1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dbus-connection.c DBusConnection object
3 *
4 * Copyright (C) 2002-2006 Red Hat Inc.
5 *
6 * Licensed under the Academic Free License version 2.1
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 *
22 */
23
24 #include <config.h>
25 #include "dbus-shared.h"
26 #include "dbus-connection.h"
27 #include "dbus-list.h"
28 #include "dbus-timeout.h"
29 #include "dbus-transport.h"
30 #include "dbus-watch.h"
31 #include "dbus-connection-internal.h"
32 #include "dbus-pending-call-internal.h"
33 #include "dbus-list.h"
34 #include "dbus-hash.h"
35 #include "dbus-message-internal.h"
36 #include "dbus-threads.h"
37 #include "dbus-protocol.h"
38 #include "dbus-dataslot.h"
39 #include "dbus-string.h"
40 #include "dbus-pending-call.h"
41 #include "dbus-object-tree.h"
42 #include "dbus-threads-internal.h"
43 #include "dbus-bus.h"
44
45 #ifdef DBUS_DISABLE_CHECKS
46 #define TOOK_LOCK_CHECK(connection)
47 #define RELEASING_LOCK_CHECK(connection)
48 #define HAVE_LOCK_CHECK(connection)
49 #else
50 #define TOOK_LOCK_CHECK(connection) do { \
51 _dbus_assert (!(connection)->have_connection_lock); \
52 (connection)->have_connection_lock = TRUE; \
53 } while (0)
54 #define RELEASING_LOCK_CHECK(connection) do { \
55 _dbus_assert ((connection)->have_connection_lock); \
56 (connection)->have_connection_lock = FALSE; \
57 } while (0)
58 #define HAVE_LOCK_CHECK(connection) _dbus_assert ((connection)->have_connection_lock)
59 /* A "DO_NOT_HAVE_LOCK_CHECK" is impossible since we need the lock to check the flag */
60 #endif
61
62 #define TRACE_LOCKS 0
63
64 #define CONNECTION_LOCK(connection) do { \
65 if (TRACE_LOCKS) { _dbus_verbose (" LOCK: %s\n", _DBUS_FUNCTION_NAME); } \
66 _dbus_mutex_lock ((connection)->mutex); \
67 TOOK_LOCK_CHECK (connection); \
68 } while (0)
69
70 #define CONNECTION_UNLOCK(connection) do { \
71 if (TRACE_LOCKS) { _dbus_verbose (" UNLOCK: %s\n", _DBUS_FUNCTION_NAME); } \
72 RELEASING_LOCK_CHECK (connection); \
73 _dbus_mutex_unlock ((connection)->mutex); \
74 } while (0)
75
76 #define DISPATCH_STATUS_NAME(s) \
77 ((s) == DBUS_DISPATCH_COMPLETE ? "complete" : \
78 (s) == DBUS_DISPATCH_DATA_REMAINS ? "data remains" : \
79 (s) == DBUS_DISPATCH_NEED_MEMORY ? "need memory" : \
80 "???")
81
82 /**
83 * @defgroup DBusConnection DBusConnection
84 * @ingroup DBus
85 * @brief Connection to another application
86 *
87 * A DBusConnection represents a connection to another
88 * application. Messages can be sent and received via this connection.
89 * The other application may be a message bus; for convenience, the
90 * function dbus_bus_get() is provided to automatically open a
91 * connection to the well-known message buses.
92 *
93 * In brief a DBusConnection is a message queue associated with some
94 * message transport mechanism such as a socket. The connection
95 * maintains a queue of incoming messages and a queue of outgoing
96 * messages.
97 *
98 * Several functions use the following terms:
99 * <ul>
100 * <li><b>read</b> means to fill the incoming message queue by reading from the socket</li>
101 * <li><b>write</b> means to drain the outgoing queue by writing to the socket</li>
102 * <li><b>dispatch</b> means to drain the incoming queue by invoking application-provided message handlers</li>
103 * </ul>
104 *
105 * The function dbus_connection_read_write_dispatch() for example does all
106 * three of these things, offering a simple alternative to a main loop.
107 *
108 * In an application with a main loop, the read/write/dispatch
109 * operations are usually separate.
110 *
111 * The connection provides #DBusWatch and #DBusTimeout objects to
112 * the main loop. These are used to know when reading, writing, or
113 * dispatching should be performed.
114 *
115 * Incoming messages are processed
116 * by calling dbus_connection_dispatch(). dbus_connection_dispatch()
117 * runs any handlers registered for the topmost message in the message
118 * queue, then discards the message, then returns.
119 *
120 * dbus_connection_get_dispatch_status() indicates whether
121 * messages are currently in the queue that need dispatching.
122 * dbus_connection_set_dispatch_status_function() allows
123 * you to set a function to be used to monitor the dispatch status.
124 *
125 * If you're using GLib or Qt add-on libraries for D-Bus, there are
126 * special convenience APIs in those libraries that hide
127 * all the details of dispatch and watch/timeout monitoring.
128 * For example, dbus_connection_setup_with_g_main().
129 *
130 * If you aren't using these add-on libraries, but want to process
131 * messages asynchronously, you must manually call
132 * dbus_connection_set_dispatch_status_function(),
133 * dbus_connection_set_watch_functions(),
134 * dbus_connection_set_timeout_functions() providing appropriate
135 * functions to integrate the connection with your application's main
136 * loop. This can be tricky to get right; main loops are not simple.
137 *
138 * If you don't need to be asynchronous, you can ignore #DBusWatch,
139 * #DBusTimeout, and dbus_connection_dispatch(). Instead,
140 * dbus_connection_read_write_dispatch() can be used.
141 *
142 * Or, in <em>very</em> simple applications,
143 * dbus_connection_pop_message() may be all you need, allowing you to
144 * avoid setting up any handler functions (see
145 * dbus_connection_add_filter(),
146 * dbus_connection_register_object_path() for more on handlers).
147 *
148 * When you use dbus_connection_send() or one of its variants to send
149 * a message, the message is added to the outgoing queue. It's
150 * actually written to the network later; either in
151 * dbus_watch_handle() invoked by your main loop, or in
152 * dbus_connection_flush() which blocks until it can write out the
153 * entire outgoing queue. The GLib/Qt add-on libraries again
154 * handle the details here for you by setting up watch functions.
155 *
156 * When a connection is disconnected, you are guaranteed to get a
157 * signal "Disconnected" from the interface
158 * #DBUS_INTERFACE_LOCAL, path
159 * #DBUS_PATH_LOCAL.
160 *
161 * You may not drop the last reference to a #DBusConnection
162 * until that connection has been disconnected.
163 *
164 * You may dispatch the unprocessed incoming message queue even if the
165 * connection is disconnected. However, "Disconnected" will always be
166 * the last message in the queue (obviously no messages are received
167 * after disconnection).
168 *
169 * After calling dbus_threads_init(), #DBusConnection has thread
170 * locks and drops them when invoking user callbacks, so in general is
171 * transparently threadsafe. However, #DBusMessage does NOT have
172 * thread locks; you must not send the same message to multiple
173 * #DBusConnection if those connections will be used from different threads,
174 * for example.
175 *
176 * Also, if you dispatch or pop messages from multiple threads, it
177 * may work in the sense that it won't crash, but it's tough to imagine
178 * sane results; it will be completely unpredictable which messages
179 * go to which threads.
180 *
181 * It's recommended to dispatch from a single thread.
182 *
183 * The most useful function to call from multiple threads at once
184 * is dbus_connection_send_with_reply_and_block(). That is,
185 * multiple threads can make method calls at the same time.
186 *
187 * If you aren't using threads, you can use a main loop and
188 * dbus_pending_call_set_notify() to achieve a similar result.
189 */
190
191 /**
192 * @defgroup DBusConnectionInternals DBusConnection implementation details
193 * @ingroup DBusInternals
194 * @brief Implementation details of DBusConnection
195 *
196 * @{
197 */
198
199 /**
200 * Internal struct representing a message filter function
201 */
202 typedef struct DBusMessageFilter DBusMessageFilter;
203
204 /**
205 * Internal struct representing a message filter function
206 */
207 struct DBusMessageFilter
208 {
209 DBusAtomic refcount; /**< Reference count */
210 DBusHandleMessageFunction function; /**< Function to call to filter */
211 void *user_data; /**< User data for the function */
212 DBusFreeFunction free_user_data_function; /**< Function to free the user data */
213 };
214
215
216 /**
217 * Internals of DBusPreallocatedSend
218 */
219 struct DBusPreallocatedSend
220 {
221 DBusConnection *connection; /**< Connection we'd send the message to */
222 DBusList *queue_link; /**< Preallocated link in the queue */
223 DBusList *counter_link; /**< Preallocated link in the resource counter */
224 };
225
226 static dbus_bool_t _dbus_modify_sigpipe = TRUE;
227
228 /**
229 * Implementation details of DBusConnection. All fields are private.
230 */
231 struct DBusConnection
232 {
233 DBusAtomic refcount; /**< Reference count. */
234
235 DBusMutex *mutex; /**< Lock on the entire DBusConnection */
236
237 DBusMutex *dispatch_mutex; /**< Protects dispatch_acquired */
238 DBusCondVar *dispatch_cond; /**< Notify when dispatch_acquired is available */
239 DBusMutex *io_path_mutex; /**< Protects io_path_acquired */
240 DBusCondVar *io_path_cond; /**< Notify when io_path_acquired is available */
241
242 DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */
243 DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */
244
245 DBusMessage *message_borrowed; /**< Filled in if the first incoming message has been borrowed;
246 * dispatch_acquired will be set by the borrower
247 */
248
249 int n_outgoing; /**< Length of outgoing queue. */
250 int n_incoming; /**< Length of incoming queue. */
251
252 DBusCounter *outgoing_counter; /**< Counts size of outgoing messages. */
253
254 DBusTransport *transport; /**< Object that sends/receives messages over network. */
255 DBusWatchList *watches; /**< Stores active watches. */
256 DBusTimeoutList *timeouts; /**< Stores active timeouts. */
257
258 DBusList *filter_list; /**< List of filters. */
259
260 DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */
261
262 DBusHashTable *pending_replies; /**< Hash of message serials to #DBusPendingCall. */
263
264 dbus_uint32_t client_serial; /**< Client serial. Increments each time a message is sent */
265 DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */
266
267 DBusWakeupMainFunction wakeup_main_function; /**< Function to wake up the mainloop */
268 void *wakeup_main_data; /**< Application data for wakeup_main_function */
269 DBusFreeFunction free_wakeup_main_data; /**< free wakeup_main_data */
270
271 DBusDispatchStatusFunction dispatch_status_function; /**< Function on dispatch status changes */
272 void *dispatch_status_data; /**< Application data for dispatch_status_function */
273 DBusFreeFunction free_dispatch_status_data; /**< free dispatch_status_data */
274
275 DBusDispatchStatus last_dispatch_status; /**< The last dispatch status we reported to the application. */
276
277 DBusList *link_cache; /**< A cache of linked list links to prevent contention
278 * for the global linked list mempool lock
279 */
280 DBusObjectTree *objects; /**< Object path handlers registered with this connection */
281
282 char *server_guid; /**< GUID of server if we are in shared_connections, #NULL if server GUID is unknown or connection is private */
283
284 /* These two MUST be bools and not bitfields, because they are protected by a separate lock
285 * from connection->mutex and all bitfields in a word have to be read/written together.
286 * So you can't have a different lock for different bitfields in the same word.
287 */
288 dbus_bool_t dispatch_acquired; /**< Someone has dispatch path (can drain incoming queue) */
289 dbus_bool_t io_path_acquired; /**< Someone has transport io path (can use the transport to read/write messages) */
290
291 unsigned int shareable : 1; /**< #TRUE if libdbus owns a reference to the connection and can return it from dbus_connection_open() more than once */
292
293 unsigned int exit_on_disconnect : 1; /**< If #TRUE, exit after handling disconnect signal */
294
295 unsigned int route_peer_messages : 1; /**< If #TRUE, if org.freedesktop.DBus.Peer messages have a bus name, don't handle them automatically */
296
297 unsigned int disconnected_message_arrived : 1; /**< We popped or are dispatching the disconnected message.
298 * if the disconnect_message_link is NULL then we queued it, but
299 * this flag is whether it got to the head of the queue.
300 */
301 unsigned int disconnected_message_processed : 1; /**< We did our default handling of the disconnected message,
302 * such as closing the connection.
303 */
304
305 #ifndef DBUS_DISABLE_CHECKS
306 unsigned int have_connection_lock : 1; /**< Used to check locking */
307 #endif
308
309 #ifndef DBUS_DISABLE_CHECKS
310 int generation; /**< _dbus_current_generation that should correspond to this connection */
311 #endif
312 };
313
314 static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection);
315 static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection,
316 DBusDispatchStatus new_status);
317 static void _dbus_connection_last_unref (DBusConnection *connection);
318 static void _dbus_connection_acquire_dispatch (DBusConnection *connection);
319 static void _dbus_connection_release_dispatch (DBusConnection *connection);
320 static DBusDispatchStatus _dbus_connection_flush_unlocked (DBusConnection *connection);
321 static void _dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection);
322 static dbus_bool_t _dbus_connection_get_is_connected_unlocked (DBusConnection *connection);
323 static dbus_bool_t _dbus_connection_peek_for_reply_unlocked (DBusConnection *connection,
324 dbus_uint32_t client_serial);
325
326 static DBusMessageFilter *
_dbus_message_filter_ref(DBusMessageFilter * filter)327 _dbus_message_filter_ref (DBusMessageFilter *filter)
328 {
329 _dbus_assert (filter->refcount.value > 0);
330 _dbus_atomic_inc (&filter->refcount);
331
332 return filter;
333 }
334
335 static void
_dbus_message_filter_unref(DBusMessageFilter * filter)336 _dbus_message_filter_unref (DBusMessageFilter *filter)
337 {
338 _dbus_assert (filter->refcount.value > 0);
339
340 if (_dbus_atomic_dec (&filter->refcount) == 1)
341 {
342 if (filter->free_user_data_function)
343 (* filter->free_user_data_function) (filter->user_data);
344
345 dbus_free (filter);
346 }
347 }
348
349 /**
350 * Acquires the connection lock.
351 *
352 * @param connection the connection.
353 */
354 void
_dbus_connection_lock(DBusConnection * connection)355 _dbus_connection_lock (DBusConnection *connection)
356 {
357 CONNECTION_LOCK (connection);
358 }
359
360 /**
361 * Releases the connection lock.
362 *
363 * @param connection the connection.
364 */
365 void
_dbus_connection_unlock(DBusConnection * connection)366 _dbus_connection_unlock (DBusConnection *connection)
367 {
368 CONNECTION_UNLOCK (connection);
369 }
370
371 /**
372 * Wakes up the main loop if it is sleeping
373 * Needed if we're e.g. queueing outgoing messages
374 * on a thread while the mainloop sleeps.
375 *
376 * @param connection the connection.
377 */
378 static void
_dbus_connection_wakeup_mainloop(DBusConnection * connection)379 _dbus_connection_wakeup_mainloop (DBusConnection *connection)
380 {
381 if (connection->wakeup_main_function)
382 (*connection->wakeup_main_function) (connection->wakeup_main_data);
383 }
384
385 #ifdef DBUS_BUILD_TESTS
386 /* For now this function isn't used */
387 /**
388 * Adds a message to the incoming message queue, returning #FALSE
389 * if there's insufficient memory to queue the message.
390 * Does not take over refcount of the message.
391 *
392 * @param connection the connection.
393 * @param message the message to queue.
394 * @returns #TRUE on success.
395 */
396 dbus_bool_t
_dbus_connection_queue_received_message(DBusConnection * connection,DBusMessage * message)397 _dbus_connection_queue_received_message (DBusConnection *connection,
398 DBusMessage *message)
399 {
400 DBusList *link;
401
402 link = _dbus_list_alloc_link (message);
403 if (link == NULL)
404 return FALSE;
405
406 dbus_message_ref (message);
407 _dbus_connection_queue_received_message_link (connection, link);
408
409 return TRUE;
410 }
411
412 /**
413 * Gets the locks so we can examine them
414 *
415 * @param connection the connection.
416 * @param mutex_loc return for the location of the main mutex pointer
417 * @param dispatch_mutex_loc return location of the dispatch mutex pointer
418 * @param io_path_mutex_loc return location of the io_path mutex pointer
419 * @param dispatch_cond_loc return location of the dispatch conditional
420 * variable pointer
421 * @param io_path_cond_loc return location of the io_path conditional
422 * variable pointer
423 */
424 void
_dbus_connection_test_get_locks(DBusConnection * connection,DBusMutex ** mutex_loc,DBusMutex ** dispatch_mutex_loc,DBusMutex ** io_path_mutex_loc,DBusCondVar ** dispatch_cond_loc,DBusCondVar ** io_path_cond_loc)425 _dbus_connection_test_get_locks (DBusConnection *connection,
426 DBusMutex **mutex_loc,
427 DBusMutex **dispatch_mutex_loc,
428 DBusMutex **io_path_mutex_loc,
429 DBusCondVar **dispatch_cond_loc,
430 DBusCondVar **io_path_cond_loc)
431 {
432 *mutex_loc = connection->mutex;
433 *dispatch_mutex_loc = connection->dispatch_mutex;
434 *io_path_mutex_loc = connection->io_path_mutex;
435 *dispatch_cond_loc = connection->dispatch_cond;
436 *io_path_cond_loc = connection->io_path_cond;
437 }
438 #endif
439
440 /**
441 * Adds a message-containing list link to the incoming message queue,
442 * taking ownership of the link and the message's current refcount.
443 * Cannot fail due to lack of memory.
444 *
445 * @param connection the connection.
446 * @param link the message link to queue.
447 */
448 void
_dbus_connection_queue_received_message_link(DBusConnection * connection,DBusList * link)449 _dbus_connection_queue_received_message_link (DBusConnection *connection,
450 DBusList *link)
451 {
452 DBusPendingCall *pending;
453 dbus_int32_t reply_serial;
454 DBusMessage *message;
455
456 _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport));
457
458 _dbus_list_append_link (&connection->incoming_messages,
459 link);
460 message = link->data;
461
462 /* If this is a reply we're waiting on, remove timeout for it */
463 reply_serial = dbus_message_get_reply_serial (message);
464 if (reply_serial != -1)
465 {
466 pending = _dbus_hash_table_lookup_int (connection->pending_replies,
467 reply_serial);
468 if (pending != NULL)
469 {
470 if (_dbus_pending_call_is_timeout_added_unlocked (pending))
471 _dbus_connection_remove_timeout_unlocked (connection,
472 _dbus_pending_call_get_timeout_unlocked (pending));
473
474 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
475 }
476 }
477
478
479
480 connection->n_incoming += 1;
481
482 _dbus_connection_wakeup_mainloop (connection);
483
484 _dbus_verbose ("Message %p (%d %s %s %s '%s' reply to %u) added to incoming queue %p, %d incoming\n",
485 message,
486 dbus_message_get_type (message),
487 dbus_message_get_path (message) ?
488 dbus_message_get_path (message) :
489 "no path",
490 dbus_message_get_interface (message) ?
491 dbus_message_get_interface (message) :
492 "no interface",
493 dbus_message_get_member (message) ?
494 dbus_message_get_member (message) :
495 "no member",
496 dbus_message_get_signature (message),
497 dbus_message_get_reply_serial (message),
498 connection,
499 connection->n_incoming);}
500
501 /**
502 * Adds a link + message to the incoming message queue.
503 * Can't fail. Takes ownership of both link and message.
504 *
505 * @param connection the connection.
506 * @param link the list node and message to queue.
507 *
508 */
509 void
_dbus_connection_queue_synthesized_message_link(DBusConnection * connection,DBusList * link)510 _dbus_connection_queue_synthesized_message_link (DBusConnection *connection,
511 DBusList *link)
512 {
513 HAVE_LOCK_CHECK (connection);
514
515 _dbus_list_append_link (&connection->incoming_messages, link);
516
517 connection->n_incoming += 1;
518
519 _dbus_connection_wakeup_mainloop (connection);
520
521 _dbus_verbose ("Synthesized message %p added to incoming queue %p, %d incoming\n",
522 link->data, connection, connection->n_incoming);
523 }
524
525
526 /**
527 * Checks whether there are messages in the outgoing message queue.
528 * Called with connection lock held.
529 *
530 * @param connection the connection.
531 * @returns #TRUE if the outgoing queue is non-empty.
532 */
533 dbus_bool_t
_dbus_connection_has_messages_to_send_unlocked(DBusConnection * connection)534 _dbus_connection_has_messages_to_send_unlocked (DBusConnection *connection)
535 {
536 HAVE_LOCK_CHECK (connection);
537 return connection->outgoing_messages != NULL;
538 }
539
540 /**
541 * Checks whether there are messages in the outgoing message queue.
542 * Use dbus_connection_flush() to block until all outgoing
543 * messages have been written to the underlying transport
544 * (such as a socket).
545 *
546 * @param connection the connection.
547 * @returns #TRUE if the outgoing queue is non-empty.
548 */
549 dbus_bool_t
dbus_connection_has_messages_to_send(DBusConnection * connection)550 dbus_connection_has_messages_to_send (DBusConnection *connection)
551 {
552 dbus_bool_t v;
553
554 _dbus_return_val_if_fail (connection != NULL, FALSE);
555
556 CONNECTION_LOCK (connection);
557 v = _dbus_connection_has_messages_to_send_unlocked (connection);
558 CONNECTION_UNLOCK (connection);
559
560 return v;
561 }
562
563 /**
564 * Gets the next outgoing message. The message remains in the
565 * queue, and the caller does not own a reference to it.
566 *
567 * @param connection the connection.
568 * @returns the message to be sent.
569 */
570 DBusMessage*
_dbus_connection_get_message_to_send(DBusConnection * connection)571 _dbus_connection_get_message_to_send (DBusConnection *connection)
572 {
573 HAVE_LOCK_CHECK (connection);
574
575 return _dbus_list_get_last (&connection->outgoing_messages);
576 }
577
578 /**
579 * Notifies the connection that a message has been sent, so the
580 * message can be removed from the outgoing queue.
581 * Called with the connection lock held.
582 *
583 * @param connection the connection.
584 * @param message the message that was sent.
585 */
586 void
_dbus_connection_message_sent(DBusConnection * connection,DBusMessage * message)587 _dbus_connection_message_sent (DBusConnection *connection,
588 DBusMessage *message)
589 {
590 DBusList *link;
591
592 HAVE_LOCK_CHECK (connection);
593
594 /* This can be called before we even complete authentication, since
595 * it's called on disconnect to clean up the outgoing queue.
596 * It's also called as we successfully send each message.
597 */
598
599 link = _dbus_list_get_last_link (&connection->outgoing_messages);
600 _dbus_assert (link != NULL);
601 _dbus_assert (link->data == message);
602
603 /* Save this link in the link cache */
604 _dbus_list_unlink (&connection->outgoing_messages,
605 link);
606 _dbus_list_prepend_link (&connection->link_cache, link);
607
608 connection->n_outgoing -= 1;
609
610 _dbus_verbose ("Message %p (%d %s %s %s '%s') removed from outgoing queue %p, %d left to send\n",
611 message,
612 dbus_message_get_type (message),
613 dbus_message_get_path (message) ?
614 dbus_message_get_path (message) :
615 "no path",
616 dbus_message_get_interface (message) ?
617 dbus_message_get_interface (message) :
618 "no interface",
619 dbus_message_get_member (message) ?
620 dbus_message_get_member (message) :
621 "no member",
622 dbus_message_get_signature (message),
623 connection, connection->n_outgoing);
624
625 /* Save this link in the link cache also */
626 _dbus_message_remove_size_counter (message, connection->outgoing_counter,
627 &link);
628 _dbus_list_prepend_link (&connection->link_cache, link);
629
630 dbus_message_unref (message);
631 }
632
633 /** Function to be called in protected_change_watch() with refcount held */
634 typedef dbus_bool_t (* DBusWatchAddFunction) (DBusWatchList *list,
635 DBusWatch *watch);
636 /** Function to be called in protected_change_watch() with refcount held */
637 typedef void (* DBusWatchRemoveFunction) (DBusWatchList *list,
638 DBusWatch *watch);
639 /** Function to be called in protected_change_watch() with refcount held */
640 typedef void (* DBusWatchToggleFunction) (DBusWatchList *list,
641 DBusWatch *watch,
642 dbus_bool_t enabled);
643
644 static dbus_bool_t
protected_change_watch(DBusConnection * connection,DBusWatch * watch,DBusWatchAddFunction add_function,DBusWatchRemoveFunction remove_function,DBusWatchToggleFunction toggle_function,dbus_bool_t enabled)645 protected_change_watch (DBusConnection *connection,
646 DBusWatch *watch,
647 DBusWatchAddFunction add_function,
648 DBusWatchRemoveFunction remove_function,
649 DBusWatchToggleFunction toggle_function,
650 dbus_bool_t enabled)
651 {
652 DBusWatchList *watches;
653 dbus_bool_t retval;
654
655 HAVE_LOCK_CHECK (connection);
656
657 /* This isn't really safe or reasonable; a better pattern is the "do everything, then
658 * drop lock and call out" one; but it has to be propagated up through all callers
659 */
660
661 watches = connection->watches;
662 if (watches)
663 {
664 connection->watches = NULL;
665 _dbus_connection_ref_unlocked (connection);
666 CONNECTION_UNLOCK (connection);
667
668 if (add_function)
669 retval = (* add_function) (watches, watch);
670 else if (remove_function)
671 {
672 retval = TRUE;
673 (* remove_function) (watches, watch);
674 }
675 else
676 {
677 retval = TRUE;
678 (* toggle_function) (watches, watch, enabled);
679 }
680
681 CONNECTION_LOCK (connection);
682 connection->watches = watches;
683 _dbus_connection_unref_unlocked (connection);
684
685 return retval;
686 }
687 else
688 return FALSE;
689 }
690
691
692 /**
693 * Adds a watch using the connection's DBusAddWatchFunction if
694 * available. Otherwise records the watch to be added when said
695 * function is available. Also re-adds the watch if the
696 * DBusAddWatchFunction changes. May fail due to lack of memory.
