
  56         m->buttons = hashmap_new(&string_hash_ops);
  57
  58         m->user_units = hashmap_new(&string_hash_ops);
  59         m->session_units = hashmap_new(&string_hash_ops);
  60
  61         if (!m->devices || !m->seats || !m->sessions || !m->sessions_by_leader || !m->users || !m->inhibitors || !m->buttons || !m->user_units || !m->session_units)
  62                 return -ENOMEM;
  63
  64         r = sd_event_default(&m->event);
  65         if (r < 0)
  66                 return r;
  67
  68         r = sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
  69         if (r < 0)
  70                 return r;
  71
  72         r = sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL);
  73         if (r < 0)
  74                 return r;
  75
  76         (void) sd_event_set_watchdog(m->event, true);
  77
  78         manager_reset_config(m);
  79
  80         *ret = TAKE_PTR(m);
  81         return 0;
  82 }
  83
  84 static Manager* manager_unref(Manager *m) {
  85         Session *session;
  86         User *u;
  87         Device *d;
  88         Seat *s;
  89         Inhibitor *i;
  90         Button *b;
  91
  92         if (!m)
  93                 return NULL;
  94
  95         while ((session = hashmap_first(m->sessions)))
  96                 session_free(session);
  97
  98         while ((u = hashmap_first(m->users)))
  99                 user_free(u);
 100
 101         while ((d = hashmap_first(m->devices)))
 102                 device_free(d);
 103
 104         while ((s = hashmap_first(m->seats)))
 105                 seat_free(s);
 106
 107         while ((i = hashmap_first(m->inhibitors)))
 108                 inhibitor_free(i);
 109
 110         while ((b = hashmap_first(m->buttons)))
 111                 button_free(b);
 112
 113         hashmap_free(m->devices);
 114         hashmap_free(m->seats);
 115         hashmap_free(m->sessions);
 116         hashmap_free(m->sessions_by_leader);
 117         hashmap_free(m->users);
 118         hashmap_free(m->inhibitors);
 119         hashmap_free(m->buttons);
 120
 121         hashmap_free(m->user_units);
 122         hashmap_free(m->session_units);
 123
 124         sd_event_source_unref(m->idle_action_event_source);
 125         sd_event_source_unref(m->inhibit_timeout_source);
 126         sd_event_source_unref(m->scheduled_shutdown_timeout_source);
 127         sd_event_source_unref(m->nologin_timeout_source);
 128         sd_event_source_unref(m->wall_message_timeout_source);
 129
 130         sd_event_source_unref(m->console_active_event_source);
 131         sd_event_source_unref(m->lid_switch_ignore_event_source);
 132
 133 #if ENABLE_UTMP
 134         sd_event_source_unref(m->utmp_event_source);
 135 #endif
 136
 137         safe_close(m->console_active_fd);
 138
 139         sd_device_monitor_unref(m->device_seat_monitor);
 140         sd_device_monitor_unref(m->device_monitor);
 141         sd_device_monitor_unref(m->device_vcsa_monitor);
 142         sd_device_monitor_unref(m->device_button_monitor);
 143
 144         if (m->unlink_nologin)
 145                 (void) unlink_or_warn("/run/nologin");
 146
 147         bus_verify_polkit_async_registry_free(m->polkit_registry);
 148
 149         sd_bus_unref(m->bus);
 150         sd_event_unref(m->event);
 151
 152         safe_close(m->reserve_vt_fd);
 153
 154         strv_free(m->kill_only_users);
 155         strv_free(m->kill_exclude_users);
 156
 157         free(m->scheduled_shutdown_type);
 158         free(m->scheduled_shutdown_tty);
 159         free(m->wall_message);
 160         free(m->action_job);
 161
 162         return mfree(m);
 163 }
 164
 165 static int manager_enumerate_devices(Manager *m) {
 166         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
 167         sd_device *d;
 168         int r;
 169
 170         assert(m);
 171
 172         /* Loads devices from udev and creates seats for them as
 173          * necessary */
 174
 175         r = sd_device_enumerator_new(&e);
 176         if (r < 0)
 177                 return r;
 178
 179         r = sd_device_enumerator_add_match_tag(e, "master-of-seat");
 180         if (r < 0)
 181                 return r;
 182
 183         FOREACH_DEVICE(e, d) {
 184                 int k;
 185
 186                 k = manager_process_seat_device(m, d);
 187                 if (k < 0)
 188                         r = k;
 189         }
 190
 191         return r;
 192 }
 193
 194 static int manager_enumerate_buttons(Manager *m) {
 195         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
 196         sd_device *d;
 197         int r;
 198
 199         assert(m);
 200
 201         /* Loads buttons from udev */
 202
 203         if (manager_all_buttons_ignored(m))
 204                 return 0;
 205
 206         r = sd_device_enumerator_new(&e);
 207         if (r < 0)
 208                 return r;
 209
 210         r = sd_device_enumerator_add_match_subsystem(e, "input", true);
 211         if (r < 0)
 212                 return r;
 213
 214         r = sd_device_enumerator_add_match_tag(e, "power-switch");
 215         if (r < 0)
 216                 return r;
 217
 218         FOREACH_DEVICE(e, d) {
 219                 int k;
 220
 221                 k = manager_process_button_device(m, d);
 222                 if (k < 0)
 223                         r = k;
 224         }
 225
 226         return r;
 227 }
 228
 229 static int manager_enumerate_seats(Manager *m) {
 230         _cleanup_closedir_ DIR *d = NULL;
 231         struct dirent *de;
 232         int r = 0;
 233
 234         assert(m);
 235
 236         /* This loads data about seats stored on disk, but does not
 237          * actually create any seats. Removes data of seats that no
