src/login/logind-session-dbus.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <sys/eventfd.h>
   4
   5 #include "sd-bus.h"
   6 #include "sd-device.h"
   7
   8 #include "alloc-util.h"
   9 #include "bus-common-errors.h"
  10 #include "bus-get-properties.h"
  11 #include "bus-label.h"
  12 #include "bus-object.h"
  13 #include "bus-polkit.h"
  14 #include "device-util.h"
  15 #include "devnum-util.h"
  16 #include "errno-util.h"
  17 #include "fd-util.h"
  18 #include "format-util.h"
  19 #include "hashmap.h"
  20 #include "log.h"
  21 #include "logind.h"
  22 #include "logind-brightness.h"
  23 #include "logind-dbus.h"
  24 #include "logind-polkit.h"
  25 #include "logind-seat.h"
  26 #include "logind-seat-dbus.h"
  27 #include "logind-session.h"
  28 #include "logind-session-dbus.h"
  29 #include "logind-session-device.h"
  30 #include "logind-user.h"
  31 #include "logind-user-dbus.h"
  32 #include "path-util.h"
  33 #include "signal-util.h"
  34 #include "string-util.h"
  35 #include "strv.h"
  36 #include "terminal-util.h"
  37 #include "user-record.h"
  38 #include "user-util.h"
  39
  40 static int property_get_user(
  41                 sd_bus *bus,
  42                 const char *path,
  43                 const char *interface,
  44                 const char *property,
  45                 sd_bus_message *reply,
  46                 void *userdata,
  47                 sd_bus_error *error) {
  48
  49         _cleanup_free_ char *p = NULL;
  50         Session *s = ASSERT_PTR(userdata);
  51
  52         assert(bus);
  53         assert(reply);
  54
  55         p = user_bus_path(s->user);
  56         if (!p)
  57                 return -ENOMEM;
  58
  59         return sd_bus_message_append(reply, "(uo)", (uint32_t) s->user->user_record->uid, p);
  60 }
  61
  62 static int property_get_name(
  63                 sd_bus *bus,
  64                 const char *path,
  65                 const char *interface,
  66                 const char *property,
  67                 sd_bus_message *reply,
  68                 void *userdata,
  69                 sd_bus_error *error) {
  70
  71         Session *s = ASSERT_PTR(userdata);
  72
  73         assert(bus);
  74         assert(reply);
  75
  76         return sd_bus_message_append(reply, "s", s->user->user_record->user_name);
  77 }
  78
  79 static int property_get_seat(
  80                 sd_bus *bus,
  81                 const char *path,
  82                 const char *interface,
  83                 const char *property,
  84                 sd_bus_message *reply,
  85                 void *userdata,
  86                 sd_bus_error *error) {
  87
  88         _cleanup_free_ char *p = NULL;
  89         Session *s = ASSERT_PTR(userdata);
  90
  91         assert(bus);
  92         assert(reply);
  93
  94         p = s->seat ? seat_bus_path(s->seat) : strdup("/");
  95         if (!p)
  96                 return -ENOMEM;
  97
  98         return sd_bus_message_append(reply, "(so)", s->seat ? s->seat->id : "", p);
  99 }
 100
 101 static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_type, session_type, SessionType);
 102 static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_class, session_class, SessionClass);
 103 static BUS_DEFINE_PROPERTY_GET(property_get_active, "b", Session, session_is_active);
 104 static BUS_DEFINE_PROPERTY_GET2(property_get_state, "s", Session, session_get_state, session_state_to_string);
 105
 106 static int property_get_idle_hint(
 107                 sd_bus *bus,
 108                 const char *path,
 109                 const char *interface,
 110                 const char *property,
 111                 sd_bus_message *reply,
 112                 void *userdata,
 113                 sd_bus_error *error) {
 114
 115         Session *s = ASSERT_PTR(userdata);
 116
 117         assert(bus);
 118         assert(reply);
 119
 120         return sd_bus_message_append(reply, "b", session_get_idle_hint(s, NULL) > 0);
 121 }
 122
 123 static int property_get_can_idle(
 124                 sd_bus *bus,
 125                 const char *path,
 126                 const char *interface,
 127                 const char *property,
 128                 sd_bus_message *reply,
 129                 void *userdata,
 130                 sd_bus_error *error) {
 131
 132         Session *s = ASSERT_PTR(userdata);
 133
 134         assert(bus);
 135         assert(reply);
 136
 137         return sd_bus_message_append(reply, "b", SESSION_CLASS_CAN_IDLE(s->class));
 138 }
 139
 140 static int property_get_can_lock(
 141                 sd_bus *bus,
 142                 const char *path,
 143                 const char *interface,
 144                 const char *property,
 145                 sd_bus_message *reply,
 146                 void *userdata,
 147                 sd_bus_error *error) {
 148
 149         Session *s = ASSERT_PTR(userdata);
 150
 151         assert(bus);
 152         assert(reply);
 153
 154         return sd_bus_message_append(reply, "b", SESSION_CLASS_CAN_LOCK(s->class));
 155 }
 156
 157 static int property_get_idle_since_hint(
 158                 sd_bus *bus,
 159                 const char *path,
 160                 const char *interface,
 161                 const char *property,
 162                 sd_bus_message *reply,
 163                 void *userdata,
 164                 sd_bus_error *error) {
 165
 166         Session *s = ASSERT_PTR(userdata);
 167         dual_timestamp t = DUAL_TIMESTAMP_NULL;
 168         uint64_t u;
 169         int r;
 170
 171         assert(bus);
 172         assert(reply);
 173
