1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dbus-message.c DBusMessage object
4 * Copyright (C) 2002, 2003, 2004, 2005 Red Hat Inc.
5 * Copyright (C) 2002, 2003 CodeFactory AB
7 * Licensed under the Academic Free License version 2.1
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include "dbus-internals.h"
26 #include "dbus-marshal-recursive.h"
27 #include "dbus-marshal-validate.h"
28 #include "dbus-marshal-byteswap.h"
29 #include "dbus-marshal-header.h"
30 #include "dbus-message-private.h"
31 #include "dbus-object-tree.h"
32 #include "dbus-memory.h"
33 #include "dbus-list.h"
37 * @defgroup DBusMessageInternals DBusMessage implementation details
38 * @ingroup DBusInternals
39 * @brief DBusMessage private implementation details.
41 * The guts of DBusMessage and its methods.
46 /* Not thread locked, but strictly const/read-only so should be OK
48 /** An static string representing an empty signature */
49 _DBUS_STRING_DEFINE_STATIC(_dbus_empty_signature_str, "");
51 /* these have wacky values to help trap uninitialized iterators;
52 * but has to fit in 3 bits
55 DBUS_MESSAGE_ITER_TYPE_READER = 3,
56 DBUS_MESSAGE_ITER_TYPE_WRITER = 7
59 /** typedef for internals of message iterator */
60 typedef struct DBusMessageRealIter DBusMessageRealIter;
63 * @brief Internals of DBusMessageIter
65 * Object representing a position in a message. All fields are internal.
67 struct DBusMessageRealIter
69 DBusMessage *message; /**< Message used */
70 dbus_uint32_t changed_stamp : CHANGED_STAMP_BITS; /**< stamp to detect invalid iters */
71 dbus_uint32_t iter_type : 3; /**< whether this is a reader or writer iter */
72 dbus_uint32_t sig_refcount : 8; /**< depth of open_signature() */
75 DBusTypeWriter writer; /**< writer */
76 DBusTypeReader reader; /**< reader */
77 } u; /**< the type writer or reader that does all the work */
81 get_const_signature (DBusHeader *header,
82 const DBusString **type_str_p,
85 if (_dbus_header_get_field_raw (header,
86 DBUS_HEADER_FIELD_SIGNATURE,
90 *type_pos_p += 1; /* skip the signature length which is 1 byte */
94 *type_str_p = &_dbus_empty_signature_str;
100 * Swaps the message to compiler byte order if required
102 * @param message the message
105 _dbus_message_byteswap (DBusMessage *message)
107 const DBusString *type_str;
110 if (message->byte_order == DBUS_COMPILER_BYTE_ORDER)
113 _dbus_verbose ("Swapping message into compiler byte order\n");
115 get_const_signature (&message->header, &type_str, &type_pos);
117 _dbus_marshal_byteswap (type_str, type_pos,
119 DBUS_COMPILER_BYTE_ORDER,
122 message->byte_order = DBUS_COMPILER_BYTE_ORDER;
124 _dbus_header_byteswap (&message->header, DBUS_COMPILER_BYTE_ORDER);
127 #define ensure_byte_order(message) \
128 if (message->byte_order != DBUS_COMPILER_BYTE_ORDER) \
129 _dbus_message_byteswap (message)
132 * Gets the data to be sent over the network for this message.
133 * The header and then the body should be written out.
134 * This function is guaranteed to always return the same
135 * data once a message is locked (with _dbus_message_lock()).
137 * @param message the message.
138 * @param header return location for message header data.
139 * @param body return location for message body data.
142 _dbus_message_get_network_data (DBusMessage *message,
143 const DBusString **header,
144 const DBusString **body)
146 _dbus_assert (message->locked);
148 *header = &message->header.data;
149 *body = &message->body;
153 * Sets the serial number of a message.
154 * This can only be done once on a message.
156 * @param message the message
157 * @param serial the serial
160 _dbus_message_set_serial (DBusMessage *message,
161 dbus_uint32_t serial)
163 _dbus_assert (message != NULL);
164 _dbus_assert (!message->locked);
165 _dbus_assert (dbus_message_get_serial (message) == 0);
167 _dbus_header_set_serial (&message->header, serial);
171 * Adds a counter to be incremented immediately with the
172 * size of this message, and decremented by the size
173 * of this message when this message if finalized.
174 * The link contains a counter with its refcount already
175 * incremented, but the counter itself not incremented.
176 * Ownership of link and counter refcount is passed to
179 * @param message the message
180 * @param link link with counter as data
183 _dbus_message_add_size_counter_link (DBusMessage *message,
186 /* right now we don't recompute the delta when message
187 * size changes, and that's OK for current purposes
188 * I think, but could be important to change later.
189 * Do recompute it whenever there are no outstanding counters,
190 * since it's basically free.
192 if (message->size_counters == NULL)
194 message->size_counter_delta =
195 _dbus_string_get_length (&message->header.data) +
196 _dbus_string_get_length (&message->body);
199 _dbus_verbose ("message has size %ld\n",
200 message->size_counter_delta);
204 _dbus_list_append_link (&message->size_counters, link);
206 _dbus_counter_adjust (link->data, message->size_counter_delta);
210 * Adds a counter to be incremented immediately with the
211 * size of this message, and decremented by the size
212 * of this message when this message if finalized.
214 * @param message the message
215 * @param counter the counter
216 * @returns #FALSE if no memory
219 _dbus_message_add_size_counter (DBusMessage *message,
220 DBusCounter *counter)
224 link = _dbus_list_alloc_link (counter);
228 _dbus_counter_ref (counter);
229 _dbus_message_add_size_counter_link (message, link);
235 * Removes a counter tracking the size of this message, and decrements
236 * the counter by the size of this message.
238 * @param message the message
239 * @param link_return return the link used
240 * @param counter the counter
243 _dbus_message_remove_size_counter (DBusMessage *message,
244 DBusCounter *counter,
245 DBusList **link_return)
249 link = _dbus_list_find_last (&message->size_counters,
251 _dbus_assert (link != NULL);
253 _dbus_list_unlink (&message->size_counters,
258 _dbus_list_free_link (link);
260 _dbus_counter_adjust (counter, - message->size_counter_delta);
262 _dbus_counter_unref (counter);
266 * Locks a message. Allows checking that applications don't keep a
267 * reference to a message in the outgoing queue and change it
268 * underneath us. Messages are locked when they enter the outgoing
269 * queue (dbus_connection_send_message()), and the library complains
270 * if the message is modified while locked.
272 * @param message the message to lock.
275 _dbus_message_lock (DBusMessage *message)
277 if (!message->locked)
279 _dbus_header_update_lengths (&message->header,
280 _dbus_string_get_length (&message->body));
282 /* must have a signature if you have a body */
283 _dbus_assert (_dbus_string_get_length (&message->body) == 0 ||
284 dbus_message_get_signature (message) != NULL);
286 message->locked = TRUE;
291 set_or_delete_string_field (DBusMessage *message,
297 return _dbus_header_delete_field (&message->header, field);
299 return _dbus_header_set_field_basic (&message->header,
306 /* Probably we don't need to use this */
308 * Sets the signature of the message, i.e. the arguments in the
309 * message payload. The signature includes only "in" arguments for
310 * #DBUS_MESSAGE_TYPE_METHOD_CALL and only "out" arguments for
311 * #DBUS_MESSAGE_TYPE_METHOD_RETURN, so is slightly different from
312 * what you might expect (it does not include the signature of the
313 * entire C++-style method).
315 * The signature is a string made up of type codes such as
316 * #DBUS_TYPE_INT32. The string is terminated with nul (nul is also
317 * the value of #DBUS_TYPE_INVALID). The macros such as
318 * #DBUS_TYPE_INT32 evaluate to integers; to assemble a signature you
319 * may find it useful to use the string forms, such as
320 * #DBUS_TYPE_INT32_AS_STRING.
322 * An "unset" or #NULL signature is considered the same as an empty
323 * signature. In fact dbus_message_get_signature() will never return
326 * @param message the message
327 * @param signature the type signature or #NULL to unset
328 * @returns #FALSE if no memory
331 _dbus_message_set_signature (DBusMessage *message,
332 const char *signature)
334 _dbus_return_val_if_fail (message != NULL, FALSE);
335 _dbus_return_val_if_fail (!message->locked, FALSE);
336 _dbus_return_val_if_fail (signature == NULL ||
337 _dbus_check_is_valid_signature (signature));
338 /* can't delete the signature if you have a message body */
339 _dbus_return_val_if_fail (_dbus_string_get_length (&message->body) == 0 ||
342 return set_or_delete_string_field (message,
343 DBUS_HEADER_FIELD_SIGNATURE,
352 * @defgroup DBusMessage DBusMessage
354 * @brief Message to be sent or received over a DBusConnection.
356 * A DBusMessage is the most basic unit of communication over a
357 * DBusConnection. A DBusConnection represents a stream of messages
358 * received from a remote application, and a stream of messages
359 * sent to a remote application.
365 * @typedef DBusMessage
367 * Opaque data type representing a message received from or to be
368 * sent to another application.
372 * Returns the serial of a message or 0 if none has been specified.
373 * The message's serial number is provided by the application sending
374 * the message and is used to identify replies to this message. All
375 * messages received on a connection will have a serial, but messages
376 * you haven't sent yet may return 0.
378 * @param message the message
379 * @returns the client serial
382 dbus_message_get_serial (DBusMessage *message)
384 _dbus_return_val_if_fail (message != NULL, 0);
386 return _dbus_header_get_serial (&message->header);
390 * Sets the reply serial of a message (the client serial
391 * of the message this is a reply to).
393 * @param message the message
394 * @param reply_serial the client serial
395 * @returns #FALSE if not enough memory
398 dbus_message_set_reply_serial (DBusMessage *message,
399 dbus_uint32_t reply_serial)
401 _dbus_return_val_if_fail (message != NULL, FALSE);
402 _dbus_return_val_if_fail (!message->locked, FALSE);
404 return _dbus_header_set_field_basic (&message->header,
405 DBUS_HEADER_FIELD_REPLY_SERIAL,
411 * Returns the serial that the message is a reply to or 0 if none.
413 * @param message the message
414 * @returns the reply serial
417 dbus_message_get_reply_serial (DBusMessage *message)
419 dbus_uint32_t v_UINT32;
421 _dbus_return_val_if_fail (message != NULL, 0);
423 if (_dbus_header_get_field_basic (&message->header,
424 DBUS_HEADER_FIELD_REPLY_SERIAL,
433 free_size_counter (void *element,
436 DBusCounter *counter = element;
437 DBusMessage *message = data;
439 _dbus_counter_adjust (counter, - message->size_counter_delta);
441 _dbus_counter_unref (counter);
445 dbus_message_finalize (DBusMessage *message)
447 _dbus_assert (message->refcount.value == 0);
449 /* This calls application callbacks! */
450 _dbus_data_slot_list_free (&message->slot_list);
452 _dbus_list_foreach (&message->size_counters,
453 free_size_counter, message);
454 _dbus_list_clear (&message->size_counters);
456 _dbus_header_free (&message->header);
457 _dbus_string_free (&message->body);
459 _dbus_assert (message->refcount.value == 0);
466 * We cache some DBusMessage to reduce the overhead of allocating
467 * them. In my profiling this consistently made about an 8%
468 * difference. It avoids the malloc for the message, the malloc for
469 * the slot list, the malloc for the header string and body string,
470 * and the associated free() calls. It does introduce another global
471 * lock which could be a performance issue in certain cases.
