1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-bus.c Convenience functions for communicating with the bus.
4 * Copyright (C) 2003 CodeFactory AB
5 * Copyright (C) 2003 Red Hat, Inc.
7 * Licensed under the Academic Free License version 2.1
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 #include "dbus-protocol.h"
28 #include "dbus-internals.h"
29 #include "dbus-message.h"
30 #include "dbus-marshal-validate.h"
31 #include "dbus-threads-internal.h"
32 #include "dbus-connection-internal.h"
33 #include "dbus-string.h"
34 #include "dbus-transport-kdbus.h"
38 * @defgroup DBusBus Message bus APIs
40 * @brief Functions for communicating with the message bus
42 * dbus_bus_get() allows all modules and libraries in a given
43 * process to share the same connection to the bus daemon by storing
44 * the connection globally.
46 * All other functions in this module are just convenience functions;
47 * most of them invoke methods on the bus daemon, by sending method
48 * call messages to #DBUS_SERVICE_DBUS. These convenience functions
49 * often make blocking method calls. If you don't want to block,
50 * you can send the method call messages manually in the same way
51 * you would any other method call message.
53 * This module is the only one in libdbus that's specific to
54 * communicating with the message bus daemon. The rest of the API can
55 * also be used for connecting to another application directly.
57 * @todo right now the default address of the system bus is hardcoded,
58 * so if you change it in the global config file suddenly you have to
59 * set DBUS_SYSTEM_BUS_ADDRESS env variable. Might be nice if the
60 * client lib somehow read the config file, or if the bus on startup
61 * somehow wrote out its address to a well-known spot, but might also
66 * @defgroup DBusBusInternals Message bus APIs internals
67 * @ingroup DBusInternals
68 * @brief Internals of functions for communicating with the message bus
74 * Block of message-bus-related data we attach to each
75 * #DBusConnection used with these convenience functions.
80 DBusConnection *connection; /**< Connection we're associated with */
81 char *unique_name; /**< Unique name of this connection */
83 unsigned int is_well_known : 1; /**< Is one of the well-known connections in our global array */
86 /** The slot we have reserved to store BusData.
88 static dbus_int32_t bus_data_slot = -1;
90 /** Number of bus types */
93 static DBusConnection *bus_connections[N_BUS_TYPES];
94 static char *bus_connection_addresses[N_BUS_TYPES] = { NULL, NULL, NULL };
96 static DBusBusType activation_bus_type = DBUS_BUS_STARTER;
98 static dbus_bool_t initialized = FALSE;
101 addresses_shutdown_func (void *data)
106 while (i < N_BUS_TYPES)
108 if (bus_connections[i] != NULL)
109 _dbus_warn_check_failed ("dbus_shutdown() called but connections were still live. This probably means the application did not drop all its references to bus connections.\n");
111 dbus_free (bus_connection_addresses[i]);
112 bus_connection_addresses[i] = NULL;
116 activation_bus_type = DBUS_BUS_STARTER;
122 get_from_env (char **connection_p,
127 _dbus_assert (*connection_p == NULL);
129 s = _dbus_getenv (env_var);
130 if (s == NULL || *s == '\0')
131 return TRUE; /* successfully didn't use the env var */
134 *connection_p = _dbus_strdup (s);
135 return *connection_p != NULL;
140 init_session_address (void)
146 /* First, look in the environment. This is the normal case on
147 * freedesktop.org/Unix systems. */
148 get_from_env (&bus_connection_addresses[DBUS_BUS_SESSION],
149 "DBUS_SESSION_BUS_ADDRESS");
150 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
152 dbus_bool_t supported;
154 DBusError error = DBUS_ERROR_INIT;
156 if (!_dbus_string_init (&addr))
160 /* So it's not in the environment - let's try a platform-specific method.
161 * On MacOS, this involves asking launchd. On Windows (not specified yet)
162 * we might do a COM lookup.
163 * Ignore errors - if we failed, fall back to autolaunch. */
164 retval = _dbus_lookup_session_address (&supported, &addr, &error);
165 if (supported && retval)
167 retval =_dbus_string_steal_data (&addr, &bus_connection_addresses[DBUS_BUS_SESSION]);
169 else if (supported && !retval)
171 if (dbus_error_is_set(&error))
172 _dbus_warn ("Dynamic session lookup supported but failed: %s\n", error.message);
174 _dbus_warn ("Dynamic session lookup supported but failed silently\n");
176 _dbus_string_free (&addr);
184 /* We have a hard-coded (but compile-time-configurable) fallback address for
185 * the session bus. */
186 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
187 bus_connection_addresses[DBUS_BUS_SESSION] =
188 _dbus_strdup (DBUS_SESSION_BUS_CONNECT_ADDRESS);
190 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
197 init_connections_unlocked (void)
205 while (i < N_BUS_TYPES)
207 bus_connections[i] = NULL;
211 /* Don't init these twice, we may run this code twice if
212 * init_connections_unlocked() fails midway through.
213 * In practice, each block below should contain only one
214 * "return FALSE" or running through twice may not
218 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
220 _dbus_verbose ("Filling in system bus address...\n");
222 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_SYSTEM],
223 "DBUS_SYSTEM_BUS_ADDRESS"))
228 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
230 /* Use default system bus address if none set in environment */
231 bus_connection_addresses[DBUS_BUS_SYSTEM] =
232 _dbus_strdup (DBUS_SYSTEM_BUS_DEFAULT_ADDRESS);
234 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
237 _dbus_verbose (" used default system bus \"%s\"\n",
238 bus_connection_addresses[DBUS_BUS_SYSTEM]);
241 _dbus_verbose (" used env var system bus \"%s\"\n",
242 bus_connection_addresses[DBUS_BUS_SYSTEM]);
244 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
246 _dbus_verbose ("Filling in session bus address...\n");
248 if (!init_session_address ())
251 _dbus_verbose (" \"%s\"\n", bus_connection_addresses[DBUS_BUS_SESSION] ?
