X-Git-Url: https://vcs.maemo.org/git/?a=blobdiff_plain;f=src%2Fdbus%2Fdbus-message.c;fp=src%2Fdbus%2Fdbus-message.c;h=edae42588790e67bb314e2aa2c8958ace529fd7b;hb=d00115111c6ab0c3f82117c4e2c3d24663c4f1ce;hp=0000000000000000000000000000000000000000;hpb=19516645fd679ce8c6779722bb831a42d0b3ddfe;p=monky diff --git a/src/dbus/dbus-message.c b/src/dbus/dbus-message.c new file mode 100644 index 0000000..edae425 --- /dev/null +++ b/src/dbus/dbus-message.c @@ -0,0 +1,4083 @@ +/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ +/* dbus-message.c DBusMessage object + * + * Copyright (C) 2002, 2003, 2004, 2005 Red Hat Inc. + * Copyright (C) 2002, 2003 CodeFactory AB + * + * Licensed under the Academic Free License version 2.1 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include "dbus-internals.h" +#include "dbus-marshal-recursive.h" +#include "dbus-marshal-validate.h" +#include "dbus-marshal-byteswap.h" +#include "dbus-marshal-header.h" +#include "dbus-signature.h" +#include "dbus-message-private.h" +#include "dbus-object-tree.h" +#include "dbus-memory.h" +#include "dbus-list.h" +#include "dbus-threads-internal.h" +#include + +static void dbus_message_finalize (DBusMessage *message); + +/** + * @defgroup DBusMessageInternals DBusMessage implementation details + * @ingroup DBusInternals + * @brief DBusMessage private implementation details. + * + * The guts of DBusMessage and its methods. + * + * @{ + */ + +/* Not thread locked, but strictly const/read-only so should be OK + */ +/** An static string representing an empty signature */ +_DBUS_STRING_DEFINE_STATIC(_dbus_empty_signature_str, ""); + +/* these have wacky values to help trap uninitialized iterators; + * but has to fit in 3 bits + */ +enum { + DBUS_MESSAGE_ITER_TYPE_READER = 3, + DBUS_MESSAGE_ITER_TYPE_WRITER = 7 +}; + +/** typedef for internals of message iterator */ +typedef struct DBusMessageRealIter DBusMessageRealIter; + +/** + * @brief Internals of DBusMessageIter + * + * Object representing a position in a message. All fields are internal. + */ +struct DBusMessageRealIter +{ + DBusMessage *message; /**< Message used */ + dbus_uint32_t changed_stamp : CHANGED_STAMP_BITS; /**< stamp to detect invalid iters */ + dbus_uint32_t iter_type : 3; /**< whether this is a reader or writer iter */ + dbus_uint32_t sig_refcount : 8; /**< depth of open_signature() */ + union + { + DBusTypeWriter writer; /**< writer */ + DBusTypeReader reader; /**< reader */ + } u; /**< the type writer or reader that does all the work */ +}; + +static void +get_const_signature (DBusHeader *header, + const DBusString **type_str_p, + int *type_pos_p) +{ + if (_dbus_header_get_field_raw (header, + DBUS_HEADER_FIELD_SIGNATURE, + type_str_p, + type_pos_p)) + { + *type_pos_p += 1; /* skip the signature length which is 1 byte */ + } + else + { + *type_str_p = &_dbus_empty_signature_str; + *type_pos_p = 0; + } +} + +/** + * Swaps the message to compiler byte order if required + * + * @param message the message + */ +static void +_dbus_message_byteswap (DBusMessage *message) +{ + const DBusString *type_str; + int type_pos; + + if (message->byte_order == DBUS_COMPILER_BYTE_ORDER) + return; + + _dbus_verbose ("Swapping message into compiler byte order\n"); + + get_const_signature (&message->header, &type_str, &type_pos); + + _dbus_marshal_byteswap (type_str, type_pos, + message->byte_order, + DBUS_COMPILER_BYTE_ORDER, + &message->body, 0); + + message->byte_order = DBUS_COMPILER_BYTE_ORDER; + + _dbus_header_byteswap (&message->header, DBUS_COMPILER_BYTE_ORDER); +} + +/** byte-swap the message if it doesn't match our byte order. + * Called only when we need the message in our own byte order, + * normally when reading arrays of integers or doubles. + * Otherwise should not be called since it would do needless + * work. + */ +#define ensure_byte_order(message) \ + if (message->byte_order != DBUS_COMPILER_BYTE_ORDER) \ + _dbus_message_byteswap (message) + +/** + * Gets the data to be sent over the network for this message. + * The header and then the body should be written out. + * This function is guaranteed to always return the same + * data once a message is locked (with dbus_message_lock()). + * + * @param message the message. + * @param header return location for message header data. + * @param body return location for message body data. + */ +void +_dbus_message_get_network_data (DBusMessage *message, + const DBusString **header, + const DBusString **body) +{ + _dbus_assert (message->locked); + + *header = &message->header.data; + *body = &message->body; +} + +/** + * Sets the serial number of a message. + * This can only be done once on a message. + * + * DBusConnection will automatically set the serial to an appropriate value + * when the message is sent; this function is only needed when encapsulating + * messages in another protocol, or otherwise bypassing DBusConnection. + * + * @param message the message + * @param serial the serial + */ +void +dbus_message_set_serial (DBusMessage *message, + dbus_uint32_t serial) +{ + _dbus_return_if_fail (message != NULL); + _dbus_return_if_fail (!message->locked); + + _dbus_header_set_serial (&message->header, serial); +} + +/** + * Adds a counter to be incremented immediately with the + * size of this message, and decremented by the size + * of this message when this message if finalized. + * The link contains a counter with its refcount already + * incremented, but the counter itself not incremented. + * Ownership of link and counter refcount is passed to + * the message. + * + * @param message the message + * @param link link with counter as data + */ +void +_dbus_message_add_size_counter_link (DBusMessage *message, + DBusList *link) +{ + /* right now we don't recompute the delta when message + * size changes, and that's OK for current purposes + * I think, but could be important to change later. + * Do recompute it whenever there are no outstanding counters, + * since it's basically free. + */ + if (message->size_counters == NULL) + { + message->size_counter_delta = + _dbus_string_get_length (&message->header.data) + + _dbus_string_get_length (&message->body); + +#if 0 + _dbus_verbose ("message has size %ld\n", + message->size_counter_delta); +#endif + } + + _dbus_list_append_link (&message->size_counters, link); + + _dbus_counter_adjust (link->data, message->size_counter_delta); +} + +/** + * Adds a counter to be incremented immediately with the + * size of this message, and decremented by the size + * of this message when this message if finalized. + * + * @param message the message + * @param counter the counter + * @returns #FALSE if no memory + */ +dbus_bool_t +_dbus_message_add_size_counter (DBusMessage *message, + DBusCounter *counter) +{ + DBusList *link; + + link = _dbus_list_alloc_link (counter); + if (link == NULL) + return FALSE; + + _dbus_counter_ref (counter); + _dbus_message_add_size_counter_link (message, link); + + return TRUE; +} + +/** + * Removes a counter tracking the size of this message, and decrements + * the counter by the size of this message. + * + * @param message the message + * @param link_return return the link used + * @param counter the counter + */ +void +_dbus_message_remove_size_counter (DBusMessage *message, + DBusCounter *counter, + DBusList **link_return) +{ + DBusList *link; + + link = _dbus_list_find_last (&message->size_counters, + counter); + _dbus_assert (link != NULL); + + _dbus_list_unlink (&message->size_counters, + link); + if (link_return) + *link_return = link; + else + _dbus_list_free_link (link); + + _dbus_counter_adjust (counter, - message->size_counter_delta); + + _dbus_counter_unref (counter); +} + +/** + * Locks a message. Allows checking that applications don't keep a + * reference to a message in the outgoing queue and change it + * underneath us. Messages are locked when they enter the outgoing + * queue (dbus_connection_send_message()), and the library complains + * if the message is modified while locked. This function may also + * called externally, for applications wrapping D-Bus in another protocol. + * + * @param message the message to lock. + */ +void +dbus_message_lock (DBusMessage *message) +{ + if (!message->locked) + { + _dbus_header_update_lengths (&message->header, + _dbus_string_get_length (&message->body)); + + /* must have a signature if you have a body */ + _dbus_assert (_dbus_string_get_length (&message->body) == 0 || + dbus_message_get_signature (message) != NULL); + + message->locked = TRUE; + } +} + +static dbus_bool_t +set_or_delete_string_field (DBusMessage *message, + int field, + int typecode, + const char *value) +{ + if (value == NULL) + return _dbus_header_delete_field (&message->header, field); + else + return _dbus_header_set_field_basic (&message->header, + field, + typecode, + &value); +} + +#if 0 +/* Probably we don't need to use this */ +/** + * Sets the signature of the message, i.e. the arguments in the + * message payload. The signature includes only "in" arguments for + * #DBUS_MESSAGE_TYPE_METHOD_CALL and only "out" arguments for + * #DBUS_MESSAGE_TYPE_METHOD_RETURN, so is slightly different from + * what you might expect (it does not include the signature of the + * entire C++-style method). + * + * The signature is a string made up of type codes such as + * #DBUS_TYPE_INT32. The string is terminated with nul (nul is also + * the value of #DBUS_TYPE_INVALID). The macros such as + * #DBUS_TYPE_INT32 evaluate to integers; to assemble a signature you + * may find it useful to use the string forms, such as + * #DBUS_TYPE_INT32_AS_STRING. + * + * An "unset" or #NULL signature is considered the same as an empty + * signature. In fact dbus_message_get_signature() will never return + * #NULL. + * + * @param message the message + * @param signature the type signature or #NULL to unset + * @returns #FALSE if no memory + */ +static dbus_bool_t +_dbus_message_set_signature (DBusMessage *message, + const char *signature) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (!message->locked, FALSE); + _dbus_return_val_if_fail (signature == NULL || + _dbus_check_is_valid_signature (signature)); + /* can't delete the signature if you have a message