473 * For the echo client/server the round trip time goes from around
474 * .000077 to .000069 with the message cache on my laptop. The sysprof
475 * change is as follows (numbers are cumulative percentage):
477 * with message cache implemented as array as it is now (0.000069 per):
478 * new_empty_header 1.46
479 * mutex_lock 0.56 # i.e. _DBUS_LOCK(message_cache)
485 * mutex_lock 0.33 # i.e. _DBUS_LOCK(message_cache)
488 * with message cache implemented as list (0.000070 per roundtrip):
489 * new_empty_header 2.72
490 * list_pop_first 1.88
494 * without cache (0.000077 per roundtrip):
495 * new_empty_header 6.7
496 * string_init_preallocated 3.43
505 * If you implement the message_cache with a list, the primary reason
506 * it's slower is that you add another thread lock (on the DBusList
510 /** Avoid caching huge messages */
511 #define MAX_MESSAGE_SIZE_TO_CACHE _DBUS_ONE_MEGABYTE
513 /** Avoid caching too many messages */
514 #define MAX_MESSAGE_CACHE_SIZE 5
516 _DBUS_DEFINE_GLOBAL_LOCK (message_cache);
517 static DBusMessage *message_cache[MAX_MESSAGE_CACHE_SIZE];
518 static int message_cache_count = 0;
519 static dbus_bool_t message_cache_shutdown_registered = FALSE;
522 dbus_message_cache_shutdown (void *data)
526 _DBUS_LOCK (message_cache);
529 while (i < MAX_MESSAGE_CACHE_SIZE)
531 if (message_cache[i])
532 dbus_message_finalize (message_cache[i]);
537 message_cache_count = 0;
538 message_cache_shutdown_registered = FALSE;
540 _DBUS_UNLOCK (message_cache);
544 * Tries to get a message from the message cache. The retrieved
545 * message will have junk in it, so it still needs to be cleared out
546 * in dbus_message_new_empty_header()
548 * @returns the message, or #NULL if none cached
551 dbus_message_get_cached (void)
553 DBusMessage *message;
558 _DBUS_LOCK (message_cache);
560 _dbus_assert (message_cache_count >= 0);
562 if (message_cache_count == 0)
564 _DBUS_UNLOCK (message_cache);
568 /* This is not necessarily true unless count > 0, and
569 * message_cache is uninitialized until the shutdown is
572 _dbus_assert (message_cache_shutdown_registered);
575 while (i < MAX_MESSAGE_CACHE_SIZE)
577 if (message_cache[i])
579 message = message_cache[i];
580 message_cache[i] = NULL;
581 message_cache_count -= 1;
586 _dbus_assert (message_cache_count >= 0);
587 _dbus_assert (i < MAX_MESSAGE_CACHE_SIZE);
588 _dbus_assert (message != NULL);
590 _DBUS_UNLOCK (message_cache);
592 _dbus_assert (message->refcount.value == 0);
593 _dbus_assert (message->size_counters == NULL);
599 * Tries to cache a message, otherwise finalize it.
601 * @param message the message
604 dbus_message_cache_or_finalize (DBusMessage *message)
606 dbus_bool_t was_cached;
609 _dbus_assert (message->refcount.value == 0);
611 /* This calls application code and has to be done first thing
612 * without holding the lock
614 _dbus_data_slot_list_clear (&message->slot_list);
616 _dbus_list_foreach (&message->size_counters,
617 free_size_counter, message);
618 _dbus_list_clear (&message->size_counters);
622 _DBUS_LOCK (message_cache);
624 if (!message_cache_shutdown_registered)
626 _dbus_assert (message_cache_count == 0);
628 if (!_dbus_register_shutdown_func (dbus_message_cache_shutdown, NULL))
632 while (i < MAX_MESSAGE_CACHE_SIZE)
634 message_cache[i] = NULL;
638 message_cache_shutdown_registered = TRUE;
641 _dbus_assert (message_cache_count >= 0);
643 if ((_dbus_string_get_length (&message->header.data) +
644 _dbus_string_get_length (&message->body)) >
645 MAX_MESSAGE_SIZE_TO_CACHE)
648 if (message_cache_count >= MAX_MESSAGE_CACHE_SIZE)
651 /* Find empty slot */
653 while (message_cache[i] != NULL)
656 _dbus_assert (i < MAX_MESSAGE_CACHE_SIZE);
658 _dbus_assert (message_cache[i] == NULL);
659 message_cache[i] = message;
660 message_cache_count += 1;
662 #ifndef DBUS_DISABLE_CHECKS
663 message->in_cache = TRUE;
667 _DBUS_UNLOCK (message_cache);
669 _dbus_assert (message->refcount.value == 0);
672 dbus_message_finalize (message);
676 dbus_message_new_empty_header (void)
678 DBusMessage *message;
679 dbus_bool_t from_cache;
681 message = dbus_message_get_cached ();
690 message = dbus_new (DBusMessage, 1);
693 #ifndef DBUS_DISABLE_CHECKS
694 message->generation = _dbus_current_generation;
698 message->refcount.value = 1;
699 message->byte_order = DBUS_COMPILER_BYTE_ORDER;
700 message->locked = FALSE;
701 #ifndef DBUS_DISABLE_CHECKS
702 message->in_cache = FALSE;
704 message->size_counters = NULL;
705 message->size_counter_delta = 0;
706 message->changed_stamp = 0;
709 _dbus_data_slot_list_init (&message->slot_list);
713 _dbus_header_reinit (&message->header, message->byte_order);
714 _dbus_string_set_length (&message->body, 0);
718 if (!_dbus_header_init (&message->header, message->byte_order))
724 if (!_dbus_string_init_preallocated (&message->body, 32))
726 _dbus_header_free (&message->header);
736 * Constructs a new message of the given message type.
737 * Types include #DBUS_MESSAGE_TYPE_METHOD_CALL,
738 * #DBUS_MESSAGE_TYPE_SIGNAL, and so forth.
740 * @param message_type type of message
741 * @returns new message or #NULL If no memory
744 dbus_message_new (int message_type)
746 DBusMessage *message;
748 _dbus_return_val_if_fail (message_type != DBUS_MESSAGE_TYPE_INVALID, NULL);
750 message = dbus_message_new_empty_header ();
754 if (!_dbus_header_create (&message->header,
756 NULL, NULL, NULL, NULL, NULL))
758 dbus_message_unref (message);
766 * Constructs a new message to invoke a method on a remote
767 * object. Returns #NULL if memory can't be allocated for the
768 * message. The destination may be #NULL in which case no destination
769 * is set; this is appropriate when using D-BUS in a peer-to-peer
770 * context (no message bus). The interface may be #NULL, which means
771 * that if multiple methods with the given name exist it is undefined
772 * which one will be invoked.
774 * @param destination name that the message should be sent to or #NULL
775 * @param path object path the message should be sent to
776 * @param interface interface to invoke method on
777 * @param method method to invoke
779 * @returns a new DBusMessage, free with dbus_message_unref()
780 * @see dbus_message_unref()
783 dbus_message_new_method_call (const char *destination,
785 const char *interface,
788 DBusMessage *message;
790 _dbus_return_val_if_fail (path != NULL, NULL);
791 _dbus_return_val_if_fail (method != NULL, NULL);
792 _dbus_return_val_if_fail (destination == NULL ||
793 _dbus_check_is_valid_bus_name (destination), NULL);
794 _dbus_return_val_if_fail (_dbus_check_is_valid_path (path), NULL);
795 _dbus_return_val_if_fail (interface == NULL ||
796 _dbus_check_is_valid_interface (interface), NULL);
797 _dbus_return_val_if_fail (_dbus_check_is_valid_member (method), NULL);
799 message = dbus_message_new_empty_header ();
803 if (!_dbus_header_create (&message->header,
804 DBUS_MESSAGE_TYPE_METHOD_CALL,
805 destination, path, interface, method, NULL))
807 dbus_message_unref (message);
815 * Constructs a message that is a reply to a method call. Returns
816 * #NULL if memory can't be allocated for the message.
818 * @param method_call the message which the created
819 * message is a reply to.
820 * @returns a new DBusMessage, free with dbus_message_unref()
821 * @see dbus_message_new_method_call(), dbus_message_unref()
824 dbus_message_new_method_return (DBusMessage *method_call)
826 DBusMessage *message;
829 _dbus_return_val_if_fail (method_call != NULL, NULL);
831 sender = dbus_message_get_sender (method_call);
833 /* sender is allowed to be null here in peer-to-peer case */
835 message = dbus_message_new_empty_header ();
839 if (!_dbus_header_create (&message->header,
840 DBUS_MESSAGE_TYPE_METHOD_RETURN,
841 sender, NULL, NULL, NULL, NULL))
843 dbus_message_unref (message);
847 dbus_message_set_no_reply (message, TRUE);
849 if (!dbus_message_set_reply_serial (message,
850 dbus_message_get_serial (method_call)))
852 dbus_message_unref (message);
860 * Constructs a new message representing a signal emission. Returns
861 * #NULL if memory can't be allocated for the message. A signal is
862 * identified by its originating interface, and the name of the
865 * @param path the path to the object emitting the signal
866 * @param interface the interface the signal is emitted from
867 * @param name name of the signal
868 * @returns a new DBusMessage, free with dbus_message_unref()
869 * @see dbus_message_unref()
872 dbus_message_new_signal (const char *path,
873 const char *interface,
876 DBusMessage *message;
878 _dbus_return_val_if_fail (path != NULL, NULL);
879 _dbus_return_val_if_fail (interface != NULL, NULL);
880 _dbus_return_val_if_fail (name != NULL, NULL);
881 _dbus_return_val_if_fail (_dbus_check_is_valid_path (path), NULL);
882 _dbus_return_val_if_fail (_dbus_check_is_valid_interface (interface), NULL);
883 _dbus_return_val_if_fail (_dbus_check_is_valid_member (name), NULL);
885 message = dbus_message_new_empty_header ();
889 if (!_dbus_header_create (&message->header,
890 DBUS_MESSAGE_TYPE_SIGNAL,
891 NULL, path, interface, name, NULL))
893 dbus_message_unref (message);
897 dbus_message_set_no_reply (message, TRUE);
903 * Creates a new message that is an error reply to a certain message.
904 * Error replies are possible in response to method calls primarily.
906 * @param reply_to the original message
907 * @param error_name the error name
908 * @param error_message the error message string or #NULL for none
909 * @returns a new error message
912 dbus_message_new_error (DBusMessage *reply_to,
913 const char *error_name,
914 const char *error_message)
916 DBusMessage *message;
918 DBusMessageIter iter;
920 _dbus_return_val_if_fail (reply_to != NULL, NULL);
921 _dbus_return_val_if_fail (error_name != NULL, NULL);
922 _dbus_return_val_if_fail (_dbus_check_is_valid_error_name (error_name), NULL);
924 sender = dbus_message_get_sender (reply_to);
926 /* sender may be NULL for non-message-bus case or
927 * when the message bus is dealing with an unregistered
930 message = dbus_message_new_empty_header ();
934 if (!_dbus_header_create (&message->header,
935 DBUS_MESSAGE_TYPE_ERROR,
936 sender, NULL, NULL, NULL, error_name))
938 dbus_message_unref (message);
942 dbus_message_set_no_reply (message, TRUE);
944 if (!dbus_message_set_reply_serial (message,
945 dbus_message_get_serial (reply_to)))
947 dbus_message_unref (message);
951 if (error_message != NULL)
953 dbus_message_iter_init_append (message, &iter);
954 if (!dbus_message_iter_append_basic (&iter,
958 dbus_message_unref (message);
967 * Creates a new message that is an error reply to a certain message.
968 * Error replies are possible in response to method calls primarily.
