src/login/logind.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <sys/types.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-locator.h"
  14 #include "bus-log-control-api.h"
  15 #include "bus-polkit.h"
  16 #include "cgroup-util.h"
  17 #include "common-signal.h"
  18 #include "constants.h"
  19 #include "daemon-util.h"
  20 #include "device-util.h"
  21 #include "devnum-util.h"
  22 #include "dirent-util.h"
  23 #include "escape.h"
  24 #include "fd-util.h"
  25 #include "format-util.h"
  26 #include "fs-util.h"
  27 #include "logind-dbus.h"
  28 #include "logind-seat-dbus.h"
  29 #include "logind-session-dbus.h"
  30 #include "logind-user-dbus.h"
  31 #include "logind.h"
  32 #include "main-func.h"
  33 #include "mkdir-label.h"
  34 #include "parse-util.h"
  35 #include "process-util.h"
  36 #include "selinux-util.h"
  37 #include "service-util.h"
  38 #include "signal-util.h"
  39 #include "strv.h"
  40 #include "terminal-util.h"
  41 #include "udev-util.h"
  42 #include "user-util.h"
  43
  44 static Manager* manager_free(Manager *m);
  45 DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free);
  46
  47 DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(device_hash_ops, char, string_hash_func, string_compare_func, Device, device_free);
  48 DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(seat_hash_ops, char, string_hash_func, string_compare_func, Seat, seat_free);
  49 DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(session_hash_ops, char, string_hash_func, string_compare_func, Session, session_free);
  50 DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(user_hash_ops, void, trivial_hash_func, trivial_compare_func, User, user_free);
  51 DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(inhibitor_hash_ops, char, string_hash_func, string_compare_func, Inhibitor, inhibitor_free);
  52 DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(button_hash_ops, char, string_hash_func, string_compare_func, Button, button_free);
  53
  54 static int manager_new(Manager **ret) {
  55         _cleanup_(manager_freep) Manager *m = NULL;
  56         int r;
  57
  58         assert(ret);
  59
  60         m = new(Manager, 1);
  61         if (!m)
  62                 return -ENOMEM;
  63
  64         *m = (Manager) {
  65                 .console_active_fd = -EBADF,
  66                 .reserve_vt_fd = -EBADF,
  67                 .enable_wall_messages = true,
  68                 .idle_action_not_before_usec = now(CLOCK_MONOTONIC),
  69                 .scheduled_shutdown_action = _HANDLE_ACTION_INVALID,
  70
  71                 .devices = hashmap_new(&device_hash_ops),
  72                 .seats = hashmap_new(&seat_hash_ops),
  73                 .sessions = hashmap_new(&session_hash_ops),
  74                 .users = hashmap_new(&user_hash_ops),
  75                 .inhibitors = hashmap_new(&inhibitor_hash_ops),
  76                 .buttons = hashmap_new(&button_hash_ops),
  77
  78                 .user_units = hashmap_new(&string_hash_ops),
  79                 .session_units = hashmap_new(&string_hash_ops),
  80         };
  81
  82         if (!m->devices || !m->seats || !m->sessions || !m->users || !m->inhibitors || !m->buttons || !m->user_units || !m->session_units)
  83                 return -ENOMEM;
  84
  85         r = sd_event_default(&m->event);
  86         if (r < 0)
  87                 return r;
  88
  89         r = sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
  90         if (r < 0)
  91                 return r;
  92
  93         r = sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL);
  94         if (r < 0)
  95                 return r;
  96
  97         r = sd_event_add_signal(m->event, NULL, SIGRTMIN+18, sigrtmin18_handler, NULL);
  98         if (r < 0)
  99                 return r;
 100
 101         r = sd_event_add_memory_pressure(m->event, NULL, NULL, NULL);
 102         if (r < 0)
 103                 log_debug_errno(r, "Failed allocate memory pressure event source, ignoring: %m");
 104
 105         (void) sd_event_set_watchdog(m->event, true);
 106
 107         manager_reset_config(m);
 108
 109         *ret = TAKE_PTR(m);
 110         return 0;
 111 }
 112
 113 static Manager* manager_free(Manager *m) {
 114         if (!m)
 115                 return NULL;
 116
 117         hashmap_free(m->devices);
 118         hashmap_free(m->seats);
 119         hashmap_free(m->sessions);
 120
 121         /* All records should have been removed by session_free */
 122         assert(hashmap_isempty(m->sessions_by_leader));
 123         hashmap_free(m->sessions_by_leader);
 124
 125         hashmap_free(m->users);
 126         hashmap_free(m->inhibitors);
 127         hashmap_free(m->buttons);
 128         hashmap_free(m->brightness_writers);
 129
 130         hashmap_free(m->user_units);
 131         hashmap_free(m->session_units);
 132
 133         sd_event_source_unref(m->idle_action_event_source);
 134         sd_event_source_unref(m->inhibit_timeout_source);
 135         sd_event_source_unref(m->scheduled_shutdown_timeout_source);
 136         sd_event_source_unref(m->nologin_timeout_source);
 137         sd_event_source_unref(m->wall_message_timeout_source);
 138
 139         sd_event_source_unref(m->console_active_event_source);
 140         sd_event_source_unref(m->lid_switch_ignore_event_source);
 141
 142         sd_event_source_unref(m->reboot_key_long_press_event_source);
 143
 144 #if ENABLE_UTMP
 145         sd_event_source_unref(m->utmp_event_source);
 146 #endif
 147
 148         safe_close(m->console_active_fd);
 149
 150         sd_device_monitor_unref(m->device_seat_monitor);
 151         sd_device_monitor_unref(m->device_monitor);
 152         sd_device_monitor_unref(m->device_vcsa_monitor);
 153         sd_device_monitor_unref(m->device_button_monitor);
 154
 155         if (m->unlink_nologin)
 156                 (void) unlink_or_warn("/run/nologin");
 157
 158         hashmap_free(m->polkit_registry);
 159
 160         sd_bus_flush_close_unref(m->bus);
 161         sd_event_unref(m->event);
 162
 163         safe_close(m->reserve_vt_fd);
 164
 165         strv_free(m->kill_only_users);
 166         strv_free(m->kill_exclude_users);
