1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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-message-private.h"
37 #include "dbus-threads.h"
38 #include "dbus-protocol.h"
39 #include "dbus-dataslot.h"
40 #include "dbus-string.h"
41 #include "dbus-signature.h"
42 #include "dbus-pending-call.h"
43 #include "dbus-object-tree.h"
44 #include "dbus-threads-internal.h"
45 #include "dbus-bus.h"
46 #include "dbus-marshal-basic.h"
47
48 #ifdef DBUS_DISABLE_CHECKS
49 #define TOOK_LOCK_CHECK(connection)
50 #define RELEASING_LOCK_CHECK(connection)
51 #define HAVE_LOCK_CHECK(connection)
52 #else
53 #define TOOK_LOCK_CHECK(connection) do { \
54 _dbus_assert (!(connection)->have_connection_lock); \
55 (connection)->have_connection_lock = TRUE; \
56 } while (0)
57 #define RELEASING_LOCK_CHECK(connection) do { \
58 _dbus_assert ((connection)->have_connection_lock); \
59 (connection)->have_connection_lock = FALSE; \
60 } while (0)
61 #define HAVE_LOCK_CHECK(connection) _dbus_assert ((connection)->have_connection_lock)
62 /* A "DO_NOT_HAVE_LOCK_CHECK" is impossible since we need the lock to check the flag */
63 #endif
64
65 #define TRACE_LOCKS 1
66
67 #define CONNECTION_LOCK(connection) do { \
68 if (TRACE_LOCKS) { _dbus_verbose ("LOCK\n"); } \
69 _dbus_rmutex_lock ((connection)->mutex); \
70 TOOK_LOCK_CHECK (connection); \
71 } while (0)
72
73 #define CONNECTION_UNLOCK(connection) _dbus_connection_unlock (connection)
74
75 #define SLOTS_LOCK(connection) do { \
76 _dbus_rmutex_lock ((connection)->slot_mutex); \
77 } while (0)
78
79 #define SLOTS_UNLOCK(connection) do { \
80 _dbus_rmutex_unlock ((connection)->slot_mutex); \
81 } while (0)
82
83 #define DISPATCH_STATUS_NAME(s) \
84 ((s) == DBUS_DISPATCH_COMPLETE ? "complete" : \
85 (s) == DBUS_DISPATCH_DATA_REMAINS ? "data remains" : \
86 (s) == DBUS_DISPATCH_NEED_MEMORY ? "need memory" : \
87 "???")
88
89 /**
90 * @defgroup DBusConnection DBusConnection
91 * @ingroup DBus
92 * @brief Connection to another application
93 *
94 * A DBusConnection represents a connection to another
95 * application. Messages can be sent and received via this connection.
96 * The other application may be a message bus; for convenience, the
97 * function dbus_bus_get() is provided to automatically open a
98 * connection to the well-known message buses.
99 *
100 * In brief a DBusConnection is a message queue associated with some
101 * message transport mechanism such as a socket. The connection
102 * maintains a queue of incoming messages and a queue of outgoing
103 * messages.
104 *
105 * Several functions use the following terms:
106 * <ul>
107 * <li><b>read</b> means to fill the incoming message queue by reading from the socket</li>
108 * <li><b>write</b> means to drain the outgoing queue by writing to the socket</li>
109 * <li><b>dispatch</b> means to drain the incoming queue by invoking application-provided message handlers</li>
110 * </ul>
111 *
112 * The function dbus_connection_read_write_dispatch() for example does all
113 * three of these things, offering a simple alternative to a main loop.
114 *
115 * In an application with a main loop, the read/write/dispatch
116 * operations are usually separate.
117 *
118 * The connection provides #DBusWatch and #DBusTimeout objects to
119 * the main loop. These are used to know when reading, writing, or
120 * dispatching should be performed.
121 *
122 * Incoming messages are processed
123 * by calling dbus_connection_dispatch(). dbus_connection_dispatch()
124 * runs any handlers registered for the topmost message in the message
125 * queue, then discards the message, then returns.
126 *
127 * dbus_connection_get_dispatch_status() indicates whether
128 * messages are currently in the queue that need dispatching.
129 * dbus_connection_set_dispatch_status_function() allows
130 * you to set a function to be used to monitor the dispatch status.
131 *
132 * If you're using GLib or Qt add-on libraries for D-Bus, there are
133 * special convenience APIs in those libraries that hide
134 * all the details of dispatch and watch/timeout monitoring.
135 * For example, dbus_connection_setup_with_g_main().
136 *
137 * If you aren't using these add-on libraries, but want to process
138 * messages asynchronously, you must manually call
139 * dbus_connection_set_dispatch_status_function(),
140 * dbus_connection_set_watch_functions(),
141 * dbus_connection_set_timeout_functions() providing appropriate
142 * functions to integrate the connection with your application's main
143 * loop. This can be tricky to get right; main loops are not simple.
144 *
145 * If you don't need to be asynchronous, you can ignore #DBusWatch,
146 * #DBusTimeout, and dbus_connection_dispatch(). Instead,
147 * dbus_connection_read_write_dispatch() can be used.
148 *
149 * Or, in <em>very</em> simple applications,
150 * dbus_connection_pop_message() may be all you need, allowing you to
151 * avoid setting up any handler functions (see
152 * dbus_connection_add_filter(),
153 * dbus_connection_register_object_path() for more on handlers).
154 *
155 * When you use dbus_connection_send() or one of its variants to send
156 * a message, the message is added to the outgoing queue. It's
157 * actually written to the network later; either in
158 * dbus_watch_handle() invoked by your main loop, or in
159 * dbus_connection_flush() which blocks until it can write out the
160 * entire outgoing queue. The GLib/Qt add-on libraries again
161 * handle the details here for you by setting up watch functions.
162 *
163 * When a connection is disconnected, you are guaranteed to get a
164 * signal "Disconnected" from the interface
165 * #DBUS_INTERFACE_LOCAL, path
166 * #DBUS_PATH_LOCAL.
167 *
168 * You may not drop the last reference to a #DBusConnection
169 * until that connection has been disconnected.
170 *
171 * You may dispatch the unprocessed incoming message queue even if the
172 * connection is disconnected. However, "Disconnected" will always be
173 * the last message in the queue (obviously no messages are received
174 * after disconnection).
175 *
176 * After calling dbus_threads_init(), #DBusConnection has thread
177 * locks and drops them when invoking user callbacks, so in general is
178 * transparently threadsafe. However, #DBusMessage does NOT have
179 * thread locks; you must not send the same message to multiple
180 * #DBusConnection if those connections will be used from different threads,
181 * for example.
182 *
183 * Also, if you dispatch or pop messages from multiple threads, it
184 * may work in the sense that it won't crash, but it's tough to imagine
185 * sane results; it will be completely unpredictable which messages
186 * go to which threads.
187 *
188 * It's recommended to dispatch from a single thread.
189 *
190 * The most useful function to call from multiple threads at once
191 * is dbus_connection_send_with_reply_and_block(). That is,
192 * multiple threads can make method calls at the same time.
193 *
194 * If you aren't using threads, you can use a main loop and
195 * dbus_pending_call_set_notify() to achieve a similar result.
196 */
197
198 /**
199 * @defgroup DBusConnectionInternals DBusConnection implementation details
200 * @ingroup DBusInternals
201 * @brief Implementation details of DBusConnection
202 *
203 * @{
204 */
205
206 static void
_dbus_connection_trace_ref(DBusConnection * connection,int old_refcount,int new_refcount,const char * why)207 _dbus_connection_trace_ref (DBusConnection *connection,
208 int old_refcount,
209 int new_refcount,
210 const char *why)
211 {
212 #ifdef DBUS_ENABLE_VERBOSE_MODE
213 static int enabled = -1;
214
215 _dbus_trace_ref ("DBusConnection", connection, old_refcount, new_refcount,
216 why, "DBUS_CONNECTION_TRACE", &enabled);
217 #endif
218 }
219
220 /**
221 * Internal struct representing a message filter function
222 */
223 typedef struct DBusMessageFilter DBusMessageFilter;
224
225 /**
226 * Internal struct representing a message filter function
227 */
228 struct DBusMessageFilter
229 {
230 DBusAtomic refcount; /**< Reference count */
231 DBusHandleMessageFunction function; /**< Function to call to filter */
232 void *user_data; /**< User data for the function */
233 DBusFreeFunction free_user_data_function; /**< Function to free the user data */
234 };
235
236
237 /**
238 * Internals of DBusPreallocatedSend
239 */
240 struct DBusPreallocatedSend
241 {
242 DBusConnection *connection; /**< Connection we'd send the message to */
243 DBusList *queue_link; /**< Preallocated link in the queue */
244 DBusList *counter_link; /**< Preallocated link in the resource counter */
245 };
246
247 #if HAVE_DECL_MSG_NOSIGNAL
248 static dbus_bool_t _dbus_modify_sigpipe = FALSE;
249 #else
250 static dbus_bool_t _dbus_modify_sigpipe = TRUE;
251 #endif
252
253 /**
254 * Implementation details of DBusConnection. All fields are private.
255 */
256 struct DBusConnection
257 {
258 DBusAtomic refcount; /**< Reference count. */
259
260 DBusRMutex *mutex; /**< Lock on the entire DBusConnection */
261
262 DBusCMutex *dispatch_mutex; /**< Protects dispatch_acquired */
263 DBusCondVar *dispatch_cond; /**< Notify when dispatch_acquired is available */
264 DBusCMutex *io_path_mutex; /**< Protects io_path_acquired */
265 DBusCondVar *io_path_cond; /**< Notify when io_path_acquired is available */
266
267 DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */
268 DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */
269 DBusList *expired_messages; /**< Messages that will be released when we next unlock. */
270
271 DBusMessage *message_borrowed; /**< Filled in if the first incoming message has been borrowed;
272 * dispatch_acquired will be set by the borrower
273 */
274
275 int n_outgoing; /**< Length of outgoing queue. */
276 int n_incoming; /**< Length of incoming queue. */
277
278 DBusCounter *outgoing_counter; /**< Counts size of outgoing messages. */
279
280 DBusTransport *transport; /**< Object that sends/receives messages over network. */
281 DBusWatchList *watches; /**< Stores active watches. */
282 DBusTimeoutList *timeouts; /**< Stores active timeouts. */
283
284 DBusList *filter_list; /**< List of filters. */
285
286 DBusRMutex *slot_mutex; /**< Lock on slot_list so overall connection lock need not be taken */
287 DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */
288
289 DBusHashTable *pending_replies; /**< Hash of message serials to #DBusPendingCall. */
290
291 dbus_uint32_t client_serial; /**< Client serial. Increments each time a message is sent */
292 DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */
293
294 DBusWakeupMainFunction wakeup_main_function; /**< Function to wake up the mainloop */
295 void *wakeup_main_data; /**< Application data for wakeup_main_function */
296 DBusFreeFunction free_wakeup_main_data; /**< free wakeup_main_data */
297
298 DBusDispatchStatusFunction dispatch_status_function; /**< Function on dispatch status changes */
299 void *dispatch_status_data; /**< Application data for dispatch_status_function */
300 DBusFreeFunction free_dispatch_status_data; /**< free dispatch_status_data */
301
302 DBusDispatchStatus last_dispatch_status; /**< The last dispatch status we reported to the application. */
303
304 DBusObjectTree *objects; /**< Object path handlers registered with this connection */
305
306 char *server_guid; /**< GUID of server if we are in shared_connections, #NULL if server GUID is unknown or connection is private */
307
308 /* These two MUST be bools and not bitfields, because they are protected by a separate lock
309 * from connection->mutex and all bitfields in a word have to be read/written together.
310 * So you can't have a different lock for different bitfields in the same word.
311 */
312 dbus_bool_t dispatch_acquired; /**< Someone has dispatch path (can drain incoming queue) */
313 dbus_bool_t io_path_acquired; /**< Someone has transport io path (can use the transport to read/write messages) */
314
315 unsigned int shareable : 1; /**< #TRUE if libdbus owns a reference to the connection and can return it from dbus_connection_open() more than once */
316
317 unsigned int exit_on_disconnect : 1; /**< If #TRUE, exit after handling disconnect signal */
318
319 unsigned int route_peer_messages : 1; /**< If #TRUE, if org.freedesktop.DBus.Peer messages have a bus name, don't handle them automatically */
320
321 unsigned int disconnected_message_arrived : 1; /**< We popped or are dispatching the disconnected message.
322 * if the disconnect_message_link is NULL then we queued it, but
323 * this flag is whether it got to the head of the queue.
324 */
325 unsigned int disconnected_message_processed : 1; /**< We did our default handling of the disconnected message,
326 * such as closing the connection.
327 */
328
329 #ifndef DBUS_DISABLE_CHECKS
330 unsigned int have_connection_lock : 1; /**< Used to check locking */
331 #endif
332
333 #if defined(DBUS_ENABLE_CHECKS) || defined(DBUS_ENABLE_ASSERT)
334 int generation; /**< _dbus_current_generation that should correspond to this connection */
335 #endif
336 };
337
338 static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection);
339 static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection,
340 DBusDispatchStatus new_status);
341 static void _dbus_connection_last_unref (DBusConnection *connection);
342 static void _dbus_connection_acquire_dispatch (DBusConnection *connection);
343 static void _dbus_connection_release_dispatch (DBusConnection *connection);
344 static DBusDispatchStatus _dbus_connection_flush_unlocked (DBusConnection *connection);
345 static void _dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection);
346 static dbus_bool_t _dbus_connection_get_is_connected_unlocked (DBusConnection *connection);
347 static dbus_bool_t _dbus_connection_peek_for_reply_unlocked (DBusConnection *connection,
348 dbus_uint32_t client_serial);
349
350 static DBusMessageFilter *
_dbus_message_filter_ref(DBusMessageFilter * filter)351 _dbus_message_filter_ref (DBusMessageFilter *filter)
352 {
353 #ifdef DBUS_DISABLE_ASSERT
354 _dbus_atomic_inc (&filter->refcount);
355 #else
356 dbus_int32_t old_value;
357
358 old_value = _dbus_atomic_inc (&filter->refcount);
359 _dbus_assert (old_value > 0);
360 #endif
361
362 return filter;
363 }
364
365 static void
_dbus_message_filter_unref(DBusMessageFilter * filter)366 _dbus_message_filter_unref (DBusMessageFilter *filter)
367 {
368 dbus_int32_t old_value;
369
370 old_value = _dbus_atomic_dec (&filter->refcount);
371 _dbus_assert (old_value > 0);
372
373 if (old_value == 1)
374 {
375 if (filter->free_user_data_function)
376 (* filter->free_user_data_function) (filter->user_data);
377
378 dbus_free (filter);
379 }
380 }
381
382 /**
383 * Acquires the connection lock.
384 *
385 * @param connection the connection.
386 */
387 void
_dbus_connection_lock(DBusConnection * connection)388 _dbus_connection_lock (DBusConnection *connection)
389 {
390 CONNECTION_LOCK (connection);
391 }
392
393 /**
394 * Releases the connection lock.
395 *
396 * @param connection the connection.
397 */
398 void
_dbus_connection_unlock(DBusConnection * connection)399 _dbus_connection_unlock (DBusConnection *connection)
400 {
401 DBusList *expired_messages;
402 DBusList *iter;
403
404 if (TRACE_LOCKS)
405 {
406 _dbus_verbose ("UNLOCK\n");
407 }
408
409 /* If we had messages that expired (fell off the incoming or outgoing
410 * queues) while we were locked, actually release them now */
411 expired_messages = connection->expired_messages;
412 connection->expired_messages = NULL;
413
414 RELEASING_LOCK_CHECK (connection);
415 _dbus_rmutex_unlock (connection->mutex);
416
417 for (iter = _dbus_list_pop_first_link (&expired_messages);
418 iter != NULL;
419 iter = _dbus_list_pop_first_link (&expired_messages))
420 {
421 DBusMessage *message = iter->data;
422
423 dbus_message_unref (message);
424 _dbus_list_free_link (iter);
425 }
426 }
427
428 /**
429 * Wakes up the main loop if it is sleeping
430 * Needed if we're e.g. queueing outgoing messages
431 * on a thread while the mainloop sleeps.
432 *
433 * @param connection the connection.
434 */
435 static void
_dbus_connection_wakeup_mainloop(DBusConnection * connection)436 _dbus_connection_wakeup_mainloop (DBusConnection *connection)
437 {
438 if (connection->wakeup_main_function)
439 (*connection->wakeup_main_function) (connection->wakeup_main_data);
440 }
441
442 #ifdef DBUS_ENABLE_EMBEDDED_TESTS
443 /**
444 * Gets the locks so we can examine them
445 *
446 * @param connection the connection.
447 * @param mutex_loc return for the location of the main mutex pointer
448 * @param dispatch_mutex_loc return location of the dispatch mutex pointer
449 * @param io_path_mutex_loc return location of the io_path mutex pointer
450 * @param dispatch_cond_loc return location of the dispatch conditional
451 * variable pointer
452 * @param io_path_cond_loc return location of the io_path conditional
453 * variable pointer
454 */
455 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)456 _dbus_connection_test_get_locks (DBusConnection *connection,
457 DBusMutex **mutex_loc,
458 DBusMutex **dispatch_mutex_loc,
459 DBusMutex **io_path_mutex_loc,
460 DBusCondVar **dispatch_cond_loc,
461 DBusCondVar **io_path_cond_loc)
462 {
463 *mutex_loc = (DBusMutex *) connection->mutex;
464 *dispatch_mutex_loc = (DBusMutex *) connection->dispatch_mutex;
465 *io_path_mutex_loc = (DBusMutex *) connection->io_path_mutex;
466 *dispatch_cond_loc = connection->dispatch_cond;
467 *io_path_cond_loc = connection->io_path_cond;
468 }
469 #endif
470
471 /**
472 * Adds a message-containing list link to the incoming message queue,
473 * taking ownership of the link and the message's current refcount.
474 * Cannot fail due to lack of memory.
475 *
476 * @param connection the connection.
477 * @param link the message link to queue.
478 */
479 void
_dbus_connection_queue_received_message_link(DBusConnection * connection,DBusList * link)480 _dbus_connection_queue_received_message_link (DBusConnection *connection,
481 DBusList *link)
482 {
483 DBusPendingCall *pending;
484 dbus_uint32_t reply_serial;
485 DBusMessage *message;
486
487 _dbus_assert (_dbus_transport_peek_is_authenticated (connection->transport));
488
489 _dbus_list_append_link (&connection->incoming_messages,
490 link);
491 message = link->data;
492
493 /* If this is a reply we're waiting on, remove timeout for it */
494 reply_serial = dbus_message_get_reply_serial (message);
495 if (reply_serial != 0)
496 {
497 pending = _dbus_hash_table_lookup_int (connection->pending_replies,
498 reply_serial);
499 if (pending != NULL)
500 {
501 if (_dbus_pending_call_is_timeout_added_unlocked (pending))
502 _dbus_connection_remove_timeout_unlocked (connection,
503 _dbus_pending_call_get_timeout_unlocked (pending));
504
505 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
506 }
507 }
508
509
510
511 connection->n_incoming += 1;
512
513 _dbus_connection_wakeup_mainloop (connection);
514
515 _dbus_verbose ("Message %p (%s %s %s %s '%s' reply to %u) added to incoming queue %p, %d incoming\n",
516 message,
517 dbus_message_type_to_string (dbus_message_get_type (message)),
518 dbus_message_get_path (message) ?
519 dbus_message_get_path (message) :
520 "no path",
521 dbus_message_get_interface (message) ?
522 dbus_message_get_interface (message) :
523 "no interface",
524 dbus_message_get_member (message) ?
525 dbus_message_get_member (message) :
526 "no member",
527 dbus_message_get_signature (message),
528 dbus_message_get_reply_serial (message),
529 connection,
530 connection->n_incoming);
531
532 _dbus_message_trace_ref (message, -1, -1,
533 "_dbus_conection_queue_received_message_link");
534 }
535
536 /**
537 * Adds a link + message to the incoming message queue.
538 * Can't fail. Takes ownership of both link and message.
539 *
540 * @param connection the connection.
541 * @param link the list node and message to queue.
542 *
543 */
544 void
_dbus_connection_queue_synthesized_message_link(DBusConnection * connection,DBusList * link)545 _dbus_connection_queue_synthesized_message_link (DBusConnection *connection,
546 DBusList *link)
547 {
548 HAVE_LOCK_CHECK (connection);
549
550 _dbus_list_append_link (&connection->incoming_messages, link);
551
552 connection->n_incoming += 1;
553
554 _dbus_connection_wakeup_mainloop (connection);
555
556 _dbus_message_trace_ref (link->data, -1, -1,
557 "_dbus_connection_queue_synthesized_message_link");
558
559 _dbus_verbose ("Synthesized message %p added to incoming queue %p, %d incoming\n",
560 link->data, connection, connection->n_incoming);
561 }
562
563
564 /**
565 * Checks whether there are messages in the outgoing message queue.
566 * Called with connection lock held.
567 *
568 * @param connection the connection.
569 * @returns #TRUE if the outgoing queue is non-empty.
570 */
571 dbus_bool_t
_dbus_connection_has_messages_to_send_unlocked(DBusConnection * connection)572 _dbus_connection_has_messages_to_send_unlocked (DBusConnection *connection)
573 {
574 HAVE_LOCK_CHECK (connection);
575 return connection->outgoing_messages != NULL;
576 }
577
578 /**
579 * Checks whether there are messages in the outgoing message queue.
580 * Use dbus_connection_flush() to block until all outgoing
581 * messages have been written to the underlying transport
582 * (such as a socket).
583 *
584 * @param connection the connection.
585 * @returns #TRUE if the outgoing queue is non-empty.
586 */
587 dbus_bool_t
dbus_connection_has_messages_to_send(DBusConnection * connection)588 dbus_connection_has_messages_to_send (DBusConnection *connection)
589 {
590 dbus_bool_t v;
591
592 _dbus_return_val_if_fail (connection != NULL, FALSE);
593
594 CONNECTION_LOCK (connection);
595 v = _dbus_connection_has_messages_to_send_unlocked (connection);
596 CONNECTION_UNLOCK (connection);
597
598 return v;
599 }
600
601 /**
602 * Gets the next outgoing message. The message remains in the
603 * queue, and the caller does not own a reference to it.
604 *
605 * @param connection the connection.
606 * @returns the message to be sent.
607 */
608 DBusMessage*
_dbus_connection_get_message_to_send(DBusConnection * connection)609 _dbus_connection_get_message_to_send (DBusConnection *connection)
610 {
611 HAVE_LOCK_CHECK (connection);
612
613 return _dbus_list_get_last (&connection->outgoing_messages);
614 }
615
616 /**
617 * Notifies the connection that a message has been sent, so the
618 * message can be removed from the outgoing queue.
619 * Called with the connection lock held.
620 *
621 * @param connection the connection.
622 * @param message the message that was sent.
623 */
624 void
_dbus_connection_message_sent_unlocked(DBusConnection * connection,DBusMessage * message)625 _dbus_connection_message_sent_unlocked (DBusConnection *connection,
626 DBusMessage *message)
627 {
628 DBusList *link;
629
630 HAVE_LOCK_CHECK (connection);
631
632 /* This can be called before we even complete authentication, since
633 * it's called on disconnect to clean up the outgoing queue.
634 * It's also called as we successfully send each message.
635 */
636
637 link = _dbus_list_get_last_link (&connection->outgoing_messages);
638 _dbus_assert (link != NULL);
639 _dbus_assert (link->data == message);
640
641 _dbus_list_unlink (&connection->outgoing_messages,
642 link);
643 _dbus_list_prepend_link (&connection->expired_messages, link);
644
645 connection->n_outgoing -= 1;
646
647 _dbus_verbose ("Message %p (%s %s %s %s '%s') removed from outgoing queue %p, %d left to send\n",
648 message,
649 dbus_message_type_to_string (dbus_message_get_type (message)),
650 dbus_message_get_path (message) ?
651 dbus_message_get_path (message) :
652 "no path",
653 dbus_message_get_interface (message) ?
654 dbus_message_get_interface (message) :
655 "no interface",
656 dbus_message_get_member (message) ?
657 dbus_message_get_member (message) :
658 "no member",
659 dbus_message_get_signature (message),
660 connection, connection->n_outgoing);
661
662 /* It's OK that in principle we call the notify function, because for the
663 * outgoing limit, there isn't one */
664 _dbus_message_remove_counter (message, connection->outgoing_counter);
665
666 /* The message will actually be unreffed when we unlock */
667 }
668
669 /** Function to be called in protected_change_watch() with refcount held */
670 typedef dbus_bool_t (* DBusWatchAddFunction) (DBusWatchList *list,
671 DBusWatch *watch);
672 /** Function to be called in protected_change_watch() with refcount held */
673 typedef void (* DBusWatchRemoveFunction) (DBusWatchList *list,
674 DBusWatch *watch);
675 /** Function to be called in protected_change_watch() with refcount held */
676 typedef void (* DBusWatchToggleFunction) (DBusWatchList *list,
677 DBusWatch *watch,
678 dbus_bool_t enabled);
679
680 static dbus_bool_t
protected_change_watch(DBusConnection * connection,DBusWatch * watch,DBusWatchAddFunction add_function,DBusWatchRemoveFunction remove_function,DBusWatchToggleFunction toggle_function,dbus_bool_t enabled)681 protected_change_watch (DBusConnection *connection,
682 DBusWatch *watch,
683 DBusWatchAddFunction add_function,
684 DBusWatchRemoveFunction remove_function,
685 DBusWatchToggleFunction toggle_function,
686 dbus_bool_t enabled)
687 {
688 dbus_bool_t retval;
689
690 HAVE_LOCK_CHECK (connection);
691
692 /* The original purpose of protected_change_watch() was to hold a
693 * ref on the connection while dropping the connection lock, then
694 * calling out to the app. This was a broken hack that did not
695 * work, since the connection was in a hosed state (no WatchList
696 * field) while calling out.
697 *
698 * So for now we'll just keep the lock while calling out. This means
699 * apps are not allowed to call DBusConnection methods inside a
700 * watch function or they will deadlock.
701 *
702 * The "real fix" is to use the _and_unlock() pattern found
703 * elsewhere in the code, to defer calling out to the app until
704 * we're about to drop locks and return flow of control to the app
705 * anyway.
706 *
707 * See http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144
708 */
709
710 if (connection->watches)
711 {
712 if (add_function)
713 retval = (* add_function) (connection->watches, watch);
714 else if (remove_function)
715 {
716 retval = TRUE;
717 (* remove_function) (connection->watches, watch);
718 }
719 else
720 {
721 retval = TRUE;
722 (* toggle_function) (connection->watches, watch, enabled);
723 }
724 return retval;
725 }
726 else
727 return FALSE;
728 }
729
730
731 /**
732 * Adds a watch using the connection's DBusAddWatchFunction if
733 * available. Otherwise records the watch to be added when said
734 * function is available. Also re-adds the watch if the
735 * DBusAddWatchFunction changes. May fail due to lack of memory.
736 * Connection lock should be held when calling this.
737 *
738 * @param connection the connection.
739 * @param watch the watch to add.
740 * @returns #TRUE on success.
741 */
742 dbus_bool_t
_dbus_connection_add_watch_unlocked(DBusConnection * connection,DBusWatch * watch)743 _dbus_connection_add_watch_unlocked (DBusConnection *connection,
744 DBusWatch *watch)
745 {
746 return protected_change_watch (connection, watch,
747 _dbus_watch_list_add_watch,
748 NULL, NULL, FALSE);
749 }
750
751 /**
752 * Removes a watch using the connection's DBusRemoveWatchFunction
753 * if available. It's an error to call this function on a watch
754 * that was not previously added.
755 * Connection lock should be held when calling this.
756 *
757 * @param connection the connection.
758 * @param watch the watch to remove.
759 */
760 void
_dbus_connection_remove_watch_unlocked(DBusConnection * connection,DBusWatch * watch)761 _dbus_connection_remove_watch_unlocked (DBusConnection *connection,
762 DBusWatch *watch)
763 {
764 protected_change_watch (connection, watch,
765 NULL,
766 _dbus_watch_list_remove_watch,
767 NULL, FALSE);
768 }
769
770 /**
771 * Toggles a watch and notifies app via connection's
772 * DBusWatchToggledFunction if available. It's an error to call this
773 * function on a watch that was not previously added.
774 * Connection lock should be held when calling this.
775 *
776 * @param connection the connection.
777 * @param watch the watch to toggle.
778 * @param enabled whether to enable or disable
779 */
780 void
_dbus_connection_toggle_watch_unlocked(DBusConnection * connection,DBusWatch * watch,dbus_bool_t enabled)781 _dbus_connection_toggle_watch_unlocked (DBusConnection *connection,
782 DBusWatch *watch,
783 dbus_bool_t enabled)
784 {
785 _dbus_assert (watch != NULL);
786
787 protected_change_watch (connection, watch,
788 NULL, NULL,
789 _dbus_watch_list_toggle_watch,
790 enabled);
791 }
792
793 /** Function to be called in protected_change_timeout() with refcount held */
794 typedef dbus_bool_t (* DBusTimeoutAddFunction) (DBusTimeoutList *list,
795 DBusTimeout *timeout);
796 /** Function to be called in protected_change_timeout() with refcount held */
797 typedef void (* DBusTimeoutRemoveFunction) (DBusTimeoutList *list,
798 DBusTimeout *timeout);
799 /** Function to be called in protected_change_timeout() with refcount held */
800 typedef void (* DBusTimeoutToggleFunction) (DBusTimeoutList *list,
801 DBusTimeout *timeout,
802 dbus_bool_t enabled);
803
804 static dbus_bool_t
protected_change_timeout(DBusConnection * connection,DBusTimeout * timeout,DBusTimeoutAddFunction add_function,DBusTimeoutRemoveFunction remove_function,DBusTimeoutToggleFunction toggle_function,dbus_bool_t enabled)805 protected_change_timeout (DBusConnection *connection,
806 DBusTimeout *timeout,
807 DBusTimeoutAddFunction add_function,
808 DBusTimeoutRemoveFunction remove_function,
809 DBusTimeoutToggleFunction toggle_function,
810 dbus_bool_t enabled)
811 {
812 dbus_bool_t retval;
813
814 HAVE_LOCK_CHECK (connection);
815
816 /* The original purpose of protected_change_timeout() was to hold a
817 * ref on the connection while dropping the connection lock, then
818 * calling out to the app. This was a broken hack that did not
819 * work, since the connection was in a hosed state (no TimeoutList
820 * field) while calling out.