970 * @param reply_to the original message
971 * @param error_name the error name
972 * @param error_format the error message format as with printf
973 * @param ... format string arguments
974 * @returns a new error message
977 dbus_message_new_error_printf (DBusMessage *reply_to,
978 const char *error_name,
979 const char *error_format,
984 DBusMessage *message;
986 _dbus_return_val_if_fail (reply_to != NULL, NULL);
987 _dbus_return_val_if_fail (error_name != NULL, NULL);
988 _dbus_return_val_if_fail (_dbus_check_is_valid_error_name (error_name), NULL);
990 if (!_dbus_string_init (&str))
993 va_start (args, error_format);
995 if (_dbus_string_append_printf_valist (&str, error_format, args))
996 message = dbus_message_new_error (reply_to, error_name,
997 _dbus_string_get_const_data (&str));
1001 _dbus_string_free (&str);
1010 * Creates a new message that is an exact replica of the message
1011 * specified, except that its refcount is set to 1, its message serial
1012 * is reset to 0, and if the original message was "locked" (in the
1013 * outgoing message queue and thus not modifiable) the new message
1014 * will not be locked.
1016 * @param message the message.
1017 * @returns the new message.
1020 dbus_message_copy (const DBusMessage *message)
1022 DBusMessage *retval;
1024 _dbus_return_val_if_fail (message != NULL, NULL);
1026 retval = dbus_new0 (DBusMessage, 1);
1030 retval->refcount.value = 1;
1031 retval->byte_order = message->byte_order;
1032 retval->locked = FALSE;
1033 #ifndef DBUS_DISABLE_CHECKS
1034 retval->generation = message->generation;
1037 if (!_dbus_header_copy (&message->header, &retval->header))
1043 if (!_dbus_string_init_preallocated (&retval->body,
1044 _dbus_string_get_length (&message->body)))
1046 _dbus_header_free (&retval->header);
1051 if (!_dbus_string_copy (&message->body, 0,
1058 _dbus_header_free (&retval->header);
1059 _dbus_string_free (&retval->body);
1067 * Increments the reference count of a DBusMessage.
1069 * @param message The message
1070 * @returns the message
1071 * @see dbus_message_unref
1074 dbus_message_ref (DBusMessage *message)
1076 dbus_int32_t old_refcount;
1078 _dbus_return_val_if_fail (message != NULL, NULL);
1079 _dbus_return_val_if_fail (message->generation == _dbus_current_generation, NULL);
1080 _dbus_return_val_if_fail (!message->in_cache, NULL);
1082 old_refcount = _dbus_atomic_inc (&message->refcount);
1083 _dbus_assert (old_refcount >= 1);
1089 * Decrements the reference count of a DBusMessage.
1091 * @param message The message
1092 * @see dbus_message_ref
1095 dbus_message_unref (DBusMessage *message)
1097 dbus_int32_t old_refcount;
1099 _dbus_return_if_fail (message != NULL);
1100 _dbus_return_if_fail (message->generation == _dbus_current_generation);
1101 _dbus_return_if_fail (!message->in_cache);
1103 old_refcount = _dbus_atomic_dec (&message->refcount);
1105 _dbus_assert (old_refcount >= 0);
1107 if (old_refcount == 1)
1109 /* Calls application callbacks! */
1110 dbus_message_cache_or_finalize (message);
1115 * Gets the type of a message. Types include
1116 * #DBUS_MESSAGE_TYPE_METHOD_CALL, #DBUS_MESSAGE_TYPE_METHOD_RETURN,
1117 * #DBUS_MESSAGE_TYPE_ERROR, #DBUS_MESSAGE_TYPE_SIGNAL, but other
1118 * types are allowed and all code must silently ignore messages of
1119 * unknown type. DBUS_MESSAGE_TYPE_INVALID will never be returned,
1123 * @param message the message
1124 * @returns the type of the message
1127 dbus_message_get_type (DBusMessage *message)
1129 _dbus_return_val_if_fail (message != NULL, DBUS_MESSAGE_TYPE_INVALID);
1131 return _dbus_header_get_message_type (&message->header);
1135 * Appends fields to a message given a variable argument list. The
1136 * variable argument list should contain the type of each argument
1137 * followed by the value to append. Appendable types are basic types,
1138 * and arrays of fixed-length basic types. To append variable-length
1139 * basic types, or any more complex value, you have to use an iterator
1140 * rather than this function.
1142 * To append a basic type, specify its type code followed by the
1143 * value. For example:
1146 * DBUS_TYPE_INT32, 42,
1147 * DBUS_TYPE_STRING, "Hello World"
1151 * dbus_int32_t val = 42;
1152 * DBUS_TYPE_INT32, val
1155 * Be sure that your provided value is the right size. For example, this
1158 * DBUS_TYPE_INT64, 42
1160 * Because the "42" will be a 32-bit integer. You need to cast to
1163 * To append an array of fixed-length basic types, pass in the
1164 * DBUS_TYPE_ARRAY typecode, the element typecode, the address of
1165 * the array pointer, and a 32-bit integer giving the number of
1166 * elements in the array. So for example:
1168 * const dbus_int32_t array[] = { 1, 2, 3 };
1169 * const dbus_int32_t *v_ARRAY = array;
1170 * DBUS_TYPE_ARRAY, DBUS_TYPE_INT32, &v_ARRAY, 3
1173 * @warning in C, given "int array[]", "&array == array" (the
1174 * comp.lang.c FAQ says otherwise, but gcc and the FAQ don't agree).
1175 * So if you're using an array instead of a pointer you have to create
1176 * a pointer variable, assign the array to it, then take the address
1177 * of the pointer variable. For strings it works to write
1178 * const char *array = "Hello" and then use &array though.
1180 * The last argument to this function must be #DBUS_TYPE_INVALID,
1181 * marking the end of the argument list.
1183 * @todo support DBUS_TYPE_STRUCT and DBUS_TYPE_VARIANT and complex arrays
1185 * @todo If this fails due to lack of memory, the message is hosed and
1186 * you have to start over building the whole message.
1188 * @param message the message
1189 * @param first_arg_type type of the first argument
1190 * @param ... value of first argument, list of additional type-value pairs
1191 * @returns #TRUE on success
1194 dbus_message_append_args (DBusMessage *message,
1201 _dbus_return_val_if_fail (message != NULL, FALSE);
1203 va_start (var_args, first_arg_type);
1204 retval = dbus_message_append_args_valist (message,
1213 * This function takes a va_list for use by language bindings.
1214 * It's otherwise the same as dbus_message_append_args().
1216 * @todo for now, if this function fails due to OOM it will leave
1217 * the message half-written and you have to discard the message
1220 * @see dbus_message_append_args.
1221 * @param message the message
1222 * @param first_arg_type type of first argument
1223 * @param var_args value of first argument, then list of type/value pairs
1224 * @returns #TRUE on success
1227 dbus_message_append_args_valist (DBusMessage *message,
1232 DBusMessageIter iter;
1234 _dbus_return_val_if_fail (message != NULL, FALSE);
1236 type = first_arg_type;
1238 dbus_message_iter_init_append (message, &iter);
1240 while (type != DBUS_TYPE_INVALID)
1242 if (_dbus_type_is_basic (type))
1244 const DBusBasicValue *value;
1245 value = va_arg (var_args, const DBusBasicValue*);
1247 if (!dbus_message_iter_append_basic (&iter,
1252 else if (type == DBUS_TYPE_ARRAY)
1255 const DBusBasicValue **value;
1257 DBusMessageIter array;
1260 element_type = va_arg (var_args, int);
1262 #ifndef DBUS_DISABLE_CHECKS
1263 if (!_dbus_type_is_fixed (element_type))
1265 _dbus_warn ("arrays of %s can't be appended with %s for now\n",
1266 _dbus_type_to_string (element_type),
1267 _DBUS_FUNCTION_NAME);
1272 value = va_arg (var_args, const DBusBasicValue**);
1273 n_elements = va_arg (var_args, int);
1275 buf[0] = element_type;
1277 if (!dbus_message_iter_open_container (&iter,
1283 if (!dbus_message_iter_append_fixed_array (&array,
1289 if (!dbus_message_iter_close_container (&iter, &array))
1292 #ifndef DBUS_DISABLE_CHECKS
1295 _dbus_warn ("type %s isn't supported yet in %s\n",
1296 _dbus_type_to_string (type), _DBUS_FUNCTION_NAME);
1301 type = va_arg (var_args, int);
1311 * Gets arguments from a message given a variable argument list. The
1312 * supported types include those supported by
1313 * dbus_message_append_args(); that is, basic types and arrays of
1314 * fixed-length basic types. The arguments are the same as they would
1315 * be for dbus_message_iter_get_basic() or
1316 * dbus_message_iter_get_fixed_array().
1318 * In addition to those types, arrays of string, object path, and
1319 * signature are supported; but these are returned as allocated memory
1320 * and must be freed with dbus_free_string_array(), while the other
1321 * types are returned as const references.
1323 * The variable argument list should contain the type of the argument
1324 * followed by a pointer to where the value should be stored. The list
1325 * is terminated with #DBUS_TYPE_INVALID.
1327 * The returned values are constant; do not free them. They point
1328 * into the #DBusMessage.
1330 * If the requested arguments are not present, or do not have the
1331 * requested types, then an error will be set.
1333 * @todo support DBUS_TYPE_STRUCT and DBUS_TYPE_VARIANT and complex arrays
1335 * @param message the message
1336 * @param error error to be filled in on failure
1337 * @param first_arg_type the first argument type
1338 * @param ... location for first argument value, then list of type-location pairs
1339 * @returns #FALSE if the error was set
1342 dbus_message_get_args (DBusMessage *message,
1350 _dbus_return_val_if_fail (message != NULL, FALSE);
1351 _dbus_return_val_if_error_is_set (error, FALSE);
1353 va_start (var_args, first_arg_type);
1354 retval = dbus_message_get_args_valist (message, error, first_arg_type, var_args);
1361 * This function takes a va_list for use by language bindings. It is
1362 * otherwise the same as dbus_message_get_args().
1364 * @see dbus_message_get_args
1365 * @param message the message
1366 * @param error error to be filled in
1367 * @param first_arg_type type of the first argument
1368 * @param var_args return location for first argument, followed by list of type/location pairs
1369 * @returns #FALSE if error was set
1372 dbus_message_get_args_valist (DBusMessage *message,
1377 DBusMessageIter iter;
1379 _dbus_return_val_if_fail (message != NULL, FALSE);
1380 _dbus_return_val_if_error_is_set (error, FALSE);
1382 dbus_message_iter_init (message, &iter);
1383 return _dbus_message_iter_get_args_valist (&iter, error, first_arg_type, var_args);
1387 _dbus_message_iter_init_common (DBusMessage *message,
1388 DBusMessageRealIter *real,
1391 _dbus_assert (sizeof (DBusMessageRealIter) <= sizeof (DBusMessageIter));
1393 /* Since the iterator will read or write who-knows-what from the
1394 * message, we need to get in the right byte order
1396 ensure_byte_order (message);
1398 real->message = message;
1399 real->changed_stamp = message->changed_stamp;
1400 real->iter_type = iter_type;
1401 real->sig_refcount = 0;
1405 * Initializes a #DBusMessageIter for reading the arguments of the
1406 * message passed in.