body */ + _dbus_return_val_if_fail (_dbus_string_get_length (&message->body) == 0 || + signature != NULL); + + return set_or_delete_string_field (message, + DBUS_HEADER_FIELD_SIGNATURE, + DBUS_TYPE_SIGNATURE, + signature); +} +#endif + +/* Message Cache + * + * We cache some DBusMessage to reduce the overhead of allocating + * them. In my profiling this consistently made about an 8% + * difference. It avoids the malloc for the message, the malloc for + * the slot list, the malloc for the header string and body string, + * and the associated free() calls. It does introduce another global + * lock which could be a performance issue in certain cases. + * + * For the echo client/server the round trip time goes from around + * .000077 to .000069 with the message cache on my laptop. The sysprof + * change is as follows (numbers are cumulative percentage): + * + * with message cache implemented as array as it is now (0.000069 per): + * new_empty_header 1.46 + * mutex_lock 0.56 # i.e. _DBUS_LOCK(message_cache) + * mutex_unlock 0.25 + * self 0.41 + * unref 2.24 + * self 0.68 + * list_clear 0.43 + * mutex_lock 0.33 # i.e. _DBUS_LOCK(message_cache) + * mutex_unlock 0.25 + * + * with message cache implemented as list (0.000070 per roundtrip): + * new_empty_header 2.72 + * list_pop_first 1.88 + * unref 3.3 + * list_prepend 1.63 + * + * without cache (0.000077 per roundtrip): + * new_empty_header 6.7 + * string_init_preallocated 3.43 + * dbus_malloc 2.43 + * dbus_malloc0 2.59 + * + * unref 4.02 + * string_free 1.82 + * dbus_free 1.63 + * dbus_free 0.71 + * + * If you implement the message_cache with a list, the primary reason + * it's slower is that you add another thread lock (on the DBusList + * mempool). + */ + +/** Avoid caching huge messages */ +#define MAX_MESSAGE_SIZE_TO_CACHE 10 * _DBUS_ONE_KILOBYTE + +/** Avoid caching too many messages */ +#define MAX_MESSAGE_CACHE_SIZE 5 + +_DBUS_DEFINE_GLOBAL_LOCK (message_cache); +static DBusMessage *message_cache[MAX_MESSAGE_CACHE_SIZE]; +static int message_cache_count = 0; +static dbus_bool_t message_cache_shutdown_registered = FALSE; + +static void +dbus_message_cache_shutdown (void *data) +{ + int i; + + _DBUS_LOCK (message_cache); + + i = 0; + while (i < MAX_MESSAGE_CACHE_SIZE) + { + if (message_cache[i]) + dbus_message_finalize (message_cache[i]); + + ++i; + } + + message_cache_count = 0; + message_cache_shutdown_registered = FALSE; + + _DBUS_UNLOCK (message_cache); +} + +/** + * Tries to get a message from the message cache. The retrieved + * message will have junk in it, so it still needs to be cleared out + * in dbus_message_new_empty_header() + * + * @returns the message, or #NULL if none cached + */ +static DBusMessage* +dbus_message_get_cached (void) +{ + DBusMessage *message; + int i; + + message = NULL; + + _DBUS_LOCK (message_cache); + + _dbus_assert (message_cache_count >= 0); + + if (message_cache_count == 0) + { + _DBUS_UNLOCK (message_cache); + return NULL; + } + + /* This is not necessarily true unless count > 0, and + * message_cache is uninitialized until the shutdown is + * registered + */ + _dbus_assert (message_cache_shutdown_registered); + + i = 0; + while (i < MAX_MESSAGE_CACHE_SIZE) + { + if (message_cache[i]) + { + message = message_cache[i]; + message_cache[i] = NULL; + message_cache_count -= 1; + break; + } + ++i; + } + _dbus_assert (message_cache_count >= 0); + _dbus_assert (i < MAX_MESSAGE_CACHE_SIZE); + _dbus_assert (message != NULL); + + _dbus_assert (message->refcount.value == 0); + _dbus_assert (message->size_counters == NULL); + + _DBUS_UNLOCK (message_cache); + + return message; +} + +static void +free_size_counter (void *element, + void *data) +{ + DBusCounter *counter = element; + DBusMessage *message = data; + + _dbus_counter_adjust (counter, - message->size_counter_delta); + + _dbus_counter_unref (counter); +} + +/** + * Tries to cache a message, otherwise finalize it. + * + * @param message the message + */ +static void +dbus_message_cache_or_finalize (DBusMessage *message) +{ + dbus_bool_t was_cached; + int i; + + _dbus_assert (message->refcount.value == 0); + + /* This calls application code and has to be done first thing + * without holding the lock + */ + _dbus_data_slot_list_clear (&message->slot_list); + + _dbus_list_foreach (&message->size_counters, + free_size_counter, message); + _dbus_list_clear (&message->size_counters); + + was_cached = FALSE; + + _DBUS_LOCK (message_cache); + + if (!message_cache_shutdown_registered) + { + _dbus_assert (message_cache_count == 0); + + if (!_dbus_register_shutdown_func (dbus_message_cache_shutdown, NULL)) + goto out; + + i = 0; + while (i < MAX_MESSAGE_CACHE_SIZE) + { + message_cache[i] = NULL; + ++i; + } + + message_cache_shutdown_registered = TRUE; + } + + _dbus_assert (message_cache_count >= 0); + + if ((_dbus_string_get_length (&message->header.data) + + _dbus_string_get_length (&message->body)) > + MAX_MESSAGE_SIZE_TO_CACHE) + goto out; + + if (message_cache_count >= MAX_MESSAGE_CACHE_SIZE) + goto out; + + /* Find empty slot */ + i = 0; + while (message_cache[i] != NULL) + ++i; + + _dbus_assert (i < MAX_MESSAGE_CACHE_SIZE); + + _dbus_assert (message_cache[i] == NULL); + message_cache[i] = message; + message_cache_count += 1; + was_cached = TRUE; +#ifndef DBUS_DISABLE_CHECKS + message->in_cache = TRUE; +#endif + + out: + _dbus_assert (message->refcount.value == 0); + + _DBUS_UNLOCK (message_cache); + + if (!was_cached) + dbus_message_finalize (message); +} + +#ifndef DBUS_DISABLE_CHECKS +static dbus_bool_t +_dbus_message_iter_check (DBusMessageRealIter *iter) +{ + if (iter == NULL) + { + _dbus_warn_check_failed ("dbus message iterator is NULL\n"); + return FALSE; + } + + if (iter->iter_type == DBUS_MESSAGE_ITER_TYPE_READER) + { + if (iter->u.reader.byte_order != iter->message->byte_order) + { + _dbus_warn_check_failed ("dbus message changed byte order since iterator was created\n"); + return FALSE; + } + /* because we swap the message into compiler order when you init an iter */ + _dbus_assert (iter->u.reader.byte_order == DBUS_COMPILER_BYTE_ORDER); + } + else if (iter->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER) + { + if (iter->u.writer.byte_order != iter->message->byte_order) + { + _dbus_warn_check_failed ("dbus message changed byte order since append iterator was created\n"); + return FALSE; + } + /* because we swap the message into compiler order when you init an iter */ + _dbus_assert (iter->u.writer.byte_order == DBUS_COMPILER_BYTE_ORDER); + } + else + { + _dbus_warn_check_failed ("dbus message iterator looks uninitialized or corrupted\n"); + return FALSE; + } + + if (iter->changed_stamp != iter->message->changed_stamp) + { + _dbus_warn_check_failed ("dbus message iterator invalid because the message has been modified (or perhaps the iterator is just uninitialized)\n"); + return FALSE; + } + + return TRUE; +} +#endif /* DBUS_DISABLE_CHECKS */ + +/** + * Implementation of the varargs arg-getting functions. + * dbus_message_get_args() is the place to go for complete + * documentation. + * + * @see dbus_message_get_args + * @param iter the message iter + * @param error error to be filled in + * @param first_arg_type type of the first argument + * @param var_args return location for first argument, followed by list of type/location pairs + * @returns #FALSE if error was set + */ +dbus_bool_t +_dbus_message_iter_get_args_valist (DBusMessageIter *iter, + DBusError *error, + int first_arg_type, + va_list var_args) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + int spec_type, msg_type, i; + dbus_bool_t retval; + + _dbus_assert (_dbus_message_iter_check (real)); + + retval = FALSE; + + spec_type = first_arg_type; + i = 0; + + while (spec_type != DBUS_TYPE_INVALID) + { + msg_type = dbus_message_iter_get_arg_type (iter); + + if (msg_type != spec_type) + { + dbus_set_error (error, DBUS_ERROR_INVALID_ARGS, + "Argument %d is specified to be of type \"%s\", but " + "is actually of type \"%s\"\n", i, + _dbus_type_to_string (spec_type), + _dbus_type_to_string (msg_type)); + + goto out; + } + + if (dbus_type_is_basic (spec_type)) + { + DBusBasicValue *ptr; + + ptr = va_arg (var_args, DBusBasicValue*); + + _dbus_assert (ptr != NULL); + + _dbus_type_reader_read_basic (&real->u.reader, + ptr); + } + else if (spec_type == DBUS_TYPE_ARRAY) + { + int element_type; + int spec_element_type; + const DBusBasicValue **ptr; + int *n_elements_p; + DBusTypeReader array; + + spec_element_type = va_arg (var_args, int); + element_type = _dbus_type_reader_get_element_type (&real->u.reader); + + if (spec_element_type != element_type) + { + dbus_set_error (error, DBUS_ERROR_INVALID_ARGS, + "Argument %d is specified to be an array of \"%s\", but " + "is actually an array of \"%s\"\n", + i, + _dbus_type_to_string (spec_element_type), + _dbus_type_to_string (element_type)); + + goto out; + } + + if (dbus_type_is_fixed (spec_element_type)) + { + ptr = va_arg (var_args, const DBusBasicValue**); + n_elements_p = va_arg (var_args, int*); + + _dbus_assert (ptr != NULL); + _dbus_assert (n_elements_p != NULL); + + _dbus_type_reader_recurse (&real->u.reader, &array); + + _dbus_type_reader_read_fixed_multi (&array, + ptr, n_elements_p); + } + else if (spec_element_type == DBUS_TYPE_STRING || + spec_element_type == DBUS_TYPE_SIGNATURE || + spec_element_type == DBUS_TYPE_OBJECT_PATH) + { + char ***str_array_p; + int n_elements; + char **str_array; + + str_array_p = va_arg (var_args, char***); + n_elements_p = va_arg (var_args, int*); + + _dbus_assert (str_array_p != NULL); + _dbus_assert (n_elements_p != NULL); + + /* Count elements in the array */ + _dbus_type_reader_recurse (&real->u.reader, &array); + + n_elements = 0; + while (_dbus_type_reader_get_current_type (&array) != DBUS_TYPE_INVALID) + { + ++n_elements; + _dbus_type_reader_next (&array); + } + + str_array = dbus_new0 (char*, n_elements + 1); + if (str_array == NULL) + { + _DBUS_SET_OOM (error); + goto out; + } + + /* Now go through and dup each string */ + _dbus_type_reader_recurse (&real->u.reader, &array); + + i = 0; + while (i < n_elements) + { + const char *s; + _dbus_type_reader_read_basic (&array, + &s); + + str_array[i] = _dbus_strdup (s); + if (str_array[i] == NULL) + { + dbus_free_string_array (str_array); + _DBUS_SET_OOM (error); + goto out; + } + + ++i; + + if (!