src/login/logind-seat-dbus.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4
   5 #include "alloc-util.h"
   6 #include "bus-common-errors.h"
   7 #include "bus-get-properties.h"
   8 #include "bus-label.h"
   9 #include "bus-polkit.h"
  10 #include "bus-util.h"
  11 #include "logind-dbus.h"
  12 #include "logind-polkit.h"
  13 #include "logind-seat-dbus.h"
  14 #include "logind-seat.h"
  15 #include "logind-session-dbus.h"
  16 #include "logind.h"
  17 #include "missing_capability.h"
  18 #include "strv.h"
  19 #include "user-util.h"
  20
  21 static BUS_DEFINE_PROPERTY_GET_GLOBAL(property_get_const_true, "b", true);
  22 static BUS_DEFINE_PROPERTY_GET(property_get_can_tty, "b", Seat, seat_can_tty);
  23 static BUS_DEFINE_PROPERTY_GET(property_get_can_graphical, "b", Seat, seat_can_graphical);
  24
  25 static int property_get_active_session(
  26                 sd_bus *bus,
  27                 const char *path,
  28                 const char *interface,
  29                 const char *property,
  30                 sd_bus_message *reply,
  31                 void *userdata,
  32                 sd_bus_error *error) {
  33
  34         _cleanup_free_ char *p = NULL;
  35         Seat *s = ASSERT_PTR(userdata);
  36
  37         assert(bus);
  38         assert(reply);
  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 = ASSERT_PTR(userdata);
  57         int r;
  58
  59         assert(bus);
  60         assert(reply);
  61
  62         r = sd_bus_message_open_container(reply, 'a', "(so)");
  63         if (r < 0)
  64                 return r;
  65
  66         LIST_FOREACH(sessions_by_seat, session, s->sessions) {
  67                 _cleanup_free_ char *p = NULL;
  68
  69                 p = session_bus_path(session);
  70                 if (!p)
  71                         return -ENOMEM;
  72
  73                 r = sd_bus_message_append(reply, "(so)", session->id, p);
  74                 if (r < 0)
  75                         return r;
  76
  77         }
  78
  79         r = sd_bus_message_close_container(reply);
  80         if (r < 0)
  81                 return r;
  82
  83         return 1;
  84 }
  85
  86 static int property_get_idle_hint(
  87                 sd_bus *bus,
  88                 const char *path,
  89                 const char *interface,
  90                 const char *property,
  91                 sd_bus_message *reply,
  92                 void *userdata,
  93                 sd_bus_error *error) {
  94
  95         Seat *s = ASSERT_PTR(userdata);
  96
  97         assert(bus);
  98         assert(reply);
  99
 100         return sd_bus_message_append(reply, "b", seat_get_idle_hint(s, NULL) > 0);
 101 }
 102
 103 static int property_get_idle_since_hint(
 104                 sd_bus *bus,
 105                 const char *path,
 106                 const char *interface,
 107                 const char *property,
 108                 sd_bus_message *reply,
 109                 void *userdata,
 110                 sd_bus_error *error) {
 111
 112         Seat *s = ASSERT_PTR(userdata);
 113         dual_timestamp t;
 114         uint64_t u;
 115         int r;
 116
 117         assert(bus);
 118         assert(reply);
 119
 120         r = seat_get_idle_hint(s, &t);
 121         if (r < 0)
 122                 return r;
 123
 124         u = streq(property, "IdleSinceHint") ? t.realtime : t.monotonic;
 125
 126         return sd_bus_message_append(reply, "t", u);
 127 }
 128
 129 int bus_seat_method_terminate(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 130         Seat *s = ASSERT_PTR(userdata);
 131         int r;
 132
 133         assert(message);
 134
 135         r = bus_verify_polkit_async(
 136                         message,
 137                         "org.freedesktop.login1.manage",
 138                         /* details= */ NULL,
 139                         &s->manager->polkit_registry,
 140                         error);
 141         if (r < 0)
 142                 return r;
 143         if (r == 0)
 144                 return 1; /* Will call us back */
 145
 146         r = seat_stop_sessions(s, /* force = */ true);
 147         if (r < 0)
 148                 return r;
 149
 150         return sd_bus_reply_method_return(message, NULL);
 151 }
 152
 153 static int method_activate_session(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 154         Seat *s = ASSERT_PTR(userdata);
 155         const char *name;
 156         Session *session;
 157         int r;
 158
 159         assert(message);
 160
 161         r = sd_bus_message_read(message, "s", &name);
 162         if (r < 0)
 163                 return r;
 164
 165         session = hashmap_get(s->manager->sessions, name);
 166         if (!session)
 167                 return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_SESSION, "No session '%s' known", name);
 168
 169         if (session->seat != s)
