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 1.2
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"
31 * @defgroup DBusBus Message bus APIs
33 * @brief Functions for communicating with the message bus
35 * @todo right now the default address of the system bus is hardcoded,
36 * so if you change it in the global config file suddenly you have to
37 * set DBUS_SYSTEM_BUS_ADDRESS env variable. Might be nice if the
38 * client lib somehow read the config file, or if the bus on startup
39 * somehow wrote out its address to a well-known spot, but might also
44 * @defgroup DBusBusInternals Message bus APIs internals
45 * @ingroup DBusInternals
46 * @brief Internals of functions for communicating with the message bus
52 * Block of message-bus-related data we attach to each
53 * #DBusConnection used with these convenience functions.
58 DBusConnection *connection; /**< Connection we're associated with */
59 char *base_service; /**< Base service name of this connection */
61 unsigned int is_well_known : 1; /**< Is one of the well-known connections in our global array */
64 /** The slot we have reserved to store BusData.
66 static dbus_int32_t bus_data_slot = -1;
68 /** Number of bus types */
71 static DBusConnection *bus_connections[N_BUS_TYPES];
72 static char *bus_connection_addresses[N_BUS_TYPES] = { NULL, NULL, NULL };
74 static DBusBusType activation_bus_type = DBUS_BUS_ACTIVATION;
76 static dbus_bool_t initialized = FALSE;
79 * Lock for globals in this file
81 _DBUS_DEFINE_GLOBAL_LOCK (bus);
84 addresses_shutdown_func (void *data)
89 while (i < N_BUS_TYPES)
91 if (bus_connections[i] != NULL)
92 _dbus_warn ("dbus_shutdown() called but connections were still live!");
94 dbus_free (bus_connection_addresses[i]);
95 bus_connection_addresses[i] = NULL;
99 activation_bus_type = DBUS_BUS_ACTIVATION;
103 get_from_env (char **connection_p,
108 _dbus_assert (*connection_p == NULL);
110 s = _dbus_getenv (env_var);
111 if (s == NULL || *s == '\0')
112 return TRUE; /* successfully didn't use the env var */
115 *connection_p = _dbus_strdup (s);
116 return *connection_p != NULL;
121 init_connections_unlocked (void)
129 while (i < N_BUS_TYPES)
131 bus_connections[i] = NULL;
135 /* Don't init these twice, we may run this code twice if
136 * init_connections_unlocked() fails midway through.
139 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
141 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_SYSTEM],
142 "DBUS_SYSTEM_BUS_ADDRESS"))
145 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
147 /* Use default system bus address if none set in environment */
148 bus_connection_addresses[DBUS_BUS_SYSTEM] =
149 #ifdef HAVE_ABSTRACT_SOCKETS
150 _dbus_strdup ("unix:abstract=" DBUS_SYSTEM_BUS_PATH);
152 _dbus_strdup ("unix:path=" DBUS_SYSTEM_BUS_PATH);
154 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
159 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
161 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_SESSION],
162 "DBUS_SESSION_BUS_ADDRESS"))
166 if (bus_connection_addresses[DBUS_BUS_ACTIVATION] == NULL)
168 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_ACTIVATION],
169 "DBUS_ACTIVATION_ADDRESS"))
173 s = _dbus_getenv ("DBUS_ACTIVATION_BUS_TYPE");
177 if (strcmp (s, "system") == 0)
178 activation_bus_type = DBUS_BUS_SYSTEM;
179 else if (strcmp (s, "session") == 0)
180 activation_bus_type = DBUS_BUS_SESSION;
183 /* If we return FALSE we have to be sure that restarting
184 * the above code will work right
187 if (!_dbus_setenv ("DBUS_ACTIVATION_ADDRESS", NULL))
190 if (!_dbus_setenv ("DBUS_ACTIVATION_BUS_TYPE", NULL))
193 if (!_dbus_register_shutdown_func (addresses_shutdown_func,
204 bus_data_free (void *data)
208 if (bd->is_well_known)
212 /* We may be stored in more than one slot */
214 while (i < N_BUS_TYPES)
216 if (bus_connections[i] == bd->connection)
217 bus_connections[i] = NULL;
224 dbus_free (bd->base_service);
227 dbus_connection_free_data_slot (&bus_data_slot);
231 ensure_bus_data (DBusConnection *connection)
235 if (!dbus_connection_allocate_data_slot (&bus_data_slot))
238 bd = dbus_connection_get_data (connection, bus_data_slot);
241 bd = dbus_new0 (BusData, 1);
244 dbus_connection_free_data_slot (&bus_data_slot);
248 bd->connection = connection;
250 if (!dbus_connection_set_data (connection, bus_data_slot, bd,
254 dbus_connection_free_data_slot (&bus_data_slot);
258 /* Data slot refcount now held by the BusData */
262 dbus_connection_free_data_slot (&bus_data_slot);
268 /** @} */ /* end of implementation details docs */
271 * @addtogroup DBusBus
276 * Connects to a bus daemon and registers the client with it.