_dbus_type_reader_next (&array)) + _dbus_assert (i == n_elements); + } + + _dbus_assert (_dbus_type_reader_get_current_type (&array) == DBUS_TYPE_INVALID); + _dbus_assert (i == n_elements); + _dbus_assert (str_array[i] == NULL); + + *str_array_p = str_array; + *n_elements_p = n_elements; + } +#ifndef DBUS_DISABLE_CHECKS + else + { + _dbus_warn ("you can't read arrays of container types (struct, variant, array) with %s for now\n", + _DBUS_FUNCTION_NAME); + goto out; + } +#endif + } +#ifndef DBUS_DISABLE_CHECKS + else + { + _dbus_warn ("you can only read arrays and basic types with %s for now\n", + _DBUS_FUNCTION_NAME); + goto out; + } +#endif + + spec_type = va_arg (var_args, int); + if (!_dbus_type_reader_next (&real->u.reader) && spec_type != DBUS_TYPE_INVALID) + { + dbus_set_error (error, DBUS_ERROR_INVALID_ARGS, + "Message has only %d arguments, but more were expected", i); + goto out; + } + + i++; + } + + retval = TRUE; + + out: + + return retval; +} + +/** @} */ + +/** + * @defgroup DBusMessage DBusMessage + * @ingroup DBus + * @brief Message to be sent or received over a #DBusConnection. + * + * A DBusMessage is the most basic unit of communication over a + * DBusConnection. A DBusConnection represents a stream of messages + * received from a remote application, and a stream of messages + * sent to a remote application. + * + * A message has a message type, returned from + * dbus_message_get_type(). This indicates whether the message is a + * method call, a reply to a method call, a signal, or an error reply. + * + * A message has header fields such as the sender, destination, method + * or signal name, and so forth. DBusMessage has accessor functions for + * these, such as dbus_message_get_member(). + * + * Convenience functions dbus_message_is_method_call(), dbus_message_is_signal(), + * and dbus_message_is_error() check several header fields at once and are + * slightly more efficient than checking the header fields with individual + * accessor functions. + * + * Finally, a message has arguments. The number and types of arguments + * are in the message's signature header field (accessed with + * dbus_message_get_signature()). Simple argument values are usually + * retrieved with dbus_message_get_args() but more complex values such + * as structs may require the use of #DBusMessageIter. + * + * The D-Bus specification goes into some more detail about header fields and + * message types. + * + * @{ + */ + +/** + * @typedef DBusMessage + * + * Opaque data type representing a message received from or to be + * sent to another application. + */ + +/** + * Returns the serial of a message or 0 if none has been specified. + * The message's serial number is provided by the application sending + * the message and is used to identify replies to this message. + * + * All messages received on a connection will have a serial provided + * by the remote application. + * + * For messages you're sending, dbus_connection_send() will assign a + * serial and return it to you. + * + * @param message the message + * @returns the serial + */ +dbus_uint32_t +dbus_message_get_serial (DBusMessage *message) +{ + _dbus_return_val_if_fail (message != NULL, 0); + + return _dbus_header_get_serial (&message->header); +} + +/** + * Sets the reply serial of a message (the serial of the message this + * is a reply to). + * + * @param message the message + * @param reply_serial the serial we're replying to + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_set_reply_serial (DBusMessage *message, + dbus_uint32_t reply_serial) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (!message->locked, FALSE); + _dbus_return_val_if_fail (reply_serial != 0, FALSE); /* 0 is invalid */ + + return _dbus_header_set_field_basic (&message->header, + DBUS_HEADER_FIELD_REPLY_SERIAL, + DBUS_TYPE_UINT32, + &reply_serial); +} + +/** + * Returns the serial that the message is a reply to or 0 if none. + * + * @param message the message + * @returns the reply serial + */ +dbus_uint32_t +dbus_message_get_reply_serial (DBusMessage *message) +{ + dbus_uint32_t v_UINT32; + + _dbus_return_val_if_fail (message != NULL, 0); + + if (_dbus_header_get_field_basic (&message->header, + DBUS_HEADER_FIELD_REPLY_SERIAL, + DBUS_TYPE_UINT32, + &v_UINT32)) + return v_UINT32; + else + return 0; +} + +static void +dbus_message_finalize (DBusMessage *message) +{ + _dbus_assert (message->refcount.value == 0); + + /* This calls application callbacks! */ + _dbus_data_slot_list_free (&message->slot_list); + + _dbus_list_foreach (&message->size_counters, + free_size_counter, message); + _dbus_list_clear (&message->size_counters); + + _dbus_header_free (&message->header); + _dbus_string_free (&message->body); + + _dbus_assert (message->refcount.value == 0); + + dbus_free (message); +} + +static DBusMessage* +dbus_message_new_empty_header (void) +{ + DBusMessage *message; + dbus_bool_t from_cache; + + message = dbus_message_get_cached (); + + if (message != NULL) + { + from_cache = TRUE; + } + else + { + from_cache = FALSE; + message = dbus_new (DBusMessage, 1); + if (message == NULL) + return NULL; +#ifndef DBUS_DISABLE_CHECKS + message->generation = _dbus_current_generation; +#endif + } + + message->refcount.value = 1; + message->byte_order = DBUS_COMPILER_BYTE_ORDER; + message->locked = FALSE; +#ifndef DBUS_DISABLE_CHECKS + message->in_cache = FALSE; +#endif + message->size_counters = NULL; + message->size_counter_delta = 0; + message->changed_stamp = 0; + + if (!from_cache) + _dbus_data_slot_list_init (&message->slot_list); + + if (from_cache) + { + _dbus_header_reinit (&message->header, message->byte_order); + _dbus_string_set_length (&message->body, 0); + } + else + { + if (!_dbus_header_init (&message->header, message->byte_order)) + { + dbus_free (message); + return NULL; + } + + if (!_dbus_string_init_preallocated (&message->body, 32)) + { + _dbus_header_free (&message->header); + dbus_free (message); + return NULL; + } + } + + return message; +} + +/** + * Constructs a new message of the given message type. + * Types include #DBUS_MESSAGE_TYPE_METHOD_CALL, + * #DBUS_MESSAGE_TYPE_SIGNAL, and so forth. + * + * Usually you want to use dbus_message_new_method_call(), + * dbus_message_new_method_return(), dbus_message_new_signal(), + * or dbus_message_new_error() instead. + * + * @param message_type type of message + * @returns new message or #NULL if no memory + */ +DBusMessage* +dbus_message_new (int message_type) +{ + DBusMessage *message; + + _dbus_return_val_if_fail (message_type != DBUS_MESSAGE_TYPE_INVALID, NULL); + + message = dbus_message_new_empty_header (); + if (message == NULL) + return NULL; + + if (!_dbus_header_create (&message->header, + message_type, + NULL, NULL, NULL, NULL, NULL)) + { + dbus_message_unref (message); + return NULL; + } + + return message; +} + +/** + * Constructs a new message to invoke a method on a remote + * object. Returns #NULL if memory can't be allocated for the + * message. The destination may be #NULL in which case no destination + * is set; this is appropriate when using D-Bus in a peer-to-peer + * context (no message bus). The interface may be #NULL, which means + * that if multiple methods with the given name exist it is undefined + * which one will be invoked. + * + * The path and method names may not be #NULL. + * + * Destination, path, interface, and method name can't contain + * any invalid characters (see the D-Bus specification). + * + * @param destination name that the message should be sent to or #NULL + * @param path object path the message should be sent to + * @param interface interface to invoke method on, or #NULL + * @param method method to invoke + * + * @returns a new DBusMessage, free with dbus_message_unref() + */ +DBusMessage* +dbus_message_new_method_call (const char *destination, + const char *path, + const char *interface, + const char *method) +{ + DBusMessage *message; + + _dbus_return_val_if_fail (path != NULL, NULL); + _dbus_return_val_if_fail (method != NULL, NULL); + _dbus_return_val_if_fail (destination == NULL || + _dbus_check_is_valid_bus_name (destination), NULL); + _dbus_return_val_if_fail (_dbus_check_is_valid_path (path), NULL); + _dbus_return_val_if_fail (interface == NULL || + _dbus_check_is_valid_interface (interface), NULL); + _dbus_return_val_if_fail (_dbus_check_is_valid_member (method), NULL); + + message = dbus_message_new_empty_header (); + if (message == NULL) + return NULL; + + if (!_dbus_header_create (&message->header, + DBUS_MESSAGE_TYPE_METHOD_CALL, + destination, path, interface, method, NULL)) + { + dbus_message_unref (message); + return NULL; + } + + return message; +} + +/** + * Constructs a message that is a reply to a method call. Returns + * #NULL if memory can't be allocated for the message. + * + * @param method_call the message being replied to + * @returns a new DBusMessage, free with dbus_message_unref() + */ +DBusMessage* +dbus_message_new_method_return (DBusMessage *method_call) +{ + DBusMessage *message; + const char *sender; + + _dbus_return_val_if_fail (method_call != NULL, NULL); + + sender = dbus_message_get_sender (method_call); + + /* sender is allowed to be null here in peer-to-peer case */ + + message = dbus_message_new_empty_header (); + if (message == NULL) + return NULL; + + if (!