 174         r = session_get_idle_hint(s, &t);
 175         if (r < 0)
 176                 return r;
 177
 178         u = streq(property, "IdleSinceHint") ? t.realtime : t.monotonic;
 179
 180         return sd_bus_message_append(reply, "t", u);
 181 }
 182
 183 static int property_get_locked_hint(
 184                 sd_bus *bus,
 185                 const char *path,
 186                 const char *interface,
 187                 const char *property,
 188                 sd_bus_message *reply,
 189                 void *userdata,
 190                 sd_bus_error *error) {
 191
 192         Session *s = ASSERT_PTR(userdata);
 193
 194         assert(bus);
 195         assert(reply);
 196
 197         return sd_bus_message_append(reply, "b", session_get_locked_hint(s) > 0);
 198 }
 199
 200 int bus_session_method_terminate(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 201         Session *s = ASSERT_PTR(userdata);
 202         int r;
 203
 204         assert(message);
 205
 206         r = bus_verify_polkit_async_full(
 207                         message,
 208                         "org.freedesktop.login1.manage",
 209                         /* details= */ NULL,
 210                         s->user->user_record->uid,
 211                         /* flags= */ 0,
 212                         &s->manager->polkit_registry,
 213                         error);
 214         if (r < 0)
 215                 return r;
 216         if (r == 0)
 217                 return 1; /* Will call us back */
 218
 219         r = session_stop(s, /* force = */ true);
 220         if (r < 0)
 221                 return r;
 222
 223         return sd_bus_reply_method_return(message, NULL);
 224 }
 225
 226 int bus_session_method_activate(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 227         Session *s = ASSERT_PTR(userdata);
 228         int r;
 229
 230         assert(message);
 231
 232         r = check_polkit_chvt(message, s->manager, error);
 233         if (r < 0)
 234                 return r;
 235         if (r == 0)
 236                 return 1; /* Will call us back */
 237
 238         r = session_activate(s);
 239         if (r < 0)
 240                 return r;
 241
 242         return sd_bus_reply_method_return(message, NULL);
 243 }
 244
 245 int bus_session_method_lock(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 246         Session *s = ASSERT_PTR(userdata);
 247         int r;
 248
 249         assert(message);
 250
 251         r = bus_verify_polkit_async_full(
 252                         message,
 253                         "org.freedesktop.login1.lock-sessions",
 254                         /* details= */ NULL,
 255                         s->user->user_record->uid,
 256                         /* flags= */ 0,
 257                         &s->manager->polkit_registry,
 258                         error);
 259         if (r < 0)
 260                 return r;
 261         if (r == 0)
 262                 return 1; /* Will call us back */
 263
 264         r = session_send_lock(s, /* lock= */ strstr(sd_bus_message_get_member(message), "Lock"));
 265         if (r == -ENOTTY)
 266                 return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Session does not support lock screen.");
 267         if (r < 0)
 268                 return r;
 269
 270         return sd_bus_reply_method_return(message, NULL);
 271 }
 272
 273 static int method_set_idle_hint(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 274         _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 275         Session *s = ASSERT_PTR(userdata);
 276         uid_t uid;
 277         int r, b;
 278
 279         assert(message);
 280
 281         r = sd_bus_message_read(message, "b", &b);
 282         if (r < 0)
 283                 return r;
 284
 285         r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
 286         if (r < 0)
 287                 return r;
 288
 289         r = sd_bus_creds_get_euid(creds, &uid);
 290         if (r < 0)
 291                 return r;
 292
 293         if (uid != 0 && uid != s->user->user_record->uid)
 294                 return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Only owner of session may set idle hint");
 295
 296         r = session_set_idle_hint(s, b);
 297         if (r == -ENOTTY)
 298                 return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Idle hint control is not supported on non-graphical and non-user sessions.");
 299         if (r < 0)
 300                 return r;
 301
 302         return sd_bus_reply_method_return(message, NULL);
 303 }
 304
 305 static int method_set_locked_hint(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 306         _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 307         Session *s = ASSERT_PTR(userdata);
 308         uid_t uid;
 309         int r, b;
 310
 311         assert(message);
 312
 313         r = sd_bus_message_read(message, "b", &b);
 314         if (r < 0)
 315                 return r;
 316
 317         r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
 318         if (r < 0)
 319                 return r;
 320
 321         r = sd_bus_creds_get_euid(creds, &uid);
 322         if (r < 0)
 323                 return r;
 324
 325         if (uid != 0 && uid != s->user->user_record->uid)
 326                 return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Only owner of session may set locked hint");
 327
 328         r = session_set_locked_hint(s, b);
 329         if (r == -ENOTTY)
 330                 return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Session does not support lock screen.");