 238          * longer exist. */
 239
 240         d = opendir("/run/systemd/seats");
 241         if (!d) {
 242                 if (errno == ENOENT)
 243                         return 0;
 244
 245                 return log_error_errno(errno, "Failed to open /run/systemd/seats: %m");
 246         }
 247
 248         FOREACH_DIRENT(de, d, return -errno) {
 249                 Seat *s;
 250                 int k;
 251
 252                 if (!dirent_is_file(de))
 253                         continue;
 254
 255                 s = hashmap_get(m->seats, de->d_name);
 256                 if (!s) {
 257                         if (unlinkat(dirfd(d), de->d_name, 0) < 0)
 258                                 log_warning("Failed to remove /run/systemd/seats/%s: %m",
 259                                             de->d_name);
 260                         continue;
 261                 }
 262
 263                 k = seat_load(s);
 264                 if (k < 0)
 265                         r = k;
 266         }
 267
 268         return r;
 269 }
 270
 271 static int manager_enumerate_linger_users(Manager *m) {
 272         _cleanup_closedir_ DIR *d = NULL;
 273         struct dirent *de;
 274         int r = 0;
 275
 276         assert(m);
 277
 278         d = opendir("/var/lib/systemd/linger");
 279         if (!d) {
 280                 if (errno == ENOENT)
 281                         return 0;
 282
 283                 return log_error_errno(errno, "Failed to open /var/lib/systemd/linger/: %m");
 284         }
 285
 286         FOREACH_DIRENT(de, d, return -errno) {
 287                 int k;
 288
 289                 if (!dirent_is_file(de))
 290                         continue;
 291
 292                 k = manager_add_user_by_name(m, de->d_name, NULL);
 293                 if (k < 0) {
 294                         log_notice_errno(k, "Couldn't add lingering user %s: %m", de->d_name);
 295                         r = k;
 296                 }
 297         }
 298
 299         return r;
 300 }
 301
 302 static int manager_enumerate_users(Manager *m) {
 303         _cleanup_closedir_ DIR *d = NULL;
 304         struct dirent *de;
 305         int r, k;
 306
 307         assert(m);
 308
 309         /* Add lingering users */
 310         r = manager_enumerate_linger_users(m);
 311
 312         /* Read in user data stored on disk */
 313         d = opendir("/run/systemd/users");
 314         if (!d) {
 315                 if (errno == ENOENT)
 316                         return 0;
 317
 318                 return log_error_errno(errno, "Failed to open /run/systemd/users: %m");
 319         }
 320
 321         FOREACH_DIRENT(de, d, return -errno) {
 322                 User *u;
 323
 324                 if (!dirent_is_file(de))
 325                         continue;
 326
 327                 k = manager_add_user_by_name(m, de->d_name, &u);
 328                 if (k < 0) {
 329                         log_error_errno(k, "Failed to add user by file name %s: %m", de->d_name);
 330
 331                         r = k;
 332                         continue;
 333                 }
 334
 335                 user_add_to_gc_queue(u);
 336
 337                 k = user_load(u);
 338                 if (k < 0)
 339                         r = k;
 340         }
 341
 342         return r;
 343 }
 344
 345 static int parse_fdname(const char *fdname, char **session_id, dev_t *dev) {
 346         _cleanup_strv_free_ char **parts = NULL;
 347         _cleanup_free_ char *id = NULL;
 348         unsigned major, minor;
 349         int r;
 350
 351         parts = strv_split(fdname, "-");
 352         if (!parts)
 353                 return -ENOMEM;
 354         if (strv_length(parts) != 5)
 355                 return -EINVAL;
 356
 357         if (!streq(parts[0], "session"))
 358                 return -EINVAL;
 359
 360         id = strdup(parts[1]);
 361         if (!id)
 362                 return -ENOMEM;
 363
 364         if (!streq(parts[2], "device"))
 365                 return -EINVAL;
 366
 367         r = safe_atou(parts[3], &major);
 368         if (r < 0)
 369                 return r;
 370         r = safe_atou(parts[4], &minor);
 371         if (r < 0)
 372                 return r;
 373
 374         *dev = makedev(major, minor);
 375         *session_id = TAKE_PTR(id);
 376
 377         return 0;
 378 }
 379
 380 static int manager_attach_fds(Manager *m) {
 381         _cleanup_strv_free_ char **fdnames = NULL;
 382         int n, i, fd;
 383
 384         /* Upon restart, PID1 will send us back all fds of session devices
 385          * that we previously opened. Each file descriptor is associated
 386          * with a given session. The session ids are passed through FDNAMES. */
 387
 388         n = sd_listen_fds_with_names(true, &fdnames);
 389         if (n <= 0)
 390                 return n;
 391
 392         for (i = 0; i < n; i++) {
 393                 _cleanup_free_ char *id = NULL;
 394                 dev_t dev;
 395                 struct stat st;
 396                 SessionDevice *sd;
 397                 Session *s;
 398                 int r;
 399
 400                 fd = SD_LISTEN_FDS_START + i;
 401
 402                 r = parse_fdname(fdnames[i], &id, &dev);
 403                 if (r < 0) {
 404                         log_debug_errno(r, "Failed to parse fd name %s: %m", fdnames[i]);
 405                         close_nointr(fd);
 406                         continue;
 407                 }
 408
 409                 s = hashmap_get(m->sessions, id);
 410                 if (!s) {
 411                         /* If the session doesn't exist anymore, the associated session