252 bus_connection_addresses[DBUS_BUS_SESSION] : "none set");
255 if (bus_connection_addresses[DBUS_BUS_STARTER] == NULL)
257 _dbus_verbose ("Filling in activation bus address...\n");
259 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_STARTER],
260 "DBUS_STARTER_ADDRESS"))
263 _dbus_verbose (" \"%s\"\n", bus_connection_addresses[DBUS_BUS_STARTER] ?
264 bus_connection_addresses[DBUS_BUS_STARTER] : "none set");
268 if (bus_connection_addresses[DBUS_BUS_STARTER] != NULL)
270 s = _dbus_getenv ("DBUS_STARTER_BUS_TYPE");
274 _dbus_verbose ("Bus activation type was set to \"%s\"\n", s);
276 if (strcmp (s, "system") == 0)
277 activation_bus_type = DBUS_BUS_SYSTEM;
278 else if (strcmp (s, "session") == 0)
279 activation_bus_type = DBUS_BUS_SESSION;
284 /* Default to the session bus instead if available */
285 if (bus_connection_addresses[DBUS_BUS_SESSION] != NULL)
287 bus_connection_addresses[DBUS_BUS_STARTER] =
288 _dbus_strdup (bus_connection_addresses[DBUS_BUS_SESSION]);
289 if (bus_connection_addresses[DBUS_BUS_STARTER] == NULL)
294 /* If we return FALSE we have to be sure that restarting
295 * the above code will work right
298 if (!_dbus_setenv ("DBUS_ACTIVATION_ADDRESS", NULL))
301 if (!_dbus_setenv ("DBUS_ACTIVATION_BUS_TYPE", NULL))
304 if (!_dbus_register_shutdown_func (addresses_shutdown_func,
315 bus_data_free (void *data)
319 if (bd->is_well_known)
323 if (!_DBUS_LOCK (bus))
324 _dbus_assert_not_reached ("global locks should have been initialized "
325 "when we attached bus data");
327 /* We may be stored in more than one slot */
328 /* This should now be impossible - these slots are supposed to
329 * be cleared on disconnect, so should not need to be cleared on
333 while (i < N_BUS_TYPES)
335 if (bus_connections[i] == bd->connection)
336 bus_connections[i] = NULL;
343 dbus_free (bd->unique_name);
346 dbus_connection_free_data_slot (&bus_data_slot);
350 ensure_bus_data (DBusConnection *connection)
354 if (!dbus_connection_allocate_data_slot (&bus_data_slot))
357 bd = dbus_connection_get_data (connection, bus_data_slot);
360 bd = dbus_new0 (BusData, 1);
363 dbus_connection_free_data_slot (&bus_data_slot);
367 bd->connection = connection;
369 if (!dbus_connection_set_data (connection, bus_data_slot, bd,
373 dbus_connection_free_data_slot (&bus_data_slot);
377 /* Data slot refcount now held by the BusData */
381 dbus_connection_free_data_slot (&bus_data_slot);
388 * Internal function that checks to see if this
389 * is a shared connection owned by the bus and if it is unref it.
391 * @param connection a connection that has been disconnected.
394 _dbus_bus_notify_shared_connection_disconnected_unlocked (DBusConnection *connection)
398 if (!_DBUS_LOCK (bus))
400 /* If it was in bus_connections, we would have initialized global locks
401 * when we added it. So, it can't be. */
405 /* We are expecting to have the connection saved in only one of these
406 * slots, but someone could in a pathological case set system and session
407 * bus to the same bus or something. Or set one of them to the starter
408 * bus without setting the starter bus type in the env variable.
409 * So we don't break the loop as soon as we find a match.
411 for (i = 0; i < N_BUS_TYPES; ++i)
413 if (bus_connections[i] == connection)
415 bus_connections[i] = NULL;
422 static DBusConnection *
423 internal_bus_get (DBusBusType type,
428 DBusConnection *connection;
430 DBusBusType address_type;
432 _dbus_return_val_if_fail (type >= 0 && type < N_BUS_TYPES, NULL);
433 _dbus_return_val_if_error_is_set (error, NULL);
437 if (!_DBUS_LOCK (bus))
439 _DBUS_SET_OOM (error);
440 /* do not "goto out", that would try to unlock */
444 if (!init_connections_unlocked ())
446 _DBUS_SET_OOM (error);
450 /* We want to use the activation address even if the
451 * activating bus is the session or system bus,
456 /* Use the real type of the activation bus for getting its
457 * connection, but only if the real type's address is available. (If
458 * the activating bus isn't a well-known bus then
459 * activation_bus_type == DBUS_BUS_STARTER)
461 if (type == DBUS_BUS_STARTER &&
462 bus_connection_addresses[activation_bus_type] != NULL)
463 type = activation_bus_type;
465 if (!private && bus_connections[type] != NULL)
467 connection = bus_connections[type];
468 dbus_connection_ref (connection);
472 address = bus_connection_addresses[address_type];
475 dbus_set_error (error, DBUS_ERROR_FAILED,
476 "Unable to determine the address of the message bus (try 'man dbus-launch' and 'man dbus-daemon' for help)");
481 connection = dbus_connection_open_private (address, error);
483 connection = dbus_connection_open (address, error);
490 _dbus_verbose (" !!! dbus_connection_open finished successfully !!!! \n"); //todo RP to be removed
492 if (!dbus_bus_register (connection, error))
494 _dbus_connection_close_possibly_shared (connection);
495 dbus_connection_unref (connection);
502 /* store a weak ref to the connection (dbus-connection.c is
503 * supposed to have a strong ref that it drops on disconnect,
504 * since this is a shared connection)
506 bus_connections[type] = connection;
509 /* By default we're bound to the lifecycle of
512 dbus_connection_set_exit_on_disconnect (connection,
515 if (!_DBUS_LOCK (bus_datas))
516 _dbus_assert_not_reached ("global locks were initialized already");
518 bd = ensure_bus_data (connection);
519 _dbus_assert (bd != NULL); /* it should have been created on
520 register, so OOM not possible */
521 bd->is_well_known = TRUE;
522 _DBUS_UNLOCK (bus_datas);
525 /* Return a reference to the caller, or NULL with error set. */
526 if (connection == NULL)
527 _DBUS_ASSERT_ERROR_IS_SET (error);
534 /** @} */ /* end of implementation details docs */
537 * @addtogroup DBusBus
542 * Connects to a bus daemon and registers the client with it. If a
543 * connection to the bus already exists, then that connection is
544 * returned. The caller of this function owns a reference to the bus.