_dbus_header_create (&message->header, + DBUS_MESSAGE_TYPE_METHOD_RETURN, + sender, NULL, NULL, NULL, NULL)) + { + dbus_message_unref (message); + return NULL; + } + + dbus_message_set_no_reply (message, TRUE); + + if (!dbus_message_set_reply_serial (message, + dbus_message_get_serial (method_call))) + { + dbus_message_unref (message); + return NULL; + } + + return message; +} + +/** + * Constructs a new message representing a signal emission. Returns + * #NULL if memory can't be allocated for the message. A signal is + * identified by its originating object path, interface, and the name + * of the signal. + * + * Path, interface, and signal name must all be valid (the D-Bus + * specification defines the syntax of these fields). + * + * @param path the path to the object emitting the signal + * @param interface the interface the signal is emitted from + * @param name name of the signal + * @returns a new DBusMessage, free with dbus_message_unref() + */ +DBusMessage* +dbus_message_new_signal (const char *path, + const char *interface, + const char *name) +{ + DBusMessage *message; + + _dbus_return_val_if_fail (path != NULL, NULL); + _dbus_return_val_if_fail (interface != NULL, NULL); + _dbus_return_val_if_fail (name != NULL, NULL); + _dbus_return_val_if_fail (_dbus_check_is_valid_path (path), NULL); + _dbus_return_val_if_fail (_dbus_check_is_valid_interface (interface), NULL); + _dbus_return_val_if_fail (_dbus_check_is_valid_member (name), NULL); + + message = dbus_message_new_empty_header (); + if (message == NULL) + return NULL; + + if (!_dbus_header_create (&message->header, + DBUS_MESSAGE_TYPE_SIGNAL, + NULL, path, interface, name, NULL)) + { + dbus_message_unref (message); + return NULL; + } + + dbus_message_set_no_reply (message, TRUE); + + return message; +} + +/** + * Creates a new message that is an error reply to another message. + * Error replies are most common in response to method calls, but + * can be returned in reply to any message. + * + * The error name must be a valid error name according to the syntax + * given in the D-Bus specification. If you don't want to make + * up an error name just use #DBUS_ERROR_FAILED. + * + * @param reply_to the message we're replying to + * @param error_name the error name + * @param error_message the error message string (or #NULL for none, but please give a message) + * @returns a new error message object, free with dbus_message_unref() + */ +DBusMessage* +dbus_message_new_error (DBusMessage *reply_to, + const char *error_name, + const char *error_message) +{ + DBusMessage *message; + const char *sender; + DBusMessageIter iter; + + _dbus_return_val_if_fail (reply_to != NULL, NULL); + _dbus_return_val_if_fail (error_name != NULL, NULL); + _dbus_return_val_if_fail (_dbus_check_is_valid_error_name (error_name), NULL); + + sender = dbus_message_get_sender (reply_to); + + /* sender may be NULL for non-message-bus case or + * when the message bus is dealing with an unregistered + * connection. + */ + message = dbus_message_new_empty_header (); + if (message == NULL) + return NULL; + + if (!_dbus_header_create (&message->header, + DBUS_MESSAGE_TYPE_ERROR, + sender, NULL, NULL, NULL, error_name)) + { + dbus_message_unref (message); + return NULL; + } + + dbus_message_set_no_reply (message, TRUE); + + if (!dbus_message_set_reply_serial (message, + dbus_message_get_serial (reply_to))) + { + dbus_message_unref (message); + return NULL; + } + + if (error_message != NULL) + { + dbus_message_iter_init_append (message, &iter); + if (!dbus_message_iter_append_basic (&iter, + DBUS_TYPE_STRING, + &error_message)) + { + dbus_message_unref (message); + return NULL; + } + } + + return message; +} + +/** + * Creates a new message that is an error reply to another message, allowing + * you to use printf formatting. + * + * See dbus_message_new_error() for details - this function is the same + * aside from the printf formatting. + * + * @todo add _DBUS_GNUC_PRINTF to this (requires moving _DBUS_GNUC_PRINTF to + * public header, see DBUS_DEPRECATED for an example) + * + * @param reply_to the original message + * @param error_name the error name + * @param error_format the error message format as with printf + * @param ... format string arguments + * @returns a new error message + */ +DBusMessage* +dbus_message_new_error_printf (DBusMessage *reply_to, + const char *error_name, + const char *error_format, + ...) +{ + va_list args; + DBusString str; + DBusMessage *message; + + _dbus_return_val_if_fail (reply_to != NULL, NULL); + _dbus_return_val_if_fail (error_name != NULL, NULL); + _dbus_return_val_if_fail (_dbus_check_is_valid_error_name (error_name), NULL); + + if (!_dbus_string_init (&str)) + return NULL; + + va_start (args, error_format); + + if (_dbus_string_append_printf_valist (&str, error_format, args)) + message = dbus_message_new_error (reply_to, error_name, + _dbus_string_get_const_data (&str)); + else + message = NULL; + + _dbus_string_free (&str); + + va_end (args); + + return message; +} + + +/** + * Creates a new message that is an exact replica of the message + * specified, except that its refcount is set to 1, its message serial + * is reset to 0, and if the original message was "locked" (in the + * outgoing message queue and thus not modifiable) the new message + * will not be locked. + * + * @param message the message + * @returns the new message.or #NULL if not enough memory + */ +DBusMessage * +dbus_message_copy (const DBusMessage *message) +{ + DBusMessage *retval; + + _dbus_return_val_if_fail (message != NULL, NULL); + + retval = dbus_new0 (DBusMessage, 1); + if (retval == NULL) + return NULL; + + retval->refcount.value = 1; + retval->byte_order = message->byte_order; + retval->locked = FALSE; +#ifndef DBUS_DISABLE_CHECKS + retval->generation = message->generation; +#endif + + if (!_dbus_header_copy (&message->header, &retval->header)) + { + dbus_free (retval); + return NULL; + } + + if (!_dbus_string_init_preallocated (&retval->body, + _dbus_string_get_length (&message->body))) + { + _dbus_header_free (&retval->header); + dbus_free (retval); + return NULL; + } + + if (!_dbus_string_copy (&message->body, 0, + &retval->body, 0)) + goto failed_copy; + + return retval; + + failed_copy: + _dbus_header_free (&retval->header); + _dbus_string_free (&retval->body); + dbus_free (retval); + + return NULL; +} + + +/** + * Increments the reference count of a DBusMessage. + * + * @param message the message + * @returns the message + * @see dbus_message_unref + */ +DBusMessage * +dbus_message_ref (DBusMessage *message) +{ + dbus_int32_t old_refcount; + + _dbus_return_val_if_fail (message != NULL, NULL); + _dbus_return_val_if_fail (message->generation == _dbus_current_generation, NULL); + _dbus_return_val_if_fail (!message->in_cache, NULL); + + old_refcount = _dbus_atomic_inc (&message->refcount); + _dbus_assert (old_refcount >= 1); + + return message; +} + +/** + * Decrements the reference count of a DBusMessage, freeing the + * message if the count reaches 0. + * + * @param message the message + * @see dbus_message_ref + */ +void +dbus_message_unref (DBusMessage *message) +{ + dbus_int32_t old_refcount; + + _dbus_return_if_fail (message != NULL); + _dbus_return_if_fail (message->generation == _dbus_current_generation); + _dbus_return_if_fail (!message->in_cache); + + old_refcount = _dbus_atomic_dec (&message->refcount); + + _dbus_assert (old_refcount >= 0); + + if (old_refcount == 1) + { + /* Calls application callbacks! */ + dbus_message_cache_or_finalize (message); + } +} + +/** + * Gets the type of a message. Types include + * #DBUS_MESSAGE_TYPE_METHOD_CALL, #DBUS_MESSAGE_TYPE_METHOD_RETURN, + * #DBUS_MESSAGE_TYPE_ERROR, #DBUS_MESSAGE_TYPE_SIGNAL, but other + * types are allowed and all code must silently ignore messages of + * unknown type. #DBUS_MESSAGE_TYPE_INVALID will never be returned. + * + * @param message the message + * @returns the type of the message + */ +int +dbus_message_get_type (DBusMessage *message) +{ + _dbus_return_val_if_fail (message != NULL, DBUS_MESSAGE_TYPE_INVALID); + + return _dbus_header_get_message_type (&message->header); +} + +/** + * Appends fields to a message given a variable argument list. The + * variable argument list should contain the type of each argument + * followed by the value to append. Appendable types are basic types, + * and arrays of fixed-length basic types. To append variable-length + * basic types, or any more complex value, you have to use an iterator + * rather than this function. + * + * To append a basic type, specify its type code followed by the + * address of the value. For example: + * + * @code + * + * dbus_int32_t v_INT32 = 42; + * const char *v_STRING = "Hello World"; + * dbus_message_append_args (message, + * DBUS_TYPE_INT32, &v_INT32, + * DBUS_TYPE_STRING, &v_STRING, + * DBUS_TYPE_INVALID); + * @endcode + * + * To append an array of fixed-length basic types, pass in the + * DBUS_TYPE_ARRAY typecode, the element typecode, the address of + * the array pointer, and a 32-bit integer giving the number of + * elements in the array. So for example: + * @code + * const dbus_int32_t array[] = { 1, 2, 3 }; + * const dbus_int32_t *v_ARRAY = array; + * dbus_message_append_args (message, + * DBUS_TYPE_ARRAY, DBUS_TYPE_INT32, &v_ARRAY, 3, + * DBUS_TYPE_INVALID); + * @endcode + * + * @warning in C, given "int array[]", "&array == array" (the + * comp.lang.c FAQ says otherwise, but gcc and the FAQ don't agree). + * So if you're using an array instead of a pointer you have to create + * a pointer variable, assign the array to it, then take the address + * of the pointer variable. For strings it works to write + * const char *array = "Hello" and then use &array though. + * + * The last argument to this function must be #DBUS_TYPE_INVALID, + * marking the end of the argument list. If you don't do this + * then libdbus won't know to stop and will read invalid memory. + * + * String/signature/path arrays should be passed in as "const char*** + * address_of_array" and "int n_elements" + * + * @todo support DBUS_TYPE_STRUCT and DBUS_TYPE_VARIANT and complex arrays + * + * @todo If this fails due to lack of memory, the message is hosed and + * you have to start over building the whole message. + * + * @param message the message + * @param first_arg_type type of the first argument + * @param ... value of first argument, list of additional type-value pairs + * @returns #TRUE on success + */ +dbus_bool_t +dbus_message_append_args (DBusMessage *message, + int first_arg_type, + ...) +{ + dbus_bool_t retval; + va_list var_args; + + _dbus_return_val_if_fail (message != NULL, FALSE); + + va_start (var_args, first_arg_type); + retval = dbus_message_append_args_valist (message, + first_arg_type, + var_args); + va_end (var_args); + + return retval; +} + +/** + * Like dbus_message_append_args() but takes a va_list for use by language bindings. + * + * @todo for now, if