1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 #include "dbus-internals.h"
27 #include "dbus-marshal-recursive.h"
28 #include "dbus-marshal-validate.h"
29 #include "dbus-marshal-byteswap.h"
30 #include "dbus-marshal-header.h"
31 #include "dbus-signature.h"
32 #include "dbus-message-private.h"
33 #include "dbus-object-tree.h"
34 #include "dbus-memory.h"
35 #include "dbus-list.h"
36 #include "dbus-threads-internal.h"
37 #ifdef HAVE_UNIX_FD_PASSING
38 #include "dbus-sysdeps-unix.h"
43 static void dbus_message_finalize (DBusMessage *message);
46 * @defgroup DBusMessageInternals DBusMessage implementation details
47 * @ingroup DBusInternals
48 * @brief DBusMessage private implementation details.
50 * The guts of DBusMessage and its methods.
55 /* Not thread locked, but strictly const/read-only so should be OK
57 /** An static string representing an empty signature */
58 _DBUS_STRING_DEFINE_STATIC(_dbus_empty_signature_str, "");
60 /* these have wacky values to help trap uninitialized iterators;
61 * but has to fit in 3 bits
64 DBUS_MESSAGE_ITER_TYPE_READER = 3,
65 DBUS_MESSAGE_ITER_TYPE_WRITER = 7
68 /** typedef for internals of message iterator */
69 typedef struct DBusMessageRealIter DBusMessageRealIter;
72 * @brief Internals of DBusMessageIter
74 * Object representing a position in a message. All fields are internal.
76 struct DBusMessageRealIter
78 DBusMessage *message; /**< Message used */
79 dbus_uint32_t changed_stamp : CHANGED_STAMP_BITS; /**< stamp to detect invalid iters */
80 dbus_uint32_t iter_type : 3; /**< whether this is a reader or writer iter */
81 dbus_uint32_t sig_refcount : 8; /**< depth of open_signature() */
84 DBusTypeWriter writer; /**< writer */
85 DBusTypeReader reader; /**< reader */
86 } u; /**< the type writer or reader that does all the work */
90 get_const_signature (DBusHeader *header,
91 const DBusString **type_str_p,
94 if (_dbus_header_get_field_raw (header,
95 DBUS_HEADER_FIELD_SIGNATURE,
99 *type_pos_p += 1; /* skip the signature length which is 1 byte */
103 *type_str_p = &_dbus_empty_signature_str;
109 * Swaps the message to compiler byte order if required
111 * @param message the message
114 _dbus_message_byteswap (DBusMessage *message)
116 const DBusString *type_str;
119 if (message->byte_order == DBUS_COMPILER_BYTE_ORDER)
122 _dbus_verbose ("Swapping message into compiler byte order\n");
124 get_const_signature (&message->header, &type_str, &type_pos);
126 _dbus_marshal_byteswap (type_str, type_pos,
128 DBUS_COMPILER_BYTE_ORDER,
131 message->byte_order = DBUS_COMPILER_BYTE_ORDER;
133 _dbus_header_byteswap (&message->header, DBUS_COMPILER_BYTE_ORDER);
136 /** byte-swap the message if it doesn't match our byte order.
137 * Called only when we need the message in our own byte order,
138 * normally when reading arrays of integers or doubles.
139 * Otherwise should not be called since it would do needless
142 #define ensure_byte_order(message) \
143 if (message->byte_order != DBUS_COMPILER_BYTE_ORDER) \
144 _dbus_message_byteswap (message)
147 * Gets the data to be sent over the network for this message.
148 * The header and then the body should be written out.
149 * This function is guaranteed to always return the same
150 * data once a message is locked (with dbus_message_lock()).
152 * @param message the message.
153 * @param header return location for message header data.
154 * @param body return location for message body data.
157 _dbus_message_get_network_data (DBusMessage *message,
158 const DBusString **header,
159 const DBusString **body)
161 _dbus_assert (message->locked);
163 *header = &message->header.data;
164 *body = &message->body;
168 * Gets the unix fds to be sent over the network for this message.
169 * This function is guaranteed to always return the same data once a
170 * message is locked (with dbus_message_lock()).
172 * @param message the message.
173 * @param fds return location of unix fd array
174 * @param n_fds return number of entries in array
176 void _dbus_message_get_unix_fds(DBusMessage *message,
180 _dbus_assert (message->locked);
182 #ifdef HAVE_UNIX_FD_PASSING
183 *fds = message->unix_fds;
184 *n_fds = message->n_unix_fds;
192 * Sets the serial number of a message.
193 * This can only be done once on a message.
195 * DBusConnection will automatically set the serial to an appropriate value
196 * when the message is sent; this function is only needed when encapsulating
197 * messages in another protocol, or otherwise bypassing DBusConnection.
199 * @param message the message
200 * @param serial the serial
203 dbus_message_set_serial (DBusMessage *message,
204 dbus_uint32_t serial)
206 _dbus_return_if_fail (message != NULL);
207 _dbus_return_if_fail (!message->locked);
209 _dbus_header_set_serial (&message->header, serial);
213 * Adds a counter to be incremented immediately with the size/unix fds
214 * of this message, and decremented by the size/unix fds of this
215 * message when this message if finalized. The link contains a
216 * counter with its refcount already incremented, but the counter
217 * itself not incremented. Ownership of link and counter refcount is
218 * passed to the message.
220 * @param message the message
221 * @param link link with counter as data
224 _dbus_message_add_counter_link (DBusMessage *message,
227 /* right now we don't recompute the delta when message
228 * size changes, and that's OK for current purposes
229 * I think, but could be important to change later.
230 * Do recompute it whenever there are no outstanding counters,
231 * since it's basically free.
233 if (message->counters == NULL)
235 message->size_counter_delta =
236 _dbus_string_get_length (&message->header.data) +
237 _dbus_string_get_length (&message->body);
239 #ifdef HAVE_UNIX_FD_PASSING
240 message->unix_fd_counter_delta = message->n_unix_fds;
244 _dbus_verbose ("message has size %ld\n",
245 message->size_counter_delta);
249 _dbus_list_append_link (&message->counters, link);
251 _dbus_counter_adjust_size (link->data, message->size_counter_delta);
253 #ifdef HAVE_UNIX_FD_PASSING
254 _dbus_counter_adjust_unix_fd (link->data, message->unix_fd_counter_delta);
259 * Adds a counter to be incremented immediately with the size/unix fds
260 * of this message, and decremented by the size/unix fds of this
261 * message when this message if finalized.
263 * @param message the message
264 * @param counter the counter
265 * @returns #FALSE if no memory
268 _dbus_message_add_counter (DBusMessage *message,
269 DBusCounter *counter)
273 link = _dbus_list_alloc_link (counter);
277 _dbus_counter_ref (counter);
278 _dbus_message_add_counter_link (message, link);
284 * Removes a counter tracking the size/unix fds of this message, and
285 * decrements the counter by the size/unix fds of this message.
287 * @param message the message
288 * @param link_return return the link used
289 * @param counter the counter
292 _dbus_message_remove_counter (DBusMessage *message,
293 DBusCounter *counter,
294 DBusList **link_return)
298 link = _dbus_list_find_last (&message->counters,
300 _dbus_assert (link != NULL);
302 _dbus_list_unlink (&message->counters,
307 _dbus_list_free_link (link);
309 _dbus_counter_adjust_size (counter, - message->size_counter_delta);
311 #ifdef HAVE_UNIX_FD_PASSING
312 _dbus_counter_adjust_unix_fd (counter, - message->unix_fd_counter_delta);
315 _dbus_counter_unref (counter);
319 * Locks a message. Allows checking that applications don't keep a
320 * reference to a message in the outgoing queue and change it
321 * underneath us. Messages are locked when they enter the outgoing
322 * queue (dbus_connection_send_message()), and the library complains
323 * if the message is modified while locked. This function may also
324 * called externally, for applications wrapping D-Bus in another protocol.
326 * @param message the message to lock.
329 dbus_message_lock (DBusMessage *message)
331 if (!message->locked)
333 _dbus_header_update_lengths (&message->header,
334 _dbus_string_get_length (&message->body));
336 /* must have a signature if you have a body */
337 _dbus_assert (_dbus_string_get_length (&message->body) == 0 ||
338 dbus_message_get_signature (message) != NULL);
340 message->locked = TRUE;
345 set_or_delete_string_field (DBusMessage *message,
351 return _dbus_header_delete_field (&message->header, field);
353 return _dbus_header_set_field_basic (&message->header,
360 /* Probably we don't need to use this */
362 * Sets the signature of the message, i.e. the arguments in the
363 * message payload. The signature includes only "in" arguments for
364 * #DBUS_MESSAGE_TYPE_METHOD_CALL and only "out" arguments for
365 * #DBUS_MESSAGE_TYPE_METHOD_RETURN, so is slightly different from
366 * what you might expect (it does not include the signature of the
367 * entire C++-style method).
369 * The signature is a string made up of type codes such as
370 * #DBUS_TYPE_INT32. The string is terminated with nul (nul is also
371 * the value of #DBUS_TYPE_INVALID). The macros such as
372 * #DBUS_TYPE_INT32 evaluate to integers; to assemble a signature you
373 * may find it useful to use the string forms, such as
374 * #DBUS_TYPE_INT32_AS_STRING.
376 * An "unset" or #NULL signature is considered the same as an empty
377 * signature. In fact dbus_message_get_signature() will never return
380 * @param message the message
381 * @param signature the type signature or #NULL to unset
382 * @returns #FALSE if no memory
385 _dbus_message_set_signature (DBusMessage *message,
386 const char *signature)
388 _dbus_return_val_if_fail (message != NULL, FALSE);
389 _dbus_return_val_if_fail (!message->locked, FALSE);
390 _dbus_return_val_if_fail (signature == NULL ||
391 _dbus_check_is_valid_signature (signature));
392 /* can't delete the signature if you have a message body */
393 _dbus_return_val_if_fail (_dbus_string_get_length (&message->body) == 0 ||
396 return set_or_delete_string_field (message,
397 DBUS_HEADER_FIELD_SIGNATURE,
405 * We cache some DBusMessage to reduce the overhead of allocating
406 * them. In my profiling this consistently made about an 8%
407 * difference. It avoids the malloc for the message, the malloc for
408 * the slot list, the malloc for the header string and body string,
409 * and the associated free() calls. It does introduce another global
410 * lock which could be a performance issue in certain cases.
412 * For the echo client/server the round trip time goes from around
413 * .000077 to .000069 with the message cache on my laptop. The sysprof
414 * change is as follows (numbers are cumulative percentage):
416 * with message cache implemented as array as it is now (0.000069 per):
417 * new_empty_header 1.46
418 * mutex_lock 0.56 # i.e. _DBUS_LOCK(message_cache)
424 * mutex_lock 0.33 # i.e. _DBUS_LOCK(message_cache)
427 * with message cache implemented as list (0.000070 per roundtrip):
428 * new_empty_header 2.72
429 * list_pop_first 1.88
433 * without cache (0.000077 per roundtrip):
434 * new_empty_header 6.7
435 * string_init_preallocated 3.43
444 * If you implement the message_cache with a list, the primary reason
445 * it's slower is that you add another thread lock (on the DBusList
449 /** Avoid caching huge messages */
450 #define MAX_MESSAGE_SIZE_TO_CACHE 10 * _DBUS_ONE_KILOBYTE
452 /** Avoid caching too many messages */
453 #define MAX_MESSAGE_CACHE_SIZE 5
455 _DBUS_DEFINE_GLOBAL_LOCK (message_cache);
456 static DBusMessage *message_cache[MAX_MESSAGE_CACHE_SIZE];
457 static int message_cache_count = 0;
458 static dbus_bool_t message_cache_shutdown_registered = FALSE;
461 dbus_message_cache_shutdown (void *data)
465 _DBUS_LOCK (message_cache);
468 while (i < MAX_MESSAGE_CACHE_SIZE)
470 if (message_cache[i])
471 dbus_message_finalize (message_cache[i]);
476 message_cache_count = 0;
477 message_cache_shutdown_registered = FALSE;
479 _DBUS_UNLOCK (message_cache);
483 * Tries to get a message from the message cache. The retrieved
484 * message will have junk in it, so it still needs to be cleared out
485 * in dbus_message_new_empty_header()
487 * @returns the message, or #NULL if none cached
490 dbus_message_get_cached (void)
492 DBusMessage *message;
497 _DBUS_LOCK (message_cache);
499 _dbus_assert (message_cache_count >= 0);
501 if (message_cache_count == 0)
503 _DBUS_UNLOCK (message_cache);
507 /* This is not necessarily true unless count > 0, and
508 * message_cache is uninitialized until the shutdown is
511 _dbus_assert (message_cache_shutdown_registered);
514 while (i < MAX_MESSAGE_CACHE_SIZE)
516 if (message_cache[i])
518 message = message_cache[i];
519 message_cache[i] = NULL;
520 message_cache_count -= 1;
525 _dbus_assert (message_cache_count >= 0);
526 _dbus_assert (i < MAX_MESSAGE_CACHE_SIZE);
527 _dbus_assert (message != NULL);
529 _dbus_assert (message->refcount.value == 0);
530 _dbus_assert (message->counters == NULL);
532 _DBUS_UNLOCK (message_cache);
537 #ifdef HAVE_UNIX_FD_PASSING
539 close_unix_fds(int *fds, unsigned *n_fds)
549 for (i = 0; i < *n_fds; i++)
551 if (!_dbus_close(fds[i], &e))
553 _dbus_warn("Failed to close file descriptor: %s\n", e.message);
560 /* We don't free the array here, in case we can recycle it later */
565 free_counter (void *element,
568 DBusCounter *counter = element;
569 DBusMessage *message = data;
571 _dbus_counter_adjust_size (counter, - message->size_counter_delta);
572 #ifdef HAVE_UNIX_FD_PASSING
573 _dbus_counter_adjust_unix_fd (counter, - message->unix_fd_counter_delta);
576 _dbus_counter_unref (counter);
580 * Tries to cache a message, otherwise finalize it.
582 * @param message the message
585 dbus_message_cache_or_finalize (DBusMessage *message)
587 dbus_bool_t was_cached;
590 _dbus_assert (message->refcount.value == 0);
592 /* This calls application code and has to be done first thing
593 * without holding the lock
595 _dbus_data_slot_list_clear (&message->slot_list);
597 _dbus_list_foreach (&message->counters,
598 free_counter, message);
599 _dbus_list_clear (&message->counters);
601 #ifdef HAVE_UNIX_FD_PASSING
602 close_unix_fds(message->unix_fds, &message->n_unix_fds);
607 _DBUS_LOCK (message_cache);
609 if (!message_cache_shutdown_registered)
611 _dbus_assert (message_cache_count == 0);
613 if (!_dbus_register_shutdown_func (dbus_message_cache_shutdown, NULL))
617 while (i < MAX_MESSAGE_CACHE_SIZE)
619 message_cache[i] = NULL;
623 message_cache_shutdown_registered = TRUE;
626 _dbus_assert (message_cache_count >= 0);
628 if ((_dbus_string_get_length (&message->header.data) +
629 _dbus_string_get_length (&message->body)) >
630 MAX_MESSAGE_SIZE_TO_CACHE)
633 if (message_cache_count >= MAX_MESSAGE_CACHE_SIZE)
636 /* Find empty slot */
638 while (message_cache[i] != NULL)
641 _dbus_assert (i < MAX_MESSAGE_CACHE_SIZE);
643 _dbus_assert (message_cache[i] == NULL);
644 message_cache[i] = message;
645 message_cache_count += 1;
647 #ifndef DBUS_DISABLE_CHECKS
648 message->in_cache = TRUE;
652 _dbus_assert (message->refcount.value == 0);
654 _DBUS_UNLOCK (message_cache);
657 dbus_message_finalize (message);
660 #ifndef DBUS_DISABLE_CHECKS
662 _dbus_message_iter_check (DBusMessageRealIter *iter)
666 _dbus_warn_check_failed ("dbus message iterator is NULL\n");
670 if (iter->iter_type == DBUS_MESSAGE_ITER_TYPE_READER)
672 if (iter->u.reader.byte_order != iter->message->byte_order)
674 _dbus_warn_check_failed ("dbus message changed byte order since iterator was created\n");
677 /* because we swap the message into compiler order when you init an iter */
678 _dbus_assert (iter->u.reader.byte_order == DBUS_COMPILER_BYTE_ORDER);
680 else if (iter->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER)
682 if (iter->u.writer.byte_order != iter->message->byte_order)
684 _dbus_warn_check_failed ("dbus message changed byte order since append iterator was created\n");
687 /* because we swap the message into compiler order when you init an iter */
688 _dbus_assert (iter->u.writer.byte_order == DBUS_COMPILER_BYTE_ORDER);
692 _dbus_warn_check_failed ("dbus message iterator looks uninitialized or corrupted\n");
696 if (iter->changed_stamp != iter->message->changed_stamp)
698 _dbus_warn_check_failed ("dbus message iterator invalid because the message has been modified (or perhaps the iterator is just uninitialized)\n");
704 #endif /* DBUS_DISABLE_CHECKS */
707 * Implementation of the varargs arg-getting functions.