 170                 return sd_bus_error_setf(error, BUS_ERROR_SESSION_NOT_ON_SEAT, "Session %s not on seat %s", name, s->id);
 171
 172         r = check_polkit_chvt(message, s->manager, error);
 173         if (r < 0)
 174                 return r;
 175         if (r == 0)
 176                 return 1; /* Will call us back */
 177
 178         r = session_activate(session);
 179         if (r < 0)
 180                 return r;
 181
 182         return sd_bus_reply_method_return(message, NULL);
 183 }
 184
 185 static int method_switch_to(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 186         Seat *s = ASSERT_PTR(userdata);
 187         unsigned to;
 188         int r;
 189
 190         assert(message);
 191
 192         r = sd_bus_message_read(message, "u", &to);
 193         if (r < 0)
 194                 return r;
 195
 196         if (to <= 0)
 197                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid virtual terminal");
 198
 199         r = check_polkit_chvt(message, s->manager, error);
 200         if (r < 0)
 201                 return r;
 202         if (r == 0)
 203                 return 1; /* Will call us back */
 204
 205         r = seat_switch_to(s, to);
 206         if (r < 0)
 207                 return r;
 208
 209         return sd_bus_reply_method_return(message, NULL);
 210 }
 211
 212 static int method_switch_to_next(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 213         Seat *s = ASSERT_PTR(userdata);
 214         int r;
 215
 216         assert(message);
 217
 218         r = check_polkit_chvt(message, s->manager, error);
 219         if (r < 0)
 220                 return r;
 221         if (r == 0)
 222                 return 1; /* Will call us back */
 223
 224         r = seat_switch_to_next(s);
 225         if (r < 0)
 226                 return r;
 227
 228         return sd_bus_reply_method_return(message, NULL);
 229 }
 230
 231 static int method_switch_to_previous(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 232         Seat *s = ASSERT_PTR(userdata);
 233         int r;
 234
 235         assert(message);
 236
 237         r = check_polkit_chvt(message, s->manager, error);
 238         if (r < 0)
 239                 return r;
 240         if (r == 0)
 241                 return 1; /* Will call us back */
 242
 243         r = seat_switch_to_previous(s);
 244         if (r < 0)
 245                 return r;
 246
 247         return sd_bus_reply_method_return(message, NULL);
 248 }
 249
 250 static int seat_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
 251         _cleanup_free_ char *e = NULL;
 252         sd_bus_message *message;
 253         Manager *m = ASSERT_PTR(userdata);
 254         const char *p;
 255         Seat *seat;
 256         int r;
 257
 258         assert(bus);
 259         assert(path);
 260         assert(interface);
 261         assert(found);
 262
 263         p = startswith(path, "/org/freedesktop/login1/seat/");
 264         if (!p)
 265                 return 0;
 266
 267         e = bus_label_unescape(p);
 268         if (!e)
 269                 return -ENOMEM;
 270
 271         message = sd_bus_get_current_message(bus);
 272
 273         r = manager_get_seat_from_creds(m, message, e, error, &seat);
 274         if (r == -ENXIO) {
 275                 sd_bus_error_free(error);
 276                 return 0;
 277         }
 278         if (r < 0)
 279                 return r;
 280
 281         *found = seat;
 282         return 1;
 283 }
 284
 285 char *seat_bus_path(Seat *s) {
 286         _cleanup_free_ char *t = NULL;
 287
 288         assert(s);
 289
 290         t = bus_label_escape(s->id);
 291         if (!t)
 292                 return NULL;
 293
 294         return strjoin("/org/freedesktop/login1/seat/", t);
 295 }
 296
 297 static int seat_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
 298         _cleanup_strv_free_ char **l = NULL;
 299         sd_bus_message *message;
 300         Manager *m = userdata;
 301         Seat *seat;
 302         int r;
 303
 304         assert(bus);
 305         assert(path);
 306         assert(nodes);
 307
 308         HASHMAP_FOREACH(seat, m->seats) {
 309                 char *p;
 310
 311                 p = seat_bus_path(seat);
 312                 if (!p)
 313                         return -ENOMEM;
 314
 315                 r = strv_consume(&l, p);
 316                 if (r < 0)
 317                         return r;
 318         }
 319
 320         message = sd_bus_get_current_message(bus);
 321         if (message) {
 322                 _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 323
 324                 r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID|SD_BUS_CREDS_AUGMENT, &creds);
 325                 if (r >= 0) {
 326                         bool may_auto = false;
 327                         const char *name;
 328
 329                         r = sd_bus_creds_get_session(creds, &name);
 330                         if (r >= 0) {
