src/login/logind-core.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <fcntl.h>
   4 #include <sys/ioctl.h>
   5 #include <sys/types.h>
   6 #include <linux/vt.h>
   7
   8 #include "sd-device.h"
   9
  10 #include "alloc-util.h"
  11 #include "bus-error.h"
  12 #include "bus-util.h"
  13 #include "cgroup-util.h"
  14 #include "conf-parser.h"
  15 #include "device-util.h"
  16 #include "efi-loader.h"
  17 #include "errno-util.h"
  18 #include "fd-util.h"
  19 #include "limits-util.h"
  20 #include "logind.h"
  21 #include "parse-util.h"
  22 #include "path-util.h"
  23 #include "process-util.h"
  24 #include "stdio-util.h"
  25 #include "strv.h"
  26 #include "terminal-util.h"
  27 #include "udev-util.h"
  28 #include "user-util.h"
  29 #include "userdb.h"
  30 #include "utmp-wtmp.h"
  31
  32 void manager_reset_config(Manager *m) {
  33         assert(m);
  34
  35         m->n_autovts = 6;
  36         m->reserve_vt = 6;
  37         m->remove_ipc = true;
  38         m->inhibit_delay_max = 5 * USEC_PER_SEC;
  39         m->user_stop_delay = 10 * USEC_PER_SEC;
  40
  41         m->handle_power_key = HANDLE_POWEROFF;
  42         m->handle_power_key_long_press = HANDLE_IGNORE;
  43         m->handle_reboot_key = HANDLE_REBOOT;
  44         m->handle_reboot_key_long_press = HANDLE_POWEROFF;
  45         m->handle_suspend_key = HANDLE_SUSPEND;
  46         m->handle_suspend_key_long_press = HANDLE_HIBERNATE;
  47         m->handle_hibernate_key = HANDLE_HIBERNATE;
  48         m->handle_hibernate_key_long_press = HANDLE_IGNORE;
  49
  50         m->handle_lid_switch = HANDLE_SUSPEND;
  51         m->handle_lid_switch_ep = _HANDLE_ACTION_INVALID;
  52         m->handle_lid_switch_docked = HANDLE_IGNORE;
  53
  54         m->power_key_ignore_inhibited = false;
  55         m->suspend_key_ignore_inhibited = false;
  56         m->hibernate_key_ignore_inhibited = false;
  57         m->lid_switch_ignore_inhibited = true;
  58         m->reboot_key_ignore_inhibited = false;
  59
  60         m->holdoff_timeout_usec = 30 * USEC_PER_SEC;
  61
  62         m->idle_action_usec = 30 * USEC_PER_MINUTE;
  63         m->idle_action = HANDLE_IGNORE;
  64
  65         m->runtime_dir_size = physical_memory_scale(10U, 100U); /* 10% */
  66         m->runtime_dir_inodes = DIV_ROUND_UP(m->runtime_dir_size, 4096); /* 4k per inode */
  67         m->sessions_max = 8192;
  68         m->inhibitors_max = 8192;
  69
  70         m->kill_user_processes = KILL_USER_PROCESSES;
  71
  72         m->kill_only_users = strv_free(m->kill_only_users);
  73         m->kill_exclude_users = strv_free(m->kill_exclude_users);
  74
  75         m->stop_idle_session_usec = USEC_INFINITY;
  76 }
  77
  78 int manager_parse_config_file(Manager *m) {
  79         assert(m);
  80
  81         return config_parse_config_file("logind.conf", "Login\0",
  82                                         config_item_perf_lookup, logind_gperf_lookup,
  83                                         CONFIG_PARSE_WARN, m);
  84 }
  85
  86 int manager_add_device(Manager *m, const char *sysfs, bool master, Device **ret_device) {
  87         Device *d;
  88
  89         assert(m);
  90         assert(sysfs);
  91
  92         d = hashmap_get(m->devices, sysfs);
  93         if (d)
  94                 /* we support adding master-flags, but not removing them */
  95                 d->master = d->master || master;
  96         else {
  97                 d = device_new(m, sysfs, master);
  98                 if (!d)
  99                         return -ENOMEM;
 100         }
 101
 102         if (ret_device)
 103                 *ret_device = d;
 104
 105         return 0;
 106 }
 107
 108 int manager_add_seat(Manager *m, const char *id, Seat **ret_seat) {
 109         Seat *s;
 110         int r;
 111
 112         assert(m);
 113         assert(id);
 114
 115         s = hashmap_get(m->seats, id);
 116         if (!s) {
 117                 r = seat_new(&s, m, id);
 118                 if (r < 0)
 119                         return r;
 120         }
 121
 122         if (ret_seat)
 123                 *ret_seat = s;
 124
 125         return 0;
 126 }
 127