 331         if (r < 0)
 332                 return r;
 333
 334         return sd_bus_reply_method_return(message, NULL);
 335 }
 336
 337 int bus_session_method_kill(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 338         Session *s = ASSERT_PTR(userdata);
 339         const char *swhom;
 340         int32_t signo;
 341         KillWhom whom;
 342         int r;
 343
 344         assert(message);
 345
 346         r = sd_bus_message_read(message, "si", &swhom, &signo);
 347         if (r < 0)
 348                 return r;
 349
 350         if (isempty(swhom))
 351                 whom = KILL_ALL;
 352         else {
 353                 whom = kill_whom_from_string(swhom);
 354                 if (whom < 0)
 355                         return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid kill parameter '%s'", swhom);
 356         }
 357
 358         if (!SIGNAL_VALID(signo))
 359                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid signal %i", signo);
 360
 361         r = bus_verify_polkit_async_full(
 362                         message,
 363                         "org.freedesktop.login1.manage",
 364                         /* details= */ NULL,
 365                         s->user->user_record->uid,
 366                         /* flags= */ 0,
 367                         &s->manager->polkit_registry,
 368                         error);
 369         if (r < 0)
 370                 return r;
 371         if (r == 0)
 372                 return 1; /* Will call us back */
 373
 374         r = session_kill(s, whom, signo, error);
 375         if (r < 0)
 376                 return r;
 377
 378         return sd_bus_reply_method_return(message, NULL);
 379 }
 380
 381 static int method_take_control(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 382         _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 383         Session *s = ASSERT_PTR(userdata);
 384         int r, force;
 385         uid_t uid;
 386
 387         assert(message);
 388
 389         r = sd_bus_message_read(message, "b", &force);
 390         if (r < 0)
 391                 return r;
 392
 393         r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
 394         if (r < 0)
 395                 return r;
 396
 397         r = sd_bus_creds_get_euid(creds, &uid);
 398         if (r < 0)
 399                 return r;
 400
 401         if (uid != 0 && (force || uid != s->user->user_record->uid))
 402                 return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Only owner of session may take control");
 403
 404         r = session_set_controller(s, sd_bus_message_get_sender(message), force, true);
 405         if (r < 0)
 406                 return r;
 407
 408         return sd_bus_reply_method_return(message, NULL);
 409 }
 410
 411 static int method_release_control(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 412         Session *s = ASSERT_PTR(userdata);
 413
 414         assert(message);
 415
 416         if (!session_is_controller(s, sd_bus_message_get_sender(message)))
 417                 return sd_bus_error_set(error, BUS_ERROR_NOT_IN_CONTROL, "You are not in control of this session");
 418
 419         session_drop_controller(s);
 420
 421         return sd_bus_reply_method_return(message, NULL);
 422 }
 423
 424 static int method_set_type(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 425         Session *s = ASSERT_PTR(userdata);
 426         const char *t;
 427         SessionType type;
 428         int r;
 429
 430         assert(message);
 431
 432         r = sd_bus_message_read(message, "s", &t);
 433         if (r < 0)
 434                 return r;
 435
 436         type = session_type_from_string(t);
 437         if (type < 0)
 438                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
 439                                          "Invalid session type '%s'", t);
 440
 441         if (!SESSION_CLASS_CAN_CHANGE_TYPE(s->class))
 442                 return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Session class doesn't support changing type.");
 443
 444         if (!session_is_controller(s, sd_bus_message_get_sender(message)))
 445                 return sd_bus_error_set(error, BUS_ERROR_NOT_IN_CONTROL, "You must be in control of this session to set type");
 446
 447         session_set_type(s, type);
 448
 449         return sd_bus_reply_method_return(message, NULL);
 450 }
 451
 452 static int method_set_class(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 453         _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 454         Session *s = ASSERT_PTR(userdata);
 455         SessionClass class;
 456         const char *c;
 457         uid_t uid;
 458         int r;
 459
 460         assert(message);
 461
 462         r = sd_bus_message_read(message, "s", &c);
 463         if (r < 0)
 464                 return r;
 465
 466         class = session_class_from_string(c);
 467         if (class < 0)
 468                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
 469                                          "Invalid session class '%s'", c);
 470
 471         /* For now, we'll allow only upgrades user-incomplete → user */
 472         if (class != SESSION_USER)
 473                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
 474                                          "Class may only be set to 'user'");
 475
 476         if (s->class == SESSION_USER) /* No change, shortcut */
 477                 return sd_bus_reply_method_return(message, NULL);
 478         if (s->class != SESSION_USER_INCOMPLETE)