 167
 168         free(m->scheduled_shutdown_tty);
 169         free(m->wall_message);
 170         free(m->action_job);
 171
 172         strv_free(m->efi_boot_loader_entries);
 173         free(m->efi_loader_entry_one_shot);
 174
 175         return mfree(m);
 176 }
 177
 178 static int manager_enumerate_devices(Manager *m) {
 179         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
 180         int r;
 181
 182         assert(m);
 183
 184         /* Loads devices from udev and creates seats for them as
 185          * necessary */
 186
 187         r = sd_device_enumerator_new(&e);
 188         if (r < 0)
 189                 return r;
 190
 191         r = sd_device_enumerator_add_match_tag(e, "master-of-seat");
 192         if (r < 0)
 193                 return r;
 194
 195         r = 0;
 196
 197         FOREACH_DEVICE(e, d) {
 198                 if (device_is_processed(d) <= 0)
 199                         continue;
 200                 RET_GATHER(r, manager_process_seat_device(m, d));
 201         }
 202
 203         return r;
 204 }
 205
 206 static int manager_enumerate_buttons(Manager *m) {
 207         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
 208         int r;
 209
 210         assert(m);
 211
 212         /* Loads buttons from udev */
 213
 214         if (manager_all_buttons_ignored(m))
 215                 return 0;
 216
 217         r = sd_device_enumerator_new(&e);
 218         if (r < 0)
 219                 return r;
 220
 221         r = sd_device_enumerator_add_match_subsystem(e, "input", true);
 222         if (r < 0)
 223                 return r;
 224
 225         r = sd_device_enumerator_add_match_tag(e, "power-switch");
 226         if (r < 0)
 227                 return r;
 228
 229         r = 0;
 230
 231         FOREACH_DEVICE(e, d) {
 232                 if (device_is_processed(d) <= 0)
 233                         continue;
 234                 RET_GATHER(r, manager_process_button_device(m, d));
 235         }
 236
 237         return r;
 238 }
 239
 240 static int manager_enumerate_seats(Manager *m) {
 241         _cleanup_closedir_ DIR *d = NULL;
 242         int r = 0;
 243
 244         assert(m);
 245
 246         /* This loads data about seats stored on disk, but does not
 247          * actually create any seats. Removes data of seats that no
 248          * longer exist. */
 249
 250         d = opendir("/run/systemd/seats");
 251         if (!d) {
 252                 if (errno == ENOENT)
 253                         return 0;
 254
 255                 return log_error_errno(errno, "Failed to open /run/systemd/seats/: %m");
 256         }
 257
 258         FOREACH_DIRENT(de, d, return -errno) {
 259                 Seat *s;
 260
 261                 if (!dirent_is_file(de))
 262                         continue;
 263
 264                 s = hashmap_get(m->seats, de->d_name);
 265                 if (!s) {
 266                         if (unlinkat(dirfd(d), de->d_name, 0) < 0)
 267                                 log_warning_errno(errno, "Failed to remove /run/systemd/seats/%s, ignoring: %m",
 268                                                   de->d_name);
 269                         continue;
 270                 }
 271
 272                 RET_GATHER(r, seat_load(s));
 273         }
 274
 275         return r;
 276 }
 277
 278 static int manager_enumerate_linger_users(Manager *m) {
 279         _cleanup_closedir_ DIR *d = NULL;
 280         int r = 0;
 281
 282         assert(m);
 283
 284         d = opendir("/var/lib/systemd/linger");
 285         if (!d) {
 286                 if (errno == ENOENT)
 287                         return 0;
 288
 289                 return log_error_errno(errno, "Failed to open /var/lib/systemd/linger/: %m");
 290         }
 291
 292         FOREACH_DIRENT(de, d, return -errno) {
 293                 _cleanup_free_ char *n = NULL;
 294                 int k;
 295
 296                 if (!dirent_is_file(de))
 297                         continue;
 298
 299                 k = cunescape(de->d_name, 0, &n);
 300                 if (k < 0) {
 301                         RET_GATHER(r, log_warning_errno(k, "Failed to unescape username '%s', ignoring: %m", de->d_name));
 302                         continue;
 303                 }
 304
 305                 k = manager_add_user_by_name(m, n, NULL);
 306                 if (k < 0)
 307                         RET_GATHER(r, log_warning_errno(k, "Couldn't add lingering user %s, ignoring: %m", de->d_name));
 308         }
 309
 310         return r;
 311 }
 312
 313 static int manager_enumerate_users(Manager *m) {
 314         _cleanup_closedir_ DIR *d = NULL;
 315         int r;
 316
 317         assert(m);
 318
 319         /* Add lingering users */
 320         r = manager_enumerate_linger_users(m);
 321
 322         /* Read in user data stored on disk */
 323         d = opendir("/run/systemd/users");
 324         if (!d) {
 325                 if (errno == ENOENT)
 326                         return 0;
 327
 328                 return log_error_errno(errno, "Failed to open /run/systemd/users/: %m");
 329         }
 330
 331         FOREACH_DIRENT(de, d, return -errno) {
 332                 User *u;
 333                 uid_t uid;
 334                 int k;
 335
 336                 if (!dirent_is_file(de))
 337                         continue;
 338
 339                 k = parse_uid(de->d_name, &uid);
 340                 if (k < 0) {
 341                         RET_GATHER(r, log_warning_errno(k, "Failed to parse filename /run/systemd/users/%s as UID, ignoring: %m", de->d_name));
 342                         continue;
 343                 }
 344
 345                 k = manager_add_user_by_uid(m, uid, &u);
 346                 if (k < 0) {
 347                         RET_GATHER(r, log_warning_errno(k, "Failed to add user by filename %s, ignoring: %m", de->d_name));
 348                         continue;
 349                 }
 350
 351                 user_add_to_gc_queue(u);
 352
 353                 RET_GATHER(r, user_load(u));
 354         }
 355
 356         return r;
 357 }
 358
 359 static int parse_fdname(const char *fdname, char **ret_session_id, dev_t *ret_devno) {