697 * Connection lock should be held when calling this.
698 *
699 * @param connection the connection.
700 * @param watch the watch to add.
701 * @returns #TRUE on success.
702 */
703 dbus_bool_t
_dbus_connection_add_watch_unlocked(DBusConnection * connection,DBusWatch * watch)704 _dbus_connection_add_watch_unlocked (DBusConnection *connection,
705 DBusWatch *watch)
706 {
707 return protected_change_watch (connection, watch,
708 _dbus_watch_list_add_watch,
709 NULL, NULL, FALSE);
710 }
711
712 /**
713 * Removes a watch using the connection's DBusRemoveWatchFunction
714 * if available. It's an error to call this function on a watch
715 * that was not previously added.
716 * Connection lock should be held when calling this.
717 *
718 * @param connection the connection.
719 * @param watch the watch to remove.
720 */
721 void
_dbus_connection_remove_watch_unlocked(DBusConnection * connection,DBusWatch * watch)722 _dbus_connection_remove_watch_unlocked (DBusConnection *connection,
723 DBusWatch *watch)
724 {
725 protected_change_watch (connection, watch,
726 NULL,
727 _dbus_watch_list_remove_watch,
728 NULL, FALSE);
729 }
730
731 /**
732 * Toggles a watch and notifies app via connection's
733 * DBusWatchToggledFunction if available. It's an error to call this
734 * function on a watch that was not previously added.
735 * Connection lock should be held when calling this.
736 *
737 * @param connection the connection.
738 * @param watch the watch to toggle.
739 * @param enabled whether to enable or disable
740 */
741 void
_dbus_connection_toggle_watch_unlocked(DBusConnection * connection,DBusWatch * watch,dbus_bool_t enabled)742 _dbus_connection_toggle_watch_unlocked (DBusConnection *connection,
743 DBusWatch *watch,
744 dbus_bool_t enabled)
745 {
746 _dbus_assert (watch != NULL);
747
748 protected_change_watch (connection, watch,
749 NULL, NULL,
750 _dbus_watch_list_toggle_watch,
751 enabled);
752 }
753
754 /** Function to be called in protected_change_timeout() with refcount held */
755 typedef dbus_bool_t (* DBusTimeoutAddFunction) (DBusTimeoutList *list,
756 DBusTimeout *timeout);
757 /** Function to be called in protected_change_timeout() with refcount held */
758 typedef void (* DBusTimeoutRemoveFunction) (DBusTimeoutList *list,
759 DBusTimeout *timeout);
760 /** Function to be called in protected_change_timeout() with refcount held */
761 typedef void (* DBusTimeoutToggleFunction) (DBusTimeoutList *list,
762 DBusTimeout *timeout,
763 dbus_bool_t enabled);
764
765 static dbus_bool_t
protected_change_timeout(DBusConnection * connection,DBusTimeout * timeout,DBusTimeoutAddFunction add_function,DBusTimeoutRemoveFunction remove_function,DBusTimeoutToggleFunction toggle_function,dbus_bool_t enabled)766 protected_change_timeout (DBusConnection *connection,
767 DBusTimeout *timeout,
768 DBusTimeoutAddFunction add_function,
769 DBusTimeoutRemoveFunction remove_function,
770 DBusTimeoutToggleFunction toggle_function,
771 dbus_bool_t enabled)
772 {
773 DBusTimeoutList *timeouts;
774 dbus_bool_t retval;
775
776 HAVE_LOCK_CHECK (connection);
777
778 /* This isn't really safe or reasonable; a better pattern is the "do everything, then
779 * drop lock and call out" one; but it has to be propagated up through all callers
780 */
781
782 timeouts = connection->timeouts;
783 if (timeouts)
784 {
785 connection->timeouts = NULL;
786 _dbus_connection_ref_unlocked (connection);
787 CONNECTION_UNLOCK (connection);
788
789 if (add_function)
790 retval = (* add_function) (timeouts, timeout);
791 else if (remove_function)
792 {
793 retval = TRUE;
794 (* remove_function) (timeouts, timeout);
795 }
796 else
797 {
798 retval = TRUE;
799 (* toggle_function) (timeouts, timeout, enabled);
800 }
801
802 CONNECTION_LOCK (connection);
803 connection->timeouts = timeouts;
804 _dbus_connection_unref_unlocked (connection);
805
806 return retval;
807 }
808 else
809 return FALSE;
810 }
811
812 /**
813 * Adds a timeout using the connection's DBusAddTimeoutFunction if
814 * available. Otherwise records the timeout to be added when said
815 * function is available. Also re-adds the timeout if the
816 * DBusAddTimeoutFunction changes. May fail due to lack of memory.
817 * The timeout will fire repeatedly until removed.
818 * Connection lock should be held when calling this.
819 *
820 * @param connection the connection.
821 * @param timeout the timeout to add.
822 * @returns #TRUE on success.
823 */
824 dbus_bool_t
_dbus_connection_add_timeout_unlocked(DBusConnection * connection,DBusTimeout * timeout)825 _dbus_connection_add_timeout_unlocked (DBusConnection *connection,
826 DBusTimeout *timeout)
827 {
828 return protected_change_timeout (connection, timeout,
829 _dbus_timeout_list_add_timeout,
830 NULL, NULL, FALSE);
831 }
832
833 /**
834 * Removes a timeout using the connection's DBusRemoveTimeoutFunction
835 * if available. It's an error to call this function on a timeout
836 * that was not previously added.
837 * Connection lock should be held when calling this.
838 *
839 * @param connection the connection.
840 * @param timeout the timeout to remove.
841 */
842 void
_dbus_connection_remove_timeout_unlocked(DBusConnection * connection,DBusTimeout * timeout)843 _dbus_connection_remove_timeout_unlocked (DBusConnection *connection,
844 DBusTimeout *timeout)
845 {
846 protected_change_timeout (connection, timeout,
847 NULL,
848 _dbus_timeout_list_remove_timeout,
849 NULL, FALSE);
850 }
851
852 /**
853 * Toggles a timeout and notifies app via connection's
854 * DBusTimeoutToggledFunction if available. It's an error to call this
855 * function on a timeout that was not previously added.
856 * Connection lock should be held when calling this.
857 *
858 * @param connection the connection.
859 * @param timeout the timeout to toggle.
860 * @param enabled whether to enable or disable
861 */
862 void
_dbus_connection_toggle_timeout_unlocked(DBusConnection * connection,DBusTimeout * timeout,dbus_bool_t enabled)863 _dbus_connection_toggle_timeout_unlocked (DBusConnection *connection,
864 DBusTimeout *timeout,
865 dbus_bool_t enabled)
866 {
867 protected_change_timeout (connection, timeout,
868 NULL, NULL,
869 _dbus_timeout_list_toggle_timeout,
870 enabled);
871 }
872
873 static dbus_bool_t
_dbus_connection_attach_pending_call_unlocked(DBusConnection * connection,DBusPendingCall * pending)874 _dbus_connection_attach_pending_call_unlocked (DBusConnection *connection,
875 DBusPendingCall *pending)
876 {
877 dbus_uint32_t reply_serial;
878 DBusTimeout *timeout;
879
880 HAVE_LOCK_CHECK (connection);
881
882 reply_serial = _dbus_pending_call_get_reply_serial_unlocked (pending);
883
884 _dbus_assert (reply_serial != 0);
885
886 timeout = _dbus_pending_call_get_timeout_unlocked (pending);
887
888 if (!_dbus_connection_add_timeout_unlocked (connection, timeout))
889 return FALSE;
890
891 if (!_dbus_hash_table_insert_int (connection->pending_replies,
892 reply_serial,
893 pending))
894 {
895 _dbus_connection_remove_timeout_unlocked (connection, timeout);
896
897 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
898 HAVE_LOCK_CHECK (connection);
899 return FALSE;
900 }
901
902 _dbus_pending_call_set_timeout_added_unlocked (pending, TRUE);
903
904 _dbus_pending_call_ref_unlocked (pending);
905
906 HAVE_LOCK_CHECK (connection);
907
908 return TRUE;
909 }
910
911 static void
free_pending_call_on_hash_removal(void * data)912 free_pending_call_on_hash_removal (void *data)
913 {
914 DBusPendingCall *pending;
915 DBusConnection *connection;
916
917 if (data == NULL)
918 return;
919
920 pending = data;
921
922 connection = _dbus_pending_call_get_connection_unlocked (pending);
923
924 HAVE_LOCK_CHECK (connection);
925
926 if (_dbus_pending_call_is_timeout_added_unlocked (pending))
927 {
928 _dbus_connection_remove_timeout_unlocked (connection,
929 _dbus_pending_call_get_timeout_unlocked (pending));
930
931 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
932 }
933
934 /* FIXME 1.0? this is sort of dangerous and undesirable to drop the lock
935 * here, but the pending call finalizer could in principle call out to
936 * application code so we pretty much have to... some larger code reorg
937 * might be needed.
938 */
939 _dbus_connection_ref_unlocked (connection);
940 _dbus_pending_call_unref_and_unlock (pending);
941 CONNECTION_LOCK (connection);
942 _dbus_connection_unref_unlocked (connection);
943 }
944
945 static void
_dbus_connection_detach_pending_call_unlocked(DBusConnection * connection,DBusPendingCall * pending)946 _dbus_connection_detach_pending_call_unlocked (DBusConnection *connection,
947 DBusPendingCall *pending)
948 {
949 /* This ends up unlocking to call the pending call finalizer, which is unexpected to
950 * say the least.
951 */
952 _dbus_hash_table_remove_int (connection->pending_replies,
953 _dbus_pending_call_get_reply_serial_unlocked (pending));
954 }
955
956 static void
_dbus_connection_detach_pending_call_and_unlock(DBusConnection * connection,DBusPendingCall * pending)957 _dbus_connection_detach_pending_call_and_unlock (DBusConnection *connection,
958 DBusPendingCall *pending)
959 {
960 /* The idea here is to avoid finalizing the pending call
961 * with the lock held, since there's a destroy notifier
962 * in pending call that goes out to application code.
963 *
964 * There's an extra unlock inside the hash table
965 * "free pending call" function FIXME...
966 */
967 _dbus_pending_call_ref_unlocked (pending);
968 _dbus_hash_table_remove_int (connection->pending_replies,
969 _dbus_pending_call_get_reply_serial_unlocked (pending));
970 _dbus_pending_call_unref_and_unlock (pending);
971 }
972
973 /**
974 * Removes a pending call from the connection, such that
975 * the pending reply will be ignored. May drop the last
976 * reference to the pending call.
977 *
978 * @param connection the connection
979 * @param pending the pending call
980 */
981 void
_dbus_connection_remove_pending_call(DBusConnection * connection,DBusPendingCall * pending)982 _dbus_connection_remove_pending_call (DBusConnection *connection,
983 DBusPendingCall *pending)
984 {
985 CONNECTION_LOCK (connection);
986 _dbus_connection_detach_pending_call_and_unlock (connection, pending);
987 }
988
989 /**
990 * Acquire the transporter I/O path. This must be done before
991 * doing any I/O in the transporter. May sleep and drop the
992 * IO path mutex while waiting for the I/O path.
993 *
994 * @param connection the connection.
995 * @param timeout_milliseconds maximum blocking time, or -1 for no limit.
996 * @returns TRUE if the I/O path was acquired.
997 */
998 static dbus_bool_t
_dbus_connection_acquire_io_path(DBusConnection * connection,int timeout_milliseconds)999 _dbus_connection_acquire_io_path (DBusConnection *connection,
1000 int timeout_milliseconds)
1001 {
1002 dbus_bool_t we_acquired;
1003
1004 HAVE_LOCK_CHECK (connection);
1005
1006 /* We don't want the connection to vanish */
1007 _dbus_connection_ref_unlocked (connection);
1008
1009 /* We will only touch io_path_acquired which is protected by our mutex */
1010 CONNECTION_UNLOCK (connection);
1011
1012 _dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME);
1013 _dbus_mutex_lock (connection->io_path_mutex);
1014
1015 _dbus_verbose ("%s start connection->io_path_acquired = %d timeout = %d\n",
1016 _DBUS_FUNCTION_NAME, connection->io_path_acquired, timeout_milliseconds);
1017
1018 we_acquired = FALSE;
1019
1020 if (connection->io_path_acquired)
1021 {
1022 if (timeout_milliseconds != -1)
1023 {
1024 _dbus_verbose ("%s waiting %d for IO path to be acquirable\n",
1025 _DBUS_FUNCTION_NAME, timeout_milliseconds);
1026
1027 if (!_dbus_condvar_wait_timeout (connection->io_path_cond,
1028 connection->io_path_mutex,
1029 timeout_milliseconds))
1030 {
1031 /* We timed out before anyone signaled. */
1032 /* (writing the loop to handle the !timedout case by
1033 * waiting longer if needed is a pain since dbus
1034 * wraps pthread_cond_timedwait to take a relative
1035 * time instead of absolute, something kind of stupid
1036 * on our part. for now it doesn't matter, we will just
1037 * end up back here eventually.)
1038 */
1039 }
1040 }
1041 else
1042 {
1043 while (connection->io_path_acquired)
1044 {
1045 _dbus_verbose ("%s waiting for IO path to be acquirable\n", _DBUS_FUNCTION_NAME);
1046 _dbus_condvar_wait (connection->io_path_cond,
1047 connection->io_path_mutex);
1048 }
1049 }
1050 }
1051
1052 if (!connection->io_path_acquired)
1053 {
1054 we_acquired = TRUE;
1055 connection->io_path_acquired = TRUE;
1056 }
1057
1058 _dbus_verbose ("%s end connection->io_path_acquired = %d we_acquired = %d\n",
1059 _DBUS_FUNCTION_NAME, connection->io_path_acquired, we_acquired);
1060
1061 _dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME);
1062 _dbus_mutex_unlock (connection->io_path_mutex);
1063
1064 CONNECTION_LOCK (connection);
1065
1066 HAVE_LOCK_CHECK (connection);
1067
1068 _dbus_connection_unref_unlocked (connection);
1069
1070 return we_acquired;
1071 }
1072
1073 /**
1074 * Release the I/O path when you're done with it. Only call
1075 * after you've acquired the I/O. Wakes up at most one thread
1076 * currently waiting to acquire the I/O path.
1077 *
1078 * @param connection the connection.
1079 */
1080 static void
_dbus_connection_release_io_path(DBusConnection * connection)1081 _dbus_connection_release_io_path (DBusConnection *connection)
1082 {
1083 HAVE_LOCK_CHECK (connection);
1084
1085 _dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME);
1086 _dbus_mutex_lock (connection->io_path_mutex);
1087
1088 _dbus_assert (connection->io_path_acquired);
1089
1090 _dbus_verbose ("%s start connection->io_path_acquired = %d\n",
1091 _DBUS_FUNCTION_NAME, connection->io_path_acquired);
1092
1093 connection->io_path_acquired = FALSE;
1094 _dbus_condvar_wake_one (connection->io_path_cond);
1095
1096 _dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME);
1097 _dbus_mutex_unlock (connection->io_path_mutex);
1098 }
1099
1100 /**
1101 * Queues incoming messages and sends outgoing messages for this
1102 * connection, optionally blocking in the process. Each call to
1103 * _dbus_connection_do_iteration_unlocked() will call select() or poll() one
1104 * time and then read or write data if possible.
1105 *
1106 * The purpose of this function is to be able to flush outgoing
1107 * messages or queue up incoming messages without returning
1108 * control to the application and causing reentrancy weirdness.
1109 *
1110 * The flags parameter allows you to specify whether to
1111 * read incoming messages, write outgoing messages, or both,
1112 * and whether to block if no immediate action is possible.
1113 *
1114 * The timeout_milliseconds parameter does nothing unless the
1115 * iteration is blocking.
1116 *
1117 * If there are no outgoing messages and DBUS_ITERATION_DO_READING
1118 * wasn't specified, then it's impossible to block, even if
1119 * you specify DBUS_ITERATION_BLOCK; in that case the function
1120 * returns immediately.
1121 *
1122 * If pending is not NULL then a check is made if the pending call
1123 * is completed after the io path has been required. If the call
1124 * has been completed nothing is done. This must be done since
1125 * the _dbus_connection_acquire_io_path releases the connection
1126 * lock for a while.
1127 *
1128 * Called with connection lock held.
1129 *
1130 * @param connection the connection.
1131 * @param pending the pending call that should be checked or NULL
1132 * @param flags iteration flags.
1133 * @param timeout_milliseconds maximum blocking time, or -1 for no limit.
1134 */
1135 void
_dbus_connection_do_iteration_unlocked(DBusConnection * connection,DBusPendingCall * pending,unsigned int flags,int timeout_milliseconds)1136 _dbus_connection_do_iteration_unlocked (DBusConnection *connection,
1137 DBusPendingCall *pending,
1138 unsigned int flags,
1139 int timeout_milliseconds)
1140 {
1141 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
1142
1143 HAVE_LOCK_CHECK (connection);
1144
1145 if (connection->n_outgoing == 0)
1146 flags &= ~DBUS_ITERATION_DO_WRITING;
1147
1148 if (_dbus_connection_acquire_io_path (connection,
1149 (flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0))
1150 {
1151 HAVE_LOCK_CHECK (connection);
1152
1153 if ( (pending != NULL) && _dbus_pending_call_get_completed_unlocked(pending))
1154 {
1155 _dbus_verbose ("pending call completed while acquiring I/O path");
1156 }
1157 else if ( (pending != NULL) &&
1158 _dbus_connection_peek_for_reply_unlocked (connection,
1159 _dbus_pending_call_get_reply_serial_unlocked (pending)))
1160 {
1161 _dbus_verbose ("pending call completed while acquiring I/O path (reply found in queue)");
1162 }
1163 else
1164 {
1165 _dbus_transport_do_iteration (connection->transport,
1166 flags, timeout_milliseconds);
1167 }
1168
1169 _dbus_connection_release_io_path (connection);
1170 }
1171
1172 HAVE_LOCK_CHECK (connection);
1173
1174 _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME);
1175 }
1176
1177 /**
1178 * Creates a new connection for the given transport. A transport
1179 * represents a message stream that uses some concrete mechanism, such
1180 * as UNIX domain sockets. May return #NULL if insufficient
1181 * memory exists to create the connection.
1182 *
1183 * @param transport the transport.
1184 * @returns the new connection, or #NULL on failure.
1185 */
1186 DBusConnection*
_dbus_connection_new_for_transport(DBusTransport * transport)1187 _dbus_connection_new_for_transport (DBusTransport *transport)
1188 {
1189 DBusConnection *connection;
1190 DBusWatchList *watch_list;
1191 DBusTimeoutList *timeout_list;
1192 DBusHashTable *pending_replies;
1193 DBusList *disconnect_link;
1194 DBusMessage *disconnect_message;
1195 DBusCounter *outgoing_counter;
1196 DBusObjectTree *objects;
1197
1198 watch_list = NULL;
1199 connection = NULL;
1200 pending_replies = NULL;
1201 timeout_list = NULL;
1202 disconnect_link = NULL;
1203 disconnect_message = NULL;
1204 outgoing_counter = NULL;
1205 objects = NULL;
1206
1207 watch_list = _dbus_watch_list_new ();
1208 if (watch_list == NULL)
1209 goto error;
1210
1211 timeout_list = _dbus_timeout_list_new ();
1212 if (timeout_list == NULL)
1213 goto error;
1214
1215 pending_replies =
1216 _dbus_hash_table_new (DBUS_HASH_INT,
1217 NULL,
1218 (DBusFreeFunction)free_pending_call_on_hash_removal);
1219 if (pending_replies == NULL)
1220 goto error;
1221
1222 connection = dbus_new0 (DBusConnection, 1);
1223 if (connection == NULL)
1224 goto error;
1225
1226 _dbus_mutex_new_at_location (&connection->mutex);
1227 if (connection->mutex == NULL)
1228 goto error;
1229
1230 _dbus_mutex_new_at_location (&connection->io_path_mutex);
1231 if (connection->io_path_mutex == NULL)
1232 goto error;
1233
1234 _dbus_mutex_new_at_location (&connection->dispatch_mutex);
1235 if (connection->dispatch_mutex == NULL)
1236 goto error;
1237
1238 _dbus_condvar_new_at_location (&connection->dispatch_cond);
1239 if (connection->dispatch_cond == NULL)
1240 goto error;
1241
1242 _dbus_condvar_new_at_location (&connection->io_path_cond);
1243 if (connection->io_path_cond == NULL)
1244 goto error;
1245
1246 disconnect_message = dbus_message_new_signal (DBUS_PATH_LOCAL,
1247 DBUS_INTERFACE_LOCAL,
1248 "Disconnected");
1249
1250 if (disconnect_message == NULL)
1251 goto error;
1252
1253 disconnect_link = _dbus_list_alloc_link (disconnect_message);
1254 if (disconnect_link == NULL)
1255 goto error;
1256
1257 outgoing_counter = _dbus_counter_new ();
1258 if (outgoing_counter == NULL)
1259 goto error;
1260
1261 objects = _dbus_object_tree_new (connection);
1262 if (objects == NULL)
1263 goto error;
1264
1265 if (_dbus_modify_sigpipe)
1266 _dbus_disable_sigpipe ();
1267
1268 connection->refcount.value = 1;
1269 connection->transport = transport;
1270 connection->watches = watch_list;
1271 connection->timeouts = timeout_list;
1272 connection->pending_replies = pending_replies;
1273 connection->outgoing_counter = outgoing_counter;
1274 connection->filter_list = NULL;
1275 connection->last_dispatch_status = DBUS_DISPATCH_COMPLETE; /* so we're notified first time there's data */
1276 connection->objects = objects;
1277 connection->exit_on_disconnect = FALSE;
1278 connection->shareable = FALSE;
1279 connection->route_peer_messages = FALSE;
1280 connection->disconnected_message_arrived = FALSE;
1281 connection->disconnected_message_processed = FALSE;
1282
1283 #ifndef DBUS_DISABLE_CHECKS
1284 connection->generation = _dbus_current_generation;
1285 #endif
1286
1287 _dbus_data_slot_list_init (&connection->slot_list);
1288
1289 connection->client_serial = 1;
1290
1291 connection->disconnect_message_link = disconnect_link;
1292
1293 CONNECTION_LOCK (connection);
1294
1295 if (!_dbus_transport_set_connection (transport, connection))
1296 {
1297 CONNECTION_UNLOCK (connection);
1298
1299 goto error;
1300 }
1301
1302 _dbus_transport_ref (transport);
1303
1304 CONNECTION_UNLOCK (connection);
1305
1306 return connection;
1307
1308 error:
1309 if (disconnect_message != NULL)
1310 dbus_message_unref (disconnect_message);
1311
1312 if (disconnect_link != NULL)
1313 _dbus_list_free_link (disconnect_link);
1314
1315 if (connection != NULL)
1316 {
1317 _dbus_condvar_free_at_location (&connection->io_path_cond);
1318 _dbus_condvar_free_at_location (&connection->dispatch_cond);
1319 _dbus_mutex_free_at_location (&connection->mutex);
1320 _dbus_mutex_free_at_location (&connection->io_path_mutex);
1321 _dbus_mutex_free_at_location (&connection->dispatch_mutex);
1322 dbus_free (connection);
1323 }
1324 if (pending_replies)
1325 _dbus_hash_table_unref (pending_replies);
1326
1327 if (watch_list)
1328 _dbus_watch_list_free (watch_list);
1329
1330 if (timeout_list)
1331 _dbus_timeout_list_free (timeout_list);
1332
1333 if (outgoing_counter)
1334 _dbus_counter_unref (outgoing_counter);
1335
1336 if (objects)
1337 _dbus_object_tree_unref (objects);
1338
1339 return NULL;
1340 }
1341
1342 /**
1343 * Increments the reference count of a DBusConnection.
1344 * Requires that the caller already holds the connection lock.
1345 *
1346 * @param connection the connection.
1347 * @returns the connection.
1348 */
1349 DBusConnection *
_dbus_connection_ref_unlocked(DBusConnection * connection)1350 _dbus_connection_ref_unlocked (DBusConnection *connection)
1351 {
1352 _dbus_assert (connection != NULL);
1353 _dbus_assert (connection->generation == _dbus_current_generation);
1354
1355 HAVE_LOCK_CHECK (connection);
1356
1357 #ifdef DBUS_HAVE_ATOMIC_INT
1358 _dbus_atomic_inc (&connection->refcount);
1359 #else
1360 _dbus_assert (connection->refcount.value > 0);
1361 connection->refcount.value += 1;
1362 #endif
1363
1364 return connection;
1365 }
1366
1367 /**
1368 * Decrements the reference count of a DBusConnection.
1369 * Requires that the caller already holds the connection lock.
1370 *
1371 * @param connection the connection.