821 *
822 * So for now we'll just keep the lock while calling out. This means
823 * apps are not allowed to call DBusConnection methods inside a
824 * timeout function or they will deadlock.
825 *
826 * The "real fix" is to use the _and_unlock() pattern found
827 * elsewhere in the code, to defer calling out to the app until
828 * we're about to drop locks and return flow of control to the app
829 * anyway.
830 *
831 * See http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144
832 */
833
834 if (connection->timeouts)
835 {
836 if (add_function)
837 retval = (* add_function) (connection->timeouts, timeout);
838 else if (remove_function)
839 {
840 retval = TRUE;
841 (* remove_function) (connection->timeouts, timeout);
842 }
843 else
844 {
845 retval = TRUE;
846 (* toggle_function) (connection->timeouts, timeout, enabled);
847 }
848 return retval;
849 }
850 else
851 return FALSE;
852 }
853
854 /**
855 * Adds a timeout using the connection's DBusAddTimeoutFunction if
856 * available. Otherwise records the timeout to be added when said
857 * function is available. Also re-adds the timeout if the
858 * DBusAddTimeoutFunction changes. May fail due to lack of memory.
859 * The timeout will fire repeatedly until removed.
860 * Connection lock should be held when calling this.
861 *
862 * @param connection the connection.
863 * @param timeout the timeout to add.
864 * @returns #TRUE on success.
865 */
866 dbus_bool_t
_dbus_connection_add_timeout_unlocked(DBusConnection * connection,DBusTimeout * timeout)867 _dbus_connection_add_timeout_unlocked (DBusConnection *connection,
868 DBusTimeout *timeout)
869 {
870 return protected_change_timeout (connection, timeout,
871 _dbus_timeout_list_add_timeout,
872 NULL, NULL, FALSE);
873 }
874
875 /**
876 * Removes a timeout using the connection's DBusRemoveTimeoutFunction
877 * if available. It's an error to call this function on a timeout
878 * that was not previously added.
879 * Connection lock should be held when calling this.
880 *
881 * @param connection the connection.
882 * @param timeout the timeout to remove.
883 */
884 void
_dbus_connection_remove_timeout_unlocked(DBusConnection * connection,DBusTimeout * timeout)885 _dbus_connection_remove_timeout_unlocked (DBusConnection *connection,
886 DBusTimeout *timeout)
887 {
888 protected_change_timeout (connection, timeout,
889 NULL,
890 _dbus_timeout_list_remove_timeout,
891 NULL, FALSE);
892 }
893
894 /**
895 * Toggles a timeout and notifies app via connection's
896 * DBusTimeoutToggledFunction if available. It's an error to call this
897 * function on a timeout that was not previously added.
898 * Connection lock should be held when calling this.
899 *
900 * @param connection the connection.
901 * @param timeout the timeout to toggle.
902 * @param enabled whether to enable or disable
903 */
904 void
_dbus_connection_toggle_timeout_unlocked(DBusConnection * connection,DBusTimeout * timeout,dbus_bool_t enabled)905 _dbus_connection_toggle_timeout_unlocked (DBusConnection *connection,
906 DBusTimeout *timeout,
907 dbus_bool_t enabled)
908 {
909 protected_change_timeout (connection, timeout,
910 NULL, NULL,
911 _dbus_timeout_list_toggle_timeout,
912 enabled);
913 }
914
915 static dbus_bool_t
_dbus_connection_attach_pending_call_unlocked(DBusConnection * connection,DBusPendingCall * pending)916 _dbus_connection_attach_pending_call_unlocked (DBusConnection *connection,
917 DBusPendingCall *pending)
918 {
919 dbus_uint32_t reply_serial;
920 DBusTimeout *timeout;
921
922 HAVE_LOCK_CHECK (connection);
923
924 reply_serial = _dbus_pending_call_get_reply_serial_unlocked (pending);
925
926 _dbus_assert (reply_serial != 0);
927
928 timeout = _dbus_pending_call_get_timeout_unlocked (pending);
929
930 if (timeout)
931 {
932 if (!_dbus_connection_add_timeout_unlocked (connection, timeout))
933 return FALSE;
934
935 if (!_dbus_hash_table_insert_int (connection->pending_replies,
936 reply_serial,
937 pending))
938 {
939 _dbus_connection_remove_timeout_unlocked (connection, timeout);
940
941 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
942 HAVE_LOCK_CHECK (connection);
943 return FALSE;
944 }
945
946 _dbus_pending_call_set_timeout_added_unlocked (pending, TRUE);
947 }
948 else
949 {
950 if (!_dbus_hash_table_insert_int (connection->pending_replies,
951 reply_serial,
952 pending))
953 {
954 HAVE_LOCK_CHECK (connection);
955 return FALSE;
956 }
957 }
958
959 _dbus_pending_call_ref_unlocked (pending);
960
961 HAVE_LOCK_CHECK (connection);
962
963 return TRUE;
964 }
965
966 static void
free_pending_call_on_hash_removal(void * data)967 free_pending_call_on_hash_removal (void *data)
968 {
969 DBusPendingCall *pending;
970 DBusConnection *connection;
971
972 if (data == NULL)
973 return;
974
975 pending = data;
976
977 connection = _dbus_pending_call_get_connection_unlocked (pending);
978
979 HAVE_LOCK_CHECK (connection);
980
981 if (_dbus_pending_call_is_timeout_added_unlocked (pending))
982 {
983 _dbus_connection_remove_timeout_unlocked (connection,
984 _dbus_pending_call_get_timeout_unlocked (pending));
985
986 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
987 }
988
989 /* FIXME 1.0? this is sort of dangerous and undesirable to drop the lock
990 * here, but the pending call finalizer could in principle call out to
991 * application code so we pretty much have to... some larger code reorg
992 * might be needed.
993 */
994 _dbus_connection_ref_unlocked (connection);
995 _dbus_pending_call_unref_and_unlock (pending);
996 CONNECTION_LOCK (connection);
997 _dbus_connection_unref_unlocked (connection);
998 }
999
1000 static void
_dbus_connection_detach_pending_call_unlocked(DBusConnection * connection,DBusPendingCall * pending)1001 _dbus_connection_detach_pending_call_unlocked (DBusConnection *connection,
1002 DBusPendingCall *pending)
1003 {
1004 /* This ends up unlocking to call the pending call finalizer, which is unexpected to
1005 * say the least.
1006 */
1007 _dbus_hash_table_remove_int (connection->pending_replies,
1008 _dbus_pending_call_get_reply_serial_unlocked (pending));
1009 }
1010
1011 static void
_dbus_connection_detach_pending_call_and_unlock(DBusConnection * connection,DBusPendingCall * pending)1012 _dbus_connection_detach_pending_call_and_unlock (DBusConnection *connection,
1013 DBusPendingCall *pending)
1014 {
1015 /* The idea here is to avoid finalizing the pending call
1016 * with the lock held, since there's a destroy notifier
1017 * in pending call that goes out to application code.
1018 *
1019 * There's an extra unlock inside the hash table
1020 * "free pending call" function FIXME...
1021 */
1022 _dbus_pending_call_ref_unlocked (pending);
1023 _dbus_hash_table_remove_int (connection->pending_replies,
1024 _dbus_pending_call_get_reply_serial_unlocked (pending));
1025
1026 if (_dbus_pending_call_is_timeout_added_unlocked (pending))
1027 _dbus_connection_remove_timeout_unlocked (connection,
1028 _dbus_pending_call_get_timeout_unlocked (pending));
1029
1030 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
1031
1032 _dbus_pending_call_unref_and_unlock (pending);
1033 }
1034
1035 /**
1036 * Removes a pending call from the connection, such that
1037 * the pending reply will be ignored. May drop the last
1038 * reference to the pending call.
1039 *
1040 * @param connection the connection
1041 * @param pending the pending call
1042 */
1043 void
_dbus_connection_remove_pending_call(DBusConnection * connection,DBusPendingCall * pending)1044 _dbus_connection_remove_pending_call (DBusConnection *connection,
1045 DBusPendingCall *pending)
1046 {
1047 CONNECTION_LOCK (connection);
1048 _dbus_connection_detach_pending_call_and_unlock (connection, pending);
1049 }
1050
1051 /**
1052 * Acquire the transporter I/O path. This must be done before
1053 * doing any I/O in the transporter. May sleep and drop the
1054 * IO path mutex while waiting for the I/O path.
1055 *
1056 * @param connection the connection.
1057 * @param timeout_milliseconds maximum blocking time, or -1 for no limit.
1058 * @returns TRUE if the I/O path was acquired.
1059 */
1060 static dbus_bool_t
_dbus_connection_acquire_io_path(DBusConnection * connection,int timeout_milliseconds)1061 _dbus_connection_acquire_io_path (DBusConnection *connection,
1062 int timeout_milliseconds)
1063 {
1064 dbus_bool_t we_acquired;
1065
1066 HAVE_LOCK_CHECK (connection);
1067
1068 /* We don't want the connection to vanish */
1069 _dbus_connection_ref_unlocked (connection);
1070
1071 /* We will only touch io_path_acquired which is protected by our mutex */
1072 CONNECTION_UNLOCK (connection);
1073
1074 _dbus_verbose ("locking io_path_mutex\n");
1075 _dbus_cmutex_lock (connection->io_path_mutex);
1076
1077 _dbus_verbose ("start connection->io_path_acquired = %d timeout = %d\n",
1078 connection->io_path_acquired, timeout_milliseconds);
1079
1080 we_acquired = FALSE;
1081
1082 if (connection->io_path_acquired)
1083 {
1084 if (timeout_milliseconds != -1)
1085 {
1086 _dbus_verbose ("waiting %d for IO path to be acquirable\n",
1087 timeout_milliseconds);
1088
1089 if (!_dbus_condvar_wait_timeout (connection->io_path_cond,
1090 connection->io_path_mutex,
1091 timeout_milliseconds))
1092 {
1093 /* We timed out before anyone signaled. */
1094 /* (writing the loop to handle the !timedout case by
1095 * waiting longer if needed is a pain since dbus
1096 * wraps pthread_cond_timedwait to take a relative
1097 * time instead of absolute, something kind of stupid
1098 * on our part. for now it doesn't matter, we will just
1099 * end up back here eventually.)
1100 */
1101 }
1102 }
1103 else
1104 {
1105 while (connection->io_path_acquired)
1106 {
1107 _dbus_verbose ("waiting for IO path to be acquirable\n");
1108 _dbus_condvar_wait (connection->io_path_cond,
1109 connection->io_path_mutex);
1110 }
1111 }
1112 }
1113
1114 if (!connection->io_path_acquired)
1115 {
1116 we_acquired = TRUE;
1117 connection->io_path_acquired = TRUE;
1118 }
1119
1120 _dbus_verbose ("end connection->io_path_acquired = %d we_acquired = %d\n",
1121 connection->io_path_acquired, we_acquired);
1122
1123 _dbus_verbose ("unlocking io_path_mutex\n");
1124 _dbus_cmutex_unlock (connection->io_path_mutex);
1125
1126 CONNECTION_LOCK (connection);
1127
1128 HAVE_LOCK_CHECK (connection);
1129
1130 _dbus_connection_unref_unlocked (connection);
1131
1132 return we_acquired;
1133 }
1134
1135 /**
1136 * Release the I/O path when you're done with it. Only call
1137 * after you've acquired the I/O. Wakes up at most one thread
1138 * currently waiting to acquire the I/O path.
1139 *
1140 * @param connection the connection.
1141 */
1142 static void
_dbus_connection_release_io_path(DBusConnection * connection)1143 _dbus_connection_release_io_path (DBusConnection *connection)
1144 {
1145 HAVE_LOCK_CHECK (connection);
1146
1147 _dbus_verbose ("locking io_path_mutex\n");
1148 _dbus_cmutex_lock (connection->io_path_mutex);
1149
1150 _dbus_assert (connection->io_path_acquired);
1151
1152 _dbus_verbose ("start connection->io_path_acquired = %d\n",
1153 connection->io_path_acquired);
1154
1155 connection->io_path_acquired = FALSE;
1156 _dbus_condvar_wake_one (connection->io_path_cond);
1157
1158 _dbus_verbose ("unlocking io_path_mutex\n");
1159 _dbus_cmutex_unlock (connection->io_path_mutex);
1160 }
1161
1162 /**
1163 * Queues incoming messages and sends outgoing messages for this
1164 * connection, optionally blocking in the process. Each call to
1165 * _dbus_connection_do_iteration_unlocked() will call select() or poll() one
1166 * time and then read or write data if possible.
1167 *
1168 * The purpose of this function is to be able to flush outgoing
1169 * messages or queue up incoming messages without returning
1170 * control to the application and causing reentrancy weirdness.
1171 *
1172 * The flags parameter allows you to specify whether to
1173 * read incoming messages, write outgoing messages, or both,
1174 * and whether to block if no immediate action is possible.
1175 *
1176 * The timeout_milliseconds parameter does nothing unless the
1177 * iteration is blocking.
1178 *
1179 * If there are no outgoing messages and DBUS_ITERATION_DO_READING
1180 * wasn't specified, then it's impossible to block, even if
1181 * you specify DBUS_ITERATION_BLOCK; in that case the function
1182 * returns immediately.
1183 *
1184 * If pending is not NULL then a check is made if the pending call
1185 * is completed after the io path has been required. If the call
1186 * has been completed nothing is done. This must be done since
1187 * the _dbus_connection_acquire_io_path releases the connection
1188 * lock for a while.
1189 *
1190 * Called with connection lock held.
1191 *
1192 * @param connection the connection.
1193 * @param pending the pending call that should be checked or NULL
1194 * @param flags iteration flags.
1195 * @param timeout_milliseconds maximum blocking time, or -1 for no limit.
1196 */
1197 void
_dbus_connection_do_iteration_unlocked(DBusConnection * connection,DBusPendingCall * pending,unsigned int flags,int timeout_milliseconds)1198 _dbus_connection_do_iteration_unlocked (DBusConnection *connection,
1199 DBusPendingCall *pending,
1200 unsigned int flags,
1201 int timeout_milliseconds)
1202 {
1203 _dbus_verbose ("start\n");
1204
1205 HAVE_LOCK_CHECK (connection);
1206
1207 if (connection->n_outgoing == 0)
1208 flags &= ~DBUS_ITERATION_DO_WRITING;
1209
1210 if (_dbus_connection_acquire_io_path (connection,
1211 (flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0))
1212 {
1213 HAVE_LOCK_CHECK (connection);
1214
1215 if ( (pending != NULL) && _dbus_pending_call_get_completed_unlocked(pending))
1216 {
1217 _dbus_verbose ("pending call completed while acquiring I/O path");
1218 }
1219 else if ( (pending != NULL) &&
1220 _dbus_connection_peek_for_reply_unlocked (connection,
1221 _dbus_pending_call_get_reply_serial_unlocked (pending)))
1222 {
1223 _dbus_verbose ("pending call completed while acquiring I/O path (reply found in queue)");
1224 }
1225 else
1226 {
1227 _dbus_transport_do_iteration (connection->transport,
1228 flags, timeout_milliseconds);
1229 }
1230
1231 _dbus_connection_release_io_path (connection);
1232 }
1233
1234 HAVE_LOCK_CHECK (connection);
1235
1236 _dbus_verbose ("end\n");
1237 }
1238
1239 /**
1240 * Creates a new connection for the given transport. A transport
1241 * represents a message stream that uses some concrete mechanism, such
1242 * as UNIX domain sockets. May return #NULL if insufficient
1243 * memory exists to create the connection.
1244 *
1245 * @param transport the transport.
1246 * @returns the new connection, or #NULL on failure.
1247 */
1248 DBusConnection*
_dbus_connection_new_for_transport(DBusTransport * transport)1249 _dbus_connection_new_for_transport (DBusTransport *transport)
1250 {
1251 DBusConnection *connection;
1252 DBusWatchList *watch_list;
1253 DBusTimeoutList *timeout_list;
1254 DBusHashTable *pending_replies;
1255 DBusList *disconnect_link;
1256 DBusMessage *disconnect_message;
1257 DBusCounter *outgoing_counter;
1258 DBusObjectTree *objects;
1259
1260 watch_list = NULL;
1261 connection = NULL;
1262 pending_replies = NULL;
1263 timeout_list = NULL;
1264 disconnect_link = NULL;
1265 disconnect_message = NULL;
1266 outgoing_counter = NULL;
1267 objects = NULL;
1268
1269 watch_list = _dbus_watch_list_new ();
1270 if (watch_list == NULL)
1271 goto error;
1272
1273 timeout_list = _dbus_timeout_list_new ();
1274 if (timeout_list == NULL)
1275 goto error;
1276
1277 pending_replies =
1278 _dbus_hash_table_new (DBUS_HASH_INT,
1279 NULL,
1280 (DBusFreeFunction)free_pending_call_on_hash_removal);
1281 if (pending_replies == NULL)
1282 goto error;
1283
1284 connection = dbus_new0 (DBusConnection, 1);
1285 if (connection == NULL)
1286 goto error;
1287
1288 _dbus_rmutex_new_at_location (&connection->mutex);
1289 if (connection->mutex == NULL)
1290 goto error;
1291
1292 _dbus_cmutex_new_at_location (&connection->io_path_mutex);
1293 if (connection->io_path_mutex == NULL)
1294 goto error;
1295
1296 _dbus_cmutex_new_at_location (&connection->dispatch_mutex);
1297 if (connection->dispatch_mutex == NULL)
1298 goto error;
1299
1300 _dbus_condvar_new_at_location (&connection->dispatch_cond);
1301 if (connection->dispatch_cond == NULL)
1302 goto error;
1303
1304 _dbus_condvar_new_at_location (&connection->io_path_cond);
1305 if (connection->io_path_cond == NULL)
1306 goto error;
1307
1308 _dbus_rmutex_new_at_location (&connection->slot_mutex);
1309 if (connection->slot_mutex == NULL)
1310 goto error;
1311
1312 disconnect_message = dbus_message_new_signal (DBUS_PATH_LOCAL,
1313 DBUS_INTERFACE_LOCAL,
1314 "Disconnected");
1315
1316 if (disconnect_message == NULL)
1317 goto error;
1318
1319 disconnect_link = _dbus_list_alloc_link (disconnect_message);
1320 if (disconnect_link == NULL)
1321 goto error;
1322
1323 outgoing_counter = _dbus_counter_new ();
1324 if (outgoing_counter == NULL)
1325 goto error;
1326
1327 objects = _dbus_object_tree_new (connection);
1328 if (objects == NULL)
1329 goto error;
1330
1331 if (_dbus_modify_sigpipe)
1332 _dbus_disable_sigpipe ();
1333
1334 /* initialized to 0: use atomic op to avoid mixing atomic and non-atomic */
1335 _dbus_atomic_inc (&connection->refcount);
1336 connection->transport = transport;
1337 connection->watches = watch_list;
1338 connection->timeouts = timeout_list;
1339 connection->pending_replies = pending_replies;
1340 connection->outgoing_counter = outgoing_counter;
1341 connection->filter_list = NULL;
1342 connection->last_dispatch_status = DBUS_DISPATCH_COMPLETE; /* so we're notified first time there's data */
1343 connection->objects = objects;
1344 connection->exit_on_disconnect = FALSE;
1345 connection->shareable = FALSE;
1346 connection->route_peer_messages = FALSE;
1347 connection->disconnected_message_arrived = FALSE;
1348 connection->disconnected_message_processed = FALSE;
1349
1350 #if defined(DBUS_ENABLE_CHECKS) || defined(DBUS_ENABLE_ASSERT)
1351 connection->generation = _dbus_current_generation;
1352 #endif
1353
1354 _dbus_data_slot_list_init (&connection->slot_list);
1355
1356 connection->client_serial = 1;
1357
1358 connection->disconnect_message_link = disconnect_link;
1359
1360 CONNECTION_LOCK (connection);
1361
1362 if (!_dbus_transport_set_connection (transport, connection))
1363 {
1364 CONNECTION_UNLOCK (connection);
1365
1366 goto error;
1367 }
1368
1369 _dbus_transport_ref (transport);
1370
1371 CONNECTION_UNLOCK (connection);
1372
1373 _dbus_connection_trace_ref (connection, 0, 1, "new_for_transport");
1374 return connection;
1375
1376 error:
1377 if (disconnect_message != NULL)
1378 dbus_message_unref (disconnect_message);
1379
1380 if (disconnect_link != NULL)
1381 _dbus_list_free_link (disconnect_link);
1382
1383 if (connection != NULL)
1384 {
1385 _dbus_condvar_free_at_location (&connection->io_path_cond);
1386 _dbus_condvar_free_at_location (&connection->dispatch_cond);
1387 _dbus_rmutex_free_at_location (&connection->mutex);
1388 _dbus_cmutex_free_at_location (&connection->io_path_mutex);
1389 _dbus_cmutex_free_at_location (&connection->dispatch_mutex);
1390 _dbus_rmutex_free_at_location (&connection->slot_mutex);
1391 dbus_free (connection);
1392 }
1393 if (pending_replies)
1394 _dbus_hash_table_unref (pending_replies);
1395
1396 if (watch_list)
1397 _dbus_watch_list_free (watch_list);
1398
1399 if (timeout_list)
1400 _dbus_timeout_list_free (timeout_list);
1401
1402 if (outgoing_counter)
1403 _dbus_counter_unref (outgoing_counter);
1404
1405 if (objects)
1406 _dbus_object_tree_unref (objects);
1407
1408 return NULL;
1409 }
1410
1411 /**
1412 * Increments the reference count of a DBusConnection.
1413 * Requires that the caller already holds the connection lock.
1414 *
1415 * @param connection the connection.
1416 * @returns the connection.
1417 */
1418 DBusConnection *
_dbus_connection_ref_unlocked(DBusConnection * connection)1419 _dbus_connection_ref_unlocked (DBusConnection *connection)
1420 {
1421 dbus_int32_t old_refcount;
1422
1423 _dbus_assert (connection != NULL);
1424 _dbus_assert (connection->generation == _dbus_current_generation);
1425
1426 HAVE_LOCK_CHECK (connection);
1427
1428 old_refcount = _dbus_atomic_inc (&connection->refcount);
1429 _dbus_connection_trace_ref (connection, old_refcount, old_refcount + 1,
1430 "ref_unlocked");
1431
1432 return connection;
1433 }
1434
1435 /**
1436 * Decrements the reference count of a DBusConnection.
1437 * Requires that the caller already holds the connection lock.
1438 *
1439 * @param connection the connection.
1440 */
1441 void
_dbus_connection_unref_unlocked(DBusConnection * connection)1442 _dbus_connection_unref_unlocked (DBusConnection *connection)
1443 {
1444 dbus_int32_t old_refcount;
1445
1446 HAVE_LOCK_CHECK (connection);
1447
1448 _dbus_assert (connection != NULL);
1449
1450 old_refcount = _dbus_atomic_dec (&connection->refcount);
1451
1452 _dbus_connection_trace_ref (connection, old_refcount, old_refcount - 1,
1453 "unref_unlocked");
1454
1455 if (old_refcount == 1)
1456 _dbus_connection_last_unref (connection);
1457 }
1458
1459 static dbus_uint32_t
_dbus_connection_get_next_client_serial(DBusConnection * connection)1460 _dbus_connection_get_next_client_serial (DBusConnection *connection)
1461 {
1462 dbus_uint32_t serial;
1463
1464 serial = connection->client_serial++;
1465
1466 if (connection->client_serial == 0)
1467 connection->client_serial = 1;
1468
1469 return serial;
1470 }
1471
1472 /**
1473 * A callback for use with dbus_watch_new() to create a DBusWatch.
1474 *
1475 * @todo This is basically a hack - we could delete _dbus_transport_handle_watch()
1476 * and the virtual handle_watch in DBusTransport if we got rid of it.
1477 * The reason this is some work is threading, see the _dbus_connection_handle_watch()
1478 * implementation.
1479 *
1480 * @param watch the watch.
1481 * @param condition the current condition of the file descriptors being watched.
1482 * @param data must be a pointer to a #DBusConnection
1483 * @returns #FALSE if the IO condition may not have been fully handled due to lack of memory
1484 */
1485 dbus_bool_t
_dbus_connection_handle_watch(DBusWatch * watch,unsigned int condition,void * data)1486 _dbus_connection_handle_watch (DBusWatch *watch,
1487 unsigned int condition,
1488 void *data)
1489 {
1490 DBusConnection *connection;
1491 dbus_bool_t retval;
1492 DBusDispatchStatus status;
1493
1494 connection = data;
1495
1496 _dbus_verbose ("start\n");
1497
1498 CONNECTION_LOCK (connection);
1499
1500 if (!_dbus_connection_acquire_io_path (connection, 1))
1501 {
1502 /* another thread is handling the message */
1503 CONNECTION_UNLOCK (connection);
1504 return TRUE;
1505 }
1506
1507 HAVE_LOCK_CHECK (connection);
1508 retval = _dbus_transport_handle_watch (connection->transport,
1509 watch, condition);
1510
1511 _dbus_connection_release_io_path (connection);
1512
1513 HAVE_LOCK_CHECK (connection);
1514
1515 _dbus_verbose ("middle\n");
1516
1517 status = _dbus_connection_get_dispatch_status_unlocked (connection);
1518
1519 /* this calls out to user code */
1520 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
1521
1522 _dbus_verbose ("end\n");
1523
1524 return retval;
1525 }
1526
1527 /* Protected by _DBUS_LOCK (shared_connections) */
1528 static DBusHashTable *shared_connections = NULL;
1529 static DBusList *shared_connections_no_guid = NULL;
1530
1531 static void
close_connection_on_shutdown(DBusConnection * connection)1532 close_connection_on_shutdown (DBusConnection *connection)
1533 {
1534 DBusMessage *message;
1535
1536 dbus_connection_ref (connection);
1537 _dbus_connection_close_possibly_shared (connection);
1538
1539 /* Churn through to the Disconnected message */
1540 while ((message = dbus_connection_pop_message (connection)))
1541 {
1542 dbus_message_unref (message);
1543 }
1544 dbus_connection_unref (connection);
1545 }
1546
1547 static void
shared_connections_shutdown(void * data)1548 shared_connections_shutdown (void *data)
1549 {
1550 int n_entries;
1551
1552 if (!_DBUS_LOCK (shared_connections))
1553 {
1554 /* We'd have initialized locks before adding anything, so there
1555 * can't be anything there. */
1556 return;
1557 }
1558
1559 /* This is a little bit unpleasant... better ideas? */
1560 while ((n_entries = _dbus_hash_table_get_n_entries (shared_connections)) > 0)
1561 {
1562 DBusConnection *connection;
1563 DBusHashIter iter;
1564
1565 _dbus_hash_iter_init (shared_connections, &iter);
1566 _dbus_hash_iter_next (&iter);
1567
1568 connection = _dbus_hash_iter_get_value (&iter);
1569
1570 _DBUS_UNLOCK (shared_connections);
1571 close_connection_on_shutdown (connection);
1572 if (!_DBUS_LOCK (shared_connections))
1573 _dbus_assert_not_reached ("global locks were already initialized");
1574
1575 /* The connection should now be dead and not in our hash ... */
1576 _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) < n_entries);
1577 }
1578
1579 _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) == 0);
1580
1581 _dbus_hash_table_unref (shared_connections);
1582 shared_connections = NULL;
1583
1584 if (shared_connections_no_guid != NULL)
1585 {
1586 DBusConnection *connection;
1587 connection = _dbus_list_pop_first (&shared_connections_no_guid);
1588 while (connection != NULL)
1589 {
1590 _DBUS_UNLOCK (shared_connections);
1591 close_connection_on_shutdown (connection);
1592 if (!_DBUS_LOCK (shared_connections))
1593 _dbus_assert_not_reached ("global locks were already initialized");
1594 connection = _dbus_list_pop_first (&shared_connections_no_guid);
1595 }
1596 }
1597
1598 shared_connections_no_guid = NULL;
1599
1600 _DBUS_UNLOCK (shared_connections);
1601 }
1602
1603 static dbus_bool_t
connection_lookup_shared(DBusAddressEntry * entry,DBusConnection ** result)1604 connection_lookup_shared (DBusAddressEntry *entry,
1605 DBusConnection **result)
1606 {
1607 _dbus_verbose ("checking for existing connection\n");
1608
1609 *result = NULL;
1610
1611 if (!_DBUS_LOCK (shared_connections))
1612 {
1613 /* If it was shared, we'd have initialized global locks when we put
1614 * it in shared_connections. */
1615 return FALSE;
1616 }
1617
1618 if (shared_connections == NULL)
1619 {
1620 _dbus_verbose ("creating shared_connections hash table\n");
1621
1622 shared_connections = _dbus_hash_table_new (DBUS_HASH_STRING,
1623 dbus_free,
1624 NULL);
1625 if (shared_connections == NULL)
1626 {
1627 _DBUS_UNLOCK (shared_connections);
1628 return FALSE;
1629 }
1630
1631 if (!_dbus_register_shutdown_func (shared_connections_shutdown, NULL))
1632 {
1633 _dbus_hash_table_unref (shared_connections);
1634 shared_connections = NULL;
1635 _DBUS_UNLOCK (shared_connections);
1636 return FALSE;
1637 }
1638
1639 _dbus_verbose (" successfully created shared_connections\n");
1640
1641 _DBUS_UNLOCK (shared_connections);
1642 return TRUE; /* no point looking up in the hash we just made */
1643 }
1644 else
1645 {
1646 const char *guid;
1647
1648 guid = dbus_address_entry_get_value (entry, "guid");
1649
1650 if (guid != NULL)
1651 {
1652 DBusConnection *connection;
1653
1654 connection = _dbus_hash_table_lookup_string (shared_connections,
1655 guid);
1656
1657 if (connection)
1658 {
1659 /* The DBusConnection can't be finalized without taking
1660 * the shared_connections lock to remove it from the
1661 * hash. So it's safe to ref the connection here.
