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         SD_BUS_METHOD("ActivateSession", "s", NULL, method_activate_session, SD_BUS_VTABLE_UNPRIVILEGED),
 309         SD_BUS_METHOD("SwitchTo", "u", NULL, method_switch_to, SD_BUS_VTABLE_UNPRIVILEGED),
 310         SD_BUS_METHOD("SwitchToNext", NULL, NULL, method_switch_to_next, SD_BUS_VTABLE_UNPRIVILEGED),
 311         SD_BUS_METHOD("SwitchToPrevious", NULL, NULL, method_switch_to_previous, SD_BUS_VTABLE_UNPRIVILEGED),
 312
 313         SD_BUS_VTABLE_END
 314 };
 315
 316 int seat_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
 317         _cleanup_free_ char *e = NULL;
 318         sd_bus_message *message;
 319         Manager *m = userdata;
 320         const char *p;
 321         Seat *seat;
 322         int r;
 323
 324         assert(bus);
 325         assert(path);
 326         assert(interface);
 327         assert(found);
 328         assert(m);
 329
 330         p = startswith(path, "/org/freedesktop/login1/seat/");
 331         if (!p)
 332                 return 0;
 333
 334         e = bus_label_unescape(p);
 335         if (!e)
 336                 return -ENOMEM;
 337
 338         message = sd_bus_get_current_message(bus);
 339
 340         r = manager_get_seat_from_creds(m, message, e, error, &seat);
 341         if (r == -ENXIO) {
 342                 sd_bus_error_free(error);
 343                 return 0;
 344         }
 345         if (r < 0)
 346                 return r;
 347
 348         *found = seat;
 349         return 1;
 350 }
 351
 352 char *seat_bus_path(Seat *s) {
 353         _cleanup_free_ char *t = NULL;
 354
 355         assert(s);
 356
 357         t = bus_label_escape(s->id);
 358         if (!t)
 359                 return NULL;
 360
 361         return strjoin("/org/freedesktop/login1/seat/", t);
 362 }
 363
 364 int seat_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
 365         _cleanup_strv_free_ char **l = NULL;
 366         sd_bus_message *message;
 367         Manager *m = userdata;
 368         Seat *seat;
 369         Iterator i;
 370         int r;
 371
 372         assert(bus);
 373         assert(path);
 374         assert(nodes);
 375
 376         HASHMAP_FOREACH(seat, m->seats, i) {
 377                 char *p;
 378
 379                 p = seat_bus_path(seat);
 380                 if (!p)
 381                         return -ENOMEM;
 382
 383                 r = strv_consume(&l, p);
 384                 if (r < 0)
 385                         return r;
 386         }
 387
 388         message = sd_bus_get_current_message(bus);
 389         if (message) {
 390                 _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 391
 392                 r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID|SD_BUS_CREDS_AUGMENT, &creds);
 393                 if (r >= 0) {
 394                         bool may_auto = false;
 395                         const char *name;
 396
 397                         r = sd_bus_creds_get_session(creds, &name);
 398                         if (r >= 0) {
 399                                 Session *session;
 400
 401                                 session = hashmap_get(m->sessions, name);
 402                                 if (session && session->seat) {
 403                                         r = strv_extend(&l, "/org/freedesktop/login1/seat/self");
 404                                         if (r < 0)
 405                                                 return r;
 406
 407                                         may_auto = true;
 408                                 }
 409                         }
 410
 411                         if (!may_auto) {
 412                                 uid_t uid;
 413
 414                                 r = sd_bus_creds_get_owner_uid(creds, &uid);
 415                                 if (r >= 0) {
 416                                         User *user;
 417
 418                                         user = hashmap_get(m->users, UID_TO_PTR(uid));
 419                                         may_auto = user && user->display && user->display->seat;
 420                                 }
 421                         }
 422
 423                         if (may_auto) {
 424                                 r = strv_extend(&l, "/org/freedesktop/login1/seat/auto");
 425                                 if (r < 0)
 426                                         return r;
 427                         }
 428                 }
 429         }
 430
 431         *nodes = TAKE_PTR(l);
 432         return 1;
 433 }
 434
 435 int seat_send_signal(Seat *s, bool new_seat) {
 436         _cleanup_free_ char *p = NULL;
 437
 438         assert(s);
 439
 440         p = seat_bus_path(s);
 441         if (!p)
 442                 return -ENOMEM;
 443
 444         return sd_bus_emit_signal(
 445                         s->manager->bus,
 446                         "/org/freedesktop/login1",
 447                         "org.freedesktop.login1.Manager",
 448                         new_seat ? "SeatNew" : "SeatRemoved",
 449                         "so", s->id, p);
 450 }
 451
 452 int seat_send_changed(Seat *s, const char *properties, ...) {
 453         _cleanup_free_ char *p = NULL;
 454         char **l;
 455
 456         assert(s);
 457
 458         if (!s->started)
 459                 return 0;
 460
 461         p = seat_bus_path(s);
 462         if (!p)
 463                 return -ENOMEM;
 464
 465         l = strv_from_stdarg_alloca(properties);
 466
 467         return sd_bus_emit_properties_changed_strv(s->manager->bus, p, "org.freedesktop.login1.Seat", l);
 468 }