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 #include "util.h"
  21
  22 static BUS_DEFINE_PROPERTY_GET_GLOBAL(property_get_const_true, "b", true);
  23 static BUS_DEFINE_PROPERTY_GET(property_get_can_tty, "b", Seat, seat_can_tty);
  24 static BUS_DEFINE_PROPERTY_GET(property_get_can_graphical, "b", Seat, seat_can_graphical);
  25
  26 static int property_get_active_session(
  27                 sd_bus *bus,
  28                 const char *path,
  29                 const char *interface,
  30                 const char *property,
  31                 sd_bus_message *reply,
  32                 void *userdata,
  33                 sd_bus_error *error) {
  34
  35         _cleanup_free_ char *p = NULL;
  36         Seat *s = userdata;
  37
  38         assert(bus);
  39         assert(reply);
  40         assert(s);
  41
  42         p = s->active ? session_bus_path(s->active) : strdup("/");
  43         if (!p)
  44                 return -ENOMEM;
  45
  46         return sd_bus_message_append(reply, "(so)", s->active ? s->active->id : "", p);
  47 }
  48
  49 static int property_get_sessions(
  50                 sd_bus *bus,
  51                 const char *path,
  52                 const char *interface,
  53                 const char *property,
  54                 sd_bus_message *reply,
  55                 void *userdata,
  56                 sd_bus_error *error) {
  57
  58         Seat *s = userdata;
  59         int r;
  60
  61         assert(bus);
  62         assert(reply);
  63         assert(s);
  64
  65         r = sd_bus_message_open_container(reply, 'a', "(so)");
  66         if (r < 0)
  67                 return r;
  68
  69         LIST_FOREACH(sessions_by_seat, session, s->sessions) {
  70                 _cleanup_free_ char *p = NULL;
  71
  72                 p = session_bus_path(session);
  73                 if (!p)
  74                         return -ENOMEM;
  75
  76                 r = sd_bus_message_append(reply, "(so)", session->id, p);
  77                 if (r < 0)
  78                         return r;
  79
  80         }
  81
  82         r = sd_bus_message_close_container(reply);
  83         if (r < 0)
  84                 return r;
  85
  86         return 1;
  87 }
  88
  89 static int property_get_idle_hint(
  90                 sd_bus *bus,
  91                 const char *path,
  92                 const char *interface,
  93                 const char *property,
  94                 sd_bus_message *reply,
  95                 void *userdata,
  96                 sd_bus_error *error) {
  97
  98         Seat *s = userdata;
  99
 100         assert(bus);
 101         assert(reply);
 102         assert(s);
 103
 104         return sd_bus_message_append(reply, "b", seat_get_idle_hint(s, NULL) > 0);
 105 }
 106
 107 static int property_get_idle_since_hint(
 108                 sd_bus *bus,
 109                 const char *path,
 110                 const char *interface,
 111                 const char *property,
 112                 sd_bus_message *reply,
 113                 void *userdata,
 114                 sd_bus_error *error) {
 115
 116         Seat *s = userdata;
 117         dual_timestamp t;
 118         uint64_t u;
 119         int r;
 120
 121         assert(bus);
 122         assert(reply);
 123         assert(s);
 124
 125         r = seat_get_idle_hint(s, &t);
 126         if (r < 0)
 127                 return r;
 128
 129         u = streq(property, "IdleSinceHint") ? t.realtime : t.monotonic;
 130
 131         return sd_bus_message_append(reply, "t", u);
 132 }
 133
 134 int bus_seat_method_terminate(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 135         Seat *s = userdata;
 136         int r;
 137
 138         assert(message);
 139         assert(s);
 140
 141         r = bus_verify_polkit_async(
 142                         message,
 143                         CAP_KILL,
 144                         "org.freedesktop.login1.manage",
 145                         NULL,
 146                         false,
 147                         UID_INVALID,
 148                         &s->manager->polkit_registry,
 149                         error);
 150         if (r < 0)
 151                 return r;
 152         if (r == 0)
 153                 return 1; /* Will call us back */
 154
 155         r = seat_stop_sessions(s, /* force = */ true);
 156         if (r < 0)
 157                 return r;
 158
 159         return sd_bus_reply_method_return(message, NULL);
 160 }
 161
 162 static int method_activate_session(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 163         Seat *s = userdata;
 164         const char *name;
 165         Session *session;
 166         int r;
 167
 168         assert(message);
 169         assert(s);
 170
 171         r = sd_bus_message_read(message, "s", &name);
 172         if (r < 0)
 173                 return r;
 174
 175         session = hashmap_get(s->manager->sessions, name);
 176         if (!session)
 177                 return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_SESSION, "No session '%s' known", name);
