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"
36 * @defgroup DBusBus Message bus APIs
38 * @brief Functions for communicating with the message bus
40 * dbus_bus_get() allows all modules and libraries in a given
41 * process to share the same connection to the bus daemon by storing
42 * the connection globally.
44 * All other functions in this module are just convenience functions;
45 * most of them invoke methods on the bus daemon, by sending method
46 * call messages to #DBUS_SERVICE_DBUS. These convenience functions
47 * often make blocking method calls. If you don't want to block,
48 * you can send the method call messages manually in the same way
49 * you would any other method call message.
51 * This module is the only one in libdbus that's specific to
52 * communicating with the message bus daemon. The rest of the API can
53 * also be used for connecting to another application directly.
55 * @todo right now the default address of the system bus is hardcoded,
56 * so if you change it in the global config file suddenly you have to
57 * set DBUS_SYSTEM_BUS_ADDRESS env variable. Might be nice if the
58 * client lib somehow read the config file, or if the bus on startup
59 * somehow wrote out its address to a well-known spot, but might also
64 * @defgroup DBusBusInternals Message bus APIs internals
65 * @ingroup DBusInternals
66 * @brief Internals of functions for communicating with the message bus
72 * Block of message-bus-related data we attach to each
73 * #DBusConnection used with these convenience functions.
78 DBusConnection *connection; /**< Connection we're associated with */
79 char *unique_name; /**< Unique name of this connection */
81 unsigned int is_well_known : 1; /**< Is one of the well-known connections in our global array */
84 /** The slot we have reserved to store BusData.
86 static dbus_int32_t bus_data_slot = -1;
88 /** Number of bus types */
91 static DBusConnection *bus_connections[N_BUS_TYPES];
92 static char *bus_connection_addresses[N_BUS_TYPES] = { NULL, NULL, NULL };
94 static DBusBusType activation_bus_type = DBUS_BUS_STARTER;
96 static dbus_bool_t initialized = FALSE;
99 * Lock for globals in this file
101 _DBUS_DEFINE_GLOBAL_LOCK (bus);
104 * Global lock covering all BusData on any connection. The bet is
105 * that some lock contention is better than more memory
106 * for a per-connection lock, but it's tough to imagine it mattering
109 _DBUS_DEFINE_GLOBAL_LOCK (bus_datas);
112 addresses_shutdown_func (void *data)
117 while (i < N_BUS_TYPES)
119 if (bus_connections[i] != NULL)
120 _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");
122 dbus_free (bus_connection_addresses[i]);
123 bus_connection_addresses[i] = NULL;
127 activation_bus_type = DBUS_BUS_STARTER;
133 get_from_env (char **connection_p,
138 _dbus_assert (*connection_p == NULL);
140 s = _dbus_getenv (env_var);
141 if (s == NULL || *s == '\0')
142 return TRUE; /* successfully didn't use the env var */
145 *connection_p = _dbus_strdup (s);
146 return *connection_p != NULL;
151 init_session_address (void)
157 /* First, look in the environment. This is the normal case on
158 * freedesktop.org/Unix systems. */
159 get_from_env (&bus_connection_addresses[DBUS_BUS_SESSION],
160 "DBUS_SESSION_BUS_ADDRESS");
161 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
163 dbus_bool_t supported;
165 DBusError error = DBUS_ERROR_INIT;
167 if (!_dbus_string_init (&addr))
171 /* So it's not in the environment - let's try a platform-specific method.
172 * On MacOS, this involves asking launchd. On Windows (not specified yet)
173 * we might do a COM lookup.
174 * Ignore errors - if we failed, fall back to autolaunch. */
175 retval = _dbus_lookup_session_address (&supported, &addr, &error);
176 if (supported && retval)
178 retval =_dbus_string_steal_data (&addr, &bus_connection_addresses[DBUS_BUS_SESSION]);
180 else if (supported && !retval)
182 if (dbus_error_is_set(&error))
183 _dbus_warn ("Dynamic session lookup supported but failed: %s\n", error.message);
185 _dbus_warn ("Dynamic session lookup supported but failed silently\n");
187 _dbus_string_free (&addr);
195 /* The DBUS_SESSION_BUS_DEFAULT_ADDRESS should have really been named
196 * DBUS_SESSION_BUS_FALLBACK_ADDRESS.
198 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
199 bus_connection_addresses[DBUS_BUS_SESSION] =
200 _dbus_strdup (DBUS_SESSION_BUS_DEFAULT_ADDRESS);
201 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
208 init_connections_unlocked (void)
216 while (i < N_BUS_TYPES)
218 bus_connections[i] = NULL;
222 /* Don't init these twice, we may run this code twice if
223 * init_connections_unlocked() fails midway through.