this function fails due to OOM it will leave + * the message half-written and you have to discard the message + * and start over. + * + * @see dbus_message_append_args. + * @param message the message + * @param first_arg_type type of first argument + * @param var_args value of first argument, then list of type/value pairs + * @returns #TRUE on success + */ +dbus_bool_t +dbus_message_append_args_valist (DBusMessage *message, + int first_arg_type, + va_list var_args) +{ + int type; + DBusMessageIter iter; + + _dbus_return_val_if_fail (message != NULL, FALSE); + + type = first_arg_type; + + dbus_message_iter_init_append (message, &iter); + + while (type != DBUS_TYPE_INVALID) + { + if (dbus_type_is_basic (type)) + { + const DBusBasicValue *value; + value = va_arg (var_args, const DBusBasicValue*); + + if (!dbus_message_iter_append_basic (&iter, + type, + value)) + goto failed; + } + else if (type == DBUS_TYPE_ARRAY) + { + int element_type; + DBusMessageIter array; + char buf[2]; + + element_type = va_arg (var_args, int); + + buf[0] = element_type; + buf[1] = '\0'; + if (!dbus_message_iter_open_container (&iter, + DBUS_TYPE_ARRAY, + buf, + &array)) + goto failed; + + if (dbus_type_is_fixed (element_type)) + { + const DBusBasicValue **value; + int n_elements; + + value = va_arg (var_args, const DBusBasicValue**); + n_elements = va_arg (var_args, int); + + if (!dbus_message_iter_append_fixed_array (&array, + element_type, + value, + n_elements)) + goto failed; + } + else if (element_type == DBUS_TYPE_STRING || + element_type == DBUS_TYPE_SIGNATURE || + element_type == DBUS_TYPE_OBJECT_PATH) + { + const char ***value_p; + const char **value; + int n_elements; + int i; + + value_p = va_arg (var_args, const char***); + n_elements = va_arg (var_args, int); + + value = *value_p; + + i = 0; + while (i < n_elements) + { + if (!dbus_message_iter_append_basic (&array, + element_type, + &value[i])) + goto failed; + ++i; + } + } + else + { + _dbus_warn ("arrays of %s can't be appended with %s for now\n", + _dbus_type_to_string (element_type), + _DBUS_FUNCTION_NAME); + goto failed; + } + + if (!dbus_message_iter_close_container (&iter, &array)) + goto failed; + } +#ifndef DBUS_DISABLE_CHECKS + else + { + _dbus_warn ("type %s isn't supported yet in %s\n", + _dbus_type_to_string (type), _DBUS_FUNCTION_NAME); + goto failed; + } +#endif + + type = va_arg (var_args, int); + } + + return TRUE; + + failed: + return FALSE; +} + +/** + * Gets arguments from a message given a variable argument list. The + * supported types include those supported by + * dbus_message_append_args(); that is, basic types and arrays of + * fixed-length basic types. The arguments are the same as they would + * be for dbus_message_iter_get_basic() or + * dbus_message_iter_get_fixed_array(). + * + * In addition to those types, arrays of string, object path, and + * signature are supported; but these are returned as allocated memory + * and must be freed with dbus_free_string_array(), while the other + * types are returned as const references. To get a string array + * pass in "char ***array_location" and "int *n_elements" + * + * The variable argument list should contain the type of the argument + * followed by a pointer to where the value should be stored. The list + * is terminated with #DBUS_TYPE_INVALID. + * + * Except for string arrays, the returned values are constant; do not + * free them. They point into the #DBusMessage. + * + * If the requested arguments are not present, or do not have the + * requested types, then an error will be set. + * + * If more arguments than requested are present, the requested + * arguments are returned and the extra arguments are ignored. + * + * @todo support DBUS_TYPE_STRUCT and DBUS_TYPE_VARIANT and complex arrays + * + * @param message the message + * @param error error to be filled in on failure + * @param first_arg_type the first argument type + * @param ... location for first argument value, then list of type-location pairs + * @returns #FALSE if the error was set + */ +dbus_bool_t +dbus_message_get_args (DBusMessage *message, + DBusError *error, + int first_arg_type, + ...) +{ + dbus_bool_t retval; + va_list var_args; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_error_is_set (error, FALSE); + + va_start (var_args, first_arg_type); + retval = dbus_message_get_args_valist (message, error, first_arg_type, var_args); + va_end (var_args); + + return retval; +} + +/** + * Like dbus_message_get_args but takes a va_list for use by language bindings. + * + * @see dbus_message_get_args + * @param message the message + * @param error error to be filled in + * @param first_arg_type type of the first argument + * @param var_args return location for first argument, followed by list of type/location pairs + * @returns #FALSE if error was set + */ +dbus_bool_t +dbus_message_get_args_valist (DBusMessage *message, + DBusError *error, + int first_arg_type, + va_list var_args) +{ + DBusMessageIter iter; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_error_is_set (error, FALSE); + + dbus_message_iter_init (message, &iter); + return _dbus_message_iter_get_args_valist (&iter, error, first_arg_type, var_args); +} + +static void +_dbus_message_iter_init_common (DBusMessage *message, + DBusMessageRealIter *real, + int iter_type) +{ + _dbus_assert (sizeof (DBusMessageRealIter) <= sizeof (DBusMessageIter)); + + /* Since the iterator will read or write who-knows-what from the + * message, we need to get in the right byte order + */ + ensure_byte_order (message); + + real->message = message; + real->changed_stamp = message->changed_stamp; + real->iter_type = iter_type; + real->sig_refcount = 0; +} + +/** + * Initializes a #DBusMessageIter for reading the arguments of the + * message passed in. + * + * When possible, dbus_message_get_args() is much more convenient. + * Some types of argument can only be read with #DBusMessageIter + * however. + * + * The easiest way to iterate is like this: + * @code + * dbus_message_iter_init (message, &iter); + * while ((current_type = dbus_message_iter_get_arg_type (&iter)) != DBUS_TYPE_INVALID) + * dbus_message_iter_next (&iter); + * @endcode + * + * #DBusMessageIter contains no allocated memory; it need not be + * freed, and can be copied by assignment or memcpy(). + * + * @param message the message + * @param iter pointer to an iterator to initialize + * @returns #FALSE if the message has no arguments + */ +dbus_bool_t +dbus_message_iter_init (DBusMessage *message, + DBusMessageIter *iter) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + const DBusString *type_str; + int type_pos; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (iter != NULL, FALSE); + + get_const_signature (&message->header, &type_str, &type_pos); + + _dbus_message_iter_init_common (message, real, + DBUS_MESSAGE_ITER_TYPE_READER); + + _dbus_type_reader_init (&real->u.reader, + message->byte_order, + type_str, type_pos, + &message->body, + 0); + + return _dbus_type_reader_get_current_type (&real->u.reader) != DBUS_TYPE_INVALID; +} + +/** + * Checks if an iterator has any more fields. + * + * @param iter the message iter + * @returns #TRUE if there are more fields following + */ +dbus_bool_t +dbus_message_iter_has_next (DBusMessageIter *iter) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + + _dbus_return_val_if_fail (_dbus_message_iter_check (real), FALSE); + _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, FALSE); + + return _dbus_type_reader_has_next (&real->u.reader); +} + +/** + * Moves the iterator to the next field, if any. If there's no next + * field, returns #FALSE. If the iterator moves forward, returns + * #TRUE. + * + * @param iter the message iter + * @returns #TRUE if the iterator was moved to the next field + */ +dbus_bool_t +dbus_message_iter_next (DBusMessageIter *iter) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + + _dbus_return_val_if_fail (_dbus_message_iter_check (real), FALSE); + _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, FALSE); + + return _dbus_type_reader_next (&real->u.reader); +} + +/** + * Returns the argument type of the argument that the message iterator + * points to. If the iterator is at the end of the message, returns + * #DBUS_TYPE_INVALID. You can thus write a loop as follows: + * + * @code + * dbus_message_iter_init (&iter); + * while ((current_type = dbus_message_iter_get_arg_type (&iter)) != DBUS_TYPE_INVALID) + * dbus_message_iter_next (&iter); + * @endcode + * + * @param iter the message iter + * @returns the argument type + */ +int +dbus_message_iter_get_arg_type (DBusMessageIter *iter) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + + _dbus_return_val_if_fail (_dbus_message_iter_check (real), DBUS_TYPE_INVALID); + _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, FALSE); + + return _dbus_type_reader_get_current_type (&real->u.reader); +} + +/** + * Returns the element type of the array that the message iterator + * points to. Note that you need to check that the iterator points to + * an array prior to using this function. + * + * @param iter the message iter + * @returns the array element type + */ +int +dbus_message_iter_get_element_type (DBusMessageIter *iter) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + + _dbus_return_val_if_fail (_dbus_message_iter_check (real), DBUS_TYPE_INVALID); + _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_READER, DBUS_TYPE_INVALID); + _dbus_return_val_if_fail (dbus_message_iter_get_arg_type (iter) == DBUS_TYPE_ARRAY, DBUS_TYPE_INVALID); + + return _dbus_type_reader_get_element_type (&real->u.reader); +} + +/** + * Recurses into a container value when reading values from a message, + * initializing a sub-iterator to use for traversing the child values + * of the container. + * + * Note that this recurses into a value, not a type, so you can only + * recurse if the value exists. The main implication of this is that + * if you have for example an empty array of array of int32, you can + * recurse into the outermost array, but it will have no values, so + * you won't be able to recurse further. There's no array of int32 to + * recurse into. + * + * If a container is an array of