 479                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
 480                                          "Only sessions with class 'user-incomplete' may change class");
 481
 482         if (s->upgrade_message)
 483                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
 484                                          "Set session class operation already in progress");
 485
 486         r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
 487         if (r < 0)
 488                 return r;
 489
 490         r = sd_bus_creds_get_euid(creds, &uid);
 491         if (r < 0)
 492                 return r;
 493
 494         if (uid != 0 && uid != s->user->user_record->uid)
 495                 return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Only owner of session may change its class");
 496
 497         session_set_class(s, class);
 498
 499         s->upgrade_message = sd_bus_message_ref(message);
 500
 501         r = session_send_upgrade_reply(s, /* error= */ NULL);
 502         if (r < 0)
 503                 return r;
 504
 505         return 1;
 506 }
 507
 508 static int method_set_display(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 509         Session *s = ASSERT_PTR(userdata);
 510         const char *display;
 511         int r;
 512
 513         assert(message);
 514
 515         r = sd_bus_message_read(message, "s", &display);
 516         if (r < 0)
 517                 return r;
 518
 519         if (!session_is_controller(s, sd_bus_message_get_sender(message)))
 520                 return sd_bus_error_set(error, BUS_ERROR_NOT_IN_CONTROL, "You must be in control of this session to set display");
 521
 522         if (!SESSION_TYPE_IS_GRAPHICAL(s->type))
 523                 return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Setting display is only supported for graphical sessions");
 524
 525         r = session_set_display(s, display);
 526         if (r < 0)
 527                 return r;
 528
 529         return sd_bus_reply_method_return(message, NULL);
 530 }
 531
 532 static int method_set_tty(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 533         Session *s = ASSERT_PTR(userdata);
 534         int fd, r, flags;
 535         _cleanup_free_ char *q = NULL;
 536
 537         assert(message);
 538
 539         r = sd_bus_message_read(message, "h", &fd);
 540         if (r < 0)
 541                 return r;
 542
 543         if (!session_is_controller(s, sd_bus_message_get_sender(message)))
 544                 return sd_bus_error_set(error, BUS_ERROR_NOT_IN_CONTROL, "You must be in control of this session to set tty");
 545
 546         assert(fd >= 0);
 547
 548         flags = fcntl(fd, F_GETFL, 0);
 549         if (flags < 0)
 550                 return -errno;
 551         if ((flags & O_ACCMODE_STRICT) != O_RDWR)
 552                 return -EACCES;
 553         if (FLAGS_SET(flags, O_PATH))
 554                 return -ENOTTY;
 555
 556         r = getttyname_malloc(fd, &q);
 557         if (r < 0)
 558                 return r;
 559
 560         r = session_set_tty(s, q);
 561         if (r < 0)
 562                 return r;
 563
 564         return sd_bus_reply_method_return(message, NULL);
 565 }
 566
 567 static int method_take_device(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 568         Session *s = ASSERT_PTR(userdata);
 569         uint32_t major, minor;
 570         _cleanup_(session_device_freep) SessionDevice *sd = NULL;
 571         dev_t dev;
 572         int r;
 573
 574         assert(message);
 575
 576         r = sd_bus_message_read(message, "uu", &major, &minor);
 577         if (r < 0)
 578                 return r;
 579
 580         if (!DEVICE_MAJOR_VALID(major) || !DEVICE_MINOR_VALID(minor))
 581                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Device major/minor is not valid.");
 582
 583         if (!SESSION_CLASS_CAN_TAKE_DEVICE(s->class))
 584                 return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Session class doesn't support taking device control.");
 585
 586         if (!session_is_controller(s, sd_bus_message_get_sender(message)))
 587                 return sd_bus_error_set(error, BUS_ERROR_NOT_IN_CONTROL, "You are not in control of this session");
 588
 589         dev = makedev(major, minor);
 590         sd = hashmap_get(s->devices, &dev);
 591         if (sd)
 592                 /* We don't allow retrieving a device multiple times.
 593                  * The related ReleaseDevice call is not ref-counted.
 594                  * The caller should use dup() if it requires more
 595                  * than one fd (it would be functionally
 596                  * equivalent). */
 597                 return sd_bus_error_set(error, BUS_ERROR_DEVICE_IS_TAKEN, "Device already taken");
 598
 599         r = session_device_new(s, dev, true, &sd);
 600         if (r < 0)
 601                 return r;
 602
 603         r = session_device_save(sd);
 604         if (r < 0)
 605                 return r;
 606
 607         r = sd_bus_reply_method_return(message, "hb", sd->fd, !sd->active);
 608         if (r < 0)
 609                 return r;
 610
 611         session_save(s);
 612         TAKE_PTR(sd);
 613
 614         return 1;
 615 }
 616
 617 static int method_release_device(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 618         Session *s = ASSERT_PTR(userdata);
 619         uint32_t major, minor;
 620         SessionDevice *sd;
 621         dev_t dev;
 622         int r;
 623
 624         assert(message);
 625
 626         r = sd_bus_message_read(message, "uu", &major, &minor);
 627         if (r < 0)