224 * In practice, each block below should contain only one
225 * "return FALSE" or running through twice may not
229 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
231 _dbus_verbose ("Filling in system bus address...\n");
233 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_SYSTEM],
234 "DBUS_SYSTEM_BUS_ADDRESS"))
239 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
241 /* Use default system bus address if none set in environment */
242 bus_connection_addresses[DBUS_BUS_SYSTEM] =
243 _dbus_strdup (DBUS_SYSTEM_BUS_DEFAULT_ADDRESS);
245 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
248 _dbus_verbose (" used default system bus \"%s\"\n",
249 bus_connection_addresses[DBUS_BUS_SYSTEM]);
252 _dbus_verbose (" used env var system bus \"%s\"\n",
253 bus_connection_addresses[DBUS_BUS_SYSTEM]);
255 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
257 _dbus_verbose ("Filling in session bus address...\n");
259 if (!init_session_address ())
262 _dbus_verbose (" \"%s\"\n", bus_connection_addresses[DBUS_BUS_SESSION] ?
263 bus_connection_addresses[DBUS_BUS_SESSION] : "none set");
266 if (bus_connection_addresses[DBUS_BUS_STARTER] == NULL)
268 _dbus_verbose ("Filling in activation bus address...\n");
270 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_STARTER],
271 "DBUS_STARTER_ADDRESS"))
274 _dbus_verbose (" \"%s\"\n", bus_connection_addresses[DBUS_BUS_STARTER] ?
275 bus_connection_addresses[DBUS_BUS_STARTER] : "none set");
279 if (bus_connection_addresses[DBUS_BUS_STARTER] != NULL)
281 s = _dbus_getenv ("DBUS_STARTER_BUS_TYPE");
285 _dbus_verbose ("Bus activation type was set to \"%s\"\n", s);
287 if (strcmp (s, "system") == 0)
288 activation_bus_type = DBUS_BUS_SYSTEM;
289 else if (strcmp (s, "session") == 0)
290 activation_bus_type = DBUS_BUS_SESSION;
295 /* Default to the session bus instead if available */
296 if (bus_connection_addresses[DBUS_BUS_SESSION] != NULL)
298 bus_connection_addresses[DBUS_BUS_STARTER] =
299 _dbus_strdup (bus_connection_addresses[DBUS_BUS_SESSION]);
300 if (bus_connection_addresses[DBUS_BUS_STARTER] == NULL)
305 /* If we return FALSE we have to be sure that restarting
306 * the above code will work right
309 if (!_dbus_setenv ("DBUS_ACTIVATION_ADDRESS", NULL))
312 if (!_dbus_setenv ("DBUS_ACTIVATION_BUS_TYPE", NULL))
315 if (!_dbus_register_shutdown_func (addresses_shutdown_func,
326 bus_data_free (void *data)
330 if (bd->is_well_known)
334 /* We may be stored in more than one slot */
335 /* This should now be impossible - these slots are supposed to
336 * be cleared on disconnect, so should not need to be cleared on
340 while (i < N_BUS_TYPES)
342 if (bus_connections[i] == bd->connection)
343 bus_connections[i] = NULL;
350 dbus_free (bd->unique_name);
353 dbus_connection_free_data_slot (&bus_data_slot);
357 ensure_bus_data (DBusConnection *connection)
361 if (!dbus_connection_allocate_data_slot (&bus_data_slot))
364 bd = dbus_connection_get_data (connection, bus_data_slot);
367 bd = dbus_new0 (BusData, 1);
370 dbus_connection_free_data_slot (&bus_data_slot);
374 bd->connection = connection;
376 if (!dbus_connection_set_data (connection, bus_data_slot, bd,
380 dbus_connection_free_data_slot (&bus_data_slot);
384 /* Data slot refcount now held by the BusData */
388 dbus_connection_free_data_slot (&bus_data_slot);
395 * Internal function that checks to see if this
396 * is a shared connection owned by the bus and if it is unref it.
398 * @param connection a connection that has been disconnected.
401 _dbus_bus_notify_shared_connection_disconnected_unlocked (DBusConnection *connection)
407 /* We are expecting to have the connection saved in only one of these
408 * slots, but someone could in a pathological case set system and session
409 * bus to the same bus or something. Or set one of them to the starter
410 * bus without setting the starter bus type in the env variable.
411 * So we don't break the loop as soon as we find a match.
413 for (i = 0; i < N_BUS_TYPES; ++i)
415 if (bus_connections[i] == connection)
417 bus_connections[i] = NULL;
424 static DBusConnection *
425 internal_bus_get (DBusBusType type,
430 DBusConnection *connection;
432 DBusBusType address_type;
434 _dbus_return_val_if_fail (type >= 0 && type < N_BUS_TYPES, NULL);
435 _dbus_return_val_if_error_is_set (error, NULL);
439 if (!init_connections_unlocked ())
442 _DBUS_SET_OOM (error);
446 /* We want to use the activation address even if the
447 * activating bus is the session or system bus,
452 /* Use the real type of the activation bus for getting its
453 * connection, but only if the real type's address is available. (If
454 * the activating bus isn't a well-known bus then
455 * activation_bus_type == DBUS_BUS_STARTER)
457 if (type == DBUS_BUS_STARTER &&
458 bus_connection_addresses[activation_bus_type] != NULL)
459 type = activation_bus_type;
461 if (!private && bus_connections[type] != NULL)
463 connection = bus_connections[type];
464 dbus_connection_ref (connection);
470 address = bus_connection_addresses[address_type];
473 dbus_set_error (error, DBUS_ERROR_FAILED,
474 "Unable to determine the address of the message bus (try 'man dbus-launch' and 'man dbus-daemon' for help)");
480 connection = dbus_connection_open_private (address, error);
482 connection = dbus_connection_open (address, error);
486 _DBUS_ASSERT_ERROR_IS_SET (error);
491 if (!dbus_bus_register (connection, error))
493 _DBUS_ASSERT_ERROR_IS_SET (error);
494 _dbus_connection_close_possibly_shared (connection);
495 dbus_connection_unref (connection);
503 /* store a weak ref to the connection (dbus-connection.c is
504 * supposed to have a strong ref that it drops on disconnect,
505 * since this is a shared connection)
507 bus_connections[type] = connection;
510 /* By default we're bound to the lifecycle of
513 dbus_connection_set_exit_on_disconnect (connection,
516 _DBUS_LOCK (bus_datas);
517 bd = ensure_bus_data (connection);
518 _dbus_assert (bd != NULL); /* it should have been created on
519 register, so OOM not possible */
520 bd->is_well_known = TRUE;
521 _DBUS_UNLOCK (bus_datas);
526 /* Return a reference to the caller */
531 /** @} */ /* end of implementation details docs */
534 * @addtogroup DBusBus
539 * Connects to a bus daemon and registers the client with it. If a
540 * connection to the bus already exists, then that connection is
541 * returned. The caller of this function owns a reference to the bus.