1408 * @param message the message
1409 * @param iter pointer to an iterator to initialize
1410 * @returns #FALSE if the message has no arguments
1413 dbus_message_iter_init (DBusMessage *message,
1414 DBusMessageIter *iter)
1416 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1417 const DBusString *type_str;
1420 _dbus_return_val_if_fail (message != NULL, FALSE);
1421 _dbus_return_val_if_fail (iter != NULL, FALSE);
1423 get_const_signature (&message->header, &type_str, &type_pos);
1425 _dbus_message_iter_init_common (message, real,
1426 DBUS_MESSAGE_ITER_TYPE_READER);
1428 _dbus_type_reader_init (&real->u.reader,
1429 message->byte_order,
1434 return _dbus_type_reader_get_current_type (&real->u.reader) != DBUS_TYPE_INVALID;
1437 #ifndef DBUS_DISABLE_CHECKS
1439 _dbus_message_iter_check (DBusMessageRealIter *iter)
1443 _dbus_warn ("dbus message iterator is NULL\n");
1447 if (iter->iter_type == DBUS_MESSAGE_ITER_TYPE_READER)
1449 if (iter->u.reader.byte_order != iter->message->byte_order)
1451 _dbus_warn ("dbus message changed byte order since iterator was created\n");
1454 /* because we swap the message into compiler order when you init an iter */
1455 _dbus_assert (iter->u.reader.byte_order == DBUS_COMPILER_BYTE_ORDER);
1457 else if (iter->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER)
1459 if (iter->u.writer.byte_order != iter->message->byte_order)
1461 _dbus_warn ("dbus message changed byte order since append iterator was created\n");
1464 /* because we swap the message into compiler order when you init an iter */
1465 _dbus_assert (iter->u.writer.byte_order == DBUS_COMPILER_BYTE_ORDER);
1469 _dbus_warn ("dbus message iterator looks uninitialized or corrupted\n");
1473 if (iter->changed_stamp != iter->message->changed_stamp)
1475 _dbus_warn ("dbus message iterator invalid because the message has been modified (or perhaps the iterator is just uninitialized)\n");
1481 #endif /* DBUS_DISABLE_CHECKS */
1484 * Checks if an iterator has any more fields.
1486 * @param iter the message iter
1487 * @returns #TRUE if there are more fields
1491 dbus_message_iter_has_next (DBusMessageIter *iter)
1493 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1495 _dbus_return_val_if_fail (_dbus_message_iter_check (real), FALSE);
1496 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, FALSE);
1498 return _dbus_type_reader_has_next (&real->u.reader);
1502 * Moves the iterator to the next field, if any. If there's no next
1503 * field, returns #FALSE. If the iterator moves forward, returns
1506 * @param iter the message iter
1507 * @returns #TRUE if the iterator was moved to the next field
1510 dbus_message_iter_next (DBusMessageIter *iter)
1512 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1514 _dbus_return_val_if_fail (_dbus_message_iter_check (real), FALSE);
1515 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, FALSE);
1517 return _dbus_type_reader_next (&real->u.reader);
1521 * Returns the argument type of the argument that the message iterator
1522 * points to. If the iterator is at the end of the message, returns
1523 * #DBUS_TYPE_INVALID. You can thus write a loop as follows:
1526 * dbus_message_iter_init (&iter);
1527 * while ((current_type = dbus_message_iter_get_arg_type (&iter)) != DBUS_TYPE_INVALID)
1528 * dbus_message_iter_next (&iter);
1531 * @param iter the message iter
1532 * @returns the argument type
1535 dbus_message_iter_get_arg_type (DBusMessageIter *iter)
1537 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1539 _dbus_return_val_if_fail (_dbus_message_iter_check (real), DBUS_TYPE_INVALID);
1540 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, FALSE);
1542 return _dbus_type_reader_get_current_type (&real->u.reader);
1546 * Returns the element type of the array that the message iterator
1547 * points to. Note that you need to check that the iterator points to
1548 * an array prior to using this function.
1550 * @param iter the message iter
1551 * @returns the array element type
1554 dbus_message_iter_get_element_type (DBusMessageIter *iter)
1556 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1558 _dbus_return_val_if_fail (_dbus_message_iter_check (real), DBUS_TYPE_INVALID);
1559 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, DBUS_TYPE_INVALID);
1560 _dbus_return_val_if_fail (dbus_message_iter_get_arg_type (iter) == DBUS_TYPE_ARRAY, DBUS_TYPE_INVALID);
1562 return _dbus_type_reader_get_element_type (&real->u.reader);
1566 * Recurses into a container value when reading values from a message,
1567 * initializing a sub-iterator to use for traversing the child values
1570 * Note that this recurses into a value, not a type, so you can only
1571 * recurse if the value exists. The main implication of this is that
1572 * if you have for example an empty array of array of int32, you can
1573 * recurse into the outermost array, but it will have no values, so
1574 * you won't be able to recurse further. There's no array of int32 to
1577 * @param iter the message iterator
1578 * @param sub the sub-iterator to initialize
1581 dbus_message_iter_recurse (DBusMessageIter *iter,
1582 DBusMessageIter *sub)
1584 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1585 DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub;
1587 _dbus_return_if_fail (_dbus_message_iter_check (real));
1588 _dbus_return_if_fail (sub != NULL);
1591 _dbus_type_reader_recurse (&real->u.reader, &real_sub->u.reader);
1595 * Reads a basic-typed value from the message iterator.
1596 * Basic types are the non-containers such as integer and string.
1598 * The value argument should be the address of a location to store
1599 * the returned value. So for int32 it should be a "dbus_int32_t*"
1600 * and for string a "const char**". The returned value is
1601 * by reference and should not be freed.
1603 * All returned values are guaranteed to fit in 8 bytes. So you can
1604 * write code like this:
1607 * #ifdef DBUS_HAVE_INT64
1608 * dbus_uint64_t value;
1610 * dbus_message_iter_get_basic (&read_iter, &value);
1611 * type = dbus_message_iter_get_arg_type (&read_iter);
1612 * dbus_message_iter_append_basic (&write_iter, type, &value);
1616 * To avoid the #DBUS_HAVE_INT64 conditional, create a struct or
1617 * something that occupies at least 8 bytes, e.g. you could use a
1618 * struct with two int32 values in it. dbus_uint64_t is just one
1619 * example of a type that's large enough to hold any possible value.
1621 * Be sure you have somehow checked that
1622 * dbus_message_iter_get_arg_type() matches the type you are
1623 * expecting, or you'll crash when you try to use an integer as a
1624 * string or something.
1626 * @param iter the iterator
1627 * @param value location to store the value
1630 dbus_message_iter_get_basic (DBusMessageIter *iter,
1633 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1635 _dbus_return_if_fail (_dbus_message_iter_check (real));
1636 _dbus_return_if_fail (value != NULL);
1638 _dbus_type_reader_read_basic (&real->u.reader,
1643 * Reads a block of fixed-length values from the message iterator.
1644 * Fixed-length values are those basic types that are not string-like,
1645 * such as integers, bool, double. The block read will be from the
1646 * current position in the array until the end of the array.
1648 * The value argument should be the address of a location to store the
1649 * returned array. So for int32 it should be a "const dbus_int32_t**"
1650 * The returned value is by reference and should not be freed.
1652 * @param iter the iterator
1653 * @param value location to store the block
1654 * @param n_elements number of elements in the block
1657 dbus_message_iter_get_fixed_array (DBusMessageIter *iter,
1661 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1663 _dbus_return_if_fail (_dbus_message_iter_check (real));
1664 _dbus_return_if_fail (value != NULL);
1665 _dbus_return_if_fail (_dbus_type_is_fixed (_dbus_type_reader_get_element_type (&real->u.reader)));
1667 _dbus_type_reader_read_fixed_multi (&real->u.reader,
1672 * This function takes a va_list for use by language bindings and is
1673 * otherwise the same as dbus_message_iter_get_args().
1674 * dbus_message_get_args() is the place to go for complete
1677 * @see dbus_message_get_args
1678 * @param iter the message iter
1679 * @param error error to be filled in
1680 * @param first_arg_type type of the first argument
1681 * @param var_args return location for first argument, followed by list of type/location pairs
1682 * @returns #FALSE if error was set
1685 _dbus_message_iter_get_args_valist (DBusMessageIter *iter,
1690 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1691 int spec_type, msg_type, i;
1694 _dbus_assert (_dbus_message_iter_check (real));
1698 spec_type = first_arg_type;
1701 while (spec_type != DBUS_TYPE_INVALID)
1703 msg_type = dbus_message_iter_get_arg_type (iter);
1705 if (msg_type != spec_type)
1707 dbus_set_error (error, DBUS_ERROR_INVALID_ARGS,
1708 "Argument %d is specified to be of type \"%s\", but "
1709 "is actually of type \"%s\"\n", i,
1710 _dbus_type_to_string (spec_type),
1711 _dbus_type_to_string (msg_type));
1716 if (_dbus_type_is_basic (spec_type))
1718 DBusBasicValue *ptr;
1720 ptr = va_arg (var_args, DBusBasicValue*);
1722 _dbus_assert (ptr != NULL);
1724 _dbus_type_reader_read_basic (&real->u.reader,
1727 else if (spec_type == DBUS_TYPE_ARRAY)
1730 int spec_element_type;
1731 const DBusBasicValue **ptr;
1733 DBusTypeReader array;
1735 spec_element_type = va_arg (var_args, int);
1736 element_type = _dbus_type_reader_get_element_type (&real->u.reader);
1738 if (spec_element_type != element_type)
1740 dbus_set_error (error, DBUS_ERROR_INVALID_ARGS,
1741 "Argument %d is specified to be an array of \"%s\", but "
1742 "is actually an array of \"%s\"\n",
1744 _dbus_type_to_string (spec_element_type),
1745 _dbus_type_to_string (element_type));
1750 if (_dbus_type_is_fixed (spec_element_type))
1752 ptr = va_arg (var_args, const DBusBasicValue**);
1753 n_elements_p = va_arg (var_args, int*);
1755 _dbus_assert (ptr != NULL);
1756 _dbus_assert (n_elements_p != NULL);
1758 _dbus_type_reader_recurse (&real->u.reader, &array);
1760 _dbus_type_reader_read_fixed_multi (&array,
1763 else if (spec_element_type == DBUS_TYPE_STRING ||
1764 spec_element_type == DBUS_TYPE_SIGNATURE ||
1765 spec_element_type == DBUS_TYPE_OBJECT_PATH)
1767 char ***str_array_p;
1771 str_array_p = va_arg (var_args, char***);
1772 n_elements_p = va_arg (var_args, int*);
1774 _dbus_assert (str_array_p != NULL);
1775 _dbus_assert (n_elements_p != NULL);
1777 /* Count elements in the array */
1778 _dbus_type_reader_recurse (&real->u.reader, &array);
1781 while (_dbus_type_reader_get_current_type (&array) != DBUS_TYPE_INVALID)
1784 _dbus_type_reader_next (&array);
1787 str_array = dbus_new0 (char*, n_elements + 1);
1788 if (str_array == NULL)
1790 _DBUS_SET_OOM (error);
1794 /* Now go through and dup each string */
1795 _dbus_type_reader_recurse (&real->u.reader, &array);
1798 while (i < n_elements)
1801 _dbus_type_reader_read_basic (&array,
1804 str_array[i] = _dbus_strdup (s);
1805 if (str_array[i] == NULL)
1807 dbus_free_string_array (str_array);
1808 _DBUS_SET_OOM (error);
1814 if (!_dbus_type_reader_next (&array))
1815 _dbus_assert (i == n_elements);
1818 _dbus_assert (_dbus_type_reader_get_current_type (&array) == DBUS_TYPE_INVALID);
1819 _dbus_assert (i == n_elements);
1820 _dbus_assert (str_array[i] == NULL);
1822 *str_array_p = str_array;
1823 *n_elements_p = n_elements;
1825 #ifndef DBUS_DISABLE_CHECKS
1828 _dbus_warn ("you can't read arrays of container types (struct, variant, array) with %s for now\n",
1829 _DBUS_FUNCTION_NAME);
1834 #ifndef DBUS_DISABLE_CHECKS
1837 _dbus_warn ("you can only read arrays and basic types with %s for now\n",
1838 _DBUS_FUNCTION_NAME);
1843 spec_type = va_arg (var_args, int);
1844 if (!_dbus_type_reader_next (&real->u.reader) && spec_type != DBUS_TYPE_INVALID)
1846 dbus_set_error (error, DBUS_ERROR_INVALID_ARGS,
1847 "Message has only %d arguments, but more were expected", i);
1862 * Initializes a #DBusMessageIter for appending arguments to the end
1865 * @todo If appending any of the arguments fails due to lack of
1866 * memory, generally the message is hosed and you have to start over
1867 * building the whole message.