708 * dbus_message_get_args() is the place to go for complete
711 * @todo This may leak memory and file descriptors if parsing fails. See #21259
713 * @see dbus_message_get_args
714 * @param iter the message iter
715 * @param error error to be filled in
716 * @param first_arg_type type of the first argument
717 * @param var_args return location for first argument, followed by list of type/location pairs
718 * @returns #FALSE if error was set
721 _dbus_message_iter_get_args_valist (DBusMessageIter *iter,
726 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
727 int spec_type, msg_type, i;
730 _dbus_assert (_dbus_message_iter_check (real));
734 spec_type = first_arg_type;
737 while (spec_type != DBUS_TYPE_INVALID)
739 msg_type = dbus_message_iter_get_arg_type (iter);
741 if (msg_type != spec_type)
743 dbus_set_error (error, DBUS_ERROR_INVALID_ARGS,
744 "Argument %d is specified to be of type \"%s\", but "
745 "is actually of type \"%s\"\n", i,
746 _dbus_type_to_string (spec_type),
747 _dbus_type_to_string (msg_type));
752 if (spec_type == DBUS_TYPE_UNIX_FD)
754 #ifdef HAVE_UNIX_FD_PASSING
758 pfd = va_arg (var_args, int*);
761 _dbus_type_reader_read_basic(&real->u.reader, &idx);
763 if (idx.u32 >= real->message->n_unix_fds)
765 dbus_set_error (error, DBUS_ERROR_INCONSISTENT_MESSAGE,
766 "Message refers to file descriptor at index %i,"
767 "but has only %i descriptors attached.\n",
769 real->message->n_unix_fds);
773 if ((nfd = _dbus_dup(real->message->unix_fds[idx.u32], error)) < 0)
778 dbus_set_error (error, DBUS_ERROR_NOT_SUPPORTED,
779 "Platform does not support file desciptor passing.\n");
783 else if (dbus_type_is_basic (spec_type))
787 ptr = va_arg (var_args, DBusBasicValue*);
789 _dbus_assert (ptr != NULL);
791 _dbus_type_reader_read_basic (&real->u.reader,
794 else if (spec_type == DBUS_TYPE_ARRAY)
797 int spec_element_type;
798 const DBusBasicValue **ptr;
800 DBusTypeReader array;
802 spec_element_type = va_arg (var_args, int);
803 element_type = _dbus_type_reader_get_element_type (&real->u.reader);
805 if (spec_element_type != element_type)
807 dbus_set_error (error, DBUS_ERROR_INVALID_ARGS,
808 "Argument %d is specified to be an array of \"%s\", but "
809 "is actually an array of \"%s\"\n",
811 _dbus_type_to_string (spec_element_type),
812 _dbus_type_to_string (element_type));
817 if (dbus_type_is_fixed (spec_element_type) &&
818 element_type != DBUS_TYPE_UNIX_FD)
820 ptr = va_arg (var_args, const DBusBasicValue**);
821 n_elements_p = va_arg (var_args, int*);
823 _dbus_assert (ptr != NULL);
824 _dbus_assert (n_elements_p != NULL);
826 _dbus_type_reader_recurse (&real->u.reader, &array);
828 _dbus_type_reader_read_fixed_multi (&array,
829 (void *) ptr, n_elements_p);
831 else if (spec_element_type == DBUS_TYPE_STRING ||
832 spec_element_type == DBUS_TYPE_SIGNATURE ||
833 spec_element_type == DBUS_TYPE_OBJECT_PATH)
839 str_array_p = va_arg (var_args, char***);
840 n_elements_p = va_arg (var_args, int*);
842 _dbus_assert (str_array_p != NULL);
843 _dbus_assert (n_elements_p != NULL);
845 /* Count elements in the array */
846 _dbus_type_reader_recurse (&real->u.reader, &array);
849 while (_dbus_type_reader_get_current_type (&array) != DBUS_TYPE_INVALID)
852 _dbus_type_reader_next (&array);
855 str_array = dbus_new0 (char*, n_elements + 1);
856 if (str_array == NULL)
858 _DBUS_SET_OOM (error);
862 /* Now go through and dup each string */
863 _dbus_type_reader_recurse (&real->u.reader, &array);
866 while (i < n_elements)
869 _dbus_type_reader_read_basic (&array,
872 str_array[i] = _dbus_strdup (s);
873 if (str_array[i] == NULL)
875 dbus_free_string_array (str_array);
876 _DBUS_SET_OOM (error);
882 if (!_dbus_type_reader_next (&array))
883 _dbus_assert (i == n_elements);
886 _dbus_assert (_dbus_type_reader_get_current_type (&array) == DBUS_TYPE_INVALID);
887 _dbus_assert (i == n_elements);
888 _dbus_assert (str_array[i] == NULL);
890 *str_array_p = str_array;
891 *n_elements_p = n_elements;
893 #ifndef DBUS_DISABLE_CHECKS
896 _dbus_warn ("you can't read arrays of container types (struct, variant, array) with %s for now\n",
897 _DBUS_FUNCTION_NAME);
902 #ifndef DBUS_DISABLE_CHECKS
905 _dbus_warn ("you can only read arrays and basic types with %s for now\n",
906 _DBUS_FUNCTION_NAME);
911 spec_type = va_arg (var_args, int);
912 if (!_dbus_type_reader_next (&real->u.reader) && spec_type != DBUS_TYPE_INVALID)
914 dbus_set_error (error, DBUS_ERROR_INVALID_ARGS,
915 "Message has only %d arguments, but more were expected", i);
932 * @defgroup DBusMessage DBusMessage
934 * @brief Message to be sent or received over a #DBusConnection.
936 * A DBusMessage is the most basic unit of communication over a
937 * DBusConnection. A DBusConnection represents a stream of messages
938 * received from a remote application, and a stream of messages
939 * sent to a remote application.
941 * A message has a message type, returned from
942 * dbus_message_get_type(). This indicates whether the message is a
943 * method call, a reply to a method call, a signal, or an error reply.
945 * A message has header fields such as the sender, destination, method
946 * or signal name, and so forth. DBusMessage has accessor functions for
947 * these, such as dbus_message_get_member().
949 * Convenience functions dbus_message_is_method_call(), dbus_message_is_signal(),
950 * and dbus_message_is_error() check several header fields at once and are
951 * slightly more efficient than checking the header fields with individual
952 * accessor functions.
954 * Finally, a message has arguments. The number and types of arguments
955 * are in the message's signature header field (accessed with
956 * dbus_message_get_signature()). Simple argument values are usually
957 * retrieved with dbus_message_get_args() but more complex values such
958 * as structs may require the use of #DBusMessageIter.
960 * The D-Bus specification goes into some more detail about header fields and
967 * @typedef DBusMessage
969 * Opaque data type representing a message received from or to be
970 * sent to another application.
974 * Returns the serial of a message or 0 if none has been specified.
975 * The message's serial number is provided by the application sending
976 * the message and is used to identify replies to this message.
978 * All messages received on a connection will have a serial provided
979 * by the remote application.
981 * For messages you're sending, dbus_connection_send() will assign a
982 * serial and return it to you.
984 * @param message the message
985 * @returns the serial
988 dbus_message_get_serial (DBusMessage *message)
990 _dbus_return_val_if_fail (message != NULL, 0);
992 return _dbus_header_get_serial (&message->header);
996 * Sets the reply serial of a message (the serial of the message this
999 * @param message the message
1000 * @param reply_serial the serial we're replying to
1001 * @returns #FALSE if not enough memory
1004 dbus_message_set_reply_serial (DBusMessage *message,
1005 dbus_uint32_t reply_serial)
1007 _dbus_return_val_if_fail (message != NULL, FALSE);
1008 _dbus_return_val_if_fail (!message->locked, FALSE);
1009 _dbus_return_val_if_fail (reply_serial != 0, FALSE); /* 0 is invalid */
1011 return _dbus_header_set_field_basic (&message->header,
1012 DBUS_HEADER_FIELD_REPLY_SERIAL,
1018 * Returns the serial that the message is a reply to or 0 if none.
1020 * @param message the message
1021 * @returns the reply serial
1024 dbus_message_get_reply_serial (DBusMessage *message)
1026 dbus_uint32_t v_UINT32;
1028 _dbus_return_val_if_fail (message != NULL, 0);
1030 if (_dbus_header_get_field_basic (&message->header,
1031 DBUS_HEADER_FIELD_REPLY_SERIAL,
1040 dbus_message_finalize (DBusMessage *message)
1042 _dbus_assert (message->refcount.value == 0);
1044 /* This calls application callbacks! */
1045 _dbus_data_slot_list_free (&message->slot_list);
1047 _dbus_list_foreach (&message->counters,
1048 free_counter, message);
1049 _dbus_list_clear (&message->counters);
1051 _dbus_header_free (&message->header);
1052 _dbus_string_free (&message->body);
1054 #ifdef HAVE_UNIX_FD_PASSING
1055 close_unix_fds(message->unix_fds, &message->n_unix_fds);
1056 dbus_free(message->unix_fds);
1059 _dbus_assert (message->refcount.value == 0);
1061 dbus_free (message);
1065 dbus_message_new_empty_header (void)
1067 DBusMessage *message;
1068 dbus_bool_t from_cache;
1070 message = dbus_message_get_cached ();
1072 if (message != NULL)
1079 message = dbus_new (DBusMessage, 1);
1080 if (message == NULL)
1082 #ifndef DBUS_DISABLE_CHECKS
1083 message->generation = _dbus_current_generation;
1086 #ifdef HAVE_UNIX_FD_PASSING
1087 message->unix_fds = NULL;
1088 message->n_unix_fds_allocated = 0;
1092 message->refcount.value = 1;
1093 message->byte_order = DBUS_COMPILER_BYTE_ORDER;
1094 message->locked = FALSE;
1095 #ifndef DBUS_DISABLE_CHECKS
1096 message->in_cache = FALSE;
1098 message->counters = NULL;
1099 message->size_counter_delta = 0;
1100 message->changed_stamp = 0;
1102 #ifdef HAVE_UNIX_FD_PASSING
1103 message->n_unix_fds = 0;
1104 message->n_unix_fds_allocated = 0;
1105 message->unix_fd_counter_delta = 0;
1109 _dbus_data_slot_list_init (&message->slot_list);
1113 _dbus_header_reinit (&message->header, message->byte_order);
1114 _dbus_string_set_length (&message->body, 0);
1118 if (!_dbus_header_init (&message->header, message->byte_order))
1120 dbus_free (message);
1124 if (!_dbus_string_init_preallocated (&message->body, 32))
1126 _dbus_header_free (&message->header);
1127 dbus_free (message);
1136 * Constructs a new message of the given message type.
1137 * Types include #DBUS_MESSAGE_TYPE_METHOD_CALL,
1138 * #DBUS_MESSAGE_TYPE_SIGNAL, and so forth.
1140 * Usually you want to use dbus_message_new_method_call(),
1141 * dbus_message_new_method_return(), dbus_message_new_signal(),
1142 * or dbus_message_new_error() instead.
1144 * @param message_type type of message
1145 * @returns new message or #NULL if no memory
1148 dbus_message_new (int message_type)
1150 DBusMessage *message;
1152 _dbus_return_val_if_fail (message_type != DBUS_MESSAGE_TYPE_INVALID, NULL);
1154 message = dbus_message_new_empty_header ();
1155 if (message == NULL)
1158 if (!_dbus_header_create (&message->header,
1160 NULL, NULL, NULL, NULL, NULL))
1162 dbus_message_unref (message);
1170 * Constructs a new message to invoke a method on a remote
1171 * object. Returns #NULL if memory can't be allocated for the
1172 * message. The destination may be #NULL in which case no destination
1173 * is set; this is appropriate when using D-Bus in a peer-to-peer
1174 * context (no message bus). The interface may be #NULL, which means
1175 * that if multiple methods with the given name exist it is undefined
1176 * which one will be invoked.
1178 * The path and method names may not be #NULL.
1180 * Destination, path, interface, and method name can't contain
1181 * any invalid characters (see the D-Bus specification).
1183 * @param destination name that the message should be sent to or #NULL
1184 * @param path object path the message should be sent to
1185 * @param interface interface to invoke method on, or #NULL
1186 * @param method method to invoke
1188 * @returns a new DBusMessage, free with dbus_message_unref()
1191 dbus_message_new_method_call (const char *destination,
1193 const char *interface,
1196 DBusMessage *message;
1198 _dbus_return_val_if_fail (path != NULL, NULL);
1199 _dbus_return_val_if_fail (method != NULL, NULL);
1200 _dbus_return_val_if_fail (destination == NULL ||
1201 _dbus_check_is_valid_bus_name (destination), NULL);
1202 _dbus_return_val_if_fail (_dbus_check_is_valid_path (path), NULL);
1203 _dbus_return_val_if_fail (interface == NULL ||
1204 _dbus_check_is_valid_interface (interface), NULL);
1205 _dbus_return_val_if_fail (_dbus_check_is_valid_member (method), NULL);
1207 message = dbus_message_new_empty_header ();
1208 if (message == NULL)
1211 if (!_dbus_header_create (&message->header,
1212 DBUS_MESSAGE_TYPE_METHOD_CALL,
1213 destination, path, interface, method, NULL))
1215 dbus_message_unref (message);
1223 * Constructs a message that is a reply to a method call. Returns
1224 * #NULL if memory can't be allocated for the message.
1226 * @param method_call the message being replied to
1227 * @returns a new DBusMessage, free with dbus_message_unref()
1230 dbus_message_new_method_return (DBusMessage *method_call)
1232 DBusMessage *message;
1235 _dbus_return_val_if_fail (method_call != NULL, NULL);
1237 sender = dbus_message_get_sender (method_call);
1239 /* sender is allowed to be null here in peer-to-peer case */
1241 message = dbus_message_new_empty_header ();
1242 if (message == NULL)
1245 if (!_dbus_header_create (&message->header,
1246 DBUS_MESSAGE_TYPE_METHOD_RETURN,
1247 sender, NULL, NULL, NULL, NULL))
1249 dbus_message_unref (message);
1253 dbus_message_set_no_reply (message, TRUE);
1255 if (!dbus_message_set_reply_serial (message,
1256 dbus_message_get_serial (method_call)))
1258 dbus_message_unref (message);
1266 * Constructs a new message representing a signal emission. Returns
1267 * #NULL if memory can't be allocated for the message. A signal is
1268 * identified by its originating object path, interface, and the name
1271 * Path, interface, and signal name must all be valid (the D-Bus
1272 * specification defines the syntax of these fields).