1372 */
1373 void
_dbus_connection_unref_unlocked(DBusConnection * connection)1374 _dbus_connection_unref_unlocked (DBusConnection *connection)
1375 {
1376 dbus_bool_t last_unref;
1377
1378 HAVE_LOCK_CHECK (connection);
1379
1380 _dbus_assert (connection != NULL);
1381
1382 /* The connection lock is better than the global
1383 * lock in the atomic increment fallback
1384 */
1385
1386 #ifdef DBUS_HAVE_ATOMIC_INT
1387 last_unref = (_dbus_atomic_dec (&connection->refcount) == 1);
1388 #else
1389 _dbus_assert (connection->refcount.value > 0);
1390
1391 connection->refcount.value -= 1;
1392 last_unref = (connection->refcount.value == 0);
1393 #if 0
1394 printf ("unref_unlocked() connection %p count = %d\n", connection, connection->refcount.value);
1395 #endif
1396 #endif
1397
1398 if (last_unref)
1399 _dbus_connection_last_unref (connection);
1400 }
1401
1402 static dbus_uint32_t
_dbus_connection_get_next_client_serial(DBusConnection * connection)1403 _dbus_connection_get_next_client_serial (DBusConnection *connection)
1404 {
1405 int serial;
1406
1407 serial = connection->client_serial++;
1408
1409 if (connection->client_serial < 0)
1410 connection->client_serial = 1;
1411
1412 return serial;
1413 }
1414
1415 /**
1416 * A callback for use with dbus_watch_new() to create a DBusWatch.
1417 *
1418 * @todo This is basically a hack - we could delete _dbus_transport_handle_watch()
1419 * and the virtual handle_watch in DBusTransport if we got rid of it.
1420 * The reason this is some work is threading, see the _dbus_connection_handle_watch()
1421 * implementation.
1422 *
1423 * @param watch the watch.
1424 * @param condition the current condition of the file descriptors being watched.
1425 * @param data must be a pointer to a #DBusConnection
1426 * @returns #FALSE if the IO condition may not have been fully handled due to lack of memory
1427 */
1428 dbus_bool_t
_dbus_connection_handle_watch(DBusWatch * watch,unsigned int condition,void * data)1429 _dbus_connection_handle_watch (DBusWatch *watch,
1430 unsigned int condition,
1431 void *data)
1432 {
1433 DBusConnection *connection;
1434 dbus_bool_t retval;
1435 DBusDispatchStatus status;
1436
1437 connection = data;
1438
1439 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
1440
1441 CONNECTION_LOCK (connection);
1442 _dbus_connection_acquire_io_path (connection, -1);
1443 HAVE_LOCK_CHECK (connection);
1444 retval = _dbus_transport_handle_watch (connection->transport,
1445 watch, condition);
1446
1447 _dbus_connection_release_io_path (connection);
1448
1449 HAVE_LOCK_CHECK (connection);
1450
1451 _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
1452
1453 status = _dbus_connection_get_dispatch_status_unlocked (connection);
1454
1455 /* this calls out to user code */
1456 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
1457
1458 _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME);
1459
1460 return retval;
1461 }
1462
1463 _DBUS_DEFINE_GLOBAL_LOCK (shared_connections);
1464 static DBusHashTable *shared_connections = NULL;
1465
1466 static void
shared_connections_shutdown(void * data)1467 shared_connections_shutdown (void *data)
1468 {
1469 int n_entries;
1470
1471 _DBUS_LOCK (shared_connections);
1472
1473 /* This is a little bit unpleasant... better ideas? */
1474 while ((n_entries = _dbus_hash_table_get_n_entries (shared_connections)) > 0)
1475 {
1476 DBusConnection *connection;
1477 DBusMessage *message;
1478 DBusHashIter iter;
1479
1480 _dbus_hash_iter_init (shared_connections, &iter);
1481 _dbus_hash_iter_next (&iter);
1482
1483 connection = _dbus_hash_iter_get_value (&iter);
1484
1485 _DBUS_UNLOCK (shared_connections);
1486
1487 dbus_connection_ref (connection);
1488 _dbus_connection_close_possibly_shared (connection);
1489
1490 /* Churn through to the Disconnected message */
1491 while ((message = dbus_connection_pop_message (connection)))
1492 {
1493 dbus_message_unref (message);
1494 }
1495 dbus_connection_unref (connection);
1496
1497 _DBUS_LOCK (shared_connections);
1498
1499 /* The connection should now be dead and not in our hash ... */
1500 _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) < n_entries);
1501 }
1502
1503 _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) == 0);
1504
1505 _dbus_hash_table_unref (shared_connections);
1506 shared_connections = NULL;
1507
1508 _DBUS_UNLOCK (shared_connections);
1509 }
1510
1511 static dbus_bool_t
connection_lookup_shared(DBusAddressEntry * entry,DBusConnection ** result)1512 connection_lookup_shared (DBusAddressEntry *entry,
1513 DBusConnection **result)
1514 {
1515 _dbus_verbose ("checking for existing connection\n");
1516
1517 *result = NULL;
1518
1519 _DBUS_LOCK (shared_connections);
1520
1521 if (shared_connections == NULL)
1522 {
1523 _dbus_verbose ("creating shared_connections hash table\n");
1524
1525 shared_connections = _dbus_hash_table_new (DBUS_HASH_STRING,
1526 dbus_free,
1527 NULL);
1528 if (shared_connections == NULL)
1529 {
1530 _DBUS_UNLOCK (shared_connections);
1531 return FALSE;
1532 }
1533
1534 if (!_dbus_register_shutdown_func (shared_connections_shutdown, NULL))
1535 {
1536 _dbus_hash_table_unref (shared_connections);
1537 shared_connections = NULL;
1538 _DBUS_UNLOCK (shared_connections);
1539 return FALSE;
1540 }
1541
1542 _dbus_verbose (" successfully created shared_connections\n");
1543
1544 _DBUS_UNLOCK (shared_connections);
1545 return TRUE; /* no point looking up in the hash we just made */
1546 }
1547 else
1548 {
1549 const char *guid;
1550
1551 guid = dbus_address_entry_get_value (entry, "guid");
1552
1553 if (guid != NULL)
1554 {
1555 DBusConnection *connection;
1556
1557 connection = _dbus_hash_table_lookup_string (shared_connections,
1558 guid);
1559
1560 if (connection)
1561 {
1562 /* The DBusConnection can't be finalized without taking
1563 * the shared_connections lock to remove it from the
1564 * hash. So it's safe to ref the connection here.
1565 * However, it may be disconnected if the Disconnected
1566 * message hasn't been processed yet, in which case we
1567 * want to pretend it isn't in the hash and avoid
1568 * returning it.
1569 *
1570 * The idea is to avoid ever returning a disconnected connection
1571 * from dbus_connection_open(). We could just synchronously
1572 * drop our shared ref to the connection on connection disconnect,
1573 * and then assert here that the connection is connected, but
1574 * that causes reentrancy headaches.
1575 */
1576 CONNECTION_LOCK (connection);
1577 if (_dbus_connection_get_is_connected_unlocked (connection))
1578 {
1579 _dbus_connection_ref_unlocked (connection);
1580 *result = connection;
1581 _dbus_verbose ("looked up existing connection to server guid %s\n",
1582 guid);
1583 }
1584 else
1585 {
1586 _dbus_verbose ("looked up existing connection to server guid %s but it was disconnected so ignoring it\n",
1587 guid);
1588 }
1589 CONNECTION_UNLOCK (connection);
1590 }
1591 }
1592
1593 _DBUS_UNLOCK (shared_connections);
1594 return TRUE;
1595 }
1596 }
1597
1598 static dbus_bool_t
connection_record_shared_unlocked(DBusConnection * connection,const char * guid)1599 connection_record_shared_unlocked (DBusConnection *connection,
1600 const char *guid)
1601 {
1602 char *guid_key;
1603 char *guid_in_connection;
1604
1605 HAVE_LOCK_CHECK (connection);
1606 _dbus_assert (connection->server_guid == NULL);
1607 _dbus_assert (connection->shareable);
1608
1609 /* get a hard ref on this connection, even if
1610 * we won't in fact store it in the hash, we still
1611 * need to hold a ref on it until it's disconnected.
1612 */
1613 _dbus_connection_ref_unlocked (connection);
1614
1615 if (guid == NULL)
1616 return TRUE; /* don't store in the hash */
1617
1618 /* A separate copy of the key is required in the hash table, because
1619 * we don't have a lock on the connection when we are doing a hash
1620 * lookup.
1621 */
1622
1623 guid_key = _dbus_strdup (guid);
1624 if (guid_key == NULL)
1625 return FALSE;
1626
1627 guid_in_connection = _dbus_strdup (guid);
1628 if (guid_in_connection == NULL)
1629 {
1630 dbus_free (guid_key);
1631 return FALSE;
1632 }
1633
1634 _DBUS_LOCK (shared_connections);
1635 _dbus_assert (shared_connections != NULL);
1636
1637 if (!_dbus_hash_table_insert_string (shared_connections,
1638 guid_key, connection))
1639 {
1640 dbus_free (guid_key);
1641 dbus_free (guid_in_connection);
1642 _DBUS_UNLOCK (shared_connections);
1643 return FALSE;
1644 }
1645
1646 connection->server_guid = guid_in_connection;
1647
1648 _dbus_verbose ("stored connection to %s to be shared\n",
1649 connection->server_guid);
1650
1651 _DBUS_UNLOCK (shared_connections);
1652
1653 _dbus_assert (connection->server_guid != NULL);
1654
1655 return TRUE;
1656 }
1657
1658 static void
connection_forget_shared_unlocked(DBusConnection * connection)1659 connection_forget_shared_unlocked (DBusConnection *connection)
1660 {
1661 HAVE_LOCK_CHECK (connection);
1662
1663 if (!connection->shareable)
1664 return;
1665
1666 if (connection->server_guid != NULL)
1667 {
1668 _dbus_verbose ("dropping connection to %s out of the shared table\n",
1669 connection->server_guid);
1670
1671 _DBUS_LOCK (shared_connections);
1672
1673 if (!_dbus_hash_table_remove_string (shared_connections,
1674 connection->server_guid))
1675 _dbus_assert_not_reached ("connection was not in the shared table");
1676
1677 dbus_free (connection->server_guid);
1678 connection->server_guid = NULL;
1679 _DBUS_UNLOCK (shared_connections);
1680 }
1681
1682 /* remove our reference held on all shareable connections */
1683 _dbus_connection_unref_unlocked (connection);
1684 }
1685
1686 static DBusConnection*
connection_try_from_address_entry(DBusAddressEntry * entry,DBusError * error)1687 connection_try_from_address_entry (DBusAddressEntry *entry,
1688 DBusError *error)
1689 {
1690 DBusTransport *transport;
1691 DBusConnection *connection;
1692
1693 transport = _dbus_transport_open (entry, error);
1694
1695 if (transport == NULL)
1696 {
1697 _DBUS_ASSERT_ERROR_IS_SET (error);
1698 return NULL;
1699 }
1700
1701 connection = _dbus_connection_new_for_transport (transport);
1702
1703 _dbus_transport_unref (transport);
1704
1705 if (connection == NULL)
1706 {
1707 _DBUS_SET_OOM (error);
1708 return NULL;
1709 }
1710
1711 #ifndef DBUS_DISABLE_CHECKS
1712 _dbus_assert (!connection->have_connection_lock);
1713 #endif
1714 return connection;
1715 }
1716
1717 /*
1718 * If the shared parameter is true, then any existing connection will
1719 * be used (and if a new connection is created, it will be available
1720 * for use by others). If the shared parameter is false, a new
1721 * connection will always be created, and the new connection will
1722 * never be returned to other callers.
1723 *
1724 * @param address the address
1725 * @param shared whether the connection is shared or private
1726 * @param error error return
1727 * @returns the connection or #NULL on error
1728 */
1729 static DBusConnection*
_dbus_connection_open_internal(const char * address,dbus_bool_t shared,DBusError * error)1730 _dbus_connection_open_internal (const char *address,
1731 dbus_bool_t shared,
1732 DBusError *error)
1733 {
1734 DBusConnection *connection;
1735 DBusAddressEntry **entries;
1736 DBusError tmp_error;
1737 DBusError first_error;
1738 int len, i;
1739
1740 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1741
1742 _dbus_verbose ("opening %s connection to: %s\n",
1743 shared ? "shared" : "private", address);
1744
1745 if (!dbus_parse_address (address, &entries, &len, error))
1746 return NULL;
1747
1748 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1749
1750 connection = NULL;
1751
1752 dbus_error_init (&tmp_error);
1753 dbus_error_init (&first_error);
1754 for (i = 0; i < len; i++)
1755 {
1756 if (shared)
1757 {
1758 if (!connection_lookup_shared (entries[i], &connection))
1759 _DBUS_SET_OOM (&tmp_error);
1760 }
1761
1762 if (connection == NULL)
1763 {
1764 connection = connection_try_from_address_entry (entries[i],
1765 &tmp_error);
1766
1767 if (connection != NULL && shared)
1768 {
1769 const char *guid;
1770
1771 connection->shareable = TRUE;
1772
1773 /* guid may be NULL */
1774 guid = dbus_address_entry_get_value (entries[i], "guid");
1775
1776 CONNECTION_LOCK (connection);
1777
1778 if (!connection_record_shared_unlocked (connection, guid))
1779 {
1780 _DBUS_SET_OOM (&tmp_error);
1781 _dbus_connection_close_possibly_shared_and_unlock (connection);
1782 dbus_connection_unref (connection);
1783 connection = NULL;
1784 }
1785 else
1786 CONNECTION_UNLOCK (connection);
1787 }
1788 }
1789
1790 if (connection)
1791 break;
1792
1793 _DBUS_ASSERT_ERROR_IS_SET (&tmp_error);
1794
1795 if (i == 0)
1796 dbus_move_error (&tmp_error, &first_error);
1797 else
1798 dbus_error_free (&tmp_error);
1799 }
1800
1801 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1802 _DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error);
1803
1804 if (connection == NULL)
1805 {
1806 _DBUS_ASSERT_ERROR_IS_SET (&first_error);
1807 dbus_move_error (&first_error, error);
1808 }
1809 else
1810 dbus_error_free (&first_error);
1811
1812 dbus_address_entries_free (entries);
1813 return connection;
1814 }
1815
1816 /**
1817 * Closes a shared OR private connection, while dbus_connection_close() can
1818 * only be used on private connections. Should only be called by the
1819 * dbus code that owns the connection - an owner must be known,
1820 * the open/close state is like malloc/free, not like ref/unref.
1821 *
1822 * @param connection the connection
1823 */
1824 void
_dbus_connection_close_possibly_shared(DBusConnection * connection)1825 _dbus_connection_close_possibly_shared (DBusConnection *connection)
1826 {
1827 _dbus_assert (connection != NULL);
1828 _dbus_assert (connection->generation == _dbus_current_generation);
1829
1830 CONNECTION_LOCK (connection);
1831 _dbus_connection_close_possibly_shared_and_unlock (connection);
1832 }
1833
1834 static DBusPreallocatedSend*
_dbus_connection_preallocate_send_unlocked(DBusConnection * connection)1835 _dbus_connection_preallocate_send_unlocked (DBusConnection *connection)
1836 {
1837 DBusPreallocatedSend *preallocated;
1838
1839 HAVE_LOCK_CHECK (connection);
1840
1841 _dbus_assert (connection != NULL);
1842
1843 preallocated = dbus_new (DBusPreallocatedSend, 1);
1844 if (preallocated == NULL)
1845 return NULL;
1846
1847 if (connection->link_cache != NULL)
1848 {
1849 preallocated->queue_link =
1850 _dbus_list_pop_first_link (&connection->link_cache);
1851 preallocated->queue_link->data = NULL;
1852 }
1853 else
1854 {
1855 preallocated->queue_link = _dbus_list_alloc_link (NULL);
1856 if (preallocated->queue_link == NULL)
1857 goto failed_0;
1858 }
1859
1860 if (connection->link_cache != NULL)
1861 {
1862 preallocated->counter_link =
1863 _dbus_list_pop_first_link (&connection->link_cache);
1864 preallocated->counter_link->data = connection->outgoing_counter;
1865 }
1866 else
1867 {
1868 preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter);
1869 if (preallocated->counter_link == NULL)
1870 goto failed_1;
1871 }
1872
1873 _dbus_counter_ref (preallocated->counter_link->data);
1874
1875 preallocated->connection = connection;
1876
1877 return preallocated;
1878
1879 failed_1:
1880 _dbus_list_free_link (preallocated->queue_link);
1881 failed_0:
1882 dbus_free (preallocated);
1883
1884 return NULL;
1885 }
1886
1887 /* Called with lock held, does not update dispatch status */
1888 static void
_dbus_connection_send_preallocated_unlocked_no_update(DBusConnection * connection,DBusPreallocatedSend * preallocated,DBusMessage * message,dbus_uint32_t * client_serial)1889 _dbus_connection_send_preallocated_unlocked_no_update (DBusConnection *connection,
1890 DBusPreallocatedSend *preallocated,
1891 DBusMessage *message,
1892 dbus_uint32_t *client_serial)
1893 {
1894 dbus_uint32_t serial;
1895 const char *sig;
1896
1897 preallocated->queue_link->data = message;
1898 _dbus_list_prepend_link (&connection->outgoing_messages,
1899 preallocated->queue_link);
1900
1901 _dbus_message_add_size_counter_link (message,
1902 preallocated->counter_link);
1903
1904 dbus_free (preallocated);
1905 preallocated = NULL;
1906
1907 dbus_message_ref (message);
1908
1909 connection->n_outgoing += 1;
1910
1911 sig = dbus_message_get_signature (message);
1912
1913 _dbus_verbose ("Message %p (%d %s %s %s '%s') for %s added to outgoing queue %p, %d pending to send\n",
1914 message,
1915 dbus_message_get_type (message),
1916 dbus_message_get_path (message) ?
1917 dbus_message_get_path (message) :
1918 "no path",
1919 dbus_message_get_interface (message) ?
1920 dbus_message_get_interface (message) :
1921 "no interface",
1922 dbus_message_get_member (message) ?
1923 dbus_message_get_member (message) :
1924 "no member",
1925 sig,
1926 dbus_message_get_destination (message) ?
1927 dbus_message_get_destination (message) :
1928 "null",
1929 connection,
1930 connection->n_outgoing);
1931
1932 if (dbus_message_get_serial (message) == 0)
1933 {
1934 serial = _dbus_connection_get_next_client_serial (connection);
1935 _dbus_message_set_serial (message, serial);
1936 if (client_serial)
1937 *client_serial = serial;
1938 }
1939 else
1940 {
1941 if (client_serial)
1942 *client_serial = dbus_message_get_serial (message);
1943 }
1944
1945 _dbus_verbose ("Message %p serial is %u\n",
1946 message, dbus_message_get_serial (message));
1947
1948 _dbus_message_lock (message);
1949
1950 /* Now we need to run an iteration to hopefully just write the messages
1951 * out immediately, and otherwise get them queued up
1952 */
1953 _dbus_connection_do_iteration_unlocked (connection,
1954 NULL,
1955 DBUS_ITERATION_DO_WRITING,
1956 -1);
1957
1958 /* If stuff is still queued up, be sure we wake up the main loop */
1959 if (connection->n_outgoing > 0)
1960 _dbus_connection_wakeup_mainloop (connection);
1961 }
1962
1963 static void
_dbus_connection_send_preallocated_and_unlock(DBusConnection * connection,DBusPreallocatedSend * preallocated,DBusMessage * message,dbus_uint32_t * client_serial)1964 _dbus_connection_send_preallocated_and_unlock (DBusConnection *connection,
1965 DBusPreallocatedSend *preallocated,
1966 DBusMessage *message,
1967 dbus_uint32_t *client_serial)
1968 {
1969 DBusDispatchStatus status;
1970
1971 HAVE_LOCK_CHECK (connection);
1972
1973 _dbus_connection_send_preallocated_unlocked_no_update (connection,
1974 preallocated,
1975 message, client_serial);
1976
1977 _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
1978 status = _dbus_connection_get_dispatch_status_unlocked (connection);
1979
1980 /* this calls out to user code */
1981 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
1982 }
1983
1984 /**
1985 * Like dbus_connection_send(), but assumes the connection
1986 * is already locked on function entry, and unlocks before returning.
1987 *
1988 * @param connection the connection
1989 * @param message the message to send
1990 * @param client_serial return location for client serial of sent message
1991 * @returns #FALSE on out-of-memory
1992 */
1993 dbus_bool_t
_dbus_connection_send_and_unlock(DBusConnection * connection,DBusMessage * message,dbus_uint32_t * client_serial)1994 _dbus_connection_send_and_unlock (DBusConnection *connection,
1995 DBusMessage *message,
1996 dbus_uint32_t *client_serial)
1997 {
1998 DBusPreallocatedSend *preallocated;
1999
2000 _dbus_assert (connection != NULL);
2001 _dbus_assert (message != NULL);
2002
2003 preallocated = _dbus_connection_preallocate_send_unlocked (connection);
2004 if (preallocated == NULL)
2005 {
2006 CONNECTION_UNLOCK (connection);
2007 return FALSE;
2008 }
2009
2010 _dbus_connection_send_preallocated_and_unlock (connection,
2011 preallocated,
2012 message,
2013 client_serial);
2014 return TRUE;
2015 }
2016
2017 /**
2018 * Used internally to handle the semantics of dbus_server_set_new_connection_function().
2019 * If the new connection function does not ref the connection, we want to close it.
2020 *
2021 * A bit of a hack, probably the new connection function should have returned a value
2022 * for whether to close, or should have had to close the connection itself if it
2023 * didn't want it.
2024 *
2025 * But, this works OK as long as the new connection function doesn't do anything
2026 * crazy like keep the connection around without ref'ing it.
2027 *
2028 * We have to lock the connection across refcount check and close in case
2029 * the new connection function spawns a thread that closes and unrefs.
2030 * In that case, if the app thread
2031 * closes and unrefs first, we'll harmlessly close again; if the app thread
2032 * still has the ref, we'll close and then the app will close harmlessly.
2033 * If the app unrefs without closing, the app is broken since if the
2034 * app refs from the new connection function it is supposed to also close.
2035 *
2036 * If we didn't atomically check the refcount and close with the lock held
2037 * though, we could screw this up.
2038 *
2039 * @param connection the connection
2040 */
2041 void
_dbus_connection_close_if_only_one_ref(DBusConnection * connection)2042 _dbus_connection_close_if_only_one_ref (DBusConnection *connection)
2043 {
2044 CONNECTION_LOCK (connection);
2045
2046 _dbus_assert (connection->refcount.value > 0);
2047
2048 if (connection->refcount.value == 1)
2049 _dbus_connection_close_possibly_shared_and_unlock (connection);
2050 else
2051 CONNECTION_UNLOCK (connection);
2052 }
2053
2054
2055 /**
2056 * When a function that blocks has been called with a timeout, and we
2057 * run out of memory, the time to wait for memory is based on the
2058 * timeout. If the caller was willing to block a long time we wait a
2059 * relatively long time for memory, if they were only willing to block
2060 * briefly then we retry for memory at a rapid rate.
2061 *
2062 * @timeout_milliseconds the timeout requested for blocking
2063 */
2064 static void
_dbus_memory_pause_based_on_timeout(int timeout_milliseconds)2065 _dbus_memory_pause_based_on_timeout (int timeout_milliseconds)
2066 {
2067 if (timeout_milliseconds == -1)
2068 _dbus_sleep_milliseconds (1000);
2069 else if (timeout_milliseconds < 100)
2070 ; /* just busy loop */
2071 else if (timeout_milliseconds <= 1000)
2072 _dbus_sleep_milliseconds (timeout_milliseconds / 3);
2073 else
2074 _dbus_sleep_milliseconds (1000);
2075 }
2076
2077 static DBusMessage *
generate_local_error_message(dbus_uint32_t serial,char * error_name,char * error_msg)2078 generate_local_error_message (dbus_uint32_t serial,
2079 char *error_name,
2080 char *error_msg)
2081 {
2082 DBusMessage *message;
2083 message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
2084 if (!message)
2085 goto out;
2086
2087 if (!dbus_message_set_error_name (message, error_name))
2088 {
2089 dbus_message_unref (message);
2090 message = NULL;
2091 goto out;
2092 }
2093
2094 dbus_message_set_no_reply (message, TRUE);
2095
2096 if (!dbus_message_set_reply_serial (message,
2097 serial))
2098 {
2099 dbus_message_unref (message);
2100 message = NULL;
2101 goto out;
2102 }
2103
2104 if (error_msg != NULL)
2105 {
2106 DBusMessageIter iter;
2107
2108 dbus_message_iter_init_append (message, &iter);
2109 if (!dbus_message_iter_append_basic (&iter,
2110 DBUS_TYPE_STRING,
2111 &error_msg))
2112 {
2113 dbus_message_unref (message);
2114 message = NULL;
2115 goto out;
2116 }
2117 }
2118
2119 out:
2120 return message;
2121 }
2122
2123 /*
2124 * Peek the incoming queue to see if we got reply for a specific serial
2125 */
2126 static dbus_bool_t
_dbus_connection_peek_for_reply_unlocked(DBusConnection * connection,dbus_uint32_t client_serial)2127 _dbus_connection_peek_for_reply_unlocked (DBusConnection *connection,
2128 dbus_uint32_t client_serial)
2129 {
2130 DBusList *link;
2131 HAVE_LOCK_CHECK (connection);
2132
2133 link = _dbus_list_get_first_link (&connection->incoming_messages);
2134
2135 while (link != NULL)
2136 {
2137 DBusMessage *reply = link->data;
2138
2139 if (dbus_message_get_reply_serial (reply) == client_serial)
2140 {
2141 _dbus_verbose ("%s reply to %d found in queue\n", _DBUS_FUNCTION_NAME, client_serial);
2142 return TRUE;
2143 }
2144 link = _dbus_list_get_next_link (&connection->incoming_messages, link);
2145 }
2146
2147 return FALSE;
2148 }
2149
2150 /* This is slightly strange since we can pop a message here without
2151 * the dispatch lock.