546 * The caller may NOT call dbus_connection_close() on this connection;
547 * see dbus_connection_open() and dbus_connection_close() for details
550 * If this function obtains a new connection object never before
551 * returned from dbus_bus_get(), it will call
552 * dbus_connection_set_exit_on_disconnect(), so the application
553 * will exit if the connection closes. You can undo this
554 * by calling dbus_connection_set_exit_on_disconnect() yourself
555 * after you get the connection.
557 * dbus_bus_get() calls dbus_bus_register() for you.
559 * If returning a newly-created connection, this function will block
560 * until authentication and bus registration are complete.
562 * @param type bus type
563 * @param error address where an error can be returned.
564 * @returns a #DBusConnection with new ref
567 dbus_bus_get (DBusBusType type,
570 return internal_bus_get (type, FALSE, error);
574 * Connects to a bus daemon and registers the client with it as with
575 * dbus_bus_register(). Unlike dbus_bus_get(), always creates a new
576 * connection. This connection will not be saved or recycled by
577 * libdbus. Caller owns a reference to the bus and must either close
578 * it or know it to be closed prior to releasing this reference.
580 * See dbus_connection_open_private() for more details on when to
581 * close and unref this connection.
583 * This function calls
584 * dbus_connection_set_exit_on_disconnect() on the new connection, so the application
585 * will exit if the connection closes. You can undo this
586 * by calling dbus_connection_set_exit_on_disconnect() yourself
587 * after you get the connection.
589 * dbus_bus_get_private() calls dbus_bus_register() for you.
591 * This function will block until authentication and bus registration
594 * @param type bus type
595 * @param error address where an error can be returned.
596 * @returns a DBusConnection with new ref
599 dbus_bus_get_private (DBusBusType type,
602 return internal_bus_get (type, TRUE, error);
605 /* kdbus add-on [RP] - bus register for kdbus
606 * Function checks if the method is kdbus. If yes - it registers on the bus, if no - does nothing and returns TRUE
607 * Must be invoked before dbus_bus_register because in kdbus it's realized in different manner
608 * and dbus_bus_register can not be used for that.
609 * It does not collide with dbus_bus_register because dbus_bus_register at the beginning checks
610 * whether unique_name has already been assigned and doesn't try to do it again.
612 dbus_bool_t dbus_bus_register_kdbus(DBusAddressEntry *entry, DBusConnection *connection, DBusError *error)
614 dbus_bool_t retval = TRUE;
617 method = dbus_address_entry_get_method (entry);
618 _dbus_assert (method != NULL);
620 if (strcmp (method, "kdbus") == 0)
624 _dbus_return_val_if_fail (connection != NULL, FALSE);
625 _dbus_return_val_if_error_is_set (error, FALSE);
629 if (!_DBUS_LOCK (bus_datas))
631 _DBUS_SET_OOM (error);
632 /* do not "goto out", that would try to unlock */
636 bd = ensure_bus_data (connection);
639 _DBUS_SET_OOM (error);
643 if (bd->unique_name != NULL)
645 _dbus_verbose ("Ignoring attempt to register the same DBusConnection %s with the message bus a second time.\n",
652 if(!bus_register_kdbus(&bd->unique_name, connection, error))
658 _DBUS_UNLOCK (bus_datas);
661 _DBUS_ASSERT_ERROR_IS_SET (error);
667 * Registers a connection with the bus. This must be the first
668 * thing an application does when connecting to the message bus.
669 * If registration succeeds, the unique name will be set,
670 * and can be obtained using dbus_bus_get_unique_name().
672 * This function will block until registration is complete.
674 * If the connection has already registered with the bus
675 * (determined by checking whether dbus_bus_get_unique_name()
676 * returns a non-#NULL value), then this function does nothing.
678 * If you use dbus_bus_get() or dbus_bus_get_private() this
679 * function will be called for you.
681 * @note Just use dbus_bus_get() or dbus_bus_get_private() instead of
682 * dbus_bus_register() and save yourself some pain. Using
683 * dbus_bus_register() manually is only useful if you have your
684 * own custom message bus not found in #DBusBusType.