1274 * @param path the path to the object emitting the signal
1275 * @param interface the interface the signal is emitted from
1276 * @param name name of the signal
1277 * @returns a new DBusMessage, free with dbus_message_unref()
1280 dbus_message_new_signal (const char *path,
1281 const char *interface,
1284 DBusMessage *message;
1286 _dbus_return_val_if_fail (path != NULL, NULL);
1287 _dbus_return_val_if_fail (interface != NULL, NULL);
1288 _dbus_return_val_if_fail (name != NULL, NULL);
1289 _dbus_return_val_if_fail (_dbus_check_is_valid_path (path), NULL);
1290 _dbus_return_val_if_fail (_dbus_check_is_valid_interface (interface), NULL);
1291 _dbus_return_val_if_fail (_dbus_check_is_valid_member (name), NULL);
1293 message = dbus_message_new_empty_header ();
1294 if (message == NULL)
1297 if (!_dbus_header_create (&message->header,
1298 DBUS_MESSAGE_TYPE_SIGNAL,
1299 NULL, path, interface, name, NULL))
1301 dbus_message_unref (message);
1305 dbus_message_set_no_reply (message, TRUE);
1311 * Creates a new message that is an error reply to another message.
1312 * Error replies are most common in response to method calls, but
1313 * can be returned in reply to any message.
1315 * The error name must be a valid error name according to the syntax
1316 * given in the D-Bus specification. If you don't want to make
1317 * up an error name just use #DBUS_ERROR_FAILED.
1319 * @param reply_to the message we're replying to
1320 * @param error_name the error name
1321 * @param error_message the error message string (or #NULL for none, but please give a message)
1322 * @returns a new error message object, free with dbus_message_unref()
1325 dbus_message_new_error (DBusMessage *reply_to,
1326 const char *error_name,
1327 const char *error_message)
1329 DBusMessage *message;
1331 DBusMessageIter iter;
1333 _dbus_return_val_if_fail (reply_to != NULL, NULL);
1334 _dbus_return_val_if_fail (error_name != NULL, NULL);
1335 _dbus_return_val_if_fail (_dbus_check_is_valid_error_name (error_name), NULL);
1337 sender = dbus_message_get_sender (reply_to);
1339 /* sender may be NULL for non-message-bus case or
1340 * when the message bus is dealing with an unregistered
1343 message = dbus_message_new_empty_header ();
1344 if (message == NULL)
1347 if (!_dbus_header_create (&message->header,
1348 DBUS_MESSAGE_TYPE_ERROR,
1349 sender, NULL, NULL, NULL, error_name))
1351 dbus_message_unref (message);
1355 dbus_message_set_no_reply (message, TRUE);
1357 if (!dbus_message_set_reply_serial (message,
1358 dbus_message_get_serial (reply_to)))
1360 dbus_message_unref (message);
1364 if (error_message != NULL)
1366 dbus_message_iter_init_append (message, &iter);
1367 if (!dbus_message_iter_append_basic (&iter,
1371 dbus_message_unref (message);
1380 * Creates a new message that is an error reply to another message, allowing
1381 * you to use printf formatting.
1383 * See dbus_message_new_error() for details - this function is the same
1384 * aside from the printf formatting.
1386 * @todo add _DBUS_GNUC_PRINTF to this (requires moving _DBUS_GNUC_PRINTF to
1387 * public header, see DBUS_DEPRECATED for an example)
1389 * @param reply_to the original message
1390 * @param error_name the error name
1391 * @param error_format the error message format as with printf
1392 * @param ... format string arguments
1393 * @returns a new error message
1396 dbus_message_new_error_printf (DBusMessage *reply_to,
1397 const char *error_name,
1398 const char *error_format,
1403 DBusMessage *message;
1405 _dbus_return_val_if_fail (reply_to != NULL, NULL);
1406 _dbus_return_val_if_fail (error_name != NULL, NULL);
1407 _dbus_return_val_if_fail (_dbus_check_is_valid_error_name (error_name), NULL);
1409 if (!_dbus_string_init (&str))
1412 va_start (args, error_format);
1414 if (_dbus_string_append_printf_valist (&str, error_format, args))
1415 message = dbus_message_new_error (reply_to, error_name,
1416 _dbus_string_get_const_data (&str));
1420 _dbus_string_free (&str);
1429 * Creates a new message that is an exact replica of the message
1430 * specified, except that its refcount is set to 1, its message serial
1431 * is reset to 0, and if the original message was "locked" (in the
1432 * outgoing message queue and thus not modifiable) the new message
1433 * will not be locked.
1435 * @todo This function can't be used in programs that try to recover from OOM errors.
1437 * @param message the message
1438 * @returns the new message.or #NULL if not enough memory or Unix file descriptors (in case the message to copy includes Unix file descriptors) can be allocated.
1441 dbus_message_copy (const DBusMessage *message)
1443 DBusMessage *retval;
1445 _dbus_return_val_if_fail (message != NULL, NULL);
1447 retval = dbus_new0 (DBusMessage, 1);
1451 retval->refcount.value = 1;
1452 retval->byte_order = message->byte_order;
1453 retval->locked = FALSE;
1454 #ifndef DBUS_DISABLE_CHECKS
1455 retval->generation = message->generation;
1458 if (!_dbus_header_copy (&message->header, &retval->header))
1464 if (!_dbus_string_init_preallocated (&retval->body,
1465 _dbus_string_get_length (&message->body)))
1467 _dbus_header_free (&retval->header);
1472 if (!_dbus_string_copy (&message->body, 0,
1476 #ifdef HAVE_UNIX_FD_PASSING
1477 retval->unix_fds = dbus_new(int, message->n_unix_fds);
1478 if (retval->unix_fds == NULL && message->n_unix_fds > 0)
1481 retval->n_unix_fds_allocated = message->n_unix_fds;
1483 for (retval->n_unix_fds = 0;
1484 retval->n_unix_fds < message->n_unix_fds;
1485 retval->n_unix_fds++)
1487 retval->unix_fds[retval->n_unix_fds] = _dbus_dup(message->unix_fds[retval->n_unix_fds], NULL);
1489 if (retval->unix_fds[retval->n_unix_fds] < 0)
1498 _dbus_header_free (&retval->header);
1499 _dbus_string_free (&retval->body);
1501 #ifdef HAVE_UNIX_FD_PASSING
1502 close_unix_fds(retval->unix_fds, &retval->n_unix_fds);
1503 dbus_free(retval->unix_fds);
1513 * Increments the reference count of a DBusMessage.
1515 * @param message the message
1516 * @returns the message
1517 * @see dbus_message_unref
1520 dbus_message_ref (DBusMessage *message)
1522 #ifndef DBUS_DISABLE_ASSERT
1523 dbus_int32_t old_refcount;
1526 _dbus_return_val_if_fail (message != NULL, NULL);
1527 _dbus_return_val_if_fail (message->generation == _dbus_current_generation, NULL);
1528 _dbus_return_val_if_fail (!message->in_cache, NULL);
1530 #ifdef DBUS_DISABLE_ASSERT
1531 _dbus_atomic_inc (&message->refcount);
1533 old_refcount = _dbus_atomic_inc (&message->refcount);
1534 _dbus_assert (old_refcount >= 1);
1541 * Decrements the reference count of a DBusMessage, freeing the
1542 * message if the count reaches 0.
1544 * @param message the message
1545 * @see dbus_message_ref
1548 dbus_message_unref (DBusMessage *message)
1550 dbus_int32_t old_refcount;
1552 _dbus_return_if_fail (message != NULL);
1553 _dbus_return_if_fail (message->generation == _dbus_current_generation);
1554 _dbus_return_if_fail (!message->in_cache);
1556 old_refcount = _dbus_atomic_dec (&message->refcount);
1558 _dbus_assert (old_refcount >= 1);
1560 if (old_refcount == 1)
1562 /* Calls application callbacks! */
1563 dbus_message_cache_or_finalize (message);
1568 * Gets the type of a message. Types include
1569 * #DBUS_MESSAGE_TYPE_METHOD_CALL, #DBUS_MESSAGE_TYPE_METHOD_RETURN,
1570 * #DBUS_MESSAGE_TYPE_ERROR, #DBUS_MESSAGE_TYPE_SIGNAL, but other
1571 * types are allowed and all code must silently ignore messages of
1572 * unknown type. #DBUS_MESSAGE_TYPE_INVALID will never be returned.
1574 * @param message the message
1575 * @returns the type of the message
1578 dbus_message_get_type (DBusMessage *message)
1580 _dbus_return_val_if_fail (message != NULL, DBUS_MESSAGE_TYPE_INVALID);
1582 return _dbus_header_get_message_type (&message->header);
1586 * Appends fields to a message given a variable argument list. The
1587 * variable argument list should contain the type of each argument
1588 * followed by the value to append. Appendable types are basic types,
1589 * and arrays of fixed-length basic types (except arrays of Unix file
1590 * descriptors). To append variable-length basic types, or any more
1591 * complex value, you have to use an iterator rather than this
1594 * To append a basic type, specify its type code followed by the
1595 * address of the value. For example:
1599 * dbus_int32_t v_INT32 = 42;
1600 * const char *v_STRING = "Hello World";
1601 * dbus_message_append_args (message,
1602 * DBUS_TYPE_INT32, &v_INT32,
1603 * DBUS_TYPE_STRING, &v_STRING,
1604 * DBUS_TYPE_INVALID);
1607 * To append an array of fixed-length basic types (except Unix file
1608 * descriptors), pass in the DBUS_TYPE_ARRAY typecode, the element
1609 * typecode, the address of the array pointer, and a 32-bit integer
1610 * giving the number of elements in the array. So for example: @code
1611 * const dbus_int32_t array[] = { 1, 2, 3 }; const dbus_int32_t
1612 * *v_ARRAY = array; dbus_message_append_args (message,
1613 * DBUS_TYPE_ARRAY, DBUS_TYPE_INT32, &v_ARRAY, 3, DBUS_TYPE_INVALID);
1616 * This function does not support arrays of Unix file descriptors. If
1617 * you need those you need to manually recurse into the array.
1619 * For Unix file descriptors this function will internally duplicate
1620 * the descriptor you passed in. Hence you may close the descriptor
1621 * immediately after this call.
1623 * @warning in C, given "int array[]", "&array == array" (the
1624 * comp.lang.c FAQ says otherwise, but gcc and the FAQ don't agree).
1625 * So if you're using an array instead of a pointer you have to create
1626 * a pointer variable, assign the array to it, then take the address
1627 * of the pointer variable. For strings it works to write
1628 * const char *array = "Hello" and then use &array though.
1630 * The last argument to this function must be #DBUS_TYPE_INVALID,
1631 * marking the end of the argument list. If you don't do this
1632 * then libdbus won't know to stop and will read invalid memory.
1634 * String/signature/path arrays should be passed in as "const char***
1635 * address_of_array" and "int n_elements"
1637 * @todo support DBUS_TYPE_STRUCT and DBUS_TYPE_VARIANT and complex arrays
1639 * @todo If this fails due to lack of memory, the message is hosed and
1640 * you have to start over building the whole message.
1642 * @param message the message
1643 * @param first_arg_type type of the first argument
1644 * @param ... value of first argument, list of additional type-value pairs
1645 * @returns #TRUE on success
1648 dbus_message_append_args (DBusMessage *message,
1655 _dbus_return_val_if_fail (message != NULL, FALSE);
1657 va_start (var_args, first_arg_type);
1658 retval = dbus_message_append_args_valist (message,
1667 * Like dbus_message_append_args() but takes a va_list for use by language bindings.
1669 * @todo for now, if this function fails due to OOM it will leave
1670 * the message half-written and you have to discard the message
1673 * @see dbus_message_append_args.
1674 * @param message the message
1675 * @param first_arg_type type of first argument
1676 * @param var_args value of first argument, then list of type/value pairs
1677 * @returns #TRUE on success
1680 dbus_message_append_args_valist (DBusMessage *message,
1685 DBusMessageIter iter;
1687 _dbus_return_val_if_fail (message != NULL, FALSE);
1689 type = first_arg_type;
1691 dbus_message_iter_init_append (message, &iter);
1693 while (type != DBUS_TYPE_INVALID)
1695 if (dbus_type_is_basic (type))
1697 const DBusBasicValue *value;
1698 value = va_arg (var_args, const DBusBasicValue*);
1700 if (!dbus_message_iter_append_basic (&iter,
1705 else if (type == DBUS_TYPE_ARRAY)
1708 DBusMessageIter array;
1711 element_type = va_arg (var_args, int);
1713 buf[0] = element_type;
1715 if (!dbus_message_iter_open_container (&iter,
1721 if (dbus_type_is_fixed (element_type) &&
1722 element_type != DBUS_TYPE_UNIX_FD)
1724 const DBusBasicValue **value;
1727 value = va_arg (var_args, const DBusBasicValue**);
1728 n_elements = va_arg (var_args, int);
1730 if (!dbus_message_iter_append_fixed_array (&array,
1734 dbus_message_iter_abandon_container (&iter, &array);
1738 else if (element_type == DBUS_TYPE_STRING ||
1739 element_type == DBUS_TYPE_SIGNATURE ||
1740 element_type == DBUS_TYPE_OBJECT_PATH)
1742 const char ***value_p;
1747 value_p = va_arg (var_args, const char***);
1748 n_elements = va_arg (var_args, int);
1753 while (i < n_elements)
1755 if (!dbus_message_iter_append_basic (&array,
1758 dbus_message_iter_abandon_container (&iter, &array);
1766 _dbus_warn ("arrays of %s can't be appended with %s for now\n",
1767 _dbus_type_to_string (element_type),
1768 _DBUS_FUNCTION_NAME);
1772 if (!dbus_message_iter_close_container (&iter, &array))
1775 #ifndef DBUS_DISABLE_CHECKS
1778 _dbus_warn ("type %s isn't supported yet in %s\n",
1779 _dbus_type_to_string (type), _DBUS_FUNCTION_NAME);
1784 type = va_arg (var_args, int);
1794 * Gets arguments from a message given a variable argument list. The
1795 * supported types include those supported by
1796 * dbus_message_append_args(); that is, basic types and arrays of
1797 * fixed-length basic types. The arguments are the same as they would
1798 * be for dbus_message_iter_get_basic() or
1799 * dbus_message_iter_get_fixed_array().
1801 * In addition to those types, arrays of string, object path, and
1802 * signature are supported; but these are returned as allocated memory
1803 * and must be freed with dbus_free_string_array(), while the other
1804 * types are returned as const references. To get a string array
1805 * pass in "char ***array_location" and "int *n_elements".
1807 * Similar to dbus_message_get_fixed_array() this function does not
1808 * support arrays of type DBUS_TYPE_UNIX_FD. If you need to parse
1809 * messages with arrays of Unix file descriptors you need to recurse
1810 * into the array manually.
1812 * Unix file descriptors that are read with this function will have
1813 * the FD_CLOEXEC flag set. If you need them without this flag set,
1814 * make sure to unset it with fcntl().
1816 * The variable argument list should contain the type of the argument
1817 * followed by a pointer to where the value should be stored. The list
1818 * is terminated with #DBUS_TYPE_INVALID.
1820 * Except for string arrays, the returned values are constant; do not
1821 * free them. They point into the #DBusMessage.
1823 * If the requested arguments are not present, or do not have the
1824 * requested types, then an error will be set.
