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 = session_activate(session);
 182         if (r < 0)
 183                 return r;
 184
 185         return sd_bus_reply_method_return(message, NULL);
 186 }
 187
 188 static int method_switch_to(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 189         Seat *s = userdata;
 190         unsigned to;
 191         int r;
 192
 193         assert(message);
 194         assert(s);
 195
 196         r = sd_bus_message_read(message, "u", &to);
 197         if (r < 0)
 198                 return r;
 199
 200         if (to <= 0)
 201                 return -EINVAL;
 202
 203         r = seat_switch_to(s, to);
 204         if (r < 0)
 205                 return r;
 206
 207         return sd_bus_reply_method_return(message, NULL);
 208 }
 209
 210 static int method_switch_to_next(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 211         Seat *s = userdata;
 212         int r;
 213
 214         assert(message);
 215         assert(s);
 216
 217         r = seat_switch_to_next(s);
 218         if (r < 0)
 219                 return r;
 220
 221         return sd_bus_reply_method_return(message, NULL);
 222 }
 223
 224 static int method_switch_to_previous(sd_bus_message *message, void *userdata, sd_bus_error *error) {
 225         Seat *s = userdata;
 226         int r;
 227
 228         assert(message);
 229         assert(s);
 230
 231         r = seat_switch_to_previous(s);
 232         if (r < 0)
 233                 return r;
 234
 235         return sd_bus_reply_method_return(message, NULL);
 236 }
 237
 238 const sd_bus_vtable seat_vtable[] = {
 239         SD_BUS_VTABLE_START(0),
 240
 241         SD_BUS_PROPERTY("Id", "s", NULL, offsetof(Seat, id), SD_BUS_VTABLE_PROPERTY_CONST),
 242         SD_BUS_PROPERTY("ActiveSession", "(so)", property_get_active_session, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 243         SD_BUS_PROPERTY("CanMultiSession", "b", property_get_can_multi_session, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 244         SD_BUS_PROPERTY("CanTTY", "b", property_get_can_tty, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 245         SD_BUS_PROPERTY("CanGraphical", "b", property_get_can_graphical, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 246         SD_BUS_PROPERTY("Sessions", "a(so)", property_get_sessions, 0, 0),
 247         SD_BUS_PROPERTY("IdleHint", "b", property_get_idle_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 248         SD_BUS_PROPERTY("IdleSinceHint", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 249         SD_BUS_PROPERTY("IdleSinceHintMonotonic", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 250
 251         SD_BUS_METHOD("Terminate", NULL, NULL, bus_seat_method_terminate, SD_BUS_VTABLE_UNPRIVILEGED),
 252         SD_BUS_METHOD("ActivateSession", "s", NULL, method_activate_session, SD_BUS_VTABLE_UNPRIVILEGED),
 253         SD_BUS_METHOD("SwitchTo", "u", NULL, method_switch_to, SD_BUS_VTABLE_UNPRIVILEGED),
 254         SD_BUS_METHOD("SwitchToNext", NULL, NULL, method_switch_to_next, SD_BUS_VTABLE_UNPRIVILEGED),
 255         SD_BUS_METHOD("SwitchToPrevious", NULL, NULL, method_switch_to_previous, SD_BUS_VTABLE_UNPRIVILEGED),
 256
 257         SD_BUS_VTABLE_END
 258 };
 259
 260 int seat_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
 261         _cleanup_free_ char *e = NULL;
 262         sd_bus_message *message;
 263         Manager *m = userdata;
 264         const char *p;
 265         Seat *seat;
 266         int r;
 267
 268         assert(bus);
 269         assert(path);
 270         assert(interface);
 271         assert(found);
 272         assert(m);
 273
 274         p = startswith(path, "/org/freedesktop/login1/seat/");
 275         if (!p)
 276                 return 0;
 277
 278         e = bus_label_unescape(p);
 279         if (!e)
 280                 return -ENOMEM;
 281
 282         message = sd_bus_get_current_message(bus);
 283
 284         r = manager_get_seat_from_creds(m, message, e, error, &seat);
 285         if (r == -ENXIO) {
 286                 sd_bus_error_free(error);
 287                 return 0;
 288         }
 289         if (r < 0)