2152 */
2153 static DBusMessage*
check_for_reply_unlocked(DBusConnection * connection,dbus_uint32_t client_serial)2154 check_for_reply_unlocked (DBusConnection *connection,
2155 dbus_uint32_t client_serial)
2156 {
2157 DBusList *link;
2158
2159 HAVE_LOCK_CHECK (connection);
2160
2161 link = _dbus_list_get_first_link (&connection->incoming_messages);
2162
2163 while (link != NULL)
2164 {
2165 DBusMessage *reply = link->data;
2166
2167 if (dbus_message_get_reply_serial (reply) == client_serial)
2168 {
2169 _dbus_list_remove_link (&connection->incoming_messages, link);
2170 connection->n_incoming -= 1;
2171 return reply;
2172 }
2173 link = _dbus_list_get_next_link (&connection->incoming_messages, link);
2174 }
2175
2176 return NULL;
2177 }
2178
2179 static void
connection_timeout_and_complete_all_pending_calls_unlocked(DBusConnection * connection)2180 connection_timeout_and_complete_all_pending_calls_unlocked (DBusConnection *connection)
2181 {
2182 /* We can't iterate over the hash in the normal way since we'll be
2183 * dropping the lock for each item. So we restart the
2184 * iter each time as we drain the hash table.
2185 */
2186
2187 while (_dbus_hash_table_get_n_entries (connection->pending_replies) > 0)
2188 {
2189 DBusPendingCall *pending;
2190 DBusHashIter iter;
2191
2192 _dbus_hash_iter_init (connection->pending_replies, &iter);
2193 _dbus_hash_iter_next (&iter);
2194
2195 pending = _dbus_hash_iter_get_value (&iter);
2196 _dbus_pending_call_ref_unlocked (pending);
2197
2198 _dbus_pending_call_queue_timeout_error_unlocked (pending,
2199 connection);
2200 _dbus_connection_remove_timeout_unlocked (connection,
2201 _dbus_pending_call_get_timeout_unlocked (pending));
2202 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
2203 _dbus_hash_iter_remove_entry (&iter);
2204
2205 _dbus_pending_call_unref_and_unlock (pending);
2206 CONNECTION_LOCK (connection);
2207 }
2208 HAVE_LOCK_CHECK (connection);
2209 }
2210
2211 static void
complete_pending_call_and_unlock(DBusConnection * connection,DBusPendingCall * pending,DBusMessage * message)2212 complete_pending_call_and_unlock (DBusConnection *connection,
2213 DBusPendingCall *pending,
2214 DBusMessage *message)
2215 {
2216 _dbus_pending_call_set_reply_unlocked (pending, message);
2217 _dbus_pending_call_ref_unlocked (pending); /* in case there's no app with a ref held */
2218 _dbus_connection_detach_pending_call_and_unlock (connection, pending);
2219
2220 /* Must be called unlocked since it invokes app callback */
2221 _dbus_pending_call_complete (pending);
2222 dbus_pending_call_unref (pending);
2223 }
2224
2225 static dbus_bool_t
check_for_reply_and_update_dispatch_unlocked(DBusConnection * connection,DBusPendingCall * pending)2226 check_for_reply_and_update_dispatch_unlocked (DBusConnection *connection,
2227 DBusPendingCall *pending)
2228 {
2229 DBusMessage *reply;
2230 DBusDispatchStatus status;
2231
2232 reply = check_for_reply_unlocked (connection,
2233 _dbus_pending_call_get_reply_serial_unlocked (pending));
2234 if (reply != NULL)
2235 {
2236 _dbus_verbose ("%s checked for reply\n", _DBUS_FUNCTION_NAME);
2237
2238 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n");
2239
2240 complete_pending_call_and_unlock (connection, pending, reply);
2241 dbus_message_unref (reply);
2242
2243 CONNECTION_LOCK (connection);
2244 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2245 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
2246 dbus_pending_call_unref (pending);
2247
2248 return TRUE;
2249 }
2250
2251 return FALSE;
2252 }
2253
2254 /**
2255 * Blocks until a pending call times out or gets a reply.
2256 *
2257 * Does not re-enter the main loop or run filter/path-registered
2258 * callbacks. The reply to the message will not be seen by
2259 * filter callbacks.
2260 *
2261 * Returns immediately if pending call already got a reply.
2262 *
2263 * @todo could use performance improvements (it keeps scanning
2264 * the whole message queue for example)
2265 *
2266 * @param pending the pending call we block for a reply on
2267 */
2268 void
_dbus_connection_block_pending_call(DBusPendingCall * pending)2269 _dbus_connection_block_pending_call (DBusPendingCall *pending)
2270 {
2271 long start_tv_sec, start_tv_usec;
2272 long end_tv_sec, end_tv_usec;
2273 long tv_sec, tv_usec;
2274 DBusDispatchStatus status;
2275 DBusConnection *connection;
2276 dbus_uint32_t client_serial;
2277 int timeout_milliseconds;
2278
2279 _dbus_assert (pending != NULL);
2280
2281 if (dbus_pending_call_get_completed (pending))
2282 return;
2283
2284 dbus_pending_call_ref (pending); /* necessary because the call could be canceled */
2285
2286 connection = _dbus_pending_call_get_connection_and_lock (pending);
2287
2288 /* Flush message queue - note, can affect dispatch status */
2289 _dbus_connection_flush_unlocked (connection);
2290
2291 client_serial = _dbus_pending_call_get_reply_serial_unlocked (pending);
2292
2293 /* note that timeout_milliseconds is limited to a smallish value
2294 * in _dbus_pending_call_new() so overflows aren't possible
2295 * below
2296 */
2297 timeout_milliseconds = dbus_timeout_get_interval (_dbus_pending_call_get_timeout_unlocked (pending));
2298
2299 _dbus_get_current_time (&start_tv_sec, &start_tv_usec);
2300 end_tv_sec = start_tv_sec + timeout_milliseconds / 1000;
2301 end_tv_usec = start_tv_usec + (timeout_milliseconds % 1000) * 1000;
2302 end_tv_sec += end_tv_usec / _DBUS_USEC_PER_SECOND;
2303 end_tv_usec = end_tv_usec % _DBUS_USEC_PER_SECOND;
2304
2305 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block %d milliseconds for reply serial %u from %ld sec %ld usec to %ld sec %ld usec\n",
2306 timeout_milliseconds,
2307 client_serial,
2308 start_tv_sec, start_tv_usec,
2309 end_tv_sec, end_tv_usec);
2310
2311 /* check to see if we already got the data off the socket */
2312 /* from another blocked pending call */
2313 if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
2314 return;
2315
2316 /* Now we wait... */
2317 /* always block at least once as we know we don't have the reply yet */
2318 _dbus_connection_do_iteration_unlocked (connection,
2319 pending,
2320 DBUS_ITERATION_DO_READING |
2321 DBUS_ITERATION_BLOCK,
2322 timeout_milliseconds);
2323
2324 recheck_status:
2325
2326 _dbus_verbose ("%s top of recheck\n", _DBUS_FUNCTION_NAME);
2327
2328 HAVE_LOCK_CHECK (connection);
2329
2330 /* queue messages and get status */
2331
2332 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2333
2334 /* the get_completed() is in case a dispatch() while we were blocking
2335 * got the reply instead of us.
2336 */
2337 if (_dbus_pending_call_get_completed_unlocked (pending))
2338 {
2339 _dbus_verbose ("Pending call completed by dispatch in %s\n", _DBUS_FUNCTION_NAME);
2340 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
2341 dbus_pending_call_unref (pending);
2342 return;
2343 }
2344
2345 if (status == DBUS_DISPATCH_DATA_REMAINS) {
2346 if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
2347 return;
2348 }
2349
2350 _dbus_get_current_time (&tv_sec, &tv_usec);
2351
2352 if (!_dbus_connection_get_is_connected_unlocked (connection))
2353 {
2354 DBusMessage *error_msg;
2355
2356 error_msg = generate_local_error_message (client_serial,
2357 DBUS_ERROR_DISCONNECTED,
2358 "Connection was disconnected before a reply was received");
2359
2360 /* on OOM error_msg is set to NULL */
2361 complete_pending_call_and_unlock (connection, pending, error_msg);
2362 dbus_pending_call_unref (pending);
2363 return;
2364 }
2365 else if (tv_sec < start_tv_sec)
2366 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): clock set backward\n");
2367 else if (connection->disconnect_message_link == NULL)
2368 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): disconnected\n");
2369 else if (tv_sec < end_tv_sec ||
2370 (tv_sec == end_tv_sec && tv_usec < end_tv_usec))
2371 {
2372 timeout_milliseconds = (end_tv_sec - tv_sec) * 1000 +
2373 (end_tv_usec - tv_usec) / 1000;
2374 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): %d milliseconds remain\n", timeout_milliseconds);
2375 _dbus_assert (timeout_milliseconds >= 0);
2376
2377 if (status == DBUS_DISPATCH_NEED_MEMORY)
2378 {
2379 /* Try sleeping a bit, as we aren't sure we need to block for reading,
2380 * we may already have a reply in the buffer and just can't process
2381 * it.
2382 */
2383 _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n");
2384
2385 _dbus_memory_pause_based_on_timeout (timeout_milliseconds);
2386 }
2387 else
2388 {
2389 /* block again, we don't have the reply buffered yet. */
2390 _dbus_connection_do_iteration_unlocked (connection,
2391 pending,
2392 DBUS_ITERATION_DO_READING |
2393 DBUS_ITERATION_BLOCK,
2394 timeout_milliseconds);
2395 }
2396
2397 goto recheck_status;
2398 }
2399
2400 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %ld milliseconds and got no reply\n",
2401 (tv_sec - start_tv_sec) * 1000 + (tv_usec - start_tv_usec) / 1000);
2402
2403 _dbus_assert (!_dbus_pending_call_get_completed_unlocked (pending));
2404
2405 /* unlock and call user code */
2406 complete_pending_call_and_unlock (connection, pending, NULL);
2407
2408 /* update user code on dispatch status */
2409 CONNECTION_LOCK (connection);
2410 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2411 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
2412 dbus_pending_call_unref (pending);
2413 }
2414
2415 /** @} */
2416
2417 /**
2418 * @addtogroup DBusConnection
2419 *
2420 * @{
2421 */
2422
2423 /**
2424 * Gets a connection to a remote address. If a connection to the given
2425 * address already exists, returns the existing connection with its
2426 * reference count incremented. Otherwise, returns a new connection
2427 * and saves the new connection for possible re-use if a future call
2428 * to dbus_connection_open() asks to connect to the same server.
2429 *
2430 * Use dbus_connection_open_private() to get a dedicated connection
2431 * not shared with other callers of dbus_connection_open().
2432 *
2433 * If the open fails, the function returns #NULL, and provides a
2434 * reason for the failure in the error parameter. Pass #NULL for the
2435 * error parameter if you aren't interested in the reason for
2436 * failure.
2437 *
2438 * Because this connection is shared, no user of the connection
2439 * may call dbus_connection_close(). However, when you are done with the
2440 * connection you should call dbus_connection_unref().
2441 *
2442 * @note Prefer dbus_connection_open() to dbus_connection_open_private()
2443 * unless you have good reason; connections are expensive enough
2444 * that it's wasteful to create lots of connections to the same
2445 * server.
2446 *
2447 * @param address the address.
2448 * @param error address where an error can be returned.
2449 * @returns new connection, or #NULL on failure.
2450 */
2451 DBusConnection*
dbus_connection_open(const char * address,DBusError * error)2452 dbus_connection_open (const char *address,
2453 DBusError *error)
2454 {
2455 DBusConnection *connection;
2456
2457 _dbus_return_val_if_fail (address != NULL, NULL);
2458 _dbus_return_val_if_error_is_set (error, NULL);
2459
2460 connection = _dbus_connection_open_internal (address,
2461 TRUE,
2462 error);
2463
2464 return connection;
2465 }
2466
2467 /**
2468 * Opens a new, dedicated connection to a remote address. Unlike
2469 * dbus_connection_open(), always creates a new connection.
2470 * This connection will not be saved or recycled by libdbus.
2471 *
2472 * If the open fails, the function returns #NULL, and provides a
2473 * reason for the failure in the error parameter. Pass #NULL for the
2474 * error parameter if you aren't interested in the reason for
2475 * failure.
2476 *
2477 * When you are done with this connection, you must
2478 * dbus_connection_close() to disconnect it,
2479 * and dbus_connection_unref() to free the connection object.
2480 *
2481 * (The dbus_connection_close() can be skipped if the
2482 * connection is already known to be disconnected, for example
2483 * if you are inside a handler for the Disconnected signal.)
2484 *
2485 * @note Prefer dbus_connection_open() to dbus_connection_open_private()
2486 * unless you have good reason; connections are expensive enough
2487 * that it's wasteful to create lots of connections to the same
2488 * server.
2489 *
2490 * @param address the address.
2491 * @param error address where an error can be returned.
2492 * @returns new connection, or #NULL on failure.
2493 */
2494 DBusConnection*
dbus_connection_open_private(const char * address,DBusError * error)2495 dbus_connection_open_private (const char *address,
2496 DBusError *error)
2497 {
2498 DBusConnection *connection;
2499
2500 _dbus_return_val_if_fail (address != NULL, NULL);
2501 _dbus_return_val_if_error_is_set (error, NULL);
2502
2503 connection = _dbus_connection_open_internal (address,
2504 FALSE,
2505 error);
2506
2507 return connection;
2508 }
2509
2510 /**
2511 * Increments the reference count of a DBusConnection.
2512 *
2513 * @param connection the connection.
2514 * @returns the connection.
2515 */
2516 DBusConnection *
dbus_connection_ref(DBusConnection * connection)2517 dbus_connection_ref (DBusConnection *connection)
2518 {
2519 _dbus_return_val_if_fail (connection != NULL, NULL);
2520 _dbus_return_val_if_fail (connection->generation == _dbus_current_generation, NULL);
2521
2522 /* The connection lock is better than the global
2523 * lock in the atomic increment fallback
2524 */
2525
2526 #ifdef DBUS_HAVE_ATOMIC_INT
2527 _dbus_atomic_inc (&connection->refcount);
2528 #else
2529 CONNECTION_LOCK (connection);
2530 _dbus_assert (connection->refcount.value > 0);
2531
2532 connection->refcount.value += 1;
2533 CONNECTION_UNLOCK (connection);
2534 #endif
2535
2536 return connection;
2537 }
2538
2539 static void
free_outgoing_message(void * element,void * data)2540 free_outgoing_message (void *element,
2541 void *data)
2542 {
2543 DBusMessage *message = element;
2544 DBusConnection *connection = data;
2545
2546 _dbus_message_remove_size_counter (message,
2547 connection->outgoing_counter,
2548 NULL);
2549 dbus_message_unref (message);
2550 }
2551
2552 /* This is run without the mutex held, but after the last reference
2553 * to the connection has been dropped we should have no thread-related
2554 * problems
2555 */
2556 static void
_dbus_connection_last_unref(DBusConnection * connection)2557 _dbus_connection_last_unref (DBusConnection *connection)
2558 {
2559 DBusList *link;
2560
2561 _dbus_verbose ("Finalizing connection %p\n", connection);
2562
2563 _dbus_assert (connection->refcount.value == 0);
2564
2565 /* You have to disconnect the connection before unref:ing it. Otherwise
2566 * you won't get the disconnected message.
2567 */
2568 _dbus_assert (!_dbus_transport_get_is_connected (connection->transport));
2569 _dbus_assert (connection->server_guid == NULL);
2570
2571 /* ---- We're going to call various application callbacks here, hope it doesn't break anything... */
2572 _dbus_object_tree_free_all_unlocked (connection->objects);
2573
2574 dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL);
2575 dbus_connection_set_wakeup_main_function (connection, NULL, NULL, NULL);
2576 dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL);
2577
2578 _dbus_watch_list_free (connection->watches);
2579 connection->watches = NULL;
2580
2581 _dbus_timeout_list_free (connection->timeouts);
2582 connection->timeouts = NULL;
2583
2584 _dbus_data_slot_list_free (&connection->slot_list);
2585
2586 link = _dbus_list_get_first_link (&connection->filter_list);
2587 while (link != NULL)
2588 {
2589 DBusMessageFilter *filter = link->data;
2590 DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
2591
2592 filter->function = NULL;
2593 _dbus_message_filter_unref (filter); /* calls app callback */
2594 link->data = NULL;
2595
2596 link = next;
2597 }
2598 _dbus_list_clear (&connection->filter_list);
2599
2600 /* ---- Done with stuff that invokes application callbacks */
2601
2602 _dbus_object_tree_unref (connection->objects);
2603
2604 _dbus_hash_table_unref (connection->pending_replies);
2605 connection->pending_replies = NULL;
2606
2607 _dbus_list_clear (&connection->filter_list);
2608
2609 _dbus_list_foreach (&connection->outgoing_messages,
2610 free_outgoing_message,
2611 connection);
2612 _dbus_list_clear (&connection->outgoing_messages);
2613
2614 _dbus_list_foreach (&connection->incoming_messages,
2615 (DBusForeachFunction) dbus_message_unref,
2616 NULL);
2617 _dbus_list_clear (&connection->incoming_messages);
2618
2619 _dbus_counter_unref (connection->outgoing_counter);
2620
2621 _dbus_transport_unref (connection->transport);
2622
2623 if (connection->disconnect_message_link)
2624 {
2625 DBusMessage *message = connection->disconnect_message_link->data;
2626 dbus_message_unref (message);
2627 _dbus_list_free_link (connection->disconnect_message_link);
2628 }
2629
2630 _dbus_list_clear (&connection->link_cache);
2631
2632 _dbus_condvar_free_at_location (&connection->dispatch_cond);
2633 _dbus_condvar_free_at_location (&connection->io_path_cond);
2634
2635 _dbus_mutex_free_at_location (&connection->io_path_mutex);
2636 _dbus_mutex_free_at_location (&connection->dispatch_mutex);
2637
2638 _dbus_mutex_free_at_location (&connection->mutex);
2639
2640 dbus_free (connection);
2641 }
2642
2643 /**
2644 * Decrements the reference count of a DBusConnection, and finalizes
2645 * it if the count reaches zero.
2646 *
2647 * Note: it is a bug to drop the last reference to a connection that
2648 * is still connected.
2649 *
2650 * For shared connections, libdbus will own a reference
2651 * as long as the connection is connected, so you can know that either
2652 * you don't have the last reference, or it's OK to drop the last reference.
2653 * Most connections are shared. dbus_connection_open() and dbus_bus_get()
2654 * return shared connections.
2655 *
2656 * For private connections, the creator of the connection must arrange for
2657 * dbus_connection_close() to be called prior to dropping the last reference.
2658 * Private connections come from dbus_connection_open_private() or dbus_bus_get_private().
2659 *
2660 * @param connection the connection.
2661 */
2662 void
dbus_connection_unref(DBusConnection * connection)2663 dbus_connection_unref (DBusConnection *connection)
2664 {
2665 dbus_bool_t last_unref;
2666
2667 _dbus_return_if_fail (connection != NULL);
2668 _dbus_return_if_fail (connection->generation == _dbus_current_generation);
2669
2670 /* The connection lock is better than the global
2671 * lock in the atomic increment fallback
2672 */
2673
2674 #ifdef DBUS_HAVE_ATOMIC_INT
2675 last_unref = (_dbus_atomic_dec (&connection->refcount) == 1);
2676 #else
2677 CONNECTION_LOCK (connection);
2678
2679 _dbus_assert (connection->refcount.value > 0);
2680
2681 connection->refcount.value -= 1;
2682 last_unref = (connection->refcount.value == 0);
2683
2684 #if 0
2685 printf ("unref() connection %p count = %d\n", connection, connection->refcount.value);
2686 #endif
2687
2688 CONNECTION_UNLOCK (connection);
2689 #endif
2690
2691 if (last_unref)
2692 {
2693 #ifndef DBUS_DISABLE_CHECKS
2694 if (_dbus_transport_get_is_connected (connection->transport))
2695 {
2696 _dbus_warn_check_failed ("The last reference on a connection was dropped without closing the connection. This is a bug in an application. See dbus_connection_unref() documentation for details.\n%s",
2697 connection->shareable ?
2698 "Most likely, the application called unref() too many times and removed a reference belonging to libdbus, since this is a shared connection.\n" :
2699 "Most likely, the application was supposed to call dbus_connection_close(), since this is a private connection.\n");
2700 return;
2701 }
2702 #endif
2703 _dbus_connection_last_unref (connection);
2704 }
2705 }
2706
2707 /*
2708 * Note that the transport can disconnect itself (other end drops us)
2709 * and in that case this function never runs. So this function must
2710 * not do anything more than disconnect the transport and update the
2711 * dispatch status.
2712 *
2713 * If the transport self-disconnects, then we assume someone will
2714 * dispatch the connection to cause the dispatch status update.
2715 */
2716 static void
_dbus_connection_close_possibly_shared_and_unlock(DBusConnection * connection)2717 _dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection)
2718 {
2719 DBusDispatchStatus status;
2720
2721 HAVE_LOCK_CHECK (connection);
2722
2723 _dbus_verbose ("Disconnecting %p\n", connection);
2724
2725 /* We need to ref because update_dispatch_status_and_unlock will unref
2726 * the connection if it was shared and libdbus was the only remaining
2727 * refcount holder.
2728 */
2729 _dbus_connection_ref_unlocked (connection);
2730
2731 _dbus_transport_disconnect (connection->transport);
2732
2733 /* This has the side effect of queuing the disconnect message link
2734 * (unless we don't have enough memory, possibly, so don't assert it).
2735 * After the disconnect message link is queued, dbus_bus_get/dbus_connection_open
2736 * should never again return the newly-disconnected connection.
2737 *
2738 * However, we only unref the shared connection and exit_on_disconnect when
2739 * the disconnect message reaches the head of the message queue,
2740 * NOT when it's first queued.
2741 */
2742 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2743
2744 /* This calls out to user code */
2745 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
2746
2747 /* Could also call out to user code */
2748 dbus_connection_unref (connection);
2749 }
2750
2751 /**
2752 * Closes a private connection, so no further data can be sent or received.
2753 * This disconnects the transport (such as a socket) underlying the
2754 * connection.
2755 *
2756 * Attempts to send messages after closing a connection are safe, but will result in
2757 * error replies generated locally in libdbus.
2758 *
2759 * This function does not affect the connection's reference count. It's
2760 * safe to close a connection more than once; all calls after the
2761 * first do nothing. It's impossible to "reopen" a connection, a
2762 * new connection must be created. This function may result in a call
2763 * to the DBusDispatchStatusFunction set with
2764 * dbus_connection_set_dispatch_status_function(), as the disconnect
2765 * message it generates needs to be dispatched.
2766 *
2767 * If a connection is dropped by the remote application, it will
2768 * close itself.
2769 *
2770 * You must close a connection prior to releasing the last reference to
2771 * the connection. If you dbus_connection_unref() for the last time
2772 * without closing the connection, the results are undefined; it
2773 * is a bug in your program and libdbus will try to print a warning.
2774 *
2775 * You may not close a shared connection. Connections created with
2776 * dbus_connection_open() or dbus_bus_get() are shared.
2777 * These connections are owned by libdbus, and applications should
2778 * only unref them, never close them. Applications can know it is
2779 * safe to unref these connections because libdbus will be holding a
2780 * reference as long as the connection is open. Thus, either the
2781 * connection is closed and it is OK to drop the last reference,
2782 * or the connection is open and the app knows it does not have the
2783 * last reference.
2784 *
2785 * Connections created with dbus_connection_open_private() or
2786 * dbus_bus_get_private() are not kept track of or referenced by
2787 * libdbus. The creator of these connections is responsible for
2788 * calling dbus_connection_close() prior to releasing the last
2789 * reference, if the connection is not already disconnected.
2790 *
2791 * @param connection the private (unshared) connection to close
2792 */
2793 void
dbus_connection_close(DBusConnection * connection)2794 dbus_connection_close (DBusConnection *connection)
2795 {
2796 _dbus_return_if_fail (connection != NULL);
2797 _dbus_return_if_fail (connection->generation == _dbus_current_generation);
2798
2799 CONNECTION_LOCK (connection);
2800
2801 #ifndef DBUS_DISABLE_CHECKS
2802 if (connection->shareable)
2803 {
2804 CONNECTION_UNLOCK (connection);
2805
2806 _dbus_warn_check_failed ("Applications must not close shared connections - see dbus_connection_close() docs. This is a bug in the application.\n");
2807 return;
2808 }
2809 #endif
2810
2811 _dbus_connection_close_possibly_shared_and_unlock (connection);
2812 }
2813
2814 static dbus_bool_t
_dbus_connection_get_is_connected_unlocked(DBusConnection * connection)2815 _dbus_connection_get_is_connected_unlocked (DBusConnection *connection)
2816 {
2817 HAVE_LOCK_CHECK (connection);
2818 return _dbus_transport_get_is_connected (connection->transport);
2819 }
2820
2821 /**
2822 * Gets whether the connection is currently open. A connection may
2823 * become disconnected when the remote application closes its end, or
2824 * exits; a connection may also be disconnected with
2825 * dbus_connection_close().
2826 *
2827 * There are not separate states for "closed" and "disconnected," the two
2828 * terms are synonymous. This function should really be called
2829 * get_is_open() but for historical reasons is not.
2830 *
2831 * @param connection the connection.
2832 * @returns #TRUE if the connection is still alive.