686 * If you open a bus connection with dbus_connection_open() or
687 * dbus_connection_open_private() you will have to dbus_bus_register()
688 * yourself, or make the appropriate registration method calls
689 * yourself. If you send the method calls yourself, call
690 * dbus_bus_set_unique_name() with the unique bus name you get from
693 * For shared connections (created with dbus_connection_open()) in a
694 * multithreaded application, you can't really make the registration
695 * calls yourself, because you don't know whether some other thread is
696 * also registering, and the bus will kick you off if you send two
697 * registration messages.
699 * If you use dbus_bus_register() however, there is a lock that
700 * keeps both apps from registering at the same time.
702 * The rule in a multithreaded app, then, is that dbus_bus_register()
703 * must be used to register, or you need to have your own locks that
704 * all threads in the app will respect.
706 * In a single-threaded application you can register by hand instead
707 * of using dbus_bus_register(), as long as you check
708 * dbus_bus_get_unique_name() to see if a unique name has already been
709 * stored by another thread before you send the registration messages.
711 * @param connection the connection
712 * @param error place to store errors
713 * @returns #TRUE on success
716 dbus_bus_register (DBusConnection *connection,
719 DBusMessage *message, *reply;
724 _dbus_return_val_if_fail (connection != NULL, FALSE);
725 _dbus_return_val_if_error_is_set (error, FALSE);
731 if (!_DBUS_LOCK (bus_datas))
733 _DBUS_SET_OOM (error);
734 /* do not "goto out", that would try to unlock */
738 bd = ensure_bus_data (connection);
741 _DBUS_SET_OOM (error);
745 if (bd->unique_name != NULL)
747 _dbus_verbose ("Ignoring attempt to register the same DBusConnection %s with the message bus a second time.\n",
754 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
761 _DBUS_SET_OOM (error);
765 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
769 else if (dbus_set_error_from_message (error, reply))
771 else if (!dbus_message_get_args (reply, error,
772 DBUS_TYPE_STRING, &name,
776 bd->unique_name = _dbus_strdup (name);
777 if (bd->unique_name == NULL)
779 _DBUS_SET_OOM (error);
786 _DBUS_UNLOCK (bus_datas);
789 dbus_message_unref (message);
792 dbus_message_unref (reply);
795 _DBUS_ASSERT_ERROR_IS_SET (error);
802 * Sets the unique name of the connection, as assigned by the message
803 * bus. Can only be used if you registered with the bus manually
804 * (i.e. if you did not call dbus_bus_register()). Can only be called
805 * once per connection. After the unique name is set, you can get it
806 * with dbus_bus_get_unique_name().
808 * The only reason to use this function is to re-implement the
809 * equivalent of dbus_bus_register() yourself. One (probably unusual)
810 * reason to do that might be to do the bus registration call
811 * asynchronously instead of synchronously.
813 * @note Just use dbus_bus_get() or dbus_bus_get_private(), or worst
814 * case dbus_bus_register(), instead of messing with this
815 * function. There's really no point creating pain for yourself by
816 * doing things manually.
818 * It's hard to use this function safely on shared connections
819 * (created by dbus_connection_open()) in a multithreaded application,
820 * because only one registration attempt can be sent to the bus. If
821 * two threads are both sending the registration message, there is no
822 * mechanism in libdbus itself to avoid sending it twice.
824 * Thus, you need a way to coordinate which thread sends the
825 * registration attempt; which also means you know which thread
826 * will call dbus_bus_set_unique_name(). If you don't know
827 * about all threads in the app (for example, if some libraries
828 * you're using might start libdbus-using threads), then you
829 * need to avoid using this function on shared connections.
831 * @param connection the connection
832 * @param unique_name the unique name
833 * @returns #FALSE if not enough memory
836 dbus_bus_set_unique_name (DBusConnection *connection,
837 const char *unique_name)
840 dbus_bool_t success = FALSE;
842 _dbus_return_val_if_fail (connection != NULL, FALSE);
843 _dbus_return_val_if_fail (unique_name != NULL, FALSE);
845 if (!_DBUS_LOCK (bus_datas))
847 /* do not "goto out", that would try to unlock */
851 bd = ensure_bus_data (connection);
855 _dbus_assert (bd->unique_name == NULL);
857 bd->unique_name = _dbus_strdup (unique_name);
858 success = bd->unique_name != NULL;
861 _DBUS_UNLOCK (bus_datas);
867 * Gets the unique name of the connection as assigned by the message
868 * bus. Only possible after the connection has been registered with
869 * the message bus. All connections returned by dbus_bus_get() or
870 * dbus_bus_get_private() have been successfully registered.
872 * The name remains valid until the connection is freed, and
873 * should not be freed by the caller.
875 * Other than dbus_bus_get(), there are two ways to set the unique
876 * name; one is dbus_bus_register(), the other is
877 * dbus_bus_set_unique_name(). You are responsible for calling
878 * dbus_bus_set_unique_name() if you register by hand instead of using
879 * dbus_bus_register().
881 * @param connection the connection
882 * @returns the unique name or #NULL on error
885 dbus_bus_get_unique_name (DBusConnection *connection)
888 const char *unique_name = NULL;
890 _dbus_return_val_if_fail (connection != NULL, NULL);
892 if (!_DBUS_LOCK (bus_datas))
894 /* We'd have initialized locks when we gave it its unique name, if it
895 * had one. Don't "goto out", that would try to unlock. */
899 bd = ensure_bus_data (connection);
903 unique_name = bd->unique_name;
906 _DBUS_UNLOCK (bus_datas);
912 * Asks the bus to return the UID the named connection authenticated
913 * as, if any. Only works on UNIX; only works for connections on the
914 * same machine as the bus. If you are not on the same machine as the
915 * bus, then calling this is probably a bad idea, since the UID will
916 * mean little to your application.