1662 * However, it may be disconnected if the Disconnected
1663 * message hasn't been processed yet, in which case we
1664 * want to pretend it isn't in the hash and avoid
1665 * returning it.
1666 *
1667 * The idea is to avoid ever returning a disconnected connection
1668 * from dbus_connection_open(). We could just synchronously
1669 * drop our shared ref to the connection on connection disconnect,
1670 * and then assert here that the connection is connected, but
1671 * that causes reentrancy headaches.
1672 */
1673 CONNECTION_LOCK (connection);
1674 if (_dbus_connection_get_is_connected_unlocked (connection))
1675 {
1676 _dbus_connection_ref_unlocked (connection);
1677 *result = connection;
1678 _dbus_verbose ("looked up existing connection to server guid %s\n",
1679 guid);
1680 }
1681 else
1682 {
1683 _dbus_verbose ("looked up existing connection to server guid %s but it was disconnected so ignoring it\n",
1684 guid);
1685 }
1686 CONNECTION_UNLOCK (connection);
1687 }
1688 }
1689
1690 _DBUS_UNLOCK (shared_connections);
1691 return TRUE;
1692 }
1693 }
1694
1695 static dbus_bool_t
connection_record_shared_unlocked(DBusConnection * connection,const char * guid)1696 connection_record_shared_unlocked (DBusConnection *connection,
1697 const char *guid)
1698 {
1699 char *guid_key;
1700 char *guid_in_connection;
1701
1702 HAVE_LOCK_CHECK (connection);
1703 _dbus_assert (connection->server_guid == NULL);
1704 _dbus_assert (connection->shareable);
1705
1706 /* get a hard ref on this connection, even if
1707 * we won't in fact store it in the hash, we still
1708 * need to hold a ref on it until it's disconnected.
1709 */
1710 _dbus_connection_ref_unlocked (connection);
1711
1712 if (guid == NULL)
1713 {
1714 if (!_DBUS_LOCK (shared_connections))
1715 return FALSE;
1716
1717 if (!_dbus_list_prepend (&shared_connections_no_guid, connection))
1718 {
1719 _DBUS_UNLOCK (shared_connections);
1720 return FALSE;
1721 }
1722
1723 _DBUS_UNLOCK (shared_connections);
1724 return TRUE; /* don't store in the hash */
1725 }
1726
1727 /* A separate copy of the key is required in the hash table, because
1728 * we don't have a lock on the connection when we are doing a hash
1729 * lookup.
1730 */
1731
1732 guid_key = _dbus_strdup (guid);
1733 if (guid_key == NULL)
1734 return FALSE;
1735
1736 guid_in_connection = _dbus_strdup (guid);
1737 if (guid_in_connection == NULL)
1738 {
1739 dbus_free (guid_key);
1740 return FALSE;
1741 }
1742
1743 if (!_DBUS_LOCK (shared_connections))
1744 {
1745 dbus_free (guid_in_connection);
1746 dbus_free (guid_key);
1747 return FALSE;
1748 }
1749
1750 _dbus_assert (shared_connections != NULL);
1751
1752 if (!_dbus_hash_table_insert_string (shared_connections,
1753 guid_key, connection))
1754 {
1755 dbus_free (guid_key);
1756 dbus_free (guid_in_connection);
1757 _DBUS_UNLOCK (shared_connections);
1758 return FALSE;
1759 }
1760
1761 connection->server_guid = guid_in_connection;
1762
1763 _dbus_verbose ("stored connection to %s to be shared\n",
1764 connection->server_guid);
1765
1766 _DBUS_UNLOCK (shared_connections);
1767
1768 _dbus_assert (connection->server_guid != NULL);
1769
1770 return TRUE;
1771 }
1772
1773 static void
connection_forget_shared_unlocked(DBusConnection * connection)1774 connection_forget_shared_unlocked (DBusConnection *connection)
1775 {
1776 HAVE_LOCK_CHECK (connection);
1777
1778 if (!connection->shareable)
1779 return;
1780
1781 if (!_DBUS_LOCK (shared_connections))
1782 {
1783 /* If it was shared, we'd have initialized global locks when we put
1784 * it in the table; so it can't be there. */
1785 return;
1786 }
1787
1788 if (connection->server_guid != NULL)
1789 {
1790 _dbus_verbose ("dropping connection to %s out of the shared table\n",
1791 connection->server_guid);
1792
1793 if (!_dbus_hash_table_remove_string (shared_connections,
1794 connection->server_guid))
1795 _dbus_assert_not_reached ("connection was not in the shared table");
1796
1797 dbus_free (connection->server_guid);
1798 connection->server_guid = NULL;
1799 }
1800 else
1801 {
1802 _dbus_list_remove (&shared_connections_no_guid, connection);
1803 }
1804
1805 _DBUS_UNLOCK (shared_connections);
1806
1807 /* remove our reference held on all shareable connections */
1808 _dbus_connection_unref_unlocked (connection);
1809 }
1810
1811 static DBusConnection*
connection_try_from_address_entry(DBusAddressEntry * entry,DBusError * error)1812 connection_try_from_address_entry (DBusAddressEntry *entry,
1813 DBusError *error)
1814 {
1815 DBusTransport *transport;
1816 DBusConnection *connection;
1817
1818 transport = _dbus_transport_open (entry, error);
1819
1820 if (transport == NULL)
1821 {
1822 _DBUS_ASSERT_ERROR_IS_SET (error);
1823 return NULL;
1824 }
1825
1826 connection = _dbus_connection_new_for_transport (transport);
1827
1828 _dbus_transport_unref (transport);
1829
1830 if (connection == NULL)
1831 {
1832 _DBUS_SET_OOM (error);
1833 return NULL;
1834 }
1835
1836 #ifndef DBUS_DISABLE_CHECKS
1837 _dbus_assert (!connection->have_connection_lock);
1838 #endif
1839 return connection;
1840 }
1841
1842 /*
1843 * If the shared parameter is true, then any existing connection will
1844 * be used (and if a new connection is created, it will be available
1845 * for use by others). If the shared parameter is false, a new
1846 * connection will always be created, and the new connection will
1847 * never be returned to other callers.
1848 *
1849 * @param address the address
1850 * @param shared whether the connection is shared or private
1851 * @param error error return
1852 * @returns the connection or #NULL on error
1853 */
1854 static DBusConnection*
_dbus_connection_open_internal(const char * address,dbus_bool_t shared,DBusError * error)1855 _dbus_connection_open_internal (const char *address,
1856 dbus_bool_t shared,
1857 DBusError *error)
1858 {
1859 DBusConnection *connection;
1860 DBusAddressEntry **entries;
1861 DBusError tmp_error = DBUS_ERROR_INIT;
1862 DBusError first_error = DBUS_ERROR_INIT;
1863 int len, i;
1864
1865 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1866
1867 _dbus_verbose ("opening %s connection to: %s\n",
1868 shared ? "shared" : "private", address);
1869
1870 if (!dbus_parse_address (address, &entries, &len, error))
1871 return NULL;
1872
1873 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1874
1875 connection = NULL;
1876
1877 for (i = 0; i < len; i++)
1878 {
1879 if (shared)
1880 {
1881 if (!connection_lookup_shared (entries[i], &connection))
1882 _DBUS_SET_OOM (&tmp_error);
1883 }
1884
1885 if (connection == NULL)
1886 {
1887 connection = connection_try_from_address_entry (entries[i],
1888 &tmp_error);
1889
1890 if (connection != NULL && shared)
1891 {
1892 const char *guid;
1893
1894 connection->shareable = TRUE;
1895
1896 /* guid may be NULL */
1897 guid = dbus_address_entry_get_value (entries[i], "guid");
1898
1899 CONNECTION_LOCK (connection);
1900
1901 if (!connection_record_shared_unlocked (connection, guid))
1902 {
1903 _DBUS_SET_OOM (&tmp_error);
1904 _dbus_connection_close_possibly_shared_and_unlock (connection);
1905 dbus_connection_unref (connection);
1906 connection = NULL;
1907 }
1908 else
1909 CONNECTION_UNLOCK (connection);
1910 }
1911 }
1912
1913 if (connection)
1914 break;
1915
1916 _DBUS_ASSERT_ERROR_IS_SET (&tmp_error);
1917
1918 if (i == 0)
1919 dbus_move_error (&tmp_error, &first_error);
1920 else
1921 dbus_error_free (&tmp_error);
1922 }
1923
1924 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1925 _DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error);
1926
1927 if (connection == NULL)
1928 {
1929 _DBUS_ASSERT_ERROR_IS_SET (&first_error);
1930 dbus_move_error (&first_error, error);
1931 }
1932 else
1933 dbus_error_free (&first_error);
1934
1935 dbus_address_entries_free (entries);
1936 return connection;
1937 }
1938
1939 /**
1940 * Closes a shared OR private connection, while dbus_connection_close() can
1941 * only be used on private connections. Should only be called by the
1942 * dbus code that owns the connection - an owner must be known,
1943 * the open/close state is like malloc/free, not like ref/unref.
1944 *
1945 * @param connection the connection
1946 */
1947 void
_dbus_connection_close_possibly_shared(DBusConnection * connection)1948 _dbus_connection_close_possibly_shared (DBusConnection *connection)
1949 {
1950 _dbus_assert (connection != NULL);
1951 _dbus_assert (connection->generation == _dbus_current_generation);
1952
1953 CONNECTION_LOCK (connection);
1954 _dbus_connection_close_possibly_shared_and_unlock (connection);
1955 }
1956
1957 static DBusPreallocatedSend*
_dbus_connection_preallocate_send_unlocked(DBusConnection * connection)1958 _dbus_connection_preallocate_send_unlocked (DBusConnection *connection)
1959 {
1960 DBusPreallocatedSend *preallocated;
1961
1962 HAVE_LOCK_CHECK (connection);
1963
1964 _dbus_assert (connection != NULL);
1965
1966 preallocated = dbus_new (DBusPreallocatedSend, 1);
1967 if (preallocated == NULL)
1968 return NULL;
1969
1970 preallocated->queue_link = _dbus_list_alloc_link (NULL);
1971 if (preallocated->queue_link == NULL)
1972 goto failed_0;
1973
1974 preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter);
1975 if (preallocated->counter_link == NULL)
1976 goto failed_1;
1977
1978 _dbus_counter_ref (preallocated->counter_link->data);
1979
1980 preallocated->connection = connection;
1981
1982 return preallocated;
1983
1984 failed_1:
1985 _dbus_list_free_link (preallocated->queue_link);
1986 failed_0:
1987 dbus_free (preallocated);
1988
1989 return NULL;
1990 }
1991
1992 /* Called with lock held, does not update dispatch status */
1993 static void
_dbus_connection_send_preallocated_unlocked_no_update(DBusConnection * connection,DBusPreallocatedSend * preallocated,DBusMessage * message,dbus_uint32_t * client_serial)1994 _dbus_connection_send_preallocated_unlocked_no_update (DBusConnection *connection,
1995 DBusPreallocatedSend *preallocated,
1996 DBusMessage *message,
1997 dbus_uint32_t *client_serial)
1998 {
1999 dbus_uint32_t serial;
2000
2001 preallocated->queue_link->data = message;
2002 _dbus_list_prepend_link (&connection->outgoing_messages,
2003 preallocated->queue_link);
2004
2005 /* It's OK that we'll never call the notify function, because for the
2006 * outgoing limit, there isn't one */
2007 _dbus_message_add_counter_link (message,
2008 preallocated->counter_link);
2009
2010 dbus_free (preallocated);
2011 preallocated = NULL;
2012
2013 dbus_message_ref (message);
2014
2015 connection->n_outgoing += 1;
2016
2017 _dbus_verbose ("Message %p (%s %s %s %s '%s') for %s added to outgoing queue %p, %d pending to send\n",
2018 message,
2019 dbus_message_type_to_string (dbus_message_get_type (message)),
2020 dbus_message_get_path (message) ?
2021 dbus_message_get_path (message) :
2022 "no path",
2023 dbus_message_get_interface (message) ?
2024 dbus_message_get_interface (message) :
2025 "no interface",
2026 dbus_message_get_member (message) ?
2027 dbus_message_get_member (message) :
2028 "no member",
2029 dbus_message_get_signature (message),
2030 dbus_message_get_destination (message) ?
2031 dbus_message_get_destination (message) :
2032 "null",
2033 connection,
2034 connection->n_outgoing);
2035
2036 if (dbus_message_get_serial (message) == 0)
2037 {
2038 serial = _dbus_connection_get_next_client_serial (connection);
2039 dbus_message_set_serial (message, serial);
2040 if (client_serial)
2041 *client_serial = serial;
2042 }
2043 else
2044 {
2045 if (client_serial)
2046 *client_serial = dbus_message_get_serial (message);
2047 }
2048
2049 _dbus_verbose ("Message %p serial is %u\n",
2050 message, dbus_message_get_serial (message));
2051
2052 dbus_message_lock (message);
2053
2054 /* Now we need to run an iteration to hopefully just write the messages
2055 * out immediately, and otherwise get them queued up
2056 */
2057 _dbus_connection_do_iteration_unlocked (connection,
2058 NULL,
2059 DBUS_ITERATION_DO_WRITING,
2060 -1);
2061
2062 /* If stuff is still queued up, be sure we wake up the main loop */
2063 if (connection->n_outgoing > 0)
2064 _dbus_connection_wakeup_mainloop (connection);
2065 }
2066
2067 static void
_dbus_connection_send_preallocated_and_unlock(DBusConnection * connection,DBusPreallocatedSend * preallocated,DBusMessage * message,dbus_uint32_t * client_serial)2068 _dbus_connection_send_preallocated_and_unlock (DBusConnection *connection,
2069 DBusPreallocatedSend *preallocated,
2070 DBusMessage *message,
2071 dbus_uint32_t *client_serial)
2072 {
2073 DBusDispatchStatus status;
2074
2075 HAVE_LOCK_CHECK (connection);
2076
2077 _dbus_connection_send_preallocated_unlocked_no_update (connection,
2078 preallocated,
2079 message, client_serial);
2080
2081 _dbus_verbose ("middle\n");
2082 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2083
2084 /* this calls out to user code */
2085 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
2086 }
2087
2088 /**
2089 * Like dbus_connection_send(), but assumes the connection
2090 * is already locked on function entry, and unlocks before returning.
2091 *
2092 * @param connection the connection
2093 * @param message the message to send
2094 * @param client_serial return location for client serial of sent message
2095 * @returns #FALSE on out-of-memory
2096 */
2097 dbus_bool_t
_dbus_connection_send_and_unlock(DBusConnection * connection,DBusMessage * message,dbus_uint32_t * client_serial)2098 _dbus_connection_send_and_unlock (DBusConnection *connection,
2099 DBusMessage *message,
2100 dbus_uint32_t *client_serial)
2101 {
2102 DBusPreallocatedSend *preallocated;
2103
2104 _dbus_assert (connection != NULL);
2105 _dbus_assert (message != NULL);
2106
2107 preallocated = _dbus_connection_preallocate_send_unlocked (connection);
2108 if (preallocated == NULL)
2109 {
2110 CONNECTION_UNLOCK (connection);
2111 return FALSE;
2112 }
2113
2114 _dbus_connection_send_preallocated_and_unlock (connection,
2115 preallocated,
2116 message,
2117 client_serial);
2118 return TRUE;
2119 }
2120
2121 /**
2122 * Used internally to handle the semantics of dbus_server_set_new_connection_function().
2123 * If the new connection function does not ref the connection, we want to close it.
2124 *
2125 * A bit of a hack, probably the new connection function should have returned a value
2126 * for whether to close, or should have had to close the connection itself if it
2127 * didn't want it.
2128 *
2129 * But, this works OK as long as the new connection function doesn't do anything
2130 * crazy like keep the connection around without ref'ing it.
2131 *
2132 * We have to lock the connection across refcount check and close in case
2133 * the new connection function spawns a thread that closes and unrefs.
2134 * In that case, if the app thread
2135 * closes and unrefs first, we'll harmlessly close again; if the app thread
2136 * still has the ref, we'll close and then the app will close harmlessly.
2137 * If the app unrefs without closing, the app is broken since if the
2138 * app refs from the new connection function it is supposed to also close.
2139 *
2140 * If we didn't atomically check the refcount and close with the lock held
2141 * though, we could screw this up.
2142 *
2143 * @param connection the connection
2144 */
2145 void
_dbus_connection_close_if_only_one_ref(DBusConnection * connection)2146 _dbus_connection_close_if_only_one_ref (DBusConnection *connection)
2147 {
2148 dbus_int32_t refcount;
2149
2150 CONNECTION_LOCK (connection);
2151
2152 refcount = _dbus_atomic_get (&connection->refcount);
2153 /* The caller should have at least one ref */
2154 _dbus_assert (refcount >= 1);
2155
2156 if (refcount == 1)
2157 _dbus_connection_close_possibly_shared_and_unlock (connection);
2158 else
2159 CONNECTION_UNLOCK (connection);
2160 }
2161
2162
2163 /**
2164 * When a function that blocks has been called with a timeout, and we
2165 * run out of memory, the time to wait for memory is based on the
2166 * timeout. If the caller was willing to block a long time we wait a
2167 * relatively long time for memory, if they were only willing to block
2168 * briefly then we retry for memory at a rapid rate.
2169 *
2170 * @param timeout_milliseconds the timeout requested for blocking
2171 */
2172 static void
_dbus_memory_pause_based_on_timeout(int timeout_milliseconds)2173 _dbus_memory_pause_based_on_timeout (int timeout_milliseconds)
2174 {
2175 if (timeout_milliseconds == -1)
2176 _dbus_sleep_milliseconds (1000);
2177 else if (timeout_milliseconds < 100)
2178 ; /* just busy loop */
2179 else if (timeout_milliseconds <= 1000)
2180 _dbus_sleep_milliseconds (timeout_milliseconds / 3);
2181 else
2182 _dbus_sleep_milliseconds (1000);
2183 }
2184
2185 static DBusMessage *
generate_local_error_message(dbus_uint32_t serial,const char * error_name,const char * error_msg)2186 generate_local_error_message (dbus_uint32_t serial,
2187 const char *error_name,
2188 const char *error_msg)
2189 {
2190 DBusMessage *message;
2191 message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
2192 if (!message)
2193 goto out;
2194
2195 if (!dbus_message_set_error_name (message, error_name))
2196 {
2197 dbus_message_unref (message);
2198 message = NULL;
2199 goto out;
2200 }
2201
2202 dbus_message_set_no_reply (message, TRUE);
2203
2204 if (!dbus_message_set_reply_serial (message,
2205 serial))
2206 {
2207 dbus_message_unref (message);
2208 message = NULL;
2209 goto out;
2210 }
2211
2212 if (error_msg != NULL)
2213 {
2214 DBusMessageIter iter;
2215
2216 dbus_message_iter_init_append (message, &iter);
2217 if (!dbus_message_iter_append_basic (&iter,
2218 DBUS_TYPE_STRING,
2219 &error_msg))
2220 {
2221 dbus_message_unref (message);
2222 message = NULL;
2223 goto out;
2224 }
2225 }
2226
2227 out:
2228 return message;
2229 }
2230
2231 /*
2232 * Peek the incoming queue to see if we got reply for a specific serial
2233 */
2234 static dbus_bool_t
_dbus_connection_peek_for_reply_unlocked(DBusConnection * connection,dbus_uint32_t client_serial)2235 _dbus_connection_peek_for_reply_unlocked (DBusConnection *connection,
2236 dbus_uint32_t client_serial)
2237 {
2238 DBusList *link;
2239 HAVE_LOCK_CHECK (connection);
2240
2241 link = _dbus_list_get_first_link (&connection->incoming_messages);
2242
2243 while (link != NULL)
2244 {
2245 DBusMessage *reply = link->data;
2246
2247 if (dbus_message_get_reply_serial (reply) == client_serial)
2248 {
2249 _dbus_verbose ("%s reply to %d found in queue\n", _DBUS_FUNCTION_NAME, client_serial);
2250 return TRUE;
2251 }
2252 link = _dbus_list_get_next_link (&connection->incoming_messages, link);
2253 }
2254
2255 return FALSE;
2256 }
2257
2258 /* This is slightly strange since we can pop a message here without
2259 * the dispatch lock.
2260 */
2261 static DBusMessage*
check_for_reply_unlocked(DBusConnection * connection,dbus_uint32_t client_serial)2262 check_for_reply_unlocked (DBusConnection *connection,
2263 dbus_uint32_t client_serial)
2264 {
2265 DBusList *link;
2266
2267 HAVE_LOCK_CHECK (connection);
2268
2269 link = _dbus_list_get_first_link (&connection->incoming_messages);
2270
2271 while (link != NULL)
2272 {
2273 DBusMessage *reply = link->data;
2274
2275 if (dbus_message_get_reply_serial (reply) == client_serial)
2276 {
2277 _dbus_list_remove_link (&connection->incoming_messages, link);
2278 connection->n_incoming -= 1;
2279 return reply;
2280 }
2281 link = _dbus_list_get_next_link (&connection->incoming_messages, link);
2282 }
2283
2284 return NULL;
2285 }
2286
2287 static void
connection_timeout_and_complete_all_pending_calls_unlocked(DBusConnection * connection)2288 connection_timeout_and_complete_all_pending_calls_unlocked (DBusConnection *connection)
2289 {
2290 /* We can't iterate over the hash in the normal way since we'll be
2291 * dropping the lock for each item. So we restart the
2292 * iter each time as we drain the hash table.
2293 */
2294
2295 while (_dbus_hash_table_get_n_entries (connection->pending_replies) > 0)
2296 {
2297 DBusPendingCall *pending;
2298 DBusHashIter iter;
2299
2300 _dbus_hash_iter_init (connection->pending_replies, &iter);
2301 _dbus_hash_iter_next (&iter);
2302
2303 pending = _dbus_hash_iter_get_value (&iter);
2304 _dbus_pending_call_ref_unlocked (pending);
2305
2306 _dbus_pending_call_queue_timeout_error_unlocked (pending,
2307 connection);
2308
2309 if (_dbus_pending_call_is_timeout_added_unlocked (pending))
2310 _dbus_connection_remove_timeout_unlocked (connection,
2311 _dbus_pending_call_get_timeout_unlocked (pending));
2312 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
2313 _dbus_hash_iter_remove_entry (&iter);
2314
2315 _dbus_pending_call_unref_and_unlock (pending);
2316 CONNECTION_LOCK (connection);
2317 }
2318 HAVE_LOCK_CHECK (connection);
2319 }
2320
2321 static void
complete_pending_call_and_unlock(DBusConnection * connection,DBusPendingCall * pending,DBusMessage * message)2322 complete_pending_call_and_unlock (DBusConnection *connection,
2323 DBusPendingCall *pending,
2324 DBusMessage *message)
2325 {
2326 _dbus_pending_call_set_reply_unlocked (pending, message);
2327 _dbus_pending_call_ref_unlocked (pending); /* in case there's no app with a ref held */
2328 _dbus_pending_call_start_completion_unlocked(pending);
2329 _dbus_connection_detach_pending_call_and_unlock (connection, pending);
2330
2331 /* Must be called unlocked since it invokes app callback */
2332 _dbus_pending_call_finish_completion (pending);
2333 dbus_pending_call_unref (pending);
2334 }
2335
2336 static dbus_bool_t
check_for_reply_and_update_dispatch_unlocked(DBusConnection * connection,DBusPendingCall * pending)2337 check_for_reply_and_update_dispatch_unlocked (DBusConnection *connection,
2338 DBusPendingCall *pending)
2339 {
2340 DBusMessage *reply;
2341 DBusDispatchStatus status;
2342
2343 reply = check_for_reply_unlocked (connection,
2344 _dbus_pending_call_get_reply_serial_unlocked (pending));
2345 if (reply != NULL)
2346 {
2347 _dbus_verbose ("checked for reply\n");
2348
2349 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n");
2350
2351 complete_pending_call_and_unlock (connection, pending, reply);
2352 dbus_message_unref (reply);
2353
2354 CONNECTION_LOCK (connection);
2355 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2356 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
2357 dbus_pending_call_unref (pending);
2358
2359 return TRUE;
2360 }
2361
2362 return FALSE;
2363 }
2364
2365 /**
2366 * Blocks until a pending call times out or gets a reply.
2367 *
2368 * Does not re-enter the main loop or run filter/path-registered
2369 * callbacks. The reply to the message will not be seen by
2370 * filter callbacks.
2371 *
2372 * Returns immediately if pending call already got a reply.
2373 *
2374 * @todo could use performance improvements (it keeps scanning
2375 * the whole message queue for example)
2376 *
2377 * @param pending the pending call we block for a reply on
2378 */
2379 void
_dbus_connection_block_pending_call(DBusPendingCall * pending)2380 _dbus_connection_block_pending_call (DBusPendingCall *pending)
2381 {
2382 long start_tv_sec, start_tv_usec;
2383 long tv_sec, tv_usec;
2384 DBusDispatchStatus status;
2385 DBusConnection *connection;
2386 dbus_uint32_t client_serial;
2387 DBusTimeout *timeout;
2388 int timeout_milliseconds, elapsed_milliseconds, remain_milliseconds;
2389
2390 _dbus_assert (pending != NULL);
2391
2392 if (dbus_pending_call_get_completed (pending))
2393 return;
2394
2395 dbus_pending_call_ref (pending); /* necessary because the call could be canceled */
2396
2397 connection = _dbus_pending_call_get_connection_and_lock (pending);
2398
2399 /* Flush message queue - note, can affect dispatch status */
2400 _dbus_connection_flush_unlocked (connection);
2401
2402 client_serial = _dbus_pending_call_get_reply_serial_unlocked (pending);
2403
2404 /* note that timeout_milliseconds is limited to a smallish value
2405 * in _dbus_pending_call_new() so overflows aren't possible
2406 * below
2407 */
2408 timeout = _dbus_pending_call_get_timeout_unlocked (pending);
2409 _dbus_get_monotonic_time (&start_tv_sec, &start_tv_usec);
2410 if (timeout)
2411 {
2412 timeout_milliseconds = dbus_timeout_get_interval (timeout);
2413
2414 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block %d milliseconds for reply serial %u from %ld sec %ld usec\n",
2415 timeout_milliseconds,
2416 client_serial,
2417 start_tv_sec, start_tv_usec);
2418 }
2419 else
2420 {
2421 timeout_milliseconds = -1;
2422
2423 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block for reply serial %u\n", client_serial);
2424 }
2425
2426 /* check to see if we already got the data off the socket */
2427 /* from another blocked pending call */
2428 if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
2429 return;
2430
2431 /* Now we wait... */
2432 /* always block at least once as we know we don't have the reply yet */
2433 _dbus_connection_do_iteration_unlocked (connection,
2434 pending,
2435 DBUS_ITERATION_DO_READING |
2436 DBUS_ITERATION_BLOCK,
2437 timeout_milliseconds);
2438
2439 recheck_status:
2440
2441 _dbus_verbose ("top of recheck\n");
2442
2443 HAVE_LOCK_CHECK (connection);
2444
2445 /* queue messages and get status */
2446
2447 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2448
2449 /* the get_completed() is in case a dispatch() while we were blocking
2450 * got the reply instead of us.
2451 */
2452 if (_dbus_pending_call_get_completed_unlocked (pending))
2453 {
2454 _dbus_verbose ("Pending call completed by dispatch\n");
2455 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
2456 dbus_pending_call_unref (pending);
2457 return;
2458 }
2459
2460 if (status == DBUS_DISPATCH_DATA_REMAINS)
2461 {
2462 if (check_for_reply_and_update_dispatch_unlocked (connection, pending))
2463 return;
2464 }
2465
2466 _dbus_get_monotonic_time (&tv_sec, &tv_usec);
2467 elapsed_milliseconds = (tv_sec - start_tv_sec) * 1000 +
2468 (tv_usec - start_tv_usec) / 1000;
2469 if (timeout_milliseconds != -1)
2470 remain_milliseconds = timeout_milliseconds - elapsed_milliseconds;
2471 else
2472 remain_milliseconds = -1;
2473
2474 if (!_dbus_connection_get_is_connected_unlocked (connection))
2475 {
2476 DBusMessage *error_msg;
2477
2478 error_msg = generate_local_error_message (client_serial,
2479 DBUS_ERROR_DISCONNECTED,
2480 "Connection was disconnected before a reply was received");
2481
2482 /* on OOM error_msg is set to NULL */
2483 complete_pending_call_and_unlock (connection, pending, error_msg);
2484 if (error_msg != NULL)
2485 dbus_message_unref (error_msg);
2486 dbus_pending_call_unref (pending);
2487 return;
2488 }
2489 else if (connection->disconnect_message_link == NULL)
2490 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): disconnected\n");
2491 else if (timeout == NULL)
2492 {
2493 if (status == DBUS_DISPATCH_NEED_MEMORY)
2494 {
2495 /* Try sleeping a bit, as we aren't sure we need to block for reading,
2496 * we may already have a reply in the buffer and just can't process
2497 * it.