 178
 179         if (session->seat != s)
 180                 return sd_bus_error_setf(error, BUS_ERROR_SESSION_NOT_ON_SEAT, "Session %s not on seat %s", name, s->id);
 181
 182         r = check_polkit_chvt(message, s->manager, error);
 183         if (r < 0)
 184                 return r;
 185         if (r == 0)
 186                 return 1; /* Will call us back */
 187
 188         r = session_activate(session);
 189         if (r < 0)
 190                 return r;
 191
 192         return sd_bus_reply_method_return(message, NULL);
 193 }
 194
 195 static int method_switch_to(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 196         Seat *s = userdata;
 197         unsigned to;
 198         int r;
 199
 200         assert(message);
 201         assert(s);
 202
 203         r = sd_bus_message_read(message, "u", &to);
 204         if (r < 0)
 205                 return r;
 206
 207         if (to <= 0)
 208                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid virtual terminal");
 209
 210         r = check_polkit_chvt(message, s->manager, error);
 211         if (r < 0)
 212                 return r;
 213         if (r == 0)
 214                 return 1; /* Will call us back */
 215
 216         r = seat_switch_to(s, to);
 217         if (r < 0)
 218                 return r;
 219
 220         return sd_bus_reply_method_return(message, NULL);
 221 }
 222
 223 static int method_switch_to_next(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 224         Seat *s = userdata;
 225         int r;
 226
 227         assert(message);
 228         assert(s);
 229
 230         r = check_polkit_chvt(message, s->manager, error);
 231         if (r < 0)
 232                 return r;
 233         if (r == 0)
 234                 return 1; /* Will call us back */
 235
 236         r = seat_switch_to_next(s);
 237         if (r < 0)
 238                 return r;
 239
 240         return sd_bus_reply_method_return(message, NULL);
 241 }
 242
 243 static int method_switch_to_previous(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 244         Seat *s = userdata;
 245         int r;
 246
 247         assert(message);
 248         assert(s);
 249
 250         r = check_polkit_chvt(message, s->manager, error);
 251         if (r < 0)
 252                 return r;
 253         if (r == 0)
 254                 return 1; /* Will call us back */
 255
 256         r = seat_switch_to_previous(s);
 257         if (r < 0)
 258                 return r;
 259
 260         return sd_bus_reply_method_return(message, NULL);
 261 }
 262
 263 static int seat_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
 264         _cleanup_free_ char *e = NULL;
 265         sd_bus_message *message;
 266         Manager *m = userdata;
 267         const char *p;
 268         Seat *seat;
 269         int r;
 270
 271         assert(bus);
 272         assert(path);
 273         assert(interface);
 274         assert(found);
 275         assert(m);
 276
 277         p = startswith(path, "/org/freedesktop/login1/seat/");
 278         if (!p)
 279                 return 0;
 280
 281         e = bus_label_unescape(p);
 282         if (!e)
 283                 return -ENOMEM;
 284
 285         message = sd_bus_get_current_message(bus);
 286
 287         r = manager_get_seat_from_creds(m, message, e, error, &seat);
 288         if (r == -ENXIO) {
 289                 sd_bus_error_free(error);
 290                 return 0;
 291         }
 292         if (r < 0)
 293                 return r;
 294
 295         *found = seat;
 296         return 1;
 297 }
 298
 299 char *seat_bus_path(Seat *s) {
 300         _cleanup_free_ char *t = NULL;
 301
 302         assert(s);
 303
 304         t = bus_label_escape(s->id);
 305         if (!t)
 306                 return NULL;
 307
 308         return strjoin("/org/freedesktop/login1/seat/", t);
 309 }
 310
 311 static int seat_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
 312         _cleanup_strv_free_ char **l = NULL;
 313         sd_bus_message *message;
 314         Manager *m = userdata;
 315         Seat *seat;
 316         int r;
 317
 318         assert(bus);
 319         assert(path);
 320         assert(nodes);
 321
 322         HASHMAP_FOREACH(seat, m->seats) {
 323                 char *p;
 324
 325                 p = seat_bus_path(seat);
 326                 if (!p)
 327                         return -ENOMEM;
 328
 329                 r = strv_consume(&l, p);
 330                 if (r < 0)
 331                         return r;
 332         }
 333
 334         message = sd_bus_get_current_message(bus);
 335         if (message) {
 336                 _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 337
 338                 r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID|SD_BUS_CREDS_AUGMENT, &creds);
 339                 if (r >= 0) {
 340                         bool may_auto = false;
 341                         const char *name;
 342