 628                 return r;
 629
 630         if (!DEVICE_MAJOR_VALID(major) || !DEVICE_MINOR_VALID(minor))
 631                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Device major/minor is not valid.");
 632
 633         if (!session_is_controller(s, sd_bus_message_get_sender(message)))
 634                 return sd_bus_error_set(error, BUS_ERROR_NOT_IN_CONTROL, "You are not in control of this session");
 635
 636         dev = makedev(major, minor);
 637         sd = hashmap_get(s->devices, &dev);
 638         if (!sd)
 639                 return sd_bus_error_set(error, BUS_ERROR_DEVICE_NOT_TAKEN, "Device not taken");
 640
 641         session_device_free(sd);
 642         session_save(s);
 643
 644         return sd_bus_reply_method_return(message, NULL);
 645 }
 646
 647 static int method_pause_device_complete(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 648         Session *s = ASSERT_PTR(userdata);
 649         uint32_t major, minor;
 650         SessionDevice *sd;
 651         dev_t dev;
 652         int r;
 653
 654         assert(message);
 655
 656         r = sd_bus_message_read(message, "uu", &major, &minor);
 657         if (r < 0)
 658                 return r;
 659
 660         if (!DEVICE_MAJOR_VALID(major) || !DEVICE_MINOR_VALID(minor))
 661                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Device major/minor is not valid.");
 662
 663         if (!session_is_controller(s, sd_bus_message_get_sender(message)))
 664                 return sd_bus_error_set(error, BUS_ERROR_NOT_IN_CONTROL, "You are not in control of this session");
 665
 666         dev = makedev(major, minor);
 667         sd = hashmap_get(s->devices, &dev);
 668         if (!sd)
 669                 return sd_bus_error_set(error, BUS_ERROR_DEVICE_NOT_TAKEN, "Device not taken");
 670
 671         session_device_complete_pause(sd);
 672
 673         return sd_bus_reply_method_return(message, NULL);
 674 }
 675
 676 static int method_set_brightness(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 677         _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 678         _cleanup_(sd_device_unrefp) sd_device *d = NULL;
 679         const char *subsystem, *name, *seat;
 680         Session *s = ASSERT_PTR(userdata);
 681         uint32_t brightness;
 682         uid_t uid;
 683         int r;
 684
 685         assert(message);
 686
 687         r = sd_bus_message_read(message, "ssu", &subsystem, &name, &brightness);
 688         if (r < 0)
 689                 return r;
 690
 691         if (!STR_IN_SET(subsystem, "backlight", "leds"))
 692                 return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Subsystem type %s not supported, must be one of 'backlight' or 'leds'.", subsystem);
 693         if (!filename_is_valid(name))
 694                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Not a valid device name %s, refusing.", name);
 695
 696         if (!s->seat)
 697                 return sd_bus_error_set(error, BUS_ERROR_NOT_YOUR_DEVICE, "Your session has no seat, refusing.");
 698         if (s->seat->active != s)
 699                 return sd_bus_error_set(error, BUS_ERROR_NOT_YOUR_DEVICE, "Session is not in foreground, refusing.");
 700
 701         r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
 702         if (r < 0)
 703                 return r;
 704
 705         r = sd_bus_creds_get_euid(creds, &uid);
 706         if (r < 0)
 707                 return r;
 708
 709         if (uid != 0 && uid != s->user->user_record->uid)
 710                 return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Only owner of session may change brightness.");
 711
 712         r = sd_device_new_from_subsystem_sysname(&d, subsystem, name);
 713         if (r < 0)
 714                 return sd_bus_error_set_errnof(error, r, "Failed to open device %s:%s: %m", subsystem, name);
 715
 716         r = device_get_seat(d, &seat);
 717         if (r < 0)
 718                 return sd_bus_error_set_errnof(error, r, "Failed to get seat of %s:%s: %m", subsystem, name);
 719         if (!streq(seat, s->seat->id))
 720                 return sd_bus_error_setf(error, BUS_ERROR_NOT_YOUR_DEVICE, "Device %s:%s does not belong to your seat %s, refusing.", subsystem, name, s->seat->id);
 721
 722         r = manager_write_brightness(s->manager, d, brightness, message);
 723         if (r < 0)
 724                 return r;
 725
 726         return 1;
 727 }
 728
 729 static int session_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
 730         _cleanup_free_ char *e = NULL;
 731         sd_bus_message *message;
 732         Manager *m = ASSERT_PTR(userdata);
 733         Session *session;
 734         const char *p;
 735         int r;
 736
 737         assert(bus);
 738         assert(path);
 739         assert(interface);
 740         assert(found);
 741
 742         p = startswith(path, "/org/freedesktop/login1/session/");
 743         if (!p)
 744                 return 0;
 745
 746         e = bus_label_unescape(p);
 747         if (!e)
 748                 return -ENOMEM;
 749
 750         message = sd_bus_get_current_message(bus);
 751
 752         r = manager_get_session_from_creds(m, message, e, error, &session);
 753         if (r == -ENXIO) {
 754                 sd_bus_error_free(error);
 755                 return 0;
 756         }
 757         if (r < 0)
 758                 return r;
 759
 760         *found = session;
 761         return 1;
 762 }
 763
 764 char* session_bus_path(Session *s) {
 765         _cleanup_free_ char *t = NULL;
 766
 767         assert(s);
 768
 769         t = bus_label_escape(s->id);