 412                          * device attached to this fd doesn't either. Let's simply close
 413                          * this fd. */
 414                         log_debug("Failed to attach fd for unknown session: %s", id);
 415                         close_nointr(fd);
 416                         continue;
 417                 }
 418
 419                 if (fstat(fd, &st) < 0) {
 420                         /* The device is allowed to go away at a random point, in which
 421                          * case fstat failing is expected. */
 422                         log_debug_errno(errno, "Failed to stat device fd for session %s: %m", id);
 423                         close_nointr(fd);
 424                         continue;
 425                 }
 426
 427                 if (!S_ISCHR(st.st_mode) || st.st_rdev != dev) {
 428                         log_debug("Device fd doesn't point to the expected character device node");
 429                         close_nointr(fd);
 430                         continue;
 431                 }
 432
 433                 sd = hashmap_get(s->devices, &dev);
 434                 if (!sd) {
 435                         /* Weird, we got an fd for a session device which wasn't
 436                          * recorded in the session state file... */
 437                         log_warning("Got fd for missing session device [%u:%u] in session %s",
 438                                     major(dev), minor(dev), s->id);
 439                         close_nointr(fd);
 440                         continue;
 441                 }
 442
 443                 log_debug("Attaching fd to session device [%u:%u] for session %s",
 444                           major(dev), minor(dev), s->id);
 445
 446                 session_device_attach_fd(sd, fd, s->was_active);
 447         }
 448
 449         return 0;
 450 }
 451
 452 static int manager_enumerate_sessions(Manager *m) {
 453         _cleanup_closedir_ DIR *d = NULL;
 454         struct dirent *de;
 455         int r = 0, k;
 456
 457         assert(m);
 458
 459         /* Read in session data stored on disk */
 460         d = opendir("/run/systemd/sessions");
 461         if (!d) {
 462                 if (errno == ENOENT)
 463                         return 0;
 464
 465                 return log_error_errno(errno, "Failed to open /run/systemd/sessions: %m");
 466         }
 467
 468         FOREACH_DIRENT(de, d, return -errno) {
 469                 struct Session *s;
 470
 471                 if (!dirent_is_file(de))
 472                         continue;
 473
 474                 if (!session_id_valid(de->d_name)) {
 475                         log_warning("Invalid session file name '%s', ignoring.", de->d_name);
 476                         r = -EINVAL;
 477                         continue;
 478                 }
 479
 480                 k = manager_add_session(m, de->d_name, &s);
 481                 if (k < 0) {
 482                         log_error_errno(k, "Failed to add session by file name %s: %m", de->d_name);
 483                         r = k;
 484                         continue;
 485                 }
 486
 487                 session_add_to_gc_queue(s);
 488
 489                 k = session_load(s);
 490                 if (k < 0)
 491                         r = k;
 492         }
 493
 494         /* We might be restarted and PID1 could have sent us back the
 495          * session device fds we previously saved. */
 496         k = manager_attach_fds(m);
 497         if (k < 0)
 498                 log_warning_errno(k, "Failed to reattach session device fds: %m");
 499
 500         return r;
 501 }
 502
 503 static int manager_enumerate_inhibitors(Manager *m) {
 504         _cleanup_closedir_ DIR *d = NULL;
 505         struct dirent *de;
 506         int r = 0;
 507
 508         assert(m);
 509
 510         d = opendir("/run/systemd/inhibit");
 511         if (!d) {
 512                 if (errno == ENOENT)
 513                         return 0;
 514
 515                 return log_error_errno(errno, "Failed to open /run/systemd/inhibit: %m");
 516         }
 517
 518         FOREACH_DIRENT(de, d, return -errno) {
 519                 int k;
 520                 Inhibitor *i;
 521
 522                 if (!dirent_is_file(de))
 523                         continue;
 524
 525                 k = manager_add_inhibitor(m, de->d_name, &i);
 526                 if (k < 0) {
 527                         log_notice_errno(k, "Couldn't add inhibitor %s: %m", de->d_name);
 528                         r = k;
 529                         continue;
 530                 }
 531
 532                 k = inhibitor_load(i);
 533                 if (k < 0)
 534                         r = k;
 535         }
 536
 537         return r;
 538 }
 539
 540 static int manager_dispatch_seat_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 541         Manager *m = userdata;
 542
 543         assert(m);
 544         assert(device);
 545
 546         manager_process_seat_device(m, device);
 547         return 0;
 548 }
 549
 550 static int manager_dispatch_device_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 551         Manager *m = userdata;
 552
 553         assert(m);
 554         assert(device);
 555
 556         manager_process_seat_device(m, device);
 557         return 0;
 558 }
 559
 560 static int manager_dispatch_vcsa_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 561         Manager *m = userdata;
 562         const char *name, *action;
 563
 564         assert(m);
 565         assert(device);
 566
 567         /* Whenever a VCSA device is removed try to reallocate our
 568          * VTs, to make sure our auto VTs never go away. */