 128 int manager_add_session(Manager *m, const char *id, Session **ret_session) {
 129         Session *s;
 130         int r;
 131
 132         assert(m);
 133         assert(id);
 134
 135         s = hashmap_get(m->sessions, id);
 136         if (!s) {
 137                 r = session_new(&s, m, id);
 138                 if (r < 0)
 139                         return r;
 140         }
 141
 142         if (ret_session)
 143                 *ret_session = s;
 144
 145         return 0;
 146 }
 147
 148 int manager_add_user(
 149                 Manager *m,
 150                 UserRecord *ur,
 151                 User **ret_user) {
 152
 153         User *u;
 154         int r;
 155
 156         assert(m);
 157         assert(ur);
 158
 159         u = hashmap_get(m->users, UID_TO_PTR(ur->uid));
 160         if (!u) {
 161                 r = user_new(&u, m, ur);
 162                 if (r < 0)
 163                         return r;
 164         }
 165
 166         if (ret_user)
 167                 *ret_user = u;
 168
 169         return 0;
 170 }
 171
 172 int manager_add_user_by_name(
 173                 Manager *m,
 174                 const char *name,
 175                 User **ret_user) {
 176
 177         _cleanup_(user_record_unrefp) UserRecord *ur = NULL;
 178         int r;
 179
 180         assert(m);
 181         assert(name);
 182
 183         r = userdb_by_name(name, USERDB_SUPPRESS_SHADOW, &ur);
 184         if (r < 0)
 185                 return r;
 186
 187         return manager_add_user(m, ur, ret_user);
 188 }
 189
 190 int manager_add_user_by_uid(
 191                 Manager *m,
 192                 uid_t uid,
 193                 User **ret_user) {
 194
 195         _cleanup_(user_record_unrefp) UserRecord *ur = NULL;
 196         int r;
 197
 198         assert(m);
 199         assert(uid_is_valid(uid));
 200
 201         r = userdb_by_uid(uid, USERDB_SUPPRESS_SHADOW, &ur);
 202         if (r < 0)
 203                 return r;
 204
 205         return manager_add_user(m, ur, ret_user);
 206 }
 207
 208 int manager_add_inhibitor(Manager *m, const char* id, Inhibitor **ret) {
 209         Inhibitor *i;
 210         int r;
 211
 212         assert(m);
 213         assert(id);
 214
 215         i = hashmap_get(m->inhibitors, id);
 216         if (!i) {
 217                 r = inhibitor_new(&i, m, id);
 218                 if (r < 0)
 219                         return r;
 220         }
 221
 222         if (ret)
 223                 *ret = i;
 224
 225         return 0;
 226 }
 227
 228 int manager_add_button(Manager *m, const char *name, Button **ret_button) {
 229         Button *b;
 230
 231         assert(m);
 232         assert(name);
 233
 234         b = hashmap_get(m->buttons, name);
 235         if (!b) {
 236                 b = button_new(m, name);
 237                 if (!b)
 238                         return -ENOMEM;
 239         }
 240
 241         if (ret_button)
 242                 *ret_button = b;
 243
 244         return 0;
 245 }
 246
 247 int manager_process_seat_device(Manager *m, sd_device *d) {
 248         Device *device;
 249         int r;
 250
 251         assert(m);
 252
 253         if (device_for_action(d, SD_DEVICE_REMOVE) ||
 254             sd_device_has_current_tag(d, "seat") <= 0) {
 255                 const char *syspath;
 256
 257                 r = sd_device_get_syspath(d, &syspath);
 258                 if (r < 0)
 259                         return 0;
 260
 261                 device = hashmap_get(m->devices, syspath);
 262                 if (!device)
 263                         return 0;
 264
 265                 seat_add_to_gc_queue(device->seat);
 266                 device_free(device);
 267
 268         } else {
 269                 const char *sn, *syspath;
 270                 bool master;
 271                 Seat *seat;
 272
 273                 if (sd_device_get_property_value(d, "ID_SEAT", &sn) < 0 || isempty(sn))
 274                         sn = "seat0";
 275
 276                 if (!seat_name_is_valid(sn)) {
 277                         log_device_warning(d, "Device with invalid seat name %s found, ignoring.", sn);
 278                         return 0;
 279                 }