2833 */
2834 dbus_bool_t
dbus_connection_get_is_connected(DBusConnection * connection)2835 dbus_connection_get_is_connected (DBusConnection *connection)
2836 {
2837 dbus_bool_t res;
2838
2839 _dbus_return_val_if_fail (connection != NULL, FALSE);
2840
2841 CONNECTION_LOCK (connection);
2842 res = _dbus_connection_get_is_connected_unlocked (connection);
2843 CONNECTION_UNLOCK (connection);
2844
2845 return res;
2846 }
2847
2848 /**
2849 * Gets whether the connection was authenticated. (Note that
2850 * if the connection was authenticated then disconnected,
2851 * this function still returns #TRUE)
2852 *
2853 * @param connection the connection
2854 * @returns #TRUE if the connection was ever authenticated
2855 */
2856 dbus_bool_t
dbus_connection_get_is_authenticated(DBusConnection * connection)2857 dbus_connection_get_is_authenticated (DBusConnection *connection)
2858 {
2859 dbus_bool_t res;
2860
2861 _dbus_return_val_if_fail (connection != NULL, FALSE);
2862
2863 CONNECTION_LOCK (connection);
2864 res = _dbus_transport_get_is_authenticated (connection->transport);
2865 CONNECTION_UNLOCK (connection);
2866
2867 return res;
2868 }
2869
2870 /**
2871 * Set whether _exit() should be called when the connection receives a
2872 * disconnect signal. The call to _exit() comes after any handlers for
2873 * the disconnect signal run; handlers can cancel the exit by calling
2874 * this function.
2875 *
2876 * By default, exit_on_disconnect is #FALSE; but for message bus
2877 * connections returned from dbus_bus_get() it will be toggled on
2878 * by default.
2879 *
2880 * @param connection the connection
2881 * @param exit_on_disconnect #TRUE if _exit() should be called after a disconnect signal
2882 */
2883 void
dbus_connection_set_exit_on_disconnect(DBusConnection * connection,dbus_bool_t exit_on_disconnect)2884 dbus_connection_set_exit_on_disconnect (DBusConnection *connection,
2885 dbus_bool_t exit_on_disconnect)
2886 {
2887 _dbus_return_if_fail (connection != NULL);
2888
2889 CONNECTION_LOCK (connection);
2890 connection->exit_on_disconnect = exit_on_disconnect != FALSE;
2891 CONNECTION_UNLOCK (connection);
2892 }
2893
2894 /**
2895 * Preallocates resources needed to send a message, allowing the message
2896 * to be sent without the possibility of memory allocation failure.
2897 * Allows apps to create a future guarantee that they can send
2898 * a message regardless of memory shortages.
2899 *
2900 * @param connection the connection we're preallocating for.
2901 * @returns the preallocated resources, or #NULL
2902 */
2903 DBusPreallocatedSend*
dbus_connection_preallocate_send(DBusConnection * connection)2904 dbus_connection_preallocate_send (DBusConnection *connection)
2905 {
2906 DBusPreallocatedSend *preallocated;
2907
2908 _dbus_return_val_if_fail (connection != NULL, NULL);
2909
2910 CONNECTION_LOCK (connection);
2911
2912 preallocated =
2913 _dbus_connection_preallocate_send_unlocked (connection);
2914
2915 CONNECTION_UNLOCK (connection);
2916
2917 return preallocated;
2918 }
2919
2920 /**
2921 * Frees preallocated message-sending resources from
2922 * dbus_connection_preallocate_send(). Should only
2923 * be called if the preallocated resources are not used
2924 * to send a message.
2925 *
2926 * @param connection the connection
2927 * @param preallocated the resources
2928 */
2929 void
dbus_connection_free_preallocated_send(DBusConnection * connection,DBusPreallocatedSend * preallocated)2930 dbus_connection_free_preallocated_send (DBusConnection *connection,
2931 DBusPreallocatedSend *preallocated)
2932 {
2933 _dbus_return_if_fail (connection != NULL);
2934 _dbus_return_if_fail (preallocated != NULL);
2935 _dbus_return_if_fail (connection == preallocated->connection);
2936
2937 _dbus_list_free_link (preallocated->queue_link);
2938 _dbus_counter_unref (preallocated->counter_link->data);
2939 _dbus_list_free_link (preallocated->counter_link);
2940 dbus_free (preallocated);
2941 }
2942
2943 /**
2944 * Sends a message using preallocated resources. This function cannot fail.
2945 * It works identically to dbus_connection_send() in other respects.
2946 * Preallocated resources comes from dbus_connection_preallocate_send().
2947 * This function "consumes" the preallocated resources, they need not
2948 * be freed separately.
2949 *
2950 * @param connection the connection
2951 * @param preallocated the preallocated resources
2952 * @param message the message to send
2953 * @param client_serial return location for client serial assigned to the message
2954 */
2955 void
dbus_connection_send_preallocated(DBusConnection * connection,DBusPreallocatedSend * preallocated,DBusMessage * message,dbus_uint32_t * client_serial)2956 dbus_connection_send_preallocated (DBusConnection *connection,
2957 DBusPreallocatedSend *preallocated,
2958 DBusMessage *message,
2959 dbus_uint32_t *client_serial)
2960 {
2961 _dbus_return_if_fail (connection != NULL);
2962 _dbus_return_if_fail (preallocated != NULL);
2963 _dbus_return_if_fail (message != NULL);
2964 _dbus_return_if_fail (preallocated->connection == connection);
2965 _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_METHOD_CALL ||
2966 dbus_message_get_member (message) != NULL);
2967 _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_SIGNAL ||
2968 (dbus_message_get_interface (message) != NULL &&
2969 dbus_message_get_member (message) != NULL));
2970
2971 CONNECTION_LOCK (connection);
2972 _dbus_connection_send_preallocated_and_unlock (connection,
2973 preallocated,
2974 message, client_serial);
2975 }
2976
2977 static dbus_bool_t
_dbus_connection_send_unlocked_no_update(DBusConnection * connection,DBusMessage * message,dbus_uint32_t * client_serial)2978 _dbus_connection_send_unlocked_no_update (DBusConnection *connection,
2979 DBusMessage *message,
2980 dbus_uint32_t *client_serial)
2981 {
2982 DBusPreallocatedSend *preallocated;
2983
2984 _dbus_assert (connection != NULL);
2985 _dbus_assert (message != NULL);
2986
2987 preallocated = _dbus_connection_preallocate_send_unlocked (connection);
2988 if (preallocated == NULL)
2989 return FALSE;
2990
2991 _dbus_connection_send_preallocated_unlocked_no_update (connection,
2992 preallocated,
2993 message,
2994 client_serial);
2995 return TRUE;
2996 }
2997
2998 /**
2999 * Adds a message to the outgoing message queue. Does not block to
3000 * write the message to the network; that happens asynchronously. To
3001 * force the message to be written, call dbus_connection_flush().
3002 * Because this only queues the message, the only reason it can
3003 * fail is lack of memory. Even if the connection is disconnected,
3004 * no error will be returned.
3005 *
3006 * If the function fails due to lack of memory, it returns #FALSE.
3007 * The function will never fail for other reasons; even if the
3008 * connection is disconnected, you can queue an outgoing message,
3009 * though obviously it won't be sent.
3010 *
3011 * The message serial is used by the remote application to send a
3012 * reply; see dbus_message_get_serial() or the D-Bus specification.
3013 *
3014 * @param connection the connection.
3015 * @param message the message to write.
3016 * @param serial return location for message serial, or #NULL if you don't care
3017 * @returns #TRUE on success.
3018 */
3019 dbus_bool_t
dbus_connection_send(DBusConnection * connection,DBusMessage * message,dbus_uint32_t * serial)3020 dbus_connection_send (DBusConnection *connection,
3021 DBusMessage *message,
3022 dbus_uint32_t *serial)
3023 {
3024 _dbus_return_val_if_fail (connection != NULL, FALSE);
3025 _dbus_return_val_if_fail (message != NULL, FALSE);
3026
3027 CONNECTION_LOCK (connection);
3028
3029 return _dbus_connection_send_and_unlock (connection,
3030 message,
3031 serial);
3032 }
3033
3034 static dbus_bool_t
reply_handler_timeout(void * data)3035 reply_handler_timeout (void *data)
3036 {
3037 DBusConnection *connection;
3038 DBusDispatchStatus status;
3039 DBusPendingCall *pending = data;
3040
3041 connection = _dbus_pending_call_get_connection_and_lock (pending);
3042
3043 _dbus_pending_call_queue_timeout_error_unlocked (pending,
3044 connection);
3045 _dbus_connection_remove_timeout_unlocked (connection,
3046 _dbus_pending_call_get_timeout_unlocked (pending));
3047 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
3048
3049 _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
3050 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3051
3052 /* Unlocks, and calls out to user code */
3053 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3054
3055 return TRUE;
3056 }
3057
3058 /**
3059 * Queues a message to send, as with dbus_connection_send(),
3060 * but also returns a #DBusPendingCall used to receive a reply to the
3061 * message. If no reply is received in the given timeout_milliseconds,
3062 * this function expires the pending reply and generates a synthetic
3063 * error reply (generated in-process, not by the remote application)
3064 * indicating that a timeout occurred.
3065 *
3066 * A #DBusPendingCall will see a reply message before any filters or
3067 * registered object path handlers. See dbus_connection_dispatch() for
3068 * details on when handlers are run.
3069 *
3070 * A #DBusPendingCall will always see exactly one reply message,
3071 * unless it's cancelled with dbus_pending_call_cancel().
3072 *
3073 * If #NULL is passed for the pending_return, the #DBusPendingCall
3074 * will still be generated internally, and used to track
3075 * the message reply timeout. This means a timeout error will
3076 * occur if no reply arrives, unlike with dbus_connection_send().
3077 *
3078 * If -1 is passed for the timeout, a sane default timeout is used. -1
3079 * is typically the best value for the timeout for this reason, unless
3080 * you want a very short or very long timeout. There is no way to
3081 * avoid a timeout entirely, other than passing INT_MAX for the
3082 * timeout to mean "very long timeout." libdbus clamps an INT_MAX
3083 * timeout down to a few hours timeout though.
3084 *
3085 * @warning if the connection is disconnected, the #DBusPendingCall
3086 * will be set to #NULL, so be careful with this.
3087 *
3088 * @param connection the connection
3089 * @param message the message to send
3090 * @param pending_return return location for a #DBusPendingCall object, or #NULL if connection is disconnected
3091 * @param timeout_milliseconds timeout in milliseconds or -1 for default
3092 * @returns #FALSE if no memory, #TRUE otherwise.
3093 *
3094 */
3095 dbus_bool_t
dbus_connection_send_with_reply(DBusConnection * connection,DBusMessage * message,DBusPendingCall ** pending_return,int timeout_milliseconds)3096 dbus_connection_send_with_reply (DBusConnection *connection,
3097 DBusMessage *message,
3098 DBusPendingCall **pending_return,
3099 int timeout_milliseconds)
3100 {
3101 DBusPendingCall *pending;
3102 dbus_int32_t serial = -1;
3103 DBusDispatchStatus status;
3104
3105 _dbus_return_val_if_fail (connection != NULL, FALSE);
3106 _dbus_return_val_if_fail (message != NULL, FALSE);
3107 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
3108
3109 if (pending_return)
3110 *pending_return = NULL;
3111
3112 CONNECTION_LOCK (connection);
3113
3114 if (!_dbus_connection_get_is_connected_unlocked (connection))
3115 {
3116 CONNECTION_UNLOCK (connection);
3117
3118 *pending_return = NULL;
3119
3120 return TRUE;
3121 }
3122
3123 pending = _dbus_pending_call_new_unlocked (connection,
3124 timeout_milliseconds,
3125 reply_handler_timeout);
3126
3127 if (pending == NULL)
3128 {
3129 CONNECTION_UNLOCK (connection);
3130 return FALSE;
3131 }
3132
3133 /* Assign a serial to the message */
3134 serial = dbus_message_get_serial (message);
3135 if (serial == 0)
3136 {
3137 serial = _dbus_connection_get_next_client_serial (connection);
3138 _dbus_message_set_serial (message, serial);
3139 }
3140
3141 if (!_dbus_pending_call_set_timeout_error_unlocked (pending, message, serial))
3142 goto error;
3143
3144 /* Insert the serial in the pending replies hash;
3145 * hash takes a refcount on DBusPendingCall.
3146 * Also, add the timeout.
3147 */
3148 if (!_dbus_connection_attach_pending_call_unlocked (connection,
3149 pending))
3150 goto error;
3151
3152 if (!_dbus_connection_send_unlocked_no_update (connection, message, NULL))
3153 {
3154 _dbus_connection_detach_pending_call_and_unlock (connection,
3155 pending);
3156 goto error_unlocked;
3157 }
3158
3159 if (pending_return)
3160 *pending_return = pending; /* hand off refcount */
3161 else
3162 {
3163 _dbus_connection_detach_pending_call_unlocked (connection, pending);
3164 /* we still have a ref to the pending call in this case, we unref
3165 * after unlocking, below
3166 */
3167 }
3168
3169 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3170
3171 /* this calls out to user code */
3172 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3173
3174 if (pending_return == NULL)
3175 dbus_pending_call_unref (pending);
3176
3177 return TRUE;
3178
3179 error:
3180 CONNECTION_UNLOCK (connection);
3181 error_unlocked:
3182 dbus_pending_call_unref (pending);
3183 return FALSE;
3184 }
3185
3186 /**
3187 * Sends a message and blocks a certain time period while waiting for
3188 * a reply. This function does not reenter the main loop,
3189 * i.e. messages other than the reply are queued up but not
3190 * processed. This function is used to invoke method calls on a
3191 * remote object.
3192 *
3193 * If a normal reply is received, it is returned, and removed from the
3194 * incoming message queue. If it is not received, #NULL is returned
3195 * and the error is set to #DBUS_ERROR_NO_REPLY. If an error reply is
3196 * received, it is converted to a #DBusError and returned as an error,
3197 * then the reply message is deleted and #NULL is returned. If
3198 * something else goes wrong, result is set to whatever is
3199 * appropriate, such as #DBUS_ERROR_NO_MEMORY or
3200 * #DBUS_ERROR_DISCONNECTED.
3201 *
3202 * @warning While this function blocks the calling thread will not be
3203 * processing the incoming message queue. This means you can end up
3204 * deadlocked if the application you're talking to needs you to reply
3205 * to a method. To solve this, either avoid the situation, block in a
3206 * separate thread from the main connection-dispatching thread, or use
3207 * dbus_pending_call_set_notify() to avoid blocking.
3208 *
3209 * @param connection the connection
3210 * @param message the message to send
3211 * @param timeout_milliseconds timeout in milliseconds or -1 for default
3212 * @param error return location for error message
3213 * @returns the message that is the reply or #NULL with an error code if the
3214 * function fails.
3215 */
3216 DBusMessage*
dbus_connection_send_with_reply_and_block(DBusConnection * connection,DBusMessage * message,int timeout_milliseconds,DBusError * error)3217 dbus_connection_send_with_reply_and_block (DBusConnection *connection,
3218 DBusMessage *message,
3219 int timeout_milliseconds,
3220 DBusError *error)
3221 {
3222 DBusMessage *reply;
3223 DBusPendingCall *pending;
3224
3225 _dbus_return_val_if_fail (connection != NULL, NULL);
3226 _dbus_return_val_if_fail (message != NULL, NULL);
3227 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, NULL);
3228 _dbus_return_val_if_error_is_set (error, NULL);
3229
3230 if (!dbus_connection_send_with_reply (connection, message,
3231 &pending, timeout_milliseconds))
3232 {
3233 _DBUS_SET_OOM (error);
3234 return NULL;
3235 }
3236
3237 if (pending == NULL)
3238 {
3239 dbus_set_error (error, DBUS_ERROR_DISCONNECTED, "Connection is closed");
3240 return NULL;
3241 }
3242
3243 dbus_pending_call_block (pending);
3244
3245 reply = dbus_pending_call_steal_reply (pending);
3246 dbus_pending_call_unref (pending);
3247
3248 /* call_complete_and_unlock() called from pending_call_block() should
3249 * always fill this in.
3250 */
3251 _dbus_assert (reply != NULL);
3252
3253 if (dbus_set_error_from_message (error, reply))
3254 {
3255 dbus_message_unref (reply);
3256 return NULL;
3257 }
3258 else
3259 return reply;
3260 }
3261
3262 /**
3263 * Blocks until the outgoing message queue is empty.
3264 * Assumes connection lock already held.
3265 *
3266 * If you call this, you MUST call update_dispatch_status afterword...
3267 *
3268 * @param connection the connection.
3269 */
3270 DBusDispatchStatus
_dbus_connection_flush_unlocked(DBusConnection * connection)3271 _dbus_connection_flush_unlocked (DBusConnection *connection)
3272 {
3273 /* We have to specify DBUS_ITERATION_DO_READING here because
3274 * otherwise we could have two apps deadlock if they are both doing
3275 * a flush(), and the kernel buffers fill up. This could change the
3276 * dispatch status.
3277 */
3278 DBusDispatchStatus status;
3279
3280 HAVE_LOCK_CHECK (connection);
3281
3282 while (connection->n_outgoing > 0 &&
3283 _dbus_connection_get_is_connected_unlocked (connection))
3284 {
3285 _dbus_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME);
3286 HAVE_LOCK_CHECK (connection);
3287 _dbus_connection_do_iteration_unlocked (connection,
3288 NULL,
3289 DBUS_ITERATION_DO_READING |
3290 DBUS_ITERATION_DO_WRITING |
3291 DBUS_ITERATION_BLOCK,
3292 -1);
3293 }
3294
3295 HAVE_LOCK_CHECK (connection);
3296 _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME);
3297 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3298
3299 HAVE_LOCK_CHECK (connection);
3300 return status;
3301 }
3302
3303 /**
3304 * Blocks until the outgoing message queue is empty.
3305 *
3306 * @param connection the connection.
3307 */
3308 void
dbus_connection_flush(DBusConnection * connection)3309 dbus_connection_flush (DBusConnection *connection)
3310 {
3311 /* We have to specify DBUS_ITERATION_DO_READING here because
3312 * otherwise we could have two apps deadlock if they are both doing
3313 * a flush(), and the kernel buffers fill up. This could change the
3314 * dispatch status.
3315 */
3316 DBusDispatchStatus status;
3317
3318 _dbus_return_if_fail (connection != NULL);
3319
3320 CONNECTION_LOCK (connection);
3321
3322 status = _dbus_connection_flush_unlocked (connection);
3323
3324 HAVE_LOCK_CHECK (connection);
3325 /* Unlocks and calls out to user code */
3326 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3327
3328 _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME);
3329 }
3330
3331 /**
3332 * This function implements dbus_connection_read_write_dispatch() and
3333 * dbus_connection_read_write() (they pass a different value for the
3334 * dispatch parameter).
3335 *
3336 * @param connection the connection
3337 * @param timeout_milliseconds max time to block or -1 for infinite
3338 * @param dispatch dispatch new messages or leave them on the incoming queue
3339 * @returns #TRUE if the disconnect message has not been processed
3340 */
3341 static dbus_bool_t
_dbus_connection_read_write_dispatch(DBusConnection * connection,int timeout_milliseconds,dbus_bool_t dispatch)3342 _dbus_connection_read_write_dispatch (DBusConnection *connection,
3343 int timeout_milliseconds,
3344 dbus_bool_t dispatch)
3345 {
3346 DBusDispatchStatus dstatus;
3347 dbus_bool_t no_progress_possible;
3348
3349 dstatus = dbus_connection_get_dispatch_status (connection);
3350
3351 if (dispatch && dstatus == DBUS_DISPATCH_DATA_REMAINS)
3352 {
3353 _dbus_verbose ("doing dispatch in %s\n", _DBUS_FUNCTION_NAME);
3354 dbus_connection_dispatch (connection);
3355 CONNECTION_LOCK (connection);
3356 }
3357 else if (dstatus == DBUS_DISPATCH_NEED_MEMORY)
3358 {
3359 _dbus_verbose ("pausing for memory in %s\n", _DBUS_FUNCTION_NAME);
3360 _dbus_memory_pause_based_on_timeout (timeout_milliseconds);
3361 CONNECTION_LOCK (connection);
3362 }
3363 else
3364 {
3365 CONNECTION_LOCK (connection);
3366 if (_dbus_connection_get_is_connected_unlocked (connection))
3367 {
3368 _dbus_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME);
3369 _dbus_connection_do_iteration_unlocked (connection,
3370 NULL,
3371 DBUS_ITERATION_DO_READING |
3372 DBUS_ITERATION_DO_WRITING |
3373 DBUS_ITERATION_BLOCK,
3374 timeout_milliseconds);
3375 }
3376 }
3377
3378 HAVE_LOCK_CHECK (connection);
3379 /* If we can dispatch, we can make progress until the Disconnected message
3380 * has been processed; if we can only read/write, we can make progress
3381 * as long as the transport is open.
3382 */
3383 if (dispatch)
3384 no_progress_possible = connection->n_incoming == 0 &&
3385 connection->disconnect_message_link == NULL;
3386 else
3387 no_progress_possible = _dbus_connection_get_is_connected_unlocked (connection);
3388 CONNECTION_UNLOCK (connection);
3389 return !no_progress_possible; /* TRUE if we can make more progress */
3390 }
3391
3392
3393 /**
3394 * This function is intended for use with applications that don't want
3395 * to write a main loop and deal with #DBusWatch and #DBusTimeout. An
3396 * example usage would be:
3397 *
3398 * @code
3399 * while (dbus_connection_read_write_dispatch (connection, -1))
3400 * ; // empty loop body
3401 * @endcode
3402 *
3403 * In this usage you would normally have set up a filter function to look
3404 * at each message as it is dispatched. The loop terminates when the last
3405 * message from the connection (the disconnected signal) is processed.
3406 *
3407 * If there are messages to dispatch, this function will
3408 * dbus_connection_dispatch() once, and return. If there are no
3409 * messages to dispatch, this function will block until it can read or
3410 * write, then read or write, then return.
3411 *
3412 * The way to think of this function is that it either makes some sort
3413 * of progress, or it blocks. Note that, while it is blocked on I/O, it
3414 * cannot be interrupted (even by other threads), which makes this function
3415 * unsuitable for applications that do more than just react to received
3416 * messages.
3417 *
3418 * The return value indicates whether the disconnect message has been
3419 * processed, NOT whether the connection is connected. This is
3420 * important because even after disconnecting, you want to process any
3421 * messages you received prior to the disconnect.
3422 *
3423 * @param connection the connection
3424 * @param timeout_milliseconds max time to block or -1 for infinite
3425 * @returns #TRUE if the disconnect message has not been processed
3426 */
3427 dbus_bool_t
dbus_connection_read_write_dispatch(DBusConnection * connection,int timeout_milliseconds)3428 dbus_connection_read_write_dispatch (DBusConnection *connection,
3429 int timeout_milliseconds)
3430 {
3431 _dbus_return_val_if_fail (connection != NULL, FALSE);
3432 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
3433 return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, TRUE);
3434 }
3435
3436
3437 /**
3438 * This function is intended for use with applications that want to
3439 * dispatch all the events in the incoming/outgoing queue before returning.
3440 * The function just calls dbus_connection_read_write_dispatch till
3441 * the incoming queue is empty.
3442 *
3443 * @param connection the connection
3444 * @param timeout_milliseconds max time to block or -1 for infinite
3445 * @returns #TRUE if the disconnect message has not been processed
3446 */
3447 dbus_bool_t
dbus_connection_read_write_dispatch_greedy(DBusConnection * connection,int timeout_milliseconds)3448 dbus_connection_read_write_dispatch_greedy (DBusConnection *connection,
3449 int timeout_milliseconds)
3450 {
3451 dbus_bool_t ret, progress_possible;
3452 int pre_incoming, pre_outgoing;
3453 do
3454 {
3455 pre_incoming = connection->n_incoming;
3456 pre_outgoing = connection->n_outgoing;
3457 ret = dbus_connection_read_write_dispatch(connection, timeout_milliseconds);
3458 /* No need to take a lock here. If another 'reader' thread has read the packet,
3459 * dbus_connection_read_write_dispatch will just return. If a writer
3460 * writes a packet between the call and the check, it will get processed
3461 * in the next call to the function.
3462 */
3463 if ((pre_incoming != connection->n_incoming ||
3464 pre_outgoing != connection->n_outgoing) &&
3465 (connection->n_incoming > 0 ||
3466 connection->n_outgoing > 0)) {
3467 progress_possible = TRUE;
3468 } else {
3469 progress_possible = FALSE;
3470 }
3471 } while (ret == TRUE && progress_possible);
3472 return ret;
3473 }
3474
3475
3476 /**
3477 * This function is intended for use with applications that don't want to
3478 * write a main loop and deal with #DBusWatch and #DBusTimeout. See also
3479 * dbus_connection_read_write_dispatch().
3480 *
3481 * As long as the connection is open, this function will block until it can
3482 * read or write, then read or write, then return #TRUE.
3483 *
3484 * If the connection is closed, the function returns #FALSE.
3485 *
3486 * The return value indicates whether reading or writing is still
3487 * possible, i.e. whether the connection is connected.
3488 *
3489 * Note that even after disconnection, messages may remain in the
3490 * incoming queue that need to be
3491 * processed. dbus_connection_read_write_dispatch() dispatches
3492 * incoming messages for you; with dbus_connection_read_write() you
3493 * have to arrange to drain the incoming queue yourself.
3494 *
3495 * @param connection the connection
3496 * @param timeout_milliseconds max time to block or -1 for infinite
3497 * @returns #TRUE if still connected
3498 */
3499 dbus_bool_t
dbus_connection_read_write(DBusConnection * connection,int timeout_milliseconds)3500 dbus_connection_read_write (DBusConnection *connection,
3501 int timeout_milliseconds)
3502 {
3503 _dbus_return_val_if_fail (connection != NULL, FALSE);
3504 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
3505 return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, FALSE);
3506 }
3507
3508 /* We need to call this anytime we pop the head of the queue, and then
3509 * update_dispatch_status_and_unlock needs to be called afterward
3510 * which will "process" the disconnected message and set
3511 * disconnected_message_processed.