277 * If a connection to the bus already exists, then that connection is returned.
279 * @todo alex thinks we should nullify the connection when we get a disconnect-message.
281 * @param type bus type
282 * @param error address where an error can be returned.
283 * @returns a DBusConnection
286 dbus_bus_get (DBusBusType type,
290 DBusConnection *connection;
292 DBusBusType address_type;
294 _dbus_return_val_if_fail (type >= 0 && type < N_BUS_TYPES, NULL);
295 _dbus_return_val_if_error_is_set (error, NULL);
299 if (!init_connections_unlocked ())
302 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
306 /* We want to use the activation address even if the
307 * activating bus is the session or system bus,
312 /* Use the real type of the activation bus for getting its
313 * connection. (If the activating bus isn't a well-known
314 * bus then activation_bus_type == DBUS_BUS_ACTIVATION)
316 if (type == DBUS_BUS_ACTIVATION)
317 type = activation_bus_type;
319 if (bus_connections[type] != NULL)
321 connection = bus_connections[type];
322 dbus_connection_ref (connection);
328 address = bus_connection_addresses[address_type];
331 dbus_set_error (error, DBUS_ERROR_FAILED,
332 "Unable to determine the address of the message bus");
337 connection = dbus_connection_open (address, error);
341 _DBUS_ASSERT_ERROR_IS_SET (error);
346 if (!dbus_bus_register (connection, error))
348 _DBUS_ASSERT_ERROR_IS_SET (error);
349 dbus_connection_disconnect (connection);
350 dbus_connection_unref (connection);
356 bus_connections[type] = connection;
357 bd = ensure_bus_data (connection);
358 _dbus_assert (bd != NULL);
360 bd->is_well_known = TRUE;
368 * Registers a connection with the bus. This must be the first
369 * thing an application does when connecting to the message bus.
370 * If registration succeeds, the base service name will be set,
371 * and can be obtained using dbus_bus_get_base_service().
373 * @todo if we get an error reply, it has to be converted into
374 * DBusError and returned
376 * @param connection the connection
377 * @param error place to store errors
378 * @returns #TRUE on success
381 dbus_bus_register (DBusConnection *connection,
384 DBusMessage *message, *reply;
389 _dbus_return_val_if_fail (connection != NULL, FALSE);
390 _dbus_return_val_if_error_is_set (error, FALSE);
394 bd = ensure_bus_data (connection);
397 _DBUS_SET_OOM (error);
401 if (bd->base_service != NULL)
403 _dbus_warn ("Attempt to register the same DBusConnection with the message bus, but it is already registered\n");
404 /* This isn't an error, it's a programming bug. We'll be nice
405 * and not _dbus_assert_not_reached()
410 message = dbus_message_new (DBUS_MESSAGE_HELLO,
416 _DBUS_SET_OOM (error);
420 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
422 dbus_message_unref (message);
426 else if (dbus_set_error_from_message (error, reply))
428 else if (!dbus_message_get_args (reply, error,
429 DBUS_TYPE_STRING, &name,
433 bd->base_service = name;
439 dbus_message_unref (reply);
442 _DBUS_ASSERT_ERROR_IS_SET (error);
449 * Sets the base service name of the connection.
450 * Can only be used if you registered with the
451 * bus manually (i.e. if you did not call
452 * dbus_bus_register()). Can only be called
453 * once per connection.
455 * @param connection the connection
456 * @param base_service the base service name
457 * @returns #FALSE if not enough memory
460 dbus_bus_set_base_service (DBusConnection *connection,
461 const char *base_service)
465 _dbus_return_val_if_fail (connection != NULL, FALSE);
466 _dbus_return_val_if_fail (base_service != NULL, FALSE);
468 bd = ensure_bus_data (connection);
472 _dbus_assert (bd->base_service == NULL);
474 bd->base_service = _dbus_strdup (base_service);
475 return bd->base_service != NULL;
479 * Gets the base service name of the connection.
480 * Only possible after the connection has been registered
481 * with the message bus.
483 * @param connection the connection
484 * @returns the base service name
487 dbus_bus_get_base_service (DBusConnection *connection)
491 _dbus_return_val_if_fail (connection != NULL, NULL);
493 bd = ensure_bus_data (connection);
497 return bd->base_service;
501 * Asks the bus to try to acquire a certain service.