2498 */
2499 _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n");
2500
2501 _dbus_memory_pause_based_on_timeout (remain_milliseconds);
2502 }
2503 else
2504 {
2505 /* block again, we don't have the reply buffered yet. */
2506 _dbus_connection_do_iteration_unlocked (connection,
2507 pending,
2508 DBUS_ITERATION_DO_READING |
2509 DBUS_ITERATION_BLOCK,
2510 remain_milliseconds);
2511 }
2512
2513 goto recheck_status;
2514 }
2515 else if (tv_sec < start_tv_sec)
2516 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): clock set backward\n");
2517 else if (elapsed_milliseconds < timeout_milliseconds)
2518 {
2519 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): %d milliseconds remain\n", remain_milliseconds);
2520
2521 if (status == DBUS_DISPATCH_NEED_MEMORY)
2522 {
2523 /* Try sleeping a bit, as we aren't sure we need to block for reading,
2524 * we may already have a reply in the buffer and just can't process
2525 * it.
2526 */
2527 _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n");
2528
2529 _dbus_memory_pause_based_on_timeout (remain_milliseconds);
2530 }
2531 else
2532 {
2533 /* block again, we don't have the reply buffered yet. */
2534 _dbus_connection_do_iteration_unlocked (connection,
2535 pending,
2536 DBUS_ITERATION_DO_READING |
2537 DBUS_ITERATION_BLOCK,
2538 remain_milliseconds);
2539 }
2540
2541 goto recheck_status;
2542 }
2543
2544 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %d milliseconds and got no reply\n",
2545 elapsed_milliseconds);
2546
2547 _dbus_assert (!_dbus_pending_call_get_completed_unlocked (pending));
2548
2549 /* unlock and call user code */
2550 complete_pending_call_and_unlock (connection, pending, NULL);
2551
2552 /* update user code on dispatch status */
2553 CONNECTION_LOCK (connection);
2554 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2555 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
2556 dbus_pending_call_unref (pending);
2557 }
2558
2559 /**
2560 * Return how many file descriptors are pending in the loader
2561 *
2562 * @param connection the connection
2563 */
2564 int
_dbus_connection_get_pending_fds_count(DBusConnection * connection)2565 _dbus_connection_get_pending_fds_count (DBusConnection *connection)
2566 {
2567 return _dbus_transport_get_pending_fds_count (connection->transport);
2568 }
2569
2570 /**
2571 * Register a function to be called whenever the number of pending file
2572 * descriptors in the loader change.
2573 *
2574 * @param connection the connection
2575 * @param callback the callback
2576 */
2577 void
_dbus_connection_set_pending_fds_function(DBusConnection * connection,DBusPendingFdsChangeFunction callback,void * data)2578 _dbus_connection_set_pending_fds_function (DBusConnection *connection,
2579 DBusPendingFdsChangeFunction callback,
2580 void *data)
2581 {
2582 _dbus_transport_set_pending_fds_function (connection->transport,
2583 callback, data);
2584 }
2585
2586 /** @} */
2587
2588 /**
2589 * @addtogroup DBusConnection
2590 *
2591 * @{
2592 */
2593
2594 /**
2595 * Gets a connection to a remote address. If a connection to the given
2596 * address already exists, returns the existing connection with its
2597 * reference count incremented. Otherwise, returns a new connection
2598 * and saves the new connection for possible re-use if a future call
2599 * to dbus_connection_open() asks to connect to the same server.
2600 *
2601 * Use dbus_connection_open_private() to get a dedicated connection
2602 * not shared with other callers of dbus_connection_open().
2603 *
2604 * If the open fails, the function returns #NULL, and provides a
2605 * reason for the failure in the error parameter. Pass #NULL for the
2606 * error parameter if you aren't interested in the reason for
2607 * failure.
2608 *
2609 * Because this connection is shared, no user of the connection
2610 * may call dbus_connection_close(). However, when you are done with the
2611 * connection you should call dbus_connection_unref().
2612 *
2613 * @note Prefer dbus_connection_open() to dbus_connection_open_private()
2614 * unless you have good reason; connections are expensive enough
2615 * that it's wasteful to create lots of connections to the same
2616 * server.
2617 *
2618 * @param address the address.
2619 * @param error address where an error can be returned.
2620 * @returns new connection, or #NULL on failure.
2621 */
2622 DBusConnection*
dbus_connection_open(const char * address,DBusError * error)2623 dbus_connection_open (const char *address,
2624 DBusError *error)
2625 {
2626 DBusConnection *connection;
2627
2628 _dbus_return_val_if_fail (address != NULL, NULL);
2629 _dbus_return_val_if_error_is_set (error, NULL);
2630
2631 connection = _dbus_connection_open_internal (address,
2632 TRUE,
2633 error);
2634
2635 return connection;
2636 }
2637
2638 /**
2639 * Opens a new, dedicated connection to a remote address. Unlike
2640 * dbus_connection_open(), always creates a new connection.
2641 * This connection will not be saved or recycled by libdbus.
2642 *
2643 * If the open fails, the function returns #NULL, and provides a
2644 * reason for the failure in the error parameter. Pass #NULL for the
2645 * error parameter if you aren't interested in the reason for
2646 * failure.
2647 *
2648 * When you are done with this connection, you must
2649 * dbus_connection_close() to disconnect it,
2650 * and dbus_connection_unref() to free the connection object.
2651 *
2652 * (The dbus_connection_close() can be skipped if the
2653 * connection is already known to be disconnected, for example
2654 * if you are inside a handler for the Disconnected signal.)
2655 *
2656 * @note Prefer dbus_connection_open() to dbus_connection_open_private()
2657 * unless you have good reason; connections are expensive enough
2658 * that it's wasteful to create lots of connections to the same
2659 * server.
2660 *
2661 * @param address the address.
2662 * @param error address where an error can be returned.
2663 * @returns new connection, or #NULL on failure.
2664 */
2665 DBusConnection*
dbus_connection_open_private(const char * address,DBusError * error)2666 dbus_connection_open_private (const char *address,
2667 DBusError *error)
2668 {
2669 DBusConnection *connection;
2670
2671 _dbus_return_val_if_fail (address != NULL, NULL);
2672 _dbus_return_val_if_error_is_set (error, NULL);
2673
2674 connection = _dbus_connection_open_internal (address,
2675 FALSE,
2676 error);
2677
2678 return connection;
2679 }
2680
2681 /**
2682 * Increments the reference count of a DBusConnection.
2683 *
2684 * @param connection the connection.
2685 * @returns the connection.
2686 */
2687 DBusConnection *
dbus_connection_ref(DBusConnection * connection)2688 dbus_connection_ref (DBusConnection *connection)
2689 {
2690 dbus_int32_t old_refcount;
2691
2692 _dbus_return_val_if_fail (connection != NULL, NULL);
2693 _dbus_return_val_if_fail (connection->generation == _dbus_current_generation, NULL);
2694 old_refcount = _dbus_atomic_inc (&connection->refcount);
2695 _dbus_connection_trace_ref (connection, old_refcount, old_refcount + 1,
2696 "ref");
2697
2698 return connection;
2699 }
2700
2701 static void
free_outgoing_message(void * element,void * data)2702 free_outgoing_message (void *element,
2703 void *data)
2704 {
2705 DBusMessage *message = element;
2706 DBusConnection *connection = data;
2707
2708 _dbus_message_remove_counter (message, connection->outgoing_counter);
2709 dbus_message_unref (message);
2710 }
2711
2712 /* This is run without the mutex held, but after the last reference
2713 * to the connection has been dropped we should have no thread-related
2714 * problems
2715 */
2716 static void
_dbus_connection_last_unref(DBusConnection * connection)2717 _dbus_connection_last_unref (DBusConnection *connection)
2718 {
2719 DBusList *link;
2720
2721 _dbus_verbose ("Finalizing connection %p\n", connection);
2722
2723 _dbus_assert (_dbus_atomic_get (&connection->refcount) == 0);
2724
2725 /* You have to disconnect the connection before unref:ing it. Otherwise
2726 * you won't get the disconnected message.
2727 */
2728 _dbus_assert (!_dbus_transport_get_is_connected (connection->transport));
2729 _dbus_assert (connection->server_guid == NULL);
2730
2731 /* ---- We're going to call various application callbacks here, hope it doesn't break anything... */
2732 _dbus_object_tree_free_all_unlocked (connection->objects);
2733
2734 dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL);
2735 dbus_connection_set_wakeup_main_function (connection, NULL, NULL, NULL);
2736 dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL);
2737 dbus_connection_set_windows_user_function (connection, NULL, NULL, NULL);
2738
2739 _dbus_watch_list_free (connection->watches);
2740 connection->watches = NULL;
2741
2742 _dbus_timeout_list_free (connection->timeouts);
2743 connection->timeouts = NULL;
2744
2745 _dbus_data_slot_list_free (&connection->slot_list);
2746
2747 link = _dbus_list_get_first_link (&connection->filter_list);
2748 while (link != NULL)
2749 {
2750 DBusMessageFilter *filter = link->data;
2751 DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link);
2752
2753 filter->function = NULL;
2754 _dbus_message_filter_unref (filter); /* calls app callback */
2755 link->data = NULL;
2756
2757 link = next;
2758 }
2759 _dbus_list_clear (&connection->filter_list);
2760
2761 /* ---- Done with stuff that invokes application callbacks */
2762
2763 _dbus_object_tree_unref (connection->objects);
2764
2765 _dbus_hash_table_unref (connection->pending_replies);
2766 connection->pending_replies = NULL;
2767
2768 _dbus_list_foreach (&connection->outgoing_messages,
2769 free_outgoing_message,
2770 connection);
2771 _dbus_list_clear (&connection->outgoing_messages);
2772
2773 _dbus_list_foreach (&connection->incoming_messages,
2774 (DBusForeachFunction) dbus_message_unref,
2775 NULL);
2776 _dbus_list_clear (&connection->incoming_messages);
2777
2778 _dbus_counter_unref (connection->outgoing_counter);
2779
2780 _dbus_transport_unref (connection->transport);
2781
2782 if (connection->disconnect_message_link)
2783 {
2784 DBusMessage *message = connection->disconnect_message_link->data;
2785 dbus_message_unref (message);
2786 _dbus_list_free_link (connection->disconnect_message_link);
2787 }
2788
2789 _dbus_condvar_free_at_location (&connection->dispatch_cond);
2790 _dbus_condvar_free_at_location (&connection->io_path_cond);
2791
2792 _dbus_cmutex_free_at_location (&connection->io_path_mutex);
2793 _dbus_cmutex_free_at_location (&connection->dispatch_mutex);
2794
2795 _dbus_rmutex_free_at_location (&connection->slot_mutex);
2796
2797 _dbus_rmutex_free_at_location (&connection->mutex);
2798
2799 dbus_free (connection);
2800 }
2801
2802 /**
2803 * Decrements the reference count of a DBusConnection, and finalizes
2804 * it if the count reaches zero.
2805 *
2806 * Note: it is a bug to drop the last reference to a connection that
2807 * is still connected.
2808 *
2809 * For shared connections, libdbus will own a reference
2810 * as long as the connection is connected, so you can know that either
2811 * you don't have the last reference, or it's OK to drop the last reference.
2812 * Most connections are shared. dbus_connection_open() and dbus_bus_get()
2813 * return shared connections.
2814 *
2815 * For private connections, the creator of the connection must arrange for
2816 * dbus_connection_close() to be called prior to dropping the last reference.
2817 * Private connections come from dbus_connection_open_private() or dbus_bus_get_private().
2818 *
2819 * @param connection the connection.
2820 */
2821 void
dbus_connection_unref(DBusConnection * connection)2822 dbus_connection_unref (DBusConnection *connection)
2823 {
2824 dbus_int32_t old_refcount;
2825
2826 _dbus_return_if_fail (connection != NULL);
2827 _dbus_return_if_fail (connection->generation == _dbus_current_generation);
2828
2829 old_refcount = _dbus_atomic_dec (&connection->refcount);
2830
2831 _dbus_connection_trace_ref (connection, old_refcount, old_refcount - 1,
2832 "unref");
2833
2834 if (old_refcount == 1)
2835 {
2836 #ifndef DBUS_DISABLE_CHECKS
2837 if (_dbus_transport_get_is_connected (connection->transport))
2838 {
2839 _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",
2840 connection->shareable ?
2841 "Most likely, the application called unref() too many times and removed a reference belonging to libdbus, since this is a shared connection." :
2842 "Most likely, the application was supposed to call dbus_connection_close(), since this is a private connection.");
2843 return;
2844 }
2845 #endif
2846 _dbus_connection_last_unref (connection);
2847 }
2848 }
2849
2850 /*
2851 * Note that the transport can disconnect itself (other end drops us)
2852 * and in that case this function never runs. So this function must
2853 * not do anything more than disconnect the transport and update the
2854 * dispatch status.
2855 *
2856 * If the transport self-disconnects, then we assume someone will
2857 * dispatch the connection to cause the dispatch status update.
2858 */
2859 static void
_dbus_connection_close_possibly_shared_and_unlock(DBusConnection * connection)2860 _dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection)
2861 {
2862 DBusDispatchStatus status;
2863
2864 HAVE_LOCK_CHECK (connection);
2865
2866 _dbus_verbose ("Disconnecting %p\n", connection);
2867
2868 /* We need to ref because update_dispatch_status_and_unlock will unref
2869 * the connection if it was shared and libdbus was the only remaining
2870 * refcount holder.
2871 */
2872 _dbus_connection_ref_unlocked (connection);
2873
2874 _dbus_transport_disconnect (connection->transport);
2875
2876 /* This has the side effect of queuing the disconnect message link
2877 * (unless we don't have enough memory, possibly, so don't assert it).
2878 * After the disconnect message link is queued, dbus_bus_get/dbus_connection_open
2879 * should never again return the newly-disconnected connection.
2880 *
2881 * However, we only unref the shared connection and exit_on_disconnect when
2882 * the disconnect message reaches the head of the message queue,
2883 * NOT when it's first queued.
2884 */
2885 status = _dbus_connection_get_dispatch_status_unlocked (connection);
2886
2887 /* This calls out to user code */
2888 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
2889
2890 /* Could also call out to user code */
2891 dbus_connection_unref (connection);
2892 }
2893
2894 /**
2895 * Closes a private connection, so no further data can be sent or received.
2896 * This disconnects the transport (such as a socket) underlying the
2897 * connection.
2898 *
2899 * Attempts to send messages after closing a connection are safe, but will result in
2900 * error replies generated locally in libdbus.
2901 *
2902 * This function does not affect the connection's reference count. It's
2903 * safe to close a connection more than once; all calls after the
2904 * first do nothing. It's impossible to "reopen" a connection, a
2905 * new connection must be created. This function may result in a call
2906 * to the DBusDispatchStatusFunction set with
2907 * dbus_connection_set_dispatch_status_function(), as the disconnect
2908 * message it generates needs to be dispatched.
2909 *
2910 * If a connection is dropped by the remote application, it will
2911 * close itself.
2912 *
2913 * You must close a connection prior to releasing the last reference to
2914 * the connection. If you dbus_connection_unref() for the last time
2915 * without closing the connection, the results are undefined; it
2916 * is a bug in your program and libdbus will try to print a warning.
2917 *
2918 * You may not close a shared connection. Connections created with
2919 * dbus_connection_open() or dbus_bus_get() are shared.
2920 * These connections are owned by libdbus, and applications should
2921 * only unref them, never close them. Applications can know it is
2922 * safe to unref these connections because libdbus will be holding a
2923 * reference as long as the connection is open. Thus, either the
2924 * connection is closed and it is OK to drop the last reference,
2925 * or the connection is open and the app knows it does not have the
2926 * last reference.
2927 *
2928 * Connections created with dbus_connection_open_private() or
2929 * dbus_bus_get_private() are not kept track of or referenced by
2930 * libdbus. The creator of these connections is responsible for
2931 * calling dbus_connection_close() prior to releasing the last
2932 * reference, if the connection is not already disconnected.
2933 *
2934 * @param connection the private (unshared) connection to close
2935 */
2936 void
dbus_connection_close(DBusConnection * connection)2937 dbus_connection_close (DBusConnection *connection)
2938 {
2939 _dbus_return_if_fail (connection != NULL);
2940 _dbus_return_if_fail (connection->generation == _dbus_current_generation);
2941
2942 CONNECTION_LOCK (connection);
2943
2944 #ifndef DBUS_DISABLE_CHECKS
2945 if (connection->shareable)
2946 {
2947 CONNECTION_UNLOCK (connection);
2948
2949 _dbus_warn_check_failed ("Applications must not close shared connections - see dbus_connection_close() docs. This is a bug in the application.");
2950 return;
2951 }
2952 #endif
2953
2954 _dbus_connection_close_possibly_shared_and_unlock (connection);
2955 }
2956
2957 static dbus_bool_t
_dbus_connection_get_is_connected_unlocked(DBusConnection * connection)2958 _dbus_connection_get_is_connected_unlocked (DBusConnection *connection)
2959 {
2960 HAVE_LOCK_CHECK (connection);
2961 return _dbus_transport_get_is_connected (connection->transport);
2962 }
2963
2964 /**
2965 * Gets whether the connection is currently open. A connection may
2966 * become disconnected when the remote application closes its end, or
2967 * exits; a connection may also be disconnected with
2968 * dbus_connection_close().
2969 *
2970 * There are not separate states for "closed" and "disconnected," the two
2971 * terms are synonymous. This function should really be called
2972 * get_is_open() but for historical reasons is not.
2973 *
2974 * @param connection the connection.
2975 * @returns #TRUE if the connection is still alive.
2976 */
2977 dbus_bool_t
dbus_connection_get_is_connected(DBusConnection * connection)2978 dbus_connection_get_is_connected (DBusConnection *connection)
2979 {
2980 dbus_bool_t res;
2981
2982 _dbus_return_val_if_fail (connection != NULL, FALSE);
2983
2984 CONNECTION_LOCK (connection);
2985 res = _dbus_connection_get_is_connected_unlocked (connection);
2986 CONNECTION_UNLOCK (connection);
2987
2988 return res;
2989 }
2990
2991 /**
2992 * Gets whether the connection was authenticated. (Note that
2993 * if the connection was authenticated then disconnected,
2994 * this function still returns #TRUE)
2995 *
2996 * @param connection the connection
2997 * @returns #TRUE if the connection was ever authenticated
2998 */
2999 dbus_bool_t
dbus_connection_get_is_authenticated(DBusConnection * connection)3000 dbus_connection_get_is_authenticated (DBusConnection *connection)
3001 {
3002 dbus_bool_t res;
3003
3004 _dbus_return_val_if_fail (connection != NULL, FALSE);
3005
3006 CONNECTION_LOCK (connection);
3007 res = _dbus_transport_try_to_authenticate (connection->transport);
3008 CONNECTION_UNLOCK (connection);
3009
3010 return res;
3011 }
3012
3013 /**
3014 * Gets whether the connection is not authenticated as a specific
3015 * user. If the connection is not authenticated, this function
3016 * returns #TRUE, and if it is authenticated but as an anonymous user,
3017 * it returns #TRUE. If it is authenticated as a specific user, then
3018 * this returns #FALSE. (Note that if the connection was authenticated
3019 * as anonymous then disconnected, this function still returns #TRUE.)
3020 *
3021 * If the connection is not anonymous, you can use
3022 * dbus_connection_get_unix_user() and
3023 * dbus_connection_get_windows_user() to see who it's authorized as.
3024 *
3025 * If you want to prevent non-anonymous authorization, use
3026 * dbus_server_set_auth_mechanisms() to remove the mechanisms that
3027 * allow proving user identity (i.e. only allow the ANONYMOUS
3028 * mechanism).
3029 *
3030 * @param connection the connection
3031 * @returns #TRUE if not authenticated or authenticated as anonymous
3032 */
3033 dbus_bool_t
dbus_connection_get_is_anonymous(DBusConnection * connection)3034 dbus_connection_get_is_anonymous (DBusConnection *connection)
3035 {
3036 dbus_bool_t res;
3037
3038 _dbus_return_val_if_fail (connection != NULL, FALSE);
3039
3040 CONNECTION_LOCK (connection);
3041 res = _dbus_transport_get_is_anonymous (connection->transport);
3042 CONNECTION_UNLOCK (connection);
3043
3044 return res;
3045 }
3046
3047 /**
3048 * Gets the ID of the server address we are authenticated to, if this
3049 * connection is on the client side. If the connection is on the
3050 * server side, this will always return #NULL - use dbus_server_get_id()
3051 * to get the ID of your own server, if you are the server side.
3052 *
3053 * If a client-side connection is not authenticated yet, the ID may be
3054 * available if it was included in the server address, but may not be
3055 * available. The only way to be sure the server ID is available
3056 * is to wait for authentication to complete.
3057 *
3058 * In general, each mode of connecting to a given server will have
3059 * its own ID. So for example, if the session bus daemon is listening
3060 * on UNIX domain sockets and on TCP, then each of those modalities
3061 * will have its own server ID.
3062 *
3063 * If you want an ID that identifies an entire session bus, look at
3064 * dbus_bus_get_id() instead (which is just a convenience wrapper
3065 * around the org.freedesktop.DBus.GetId method invoked on the bus).
3066 *
3067 * You can also get a machine ID; see dbus_try_get_local_machine_id() to
3068 * get the machine you are on. There isn't a convenience wrapper, but
3069 * you can invoke org.freedesktop.DBus.Peer.GetMachineId on any peer
3070 * to get the machine ID on the other end.
3071 *
3072 * The D-Bus specification describes the server ID and other IDs in a
3073 * bit more detail.
3074 *
3075 * @param connection the connection
3076 * @returns the server ID or #NULL if no memory or the connection is server-side
3077 */
3078 char*
dbus_connection_get_server_id(DBusConnection * connection)3079 dbus_connection_get_server_id (DBusConnection *connection)
3080 {
3081 char *id;
3082
3083 _dbus_return_val_if_fail (connection != NULL, NULL);
3084
3085 CONNECTION_LOCK (connection);
3086 id = _dbus_strdup (_dbus_transport_get_server_id (connection->transport));
3087 CONNECTION_UNLOCK (connection);
3088
3089 return id;
3090 }
3091
3092 /**
3093 * Tests whether a certain type can be send via the connection. This
3094 * will always return TRUE for all types, with the exception of
3095 * DBUS_TYPE_UNIX_FD. The function will return TRUE for
3096 * DBUS_TYPE_UNIX_FD only on systems that know Unix file descriptors
3097 * and can send them via the chosen transport and when the remote side
3098 * supports this.
3099 *
3100 * This function can be used to do runtime checking for types that
3101 * might be unknown to the specific D-Bus client implementation
3102 * version, i.e. it will return FALSE for all types this
3103 * implementation does not know, including invalid or reserved types.
3104 *
3105 * @param connection the connection
3106 * @param type the type to check
3107 * @returns TRUE if the type may be send via the connection
3108 */
3109 dbus_bool_t
dbus_connection_can_send_type(DBusConnection * connection,int type)3110 dbus_connection_can_send_type(DBusConnection *connection,
3111 int type)
3112 {
3113 _dbus_return_val_if_fail (connection != NULL, FALSE);
3114
3115 if (!dbus_type_is_valid (type))
3116 return FALSE;
3117
3118 if (type != DBUS_TYPE_UNIX_FD)
3119 return TRUE;
3120
3121 #ifdef HAVE_UNIX_FD_PASSING
3122 {
3123 dbus_bool_t b;
3124
3125 CONNECTION_LOCK(connection);
3126 b = _dbus_transport_can_pass_unix_fd(connection->transport);
3127 CONNECTION_UNLOCK(connection);
3128
3129 return b;
3130 }
3131 #endif
3132
3133 return FALSE;
3134 }
3135
3136 /**
3137 * Set whether _exit() should be called when the connection receives a
3138 * disconnect signal. The call to _exit() comes after any handlers for
3139 * the disconnect signal run; handlers can cancel the exit by calling
3140 * this function.
3141 *
3142 * By default, exit_on_disconnect is #FALSE; but for message bus
3143 * connections returned from dbus_bus_get() it will be toggled on
3144 * by default.
3145 *
3146 * @param connection the connection
3147 * @param exit_on_disconnect #TRUE if _exit() should be called after a disconnect signal
3148 */
3149 void
dbus_connection_set_exit_on_disconnect(DBusConnection * connection,dbus_bool_t exit_on_disconnect)3150 dbus_connection_set_exit_on_disconnect (DBusConnection *connection,
3151 dbus_bool_t exit_on_disconnect)
3152 {
3153 _dbus_return_if_fail (connection != NULL);
3154
3155 CONNECTION_LOCK (connection);
3156 connection->exit_on_disconnect = exit_on_disconnect != FALSE;
3157 CONNECTION_UNLOCK (connection);
3158 }
3159
3160 /**
3161 * Preallocates resources needed to send a message, allowing the message
3162 * to be sent without the possibility of memory allocation failure.
3163 * Allows apps to create a future guarantee that they can send
3164 * a message regardless of memory shortages.
3165 *
3166 * @param connection the connection we're preallocating for.
3167 * @returns the preallocated resources, or #NULL
3168 */
3169 DBusPreallocatedSend*
dbus_connection_preallocate_send(DBusConnection * connection)3170 dbus_connection_preallocate_send (DBusConnection *connection)
3171 {
3172 DBusPreallocatedSend *preallocated;
3173
3174 _dbus_return_val_if_fail (connection != NULL, NULL);
3175
3176 CONNECTION_LOCK (connection);
3177
3178 preallocated =
3179 _dbus_connection_preallocate_send_unlocked (connection);
3180
3181 CONNECTION_UNLOCK (connection);
3182
3183 return preallocated;
3184 }
3185
3186 /**
3187 * Frees preallocated message-sending resources from
3188 * dbus_connection_preallocate_send(). Should only
3189 * be called if the preallocated resources are not used
3190 * to send a message.
3191 *
3192 * @param connection the connection
3193 * @param preallocated the resources
3194 */
3195 void
dbus_connection_free_preallocated_send(DBusConnection * connection,DBusPreallocatedSend * preallocated)3196 dbus_connection_free_preallocated_send (DBusConnection *connection,
3197 DBusPreallocatedSend *preallocated)
3198 {
3199 _dbus_return_if_fail (connection != NULL);
3200 _dbus_return_if_fail (preallocated != NULL);
3201 _dbus_return_if_fail (connection == preallocated->connection);
3202
3203 _dbus_list_free_link (preallocated->queue_link);
3204 _dbus_counter_unref (preallocated->counter_link->data);
3205 _dbus_list_free_link (preallocated->counter_link);
3206 dbus_free (preallocated);
3207 }
3208
3209 /**
3210 * Sends a message using preallocated resources. This function cannot fail.
3211 * It works identically to dbus_connection_send() in other respects.
3212 * Preallocated resources comes from dbus_connection_preallocate_send().
3213 * This function "consumes" the preallocated resources, they need not
3214 * be freed separately.
3215 *
3216 * @param connection the connection
3217 * @param preallocated the preallocated resources
3218 * @param message the message to send
3219 * @param client_serial return location for client serial assigned to the message
3220 */
3221 void
dbus_connection_send_preallocated(DBusConnection * connection,DBusPreallocatedSend * preallocated,DBusMessage * message,dbus_uint32_t * client_serial)3222 dbus_connection_send_preallocated (DBusConnection *connection,
3223 DBusPreallocatedSend *preallocated,
3224 DBusMessage *message,
3225 dbus_uint32_t *client_serial)
3226 {
3227 _dbus_return_if_fail (connection != NULL);
3228 _dbus_return_if_fail (preallocated != NULL);
3229 _dbus_return_if_fail (message != NULL);
3230 _dbus_return_if_fail (preallocated->connection == connection);
3231 _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_METHOD_CALL ||
3232 dbus_message_get_member (message) != NULL);
3233 _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_SIGNAL ||
3234 (dbus_message_get_interface (message) != NULL &&
3235 dbus_message_get_member (message) != NULL));
3236
3237 CONNECTION_LOCK (connection);
3238
3239 #ifdef HAVE_UNIX_FD_PASSING
3240
3241 if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
3242 message->n_unix_fds > 0)
3243 {
3244 /* Refuse to send fds on a connection that cannot handle
3245 them. Unfortunately we cannot return a proper error here, so
3246 the best we can is just return. */
3247 CONNECTION_UNLOCK (connection);
3248 return;
3249 }
3250
3251 #endif
3252
3253 _dbus_connection_send_preallocated_and_unlock (connection,
3254 preallocated,
3255 message, client_serial);
3256 }
3257
3258 static dbus_bool_t
_dbus_connection_send_unlocked_no_update(DBusConnection * connection,DBusMessage * message,dbus_uint32_t * client_serial)3259 _dbus_connection_send_unlocked_no_update (DBusConnection *connection,
3260 DBusMessage *message,
3261 dbus_uint32_t *client_serial)
3262 {
3263 DBusPreallocatedSend *preallocated;
3264
3265 _dbus_assert (connection != NULL);
3266 _dbus_assert (message != NULL);
3267
3268 preallocated = _dbus_connection_preallocate_send_unlocked (connection);
3269 if (preallocated == NULL)
3270 return FALSE;
3271
3272 _dbus_connection_send_preallocated_unlocked_no_update (connection,
3273 preallocated,
3274 message,
3275 client_serial);
3276 return TRUE;
3277 }
3278
3279 /**
3280 * Adds a message to the outgoing message queue. Does not block to
3281 * write the message to the network; that happens asynchronously. To
3282 * force the message to be written, call dbus_connection_flush() however
3283 * it is not necessary to call dbus_connection_flush() by hand; the
3284 * message will be sent the next time the main loop is run.