918 * For the system message bus you're guaranteed to be on the same
919 * machine since it only listens on a UNIX domain socket (at least,
920 * as shipped by default).
922 * This function only works for connections that authenticated as
923 * a UNIX user, right now that includes all bus connections, but
924 * it's very possible to have connections with no associated UID.
925 * So check for errors and do something sensible if they happen.
927 * This function will always return an error on Windows.
929 * @param connection the connection
930 * @param name a name owned by the connection
931 * @param error location to store the error
932 * @returns the unix user id, or ((unsigned)-1) if error is set
935 dbus_bus_get_unix_user (DBusConnection *connection,
939 DBusMessage *message, *reply;
942 _dbus_return_val_if_fail (connection != NULL, DBUS_UID_UNSET);
943 _dbus_return_val_if_fail (name != NULL, DBUS_UID_UNSET);
944 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), DBUS_UID_UNSET);
945 _dbus_return_val_if_error_is_set (error, DBUS_UID_UNSET);
947 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
950 "GetConnectionUnixUser");
954 _DBUS_SET_OOM (error);
955 return DBUS_UID_UNSET;
958 if (!dbus_message_append_args (message,
959 DBUS_TYPE_STRING, &name,
962 dbus_message_unref (message);
963 _DBUS_SET_OOM (error);
964 return DBUS_UID_UNSET;
967 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
970 dbus_message_unref (message);
974 _DBUS_ASSERT_ERROR_IS_SET (error);
975 return DBUS_UID_UNSET;
978 if (dbus_set_error_from_message (error, reply))
980 _DBUS_ASSERT_ERROR_IS_SET (error);
981 dbus_message_unref (reply);
982 return DBUS_UID_UNSET;
985 if (!dbus_message_get_args (reply, error,
986 DBUS_TYPE_UINT32, &uid,
989 _DBUS_ASSERT_ERROR_IS_SET (error);
990 dbus_message_unref (reply);
991 return DBUS_UID_UNSET;
994 dbus_message_unref (reply);
996 return (unsigned long) uid;
1000 * Asks the bus to return its globally unique ID, as described in the
1001 * D-Bus specification. For the session bus, this is useful as a way
1002 * to uniquely identify each user session. For the system bus,
1003 * probably the bus ID is not useful; instead, use the machine ID
1004 * since it's accessible without necessarily connecting to the bus and
1005 * may be persistent beyond a single bus instance (across reboots for
1006 * example). See dbus_get_local_machine_id().
1008 * In addition to an ID for each bus and an ID for each machine, there is
1009 * an ID for each address that the bus is listening on; that can
1010 * be retrieved with dbus_connection_get_server_id(), though it is
1011 * probably not very useful.
1013 * @param connection the connection
1014 * @param error location to store the error
1015 * @returns the bus ID or #NULL if error is set
1018 dbus_bus_get_id (DBusConnection *connection,
1021 DBusMessage *message, *reply;
1023 const char *v_STRING;
1025 _dbus_return_val_if_fail (connection != NULL, NULL);
1026 _dbus_return_val_if_error_is_set (error, NULL);
1028 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1030 DBUS_INTERFACE_DBUS,
1033 if (message == NULL)
1035 _DBUS_SET_OOM (error);
1039 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
1042 dbus_message_unref (message);
1046 _DBUS_ASSERT_ERROR_IS_SET (error);
1050 if (dbus_set_error_from_message (error, reply))
1052 _DBUS_ASSERT_ERROR_IS_SET (error);
1053 dbus_message_unref (reply);
1058 if (!dbus_message_get_args (reply, error,
1059 DBUS_TYPE_STRING, &v_STRING,
1062 _DBUS_ASSERT_ERROR_IS_SET (error);
1063 dbus_message_unref (reply);
1067 id = _dbus_strdup (v_STRING); /* may be NULL */
1069 dbus_message_unref (reply);
1072 _DBUS_SET_OOM (error);
1074 /* FIXME it might be nice to cache the ID locally */
1080 * Asks the bus to assign the given name to this connection by invoking
1081 * the RequestName method on the bus. This method is fully documented
1082 * in the D-Bus specification. For quick reference, the flags and
1083 * result codes are discussed here, but the specification is the
1084 * canonical version of this information.
1086 * First you should know that for each bus name, the bus stores
1087 * a queue of connections that would like to own it. Only
1088 * one owns it at a time - called the primary owner. If the primary
1089 * owner releases the name or disconnects, then the next owner in the
1090 * queue atomically takes over.
1092 * So for example if you have an application org.freedesktop.TextEditor
1093 * and multiple instances of it can be run, you can have all of them
1094 * sitting in the queue. The first one to start up will receive messages
1095 * sent to org.freedesktop.TextEditor, but if that one exits another
1096 * will become the primary owner and receive messages.
1098 * The queue means you don't need to manually watch for the current owner to
1099 * disappear and then request the name again.
1101 * When requesting a name, you can specify several flags.
1103 * #DBUS_NAME_FLAG_ALLOW_REPLACEMENT and #DBUS_NAME_FLAG_DO_NOT_QUEUE
1104 * are properties stored by the bus for this connection with respect to
1105 * each requested bus name. These properties are stored even if the
1106 * connection is queued and does not become the primary owner.
1107 * You can update these flags by calling RequestName again (even if
1108 * you already own the name).