 331                                 Session *session;
 332
 333                                 session = hashmap_get(m->sessions, name);
 334                                 if (session && session->seat) {
 335                                         r = strv_extend(&l, "/org/freedesktop/login1/seat/self");
 336                                         if (r < 0)
 337                                                 return r;
 338
 339                                         may_auto = true;
 340                                 }
 341                         }
 342
 343                         if (!may_auto) {
 344                                 uid_t uid;
 345
 346                                 r = sd_bus_creds_get_owner_uid(creds, &uid);
 347                                 if (r >= 0) {
 348                                         User *user;
 349
 350                                         user = hashmap_get(m->users, UID_TO_PTR(uid));
 351                                         may_auto = user && user->display && user->display->seat;
 352                                 }
 353                         }
 354
 355                         if (may_auto) {
 356                                 r = strv_extend(&l, "/org/freedesktop/login1/seat/auto");
 357                                 if (r < 0)
 358                                         return r;
 359                         }
 360                 }
 361         }
 362
 363         *nodes = TAKE_PTR(l);
 364         return 1;
 365 }
 366
 367 int seat_send_signal(Seat *s, bool new_seat) {
 368         _cleanup_free_ char *p = NULL;
 369
 370         assert(s);
 371
 372         p = seat_bus_path(s);
 373         if (!p)
 374                 return -ENOMEM;
 375
 376         return sd_bus_emit_signal(
 377                         s->manager->bus,
 378                         "/org/freedesktop/login1",
 379                         "org.freedesktop.login1.Manager",
 380                         new_seat ? "SeatNew" : "SeatRemoved",
 381                         "so", s->id, p);
 382 }
 383
 384 int seat_send_changed(Seat *s, const char *properties, ...) {
 385         _cleanup_free_ char *p = NULL;
 386         char **l;
 387
 388         assert(s);
 389
 390         if (!s->started)
 391                 return 0;
 392
 393         p = seat_bus_path(s);
 394         if (!p)
 395                 return -ENOMEM;
 396
 397         l = strv_from_stdarg_alloca(properties);
 398
 399         return sd_bus_emit_properties_changed_strv(s->manager->bus, p, "org.freedesktop.login1.Seat", l);
 400 }
 401
 402 static const sd_bus_vtable seat_vtable[] = {
 403         SD_BUS_VTABLE_START(0),
 404
 405         SD_BUS_PROPERTY("Id", "s", NULL, offsetof(Seat, id), SD_BUS_VTABLE_PROPERTY_CONST),
 406         SD_BUS_PROPERTY("ActiveSession", "(so)", property_get_active_session, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 407         SD_BUS_PROPERTY("CanMultiSession", "b", property_get_const_true, 0, SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_HIDDEN),
 408         SD_BUS_PROPERTY("CanTTY", "b", property_get_can_tty, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 409         SD_BUS_PROPERTY("CanGraphical", "b", property_get_can_graphical, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 410         SD_BUS_PROPERTY("Sessions", "a(so)", property_get_sessions, 0, 0),
 411         SD_BUS_PROPERTY("IdleHint", "b", property_get_idle_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 412         SD_BUS_PROPERTY("IdleSinceHint", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 413         SD_BUS_PROPERTY("IdleSinceHintMonotonic", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 414
 415         SD_BUS_METHOD("Terminate", NULL, NULL, bus_seat_method_terminate, SD_BUS_VTABLE_UNPRIVILEGED),
 416
 417         SD_BUS_METHOD_WITH_ARGS("ActivateSession",
 418                                 SD_BUS_ARGS("s", session_id),
 419                                 SD_BUS_NO_RESULT,
 420                                 method_activate_session,
 421                                 SD_BUS_VTABLE_UNPRIVILEGED),
 422         SD_BUS_METHOD_WITH_ARGS("SwitchTo",
 423                                 SD_BUS_ARGS("u", vtnr),
 424                                 SD_BUS_NO_RESULT,
 425                                 method_switch_to,
 426                                 SD_BUS_VTABLE_UNPRIVILEGED),
 427
 428         SD_BUS_METHOD("SwitchToNext", NULL, NULL, method_switch_to_next, SD_BUS_VTABLE_UNPRIVILEGED),
 429         SD_BUS_METHOD("SwitchToPrevious", NULL, NULL, method_switch_to_previous, SD_BUS_VTABLE_UNPRIVILEGED),
 430
 431         SD_BUS_VTABLE_END
 432 };
 433
 434 const BusObjectImplementation seat_object = {
 435         "/org/freedesktop/login1/seat",
 436         "org.freedesktop.login1.Seat",
 437         .fallback_vtables = BUS_FALLBACK_VTABLES({seat_vtable, seat_object_find}),
 438         .node_enumerator = seat_node_enumerator,
 439 };