 280
 281                 seat = hashmap_get(m->seats, sn);
 282                 master = sd_device_has_current_tag(d, "master-of-seat") > 0;
 283
 284                 /* Ignore non-master devices for unknown seats */
 285                 if (!master && !seat)
 286                         return 0;
 287
 288                 r = sd_device_get_syspath(d, &syspath);
 289                 if (r < 0)
 290                         return r;
 291
 292                 r = manager_add_device(m, syspath, master, &device);
 293                 if (r < 0)
 294                         return r;
 295
 296                 if (!seat) {
 297                         r = manager_add_seat(m, sn, &seat);
 298                         if (r < 0) {
 299                                 if (!device->seat)
 300                                         device_free(device);
 301
 302                                 return r;
 303                         }
 304                 }
 305
 306                 device_attach(device, seat);
 307                 seat_start(seat);
 308         }
 309
 310         return 0;
 311 }
 312
 313 int manager_process_button_device(Manager *m, sd_device *d) {
 314         const char *sysname;
 315         Button *b;
 316         int r;
 317
 318         assert(m);
 319
 320         r = sd_device_get_sysname(d, &sysname);
 321         if (r < 0)
 322                 return r;
 323
 324         if (device_for_action(d, SD_DEVICE_REMOVE) ||
 325             sd_device_has_current_tag(d, "power-switch") <= 0) {
 326
 327                 b = hashmap_get(m->buttons, sysname);
 328                 if (!b)
 329                         return 0;
 330
 331                 button_free(b);
 332
 333         } else {
 334                 const char *sn;
 335
 336                 r = manager_add_button(m, sysname, &b);
 337                 if (r < 0)
 338                         return r;
 339
 340                 if (sd_device_get_property_value(d, "ID_SEAT", &sn) < 0 || isempty(sn))
 341                         sn = "seat0";
 342
 343                 button_set_seat(b, sn);
 344
 345                 r = button_open(b);
 346                 if (r < 0) /* event device doesn't have any keys or switches relevant to us? (or any other error
 347                             * opening the device?) let's close the button again. */
 348                         button_free(b);
 349         }
 350
 351         return 0;
 352 }
 353
 354 int manager_get_session_by_pid(Manager *m, pid_t pid, Session **ret) {
 355         _cleanup_free_ char *unit = NULL;
 356         Session *s;
 357         int r;
 358
 359         assert(m);
 360
 361         if (!pid_is_valid(pid))
 362                 return -EINVAL;
 363
 364         s = hashmap_get(m->sessions_by_leader, PID_TO_PTR(pid));
 365         if (!s) {
 366                 r = cg_pid_get_unit(pid, &unit);
 367                 if (r >= 0)
 368                         s = hashmap_get(m->session_units, unit);
 369         }
 370
 371         if (ret)
 372                 *ret = s;
 373
 374         return !!s;
 375 }
 376
 377 int manager_get_user_by_pid(Manager *m, pid_t pid, User **ret) {
 378         _cleanup_free_ char *unit = NULL;
 379         User *u = NULL;
 380         int r;
 381
 382         assert(m);
 383
 384         if (!pid_is_valid(pid))
 385                 return -EINVAL;
 386
 387         r = cg_pid_get_slice(pid, &unit);
 388         if (r >= 0)
 389                 u = hashmap_get(m->user_units, unit);
 390
 391         if (ret)
 392                 *ret = u;
 393
 394         return !!u;
 395 }
 396
 397 int manager_get_idle_hint(Manager *m, dual_timestamp *t) {
 398         Session *s;
 399         bool idle_hint;
 400         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 401
 402         assert(m);
 403
 404         idle_hint = !manager_is_inhibited(m, INHIBIT_IDLE, INHIBIT_BLOCK, t, false, false, 0, NULL);
 405
 406         HASHMAP_FOREACH(s, m->sessions) {
 407                 dual_timestamp k;
 408                 int ih;
 409
 410                 ih = session_get_idle_hint(s, &k);
 411                 if (ih < 0)
 412                         return ih;
 413