 360         _cleanup_strv_free_ char **parts = NULL;
 361         _cleanup_free_ char *id = NULL;
 362         int r;
 363
 364         assert(ret_session_id);
 365         assert(ret_devno);
 366
 367         parts = strv_split(fdname, "-");
 368         if (!parts)
 369                 return -ENOMEM;
 370
 371         if (_unlikely_(!streq(parts[0], "session")))
 372                 return -EINVAL;
 373
 374         id = strdup(parts[1]);
 375         if (!id)
 376                 return -ENOMEM;
 377
 378         if (streq(parts[2], "leader")) {
 379                 *ret_session_id = TAKE_PTR(id);
 380                 *ret_devno = 0;
 381
 382                 return 0;
 383         }
 384
 385         if (_unlikely_(!streq(parts[2], "device")))
 386                 return -EINVAL;
 387
 388         unsigned major, minor;
 389
 390         r = safe_atou(parts[3], &major);
 391         if (r < 0)
 392                 return r;
 393
 394         r = safe_atou(parts[4], &minor);
 395         if (r < 0)
 396                 return r;
 397
 398         *ret_session_id = TAKE_PTR(id);
 399         *ret_devno = makedev(major, minor);
 400
 401         return 0;
 402 }
 403
 404 static int deliver_session_device_fd(Session *s, const char *fdname, int fd, dev_t devno) {
 405         SessionDevice *sd;
 406         struct stat st;
 407
 408         assert(s);
 409         assert(fdname);
 410         assert(fd >= 0);
 411         assert(devno > 0);
 412
 413         if (fstat(fd, &st) < 0)
 414                 /* The device is allowed to go away at a random point, in which case fstat() failing is
 415                  * expected. */
 416                 return log_debug_errno(errno, "Failed to stat device fd '%s' for session '%s': %m",
 417                                        fdname, s->id);
 418
 419         if (!S_ISCHR(st.st_mode) || st.st_rdev != devno)
 420                 return log_debug_errno(SYNTHETIC_ERRNO(ENODEV),
 421                                        "Device fd '%s' doesn't point to the expected character device node.",
 422                                        fdname);
 423
 424         sd = hashmap_get(s->devices, &devno);
 425         if (!sd)
 426                 /* Weird, we got an fd for a session device which wasn't recorded in the session state
 427                  * file... */
 428                 return log_warning_errno(SYNTHETIC_ERRNO(ENODEV),
 429                                          "Got session device fd '%s' [" DEVNUM_FORMAT_STR "], but not present in session state.",
 430                                          fdname, DEVNUM_FORMAT_VAL(devno));
 431
 432         log_debug("Attaching session device fd '%s' [" DEVNUM_FORMAT_STR "] to session '%s'.",
 433                   fdname, DEVNUM_FORMAT_VAL(devno), s->id);
 434
 435         session_device_attach_fd(sd, fd, s->was_active);
 436         return 0;
 437 }
 438
 439 static int deliver_session_leader_fd_consume(Session *s, const char *fdname, int fd) {
 440         _cleanup_(pidref_done) PidRef leader_fdstore = PIDREF_NULL;
 441         int r;
 442
 443         assert(s);
 444         assert(fdname);
 445         assert(fd >= 0);
 446
 447         if (!pid_is_valid(s->deserialized_pid)) {
 448                 r = log_warning_errno(SYNTHETIC_ERRNO(EOWNERDEAD),
 449                                       "Got leader pidfd for session '%s', but LEADER= is not set, refusing.",
 450                                       s->id);
 451                 goto fail_close;
 452         }
 453
 454         if (!s->leader_fd_saved)
 455                 log_warning("Got leader pidfd for session '%s', but not recorded in session state, proceeding anyway.",
 456                             s->id);
 457         else
 458                 assert(!pidref_is_set(&s->leader));
 459
 460         r = pidref_set_pidfd_take(&leader_fdstore, fd);
 461         if (r < 0) {
 462                 if (r == -ESRCH)
 463                         log_debug_errno(r, "Leader of session '%s' is gone while deserializing.", s->id);
 464                 else
 465                         log_warning_errno(r, "Failed to create reference to leader of session '%s': %m", s->id);
 466                 goto fail_close;
 467         }
 468
 469         if (leader_fdstore.pid != s->deserialized_pid)
 470                 log_warning("Leader from pidfd (" PID_FMT ") doesn't match with LEADER=" PID_FMT " for session '%s', proceeding anyway.",
 471                             leader_fdstore.pid, s->deserialized_pid, s->id);
 472
 473         r = session_set_leader_consume(s, TAKE_PIDREF(leader_fdstore));
 474         if (r < 0)
 475                 return log_warning_errno(r, "Failed to attach leader pidfd for session '%s': %m", s->id);
 476
 477         return 0;
 478
 479 fail_close:
 480         close_and_notify_warn(fd, fdname);
 481         return r;
 482 }
 483
 484 static int manager_attach_session_fd_one_consume(Manager *m, const char *fdname, int fd) {
 485         _cleanup_free_ char *id = NULL;
 486         dev_t devno = 0; /* Explicit initialization to appease gcc */
 487         Session *s;
 488         int r;
 489
 490         assert(m);
 491         assert(fdname);
 492         assert(fd >= 0);
 493
 494         r = parse_fdname(fdname, &id, &devno);
 495         if (r < 0) {
 496                 log_warning_errno(r, "Failed to parse stored fd name '%s': %m", fdname);
 497                 goto fail_close;
 498         }
 499
 500         s = hashmap_get(m->sessions, id);
 501         if (!s) {
 502                 /* If the session doesn't exist anymore, let's simply close this fd. */
 503                 r = log_debug_errno(SYNTHETIC_ERRNO(ENXIO),
 504                                     "Cannot attach fd '%s' to unknown session '%s', ignoring.", fdname, id);
 505                 goto fail_close;
 506         }
 507
 508         if (devno > 0) {
 509                 r = deliver_session_device_fd(s, fdname, fd, devno);
 510                 if (r < 0)
 511                         goto fail_close;
 512                 return 0;
 513         }
 514
 515         /* Takes ownership of fd on both success and failure */
 516         return deliver_session_leader_fd_consume(s, fdname, fd);