543 * The caller may NOT call dbus_connection_close() on this connection;
544 * see dbus_connection_open() and dbus_connection_close() for details
547 * If this function obtains a new connection object never before
548 * returned from dbus_bus_get(), it will call
549 * dbus_connection_set_exit_on_disconnect(), so the application
550 * will exit if the connection closes. You can undo this
551 * by calling dbus_connection_set_exit_on_disconnect() yourself
552 * after you get the connection.
554 * dbus_bus_get() calls dbus_bus_register() for you.
556 * If returning a newly-created connection, this function will block
557 * until authentication and bus registration are complete.
559 * @param type bus type
560 * @param error address where an error can be returned.
561 * @returns a #DBusConnection with new ref
564 dbus_bus_get (DBusBusType type,
567 return internal_bus_get (type, FALSE, error);
571 * Connects to a bus daemon and registers the client with it as with
572 * dbus_bus_register(). Unlike dbus_bus_get(), always creates a new
573 * connection. This connection will not be saved or recycled by
574 * libdbus. Caller owns a reference to the bus and must either close
575 * it or know it to be closed prior to releasing this reference.
577 * See dbus_connection_open_private() for more details on when to
578 * close and unref this connection.
580 * This function calls
581 * dbus_connection_set_exit_on_disconnect() on the new connection, so the application
582 * will exit if the connection closes. You can undo this
583 * by calling dbus_connection_set_exit_on_disconnect() yourself
584 * after you get the connection.
586 * dbus_bus_get_private() calls dbus_bus_register() for you.
588 * This function will block until authentication and bus registration
591 * @param type bus type
592 * @param error address where an error can be returned.
593 * @returns a DBusConnection with new ref
596 dbus_bus_get_private (DBusBusType type,
599 return internal_bus_get (type, TRUE, error);
603 * Registers a connection with the bus. This must be the first
604 * thing an application does when connecting to the message bus.
605 * If registration succeeds, the unique name will be set,
606 * and can be obtained using dbus_bus_get_unique_name().
608 * This function will block until registration is complete.
610 * If the connection has already registered with the bus
611 * (determined by checking whether dbus_bus_get_unique_name()
612 * returns a non-#NULL value), then this function does nothing.
614 * If you use dbus_bus_get() or dbus_bus_get_private() this
615 * function will be called for you.
617 * @note Just use dbus_bus_get() or dbus_bus_get_private() instead of
618 * dbus_bus_register() and save yourself some pain. Using
619 * dbus_bus_register() manually is only useful if you have your
620 * own custom message bus not found in #DBusBusType.
622 * If you open a bus connection with dbus_connection_open() or
623 * dbus_connection_open_private() you will have to dbus_bus_register()
624 * yourself, or make the appropriate registration method calls
625 * yourself. If you send the method calls yourself, call
626 * dbus_bus_set_unique_name() with the unique bus name you get from
629 * For shared connections (created with dbus_connection_open()) in a
630 * multithreaded application, you can't really make the registration
631 * calls yourself, because you don't know whether some other thread is
632 * also registering, and the bus will kick you off if you send two
633 * registration messages.
635 * If you use dbus_bus_register() however, there is a lock that
636 * keeps both apps from registering at the same time.
638 * The rule in a multithreaded app, then, is that dbus_bus_register()
639 * must be used to register, or you need to have your own locks that
640 * all threads in the app will respect.
642 * In a single-threaded application you can register by hand instead
643 * of using dbus_bus_register(), as long as you check
644 * dbus_bus_get_unique_name() to see if a unique name has already been
645 * stored by another thread before you send the registration messages.
