src/login/logind-seat-dbus.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4
   5 #include "alloc-util.h"
   6 #include "bus-common-errors.h"
   7 #include "bus-label.h"
   8 #include "bus-polkit.h"
   9 #include "bus-util.h"
  10 #include "logind-dbus.h"
  11 #include "logind-seat-dbus.h"
  12 #include "logind-seat.h"
  13 #include "logind-session-dbus.h"
  14 #include "logind.h"
  15 #include "missing_capability.h"
  16 #include "strv.h"
  17 #include "user-util.h"
  18 #include "util.h"
  19
  20 static BUS_DEFINE_PROPERTY_GET(property_get_can_multi_session, "b", Seat, seat_can_multi_session);
  21 static BUS_DEFINE_PROPERTY_GET(property_get_can_tty, "b", Seat, seat_can_tty);
  22 static BUS_DEFINE_PROPERTY_GET(property_get_can_graphical, "b", Seat, seat_can_graphical);
  23
  24 static int property_get_active_session(
  25                 sd_bus *bus,
  26                 const char *path,
  27                 const char *interface,
  28                 const char *property,
  29                 sd_bus_message *reply,
  30                 void *userdata,
  31                 sd_bus_error *error) {
  32
  33         _cleanup_free_ char *p = NULL;
  34         Seat *s = userdata;
  35
  36         assert(bus);
  37         assert(reply);
  38         assert(s);
  39
  40         p = s->active ? session_bus_path(s->active) : strdup("/");
  41         if (!p)
  42                 return -ENOMEM;
  43
  44         return sd_bus_message_append(reply, "(so)", s->active ? s->active->id : "", p);
  45 }
  46
  47 static int property_get_sessions(
  48                 sd_bus *bus,
  49                 const char *path,
  50                 const char *interface,
  51                 const char *property,
  52                 sd_bus_message *reply,
  53                 void *userdata,
  54                 sd_bus_error *error) {
  55
  56         Seat *s = userdata;
  57         Session *session;
  58         int r;
  59
  60         assert(bus);
  61         assert(reply);
  62         assert(s);
  63
  64         r = sd_bus_message_open_container(reply, 'a', "(so)");
  65         if (r < 0)
  66                 return r;
  67
  68         LIST_FOREACH(sessions_by_seat, session, s->sessions) {
  69                 _cleanup_free_ char *p = NULL;
  70
  71                 p = session_bus_path(session);
  72                 if (!p)
  73                         return -ENOMEM;
  74
  75                 r = sd_bus_message_append(reply, "(so)", session->id, p);
  76                 if (r < 0)
  77                         return r;
  78
  79         }
  80
  81         r = sd_bus_message_close_container(reply);
  82         if (r < 0)
  83                 return r;
  84
  85         return 1;
  86 }
  87
  88 static int property_get_idle_hint(
  89                 sd_bus *bus,
  90                 const char *path,
  91                 const char *interface,
  92                 const char *property,
  93                 sd_bus_message *reply,
  94                 void *userdata,
  95                 sd_bus_error *error) {
  96
  97         Seat *s = userdata;
  98
  99         assert(bus);
 100         assert(reply);
 101         assert(s);
 102
 103         return sd_bus_message_append(reply, "b", seat_get_idle_hint(s, NULL) > 0);
 104 }
 105
 106 static int property_get_idle_since_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         Seat *s = userdata;
 116         dual_timestamp t;
 117         uint64_t u;
 118         int r;
 119
 120         assert(bus);
 121         assert(reply);
 122         assert(s);
 123
 124         r = seat_get_idle_hint(s, &t);
 125         if (r < 0)
 126                 return r;
 127
 128         u = streq(property, "IdleSinceHint") ? t.realtime : t.monotonic;
 129
 130         return sd_bus_message_append(reply, "t", u);
 131 }
 132
 133 int bus_seat_method_terminate(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 134         Seat *s = userdata;
 135         int r;
 136
 137         assert(message);
 138         assert(s);
 139
 140         r = bus_verify_polkit_async(
 141                         message,
 142                         CAP_KILL,
 143                         "org.freedesktop.login1.manage",
 144                         NULL,
 145                         false,
 146                         UID_INVALID,
 147                         &s->manager->polkit_registry,
 148                         error);
 149         if (r < 0)
 150                 return r;
 151         if (r == 0)
 152                 return 1; /* Will call us back */
 153
 154         r = seat_stop_sessions(s, true);
 155         if (r < 0)
 156                 return r;
 157
 158         return sd_bus_reply_method_return(message, NULL);
 159 }
 160
 161 static int method_activate_session(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 162         Seat *s = userdata;
 163         const char *name;
 164         Session *session;
 165         int r;
 166
 167         assert(message);
 168         assert(s);
 169
 170         r = sd_bus_message_read(message, "s", &name);
 171         if (r < 0)
 172                 return r;
 173
 174         session = hashmap_get(s->manager->sessions, name);
 175         if (!session)
 176                 return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_SESSION, "No session '%s' known", name);
 177
 178         if (session->seat != s)
 179                 return sd_bus_error_setf(error, BUS_ERROR_SESSION_NOT_ON_SEAT, "Session %s not on seat %s", name, s->id);
