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
39 * @defgroup DBusBusInternals Message bus APIs internals
40 * @ingroup DBusInternals
41 * @brief Internals of functions for communicating with the message bus
47 * Block of message-bus-related data we attach to each
48 * #DBusConnection used with these convenience functions.
53 DBusConnection *connection; /**< Connection we're associated with */
54 char *base_service; /**< Base service name of this connection */
56 unsigned int is_well_known : 1; /**< Is one of the well-known connections in our global array */
59 /** The slot we have reserved to store BusData.
61 static dbus_int32_t bus_data_slot = -1;
63 /** Number of bus types */
66 static DBusConnection *bus_connections[N_BUS_TYPES];
67 static char *bus_connection_addresses[N_BUS_TYPES] = { NULL, NULL, NULL };
69 static DBusBusType activation_bus_type = DBUS_BUS_ACTIVATION;
71 static dbus_bool_t initialized = FALSE;
74 * Lock for globals in this file
76 _DBUS_DEFINE_GLOBAL_LOCK (bus);
79 addresses_shutdown_func (void *data)
84 while (i < N_BUS_TYPES)
86 if (bus_connections[i] != NULL)
87 _dbus_warn ("dbus_shutdown() called but connections were still live!");
89 dbus_free (bus_connection_addresses[i]);
90 bus_connection_addresses[i] = NULL;
94 activation_bus_type = DBUS_BUS_ACTIVATION;
98 get_from_env (char **connection_p,
103 _dbus_assert (*connection_p == NULL);
105 s = _dbus_getenv (env_var);
106 if (s == NULL || *s == '\0')
107 return TRUE; /* successfully didn't use the env var */
110 *connection_p = _dbus_strdup (s);
111 return *connection_p != NULL;
116 init_connections_unlocked (void)
124 while (i < N_BUS_TYPES)
126 bus_connections[i] = NULL;
130 /* Don't init these twice, we may run this code twice if
131 * init_connections_unlocked() fails midway through.
134 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
136 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_SYSTEM],
137 "DBUS_SYSTEM_BUS_ADDRESS"))
140 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
142 /* Use default system bus address if none set in environment */
143 bus_connection_addresses[DBUS_BUS_SYSTEM] =
144 _dbus_strdup ("unix:path=" DBUS_SYSTEM_BUS_PATH);
145 if (bus_connection_addresses[DBUS_BUS_SYSTEM] == NULL)
150 if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
152 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_SESSION],
153 "DBUS_SESSION_BUS_ADDRESS"))
157 if (bus_connection_addresses[DBUS_BUS_ACTIVATION] == NULL)
159 if (!get_from_env (&bus_connection_addresses[DBUS_BUS_ACTIVATION],
160 "DBUS_ACTIVATION_ADDRESS"))
164 s = _dbus_getenv ("DBUS_ACTIVATION_BUS_TYPE");
168 if (strcmp (s, "system") == 0)
169 activation_bus_type = DBUS_BUS_SYSTEM;
170 else if (strcmp (s, "session") == 0)
171 activation_bus_type = DBUS_BUS_SESSION;
174 /* If we return FALSE we have to be sure that restarting
175 * the above code will work right
178 if (!_dbus_setenv ("DBUS_ACTIVATION_ADDRESS", NULL))
181 if (!_dbus_setenv ("DBUS_ACTIVATION_BUS_TYPE", NULL))
184 if (!_dbus_register_shutdown_func (addresses_shutdown_func,
195 bus_data_free (void *data)
199 if (bd->is_well_known)
203 /* We may be stored in more than one slot */
205 while (i < N_BUS_TYPES)
207 if (bus_connections[i] == bd->connection)
208 bus_connections[i] = NULL;
215 dbus_free (bd->base_service);
218 dbus_connection_free_data_slot (&bus_data_slot);
222 ensure_bus_data (DBusConnection *connection)
226 if (!dbus_connection_allocate_data_slot (&bus_data_slot))
229 bd = dbus_connection_get_data (connection, bus_data_slot);
232 bd = dbus_new0 (BusData, 1);
235 dbus_connection_free_data_slot (&bus_data_slot);
239 bd->connection = connection;
241 if (!dbus_connection_set_data (connection, bus_data_slot, bd,
245 dbus_connection_free_data_slot (&bus_data_slot);
249 /* Data slot refcount now held by the BusData */
253 dbus_connection_free_data_slot (&bus_data_slot);
259 /** @} */ /* end of implementation details docs */
262 * @addtogroup DBusBus
267 * Connects to a bus daemon and registers the client with it.