 414                 if (!ih) {
 415                         if (!idle_hint) {
 416                                 if (k.monotonic < ts.monotonic)
 417                                         ts = k;
 418                         } else {
 419                                 idle_hint = false;
 420                                 ts = k;
 421                         }
 422                 } else if (idle_hint) {
 423
 424                         if (k.monotonic > ts.monotonic)
 425                                 ts = k;
 426                 }
 427         }
 428
 429         if (t)
 430                 *t = ts;
 431
 432         return idle_hint;
 433 }
 434
 435 bool manager_shall_kill(Manager *m, const char *user) {
 436         assert(m);
 437         assert(user);
 438
 439         if (!m->kill_exclude_users && streq(user, "root"))
 440                 return false;
 441
 442         if (strv_contains(m->kill_exclude_users, user))
 443                 return false;
 444
 445         if (!strv_isempty(m->kill_only_users))
 446                 return strv_contains(m->kill_only_users, user);
 447
 448         return m->kill_user_processes;
 449 }
 450
 451 int config_parse_n_autovts(
 452                 const char *unit,
 453                 const char *filename,
 454                 unsigned line,
 455                 const char *section,
 456                 unsigned section_line,
 457                 const char *lvalue,
 458                 int ltype,
 459                 const char *rvalue,
 460                 void *data,
 461                 void *userdata) {
 462
 463         unsigned *n = ASSERT_PTR(data);
 464         unsigned o;
 465         int r;
 466
 467         assert(filename);
 468         assert(lvalue);
 469         assert(rvalue);
 470
 471         r = safe_atou(rvalue, &o);
 472         if (r < 0) {
 473                 log_syntax(unit, LOG_WARNING, filename, line, r,
 474                            "Failed to parse number of autovts, ignoring: %s", rvalue);
 475                 return 0;
 476         }
 477
 478         if (o > 15) {
 479                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 480                            "A maximum of 15 autovts are supported, ignoring: %s", rvalue);
 481                 return 0;
 482         }
 483
 484         *n = o;
 485         return 0;
 486 }
 487
 488 static int vt_is_busy(unsigned vtnr) {
 489         struct vt_stat vt_stat;
 490         int r;
 491         _cleanup_close_ int fd = -EBADF;
 492
 493         assert(vtnr >= 1);
 494
 495         /* VT_GETSTATE "cannot return state for more than 16 VTs, since v_state is short" */
 496         assert(vtnr <= 15);
 497
 498         /* We explicitly open /dev/tty1 here instead of /dev/tty0. If
 499          * we'd open the latter we'd open the foreground tty which
 500          * hence would be unconditionally busy. By opening /dev/tty1
 501          * we avoid this. Since tty1 is special and needs to be an
 502          * explicitly loaded getty or DM this is safe. */
 503
 504         fd = open_terminal("/dev/tty1", O_RDWR|O_NOCTTY|O_CLOEXEC);
 505         if (fd < 0)
 506                 return -errno;
 507
 508         if (ioctl(fd, VT_GETSTATE, &vt_stat) < 0)
 509                 r = -errno;
 510         else
 511                 r = !!(vt_stat.v_state & (1 << vtnr));
 512
 513         return r;
 514 }
 515
 516 int manager_spawn_autovt(Manager *m, unsigned vtnr) {
 517         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 518         char name[sizeof("autovt@tty.service") + DECIMAL_STR_MAX(unsigned)];
 519         int r;
 520
 521         assert(m);
 522         assert(vtnr >= 1);
 523
 524         if (vtnr > m->n_autovts &&
 525             vtnr != m->reserve_vt)
 526                 return 0;
 527
 528         if (vtnr != m->reserve_vt) {
 529                 /* If this is the reserved TTY, we'll start the getty
 530                  * on it in any case, but otherwise only if it is not
 531                  * busy. */
 532
 533                 r = vt_is_busy(vtnr);
 534                 if (r < 0)
 535                         return r;
 536                 else if (r > 0)