1110 * #DBUS_NAME_FLAG_ALLOW_REPLACEMENT means that another requestor of the
1111 * name can take it away from you by specifying #DBUS_NAME_FLAG_REPLACE_EXISTING.
1113 * #DBUS_NAME_FLAG_DO_NOT_QUEUE means that if you aren't the primary owner,
1114 * you don't want to be queued up - you only care about being the
1117 * Unlike the other two flags, #DBUS_NAME_FLAG_REPLACE_EXISTING is a property
1118 * of the individual RequestName call, i.e. the bus does not persistently
1119 * associate it with the connection-name pair. If a RequestName call includes
1120 * the #DBUS_NAME_FLAG_REPLACE_EXISTING flag, and the current primary
1121 * owner has #DBUS_NAME_FLAG_ALLOW_REPLACEMENT set, then the current primary
1122 * owner will be kicked off.
1124 * If no flags are given, an application will receive the requested
1125 * name only if the name is currently unowned; and it will NOT give
1126 * up the name if another application asks to take it over using
1127 * #DBUS_NAME_FLAG_REPLACE_EXISTING.
1129 * This function returns a result code. The possible result codes
1132 * #DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER means that the name had no
1133 * existing owner, and the caller is now the primary owner; or that
1134 * the name had an owner, and the caller specified
1135 * #DBUS_NAME_FLAG_REPLACE_EXISTING, and the current owner
1136 * specified #DBUS_NAME_FLAG_ALLOW_REPLACEMENT.
1138 * #DBUS_REQUEST_NAME_REPLY_IN_QUEUE happens only if the caller does NOT
1139 * specify #DBUS_NAME_FLAG_DO_NOT_QUEUE and either the current owner
1140 * did NOT specify #DBUS_NAME_FLAG_ALLOW_REPLACEMENT or the caller did NOT
1141 * specify #DBUS_NAME_FLAG_REPLACE_EXISTING. In this case the caller ends up
1142 * in a queue to own the name after the current owner gives it up.
1144 * #DBUS_REQUEST_NAME_REPLY_EXISTS happens if the name has an owner
1145 * already and the caller specifies #DBUS_NAME_FLAG_DO_NOT_QUEUE
1146 * and either the current owner has NOT specified
1147 * #DBUS_NAME_FLAG_ALLOW_REPLACEMENT or the caller did NOT specify
1148 * #DBUS_NAME_FLAG_REPLACE_EXISTING.
1150 * #DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER happens if an application
1151 * requests a name it already owns. (Re-requesting a name is useful if
1152 * you want to change the #DBUS_NAME_FLAG_ALLOW_REPLACEMENT or
1153 * #DBUS_NAME_FLAG_DO_NOT_QUEUE settings.)
1155 * When a service represents an application, say "text editor," then
1156 * it should specify #DBUS_NAME_FLAG_ALLOW_REPLACEMENT if it wants
1157 * the last editor started to be the user's editor vs. the first one
1158 * started. Then any editor that can be the user's editor should
1159 * specify #DBUS_NAME_FLAG_REPLACE_EXISTING to either take over
1160 * (last-started-wins) or be queued up (first-started-wins) according
1161 * to whether #DBUS_NAME_FLAG_ALLOW_REPLACEMENT was given.
1163 * Conventionally, single-instance applications often offer a command
1164 * line option called --replace which means to replace the current
1165 * instance. To implement this, always set
1166 * #DBUS_NAME_FLAG_ALLOW_REPLACEMENT when you request your
1167 * application's bus name. When you lose ownership of your bus name,
1168 * you need to exit. Look for the signal "NameLost" from
1169 * #DBUS_SERVICE_DBUS and #DBUS_INTERFACE_DBUS (the signal's first
1170 * argument is the bus name that was lost). If starting up without
1171 * --replace, do not specify #DBUS_NAME_FLAG_REPLACE_EXISTING, and
1172 * exit if you fail to become the bus name owner. If --replace is
1173 * given, ask to replace the old owner.
1175 * @param connection the connection
1176 * @param name the name to request
1177 * @param flags flags
1178 * @param error location to store the error
1179 * @returns a result code, -1 if error is set
1182 dbus_bus_request_name (DBusConnection *connection,
1187 DBusMessage *message, *reply;
1188 dbus_uint32_t result;
1190 _dbus_return_val_if_fail (connection != NULL, 0);
1191 _dbus_return_val_if_fail (name != NULL, 0);
1192 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), 0);
1193 _dbus_return_val_if_error_is_set (error, 0);
1195 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1197 DBUS_INTERFACE_DBUS,
1200 if (message == NULL)
1202 _DBUS_SET_OOM (error);
1206 if (!dbus_message_append_args (message,
1207 DBUS_TYPE_STRING, &name,
1208 DBUS_TYPE_UINT32, &flags,
1211 dbus_message_unref (message);
1212 _DBUS_SET_OOM (error);
1216 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
1219 dbus_message_unref (message);
1223 _DBUS_ASSERT_ERROR_IS_SET (error);
1227 if (dbus_set_error_from_message (error, reply))
1229 _DBUS_ASSERT_ERROR_IS_SET (error);
1230 dbus_message_unref (reply);
1234 if (!dbus_message_get_args (reply, error,
1235 DBUS_TYPE_UINT32, &result,
1238 _DBUS_ASSERT_ERROR_IS_SET (error);
1239 dbus_message_unref (reply);
1243 dbus_message_unref (reply);
1250 * Asks the bus to unassign the given name from this connection by
1251 * invoking the ReleaseName method on the bus. The "ReleaseName"
1252 * method is canonically documented in the D-Bus specification.
