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"
30 * @defgroup DBusBus Message bus APIs
32 * @brief Functions for communicating with the message bus
38 * @defgroup DBusBusInternals Message bus APIs internals
39 * @ingroup DBusInternals
40 * @brief Internals of functions for communicating with the message bus
46 * Block of message-bus-related data we attach to each
47 * #DBusConnection used with these convenience functions.
52 char *base_service; /**< Base service name of this connection */
54 DBusConnection **connection; /**< Pointer to bus_connections entry */
57 /** The slot we have reserved to store BusData
59 static int bus_data_slot = -1;
60 /** Number of connections using the slot
62 static int bus_data_slot_refcount = 0;
65 * Lock for bus_data_slot and bus_data_slot_refcount
67 _DBUS_DEFINE_GLOBAL_LOCK (bus);
75 if (bus_data_slot < 0)
77 bus_data_slot = dbus_connection_allocate_data_slot ();
79 if (bus_data_slot < 0)
85 _dbus_assert (bus_data_slot_refcount == 0);
88 bus_data_slot_refcount += 1;
96 data_slot_unref (void)
100 _dbus_assert (bus_data_slot_refcount > 0);
101 _dbus_assert (bus_data_slot >= 0);
103 bus_data_slot_refcount -= 1;
105 if (bus_data_slot_refcount == 0)
107 dbus_connection_free_data_slot (bus_data_slot);
115 bus_data_free (void *data)
122 *bd->connection = NULL;
126 dbus_free (bd->base_service);
133 ensure_bus_data (DBusConnection *connection)
137 if (!data_slot_ref ())
140 bd = dbus_connection_get_data (connection, bus_data_slot);
143 bd = dbus_new0 (BusData, 1);
150 if (!dbus_connection_set_data (connection, bus_data_slot, bd,
158 /* Data slot refcount now held by the BusData */
168 /** @} */ /* end of implementation details docs */
171 * @addtogroup DBusBus
175 /** Number of bus types */
178 static DBusConnection *bus_connections[BUS_TYPES];
181 * Connects to a bus daemon and registers the client with it.
182 * If a connection to the bus already exists, then that connection is returned.
184 * @todo alex thinks we should nullify the connection when we get a disconnect-message.
186 * @param type bus type
187 * @param error address where an error can be returned.
188 * @returns a DBusConnection
191 dbus_bus_get (DBusBusType type,
194 const char *name, *value;
195 DBusConnection *connection;
198 if (type <= 0 || type >= BUS_TYPES)
200 _dbus_assert_not_reached ("Invalid bus type specified.");
207 if (bus_connections[type] != NULL)
209 connection = bus_connections[type];
210 dbus_connection_ref (connection);
218 case DBUS_BUS_SESSION:
219 name = "DBUS_SESSION_BUS_ADDRESS";
221 case DBUS_BUS_SYSTEM:
222 name = "DBUS_SYSTEM_BUS_ADDRESS";
226 value = _dbus_getenv (name);
228 if (type == DBUS_BUS_SYSTEM &&
229 (value == NULL || *value == '\0'))
231 /* Use default system bus address if none set */
232 value = "unix:path=" DBUS_SYSTEM_BUS_PATH;
235 if (value == NULL || *value == '\0')
237 dbus_set_error (error, DBUS_ERROR_FAILED,
238 "Environment variable %s not set, address of message bus unknown",
245 connection = dbus_connection_open (value, error);
253 if (!dbus_bus_register (connection, error))
255 dbus_connection_disconnect (connection);
256 dbus_connection_unref (connection);
262 bus_connections[type] = connection;
263 bd = ensure_bus_data (connection);
264 _dbus_assert (bd != NULL);
266 bd->connection = &bus_connections[type];
274 * Registers a connection with the bus. This must be the first
275 * thing an application does when connecting to the message bus.
276 * If registration succeeds, the base service name will be set,
277 * and can be obtained using dbus_bus_get_base_service().