647 * @param connection the connection
648 * @param error place to store errors
649 * @returns #TRUE on success
652 dbus_bus_register (DBusConnection *connection,
655 DBusMessage *message, *reply;
660 _dbus_return_val_if_fail (connection != NULL, FALSE);
661 _dbus_return_val_if_error_is_set (error, FALSE);
667 _DBUS_LOCK (bus_datas);
669 bd = ensure_bus_data (connection);
672 _DBUS_SET_OOM (error);
676 if (bd->unique_name != NULL)
678 _dbus_verbose ("Ignoring attempt to register the same DBusConnection %s with the message bus a second time.\n",
685 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
692 _DBUS_SET_OOM (error);
696 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
700 else if (dbus_set_error_from_message (error, reply))
702 else if (!dbus_message_get_args (reply, error,
703 DBUS_TYPE_STRING, &name,
707 bd->unique_name = _dbus_strdup (name);
708 if (bd->unique_name == NULL)
710 _DBUS_SET_OOM (error);
717 _DBUS_UNLOCK (bus_datas);
720 dbus_message_unref (message);
723 dbus_message_unref (reply);
726 _DBUS_ASSERT_ERROR_IS_SET (error);
733 * Sets the unique name of the connection, as assigned by the message
734 * bus. Can only be used if you registered with the bus manually
735 * (i.e. if you did not call dbus_bus_register()). Can only be called
736 * once per connection. After the unique name is set, you can get it
737 * with dbus_bus_get_unique_name().
739 * The only reason to use this function is to re-implement the
740 * equivalent of dbus_bus_register() yourself. One (probably unusual)
741 * reason to do that might be to do the bus registration call
742 * asynchronously instead of synchronously.
744 * @note Just use dbus_bus_get() or dbus_bus_get_private(), or worst
745 * case dbus_bus_register(), instead of messing with this
746 * function. There's really no point creating pain for yourself by
747 * doing things manually.
749 * It's hard to use this function safely on shared connections
750 * (created by dbus_connection_open()) in a multithreaded application,
751 * because only one registration attempt can be sent to the bus. If
752 * two threads are both sending the registration message, there is no
753 * mechanism in libdbus itself to avoid sending it twice.
755 * Thus, you need a way to coordinate which thread sends the
756 * registration attempt; which also means you know which thread
757 * will call dbus_bus_set_unique_name(). If you don't know
758 * about all threads in the app (for example, if some libraries
759 * you're using might start libdbus-using threads), then you
760 * need to avoid using this function on shared connections.
762 * @param connection the connection
763 * @param unique_name the unique name
764 * @returns #FALSE if not enough memory
767 dbus_bus_set_unique_name (DBusConnection *connection,
768 const char *unique_name)
771 dbus_bool_t success = FALSE;
773 _dbus_return_val_if_fail (connection != NULL, FALSE);
774 _dbus_return_val_if_fail (unique_name != NULL, FALSE);
776 _DBUS_LOCK (bus_datas);
778 bd = ensure_bus_data (connection);
782 _dbus_assert (bd->unique_name == NULL);
784 bd->unique_name = _dbus_strdup (unique_name);
785 success = bd->unique_name != NULL;
788 _DBUS_UNLOCK (bus_datas);
794 * Gets the unique name of the connection as assigned by the message
795 * bus. Only possible after the connection has been registered with
796 * the message bus. All connections returned by dbus_bus_get() or
797 * dbus_bus_get_private() have been successfully registered.
799 * The name remains valid until the connection is freed, and
800 * should not be freed by the caller.
802 * Other than dbus_bus_get(), there are two ways to set the unique
803 * name; one is dbus_bus_register(), the other is
804 * dbus_bus_set_unique_name(). You are responsible for calling
805 * dbus_bus_set_unique_name() if you register by hand instead of using
806 * dbus_bus_register().
808 * @param connection the connection
809 * @returns the unique name or #NULL on error
812 dbus_bus_get_unique_name (DBusConnection *connection)
815 const char *unique_name = NULL;
817 _dbus_return_val_if_fail (connection != NULL, NULL);
819 _DBUS_LOCK (bus_datas);
821 bd = ensure_bus_data (connection);
825 unique_name = bd->unique_name;
828 _DBUS_UNLOCK (bus_datas);
834 * Asks the bus to return the UID the named connection authenticated
835 * as, if any. Only works on UNIX; only works for connections on the
836 * same machine as the bus. If you are not on the same machine as the
837 * bus, then calling this is probably a bad idea, since the UID will
838 * mean little to your application.
840 * For the system message bus you're guaranteed to be on the same
841 * machine since it only listens on a UNIX domain socket (at least,
842 * as shipped by default).
844 * This function only works for connections that authenticated as
845 * a UNIX user, right now that includes all bus connections, but
846 * it's very possible to have connections with no associated UID.
847 * So check for errors and do something sensible if they happen.
849 * This function will always return an error on Windows.