3285 * dbus_connection_flush() should only be used, for example, if
3286 * the application was expected to exit before running the main loop.
3287 *
3288 * Because this only queues the message, the only reason it can
3289 * fail is lack of memory. Even if the connection is disconnected,
3290 * no error will be returned. If the function fails due to lack of memory,
3291 * it returns #FALSE. The function will never fail for other reasons; even
3292 * if the connection is disconnected, you can queue an outgoing message,
3293 * though obviously it won't be sent.
3294 *
3295 * The message serial is used by the remote application to send a
3296 * reply; see dbus_message_get_serial() or the D-Bus specification.
3297 *
3298 * dbus_message_unref() can be called as soon as this method returns
3299 * as the message queue will hold its own ref until the message is sent.
3300 *
3301 * @param connection the connection.
3302 * @param message the message to write.
3303 * @param serial return location for message serial, or #NULL if you don't care
3304 * @returns #TRUE on success.
3305 */
3306 dbus_bool_t
dbus_connection_send(DBusConnection * connection,DBusMessage * message,dbus_uint32_t * serial)3307 dbus_connection_send (DBusConnection *connection,
3308 DBusMessage *message,
3309 dbus_uint32_t *serial)
3310 {
3311 _dbus_return_val_if_fail (connection != NULL, FALSE);
3312 _dbus_return_val_if_fail (message != NULL, FALSE);
3313
3314 CONNECTION_LOCK (connection);
3315
3316 #ifdef HAVE_UNIX_FD_PASSING
3317
3318 if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
3319 message->n_unix_fds > 0)
3320 {
3321 /* Refuse to send fds on a connection that cannot handle
3322 them. Unfortunately we cannot return a proper error here, so
3323 the best we can is just return. */
3324 CONNECTION_UNLOCK (connection);
3325 return FALSE;
3326 }
3327
3328 #endif
3329
3330 return _dbus_connection_send_and_unlock (connection,
3331 message,
3332 serial);
3333 }
3334
3335 static dbus_bool_t
reply_handler_timeout(void * data)3336 reply_handler_timeout (void *data)
3337 {
3338 DBusConnection *connection;
3339 DBusDispatchStatus status;
3340 DBusPendingCall *pending = data;
3341
3342 connection = _dbus_pending_call_get_connection_and_lock (pending);
3343 _dbus_connection_ref_unlocked (connection);
3344
3345 _dbus_pending_call_queue_timeout_error_unlocked (pending,
3346 connection);
3347 _dbus_connection_remove_timeout_unlocked (connection,
3348 _dbus_pending_call_get_timeout_unlocked (pending));
3349 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE);
3350
3351 _dbus_verbose ("middle\n");
3352 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3353
3354 /* Unlocks, and calls out to user code */
3355 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3356 dbus_connection_unref (connection);
3357
3358 return TRUE;
3359 }
3360
3361 /**
3362 * Queues a message to send, as with dbus_connection_send(),
3363 * but also returns a #DBusPendingCall used to receive a reply to the
3364 * message. If no reply is received in the given timeout_milliseconds,
3365 * this function expires the pending reply and generates a synthetic
3366 * error reply (generated in-process, not by the remote application)
3367 * indicating that a timeout occurred.
3368 *
3369 * A #DBusPendingCall will see a reply message before any filters or
3370 * registered object path handlers. See dbus_connection_dispatch() for
3371 * details on when handlers are run.
3372 *
3373 * A #DBusPendingCall will always see exactly one reply message,
3374 * unless it's cancelled with dbus_pending_call_cancel().
3375 *
3376 * If #NULL is passed for the pending_return, the #DBusPendingCall
3377 * will still be generated internally, and used to track
3378 * the message reply timeout. This means a timeout error will
3379 * occur if no reply arrives, unlike with dbus_connection_send().
3380 *
3381 * If -1 is passed for the timeout, a sane default timeout is used. -1
3382 * is typically the best value for the timeout for this reason, unless
3383 * you want a very short or very long timeout. If #DBUS_TIMEOUT_INFINITE is
3384 * passed for the timeout, no timeout will be set and the call will block
3385 * forever.
3386 *
3387 * @warning if the connection is disconnected or you try to send Unix
3388 * file descriptors on a connection that does not support them, the
3389 * #DBusPendingCall will be set to #NULL, so be careful with this.
3390 *
3391 * @param connection the connection
3392 * @param message the message to send
3393 * @param pending_return return location for a #DBusPendingCall
3394 * object, or #NULL if connection is disconnected or when you try to
3395 * send Unix file descriptors on a connection that does not support
3396 * them.
3397 * @param timeout_milliseconds timeout in milliseconds, -1 (or
3398 * #DBUS_TIMEOUT_USE_DEFAULT) for default or #DBUS_TIMEOUT_INFINITE for no
3399 * timeout
3400 * @returns #FALSE if no memory, #TRUE otherwise.
3401 *
3402 */
3403 dbus_bool_t
dbus_connection_send_with_reply(DBusConnection * connection,DBusMessage * message,DBusPendingCall ** pending_return,int timeout_milliseconds)3404 dbus_connection_send_with_reply (DBusConnection *connection,
3405 DBusMessage *message,
3406 DBusPendingCall **pending_return,
3407 int timeout_milliseconds)
3408 {
3409 DBusPendingCall *pending;
3410 dbus_int32_t serial = -1;
3411 DBusDispatchStatus status;
3412
3413 _dbus_return_val_if_fail (connection != NULL, FALSE);
3414 _dbus_return_val_if_fail (message != NULL, FALSE);
3415 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
3416
3417 if (pending_return)
3418 *pending_return = NULL;
3419
3420 CONNECTION_LOCK (connection);
3421
3422 #ifdef HAVE_UNIX_FD_PASSING
3423
3424 if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
3425 message->n_unix_fds > 0)
3426 {
3427 /* Refuse to send fds on a connection that cannot handle
3428 them. Unfortunately we cannot return a proper error here, so
3429 the best we can do is return TRUE but leave *pending_return
3430 as NULL. */
3431 CONNECTION_UNLOCK (connection);
3432 return TRUE;
3433 }
3434
3435 #endif
3436
3437 if (!_dbus_connection_get_is_connected_unlocked (connection))
3438 {
3439 CONNECTION_UNLOCK (connection);
3440
3441 return TRUE;
3442 }
3443
3444 pending = _dbus_pending_call_new_unlocked (connection,
3445 timeout_milliseconds,
3446 reply_handler_timeout);
3447
3448 if (pending == NULL)
3449 {
3450 CONNECTION_UNLOCK (connection);
3451 return FALSE;
3452 }
3453
3454 /* Assign a serial to the message */
3455 serial = dbus_message_get_serial (message);
3456 if (serial == 0)
3457 {
3458 serial = _dbus_connection_get_next_client_serial (connection);
3459 dbus_message_set_serial (message, serial);
3460 }
3461
3462 if (!_dbus_pending_call_set_timeout_error_unlocked (pending, message, serial))
3463 goto error;
3464
3465 /* Insert the serial in the pending replies hash;
3466 * hash takes a refcount on DBusPendingCall.
3467 * Also, add the timeout.
3468 */
3469 if (!_dbus_connection_attach_pending_call_unlocked (connection,
3470 pending))
3471 goto error;
3472
3473 if (!_dbus_connection_send_unlocked_no_update (connection, message, NULL))
3474 {
3475 _dbus_connection_detach_pending_call_and_unlock (connection,
3476 pending);
3477 goto error_unlocked;
3478 }
3479
3480 if (pending_return)
3481 *pending_return = pending; /* hand off refcount */
3482 else
3483 {
3484 _dbus_connection_detach_pending_call_unlocked (connection, pending);
3485 /* we still have a ref to the pending call in this case, we unref
3486 * after unlocking, below
3487 */
3488 }
3489
3490 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3491
3492 /* this calls out to user code */
3493 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3494
3495 if (pending_return == NULL)
3496 dbus_pending_call_unref (pending);
3497
3498 return TRUE;
3499
3500 error:
3501 CONNECTION_UNLOCK (connection);
3502 error_unlocked:
3503 dbus_pending_call_unref (pending);
3504 return FALSE;
3505 }
3506
3507 /**
3508 * Sends a message and blocks a certain time period while waiting for
3509 * a reply. This function does not reenter the main loop,
3510 * i.e. messages other than the reply are queued up but not
3511 * processed. This function is used to invoke method calls on a
3512 * remote object.
3513 *
3514 * If a normal reply is received, it is returned, and removed from the
3515 * incoming message queue. If it is not received, #NULL is returned
3516 * and the error is set to #DBUS_ERROR_NO_REPLY. If an error reply is
3517 * received, it is converted to a #DBusError and returned as an error,
3518 * then the reply message is deleted and #NULL is returned. If
3519 * something else goes wrong, result is set to whatever is
3520 * appropriate, such as #DBUS_ERROR_NO_MEMORY or
3521 * #DBUS_ERROR_DISCONNECTED.
3522 *
3523 * @warning While this function blocks the calling thread will not be
3524 * processing the incoming message queue. This means you can end up
3525 * deadlocked if the application you're talking to needs you to reply
3526 * to a method. To solve this, either avoid the situation, block in a
3527 * separate thread from the main connection-dispatching thread, or use
3528 * dbus_pending_call_set_notify() to avoid blocking.
3529 *
3530 * @param connection the connection
3531 * @param message the message to send
3532 * @param timeout_milliseconds timeout in milliseconds, -1 (or
3533 * #DBUS_TIMEOUT_USE_DEFAULT) for default or #DBUS_TIMEOUT_INFINITE for no
3534 * timeout
3535 * @param error return location for error message
3536 * @returns the message that is the reply or #NULL with an error code if the
3537 * function fails.
3538 */
3539 DBusMessage*
dbus_connection_send_with_reply_and_block(DBusConnection * connection,DBusMessage * message,int timeout_milliseconds,DBusError * error)3540 dbus_connection_send_with_reply_and_block (DBusConnection *connection,
3541 DBusMessage *message,
3542 int timeout_milliseconds,
3543 DBusError *error)
3544 {
3545 DBusMessage *reply;
3546 DBusPendingCall *pending;
3547
3548 _dbus_return_val_if_fail (connection != NULL, NULL);
3549 _dbus_return_val_if_fail (message != NULL, NULL);
3550 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, NULL);
3551 _dbus_return_val_if_error_is_set (error, NULL);
3552
3553 #ifdef HAVE_UNIX_FD_PASSING
3554
3555 CONNECTION_LOCK (connection);
3556 if (!_dbus_transport_can_pass_unix_fd(connection->transport) &&
3557 message->n_unix_fds > 0)
3558 {
3559 CONNECTION_UNLOCK (connection);
3560 dbus_set_error(error, DBUS_ERROR_FAILED, "Cannot send file descriptors on this connection.");
3561 return NULL;
3562 }
3563 CONNECTION_UNLOCK (connection);
3564
3565 #endif
3566
3567 if (!dbus_connection_send_with_reply (connection, message,
3568 &pending, timeout_milliseconds))
3569 {
3570 _DBUS_SET_OOM (error);
3571 return NULL;
3572 }
3573
3574 if (pending == NULL)
3575 {
3576 dbus_set_error (error, DBUS_ERROR_DISCONNECTED, "Connection is closed");
3577 return NULL;
3578 }
3579
3580 dbus_pending_call_block (pending);
3581
3582 reply = dbus_pending_call_steal_reply (pending);
3583 dbus_pending_call_unref (pending);
3584
3585 /* call_complete_and_unlock() called from pending_call_block() should
3586 * always fill this in.
3587 */
3588 _dbus_assert (reply != NULL);
3589
3590 if (dbus_set_error_from_message (error, reply))
3591 {
3592 dbus_message_unref (reply);
3593 return NULL;
3594 }
3595 else
3596 return reply;
3597 }
3598
3599 /**
3600 * Blocks until the outgoing message queue is empty.
3601 * Assumes connection lock already held.
3602 *
3603 * If you call this, you MUST call update_dispatch_status afterword...
3604 *
3605 * @param connection the connection.
3606 */
3607 static DBusDispatchStatus
_dbus_connection_flush_unlocked(DBusConnection * connection)3608 _dbus_connection_flush_unlocked (DBusConnection *connection)
3609 {
3610 /* We have to specify DBUS_ITERATION_DO_READING here because
3611 * otherwise we could have two apps deadlock if they are both doing
3612 * a flush(), and the kernel buffers fill up. This could change the
3613 * dispatch status.
3614 */
3615 DBusDispatchStatus status;
3616
3617 HAVE_LOCK_CHECK (connection);
3618
3619 while (connection->n_outgoing > 0 &&
3620 _dbus_connection_get_is_connected_unlocked (connection))
3621 {
3622 _dbus_verbose ("doing iteration in\n");
3623 HAVE_LOCK_CHECK (connection);
3624 _dbus_connection_do_iteration_unlocked (connection,
3625 NULL,
3626 DBUS_ITERATION_DO_READING |
3627 DBUS_ITERATION_DO_WRITING |
3628 DBUS_ITERATION_BLOCK,
3629 -1);
3630 }
3631
3632 HAVE_LOCK_CHECK (connection);
3633 _dbus_verbose ("middle\n");
3634 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3635
3636 HAVE_LOCK_CHECK (connection);
3637 return status;
3638 }
3639
3640 /**
3641 * Blocks until the outgoing message queue is empty.
3642 *
3643 * @param connection the connection.
3644 */
3645 void
dbus_connection_flush(DBusConnection * connection)3646 dbus_connection_flush (DBusConnection *connection)
3647 {
3648 /* We have to specify DBUS_ITERATION_DO_READING here because
3649 * otherwise we could have two apps deadlock if they are both doing
3650 * a flush(), and the kernel buffers fill up. This could change the
3651 * dispatch status.
3652 */
3653 DBusDispatchStatus status;
3654
3655 _dbus_return_if_fail (connection != NULL);
3656
3657 CONNECTION_LOCK (connection);
3658
3659 status = _dbus_connection_flush_unlocked (connection);
3660
3661 HAVE_LOCK_CHECK (connection);
3662 /* Unlocks and calls out to user code */
3663 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3664
3665 _dbus_verbose ("end\n");
3666 }
3667
3668 /**
3669 * This function implements dbus_connection_read_write_dispatch() and
3670 * dbus_connection_read_write() (they pass a different value for the
3671 * dispatch parameter).
3672 *
3673 * @param connection the connection
3674 * @param timeout_milliseconds max time to block or -1 for infinite
3675 * @param dispatch dispatch new messages or leave them on the incoming queue
3676 * @returns #TRUE if the disconnect message has not been processed
3677 */
3678 static dbus_bool_t
_dbus_connection_read_write_dispatch(DBusConnection * connection,int timeout_milliseconds,dbus_bool_t dispatch)3679 _dbus_connection_read_write_dispatch (DBusConnection *connection,
3680 int timeout_milliseconds,
3681 dbus_bool_t dispatch)
3682 {
3683 DBusDispatchStatus dstatus;
3684 dbus_bool_t progress_possible;
3685
3686 /* Need to grab a ref here in case we're a private connection and
3687 * the user drops the last ref in a handler we call; see bug
3688 * https://bugs.freedesktop.org/show_bug.cgi?id=15635
3689 */
3690 dbus_connection_ref (connection);
3691 dstatus = dbus_connection_get_dispatch_status (connection);
3692
3693 if (dispatch && dstatus == DBUS_DISPATCH_DATA_REMAINS)
3694 {
3695 _dbus_verbose ("doing dispatch\n");
3696 dbus_connection_dispatch (connection);
3697 CONNECTION_LOCK (connection);
3698 }
3699 else if (dstatus == DBUS_DISPATCH_NEED_MEMORY)
3700 {
3701 _dbus_verbose ("pausing for memory\n");
3702 _dbus_memory_pause_based_on_timeout (timeout_milliseconds);
3703 CONNECTION_LOCK (connection);
3704 }
3705 else
3706 {
3707 CONNECTION_LOCK (connection);
3708 if (_dbus_connection_get_is_connected_unlocked (connection))
3709 {
3710 _dbus_verbose ("doing iteration\n");
3711 _dbus_connection_do_iteration_unlocked (connection,
3712 NULL,
3713 DBUS_ITERATION_DO_READING |
3714 DBUS_ITERATION_DO_WRITING |
3715 DBUS_ITERATION_BLOCK,
3716 timeout_milliseconds);
3717 }
3718 }
3719
3720 HAVE_LOCK_CHECK (connection);
3721 /* If we can dispatch, we can make progress until the Disconnected message
3722 * has been processed; if we can only read/write, we can make progress
3723 * as long as the transport is open.
3724 */
3725 if (dispatch)
3726 progress_possible = connection->n_incoming != 0 ||
3727 connection->disconnect_message_link != NULL;
3728 else
3729 progress_possible = _dbus_connection_get_is_connected_unlocked (connection);
3730
3731 CONNECTION_UNLOCK (connection);
3732
3733 dbus_connection_unref (connection);
3734
3735 return progress_possible; /* TRUE if we can make more progress */
3736 }
3737
3738
3739 /**
3740 * This function is intended for use with applications that don't want
3741 * to write a main loop and deal with #DBusWatch and #DBusTimeout. An
3742 * example usage would be:
3743 *
3744 * @code
3745 * while (dbus_connection_read_write_dispatch (connection, -1))
3746 * ; // empty loop body
3747 * @endcode
3748 *
3749 * In this usage you would normally have set up a filter function to look
3750 * at each message as it is dispatched. The loop terminates when the last
3751 * message from the connection (the disconnected signal) is processed.
3752 *
3753 * If there are messages to dispatch, this function will
3754 * dbus_connection_dispatch() once, and return. If there are no
3755 * messages to dispatch, this function will block until it can read or
3756 * write, then read or write, then return.
3757 *
3758 * The way to think of this function is that it either makes some sort
3759 * of progress, or it blocks. Note that, while it is blocked on I/O, it
3760 * cannot be interrupted (even by other threads), which makes this function
3761 * unsuitable for applications that do more than just react to received
3762 * messages.
3763 *
3764 * The return value indicates whether the disconnect message has been
3765 * processed, NOT whether the connection is connected. This is
3766 * important because even after disconnecting, you want to process any
3767 * messages you received prior to the disconnect.
3768 *
3769 * @param connection the connection
3770 * @param timeout_milliseconds max time to block or -1 for infinite
3771 * @returns #TRUE if the disconnect message has not been processed
3772 */
3773 dbus_bool_t
dbus_connection_read_write_dispatch(DBusConnection * connection,int timeout_milliseconds)3774 dbus_connection_read_write_dispatch (DBusConnection *connection,
3775 int timeout_milliseconds)
3776 {
3777 _dbus_return_val_if_fail (connection != NULL, FALSE);
3778 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
3779 return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, TRUE);
3780 }
3781
3782 /**
3783 * This function is intended for use with applications that don't want to
3784 * write a main loop and deal with #DBusWatch and #DBusTimeout. See also
3785 * dbus_connection_read_write_dispatch().
3786 *
3787 * As long as the connection is open, this function will block until it can
3788 * read or write, then read or write, then return #TRUE.
3789 *
3790 * If the connection is closed, the function returns #FALSE.
3791 *
3792 * The return value indicates whether reading or writing is still
3793 * possible, i.e. whether the connection is connected.
3794 *
3795 * Note that even after disconnection, messages may remain in the
3796 * incoming queue that need to be
3797 * processed. dbus_connection_read_write_dispatch() dispatches
3798 * incoming messages for you; with dbus_connection_read_write() you
3799 * have to arrange to drain the incoming queue yourself.
3800 *
3801 * @param connection the connection
3802 * @param timeout_milliseconds max time to block or -1 for infinite
3803 * @returns #TRUE if still connected
3804 */
3805 dbus_bool_t
dbus_connection_read_write(DBusConnection * connection,int timeout_milliseconds)3806 dbus_connection_read_write (DBusConnection *connection,
3807 int timeout_milliseconds)
3808 {
3809 _dbus_return_val_if_fail (connection != NULL, FALSE);
3810 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE);
3811 return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, FALSE);
3812 }
3813
3814 /* We need to call this anytime we pop the head of the queue, and then
3815 * update_dispatch_status_and_unlock needs to be called afterward
3816 * which will "process" the disconnected message and set
3817 * disconnected_message_processed.
3818 */
3819 static void
check_disconnected_message_arrived_unlocked(DBusConnection * connection,DBusMessage * head_of_queue)3820 check_disconnected_message_arrived_unlocked (DBusConnection *connection,
3821 DBusMessage *head_of_queue)
3822 {
3823 HAVE_LOCK_CHECK (connection);
3824
3825 /* checking that the link is NULL is an optimization to avoid the is_signal call */
3826 if (connection->disconnect_message_link == NULL &&
3827 dbus_message_is_signal (head_of_queue,
3828 DBUS_INTERFACE_LOCAL,
3829 "Disconnected"))
3830 {
3831 connection->disconnected_message_arrived = TRUE;
3832 }
3833 }
3834
3835 /**
3836 * Returns the first-received message from the incoming message queue,
3837 * leaving it in the queue. If the queue is empty, returns #NULL.
3838 *
3839 * The caller does not own a reference to the returned message, and
3840 * must either return it using dbus_connection_return_message() or
3841 * keep it after calling dbus_connection_steal_borrowed_message(). No
3842 * one can get at the message while its borrowed, so return it as
3843 * quickly as possible and don't keep a reference to it after
3844 * returning it. If you need to keep the message, make a copy of it.
3845 *
3846 * dbus_connection_dispatch() will block if called while a borrowed
3847 * message is outstanding; only one piece of code can be playing with
3848 * the incoming queue at a time. This function will block if called
3849 * during a dbus_connection_dispatch().
3850 *
3851 * @param connection the connection.
3852 * @returns next message in the incoming queue.
3853 */
3854 DBusMessage*
dbus_connection_borrow_message(DBusConnection * connection)3855 dbus_connection_borrow_message (DBusConnection *connection)
3856 {
3857 DBusDispatchStatus status;
3858 DBusMessage *message;
3859
3860 _dbus_return_val_if_fail (connection != NULL, NULL);
3861
3862 _dbus_verbose ("start\n");
3863
3864 /* this is called for the side effect that it queues
3865 * up any messages from the transport
3866 */
3867 status = dbus_connection_get_dispatch_status (connection);
3868 if (status != DBUS_DISPATCH_DATA_REMAINS)
3869 return NULL;
3870
3871 CONNECTION_LOCK (connection);
3872
3873 _dbus_connection_acquire_dispatch (connection);
3874
3875 /* While a message is outstanding, the dispatch lock is held */
3876 _dbus_assert (connection->message_borrowed == NULL);
3877
3878 connection->message_borrowed = _dbus_list_get_first (&connection->incoming_messages);
3879
3880 message = connection->message_borrowed;
3881
3882 check_disconnected_message_arrived_unlocked (connection, message);
3883
3884 /* Note that we KEEP the dispatch lock until the message is returned */
3885 if (message == NULL)
3886 _dbus_connection_release_dispatch (connection);
3887
3888 CONNECTION_UNLOCK (connection);
3889
3890 _dbus_message_trace_ref (message, -1, -1, "dbus_connection_borrow_message");
3891
3892 /* We don't update dispatch status until it's returned or stolen */
3893
3894 return message;
3895 }
3896
3897 /**
3898 * Used to return a message after peeking at it using
3899 * dbus_connection_borrow_message(). Only called if
3900 * message from dbus_connection_borrow_message() was non-#NULL.
3901 *
3902 * @param connection the connection
3903 * @param message the message from dbus_connection_borrow_message()
3904 */
3905 void
dbus_connection_return_message(DBusConnection * connection,DBusMessage * message)3906 dbus_connection_return_message (DBusConnection *connection,
3907 DBusMessage *message)
3908 {
3909 DBusDispatchStatus status;
3910
3911 _dbus_return_if_fail (connection != NULL);
3912 _dbus_return_if_fail (message != NULL);
3913 _dbus_return_if_fail (message == connection->message_borrowed);
3914 _dbus_return_if_fail (connection->dispatch_acquired);
3915
3916 CONNECTION_LOCK (connection);
3917
3918 _dbus_assert (message == connection->message_borrowed);
3919
3920 connection->message_borrowed = NULL;
3921
3922 _dbus_connection_release_dispatch (connection);
3923
3924 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3925 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3926
3927 _dbus_message_trace_ref (message, -1, -1, "dbus_connection_return_message");
3928 }
3929
3930 /**
3931 * Used to keep a message after peeking at it using
3932 * dbus_connection_borrow_message(). Before using this function, see
3933 * the caveats/warnings in the documentation for
3934 * dbus_connection_pop_message().
3935 *
3936 * @param connection the connection
3937 * @param message the message from dbus_connection_borrow_message()
3938 */
3939 void
dbus_connection_steal_borrowed_message(DBusConnection * connection,DBusMessage * message)3940 dbus_connection_steal_borrowed_message (DBusConnection *connection,
3941 DBusMessage *message)
3942 {
3943 DBusMessage *pop_message;
3944 DBusDispatchStatus status;
3945
3946 _dbus_return_if_fail (connection != NULL);
3947 _dbus_return_if_fail (message != NULL);
3948 _dbus_return_if_fail (message == connection->message_borrowed);
3949 _dbus_return_if_fail (connection->dispatch_acquired);
3950
3951 CONNECTION_LOCK (connection);
3952
3953 _dbus_assert (message == connection->message_borrowed);
3954
3955 pop_message = _dbus_list_pop_first (&connection->incoming_messages);
3956 _dbus_assert (message == pop_message);
3957 (void) pop_message; /* unused unless asserting */
3958
3959 connection->n_incoming -= 1;
3960
3961 _dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n",
3962 message, connection->n_incoming);
3963
3964 connection->message_borrowed = NULL;
3965
3966 _dbus_connection_release_dispatch (connection);
3967
3968 status = _dbus_connection_get_dispatch_status_unlocked (connection);
3969 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
3970 _dbus_message_trace_ref (message, -1, -1,
3971 "dbus_connection_steal_borrowed_message");
3972 }
3973
3974 /* See dbus_connection_pop_message, but requires the caller to own
3975 * the lock before calling. May drop the lock while running.
3976 */
3977 static DBusList*
_dbus_connection_pop_message_link_unlocked(DBusConnection * connection)3978 _dbus_connection_pop_message_link_unlocked (DBusConnection *connection)
3979 {
3980 HAVE_LOCK_CHECK (connection);
3981
3982 _dbus_assert (connection->message_borrowed == NULL);
3983
3984 if (connection->n_incoming > 0)
3985 {
3986 DBusList *link;
3987
3988 link = _dbus_list_pop_first_link (&connection->incoming_messages);
3989 connection->n_incoming -= 1;
3990
3991 _dbus_verbose ("Message %p (%s %s %s %s sig:'%s' serial:%u) removed from incoming queue %p, %d incoming\n",
3992 link->data,
3993 dbus_message_type_to_string (dbus_message_get_type (link->data)),
3994 dbus_message_get_path (link->data) ?
3995 dbus_message_get_path (link->data) :
3996 "no path",
3997 dbus_message_get_interface (link->data) ?
3998 dbus_message_get_interface (link->data) :
3999 "no interface",
4000 dbus_message_get_member (link->data) ?
4001 dbus_message_get_member (link->data) :
4002 "no member",
4003 dbus_message_get_signature (link->data),
4004 dbus_message_get_serial (link->data),
4005 connection, connection->n_incoming);
4006
4007 _dbus_message_trace_ref (link->data, -1, -1,
4008 "_dbus_connection_pop_message_link_unlocked");
4009
4010 check_disconnected_message_arrived_unlocked (connection, link->data);
4011
4012 return link;
4013 }
4014 else
4015 return NULL;
4016 }
4017
4018 /* See dbus_connection_pop_message, but requires the caller to own
4019 * the lock before calling. May drop the lock while running.
4020 */
4021 static DBusMessage*
_dbus_connection_pop_message_unlocked(DBusConnection * connection)4022 _dbus_connection_pop_message_unlocked (DBusConnection *connection)
4023 {
4024 DBusList *link;
4025
4026 HAVE_LOCK_CHECK (connection);
4027
4028 link = _dbus_connection_pop_message_link_unlocked (connection);
4029
4030 if (link != NULL)
4031 {
4032 DBusMessage *message;
4033
4034 message = link->data;
4035
4036 _dbus_list_free_link (link);
4037
4038 return message;
4039 }
4040 else
4041 return NULL;
4042 }
4043
4044 static void
_dbus_connection_putback_message_link_unlocked(DBusConnection * connection,DBusList * message_link)4045 _dbus_connection_putback_message_link_unlocked (DBusConnection *connection,
4046 DBusList *message_link)
4047 {
4048 HAVE_LOCK_CHECK (connection);
4049
4050 _dbus_assert (message_link != NULL);
4051 /* You can't borrow a message while a link is outstanding */
4052 _dbus_assert (connection->message_borrowed == NULL);
4053 /* We had to have the dispatch lock across the pop/putback */
4054 _dbus_assert (connection->dispatch_acquired);
4055
4056 _dbus_list_prepend_link (&connection->incoming_messages,
4057 message_link);
4058 connection->n_incoming += 1;
4059
4060 _dbus_verbose ("Message %p (%s %s %s '%s') put back into queue %p, %d incoming\n",
4061 message_link->data,
4062 dbus_message_type_to_string (dbus_message_get_type (message_link->data)),
4063 dbus_message_get_interface (message_link->data) ?