3512 */
3513 static void
check_disconnected_message_arrived_unlocked(DBusConnection * connection,DBusMessage * head_of_queue)3514 check_disconnected_message_arrived_unlocked (DBusConnection *connection,
3515 DBusMessage *head_of_queue)
3516 {
3517 HAVE_LOCK_CHECK (connection);
3518
3519 /* checking that the link is NULL is an optimization to avoid the is_signal call */
3520 if (connection->disconnect_message_link == NULL &&
3521 dbus_message_is_signal (head_of_queue,
3522 DBUS_INTERFACE_LOCAL,
3523 "Disconnected"))
3524 {
3525 connection->disconnected_message_arrived = TRUE;
3526 }
3527 }
3528
3529 /**
3530 * Returns the first-received message from the incoming message queue,
3531 * leaving it in the queue. If the queue is empty, returns #NULL.
3532 *
3533 * The caller does not own a reference to the returned message, and
3534 * must either return it using dbus_connection_return_message() or
3535 * keep it after calling dbus_connection_steal_borrowed_message(). No
3536 * one can get at the message while its borrowed, so return it as
3537 * quickly as possible and don't keep a reference to it after
3538 * returning it. If you need to keep the message, make a copy of it.
3539 *
3540 * dbus_connection_dispatch() will block if called while a borrowed
3541 * message is outstanding; only one piece of code can be playing with
3542 * the incoming queue at a time. This function will block if called
3543 * during a dbus_connection_dispatch().
3544 *
3545 * @param connection the connection.
3546 * @returns next message in the incoming queue.
3547 */
3548 DBusMessage*
dbus_connection_borrow_message(DBusConnection * connection)3549 dbus_connection_borrow_message (DBusConnection *connection)
3550 {
3551 DBusDispatchStatus status;
3552 DBusMessage *message;
3553
3554 _dbus_return_val_if_fail (connection != NULL, NULL);
3555
3556 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
3557
3558 /* this is called for the side effect that it queues
3559 * up any messages from the transport
3560 */
3561 status = dbus_connection_get_dispatch_status (connection);
3562 if (status != DBUS_DISPATCH_DATA_REMAINS)
3563 return NULL;
3564
3565 CONNECTION_LOCK (connection);
3566
3567 _dbus_connection_acquire_dispatch (connection);
3568
3569 /* While a message is outstanding, the dispatch lock is held */
3570 _dbus_assert (connection->message_borrowed == NULL);
3571
3572 connection->message_borrowed = _dbus_list_get_first (&connection->incoming_messages);
3573
3574 message = connection->message_borrowed;
3575
3576 check_disconnected_message_arrived_unlocked (connection, message);
3577
3578 /* Note that we KEEP the dispatch lock until the message is returned */
3579 if (message == NULL)
3580 _dbus_connection_release_dispatch (connection);
3581
3582 CONNECTION_UNLOCK (connection);
3583
3584 /* We don't update dispatch status until it's returned or stolen */
3585
3586 return message;
3587 }
3588
3589 /**
3590 * Used to return a message after peeking at it using
3591 * dbus_connection_borrow_message(). Only called if
3592 * message from dbus_connection_borrow_message() was non-#NULL.
3593 *
3594 * @param connection the connection
3595 * @param message the message from dbus_connection_borrow_message()
3596 */
3597 void
dbus_connection_return_message(DBusConnection * connection,DBusMessage * message)3598 dbus_connection_return_message (DBusConnection *connection,
3599 DBusMessage *message)
3600 {
3601 DBusDispatchStatus status;
3602
3603 _dbus_return_if_fail (connection != NULL);
3604 _dbus_return_if_fail (message != NULL);
3605 _dbus_return_if_fail (message == connection->message_borrowed);
3606 _dbus_return_if_fail (connection->dispatch_acquired);
3607
3608 CONNECTION_LOCK (connection);
3609
3610 _dbus_assert (message == connection->message_borrowed);
3611
3612 connection->message_borrowed = NULL;
3613
3614 _dbus_connection_release_dispatch (connection);
3615
3616 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3617 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3618 }
3619
3620 /**
3621 * Used to keep a message after peeking at it using
3622 * dbus_connection_borrow_message(). Before using this function, see
3623 * the caveats/warnings in the documentation for
3624 * dbus_connection_pop_message().
3625 *
3626 * @param connection the connection
3627 * @param message the message from dbus_connection_borrow_message()
3628 */
3629 void
dbus_connection_steal_borrowed_message(DBusConnection * connection,DBusMessage * message)3630 dbus_connection_steal_borrowed_message (DBusConnection *connection,
3631 DBusMessage *message)
3632 {
3633 DBusMessage *pop_message;
3634 DBusDispatchStatus status;
3635
3636 _dbus_return_if_fail (connection != NULL);
3637 _dbus_return_if_fail (message != NULL);
3638 _dbus_return_if_fail (message == connection->message_borrowed);
3639 _dbus_return_if_fail (connection->dispatch_acquired);
3640
3641 CONNECTION_LOCK (connection);
3642
3643 _dbus_assert (message == connection->message_borrowed);
3644
3645 pop_message = _dbus_list_pop_first (&connection->incoming_messages);
3646 _dbus_assert (message == pop_message);
3647
3648 connection->n_incoming -= 1;
3649
3650 _dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n",
3651 message, connection->n_incoming);
3652
3653 connection->message_borrowed = NULL;
3654
3655 _dbus_connection_release_dispatch (connection);
3656
3657 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3658 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3659 }
3660
3661 /* See dbus_connection_pop_message, but requires the caller to own
3662 * the lock before calling. May drop the lock while running.
3663 */
3664 static DBusList*
_dbus_connection_pop_message_link_unlocked(DBusConnection * connection)3665 _dbus_connection_pop_message_link_unlocked (DBusConnection *connection)
3666 {
3667 HAVE_LOCK_CHECK (connection);
3668
3669 _dbus_assert (connection->message_borrowed == NULL);
3670
3671 if (connection->n_incoming > 0)
3672 {
3673 DBusList *link;
3674
3675 link = _dbus_list_pop_first_link (&connection->incoming_messages);
3676 connection->n_incoming -= 1;
3677
3678 _dbus_verbose ("Message %p (%d %s %s %s '%s') removed from incoming queue %p, %d incoming\n",
3679 link->data,
3680 dbus_message_get_type (link->data),
3681 dbus_message_get_path (link->data) ?
3682 dbus_message_get_path (link->data) :
3683 "no path",
3684 dbus_message_get_interface (link->data) ?
3685 dbus_message_get_interface (link->data) :
3686 "no interface",
3687 dbus_message_get_member (link->data) ?
3688 dbus_message_get_member (link->data) :
3689 "no member",
3690 dbus_message_get_signature (link->data),
3691 connection, connection->n_incoming);
3692
3693 check_disconnected_message_arrived_unlocked (connection, link->data);
3694
3695 return link;
3696 }
3697 else
3698 return NULL;
3699 }
3700
3701 /* See dbus_connection_pop_message, but requires the caller to own
3702 * the lock before calling. May drop the lock while running.
3703 */
3704 static DBusMessage*
_dbus_connection_pop_message_unlocked(DBusConnection * connection)3705 _dbus_connection_pop_message_unlocked (DBusConnection *connection)
3706 {
3707 DBusList *link;
3708
3709 HAVE_LOCK_CHECK (connection);
3710
3711 link = _dbus_connection_pop_message_link_unlocked (connection);
3712
3713 if (link != NULL)
3714 {
3715 DBusMessage *message;
3716
3717 message = link->data;
3718
3719 _dbus_list_free_link (link);
3720
3721 return message;
3722 }
3723 else
3724 return NULL;
3725 }
3726
3727 static void
_dbus_connection_putback_message_link_unlocked(DBusConnection * connection,DBusList * message_link)3728 _dbus_connection_putback_message_link_unlocked (DBusConnection *connection,
3729 DBusList *message_link)
3730 {
3731 HAVE_LOCK_CHECK (connection);
3732
3733 _dbus_assert (message_link != NULL);
3734 /* You can't borrow a message while a link is outstanding */
3735 _dbus_assert (connection->message_borrowed == NULL);
3736 /* We had to have the dispatch lock across the pop/putback */
3737 _dbus_assert (connection->dispatch_acquired);
3738
3739 _dbus_list_prepend_link (&connection->incoming_messages,
3740 message_link);
3741 connection->n_incoming += 1;
3742
3743 _dbus_verbose ("Message %p (%d %s %s '%s') put back into queue %p, %d incoming\n",
3744 message_link->data,
3745 dbus_message_get_type (message_link->data),
3746 dbus_message_get_interface (message_link->data) ?
3747 dbus_message_get_interface (message_link->data) :
3748 "no interface",
3749 dbus_message_get_member (message_link->data) ?
3750 dbus_message_get_member (message_link->data) :
3751 "no member",
3752 dbus_message_get_signature (message_link->data),
3753 connection, connection->n_incoming);
3754 }
3755
3756 /**
3757 * Returns the first-received message from the incoming message queue,
3758 * removing it from the queue. The caller owns a reference to the
3759 * returned message. If the queue is empty, returns #NULL.
3760 *
3761 * This function bypasses any message handlers that are registered,
3762 * and so using it is usually wrong. Instead, let the main loop invoke
3763 * dbus_connection_dispatch(). Popping messages manually is only
3764 * useful in very simple programs that don't share a #DBusConnection
3765 * with any libraries or other modules.
3766 *
3767 * There is a lock that covers all ways of accessing the incoming message
3768 * queue, so dbus_connection_dispatch(), dbus_connection_pop_message(),
3769 * dbus_connection_borrow_message(), etc. will all block while one of the others
3770 * in the group is running.
3771 *
3772 * @param connection the connection.
3773 * @returns next message in the incoming queue.
3774 */
3775 DBusMessage*
dbus_connection_pop_message(DBusConnection * connection)3776 dbus_connection_pop_message (DBusConnection *connection)
3777 {
3778 DBusMessage *message;
3779 DBusDispatchStatus status;
3780
3781 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
3782
3783 /* this is called for the side effect that it queues
3784 * up any messages from the transport
3785 */
3786 status = dbus_connection_get_dispatch_status (connection);
3787 if (status != DBUS_DISPATCH_DATA_REMAINS)
3788 return NULL;
3789
3790 CONNECTION_LOCK (connection);
3791 _dbus_connection_acquire_dispatch (connection);
3792 HAVE_LOCK_CHECK (connection);
3793
3794 message = _dbus_connection_pop_message_unlocked (connection);
3795
3796 _dbus_verbose ("Returning popped message %p\n", message);
3797
3798 _dbus_connection_release_dispatch (connection);
3799
3800 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3801 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3802
3803 return message;
3804 }
3805
3806 /**
3807 * Acquire the dispatcher. This is a separate lock so the main
3808 * connection lock can be dropped to call out to application dispatch
3809 * handlers.
3810 *
3811 * @param connection the connection.
3812 */
3813 static void
_dbus_connection_acquire_dispatch(DBusConnection * connection)3814 _dbus_connection_acquire_dispatch (DBusConnection *connection)
3815 {
3816 HAVE_LOCK_CHECK (connection);
3817
3818 _dbus_connection_ref_unlocked (connection);
3819 CONNECTION_UNLOCK (connection);
3820
3821 _dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME);
3822 _dbus_mutex_lock (connection->dispatch_mutex);
3823
3824 while (connection->dispatch_acquired)
3825 {
3826 _dbus_verbose ("%s waiting for dispatch to be acquirable\n", _DBUS_FUNCTION_NAME);
3827 _dbus_condvar_wait (connection->dispatch_cond,
3828 connection->dispatch_mutex);
3829 }
3830
3831 _dbus_assert (!connection->dispatch_acquired);
3832
3833 connection->dispatch_acquired = TRUE;
3834
3835 _dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME);
3836 _dbus_mutex_unlock (connection->dispatch_mutex);
3837
3838 CONNECTION_LOCK (connection);
3839 _dbus_connection_unref_unlocked (connection);
3840 }
3841
3842 /**
3843 * Release the dispatcher when you're done with it. Only call
3844 * after you've acquired the dispatcher. Wakes up at most one
3845 * thread currently waiting to acquire the dispatcher.
3846 *
3847 * @param connection the connection.
3848 */
3849 static void
_dbus_connection_release_dispatch(DBusConnection * connection)3850 _dbus_connection_release_dispatch (DBusConnection *connection)
3851 {
3852 HAVE_LOCK_CHECK (connection);
3853
3854 _dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME);
3855 _dbus_mutex_lock (connection->dispatch_mutex);
3856
3857 _dbus_assert (connection->dispatch_acquired);
3858
3859 connection->dispatch_acquired = FALSE;
3860 _dbus_condvar_wake_one (connection->dispatch_cond);
3861
3862 _dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME);
3863 _dbus_mutex_unlock (connection->dispatch_mutex);
3864 }
3865
3866 static void
_dbus_connection_failed_pop(DBusConnection * connection,DBusList * message_link)3867 _dbus_connection_failed_pop (DBusConnection *connection,
3868 DBusList *message_link)
3869 {
3870 _dbus_list_prepend_link (&connection->incoming_messages,
3871 message_link);
3872 connection->n_incoming += 1;
3873 }
3874
3875 /* Note this may be called multiple times since we don't track whether we already did it */
3876 static void
notify_disconnected_unlocked(DBusConnection * connection)3877 notify_disconnected_unlocked (DBusConnection *connection)
3878 {
3879 HAVE_LOCK_CHECK (connection);
3880
3881 /* Set the weakref in dbus-bus.c to NULL, so nobody will get a disconnected
3882 * connection from dbus_bus_get(). We make the same guarantee for
3883 * dbus_connection_open() but in a different way since we don't want to
3884 * unref right here; we instead check for connectedness before returning
3885 * the connection from the hash.
3886 */
3887 _dbus_bus_notify_shared_connection_disconnected_unlocked (connection);
3888
3889 /* Dump the outgoing queue, we aren't going to be able to
3890 * send it now, and we'd like accessors like
3891 * dbus_connection_get_outgoing_size() to be accurate.
3892 */
3893 if (connection->n_outgoing > 0)
3894 {
3895 DBusList *link;
3896
3897 _dbus_verbose ("Dropping %d outgoing messages since we're disconnected\n",
3898 connection->n_outgoing);
3899
3900 while ((link = _dbus_list_get_last_link (&connection->outgoing_messages)))
3901 {
3902 _dbus_connection_message_sent (connection, link->data);
3903 }
3904 }
3905 }
3906
3907 /* Note this may be called multiple times since we don't track whether we already did it */
3908 static DBusDispatchStatus
notify_disconnected_and_dispatch_complete_unlocked(DBusConnection * connection)3909 notify_disconnected_and_dispatch_complete_unlocked (DBusConnection *connection)
3910 {
3911 HAVE_LOCK_CHECK (connection);
3912
3913 if (connection->disconnect_message_link != NULL)
3914 {
3915 _dbus_verbose ("Sending disconnect message from %s\n",
3916 _DBUS_FUNCTION_NAME);
3917
3918 /* If we have pending calls, queue their timeouts - we want the Disconnected
3919 * to be the last message, after these timeouts.
3920 */
3921 connection_timeout_and_complete_all_pending_calls_unlocked (connection);
3922
3923 /* We haven't sent the disconnect message already,
3924 * and all real messages have been queued up.
3925 */
3926 _dbus_connection_queue_synthesized_message_link (connection,
3927 connection->disconnect_message_link);
3928 connection->disconnect_message_link = NULL;
3929
3930 return DBUS_DISPATCH_DATA_REMAINS;
3931 }
3932
3933 return DBUS_DISPATCH_COMPLETE;
3934 }
3935
3936 static DBusDispatchStatus
_dbus_connection_get_dispatch_status_unlocked(DBusConnection * connection)3937 _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection)
3938 {
3939 HAVE_LOCK_CHECK (connection);
3940
3941 if (connection->n_incoming > 0)
3942 return DBUS_DISPATCH_DATA_REMAINS;
3943 else if (!_dbus_transport_queue_messages (connection->transport))
3944 return DBUS_DISPATCH_NEED_MEMORY;
3945 else
3946 {
3947 DBusDispatchStatus status;
3948 dbus_bool_t is_connected;
3949
3950 status = _dbus_transport_get_dispatch_status (connection->transport);
3951 is_connected = _dbus_transport_get_is_connected (connection->transport);
3952
3953 _dbus_verbose ("dispatch status = %s is_connected = %d\n",
3954 DISPATCH_STATUS_NAME (status), is_connected);
3955
3956 if (!is_connected)
3957 {
3958 /* It's possible this would be better done by having an explicit
3959 * notification from _dbus_transport_disconnect() that would
3960 * synchronously do this, instead of waiting for the next dispatch
3961 * status check. However, probably not good to change until it causes
3962 * a problem.
3963 */
3964 notify_disconnected_unlocked (connection);
3965
3966 /* I'm not sure this is needed; the idea is that we want to
3967 * queue the Disconnected only after we've read all the
3968 * messages, but if we're disconnected maybe we are guaranteed
3969 * to have read them all ?
3970 */
3971 if (status == DBUS_DISPATCH_COMPLETE)
3972 status = notify_disconnected_and_dispatch_complete_unlocked (connection);
3973 }
3974
3975 if (status != DBUS_DISPATCH_COMPLETE)
3976 return status;
3977 else if (connection->n_incoming > 0)
3978 return DBUS_DISPATCH_DATA_REMAINS;
3979 else
3980 return DBUS_DISPATCH_COMPLETE;
3981 }
3982 }
3983
3984 static void
_dbus_connection_update_dispatch_status_and_unlock(DBusConnection * connection,DBusDispatchStatus new_status)3985 _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection,
3986 DBusDispatchStatus new_status)
3987 {
3988 dbus_bool_t changed;
3989 DBusDispatchStatusFunction function;
3990 void *data;
3991
3992 HAVE_LOCK_CHECK (connection);
3993
3994 _dbus_connection_ref_unlocked (connection);
3995
3996 changed = new_status != connection->last_dispatch_status;
3997
3998 connection->last_dispatch_status = new_status;
3999
4000 function = connection->dispatch_status_function;
4001 data = connection->dispatch_status_data;
4002
4003 if (connection->disconnected_message_arrived &&
4004 !connection->disconnected_message_processed)
4005 {
4006 connection->disconnected_message_processed = TRUE;
4007
4008 /* this does an unref, but we have a ref
4009 * so we should not run the finalizer here
4010 * inside the lock.
4011 */
4012 connection_forget_shared_unlocked (connection);
4013
4014 if (connection->exit_on_disconnect)
4015 {
4016 CONNECTION_UNLOCK (connection);
4017
4018 _dbus_verbose ("Exiting on Disconnected signal\n");
4019 _dbus_exit (1);
4020 _dbus_assert_not_reached ("Call to exit() returned");
4021 }
4022 }
4023
4024 /* We drop the lock */
4025 CONNECTION_UNLOCK (connection);
4026
4027 if (changed && function)
4028 {
4029 _dbus_verbose ("Notifying of change to dispatch status of %p now %d (%s)\n",
4030 connection, new_status,
4031 DISPATCH_STATUS_NAME (new_status));
4032 (* function) (connection, new_status, data);
4033 }
4034
4035 dbus_connection_unref (connection);
4036 }
4037
4038 /**
4039 * Gets the current state of the incoming message queue.
4040 * #DBUS_DISPATCH_DATA_REMAINS indicates that the message queue
4041 * may contain messages. #DBUS_DISPATCH_COMPLETE indicates that the
4042 * incoming queue is empty. #DBUS_DISPATCH_NEED_MEMORY indicates that
4043 * there could be data, but we can't know for sure without more
4044 * memory.
4045 *
4046 * To process the incoming message queue, use dbus_connection_dispatch()
4047 * or (in rare cases) dbus_connection_pop_message().
4048 *
4049 * Note, #DBUS_DISPATCH_DATA_REMAINS really means that either we
4050 * have messages in the queue, or we have raw bytes buffered up
4051 * that need to be parsed. When these bytes are parsed, they
4052 * may not add up to an entire message. Thus, it's possible
4053 * to see a status of #DBUS_DISPATCH_DATA_REMAINS but not
4054 * have a message yet.
4055 *
4056 * In particular this happens on initial connection, because all sorts
4057 * of authentication protocol stuff has to be parsed before the
4058 * first message arrives.
4059 *
4060 * @param connection the connection.
4061 * @returns current dispatch status
4062 */
4063 DBusDispatchStatus
dbus_connection_get_dispatch_status(DBusConnection * connection)4064 dbus_connection_get_dispatch_status (DBusConnection *connection)
4065 {
4066 DBusDispatchStatus status;
4067
4068 _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);
4069
4070 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
4071
4072 CONNECTION_LOCK (connection);
4073
4074 status = _dbus_connection_get_dispatch_status_unlocked (connection);
4075
4076 CONNECTION_UNLOCK (connection);
4077
4078 return status;
4079 }
4080
4081 /**
4082 * Filter funtion for handling the Peer standard interface.
4083 */
4084 static DBusHandlerResult
_dbus_connection_peer_filter_unlocked_no_update(DBusConnection * connection,DBusMessage * message)4085 _dbus_connection_peer_filter_unlocked_no_update (DBusConnection *connection,
4086 DBusMessage *message)
4087 {
4088 if (connection->route_peer_messages && dbus_message_get_destination (message) != NULL)
4089 {
4090 /* This means we're letting the bus route this message */
4091 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
4092 }
4093 else if (dbus_message_is_method_call (message,
4094 DBUS_INTERFACE_PEER,
4095 "Ping"))
4096 {
4097 DBusMessage *ret;
4098 dbus_bool_t sent;
4099
4100 ret = dbus_message_new_method_return (message);
4101 if (ret == NULL)
4102 return DBUS_HANDLER_RESULT_NEED_MEMORY;
4103
4104 sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
4105
4106 dbus_message_unref (ret);
4107
4108 if (!sent)
4109 return DBUS_HANDLER_RESULT_NEED_MEMORY;
4110
4111 return DBUS_HANDLER_RESULT_HANDLED;
4112 }
4113 else if (dbus_message_is_method_call (message,
4114 DBUS_INTERFACE_PEER,
4115 "GetMachineId"))
4116 {
4117 DBusMessage *ret;
4118 dbus_bool_t sent;
4119 DBusString uuid;
4120
4121 ret = dbus_message_new_method_return (message);
4122 if (ret == NULL)
4123 return DBUS_HANDLER_RESULT_NEED_MEMORY;
4124
4125 sent = FALSE;
4126 _dbus_string_init (&uuid);
4127 if (_dbus_get_local_machine_uuid_encoded (&uuid))
4128 {
4129 const char *v_STRING = _dbus_string_get_const_data (&uuid);
4130 if (dbus_message_append_args (ret,
4131 DBUS_TYPE_STRING, &v_STRING,
4132 DBUS_TYPE_INVALID))
4133 {
4134 sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
4135 }
4136 }
4137 _dbus_string_free (&uuid);
4138
4139 dbus_message_unref (ret);
4140
4141 if (!sent)
4142 return DBUS_HANDLER_RESULT_NEED_MEMORY;
4143
4144 return DBUS_HANDLER_RESULT_HANDLED;
4145 }
4146 else if (dbus_message_has_interface (message, DBUS_INTERFACE_PEER))
4147 {
4148 /* We need to bounce anything else with this interface, otherwise apps
4149 * could start extending the interface and when we added extensions
4150 * here to DBusConnection we'd break those apps.
4151 */
4152
4153 DBusMessage *ret;
4154 dbus_bool_t sent;
4155
4156 ret = dbus_message_new_error (message,
4157 DBUS_ERROR_UNKNOWN_METHOD,
4158 "Unknown method invoked on org.freedesktop.DBus.Peer interface");
4159 if (ret == NULL)
4160 return DBUS_HANDLER_RESULT_NEED_MEMORY;
4161
4162 sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
4163
4164 dbus_message_unref (ret);
4165
4166 if (!sent)
4167 return DBUS_HANDLER_RESULT_NEED_MEMORY;
4168
4169 return DBUS_HANDLER_RESULT_HANDLED;
4170 }
4171 else
4172 {
4173 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
4174 }
4175 }
4176
4177 /**
4178 * Processes all builtin filter functions
4179 *
4180 * If the spec specifies a standard interface
4181 * they should be processed from this method
4182 **/
4183 static DBusHandlerResult
_dbus_connection_run_builtin_filters_unlocked_no_update(DBusConnection * connection,DBusMessage * message)4184 _dbus_connection_run_builtin_filters_unlocked_no_update (DBusConnection *connection,
4185 DBusMessage *message)
4186 {
4187 /* We just run one filter for now but have the option to run more
4188 if the spec calls for it in the future */
4189
4190 return _dbus_connection_peer_filter_unlocked_no_update (connection, message);
4191 }
4192
4193 /**
4194 * Processes any incoming data.
4195 *
4196 * If there's incoming raw data that has not yet been parsed, it is
4197 * parsed, which may or may not result in adding messages to the
4198 * incoming queue.
4199 *
4200 * The incoming data buffer is filled when the connection reads from
4201 * its underlying transport (such as a socket). Reading usually
4202 * happens in dbus_watch_handle() or dbus_connection_read_write().
4203 *
4204 * If there are complete messages in the incoming queue,
4205 * dbus_connection_dispatch() removes one message from the queue and
4206 * processes it. Processing has three steps.
4207 *
4208 * First, any method replies are passed to #DBusPendingCall or
4209 * dbus_connection_send_with_reply_and_block() in order to
4210 * complete the pending method call.
4211 *
4212 * Second, any filters registered with dbus_connection_add_filter()
4213 * are run. If any filter returns #DBUS_HANDLER_RESULT_HANDLED
4214 * then processing stops after that filter.
4215 *
4216 * Third, if the message is a method call it is forwarded to
4217 * any registered object path handlers added with
4218 * dbus_connection_register_object_path() or
4219 * dbus_connection_register_fallback().
4220 *
4221 * A single call to dbus_connection_dispatch() will process at most
4222 * one message; it will not clear the entire message queue.