 569
 570         if (sd_device_get_sysname(device, &name) >= 0 &&
 571             startswith(name, "vcsa") &&
 572             sd_device_get_property_value(device, "ACTION", &action) >= 0 &&
 573             streq(action, "remove"))
 574                 seat_preallocate_vts(m->seat0);
 575
 576         return 0;
 577 }
 578
 579 static int manager_dispatch_button_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 580         Manager *m = userdata;
 581
 582         assert(m);
 583         assert(device);
 584
 585         manager_process_button_device(m, device);
 586         return 0;
 587 }
 588
 589 static int manager_dispatch_console(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 590         Manager *m = userdata;
 591
 592         assert(m);
 593         assert(m->seat0);
 594         assert(m->console_active_fd == fd);
 595
 596         seat_read_active_vt(m->seat0);
 597         return 0;
 598 }
 599
 600 static int manager_reserve_vt(Manager *m) {
 601         _cleanup_free_ char *p = NULL;
 602
 603         assert(m);
 604
 605         if (m->reserve_vt <= 0)
 606                 return 0;
 607
 608         if (asprintf(&p, "/dev/tty%u", m->reserve_vt) < 0)
 609                 return log_oom();
 610
 611         m->reserve_vt_fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
 612         if (m->reserve_vt_fd < 0) {
 613
 614                 /* Don't complain on VT-less systems */
 615                 if (errno != ENOENT)
 616                         log_warning_errno(errno, "Failed to pin reserved VT: %m");
 617                 return -errno;
 618         }
 619
 620         return 0;
 621 }
 622
 623 static int manager_connect_bus(Manager *m) {
 624         int r;
 625
 626         assert(m);
 627         assert(!m->bus);
 628
 629         r = sd_bus_default_system(&m->bus);
 630         if (r < 0)
 631                 return log_error_errno(r, "Failed to connect to system bus: %m");
 632
 633         r = sd_bus_add_object_vtable(m->bus, NULL, "/org/freedesktop/login1", "org.freedesktop.login1.Manager", manager_vtable, m);
 634         if (r < 0)
 635                 return log_error_errno(r, "Failed to add manager object vtable: %m");
 636
 637         r = sd_bus_add_fallback_vtable(m->bus, NULL, "/org/freedesktop/login1/seat", "org.freedesktop.login1.Seat", seat_vtable, seat_object_find, m);
 638         if (r < 0)
 639                 return log_error_errno(r, "Failed to add seat object vtable: %m");
 640
 641         r = sd_bus_add_node_enumerator(m->bus, NULL, "/org/freedesktop/login1/seat", seat_node_enumerator, m);
 642         if (r < 0)
 643                 return log_error_errno(r, "Failed to add seat enumerator: %m");
 644
 645         r = sd_bus_add_fallback_vtable(m->bus, NULL, "/org/freedesktop/login1/session", "org.freedesktop.login1.Session", session_vtable, session_object_find, m);
 646         if (r < 0)
 647                 return log_error_errno(r, "Failed to add session object vtable: %m");
 648
 649         r = sd_bus_add_node_enumerator(m->bus, NULL, "/org/freedesktop/login1/session", session_node_enumerator, m);
 650         if (r < 0)
 651                 return log_error_errno(r, "Failed to add session enumerator: %m");
 652
 653         r = sd_bus_add_fallback_vtable(m->bus, NULL, "/org/freedesktop/login1/user", "org.freedesktop.login1.User", user_vtable, user_object_find, m);
 654         if (r < 0)
 655                 return log_error_errno(r, "Failed to add user object vtable: %m");
 656
 657         r = sd_bus_add_node_enumerator(m->bus, NULL, "/org/freedesktop/login1/user", user_node_enumerator, m);
 658         if (r < 0)
 659                 return log_error_errno(r, "Failed to add user enumerator: %m");
 660
 661         r = sd_bus_match_signal_async(
 662                         m->bus,
 663                         NULL,
 664                         "org.freedesktop.systemd1",
 665                         "/org/freedesktop/systemd1",
 666                         "org.freedesktop.systemd1.Manager",
 667                         "JobRemoved",
 668                         match_job_removed, NULL, m);
 669         if (r < 0)
 670                 return log_error_errno(r, "Failed to request match for JobRemoved: %m");
 671
 672         r = sd_bus_match_signal_async(
 673                         m->bus,
 674                         NULL,
 675                         "org.freedesktop.systemd1",
 676                         "/org/freedesktop/systemd1",
 677                         "org.freedesktop.systemd1.Manager",
 678                         "UnitRemoved",
 679                         match_unit_removed, NULL, m);
 680         if (r < 0)
 681                 return log_error_errno(r, "Failed to request match for UnitRemoved: %m");
 682
 683         r = sd_bus_match_signal_async(
 684                         m->bus,
 685                         NULL,
 686                         "org.freedesktop.systemd1",
 687                         NULL,
 688                         "org.freedesktop.DBus.Properties",
 689                         "PropertiesChanged",
 690                         match_properties_changed, NULL, m);
 691         if (r < 0)
 692                 return log_error_errno(r, "Failed to request match for PropertiesChanged: %m");
 693
 694         r = sd_bus_match_signal_async(
 695                         m->bus,
 696                         NULL,
 697                         "org.freedesktop.systemd1",
 698                         "/org/freedesktop/systemd1",
 699                         "org.freedesktop.systemd1.Manager",
 700                         "Reloading",
 701                         match_reloading, NULL, m);
 702         if (r < 0)