 537                         return -EBUSY;
 538         }
 539
 540         xsprintf(name, "autovt@tty%u.service", vtnr);
 541         r = sd_bus_call_method(
 542                         m->bus,
 543                         "org.freedesktop.systemd1",
 544                         "/org/freedesktop/systemd1",
 545                         "org.freedesktop.systemd1.Manager",
 546                         "StartUnit",
 547                         &error,
 548                         NULL,
 549                         "ss", name, "fail");
 550         if (r < 0)
 551                 return log_error_errno(r, "Failed to start %s: %s", name, bus_error_message(&error, r));
 552
 553         return 0;
 554 }
 555
 556 bool manager_is_lid_closed(Manager *m) {
 557         Button *b;
 558
 559         HASHMAP_FOREACH(b, m->buttons)
 560                 if (b->lid_closed)
 561                         return true;
 562
 563         return false;
 564 }
 565
 566 static bool manager_is_docked(Manager *m) {
 567         Button *b;
 568
 569         HASHMAP_FOREACH(b, m->buttons)
 570                 if (b->docked)
 571                         return true;
 572
 573         return false;
 574 }
 575
 576 static int manager_count_external_displays(Manager *m) {
 577         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
 578         sd_device *d;
 579         int r, n = 0;
 580
 581         r = sd_device_enumerator_new(&e);
 582         if (r < 0)
 583                 return r;
 584
 585         r = sd_device_enumerator_allow_uninitialized(e);
 586         if (r < 0)
 587                 return r;
 588
 589         r = sd_device_enumerator_add_match_subsystem(e, "drm", true);
 590         if (r < 0)
 591                 return r;
 592
 593         FOREACH_DEVICE(e, d) {
 594                 const char *status, *enabled, *dash, *nn, *subsys;
 595                 sd_device *p;
 596
 597                 if (sd_device_get_parent(d, &p) < 0)
 598                         continue;
 599
 600                 /* If the parent shares the same subsystem as the
 601                  * device we are looking at then it is a connector,
 602                  * which is what we are interested in. */
 603                 if (sd_device_get_subsystem(p, &subsys) < 0 || !streq(subsys, "drm"))
 604                         continue;
 605
 606                 if (sd_device_get_sysname(d, &nn) < 0)
 607                         continue;
 608
 609                 /* Ignore internal displays: the type is encoded in the sysfs name, as the second dash
 610                  * separated item (the first is the card name, the last the connector number). We implement a
 611                  * deny list of external displays here, rather than an allow list of internal ones, to ensure
 612                  * we don't block suspends too eagerly. */
 613                 dash = strchr(nn, '-');
 614                 if (!dash)
 615                         continue;
 616
 617                 dash++;
 618                 if (!STARTSWITH_SET(dash,
 619                                     "VGA-", "DVI-I-", "DVI-D-", "DVI-A-"
 620                                     "Composite-", "SVIDEO-", "Component-",
 621                                     "DIN-", "DP-", "HDMI-A-", "HDMI-B-", "TV-"))
 622                         continue;
 623
 624                 /* Ignore ports that are not enabled */
 625                 if (sd_device_get_sysattr_value(d, "enabled", &enabled) < 0 || !streq(enabled, "enabled"))
 626                         continue;
 627
 628                 /* We count any connector which is not explicitly
 629                  * "disconnected" as connected. */
 630                 if (sd_device_get_sysattr_value(d, "status", &status) < 0 || !streq(status, "disconnected"))
 631                         n++;
 632         }
 633
 634         return n;
 635 }
 636
 637 bool manager_is_docked_or_external_displays(Manager *m) {
 638         int n;
 639
 640         /* If we are docked don't react to lid closing */
 641         if (manager_is_docked(m)) {
 642                 log_debug("System is docked.");
 643                 return true;
 644         }
 645
 646         /* If we have more than one display connected,
