1 /* -*- mode: C; c-file-style: "gnu" -*- */
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 #include "dbus-protocol.h"
27 #include "dbus-internals.h"
28 #include "dbus-message.h"
32 * @defgroup DBusBus Message bus APIs
34 * @brief Functions for communicating with the message bus
36 * @todo right now the default address of the system bus is hardcoded,
37 * so if you change it in the global config file suddenly you have to
38 * set DBUS_SYSTEM_BUS_ADDRESS env variable. Might be nice if the
39 * client lib somehow read the config file, or if the bus on startup
40 * somehow wrote out its address to a well-known spot, but might also
45 * @defgroup DBusBusInternals Message bus APIs internals
46 * @ingroup DBusInternals
47 * @brief Internals of functions for communicating with the message bus
53 * Block of message-bus-related data we attach to each
54 * #DBusConnection used with these convenience functions.
57 * @todo get rid of most of these; they should be done
58 * with DBusGProxy and the Qt equivalent, i.e. the same
59 * way any other interface would be used.
63 DBusConnection *connection; /**< Connection we're associated with */
64 char *unique_name; /**< Unique name of this connection */
66 unsigned int is_well_known : 1; /**< Is one of the well-known connections in our global array */
69 /** The slot we have reserved to store BusData.
71 static dbus_int32_t bus_data_slot = -1;
73 /** Number of bus types */
76 static DBusConnection *bus_connections[N_BUS_TYPES];
77 static char *bus_connection_addresses[N_BUS_TYPES] = { NULL, NULL, NULL };
79 static DBusBusType activation_bus_type = DBUS_BUS_STARTER;
81 static dbus_bool_t initialized = FALSE;
84 * Lock for globals in this file
86 _DBUS_DEFINE_GLOBAL_LOCK (bus);
89 addresses_shutdown_func (void *data)
94 while (i < N_BUS_TYPES)
96 if (bus_connections[i] != NULL)
97 _dbus_warn ("dbus_shutdown() called but connections were still live!");
99 dbus_free (bus_connection_addresses[i]);
100 bus_connection_addresses[i] = NULL;
104 activation_bus_type = DBUS_BUS_STARTER;
108 get_from_env (char **connection_p,
113 _dbus_assert (*connection_p == NULL);
115 s = _dbus_getenv (env_var);
116 if (s == NULL || *s == '\0')
117 return TRUE; /* successfully didn't use the env var */
120 *connection_p = _dbus_strdup (s);
121 return *connection_p != NULL;
126 init_connections_unlocked (void)
134 while (i < N_BUS_TYPES)
136 bus_connections[i] = NULL;
140 /* Don't init these twice, we may run this code twice if
141 * init_connections_unlocked() fails midway through.
142 * In practice, each block below should contain only one
143 * "return FALSE" or running through twice may not
147 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
149 _dbus_verbose ("Filling in system bus address...\n");
151 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_SYSTEM],
152 "DBUS_SYSTEM_BUS_ADDRESS"))
157 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
159 /* Use default system bus address if none set in environment */
160 bus_connection_addresses[DBUS_BUS_SYSTEM] =
161 _dbus_strdup (DBUS_SYSTEM_BUS_DEFAULT_ADDRESS);
162 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
165 _dbus_verbose (" used default system bus \"%s\"\n",
166 bus_connection_addresses[DBUS_BUS_SYSTEM]);
169 _dbus_verbose (" used env var system bus \"%s\"\n",
170 bus_connection_addresses[DBUS_BUS_SYSTEM]);
172 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
174 _dbus_verbose ("Filling in session bus address...\n");
176 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_SESSION],
177 "DBUS_SESSION_BUS_ADDRESS"))
179 _dbus_verbose (" \"%s\"\n", bus_connection_addresses[DBUS_BUS_SESSION] ?
180 bus_connection_addresses[DBUS_BUS_SESSION] : "none set");
183 if (bus_connection_addresses[DBUS_BUS_STARTER] == NULL)
185 _dbus_verbose ("Filling in activation bus address...\n");
187 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_STARTER],
188 "DBUS_STARTER_ADDRESS"))
191 _dbus_verbose (" \"%s\"\n", bus_connection_addresses[DBUS_BUS_STARTER] ?