 703                 return log_error_errno(r, "Failed to request match for Reloading: %m");
 704
 705         r = sd_bus_call_method_async(
 706                         m->bus,
 707                         NULL,
 708                         "org.freedesktop.systemd1",
 709                         "/org/freedesktop/systemd1",
 710                         "org.freedesktop.systemd1.Manager",
 711                         "Subscribe",
 712                         NULL, NULL,
 713                         NULL);
 714         if (r < 0)
 715                 return log_error_errno(r, "Failed to enable subscription: %m");
 716
 717         r = sd_bus_request_name_async(m->bus, NULL, "org.freedesktop.login1", 0, NULL, NULL);
 718         if (r < 0)
 719                 return log_error_errno(r, "Failed to request name: %m");
 720
 721         r = sd_bus_attach_event(m->bus, m->event, SD_EVENT_PRIORITY_NORMAL);
 722         if (r < 0)
 723                 return log_error_errno(r, "Failed to attach bus to event loop: %m");
 724
 725         return 0;
 726 }
 727
 728 static int manager_vt_switch(sd_event_source *src, const struct signalfd_siginfo *si, void *data) {
 729         Manager *m = data;
 730         Session *active, *iter;
 731
 732         /*
 733          * We got a VT-switch signal and we have to acknowledge it immediately.
 734          * Preferably, we'd just use m->seat0->active->vtfd, but unfortunately,
 735          * old user-space might run multiple sessions on a single VT, *sigh*.
 736          * Therefore, we have to iterate all sessions and find one with a vtfd
 737          * on the requested VT.
 738          * As only VTs with active controllers have VT_PROCESS set, our current
 739          * notion of the active VT might be wrong (for instance if the switch
 740          * happens while we setup VT_PROCESS). Therefore, read the current VT
 741          * first and then use s->active->vtnr as reference. Note that this is
 742          * not racy, as no further VT-switch can happen as long as we're in
 743          * synchronous VT_PROCESS mode.
 744          */
 745
 746         assert(m->seat0);
 747         seat_read_active_vt(m->seat0);
 748
 749         active = m->seat0->active;
 750         if (!active || active->vtnr < 1) {
 751                 _cleanup_close_ int fd = -1;
 752                 int r;
 753
 754                 /* We are requested to acknowledge the VT-switch signal by the kernel but
 755                  * there's no registered sessions for the current VT. Normally this
 756                  * shouldn't happen but something wrong might have happened when we tried
 757                  * to release the VT. Better be safe than sorry, and try to release the VT
 758                  * one more time otherwise the user will be locked with the current VT. */
 759
 760                 log_warning("Received VT_PROCESS signal without a registered session, restoring VT.");
 761
 762                 /* At this point we only have the kernel mapping for referring to the
 763                  * current VT. */
 764                 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
 765                 if (fd < 0) {
 766                         log_warning_errno(fd, "Failed to open, ignoring: %m");
 767                         return 0;
 768                 }
 769
 770                 r = vt_release(fd, true);
 771                 if (r < 0)
 772                         log_warning_errno(r, "Failed to release VT, ignoring: %m");
 773
 774                 return 0;
 775         }
 776
 777         if (active->vtfd >= 0) {
 778                 session_leave_vt(active);
 779         } else {
 780                 LIST_FOREACH(sessions_by_seat, iter, m->seat0->sessions) {
 781                         if (iter->vtnr == active->vtnr && iter->vtfd >= 0) {
 782                                 session_leave_vt(iter);
 783                                 break;
 784                         }
 785                 }
 786         }
 787
 788         return 0;
 789 }
 790
 791 static int manager_connect_console(Manager *m) {
 792         int r;
 793
 794         assert(m);
 795         assert(m->console_active_fd < 0);
 796
 797         /* On certain systems (such as S390, Xen, and containers) /dev/tty0 does not exist (as there is no VC), so
 798          * don't fail if we can't open it. */
 799
 800         if (access("/dev/tty0", F_OK) < 0)
 801                 return 0;
 802
 803         m->console_active_fd = open("/sys/class/tty/tty0/active", O_RDONLY|O_NOCTTY|O_CLOEXEC);
 804         if (m->console_active_fd < 0) {
 805
 806                 /* On some systems /dev/tty0 may exist even though /sys/class/tty/tty0 does not. These are broken, but
 807                  * common. Let's complain but continue anyway. */
 808                 if (errno == ENOENT) {
 809                         log_warning_errno(errno, "System has /dev/tty0 but not /sys/class/tty/tty0/active which is broken, ignoring: %m");
 810                         return 0;
 811                 }
 812
 813                 return log_error_errno(errno, "Failed to open /sys/class/tty/tty0/active: %m");
 814         }
 815
 816         r = sd_event_add_io(m->event, &m->console_active_event_source, m->console_active_fd, 0, manager_dispatch_console, m);
 817         if (r < 0)
 818                 return log_error_errno(r, "Failed to watch foreground console: %m");
 819
 820         /*
 821          * SIGRTMIN is used as global VT-release signal, SIGRTMIN + 1 is used
 822          * as VT-acquire signal. We ignore any acquire-events (yes, we still
 823          * have to provide a valid signal-number for it!) and acknowledge all
 824          * release events immediately.