851 * @param connection the connection
852 * @param name a name owned by the connection
853 * @param error location to store the error
854 * @returns the unix user id, or ((unsigned)-1) if error is set
857 dbus_bus_get_unix_user (DBusConnection *connection,
861 DBusMessage *message, *reply;
864 _dbus_return_val_if_fail (connection != NULL, DBUS_UID_UNSET);
865 _dbus_return_val_if_fail (name != NULL, DBUS_UID_UNSET);
866 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), DBUS_UID_UNSET);
867 _dbus_return_val_if_error_is_set (error, DBUS_UID_UNSET);
869 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
872 "GetConnectionUnixUser");
876 _DBUS_SET_OOM (error);
877 return DBUS_UID_UNSET;
880 if (!dbus_message_append_args (message,
881 DBUS_TYPE_STRING, &name,
884 dbus_message_unref (message);
885 _DBUS_SET_OOM (error);
886 return DBUS_UID_UNSET;
889 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
892 dbus_message_unref (message);
896 _DBUS_ASSERT_ERROR_IS_SET (error);
897 return DBUS_UID_UNSET;
900 if (dbus_set_error_from_message (error, reply))
902 _DBUS_ASSERT_ERROR_IS_SET (error);
903 dbus_message_unref (reply);
904 return DBUS_UID_UNSET;
907 if (!dbus_message_get_args (reply, error,
908 DBUS_TYPE_UINT32, &uid,
911 _DBUS_ASSERT_ERROR_IS_SET (error);
912 dbus_message_unref (reply);
913 return DBUS_UID_UNSET;
916 dbus_message_unref (reply);
918 return (unsigned long) uid;
922 * Asks the bus to return its globally unique ID, as described in the
923 * D-Bus specification. For the session bus, this is useful as a way
924 * to uniquely identify each user session. For the system bus,
925 * probably the bus ID is not useful; instead, use the machine ID
926 * since it's accessible without necessarily connecting to the bus and
927 * may be persistent beyond a single bus instance (across reboots for
928 * example). See dbus_get_local_machine_id().
930 * In addition to an ID for each bus and an ID for each machine, there is
931 * an ID for each address that the bus is listening on; that can
932 * be retrieved with dbus_connection_get_server_id(), though it is
933 * probably not very useful.
935 * @param connection the connection
936 * @param error location to store the error
937 * @returns the bus ID or #NULL if error is set
940 dbus_bus_get_id (DBusConnection *connection,
943 DBusMessage *message, *reply;
945 const char *v_STRING;
947 _dbus_return_val_if_fail (connection != NULL, NULL);
948 _dbus_return_val_if_error_is_set (error, NULL);
950 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
957 _DBUS_SET_OOM (error);
961 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
964 dbus_message_unref (message);
968 _DBUS_ASSERT_ERROR_IS_SET (error);
972 if (dbus_set_error_from_message (error, reply))
974 _DBUS_ASSERT_ERROR_IS_SET (error);
975 dbus_message_unref (reply);
980 if (!dbus_message_get_args (reply, error,
981 DBUS_TYPE_STRING, &v_STRING,
984 _DBUS_ASSERT_ERROR_IS_SET (error);
985 dbus_message_unref (reply);
989 id = _dbus_strdup (v_STRING); /* may be NULL */
991 dbus_message_unref (reply);
994 _DBUS_SET_OOM (error);
996 /* FIXME it might be nice to cache the ID locally */
1002 * Asks the bus to assign the given name to this connection by invoking
1003 * the RequestName method on the bus. This method is fully documented
1004 * in the D-Bus specification. For quick reference, the flags and
1005 * result codes are discussed here, but the specification is the
1006 * canonical version of this information.
1008 * First you should know that for each bus name, the bus stores
1009 * a queue of connections that would like to own it. Only
1010 * one owns it at a time - called the primary owner. If the primary
1011 * owner releases the name or disconnects, then the next owner in the
1012 * queue atomically takes over.
1014 * So for example if you have an application org.freedesktop.TextEditor
1015 * and multiple instances of it can be run, you can have all of them
1016 * sitting in the queue. The first one to start up will receive messages
1017 * sent to org.freedesktop.TextEditor, but if that one exits another
1018 * will become the primary owner and receive messages.
1020 * The queue means you don't need to manually watch for the current owner to
1021 * disappear and then request the name again.
1023 * When requesting a name, you can specify several flags.
1025 * #DBUS_NAME_FLAG_ALLOW_REPLACEMENT and #DBUS_NAME_FLAG_DO_NOT_QUEUE
1026 * are properties stored by the bus for this connection with respect to
1027 * each requested bus name. These properties are stored even if the
1028 * connection is queued and does not become the primary owner.
1029 * You can update these flags by calling RequestName again (even if
1030 * you already own the name).
1032 * #DBUS_NAME_FLAG_ALLOW_REPLACEMENT means that another requestor of the
1033 * name can take it away from you by specifying #DBUS_NAME_FLAG_REPLACE_EXISTING.
1035 * #DBUS_NAME_FLAG_DO_NOT_QUEUE means that if you aren't the primary owner,
1036 * you don't want to be queued up - you only care about being the
1039 * Unlike the other two flags, #DBUS_NAME_FLAG_REPLACE_EXISTING is a property
1040 * of the individual RequestName call, i.e. the bus does not persistently
1041 * associate it with the connection-name pair. If a RequestName call includes
1042 * the #DBUS_NAME_FLAG_REPLACE_EXISTING flag, and the current primary
1043 * owner has #DBUS_NAME_FLAG_ALLOW_REPLACEMENT set, then the current primary
1044 * owner will be kicked off.
1046 * If no flags are given, an application will receive the requested
1047 * name only if the name is currently unowned; and it will NOT give
1048 * up the name if another application asks to take it over using
1049 * #DBUS_NAME_FLAG_REPLACE_EXISTING.