4223 *
4224 * Be careful about calling dbus_connection_dispatch() from inside a
4225 * message handler, i.e. calling dbus_connection_dispatch()
4226 * recursively. If threads have been initialized with a recursive
4227 * mutex function, then this will not deadlock; however, it can
4228 * certainly confuse your application.
4229 *
4230 * @todo some FIXME in here about handling DBUS_HANDLER_RESULT_NEED_MEMORY
4231 *
4232 * @param connection the connection
4233 * @returns dispatch status, see dbus_connection_get_dispatch_status()
4234 */
4235 DBusDispatchStatus
dbus_connection_dispatch(DBusConnection * connection)4236 dbus_connection_dispatch (DBusConnection *connection)
4237 {
4238 DBusMessage *message;
4239 DBusList *link, *filter_list_copy, *message_link;
4240 DBusHandlerResult result;
4241 DBusPendingCall *pending;
4242 dbus_int32_t reply_serial;
4243 DBusDispatchStatus status;
4244
4245 _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);
4246
4247 _dbus_verbose ("%s\n", _DBUS_FUNCTION_NAME);
4248
4249 CONNECTION_LOCK (connection);
4250 status = _dbus_connection_get_dispatch_status_unlocked (connection);
4251 if (status != DBUS_DISPATCH_DATA_REMAINS)
4252 {
4253 /* unlocks and calls out to user code */
4254 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
4255 return status;
4256 }
4257
4258 /* We need to ref the connection since the callback could potentially
4259 * drop the last ref to it
4260 */
4261 _dbus_connection_ref_unlocked (connection);
4262
4263 _dbus_connection_acquire_dispatch (connection);
4264 HAVE_LOCK_CHECK (connection);
4265
4266 message_link = _dbus_connection_pop_message_link_unlocked (connection);
4267 if (message_link == NULL)
4268 {
4269 /* another thread dispatched our stuff */
4270
4271 _dbus_verbose ("another thread dispatched message (during acquire_dispatch above)\n");
4272
4273 _dbus_connection_release_dispatch (connection);
4274
4275 status = _dbus_connection_get_dispatch_status_unlocked (connection);
4276
4277 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
4278
4279 dbus_connection_unref (connection);
4280
4281 return status;
4282 }
4283
4284 message = message_link->data;
4285
4286 _dbus_verbose (" dispatching message %p (%d %s %s '%s')\n",
4287 message,
4288 dbus_message_get_type (message),
4289 dbus_message_get_interface (message) ?
4290 dbus_message_get_interface (message) :
4291 "no interface",
4292 dbus_message_get_member (message) ?
4293 dbus_message_get_member (message) :
4294 "no member",
4295 dbus_message_get_signature (message));
4296
4297 result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
4298
4299 /* Pending call handling must be first, because if you do
4300 * dbus_connection_send_with_reply_and_block() or
4301 * dbus_pending_call_block() then no handlers/filters will be run on
4302 * the reply. We want consistent semantics in the case where we
4303 * dbus_connection_dispatch() the reply.
4304 */
4305
4306 reply_serial = dbus_message_get_reply_serial (message);
4307 pending = _dbus_hash_table_lookup_int (connection->pending_replies,
4308 reply_serial);
4309 if (pending)
4310 {
4311 _dbus_verbose ("Dispatching a pending reply\n");
4312 complete_pending_call_and_unlock (connection, pending, message);
4313 pending = NULL; /* it's probably unref'd */
4314
4315 CONNECTION_LOCK (connection);
4316 _dbus_verbose ("pending call completed in dispatch\n");
4317 result = DBUS_HANDLER_RESULT_HANDLED;
4318 goto out;
4319 }
4320
4321 result = _dbus_connection_run_builtin_filters_unlocked_no_update (connection, message);
4322 if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
4323 goto out;
4324
4325 if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy))
4326 {
4327 _dbus_connection_release_dispatch (connection);
4328 HAVE_LOCK_CHECK (connection);
4329
4330 _dbus_connection_failed_pop (connection, message_link);
4331
4332 /* unlocks and calls user code */
4333 _dbus_connection_update_dispatch_status_and_unlock (connection,
4334 DBUS_DISPATCH_NEED_MEMORY);
4335
4336 if (pending)
4337 dbus_pending_call_unref (pending);
4338 dbus_connection_unref (connection);
4339
4340 return DBUS_DISPATCH_NEED_MEMORY;
4341 }
4342
4343 _dbus_list_foreach (&filter_list_copy,
4344 (DBusForeachFunction)_dbus_message_filter_ref,
4345 NULL);
4346
4347 /* We're still protected from dispatch() reentrancy here
4348 * since we acquired the dispatcher
4349 */
4350 CONNECTION_UNLOCK (connection);
4351
4352 link = _dbus_list_get_first_link (&filter_list_copy);
4353 while (link != NULL)
4354 {
4355 DBusMessageFilter *filter = link->data;
4356 DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link);
4357
4358 if (filter->function == NULL)
4359 {
4360 _dbus_verbose (" filter was removed in a callback function\n");
4361 link = next;
4362 continue;
4363 }
4364
4365 _dbus_verbose (" running filter on message %p\n", message);
4366 result = (* filter->function) (connection, message, filter->user_data);
4367
4368 if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
4369 break;
4370
4371 link = next;
4372 }
4373
4374 _dbus_list_foreach (&filter_list_copy,
4375 (DBusForeachFunction)_dbus_message_filter_unref,
4376 NULL);
4377 _dbus_list_clear (&filter_list_copy);
4378
4379 CONNECTION_LOCK (connection);
4380
4381 if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
4382 {
4383 _dbus_verbose ("No memory in %s\n", _DBUS_FUNCTION_NAME);
4384 goto out;
4385 }
4386 else if (result == DBUS_HANDLER_RESULT_HANDLED)
4387 {
4388 _dbus_verbose ("filter handled message in dispatch\n");
4389 goto out;
4390 }
4391
4392 /* We're still protected from dispatch() reentrancy here
4393 * since we acquired the dispatcher
4394 */
4395 _dbus_verbose (" running object path dispatch on message %p (%d %s %s '%s')\n",
4396 message,
4397 dbus_message_get_type (message),
4398 dbus_message_get_interface (message) ?
4399 dbus_message_get_interface (message) :
4400 "no interface",
4401 dbus_message_get_member (message) ?
4402 dbus_message_get_member (message) :
4403 "no member",
4404 dbus_message_get_signature (message));
4405
4406 HAVE_LOCK_CHECK (connection);
4407 result = _dbus_object_tree_dispatch_and_unlock (connection->objects,
4408 message);
4409
4410 CONNECTION_LOCK (connection);
4411
4412 if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
4413 {
4414 _dbus_verbose ("object tree handled message in dispatch\n");
4415 goto out;
4416 }
4417
4418 if (dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_CALL)
4419 {
4420 DBusMessage *reply;
4421 DBusString str;
4422 DBusPreallocatedSend *preallocated;
4423
4424 _dbus_verbose (" sending error %s\n",
4425 DBUS_ERROR_UNKNOWN_METHOD);
4426
4427 if (!_dbus_string_init (&str))
4428 {
4429 result = DBUS_HANDLER_RESULT_NEED_MEMORY;
4430 _dbus_verbose ("no memory for error string in dispatch\n");
4431 goto out;
4432 }
4433
4434 if (!_dbus_string_append_printf (&str,
4435 "Method \"%s\" with signature \"%s\" on interface \"%s\" doesn't exist\n",
4436 dbus_message_get_member (message),
4437 dbus_message_get_signature (message),
4438 dbus_message_get_interface (message)))
4439 {
4440 _dbus_string_free (&str);
4441 result = DBUS_HANDLER_RESULT_NEED_MEMORY;
4442 _dbus_verbose ("no memory for error string in dispatch\n");
4443 goto out;
4444 }
4445
4446 reply = dbus_message_new_error (message,
4447 DBUS_ERROR_UNKNOWN_METHOD,
4448 _dbus_string_get_const_data (&str));
4449 _dbus_string_free (&str);
4450
4451 if (reply == NULL)
4452 {
4453 result = DBUS_HANDLER_RESULT_NEED_MEMORY;
4454 _dbus_verbose ("no memory for error reply in dispatch\n");
4455 goto out;
4456 }
4457
4458 preallocated = _dbus_connection_preallocate_send_unlocked (connection);
4459
4460 if (preallocated == NULL)
4461 {
4462 dbus_message_unref (reply);
4463 result = DBUS_HANDLER_RESULT_NEED_MEMORY;
4464 _dbus_verbose ("no memory for error send in dispatch\n");
4465 goto out;
4466 }
4467
4468 _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated,
4469 reply, NULL);
4470
4471 dbus_message_unref (reply);
4472
4473 result = DBUS_HANDLER_RESULT_HANDLED;
4474 }
4475
4476 _dbus_verbose (" done dispatching %p (%d %s %s '%s') on connection %p\n", message,
4477 dbus_message_get_type (message),
4478 dbus_message_get_interface (message) ?
4479 dbus_message_get_interface (message) :
4480 "no interface",
4481 dbus_message_get_member (message) ?
4482 dbus_message_get_member (message) :
4483 "no member",
4484 dbus_message_get_signature (message),
4485 connection);
4486
4487 out:
4488 if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
4489 {
4490 _dbus_verbose ("out of memory in %s\n", _DBUS_FUNCTION_NAME);
4491
4492 /* Put message back, and we'll start over.
4493 * Yes this means handlers must be idempotent if they
4494 * don't return HANDLED; c'est la vie.
4495 */
4496 _dbus_connection_putback_message_link_unlocked (connection,
4497 message_link);
4498 }
4499 else
4500 {
4501 _dbus_verbose (" ... done dispatching in %s\n", _DBUS_FUNCTION_NAME);
4502
4503 _dbus_list_free_link (message_link);
4504 dbus_message_unref (message); /* don't want the message to count in max message limits
4505 * in computing dispatch status below
4506 */
4507 }
4508
4509 _dbus_connection_release_dispatch (connection);
4510 HAVE_LOCK_CHECK (connection);
4511
4512 _dbus_verbose ("%s before final status update\n", _DBUS_FUNCTION_NAME);
4513 status = _dbus_connection_get_dispatch_status_unlocked (connection);
4514
4515 /* unlocks and calls user code */
4516 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
4517
4518 dbus_connection_unref (connection);
4519
4520 return status;
4521 }
4522
4523 /**
4524 * Sets the watch functions for the connection. These functions are
4525 * responsible for making the application's main loop aware of file
4526 * descriptors that need to be monitored for events, using select() or
4527 * poll(). When using Qt, typically the DBusAddWatchFunction would
4528 * create a QSocketNotifier. When using GLib, the DBusAddWatchFunction
4529 * could call g_io_add_watch(), or could be used as part of a more
4530 * elaborate GSource. Note that when a watch is added, it may
4531 * not be enabled.
4532 *
4533 * The DBusWatchToggledFunction notifies the application that the
4534 * watch has been enabled or disabled. Call dbus_watch_get_enabled()
4535 * to check this. A disabled watch should have no effect, and enabled
4536 * watch should be added to the main loop. This feature is used
4537 * instead of simply adding/removing the watch because
4538 * enabling/disabling can be done without memory allocation. The
4539 * toggled function may be NULL if a main loop re-queries
4540 * dbus_watch_get_enabled() every time anyway.
4541 *
4542 * The DBusWatch can be queried for the file descriptor to watch using
4543 * dbus_watch_get_fd(), and for the events to watch for using
4544 * dbus_watch_get_flags(). The flags returned by
4545 * dbus_watch_get_flags() will only contain DBUS_WATCH_READABLE and
4546 * DBUS_WATCH_WRITABLE, never DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR;
4547 * all watches implicitly include a watch for hangups, errors, and
4548 * other exceptional conditions.
4549 *
4550 * Once a file descriptor becomes readable or writable, or an exception
4551 * occurs, dbus_watch_handle() should be called to
4552 * notify the connection of the file descriptor's condition.
4553 *
4554 * dbus_watch_handle() cannot be called during the
4555 * DBusAddWatchFunction, as the connection will not be ready to handle
4556 * that watch yet.
4557 *
4558 * It is not allowed to reference a DBusWatch after it has been passed
4559 * to remove_function.
4560 *
4561 * If #FALSE is returned due to lack of memory, the failure may be due
4562 * to a #FALSE return from the new add_function. If so, the
4563 * add_function may have been called successfully one or more times,
4564 * but the remove_function will also have been called to remove any
4565 * successful adds. i.e. if #FALSE is returned the net result
4566 * should be that dbus_connection_set_watch_functions() has no effect,
4567 * but the add_function and remove_function may have been called.
4568 *
4569 * @todo We need to drop the lock when we call the
4570 * add/remove/toggled functions which can be a side effect
4571 * of setting the watch functions.
4572 *
4573 * @param connection the connection.
4574 * @param add_function function to begin monitoring a new descriptor.
4575 * @param remove_function function to stop monitoring a descriptor.
4576 * @param toggled_function function to notify of enable/disable
4577 * @param data data to pass to add_function and remove_function.
4578 * @param free_data_function function to be called to free the data.
4579 * @returns #FALSE on failure (no memory)
4580 */
4581 dbus_bool_t
dbus_connection_set_watch_functions(DBusConnection * connection,DBusAddWatchFunction add_function,DBusRemoveWatchFunction remove_function,DBusWatchToggledFunction toggled_function,void * data,DBusFreeFunction free_data_function)4582 dbus_connection_set_watch_functions (DBusConnection *connection,
4583 DBusAddWatchFunction add_function,
4584 DBusRemoveWatchFunction remove_function,
4585 DBusWatchToggledFunction toggled_function,
4586 void *data,
4587 DBusFreeFunction free_data_function)
4588 {
4589 dbus_bool_t retval;
4590 DBusWatchList *watches;
4591
4592 _dbus_return_val_if_fail (connection != NULL, FALSE);
4593
4594 CONNECTION_LOCK (connection);
4595
4596 #ifndef DBUS_DISABLE_CHECKS
4597 if (connection->watches == NULL)
4598 {
4599 _dbus_warn_check_failed ("Re-entrant call to %s is not allowed\n",
4600 _DBUS_FUNCTION_NAME);
4601 return FALSE;
4602 }
4603 #endif
4604
4605 /* ref connection for slightly better reentrancy */
4606 _dbus_connection_ref_unlocked (connection);
4607
4608 /* This can call back into user code, and we need to drop the
4609 * connection lock when it does. This is kind of a lame
4610 * way to do it.
4611 */
4612 watches = connection->watches;
4613 connection->watches = NULL;
4614 CONNECTION_UNLOCK (connection);
4615
4616 retval = _dbus_watch_list_set_functions (watches,
4617 add_function, remove_function,
4618 toggled_function,
4619 data, free_data_function);
4620 CONNECTION_LOCK (connection);
4621 connection->watches = watches;
4622
4623 CONNECTION_UNLOCK (connection);
4624 /* drop our paranoid refcount */
4625 dbus_connection_unref (connection);
4626
4627 return retval;
4628 }
4629
4630 /**
4631 * Sets the timeout functions for the connection. These functions are
4632 * responsible for making the application's main loop aware of timeouts.
4633 * When using Qt, typically the DBusAddTimeoutFunction would create a
4634 * QTimer. When using GLib, the DBusAddTimeoutFunction would call
4635 * g_timeout_add.
4636 *
4637 * The DBusTimeoutToggledFunction notifies the application that the
4638 * timeout has been enabled or disabled. Call
4639 * dbus_timeout_get_enabled() to check this. A disabled timeout should
4640 * have no effect, and enabled timeout should be added to the main
4641 * loop. This feature is used instead of simply adding/removing the
4642 * timeout because enabling/disabling can be done without memory
4643 * allocation. With Qt, QTimer::start() and QTimer::stop() can be used
4644 * to enable and disable. The toggled function may be NULL if a main
4645 * loop re-queries dbus_timeout_get_enabled() every time anyway.
4646 * Whenever a timeout is toggled, its interval may change.
4647 *
4648 * The DBusTimeout can be queried for the timer interval using
4649 * dbus_timeout_get_interval(). dbus_timeout_handle() should be called
4650 * repeatedly, each time the interval elapses, starting after it has
4651 * elapsed once. The timeout stops firing when it is removed with the
4652 * given remove_function. The timer interval may change whenever the
4653 * timeout is added, removed, or toggled.
4654 *
4655 * @param connection the connection.
4656 * @param add_function function to add a timeout.
4657 * @param remove_function function to remove a timeout.
4658 * @param toggled_function function to notify of enable/disable
4659 * @param data data to pass to add_function and remove_function.
4660 * @param free_data_function function to be called to free the data.
4661 * @returns #FALSE on failure (no memory)
4662 */
4663 dbus_bool_t
dbus_connection_set_timeout_functions(DBusConnection * connection,DBusAddTimeoutFunction add_function,DBusRemoveTimeoutFunction remove_function,DBusTimeoutToggledFunction toggled_function,void * data,DBusFreeFunction free_data_function)4664 dbus_connection_set_timeout_functions (DBusConnection *connection,
4665 DBusAddTimeoutFunction add_function,
4666 DBusRemoveTimeoutFunction remove_function,
4667 DBusTimeoutToggledFunction toggled_function,
4668 void *data,
4669 DBusFreeFunction free_data_function)
4670 {
4671 dbus_bool_t retval;
4672 DBusTimeoutList *timeouts;
4673
4674 _dbus_return_val_if_fail (connection != NULL, FALSE);
4675
4676 CONNECTION_LOCK (connection);
4677
4678 #ifndef DBUS_DISABLE_CHECKS
4679 if (connection->timeouts == NULL)
4680 {
4681 _dbus_warn_check_failed ("Re-entrant call to %s is not allowed\n",
4682 _DBUS_FUNCTION_NAME);
4683 return FALSE;
4684 }
4685 #endif
4686
4687 /* ref connection for slightly better reentrancy */
4688 _dbus_connection_ref_unlocked (connection);
4689
4690 timeouts = connection->timeouts;
4691 connection->timeouts = NULL;
4692 CONNECTION_UNLOCK (connection);
4693
4694 retval = _dbus_timeout_list_set_functions (timeouts,
4695 add_function, remove_function,
4696 toggled_function,
4697 data, free_data_function);
4698 CONNECTION_LOCK (connection);
4699 connection->timeouts = timeouts;
4700
4701 CONNECTION_UNLOCK (connection);
4702 /* drop our paranoid refcount */
4703 dbus_connection_unref (connection);
4704
4705 return retval;
4706 }
4707
4708 /**
4709 * Sets the mainloop wakeup function for the connection. This function
4710 * is responsible for waking up the main loop (if its sleeping in
4711 * another thread) when some some change has happened to the
4712 * connection that the mainloop needs to reconsider (e.g. a message
4713 * has been queued for writing). When using Qt, this typically
4714 * results in a call to QEventLoop::wakeUp(). When using GLib, it
4715 * would call g_main_context_wakeup().
4716 *
4717 * @param connection the connection.
4718 * @param wakeup_main_function function to wake up the mainloop
4719 * @param data data to pass wakeup_main_function
4720 * @param free_data_function function to be called to free the data.
4721 */
4722 void
dbus_connection_set_wakeup_main_function(DBusConnection * connection,DBusWakeupMainFunction wakeup_main_function,void * data,DBusFreeFunction free_data_function)4723 dbus_connection_set_wakeup_main_function (DBusConnection *connection,
4724 DBusWakeupMainFunction wakeup_main_function,
4725 void *data,
4726 DBusFreeFunction free_data_function)
4727 {
4728 void *old_data;
4729 DBusFreeFunction old_free_data;
4730
4731 _dbus_return_if_fail (connection != NULL);
4732
4733 CONNECTION_LOCK (connection);
4734 old_data = connection->wakeup_main_data;
4735 old_free_data = connection->free_wakeup_main_data;
4736
4737 connection->wakeup_main_function = wakeup_main_function;
4738 connection->wakeup_main_data = data;
4739 connection->free_wakeup_main_data = free_data_function;
4740
4741 CONNECTION_UNLOCK (connection);
4742
4743 /* Callback outside the lock */
4744 if (old_free_data)
4745 (*old_free_data) (old_data);
4746 }
4747
4748 /**
4749 * Set a function to be invoked when the dispatch status changes.
4750 * If the dispatch status is #DBUS_DISPATCH_DATA_REMAINS, then
4751 * dbus_connection_dispatch() needs to be called to process incoming
4752 * messages. However, dbus_connection_dispatch() MUST NOT BE CALLED
4753 * from inside the DBusDispatchStatusFunction. Indeed, almost
4754 * any reentrancy in this function is a bad idea. Instead,
4755 * the DBusDispatchStatusFunction should simply save an indication
4756 * that messages should be dispatched later, when the main loop
4757 * is re-entered.
4758 *
4759 * If you don't set a dispatch status function, you have to be sure to
4760 * dispatch on every iteration of your main loop, especially if
4761 * dbus_watch_handle() or dbus_timeout_handle() were called.
4762 *
4763 * @param connection the connection
4764 * @param function function to call on dispatch status changes
4765 * @param data data for function
4766 * @param free_data_function free the function data
4767 */
4768 void
dbus_connection_set_dispatch_status_function(DBusConnection * connection,DBusDispatchStatusFunction function,void * data,DBusFreeFunction free_data_function)4769 dbus_connection_set_dispatch_status_function (DBusConnection *connection,
4770 DBusDispatchStatusFunction function,
4771 void *data,
4772 DBusFreeFunction free_data_function)
4773 {
4774 void *old_data;
4775 DBusFreeFunction old_free_data;
4776
4777 _dbus_return_if_fail (connection != NULL);
4778
4779 CONNECTION_LOCK (connection);
4780 old_data = connection->dispatch_status_data;
4781 old_free_data = connection->free_dispatch_status_data;
4782
4783 connection->dispatch_status_function = function;
4784 connection->dispatch_status_data = data;
4785 connection->free_dispatch_status_data = free_data_function;
4786
4787 CONNECTION_UNLOCK (connection);
4788
4789 /* Callback outside the lock */
4790 if (old_free_data)
4791 (*old_free_data) (old_data);
4792 }
4793
4794 /**
4795 * Get the UNIX file descriptor of the connection, if any. This can
4796 * be used for SELinux access control checks with getpeercon() for
4797 * example. DO NOT read or write to the file descriptor, or try to
4798 * select() on it; use DBusWatch for main loop integration. Not all
4799 * connections will have a file descriptor. So for adding descriptors
4800 * to the main loop, use dbus_watch_get_fd() and so forth.
4801 *
4802 * If the connection is socket-based, you can also use
4803 * dbus_connection_get_socket(), which will work on Windows too.
4804 * This function always fails on Windows.
4805 *
4806 * Right now the returned descriptor is always a socket, but
4807 * that is not guaranteed.
4808 *
4809 * @param connection the connection
4810 * @param fd return location for the file descriptor.
4811 * @returns #TRUE if fd is successfully obtained.
4812 */
4813 dbus_bool_t
dbus_connection_get_unix_fd(DBusConnection * connection,int * fd)4814 dbus_connection_get_unix_fd (DBusConnection *connection,
4815 int *fd)
4816 {
4817 _dbus_return_val_if_fail (connection != NULL, FALSE);
4818 _dbus_return_val_if_fail (connection->transport != NULL, FALSE);
4819
4820 #ifdef DBUS_WIN
4821 /* FIXME do this on a lower level */
4822 return FALSE;
4823 #endif
4824
4825 return dbus_connection_get_socket(connection, fd);
4826 }
4827
4828 /**
4829 * Gets the underlying Windows or UNIX socket file descriptor
4830 * of the connection, if any. DO NOT read or write to the file descriptor, or try to
4831 * select() on it; use DBusWatch for main loop integration. Not all
4832 * connections will have a socket. So for adding descriptors
4833 * to the main loop, use dbus_watch_get_fd() and so forth.
4834 *
4835 * If the connection is not socket-based, this function will return FALSE,
4836 * even if the connection does have a file descriptor of some kind.
4837 * i.e. this function always returns specifically a socket file descriptor.
4838 *
4839 * @param connection the connection
4840 * @param fd return location for the file descriptor.
4841 * @returns #TRUE if fd is successfully obtained.
4842 */
4843 dbus_bool_t
dbus_connection_get_socket(DBusConnection * connection,int * fd)4844 dbus_connection_get_socket(DBusConnection *connection,
4845 int *fd)
4846 {
4847 dbus_bool_t retval;
4848
4849 _dbus_return_val_if_fail (connection != NULL, FALSE);
4850 _dbus_return_val_if_fail (connection->transport != NULL, FALSE);
4851
4852 CONNECTION_LOCK (connection);
4853
4854 retval = _dbus_transport_get_socket_fd (connection->transport,
4855 fd);
4856
4857 CONNECTION_UNLOCK (connection);
4858
4859 return retval;
4860 }
4861
4862
4863 /**
4864 * Gets the UNIX user ID of the connection if known. Returns #TRUE if
4865 * the uid is filled in. Always returns #FALSE on non-UNIX platforms.
4866 * Always returns #FALSE prior to authenticating the connection.
4867 *
4868 * The UID is only read by servers from clients; clients can't usually
4869 * get the UID of servers, because servers do not authenticate to
4870 * clients. The returned UID is the UID the connection authenticated
4871 * as.
4872 *
4873 * The message bus is a server and the apps connecting to the bus
4874 * are clients.
4875 *
4876 * You can ask the bus to tell you the UID of another connection though
4877 * if you like; this is done with dbus_bus_get_unix_user().