fixed-length types, it is much more + * efficient to use dbus_message_iter_get_fixed_array() to get the + * whole array in one shot, rather than individually walking over the + * array elements. + * + * Be sure you have somehow checked that + * dbus_message_iter_get_arg_type() matches the type you are expecting + * to recurse into. Results of this function are undefined if there is + * no container to recurse into at the current iterator position. + * + * @param iter the message iterator + * @param sub the sub-iterator to initialize + */ +void +dbus_message_iter_recurse (DBusMessageIter *iter, + DBusMessageIter *sub) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub; + + _dbus_return_if_fail (_dbus_message_iter_check (real)); + _dbus_return_if_fail (sub != NULL); + + *real_sub = *real; + _dbus_type_reader_recurse (&real->u.reader, &real_sub->u.reader); +} + +/** + * Returns the current signature of a message iterator. This + * is useful primarily for dealing with variants; one can + * recurse into a variant and determine the signature of + * the variant's value. + * + * The returned string must be freed with dbus_free(). + * + * @param iter the message iterator + * @returns the contained signature, or NULL if out of memory + */ +char * +dbus_message_iter_get_signature (DBusMessageIter *iter) +{ + const DBusString *sig; + DBusString retstr; + char *ret; + int start, len; + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + + _dbus_return_val_if_fail (_dbus_message_iter_check (real), NULL); + + if (!_dbus_string_init (&retstr)) + return NULL; + + _dbus_type_reader_get_signature (&real->u.reader, &sig, + &start, &len); + if (!_dbus_string_append_len (&retstr, + _dbus_string_get_const_data (sig) + start, + len)) + return NULL; + if (!_dbus_string_steal_data (&retstr, &ret)) + return NULL; + _dbus_string_free (&retstr); + return ret; +} + +/** + * Reads a basic-typed value from the message iterator. + * Basic types are the non-containers such as integer and string. + * + * The value argument should be the address of a location to store + * the returned value. So for int32 it should be a "dbus_int32_t*" + * and for string a "const char**". The returned value is + * by reference and should not be freed. + * + * Be sure you have somehow checked that + * dbus_message_iter_get_arg_type() matches the type you are + * expecting, or you'll crash when you try to use an integer as a + * string or something. + * + * To read any container type (array, struct, dict) you will need + * to recurse into the container with dbus_message_iter_recurse(). + * If the container is an array of fixed-length values, you can + * get all the array elements at once with + * dbus_message_iter_get_fixed_array(). Otherwise, you have to + * iterate over the container's contents one value at a time. + * + * All basic-typed values are guaranteed to fit in 8 bytes. So you can + * write code like this: + * + * @code + * dbus_uint64_t value; + * int type; + * dbus_message_iter_get_basic (&read_iter, &value); + * type = dbus_message_iter_get_arg_type (&read_iter); + * dbus_message_iter_append_basic (&write_iter, type, &value); + * @endcode + * + * On some really obscure platforms dbus_uint64_t might not exist, if + * you need to worry about this you will know. dbus_uint64_t is just + * one example of a type that's large enough to hold any possible + * value, you could use a struct or char[8] instead if you like. + * + * @param iter the iterator + * @param value location to store the value + */ +void +dbus_message_iter_get_basic (DBusMessageIter *iter, + void *value) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + + _dbus_return_if_fail (_dbus_message_iter_check (real)); + _dbus_return_if_fail (value != NULL); + + _dbus_type_reader_read_basic (&real->u.reader, + value); +} + +/** + * Returns the number of bytes in the array as marshaled in the wire + * protocol. The iterator must currently be inside an array-typed + * value. + * + * This function is deprecated on the grounds that it is stupid. Why + * would you want to know how many bytes are in the array as marshaled + * in the wire protocol? For now, use the n_elements returned from + * dbus_message_iter_get_fixed_array() instead, or iterate over the + * array values and count them. + * + * @todo introduce a variant of this get_n_elements that returns + * the number of elements, though with a non-fixed array it will not + * be very efficient, so maybe it's not good. + * + * @param iter the iterator + * @returns the number of bytes in the array + */ +int +dbus_message_iter_get_array_len (DBusMessageIter *iter) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + + _dbus_return_val_if_fail (_dbus_message_iter_check (real), 0); + + return _dbus_type_reader_get_array_length (&real->u.reader); +} + +/** + * Reads a block of fixed-length values from the message iterator. + * Fixed-length values are those basic types that are not string-like, + * such as integers, bool, double. The returned block will be from the + * current position in the array until the end of the array. + * + * The message iter should be "in" the array (that is, you recurse into the + * array, and then you call dbus_message_iter_get_fixed_array() on the + * "sub-iterator" created by dbus_message_iter_recurse()). + * + * The value argument should be the address of a location to store the + * returned array. So for int32 it should be a "const dbus_int32_t**" + * The returned value is by reference and should not be freed. + * + * This function should only be used if dbus_type_is_fixed() returns + * #TRUE for the element type. + * + * If an array's elements are not fixed in size, you have to recurse + * into the array with dbus_message_iter_recurse() and read the + * elements one by one. + * + * Because the array is not copied, this function runs in constant + * time and is fast; it's much preferred over walking the entire array + * with an iterator. (However, you can always use + * dbus_message_iter_recurse(), even for fixed-length types; + * dbus_message_iter_get_fixed_array() is just an optimization.) + * + * @param iter the iterator + * @param value location to store the block + * @param n_elements number of elements in the block + */ +void +dbus_message_iter_get_fixed_array (DBusMessageIter *iter, + void *value, + int *n_elements) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + int subtype = _dbus_type_reader_get_current_type(&real->u.reader); + + _dbus_return_if_fail (_dbus_message_iter_check (real)); + _dbus_return_if_fail (value != NULL); + _dbus_return_if_fail ((subtype == DBUS_TYPE_INVALID) || + dbus_type_is_fixed (subtype)); + + _dbus_type_reader_read_fixed_multi (&real->u.reader, + value, n_elements); +} + +/** + * Initializes a #DBusMessageIter for appending arguments to the end + * of a message. + * + * @todo If appending any of the arguments fails due to lack of + * memory, the message is hosed and you have to start over building + * the whole message. + * + * @param message the message + * @param iter pointer to an iterator to initialize + */ +void +dbus_message_iter_init_append (DBusMessage *message, + DBusMessageIter *iter) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + + _dbus_return_if_fail (message != NULL); + _dbus_return_if_fail (iter != NULL); + + _dbus_message_iter_init_common (message, real, + DBUS_MESSAGE_ITER_TYPE_WRITER); + + /* We create the signature string and point iterators at it "on demand" + * when a value is actually appended. That means that init() never fails + * due to OOM. + */ + _dbus_type_writer_init_types_delayed (&real->u.writer, + message->byte_order, + &message->body, + _dbus_string_get_length (&message->body)); +} + +/** + * Creates a temporary signature string containing the current + * signature, stores it in the iterator, and points the iterator to + * the end of it. Used any time we write to the message. + * + * @param real an iterator without a type_str + * @returns #FALSE if no memory + */ +static dbus_bool_t +_dbus_message_iter_open_signature (DBusMessageRealIter *real) +{ + DBusString *str; + const DBusString *current_sig; + int current_sig_pos; + + _dbus_assert (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER); + + if (real->u.writer.type_str != NULL) + { + _dbus_assert (real->sig_refcount > 0); + real->sig_refcount += 1; + return TRUE; + } + + str = dbus_new (DBusString, 1); + if (str == NULL) + return FALSE; + + if (!_dbus_header_get_field_raw (&real->message->header, + DBUS_HEADER_FIELD_SIGNATURE, + ¤t_sig, ¤t_sig_pos)) + current_sig = NULL; + + if (current_sig) + { + int current_len; + + current_len = _dbus_string_get_byte (current_sig, current_sig_pos); + current_sig_pos += 1; /* move on to sig data */ + + if (!_dbus_string_init_preallocated (str, current_len + 4)) + { + dbus_free (str); + return FALSE; + } + + if (!_dbus_string_copy_len (current_sig, current_sig_pos, current_len, + str, 0)) + { + _dbus_string_free (str); + dbus_free (str); + return FALSE; + } + } + else + { + if (!_dbus_string_init_preallocated (str, 4)) + { + dbus_free (str); + return FALSE; + } + } + + real->sig_refcount = 1; + + _dbus_type_writer_add_types (&real->u.writer, + str, _dbus_string_get_length (str)); + return TRUE; +} + +/** + * Sets the new signature as the message signature, frees the + * signature string, and marks the iterator as not having a type_str + * anymore. Frees the signature even if it fails, so you can't + * really recover from failure. Kinda busted. + * + * @param real an iterator without a type_str + * @returns #FALSE if no memory + */ +static dbus_bool_t +_dbus_message_iter_close_signature (DBusMessageRealIter *real) +{ + DBusString *str; + const char *v_STRING; + dbus_bool_t retval; + + _dbus_assert (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER); + _dbus_assert (real->u.writer.type_str != NULL); + _dbus_assert (real->sig_refcount > 0); + + real->sig_refcount -= 1; + + if (real->sig_refcount > 0) + return TRUE; + _dbus_assert (real->sig_refcount == 0); + + retval = TRUE; + + str = real->u.writer.type_str; + + v_STRING = _dbus_string_get_const_data (str); + if (!