4064 dbus_message_get_interface (message_link->data) :
4065 "no interface",
4066 dbus_message_get_member (message_link->data) ?
4067 dbus_message_get_member (message_link->data) :
4068 "no member",
4069 dbus_message_get_signature (message_link->data),
4070 connection, connection->n_incoming);
4071
4072 _dbus_message_trace_ref (message_link->data, -1, -1,
4073 "_dbus_connection_putback_message_link_unlocked");
4074 }
4075
4076 /**
4077 * Returns the first-received message from the incoming message queue,
4078 * removing it from the queue. The caller owns a reference to the
4079 * returned message. If the queue is empty, returns #NULL.
4080 *
4081 * This function bypasses any message handlers that are registered,
4082 * and so using it is usually wrong. Instead, let the main loop invoke
4083 * dbus_connection_dispatch(). Popping messages manually is only
4084 * useful in very simple programs that don't share a #DBusConnection
4085 * with any libraries or other modules.
4086 *
4087 * There is a lock that covers all ways of accessing the incoming message
4088 * queue, so dbus_connection_dispatch(), dbus_connection_pop_message(),
4089 * dbus_connection_borrow_message(), etc. will all block while one of the others
4090 * in the group is running.
4091 *
4092 * @param connection the connection.
4093 * @returns next message in the incoming queue.
4094 */
4095 DBusMessage*
dbus_connection_pop_message(DBusConnection * connection)4096 dbus_connection_pop_message (DBusConnection *connection)
4097 {
4098 DBusMessage *message;
4099 DBusDispatchStatus status;
4100
4101 _dbus_verbose ("start\n");
4102
4103 /* this is called for the side effect that it queues
4104 * up any messages from the transport
4105 */
4106 status = dbus_connection_get_dispatch_status (connection);
4107 if (status != DBUS_DISPATCH_DATA_REMAINS)
4108 return NULL;
4109
4110 CONNECTION_LOCK (connection);
4111 _dbus_connection_acquire_dispatch (connection);
4112 HAVE_LOCK_CHECK (connection);
4113
4114 message = _dbus_connection_pop_message_unlocked (connection);
4115
4116 _dbus_verbose ("Returning popped message %p\n", message);
4117
4118 _dbus_connection_release_dispatch (connection);
4119
4120 status = _dbus_connection_get_dispatch_status_unlocked (connection);
4121 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
4122
4123 return message;
4124 }
4125
4126 /**
4127 * Acquire the dispatcher. This is a separate lock so the main
4128 * connection lock can be dropped to call out to application dispatch
4129 * handlers.
4130 *
4131 * @param connection the connection.
4132 */
4133 static void
_dbus_connection_acquire_dispatch(DBusConnection * connection)4134 _dbus_connection_acquire_dispatch (DBusConnection *connection)
4135 {
4136 HAVE_LOCK_CHECK (connection);
4137
4138 _dbus_connection_ref_unlocked (connection);
4139 CONNECTION_UNLOCK (connection);
4140
4141 _dbus_verbose ("locking dispatch_mutex\n");
4142 _dbus_cmutex_lock (connection->dispatch_mutex);
4143
4144 while (connection->dispatch_acquired)
4145 {
4146 _dbus_verbose ("waiting for dispatch to be acquirable\n");
4147 _dbus_condvar_wait (connection->dispatch_cond,
4148 connection->dispatch_mutex);
4149 }
4150
4151 _dbus_assert (!connection->dispatch_acquired);
4152
4153 connection->dispatch_acquired = TRUE;
4154
4155 _dbus_verbose ("unlocking dispatch_mutex\n");
4156 _dbus_cmutex_unlock (connection->dispatch_mutex);
4157
4158 CONNECTION_LOCK (connection);
4159 _dbus_connection_unref_unlocked (connection);
4160 }
4161
4162 /**
4163 * Release the dispatcher when you're done with it. Only call
4164 * after you've acquired the dispatcher. Wakes up at most one
4165 * thread currently waiting to acquire the dispatcher.
4166 *
4167 * @param connection the connection.
4168 */
4169 static void
_dbus_connection_release_dispatch(DBusConnection * connection)4170 _dbus_connection_release_dispatch (DBusConnection *connection)
4171 {
4172 HAVE_LOCK_CHECK (connection);
4173
4174 _dbus_verbose ("locking dispatch_mutex\n");
4175 _dbus_cmutex_lock (connection->dispatch_mutex);
4176
4177 _dbus_assert (connection->dispatch_acquired);
4178
4179 connection->dispatch_acquired = FALSE;
4180 _dbus_condvar_wake_one (connection->dispatch_cond);
4181
4182 _dbus_verbose ("unlocking dispatch_mutex\n");
4183 _dbus_cmutex_unlock (connection->dispatch_mutex);
4184 }
4185
4186 static void
_dbus_connection_failed_pop(DBusConnection * connection,DBusList * message_link)4187 _dbus_connection_failed_pop (DBusConnection *connection,
4188 DBusList *message_link)
4189 {
4190 _dbus_list_prepend_link (&connection->incoming_messages,
4191 message_link);
4192 connection->n_incoming += 1;
4193 }
4194
4195 /* Note this may be called multiple times since we don't track whether we already did it */
4196 static void
notify_disconnected_unlocked(DBusConnection * connection)4197 notify_disconnected_unlocked (DBusConnection *connection)
4198 {
4199 HAVE_LOCK_CHECK (connection);
4200
4201 /* Set the weakref in dbus-bus.c to NULL, so nobody will get a disconnected
4202 * connection from dbus_bus_get(). We make the same guarantee for
4203 * dbus_connection_open() but in a different way since we don't want to
4204 * unref right here; we instead check for connectedness before returning
4205 * the connection from the hash.
4206 */
4207 _dbus_bus_notify_shared_connection_disconnected_unlocked (connection);
4208
4209 /* Dump the outgoing queue, we aren't going to be able to
4210 * send it now, and we'd like accessors like
4211 * dbus_connection_get_outgoing_size() to be accurate.
4212 */
4213 if (connection->n_outgoing > 0)
4214 {
4215 DBusList *link;
4216
4217 _dbus_verbose ("Dropping %d outgoing messages since we're disconnected\n",
4218 connection->n_outgoing);
4219
4220 while ((link = _dbus_list_get_last_link (&connection->outgoing_messages)))
4221 {
4222 _dbus_connection_message_sent_unlocked (connection, link->data);
4223 }
4224 }
4225 }
4226
4227 /* Note this may be called multiple times since we don't track whether we already did it */
4228 static DBusDispatchStatus
notify_disconnected_and_dispatch_complete_unlocked(DBusConnection * connection)4229 notify_disconnected_and_dispatch_complete_unlocked (DBusConnection *connection)
4230 {
4231 HAVE_LOCK_CHECK (connection);
4232
4233 if (connection->disconnect_message_link != NULL)
4234 {
4235 _dbus_verbose ("Sending disconnect message\n");
4236
4237 /* If we have pending calls, queue their timeouts - we want the Disconnected
4238 * to be the last message, after these timeouts.
4239 */
4240 connection_timeout_and_complete_all_pending_calls_unlocked (connection);
4241
4242 /* We haven't sent the disconnect message already,
4243 * and all real messages have been queued up.
4244 */
4245 _dbus_connection_queue_synthesized_message_link (connection,
4246 connection->disconnect_message_link);
4247 connection->disconnect_message_link = NULL;
4248
4249 return DBUS_DISPATCH_DATA_REMAINS;
4250 }
4251
4252 return DBUS_DISPATCH_COMPLETE;
4253 }
4254
4255 static DBusDispatchStatus
_dbus_connection_get_dispatch_status_unlocked(DBusConnection * connection)4256 _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection)
4257 {
4258 HAVE_LOCK_CHECK (connection);
4259
4260 if (connection->n_incoming > 0)
4261 return DBUS_DISPATCH_DATA_REMAINS;
4262 else if (!_dbus_transport_queue_messages (connection->transport))
4263 return DBUS_DISPATCH_NEED_MEMORY;
4264 else
4265 {
4266 DBusDispatchStatus status;
4267 dbus_bool_t is_connected;
4268
4269 status = _dbus_transport_get_dispatch_status (connection->transport);
4270 is_connected = _dbus_transport_get_is_connected (connection->transport);
4271
4272 _dbus_verbose ("dispatch status = %s is_connected = %d\n",
4273 DISPATCH_STATUS_NAME (status), is_connected);
4274
4275 if (!is_connected)
4276 {
4277 /* It's possible this would be better done by having an explicit
4278 * notification from _dbus_transport_disconnect() that would
4279 * synchronously do this, instead of waiting for the next dispatch
4280 * status check. However, probably not good to change until it causes
4281 * a problem.
4282 */
4283 notify_disconnected_unlocked (connection);
4284
4285 /* I'm not sure this is needed; the idea is that we want to
4286 * queue the Disconnected only after we've read all the
4287 * messages, but if we're disconnected maybe we are guaranteed
4288 * to have read them all ?
4289 */
4290 if (status == DBUS_DISPATCH_COMPLETE)
4291 status = notify_disconnected_and_dispatch_complete_unlocked (connection);
4292 }
4293
4294 if (status != DBUS_DISPATCH_COMPLETE)
4295 return status;
4296 else if (connection->n_incoming > 0)
4297 return DBUS_DISPATCH_DATA_REMAINS;
4298 else
4299 return DBUS_DISPATCH_COMPLETE;
4300 }
4301 }
4302
4303 static void
_dbus_connection_update_dispatch_status_and_unlock(DBusConnection * connection,DBusDispatchStatus new_status)4304 _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection,
4305 DBusDispatchStatus new_status)
4306 {
4307 dbus_bool_t changed;
4308 DBusDispatchStatusFunction function;
4309 void *data;
4310
4311 HAVE_LOCK_CHECK (connection);
4312
4313 _dbus_connection_ref_unlocked (connection);
4314
4315 changed = new_status != connection->last_dispatch_status;
4316
4317 connection->last_dispatch_status = new_status;
4318
4319 function = connection->dispatch_status_function;
4320 data = connection->dispatch_status_data;
4321
4322 if (connection->disconnected_message_arrived &&
4323 !connection->disconnected_message_processed)
4324 {
4325 connection->disconnected_message_processed = TRUE;
4326
4327 /* this does an unref, but we have a ref
4328 * so we should not run the finalizer here
4329 * inside the lock.
4330 */
4331 connection_forget_shared_unlocked (connection);
4332
4333 if (connection->exit_on_disconnect)
4334 {
4335 CONNECTION_UNLOCK (connection);
4336
4337 _dbus_verbose ("Exiting on Disconnected signal\n");
4338 _dbus_exit (1);
4339 _dbus_assert_not_reached ("Call to exit() returned");
4340 }
4341 }
4342
4343 /* We drop the lock */
4344 CONNECTION_UNLOCK (connection);
4345
4346 if (changed && function)
4347 {
4348 _dbus_verbose ("Notifying of change to dispatch status of %p now %d (%s)\n",
4349 connection, new_status,
4350 DISPATCH_STATUS_NAME (new_status));
4351 (* function) (connection, new_status, data);
4352 }
4353
4354 dbus_connection_unref (connection);
4355 }
4356
4357 /**
4358 * Gets the current state of the incoming message queue.
4359 * #DBUS_DISPATCH_DATA_REMAINS indicates that the message queue
4360 * may contain messages. #DBUS_DISPATCH_COMPLETE indicates that the
4361 * incoming queue is empty. #DBUS_DISPATCH_NEED_MEMORY indicates that
4362 * there could be data, but we can't know for sure without more
4363 * memory.
4364 *
4365 * To process the incoming message queue, use dbus_connection_dispatch()
4366 * or (in rare cases) dbus_connection_pop_message().
4367 *
4368 * Note, #DBUS_DISPATCH_DATA_REMAINS really means that either we
4369 * have messages in the queue, or we have raw bytes buffered up
4370 * that need to be parsed. When these bytes are parsed, they
4371 * may not add up to an entire message. Thus, it's possible
4372 * to see a status of #DBUS_DISPATCH_DATA_REMAINS but not
4373 * have a message yet.
4374 *
4375 * In particular this happens on initial connection, because all sorts
4376 * of authentication protocol stuff has to be parsed before the
4377 * first message arrives.
4378 *
4379 * @param connection the connection.
4380 * @returns current dispatch status
4381 */
4382 DBusDispatchStatus
dbus_connection_get_dispatch_status(DBusConnection * connection)4383 dbus_connection_get_dispatch_status (DBusConnection *connection)
4384 {
4385 DBusDispatchStatus status;
4386
4387 _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);
4388
4389 _dbus_verbose ("start\n");
4390
4391 CONNECTION_LOCK (connection);
4392
4393 status = _dbus_connection_get_dispatch_status_unlocked (connection);
4394
4395 CONNECTION_UNLOCK (connection);
4396
4397 return status;
4398 }
4399
4400 /**
4401 * Filter funtion for handling the Peer standard interface.
4402 */
4403 static DBusHandlerResult
_dbus_connection_peer_filter_unlocked_no_update(DBusConnection * connection,DBusMessage * message)4404 _dbus_connection_peer_filter_unlocked_no_update (DBusConnection *connection,
4405 DBusMessage *message)
4406 {
4407 dbus_bool_t sent = FALSE;
4408 DBusMessage *ret = NULL;
4409 DBusList *expire_link;
4410
4411 if (connection->route_peer_messages && dbus_message_get_destination (message) != NULL)
4412 {
4413 /* This means we're letting the bus route this message */
4414 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
4415 }
4416
4417 if (!dbus_message_has_interface (message, DBUS_INTERFACE_PEER))
4418 {
4419 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
4420 }
4421
4422 /* Preallocate a linked-list link, so that if we need to dispose of a
4423 * message, we can attach it to the expired list */
4424 expire_link = _dbus_list_alloc_link (NULL);
4425
4426 if (!expire_link)
4427 return DBUS_HANDLER_RESULT_NEED_MEMORY;
4428
4429 if (dbus_message_is_method_call (message,
4430 DBUS_INTERFACE_PEER,
4431 "Ping"))
4432 {
4433 ret = dbus_message_new_method_return (message);
4434 if (ret == NULL)
4435 goto out;
4436
4437 sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
4438 }
4439 else if (dbus_message_is_method_call (message,
4440 DBUS_INTERFACE_PEER,
4441 "GetMachineId"))
4442 {
4443 DBusString uuid;
4444 DBusError error = DBUS_ERROR_INIT;
4445
4446 if (!_dbus_string_init (&uuid))
4447 goto out;
4448
4449 if (_dbus_get_local_machine_uuid_encoded (&uuid, &error))
4450 {
4451 const char *v_STRING;
4452
4453 ret = dbus_message_new_method_return (message);
4454
4455 if (ret == NULL)
4456 {
4457 _dbus_string_free (&uuid);
4458 goto out;
4459 }
4460
4461 v_STRING = _dbus_string_get_const_data (&uuid);
4462 if (dbus_message_append_args (ret,
4463 DBUS_TYPE_STRING, &v_STRING,
4464 DBUS_TYPE_INVALID))
4465 {
4466 sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
4467 }
4468 }
4469 else if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
4470 {
4471 dbus_error_free (&error);
4472 goto out;
4473 }
4474 else
4475 {
4476 ret = dbus_message_new_error (message, error.name, error.message);
4477 dbus_error_free (&error);
4478
4479 if (ret == NULL)
4480 goto out;
4481
4482 sent = _dbus_connection_send_unlocked_no_update (connection, ret,
4483 NULL);
4484 }
4485
4486 _dbus_string_free (&uuid);
4487 }
4488 else
4489 {
4490 /* We need to bounce anything else with this interface, otherwise apps
4491 * could start extending the interface and when we added extensions
4492 * here to DBusConnection we'd break those apps.
4493 */
4494 ret = dbus_message_new_error (message,
4495 DBUS_ERROR_UNKNOWN_METHOD,
4496 "Unknown method invoked on org.freedesktop.DBus.Peer interface");
4497 if (ret == NULL)
4498 goto out;
4499
4500 sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL);
4501 }
4502
4503 out:
4504 if (ret == NULL)
4505 {
4506 _dbus_list_free_link (expire_link);
4507 }
4508 else
4509 {
4510 /* It'll be safe to unref the reply when we unlock */
4511 expire_link->data = ret;
4512 _dbus_list_prepend_link (&connection->expired_messages, expire_link);
4513 }
4514
4515 if (!sent)
4516 return DBUS_HANDLER_RESULT_NEED_MEMORY;
4517
4518 return DBUS_HANDLER_RESULT_HANDLED;
4519 }
4520
4521 /**
4522 * Processes all builtin filter functions
4523 *
4524 * If the spec specifies a standard interface
4525 * they should be processed from this method
4526 **/
4527 static DBusHandlerResult
_dbus_connection_run_builtin_filters_unlocked_no_update(DBusConnection * connection,DBusMessage * message)4528 _dbus_connection_run_builtin_filters_unlocked_no_update (DBusConnection *connection,
4529 DBusMessage *message)
4530 {
4531 /* We just run one filter for now but have the option to run more
4532 if the spec calls for it in the future */
4533
4534 return _dbus_connection_peer_filter_unlocked_no_update (connection, message);
4535 }
4536
4537 /**
4538 * Processes any incoming data.
4539 *
4540 * If there's incoming raw data that has not yet been parsed, it is
4541 * parsed, which may or may not result in adding messages to the
4542 * incoming queue.
4543 *
4544 * The incoming data buffer is filled when the connection reads from
4545 * its underlying transport (such as a socket). Reading usually
4546 * happens in dbus_watch_handle() or dbus_connection_read_write().
4547 *
4548 * If there are complete messages in the incoming queue,
4549 * dbus_connection_dispatch() removes one message from the queue and
4550 * processes it. Processing has three steps.
4551 *
4552 * First, any method replies are passed to #DBusPendingCall or
4553 * dbus_connection_send_with_reply_and_block() in order to
4554 * complete the pending method call.
4555 *
4556 * Second, any filters registered with dbus_connection_add_filter()
4557 * are run. If any filter returns #DBUS_HANDLER_RESULT_HANDLED
4558 * then processing stops after that filter.
4559 *
4560 * Third, if the message is a method call it is forwarded to
4561 * any registered object path handlers added with
4562 * dbus_connection_register_object_path() or
4563 * dbus_connection_register_fallback().
4564 *
4565 * A single call to dbus_connection_dispatch() will process at most
4566 * one message; it will not clear the entire message queue.
4567 *
4568 * Be careful about calling dbus_connection_dispatch() from inside a
4569 * message handler, i.e. calling dbus_connection_dispatch()
4570 * recursively. If threads have been initialized with a recursive
4571 * mutex function, then this will not deadlock; however, it can
4572 * certainly confuse your application.
4573 *
4574 * @todo some FIXME in here about handling DBUS_HANDLER_RESULT_NEED_MEMORY
4575 *
4576 * @param connection the connection
4577 * @returns dispatch status, see dbus_connection_get_dispatch_status()
4578 */
4579 DBusDispatchStatus
dbus_connection_dispatch(DBusConnection * connection)4580 dbus_connection_dispatch (DBusConnection *connection)
4581 {
4582 DBusMessage *message;
4583 DBusList *link, *filter_list_copy, *message_link;
4584 DBusHandlerResult result;
4585 DBusPendingCall *pending;
4586 dbus_int32_t reply_serial;
4587 DBusDispatchStatus status;
4588 dbus_bool_t found_object;
4589
4590 _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE);
4591
4592 _dbus_verbose ("\n");
4593
4594 CONNECTION_LOCK (connection);
4595 status = _dbus_connection_get_dispatch_status_unlocked (connection);
4596 if (status != DBUS_DISPATCH_DATA_REMAINS)
4597 {
4598 /* unlocks and calls out to user code */
4599 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
4600 return status;
4601 }
4602
4603 /* We need to ref the connection since the callback could potentially
4604 * drop the last ref to it
4605 */
4606 _dbus_connection_ref_unlocked (connection);
4607
4608 _dbus_connection_acquire_dispatch (connection);
4609 HAVE_LOCK_CHECK (connection);
4610
4611 message_link = _dbus_connection_pop_message_link_unlocked (connection);
4612 if (message_link == NULL)
4613 {
4614 /* another thread dispatched our stuff */
4615
4616 _dbus_verbose ("another thread dispatched message (during acquire_dispatch above)\n");
4617
4618 _dbus_connection_release_dispatch (connection);
4619
4620 status = _dbus_connection_get_dispatch_status_unlocked (connection);
4621
4622 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
4623
4624 dbus_connection_unref (connection);
4625
4626 return status;
4627 }
4628
4629 message = message_link->data;
4630
4631 _dbus_verbose (" dispatching message %p (%s %s %s '%s')\n",
4632 message,
4633 dbus_message_type_to_string (dbus_message_get_type (message)),
4634 dbus_message_get_interface (message) ?
4635 dbus_message_get_interface (message) :
4636 "no interface",
4637 dbus_message_get_member (message) ?
4638 dbus_message_get_member (message) :
4639 "no member",
4640 dbus_message_get_signature (message));
4641
4642 result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
4643
4644 /* Pending call handling must be first, because if you do
4645 * dbus_connection_send_with_reply_and_block() or
4646 * dbus_pending_call_block() then no handlers/filters will be run on
4647 * the reply. We want consistent semantics in the case where we
4648 * dbus_connection_dispatch() the reply.
4649 */
4650
4651 reply_serial = dbus_message_get_reply_serial (message);
4652 pending = _dbus_hash_table_lookup_int (connection->pending_replies,
4653 reply_serial);
4654 if (pending)
4655 {
4656 _dbus_verbose ("Dispatching a pending reply\n");
4657 complete_pending_call_and_unlock (connection, pending, message);
4658 pending = NULL; /* it's probably unref'd */
4659
4660 CONNECTION_LOCK (connection);
4661 _dbus_verbose ("pending call completed in dispatch\n");
4662 result = DBUS_HANDLER_RESULT_HANDLED;
4663 goto out;
4664 }
4665
4666 result = _dbus_connection_run_builtin_filters_unlocked_no_update (connection, message);
4667 if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
4668 goto out;
4669
4670 if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy))
4671 {
4672 _dbus_connection_release_dispatch (connection);
4673 HAVE_LOCK_CHECK (connection);
4674
4675 _dbus_connection_failed_pop (connection, message_link);
4676
4677 /* unlocks and calls user code */
4678 _dbus_connection_update_dispatch_status_and_unlock (connection,
4679 DBUS_DISPATCH_NEED_MEMORY);
4680 dbus_connection_unref (connection);
4681
4682 return DBUS_DISPATCH_NEED_MEMORY;
4683 }
4684
4685 _dbus_list_foreach (&filter_list_copy,
4686 (DBusForeachFunction)_dbus_message_filter_ref,
4687 NULL);
4688
4689 /* We're still protected from dispatch() reentrancy here
4690 * since we acquired the dispatcher
4691 */
4692 CONNECTION_UNLOCK (connection);
4693
4694 link = _dbus_list_get_first_link (&filter_list_copy);
4695 while (link != NULL)
4696 {
4697 DBusMessageFilter *filter = link->data;
4698 DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link);
4699
4700 if (filter->function == NULL)
4701 {
4702 _dbus_verbose (" filter was removed in a callback function\n");
4703 link = next;
4704 continue;
4705 }
4706
4707 _dbus_verbose (" running filter on message %p\n", message);
4708 result = (* filter->function) (connection, message, filter->user_data);
4709
4710 if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
4711 break;
4712
4713 link = next;
4714 }
4715
4716 _dbus_list_foreach (&filter_list_copy,
4717 (DBusForeachFunction)_dbus_message_filter_unref,
4718 NULL);
4719 _dbus_list_clear (&filter_list_copy);
4720
4721 CONNECTION_LOCK (connection);
4722
4723 if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
4724 {
4725 _dbus_verbose ("No memory\n");
4726 goto out;
4727 }
4728 else if (result == DBUS_HANDLER_RESULT_HANDLED)
4729 {
4730 _dbus_verbose ("filter handled message in dispatch\n");
4731 goto out;
4732 }
4733
4734 /* We're still protected from dispatch() reentrancy here
4735 * since we acquired the dispatcher
4736 */
4737 _dbus_verbose (" running object path dispatch on message %p (%s %s %s '%s')\n",
4738 message,
4739 dbus_message_type_to_string (dbus_message_get_type (message)),
4740 dbus_message_get_interface (message) ?
4741 dbus_message_get_interface (message) :
4742 "no interface",
4743 dbus_message_get_member (message) ?
4744 dbus_message_get_member (message) :
4745 "no member",
4746 dbus_message_get_signature (message));
4747
4748 HAVE_LOCK_CHECK (connection);
4749 result = _dbus_object_tree_dispatch_and_unlock (connection->objects,
4750 message,
4751 &found_object);
4752
4753 CONNECTION_LOCK (connection);
4754
4755 if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED)
4756 {
4757 _dbus_verbose ("object tree handled message in dispatch\n");
4758 goto out;
4759 }
4760
4761 if (dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_CALL)
4762 {
4763 DBusMessage *reply;
4764 DBusString str;
4765 DBusPreallocatedSend *preallocated;
4766 DBusList *expire_link;
4767
4768 _dbus_verbose (" sending error %s\n",
4769 DBUS_ERROR_UNKNOWN_METHOD);
4770
4771 if (!_dbus_string_init (&str))
4772 {
4773 result = DBUS_HANDLER_RESULT_NEED_MEMORY;
4774 _dbus_verbose ("no memory for error string in dispatch\n");
4775 goto out;
4776 }
4777
4778 if (!_dbus_string_append_printf (&str,
4779 "Method \"%s\" with signature \"%s\" on interface \"%s\" doesn't exist\n",
4780 dbus_message_get_member (message),
4781 dbus_message_get_signature (message),
4782 dbus_message_get_interface (message)))
4783 {
4784 _dbus_string_free (&str);
4785 result = DBUS_HANDLER_RESULT_NEED_MEMORY;
4786 _dbus_verbose ("no memory for error string in dispatch\n");
4787 goto out;
4788 }
4789
4790 reply = dbus_message_new_error (message,
4791 found_object ? DBUS_ERROR_UNKNOWN_METHOD : DBUS_ERROR_UNKNOWN_OBJECT,
4792 _dbus_string_get_const_data (&str));
4793 _dbus_string_free (&str);
4794
4795 if (reply == NULL)
4796 {
4797 result = DBUS_HANDLER_RESULT_NEED_MEMORY;
4798 _dbus_verbose ("no memory for error reply in dispatch\n");
4799 goto out;
4800 }
4801
4802 expire_link = _dbus_list_alloc_link (reply);
4803
4804 if (expire_link == NULL)
4805 {
4806 dbus_message_unref (reply);
4807 result = DBUS_HANDLER_RESULT_NEED_MEMORY;
4808 _dbus_verbose ("no memory for error send in dispatch\n");
4809 goto out;
4810 }
4811
4812 preallocated = _dbus_connection_preallocate_send_unlocked (connection);
4813
4814 if (preallocated == NULL)
4815 {
4816 _dbus_list_free_link (expire_link);
4817 /* It's OK that this is finalized, because it hasn't been seen by
4818 * anything that could attach user callbacks */
4819 dbus_message_unref (reply);
4820 result = DBUS_HANDLER_RESULT_NEED_MEMORY;
4821 _dbus_verbose ("no memory for error send in dispatch\n");
4822 goto out;
4823 }
4824
4825 _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated,
4826 reply, NULL);
4827 /* reply will be freed when we release the lock */
4828 _dbus_list_prepend_link (&connection->expired_messages, expire_link);
4829
4830 result = DBUS_HANDLER_RESULT_HANDLED;
4831 }
4832
4833 _dbus_verbose (" done dispatching %p (%s %s %s '%s') on connection %p\n", message,
4834 dbus_message_type_to_string (dbus_message_get_type (message)),
4835 dbus_message_get_interface (message) ?
4836 dbus_message_get_interface (message) :
4837 "no interface",
4838 dbus_message_get_member (message) ?
4839 dbus_message_get_member (message) :
4840 "no member",
4841 dbus_message_get_signature (message),
4842 connection);
4843
4844 out:
4845 if (result == DBUS_HANDLER_RESULT_NEED_MEMORY)
4846 {
4847 _dbus_verbose ("out of memory\n");
4848
4849 /* Put message back, and we'll start over.
4850 * Yes this means handlers must be idempotent if they
4851 * don't return HANDLED; c'est la vie.
4852 */
4853 _dbus_connection_putback_message_link_unlocked (connection,
4854 message_link);
4855 /* now we don't want to free them */
4856 message_link = NULL;
4857 message = NULL;
4858 }
4859 else
4860 {
4861 _dbus_verbose (" ... done dispatching\n");
4862 }
4863
4864 _dbus_connection_release_dispatch (connection);
4865 HAVE_LOCK_CHECK (connection);
4866
4867 if (message != NULL)
4868 {
4869 /* We don't want this message to count in maximum message limits when
4870 * computing the dispatch status, below. We have to drop the lock
4871 * temporarily, because finalizing a message can trigger callbacks.
4872 *
4873 * We have a reference to the connection, and we don't use any cached
4874 * pointers to the connection's internals below this point, so it should
4875 * be safe to drop the lock and take it back. */
4876 CONNECTION_UNLOCK (connection);
4877 dbus_message_unref (message);
4878 CONNECTION_LOCK (connection);
4879 }
4880
4881 if (message_link != NULL)
4882 _dbus_list_free_link (message_link);
4883
4884 _dbus_verbose ("before final status update\n");
4885 status = _dbus_connection_get_dispatch_status_unlocked (connection);
4886
4887 /* unlocks and calls user code */
4888 _dbus_connection_update_dispatch_status_and_unlock (connection, status);
4889
4890 dbus_connection_unref (connection);
4891
4892 return status;
4893 }
4894
4895 /**
4896 * Sets the watch functions for the connection. These functions are
4897 * responsible for making the application's main loop aware of file
4898 * descriptors that need to be monitored for events, using select() or
4899 * poll(). When using Qt, typically the DBusAddWatchFunction would
4900 * create a QSocketNotifier. When using GLib, the DBusAddWatchFunction
4901 * could call g_io_add_watch(), or could be used as part of a more
4902 * elaborate GSource. Note that when a watch is added, it may
4903 * not be enabled.