1254 * Possible results are: #DBUS_RELEASE_NAME_REPLY_RELEASED
1255 * which means you owned the name or were in the queue to own it,
1256 * and and now you don't own it and aren't in the queue.
1257 * #DBUS_RELEASE_NAME_REPLY_NOT_OWNER which means someone else
1258 * owns the name so you can't release it.
1259 * #DBUS_RELEASE_NAME_REPLY_NON_EXISTENT
1260 * which means nobody owned the name.
1262 * @param connection the connection
1263 * @param name the name to remove
1264 * @param error location to store the error
1265 * @returns a result code, -1 if error is set
1268 dbus_bus_release_name (DBusConnection *connection,
1272 DBusMessage *message, *reply;
1273 dbus_uint32_t result;
1275 _dbus_return_val_if_fail (connection != NULL, 0);
1276 _dbus_return_val_if_fail (name != NULL, 0);
1277 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), 0);
1278 _dbus_return_val_if_error_is_set (error, 0);
1280 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1282 DBUS_INTERFACE_DBUS,
1285 if (message == NULL)
1287 _DBUS_SET_OOM (error);
1291 if (!dbus_message_append_args (message,
1292 DBUS_TYPE_STRING, &name,
1295 dbus_message_unref (message);
1296 _DBUS_SET_OOM (error);
1300 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
1303 dbus_message_unref (message);
1307 _DBUS_ASSERT_ERROR_IS_SET (error);
1311 if (dbus_set_error_from_message (error, reply))
1313 _DBUS_ASSERT_ERROR_IS_SET (error);
1314 dbus_message_unref (reply);
1318 if (!dbus_message_get_args (reply, error,
1319 DBUS_TYPE_UINT32, &result,
1322 _DBUS_ASSERT_ERROR_IS_SET (error);
1323 dbus_message_unref (reply);
1327 dbus_message_unref (reply);
1333 * Asks the bus whether a certain name has an owner.
1335 * Using this can easily result in a race condition,
1336 * since an owner can appear or disappear after you
1339 * If you want to request a name, just request it;
1340 * if you want to avoid replacing a current owner,
1341 * don't specify #DBUS_NAME_FLAG_REPLACE_EXISTING and
1342 * you will get an error if there's already an owner.
1344 * @param connection the connection
1345 * @param name the name
1346 * @param error location to store any errors
1347 * @returns #TRUE if the name exists, #FALSE if not or on error
1350 dbus_bus_name_has_owner (DBusConnection *connection,
1354 DBusMessage *message, *reply;
1357 _dbus_return_val_if_fail (connection != NULL, FALSE);
1358 _dbus_return_val_if_fail (name != NULL, FALSE);
1359 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), FALSE);
1360 _dbus_return_val_if_error_is_set (error, FALSE);
1362 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1364 DBUS_INTERFACE_DBUS,
1366 if (message == NULL)
1368 _DBUS_SET_OOM (error);
1372 if (!dbus_message_append_args (message,
1373 DBUS_TYPE_STRING, &name,
1376 dbus_message_unref (message);
1377 _DBUS_SET_OOM (error);
1381 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
1382 dbus_message_unref (message);
1386 _DBUS_ASSERT_ERROR_IS_SET (error);
1390 if (!dbus_message_get_args (reply, error,
1391 DBUS_TYPE_BOOLEAN, &exists,
1394 _DBUS_ASSERT_ERROR_IS_SET (error);
1395 dbus_message_unref (reply);
1399 dbus_message_unref (reply);
1404 * Starts a service that will request ownership of the given name.
1405 * The returned result will be one of be one of
1406 * #DBUS_START_REPLY_SUCCESS or #DBUS_START_REPLY_ALREADY_RUNNING if
1407 * successful. Pass #NULL if you don't care about the result.
1409 * The flags parameter is for future expansion, currently you should
1412 * It's often easier to avoid explicitly starting services, and
1413 * just send a method call to the service's bus name instead.
1414 * Method calls start a service to handle them by default
1415 * unless you call dbus_message_set_auto_start() to disable this
1418 * @param connection the connection
1419 * @param name the name we want the new service to request
1420 * @param flags the flags (should always be 0 for now)
1421 * @param result a place to store the result or #NULL
1422 * @param error location to store any errors
1423 * @returns #TRUE if the activation succeeded, #FALSE if not
1426 dbus_bus_start_service_by_name (DBusConnection *connection,
1428 dbus_uint32_t flags,
1429 dbus_uint32_t *result,
1435 _dbus_return_val_if_fail (connection != NULL, FALSE);
1436 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), FALSE);
1438 msg = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1440 DBUS_INTERFACE_DBUS,
1441 "StartServiceByName");
1443 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, &name,
1444 DBUS_TYPE_UINT32, &flags, DBUS_TYPE_INVALID))
1446 dbus_message_unref (msg);
1447 _DBUS_SET_OOM (error);
1451 reply = dbus_connection_send_with_reply_and_block (connection, msg,
1453 dbus_message_unref (msg);
1457 _DBUS_ASSERT_ERROR_IS_SET (error);
1461 if (dbus_set_error_from_message (error, reply))
1463 _DBUS_ASSERT_ERROR_IS_SET (error);
1464 dbus_message_unref (reply);
1468 if (result != NULL &&
1469 !dbus_message_get_args (reply, error, DBUS_TYPE_UINT32,
1470 result, DBUS_TYPE_INVALID))
1472 _DBUS_ASSERT_ERROR_IS_SET (error);
1473 dbus_message_unref (reply);
1477 dbus_message_unref (reply);
1482 send_no_return_values (DBusConnection *connection,
1488 /* Block to check success codepath */
1491 reply = dbus_connection_send_with_reply_and_block (connection, msg,
1495 _DBUS_ASSERT_ERROR_IS_SET (error);
1497 dbus_message_unref (reply);
1501 /* Silently-fail nonblocking codepath */
1502 dbus_message_set_no_reply (msg, TRUE);
1503 dbus_connection_send (connection, msg, NULL);
1508 * Adds a match rule to match messages going through the message bus.