_dbus_header_set_field_basic (&real->message->header, + DBUS_HEADER_FIELD_SIGNATURE, + DBUS_TYPE_SIGNATURE, + &v_STRING)) + retval = FALSE; + + _dbus_type_writer_remove_types (&real->u.writer); + _dbus_string_free (str); + dbus_free (str); + + return retval; +} + +#ifndef DBUS_DISABLE_CHECKS +static dbus_bool_t +_dbus_message_iter_append_check (DBusMessageRealIter *iter) +{ + if (!_dbus_message_iter_check (iter)) + return FALSE; + + if (iter->message->locked) + { + _dbus_warn_check_failed ("dbus append iterator can't be used: message is locked (has already been sent)\n"); + return FALSE; + } + + return TRUE; +} +#endif /* DBUS_DISABLE_CHECKS */ + +/** + * Appends a basic-typed value to the message. The basic types are the + * non-container types such as integer and string. + * + * The "value" argument should be the address of a basic-typed value. + * So for string, const char**. For integer, dbus_int32_t*. + * + * @todo If this fails due to lack of memory, the message is hosed and + * you have to start over building the whole message. + * + * @param iter the append iterator + * @param type the type of the value + * @param value the address of the value + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_iter_append_basic (DBusMessageIter *iter, + int type, + const void *value) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + dbus_bool_t ret; + + _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE); + _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE); + _dbus_return_val_if_fail (dbus_type_is_basic (type), FALSE); + _dbus_return_val_if_fail (value != NULL, FALSE); + + if (!_dbus_message_iter_open_signature (real)) + return FALSE; + + ret = _dbus_type_writer_write_basic (&real->u.writer, type, value); + + if (!_dbus_message_iter_close_signature (real)) + ret = FALSE; + + return ret; +} + +/** + * Appends a block of fixed-length values to an array. The + * fixed-length types are all basic types that are not string-like. So + * int32, double, bool, etc. You must call + * dbus_message_iter_open_container() to open an array of values + * before calling this function. You may call this function multiple + * times (and intermixed with calls to + * dbus_message_iter_append_basic()) for the same array. + * + * The "value" argument should be the address of the array. So for + * integer, "dbus_int32_t**" is expected for example. + * + * @warning in C, given "int array[]", "&array == array" (the + * comp.lang.c FAQ says otherwise, but gcc and the FAQ don't agree). + * So if you're using an array instead of a pointer you have to create + * a pointer variable, assign the array to it, then take the address + * of the pointer variable. + * @code + * const dbus_int32_t array[] = { 1, 2, 3 }; + * const dbus_int32_t *v_ARRAY = array; + * if (!dbus_message_iter_append_fixed_array (&iter, DBUS_TYPE_INT32, &v_ARRAY, 3)) + * fprintf (stderr, "No memory!\n"); + * @endcode + * For strings it works to write const char *array = "Hello" and then + * use &array though. + * + * @todo If this fails due to lack of memory, the message is hosed and + * you have to start over building the whole message. + * + * @param iter the append iterator + * @param element_type the type of the array elements + * @param value the address of the array + * @param n_elements the number of elements to append + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_iter_append_fixed_array (DBusMessageIter *iter, + int element_type, + const void *value, + int n_elements) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + dbus_bool_t ret; + + _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE); + _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE); + _dbus_return_val_if_fail (dbus_type_is_fixed (element_type), FALSE); + _dbus_return_val_if_fail (real->u.writer.container_type == DBUS_TYPE_ARRAY, FALSE); + _dbus_return_val_if_fail (value != NULL, FALSE); + _dbus_return_val_if_fail (n_elements >= 0, FALSE); + _dbus_return_val_if_fail (n_elements <= + DBUS_MAXIMUM_ARRAY_LENGTH / _dbus_type_get_alignment (element_type), + FALSE); + + ret = _dbus_type_writer_write_fixed_multi (&real->u.writer, element_type, value, n_elements); + + return ret; +} + +/** + * Appends a container-typed value to the message; you are required to + * append the contents of the container using the returned + * sub-iterator, and then call + * dbus_message_iter_close_container(). Container types are for + * example struct, variant, and array. For variants, the + * contained_signature should be the type of the single value inside + * the variant. For structs and dict entries, contained_signature + * should be #NULL; it will be set to whatever types you write into + * the struct. For arrays, contained_signature should be the type of + * the array elements. + * + * @todo If this fails due to lack of memory, the message is hosed and + * you have to start over building the whole message. + * + * @param iter the append iterator + * @param type the type of the value + * @param contained_signature the type of container contents + * @param sub sub-iterator to initialize + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_iter_open_container (DBusMessageIter *iter, + int type, + const char *contained_signature, + DBusMessageIter *sub) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub; + DBusString contained_str; + + _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE); + _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE); + _dbus_return_val_if_fail (dbus_type_is_container (type), FALSE); + _dbus_return_val_if_fail (sub != NULL, FALSE); + _dbus_return_val_if_fail ((type == DBUS_TYPE_STRUCT && + contained_signature == NULL) || + (type == DBUS_TYPE_DICT_ENTRY && + contained_signature == NULL) || + (type == DBUS_TYPE_VARIANT && + contained_signature != NULL) || + (type == DBUS_TYPE_ARRAY && + contained_signature != NULL), FALSE); + + /* this would fail if the contained_signature is a dict entry, since + * dict entries are invalid signatures standalone (they must be in + * an array) + */ + _dbus_return_val_if_fail ((type == DBUS_TYPE_ARRAY && contained_signature && *contained_signature == DBUS_DICT_ENTRY_BEGIN_CHAR) || + (contained_signature == NULL || + _dbus_check_is_valid_signature (contained_signature)), + FALSE); + + if (!_dbus_message_iter_open_signature (real)) + return FALSE; + + *real_sub = *real; + + if (contained_signature != NULL) + { + _dbus_string_init_const (&contained_str, contained_signature); + + return _dbus_type_writer_recurse (&real->u.writer, + type, + &contained_str, 0, + &real_sub->u.writer); + } + else + { + return _dbus_type_writer_recurse (&real->u.writer, + type, + NULL, 0, + &real_sub->u.writer); + } +} + + +/** + * Closes a container-typed value appended to the message; may write + * out more information to the message known only after the entire + * container is written, and may free resources created by + * dbus_message_iter_open_container(). + * + * @todo If this fails due to lack of memory, the message is hosed and + * you have to start over building the whole message. + * + * @param iter the append iterator + * @param sub sub-iterator to close + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_iter_close_container (DBusMessageIter *iter, + DBusMessageIter *sub) +{ + DBusMessageRealIter *real = (DBusMessageRealIter *)iter; + DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub; + dbus_bool_t ret; + + _dbus_return_val_if_fail (_dbus_message_iter_append_check (real), FALSE); + _dbus_return_val_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE); + _dbus_return_val_if_fail (_dbus_message_iter_append_check (real_sub), FALSE); + _dbus_return_val_if_fail (real_sub->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER, FALSE); + + ret = _dbus_type_writer_unrecurse (&real->u.writer, + &real_sub->u.writer); + + if (!_dbus_message_iter_close_signature (real)) + ret = FALSE; + + return ret; +} + +/** + * Sets a flag indicating that the message does not want a reply; if + * this flag is set, the other end of the connection may (but is not + * required to) optimize by not sending method return or error + * replies. If this flag is set, there is no way to know whether the + * message successfully arrived at the remote end. Normally you know a + * message was received when you receive the reply to it. + * + * The flag is #FALSE by default, that is by default the other end is + * required to reply. + * + * On the protocol level this toggles #DBUS_HEADER_FLAG_NO_REPLY_EXPECTED + * + * @param message the message + * @param no_reply #TRUE if no reply is desired + */ +void +dbus_message_set_no_reply (DBusMessage *message, + dbus_bool_t no_reply) +{ + _dbus_return_if_fail (message != NULL); + _dbus_return_if_fail (!message->locked); + + _dbus_header_toggle_flag (&message->header, + DBUS_HEADER_FLAG_NO_REPLY_EXPECTED, + no_reply); +} + +/** + * Returns #TRUE if the message does not expect + * a reply. + * + * @param message the message + * @returns #TRUE if the message sender isn't waiting for a reply + */ +dbus_bool_t +dbus_message_get_no_reply (DBusMessage *message) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + + return _dbus_header_get_flag (&message->header, + DBUS_HEADER_FLAG_NO_REPLY_EXPECTED); +} + +/** + * Sets a flag indicating that an owner for the destination name will + * be automatically started before the message is delivered. When this + * flag is set, the message is held until a name owner finishes + * starting up, or fails to start up. In case of failure, the reply + * will be an error. + * + * The flag is set to #TRUE by default, i.e. auto starting is the default. + * + * On the protocol level this toggles #DBUS_HEADER_FLAG_NO_AUTO_START + * + * @param message the message + * @param auto_start #TRUE if auto-starting is desired + */ +void +dbus_message_set_auto_start (DBusMessage *message, + dbus_bool_t auto_start) +{ + _dbus_return_if_fail (message != NULL); + _dbus_return_if_fail (!message->locked); + + _dbus_header_toggle_flag (&message->header, + DBUS_HEADER_FLAG_NO_AUTO_START, + !auto_start); +} + +/** + * Returns #TRUE if the message will cause an owner for + * destination name to be auto-started. + * + * @param message the message + * @returns #TRUE if the message will use auto-start + */ +dbus_bool_t +dbus_message_get_auto_start (DBusMessage *message) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + + return !