192 bus_connection_addresses[DBUS_BUS_STARTER] : "none set");
196 if (bus_connection_addresses[DBUS_BUS_STARTER] != NULL)
198 s = _dbus_getenv ("DBUS_STARTER_BUS_TYPE");
202 _dbus_verbose ("Bus activation type was set to \"%s\"\n", s);
204 if (strcmp (s, "system") == 0)
205 activation_bus_type = DBUS_BUS_SYSTEM;
206 else if (strcmp (s, "session") == 0)
207 activation_bus_type = DBUS_BUS_SESSION;
212 /* Default to the session bus instead if available */
213 if (bus_connection_addresses[DBUS_BUS_SESSION] != NULL)
215 bus_connection_addresses[DBUS_BUS_STARTER] =
216 _dbus_strdup (bus_connection_addresses[DBUS_BUS_SESSION]);
217 if (bus_connection_addresses[DBUS_BUS_STARTER] == NULL)
222 /* If we return FALSE we have to be sure that restarting
223 * the above code will work right
226 if (!_dbus_setenv ("DBUS_ACTIVATION_ADDRESS", NULL))
229 if (!_dbus_setenv ("DBUS_ACTIVATION_BUS_TYPE", NULL))
232 if (!_dbus_register_shutdown_func (addresses_shutdown_func,
243 bus_data_free (void *data)
247 if (bd->is_well_known)
251 /* We may be stored in more than one slot */
253 while (i < N_BUS_TYPES)
255 if (bus_connections[i] == bd->connection)
256 bus_connections[i] = NULL;
263 dbus_free (bd->unique_name);
266 dbus_connection_free_data_slot (&bus_data_slot);
270 ensure_bus_data (DBusConnection *connection)
274 if (!dbus_connection_allocate_data_slot (&bus_data_slot))
277 bd = dbus_connection_get_data (connection, bus_data_slot);
280 bd = dbus_new0 (BusData, 1);
283 dbus_connection_free_data_slot (&bus_data_slot);
287 bd->connection = connection;
289 if (!dbus_connection_set_data (connection, bus_data_slot, bd,
293 dbus_connection_free_data_slot (&bus_data_slot);
297 /* Data slot refcount now held by the BusData */
301 dbus_connection_free_data_slot (&bus_data_slot);
307 /** @} */ /* end of implementation details docs */
310 * @addtogroup DBusBus
315 * Connects to a bus daemon and registers the client with it. If a
316 * connection to the bus already exists, then that connection is
317 * returned. Caller owns a reference to the bus.
319 * @todo alex thinks we should nullify the connection when we get a disconnect-message.
321 * @param type bus type
322 * @param error address where an error can be returned.
323 * @returns a DBusConnection with new ref
326 dbus_bus_get (DBusBusType type,
330 DBusConnection *connection;
332 DBusBusType address_type;
334 _dbus_return_val_if_fail (type >= 0 && type < N_BUS_TYPES, NULL);
335 _dbus_return_val_if_error_is_set (error, NULL);
339 if (!init_connections_unlocked ())
342 _DBUS_SET_OOM (error);
346 /* We want to use the activation address even if the
347 * activating bus is the session or system bus,
352 /* Use the real type of the activation bus for getting its
353 * connection, but only if the real type's address is available. (If
354 * the activating bus isn't a well-known bus then
355 * activation_bus_type == DBUS_BUS_STARTER)
357 if (type == DBUS_BUS_STARTER &&
358 bus_connection_addresses[activation_bus_type] != NULL)
359 type = activation_bus_type;
361 if (bus_connections[type] != NULL)
363 connection = bus_connections[type];
364 dbus_connection_ref (connection);
370 address = bus_connection_addresses[address_type];
373 dbus_set_error (error, DBUS_ERROR_FAILED,
374 "Unable to determine the address of the message bus");
379 connection = dbus_connection_open (address, error);
383 _DBUS_ASSERT_ERROR_IS_SET (error);
388 /* By default we're bound to the lifecycle of
391 dbus_connection_set_exit_on_disconnect (connection,
394 if (!dbus_bus_register (connection, error))
396 _DBUS_ASSERT_ERROR_IS_SET (error);
397 dbus_connection_disconnect (connection);
398 dbus_connection_unref (connection);
404 bus_connections[type] = connection;
405 bd = ensure_bus_data (connection);
406 _dbus_assert (bd != NULL);
408 bd->is_well_known = TRUE;
416 * Registers a connection with the bus. This must be the first
417 * thing an application does when connecting to the message bus.