 180
 181         r = bus_verify_polkit_async(
 182                         message,
 183                         CAP_SYS_ADMIN,
 184                         "org.freedesktop.login1.chvt",
 185                         NULL,
 186                         false,
 187                         UID_INVALID,
 188                         &s->manager->polkit_registry,
 189                         error);
 190         if (r < 0)
 191                 return r;
 192         if (r == 0)
 193                 return 1; /* Will call us back */
 194
 195         r = session_activate(session);
 196         if (r < 0)
 197                 return r;
 198
 199         return sd_bus_reply_method_return(message, NULL);
 200 }
 201
 202 static int method_switch_to(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 203         Seat *s = userdata;
 204         unsigned to;
 205         int r;
 206
 207         assert(message);
 208         assert(s);
 209
 210         r = sd_bus_message_read(message, "u", &to);
 211         if (r < 0)
 212                 return r;
 213
 214         if (to <= 0)
 215                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid virtual terminal");
 216
 217         r = bus_verify_polkit_async(
 218                         message,
 219                         CAP_SYS_ADMIN,
 220                         "org.freedesktop.login1.chvt",
 221                         NULL,
 222                         false,
 223                         UID_INVALID,
 224                         &s->manager->polkit_registry,
 225                         error);
 226         if (r < 0)
 227                 return r;
 228         if (r == 0)
 229                 return 1; /* Will call us back */
 230
 231         r = seat_switch_to(s, to);
 232         if (r < 0)
 233                 return r;
 234
 235         return sd_bus_reply_method_return(message, NULL);
 236 }
 237
 238 static int method_switch_to_next(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 239         Seat *s = userdata;
 240         int r;
 241
 242         assert(message);
 243         assert(s);
 244
 245         r = bus_verify_polkit_async(
 246                         message,
 247                         CAP_SYS_ADMIN,
 248                         "org.freedesktop.login1.chvt",
 249                         NULL,
 250                         false,
 251                         UID_INVALID,
 252                         &s->manager->polkit_registry,
 253                         error);
 254         if (r < 0)
 255                 return r;
 256         if (r == 0)
 257                 return 1; /* Will call us back */
 258
 259         r = seat_switch_to_next(s);
 260         if (r < 0)
 261                 return r;
 262
 263         return sd_bus_reply_method_return(message, NULL);
 264 }
 265
 266 static int method_switch_to_previous(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 267         Seat *s = userdata;
 268         int r;
 269
 270         assert(message);
 271         assert(s);
 272
 273         r = bus_verify_polkit_async(
 274                         message,
 275                         CAP_SYS_ADMIN,
 276                         "org.freedesktop.login1.chvt",
 277                         NULL,
 278                         false,
 279                         UID_INVALID,
 280                         &s->manager->polkit_registry,
 281                         error);
 282         if (r < 0)
 283                 return r;
 284         if (r == 0)
 285                 return 1; /* Will call us back */
 286
 287         r = seat_switch_to_previous(s);
 288         if (r < 0)
 289                 return r;
 290
 291         return sd_bus_reply_method_return(message, NULL);
 292 }
 293
 294 const sd_bus_vtable seat_vtable[] = {
 295         SD_BUS_VTABLE_START(0),
 296
 297         SD_BUS_PROPERTY("Id", "s", NULL, offsetof(Seat, id), SD_BUS_VTABLE_PROPERTY_CONST),
 298         SD_BUS_PROPERTY("ActiveSession", "(so)", property_get_active_session, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 299         SD_BUS_PROPERTY("CanMultiSession", "b", property_get_can_multi_session, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 300         SD_BUS_PROPERTY("CanTTY", "b", property_get_can_tty, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 301         SD_BUS_PROPERTY("CanGraphical", "b", property_get_can_graphical, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 302         SD_BUS_PROPERTY("Sessions", "a(so)", property_get_sessions, 0, 0),
 303         SD_BUS_PROPERTY("IdleHint", "b", property_get_idle_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 304         SD_BUS_PROPERTY("IdleSinceHint", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 305         SD_BUS_PROPERTY("IdleSinceHintMonotonic", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 306
 307         SD_BUS_METHOD("Terminate", NULL, NULL, bus_seat_method_terminate, SD_BUS_VTABLE_UNPRIVILEGED),
 308
 309         SD_BUS_METHOD_WITH_NAMES("ActivateSession",
 310                                  "s",
 311                                  SD_BUS_PARAM(session_id),
 312                                  NULL,,
 313                                  method_activate_session,
 314                                  SD_BUS_VTABLE_UNPRIVILEGED),
 315         SD_BUS_METHOD_WITH_NAMES("SwitchTo",
 316                                  "u",
 317                                  SD_BUS_PARAM(vtnr),
 318                                  NULL,,