 517
 518 fail_close:
 519         close_and_notify_warn(fd, fdname);
 520         return r;
 521 }
 522
 523 static int manager_enumerate_sessions(Manager *m) {
 524         _cleanup_strv_free_ char **fdnames = NULL;
 525         _cleanup_closedir_ DIR *d = NULL;
 526         int r = 0, n;
 527
 528         assert(m);
 529
 530         /* Read in session data stored on disk */
 531         d = opendir("/run/systemd/sessions");
 532         if (!d) {
 533                 if (errno == ENOENT)
 534                         return 0;
 535
 536                 return log_error_errno(errno, "Failed to open /run/systemd/sessions/: %m");
 537         }
 538
 539         FOREACH_DIRENT(de, d, return -errno) {
 540                 Session *s;
 541                 int k;
 542
 543                 if (!dirent_is_file(de))
 544                         continue;
 545
 546                 k = manager_add_session(m, de->d_name, &s);
 547                 if (k < 0) {
 548                         RET_GATHER(r, log_warning_errno(k, "Failed to add session by filename %s, ignoring: %m", de->d_name));
 549                         continue;
 550                 }
 551
 552                 session_add_to_gc_queue(s);
 553
 554                 k = session_load(s);
 555                 if (k < 0)
 556                         RET_GATHER(r, log_warning_errno(k, "Failed to deserialize session '%s', ignoring: %m", s->id));
 557         }
 558
 559         n = sd_listen_fds_with_names(/* unset_environment = */ true, &fdnames);
 560         if (n < 0)
 561                 return log_error_errno(n, "Failed to acquire passed fd list: %m");
 562
 563         for (int i = 0; i < n; i++) {
 564                 int fd = SD_LISTEN_FDS_START + i;
 565
 566                 RET_GATHER(r, manager_attach_session_fd_one_consume(m, fdnames[i], fd));
 567         }
 568
 569         return r;
 570 }
 571
 572 static int manager_enumerate_inhibitors(Manager *m) {
 573         _cleanup_closedir_ DIR *d = NULL;
 574         int r = 0;
 575
 576         assert(m);
 577
 578         d = opendir("/run/systemd/inhibit");
 579         if (!d) {
 580                 if (errno == ENOENT)
 581                         return 0;
 582
 583                 return log_error_errno(errno, "Failed to open /run/systemd/inhibit/: %m");
 584         }
 585
 586         FOREACH_DIRENT(de, d, return -errno) {
 587                 Inhibitor *i;
 588                 int k;
 589
 590                 if (!dirent_is_file(de))
 591                         continue;
 592
 593                 k = manager_add_inhibitor(m, de->d_name, &i);
 594                 if (k < 0) {
 595                         RET_GATHER(r, log_warning_errno(k, "Couldn't add inhibitor %s, ignoring: %m", de->d_name));
 596                         continue;
 597                 }
 598
 599                 RET_GATHER(r, inhibitor_load(i));
 600         }
 601
 602         return r;
 603 }
 604
 605 static int manager_dispatch_seat_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 606         Manager *m = ASSERT_PTR(userdata);
 607
 608         assert(device);
 609
 610         manager_process_seat_device(m, device);
 611         return 0;
 612 }
 613
 614 static int manager_dispatch_device_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 615         Manager *m = ASSERT_PTR(userdata);
 616
 617         assert(device);
 618
 619         manager_process_seat_device(m, device);
 620         return 0;
 621 }
 622
 623 static int manager_dispatch_vcsa_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 624         Manager *m = ASSERT_PTR(userdata);
 625         const char *name;
 626
 627         assert(device);
 628
 629         /* Whenever a VCSA device is removed try to reallocate our
 630          * VTs, to make sure our auto VTs never go away. */
 631
 632         if (sd_device_get_sysname(device, &name) >= 0 &&
 633             startswith(name, "vcsa") &&
 634             device_for_action(device, SD_DEVICE_REMOVE))
 635                 seat_preallocate_vts(m->seat0);
 636
 637         return 0;
 638 }
 639
 640 static int manager_dispatch_button_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 641         Manager *m = ASSERT_PTR(userdata);
 642
 643         assert(device);
 644
 645         manager_process_button_device(m, device);
 646         return 0;
 647 }
 648
 649 static int manager_dispatch_console(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 650         Manager *m = ASSERT_PTR(userdata);
 651
 652         assert(m->seat0);
 653         assert(m->console_active_fd == fd);
 654
 655         seat_read_active_vt(m->seat0);
 656         return 0;
 657 }
 658
 659 static int manager_reserve_vt(Manager *m) {
 660         _cleanup_free_ char *p = NULL;
 661
 662         assert(m);
 663
 664         if (m->reserve_vt <= 0)
 665                 return 0;
 666
 667         if (asprintf(&p, "/dev/tty%u", m->reserve_vt) < 0)
 668                 return log_oom();
 669
 670         m->reserve_vt_fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
 671         if (m->reserve_vt_fd < 0) {
 672
 673                 /* Don't complain on VT-less systems */
 674                 if (errno != ENOENT)
 675                         log_warning_errno(errno, "Failed to pin reserved VT: %m");
 676                 return -errno;
 677         }
 678
 679         return 0;
 680 }
 681
 682 static int manager_connect_bus(Manager *m) {
 683         int r;
 684
 685         assert(m);
 686         assert(!m->bus);
 687
 688         r = sd_bus_default_system(&m->bus);
 689         if (r < 0)
 690                 return log_error_errno(r, "Failed to connect to system bus: %m");
 691
 692         r = bus_add_implementation(m->bus, &manager_object, m);
 693         if (r < 0)
 694                 return r;
 695
 696         r = bus_log_control_api_register(m->bus);
 697         if (r < 0)
 698                 return r;
 699
 700         r = bus_match_signal_async(m->bus, NULL, bus_systemd_mgr, "JobRemoved", match_job_removed, NULL, m);
 701         if (r < 0)
 702                 return log_error_errno(r, "Failed to request match for JobRemoved: %m");
 703
 704         r = bus_match_signal_async(m->bus, NULL, bus_systemd_mgr, "UnitRemoved", match_unit_removed, NULL, m);