1826 * If more arguments than requested are present, the requested
1827 * arguments are returned and the extra arguments are ignored.
1829 * @todo support DBUS_TYPE_STRUCT and DBUS_TYPE_VARIANT and complex arrays
1831 * @param message the message
1832 * @param error error to be filled in on failure
1833 * @param first_arg_type the first argument type
1834 * @param ... location for first argument value, then list of type-location pairs
1835 * @returns #FALSE if the error was set
1838 dbus_message_get_args (DBusMessage *message,
1846 _dbus_return_val_if_fail (message != NULL, FALSE);
1847 _dbus_return_val_if_error_is_set (error, FALSE);
1849 va_start (var_args, first_arg_type);
1850 retval = dbus_message_get_args_valist (message, error, first_arg_type, var_args);
1857 * Like dbus_message_get_args but takes a va_list for use by language bindings.
1859 * @see dbus_message_get_args
1860 * @param message the message
1861 * @param error error to be filled in
1862 * @param first_arg_type type of the first argument
1863 * @param var_args return location for first argument, followed by list of type/location pairs
1864 * @returns #FALSE if error was set
1867 dbus_message_get_args_valist (DBusMessage *message,
1872 DBusMessageIter iter;
1874 _dbus_return_val_if_fail (message != NULL, FALSE);
1875 _dbus_return_val_if_error_is_set (error, FALSE);
1877 dbus_message_iter_init (message, &iter);
1878 return _dbus_message_iter_get_args_valist (&iter, error, first_arg_type, var_args);
1882 _dbus_message_iter_init_common (DBusMessage *message,
1883 DBusMessageRealIter *real,
1886 _dbus_assert (sizeof (DBusMessageRealIter) <= sizeof (DBusMessageIter));
1888 /* Since the iterator will read or write who-knows-what from the
1889 * message, we need to get in the right byte order
1891 ensure_byte_order (message);
1893 real->message = message;
1894 real->changed_stamp = message->changed_stamp;
1895 real->iter_type = iter_type;
1896 real->sig_refcount = 0;
1900 * Initializes a #DBusMessageIter for reading the arguments of the
1901 * message passed in.
1903 * When possible, dbus_message_get_args() is much more convenient.
1904 * Some types of argument can only be read with #DBusMessageIter
1907 * The easiest way to iterate is like this:
1909 * dbus_message_iter_init (message, &iter);
1910 * while ((current_type = dbus_message_iter_get_arg_type (&iter)) != DBUS_TYPE_INVALID)
1911 * dbus_message_iter_next (&iter);
1914 * #DBusMessageIter contains no allocated memory; it need not be
1915 * freed, and can be copied by assignment or memcpy().
1917 * @param message the message
1918 * @param iter pointer to an iterator to initialize
1919 * @returns #FALSE if the message has no arguments
1922 dbus_message_iter_init (DBusMessage *message,
1923 DBusMessageIter *iter)
1925 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1926 const DBusString *type_str;
1929 _dbus_return_val_if_fail (message != NULL, FALSE);
1930 _dbus_return_val_if_fail (iter != NULL, FALSE);
1932 get_const_signature (&message->header, &type_str, &type_pos);
1934 _dbus_message_iter_init_common (message, real,
1935 DBUS_MESSAGE_ITER_TYPE_READER);
1937 _dbus_type_reader_init (&real->u.reader,
1938 message->byte_order,
1943 return _dbus_type_reader_get_current_type (&real->u.reader) != DBUS_TYPE_INVALID;
1947 * Checks if an iterator has any more fields.
1949 * @param iter the message iter
1950 * @returns #TRUE if there are more fields following
1953 dbus_message_iter_has_next (DBusMessageIter *iter)
1955 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1957 _dbus_return_val_if_fail (_dbus_message_iter_check (real), FALSE);
1958 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, FALSE);
1960 return _dbus_type_reader_has_next (&real->u.reader);
1964 * Moves the iterator to the next field, if any. If there's no next
1965 * field, returns #FALSE. If the iterator moves forward, returns
1968 * @param iter the message iter
1969 * @returns #TRUE if the iterator was moved to the next field
1972 dbus_message_iter_next (DBusMessageIter *iter)
1974 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
1976 _dbus_return_val_if_fail (_dbus_message_iter_check (real), FALSE);
1977 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, FALSE);
1979 return _dbus_type_reader_next (&real->u.reader);
1983 * Returns the argument type of the argument that the message iterator
1984 * points to. If the iterator is at the end of the message, returns
1985 * #DBUS_TYPE_INVALID. You can thus write a loop as follows:
1988 * dbus_message_iter_init (message, &iter);
1989 * while ((current_type = dbus_message_iter_get_arg_type (&iter)) != DBUS_TYPE_INVALID)
1990 * dbus_message_iter_next (&iter);
1993 * @param iter the message iter
1994 * @returns the argument type
1997 dbus_message_iter_get_arg_type (DBusMessageIter *iter)
1999 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2001 _dbus_return_val_if_fail (_dbus_message_iter_check (real), DBUS_TYPE_INVALID);
2002 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, FALSE);
2004 return _dbus_type_reader_get_current_type (&real->u.reader);
2008 * Returns the element type of the array that the message iterator
2009 * points to. Note that you need to check that the iterator points to
2010 * an array prior to using this function.
2012 * @param iter the message iter
2013 * @returns the array element type
2016 dbus_message_iter_get_element_type (DBusMessageIter *iter)
2018 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2020 _dbus_return_val_if_fail (_dbus_message_iter_check (real), DBUS_TYPE_INVALID);
2021 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, DBUS_TYPE_INVALID);
2022 _dbus_return_val_if_fail (dbus_message_iter_get_arg_type (iter) == DBUS_TYPE_ARRAY, DBUS_TYPE_INVALID);
2024 return _dbus_type_reader_get_element_type (&real->u.reader);
2028 * Recurses into a container value when reading values from a message,
2029 * initializing a sub-iterator to use for traversing the child values
2032 * Note that this recurses into a value, not a type, so you can only
2033 * recurse if the value exists. The main implication of this is that
2034 * if you have for example an empty array of array of int32, you can
2035 * recurse into the outermost array, but it will have no values, so
2036 * you won't be able to recurse further. There's no array of int32 to
2039 * If a container is an array of fixed-length types (except Unix file
2040 * descriptors), it is much more efficient to use
2041 * dbus_message_iter_get_fixed_array() to get the whole array in one
2042 * shot, rather than individually walking over the array elements.
2044 * Be sure you have somehow checked that
2045 * dbus_message_iter_get_arg_type() matches the type you are expecting
2046 * to recurse into. Results of this function are undefined if there is
2047 * no container to recurse into at the current iterator position.
2049 * @param iter the message iterator
2050 * @param sub the sub-iterator to initialize
2053 dbus_message_iter_recurse (DBusMessageIter *iter,
2054 DBusMessageIter *sub)
2056 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2057 DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub;
2059 _dbus_return_if_fail (_dbus_message_iter_check (real));
2060 _dbus_return_if_fail (sub != NULL);
2063 _dbus_type_reader_recurse (&real->u.reader, &real_sub->u.reader);
2067 * Returns the current signature of a message iterator. This
2068 * is useful primarily for dealing with variants; one can
2069 * recurse into a variant and determine the signature of
2070 * the variant's value.
2072 * The returned string must be freed with dbus_free().
2074 * @param iter the message iterator
2075 * @returns the contained signature, or NULL if out of memory
2078 dbus_message_iter_get_signature (DBusMessageIter *iter)
2080 const DBusString *sig;
2084 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2086 _dbus_return_val_if_fail (_dbus_message_iter_check (real), NULL);
2088 if (!_dbus_string_init (&retstr))
2091 _dbus_type_reader_get_signature (&real->u.reader, &sig,
2093 if (!_dbus_string_append_len (&retstr,
2094 _dbus_string_get_const_data (sig) + start,
2097 if (!_dbus_string_steal_data (&retstr, &ret))
2099 _dbus_string_free (&retstr);
2104 * Reads a basic-typed value from the message iterator.
2105 * Basic types are the non-containers such as integer and string.
2107 * The value argument should be the address of a location to store
2108 * the returned value. So for int32 it should be a "dbus_int32_t*"
2109 * and for string a "const char**". The returned value is
2110 * by reference and should not be freed.
2112 * This call duplicates Unix file descriptors when reading them. It is
2113 * your job to close them when you don't need them anymore.
2115 * Unix file descriptors that are read with this function will have
2116 * the FD_CLOEXEC flag set. If you need them without this flag set,
2117 * make sure to unset it with fcntl().
2119 * Be sure you have somehow checked that
2120 * dbus_message_iter_get_arg_type() matches the type you are
2121 * expecting, or you'll crash when you try to use an integer as a
2122 * string or something.
2124 * To read any container type (array, struct, dict) you will need to
2125 * recurse into the container with dbus_message_iter_recurse(). If
2126 * the container is an array of fixed-length values (except Unix file
2127 * descriptors), you can get all the array elements at once with
2128 * dbus_message_iter_get_fixed_array(). Otherwise, you have to iterate
2129 * over the container's contents one value at a time.
2131 * All basic-typed values are guaranteed to fit in 8 bytes. So you can
2132 * write code like this:
2135 * dbus_uint64_t value;
2137 * dbus_message_iter_get_basic (&read_iter, &value);
2138 * type = dbus_message_iter_get_arg_type (&read_iter);
2139 * dbus_message_iter_append_basic (&write_iter, type, &value);
2142 * On some really obscure platforms dbus_uint64_t might not exist, if
2143 * you need to worry about this you will know. dbus_uint64_t is just
2144 * one example of a type that's large enough to hold any possible
2145 * value, you could use a struct or char[8] instead if you like.
2147 * @param iter the iterator
2148 * @param value location to store the value
2151 dbus_message_iter_get_basic (DBusMessageIter *iter,
2154 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2156 _dbus_return_if_fail (_dbus_message_iter_check (real));
2157 _dbus_return_if_fail (value != NULL);
2159 if (dbus_message_iter_get_arg_type (iter) == DBUS_TYPE_UNIX_FD)
2161 #ifdef HAVE_UNIX_FD_PASSING
2164 _dbus_type_reader_read_basic(&real->u.reader, &idx);
2166 if (idx.u32 >= real->message->n_unix_fds) {
2167 /* Hmm, we cannot really signal an error here, so let's make
2168 sure to return an invalid fd. */
2169 *((int*) value) = -1;
2173 *((int*) value) = _dbus_dup(real->message->unix_fds[idx.u32], NULL);
2175 *((int*) value) = -1;
2180 _dbus_type_reader_read_basic (&real->u.reader,
2186 * Returns the number of bytes in the array as marshaled in the wire
2187 * protocol. The iterator must currently be inside an array-typed
2190 * This function is deprecated on the grounds that it is stupid. Why
2191 * would you want to know how many bytes are in the array as marshaled
2192 * in the wire protocol? For now, use the n_elements returned from
2193 * dbus_message_iter_get_fixed_array() instead, or iterate over the
2194 * array values and count them.
2196 * @todo introduce a variant of this get_n_elements that returns
2197 * the number of elements, though with a non-fixed array it will not
2198 * be very efficient, so maybe it's not good.
2200 * @param iter the iterator
2201 * @returns the number of bytes in the array
2204 dbus_message_iter_get_array_len (DBusMessageIter *iter)
2206 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2208 _dbus_return_val_if_fail (_dbus_message_iter_check (real), 0);
2210 return _dbus_type_reader_get_array_length (&real->u.reader);
2214 * Reads a block of fixed-length values from the message iterator.
2215 * Fixed-length values are those basic types that are not string-like,
2216 * such as integers, bool, double. The returned block will be from the
2217 * current position in the array until the end of the array.
2219 * There is one exception here: although DBUS_TYPE_UNIX_FD is
2220 * considered a 'fixed' type arrays of this type may not be read with
2223 * The message iter should be "in" the array (that is, you recurse into the
2224 * array, and then you call dbus_message_iter_get_fixed_array() on the
2225 * "sub-iterator" created by dbus_message_iter_recurse()).
2227 * The value argument should be the address of a location to store the
2228 * returned array. So for int32 it should be a "const dbus_int32_t**"
2229 * The returned value is by reference and should not be freed.
2231 * This function should only be used if dbus_type_is_fixed() returns
2232 * #TRUE for the element type.
2234 * If an array's elements are not fixed in size, you have to recurse
2235 * into the array with dbus_message_iter_recurse() and read the
2236 * elements one by one.
2238 * Because the array is not copied, this function runs in constant
2239 * time and is fast; it's much preferred over walking the entire array
2240 * with an iterator. (However, you can always use
2241 * dbus_message_iter_recurse(), even for fixed-length types;
2242 * dbus_message_iter_get_fixed_array() is just an optimization.)
2244 * @param iter the iterator
2245 * @param value location to store the block
2246 * @param n_elements number of elements in the block
2249 dbus_message_iter_get_fixed_array (DBusMessageIter *iter,
2253 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2254 int subtype = _dbus_type_reader_get_current_type(&real->u.reader);
2256 _dbus_return_if_fail (_dbus_message_iter_check (real));
2257 _dbus_return_if_fail (value != NULL);
2258 _dbus_return_if_fail ((subtype == DBUS_TYPE_INVALID) ||
2259 (dbus_type_is_fixed (subtype) && subtype != DBUS_TYPE_UNIX_FD));
2261 _dbus_type_reader_read_fixed_multi (&real->u.reader,
2266 * Initializes a #DBusMessageIter for appending arguments to the end
2269 * @todo If appending any of the arguments fails due to lack of
2270 * memory, the message is hosed and you have to start over building
2271 * the whole message.
2273 * @param message the message
2274 * @param iter pointer to an iterator to initialize
2277 dbus_message_iter_init_append (DBusMessage *message,
2278 DBusMessageIter *iter)
2280 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2282 _dbus_return_if_fail (message != NULL);
2283 _dbus_return_if_fail (iter != NULL);
2285 _dbus_message_iter_init_common (message, real,
2286 DBUS_MESSAGE_ITER_TYPE_WRITER);
2288 /* We create the signature string and point iterators at it "on demand"
2289 * when a value is actually appended. That means that init() never fails
2292 _dbus_type_writer_init_types_delayed (&real->u.writer,
2293 message->byte_order,
2295 _dbus_string_get_length (&message->body));
2299 * Creates a temporary signature string containing the current
2300 * signature, stores it in the iterator, and points the iterator to
2301 * the end of it. Used any time we write to the message.
2303 * @param real an iterator without a type_str
2304 * @returns #FALSE if no memory
2307 _dbus_message_iter_open_signature (DBusMessageRealIter *real)
2310 const DBusString *current_sig;
2311 int current_sig_pos;
2313 _dbus_assert (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
2315 if (real->u.writer.type_str != NULL)
2317 _dbus_assert (real->sig_refcount > 0);
2318 real->sig_refcount += 1;
2322 str = dbus_new (DBusString, 1);
2326 if (!_dbus_header_get_field_raw (&real->message->header,
2327 DBUS_HEADER_FIELD_SIGNATURE,
2328 ¤t_sig, ¤t_sig_pos))
2335 current_len = _dbus_string_get_byte (current_sig, current_sig_pos);
2336 current_sig_pos += 1; /* move on to sig data */
2338 if (!_dbus_string_init_preallocated (str, current_len + 4))
2344 if (!_dbus_string_copy_len (current_sig, current_sig_pos, current_len,
2347 _dbus_string_free (str);
2354 if (!_dbus_string_init_preallocated (str, 4))
2361 real->sig_refcount = 1;
2363 _dbus_type_writer_add_types (&real->u.writer,
2364 str, _dbus_string_get_length (str));
2369 * Sets the new signature as the message signature, frees the
2370 * signature string, and marks the iterator as not having a type_str
2371 * anymore. Frees the signature even if it fails, so you can't
2372 * really recover from failure. Kinda busted.