 647          * assume that we are docked. */
 648         n = manager_count_external_displays(m);
 649         if (n < 0)
 650                 log_warning_errno(n, "Display counting failed: %m");
 651         else if (n >= 1) {
 652                 log_debug("External (%i) displays connected.", n);
 653                 return true;
 654         }
 655
 656         return false;
 657 }
 658
 659 bool manager_is_on_external_power(void) {
 660         int r;
 661
 662         /* For now we only check for AC power, but 'external power' can apply to anything that isn't an internal
 663          * battery */
 664         r = on_ac_power();
 665         if (r < 0)
 666                 log_warning_errno(r, "Failed to read AC power status: %m");
 667
 668         return r != 0; /* Treat failure as 'on AC' */
 669 }
 670
 671 bool manager_all_buttons_ignored(Manager *m) {
 672         assert(m);
 673
 674         if (m->handle_power_key != HANDLE_IGNORE)
 675                 return false;
 676         if (m->handle_power_key_long_press != HANDLE_IGNORE)
 677                 return false;
 678         if (m->handle_suspend_key != HANDLE_IGNORE)
 679                 return false;
 680         if (m->handle_suspend_key_long_press != HANDLE_IGNORE)
 681                 return false;
 682         if (m->handle_hibernate_key != HANDLE_IGNORE)
 683                 return false;
 684         if (m->handle_hibernate_key_long_press != HANDLE_IGNORE)
 685                 return false;
 686         if (m->handle_reboot_key != HANDLE_IGNORE)
 687                 return false;
 688         if (m->handle_reboot_key_long_press != HANDLE_IGNORE)
 689                 return false;
 690         if (m->handle_lid_switch != HANDLE_IGNORE)
 691                 return false;
 692         if (!IN_SET(m->handle_lid_switch_ep, _HANDLE_ACTION_INVALID, HANDLE_IGNORE))
 693                 return false;
 694         if (m->handle_lid_switch_docked != HANDLE_IGNORE)
 695                 return false;
 696
 697         return true;
 698 }
 699
 700 int manager_read_utmp(Manager *m) {
 701 #if ENABLE_UTMP
 702         int r;
 703         _unused_ _cleanup_(utxent_cleanup) bool utmpx = false;
 704
 705         assert(m);
 706
 707         if (utmpxname(_PATH_UTMPX) < 0)
 708                 return log_error_errno(errno, "Failed to set utmp path to " _PATH_UTMPX ": %m");
 709
 710         utmpx = utxent_start();
 711
 712         for (;;) {
 713                 _cleanup_free_ char *t = NULL;
 714                 struct utmpx *u;
 715                 const char *c;
 716                 Session *s;
 717
 718                 errno = 0;
 719                 u = getutxent();
 720                 if (!u) {
 721                         if (errno == ENOENT)
 722                                 log_debug_errno(errno, _PATH_UTMPX " does not exist, ignoring.");
 723                         else if (errno != 0)
 724                                 log_warning_errno(errno, "Failed to read " _PATH_UTMPX ", ignoring: %m");
 725                         return 0;
 726                 }
 727
 728                 if (u->ut_type != USER_PROCESS)
 729                         continue;
 730
 731                 if (!pid_is_valid(u->ut_pid))
 732                         continue;
 733
 734                 t = strndup(u->ut_line, sizeof(u->ut_line));
 735                 if (!t)
 736                         return log_oom();
 737
 738                 c = path_startswith(t, "/dev/");
 739                 if (c) {
 740                         r = free_and_strdup(&t, c);
 741                         if (r < 0)
 742                                 return log_oom();
 743                 }
 744
 745                 if (isempty(t))
 746                         continue;
 747
 748                 s = hashmap_get(m->sessions_by_leader, PID_TO_PTR(u->ut_pid));
 749                 if (!s)
 750                         continue;
 751
 752                 if (s->tty_validity == TTY_FROM_UTMP && !streq_ptr(s->tty, t)) {
 753                         /* This may happen on multiplexed SSH connection (i.e. 'SSH connection sharing'). In