 705         if (r < 0)
 706                 return log_error_errno(r, "Failed to request match for UnitRemoved: %m");
 707
 708         r = sd_bus_match_signal_async(
 709                         m->bus,
 710                         NULL,
 711                         "org.freedesktop.systemd1",
 712                         NULL,
 713                         "org.freedesktop.DBus.Properties",
 714                         "PropertiesChanged",
 715                         match_properties_changed, NULL, m);
 716         if (r < 0)
 717                 return log_error_errno(r, "Failed to request match for PropertiesChanged: %m");
 718
 719         r = bus_match_signal_async(m->bus, NULL, bus_systemd_mgr, "Reloading", match_reloading, NULL, m);
 720         if (r < 0)
 721                 return log_error_errno(r, "Failed to request match for Reloading: %m");
 722
 723         r = bus_call_method_async(m->bus, NULL, bus_systemd_mgr, "Subscribe", NULL, NULL, NULL);
 724         if (r < 0)
 725                 return log_error_errno(r, "Failed to enable subscription: %m");
 726
 727         r = sd_bus_request_name_async(m->bus, NULL, "org.freedesktop.login1", 0, NULL, NULL);
 728         if (r < 0)
 729                 return log_error_errno(r, "Failed to request name: %m");
 730
 731         r = sd_bus_attach_event(m->bus, m->event, SD_EVENT_PRIORITY_NORMAL);
 732         if (r < 0)
 733                 return log_error_errno(r, "Failed to attach bus to event loop: %m");
 734
 735         return 0;
 736 }
 737
 738 static int manager_vt_switch(sd_event_source *src, const struct signalfd_siginfo *si, void *data) {
 739         Manager *m = ASSERT_PTR(data);
 740         Session *active;
 741
 742         /*
 743          * We got a VT-switch signal and we have to acknowledge it immediately.
 744          * Preferably, we'd just use m->seat0->active->vtfd, but unfortunately,
 745          * old user-space might run multiple sessions on a single VT, *sigh*.
 746          * Therefore, we have to iterate all sessions and find one with a vtfd
 747          * on the requested VT.
 748          * As only VTs with active controllers have VT_PROCESS set, our current
 749          * notion of the active VT might be wrong (for instance if the switch
 750          * happens while we setup VT_PROCESS). Therefore, read the current VT
 751          * first and then use s->active->vtnr as reference. Note that this is
 752          * not racy, as no further VT-switch can happen as long as we're in
 753          * synchronous VT_PROCESS mode.
 754          */
 755
 756         assert(m->seat0);
 757
 758         seat_read_active_vt(m->seat0);
 759
 760         active = m->seat0->active;
 761         if (!active || active->vtnr < 1) {
 762                 _cleanup_close_ int fd = -EBADF;
 763                 int r;
 764
 765                 /* We are requested to acknowledge the VT-switch signal by the kernel but
 766                  * there's no registered sessions for the current VT. Normally this
 767                  * shouldn't happen but something wrong might have happened when we tried
 768                  * to release the VT. Better be safe than sorry, and try to release the VT
 769                  * one more time otherwise the user will be locked with the current VT. */
 770
 771                 log_warning("Received VT_PROCESS signal without a registered session, restoring VT.");
 772
 773                 /* At this point we only have the kernel mapping for referring to the current VT. */
 774                 fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
 775                 if (fd < 0) {
 776                         log_warning_errno(fd, "Failed to open current VT, ignoring: %m");
 777                         return 0;
 778                 }
 779
 780                 r = vt_release(fd, /* restore = */ true);
 781                 if (r < 0)
 782                         log_warning_errno(r, "Failed to release current VT, ignoring: %m");
 783
 784                 return 0;
 785         }
 786
 787         if (active->vtfd >= 0)
 788                 session_leave_vt(active);
 789         else
 790                 LIST_FOREACH(sessions_by_seat, iter, m->seat0->sessions)
 791                         if (iter->vtnr == active->vtnr && iter->vtfd >= 0) {
 792                                 session_leave_vt(iter);
 793                                 break;
 794                         }
 795
 796         return 0;
 797 }
 798
 799 static int manager_connect_console(Manager *m) {
 800         int r;
 801
 802         assert(m);
 803         assert(m->console_active_fd < 0);
 804
 805         /* On certain systems (such as S390, Xen, and containers) /dev/tty0 does not exist (as there is no VC), so
 806          * don't fail if we can't open it. */
 807
 808         if (access("/dev/tty0", F_OK) < 0)
 809                 return 0;
 810
 811         m->console_active_fd = open("/sys/class/tty/tty0/active", O_RDONLY|O_NOCTTY|O_CLOEXEC);
 812         if (m->console_active_fd < 0) {
 813
 814                 /* On some systems /dev/tty0 may exist even though /sys/class/tty/tty0 does not. These are broken, but
 815                  * common. Let's complain but continue anyway. */
 816                 if (errno == ENOENT) {
 817                         log_warning_errno(errno, "System has /dev/tty0 but not /sys/class/tty/tty0/active which is broken, ignoring: %m");
 818                         return 0;
 819                 }
 820
 821                 return log_error_errno(errno, "Failed to open /sys/class/tty/tty0/active: %m");
 822         }
 823
 824         r = sd_event_add_io(m->event, &m->console_active_event_source, m->console_active_fd, 0, manager_dispatch_console, m);
 825         if (r < 0)
 826                 return log_error_errno(r, "Failed to watch foreground console: %m");
 827
 828         /*
 829          * SIGRTMIN is used as global VT-release signal, SIGRTMIN + 1 is used
 830          * as VT-acquire signal. We ignore any acquire-events (yes, we still
 831          * have to provide a valid signal-number for it!) and acknowledge all
 832          * release events immediately.