2374 * @param real an iterator without a type_str
2375 * @returns #FALSE if no memory
2378 _dbus_message_iter_close_signature (DBusMessageRealIter *real)
2381 const char *v_STRING;
2384 _dbus_assert (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
2385 _dbus_assert (real->u.writer.type_str != NULL);
2386 _dbus_assert (real->sig_refcount > 0);
2388 real->sig_refcount -= 1;
2390 if (real->sig_refcount > 0)
2392 _dbus_assert (real->sig_refcount == 0);
2396 str = real->u.writer.type_str;
2398 v_STRING = _dbus_string_get_const_data (str);
2399 if (!_dbus_header_set_field_basic (&real->message->header,
2400 DBUS_HEADER_FIELD_SIGNATURE,
2401 DBUS_TYPE_SIGNATURE,
2405 _dbus_type_writer_remove_types (&real->u.writer);
2406 _dbus_string_free (str);
2413 * Frees the signature string and marks the iterator as not having a
2414 * type_str anymore. Since the new signature is not set, the message
2415 * will generally be hosed after this is called.
2417 * @param real an iterator without a type_str
2420 _dbus_message_iter_abandon_signature (DBusMessageRealIter *real)
2424 _dbus_assert (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
2425 _dbus_assert (real->u.writer.type_str != NULL);
2426 _dbus_assert (real->sig_refcount > 0);
2428 real->sig_refcount -= 1;
2430 if (real->sig_refcount > 0)
2432 _dbus_assert (real->sig_refcount == 0);
2434 str = real->u.writer.type_str;
2436 _dbus_type_writer_remove_types (&real->u.writer);
2437 _dbus_string_free (str);
2441 #ifndef DBUS_DISABLE_CHECKS
2443 _dbus_message_iter_append_check (DBusMessageRealIter *iter)
2445 if (!_dbus_message_iter_check (iter))
2448 if (iter->message->locked)
2450 _dbus_warn_check_failed ("dbus append iterator can't be used: message is locked (has already been sent)\n");
2456 #endif /* DBUS_DISABLE_CHECKS */
2458 #ifdef HAVE_UNIX_FD_PASSING
2460 expand_fd_array(DBusMessage *m,
2465 /* This makes space for adding n new fds to the array and returns a
2466 pointer to the place were the first fd should be put. */
2468 if (m->n_unix_fds + n > m->n_unix_fds_allocated)
2473 /* Make twice as much space as necessary */
2474 k = (m->n_unix_fds + n) * 2;
2476 /* Allocate at least four */
2480 p = dbus_realloc(m->unix_fds, k * sizeof(int));
2485 m->n_unix_fds_allocated = k;
2488 return m->unix_fds + m->n_unix_fds;
2493 * Appends a basic-typed value to the message. The basic types are the
2494 * non-container types such as integer and string.
2496 * The "value" argument should be the address of a basic-typed value.
2497 * So for string, const char**. For integer, dbus_int32_t*.
2499 * For Unix file descriptors this function will internally duplicate
2500 * the descriptor you passed in. Hence you may close the descriptor
2501 * immediately after this call.
2503 * @todo If this fails due to lack of memory, the message is hosed and
2504 * you have to start over building the whole message.
2506 * @param iter the append iterator
2507 * @param type the type of the value
2508 * @param value the address of the value
2509 * @returns #FALSE if not enough memory
2512 dbus_message_iter_append_basic (DBusMessageIter *iter,
2516 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2519 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE);
2520 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2521 _dbus_return_val_if_fail (dbus_type_is_basic (type), FALSE);
2522 _dbus_return_val_if_fail (value != NULL, FALSE);
2524 #ifndef DBUS_DISABLE_CHECKS
2527 const char * const *string_p;
2528 const dbus_bool_t *bool_p;
2530 case DBUS_TYPE_STRING:
2532 _dbus_return_val_if_fail (_dbus_check_is_valid_utf8 (*string_p), FALSE);
2535 case DBUS_TYPE_OBJECT_PATH:
2537 _dbus_return_val_if_fail (_dbus_check_is_valid_path (*string_p), FALSE);
2540 case DBUS_TYPE_SIGNATURE:
2542 _dbus_return_val_if_fail (_dbus_check_is_valid_signature (*string_p), FALSE);
2545 case DBUS_TYPE_BOOLEAN:
2547 _dbus_return_val_if_fail (*bool_p == 0 || *bool_p == 1, FALSE);
2552 /* nothing to check, all possible values are allowed */
2557 if (!_dbus_message_iter_open_signature (real))
2560 if (type == DBUS_TYPE_UNIX_FD)
2562 #ifdef HAVE_UNIX_FD_PASSING
2566 /* First step, include the fd in the fd list of this message */
2567 if (!(fds = expand_fd_array(real->message, 1)))
2570 *fds = _dbus_dup(*(int*) value, NULL);
2574 u = real->message->n_unix_fds;
2576 /* Second step, write the index to the fd */
2577 if (!(ret = _dbus_type_writer_write_basic (&real->u.writer, DBUS_TYPE_UNIX_FD, &u))) {
2578 _dbus_close(*fds, NULL);
2582 real->message->n_unix_fds += 1;
2585 /* Final step, update the header accordingly */
2586 ret = _dbus_header_set_field_basic (&real->message->header,
2587 DBUS_HEADER_FIELD_UNIX_FDS,
2591 /* If any of these operations fail the message is
2592 hosed. However, no memory or fds should be leaked since what
2593 has been added to message has been added to the message, and
2594 can hence be accounted for when the message is being
2602 ret = _dbus_type_writer_write_basic (&real->u.writer, type, value);
2605 if (!_dbus_message_iter_close_signature (real))
2612 * Appends a block of fixed-length values to an array. The
2613 * fixed-length types are all basic types that are not string-like. So
2614 * int32, double, bool, etc. (Unix file descriptors however are not
2615 * supported.) You must call dbus_message_iter_open_container() to
2616 * open an array of values before calling this function. You may call
2617 * this function multiple times (and intermixed with calls to
2618 * dbus_message_iter_append_basic()) for the same array.
2620 * The "value" argument should be the address of the array. So for
2621 * integer, "dbus_int32_t**" is expected for example.
2623 * @warning in C, given "int array[]", "&array == array" (the
2624 * comp.lang.c FAQ says otherwise, but gcc and the FAQ don't agree).
2625 * So if you're using an array instead of a pointer you have to create
2626 * a pointer variable, assign the array to it, then take the address
2627 * of the pointer variable.
2629 * const dbus_int32_t array[] = { 1, 2, 3 };
2630 * const dbus_int32_t *v_ARRAY = array;
2631 * if (!dbus_message_iter_append_fixed_array (&iter, DBUS_TYPE_INT32, &v_ARRAY, 3))
2632 * fprintf (stderr, "No memory!\n");
2634 * For strings it works to write const char *array = "Hello" and then
2635 * use &array though.
2637 * @todo If this fails due to lack of memory, the message is hosed and
2638 * you have to start over building the whole message.
2640 * @param iter the append iterator
2641 * @param element_type the type of the array elements
2642 * @param value the address of the array
2643 * @param n_elements the number of elements to append
2644 * @returns #FALSE if not enough memory
2647 dbus_message_iter_append_fixed_array (DBusMessageIter *iter,
2652 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2655 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE);
2656 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2657 _dbus_return_val_if_fail (dbus_type_is_fixed (element_type) && element_type != DBUS_TYPE_UNIX_FD, FALSE);
2658 _dbus_return_val_if_fail (real->u.writer.container_type == DBUS_TYPE_ARRAY, FALSE);
2659 _dbus_return_val_if_fail (value != NULL, FALSE);
2660 _dbus_return_val_if_fail (n_elements >= 0, FALSE);
2661 _dbus_return_val_if_fail (n_elements <=
2662 DBUS_MAXIMUM_ARRAY_LENGTH / _dbus_type_get_alignment (element_type),
2665 #ifndef DBUS_DISABLE_CHECKS
2666 if (element_type == DBUS_TYPE_BOOLEAN)
2668 const dbus_bool_t * const *bools = value;
2671 for (i = 0; i < n_elements; i++)
2673 _dbus_return_val_if_fail ((*bools)[i] == 0 || (*bools)[i] == 1, FALSE);
2678 ret = _dbus_type_writer_write_fixed_multi (&real->u.writer, element_type, value, n_elements);
2684 * Appends a container-typed value to the message; you are required to
2685 * append the contents of the container using the returned
2686 * sub-iterator, and then call
2687 * dbus_message_iter_close_container(). Container types are for
2688 * example struct, variant, and array. For variants, the
2689 * contained_signature should be the type of the single value inside
2690 * the variant. For structs and dict entries, contained_signature
2691 * should be #NULL; it will be set to whatever types you write into
2692 * the struct. For arrays, contained_signature should be the type of
2693 * the array elements.
2695 * @todo If this fails due to lack of memory, the message is hosed and
2696 * you have to start over building the whole message.
2698 * @param iter the append iterator
2699 * @param type the type of the value
2700 * @param contained_signature the type of container contents
2701 * @param sub sub-iterator to initialize
2702 * @returns #FALSE if not enough memory
2705 dbus_message_iter_open_container (DBusMessageIter *iter,
2707 const char *contained_signature,
2708 DBusMessageIter *sub)
2710 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2711 DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub;
2712 DBusString contained_str;
2714 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE);
2715 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2716 _dbus_return_val_if_fail (dbus_type_is_container (type), FALSE);
2717 _dbus_return_val_if_fail (sub != NULL, FALSE);
2718 _dbus_return_val_if_fail ((type == DBUS_TYPE_STRUCT &&
2719 contained_signature == NULL) ||
2720 (type == DBUS_TYPE_DICT_ENTRY &&
2721 contained_signature == NULL) ||
2722 (type == DBUS_TYPE_VARIANT &&
2723 contained_signature != NULL) ||
2724 (type == DBUS_TYPE_ARRAY &&
2725 contained_signature != NULL), FALSE);
2727 /* this would fail if the contained_signature is a dict entry, since
2728 * dict entries are invalid signatures standalone (they must be in
2731 _dbus_return_val_if_fail ((type == DBUS_TYPE_ARRAY && contained_signature && *contained_signature == DBUS_DICT_ENTRY_BEGIN_CHAR) ||
2732 (contained_signature == NULL ||
2733 _dbus_check_is_valid_signature (contained_signature)),
2736 if (!_dbus_message_iter_open_signature (real))
2741 if (contained_signature != NULL)
2743 _dbus_string_init_const (&contained_str, contained_signature);
2745 return _dbus_type_writer_recurse (&real->u.writer,
2748 &real_sub->u.writer);
2752 return _dbus_type_writer_recurse (&real->u.writer,
2755 &real_sub->u.writer);
2761 * Closes a container-typed value appended to the message; may write
2762 * out more information to the message known only after the entire
2763 * container is written, and may free resources created by
2764 * dbus_message_iter_open_container().
2766 * @todo If this fails due to lack of memory, the message is hosed and
2767 * you have to start over building the whole message.
2769 * @param iter the append iterator
2770 * @param sub sub-iterator to close
2771 * @returns #FALSE if not enough memory
2774 dbus_message_iter_close_container (DBusMessageIter *iter,
2775 DBusMessageIter *sub)
2777 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2778 DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub;
2781 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE);
2782 _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2783 _dbus_return_val_if_fail (_dbus_message_iter_append_check (real_sub), FALSE);
2784 _dbus_return_val_if_fail (real_sub->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE);
2786 ret = _dbus_type_writer_unrecurse (&real->u.writer,
2787 &real_sub->u.writer);
2789 if (!_dbus_message_iter_close_signature (real))
2796 * Abandons creation of a contained-typed value and frees resources created
2797 * by dbus_message_iter_open_container(). Once this returns, the message
2798 * is hosed and you have to start over building the whole message.
2800 * This should only be used to abandon creation of a message when you have
2803 * @param iter the append iterator
2804 * @param sub sub-iterator to close
2807 dbus_message_iter_abandon_container (DBusMessageIter *iter,
2808 DBusMessageIter *sub)
2810 DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
2811 DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub;
2813 _dbus_return_if_fail (_dbus_message_iter_append_check (real));
2814 _dbus_return_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
2815 _dbus_return_if_fail (_dbus_message_iter_append_check (real_sub));
2816 _dbus_return_if_fail (real_sub->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
2818 _dbus_message_iter_abandon_signature (real);
2822 * Sets a flag indicating that the message does not want a reply; if
2823 * this flag is set, the other end of the connection may (but is not
2824 * required to) optimize by not sending method return or error
2825 * replies. If this flag is set, there is no way to know whether the
2826 * message successfully arrived at the remote end. Normally you know a
2827 * message was received when you receive the reply to it.
2829 * The flag is #FALSE by default, that is by default the other end is
2830 * required to reply.
2832 * On the protocol level this toggles #DBUS_HEADER_FLAG_NO_REPLY_EXPECTED
2834 * @param message the message
2835 * @param no_reply #TRUE if no reply is desired
2838 dbus_message_set_no_reply (DBusMessage *message,
2839 dbus_bool_t no_reply)
2841 _dbus_return_if_fail (message != NULL);
2842 _dbus_return_if_fail (!message->locked);
2844 _dbus_header_toggle_flag (&message->header,
2845 DBUS_HEADER_FLAG_NO_REPLY_EXPECTED,
2850 * Returns #TRUE if the message does not expect
2853 * @param message the message
2854 * @returns #TRUE if the message sender isn't waiting for a reply
2857 dbus_message_get_no_reply (DBusMessage *message)
2859 _dbus_return_val_if_fail (message != NULL, FALSE);
2861 return _dbus_header_get_flag (&message->header,
2862 DBUS_HEADER_FLAG_NO_REPLY_EXPECTED);
2866 * Sets a flag indicating that an owner for the destination name will
2867 * be automatically started before the message is delivered. When this
2868 * flag is set, the message is held until a name owner finishes
2869 * starting up, or fails to start up. In case of failure, the reply
2872 * The flag is set to #TRUE by default, i.e. auto starting is the default.
2874 * On the protocol level this toggles #DBUS_HEADER_FLAG_NO_AUTO_START
2876 * @param message the message
2877 * @param auto_start #TRUE if auto-starting is desired
2880 dbus_message_set_auto_start (DBusMessage *message,
2881 dbus_bool_t auto_start)
2883 _dbus_return_if_fail (message != NULL);
2884 _dbus_return_if_fail (!message->locked);
2886 _dbus_header_toggle_flag (&message->header,
2887 DBUS_HEADER_FLAG_NO_AUTO_START,
2892 * Returns #TRUE if the message will cause an owner for
2893 * destination name to be auto-started.
2895 * @param message the message
2896 * @returns #TRUE if the message will use auto-start
2899 dbus_message_get_auto_start (DBusMessage *message)
2901 _dbus_return_val_if_fail (message != NULL, FALSE);
2903 return !_dbus_header_get_flag (&message->header,
2904 DBUS_HEADER_FLAG_NO_AUTO_START);
2909 * Sets the object path this message is being sent to (for
2910 * DBUS_MESSAGE_TYPE_METHOD_CALL) or the one a signal is being
2911 * emitted from (for DBUS_MESSAGE_TYPE_SIGNAL).
2913 * The path must contain only valid characters as defined
2914 * in the D-Bus specification.