 825          */
 826
 827         if (SIGRTMIN + 1 > SIGRTMAX) {
 828                 log_error("Not enough real-time signals available: %u-%u", SIGRTMIN, SIGRTMAX);
 829                 return -EINVAL;
 830         }
 831
 832         assert_se(ignore_signals(SIGRTMIN + 1, -1) >= 0);
 833         assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGRTMIN, -1) >= 0);
 834
 835         r = sd_event_add_signal(m->event, NULL, SIGRTMIN, manager_vt_switch, m);
 836         if (r < 0)
 837                 return log_error_errno(r, "Failed to subscribe to signal: %m");
 838
 839         return 0;
 840 }
 841
 842 static int manager_connect_udev(Manager *m) {
 843         int r;
 844
 845         assert(m);
 846         assert(!m->device_seat_monitor);
 847         assert(!m->device_monitor);
 848         assert(!m->device_vcsa_monitor);
 849         assert(!m->device_button_monitor);
 850
 851         r = sd_device_monitor_new(&m->device_seat_monitor);
 852         if (r < 0)
 853                 return r;
 854
 855         r = sd_device_monitor_filter_add_match_tag(m->device_seat_monitor, "master-of-seat");
 856         if (r < 0)
 857                 return r;
 858
 859         r = sd_device_monitor_attach_event(m->device_seat_monitor, m->event);
 860         if (r < 0)
 861                 return r;
 862
 863         r = sd_device_monitor_start(m->device_seat_monitor, manager_dispatch_seat_udev, m);
 864         if (r < 0)
 865                 return r;
 866
 867         (void) sd_event_source_set_description(sd_device_monitor_get_event_source(m->device_seat_monitor), "logind-seat-monitor");
 868
 869         r = sd_device_monitor_new(&m->device_monitor);
 870         if (r < 0)
 871                 return r;
 872
 873         r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "input", NULL);
 874         if (r < 0)
 875                 return r;
 876
 877         r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "graphics", NULL);
 878         if (r < 0)
 879                 return r;
 880
 881         r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "drm", NULL);
 882         if (r < 0)
 883                 return r;
 884
 885         r = sd_device_monitor_attach_event(m->device_monitor, m->event);
 886         if (r < 0)
 887                 return r;
 888
 889         r = sd_device_monitor_start(m->device_monitor, manager_dispatch_device_udev, m);
 890         if (r < 0)
 891                 return r;
 892
 893         (void) sd_event_source_set_description(sd_device_monitor_get_event_source(m->device_monitor), "logind-device-monitor");
 894
 895         /* Don't watch keys if nobody cares */
 896         if (!manager_all_buttons_ignored(m)) {
 897                 r = sd_device_monitor_new(&m->device_button_monitor);
 898                 if (r < 0)
 899                         return r;
 900
 901                 r = sd_device_monitor_filter_add_match_tag(m->device_button_monitor, "power-switch");
 902                 if (r < 0)
 903                         return r;
 904
 905                 r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_button_monitor, "input", NULL);
 906                 if (r < 0)
 907                         return r;
 908
 909                 r = sd_device_monitor_attach_event(m->device_button_monitor, m->event);
 910                 if (r < 0)
 911                         return r;
 912
 913                 r = sd_device_monitor_start(m->device_button_monitor, manager_dispatch_button_udev, m);
 914                 if (r < 0)
 915                         return r;
 916
 917                 (void) sd_event_source_set_description(sd_device_monitor_get_event_source(m->device_button_monitor), "logind-button-monitor");
 918         }
 919
 920         /* Don't bother watching VCSA devices, if nobody cares */
 921         if (m->n_autovts > 0 && m->console_active_fd >= 0) {
 922
 923                 r = sd_device_monitor_new(&m->device_vcsa_monitor);
 924                 if (r < 0)
 925                         return r;
 926
 927                 r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_vcsa_monitor, "vc", NULL);
 928                 if (r < 0)
 929                         return r;
 930
 931                 r = sd_device_monitor_attach_event(m->device_vcsa_monitor, m->event);
 932                 if (r < 0)
 933                         return r;
 934
 935                 r = sd_device_monitor_start(m->device_vcsa_monitor, manager_dispatch_vcsa_udev, m);
 936                 if (r < 0)
 937                         return r;
 938
 939                 (void) sd_event_source_set_description(sd_device_monitor_get_event_source(m->device_vcsa_monitor), "logind-vcsa-monitor");
 940         }
 941
 942         return 0;
 943 }
 944
 945 static void manager_gc(Manager *m, bool drop_not_started) {
 946         Seat *seat;
 947         Session *session;
 948         User *user;
 949
 950         assert(m);
 951
 952         while ((seat = m->seat_gc_queue)) {
 953                 LIST_REMOVE(gc_queue, m->seat_gc_queue, seat);
 954                 seat->in_gc_queue = false;
 955
 956                 if (seat_may_gc(seat, drop_not_started)) {
 957                         seat_stop(seat, false);
 958                         seat_free(seat);
 959                 }
 960         }
 961
 962         while ((session = m->session_gc_queue)) {