 754                          * this case PAM and utmp sessions don't match. In such a case let's invalidate the TTY
 755                          * information and never acquire it again. */
 756
 757                         s->tty = mfree(s->tty);
 758                         s->tty_validity = TTY_UTMP_INCONSISTENT;
 759                         log_debug("Session '%s' has inconsistent TTY information, dropping TTY information.", s->id);
 760                         continue;
 761                 }
 762
 763                 /* Never override what we figured out once */
 764                 if (s->tty || s->tty_validity >= 0)
 765                         continue;
 766
 767                 s->tty = TAKE_PTR(t);
 768                 s->tty_validity = TTY_FROM_UTMP;
 769                 log_debug("Acquired TTY information '%s' from utmp for session '%s'.", s->tty, s->id);
 770         }
 771
 772 #else
 773         return 0;
 774 #endif
 775 }
 776
 777 #if ENABLE_UTMP
 778 static int manager_dispatch_utmp(sd_event_source *s, const struct inotify_event *event, void *userdata) {
 779         Manager *m = ASSERT_PTR(userdata);
 780
 781         /* If there's indication the file itself might have been removed or became otherwise unavailable, then let's
 782          * reestablish the watch on whatever there's now. */
 783         if ((event->mask & (IN_ATTRIB|IN_DELETE_SELF|IN_MOVE_SELF|IN_Q_OVERFLOW|IN_UNMOUNT)) != 0)
 784                 manager_connect_utmp(m);
 785
 786         (void) manager_read_utmp(m);
 787         return 0;
 788 }
 789 #endif
 790
 791 void manager_connect_utmp(Manager *m) {
 792 #if ENABLE_UTMP
 793         sd_event_source *s = NULL;
 794         int r;
 795
 796         assert(m);
 797
 798         /* Watch utmp for changes via inotify. We do this to deal with tools such as ssh, which will register the PAM
 799          * session early, and acquire a TTY only much later for the connection. Thus during PAM the TTY won't be known
 800          * yet. ssh will register itself with utmp when it finally acquired the TTY. Hence, let's make use of this, and
 801          * watch utmp for the TTY asynchronously. We use the PAM session's leader PID as key, to find the right entry.
 802          *
 803          * Yes, relying on utmp is pretty ugly, but it's good enough for informational purposes, as well as idle
 804          * detection (which, for tty sessions, relies on the TTY used) */
 805
 806         r = sd_event_add_inotify(m->event, &s, _PATH_UTMPX, IN_MODIFY|IN_MOVE_SELF|IN_DELETE_SELF|IN_ATTRIB, manager_dispatch_utmp, m);
 807         if (r < 0)
 808                 log_full_errno(r == -ENOENT ? LOG_DEBUG: LOG_WARNING, r, "Failed to create inotify watch on " _PATH_UTMPX ", ignoring: %m");
 809         else {
 810                 r = sd_event_source_set_priority(s, SD_EVENT_PRIORITY_IDLE);
 811                 if (r < 0)
 812                         log_warning_errno(r, "Failed to adjust utmp event source priority, ignoring: %m");
 813
 814                 (void) sd_event_source_set_description(s, "utmp");
 815         }
 816
 817         sd_event_source_unref(m->utmp_event_source);
 818         m->utmp_event_source = s;
 819 #endif
 820 }
 821
 822 void manager_reconnect_utmp(Manager *m) {
 823 #if ENABLE_UTMP
 824         assert(m);
 825
 826         if (m->utmp_event_source)
 827                 return;
 828
 829         manager_connect_utmp(m);
 830 #endif
 831 }
 832
 833 int manager_read_efi_boot_loader_entries(Manager *m) {
 834 #if ENABLE_EFI
 835         int r;
 836
 837         assert(m);
 838         if (m->efi_boot_loader_entries_set)
 839                 return 0;
 840
 841         r = efi_loader_get_entries(&m->efi_boot_loader_entries);
 842         if (r == -ENOENT || ERRNO_IS_NOT_SUPPORTED(r)) {
 843                 log_debug_errno(r, "Boot loader reported no entries.");
 844                 m->efi_boot_loader_entries_set = true;
 845                 return 0;
 846         }
 847         if (r < 0)
 848                 return log_error_errno(r, "Failed to determine entries reported by boot loader: %m");
 849
 850         m->efi_boot_loader_entries_set = true;
 851         return 1;
 852 #else
 853         return 0;
 854 #endif
 855 }