268 * If a connection to the bus already exists, then that connection is returned.
270 * @todo alex thinks we should nullify the connection when we get a disconnect-message.
272 * @param type bus type
273 * @param error address where an error can be returned.
274 * @returns a DBusConnection
277 dbus_bus_get (DBusBusType type,
281 DBusConnection *connection;
283 DBusBusType address_type;
285 _dbus_return_val_if_fail (type >= 0 && type < N_BUS_TYPES, NULL);
286 _dbus_return_val_if_error_is_set (error, NULL);
290 if (!init_connections_unlocked ())
293 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
297 /* We want to use the activation address even if the
298 * activating bus is the session or system bus,
303 /* Use the real type of the activation bus for getting its
304 * connection. (If the activating bus isn't a well-known
305 * bus then activation_bus_type == DBUS_BUS_ACTIVATION)
307 if (type == DBUS_BUS_ACTIVATION)
308 type = activation_bus_type;
310 if (bus_connections[type] != NULL)
312 connection = bus_connections[type];
313 dbus_connection_ref (connection);
319 address = bus_connection_addresses[address_type];
322 dbus_set_error (error, DBUS_ERROR_FAILED,
323 "Unable to determine the address of the message bus");
328 connection = dbus_connection_open (address, error);
332 _DBUS_ASSERT_ERROR_IS_SET (error);
337 if (!dbus_bus_register (connection, error))
339 _DBUS_ASSERT_ERROR_IS_SET (error);
340 dbus_connection_disconnect (connection);
341 dbus_connection_unref (connection);
347 bus_connections[type] = connection;
348 bd = ensure_bus_data (connection);
349 _dbus_assert (bd != NULL);
351 bd->is_well_known = TRUE;
359 * Registers a connection with the bus. This must be the first
360 * thing an application does when connecting to the message bus.
361 * If registration succeeds, the base service name will be set,
362 * and can be obtained using dbus_bus_get_base_service().
364 * @todo if we get an error reply, it has to be converted into
365 * DBusError and returned
367 * @param connection the connection
368 * @param error place to store errors
369 * @returns #TRUE on success
372 dbus_bus_register (DBusConnection *connection,
375 DBusMessage *message, *reply;
380 _dbus_return_val_if_fail (connection != NULL, FALSE);
381 _dbus_return_val_if_error_is_set (error, FALSE);
385 bd = ensure_bus_data (connection);
388 _DBUS_SET_OOM (error);
392 if (bd->base_service != NULL)
394 _dbus_warn ("Attempt to register the same DBusConnection with the message bus, but it is already registered\n");
395 /* This isn't an error, it's a programming bug. We'll be nice
396 * and not _dbus_assert_not_reached()
401 message = dbus_message_new_method_call (DBUS_MESSAGE_HELLO,
407 _DBUS_SET_OOM (error);
411 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
413 dbus_message_unref (message);
417 else if (dbus_set_error_from_message (error, reply))
419 else if (!dbus_message_get_args (reply, error,
420 DBUS_TYPE_STRING, &name,
424 bd->base_service = name;
430 dbus_message_unref (reply);
433 _DBUS_ASSERT_ERROR_IS_SET (error);
440 * Sets the base service name of the connection.
441 * Can only be used if you registered with the
442 * bus manually (i.e. if you did not call
443 * dbus_bus_register()). Can only be called
444 * once per connection.
446 * @param connection the connection
447 * @param base_service the base service name
448 * @returns #FALSE if not enough memory
451 dbus_bus_set_base_service (DBusConnection *connection,
452 const char *base_service)
456 _dbus_return_val_if_fail (connection != NULL, FALSE);
457 _dbus_return_val_if_fail (base_service != NULL, FALSE);
459 bd = ensure_bus_data (connection);
463 _dbus_assert (bd->base_service == NULL);
465 bd->base_service = _dbus_strdup (base_service);
466 return bd->base_service != NULL;
470 * Gets the base service name of the connection.
471 * Only possible after the connection has been registered
472 * with the message bus.
474 * @param connection the connection
475 * @returns the base service name
478 dbus_bus_get_base_service (DBusConnection *connection)
482 _dbus_return_val_if_fail (connection != NULL, NULL);
484 bd = ensure_bus_data (connection);
488 return bd->base_service;
492 * Asks the bus to try to acquire a certain service.