 963                 LIST_REMOVE(gc_queue, m->session_gc_queue, session);
 964                 session->in_gc_queue = false;
 965
 966                 /* First, if we are not closing yet, initiate stopping */
 967                 if (session_may_gc(session, drop_not_started) &&
 968                     session_get_state(session) != SESSION_CLOSING)
 969                         (void) session_stop(session, false);
 970
 971                 /* Normally, this should make the session referenced
 972                  * again, if it doesn't then let's get rid of it
 973                  * immediately */
 974                 if (session_may_gc(session, drop_not_started)) {
 975                         (void) session_finalize(session);
 976                         session_free(session);
 977                 }
 978         }
 979
 980         while ((user = m->user_gc_queue)) {
 981                 LIST_REMOVE(gc_queue, m->user_gc_queue, user);
 982                 user->in_gc_queue = false;
 983
 984                 /* First step: queue stop jobs */
 985                 if (user_may_gc(user, drop_not_started))
 986                         (void) user_stop(user, false);
 987
 988                 /* Second step: finalize user */
 989                 if (user_may_gc(user, drop_not_started)) {
 990                         (void) user_finalize(user);
 991                         user_free(user);
 992                 }
 993         }
 994 }
 995
 996 static int manager_dispatch_idle_action(sd_event_source *s, uint64_t t, void *userdata) {
 997         Manager *m = userdata;
 998         struct dual_timestamp since;
 999         usec_t n, elapse;
1000         int r;
1001
1002         assert(m);
1003
1004         if (m->idle_action == HANDLE_IGNORE ||
1005             m->idle_action_usec <= 0)
1006                 return 0;
1007
1008         n = now(CLOCK_MONOTONIC);
1009
1010         r = manager_get_idle_hint(m, &since);
1011         if (r <= 0)
1012                 /* Not idle. Let's check if after a timeout it might be idle then. */
1013                 elapse = n + m->idle_action_usec;
1014         else {
1015                 /* Idle! Let's see if it's time to do something, or if
1016                  * we shall sleep for longer. */
1017
1018                 if (n >= since.monotonic + m->idle_action_usec &&
1019                     (m->idle_action_not_before_usec <= 0 || n >= m->idle_action_not_before_usec + m->idle_action_usec)) {
1020                         log_info("System idle. Taking action.");
1021
1022                         manager_handle_action(m, 0, m->idle_action, false, false);
1023                         m->idle_action_not_before_usec = n;
1024                 }
1025
1026                 elapse = MAX(since.monotonic, m->idle_action_not_before_usec) + m->idle_action_usec;
1027         }
1028
1029         if (!m->idle_action_event_source) {
1030
1031                 r = sd_event_add_time(
1032                                 m->event,
1033                                 &m->idle_action_event_source,
1034                                 CLOCK_MONOTONIC,
1035                                 elapse, USEC_PER_SEC*30,
1036                                 manager_dispatch_idle_action, m);
1037                 if (r < 0)
1038                         return log_error_errno(r, "Failed to add idle event source: %m");
1039
1040                 r = sd_event_source_set_priority(m->idle_action_event_source, SD_EVENT_PRIORITY_IDLE+10);
1041                 if (r < 0)
1042                         return log_error_errno(r, "Failed to set idle event source priority: %m");
1043         } else {
1044                 r = sd_event_source_set_time(m->idle_action_event_source, elapse);
1045                 if (r < 0)
1046                         return log_error_errno(r, "Failed to set idle event timer: %m");
1047
1048                 r = sd_event_source_set_enabled(m->idle_action_event_source, SD_EVENT_ONESHOT);
1049                 if (r < 0)
1050                         return log_error_errno(r, "Failed to enable idle event timer: %m");
1051         }
1052
1053         return 0;
1054 }
1055
1056 static int manager_dispatch_reload_signal(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
1057         Manager *m = userdata;
1058         int r;
1059
1060         manager_reset_config(m);
1061         r = manager_parse_config_file(m);
1062         if (r < 0)
1063                 log_warning_errno(r, "Failed to parse config file, using defaults: %m");
1064         else
1065                 log_info("Config file reloaded.");
1066
1067         return 0;
1068 }
1069
1070 static int manager_startup(Manager *m) {
1071         int r;
1072         Seat *seat;
1073         Session *session;
1074         User *user;
1075         Button *button;
1076         Inhibitor *inhibitor;
1077         Iterator i;
1078
1079         assert(m);
1080
1081         r = sd_event_add_signal(m->event, NULL, SIGHUP, manager_dispatch_reload_signal, m);
1082         if (r < 0)
1083                 return log_error_errno(r, "Failed to register SIGHUP handler: %m");
1084
1085         /* Connect to utmp */
1086         manager_connect_utmp(m);
1087
1088         /* Connect to console */
1089         r = manager_connect_console(m);
1090         if (r < 0)
1091                 return r;
1092
1093         /* Connect to udev */
1094         r = manager_connect_udev(m);
1095         if (r < 0)