1051 * This function returns a result code. The possible result codes
1054 * #DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER means that the name had no
1055 * existing owner, and the caller is now the primary owner; or that
1056 * the name had an owner, and the caller specified
1057 * #DBUS_NAME_FLAG_REPLACE_EXISTING, and the current owner
1058 * specified #DBUS_NAME_FLAG_ALLOW_REPLACEMENT.
1060 * #DBUS_REQUEST_NAME_REPLY_IN_QUEUE happens only if the caller does NOT
1061 * specify #DBUS_NAME_FLAG_DO_NOT_QUEUE and either the current owner
1062 * did NOT specify #DBUS_NAME_FLAG_ALLOW_REPLACEMENT or the caller did NOT
1063 * specify #DBUS_NAME_FLAG_REPLACE_EXISTING. In this case the caller ends up
1064 * in a queue to own the name after the current owner gives it up.
1066 * #DBUS_REQUEST_NAME_REPLY_EXISTS happens if the name has an owner
1067 * already and the caller specifies #DBUS_NAME_FLAG_DO_NOT_QUEUE
1068 * and either the current owner has NOT specified
1069 * #DBUS_NAME_FLAG_ALLOW_REPLACEMENT or the caller did NOT specify
1070 * #DBUS_NAME_FLAG_REPLACE_EXISTING.
1072 * #DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER happens if an application
1073 * requests a name it already owns. (Re-requesting a name is useful if
1074 * you want to change the #DBUS_NAME_FLAG_ALLOW_REPLACEMENT or
1075 * #DBUS_NAME_FLAG_DO_NOT_QUEUE settings.)
1077 * When a service represents an application, say "text editor," then
1078 * it should specify #DBUS_NAME_FLAG_ALLOW_REPLACEMENT if it wants
1079 * the last editor started to be the user's editor vs. the first one
1080 * started. Then any editor that can be the user's editor should
1081 * specify #DBUS_NAME_FLAG_REPLACE_EXISTING to either take over
1082 * (last-started-wins) or be queued up (first-started-wins) according
1083 * to whether #DBUS_NAME_FLAG_ALLOW_REPLACEMENT was given.
1085 * Conventionally, single-instance applications often offer a command
1086 * line option called --replace which means to replace the current
1087 * instance. To implement this, always set
1088 * #DBUS_NAME_FLAG_ALLOW_REPLACEMENT when you request your
1089 * application's bus name. When you lose ownership of your bus name,
1090 * you need to exit. Look for the signal "NameLost" from
1091 * #DBUS_SERVICE_DBUS and #DBUS_INTERFACE_DBUS (the signal's first
1092 * argument is the bus name that was lost). If starting up without
1093 * --replace, do not specify #DBUS_NAME_FLAG_REPLACE_EXISTING, and
1094 * exit if you fail to become the bus name owner. If --replace is
1095 * given, ask to replace the old owner.
1097 * @param connection the connection
1098 * @param name the name to request
1099 * @param flags flags
1100 * @param error location to store the error
1101 * @returns a result code, -1 if error is set
1104 dbus_bus_request_name (DBusConnection *connection,
1109 DBusMessage *message, *reply;
1110 dbus_uint32_t result;
1112 _dbus_return_val_if_fail (connection != NULL, 0);
1113 _dbus_return_val_if_fail (name != NULL, 0);
1114 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), 0);
1115 _dbus_return_val_if_error_is_set (error, 0);
1117 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1119 DBUS_INTERFACE_DBUS,
1122 if (message == NULL)
1124 _DBUS_SET_OOM (error);
1128 if (!dbus_message_append_args (message,
1129 DBUS_TYPE_STRING, &name,
1130 DBUS_TYPE_UINT32, &flags,
1133 dbus_message_unref (message);
1134 _DBUS_SET_OOM (error);
1138 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
1141 dbus_message_unref (message);
1145 _DBUS_ASSERT_ERROR_IS_SET (error);
1149 if (dbus_set_error_from_message (error, reply))
1151 _DBUS_ASSERT_ERROR_IS_SET (error);
1152 dbus_message_unref (reply);
1156 if (!dbus_message_get_args (reply, error,
1157 DBUS_TYPE_UINT32, &result,
1160 _DBUS_ASSERT_ERROR_IS_SET (error);
1161 dbus_message_unref (reply);
1165 dbus_message_unref (reply);
1172 * Asks the bus to unassign the given name from this connection by
1173 * invoking the ReleaseName method on the bus. The "ReleaseName"
1174 * method is canonically documented in the D-Bus specification.
1176 * Possible results are: #DBUS_RELEASE_NAME_REPLY_RELEASED
1177 * which means you owned the name or were in the queue to own it,
1178 * and and now you don't own it and aren't in the queue.
1179 * #DBUS_RELEASE_NAME_REPLY_NOT_OWNER which means someone else
1180 * owns the name so you can't release it.
1181 * #DBUS_RELEASE_NAME_REPLY_NON_EXISTENT
1182 * which means nobody owned the name.