 833          */
 834
 835         if (SIGRTMIN + 1 > SIGRTMAX)
 836                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
 837                                        "Not enough real-time signals available: %i-%i",
 838                                        SIGRTMIN, SIGRTMAX);
 839
 840         assert_se(ignore_signals(SIGRTMIN + 1) >= 0);
 841         assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGRTMIN) >= 0);
 842
 843         r = sd_event_add_signal(m->event, NULL, SIGRTMIN, manager_vt_switch, m);
 844         if (r < 0)
 845                 return log_error_errno(r, "Failed to subscribe to signal: %m");
 846
 847         return 0;
 848 }
 849
 850 static int manager_connect_udev(Manager *m) {
 851         int r;
 852
 853         assert(m);
 854         assert(!m->device_seat_monitor);
 855         assert(!m->device_monitor);
 856         assert(!m->device_vcsa_monitor);
 857         assert(!m->device_button_monitor);
 858
 859         r = sd_device_monitor_new(&m->device_seat_monitor);
 860         if (r < 0)
 861                 return r;
 862
 863         r = sd_device_monitor_filter_add_match_tag(m->device_seat_monitor, "master-of-seat");
 864         if (r < 0)
 865                 return r;
 866
 867         r = sd_device_monitor_attach_event(m->device_seat_monitor, m->event);
 868         if (r < 0)
 869                 return r;
 870
 871         r = sd_device_monitor_start(m->device_seat_monitor, manager_dispatch_seat_udev, m);
 872         if (r < 0)
 873                 return r;
 874
 875         (void) sd_device_monitor_set_description(m->device_seat_monitor, "seat");
 876
 877         r = sd_device_monitor_new(&m->device_monitor);
 878         if (r < 0)
 879                 return r;
 880
 881         r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "input", NULL);
 882         if (r < 0)
 883                 return r;
 884
 885         r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "graphics", NULL);
 886         if (r < 0)
 887                 return r;
 888
 889         r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "drm", NULL);
 890         if (r < 0)
 891                 return r;
 892
 893         r = sd_device_monitor_attach_event(m->device_monitor, m->event);
 894         if (r < 0)
 895                 return r;
 896
 897         r = sd_device_monitor_start(m->device_monitor, manager_dispatch_device_udev, m);
 898         if (r < 0)
 899                 return r;
 900
 901         (void) sd_device_monitor_set_description(m->device_monitor, "input,graphics,drm");
 902
 903         /* Don't watch keys if nobody cares */
 904         if (!manager_all_buttons_ignored(m)) {
 905                 r = sd_device_monitor_new(&m->device_button_monitor);
 906                 if (r < 0)
 907                         return r;
 908
 909                 r = sd_device_monitor_filter_add_match_tag(m->device_button_monitor, "power-switch");
 910                 if (r < 0)
 911                         return r;
 912
 913                 r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_button_monitor, "input", NULL);
 914                 if (r < 0)
 915                         return r;
 916
 917                 r = sd_device_monitor_attach_event(m->device_button_monitor, m->event);
 918                 if (r < 0)
 919                         return r;
 920
 921                 r = sd_device_monitor_start(m->device_button_monitor, manager_dispatch_button_udev, m);
 922                 if (r < 0)
 923                         return r;
 924
 925                 (void) sd_device_monitor_set_description(m->device_button_monitor, "button");
 926         }
 927
 928         /* Don't bother watching VCSA devices, if nobody cares */
 929         if (m->n_autovts > 0 && m->console_active_fd >= 0) {
 930
 931                 r = sd_device_monitor_new(&m->device_vcsa_monitor);
 932                 if (r < 0)
 933                         return r;
 934
 935                 r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_vcsa_monitor, "vc", NULL);
 936                 if (r < 0)
 937                         return r;
 938
 939                 r = sd_device_monitor_attach_event(m->device_vcsa_monitor, m->event);
 940                 if (r < 0)
 941                         return r;
 942
 943                 r = sd_device_monitor_start(m->device_vcsa_monitor, manager_dispatch_vcsa_udev, m);
 944                 if (r < 0)
 945                         return r;
 946
 947                 (void) sd_device_monitor_set_description(m->device_vcsa_monitor, "vcsa");
 948         }
 949
 950         return 0;
 951 }
 952
 953 static void manager_gc(Manager *m, bool drop_not_started) {
 954         Seat *seat;
 955         Session *session;
 956         User *user;
 957
 958         assert(m);
 959
 960         while ((seat = LIST_POP(gc_queue, m->seat_gc_queue))) {
 961                 seat->in_gc_queue = false;
 962
 963                 if (seat_may_gc(seat, drop_not_started)) {
 964                         seat_stop(seat, /* force = */ false);
 965                         seat_free(seat);
 966                 }
 967         }
 968
 969         while ((session = LIST_POP(gc_queue, m->session_gc_queue))) {
 970                 session->in_gc_queue = false;
 971
 972                 /* First, if we are not closing yet, initiate stopping. */
 973                 if (session_may_gc(session, drop_not_started) &&
 974                     session_get_state(session) != SESSION_CLOSING)
 975                         (void) session_stop(session, /* force = */ false);
 976
 977                 /* Normally, this should make the session referenced again, if it doesn't then let's get rid
 978                  * of it immediately. */