1869 * @param message the message
1870 * @param iter pointer to an iterator to initialize
1873 dbus_message_iter_init_append (DBusMessage *message,
1874 DBusMessageIter *iter)
1876 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1878 _dbus_return_if_fail (message != NULL);
1879 _dbus_return_if_fail (iter != NULL);
1881 _dbus_message_iter_init_common (message, real,
1882 DBUS_MESSAGE_ITER_TYPE_WRITER);
1884 /* We create the signature string and point iterators at it "on demand"
1885 * when a value is actually appended. That means that init() never fails
1888 _dbus_type_writer_init_types_delayed (&real->u.writer,
1889 message->byte_order,
1891 _dbus_string_get_length (&message->body));
1895 * Creates a temporary signature string containing the current
1896 * signature, stores it in the iterator, and points the iterator to
1897 * the end of it. Used any time we write to the message.
1899 * @param real an iterator without a type_str
1900 * @returns #FALSE if no memory
1903 _dbus_message_iter_open_signature (DBusMessageRealIter *real)
1906 const DBusString *current_sig;
1907 int current_sig_pos;
1909 _dbus_assert (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
1911 if (real->u.writer.type_str != NULL)
1913 _dbus_assert (real->sig_refcount > 0);
1914 real->sig_refcount += 1;
1918 str = dbus_new (DBusString, 1);
1922 if (!_dbus_header_get_field_raw (&real->message->header,
1923 DBUS_HEADER_FIELD_SIGNATURE,
1924 ¤t_sig, ¤t_sig_pos))
1931 current_len = _dbus_string_get_byte (current_sig, current_sig_pos);
1932 current_sig_pos += 1; /* move on to sig data */
1934 if (!_dbus_string_init_preallocated (str, current_len + 4))
1940 if (!_dbus_string_copy_len (current_sig, current_sig_pos, current_len,
1943 _dbus_string_free (str);
1950 if (!_dbus_string_init_preallocated (str, 4))
1957 real->sig_refcount = 1;
1959 _dbus_type_writer_add_types (&real->u.writer,
1960 str, _dbus_string_get_length (str));
1965 * Sets the new signature as the message signature, frees the
1966 * signature string, and marks the iterator as not having a type_str
1967 * anymore. Frees the signature even if it fails, so you can't
1968 * really recover from failure. Kinda busted.
1970 * @param real an iterator without a type_str
1971 * @returns #FALSE if no memory
1974 _dbus_message_iter_close_signature (DBusMessageRealIter *real)
1977 const char *v_STRING;
1980 _dbus_assert (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
1981 _dbus_assert (real->u.writer.type_str != NULL);
1982 _dbus_assert (real->sig_refcount > 0);
1984 real->sig_refcount -= 1;
1986 if (real->sig_refcount > 0)
1988 _dbus_assert (real->sig_refcount == 0);
1992 str = real->u.writer.type_str;
1994 v_STRING = _dbus_string_get_const_data (str);
1995 if (!_dbus_header_set_field_basic (&real->message->header,
1996 DBUS_HEADER_FIELD_SIGNATURE,
1997 DBUS_TYPE_SIGNATURE,
2001 _dbus_type_writer_remove_types (&real->u.writer);
2002 _dbus_string_free (str);
2008 #ifndef DBUS_DISABLE_CHECKS
2010 _dbus_message_iter_append_check (DBusMessageRealIter *iter)
2012 if (!_dbus_message_iter_check (iter))
2015 if (iter->message->locked)
2017 _dbus_warn ("dbus append iterator can't be used: message is locked (has already been sent)\n");
2023 #endif /* DBUS_DISABLE_CHECKS */
2026 * Appends a basic-typed value to the message. The basic types are the
2027 * non-container types such as integer and string.
2029 * The "value" argument should be the address of a basic-typed value.
2030 * So for string, const char**. For integer, dbus_int32_t*.
2032 * @todo If this fails due to lack of memory, the message is hosed and
2033 * you have to start over building the whole message.
2035 * @param iter the append iterator
2036 * @param type the type of the value
2037 * @param value the address of the value
2038 * @returns #FALSE if not enough memory
2041 dbus_message_iter_append_basic (DBusMessageIter *iter,
2045 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2048 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE);
2049 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2050 _dbus_return_val_if_fail (_dbus_type_is_basic (type), FALSE);
2051 _dbus_return_val_if_fail (value != NULL, FALSE);
2053 if (!_dbus_message_iter_open_signature (real))
2056 ret = _dbus_type_writer_write_basic (&real->u.writer, type, value);
2058 if (!_dbus_message_iter_close_signature (real))
2065 * Appends a block of fixed-length values to an array. The
2066 * fixed-length types are all basic types that are not string-like. So
2067 * int32, double, bool, etc. You must call
2068 * dbus_message_iter_open_container() to open an array of values
2069 * before calling this function. You may call this function multiple
2070 * times (and intermixed with calls to
2071 * dbus_message_iter_append_basic()) for the same array.
2073 * The "value" argument should be the address of the array. So for
2074 * integer, "dbus_int32_t**" is expected for example.
2076 * @warning in C, given "int array[]", "&array == array" (the
2077 * comp.lang.c FAQ says otherwise, but gcc and the FAQ don't agree).
2078 * So if you're using an array instead of a pointer you have to create
2079 * a pointer variable, assign the array to it, then take the address
2080 * of the pointer variable.
2082 * const dbus_int32_t array[] = { 1, 2, 3 };
2083 * const dbus_int32_t *v_ARRAY = array;
2084 * if (!dbus_message_iter_append_fixed_array (&iter, DBUS_TYPE_INT32, &v_ARRAY, 3))
2085 * fprintf (stderr, "No memory!\n");
2087 * For strings it works to write const char *array = "Hello" and then
2088 * use &array though.
2090 * @todo If this fails due to lack of memory, the message is hosed and
2091 * you have to start over building the whole message.
2093 * @param iter the append iterator
2094 * @param element_type the type of the array elements
2095 * @param value the address of the array
2096 * @param n_elements the number of elements to append
2097 * @returns #FALSE if not enough memory
2100 dbus_message_iter_append_fixed_array (DBusMessageIter *iter,
2105 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2108 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE);
2109 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2110 _dbus_return_val_if_fail (_dbus_type_is_fixed (element_type), FALSE);
2111 _dbus_return_val_if_fail (real->u.writer.container_type == DBUS_TYPE_ARRAY, FALSE);
2112 _dbus_return_val_if_fail (value != NULL, FALSE);
2113 _dbus_return_val_if_fail (n_elements >= 0, FALSE);
2114 _dbus_return_val_if_fail (n_elements <=
2115 DBUS_MAXIMUM_ARRAY_LENGTH / _dbus_type_get_alignment (element_type),
2118 ret = _dbus_type_writer_write_fixed_multi (&real->u.writer, element_type, value, n_elements);
2124 * Appends a container-typed value to the message; you are required to
2125 * append the contents of the container using the returned
2126 * sub-iterator, and then call
2127 * dbus_message_iter_close_container(). Container types are for
2128 * example struct, variant, and array. For variants, the
2129 * contained_signature should be the type of the single value inside
2130 * the variant. For structs and dict entries, contained_signature
2131 * should be #NULL; it will be set to whatever types you write into
2132 * the struct. For arrays, contained_signature should be the type of
2133 * the array elements.
2135 * @todo If this fails due to lack of memory, the message is hosed and
2136 * you have to start over building the whole message.
2138 * @param iter the append iterator
2139 * @param type the type of the value
2140 * @param contained_signature the type of container contents
2141 * @param sub sub-iterator to initialize
2142 * @returns #FALSE if not enough memory
2145 dbus_message_iter_open_container (DBusMessageIter *iter,
2147 const char *contained_signature,
2148 DBusMessageIter *sub)
2150 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2151 DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub;
2152 DBusString contained_str;
2154 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE);
2155 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2156 _dbus_return_val_if_fail (_dbus_type_is_container (type), FALSE);
2157 _dbus_return_val_if_fail (sub != NULL, FALSE);
2158 _dbus_return_val_if_fail ((type == DBUS_TYPE_STRUCT &&
2159 contained_signature == NULL) ||
2160 (type == DBUS_TYPE_DICT_ENTRY &&
2161 contained_signature == NULL) ||
2162 contained_signature != NULL, FALSE);
2165 /* FIXME this would fail if the contained_signature is a dict entry,
2166 * since dict entries are invalid signatures standalone (they must be in
2169 _dbus_return_val_if_fail (contained_signature == NULL ||
2170 _dbus_check_is_valid_signature (contained_signature));
2173 if (!_dbus_message_iter_open_signature (real))
2178 if (contained_signature != NULL)
2180 _dbus_string_init_const (&contained_str, contained_signature);
2182 return _dbus_type_writer_recurse (&real->u.writer,
2185 &real_sub->u.writer);
2189 return _dbus_type_writer_recurse (&real->u.writer,
2192 &real_sub->u.writer);
2198 * Closes a container-typed value appended to the message; may write
2199 * out more information to the message known only after the entire
2200 * container is written, and may free resources created by
2201 * dbus_message_iter_open_container().
2203 * @todo If this fails due to lack of memory, the message is hosed and
2204 * you have to start over building the whole message.
2206 * @param iter the append iterator
2207 * @param sub sub-iterator to close
2208 * @returns #FALSE if not enough memory
2211 dbus_message_iter_close_container (DBusMessageIter *iter,
2212 DBusMessageIter *sub)
2214 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2215 DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub;
2218 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE);
2219 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2220 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real_sub), FALSE);
2221 _dbus_return_val_if_fail (real_sub->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2223 ret = _dbus_type_writer_unrecurse (&real->u.writer,
2224 &real_sub->u.writer);
2226 if (!_dbus_message_iter_close_signature (real))
2233 * Sets a flag indicating that the message does not want a reply; if
2234 * this flag is set, the other end of the connection may (but is not
2235 * required to) optimize by not sending method return or error
2236 * replies. If this flag is set, there is no way to know whether the
2237 * message successfully arrived at the remote end. Normally you know a
2238 * message was received when you receive the reply to it.
2240 * @param message the message
2241 * @param no_reply #TRUE if no reply is desired
2244 dbus_message_set_no_reply (DBusMessage *message,
2245 dbus_bool_t no_reply)
2247 _dbus_return_if_fail (message != NULL);
2248 _dbus_return_if_fail (!message->locked);
2250 _dbus_header_toggle_flag (&message->header,
2251 DBUS_HEADER_FLAG_NO_REPLY_EXPECTED,
2256 * Returns #TRUE if the message does not expect
2259 * @param message the message
2260 * @returns #TRUE if the message sender isn't waiting for a reply
2263 dbus_message_get_no_reply (DBusMessage *message)
2265 _dbus_return_val_if_fail (message != NULL, FALSE);
2267 return _dbus_header_get_flag (&message->header,
2268 DBUS_HEADER_FLAG_NO_REPLY_EXPECTED);
2272 * Sets a flag indicating that an owner for the destination name will
2273 * be automatically started before the message is delivered. When this
2274 * flag is set, the message is held until a name owner finishes
2275 * starting up, or fails to start up. In case of failure, the reply
2278 * @param message the message
2279 * @param auto_start #TRUE if auto-starting is desired
2282 dbus_message_set_auto_start (DBusMessage *message,
2283 dbus_bool_t auto_start)
2285 _dbus_return_if_fail (message != NULL);
2286 _dbus_return_if_fail (!message->locked);
2288 _dbus_header_toggle_flag (&message->header,
2289 DBUS_HEADER_FLAG_NO_AUTO_START,
2294 * Returns #TRUE if the message will cause an owner for
2295 * destination name to be auto-started.