 290                 return r;
 291
 292         *found = seat;
 293         return 1;
 294 }
 295
 296 char *seat_bus_path(Seat *s) {
 297         _cleanup_free_ char *t = NULL;
 298
 299         assert(s);
 300
 301         t = bus_label_escape(s->id);
 302         if (!t)
 303                 return NULL;
 304
 305         return strjoin("/org/freedesktop/login1/seat/", t);
 306 }
 307
 308 int seat_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
 309         _cleanup_strv_free_ char **l = NULL;
 310         sd_bus_message *message;
 311         Manager *m = userdata;
 312         Seat *seat;
 313         Iterator i;
 314         int r;
 315
 316         assert(bus);
 317         assert(path);
 318         assert(nodes);
 319
 320         HASHMAP_FOREACH(seat, m->seats, i) {
 321                 char *p;
 322
 323                 p = seat_bus_path(seat);
 324                 if (!p)
 325                         return -ENOMEM;
 326
 327                 r = strv_consume(&l, p);
 328                 if (r < 0)
 329                         return r;
 330         }
 331
 332         message = sd_bus_get_current_message(bus);
 333         if (message) {
 334                 _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
 335
 336                 r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID|SD_BUS_CREDS_AUGMENT, &creds);
 337                 if (r >= 0) {
 338                         bool may_auto = false;
 339                         const char *name;
 340
 341                         r = sd_bus_creds_get_session(creds, &name);
 342                         if (r >= 0) {
 343                                 Session *session;
 344
 345                                 session = hashmap_get(m->sessions, name);
 346                                 if (session && session->seat) {
 347                                         r = strv_extend(&l, "/org/freedesktop/login1/seat/self");
 348                                         if (r < 0)
 349                                                 return r;
 350
 351                                         may_auto = true;
 352                                 }
 353                         }
 354
 355                         if (!may_auto) {
 356                                 uid_t uid;
 357
 358                                 r = sd_bus_creds_get_owner_uid(creds, &uid);
 359                                 if (r >= 0) {
 360                                         User *user;
 361
 362                                         user = hashmap_get(m->users, UID_TO_PTR(uid));
 363                                         may_auto = user && user->display && user->display->seat;
 364                                 }
 365                         }
 366
 367                         if (may_auto) {
 368                                 r = strv_extend(&l, "/org/freedesktop/login1/seat/auto");
 369                                 if (r < 0)
 370                                         return r;
 371                         }
 372                 }
 373         }
 374
 375         *nodes = TAKE_PTR(l);
 376         return 1;
 377 }
 378
 379 int seat_send_signal(Seat *s, bool new_seat) {
 380         _cleanup_free_ char *p = NULL;
 381
 382         assert(s);
 383
 384         p = seat_bus_path(s);
 385         if (!p)
 386                 return -ENOMEM;
 387
 388         return sd_bus_emit_signal(
 389                         s->manager->bus,
 390                         "/org/freedesktop/login1",
 391                         "org.freedesktop.login1.Manager",
 392                         new_seat ? "SeatNew" : "SeatRemoved",
 393                         "so", s->id, p);
 394 }
 395
 396 int seat_send_changed(Seat *s, const char *properties, ...) {
 397         _cleanup_free_ char *p = NULL;
 398         char **l;
 399
 400         assert(s);
 401
 402         if (!s->started)
 403                 return 0;
 404
 405         p = seat_bus_path(s);
 406         if (!p)
 407                 return -ENOMEM;
 408
 409         l = strv_from_stdarg_alloca(properties);
 410
 411         return sd_bus_emit_properties_changed_strv(s->manager->bus, p, "org.freedesktop.login1.Seat", l);
 412 }