1184 * @param connection the connection
1185 * @param name the name to remove
1186 * @param error location to store the error
1187 * @returns a result code, -1 if error is set
1190 dbus_bus_release_name (DBusConnection *connection,
1194 DBusMessage *message, *reply;
1195 dbus_uint32_t result;
1197 _dbus_return_val_if_fail (connection != NULL, 0);
1198 _dbus_return_val_if_fail (name != NULL, 0);
1199 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), 0);
1200 _dbus_return_val_if_error_is_set (error, 0);
1202 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1204 DBUS_INTERFACE_DBUS,
1207 if (message == NULL)
1209 _DBUS_SET_OOM (error);
1213 if (!dbus_message_append_args (message,
1214 DBUS_TYPE_STRING, &name,
1217 dbus_message_unref (message);
1218 _DBUS_SET_OOM (error);
1222 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
1225 dbus_message_unref (message);
1229 _DBUS_ASSERT_ERROR_IS_SET (error);
1233 if (dbus_set_error_from_message (error, reply))
1235 _DBUS_ASSERT_ERROR_IS_SET (error);
1236 dbus_message_unref (reply);
1240 if (!dbus_message_get_args (reply, error,
1241 DBUS_TYPE_UINT32, &result,
1244 _DBUS_ASSERT_ERROR_IS_SET (error);
1245 dbus_message_unref (reply);
1249 dbus_message_unref (reply);
1255 * Asks the bus whether a certain name has an owner.
1257 * Using this can easily result in a race condition,
1258 * since an owner can appear or disappear after you
1261 * If you want to request a name, just request it;
1262 * if you want to avoid replacing a current owner,
1263 * don't specify #DBUS_NAME_FLAG_REPLACE_EXISTING and
1264 * you will get an error if there's already an owner.
1266 * @param connection the connection
1267 * @param name the name
1268 * @param error location to store any errors
1269 * @returns #TRUE if the name exists, #FALSE if not or on error
1272 dbus_bus_name_has_owner (DBusConnection *connection,
1276 DBusMessage *message, *reply;
1279 _dbus_return_val_if_fail (connection != NULL, FALSE);
1280 _dbus_return_val_if_fail (name != NULL, FALSE);
1281 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), FALSE);
1282 _dbus_return_val_if_error_is_set (error, FALSE);
1284 message = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1286 DBUS_INTERFACE_DBUS,
1288 if (message == NULL)
1290 _DBUS_SET_OOM (error);
1294 if (!dbus_message_append_args (message,
1295 DBUS_TYPE_STRING, &name,
1298 dbus_message_unref (message);
1299 _DBUS_SET_OOM (error);
1303 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
1304 dbus_message_unref (message);
1308 _DBUS_ASSERT_ERROR_IS_SET (error);
1312 if (!dbus_message_get_args (reply, error,
1313 DBUS_TYPE_BOOLEAN, &exists,
1316 _DBUS_ASSERT_ERROR_IS_SET (error);
1317 dbus_message_unref (reply);
1321 dbus_message_unref (reply);
1326 * Starts a service that will request ownership of the given name.
1327 * The returned result will be one of be one of
1328 * #DBUS_START_REPLY_SUCCESS or #DBUS_START_REPLY_ALREADY_RUNNING if
1329 * successful. Pass #NULL if you don't care about the result.
1331 * The flags parameter is for future expansion, currently you should
1334 * It's often easier to avoid explicitly starting services, and
1335 * just send a method call to the service's bus name instead.
1336 * Method calls start a service to handle them by default
1337 * unless you call dbus_message_set_auto_start() to disable this
1340 * @param connection the connection
1341 * @param name the name we want the new service to request
1342 * @param flags the flags (should always be 0 for now)
1343 * @param result a place to store the result or #NULL
1344 * @param error location to store any errors
1345 * @returns #TRUE if the activation succeeded, #FALSE if not
1348 dbus_bus_start_service_by_name (DBusConnection *connection,
1350 dbus_uint32_t flags,
1351 dbus_uint32_t *result,
1357 _dbus_return_val_if_fail (connection != NULL, FALSE);
1358 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), FALSE);
1360 msg = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1362 DBUS_INTERFACE_DBUS,
1363 "StartServiceByName");
1365 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, &name,
1366 DBUS_TYPE_UINT32, &flags, DBUS_TYPE_INVALID))
1368 dbus_message_unref (msg);
1369 _DBUS_SET_OOM (error);
1373 reply = dbus_connection_send_with_reply_and_block (connection, msg,
1375 dbus_message_unref (msg);
1379 _DBUS_ASSERT_ERROR_IS_SET (error);
1383 if (dbus_set_error_from_message (error, reply))
1385 _DBUS_ASSERT_ERROR_IS_SET (error);
1386 dbus_message_unref (reply);
1390 if (result != NULL &&
1391 !dbus_message_get_args (reply, error, DBUS_TYPE_UINT32,
1392 result, DBUS_TYPE_INVALID))
1394 _DBUS_ASSERT_ERROR_IS_SET (error);
1395 dbus_message_unref (reply);
1399 dbus_message_unref (reply);
1404 send_no_return_values (DBusConnection *connection,
1410 /* Block to check success codepath */
1413 reply = dbus_connection_send_with_reply_and_block (connection, msg,
1417 _DBUS_ASSERT_ERROR_IS_SET (error);
1419 dbus_message_unref (reply);
1423 /* Silently-fail nonblocking codepath */
1424 dbus_message_set_no_reply (msg, TRUE);
1425 dbus_connection_send (connection, msg, NULL);
1430 * Adds a match rule to match messages going through the message bus.