418 * If registration succeeds, the unique name will be set,
419 * and can be obtained using dbus_bus_get_unique_name().
421 * @param connection the connection
422 * @param error place to store errors
423 * @returns #TRUE on success
426 dbus_bus_register (DBusConnection *connection,
429 DBusMessage *message, *reply;
434 _dbus_return_val_if_fail (connection != NULL, FALSE);
435 _dbus_return_val_if_error_is_set (error, FALSE);
439 bd = ensure_bus_data (connection);
442 _DBUS_SET_OOM (error);
446 if (bd->unique_name != NULL)
448 _dbus_warn ("Attempt to register the same DBusConnection with the message bus, but it is already registered\n");
449 /* This isn't an error, it's a programming bug. We'll be nice
450 * and not _dbus_assert_not_reached()
455 message = dbus_message_new_method_call (DBUS_SERVICE_ORG_FREEDESKTOP_DBUS,
456 DBUS_PATH_ORG_FREEDESKTOP_DBUS,
457 DBUS_INTERFACE_ORG_FREEDESKTOP_DBUS,
462 _DBUS_SET_OOM (error);
466 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
468 dbus_message_unref (message);
472 else if (dbus_set_error_from_message (error, reply))
474 else if (!dbus_message_get_args (reply, error,
475 DBUS_TYPE_STRING, &name,
479 bd->unique_name = _dbus_strdup (name);
480 if (bd->unique_name == NULL)
482 _DBUS_SET_OOM (error);
490 dbus_message_unref (reply);
493 _DBUS_ASSERT_ERROR_IS_SET (error);
500 * Sets the unique name of the connection. Can only be used if you
501 * registered with the bus manually (i.e. if you did not call
502 * dbus_bus_register()). Can only be called once per connection.
504 * @param connection the connection
505 * @param unique_name the unique name
506 * @returns #FALSE if not enough memory
509 dbus_bus_set_unique_name (DBusConnection *connection,
510 const char *unique_name)
514 _dbus_return_val_if_fail (connection != NULL, FALSE);
515 _dbus_return_val_if_fail (unique_name != NULL, FALSE);
517 bd = ensure_bus_data (connection);
521 _dbus_assert (bd->unique_name == NULL);
523 bd->unique_name = _dbus_strdup (unique_name);
524 return bd->unique_name != NULL;
528 * Gets the unique name of the connection. Only possible after the
529 * connection has been registered with the message bus.
531 * @param connection the connection
532 * @returns the unique name
535 dbus_bus_get_unique_name (DBusConnection *connection)
539 _dbus_return_val_if_fail (connection != NULL, NULL);
541 bd = ensure_bus_data (connection);
545 return bd->unique_name;
549 * Asks the bus to return the uid of the named
552 * @param connection the connection
553 * @param name a name owned by the connection
554 * @param error location to store the error
555 * @returns a result code, -1 if error is set
558 dbus_bus_get_unix_user (DBusConnection *connection,
562 DBusMessage *message, *reply;
565 _dbus_return_val_if_fail (connection != NULL, DBUS_UID_UNSET);
566 _dbus_return_val_if_fail (name != NULL, DBUS_UID_UNSET);
567 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), DBUS_UID_UNSET);
568 _dbus_return_val_if_error_is_set (error, DBUS_UID_UNSET);
570 message = dbus_message_new_method_call (DBUS_SERVICE_ORG_FREEDESKTOP_DBUS,
571 DBUS_PATH_ORG_FREEDESKTOP_DBUS,
572 DBUS_INTERFACE_ORG_FREEDESKTOP_DBUS,
573 "GetConnectionUnixUser");
577 _DBUS_SET_OOM (error);
578 return DBUS_UID_UNSET;
581 if (!dbus_message_append_args (message,
582 DBUS_TYPE_STRING, &name,
585 dbus_message_unref (message);
586 _DBUS_SET_OOM (error);
587 return DBUS_UID_UNSET;
590 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
593 dbus_message_unref (message);
597 _DBUS_ASSERT_ERROR_IS_SET (error);
598 return DBUS_UID_UNSET;
601 if (dbus_set_error_from_message (error, reply))
603 _DBUS_ASSERT_ERROR_IS_SET (error);
604 dbus_message_unref (reply);
605 return DBUS_UID_UNSET;
608 if (!dbus_message_get_args (reply, error,
609 DBUS_TYPE_UINT32, &uid,
612 _DBUS_ASSERT_ERROR_IS_SET (error);
613 dbus_message_unref (reply);
614 return DBUS_UID_UNSET;
617 dbus_message_unref (reply);
619 return (unsigned long) uid;
624 * Asks the bus to assign the given name to this connection.