 319                                  method_switch_to,
 320                                  SD_BUS_VTABLE_UNPRIVILEGED),
 321
 322         SD_BUS_METHOD("SwitchToNext", NULL, NULL, method_switch_to_next, SD_BUS_VTABLE_UNPRIVILEGED),
 323         SD_BUS_METHOD("SwitchToPrevious", NULL, NULL, method_switch_to_previous, SD_BUS_VTABLE_UNPRIVILEGED),
 324
 325         SD_BUS_VTABLE_END
 326 };
 327
 328 int seat_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
 329         _cleanup_free_ char *e = NULL;
 330         sd_bus_message *message;
 331         Manager *m = userdata;
 332         const char *p;
 333         Seat *seat;
 334         int r;
 335
 336         assert(bus);
 337         assert(path);
 338         assert(interface);
 339         assert(found);
 340         assert(m);
 341
 342         p = startswith(path, "/org/freedesktop/login1/seat/");
 343         if (!p)
 344                 return 0;
 345
 346         e = bus_label_unescape(p);
 347         if (!e)
 348                 return -ENOMEM;
 349
 350         message = sd_bus_get_current_message(bus);
 351
 352         r = manager_get_seat_from_creds(m, message, e, error, &seat);
 353         if (r == -ENXIO) {
 354                 sd_bus_error_free(error);
 355                 return 0;
 356         }
 357         if (r < 0)
 358                 return r;
 359
 360         *found = seat;
 361         return 1;
 362 }
 363
 364 char *seat_bus_path(Seat *s) {
 365         _cleanup_free_ char *t = NULL;
 366
 367         assert(s);
 368
 369         t = bus_label_escape(s->id);
 370         if (!t)
 371                 return NULL;
 372
 373         return strjoin("/org/freedesktop/login1/seat/", t);
 374 }
 375
 376 int seat_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
 377         _cleanup_strv_free_ char **l = NULL;
 378         sd_bus_message *message;
 379         Manager *m = userdata;
 380         Seat *seat;
 381         Iterator i;
 382         int r;
 383
 384         assert(bus);
 385         assert(path);
 386         assert(nodes);
 387
 388         HASHMAP_FOREACH(seat, m->seats, i) {
 389                 char *p;
 390
 391                 p = seat_bus_path(seat);
 392                 if (!p)
 393                         return -ENOMEM;
 394
 395                 r = strv_consume(&l, p);
 396                 if (r < 0)
 397                         return r;
 398         }
 399
 400         message = sd_bus_get_current_message(bus);
 401         if (message) {
 402                 _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 403
 404                 r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID|SD_BUS_CREDS_AUGMENT, &creds);
 405                 if (r >= 0) {
 406                         bool may_auto = false;
 407                         const char *name;
 408
 409                         r = sd_bus_creds_get_session(creds, &name);
 410                         if (r >= 0) {
 411                                 Session *session;
 412
 413                                 session = hashmap_get(m->sessions, name);
 414                                 if (session && session->seat) {
 415                                         r = strv_extend(&l, "/org/freedesktop/login1/seat/self");
 416                                         if (r < 0)
 417                                                 return r;
 418
 419                                         may_auto = true;
 420                                 }
 421                         }
 422
 423                         if (!may_auto) {
 424                                 uid_t uid;
 425
 426                                 r = sd_bus_creds_get_owner_uid(creds, &uid);
 427                                 if (r >= 0) {
 428                                         User *user;
 429
 430                                         user = hashmap_get(m->users, UID_TO_PTR(uid));
 431                                         may_auto = user && user->display && user->display->seat;
 432                                 }
 433                         }
 434
 435                         if (may_auto) {
 436                                 r = strv_extend(&l, "/org/freedesktop/login1/seat/auto");
 437                                 if (r < 0)
 438                                         return r;
 439                         }
 440                 }
 441         }
 442
 443         *nodes = TAKE_PTR(l);
 444         return 1;
 445 }
 446
 447 int seat_send_signal(Seat *s, bool new_seat) {
 448         _cleanup_free_ char *p = NULL;
 449
 450         assert(s);
 451
 452         p = seat_bus_path(s);
 453         if (!p)
 454                 return -ENOMEM;
 455
 456         return sd_bus_emit_signal(
 457                         s->manager->bus,
 458                         "/org/freedesktop/login1",
 459                         "org.freedesktop.login1.Manager",
 460                         new_seat ? "SeatNew" : "SeatRemoved",
 461                         "so", s->id, p);
 462 }
 463
 464 int seat_send_changed(Seat *s, const char *properties, ...) {
 465         _cleanup_free_ char *p = NULL;
 466         char **l;
 467
 468         assert(s);
 469
 470         if (!s->started)
 471                 return 0;
 472
 473         p = seat_bus_path(s);
 474         if (!p)
 475                 return -ENOMEM;
 476
 477         l = strv_from_stdarg_alloca(properties);
 478
 479         return sd_bus_emit_properties_changed_strv(s->manager->bus, p, "org.freedesktop.login1.Seat", l);
 480 }