2916 * @param message the message
2917 * @param object_path the path or #NULL to unset
2918 * @returns #FALSE if not enough memory
2921 dbus_message_set_path (DBusMessage *message,
2922 const char *object_path)
2924 _dbus_return_val_if_fail (message != NULL, FALSE);
2925 _dbus_return_val_if_fail (!message->locked, FALSE);
2926 _dbus_return_val_if_fail (object_path == NULL ||
2927 _dbus_check_is_valid_path (object_path),
2930 return set_or_delete_string_field (message,
2931 DBUS_HEADER_FIELD_PATH,
2932 DBUS_TYPE_OBJECT_PATH,
2937 * Gets the object path this message is being sent to (for
2938 * DBUS_MESSAGE_TYPE_METHOD_CALL) or being emitted from (for
2939 * DBUS_MESSAGE_TYPE_SIGNAL). Returns #NULL if none.
2941 * See also dbus_message_get_path_decomposed().
2943 * The returned string becomes invalid if the message is
2944 * modified, since it points into the wire-marshaled message data.
2946 * @param message the message
2947 * @returns the path (should not be freed) or #NULL
2950 dbus_message_get_path (DBusMessage *message)
2954 _dbus_return_val_if_fail (message != NULL, NULL);
2956 v = NULL; /* in case field doesn't exist */
2957 _dbus_header_get_field_basic (&message->header,
2958 DBUS_HEADER_FIELD_PATH,
2959 DBUS_TYPE_OBJECT_PATH,
2965 * Checks if the message has a particular object path. The object
2966 * path is the destination object for a method call or the emitting
2967 * object for a signal.
2969 * @param message the message
2970 * @param path the path name
2971 * @returns #TRUE if there is a path field in the header
2974 dbus_message_has_path (DBusMessage *message,
2977 const char *msg_path;
2978 msg_path = dbus_message_get_path (message);
2980 if (msg_path == NULL)
2991 if (strcmp (msg_path, path) == 0)
2998 * Gets the object path this message is being sent to
2999 * (for DBUS_MESSAGE_TYPE_METHOD_CALL) or being emitted
3000 * from (for DBUS_MESSAGE_TYPE_SIGNAL) in a decomposed
3001 * format (one array element per path component).
3002 * Free the returned array with dbus_free_string_array().
3004 * An empty but non-NULL path array means the path "/".
3005 * So the path "/foo/bar" becomes { "foo", "bar", NULL }
3006 * and the path "/" becomes { NULL }.
3008 * See also dbus_message_get_path().
3010 * @todo this could be optimized by using the len from the message
3011 * instead of calling strlen() again
3013 * @param message the message
3014 * @param path place to store allocated array of path components; #NULL set here if no path field exists
3015 * @returns #FALSE if no memory to allocate the array
3018 dbus_message_get_path_decomposed (DBusMessage *message,
3023 _dbus_return_val_if_fail (message != NULL, FALSE);
3024 _dbus_return_val_if_fail (path != NULL, FALSE);
3028 v = dbus_message_get_path (message);
3031 if (!_dbus_decompose_path (v, strlen (v),
3039 * Sets the interface this message is being sent to
3040 * (for DBUS_MESSAGE_TYPE_METHOD_CALL) or
3041 * the interface a signal is being emitted from
3042 * (for DBUS_MESSAGE_TYPE_SIGNAL).
3044 * The interface name must contain only valid characters as defined
3045 * in the D-Bus specification.
3047 * @param message the message
3048 * @param interface the interface or #NULL to unset
3049 * @returns #FALSE if not enough memory
3052 dbus_message_set_interface (DBusMessage *message,
3053 const char *interface)
3055 _dbus_return_val_if_fail (message != NULL, FALSE);
3056 _dbus_return_val_if_fail (!message->locked, FALSE);
3057 _dbus_return_val_if_fail (interface == NULL ||
3058 _dbus_check_is_valid_interface (interface),
3061 return set_or_delete_string_field (message,
3062 DBUS_HEADER_FIELD_INTERFACE,
3068 * Gets the interface this message is being sent to
3069 * (for DBUS_MESSAGE_TYPE_METHOD_CALL) or being emitted
3070 * from (for DBUS_MESSAGE_TYPE_SIGNAL).
3071 * The interface name is fully-qualified (namespaced).
3072 * Returns #NULL if none.
3074 * The returned string becomes invalid if the message is
3075 * modified, since it points into the wire-marshaled message data.
3077 * @param message the message
3078 * @returns the message interface (should not be freed) or #NULL
3081 dbus_message_get_interface (DBusMessage *message)
3085 _dbus_return_val_if_fail (message != NULL, NULL);
3087 v = NULL; /* in case field doesn't exist */
3088 _dbus_header_get_field_basic (&message->header,
3089 DBUS_HEADER_FIELD_INTERFACE,
3096 * Checks if the message has an interface
3098 * @param message the message
3099 * @param interface the interface name
3100 * @returns #TRUE if the interface field in the header matches
3103 dbus_message_has_interface (DBusMessage *message,
3104 const char *interface)
3106 const char *msg_interface;
3107 msg_interface = dbus_message_get_interface (message);
3109 if (msg_interface == NULL)
3111 if (interface == NULL)
3117 if (interface == NULL)
3120 if (strcmp (msg_interface, interface) == 0)
3128 * Sets the interface member being invoked
3129 * (DBUS_MESSAGE_TYPE_METHOD_CALL) or emitted
3130 * (DBUS_MESSAGE_TYPE_SIGNAL).
3132 * The member name must contain only valid characters as defined
3133 * in the D-Bus specification.
3135 * @param message the message
3136 * @param member the member or #NULL to unset
3137 * @returns #FALSE if not enough memory
3140 dbus_message_set_member (DBusMessage *message,
3143 _dbus_return_val_if_fail (message != NULL, FALSE);
3144 _dbus_return_val_if_fail (!message->locked, FALSE);
3145 _dbus_return_val_if_fail (member == NULL ||
3146 _dbus_check_is_valid_member (member),
3149 return set_or_delete_string_field (message,
3150 DBUS_HEADER_FIELD_MEMBER,
3156 * Gets the interface member being invoked
3157 * (DBUS_MESSAGE_TYPE_METHOD_CALL) or emitted
3158 * (DBUS_MESSAGE_TYPE_SIGNAL). Returns #NULL if none.
3160 * The returned string becomes invalid if the message is
3161 * modified, since it points into the wire-marshaled message data.
3163 * @param message the message
3164 * @returns the member name (should not be freed) or #NULL
3167 dbus_message_get_member (DBusMessage *message)
3171 _dbus_return_val_if_fail (message != NULL, NULL);
3173 v = NULL; /* in case field doesn't exist */
3174 _dbus_header_get_field_basic (&message->header,
3175 DBUS_HEADER_FIELD_MEMBER,
3182 * Checks if the message has an interface member
3184 * @param message the message
3185 * @param member the member name
3186 * @returns #TRUE if there is a member field in the header
3189 dbus_message_has_member (DBusMessage *message,
3192 const char *msg_member;
3193 msg_member = dbus_message_get_member (message);
3195 if (msg_member == NULL)
3206 if (strcmp (msg_member, member) == 0)
3214 * Sets the name of the error (DBUS_MESSAGE_TYPE_ERROR).
3215 * The name is fully-qualified (namespaced).
3217 * The error name must contain only valid characters as defined
3218 * in the D-Bus specification.
3220 * @param message the message
3221 * @param error_name the name or #NULL to unset
3222 * @returns #FALSE if not enough memory
3225 dbus_message_set_error_name (DBusMessage *message,
3226 const char *error_name)
3228 _dbus_return_val_if_fail (message != NULL, FALSE);
3229 _dbus_return_val_if_fail (!message->locked, FALSE);
3230 _dbus_return_val_if_fail (error_name == NULL ||
3231 _dbus_check_is_valid_error_name (error_name),
3234 return set_or_delete_string_field (message,
3235 DBUS_HEADER_FIELD_ERROR_NAME,
3241 * Gets the error name (DBUS_MESSAGE_TYPE_ERROR only)
3244 * The returned string becomes invalid if the message is
3245 * modified, since it points into the wire-marshaled message data.
3247 * @param message the message
3248 * @returns the error name (should not be freed) or #NULL
3251 dbus_message_get_error_name (DBusMessage *message)
3255 _dbus_return_val_if_fail (message != NULL, NULL);
3257 v = NULL; /* in case field doesn't exist */
3258 _dbus_header_get_field_basic (&message->header,
3259 DBUS_HEADER_FIELD_ERROR_NAME,
3266 * Sets the message's destination. The destination is the name of
3267 * another connection on the bus and may be either the unique name
3268 * assigned by the bus to each connection, or a well-known name
3269 * specified in advance.
3271 * The destination name must contain only valid characters as defined
3272 * in the D-Bus specification.
3274 * @param message the message
3275 * @param destination the destination name or #NULL to unset
3276 * @returns #FALSE if not enough memory
3279 dbus_message_set_destination (DBusMessage *message,
3280 const char *destination)
3282 _dbus_return_val_if_fail (message != NULL, FALSE);
3283 _dbus_return_val_if_fail (!message->locked, FALSE);
3284 _dbus_return_val_if_fail (destination == NULL ||
3285 _dbus_check_is_valid_bus_name (destination),
3288 return set_or_delete_string_field (message,
3289 DBUS_HEADER_FIELD_DESTINATION,
3295 * Gets the destination of a message or #NULL if there is none set.
3297 * The returned string becomes invalid if the message is
3298 * modified, since it points into the wire-marshaled message data.
3300 * @param message the message
3301 * @returns the message destination (should not be freed) or #NULL
3304 dbus_message_get_destination (DBusMessage *message)
3308 _dbus_return_val_if_fail (message != NULL, NULL);
3310 v = NULL; /* in case field doesn't exist */
3311 _dbus_header_get_field_basic (&message->header,
3312 DBUS_HEADER_FIELD_DESTINATION,
3319 * Sets the message sender.
3321 * The sender must be a valid bus name as defined in the D-Bus
3324 * Usually you don't want to call this. The message bus daemon will
3325 * call it to set the origin of each message. If you aren't implementing
3326 * a message bus daemon you shouldn't need to set the sender.
3328 * @param message the message
3329 * @param sender the sender or #NULL to unset
3330 * @returns #FALSE if not enough memory
3333 dbus_message_set_sender (DBusMessage *message,
3336 _dbus_return_val_if_fail (message != NULL, FALSE);
3337 _dbus_return_val_if_fail (!message->locked, FALSE);
3338 _dbus_return_val_if_fail (sender == NULL ||
3339 _dbus_check_is_valid_bus_name (sender),
3342 return set_or_delete_string_field (message,
3343 DBUS_HEADER_FIELD_SENDER,
3349 * Gets the unique name of the connection which originated this
3350 * message, or #NULL if unknown or inapplicable. The sender is filled
3351 * in by the message bus.
3353 * Note, the returned sender is always the unique bus name.
3354 * Connections may own multiple other bus names, but those
3355 * are not found in the sender field.
3357 * The returned string becomes invalid if the message is
3358 * modified, since it points into the wire-marshaled message data.
3360 * @param message the message
3361 * @returns the unique name of the sender or #NULL
3364 dbus_message_get_sender (DBusMessage *message)
3368 _dbus_return_val_if_fail (message != NULL, NULL);
3370 v = NULL; /* in case field doesn't exist */
3371 _dbus_header_get_field_basic (&message->header,
3372 DBUS_HEADER_FIELD_SENDER,
3379 * Gets the type signature of the message, i.e. the arguments in the
3380 * message payload. The signature includes only "in" arguments for
3381 * #DBUS_MESSAGE_TYPE_METHOD_CALL and only "out" arguments for
3382 * #DBUS_MESSAGE_TYPE_METHOD_RETURN, so is slightly different from
3383 * what you might expect (that is, it does not include the signature of the
3384 * entire C++-style method).
3386 * The signature is a string made up of type codes such as
3387 * #DBUS_TYPE_INT32. The string is terminated with nul (nul is also
3388 * the value of #DBUS_TYPE_INVALID).
3390 * The returned string becomes invalid if the message is
3391 * modified, since it points into the wire-marshaled message data.
3393 * @param message the message
3394 * @returns the type signature
3397 dbus_message_get_signature (DBusMessage *message)
3399 const DBusString *type_str;
3402 _dbus_return_val_if_fail (message != NULL, NULL);
3404 get_const_signature (&message->header, &type_str, &type_pos);
3406 return _dbus_string_get_const_data_len (type_str, type_pos, 0);
3410 _dbus_message_has_type_interface_member (DBusMessage *message,
3412 const char *interface,
3417 _dbus_assert (message != NULL);
3418 _dbus_assert (interface != NULL);
3419 _dbus_assert (member != NULL);
3421 if (dbus_message_get_type (message) != type)
3424 /* Optimize by checking the short member name first
3425 * instead of the longer interface name
3428 n = dbus_message_get_member (message);
3430 if (n && strcmp (n, member) == 0)
3432 n = dbus_message_get_interface (message);
3434 if (n == NULL || strcmp (n, interface) == 0)
3442 * Checks whether the message is a method call with the given
3443 * interface and member fields. If the message is not
3444 * #DBUS_MESSAGE_TYPE_METHOD_CALL, or has a different interface or
3445 * member field, returns #FALSE. If the interface field is missing,
3446 * then it will be assumed equal to the provided interface. The D-Bus
3447 * protocol allows method callers to leave out the interface name.
3449 * @param message the message
3450 * @param interface the name to check (must not be #NULL)
3451 * @param method the name to check (must not be #NULL)
3453 * @returns #TRUE if the message is the specified method call
3456 dbus_message_is_method_call (DBusMessage *message,
3457 const char *interface,
3460 _dbus_return_val_if_fail (message != NULL, FALSE);
3461 _dbus_return_val_if_fail (interface != NULL, FALSE);
3462 _dbus_return_val_if_fail (method != NULL, FALSE);
3463 /* don't check that interface/method are valid since it would be
3464 * expensive, and not catch many common errors
3467 return _dbus_message_has_type_interface_member (message,
3468 DBUS_MESSAGE_TYPE_METHOD_CALL,
3473 * Checks whether the message is a signal with the given interface and
3474 * member fields. If the message is not #DBUS_MESSAGE_TYPE_SIGNAL, or
3475 * has a different interface or member field, returns #FALSE.
3477 * @param message the message
3478 * @param interface the name to check (must not be #NULL)
3479 * @param signal_name the name to check (must not be #NULL)
3481 * @returns #TRUE if the message is the specified signal
3484 dbus_message_is_signal (DBusMessage *message,
3485 const char *interface,
3486 const char *signal_name)
3488 _dbus_return_val_if_fail (message != NULL, FALSE);
3489 _dbus_return_val_if_fail (interface != NULL, FALSE);
3490 _dbus_return_val_if_fail (signal_name != NULL, FALSE);
3491 /* don't check that interface/name are valid since it would be
3492 * expensive, and not catch many common errors
3495 return _dbus_message_has_type_interface_member (message,
3496 DBUS_MESSAGE_TYPE_SIGNAL,
3497 interface, signal_name);
3501 * Checks whether the message is an error reply with the given error
3502 * name. If the message is not #DBUS_MESSAGE_TYPE_ERROR, or has a
3503 * different name, returns #FALSE.
3505 * @param message the message
3506 * @param error_name the name to check (must not be #NULL)
3508 * @returns #TRUE if the message is the specified error
3511 dbus_message_is_error (DBusMessage *message,
3512 const char *error_name)
3516 _dbus_return_val_if_fail (message != NULL, FALSE);
3517 _dbus_return_val_if_fail (error_name != NULL, FALSE);
3518 /* don't check that error_name is valid since it would be expensive,
3519 * and not catch many common errors
3522 if (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_ERROR)
3525 n = dbus_message_get_error_name (message);
3527 if (n && strcmp (n, error_name) == 0)
3534 * Checks whether the message was sent to the given name. If the
3535 * message has no destination specified or has a different
3536 * destination, returns #FALSE.