 770         if (!t)
 771                 return NULL;
 772
 773         return strjoin("/org/freedesktop/login1/session/", t);
 774 }
 775
 776 static int session_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
 777         _cleanup_strv_free_ char **l = NULL;
 778         sd_bus_message *message;
 779         Manager *m = userdata;
 780         Session *session;
 781         int r;
 782
 783         assert(bus);
 784         assert(path);
 785         assert(nodes);
 786
 787         HASHMAP_FOREACH(session, m->sessions) {
 788                 char *p;
 789
 790                 p = session_bus_path(session);
 791                 if (!p)
 792                         return -ENOMEM;
 793
 794                 r = strv_consume(&l, p);
 795                 if (r < 0)
 796                         return r;
 797         }
 798
 799         message = sd_bus_get_current_message(bus);
 800         if (message) {
 801                 _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 802
 803                 r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID|SD_BUS_CREDS_AUGMENT, &creds);
 804                 if (r >= 0) {
 805                         bool may_auto = false;
 806                         const char *name;
 807
 808                         r = sd_bus_creds_get_session(creds, &name);
 809                         if (r >= 0) {
 810                                 session = hashmap_get(m->sessions, name);
 811                                 if (session) {
 812                                         r = strv_extend(&l, "/org/freedesktop/login1/session/self");
 813                                         if (r < 0)
 814                                                 return r;
 815
 816                                         may_auto = true;
 817                                 }
 818                         }
 819
 820                         if (!may_auto) {
 821                                 uid_t uid;
 822
 823                                 r = sd_bus_creds_get_owner_uid(creds, &uid);
 824                                 if (r >= 0) {
 825                                         User *user;
 826
 827                                         user = hashmap_get(m->users, UID_TO_PTR(uid));
 828                                         may_auto = user && user->display;
 829                                 }
 830                         }
 831
 832                         if (may_auto) {
 833                                 r = strv_extend(&l, "/org/freedesktop/login1/session/auto");
 834                                 if (r < 0)
 835                                         return r;
 836                         }
 837                 }
 838         }
 839
 840         *nodes = TAKE_PTR(l);
 841         return 1;
 842 }
 843
 844 int session_send_signal(Session *s, bool new_session) {
 845         _cleanup_free_ char *p = NULL;
 846
 847         assert(s);
 848
 849         p = session_bus_path(s);
 850         if (!p)
 851                 return -ENOMEM;
 852
 853         return sd_bus_emit_signal(
 854                         s->manager->bus,
 855                         "/org/freedesktop/login1",
 856                         "org.freedesktop.login1.Manager",
 857                         new_session ? "SessionNew" : "SessionRemoved",
 858                         "so", s->id, p);
 859 }
 860
 861 int session_send_changed_strv(Session *s, char **properties) {
 862         _cleanup_free_ char *p = NULL;
 863
 864         assert(s);
 865
 866         if (!s->started)
 867                 return 0;
 868
 869         p = session_bus_path(s);
 870         if (!p)
 871                 return -ENOMEM;
 872
 873         return sd_bus_emit_properties_changed_strv(s->manager->bus, p, "org.freedesktop.login1.Session", properties);
 874 }
 875
 876 int session_send_lock(Session *s, bool lock) {
 877         _cleanup_free_ char *p = NULL;
 878
 879         assert(s);
 880
 881         if (!SESSION_CLASS_CAN_LOCK(s->class))
 882                 return -ENOTTY;
 883
 884         p = session_bus_path(s);
 885         if (!p)
 886                 return -ENOMEM;
 887
 888         return sd_bus_emit_signal(
 889                         s->manager->bus,
 890                         p,
 891                         "org.freedesktop.login1.Session",
 892                         lock ? "Lock" : "Unlock",
 893                         NULL);
 894 }
 895
 896 int session_send_lock_all(Manager *m, bool lock) {
 897         Session *session;
 898         int r = 0;
 899
 900         assert(m);
 901
 902         HASHMAP_FOREACH(session, m->sessions) {
 903
 904                 if (!SESSION_CLASS_CAN_LOCK(session->class))
 905                         continue;
 906
 907                 RET_GATHER(r, session_send_lock(session, lock));
 908         }
 909
 910         return r;
 911 }
 912
 913 int session_send_create_reply_bus(Session *s, const sd_bus_error *error) {
 914         assert(s);
 915
 916         /* This is called after the session scope and the user service were successfully created, and
 917          * finishes where manager_create_session() left off. */
 918
 919         _cleanup_(sd_bus_message_unrefp) sd_bus_message *c = TAKE_PTR(s->create_message);
 920         if (!c)
 921                 return 0;
 922
 923         if (sd_bus_error_is_set(error))
 924                 return sd_bus_reply_method_error(c, error);
 925
 926         /* Prior to v258, logind tracked sessions by installing a fifo in client and subscribe to its EOF.
 927          * Now we can fully rely on pidfd for this, but still need to return *something* to the client.