2297 * @param message the message
2298 * @returns #TRUE if the message will use auto-start
2301 dbus_message_get_auto_start (DBusMessage *message)
2303 _dbus_return_val_if_fail (message != NULL, FALSE);
2305 return !_dbus_header_get_flag (&message->header,
2306 DBUS_HEADER_FLAG_NO_AUTO_START);
2311 * Sets the object path this message is being sent to (for
2312 * DBUS_MESSAGE_TYPE_METHOD_CALL) or the one a signal is being
2313 * emitted from (for DBUS_MESSAGE_TYPE_SIGNAL).
2315 * @param message the message
2316 * @param object_path the path or #NULL to unset
2317 * @returns #FALSE if not enough memory
2320 dbus_message_set_path (DBusMessage *message,
2321 const char *object_path)
2323 _dbus_return_val_if_fail (message != NULL, FALSE);
2324 _dbus_return_val_if_fail (!message->locked, FALSE);
2325 _dbus_return_val_if_fail (object_path == NULL ||
2326 _dbus_check_is_valid_path (object_path),
2329 return set_or_delete_string_field (message,
2330 DBUS_HEADER_FIELD_PATH,
2331 DBUS_TYPE_OBJECT_PATH,
2336 * Gets the object path this message is being sent to (for
2337 * DBUS_MESSAGE_TYPE_METHOD_CALL) or being emitted from (for
2338 * DBUS_MESSAGE_TYPE_SIGNAL). Returns #NULL if none.
2340 * @param message the message
2341 * @returns the path (should not be freed) or #NULL
2344 dbus_message_get_path (DBusMessage *message)
2348 _dbus_return_val_if_fail (message != NULL, NULL);
2350 v = NULL; /* in case field doesn't exist */
2351 _dbus_header_get_field_basic (&message->header,
2352 DBUS_HEADER_FIELD_PATH,
2353 DBUS_TYPE_OBJECT_PATH,
2359 * Gets the object path this message is being sent to
2360 * (for DBUS_MESSAGE_TYPE_METHOD_CALL) or being emitted
2361 * from (for DBUS_MESSAGE_TYPE_SIGNAL) in a decomposed
2362 * format (one array element per path component).
2363 * Free the returned array with dbus_free_string_array().
2365 * An empty but non-NULL path array means the path "/".
2366 * So the path "/foo/bar" becomes { "foo", "bar", NULL }
2367 * and the path "/" becomes { NULL }.
2369 * @todo this could be optimized by using the len from the message
2370 * instead of calling strlen() again
2372 * @param message the message
2373 * @param path place to store allocated array of path components; #NULL set here if no path field exists
2374 * @returns #FALSE if no memory to allocate the array
2377 dbus_message_get_path_decomposed (DBusMessage *message,
2382 _dbus_return_val_if_fail (message != NULL, FALSE);
2383 _dbus_return_val_if_fail (path != NULL, FALSE);
2387 v = dbus_message_get_path (message);
2390 if (!_dbus_decompose_path (v, strlen (v),
2398 * Sets the interface this message is being sent to
2399 * (for DBUS_MESSAGE_TYPE_METHOD_CALL) or
2400 * the interface a signal is being emitted from
2401 * (for DBUS_MESSAGE_TYPE_SIGNAL).
2403 * @param message the message
2404 * @param interface the interface or #NULL to unset
2405 * @returns #FALSE if not enough memory
2408 dbus_message_set_interface (DBusMessage *message,
2409 const char *interface)
2411 _dbus_return_val_if_fail (message != NULL, FALSE);
2412 _dbus_return_val_if_fail (!message->locked, FALSE);
2413 _dbus_return_val_if_fail (interface == NULL ||
2414 _dbus_check_is_valid_interface (interface),
2417 return set_or_delete_string_field (message,
2418 DBUS_HEADER_FIELD_INTERFACE,
2424 * Gets the interface this message is being sent to
2425 * (for DBUS_MESSAGE_TYPE_METHOD_CALL) or being emitted
2426 * from (for DBUS_MESSAGE_TYPE_SIGNAL).
2427 * The interface name is fully-qualified (namespaced).
2428 * Returns #NULL if none.
2430 * @param message the message
2431 * @returns the message interface (should not be freed) or #NULL
2434 dbus_message_get_interface (DBusMessage *message)
2438 _dbus_return_val_if_fail (message != NULL, NULL);
2440 v = NULL; /* in case field doesn't exist */
2441 _dbus_header_get_field_basic (&message->header,
2442 DBUS_HEADER_FIELD_INTERFACE,
2449 * Sets the interface member being invoked
2450 * (DBUS_MESSAGE_TYPE_METHOD_CALL) or emitted
2451 * (DBUS_MESSAGE_TYPE_SIGNAL).
2452 * The interface name is fully-qualified (namespaced).
2454 * @param message the message
2455 * @param member the member or #NULL to unset
2456 * @returns #FALSE if not enough memory
2459 dbus_message_set_member (DBusMessage *message,
2462 _dbus_return_val_if_fail (message != NULL, FALSE);
2463 _dbus_return_val_if_fail (!message->locked, FALSE);
2464 _dbus_return_val_if_fail (member == NULL ||
2465 _dbus_check_is_valid_member (member),
2468 return set_or_delete_string_field (message,
2469 DBUS_HEADER_FIELD_MEMBER,
2475 * Gets the interface member being invoked
2476 * (DBUS_MESSAGE_TYPE_METHOD_CALL) or emitted
2477 * (DBUS_MESSAGE_TYPE_SIGNAL). Returns #NULL if none.
2479 * @param message the message
2480 * @returns the member name (should not be freed) or #NULL
2483 dbus_message_get_member (DBusMessage *message)
2487 _dbus_return_val_if_fail (message != NULL, NULL);
2489 v = NULL; /* in case field doesn't exist */
2490 _dbus_header_get_field_basic (&message->header,
2491 DBUS_HEADER_FIELD_MEMBER,
2498 * Sets the name of the error (DBUS_MESSAGE_TYPE_ERROR).
2499 * The name is fully-qualified (namespaced).
2501 * @param message the message
2502 * @param error_name the name or #NULL to unset
2503 * @returns #FALSE if not enough memory
2506 dbus_message_set_error_name (DBusMessage *message,
2507 const char *error_name)
2509 _dbus_return_val_if_fail (message != NULL, FALSE);
2510 _dbus_return_val_if_fail (!message->locked, FALSE);
2511 _dbus_return_val_if_fail (error_name == NULL ||
2512 _dbus_check_is_valid_error_name (error_name),
2515 return set_or_delete_string_field (message,
2516 DBUS_HEADER_FIELD_ERROR_NAME,
2522 * Gets the error name (DBUS_MESSAGE_TYPE_ERROR only)
2525 * @param message the message
2526 * @returns the error name (should not be freed) or #NULL
2529 dbus_message_get_error_name (DBusMessage *message)
2533 _dbus_return_val_if_fail (message != NULL, NULL);
2535 v = NULL; /* in case field doesn't exist */
2536 _dbus_header_get_field_basic (&message->header,
2537 DBUS_HEADER_FIELD_ERROR_NAME,
2544 * Sets the message's destination. The destination is the name of
2545 * another connection on the bus and may be either the unique name
2546 * assigned by the bus to each connection, or a well-known name
2547 * specified in advance.
2549 * @param message the message
2550 * @param destination the destination name or #NULL to unset
2551 * @returns #FALSE if not enough memory
2554 dbus_message_set_destination (DBusMessage *message,
2555 const char *destination)
2557 _dbus_return_val_if_fail (message != NULL, FALSE);
2558 _dbus_return_val_if_fail (!message->locked, FALSE);
2559 _dbus_return_val_if_fail (destination == NULL ||
2560 _dbus_check_is_valid_bus_name (destination),
2563 return set_or_delete_string_field (message,
2564 DBUS_HEADER_FIELD_DESTINATION,
2570 * Gets the destination of a message or #NULL if there is none set.
2572 * @param message the message
2573 * @returns the message destination (should not be freed) or #NULL
2576 dbus_message_get_destination (DBusMessage *message)
2580 _dbus_return_val_if_fail (message != NULL, NULL);
2582 v = NULL; /* in case field doesn't exist */
2583 _dbus_header_get_field_basic (&message->header,
2584 DBUS_HEADER_FIELD_DESTINATION,
2591 * Sets the message sender.
2593 * @param message the message
2594 * @param sender the sender or #NULL to unset
2595 * @returns #FALSE if not enough memory
2598 dbus_message_set_sender (DBusMessage *message,
2601 _dbus_return_val_if_fail (message != NULL, FALSE);
2602 _dbus_return_val_if_fail (!message->locked, FALSE);
2603 _dbus_return_val_if_fail (sender == NULL ||
2604 _dbus_check_is_valid_bus_name (sender),
2607 return set_or_delete_string_field (message,
2608 DBUS_HEADER_FIELD_SENDER,
2614 * Gets the unique name of the connection which originated this
2615 * message, or #NULL if unknown or inapplicable. The sender is filled
2616 * in by the message bus.
2618 * @param message the message
2619 * @returns the unique name of the sender or #NULL
2622 dbus_message_get_sender (DBusMessage *message)
2626 _dbus_return_val_if_fail (message != NULL, NULL);
2628 v = NULL; /* in case field doesn't exist */
2629 _dbus_header_get_field_basic (&message->header,
2630 DBUS_HEADER_FIELD_SENDER,
2637 * Gets the type signature of the message, i.e. the arguments in the
2638 * message payload. The signature includes only "in" arguments for
2639 * #DBUS_MESSAGE_TYPE_METHOD_CALL and only "out" arguments for
2640 * #DBUS_MESSAGE_TYPE_METHOD_RETURN, so is slightly different from
2641 * what you might expect (it does not include the signature of the
2642 * entire C++-style method).
2644 * The signature is a string made up of type codes such as
2645 * #DBUS_TYPE_INT32. The string is terminated with nul (nul is also
2646 * the value of #DBUS_TYPE_INVALID).
2648 * @param message the message
2649 * @returns the type signature
2652 dbus_message_get_signature (DBusMessage *message)
2654 const DBusString *type_str;
2657 _dbus_return_val_if_fail (message != NULL, NULL);
2659 get_const_signature (&message->header, &type_str, &type_pos);
2661 return _dbus_string_get_const_data_len (type_str, type_pos, 0);
2665 _dbus_message_has_type_interface_member (DBusMessage *message,
2667 const char *interface,
2672 _dbus_assert (message != NULL);
2673 _dbus_assert (interface != NULL);
2674 _dbus_assert (member != NULL);
2676 if (dbus_message_get_type (message) != type)
2679 /* Optimize by checking the short member name first
2680 * instead of the longer interface name
2683 n = dbus_message_get_member (message);
2685 if (n && strcmp (n, member) == 0)
2687 n = dbus_message_get_interface (message);
2689 if (n == NULL || strcmp (n, interface) == 0)
2697 * Checks whether the message is a method call with the given
2698 * interface and member fields. If the message is not
2699 * #DBUS_MESSAGE_TYPE_METHOD_CALL, or has a different interface or
2700 * member field, returns #FALSE. If the interface field is missing,
2701 * then it will be assumed equal to the provided interface. The D-BUS
2702 * protocol allows method callers to leave out the interface name.