3538 * @param message the message
3539 * @param name the name to check (must not be #NULL)
3541 * @returns #TRUE if the message has the given destination name
3544 dbus_message_has_destination (DBusMessage *message,
3549 _dbus_return_val_if_fail (message != NULL, FALSE);
3550 _dbus_return_val_if_fail (name != NULL, FALSE);
3551 /* don't check that name is valid since it would be expensive, and
3552 * not catch many common errors
3555 s = dbus_message_get_destination (message);
3557 if (s && strcmp (s, name) == 0)
3564 * Checks whether the message has the given unique name as its sender.
3565 * If the message has no sender specified or has a different sender,
3566 * returns #FALSE. Note that a peer application will always have the
3567 * unique name of the connection as the sender. So you can't use this
3568 * function to see whether a sender owned a well-known name.
3570 * Messages from the bus itself will have #DBUS_SERVICE_DBUS
3573 * @param message the message
3574 * @param name the name to check (must not be #NULL)
3576 * @returns #TRUE if the message has the given sender
3579 dbus_message_has_sender (DBusMessage *message,
3584 _dbus_return_val_if_fail (message != NULL, FALSE);
3585 _dbus_return_val_if_fail (name != NULL, FALSE);
3586 /* don't check that name is valid since it would be expensive, and
3587 * not catch many common errors
3590 s = dbus_message_get_sender (message);
3592 if (s && strcmp (s, name) == 0)
3599 * Checks whether the message has the given signature; see
3600 * dbus_message_get_signature() for more details on what the signature
3603 * @param message the message
3604 * @param signature typecode array
3605 * @returns #TRUE if message has the given signature
3608 dbus_message_has_signature (DBusMessage *message,
3609 const char *signature)
3613 _dbus_return_val_if_fail (message != NULL, FALSE);
3614 _dbus_return_val_if_fail (signature != NULL, FALSE);
3615 /* don't check that signature is valid since it would be expensive,
3616 * and not catch many common errors
3619 s = dbus_message_get_signature (message);
3621 if (s && strcmp (s, signature) == 0)
3628 * Sets a #DBusError based on the contents of the given
3629 * message. The error is only set if the message
3630 * is an error message, as in #DBUS_MESSAGE_TYPE_ERROR.
3631 * The name of the error is set to the name of the message,
3632 * and the error message is set to the first argument
3633 * if the argument exists and is a string.
3635 * The return value indicates whether the error was set (the error is
3636 * set if and only if the message is an error message). So you can
3637 * check for an error reply and convert it to DBusError in one go:
3639 * if (dbus_set_error_from_message (error, reply))
3645 * @param error the error to set
3646 * @param message the message to set it from
3647 * @returns #TRUE if the message had type #DBUS_MESSAGE_TYPE_ERROR
3650 dbus_set_error_from_message (DBusError *error,
3651 DBusMessage *message)
3655 _dbus_return_val_if_fail (message != NULL, FALSE);
3656 _dbus_return_val_if_error_is_set (error, FALSE);
3658 if (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_ERROR)
3662 dbus_message_get_args (message, NULL,
3663 DBUS_TYPE_STRING, &str,
3666 dbus_set_error (error, dbus_message_get_error_name (message),
3667 str ? "%s" : NULL, str);
3673 * Checks whether a message contains unix fds
3675 * @param message the message
3676 * @returns #TRUE if the message contains unix fds
3679 dbus_message_contains_unix_fds(DBusMessage *message)
3681 #ifdef HAVE_UNIX_FD_PASSING
3682 _dbus_assert(message);
3684 return message->n_unix_fds > 0;
3693 * @addtogroup DBusMessageInternals
3699 * The initial buffer size of the message loader.
3701 * @todo this should be based on min header size plus some average
3702 * body size, or something. Or rather, the min header size only, if we
3703 * want to try to read only the header, store that in a DBusMessage,
3704 * then read only the body and store that, etc., depends on
3705 * how we optimize _dbus_message_loader_get_buffer() and what
3706 * the exact message format is.
3708 #define INITIAL_LOADER_DATA_LEN 32
3711 * Creates a new message loader. Returns #NULL if memory can't
3714 * @returns new loader, or #NULL.
3717 _dbus_message_loader_new (void)
3719 DBusMessageLoader *loader;
3721 loader = dbus_new0 (DBusMessageLoader, 1);
3725 loader->refcount = 1;
3727 loader->corrupted = FALSE;
3728 loader->corruption_reason = DBUS_VALID;
3730 /* this can be configured by the app, but defaults to the protocol max */
3731 loader->max_message_size = DBUS_MAXIMUM_MESSAGE_LENGTH;
3733 /* We set a very relatively conservative default here since due to how
3734 SCM_RIGHTS works we need to preallocate an fd array of the maximum
3735 number of unix fds we want to receive in advance. A
3736 try-and-reallocate loop is not possible. */
3737 loader->max_message_unix_fds = 1024;
3739 if (!_dbus_string_init (&loader->data))
3745 /* preallocate the buffer for speed, ignore failure */
3746 _dbus_string_set_length (&loader->data, INITIAL_LOADER_DATA_LEN);
3747 _dbus_string_set_length (&loader->data, 0);
3749 #ifdef HAVE_UNIX_FD_PASSING
3750 loader->unix_fds = NULL;
3751 loader->n_unix_fds = loader->n_unix_fds_allocated = 0;
3752 loader->unix_fds_outstanding = FALSE;
3759 * Increments the reference count of the loader.
3761 * @param loader the loader.
3762 * @returns the loader
3765 _dbus_message_loader_ref (DBusMessageLoader *loader)
3767 loader->refcount += 1;
3773 * Decrements the reference count of the loader and finalizes the
3774 * loader when the count reaches zero.
3776 * @param loader the loader.
3779 _dbus_message_loader_unref (DBusMessageLoader *loader)
3781 loader->refcount -= 1;
3782 if (loader->refcount == 0)
3784 #ifdef HAVE_UNIX_FD_PASSING
3785 close_unix_fds(loader->unix_fds, &loader->n_unix_fds);
3786 dbus_free(loader->unix_fds);
3788 _dbus_list_foreach (&loader->messages,
3789 (DBusForeachFunction) dbus_message_unref,
3791 _dbus_list_clear (&loader->messages);
3792 _dbus_string_free (&loader->data);
3798 * Gets the buffer to use for reading data from the network. Network
3799 * data is read directly into an allocated buffer, which is then used
3800 * in the DBusMessage, to avoid as many extra memcpy's as possible.
3801 * The buffer must always be returned immediately using
3802 * _dbus_message_loader_return_buffer(), even if no bytes are
3803 * successfully read.
3805 * @todo this function can be a lot more clever. For example
3806 * it can probably always return a buffer size to read exactly
3807 * the body of the next message, thus avoiding any memory wastage
3810 * @todo we need to enforce a max length on strings in header fields.
3812 * @param loader the message loader.
3813 * @param buffer the buffer
3816 _dbus_message_loader_get_buffer (DBusMessageLoader *loader,
3817 DBusString **buffer)
3819 _dbus_assert (!loader->buffer_outstanding);
3821 *buffer = &loader->data;
3823 loader->buffer_outstanding = TRUE;
3827 * Returns a buffer obtained from _dbus_message_loader_get_buffer(),
3828 * indicating to the loader how many bytes of the buffer were filled
3829 * in. This function must always be called, even if no bytes were
3830 * successfully read.
3832 * @param loader the loader.
3833 * @param buffer the buffer.
3834 * @param bytes_read number of bytes that were read into the buffer.
3837 _dbus_message_loader_return_buffer (DBusMessageLoader *loader,
3841 _dbus_assert (loader->buffer_outstanding);
3842 _dbus_assert (buffer == &loader->data);
3844 loader->buffer_outstanding = FALSE;
3848 * Gets the buffer to use for reading unix fds from the network.
3850 * This works similar to _dbus_message_loader_get_buffer()
3852 * @param loader the message loader.
3853 * @param fds the array to read fds into
3854 * @param max_n_fds how many fds to read at most
3855 * @return TRUE on success, FALSE on OOM
3858 _dbus_message_loader_get_unix_fds(DBusMessageLoader *loader,
3860 unsigned *max_n_fds)
3862 #ifdef HAVE_UNIX_FD_PASSING
3863 _dbus_assert (!loader->unix_fds_outstanding);
3865 /* Allocate space where we can put the fds we read. We allocate
3866 space for max_message_unix_fds since this is an
3867 upper limit how many fds can be received within a single
3868 message. Since SCM_RIGHTS doesn't allow a reallocate+retry logic
3869 we are allocating the maximum possible array size right from the
3870 beginning. This sucks a bit, however unless SCM_RIGHTS is fixed
3871 there is no better way. */
3873 if (loader->n_unix_fds_allocated < loader->max_message_unix_fds)
3875 int *a = dbus_realloc(loader->unix_fds,
3876 loader->max_message_unix_fds * sizeof(loader->unix_fds[0]));
3881 loader->unix_fds = a;
3882 loader->n_unix_fds_allocated = loader->max_message_unix_fds;
3885 *fds = loader->unix_fds + loader->n_unix_fds;
3886 *max_n_fds = loader->n_unix_fds_allocated - loader->n_unix_fds;
3888 loader->unix_fds_outstanding = TRUE;
3891 _dbus_assert_not_reached("Platform doesn't support unix fd passing");
3897 * Returns a buffer obtained from _dbus_message_loader_get_unix_fds().
3899 * This works similar to _dbus_message_loader_return_buffer()
3901 * @param loader the message loader.
3902 * @param fds the array fds were read into
3903 * @param max_n_fds how many fds were read
3907 _dbus_message_loader_return_unix_fds(DBusMessageLoader *loader,
3911 #ifdef HAVE_UNIX_FD_PASSING
3912 _dbus_assert(loader->unix_fds_outstanding);
3913 _dbus_assert(loader->unix_fds + loader->n_unix_fds == fds);
3914 _dbus_assert(loader->n_unix_fds + n_fds <= loader->n_unix_fds_allocated);
3916 loader->n_unix_fds += n_fds;
3917 loader->unix_fds_outstanding = FALSE;
3919 _dbus_assert_not_reached("Platform doesn't support unix fd passing");
3924 * FIXME when we move the header out of the buffer, that memmoves all
3925 * buffered messages. Kind of crappy.
3927 * Also we copy the header and body, which is kind of crappy. To
3928 * avoid this, we have to allow header and body to be in a single
3929 * memory block, which is good for messages we read and bad for
3930 * messages we are creating. But we could move_len() the buffer into
3931 * this single memory block, and move_len() will just swap the buffers
3932 * if you're moving the entire buffer replacing the dest string.
3934 * We could also have the message loader tell the transport how many
3935 * bytes to read; so it would first ask for some arbitrary number like
3936 * 256, then if the message was incomplete it would use the
3937 * header/body len to ask for exactly the size of the message (or
3938 * blocks the size of a typical kernel buffer for the socket). That
3939 * way we don't get trailing bytes in the buffer that have to be
3940 * memmoved. Though I suppose we also don't have a chance of reading a
3941 * bunch of small messages at once, so the optimization may be stupid.
3943 * Another approach would be to keep a "start" index into
3944 * loader->data and only delete it occasionally, instead of after
3945 * each message is loaded.
3947 * load_message() returns FALSE if not enough memory OR the loader was corrupted
3950 load_message (DBusMessageLoader *loader,
3951 DBusMessage *message,
3953 int fields_array_len,
3958 DBusValidity validity;
3959 const DBusString *type_str;
3961 DBusValidationMode mode;
3962 dbus_uint32_t n_unix_fds = 0;
3964 mode = DBUS_VALIDATION_MODE_DATA_IS_UNTRUSTED;
3969 _dbus_verbose_bytes_of_string (&loader->data, 0, header_len /* + body_len */);
3972 /* 1. VALIDATE AND COPY OVER HEADER */
3973 _dbus_assert (_dbus_string_get_length (&message->header.data) == 0);
3974 _dbus_assert ((header_len + body_len) <= _dbus_string_get_length (&loader->data));
3976 if (!_dbus_header_load (&message->header,
3984 _dbus_string_get_length (&loader->data)))
3986 _dbus_verbose ("Failed to load header for new message code %d\n", validity);
3988 /* assert here so we can catch any code that still uses DBUS_VALID to indicate
3989 oom errors. They should use DBUS_VALIDITY_UNKNOWN_OOM_ERROR instead */
3990 _dbus_assert (validity != DBUS_VALID);
3992 if (validity == DBUS_VALIDITY_UNKNOWN_OOM_ERROR)
3996 loader->corrupted = TRUE;
3997 loader->corruption_reason = validity;
4002 _dbus_assert (validity == DBUS_VALID);
4004 message->byte_order = byte_order;
4006 /* 2. VALIDATE BODY */
4007 if (mode != DBUS_VALIDATION_MODE_WE_TRUST_THIS_DATA_ABSOLUTELY)
4009 get_const_signature (&message->header, &type_str, &type_pos);
4011 /* Because the bytes_remaining arg is NULL, this validates that the
4012 * body is the right length
4014 validity = _dbus_validate_body_with_reason (type_str,
4021 if (validity != DBUS_VALID)
4023 _dbus_verbose ("Failed to validate message body code %d\n", validity);
4025 loader->corrupted = TRUE;
4026 loader->corruption_reason = validity;
4032 /* 3. COPY OVER UNIX FDS */
4033 _dbus_header_get_field_basic(&message->header,
4034 DBUS_HEADER_FIELD_UNIX_FDS,
4038 #ifdef HAVE_UNIX_FD_PASSING
4040 if (n_unix_fds > loader->n_unix_fds)
4042 _dbus_verbose("Message contains references to more unix fds than were sent %u != %u\n",
4043 n_unix_fds, loader->n_unix_fds);
4045 loader->corrupted = TRUE;
4046 loader->corruption_reason = DBUS_INVALID_MISSING_UNIX_FDS;
4050 /* If this was a recycled message there might still be
4051 some memory allocated for the fds */
4052 dbus_free(message->unix_fds);
4056 message->unix_fds = _dbus_memdup(loader->unix_fds, n_unix_fds * sizeof(message->unix_fds[0]));
4057 if (message->unix_fds == NULL)
4059 _dbus_verbose ("Failed to allocate file descriptor array\n");
4064 message->n_unix_fds_allocated = message->n_unix_fds = n_unix_fds;
4065 loader->n_unix_fds -= n_unix_fds;
4066 memmove(loader->unix_fds + n_unix_fds, loader->unix_fds, loader->n_unix_fds);
4069 message->unix_fds = NULL;
4075 _dbus_verbose ("Hmm, message claims to come with file descriptors "
4076 "but that's not supported on our platform, disconnecting.\n");
4078 loader->corrupted = TRUE;
4079 loader->corruption_reason = DBUS_INVALID_MISSING_UNIX_FDS;
4085 /* 3. COPY OVER BODY AND QUEUE MESSAGE */
4087 if (!_dbus_list_append (&loader->messages, message))
4089 _dbus_verbose ("Failed to append new message to loader queue\n");
4094 _dbus_assert (_dbus_string_get_length (&message->body) == 0);
4095 _dbus_assert (_dbus_string_get_length (&loader->data) >=
4096 (header_len + body_len));
4098 if (!_dbus_string_copy_len (&loader->data, header_len, body_len, &message->body, 0))
4100 _dbus_verbose ("Failed to move body into new message\n");
4105 _dbus_string_delete (&loader->data, 0, header_len + body_len);
4107 /* don't waste more than 2k of memory */
4108 _dbus_string_compact (&loader->data, 2048);
4110 _dbus_assert (_dbus_string_get_length (&message->header.data) == header_len);
4111 _dbus_assert (_dbus_string_get_length (&message->body) == body_len);
4113 _dbus_verbose ("Loaded message %p\n", message);
4115 _dbus_assert (!oom);
4116 _dbus_assert (!loader->corrupted);
4117 _dbus_assert (loader->messages != NULL);
4118 _dbus_assert (_dbus_list_find_last (&loader->messages, message) != NULL);
4126 /* does nothing if the message isn't in the list */
4127 _dbus_list_remove_last (&loader->messages, message);
4130 _dbus_assert (!loader->corrupted);
4132 _dbus_assert (loader->corrupted);
4134 _dbus_verbose_bytes_of_string (&loader->data, 0, _dbus_string_get_length (&loader->data));
4140 * Converts buffered data into messages, if we have enough data. If
4141 * we don't have enough data, does nothing.