1096                 return log_error_errno(r, "Failed to create udev watchers: %m");
1097
1098         /* Connect to the bus */
1099         r = manager_connect_bus(m);
1100         if (r < 0)
1101                 return r;
1102
1103         /* Instantiate magic seat 0 */
1104         r = manager_add_seat(m, "seat0", &m->seat0);
1105         if (r < 0)
1106                 return log_error_errno(r, "Failed to add seat0: %m");
1107
1108         r = manager_set_lid_switch_ignore(m, 0 + m->holdoff_timeout_usec);
1109         if (r < 0)
1110                 log_warning_errno(r, "Failed to set up lid switch ignore event source: %m");
1111
1112         /* Deserialize state */
1113         r = manager_enumerate_devices(m);
1114         if (r < 0)
1115                 log_warning_errno(r, "Device enumeration failed: %m");
1116
1117         r = manager_enumerate_seats(m);
1118         if (r < 0)
1119                 log_warning_errno(r, "Seat enumeration failed: %m");
1120
1121         r = manager_enumerate_users(m);
1122         if (r < 0)
1123                 log_warning_errno(r, "User enumeration failed: %m");
1124
1125         r = manager_enumerate_sessions(m);
1126         if (r < 0)
1127                 log_warning_errno(r, "Session enumeration failed: %m");
1128
1129         r = manager_enumerate_inhibitors(m);
1130         if (r < 0)
1131                 log_warning_errno(r, "Inhibitor enumeration failed: %m");
1132
1133         r = manager_enumerate_buttons(m);
1134         if (r < 0)
1135                 log_warning_errno(r, "Button enumeration failed: %m");
1136
1137         /* Remove stale objects before we start them */
1138         manager_gc(m, false);
1139
1140         /* Reserve the special reserved VT */
1141         manager_reserve_vt(m);
1142
1143         /* Read in utmp if it exists */
1144         manager_read_utmp(m);
1145
1146         /* And start everything */
1147         HASHMAP_FOREACH(seat, m->seats, i)
1148                 (void) seat_start(seat);
1149
1150         HASHMAP_FOREACH(user, m->users, i)
1151                 (void) user_start(user);
1152
1153         HASHMAP_FOREACH(session, m->sessions, i)
1154                 (void) session_start(session, NULL, NULL);
1155
1156         HASHMAP_FOREACH(inhibitor, m->inhibitors, i)
1157                 inhibitor_start(inhibitor);
1158
1159         HASHMAP_FOREACH(button, m->buttons, i)
1160                 button_check_switches(button);
1161
1162         manager_dispatch_idle_action(NULL, 0, m);
1163
1164         return 0;
1165 }
1166
1167 static int manager_run(Manager *m) {
1168         int r;
1169
1170         assert(m);
1171
1172         for (;;) {
1173                 r = sd_event_get_state(m->event);
1174                 if (r < 0)
1175                         return r;
1176                 if (r == SD_EVENT_FINISHED)
1177                         return 0;
1178
1179                 manager_gc(m, true);
1180
1181                 r = manager_dispatch_delayed(m, false);
1182                 if (r < 0)
1183                         return r;
1184                 if (r > 0)
1185                         continue;
1186
1187                 r = sd_event_run(m->event, (uint64_t) -1);
1188                 if (r < 0)
1189                         return r;
1190         }
1191 }
1192
1193 static int run(int argc, char *argv[]) {
1194         _cleanup_(manager_unrefp) Manager *m = NULL;
1195         int r;
1196
1197         log_set_facility(LOG_AUTH);
1198         log_setup_service();
1199
1200         umask(0022);
1201
1202         if (argc != 1) {
1203                 log_error("This program takes no arguments.");
1204                 return -EINVAL;
1205         }
1206
1207         r = mac_selinux_init();
1208         if (r < 0)
1209                 return log_error_errno(r, "Could not initialize labelling: %m");
1210
1211         /* Always create the directories people can create inotify watches in. Note that some applications might check
1212          * for the existence of /run/systemd/seats/ to determine whether logind is available, so please always make
1213          * sure these directories are created early on and unconditionally. */
1214         (void) mkdir_label("/run/systemd/seats", 0755);
1215         (void) mkdir_label("/run/systemd/users", 0755);
1216         (void) mkdir_label("/run/systemd/sessions", 0755);
1217
1218         assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGHUP, SIGTERM, SIGINT, -1) >= 0);
1219
1220         r = manager_new(&m);
1221         if (r < 0)
1222                 return log_error_errno(r, "Failed to allocate manager object: %m");
1223
1224         (void) manager_parse_config_file(m);
1225
1226         r = manager_startup(m);
1227         if (r < 0)
1228                 return log_error_errno(r, "Failed to fully start up daemon: %m");
1229
1230         log_debug("systemd-logind running as pid "PID_FMT, getpid_cached());
1231         (void) sd_notify(false,
1232                          "READY=1\n"
1233                          "STATUS=Processing requests...");
1234
1235         r = manager_run(m);
1236
1237         log_debug("systemd-logind stopped as pid "PID_FMT, getpid_cached());
1238         (void) sd_notify(false,
1239                          "STOPPING=1\n"
1240                          "STATUS=Shutting down...");
1241
1242         return r;
1243 }
1244
1245 DEFINE_MAIN_FUNCTION(run);