626 * @todo these docs are not complete, need to document the
627 * return value and flags
629 * @todo if we get an error reply, it has to be converted into
630 * DBusError and returned
632 * @param connection the connection
633 * @param name the name to request
635 * @param error location to store the error
636 * @returns a result code, -1 if error is set
639 dbus_bus_request_name (DBusConnection *connection,
644 DBusMessage *message, *reply;
645 dbus_uint32_t result;
647 _dbus_return_val_if_fail (connection != NULL, 0);
648 _dbus_return_val_if_fail (name != NULL, 0);
649 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), 0);
650 _dbus_return_val_if_error_is_set (error, 0);
652 message = dbus_message_new_method_call (DBUS_SERVICE_ORG_FREEDESKTOP_DBUS,
653 DBUS_PATH_ORG_FREEDESKTOP_DBUS,
654 DBUS_INTERFACE_ORG_FREEDESKTOP_DBUS,
659 _DBUS_SET_OOM (error);
663 if (!dbus_message_append_args (message,
664 DBUS_TYPE_STRING, &name,
665 DBUS_TYPE_UINT32, &flags,
668 dbus_message_unref (message);
669 _DBUS_SET_OOM (error);
673 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
676 dbus_message_unref (message);
680 _DBUS_ASSERT_ERROR_IS_SET (error);
684 if (dbus_set_error_from_message (error, reply))
686 _DBUS_ASSERT_ERROR_IS_SET (error);
687 dbus_message_unref (reply);
691 if (!dbus_message_get_args (reply, error,
692 DBUS_TYPE_UINT32, &result,
695 _DBUS_ASSERT_ERROR_IS_SET (error);
696 dbus_message_unref (reply);
700 dbus_message_unref (reply);
706 * Checks whether a certain name has an owner.
708 * @param connection the connection
709 * @param name the name
710 * @param error location to store any errors
711 * @returns #TRUE if the name exists, #FALSE if not or on error
714 dbus_bus_name_has_owner (DBusConnection *connection,
718 DBusMessage *message, *reply;
721 _dbus_return_val_if_fail (connection != NULL, FALSE);
722 _dbus_return_val_if_fail (name != NULL, FALSE);
723 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), FALSE);
724 _dbus_return_val_if_error_is_set (error, FALSE);
726 message = dbus_message_new_method_call (DBUS_SERVICE_ORG_FREEDESKTOP_DBUS,
727 DBUS_PATH_ORG_FREEDESKTOP_DBUS,
728 DBUS_INTERFACE_ORG_FREEDESKTOP_DBUS,
732 _DBUS_SET_OOM (error);
736 if (!dbus_message_append_args (message,
737 DBUS_TYPE_STRING, &name,
740 dbus_message_unref (message);
741 _DBUS_SET_OOM (error);
745 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
746 dbus_message_unref (message);
750 _DBUS_ASSERT_ERROR_IS_SET (error);
754 if (!dbus_message_get_args (reply, error,
755 DBUS_TYPE_BOOLEAN, &exists,
758 _DBUS_ASSERT_ERROR_IS_SET (error);
759 dbus_message_unref (reply);
763 dbus_message_unref (reply);
768 * Starts a service that will request ownership of the given name.
769 * The returned result will be one of be one of
770 * #DBUS_START_REPLY_SUCCESS or #DBUS_START_REPLY_ALREADY_RUNNING if
771 * successful. Pass #NULL if you don't care about the result.