4143 * @todo we need to check that the proper named header fields exist
4144 * for each message type.
4146 * @todo If a message has unknown type, we should probably eat it
4147 * right here rather than passing it out to applications. However
4148 * it's not an error to see messages of unknown type.
4150 * @param loader the loader.
4151 * @returns #TRUE if we had enough memory to finish.
4154 _dbus_message_loader_queue_messages (DBusMessageLoader *loader)
4156 while (!loader->corrupted &&
4157 _dbus_string_get_length (&loader->data) >= DBUS_MINIMUM_HEADER_SIZE)
4159 DBusValidity validity;
4160 int byte_order, fields_array_len, header_len, body_len;
4162 if (_dbus_header_have_message_untrusted (loader->max_message_size,
4169 _dbus_string_get_length (&loader->data)))
4171 DBusMessage *message;
4173 _dbus_assert (validity == DBUS_VALID);
4175 message = dbus_message_new_empty_header ();
4176 if (message == NULL)
4179 if (!load_message (loader, message,
4180 byte_order, fields_array_len,
4181 header_len, body_len))
4183 dbus_message_unref (message);
4184 /* load_message() returns false if corrupted or OOM; if
4185 * corrupted then return TRUE for not OOM
4187 return loader->corrupted;
4190 _dbus_assert (loader->messages != NULL);
4191 _dbus_assert (_dbus_list_find_last (&loader->messages, message) != NULL);
4195 _dbus_verbose ("Initial peek at header says we don't have a whole message yet, or data broken with invalid code %d\n",
4197 if (validity != DBUS_VALID)
4199 loader->corrupted = TRUE;
4200 loader->corruption_reason = validity;
4210 * Peeks at first loaded message, returns #NULL if no messages have
4213 * @param loader the loader.
4214 * @returns the next message, or #NULL if none.
4217 _dbus_message_loader_peek_message (DBusMessageLoader *loader)
4219 if (loader->messages)
4220 return loader->messages->data;
4226 * Pops a loaded message (passing ownership of the message
4227 * to the caller). Returns #NULL if no messages have been
4230 * @param loader the loader.
4231 * @returns the next message, or #NULL if none.
4234 _dbus_message_loader_pop_message (DBusMessageLoader *loader)
4236 return _dbus_list_pop_first (&loader->messages);
4240 * Pops a loaded message inside a list link (passing ownership of the
4241 * message and link to the caller). Returns #NULL if no messages have
4244 * @param loader the loader.
4245 * @returns the next message link, or #NULL if none.
4248 _dbus_message_loader_pop_message_link (DBusMessageLoader *loader)
4250 return _dbus_list_pop_first_link (&loader->messages);
4254 * Returns a popped message link, used to undo a pop.
4256 * @param loader the loader
4257 * @param link the link with a message in it
4260 _dbus_message_loader_putback_message_link (DBusMessageLoader *loader,
4263 _dbus_list_prepend_link (&loader->messages, link);
4267 * Checks whether the loader is confused due to bad data.
4268 * If messages are received that are invalid, the
4269 * loader gets confused and gives up permanently.
4270 * This state is called "corrupted."
4272 * @param loader the loader
4273 * @returns #TRUE if the loader is hosed.
4276 _dbus_message_loader_get_is_corrupted (DBusMessageLoader *loader)
4278 _dbus_assert ((loader->corrupted && loader->corruption_reason != DBUS_VALID) ||
4279 (!loader->corrupted && loader->corruption_reason == DBUS_VALID));
4280 return loader->corrupted;
4284 * Checks what kind of bad data confused the loader.
4286 * @param loader the loader
4287 * @returns why the loader is hosed, or DBUS_VALID if it isn't.
4290 _dbus_message_loader_get_corruption_reason (DBusMessageLoader *loader)
4292 _dbus_assert ((loader->corrupted && loader->corruption_reason != DBUS_VALID) ||
4293 (!loader->corrupted && loader->corruption_reason == DBUS_VALID));
4295 return loader->corruption_reason;
4299 * Sets the maximum size message we allow.
4301 * @param loader the loader
4302 * @param size the max message size in bytes
4305 _dbus_message_loader_set_max_message_size (DBusMessageLoader *loader,
4308 if (size > DBUS_MAXIMUM_MESSAGE_LENGTH)
4310 _dbus_verbose ("clamping requested max message size %ld to %d\n",
4311 size, DBUS_MAXIMUM_MESSAGE_LENGTH);
4312 size = DBUS_MAXIMUM_MESSAGE_LENGTH;
4314 loader->max_message_size = size;
4318 * Gets the maximum allowed message size in bytes.
4320 * @param loader the loader
4321 * @returns max size in bytes
4324 _dbus_message_loader_get_max_message_size (DBusMessageLoader *loader)
4326 return loader->max_message_size;
4330 * Sets the maximum unix fds per message we allow.
4332 * @param loader the loader
4333 * @param size the max number of unix fds in a message
4336 _dbus_message_loader_set_max_message_unix_fds (DBusMessageLoader *loader,
4339 if (n > DBUS_MAXIMUM_MESSAGE_UNIX_FDS)
4341 _dbus_verbose ("clamping requested max message unix_fds %ld to %d\n",
4342 n, DBUS_MAXIMUM_MESSAGE_UNIX_FDS);
4343 n = DBUS_MAXIMUM_MESSAGE_UNIX_FDS;
4345 loader->max_message_unix_fds = n;
4349 * Gets the maximum allowed number of unix fds per message
4351 * @param loader the loader
4352 * @returns max unix fds
4355 _dbus_message_loader_get_max_message_unix_fds (DBusMessageLoader *loader)
4357 return loader->max_message_unix_fds;
4360 static DBusDataSlotAllocator slot_allocator;
4361 _DBUS_DEFINE_GLOBAL_LOCK (message_slots);
4364 * Allocates an integer ID to be used for storing application-specific
4365 * data on any DBusMessage. The allocated ID may then be used
4366 * with dbus_message_set_data() and dbus_message_get_data().
4367 * The passed-in slot must be initialized to -1, and is filled in
4368 * with the slot ID. If the passed-in slot is not -1, it's assumed
4369 * to be already allocated, and its refcount is incremented.
4371 * The allocated slot is global, i.e. all DBusMessage objects will
4372 * have a slot with the given integer ID reserved.
4374 * @param slot_p address of a global variable storing the slot
4375 * @returns #FALSE on failure (no memory)
4378 dbus_message_allocate_data_slot (dbus_int32_t *slot_p)
4380 return _dbus_data_slot_allocator_alloc (&slot_allocator,
4381 &_DBUS_LOCK_NAME (message_slots),
4386 * Deallocates a global ID for message data slots.
4387 * dbus_message_get_data() and dbus_message_set_data() may no
4388 * longer be used with this slot. Existing data stored on existing
4389 * DBusMessage objects will be freed when the message is
4390 * finalized, but may not be retrieved (and may only be replaced if
4391 * someone else reallocates the slot). When the refcount on the
4392 * passed-in slot reaches 0, it is set to -1.
4394 * @param slot_p address storing the slot to deallocate
4397 dbus_message_free_data_slot (dbus_int32_t *slot_p)
4399 _dbus_return_if_fail (*slot_p >= 0);
4401 _dbus_data_slot_allocator_free (&slot_allocator, slot_p);
4405 * Stores a pointer on a DBusMessage, along
4406 * with an optional function to be used for freeing
4407 * the data when the data is set again, or when
4408 * the message is finalized. The slot number
4409 * must have been allocated with dbus_message_allocate_data_slot().
4411 * @param message the message
4412 * @param slot the slot number
4413 * @param data the data to store
4414 * @param free_data_func finalizer function for the data
4415 * @returns #TRUE if there was enough memory to store the data
4418 dbus_message_set_data (DBusMessage *message,
4421 DBusFreeFunction free_data_func)
4423 DBusFreeFunction old_free_func;
4427 _dbus_return_val_if_fail (message != NULL, FALSE);
4428 _dbus_return_val_if_fail (slot >= 0, FALSE);
4430 retval = _dbus_data_slot_list_set (&slot_allocator,
4431 &message->slot_list,
4432 slot, data, free_data_func,
4433 &old_free_func, &old_data);
4437 /* Do the actual free outside the message lock */
4439 (* old_free_func) (old_data);
4446 * Retrieves data previously set with dbus_message_set_data().
4447 * The slot must still be allocated (must not have been freed).
4449 * @param message the message
4450 * @param slot the slot to get data from
4451 * @returns the data, or #NULL if not found
4454 dbus_message_get_data (DBusMessage *message,
4459 _dbus_return_val_if_fail (message != NULL, NULL);
4461 res = _dbus_data_slot_list_get (&slot_allocator,
4462 &message->slot_list,
4469 * Utility function to convert a machine-readable (not translated)
4470 * string into a D-Bus message type.
4473 * "method_call" -> DBUS_MESSAGE_TYPE_METHOD_CALL
4474 * "method_return" -> DBUS_MESSAGE_TYPE_METHOD_RETURN
4475 * "signal" -> DBUS_MESSAGE_TYPE_SIGNAL
4476 * "error" -> DBUS_MESSAGE_TYPE_ERROR
4477 * anything else -> DBUS_MESSAGE_TYPE_INVALID
4482 dbus_message_type_from_string (const char *type_str)
4484 if (strcmp (type_str, "method_call") == 0)
4485 return DBUS_MESSAGE_TYPE_METHOD_CALL;
4486 if (strcmp (type_str, "method_return") == 0)
4487 return DBUS_MESSAGE_TYPE_METHOD_RETURN;
4488 else if (strcmp (type_str, "signal") == 0)
4489 return DBUS_MESSAGE_TYPE_SIGNAL;
4490 else if (strcmp (type_str, "error") == 0)
4491 return DBUS_MESSAGE_TYPE_ERROR;
4493 return DBUS_MESSAGE_TYPE_INVALID;
4497 * Utility function to convert a D-Bus message type into a
4498 * machine-readable string (not translated).
4501 * DBUS_MESSAGE_TYPE_METHOD_CALL -> "method_call"
4502 * DBUS_MESSAGE_TYPE_METHOD_RETURN -> "method_return"
4503 * DBUS_MESSAGE_TYPE_SIGNAL -> "signal"
4504 * DBUS_MESSAGE_TYPE_ERROR -> "error"
4505 * DBUS_MESSAGE_TYPE_INVALID -> "invalid"
4510 dbus_message_type_to_string (int type)
4514 case DBUS_MESSAGE_TYPE_METHOD_CALL:
4515 return "method_call";
4516 case DBUS_MESSAGE_TYPE_METHOD_RETURN:
4517 return "method_return";
4518 case DBUS_MESSAGE_TYPE_SIGNAL:
4520 case DBUS_MESSAGE_TYPE_ERROR:
4528 * Turn a DBusMessage into the marshalled form as described in the D-Bus
4531 * Generally, this function is only useful for encapsulating D-Bus messages in
4532 * a different protocol.
4534 * @param msg the DBusMessage
4535 * @param marshalled_data_p the location to save the marshalled form to
4536 * @param len_p the location to save the length of the marshalled form to
4537 * @returns #FALSE if there was not enough memory
4540 dbus_message_marshal (DBusMessage *msg,
4541 char **marshalled_data_p,
4545 dbus_bool_t was_locked;
4547 _dbus_return_val_if_fail (msg != NULL, FALSE);
4548 _dbus_return_val_if_fail (marshalled_data_p != NULL, FALSE);
4549 _dbus_return_val_if_fail (len_p != NULL, FALSE);
4551 if (!_dbus_string_init (&tmp))
4554 /* Ensure the message is locked, to ensure the length header is filled in. */
4555 was_locked = msg->locked;
4558 dbus_message_lock (msg);
4560 if (!_dbus_string_copy (&(msg->header.data), 0, &tmp, 0))
4563 *len_p = _dbus_string_get_length (&tmp);
4565 if (!_dbus_string_copy (&(msg->body), 0, &tmp, *len_p))
4568 *len_p = _dbus_string_get_length (&tmp);
4570 if (!_dbus_string_steal_data (&tmp, marshalled_data_p))
4573 _dbus_string_free (&tmp);
4576 msg->locked = FALSE;
4581 _dbus_string_free (&tmp);
4584 msg->locked = FALSE;
4590 * Demarshal a D-Bus message from the format described in the D-Bus
4593 * Generally, this function is only useful for encapsulating D-Bus messages in
4594 * a different protocol.
4596 * @param str the marshalled DBusMessage
4597 * @param len the length of str
4598 * @param error the location to save errors to
4599 * @returns #NULL if there was an error
4602 dbus_message_demarshal (const char *str,
4606 DBusMessageLoader *loader;
4610 _dbus_return_val_if_fail (str != NULL, NULL);
4612 loader = _dbus_message_loader_new ();
4617 _dbus_message_loader_get_buffer (loader, &buffer);
4618 _dbus_string_append_len (buffer, str, len);
4619 _dbus_message_loader_return_buffer (loader, buffer, len);
4621 if (!_dbus_message_loader_queue_messages (loader))
4624 if (_dbus_message_loader_get_is_corrupted (loader))
4627 msg = _dbus_message_loader_pop_message (loader);
4632 _dbus_message_loader_unref (loader);
4636 dbus_set_error (error, DBUS_ERROR_INVALID_ARGS, "Message is corrupted (%s)",
4637 _dbus_validity_to_error_message (loader->corruption_reason));
4638 _dbus_message_loader_unref (loader);
4642 _DBUS_SET_OOM (error);
4643 _dbus_message_loader_unref (loader);
4648 * Returns the number of bytes required to be in the buffer to demarshal a
4651 * Generally, this function is only useful for encapsulating D-Bus messages in
4652 * a different protocol.
4654 * @param str data to be marshalled
4655 * @param len the length of str
4656 * @param error the location to save errors to
4657 * @returns -1 if there was no valid data to be demarshalled, 0 if there wasn't enough data to determine how much should be demarshalled. Otherwise returns the number of bytes to be demarshalled
4661 dbus_message_demarshal_bytes_needed(const char *buf,
4665 int byte_order, fields_array_len, header_len, body_len;
4666 DBusValidity validity = DBUS_VALID;
4669 if (!buf || len < DBUS_MINIMUM_HEADER_SIZE)
4672 if (len > DBUS_MAXIMUM_MESSAGE_LENGTH)
4673 len = DBUS_MAXIMUM_MESSAGE_LENGTH;
4674 _dbus_string_init_const_len (&str, buf, len);
4676 validity = DBUS_VALID;
4678 = _dbus_header_have_message_untrusted(DBUS_MAXIMUM_MESSAGE_LENGTH,
4679 &validity, &byte_order,
4685 _dbus_string_free (&str);
4687 if (validity == DBUS_VALID)
4689 _dbus_assert (have_message || (header_len + body_len) > len);
4690 return header_len + body_len;
4694 return -1; /* broken! */
4700 /* tests in dbus-message-util.c */