4904 *
4905 * The DBusWatchToggledFunction notifies the application that the
4906 * watch has been enabled or disabled. Call dbus_watch_get_enabled()
4907 * to check this. A disabled watch should have no effect, and enabled
4908 * watch should be added to the main loop. This feature is used
4909 * instead of simply adding/removing the watch because
4910 * enabling/disabling can be done without memory allocation. The
4911 * toggled function may be NULL if a main loop re-queries
4912 * dbus_watch_get_enabled() every time anyway.
4913 *
4914 * The DBusWatch can be queried for the file descriptor to watch using
4915 * dbus_watch_get_unix_fd() or dbus_watch_get_socket(), and for the
4916 * events to watch for using dbus_watch_get_flags(). The flags
4917 * returned by dbus_watch_get_flags() will only contain
4918 * DBUS_WATCH_READABLE and DBUS_WATCH_WRITABLE, never
4919 * DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR; all watches implicitly
4920 * include a watch for hangups, errors, and other exceptional
4921 * conditions.
4922 *
4923 * Once a file descriptor becomes readable or writable, or an exception
4924 * occurs, dbus_watch_handle() should be called to
4925 * notify the connection of the file descriptor's condition.
4926 *
4927 * dbus_watch_handle() cannot be called during the
4928 * DBusAddWatchFunction, as the connection will not be ready to handle
4929 * that watch yet.
4930 *
4931 * It is not allowed to reference a DBusWatch after it has been passed
4932 * to remove_function.
4933 *
4934 * If #FALSE is returned due to lack of memory, the failure may be due
4935 * to a #FALSE return from the new add_function. If so, the
4936 * add_function may have been called successfully one or more times,
4937 * but the remove_function will also have been called to remove any
4938 * successful adds. i.e. if #FALSE is returned the net result
4939 * should be that dbus_connection_set_watch_functions() has no effect,
4940 * but the add_function and remove_function may have been called.
4941 *
4942 * @note The thread lock on DBusConnection is held while
4943 * watch functions are invoked, so inside these functions you
4944 * may not invoke any methods on DBusConnection or it will deadlock.
4945 * See the comments in the code or http://lists.freedesktop.org/archives/dbus/2007-July/tread.html#8144
4946 * if you encounter this issue and want to attempt writing a patch.
4947 *
4948 * @param connection the connection.
4949 * @param add_function function to begin monitoring a new descriptor.
4950 * @param remove_function function to stop monitoring a descriptor.
4951 * @param toggled_function function to notify of enable/disable
4952 * @param data data to pass to add_function and remove_function.
4953 * @param free_data_function function to be called to free the data.
4954 * @returns #FALSE on failure (no memory)
4955 */
4956 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)4957 dbus_connection_set_watch_functions (DBusConnection *connection,
4958 DBusAddWatchFunction add_function,
4959 DBusRemoveWatchFunction remove_function,
4960 DBusWatchToggledFunction toggled_function,
4961 void *data,
4962 DBusFreeFunction free_data_function)
4963 {
4964 dbus_bool_t retval;
4965
4966 _dbus_return_val_if_fail (connection != NULL, FALSE);
4967
4968 CONNECTION_LOCK (connection);
4969
4970 retval = _dbus_watch_list_set_functions (connection->watches,
4971 add_function, remove_function,
4972 toggled_function,
4973 data, free_data_function);
4974
4975 CONNECTION_UNLOCK (connection);
4976
4977 return retval;
4978 }
4979
4980 /**
4981 * Sets the timeout functions for the connection. These functions are
4982 * responsible for making the application's main loop aware of timeouts.
4983 * When using Qt, typically the DBusAddTimeoutFunction would create a
4984 * QTimer. When using GLib, the DBusAddTimeoutFunction would call
4985 * g_timeout_add.
4986 *
4987 * The DBusTimeoutToggledFunction notifies the application that the
4988 * timeout has been enabled or disabled. Call
4989 * dbus_timeout_get_enabled() to check this. A disabled timeout should
4990 * have no effect, and enabled timeout should be added to the main
4991 * loop. This feature is used instead of simply adding/removing the
4992 * timeout because enabling/disabling can be done without memory
4993 * allocation. With Qt, QTimer::start() and QTimer::stop() can be used
4994 * to enable and disable. The toggled function may be NULL if a main
4995 * loop re-queries dbus_timeout_get_enabled() every time anyway.
4996 * Whenever a timeout is toggled, its interval may change.
4997 *
4998 * The DBusTimeout can be queried for the timer interval using
4999 * dbus_timeout_get_interval(). dbus_timeout_handle() should be called
5000 * repeatedly, each time the interval elapses, starting after it has
5001 * elapsed once. The timeout stops firing when it is removed with the
5002 * given remove_function. The timer interval may change whenever the
5003 * timeout is added, removed, or toggled.
5004 *
5005 * @note The thread lock on DBusConnection is held while
5006 * timeout functions are invoked, so inside these functions you
5007 * may not invoke any methods on DBusConnection or it will deadlock.
5008 * See the comments in the code or http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144
5009 * if you encounter this issue and want to attempt writing a patch.
5010 *
5011 * @param connection the connection.
5012 * @param add_function function to add a timeout.
5013 * @param remove_function function to remove a timeout.
5014 * @param toggled_function function to notify of enable/disable
5015 * @param data data to pass to add_function and remove_function.
5016 * @param free_data_function function to be called to free the data.
5017 * @returns #FALSE on failure (no memory)
5018 */
5019 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)5020 dbus_connection_set_timeout_functions (DBusConnection *connection,
5021 DBusAddTimeoutFunction add_function,
5022 DBusRemoveTimeoutFunction remove_function,
5023 DBusTimeoutToggledFunction toggled_function,
5024 void *data,
5025 DBusFreeFunction free_data_function)
5026 {
5027 dbus_bool_t retval;
5028
5029 _dbus_return_val_if_fail (connection != NULL, FALSE);
5030
5031 CONNECTION_LOCK (connection);
5032
5033 retval = _dbus_timeout_list_set_functions (connection->timeouts,
5034 add_function, remove_function,
5035 toggled_function,
5036 data, free_data_function);
5037
5038 CONNECTION_UNLOCK (connection);
5039
5040 return retval;
5041 }
5042
5043 /**
5044 * Sets the mainloop wakeup function for the connection. This function
5045 * is responsible for waking up the main loop (if its sleeping in
5046 * another thread) when some some change has happened to the
5047 * connection that the mainloop needs to reconsider (e.g. a message
5048 * has been queued for writing). When using Qt, this typically
5049 * results in a call to QEventLoop::wakeUp(). When using GLib, it
5050 * would call g_main_context_wakeup().
5051 *
5052 * @param connection the connection.
5053 * @param wakeup_main_function function to wake up the mainloop
5054 * @param data data to pass wakeup_main_function
5055 * @param free_data_function function to be called to free the data.
5056 */
5057 void
dbus_connection_set_wakeup_main_function(DBusConnection * connection,DBusWakeupMainFunction wakeup_main_function,void * data,DBusFreeFunction free_data_function)5058 dbus_connection_set_wakeup_main_function (DBusConnection *connection,
5059 DBusWakeupMainFunction wakeup_main_function,
5060 void *data,
5061 DBusFreeFunction free_data_function)
5062 {
5063 void *old_data;
5064 DBusFreeFunction old_free_data;
5065
5066 _dbus_return_if_fail (connection != NULL);
5067
5068 CONNECTION_LOCK (connection);
5069 old_data = connection->wakeup_main_data;
5070 old_free_data = connection->free_wakeup_main_data;
5071
5072 connection->wakeup_main_function = wakeup_main_function;
5073 connection->wakeup_main_data = data;
5074 connection->free_wakeup_main_data = free_data_function;
5075
5076 CONNECTION_UNLOCK (connection);
5077
5078 /* Callback outside the lock */
5079 if (old_free_data)
5080 (*old_free_data) (old_data);
5081 }
5082
5083 /**
5084 * Set a function to be invoked when the dispatch status changes.
5085 * If the dispatch status is #DBUS_DISPATCH_DATA_REMAINS, then
5086 * dbus_connection_dispatch() needs to be called to process incoming
5087 * messages. However, dbus_connection_dispatch() MUST NOT BE CALLED
5088 * from inside the DBusDispatchStatusFunction. Indeed, almost
5089 * any reentrancy in this function is a bad idea. Instead,
5090 * the DBusDispatchStatusFunction should simply save an indication
5091 * that messages should be dispatched later, when the main loop
5092 * is re-entered.
5093 *
5094 * If you don't set a dispatch status function, you have to be sure to
5095 * dispatch on every iteration of your main loop, especially if
5096 * dbus_watch_handle() or dbus_timeout_handle() were called.
5097 *
5098 * @param connection the connection
5099 * @param function function to call on dispatch status changes
5100 * @param data data for function
5101 * @param free_data_function free the function data
5102 */
5103 void
dbus_connection_set_dispatch_status_function(DBusConnection * connection,DBusDispatchStatusFunction function,void * data,DBusFreeFunction free_data_function)5104 dbus_connection_set_dispatch_status_function (DBusConnection *connection,
5105 DBusDispatchStatusFunction function,
5106 void *data,
5107 DBusFreeFunction free_data_function)
5108 {
5109 void *old_data;
5110 DBusFreeFunction old_free_data;
5111
5112 _dbus_return_if_fail (connection != NULL);
5113
5114 CONNECTION_LOCK (connection);
5115 old_data = connection->dispatch_status_data;
5116 old_free_data = connection->free_dispatch_status_data;
5117
5118 connection->dispatch_status_function = function;
5119 connection->dispatch_status_data = data;
5120 connection->free_dispatch_status_data = free_data_function;
5121
5122 CONNECTION_UNLOCK (connection);
5123
5124 /* Callback outside the lock */
5125 if (old_free_data)
5126 (*old_free_data) (old_data);
5127 }
5128
5129 /**
5130 * Get the UNIX file descriptor of the connection, if any. This can
5131 * be used for SELinux access control checks with getpeercon() for
5132 * example. DO NOT read or write to the file descriptor, or try to
5133 * select() on it; use DBusWatch for main loop integration. Not all
5134 * connections will have a file descriptor. So for adding descriptors
5135 * to the main loop, use dbus_watch_get_unix_fd() and so forth.
5136 *
5137 * If the connection is socket-based, you can also use
5138 * dbus_connection_get_socket(), which will work on Windows too.
5139 * This function always fails on Windows.
5140 *
5141 * Right now the returned descriptor is always a socket, but
5142 * that is not guaranteed.
5143 *
5144 * @param connection the connection
5145 * @param fd return location for the file descriptor.
5146 * @returns #TRUE if fd is successfully obtained.
5147 */
5148 dbus_bool_t
dbus_connection_get_unix_fd(DBusConnection * connection,int * fd)5149 dbus_connection_get_unix_fd (DBusConnection *connection,
5150 int *fd)
5151 {
5152 _dbus_return_val_if_fail (connection != NULL, FALSE);
5153 _dbus_return_val_if_fail (connection->transport != NULL, FALSE);
5154
5155 #ifdef DBUS_WIN
5156 /* FIXME do this on a lower level */
5157 return FALSE;
5158 #endif
5159
5160 return dbus_connection_get_socket(connection, fd);
5161 }
5162
5163 /**
5164 * Gets the underlying Windows or UNIX socket file descriptor
5165 * of the connection, if any. DO NOT read or write to the file descriptor, or try to
5166 * select() on it; use DBusWatch for main loop integration. Not all
5167 * connections will have a socket. So for adding descriptors
5168 * to the main loop, use dbus_watch_get_socket() and so forth.
5169 *
5170 * If the connection is not socket-based, this function will return FALSE,
5171 * even if the connection does have a file descriptor of some kind.
5172 * i.e. this function always returns specifically a socket file descriptor.
5173 *
5174 * @param connection the connection
5175 * @param fd return location for the file descriptor.
5176 * @returns #TRUE if fd is successfully obtained.
5177 */
5178 dbus_bool_t
dbus_connection_get_socket(DBusConnection * connection,int * fd)5179 dbus_connection_get_socket(DBusConnection *connection,
5180 int *fd)
5181 {
5182 dbus_bool_t retval;
5183 DBusSocket s = DBUS_SOCKET_INIT;
5184
5185 _dbus_return_val_if_fail (connection != NULL, FALSE);
5186 _dbus_return_val_if_fail (connection->transport != NULL, FALSE);
5187
5188 CONNECTION_LOCK (connection);
5189
5190 retval = _dbus_transport_get_socket_fd (connection->transport, &s);
5191
5192 if (retval)
5193 {
5194 *fd = _dbus_socket_get_int (s);
5195 }
5196
5197 CONNECTION_UNLOCK (connection);
5198
5199 return retval;
5200 }
5201
5202
5203 /**
5204 * Gets the UNIX user ID of the connection if known. Returns #TRUE if
5205 * the uid is filled in. Always returns #FALSE on non-UNIX platforms
5206 * for now, though in theory someone could hook Windows to NIS or
5207 * something. Always returns #FALSE prior to authenticating the
5208 * connection.
5209 *
5210 * The UID is only read by servers from clients; clients can't usually
5211 * get the UID of servers, because servers do not authenticate to
5212 * clients. The returned UID is the UID the connection authenticated
5213 * as.
5214 *
5215 * The message bus is a server and the apps connecting to the bus
5216 * are clients.
5217 *
5218 * You can ask the bus to tell you the UID of another connection though
5219 * if you like; this is done with dbus_bus_get_unix_user().
5220 *
5221 * @param connection the connection
5222 * @param uid return location for the user ID
5223 * @returns #TRUE if uid is filled in with a valid user ID
5224 */
5225 dbus_bool_t
dbus_connection_get_unix_user(DBusConnection * connection,unsigned long * uid)5226 dbus_connection_get_unix_user (DBusConnection *connection,
5227 unsigned long *uid)
5228 {
5229 dbus_bool_t result;
5230
5231 _dbus_return_val_if_fail (connection != NULL, FALSE);
5232 _dbus_return_val_if_fail (uid != NULL, FALSE);
5233
5234 CONNECTION_LOCK (connection);
5235
5236 if (!_dbus_transport_try_to_authenticate (connection->transport))
5237 result = FALSE;
5238 else
5239 result = _dbus_transport_get_unix_user (connection->transport,
5240 uid);
5241
5242 #ifdef DBUS_WIN
5243 _dbus_assert (!result);
5244 #endif
5245
5246 CONNECTION_UNLOCK (connection);
5247
5248 return result;
5249 }
5250
5251 /**
5252 * Gets the process ID of the connection if any.
5253 * Returns #TRUE if the pid is filled in.
5254 * Always returns #FALSE prior to authenticating the
5255 * connection.
5256 *
5257 * @param connection the connection
5258 * @param pid return location for the process ID
5259 * @returns #TRUE if uid is filled in with a valid process ID
5260 */
5261 dbus_bool_t
dbus_connection_get_unix_process_id(DBusConnection * connection,unsigned long * pid)5262 dbus_connection_get_unix_process_id (DBusConnection *connection,
5263 unsigned long *pid)
5264 {
5265 dbus_bool_t result;
5266
5267 _dbus_return_val_if_fail (connection != NULL, FALSE);
5268 _dbus_return_val_if_fail (pid != NULL, FALSE);
5269
5270 CONNECTION_LOCK (connection);
5271
5272 if (!_dbus_transport_try_to_authenticate (connection->transport))
5273 result = FALSE;
5274 else
5275 result = _dbus_transport_get_unix_process_id (connection->transport,
5276 pid);
5277
5278 CONNECTION_UNLOCK (connection);
5279
5280 return result;
5281 }
5282
5283 /**
5284 * Gets the ADT audit data of the connection if any.
5285 * Returns #TRUE if the structure pointer is returned.
5286 * Always returns #FALSE prior to authenticating the
5287 * connection.
5288 *
5289 * @param connection the connection
5290 * @param data return location for audit data
5291 * @param data_size return location for length of audit data
5292 * @returns #TRUE if audit data is filled in with a valid ucred pointer
5293 */
5294 dbus_bool_t
dbus_connection_get_adt_audit_session_data(DBusConnection * connection,void ** data,dbus_int32_t * data_size)5295 dbus_connection_get_adt_audit_session_data (DBusConnection *connection,
5296 void **data,
5297 dbus_int32_t *data_size)
5298 {
5299 dbus_bool_t result;
5300
5301 _dbus_return_val_if_fail (connection != NULL, FALSE);
5302 _dbus_return_val_if_fail (data != NULL, FALSE);
5303 _dbus_return_val_if_fail (data_size != NULL, FALSE);
5304
5305 CONNECTION_LOCK (connection);
5306
5307 if (!_dbus_transport_try_to_authenticate (connection->transport))
5308 result = FALSE;
5309 else
5310 result = _dbus_transport_get_adt_audit_session_data (connection->transport,
5311 data,
5312 data_size);
5313 CONNECTION_UNLOCK (connection);
5314
5315 return result;
5316 }
5317
5318 /**
5319 * Sets a predicate function used to determine whether a given user ID
5320 * is allowed to connect. When an incoming connection has
5321 * authenticated with a particular user ID, this function is called;
5322 * if it returns #TRUE, the connection is allowed to proceed,
5323 * otherwise the connection is disconnected.
5324 *
5325 * If the function is set to #NULL (as it is by default), then
5326 * only the same UID as the server process will be allowed to
5327 * connect. Also, root is always allowed to connect.
5328 *
5329 * On Windows, the function will be set and its free_data_function will
5330 * be invoked when the connection is freed or a new function is set.
5331 * However, the function will never be called, because there are
5332 * no UNIX user ids to pass to it, or at least none of the existing
5333 * auth protocols would allow authenticating as a UNIX user on Windows.
5334 *
5335 * @param connection the connection
5336 * @param function the predicate
5337 * @param data data to pass to the predicate
5338 * @param free_data_function function to free the data
5339 */
5340 void
dbus_connection_set_unix_user_function(DBusConnection * connection,DBusAllowUnixUserFunction function,void * data,DBusFreeFunction free_data_function)5341 dbus_connection_set_unix_user_function (DBusConnection *connection,
5342 DBusAllowUnixUserFunction function,
5343 void *data,
5344 DBusFreeFunction free_data_function)
5345 {
5346 void *old_data = NULL;
5347 DBusFreeFunction old_free_function = NULL;
5348
5349 _dbus_return_if_fail (connection != NULL);
5350
5351 CONNECTION_LOCK (connection);
5352 _dbus_transport_set_unix_user_function (connection->transport,
5353 function, data, free_data_function,
5354 &old_data, &old_free_function);
5355 CONNECTION_UNLOCK (connection);
5356
5357 if (old_free_function != NULL)
5358 (* old_free_function) (old_data);
5359 }
5360
5361 /* Same calling convention as dbus_connection_get_windows_user */
5362 dbus_bool_t
_dbus_connection_get_linux_security_label(DBusConnection * connection,char ** label_p)5363 _dbus_connection_get_linux_security_label (DBusConnection *connection,
5364 char **label_p)
5365 {
5366 dbus_bool_t result;
5367
5368 _dbus_assert (connection != NULL);
5369 _dbus_assert (label_p != NULL);
5370
5371 CONNECTION_LOCK (connection);
5372
5373 if (!_dbus_transport_try_to_authenticate (connection->transport))
5374 result = FALSE;
5375 else
5376 result = _dbus_transport_get_linux_security_label (connection->transport,
5377 label_p);
5378 #ifndef __linux__
5379 _dbus_assert (!result);
5380 #endif
5381
5382 CONNECTION_UNLOCK (connection);
5383
5384 return result;
5385 }
5386
5387 /**
5388 * Gets the Windows user SID of the connection if known. Returns
5389 * #TRUE if the ID is filled in. Always returns #FALSE on non-Windows
5390 * platforms for now, though in theory someone could hook UNIX to
5391 * Active Directory or something. Always returns #FALSE prior to
5392 * authenticating the connection.
5393 *
5394 * The user is only read by servers from clients; clients can't usually
5395 * get the user of servers, because servers do not authenticate to
5396 * clients. The returned user is the user the connection authenticated
5397 * as.
5398 *
5399 * The message bus is a server and the apps connecting to the bus
5400 * are clients.
5401 *
5402 * The returned user string has to be freed with dbus_free().
5403 *
5404 * The return value indicates whether the user SID is available;
5405 * if it's available but we don't have the memory to copy it,
5406 * then the return value is #TRUE and #NULL is given as the SID.
5407 *
5408 * @todo We would like to be able to say "You can ask the bus to tell
5409 * you the user of another connection though if you like; this is done
5410 * with dbus_bus_get_windows_user()." But this has to be implemented
5411 * in bus/driver.c and dbus/dbus-bus.c, and is pointless anyway
5412 * since on Windows we only use the session bus for now.
5413 *
5414 * @param connection the connection
5415 * @param windows_sid_p return location for an allocated copy of the user ID, or #NULL if no memory
5416 * @returns #TRUE if user is available (returned value may be #NULL anyway if no memory)
5417 */
5418 dbus_bool_t
dbus_connection_get_windows_user(DBusConnection * connection,char ** windows_sid_p)5419 dbus_connection_get_windows_user (DBusConnection *connection,
5420 char **windows_sid_p)
5421 {
5422 dbus_bool_t result;
5423
5424 _dbus_return_val_if_fail (connection != NULL, FALSE);
5425 _dbus_return_val_if_fail (windows_sid_p != NULL, FALSE);
5426
5427 CONNECTION_LOCK (connection);
5428
5429 if (!_dbus_transport_try_to_authenticate (connection->transport))
5430 result = FALSE;
5431 else
5432 result = _dbus_transport_get_windows_user (connection->transport,
5433 windows_sid_p);
5434
5435 #ifdef DBUS_UNIX
5436 _dbus_assert (!result);
5437 #endif
5438
5439 CONNECTION_UNLOCK (connection);
5440
5441 return result;
5442 }
5443
5444 /**
5445 * Sets a predicate function used to determine whether a given user ID
5446 * is allowed to connect. When an incoming connection has
5447 * authenticated with a particular user ID, this function is called;
5448 * if it returns #TRUE, the connection is allowed to proceed,
5449 * otherwise the connection is disconnected.
5450 *
5451 * If the function is set to #NULL (as it is by default), then
5452 * only the same user owning the server process will be allowed to
5453 * connect.
5454 *
5455 * On UNIX, the function will be set and its free_data_function will
5456 * be invoked when the connection is freed or a new function is set.
5457 * However, the function will never be called, because there is no
5458 * way right now to authenticate as a Windows user on UNIX.
5459 *
5460 * @param connection the connection
5461 * @param function the predicate
5462 * @param data data to pass to the predicate
5463 * @param free_data_function function to free the data
5464 */
5465 void
dbus_connection_set_windows_user_function(DBusConnection * connection,DBusAllowWindowsUserFunction function,void * data,DBusFreeFunction free_data_function)5466 dbus_connection_set_windows_user_function (DBusConnection *connection,
5467 DBusAllowWindowsUserFunction function,
5468 void *data,
5469 DBusFreeFunction free_data_function)
5470 {
5471 void *old_data = NULL;
5472 DBusFreeFunction old_free_function = NULL;
5473
5474 _dbus_return_if_fail (connection != NULL);
5475
5476 CONNECTION_LOCK (connection);
5477 _dbus_transport_set_windows_user_function (connection->transport,
5478 function, data, free_data_function,
5479 &old_data, &old_free_function);
5480 CONNECTION_UNLOCK (connection);
5481
5482 if (old_free_function != NULL)
5483 (* old_free_function) (old_data);
5484 }
5485
5486 /**
5487 * This function must be called on the server side of a connection when the
5488 * connection is first seen in the #DBusNewConnectionFunction. If set to
5489 * #TRUE (the default is #FALSE), then the connection can proceed even if
5490 * the client does not authenticate as some user identity, i.e. clients
5491 * can connect anonymously.
5492 *
5493 * This setting interacts with the available authorization mechanisms
5494 * (see dbus_server_set_auth_mechanisms()). Namely, an auth mechanism
5495 * such as ANONYMOUS that supports anonymous auth must be included in
5496 * the list of available mechanisms for anonymous login to work.
5497 *
5498 * This setting also changes the default rule for connections
5499 * authorized as a user; normally, if a connection authorizes as
5500 * a user identity, it is permitted if the user identity is
5501 * root or the user identity matches the user identity of the server
5502 * process. If anonymous connections are allowed, however,
5503 * then any user identity is allowed.
5504 *
5505 * You can override the rules for connections authorized as a
5506 * user identity with dbus_connection_set_unix_user_function()
5507 * and dbus_connection_set_windows_user_function().
5508 *
5509 * @param connection the connection
5510 * @param value whether to allow authentication as an anonymous user
5511 */
5512 void
dbus_connection_set_allow_anonymous(DBusConnection * connection,dbus_bool_t value)5513 dbus_connection_set_allow_anonymous (DBusConnection *connection,
5514 dbus_bool_t value)
5515 {
5516 _dbus_return_if_fail (connection != NULL);
5517
5518 CONNECTION_LOCK (connection);
5519 _dbus_transport_set_allow_anonymous (connection->transport, value);
5520 CONNECTION_UNLOCK (connection);
5521 }
5522
5523 /**
5524 *
5525 * Normally #DBusConnection automatically handles all messages to the
5526 * org.freedesktop.DBus.Peer interface. However, the message bus wants
5527 * to be able to route methods on that interface through the bus and
5528 * to other applications. If routing peer messages is enabled, then
5529 * messages with the org.freedesktop.DBus.Peer interface that also
5530 * have a bus destination name set will not be automatically
5531 * handled by the #DBusConnection and instead will be dispatched
5532 * normally to the application.
5533 *
5534 * If a normal application sets this flag, it can break things badly.
5535 * So don't set this unless you are the message bus.
5536 *
5537 * @param connection the connection
5538 * @param value #TRUE to pass through org.freedesktop.DBus.Peer messages with a bus name set
5539 */
5540 void
dbus_connection_set_route_peer_messages(DBusConnection * connection,dbus_bool_t value)5541 dbus_connection_set_route_peer_messages (DBusConnection *connection,
5542 dbus_bool_t value)
5543 {
5544 _dbus_return_if_fail (connection != NULL);
5545
5546 CONNECTION_LOCK (connection);
5547 connection->route_peer_messages = value;
5548 CONNECTION_UNLOCK (connection);
5549 }
5550
5551 /**
5552 * Adds a message filter. Filters are handlers that are run on all
5553 * incoming messages, prior to the objects registered with
5554 * dbus_connection_register_object_path(). Filters are run in the
5555 * order that they were added. The same handler can be added as a
5556 * filter more than once, in which case it will be run more than once.
5557 * Filters added during a filter callback won't be run on the message
5558 * being processed.
5559 *
5560 * @todo we don't run filters on messages while blocking without
5561 * entering the main loop, since filters are run as part of
5562 * dbus_connection_dispatch(). This is probably a feature, as filters
5563 * could create arbitrary reentrancy. But kind of sucks if you're
5564 * trying to filter METHOD_RETURN for some reason.
5565 *
5566 * @param connection the connection
5567 * @param function function to handle messages
5568 * @param user_data user data to pass to the function
5569 * @param free_data_function function to use for freeing user data
5570 * @returns #TRUE on success, #FALSE if not enough memory.
5571 */
5572 dbus_bool_t
dbus_connection_add_filter(DBusConnection * connection,DBusHandleMessageFunction function,void * user_data,DBusFreeFunction free_data_function)5573 dbus_connection_add_filter (DBusConnection *connection,
5574 DBusHandleMessageFunction function,
5575 void *user_data,
5576 DBusFreeFunction free_data_function)
5577 {
5578 DBusMessageFilter *filter;
5579
5580 _dbus_return_val_if_fail (connection != NULL, FALSE);
5581 _dbus_return_val_if_fail (function != NULL, FALSE);
5582
5583 filter = dbus_new0 (DBusMessageFilter, 1);
5584 if (filter == NULL)
5585 return FALSE;
5586
5587 _dbus_atomic_inc (&filter->refcount);
5588
5589 CONNECTION_LOCK (connection);
5590
5591 if (!_dbus_list_append (&connection->filter_list,
5592 filter))
5593 {
5594 _dbus_message_filter_unref (filter);
5595 CONNECTION_UNLOCK (connection);
5596 return FALSE;
5597 }
5598
5599 /* Fill in filter after all memory allocated,
5600 * so we don't run the free_user_data_function
5601 * if the add_filter() fails
5602 */
5603
5604 filter->function = function;
5605 filter->user_data = user_data;
5606 filter->free_user_data_function = free_data_function;
5607
5608 CONNECTION_UNLOCK (connection);
5609 return TRUE;
5610 }
5611
5612 /**
5613 * Removes a previously-added message filter. It is a programming
5614 * error to call this function for a handler that has not been added
5615 * as a filter. If the given handler was added more than once, only
5616 * one instance of it will be removed (the most recently-added
5617 * instance).