 979                 if (session_may_gc(session, drop_not_started)) {
 980                         (void) session_finalize(session);
 981                         session_free(session);
 982                 }
 983         }
 984
 985         while ((user = LIST_POP(gc_queue, m->user_gc_queue))) {
 986                 user->in_gc_queue = false;
 987
 988                 /* First step: queue stop jobs */
 989                 if (user_may_gc(user, drop_not_started))
 990                         (void) user_stop(user, false);
 991
 992                 /* Second step: finalize user */
 993                 if (user_may_gc(user, drop_not_started)) {
 994                         (void) user_finalize(user);
 995                         user_free(user);
 996                 }
 997         }
 998 }
 999
1000 static int manager_dispatch_idle_action(sd_event_source *s, uint64_t t, void *userdata) {
1001         Manager *m = ASSERT_PTR(userdata);
1002         struct dual_timestamp since;
1003         usec_t n, elapse;
1004         int r;
1005
1006         if (m->idle_action == HANDLE_IGNORE ||
1007             m->idle_action_usec <= 0)
1008                 return 0;
1009
1010         n = now(CLOCK_MONOTONIC);
1011
1012         r = manager_get_idle_hint(m, &since);
1013         if (r <= 0) {
1014                 /* Not idle. Let's check if after a timeout it might be idle then. */
1015                 elapse = n + m->idle_action_usec;
1016                 m->was_idle = false;
1017         } else {
1018
1019                 /* Idle! Let's see if it's time to do something, or if
1020                  * we shall sleep for longer. */
1021
1022                 if (n >= since.monotonic + m->idle_action_usec &&
1023                     (m->idle_action_not_before_usec <= 0 || n >= m->idle_action_not_before_usec + m->idle_action_usec)) {
1024                         bool is_edge = false;
1025
1026                         /* We weren't idle previously or some activity happened while we were sleeping, and now we are
1027                          * idle. Let's remember that for the next time and make this an edge transition. */
1028                         if (!m->was_idle || since.monotonic >= m->idle_action_not_before_usec) {
1029                                 is_edge = true;
1030                                 m->was_idle = true;
1031                         }
1032
1033                         if (m->idle_action == HANDLE_LOCK && !is_edge)
1034                                 /* We are idle and we were before so we are actually not taking any action. */
1035                                 log_debug("System idle.");
1036                         else
1037                                 log_info("System idle. Will %s now.", handle_action_verb_to_string(m->idle_action));
1038
1039                         manager_handle_action(m, 0, m->idle_action, false, is_edge);
1040                         m->idle_action_not_before_usec = n;
1041                 }
1042
1043                 elapse = MAX(since.monotonic, m->idle_action_not_before_usec) + m->idle_action_usec;
1044         }
1045
1046         if (!m->idle_action_event_source) {
1047
1048                 r = sd_event_add_time(
1049                                 m->event,
1050                                 &m->idle_action_event_source,
1051                                 CLOCK_MONOTONIC,
1052                                 elapse, MIN(USEC_PER_SEC*30, m->idle_action_usec), /* accuracy of 30s, but don't have an accuracy lower than the idle action timeout */
1053                                 manager_dispatch_idle_action, m);
1054                 if (r < 0)
1055                         return log_error_errno(r, "Failed to add idle event source: %m");
1056
1057                 r = sd_event_source_set_priority(m->idle_action_event_source, SD_EVENT_PRIORITY_IDLE+10);
1058                 if (r < 0)
1059                         return log_error_errno(r, "Failed to set idle event source priority: %m");
1060         } else {
1061                 r = sd_event_source_set_time(m->idle_action_event_source, elapse);
1062                 if (r < 0)
1063                         return log_error_errno(r, "Failed to set idle event timer: %m");
1064
1065                 r = sd_event_source_set_enabled(m->idle_action_event_source, SD_EVENT_ONESHOT);
1066                 if (r < 0)
1067                         return log_error_errno(r, "Failed to enable idle event timer: %m");
1068         }
1069
1070         return 0;
1071 }
1072
1073 static int manager_dispatch_reload_signal(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
1074         Manager *m = userdata;
1075         int r;
1076
1077         (void) notify_reloading();
1078
1079         manager_reset_config(m);
1080         r = manager_parse_config_file(m);
1081         if (r < 0)
1082                 log_warning_errno(r, "Failed to parse config file, using defaults: %m");
1083         else
1084                 log_info("Config file reloaded.");
1085
1086         (void) sd_notify(/* unset= */ false, NOTIFY_READY);
1087         return 0;
1088 }
1089
1090 static int manager_startup(Manager *m) {
1091         int r;
1092         Seat *seat;
1093         Session *session;
1094         User *user;
1095         Button *button;
1096         Inhibitor *inhibitor;
1097
1098         assert(m);
1099
1100         r = sd_event_add_signal(m->event, NULL, SIGHUP, manager_dispatch_reload_signal, m);
1101         if (r < 0)
1102                 return log_error_errno(r, "Failed to register SIGHUP handler: %m");
1103
1104         /* Connect to utmp */
1105         manager_connect_utmp(m);
1106
1107         /* Connect to console */
1108         r = manager_connect_console(m);
1109         if (r < 0)