494 * @todo these docs are not complete, need to document the
495 * return value and flags
497 * @todo if we get an error reply, it has to be converted into
498 * DBusError and returned
500 * @param connection the connection
501 * @param service_name the service name
503 * @param error location to store the error
504 * @returns a result code, -1 if error is set
507 dbus_bus_acquire_service (DBusConnection *connection,
508 const char *service_name,
512 DBusMessage *message, *reply;
513 dbus_uint32_t service_result;
515 _dbus_return_val_if_fail (connection != NULL, 0);
516 _dbus_return_val_if_fail (service_name != NULL, 0);
517 _dbus_return_val_if_error_is_set (error, 0);
519 message = dbus_message_new_method_call (DBUS_MESSAGE_ACQUIRE_SERVICE,
525 _DBUS_SET_OOM (error);
529 if (!dbus_message_append_args (message,
530 DBUS_TYPE_STRING, service_name,
531 DBUS_TYPE_UINT32, flags,
534 dbus_message_unref (message);
535 _DBUS_SET_OOM (error);
539 reply = dbus_connection_send_with_reply_and_block (connection, message, -1,
542 dbus_message_unref (message);
546 _DBUS_ASSERT_ERROR_IS_SET (error);
550 if (dbus_set_error_from_message (error, reply))
552 _DBUS_ASSERT_ERROR_IS_SET (error);
553 dbus_message_unref (reply);
557 if (!dbus_message_get_args (reply, error,
558 DBUS_TYPE_UINT32, &service_result,
561 _DBUS_ASSERT_ERROR_IS_SET (error);
562 dbus_message_unref (reply);
566 dbus_message_unref (reply);
568 return service_result;
572 * Checks whether a certain service exists.
574 * @todo the SERVICE_EXISTS message should use BOOLEAN not UINT32
576 * @param connection the connection
577 * @param service_name the service name
578 * @param error location to store any errors
579 * @returns #TRUE if the service exists, #FALSE if not or on error
582 dbus_bus_service_exists (DBusConnection *connection,
583 const char *service_name,
586 DBusMessage *message, *reply;
589 _dbus_return_val_if_fail (connection != NULL, FALSE);
590 _dbus_return_val_if_fail (service_name != NULL, FALSE);
591 _dbus_return_val_if_error_is_set (error, FALSE);
593 message = dbus_message_new_method_call (DBUS_MESSAGE_SERVICE_EXISTS,
597 _DBUS_SET_OOM (error);
601 if (!dbus_message_append_args (message,
602 DBUS_TYPE_STRING, service_name,
605 dbus_message_unref (message);
606 _DBUS_SET_OOM (error);
610 reply = dbus_connection_send_with_reply_and_block (connection, message, -1, error);
611 dbus_message_unref (message);
615 _DBUS_ASSERT_ERROR_IS_SET (error);
619 if (!dbus_message_get_args (reply, error,
620 DBUS_TYPE_UINT32, &exists,
623 _DBUS_ASSERT_ERROR_IS_SET (error);
627 return (exists != FALSE);
631 * Activates a given service
633 * @param connection the connection
634 * @param service_name the service name
635 * @param flags the flags
636 * @param result a place to store the result of the activation, which will
637 * be one of DBUS_ACTIVATION_REPLY_ACTIVATED or
638 * DBUS_ACTIVATION_REPLY_ALREADY_ACTIVE if successful. Pass NULL if you
639 * don't care about the result.
640 * @param error location to store any errors
641 * @returns #TRUE if the activation succeeded, #FALSE if not
643 * @todo document what the flags do
646 dbus_bus_activate_service (DBusConnection *connection,
647 const char *service_name,
649 dbus_uint32_t *result,
655 msg = dbus_message_new_method_call (DBUS_MESSAGE_ACTIVATE_SERVICE,
658 if (!dbus_message_append_args (msg, DBUS_TYPE_STRING, service_name,
659 DBUS_TYPE_UINT32, flags, DBUS_TYPE_INVALID))
661 dbus_message_unref (msg);
662 _DBUS_SET_OOM (error);
666 reply = dbus_connection_send_with_reply_and_block (connection, msg,
668 dbus_message_unref (msg);
672 _DBUS_ASSERT_ERROR_IS_SET (error);
676 if (dbus_set_error_from_message (error, reply))
678 _DBUS_ASSERT_ERROR_IS_SET (error);
679 dbus_message_unref (reply);
683 if (result != NULL &&
684 !dbus_message_get_args (reply, error, DBUS_TYPE_UINT32,
685 result, DBUS_TYPE_INVALID))
687 _DBUS_ASSERT_ERROR_IS_SET (error);
688 dbus_message_unref (reply);
692 dbus_message_unref (reply);