773 * @param connection the connection
774 * @param name the name we want the new service to request
775 * @param flags the flags
776 * @param result a place to store the result or #NULL
777 * @param error location to store any errors
778 * @returns #TRUE if the activation succeeded, #FALSE if not
780 * @todo document what the flags do
783 dbus_bus_start_service_by_name (DBusConnection *connection,
786 dbus_uint32_t *result,
792 _dbus_return_val_if_fail (connection != NULL, FALSE);
793 _dbus_return_val_if_fail (_dbus_check_is_valid_bus_name (name), FALSE);
795 msg = dbus_message_new_method_call (DBUS_SERVICE_ORG_FREEDESKTOP_DBUS,
796 DBUS_PATH_ORG_FREEDESKTOP_DBUS,
797 DBUS_INTERFACE_ORG_FREEDESKTOP_DBUS,
798 "StartServiceByName");
800 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, &name,
801 DBUS_TYPE_UINT32, &flags, DBUS_TYPE_INVALID))
803 dbus_message_unref (msg);
804 _DBUS_SET_OOM (error);
808 reply = dbus_connection_send_with_reply_and_block (connection, msg,
810 dbus_message_unref (msg);
814 _DBUS_ASSERT_ERROR_IS_SET (error);
818 if (dbus_set_error_from_message (error, reply))
820 _DBUS_ASSERT_ERROR_IS_SET (error);
821 dbus_message_unref (reply);
825 if (result != NULL &&
826 !dbus_message_get_args (reply, error, DBUS_TYPE_UINT32,
827 result, DBUS_TYPE_INVALID))
829 _DBUS_ASSERT_ERROR_IS_SET (error);
830 dbus_message_unref (reply);
834 dbus_message_unref (reply);
839 send_no_return_values (DBusConnection *connection,
845 /* Block to check success codepath */
848 reply = dbus_connection_send_with_reply_and_block (connection, msg,
852 _DBUS_ASSERT_ERROR_IS_SET (error);
854 dbus_message_unref (reply);
858 /* Silently-fail nonblocking codepath */
859 dbus_message_set_no_reply (msg, TRUE);
860 dbus_connection_send (connection, msg, NULL);
865 * Adds a match rule to match messages going through the message bus.
866 * The "rule" argument is the string form of a match rule.
868 * If you pass #NULL for the error, this function will not
869 * block; the match thus won't be added until you flush the
870 * connection, and if there's an error adding the match
871 * (only possible error is lack of resources in the bus),
872 * you won't find out about it.
874 * If you pass non-#NULL for the error this function will
875 * block until it gets a reply.
877 * Normal API conventions would have the function return
878 * a boolean value indicating whether the error was set,
879 * but that would require blocking always to determine
882 * @param connection connection to the message bus
883 * @param rule textual form of match rule
884 * @param error location to store any errors
887 dbus_bus_add_match (DBusConnection *connection,
893 _dbus_return_if_fail (rule != NULL);
895 msg = dbus_message_new_method_call (DBUS_SERVICE_ORG_FREEDESKTOP_DBUS,
896 DBUS_PATH_ORG_FREEDESKTOP_DBUS,
897 DBUS_INTERFACE_ORG_FREEDESKTOP_DBUS,
902 _DBUS_SET_OOM (error);
906 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, &rule,
909 dbus_message_unref (msg);
910 _DBUS_SET_OOM (error);
914 send_no_return_values (connection, msg, error);
916 dbus_message_unref (msg);
920 * Removes a previously-added match rule "by value" (the most
921 * recently-added identical rule gets removed). The "rule" argument
922 * is the string form of a match rule.
924 * If you pass #NULL for the error, this function will not
925 * block; otherwise it will. See detailed explanation in
926 * docs for dbus_bus_add_match().
928 * @param connection connection to the message bus
929 * @param rule textual form of match rule
930 * @param error location to store any errors
933 dbus_bus_remove_match (DBusConnection *connection,
939 _dbus_return_if_fail (rule != NULL);
941 msg = dbus_message_new_method_call (DBUS_SERVICE_ORG_FREEDESKTOP_DBUS,
942 DBUS_PATH_ORG_FREEDESKTOP_DBUS,
943 DBUS_INTERFACE_ORG_FREEDESKTOP_DBUS,
946 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, &rule,
949 dbus_message_unref (msg);
950 _DBUS_SET_OOM (error);
954 send_no_return_values (connection, msg, error);
956 dbus_message_unref (msg);