 928          * Allocate something lightweight and isolated as placeholder. */
 929         _cleanup_close_ int fd = eventfd(0, EFD_CLOEXEC);
 930         if (fd < 0)
 931                 return -errno;
 932
 933         _cleanup_free_ char *p = session_bus_path(s);
 934         if (!p)
 935                 return -ENOMEM;
 936
 937         log_debug("Sending D-Bus reply about created session: "
 938                   "id=%s object_path=%s uid=" UID_FMT " runtime_path=%s seat=%s vtnr=%u",
 939                   s->id,
 940                   p,
 941                   s->user->user_record->uid,
 942                   s->user->runtime_path,
 943                   s->seat ? s->seat->id : "",
 944                   s->vtnr);
 945
 946         return sd_bus_reply_method_return(
 947                         c, "soshusub",
 948                         s->id,
 949                         p,
 950                         s->user->runtime_path,
 951                         fd, /* not really used - see comments above */
 952                         (uint32_t) s->user->user_record->uid,
 953                         s->seat ? s->seat->id : "",
 954                         (uint32_t) s->vtnr,
 955                         false);
 956 }
 957
 958 int session_send_upgrade_reply(Session *s, const sd_bus_error *error) {
 959         _cleanup_(sd_bus_message_unrefp) sd_bus_message *c = NULL;
 960         assert(s);
 961
 962         if (!s->upgrade_message)
 963                 return 0;
 964
 965         /* See comments in session_send_create_reply */
 966         if (!sd_bus_error_is_set(error) && session_job_pending(s))
 967                 return 0;
 968
 969         c = TAKE_PTR(s->upgrade_message);
 970         if (error)
 971                 return sd_bus_reply_method_error(c, error);
 972
 973         session_save(s);
 974
 975         return sd_bus_reply_method_return(c, NULL);
 976 }
 977
 978 static const sd_bus_vtable session_vtable[] = {
 979         SD_BUS_VTABLE_START(0),
 980
 981         SD_BUS_PROPERTY("Id", "s", NULL, offsetof(Session, id), SD_BUS_VTABLE_PROPERTY_CONST),
 982         SD_BUS_PROPERTY("User", "(uo)", property_get_user, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 983         SD_BUS_PROPERTY("Name", "s", property_get_name, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 984         BUS_PROPERTY_DUAL_TIMESTAMP("Timestamp", offsetof(Session, timestamp), SD_BUS_VTABLE_PROPERTY_CONST),
 985         SD_BUS_PROPERTY("VTNr", "u", NULL, offsetof(Session, vtnr), SD_BUS_VTABLE_PROPERTY_CONST),
 986         SD_BUS_PROPERTY("Seat", "(so)", property_get_seat, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 987         SD_BUS_PROPERTY("TTY", "s", NULL, offsetof(Session, tty), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 988         SD_BUS_PROPERTY("Display", "s", NULL, offsetof(Session, display), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 989         SD_BUS_PROPERTY("Remote", "b", bus_property_get_bool, offsetof(Session, remote), SD_BUS_VTABLE_PROPERTY_CONST),
 990         SD_BUS_PROPERTY("RemoteHost", "s", NULL, offsetof(Session, remote_host), SD_BUS_VTABLE_PROPERTY_CONST),
 991         SD_BUS_PROPERTY("RemoteUser", "s", NULL, offsetof(Session, remote_user), SD_BUS_VTABLE_PROPERTY_CONST),
 992         SD_BUS_PROPERTY("Service", "s", NULL, offsetof(Session, service), SD_BUS_VTABLE_PROPERTY_CONST),
 993         SD_BUS_PROPERTY("Desktop", "s", NULL, offsetof(Session, desktop), SD_BUS_VTABLE_PROPERTY_CONST),
 994         SD_BUS_PROPERTY("Scope", "s", NULL, offsetof(Session, scope), SD_BUS_VTABLE_PROPERTY_CONST),
 995         SD_BUS_PROPERTY("Leader", "u", bus_property_get_pid, offsetof(Session, leader.pid), SD_BUS_VTABLE_PROPERTY_CONST),
 996         SD_BUS_PROPERTY("LeaderPIDFDId", "t", bus_property_get_pidfdid, offsetof(Session, leader), SD_BUS_VTABLE_PROPERTY_CONST),
 997         SD_BUS_PROPERTY("Audit", "u", NULL, offsetof(Session, audit_id), SD_BUS_VTABLE_PROPERTY_CONST),
 998         SD_BUS_PROPERTY("Type", "s", property_get_type, offsetof(Session, type), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 999         SD_BUS_PROPERTY("Class", "s", property_get_class, offsetof(Session, class), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
1000         SD_BUS_PROPERTY("Active", "b", property_get_active, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
1001         SD_BUS_PROPERTY("State", "s", property_get_state, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
1002         SD_BUS_PROPERTY("IdleHint", "b", property_get_idle_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
1003         SD_BUS_PROPERTY("IdleSinceHint", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
1004         SD_BUS_PROPERTY("IdleSinceHintMonotonic", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
1005         SD_BUS_PROPERTY("CanIdle", "b", property_get_can_idle, 0, SD_BUS_VTABLE_PROPERTY_CONST),
1006         SD_BUS_PROPERTY("CanLock", "b", property_get_can_lock, 0, SD_BUS_VTABLE_PROPERTY_CONST),
1007         SD_BUS_PROPERTY("LockedHint", "b", property_get_locked_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
1008
1009         SD_BUS_METHOD("Terminate",
1010                       NULL,
1011                       NULL,
1012                       bus_session_method_terminate,