503 * @todo these docs are not complete, need to document the
504 * return value and flags
506 * @todo if we get an error reply, it has to be converted into
507 * DBusError and returned
509 * @param connection the connection
510 * @param service_name the service name
512 * @param error location to store the error
513 * @returns a result code, -1 if error is set
516 dbus_bus_acquire_service (DBusConnection *connection,
517 const char *service_name,
521 DBusMessage *message, *reply;
522 dbus_uint32_t service_result;
524 _dbus_return_val_if_fail (connection != NULL, 0);
525 _dbus_return_val_if_fail (service_name != NULL, 0);
526 _dbus_return_val_if_error_is_set (error, 0);
528 message = dbus_message_new (DBUS_MESSAGE_ACQUIRE_SERVICE,
534 _DBUS_SET_OOM (error);
538 if (!dbus_message_append_args (message,
539 DBUS_TYPE_STRING, service_name,
540 DBUS_TYPE_UINT32, flags,
543 dbus_message_unref (message);
544 _DBUS_SET_OOM (error);
548 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
551 dbus_message_unref (message);
555 _DBUS_ASSERT_ERROR_IS_SET (error);
559 if (dbus_set_error_from_message (error, reply))
561 _DBUS_ASSERT_ERROR_IS_SET (error);
562 dbus_message_unref (reply);
566 if (!dbus_message_get_args (reply, error,
567 DBUS_TYPE_UINT32, &service_result,
570 _DBUS_ASSERT_ERROR_IS_SET (error);
571 dbus_message_unref (reply);
575 dbus_message_unref (reply);
577 return service_result;
581 * Checks whether a certain service exists.
583 * @todo the SERVICE_EXISTS message should use BOOLEAN not UINT32
585 * @param connection the connection
586 * @param service_name the service name
587 * @param error location to store any errors
588 * @returns #TRUE if the service exists, #FALSE if not or on error
591 dbus_bus_service_exists (DBusConnection *connection,
592 const char *service_name,
595 DBusMessage *message, *reply;
598 _dbus_return_val_if_fail (connection != NULL, FALSE);
599 _dbus_return_val_if_fail (service_name != NULL, FALSE);
600 _dbus_return_val_if_error_is_set (error, FALSE);
602 message = dbus_message_new (DBUS_MESSAGE_SERVICE_EXISTS,
606 _DBUS_SET_OOM (error);
610 if (!dbus_message_append_args (message,
611 DBUS_TYPE_STRING, service_name,
614 dbus_message_unref (message);
615 _DBUS_SET_OOM (error);
619 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
620 dbus_message_unref (message);
624 _DBUS_ASSERT_ERROR_IS_SET (error);
628 if (!dbus_message_get_args (reply, error,
629 DBUS_TYPE_UINT32, &exists,
632 _DBUS_ASSERT_ERROR_IS_SET (error);
636 return (exists != FALSE);
640 * Activates a given service
642 * @param connection the connection
643 * @param service_name the service name
644 * @param flags the flags
645 * @param result a place to store the result of the activation, which will
646 * be one of DBUS_ACTIVATION_REPLY_ACTIVATED or
647 * DBUS_ACTIVATION_REPLY_ALREADY_ACTIVE if successful. Pass NULL if you
648 * don't care about the result.
649 * @param error location to store any errors
650 * @returns #TRUE if the activation succeeded, #FALSE if not
652 * @todo document what the flags do
655 dbus_bus_activate_service (DBusConnection *connection,
656 const char *service_name,
658 dbus_uint32_t *result,
664 msg = dbus_message_new (DBUS_MESSAGE_ACTIVATE_SERVICE,
667 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, service_name,
668 DBUS_TYPE_UINT32, flags, DBUS_TYPE_INVALID))
670 dbus_message_unref (msg);
671 _DBUS_SET_OOM (error);
675 reply = dbus_connection_send_with_reply_and_block (connection, msg,
677 dbus_message_unref (msg);
681 _DBUS_ASSERT_ERROR_IS_SET (error);
685 if (dbus_set_error_from_message (error, reply))
687 _DBUS_ASSERT_ERROR_IS_SET (error);
688 dbus_message_unref (reply);
692 if (result != NULL &&
693 !dbus_message_get_args (reply, error, DBUS_TYPE_UINT32,
694 result, DBUS_TYPE_INVALID))
696 _DBUS_ASSERT_ERROR_IS_SET (error);
697 dbus_message_unref (reply);
701 dbus_message_unref (reply);