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