5618 *
5619 * @param connection the connection
5620 * @param function the handler to remove
5621 * @param user_data user data for the handler to remove
5622 *
5623 */
5624 void
dbus_connection_remove_filter(DBusConnection * connection,DBusHandleMessageFunction function,void * user_data)5625 dbus_connection_remove_filter (DBusConnection *connection,
5626 DBusHandleMessageFunction function,
5627 void *user_data)
5628 {
5629 DBusList *link;
5630 DBusMessageFilter *filter;
5631
5632 _dbus_return_if_fail (connection != NULL);
5633 _dbus_return_if_fail (function != NULL);
5634
5635 CONNECTION_LOCK (connection);
5636
5637 filter = NULL;
5638
5639 link = _dbus_list_get_last_link (&connection->filter_list);
5640 while (link != NULL)
5641 {
5642 filter = link->data;
5643
5644 if (filter->function == function &&
5645 filter->user_data == user_data)
5646 {
5647 _dbus_list_remove_link (&connection->filter_list, link);
5648 filter->function = NULL;
5649
5650 break;
5651 }
5652
5653 link = _dbus_list_get_prev_link (&connection->filter_list, link);
5654 filter = NULL;
5655 }
5656
5657 CONNECTION_UNLOCK (connection);
5658
5659 #ifndef DBUS_DISABLE_CHECKS
5660 if (filter == NULL)
5661 {
5662 _dbus_warn_check_failed ("Attempt to remove filter function %p user data %p, but no such filter has been added",
5663 function, user_data);
5664 return;
5665 }
5666 #endif
5667
5668 /* Call application code */
5669 if (filter->free_user_data_function)
5670 (* filter->free_user_data_function) (filter->user_data);
5671
5672 filter->free_user_data_function = NULL;
5673 filter->user_data = NULL;
5674
5675 _dbus_message_filter_unref (filter);
5676 }
5677
5678 /**
5679 * Registers a handler for a given path or subsection in the object
5680 * hierarchy. The given vtable handles messages sent to exactly the
5681 * given path or also for paths bellow that, depending on fallback
5682 * parameter.
5683 *
5684 * @param connection the connection
5685 * @param fallback whether to handle messages also for "subdirectory"
5686 * @param path a '/' delimited string of path elements
5687 * @param vtable the virtual table
5688 * @param user_data data to pass to functions in the vtable
5689 * @param error address where an error can be returned
5690 * @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
5691 * #DBUS_ERROR_OBJECT_PATH_IN_USE) is reported
5692 */
5693 static dbus_bool_t
_dbus_connection_register_object_path(DBusConnection * connection,dbus_bool_t fallback,const char * path,const DBusObjectPathVTable * vtable,void * user_data,DBusError * error)5694 _dbus_connection_register_object_path (DBusConnection *connection,
5695 dbus_bool_t fallback,
5696 const char *path,
5697 const DBusObjectPathVTable *vtable,
5698 void *user_data,
5699 DBusError *error)
5700 {
5701 char **decomposed_path;
5702 dbus_bool_t retval;
5703
5704 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
5705 return FALSE;
5706
5707 CONNECTION_LOCK (connection);
5708
5709 retval = _dbus_object_tree_register (connection->objects,
5710 fallback,
5711 (const char **) decomposed_path, vtable,
5712 user_data, error);
5713
5714 CONNECTION_UNLOCK (connection);
5715
5716 dbus_free_string_array (decomposed_path);
5717
5718 return retval;
5719 }
5720
5721 /**
5722 * Registers a handler for a given path in the object hierarchy.
5723 * The given vtable handles messages sent to exactly the given path.
5724 *
5725 * @param connection the connection
5726 * @param path a '/' delimited string of path elements
5727 * @param vtable the virtual table
5728 * @param user_data data to pass to functions in the vtable
5729 * @param error address where an error can be returned
5730 * @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
5731 * #DBUS_ERROR_OBJECT_PATH_IN_USE) is reported
5732 */
5733 dbus_bool_t
dbus_connection_try_register_object_path(DBusConnection * connection,const char * path,const DBusObjectPathVTable * vtable,void * user_data,DBusError * error)5734 dbus_connection_try_register_object_path (DBusConnection *connection,
5735 const char *path,
5736 const DBusObjectPathVTable *vtable,
5737 void *user_data,
5738 DBusError *error)
5739 {
5740 _dbus_return_val_if_fail (connection != NULL, FALSE);
5741 _dbus_return_val_if_fail (path != NULL, FALSE);
5742 _dbus_return_val_if_fail (path[0] == '/', FALSE);
5743 _dbus_return_val_if_fail (vtable != NULL, FALSE);
5744
5745 return _dbus_connection_register_object_path (connection, FALSE, path, vtable, user_data, error);
5746 }
5747
5748 /**
5749 * Registers a handler for a given path in the object hierarchy.
5750 * The given vtable handles messages sent to exactly the given path.
5751 *
5752 * It is a bug to call this function for object paths which already
5753 * have a handler. Use dbus_connection_try_register_object_path() if this
5754 * might be the case.
5755 *
5756 * @param connection the connection
5757 * @param path a '/' delimited string of path elements
5758 * @param vtable the virtual table
5759 * @param user_data data to pass to functions in the vtable
5760 * @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
5761 * #DBUS_ERROR_OBJECT_PATH_IN_USE) ocurred
5762 */
5763 dbus_bool_t
dbus_connection_register_object_path(DBusConnection * connection,const char * path,const DBusObjectPathVTable * vtable,void * user_data)5764 dbus_connection_register_object_path (DBusConnection *connection,
5765 const char *path,
5766 const DBusObjectPathVTable *vtable,
5767 void *user_data)
5768 {
5769 dbus_bool_t retval;
5770 DBusError error = DBUS_ERROR_INIT;
5771
5772 _dbus_return_val_if_fail (connection != NULL, FALSE);
5773 _dbus_return_val_if_fail (path != NULL, FALSE);
5774 _dbus_return_val_if_fail (path[0] == '/', FALSE);
5775 _dbus_return_val_if_fail (vtable != NULL, FALSE);
5776
5777 retval = _dbus_connection_register_object_path (connection, FALSE, path, vtable, user_data, &error);
5778
5779 if (dbus_error_has_name (&error, DBUS_ERROR_OBJECT_PATH_IN_USE))
5780 {
5781 _dbus_warn ("%s", error.message);
5782 dbus_error_free (&error);
5783 return FALSE;
5784 }
5785
5786 return retval;
5787 }
5788
5789 /**
5790 * Registers a fallback handler for a given subsection of the object
5791 * hierarchy. The given vtable handles messages at or below the given
5792 * path. You can use this to establish a default message handling
5793 * policy for a whole "subdirectory."
5794 *
5795 * @param connection the connection
5796 * @param path a '/' delimited string of path elements
5797 * @param vtable the virtual table
5798 * @param user_data data to pass to functions in the vtable
5799 * @param error address where an error can be returned
5800 * @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
5801 * #DBUS_ERROR_OBJECT_PATH_IN_USE) is reported
5802 */
5803 dbus_bool_t
dbus_connection_try_register_fallback(DBusConnection * connection,const char * path,const DBusObjectPathVTable * vtable,void * user_data,DBusError * error)5804 dbus_connection_try_register_fallback (DBusConnection *connection,
5805 const char *path,
5806 const DBusObjectPathVTable *vtable,
5807 void *user_data,
5808 DBusError *error)
5809 {
5810 _dbus_return_val_if_fail (connection != NULL, FALSE);
5811 _dbus_return_val_if_fail (path != NULL, FALSE);
5812 _dbus_return_val_if_fail (path[0] == '/', FALSE);
5813 _dbus_return_val_if_fail (vtable != NULL, FALSE);
5814
5815 return _dbus_connection_register_object_path (connection, TRUE, path, vtable, user_data, error);
5816 }
5817
5818 /**
5819 * Registers a fallback handler for a given subsection of the object
5820 * hierarchy. The given vtable handles messages at or below the given
5821 * path. You can use this to establish a default message handling
5822 * policy for a whole "subdirectory."
5823 *
5824 * It is a bug to call this function for object paths which already
5825 * have a handler. Use dbus_connection_try_register_fallback() if this
5826 * might be the case.
5827 *
5828 * @param connection the connection
5829 * @param path a '/' delimited string of path elements
5830 * @param vtable the virtual table
5831 * @param user_data data to pass to functions in the vtable
5832 * @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or
5833 * #DBUS_ERROR_OBJECT_PATH_IN_USE) occured
5834 */
5835 dbus_bool_t
dbus_connection_register_fallback(DBusConnection * connection,const char * path,const DBusObjectPathVTable * vtable,void * user_data)5836 dbus_connection_register_fallback (DBusConnection *connection,
5837 const char *path,
5838 const DBusObjectPathVTable *vtable,
5839 void *user_data)
5840 {
5841 dbus_bool_t retval;
5842 DBusError error = DBUS_ERROR_INIT;
5843
5844 _dbus_return_val_if_fail (connection != NULL, FALSE);
5845 _dbus_return_val_if_fail (path != NULL, FALSE);
5846 _dbus_return_val_if_fail (path[0] == '/', FALSE);
5847 _dbus_return_val_if_fail (vtable != NULL, FALSE);
5848
5849 retval = _dbus_connection_register_object_path (connection, TRUE, path, vtable, user_data, &error);
5850
5851 if (dbus_error_has_name (&error, DBUS_ERROR_OBJECT_PATH_IN_USE))
5852 {
5853 _dbus_warn ("%s", error.message);
5854 dbus_error_free (&error);
5855 return FALSE;
5856 }
5857
5858 return retval;
5859 }
5860
5861 /**
5862 * Unregisters the handler registered with exactly the given path.
5863 * It's a bug to call this function for a path that isn't registered.
5864 * Can unregister both fallback paths and object paths.
5865 *
5866 * @param connection the connection
5867 * @param path a '/' delimited string of path elements
5868 * @returns #FALSE if not enough memory
5869 */
5870 dbus_bool_t
dbus_connection_unregister_object_path(DBusConnection * connection,const char * path)5871 dbus_connection_unregister_object_path (DBusConnection *connection,
5872 const char *path)
5873 {
5874 char **decomposed_path;
5875
5876 _dbus_return_val_if_fail (connection != NULL, FALSE);
5877 _dbus_return_val_if_fail (path != NULL, FALSE);
5878 _dbus_return_val_if_fail (path[0] == '/', FALSE);
5879
5880 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
5881 return FALSE;
5882
5883 CONNECTION_LOCK (connection);
5884
5885 _dbus_object_tree_unregister_and_unlock (connection->objects, (const char **) decomposed_path);
5886
5887 dbus_free_string_array (decomposed_path);
5888
5889 return TRUE;
5890 }
5891
5892 /**
5893 * Gets the user data passed to dbus_connection_register_object_path()
5894 * or dbus_connection_register_fallback(). If nothing was registered
5895 * at this path, the data is filled in with #NULL.
5896 *
5897 * @param connection the connection
5898 * @param path the path you registered with
5899 * @param data_p location to store the user data, or #NULL
5900 * @returns #FALSE if not enough memory
5901 */
5902 dbus_bool_t
dbus_connection_get_object_path_data(DBusConnection * connection,const char * path,void ** data_p)5903 dbus_connection_get_object_path_data (DBusConnection *connection,
5904 const char *path,
5905 void **data_p)
5906 {
5907 char **decomposed_path;
5908
5909 _dbus_return_val_if_fail (connection != NULL, FALSE);
5910 _dbus_return_val_if_fail (path != NULL, FALSE);
5911 _dbus_return_val_if_fail (data_p != NULL, FALSE);
5912
5913 *data_p = NULL;
5914
5915 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL))
5916 return FALSE;
5917
5918 CONNECTION_LOCK (connection);
5919
5920 *data_p = _dbus_object_tree_get_user_data_unlocked (connection->objects, (const char**) decomposed_path);
5921
5922 CONNECTION_UNLOCK (connection);
5923
5924 dbus_free_string_array (decomposed_path);
5925
5926 return TRUE;
5927 }
5928
5929 /**
5930 * Lists the registered fallback handlers and object path handlers at
5931 * the given parent_path. The returned array should be freed with
5932 * dbus_free_string_array().
5933 *
5934 * @param connection the connection
5935 * @param parent_path the path to list the child handlers of
5936 * @param child_entries returns #NULL-terminated array of children
5937 * @returns #FALSE if no memory to allocate the child entries
5938 */
5939 dbus_bool_t
dbus_connection_list_registered(DBusConnection * connection,const char * parent_path,char *** child_entries)5940 dbus_connection_list_registered (DBusConnection *connection,
5941 const char *parent_path,
5942 char ***child_entries)
5943 {
5944 char **decomposed_path;
5945 dbus_bool_t retval;
5946 _dbus_return_val_if_fail (connection != NULL, FALSE);
5947 _dbus_return_val_if_fail (parent_path != NULL, FALSE);
5948 _dbus_return_val_if_fail (parent_path[0] == '/', FALSE);
5949 _dbus_return_val_if_fail (child_entries != NULL, FALSE);
5950
5951 if (!_dbus_decompose_path (parent_path, strlen (parent_path), &decomposed_path, NULL))
5952 return FALSE;
5953
5954 CONNECTION_LOCK (connection);
5955
5956 retval = _dbus_object_tree_list_registered_and_unlock (connection->objects,
5957 (const char **) decomposed_path,
5958 child_entries);
5959 dbus_free_string_array (decomposed_path);
5960
5961 return retval;
5962 }
5963
5964 static DBusDataSlotAllocator slot_allocator =
5965 _DBUS_DATA_SLOT_ALLOCATOR_INIT (_DBUS_LOCK_NAME (connection_slots));
5966
5967 /**
5968 * Allocates an integer ID to be used for storing application-specific
5969 * data on any DBusConnection. The allocated ID may then be used
5970 * with dbus_connection_set_data() and dbus_connection_get_data().
5971 * The passed-in slot must be initialized to -1, and is filled in
5972 * with the slot ID. If the passed-in slot is not -1, it's assumed
5973 * to be already allocated, and its refcount is incremented.
5974 *
5975 * The allocated slot is global, i.e. all DBusConnection objects will
5976 * have a slot with the given integer ID reserved.
5977 *
5978 * @param slot_p address of a global variable storing the slot
5979 * @returns #FALSE on failure (no memory)
5980 */
5981 dbus_bool_t
dbus_connection_allocate_data_slot(dbus_int32_t * slot_p)5982 dbus_connection_allocate_data_slot (dbus_int32_t *slot_p)
5983 {
5984 return _dbus_data_slot_allocator_alloc (&slot_allocator,
5985 slot_p);
5986 }
5987
5988 /**
5989 * Deallocates a global ID for connection data slots.
5990 * dbus_connection_get_data() and dbus_connection_set_data() may no
5991 * longer be used with this slot. Existing data stored on existing
5992 * DBusConnection objects will be freed when the connection is
5993 * finalized, but may not be retrieved (and may only be replaced if
5994 * someone else reallocates the slot). When the refcount on the
5995 * passed-in slot reaches 0, it is set to -1.
5996 *
5997 * @param slot_p address storing the slot to deallocate
5998 */
5999 void
dbus_connection_free_data_slot(dbus_int32_t * slot_p)6000 dbus_connection_free_data_slot (dbus_int32_t *slot_p)
6001 {
6002 _dbus_return_if_fail (*slot_p >= 0);
6003
6004 _dbus_data_slot_allocator_free (&slot_allocator, slot_p);
6005 }
6006
6007 /**
6008 * Stores a pointer on a DBusConnection, along
6009 * with an optional function to be used for freeing
6010 * the data when the data is set again, or when
6011 * the connection is finalized. The slot number
6012 * must have been allocated with dbus_connection_allocate_data_slot().
6013 *
6014 * @note This function does not take the
6015 * main thread lock on DBusConnection, which allows it to be
6016 * used from inside watch and timeout functions. (See the
6017 * note in docs for dbus_connection_set_watch_functions().)
6018 * A side effect of this is that you need to know there's
6019 * a reference held on the connection while invoking
6020 * dbus_connection_set_data(), or the connection could be
6021 * finalized during dbus_connection_set_data().
6022 *
6023 * @param connection the connection
6024 * @param slot the slot number
6025 * @param data the data to store
6026 * @param free_data_func finalizer function for the data
6027 * @returns #TRUE if there was enough memory to store the data
6028 */
6029 dbus_bool_t
dbus_connection_set_data(DBusConnection * connection,dbus_int32_t slot,void * data,DBusFreeFunction free_data_func)6030 dbus_connection_set_data (DBusConnection *connection,
6031 dbus_int32_t slot,
6032 void *data,
6033 DBusFreeFunction free_data_func)
6034 {
6035 DBusFreeFunction old_free_func;
6036 void *old_data;
6037 dbus_bool_t retval;
6038
6039 _dbus_return_val_if_fail (connection != NULL, FALSE);
6040 _dbus_return_val_if_fail (slot >= 0, FALSE);
6041
6042 SLOTS_LOCK (connection);
6043
6044 retval = _dbus_data_slot_list_set (&slot_allocator,
6045 &connection->slot_list,
6046 slot, data, free_data_func,
6047 &old_free_func, &old_data);
6048
6049 SLOTS_UNLOCK (connection);
6050
6051 if (retval)
6052 {
6053 /* Do the actual free outside the connection lock */
6054 if (old_free_func)
6055 (* old_free_func) (old_data);
6056 }
6057
6058 return retval;
6059 }
6060
6061 /**
6062 * Retrieves data previously set with dbus_connection_set_data().
6063 * The slot must still be allocated (must not have been freed).
6064 *
6065 * @note This function does not take the
6066 * main thread lock on DBusConnection, which allows it to be
6067 * used from inside watch and timeout functions. (See the
6068 * note in docs for dbus_connection_set_watch_functions().)
6069 * A side effect of this is that you need to know there's
6070 * a reference held on the connection while invoking
6071 * dbus_connection_get_data(), or the connection could be
6072 * finalized during dbus_connection_get_data().
6073 *
6074 * @param connection the connection
6075 * @param slot the slot to get data from
6076 * @returns the data, or #NULL if not found
6077 */
6078 void*
dbus_connection_get_data(DBusConnection * connection,dbus_int32_t slot)6079 dbus_connection_get_data (DBusConnection *connection,
6080 dbus_int32_t slot)
6081 {
6082 void *res;
6083
6084 _dbus_return_val_if_fail (connection != NULL, NULL);
6085 _dbus_return_val_if_fail (slot >= 0, NULL);
6086
6087 SLOTS_LOCK (connection);
6088
6089 res = _dbus_data_slot_list_get (&slot_allocator,
6090 &connection->slot_list,
6091 slot);
6092
6093 SLOTS_UNLOCK (connection);
6094
6095 return res;
6096 }
6097
6098 /**
6099 * This function sets a global flag for whether dbus_connection_new()
6100 * will set SIGPIPE behavior to SIG_IGN.
6101 *
6102 * @param will_modify_sigpipe #TRUE to allow sigpipe to be set to SIG_IGN
6103 */
6104 void
dbus_connection_set_change_sigpipe(dbus_bool_t will_modify_sigpipe)6105 dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe)
6106 {
6107 _dbus_modify_sigpipe = will_modify_sigpipe != FALSE;
6108 }
6109
6110 /**
6111 * Specifies the maximum size message this connection is allowed to
6112 * receive. Larger messages will result in disconnecting the
6113 * connection.
6114 *
6115 * @param connection a #DBusConnection
6116 * @param size maximum message size the connection can receive, in bytes
6117 */
6118 void
dbus_connection_set_max_message_size(DBusConnection * connection,long size)6119 dbus_connection_set_max_message_size (DBusConnection *connection,
6120 long size)
6121 {
6122 _dbus_return_if_fail (connection != NULL);
6123
6124 CONNECTION_LOCK (connection);
6125 _dbus_transport_set_max_message_size (connection->transport,
6126 size);
6127 CONNECTION_UNLOCK (connection);
6128 }
6129
6130 /**
6131 * Gets the value set by dbus_connection_set_max_message_size().
6132 *
6133 * @param connection the connection
6134 * @returns the max size of a single message
6135 */
6136 long
dbus_connection_get_max_message_size(DBusConnection * connection)6137 dbus_connection_get_max_message_size (DBusConnection *connection)
6138 {
6139 long res;
6140
6141 _dbus_return_val_if_fail (connection != NULL, 0);
6142
6143 CONNECTION_LOCK (connection);
6144 res = _dbus_transport_get_max_message_size (connection->transport);
6145 CONNECTION_UNLOCK (connection);
6146 return res;
6147 }
6148
6149 /**
6150 * Specifies the maximum number of unix fds a message on this
6151 * connection is allowed to receive. Messages with more unix fds will
6152 * result in disconnecting the connection.
6153 *
6154 * @param connection a #DBusConnection
6155 * @param n maximum message unix fds the connection can receive
6156 */
6157 void
dbus_connection_set_max_message_unix_fds(DBusConnection * connection,long n)6158 dbus_connection_set_max_message_unix_fds (DBusConnection *connection,
6159 long n)
6160 {
6161 _dbus_return_if_fail (connection != NULL);
6162
6163 CONNECTION_LOCK (connection);
6164 _dbus_transport_set_max_message_unix_fds (connection->transport,
6165 n);
6166 CONNECTION_UNLOCK (connection);
6167 }
6168
6169 /**
6170 * Gets the value set by dbus_connection_set_max_message_unix_fds().
6171 *
6172 * @param connection the connection
6173 * @returns the max numer of unix fds of a single message
6174 */
6175 long
dbus_connection_get_max_message_unix_fds(DBusConnection * connection)6176 dbus_connection_get_max_message_unix_fds (DBusConnection *connection)
6177 {
6178 long res;
6179
6180 _dbus_return_val_if_fail (connection != NULL, 0);
6181
6182 CONNECTION_LOCK (connection);
6183 res = _dbus_transport_get_max_message_unix_fds (connection->transport);
6184 CONNECTION_UNLOCK (connection);
6185 return res;
6186 }
6187
6188 /**
6189 * Sets the maximum total number of bytes that can be used for all messages
6190 * received on this connection. Messages count toward the maximum until
6191 * they are finalized. When the maximum is reached, the connection will
6192 * not read more data until some messages are finalized.
6193 *
6194 * The semantics of the maximum are: if outstanding messages are
6195 * already above the maximum, additional messages will not be read.
6196 * The semantics are not: if the next message would cause us to exceed
6197 * the maximum, we don't read it. The reason is that we don't know the
6198 * size of a message until after we read it.
6199 *
6200 * Thus, the max live messages size can actually be exceeded
6201 * by up to the maximum size of a single message.
6202 *
6203 * Also, if we read say 1024 bytes off the wire in a single read(),
6204 * and that contains a half-dozen small messages, we may exceed the
6205 * size max by that amount. But this should be inconsequential.
6206 *
6207 * This does imply that we can't call read() with a buffer larger
6208 * than we're willing to exceed this limit by.
6209 *
6210 * @param connection the connection
6211 * @param size the maximum size in bytes of all outstanding messages
6212 */
6213 void
dbus_connection_set_max_received_size(DBusConnection * connection,long size)6214 dbus_connection_set_max_received_size (DBusConnection *connection,
6215 long size)
6216 {
6217 _dbus_return_if_fail (connection != NULL);
6218
6219 CONNECTION_LOCK (connection);
6220 _dbus_transport_set_max_received_size (connection->transport,
6221 size);
6222 CONNECTION_UNLOCK (connection);
6223 }
6224
6225 /**
6226 * Gets the value set by dbus_connection_set_max_received_size().
6227 *
6228 * @param connection the connection
6229 * @returns the max size of all live messages
6230 */
6231 long
dbus_connection_get_max_received_size(DBusConnection * connection)6232 dbus_connection_get_max_received_size (DBusConnection *connection)
6233 {
6234 long res;
6235
6236 _dbus_return_val_if_fail (connection != NULL, 0);
6237
6238 CONNECTION_LOCK (connection);
6239 res = _dbus_transport_get_max_received_size (connection->transport);
6240 CONNECTION_UNLOCK (connection);
6241 return res;
6242 }
6243
6244 /**
6245 * Sets the maximum total number of unix fds that can be used for all messages
6246 * received on this connection. Messages count toward the maximum until
6247 * they are finalized. When the maximum is reached, the connection will
6248 * not read more data until some messages are finalized.
6249 *
6250 * The semantics are analogous to those of dbus_connection_set_max_received_size().
6251 *
6252 * @param connection the connection
6253 * @param n the maximum size in bytes of all outstanding messages
6254 */
6255 void
dbus_connection_set_max_received_unix_fds(DBusConnection * connection,long n)6256 dbus_connection_set_max_received_unix_fds (DBusConnection *connection,
6257 long n)
6258 {
6259 _dbus_return_if_fail (connection != NULL);
6260
6261 CONNECTION_LOCK (connection);
6262 _dbus_transport_set_max_received_unix_fds (connection->transport,
6263 n);
6264 CONNECTION_UNLOCK (connection);
6265 }
6266
6267 /**
6268 * Gets the value set by dbus_connection_set_max_received_unix_fds().
6269 *
6270 * @param connection the connection
6271 * @returns the max unix fds of all live messages
6272 */
6273 long
dbus_connection_get_max_received_unix_fds(DBusConnection * connection)6274 dbus_connection_get_max_received_unix_fds (DBusConnection *connection)
6275 {
6276 long res;
6277
6278 _dbus_return_val_if_fail (connection != NULL, 0);
6279
6280 CONNECTION_LOCK (connection);
6281 res = _dbus_transport_get_max_received_unix_fds (connection->transport);
6282 CONNECTION_UNLOCK (connection);
6283 return res;
6284 }
6285
6286 /**
6287 * Gets the approximate size in bytes of all messages in the outgoing
6288 * message queue. The size is approximate in that you shouldn't use
6289 * it to decide how many bytes to read off the network or anything
6290 * of that nature, as optimizations may choose to tell small white lies
6291 * to avoid performance overhead.
6292 *
6293 * @param connection the connection
6294 * @returns the number of bytes that have been queued up but not sent
6295 */
6296 long
dbus_connection_get_outgoing_size(DBusConnection * connection)6297 dbus_connection_get_outgoing_size (DBusConnection *connection)
6298 {
6299 long res;
6300
6301 _dbus_return_val_if_fail (connection != NULL, 0);
6302
6303 CONNECTION_LOCK (connection);
6304 res = _dbus_counter_get_size_value (connection->outgoing_counter);
6305 CONNECTION_UNLOCK (connection);
6306 return res;
6307 }
6308
6309 #ifdef DBUS_ENABLE_STATS
6310 void
_dbus_connection_get_stats(DBusConnection * connection,dbus_uint32_t * in_messages,dbus_uint32_t * in_bytes,dbus_uint32_t * in_fds,dbus_uint32_t * in_peak_bytes,dbus_uint32_t * in_peak_fds,dbus_uint32_t * out_messages,dbus_uint32_t * out_bytes,dbus_uint32_t * out_fds,dbus_uint32_t * out_peak_bytes,dbus_uint32_t * out_peak_fds)6311 _dbus_connection_get_stats (DBusConnection *connection,
6312 dbus_uint32_t *in_messages,
6313 dbus_uint32_t *in_bytes,
6314 dbus_uint32_t *in_fds,
6315 dbus_uint32_t *in_peak_bytes,
6316 dbus_uint32_t *in_peak_fds,
6317 dbus_uint32_t *out_messages,
6318 dbus_uint32_t *out_bytes,
6319 dbus_uint32_t *out_fds,
6320 dbus_uint32_t *out_peak_bytes,
6321 dbus_uint32_t *out_peak_fds)
6322 {
6323 CONNECTION_LOCK (connection);
6324
6325 if (in_messages != NULL)
6326 *in_messages = connection->n_incoming;
6327
6328 _dbus_transport_get_stats (connection->transport,
6329 in_bytes, in_fds, in_peak_bytes, in_peak_fds);
6330
6331 if (out_messages != NULL)
6332 *out_messages = connection->n_outgoing;
6333
6334 if (out_bytes != NULL)
6335 *out_bytes = _dbus_counter_get_size_value (connection->outgoing_counter);
6336
6337 if (out_fds != NULL)
6338 *out_fds = _dbus_counter_get_unix_fd_value (connection->outgoing_counter);
6339
6340 if (out_peak_bytes != NULL)
6341 *out_peak_bytes = _dbus_counter_get_peak_size_value (connection->outgoing_counter);
6342
6343 if (out_peak_fds != NULL)
6344 *out_peak_fds = _dbus_counter_get_peak_unix_fd_value (connection->outgoing_counter);
6345
6346 CONNECTION_UNLOCK (connection);
6347 }
6348 #endif /* DBUS_ENABLE_STATS */
6349
6350 /**
6351 * Gets the approximate number of uni fds of all messages in the
6352 * outgoing message queue.
6353 *
6354 * @param connection the connection
6355 * @returns the number of unix fds that have been queued up but not sent
6356 */
6357 long
dbus_connection_get_outgoing_unix_fds(DBusConnection * connection)6358 dbus_connection_get_outgoing_unix_fds (DBusConnection *connection)
6359 {
6360 long res;
6361
6362 _dbus_return_val_if_fail (connection != NULL, 0);
6363
6364 CONNECTION_LOCK (connection);
6365 res = _dbus_counter_get_unix_fd_value (connection->outgoing_counter);
6366 CONNECTION_UNLOCK (connection);
6367 return res;
6368 }
6369
6370 #ifdef DBUS_ENABLE_EMBEDDED_TESTS
6371 /**
6372 * Returns the address of the transport object of this connection
6373 *
6374 * @param connection the connection
6375 * @returns the address string
6376 */
6377 const char*
_dbus_connection_get_address(DBusConnection * connection)6378 _dbus_connection_get_address (DBusConnection *connection)
6379 {
6380 return _dbus_transport_get_address (connection->transport);
6381 }
6382 #endif
6383
6384 /** @} */
6385