1110                 return r;
1111
1112         /* Connect to udev */
1113         r = manager_connect_udev(m);
1114         if (r < 0)
1115                 return log_error_errno(r, "Failed to create udev watchers: %m");
1116
1117         /* Connect to the bus */
1118         r = manager_connect_bus(m);
1119         if (r < 0)
1120                 return r;
1121
1122         /* Instantiate magic seat 0 */
1123         r = manager_add_seat(m, "seat0", &m->seat0);
1124         if (r < 0)
1125                 return log_error_errno(r, "Failed to add seat0: %m");
1126
1127         r = manager_set_lid_switch_ignore(m, 0 + m->holdoff_timeout_usec);
1128         if (r < 0)
1129                 log_warning_errno(r, "Failed to set up lid switch ignore event source: %m");
1130
1131         /* Deserialize state */
1132         r = manager_enumerate_devices(m);
1133         if (r < 0)
1134                 log_warning_errno(r, "Device enumeration failed: %m");
1135
1136         r = manager_enumerate_seats(m);
1137         if (r < 0)
1138                 log_warning_errno(r, "Seat enumeration failed: %m");
1139
1140         r = manager_enumerate_users(m);
1141         if (r < 0)
1142                 log_warning_errno(r, "User enumeration failed: %m");
1143
1144         r = manager_enumerate_sessions(m);
1145         if (r < 0)
1146                 log_warning_errno(r, "Session enumeration failed: %m");
1147
1148         r = manager_enumerate_inhibitors(m);
1149         if (r < 0)
1150                 log_warning_errno(r, "Inhibitor enumeration failed: %m");
1151
1152         r = manager_enumerate_buttons(m);
1153         if (r < 0)
1154                 log_warning_errno(r, "Button enumeration failed: %m");
1155
1156         manager_load_scheduled_shutdown(m);
1157
1158         /* Remove stale objects before we start them */
1159         manager_gc(m, false);
1160
1161         /* Reserve the special reserved VT */
1162         manager_reserve_vt(m);
1163
1164         /* Read in utmp if it exists */
1165         manager_read_utmp(m);
1166
1167         /* And start everything */
1168         HASHMAP_FOREACH(seat, m->seats)
1169                 (void) seat_start(seat);
1170
1171         HASHMAP_FOREACH(user, m->users)
1172                 (void) user_start(user);
1173
1174         HASHMAP_FOREACH(session, m->sessions)
1175                 (void) session_start(session, NULL, NULL);
1176
1177         HASHMAP_FOREACH(inhibitor, m->inhibitors) {
1178                 (void) inhibitor_start(inhibitor);
1179
1180                 /* Let's see if the inhibitor is dead now, then remove it */
1181                 if (inhibitor_is_orphan(inhibitor)) {
1182                         inhibitor_stop(inhibitor);
1183                         inhibitor_free(inhibitor);
1184                 }
1185         }
1186
1187         HASHMAP_FOREACH(button, m->buttons)
1188                 button_check_switches(button);
1189
1190         manager_dispatch_idle_action(NULL, 0, m);
1191
1192         return 0;
1193 }
1194
1195 static int manager_run(Manager *m) {
1196         int r;
1197
1198         assert(m);
1199
1200         for (;;) {
1201                 r = sd_event_get_state(m->event);
1202                 if (r < 0)
1203                         return r;
1204                 if (r == SD_EVENT_FINISHED)
1205                         return 0;
1206
1207                 manager_gc(m, true);
1208
1209                 r = manager_dispatch_delayed(m, false);
1210                 if (r < 0)
1211                         return r;
1212                 if (r > 0)
1213                         continue;
1214
1215                 r = sd_event_run(m->event, UINT64_MAX);
1216                 if (r < 0)
1217                         return r;
1218         }
1219 }
1220
1221 static int run(int argc, char *argv[]) {
1222         _cleanup_(manager_freep) Manager *m = NULL;
1223         _unused_ _cleanup_(notify_on_cleanup) const char *notify_message = NULL;
1224         int r;
1225
1226         log_set_facility(LOG_AUTH);
1227         log_setup();
1228
1229         r = service_parse_argv("systemd-logind.service",
1230                                "Manager for user logins and devices and privileged operations.",
1231                                BUS_IMPLEMENTATIONS(&manager_object,
1232                                                    &log_control_object),
1233                                argc, argv);
1234         if (r <= 0)
1235                 return r;
1236
1237         umask(0022);
1238
1239         r = mac_init();
1240         if (r < 0)
1241                 return r;
1242
1243         /* Always create the directories people can create inotify watches in. Note that some applications
1244          * might check for the existence of /run/systemd/seats/ to determine whether logind is available, so
1245          * please always make sure these directories are created early on and unconditionally. */
1246         (void) mkdir_label("/run/systemd/seats", 0755);
1247         (void) mkdir_label("/run/systemd/users", 0755);
1248         (void) mkdir_label("/run/systemd/sessions", 0755);
1249
1250         assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGHUP, SIGTERM, SIGINT, SIGCHLD, SIGRTMIN+18) >= 0);
1251
1252         r = manager_new(&m);
1253         if (r < 0)
1254                 return log_error_errno(r, "Failed to allocate manager object: %m");
1255
1256         (void) manager_parse_config_file(m);
1257
1258         r = manager_startup(m);
1259         if (r < 0)
1260                 return log_error_errno(r, "Failed to fully start up daemon: %m");
1261
1262         notify_message = notify_start(NOTIFY_READY, NOTIFY_STOPPING);
1263         return manager_run(m);
1264 }
1265
1266 DEFINE_MAIN_FUNCTION(run);