1431 * The "rule" argument is the string form of a match rule.
1433 * If you pass #NULL for the error, this function will not
1434 * block; the match thus won't be added until you flush the
1435 * connection, and if there's an error adding the match
1436 * you won't find out about it. This is generally acceptable, since the
1437 * possible errors (including a lack of resources in the bus, the connection
1438 * having exceeded its quota of active match rules, or the match rule being
1439 * unparseable) are generally unrecoverable.
1441 * If you pass non-#NULL for the error this function will
1442 * block until it gets a reply. This may be useful when using match rule keys
1443 * introduced in recent versions of D-Bus, like 'arg0namespace', to allow the
1444 * application to fall back to less efficient match rules supported by older
1445 * versions of the daemon if the running version is not new enough; or when
1446 * using user-supplied rules rather than rules hard-coded at compile time.
1448 * Normal API conventions would have the function return
1449 * a boolean value indicating whether the error was set,
1450 * but that would require blocking always to determine
1453 * The AddMatch method is fully documented in the D-Bus
1454 * specification. For quick reference, the format of the
1455 * match rules is discussed here, but the specification
1456 * is the canonical version of this information.
1458 * Rules are specified as a string of comma separated
1459 * key/value pairs. An example is
1460 * "type='signal',sender='org.freedesktop.DBus',
1461 * interface='org.freedesktop.DBus',member='Foo',
1462 * path='/bar/foo',destination=':452345.34'"
1464 * Possible keys you can match on are type, sender,
1465 * interface, member, path, destination and numbered
1466 * keys to match message args (keys are 'arg0', 'arg1', etc.).
1467 * Omitting a key from the rule indicates
1468 * a wildcard match. For instance omitting
1469 * the member from a match rule but adding a sender would
1470 * let all messages from that sender through regardless of
1473 * Matches are inclusive not exclusive so as long as one
1474 * rule matches the message will get through. It is important
1475 * to note this because every time a message is received the
1476 * application will be paged into memory to process it. This
1477 * can cause performance problems such as draining batteries
1478 * on embedded platforms.
1480 * If you match message args ('arg0', 'arg1', and so forth)
1481 * only string arguments will match. That is, arg0='5' means
1482 * match the string "5" not the integer 5.
1484 * Currently there is no way to match against non-string arguments.
1486 * A specialised form of wildcard matching on arguments is
1487 * supported for path-like namespaces. If your argument match has
1488 * a 'path' suffix (eg: "arg0path='/some/path/'") then it is
1489 * considered a match if the argument exactly matches the given
1490 * string or if one of them ends in a '/' and is a prefix of the
1493 * Matching on interface is tricky because method call
1494 * messages only optionally specify the interface.
1495 * If a message omits the interface, then it will NOT match
1496 * if the rule specifies an interface name. This means match
1497 * rules on method calls should not usually give an interface.
1499 * However, signal messages are required to include the interface
1500 * so when matching signals usually you should specify the interface
1501 * in the match rule.
1503 * For security reasons, you can match arguments only up to
1504 * #DBUS_MAXIMUM_MATCH_RULE_ARG_NUMBER.
1506 * Match rules have a maximum length of #DBUS_MAXIMUM_MATCH_RULE_LENGTH
1509 * Both of these maximums are much higher than you're likely to need,
1510 * they only exist because the D-Bus bus daemon has fixed limits on
1511 * all resource usage.
1513 * @param connection connection to the message bus
1514 * @param rule textual form of match rule
1515 * @param error location to store any errors
1518 dbus_bus_add_match (DBusConnection *connection,
1524 _dbus_return_if_fail (rule != NULL);
1526 msg = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1528 DBUS_INTERFACE_DBUS,
1533 _DBUS_SET_OOM (error);
1537 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, &rule,
1540 dbus_message_unref (msg);
1541 _DBUS_SET_OOM (error);
1545 send_no_return_values (connection, msg, error);
1547 dbus_message_unref (msg);
1551 * Removes a previously-added match rule "by value" (the most
1552 * recently-added identical rule gets removed). The "rule" argument
1553 * is the string form of a match rule.
1555 * The bus compares match rules semantically, not textually, so
1556 * whitespace and ordering don't have to be identical to
1557 * the rule you passed to dbus_bus_add_match().
1559 * If you pass #NULL for the error, this function will not
1560 * block; otherwise it will. See detailed explanation in
1561 * docs for dbus_bus_add_match().
1563 * @param connection connection to the message bus
1564 * @param rule textual form of match rule
1565 * @param error location to store any errors
1568 dbus_bus_remove_match (DBusConnection *connection,
1574 _dbus_return_if_fail (rule != NULL);
1576 msg = dbus_message_new_method_call (DBUS_SERVICE_DBUS,
1578 DBUS_INTERFACE_DBUS,
1581 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, &rule,
1584 dbus_message_unref (msg);
1585 _DBUS_SET_OOM (error);
1589 send_no_return_values (connection, msg, error);
1591 dbus_message_unref (msg);