2704 * @param message the message
2705 * @param interface the name to check (must not be #NULL)
2706 * @param method the name to check (must not be #NULL)
2708 * @returns #TRUE if the message is the specified method call
2711 dbus_message_is_method_call (DBusMessage *message,
2712 const char *interface,
2715 _dbus_return_val_if_fail (message != NULL, FALSE);
2716 _dbus_return_val_if_fail (interface != NULL, FALSE);
2717 _dbus_return_val_if_fail (method != NULL, FALSE);
2718 /* don't check that interface/method are valid since it would be
2719 * expensive, and not catch many common errors
2722 return _dbus_message_has_type_interface_member (message,
2723 DBUS_MESSAGE_TYPE_METHOD_CALL,
2728 * Checks whether the message is a signal with the given interface and
2729 * member fields. If the message is not #DBUS_MESSAGE_TYPE_SIGNAL, or
2730 * has a different interface or member field, returns #FALSE. If the
2731 * interface field in the message is missing, it is assumed to match
2732 * any interface you pass in to this function.
2734 * @param message the message
2735 * @param interface the name to check (must not be #NULL)
2736 * @param signal_name the name to check (must not be #NULL)
2738 * @returns #TRUE if the message is the specified signal
2741 dbus_message_is_signal (DBusMessage *message,
2742 const char *interface,
2743 const char *signal_name)
2745 _dbus_return_val_if_fail (message != NULL, FALSE);
2746 _dbus_return_val_if_fail (interface != NULL, FALSE);
2747 _dbus_return_val_if_fail (signal_name != NULL, FALSE);
2748 /* don't check that interface/name are valid since it would be
2749 * expensive, and not catch many common errors
2752 return _dbus_message_has_type_interface_member (message,
2753 DBUS_MESSAGE_TYPE_SIGNAL,
2754 interface, signal_name);
2758 * Checks whether the message is an error reply with the given error
2759 * name. If the message is not #DBUS_MESSAGE_TYPE_ERROR, or has a
2760 * different name, returns #FALSE.
2762 * @param message the message
2763 * @param error_name the name to check (must not be #NULL)
2765 * @returns #TRUE if the message is the specified error
2768 dbus_message_is_error (DBusMessage *message,
2769 const char *error_name)
2773 _dbus_return_val_if_fail (message != NULL, FALSE);
2774 _dbus_return_val_if_fail (error_name != NULL, FALSE);
2775 /* don't check that error_name is valid since it would be expensive,
2776 * and not catch many common errors
2779 if (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_ERROR)
2782 n = dbus_message_get_error_name (message);
2784 if (n && strcmp (n, error_name) == 0)
2791 * Checks whether the message was sent to the given name. If the
2792 * message has no destination specified or has a different
2793 * destination, returns #FALSE.
2795 * @param message the message
2796 * @param name the name to check (must not be #NULL)
2798 * @returns #TRUE if the message has the given destination name
2801 dbus_message_has_destination (DBusMessage *message,
2806 _dbus_return_val_if_fail (message != NULL, FALSE);
2807 _dbus_return_val_if_fail (name != NULL, FALSE);
2808 /* don't check that name is valid since it would be expensive, and
2809 * not catch many common errors
2812 s = dbus_message_get_destination (message);
2814 if (s && strcmp (s, name) == 0)
2821 * Checks whether the message has the given unique name as its sender.
2822 * If the message has no sender specified or has a different sender,
2823 * returns #FALSE. Note that a peer application will always have the
2824 * unique name of the connection as the sender. So you can't use this
2825 * function to see whether a sender owned a well-known name.
2827 * Messages from the bus itself will have #DBUS_SERVICE_ORG_FREEDESKTOP_DBUS
2830 * @param message the message
2831 * @param name the name to check (must not be #NULL)
2833 * @returns #TRUE if the message has the given sender
2836 dbus_message_has_sender (DBusMessage *message,
2841 _dbus_return_val_if_fail (message != NULL, FALSE);
2842 _dbus_return_val_if_fail (name != NULL, FALSE);
2843 /* don't check that name is valid since it would be expensive, and
2844 * not catch many common errors
2847 s = dbus_message_get_sender (message);
2849 if (s && strcmp (s, name) == 0)
2856 * Checks whether the message has the given signature; see
2857 * dbus_message_get_signature() for more details on what the signature
2860 * @param message the message
2861 * @param signature typecode array
2862 * @returns #TRUE if message has the given signature
2865 dbus_message_has_signature (DBusMessage *message,
2866 const char *signature)
2870 _dbus_return_val_if_fail (message != NULL, FALSE);
2871 _dbus_return_val_if_fail (signature != NULL, FALSE);
2872 /* don't check that signature is valid since it would be expensive,
2873 * and not catch many common errors
2876 s = dbus_message_get_signature (message);
2878 if (s && strcmp (s, signature) == 0)
2885 * Sets a #DBusError based on the contents of the given
2886 * message. The error is only set if the message
2887 * is an error message, as in DBUS_MESSAGE_TYPE_ERROR.
2888 * The name of the error is set to the name of the message,
2889 * and the error message is set to the first argument
2890 * if the argument exists and is a string.
2892 * The return value indicates whether the error was set (the error is
2893 * set if and only if the message is an error message). So you can
2894 * check for an error reply and convert it to DBusError in one go:
2896 * if (dbus_set_error_from_message (error, reply))
2902 * @param error the error to set
2903 * @param message the message to set it from
2904 * @returns #TRUE if dbus_message_get_is_error() returns #TRUE for the message
2907 dbus_set_error_from_message (DBusError *error,
2908 DBusMessage *message)
2912 _dbus_return_val_if_fail (message != NULL, FALSE);
2913 _dbus_return_val_if_error_is_set (error, FALSE);
2915 if (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_ERROR)
2919 dbus_message_get_args (message, NULL,
2920 DBUS_TYPE_STRING, &str,
2923 dbus_set_error (error, dbus_message_get_error_name (message),
2924 str ? "%s" : NULL, str);
2932 * @addtogroup DBusMessageInternals
2938 * The initial buffer size of the message loader.
2940 * @todo this should be based on min header size plus some average
2941 * body size, or something. Or rather, the min header size only, if we
2942 * want to try to read only the header, store that in a DBusMessage,
2943 * then read only the body and store that, etc., depends on
2944 * how we optimize _dbus_message_loader_get_buffer() and what
2945 * the exact message format is.
2947 #define INITIAL_LOADER_DATA_LEN 32
2950 * Creates a new message loader. Returns #NULL if memory can't
2953 * @returns new loader, or #NULL.
2956 _dbus_message_loader_new (void)
2958 DBusMessageLoader *loader;
2960 loader = dbus_new0 (DBusMessageLoader, 1);
2964 loader->refcount = 1;
2966 loader->corrupted = FALSE;
2967 loader->corruption_reason = DBUS_VALID;
2969 /* this can be configured by the app, but defaults to the protocol max */
2970 loader->max_message_size = DBUS_MAXIMUM_MESSAGE_LENGTH;
2972 if (!_dbus_string_init (&loader->data))
2978 /* preallocate the buffer for speed, ignore failure */
2979 _dbus_string_set_length (&loader->data, INITIAL_LOADER_DATA_LEN);
2980 _dbus_string_set_length (&loader->data, 0);
2986 * Increments the reference count of the loader.
2988 * @param loader the loader.
2989 * @returns the loader
2992 _dbus_message_loader_ref (DBusMessageLoader *loader)
2994 loader->refcount += 1;
3000 * Decrements the reference count of the loader and finalizes the
3001 * loader when the count reaches zero.
3003 * @param loader the loader.
3006 _dbus_message_loader_unref (DBusMessageLoader *loader)
3008 loader->refcount -= 1;
3009 if (loader->refcount == 0)
3011 _dbus_list_foreach (&loader->messages,
3012 (DBusForeachFunction) dbus_message_unref,
3014 _dbus_list_clear (&loader->messages);
3015 _dbus_string_free (&loader->data);
3021 * Gets the buffer to use for reading data from the network. Network
3022 * data is read directly into an allocated buffer, which is then used
3023 * in the DBusMessage, to avoid as many extra memcpy's as possible.
3024 * The buffer must always be returned immediately using
3025 * _dbus_message_loader_return_buffer(), even if no bytes are
3026 * successfully read.
3028 * @todo this function can be a lot more clever. For example
3029 * it can probably always return a buffer size to read exactly
3030 * the body of the next message, thus avoiding any memory wastage
3033 * @todo we need to enforce a max length on strings in header fields.
3035 * @param loader the message loader.
3036 * @param buffer the buffer
3039 _dbus_message_loader_get_buffer (DBusMessageLoader *loader,
3040 DBusString **buffer)
3042 _dbus_assert (!loader->buffer_outstanding);
3044 *buffer = &loader->data;
3046 loader->buffer_outstanding = TRUE;
3050 * Returns a buffer obtained from _dbus_message_loader_get_buffer(),
3051 * indicating to the loader how many bytes of the buffer were filled
3052 * in. This function must always be called, even if no bytes were
3053 * successfully read.
3055 * @param loader the loader.
3056 * @param buffer the buffer.
3057 * @param bytes_read number of bytes that were read into the buffer.
3060 _dbus_message_loader_return_buffer (DBusMessageLoader *loader,
3064 _dbus_assert (loader->buffer_outstanding);
3065 _dbus_assert (buffer == &loader->data);
3067 loader->buffer_outstanding = FALSE;
3071 * FIXME when we move the header out of the buffer, that memmoves all
3072 * buffered messages. Kind of crappy.
3074 * Also we copy the header and body, which is kind of crappy. To
3075 * avoid this, we have to allow header and body to be in a single
3076 * memory block, which is good for messages we read and bad for
3077 * messages we are creating. But we could move_len() the buffer into
3078 * this single memory block, and move_len() will just swap the buffers
3079 * if you're moving the entire buffer replacing the dest string.
3081 * We could also have the message loader tell the transport how many
3082 * bytes to read; so it would first ask for some arbitrary number like
3083 * 256, then if the message was incomplete it would use the
3084 * header/body len to ask for exactly the size of the message (or
3085 * blocks the size of a typical kernel buffer for the socket). That
3086 * way we don't get trailing bytes in the buffer that have to be
3087 * memmoved. Though I suppose we also don't have a chance of reading a
3088 * bunch of small messages at once, so the optimization may be stupid.
3090 * Another approach would be to keep a "start" index into
3091 * loader->data and only delete it occasionally, instead of after
3092 * each message is loaded.