1509 * The "rule" argument is the string form of a match rule.
1511 * If you pass #NULL for the error, this function will not
1512 * block; the match thus won't be added until you flush the
1513 * connection, and if there's an error adding the match
1514 * you won't find out about it. This is generally acceptable, since the
1515 * possible errors (including a lack of resources in the bus, the connection
1516 * having exceeded its quota of active match rules, or the match rule being
1517 * unparseable) are generally unrecoverable.
1519 * If you pass non-#NULL for the error this function will
1520 * block until it gets a reply. This may be useful when using match rule keys
1521 * introduced in recent versions of D-Bus, like 'arg0namespace', to allow the
1522 * application to fall back to less efficient match rules supported by older
1523 * versions of the daemon if the running version is not new enough; or when
1524 * using user-supplied rules rather than rules hard-coded at compile time.
1526 * Normal API conventions would have the function return
1527 * a boolean value indicating whether the error was set,
1528 * but that would require blocking always to determine
1531 * The AddMatch method is fully documented in the D-Bus
1532 * specification. For quick reference, the format of the
1533 * match rules is discussed here, but the specification
1534 * is the canonical version of this information.
1536 * Rules are specified as a string of comma separated
1537 * key/value pairs. An example is
1538 * "type='signal',sender='org.freedesktop.DBus',
1539 * interface='org.freedesktop.DBus',member='Foo',
1540 * path='/bar/foo',destination=':452345.34'"
1542 * Possible keys you can match on are type, sender,
1543 * interface, member, path, destination and numbered
1544 * keys to match message args (keys are 'arg0', 'arg1', etc.).
1545 * Omitting a key from the rule indicates
1546 * a wildcard match. For instance omitting
1547 * the member from a match rule but adding a sender would
1548 * let all messages from that sender through regardless of
1551 * Matches are inclusive not exclusive so as long as one
1552 * rule matches the message will get through. It is important
1553 * to note this because every time a message is received the
1554 * application will be paged into memory to process it. This
1555 * can cause performance problems such as draining batteries
1556 * on embedded platforms.
1558 * If you match message args ('arg0', 'arg1', and so forth)
1559 * only string arguments will match. That is, arg0='5' means
1560 * match the string "5" not the integer 5.
1562 * Currently there is no way to match against non-string arguments.
1564 * A specialised form of wildcard matching on arguments is
1565 * supported for path-like namespaces. If your argument match has
1566 * a 'path' suffix (eg: "arg0path='/some/path/'") then it is
1567 * considered a match if the argument exactly matches the given
1568 * string or if one of them ends in a '/' and is a prefix of the
1571 * Matching on interface is tricky because method call
1572 * messages only optionally specify the interface.
1573 * If a message omits the interface, then it will NOT match
1574 * if the rule specifies an interface name. This means match
1575 * rules on method calls should not usually give an interface.
1577 * However, signal messages are required to include the interface
1578 * so when matching signals usually you should specify the interface
1579 * in the match rule.
1581 * For security reasons, you can match arguments only up to
1582 * #DBUS_MAXIMUM_MATCH_RULE_ARG_NUMBER.
1584 * Match rules have a maximum length of #DBUS_MAXIMUM_MATCH_RULE_LENGTH
1587 * Both of these maximums are much higher than you're likely to need,
1588 * they only exist because the D-Bus bus daemon has fixed limits on
1589 * all resource usage.
1591 * @param connection connection to the message bus
1592 * @param rule textual form of match rule
1593 * @param error location to store any errors
1596 dbus_bus_add_match (DBusConnection *connection,
1602 _dbus_return_if_fail (rule != NULL);
1604 msg = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1606 DBUS_INTERFACE_DBUS,
1611 _DBUS_SET_OOM (error);
1615 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, &rule,
1618 dbus_message_unref (msg);
1619 _DBUS_SET_OOM (error);
1623 send_no_return_values (connection, msg, error);
1625 dbus_message_unref (msg);
1629 * Removes a previously-added match rule "by value" (the most
1630 * recently-added identical rule gets removed). The "rule" argument
1631 * is the string form of a match rule.
1633 * The bus compares match rules semantically, not textually, so
1634 * whitespace and ordering don't have to be identical to
1635 * the rule you passed to dbus_bus_add_match().
1637 * If you pass #NULL for the error, this function will not
1638 * block; otherwise it will. See detailed explanation in
1639 * docs for dbus_bus_add_match().
1641 * @param connection connection to the message bus
1642 * @param rule textual form of match rule
1643 * @param error location to store any errors
1646 dbus_bus_remove_match (DBusConnection *connection,
1652 _dbus_return_if_fail (rule != NULL);
1654 msg = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1656 DBUS_INTERFACE_DBUS,
1659 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, &rule,
1662 dbus_message_unref (msg);
1663 _DBUS_SET_OOM (error);
1667 send_no_return_values (connection, msg, error);
1669 dbus_message_unref (msg);