279 * @todo if we get an error reply, it has to be converted into
280 * DBusError and returned
282 * @param connection the connection
283 * @param error place to store errors
284 * @returns #TRUE on success
287 dbus_bus_register (DBusConnection *connection,
290 DBusMessage *message, *reply;
294 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
296 bd = ensure_bus_data (connection);
299 _DBUS_SET_OOM (error);
303 if (bd->base_service != NULL)
305 _dbus_warn ("Attempt to register the same DBusConnection with the message bus, but it is already registered\n");
306 /* This isn't an error, it's a programming bug. We'll be nice
307 * and not _dbus_assert_not_reached()
312 message = dbus_message_new (DBUS_SERVICE_DBUS,
317 _DBUS_SET_OOM (error);
321 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
323 dbus_message_unref (message);
327 _DBUS_ASSERT_ERROR_IS_SET (error);
331 if (!dbus_message_get_args (reply, error,
332 DBUS_TYPE_STRING, &name,
335 _DBUS_ASSERT_ERROR_IS_SET (error);
339 bd->base_service = name;
346 * Sets the base service name of the connection.
347 * Can only be used if you registered with the
348 * bus manually (i.e. if you did not call
349 * dbus_bus_register()). Can only be called
350 * once per connection.
352 * @param connection the connection
353 * @param base_service the base service name
354 * @returns #FALSE if not enough memory
357 dbus_bus_set_base_service (DBusConnection *connection,
358 const char *base_service)
362 bd = ensure_bus_data (connection);
366 _dbus_assert (bd->base_service == NULL);
367 _dbus_assert (base_service != NULL);
369 bd->base_service = _dbus_strdup (base_service);
370 return bd->base_service != NULL;
374 * Gets the base service name of the connection.
375 * Only possible after the connection has been registered
376 * with the message bus.
378 * @param connection the connection
379 * @returns the base service name
382 dbus_bus_get_base_service (DBusConnection *connection)
386 bd = ensure_bus_data (connection);
390 return bd->base_service;
394 * Asks the bus to try to acquire a certain service.
396 * @todo these docs are not complete, need to document the
397 * return value and flags
399 * @todo if we get an error reply, it has to be converted into
400 * DBusError and returned
402 * @param connection the connection
403 * @param service_name the service name
405 * @param error location to store the error
406 * @returns a result code, -1 if error is set
409 dbus_bus_acquire_service (DBusConnection *connection,
410 const char *service_name,
414 DBusMessage *message, *reply;
417 message = dbus_message_new (DBUS_SERVICE_DBUS,
418 DBUS_MESSAGE_ACQUIRE_SERVICE);
422 _DBUS_SET_OOM (error);
426 if (!dbus_message_append_args (message,
427 DBUS_TYPE_STRING, service_name,
428 DBUS_TYPE_UINT32, flags,
431 dbus_message_unref (message);
432 _DBUS_SET_OOM (error);
436 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
439 dbus_message_unref (message);
443 _DBUS_ASSERT_ERROR_IS_SET (error);
447 if (!dbus_message_get_args (reply, error,
448 DBUS_TYPE_UINT32, &service_result,
451 _DBUS_ASSERT_ERROR_IS_SET (error);
455 return service_result;
459 * Checks whether a certain service exists.
461 * @todo the SERVICE_EXISTS message should use BOOLEAN not UINT32
463 * @param connection the connection
464 * @param service_name the service name
465 * @param error location to store any errors
466 * @returns #TRUE if the service exists, #FALSE if not or on error
469 dbus_bus_service_exists (DBusConnection *connection,
470 const char *service_name,
473 DBusMessage *message, *reply;
476 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
478 message = dbus_message_new (DBUS_SERVICE_DBUS,
479 DBUS_MESSAGE_SERVICE_EXISTS);
482 _DBUS_SET_OOM (error);
486 if (!dbus_message_append_args (message,
487 DBUS_TYPE_STRING, service_name,
490 dbus_message_unref (message);
491 _DBUS_SET_OOM (error);
495 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
496 dbus_message_unref (message);
500 _DBUS_ASSERT_ERROR_IS_SET (error);
504 if (!dbus_message_get_args (reply, error,
505 DBUS_TYPE_UINT32, &exists,
508 _DBUS_ASSERT_ERROR_IS_SET (error);
512 return (exists != FALSE);