 343                         r = sd_bus_creds_get_session(creds, &name);
 344                         if (r >= 0) {
 345                                 Session *session;
 346
 347                                 session = hashmap_get(m->sessions, name);
 348                                 if (session && session->seat) {
 349                                         r = strv_extend(&l, "/org/freedesktop/login1/seat/self");
 350                                         if (r < 0)
 351                                                 return r;
 352
 353                                         may_auto = true;
 354                                 }
 355                         }
 356
 357                         if (!may_auto) {
 358                                 uid_t uid;
 359
 360                                 r = sd_bus_creds_get_owner_uid(creds, &uid);
 361                                 if (r >= 0) {
 362                                         User *user;
 363
 364                                         user = hashmap_get(m->users, UID_TO_PTR(uid));
 365                                         may_auto = user && user->display && user->display->seat;
 366                                 }
 367                         }
 368
 369                         if (may_auto) {
 370                                 r = strv_extend(&l, "/org/freedesktop/login1/seat/auto");
 371                                 if (r < 0)
 372                                         return r;
 373                         }
 374                 }
 375         }
 376
 377         *nodes = TAKE_PTR(l);
 378         return 1;
 379 }
 380
 381 int seat_send_signal(Seat *s, bool new_seat) {
 382         _cleanup_free_ char *p = NULL;
 383
 384         assert(s);
 385
 386         p = seat_bus_path(s);
 387         if (!p)
 388                 return -ENOMEM;
 389
 390         return sd_bus_emit_signal(
 391                         s->manager->bus,
 392                         "/org/freedesktop/login1",
 393                         "org.freedesktop.login1.Manager",
 394                         new_seat ? "SeatNew" : "SeatRemoved",
 395                         "so", s->id, p);
 396 }
 397
 398 int seat_send_changed(Seat *s, const char *properties, ...) {
 399         _cleanup_free_ char *p = NULL;
 400         char **l;
 401
 402         assert(s);
 403
 404         if (!s->started)
 405                 return 0;
 406
 407         p = seat_bus_path(s);
 408         if (!p)
 409                 return -ENOMEM;
 410
 411         l = strv_from_stdarg_alloca(properties);
 412
 413         return sd_bus_emit_properties_changed_strv(s->manager->bus, p, "org.freedesktop.login1.Seat", l);
 414 }
 415
 416 static const sd_bus_vtable seat_vtable[] = {
 417         SD_BUS_VTABLE_START(0),
 418
 419         SD_BUS_PROPERTY("Id", "s", NULL, offsetof(Seat, id), SD_BUS_VTABLE_PROPERTY_CONST),
 420         SD_BUS_PROPERTY("ActiveSession", "(so)", property_get_active_session, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 421         SD_BUS_PROPERTY("CanMultiSession", "b", property_get_const_true, 0, SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_HIDDEN),
 422         SD_BUS_PROPERTY("CanTTY", "b", property_get_can_tty, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 423         SD_BUS_PROPERTY("CanGraphical", "b", property_get_can_graphical, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 424         SD_BUS_PROPERTY("Sessions", "a(so)", property_get_sessions, 0, 0),
 425         SD_BUS_PROPERTY("IdleHint", "b", property_get_idle_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 426         SD_BUS_PROPERTY("IdleSinceHint", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 427         SD_BUS_PROPERTY("IdleSinceHintMonotonic", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 428
 429         SD_BUS_METHOD("Terminate", NULL, NULL, bus_seat_method_terminate, SD_BUS_VTABLE_UNPRIVILEGED),
 430
 431         SD_BUS_METHOD_WITH_ARGS("ActivateSession",
 432                                 SD_BUS_ARGS("s", session_id),
 433                                 SD_BUS_NO_RESULT,
 434                                 method_activate_session,
 435                                 SD_BUS_VTABLE_UNPRIVILEGED),
 436         SD_BUS_METHOD_WITH_ARGS("SwitchTo",
 437                                 SD_BUS_ARGS("u", vtnr),
 438                                 SD_BUS_NO_RESULT,
 439                                 method_switch_to,
 440                                 SD_BUS_VTABLE_UNPRIVILEGED),
 441
 442         SD_BUS_METHOD("SwitchToNext", NULL, NULL, method_switch_to_next, SD_BUS_VTABLE_UNPRIVILEGED),
 443         SD_BUS_METHOD("SwitchToPrevious", NULL, NULL, method_switch_to_previous, SD_BUS_VTABLE_UNPRIVILEGED),
 444
 445         SD_BUS_VTABLE_END
 446 };
 447
 448 const BusObjectImplementation seat_object = {
 449         "/org/freedesktop/login1/seat",
 450         "org.freedesktop.login1.Seat",
 451         .fallback_vtables = BUS_FALLBACK_VTABLES({seat_vtable, seat_object_find}),
 452         .node_enumerator = seat_node_enumerator,
 453 };