3094 * load_message() returns FALSE if not enough memory OR the loader was corrupted
3097 load_message (DBusMessageLoader *loader,
3098 DBusMessage *message,
3100 int fields_array_len,
3105 DBusValidity validity;
3106 const DBusString *type_str;
3108 DBusValidationMode mode;
3110 mode = DBUS_VALIDATION_MODE_DATA_IS_UNTRUSTED;
3115 _dbus_verbose_bytes_of_string (&loader->data, 0, header_len /* + body_len */);
3118 /* 1. VALIDATE AND COPY OVER HEADER */
3119 _dbus_assert (_dbus_string_get_length (&message->header.data) == 0);
3120 _dbus_assert ((header_len + body_len) <= _dbus_string_get_length (&loader->data));
3122 if (!_dbus_header_load (&message->header,
3130 _dbus_string_get_length (&loader->data)))
3132 _dbus_verbose ("Failed to load header for new message code %d\n", validity);
3133 if (validity == DBUS_VALID)
3137 loader->corrupted = TRUE;
3138 loader->corruption_reason = validity;
3143 _dbus_assert (validity == DBUS_VALID);
3145 message->byte_order = byte_order;
3147 /* 2. VALIDATE BODY */
3148 if (mode != DBUS_VALIDATION_MODE_WE_TRUST_THIS_DATA_ABSOLUTELY)
3150 get_const_signature (&message->header, &type_str, &type_pos);
3152 /* Because the bytes_remaining arg is NULL, this validates that the
3153 * body is the right length
3155 validity = _dbus_validate_body_with_reason (type_str,
3162 if (validity != DBUS_VALID)
3164 _dbus_verbose ("Failed to validate message body code %d\n", validity);
3166 loader->corrupted = TRUE;
3167 loader->corruption_reason = validity;
3173 /* 3. COPY OVER BODY AND QUEUE MESSAGE */
3175 if (!_dbus_list_append (&loader->messages, message))
3177 _dbus_verbose ("Failed to append new message to loader queue\n");
3182 _dbus_assert (_dbus_string_get_length (&message->body) == 0);
3183 _dbus_assert (_dbus_string_get_length (&loader->data) >=
3184 (header_len + body_len));
3186 if (!_dbus_string_copy_len (&loader->data, header_len, body_len, &message->body, 0))
3188 _dbus_verbose ("Failed to move body into new message\n");
3193 _dbus_string_delete (&loader->data, 0, header_len + body_len);
3195 _dbus_assert (_dbus_string_get_length (&message->header.data) == header_len);
3196 _dbus_assert (_dbus_string_get_length (&message->body) == body_len);
3198 _dbus_verbose ("Loaded message %p\n", message);
3200 _dbus_assert (!oom);
3201 _dbus_assert (!loader->corrupted);
3202 _dbus_assert (loader->messages != NULL);
3203 _dbus_assert (_dbus_list_find_last (&loader->messages, message) != NULL);
3211 /* does nothing if the message isn't in the list */
3212 _dbus_list_remove_last (&loader->messages, message);
3215 _dbus_assert (!loader->corrupted);
3217 _dbus_assert (loader->corrupted);
3219 _dbus_verbose_bytes_of_string (&loader->data, 0, _dbus_string_get_length (&loader->data));
3225 * Converts buffered data into messages, if we have enough data. If
3226 * we don't have enough data, does nothing.
3228 * @todo we need to check that the proper named header fields exist
3229 * for each message type.
3231 * @todo If a message has unknown type, we should probably eat it
3232 * right here rather than passing it out to applications. However
3233 * it's not an error to see messages of unknown type.
3235 * @param loader the loader.
3236 * @returns #TRUE if we had enough memory to finish.
3239 _dbus_message_loader_queue_messages (DBusMessageLoader *loader)
3241 while (!loader->corrupted &&
3242 _dbus_string_get_length (&loader->data) >= DBUS_MINIMUM_HEADER_SIZE)
3244 DBusValidity validity;
3245 int byte_order, fields_array_len, header_len, body_len;
3247 if (_dbus_header_have_message_untrusted (loader->max_message_size,
3254 _dbus_string_get_length (&loader->data)))
3256 DBusMessage *message;
3258 _dbus_assert (validity == DBUS_VALID);
3260 message = dbus_message_new_empty_header ();
3261 if (message == NULL)
3264 if (!load_message (loader, message,
3265 byte_order, fields_array_len,
3266 header_len, body_len))
3268 dbus_message_unref (message);
3269 /* load_message() returns false if corrupted or OOM; if
3270 * corrupted then return TRUE for not OOM
3272 return loader->corrupted;
3275 _dbus_assert (loader->messages != NULL);
3276 _dbus_assert (_dbus_list_find_last (&loader->messages, message) != NULL);
3280 _dbus_verbose ("Initial peek at header says we don't have a whole message yet, or data broken with invalid code %d\n",
3282 if (validity != DBUS_VALID)
3284 loader->corrupted = TRUE;
3285 loader->corruption_reason = validity;
3295 * Peeks at first loaded message, returns #NULL if no messages have
3298 * @param loader the loader.
3299 * @returns the next message, or #NULL if none.
3302 _dbus_message_loader_peek_message (DBusMessageLoader *loader)
3304 if (loader->messages)
3305 return loader->messages->data;
3311 * Pops a loaded message (passing ownership of the message
3312 * to the caller). Returns #NULL if no messages have been
3315 * @param loader the loader.
3316 * @returns the next message, or #NULL if none.
3319 _dbus_message_loader_pop_message (DBusMessageLoader *loader)
3321 return _dbus_list_pop_first (&loader->messages);
3325 * Pops a loaded message inside a list link (passing ownership of the
3326 * message and link to the caller). Returns #NULL if no messages have
3329 * @param loader the loader.
3330 * @returns the next message link, or #NULL if none.
3333 _dbus_message_loader_pop_message_link (DBusMessageLoader *loader)
3335 return _dbus_list_pop_first_link (&loader->messages);
3339 * Returns a popped message link, used to undo a pop.
3341 * @param loader the loader
3342 * @param link the link with a message in it
3345 _dbus_message_loader_putback_message_link (DBusMessageLoader *loader,
3348 _dbus_list_prepend_link (&loader->messages, link);
3352 * Checks whether the loader is confused due to bad data.
3353 * If messages are received that are invalid, the
3354 * loader gets confused and gives up permanently.
3355 * This state is called "corrupted."
3357 * @param loader the loader
3358 * @returns #TRUE if the loader is hosed.
3361 _dbus_message_loader_get_is_corrupted (DBusMessageLoader *loader)
3363 _dbus_assert ((loader->corrupted && loader->corruption_reason != DBUS_VALID) ||
3364 (!loader->corrupted && loader->corruption_reason == DBUS_VALID));
3365 return loader->corrupted;
3369 * Sets the maximum size message we allow.
3371 * @param loader the loader
3372 * @param size the max message size in bytes
3375 _dbus_message_loader_set_max_message_size (DBusMessageLoader *loader,
3378 if (size > DBUS_MAXIMUM_MESSAGE_LENGTH)
3380 _dbus_verbose ("clamping requested max message size %ld to %d\n",
3381 size, DBUS_MAXIMUM_MESSAGE_LENGTH);
3382 size = DBUS_MAXIMUM_MESSAGE_LENGTH;
3384 loader->max_message_size = size;
3388 * Gets the maximum allowed message size in bytes.
3390 * @param loader the loader
3391 * @returns max size in bytes
3394 _dbus_message_loader_get_max_message_size (DBusMessageLoader *loader)
3396 return loader->max_message_size;
3399 static DBusDataSlotAllocator slot_allocator;
3400 _DBUS_DEFINE_GLOBAL_LOCK (message_slots);
3403 * Allocates an integer ID to be used for storing application-specific
3404 * data on any DBusMessage. The allocated ID may then be used
3405 * with dbus_message_set_data() and dbus_message_get_data().
3406 * The passed-in slot must be initialized to -1, and is filled in
3407 * with the slot ID. If the passed-in slot is not -1, it's assumed
3408 * to be already allocated, and its refcount is incremented.
3410 * The allocated slot is global, i.e. all DBusMessage objects will
3411 * have a slot with the given integer ID reserved.
3413 * @param slot_p address of a global variable storing the slot
3414 * @returns #FALSE on failure (no memory)
3417 dbus_message_allocate_data_slot (dbus_int32_t *slot_p)
3419 return _dbus_data_slot_allocator_alloc (&slot_allocator,
3420 _DBUS_LOCK_NAME (message_slots),
3425 * Deallocates a global ID for message data slots.
3426 * dbus_message_get_data() and dbus_message_set_data() may no
3427 * longer be used with this slot. Existing data stored on existing
3428 * DBusMessage objects will be freed when the message is
3429 * finalized, but may not be retrieved (and may only be replaced if
3430 * someone else reallocates the slot). When the refcount on the
3431 * passed-in slot reaches 0, it is set to -1.
3433 * @param slot_p address storing the slot to deallocate
3436 dbus_message_free_data_slot (dbus_int32_t *slot_p)
3438 _dbus_return_if_fail (*slot_p >= 0);
3440 _dbus_data_slot_allocator_free (&slot_allocator, slot_p);
3444 * Stores a pointer on a DBusMessage, along
3445 * with an optional function to be used for freeing
3446 * the data when the data is set again, or when
3447 * the message is finalized. The slot number
3448 * must have been allocated with dbus_message_allocate_data_slot().
3450 * @param message the message
3451 * @param slot the slot number
3452 * @param data the data to store
3453 * @param free_data_func finalizer function for the data
3454 * @returns #TRUE if there was enough memory to store the data
3457 dbus_message_set_data (DBusMessage *message,
3460 DBusFreeFunction free_data_func)
3462 DBusFreeFunction old_free_func;
3466 _dbus_return_val_if_fail (message != NULL, FALSE);
3467 _dbus_return_val_if_fail (slot >= 0, FALSE);
3469 retval = _dbus_data_slot_list_set (&slot_allocator,
3470 &message->slot_list,
3471 slot, data, free_data_func,
3472 &old_free_func, &old_data);
3476 /* Do the actual free outside the message lock */
3478 (* old_free_func) (old_data);
3485 * Retrieves data previously set with dbus_message_set_data().
3486 * The slot must still be allocated (must not have been freed).
3488 * @param message the message
3489 * @param slot the slot to get data from
3490 * @returns the data, or #NULL if not found
3493 dbus_message_get_data (DBusMessage *message,
3498 _dbus_return_val_if_fail (message != NULL, NULL);
3500 res = _dbus_data_slot_list_get (&slot_allocator,
3501 &message->slot_list,
3508 * Utility function to convert a machine-readable (not translated)
3509 * string into a D-BUS message type.
3512 * "method_call" -> DBUS_MESSAGE_TYPE_METHOD_CALL
3513 * "method_return" -> DBUS_MESSAGE_TYPE_METHOD_RETURN
3514 * "signal" -> DBUS_MESSAGE_TYPE_SIGNAL
3515 * "error" -> DBUS_MESSAGE_TYPE_ERROR
3516 * anything else -> DBUS_MESSAGE_TYPE_INVALID
3521 dbus_message_type_from_string (const char *type_str)
3523 if (strcmp (type_str, "method_call") == 0)
3524 return DBUS_MESSAGE_TYPE_METHOD_CALL;
3525 if (strcmp (type_str, "method_return") == 0)
3526 return DBUS_MESSAGE_TYPE_METHOD_RETURN;
3527 else if (strcmp (type_str, "signal") == 0)
3528 return DBUS_MESSAGE_TYPE_SIGNAL;
3529 else if (strcmp (type_str, "error") == 0)
3530 return DBUS_MESSAGE_TYPE_ERROR;
3532 return DBUS_MESSAGE_TYPE_INVALID;
3536 * Utility function to convert a D-BUS message type into a
3537 * machine-readable string (not translated).
3540 * DBUS_MESSAGE_TYPE_METHOD_CALL -> "method_call"
3541 * DBUS_MESSAGE_TYPE_METHOD_RETURN -> "method_return"
3542 * DBUS_MESSAGE_TYPE_SIGNAL -> "signal"
3543 * DBUS_MESSAGE_TYPE_ERROR -> "error"
3544 * DBUS_MESSAGE_TYPE_INVALID -> "invalid"
3549 dbus_message_type_to_string (int type)
3553 case DBUS_MESSAGE_TYPE_METHOD_CALL:
3554 return "method_call";
3555 case DBUS_MESSAGE_TYPE_METHOD_RETURN:
3556 return "method_return";
3557 case DBUS_MESSAGE_TYPE_SIGNAL:
3559 case DBUS_MESSAGE_TYPE_ERROR:
3568 /* tests in dbus-message-util.c */