4878 *
4879 * @param connection the connection
4880 * @param uid return location for the user ID
4881 * @returns #TRUE if uid is filled in with a valid user ID
4882 */
4883 dbus_bool_t
dbus_connection_get_unix_user(DBusConnection * connection,unsigned long * uid)4884 dbus_connection_get_unix_user (DBusConnection *connection,
4885 unsigned long *uid)
4886 {
4887 dbus_bool_t result;
4888
4889 _dbus_return_val_if_fail (connection != NULL, FALSE);
4890 _dbus_return_val_if_fail (uid != NULL, FALSE);
4891
4892 #ifdef DBUS_WIN
4893 /* FIXME this should be done at a lower level, but it's kind of hard,
4894 * just want to be sure we don't ship with this API returning
4895 * some weird internal fake uid for 1.0
4896 */
4897 return FALSE;
4898 #endif
4899
4900 CONNECTION_LOCK (connection);
4901
4902 if (!_dbus_transport_get_is_authenticated (connection->transport))
4903 result = FALSE;
4904 else
4905 result = _dbus_transport_get_unix_user (connection->transport,
4906 uid);
4907 CONNECTION_UNLOCK (connection);
4908
4909 return result;
4910 }
4911
4912 /**
4913 * Gets the process ID of the connection if any.
4914 * Returns #TRUE if the uid is filled in.
4915 * Always returns #FALSE prior to authenticating the
4916 * connection.
4917 *
4918 * @param connection the connection
4919 * @param pid return location for the process ID
4920 * @returns #TRUE if uid is filled in with a valid process ID
4921 */
4922 dbus_bool_t
dbus_connection_get_unix_process_id(DBusConnection * connection,unsigned long * pid)4923 dbus_connection_get_unix_process_id (DBusConnection *connection,
4924 unsigned long *pid)
4925 {
4926 dbus_bool_t result;
4927
4928 _dbus_return_val_if_fail (connection != NULL, FALSE);
4929 _dbus_return_val_if_fail (pid != NULL, FALSE);
4930
4931 #ifdef DBUS_WIN
4932 /* FIXME this should be done at a lower level, but it's kind of hard,
4933 * just want to be sure we don't ship with this API returning
4934 * some weird internal fake uid for 1.0
4935 */
4936 return FALSE;
4937 #endif
4938
4939 CONNECTION_LOCK (connection);
4940
4941 if (!_dbus_transport_get_is_authenticated (connection->transport))
4942 result = FALSE;
4943 else
4944 result = _dbus_transport_get_unix_process_id (connection->transport,
4945 pid);
4946 CONNECTION_UNLOCK (connection);
4947
4948 return result;
4949 }
4950
4951 /**
4952 * Sets a predicate function used to determine whether a given user ID
4953 * is allowed to connect. When an incoming connection has
4954 * authenticated with a particular user ID, this function is called;
4955 * if it returns #TRUE, the connection is allowed to proceed,
4956 * otherwise the connection is disconnected.
4957 *
4958 * If the function is set to #NULL (as it is by default), then
4959 * only the same UID as the server process will be allowed to
4960 * connect.
4961 *
4962 * On Windows, the function will be set and its free_data_function will
4963 * be invoked when the connection is freed or a new function is set.
4964 * However, the function will never be called, because there are
4965 * no UNIX user ids to pass to it.
4966 *
4967 * @todo add a Windows API analogous to dbus_connection_set_unix_user_function()
4968 *
4969 * @param connection the connection
4970 * @param function the predicate
4971 * @param data data to pass to the predicate
4972 * @param free_data_function function to free the data
4973 */
4974 void
dbus_connection_set_unix_user_function(DBusConnection * connection,DBusAllowUnixUserFunction function,void * data,DBusFreeFunction free_data_function)4975 dbus_connection_set_unix_user_function (DBusConnection *connection,
4976 DBusAllowUnixUserFunction function,
4977 void *data,
4978 DBusFreeFunction free_data_function)
4979 {
4980 void *old_data = NULL;
4981 DBusFreeFunction old_free_function = NULL;
4982
4983 _dbus_return_if_fail (connection != NULL);
4984
4985 CONNECTION_LOCK (connection);
4986 _dbus_transport_set_unix_user_function (connection->transport,
4987 function, data, free_data_function,
4988 &old_data, &old_free_function);
4989 CONNECTION_UNLOCK (connection);
4990
4991 if (old_free_function != NULL)
4992 (* old_free_function) (old_data);
4993 }
4994
4995 /**
4996 *
4997 * Normally #DBusConnection automatically handles all messages to the
4998 * org.freedesktop.DBus.Peer interface. However, the message bus wants
4999 * to be able to route methods on that interface through the bus and
5000 * to other applications. If routing peer messages is enabled, then
5001 * messages with the org.freedesktop.DBus.Peer interface that also
5002 * have a bus destination name set will not be automatically
5003 * handled by the #DBusConnection and instead will be dispatched
5004 * normally to the application.
5005 *
5006 *
5007 * If a normal application sets this flag, it can break things badly.
5008 * So don't set this unless you are the message bus.
5009 *
5010 * @param connection the connection
5011 * @param value #TRUE to pass through org.freedesktop.DBus.Peer messages with a bus name set
5012 */
5013 void
dbus_connection_set_route_peer_messages(DBusConnection * connection,dbus_bool_t value)5014 dbus_connection_set_route_peer_messages (DBusConnection *connection,
5015 dbus_bool_t value)
5016 {
5017 _dbus_return_if_fail (connection != NULL);
5018
5019 CONNECTION_LOCK (connection);
5020 connection->route_peer_messages = TRUE;
5021 CONNECTION_UNLOCK (connection);
5022 }
5023
5024 /**
5025 * Adds a message filter. Filters are handlers that are run on all
5026 * incoming messages, prior to the objects registered with
5027 * dbus_connection_register_object_path(). Filters are run in the
5028 * order that they were added. The same handler can be added as a
5029 * filter more than once, in which case it will be run more than once.
5030 * Filters added during a filter callback won't be run on the message
5031 * being processed.
5032 *
5033 * @todo we don't run filters on messages while blocking without
5034 * entering the main loop, since filters are run as part of
5035 * dbus_connection_dispatch(). This is probably a feature, as filters
5036 * could create arbitrary reentrancy. But kind of sucks if you're
5037 * trying to filter METHOD_RETURN for some reason.
5038 *
5039 * @param connection the connection
5040 * @param function function to handle messages
5041 * @param user_data user data to pass to the function
5042 * @param free_data_function function to use for freeing user data
5043 * @returns #TRUE on success, #FALSE if not enough memory.
5044 */
5045 dbus_bool_t
dbus_connection_add_filter(DBusConnection * connection,DBusHandleMessageFunction function,void * user_data,DBusFreeFunction free_data_function)5046 dbus_connection_add_filter (DBusConnection *connection,
5047 DBusHandleMessageFunction function,
5048 void *user_data,
5049 DBusFreeFunction free_data_function)
5050 {
5051 DBusMessageFilter *filter;
5052
5053 _dbus_return_val_if_fail (connection != NULL, FALSE);
5054 _dbus_return_val_if_fail (function != NULL, FALSE);
5055
5056 filter = dbus_new0 (DBusMessageFilter, 1);
5057 if (filter == NULL)
5058 return FALSE;
5059
5060 filter->refcount.value = 1;
5061
5062 CONNECTION_LOCK (connection);
5063
5064 if (!_dbus_list_append (&connection->filter_list,
5065 filter))
5066 {
5067 _dbus_message_filter_unref (filter);
5068 CONNECTION_UNLOCK (connection);
5069 return FALSE;
5070 }
5071
5072 /* Fill in filter after all memory allocated,
5073 * so we don't run the free_user_data_function
5074 * if the add_filter() fails
5075 */
5076
5077 filter->function = function;
5078 filter->user_data = user_data;
5079 filter->free_user_data_function = free_data_function;
5080
5081 CONNECTION_UNLOCK (connection);
5082 return TRUE;
5083 }
5084
5085 /**
5086 * Removes a previously-added message filter. It is a programming
5087 * error to call this function for a handler that has not been added
5088 * as a filter. If the given handler was added more than once, only
5089 * one instance of it will be removed (the most recently-added
5090 * instance).
5091 *
5092 * @param connection the connection
5093 * @param function the handler to remove
5094 * @param user_data user data for the handler to remove
5095 *
5096 */
5097 void
dbus_connection_remove_filter(DBusConnection * connection,DBusHandleMessageFunction function,void * user_data)5098 dbus_connection_remove_filter (DBusConnection *connection,
5099 DBusHandleMessageFunction function,
5100 void *user_data)
5101 {
5102 DBusList *link;
5103 DBusMessageFilter *filter;
5104
5105 _dbus_return_if_fail (connection != NULL);
5106 _dbus_return_if_fail (function != NULL);
5107
5108 CONNECTION_LOCK (connection);
5109
5110 filter = NULL;
5111
5112 link = _dbus_list_get_last_link (&connection->filter_list);
5113 while (link != NULL)
5114 {
5115 filter = link->data;
5116
5117 if (filter->function == function &&
5118 filter->user_data == user_data)
5119 {
5120 _dbus_list_remove_link (&connection->filter_list, link);
5121 filter->function = NULL;
5122
5123 break;
5124 }
5125
5126 link = _dbus_list_get_prev_link (&connection->filter_list, link);
5127 }
5128
5129 CONNECTION_UNLOCK (connection);
5130
5131 #ifndef DBUS_DISABLE_CHECKS
5132 if (filter == NULL)
5133 {
5134 _dbus_warn_check_failed ("Attempt to remove filter function %p user data %p, but no such filter has been added\n",
5135 function, user_data);
5136 return;
5137 }
5138 #endif
5139
5140 /* Call application code */
5141 if (filter->free_user_data_function)
5142 (* filter->free_user_data_function) (filter->user_data);
5143
5144 filter->free_user_data_function = NULL;
5145 filter->user_data = NULL;
5146
5147 _dbus_message_filter_unref (filter);
5148 }
5149
5150 /**
5151 * Registers a handler for a given path in the object hierarchy.
5152 * The given vtable handles messages sent to exactly the given path.
5153 *
5154 *
5155 * @param connection the connection
5156 * @param path a '/' delimited string of path elements
5157 * @param vtable the virtual table
5158 * @param user_data data to pass to functions in the vtable
5159 * @returns #FALSE if not enough memory
5160 */
5161 dbus_bool_t
dbus_connection_register_object_path(DBusConnection * connection,const char * path,const DBusObjectPathVTable * vtable,void * user_data)5162 dbus_connection_register_object_path (DBusConnection *connection,
5163 const char *path,
5164 const DBusObjectPathVTable *vtable,
5165 void *user_data)
5166 {
5167 char **decomposed_path;
5168 dbus_bool_t retval;
5169
5170 _dbus_return_val_if_fail (connection != NULL, FALSE);
5171 _dbus_return_val_if_fail (path != NULL, FALSE);
5172 _dbus_return_val_if_fail (path[0] == '/', FALSE);
5173 _dbus_return_val_if_fail (vtable != NULL, FALSE);
5174
5175 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
5176 return FALSE;
5177
5178 CONNECTION_LOCK (connection);
5179
5180 retval = _dbus_object_tree_register (connection->objects,
5181 FALSE,
5182 (const char **) decomposed_path, vtable,
5183 user_data);
5184
5185 CONNECTION_UNLOCK (connection);
5186
5187 dbus_free_string_array (decomposed_path);
5188
5189 return retval;
5190 }
5191
5192 /**
5193 * Registers a fallback handler for a given subsection of the object
5194 * hierarchy. The given vtable handles messages at or below the given
5195 * path. You can use this to establish a default message handling
5196 * policy for a whole "subdirectory."
5197 *
5198 * @param connection the connection
5199 * @param path a '/' delimited string of path elements
5200 * @param vtable the virtual table
5201 * @param user_data data to pass to functions in the vtable
5202 * @returns #FALSE if not enough memory
5203 */
5204 dbus_bool_t
dbus_connection_register_fallback(DBusConnection * connection,const char * path,const DBusObjectPathVTable * vtable,void * user_data)5205 dbus_connection_register_fallback (DBusConnection *connection,
5206 const char *path,
5207 const DBusObjectPathVTable *vtable,
5208 void *user_data)
5209 {
5210 char **decomposed_path;
5211 dbus_bool_t retval;
5212
5213 _dbus_return_val_if_fail (connection != NULL, FALSE);
5214 _dbus_return_val_if_fail (path != NULL, FALSE);
5215 _dbus_return_val_if_fail (path[0] == '/', FALSE);
5216 _dbus_return_val_if_fail (vtable != NULL, FALSE);
5217
5218 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
5219 return FALSE;
5220
5221 CONNECTION_LOCK (connection);
5222
5223 retval = _dbus_object_tree_register (connection->objects,
5224 TRUE,
5225 (const char **) decomposed_path, vtable,
5226 user_data);
5227
5228 CONNECTION_UNLOCK (connection);
5229
5230 dbus_free_string_array (decomposed_path);
5231
5232 return retval;
5233 }
5234
5235 /**
5236 * Unregisters the handler registered with exactly the given path.
5237 * It's a bug to call this function for a path that isn't registered.
5238 * Can unregister both fallback paths and object paths.
5239 *
5240 * @param connection the connection
5241 * @param path a '/' delimited string of path elements
5242 * @returns #FALSE if not enough memory
5243 */
5244 dbus_bool_t
dbus_connection_unregister_object_path(DBusConnection * connection,const char * path)5245 dbus_connection_unregister_object_path (DBusConnection *connection,
5246 const char *path)
5247 {
5248 char **decomposed_path;
5249
5250 _dbus_return_val_if_fail (connection != NULL, FALSE);
5251 _dbus_return_val_if_fail (path != NULL, FALSE);
5252 _dbus_return_val_if_fail (path[0] == '/', FALSE);
5253
5254 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
5255 return FALSE;
5256
5257 CONNECTION_LOCK (connection);
5258
5259 _dbus_object_tree_unregister_and_unlock (connection->objects, (const char **) decomposed_path);
5260
5261 dbus_free_string_array (decomposed_path);
5262
5263 return TRUE;
5264 }
5265
5266 /**
5267 * Gets the user data passed to dbus_connection_register_object_path()
5268 * or dbus_connection_register_fallback(). If nothing was registered
5269 * at this path, the data is filled in with #NULL.
5270 *
5271 * @param connection the connection
5272 * @param path the path you registered with
5273 * @param data_p location to store the user data, or #NULL
5274 * @returns #FALSE if not enough memory
5275 */
5276 dbus_bool_t
dbus_connection_get_object_path_data(DBusConnection * connection,const char * path,void ** data_p)5277 dbus_connection_get_object_path_data (DBusConnection *connection,
5278 const char *path,
5279 void **data_p)
5280 {
5281 char **decomposed_path;
5282
5283 _dbus_return_val_if_fail (connection != NULL, FALSE);
5284 _dbus_return_val_if_fail (path != NULL, FALSE);
5285 _dbus_return_val_if_fail (data_p != NULL, FALSE);
5286
5287 *data_p = NULL;
5288
5289 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
5290 return FALSE;
5291
5292 CONNECTION_LOCK (connection);
5293
5294 *data_p = _dbus_object_tree_get_user_data_unlocked (connection->objects, (const char**) decomposed_path);
5295
5296 CONNECTION_UNLOCK (connection);
5297
5298 dbus_free_string_array (decomposed_path);
5299
5300 return TRUE;
5301 }
5302
5303 /**
5304 * Lists the registered fallback handlers and object path handlers at
5305 * the given parent_path. The returned array should be freed with
5306 * dbus_free_string_array().
5307 *
5308 * @param connection the connection
5309 * @param parent_path the path to list the child handlers of
5310 * @param child_entries returns #NULL-terminated array of children
5311 * @returns #FALSE if no memory to allocate the child entries
5312 */
5313 dbus_bool_t
dbus_connection_list_registered(DBusConnection * connection,const char * parent_path,char *** child_entries)5314 dbus_connection_list_registered (DBusConnection *connection,
5315 const char *parent_path,
5316 char ***child_entries)
5317 {
5318 char **decomposed_path;
5319 dbus_bool_t retval;
5320 _dbus_return_val_if_fail (connection != NULL, FALSE);
5321 _dbus_return_val_if_fail (parent_path != NULL, FALSE);
5322 _dbus_return_val_if_fail (parent_path[0] == '/', FALSE);
5323 _dbus_return_val_if_fail (child_entries != NULL, FALSE);
5324
5325 if (!_dbus_decompose_path (parent_path, strlen (parent_path), &decomposed_path, NULL))
5326 return FALSE;
5327
5328 CONNECTION_LOCK (connection);
5329
5330 retval = _dbus_object_tree_list_registered_and_unlock (connection->objects,
5331 (const char **) decomposed_path,
5332 child_entries);
5333 dbus_free_string_array (decomposed_path);
5334
5335 return retval;
5336 }
5337
5338 static DBusDataSlotAllocator slot_allocator;
5339 _DBUS_DEFINE_GLOBAL_LOCK (connection_slots);
5340
5341 /**
5342 * Allocates an integer ID to be used for storing application-specific
5343 * data on any DBusConnection. The allocated ID may then be used
5344 * with dbus_connection_set_data() and dbus_connection_get_data().
5345 * The passed-in slot must be initialized to -1, and is filled in
5346 * with the slot ID. If the passed-in slot is not -1, it's assumed
5347 * to be already allocated, and its refcount is incremented.
5348 *
5349 * The allocated slot is global, i.e. all DBusConnection objects will
5350 * have a slot with the given integer ID reserved.
5351 *
5352 * @param slot_p address of a global variable storing the slot
5353 * @returns #FALSE on failure (no memory)
5354 */
5355 dbus_bool_t
dbus_connection_allocate_data_slot(dbus_int32_t * slot_p)5356 dbus_connection_allocate_data_slot (dbus_int32_t *slot_p)
5357 {
5358 return _dbus_data_slot_allocator_alloc (&slot_allocator,
5359 &_DBUS_LOCK_NAME (connection_slots),
5360 slot_p);
5361 }
5362
5363 /**
5364 * Deallocates a global ID for connection data slots.
5365 * dbus_connection_get_data() and dbus_connection_set_data() may no
5366 * longer be used with this slot. Existing data stored on existing
5367 * DBusConnection objects will be freed when the connection is
5368 * finalized, but may not be retrieved (and may only be replaced if
5369 * someone else reallocates the slot). When the refcount on the
5370 * passed-in slot reaches 0, it is set to -1.
5371 *
5372 * @param slot_p address storing the slot to deallocate
5373 */
5374 void
dbus_connection_free_data_slot(dbus_int32_t * slot_p)5375 dbus_connection_free_data_slot (dbus_int32_t *slot_p)
5376 {
5377 _dbus_return_if_fail (*slot_p >= 0);
5378
5379 _dbus_data_slot_allocator_free (&slot_allocator, slot_p);
5380 }
5381
5382 /**
5383 * Stores a pointer on a DBusConnection, along
5384 * with an optional function to be used for freeing
5385 * the data when the data is set again, or when
5386 * the connection is finalized. The slot number
5387 * must have been allocated with dbus_connection_allocate_data_slot().
5388 *
5389 * @param connection the connection
5390 * @param slot the slot number
5391 * @param data the data to store
5392 * @param free_data_func finalizer function for the data
5393 * @returns #TRUE if there was enough memory to store the data
5394 */
5395 dbus_bool_t
dbus_connection_set_data(DBusConnection * connection,dbus_int32_t slot,void * data,DBusFreeFunction free_data_func)5396 dbus_connection_set_data (DBusConnection *connection,
5397 dbus_int32_t slot,
5398 void *data,
5399 DBusFreeFunction free_data_func)
5400 {
5401 DBusFreeFunction old_free_func;
5402 void *old_data;
5403 dbus_bool_t retval;
5404
5405 _dbus_return_val_if_fail (connection != NULL, FALSE);
5406 _dbus_return_val_if_fail (slot >= 0, FALSE);
5407
5408 CONNECTION_LOCK (connection);
5409
5410 retval = _dbus_data_slot_list_set (&slot_allocator,
5411 &connection->slot_list,
5412 slot, data, free_data_func,
5413 &old_free_func, &old_data);
5414
5415 CONNECTION_UNLOCK (connection);
5416
5417 if (retval)
5418 {
5419 /* Do the actual free outside the connection lock */
5420 if (old_free_func)
5421 (* old_free_func) (old_data);
5422 }
5423
5424 return retval;
5425 }
5426
5427 /**
5428 * Retrieves data previously set with dbus_connection_set_data().
5429 * The slot must still be allocated (must not have been freed).
5430 *
5431 * @param connection the connection
5432 * @param slot the slot to get data from
5433 * @returns the data, or #NULL if not found
5434 */
5435 void*
dbus_connection_get_data(DBusConnection * connection,dbus_int32_t slot)5436 dbus_connection_get_data (DBusConnection *connection,
5437 dbus_int32_t slot)
5438 {
5439 void *res;
5440
5441 _dbus_return_val_if_fail (connection != NULL, NULL);
5442
5443 CONNECTION_LOCK (connection);
5444
5445 res = _dbus_data_slot_list_get (&slot_allocator,
5446 &connection->slot_list,
5447 slot);
5448
5449 CONNECTION_UNLOCK (connection);
5450
5451 return res;
5452 }
5453
5454 /**
5455 * This function sets a global flag for whether dbus_connection_new()
5456 * will set SIGPIPE behavior to SIG_IGN.
5457 *
5458 * @param will_modify_sigpipe #TRUE to allow sigpipe to be set to SIG_IGN
5459 */
5460 void
dbus_connection_set_change_sigpipe(dbus_bool_t will_modify_sigpipe)5461 dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe)
5462 {
5463 _dbus_modify_sigpipe = will_modify_sigpipe != FALSE;
5464 }
5465
5466 /**
5467 * Specifies the maximum size message this connection is allowed to
5468 * receive. Larger messages will result in disconnecting the
5469 * connection.
5470 *
5471 * @param connection a #DBusConnection
5472 * @param size maximum message size the connection can receive, in bytes
5473 */
5474 void
dbus_connection_set_max_message_size(DBusConnection * connection,long size)5475 dbus_connection_set_max_message_size (DBusConnection *connection,
5476 long size)
5477 {
5478 _dbus_return_if_fail (connection != NULL);
5479
5480 CONNECTION_LOCK (connection);
5481 _dbus_transport_set_max_message_size (connection->transport,
5482 size);
5483 CONNECTION_UNLOCK (connection);
5484 }
5485
5486 /**
5487 * Gets the value set by dbus_connection_set_max_message_size().
5488 *
5489 * @param connection the connection
5490 * @returns the max size of a single message
5491 */
5492 long
dbus_connection_get_max_message_size(DBusConnection * connection)5493 dbus_connection_get_max_message_size (DBusConnection *connection)
5494 {
5495 long res;
5496
5497 _dbus_return_val_if_fail (connection != NULL, 0);
5498
5499 CONNECTION_LOCK (connection);
5500 res = _dbus_transport_get_max_message_size (connection->transport);
5501 CONNECTION_UNLOCK (connection);
5502 return res;
5503 }
5504
5505 /**
5506 * Sets the maximum total number of bytes that can be used for all messages
5507 * received on this connection. Messages count toward the maximum until
5508 * they are finalized. When the maximum is reached, the connection will
5509 * not read more data until some messages are finalized.
5510 *
5511 * The semantics of the maximum are: if outstanding messages are
5512 * already above the maximum, additional messages will not be read.
5513 * The semantics are not: if the next message would cause us to exceed
5514 * the maximum, we don't read it. The reason is that we don't know the
5515 * size of a message until after we read it.
5516 *
5517 * Thus, the max live messages size can actually be exceeded
5518 * by up to the maximum size of a single message.
5519 *
5520 * Also, if we read say 1024 bytes off the wire in a single read(),
5521 * and that contains a half-dozen small messages, we may exceed the
5522 * size max by that amount. But this should be inconsequential.
5523 *
5524 * This does imply that we can't call read() with a buffer larger
5525 * than we're willing to exceed this limit by.
5526 *
5527 * @param connection the connection
5528 * @param size the maximum size in bytes of all outstanding messages
5529 */
5530 void
dbus_connection_set_max_received_size(DBusConnection * connection,long size)5531 dbus_connection_set_max_received_size (DBusConnection *connection,
5532 long size)
5533 {
5534 _dbus_return_if_fail (connection != NULL);
5535
5536 CONNECTION_LOCK (connection);
5537 _dbus_transport_set_max_received_size (connection->transport,
5538 size);
5539 CONNECTION_UNLOCK (connection);
5540 }
5541
5542 /**
5543 * Gets the value set by dbus_connection_set_max_received_size().
5544 *
5545 * @param connection the connection
5546 * @returns the max size of all live messages
5547 */
5548 long
dbus_connection_get_max_received_size(DBusConnection * connection)5549 dbus_connection_get_max_received_size (DBusConnection *connection)
5550 {
5551 long res;
5552
5553 _dbus_return_val_if_fail (connection != NULL, 0);
5554
5555 CONNECTION_LOCK (connection);
5556 res = _dbus_transport_get_max_received_size (connection->transport);
5557 CONNECTION_UNLOCK (connection);
5558 return res;
5559 }
5560
5561 /**
5562 * Gets the approximate size in bytes of all messages in the outgoing
5563 * message queue. The size is approximate in that you shouldn't use
5564 * it to decide how many bytes to read off the network or anything
5565 * of that nature, as optimizations may choose to tell small white lies
5566 * to avoid performance overhead.
5567 *
5568 * @param connection the connection
5569 * @returns the number of bytes that have been queued up but not sent
5570 */
5571 long
dbus_connection_get_outgoing_size(DBusConnection * connection)5572 dbus_connection_get_outgoing_size (DBusConnection *connection)
5573 {
5574 long res;
5575
5576 _dbus_return_val_if_fail (connection != NULL, 0);
5577
5578 CONNECTION_LOCK (connection);
5579 res = _dbus_counter_get_value (connection->outgoing_counter);
5580 CONNECTION_UNLOCK (connection);
5581 return res;
5582 }
5583
5584 /** @} */
5585