1013                       SD_BUS_VTABLE_UNPRIVILEGED),
1014         SD_BUS_METHOD("Activate",
1015                       NULL,
1016                       NULL,
1017                       bus_session_method_activate,
1018                       SD_BUS_VTABLE_UNPRIVILEGED),
1019         SD_BUS_METHOD("Lock",
1020                       NULL,
1021                       NULL,
1022                       bus_session_method_lock,
1023                       SD_BUS_VTABLE_UNPRIVILEGED),
1024         SD_BUS_METHOD("Unlock",
1025                       NULL,
1026                       NULL,
1027                       bus_session_method_lock,
1028                       SD_BUS_VTABLE_UNPRIVILEGED),
1029         SD_BUS_METHOD_WITH_ARGS("SetIdleHint",
1030                                 SD_BUS_ARGS("b", idle),
1031                                 SD_BUS_NO_RESULT,
1032                                 method_set_idle_hint,
1033                                 SD_BUS_VTABLE_UNPRIVILEGED),
1034         SD_BUS_METHOD_WITH_ARGS("SetLockedHint",
1035                                 SD_BUS_ARGS("b", locked),
1036                                 SD_BUS_NO_RESULT,
1037                                 method_set_locked_hint,
1038                                 SD_BUS_VTABLE_UNPRIVILEGED),
1039         SD_BUS_METHOD_WITH_ARGS("Kill",
1040                                 SD_BUS_ARGS("s", whom, "i", signal_number),
1041                                 SD_BUS_NO_RESULT,
1042                                 bus_session_method_kill,
1043                                 SD_BUS_VTABLE_UNPRIVILEGED),
1044         SD_BUS_METHOD_WITH_ARGS("TakeControl",
1045                                 SD_BUS_ARGS("b", force),
1046                                 SD_BUS_NO_RESULT,
1047                                 method_take_control,
1048                                 SD_BUS_VTABLE_UNPRIVILEGED),
1049         SD_BUS_METHOD("ReleaseControl",
1050                       NULL,
1051                       NULL,
1052                       method_release_control,
1053                       SD_BUS_VTABLE_UNPRIVILEGED),
1054         SD_BUS_METHOD_WITH_ARGS("SetType",
1055                                 SD_BUS_ARGS("s", type),
1056                                 SD_BUS_NO_RESULT,
1057                                 method_set_type,
1058                                 SD_BUS_VTABLE_UNPRIVILEGED),
1059         SD_BUS_METHOD_WITH_ARGS("SetClass",
1060                                 SD_BUS_ARGS("s", class),
1061                                 SD_BUS_NO_RESULT,
1062                                 method_set_class,
1063                                 SD_BUS_VTABLE_UNPRIVILEGED),
1064         SD_BUS_METHOD_WITH_ARGS("SetDisplay",
1065                                 SD_BUS_ARGS("s", display),
1066                                 SD_BUS_NO_RESULT,
1067                                 method_set_display,
1068                                 SD_BUS_VTABLE_UNPRIVILEGED),
1069         SD_BUS_METHOD_WITH_ARGS("SetTTY",
1070                                 SD_BUS_ARGS("h", tty_fd),
1071                                 SD_BUS_NO_RESULT,
1072                                 method_set_tty,
1073                                 SD_BUS_VTABLE_UNPRIVILEGED),
1074         SD_BUS_METHOD_WITH_ARGS("TakeDevice",
1075                                 SD_BUS_ARGS("u", major, "u", minor),
1076                                 SD_BUS_RESULT("h", fd, "b", inactive),
1077                                 method_take_device,
1078                                 SD_BUS_VTABLE_UNPRIVILEGED),
1079         SD_BUS_METHOD_WITH_ARGS("ReleaseDevice",
1080                                 SD_BUS_ARGS("u", major, "u", minor),
1081                                 SD_BUS_NO_RESULT,
1082                                 method_release_device,
1083                                 SD_BUS_VTABLE_UNPRIVILEGED),
1084         SD_BUS_METHOD_WITH_ARGS("PauseDeviceComplete",
1085                                 SD_BUS_ARGS("u", major, "u", minor),
1086                                 SD_BUS_NO_RESULT,
1087                                 method_pause_device_complete,
1088                                 SD_BUS_VTABLE_UNPRIVILEGED),
1089         SD_BUS_METHOD_WITH_ARGS("SetBrightness",
1090                                 SD_BUS_ARGS("s", subsystem, "s", name, "u", brightness),
1091                                 SD_BUS_NO_RESULT,
1092                                 method_set_brightness,
1093                                 SD_BUS_VTABLE_UNPRIVILEGED),
1094
1095         SD_BUS_SIGNAL_WITH_ARGS("PauseDevice",
1096                                 SD_BUS_ARGS("u", major, "u", minor, "s", type),
1097                                 0),
1098         SD_BUS_SIGNAL_WITH_ARGS("ResumeDevice",
1099                                 SD_BUS_ARGS("u", major, "u", minor, "h", fd),
1100                                 0),
1101         SD_BUS_SIGNAL("Lock", NULL, 0),
1102         SD_BUS_SIGNAL("Unlock", NULL, 0),
1103
1104         SD_BUS_VTABLE_END
1105 };
1106
1107 const BusObjectImplementation session_object = {
1108         "/org/freedesktop/login1/session",
1109         "org.freedesktop.login1.Session",
1110         .fallback_vtables = BUS_FALLBACK_VTABLES({session_vtable, session_object_find}),
1111         .node_enumerator = session_node_enumerator,
1112 };