_dbus_header_get_flag (&message->header, + DBUS_HEADER_FLAG_NO_AUTO_START); +} + + +/** + * Sets the object path this message is being sent to (for + * DBUS_MESSAGE_TYPE_METHOD_CALL) or the one a signal is being + * emitted from (for DBUS_MESSAGE_TYPE_SIGNAL). + * + * The path must contain only valid characters as defined + * in the D-Bus specification. + * + * @param message the message + * @param object_path the path or #NULL to unset + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_set_path (DBusMessage *message, + const char *object_path) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (!message->locked, FALSE); + _dbus_return_val_if_fail (object_path == NULL || + _dbus_check_is_valid_path (object_path), + FALSE); + + return set_or_delete_string_field (message, + DBUS_HEADER_FIELD_PATH, + DBUS_TYPE_OBJECT_PATH, + object_path); +} + +/** + * Gets the object path this message is being sent to (for + * DBUS_MESSAGE_TYPE_METHOD_CALL) or being emitted from (for + * DBUS_MESSAGE_TYPE_SIGNAL). Returns #NULL if none. + * + * See also dbus_message_get_path_decomposed(). + * + * The returned string becomes invalid if the message is + * modified, since it points into the wire-marshaled message data. + * + * @param message the message + * @returns the path (should not be freed) or #NULL + */ +const char* +dbus_message_get_path (DBusMessage *message) +{ + const char *v; + + _dbus_return_val_if_fail (message != NULL, NULL); + + v = NULL; /* in case field doesn't exist */ + _dbus_header_get_field_basic (&message->header, + DBUS_HEADER_FIELD_PATH, + DBUS_TYPE_OBJECT_PATH, + &v); + return v; +} + +/** + * Checks if the message has a particular object path. The object + * path is the destination object for a method call or the emitting + * object for a signal. + * + * @param message the message + * @param path the path name + * @returns #TRUE if there is a path field in the header + */ +dbus_bool_t +dbus_message_has_path (DBusMessage *message, + const char *path) +{ + const char *msg_path; + msg_path = dbus_message_get_path (message); + + if (msg_path == NULL) + { + if (path == NULL) + return TRUE; + else + return FALSE; + } + + if (path == NULL) + return FALSE; + + if (strcmp (msg_path, path) == 0) + return TRUE; + + return FALSE; +} + +/** + * Gets the object path this message is being sent to + * (for DBUS_MESSAGE_TYPE_METHOD_CALL) or being emitted + * from (for DBUS_MESSAGE_TYPE_SIGNAL) in a decomposed + * format (one array element per path component). + * Free the returned array with dbus_free_string_array(). + * + * An empty but non-NULL path array means the path "/". + * So the path "/foo/bar" becomes { "foo", "bar", NULL } + * and the path "/" becomes { NULL }. + * + * See also dbus_message_get_path(). + * + * @todo this could be optimized by using the len from the message + * instead of calling strlen() again + * + * @param message the message + * @param path place to store allocated array of path components; #NULL set here if no path field exists + * @returns #FALSE if no memory to allocate the array + */ +dbus_bool_t +dbus_message_get_path_decomposed (DBusMessage *message, + char ***path) +{ + const char *v; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (path != NULL, FALSE); + + *path = NULL; + + v = dbus_message_get_path (message); + if (v != NULL) + { + if (!_dbus_decompose_path (v, strlen (v), + path, NULL)) + return FALSE; + } + return TRUE; +} + +/** + * Sets the interface this message is being sent to + * (for DBUS_MESSAGE_TYPE_METHOD_CALL) or + * the interface a signal is being emitted from + * (for DBUS_MESSAGE_TYPE_SIGNAL). + * + * The interface name must contain only valid characters as defined + * in the D-Bus specification. + * + * @param message the message + * @param interface the interface or #NULL to unset + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_set_interface (DBusMessage *message, + const char *interface) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (!message->locked, FALSE); + _dbus_return_val_if_fail (interface == NULL || + _dbus_check_is_valid_interface (interface), + FALSE); + + return set_or_delete_string_field (message, + DBUS_HEADER_FIELD_INTERFACE, + DBUS_TYPE_STRING, + interface); +} + +/** + * Gets the interface this message is being sent to + * (for DBUS_MESSAGE_TYPE_METHOD_CALL) or being emitted + * from (for DBUS_MESSAGE_TYPE_SIGNAL). + * The interface name is fully-qualified (namespaced). + * Returns #NULL if none. + * + * The returned string becomes invalid if the message is + * modified, since it points into the wire-marshaled message data. + * + * @param message the message + * @returns the message interface (should not be freed) or #NULL + */ +const char* +dbus_message_get_interface (DBusMessage *message) +{ + const char *v; + + _dbus_return_val_if_fail (message != NULL, NULL); + + v = NULL; /* in case field doesn't exist */ + _dbus_header_get_field_basic (&message->header, + DBUS_HEADER_FIELD_INTERFACE, + DBUS_TYPE_STRING, + &v); + return v; +} + +/** + * Checks if the message has an interface + * + * @param message the message + * @param interface the interface name + * @returns #TRUE if the interface field in the header matches + */ +dbus_bool_t +dbus_message_has_interface (DBusMessage *message, + const char *interface) +{ + const char *msg_interface; + msg_interface = dbus_message_get_interface (message); + + if (msg_interface == NULL) + { + if (interface == NULL) + return TRUE; + else + return FALSE; + } + + if (interface == NULL) + return FALSE; + + if (strcmp (msg_interface, interface) == 0) + return TRUE; + + return FALSE; + +} + +/** + * Sets the interface member being invoked + * (DBUS_MESSAGE_TYPE_METHOD_CALL) or emitted + * (DBUS_MESSAGE_TYPE_SIGNAL). + * + * The member name must contain only valid characters as defined + * in the D-Bus specification. + * + * @param message the message + * @param member the member or #NULL to unset + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_set_member (DBusMessage *message, + const char *member) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (!message->locked, FALSE); + _dbus_return_val_if_fail (member == NULL || + _dbus_check_is_valid_member (member), + FALSE); + + return set_or_delete_string_field (message, + DBUS_HEADER_FIELD_MEMBER, + DBUS_TYPE_STRING, + member); +} + +/** + * Gets the interface member being invoked + * (DBUS_MESSAGE_TYPE_METHOD_CALL) or emitted + * (DBUS_MESSAGE_TYPE_SIGNAL). Returns #NULL if none. + * + * The returned string becomes invalid if the message is + * modified, since it points into the wire-marshaled message data. + * + * @param message the message + * @returns the member name (should not be freed) or #NULL + */ +const char* +dbus_message_get_member (DBusMessage *message) +{ + const char *v; + + _dbus_return_val_if_fail (message != NULL, NULL); + + v = NULL; /* in case field doesn't exist */ + _dbus_header_get_field_basic (&message->header, + DBUS_HEADER_FIELD_MEMBER, + DBUS_TYPE_STRING, + &v); + return v; +} + +/** + * Checks if the message has an interface member + * + * @param message the message + * @param member the member name + * @returns #TRUE if there is a member field in the header + */ +dbus_bool_t +dbus_message_has_member (DBusMessage *message, + const char *member) +{ + const char *msg_member; + msg_member = dbus_message_get_member (message); + + if (msg_member == NULL) + { + if (member == NULL) + return TRUE; + else + return FALSE; + } + + if (member == NULL) + return FALSE; + + if (strcmp (msg_member, member) == 0) + return TRUE; + + return FALSE; + +} + +/** + * Sets the name of the error (DBUS_MESSAGE_TYPE_ERROR). + * The name is fully-qualified (namespaced). + * + * The error name must contain only valid characters as defined + * in the D-Bus specification. + * + * @param message the message + * @param error_name the name or #NULL to unset + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_set_error_name (DBusMessage *message, + const char *error_name) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (!message->locked, FALSE); + _dbus_return_val_if_fail (error_name == NULL || + _dbus_check_is_valid_error_name (error_name), + FALSE); + + return set_or_delete_string_field (message, + DBUS_HEADER_FIELD_ERROR_NAME, + DBUS_TYPE_STRING, + error_name); +} + +/** + * Gets the error name (DBUS_MESSAGE_TYPE_ERROR only) + * or #NULL if none. + * + * The returned string becomes invalid if the message is + * modified, since it points into the wire-marshaled message data. + * + * @param message the message + * @returns the error name (should not be freed) or #NULL + */ +const char* +dbus_message_get_error_name (DBusMessage *message) +{ + const char *v; + + _dbus_return_val_if_fail (message != NULL, NULL); + + v = NULL; /* in case field doesn't exist */ + _dbus_header_get_field_basic (&message->header, + DBUS_HEADER_FIELD_ERROR_NAME, + DBUS_TYPE_STRING, + &v); + return v; +} + +/** + * Sets the message's destination. The destination is the name of + * another connection on the bus and may be either the unique name + * assigned by the bus to each connection, or a well-known name + * specified in advance. + * + * The destination name must contain only valid characters as defined + * in the D-Bus specification. + * + * @param message the message + * @param destination the destination name or #NULL to unset + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_set_destination (DBusMessage *message, + const char *destination) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (!message->locked, FALSE); + _dbus_return_val_if_fail (destination == NULL || + _dbus_check_is_valid_bus_name (destination), + FALSE); + + return set_or_delete_string_field (message, + DBUS_HEADER_FIELD_DESTINATION, + DBUS_TYPE_STRING, + destination); +} + +/** + * Gets the destination of a message or #NULL if there is none set. + * + * The returned string becomes invalid if the message is + * modified, since it points into the wire-marshaled message data. + * + * @param message the message + * @returns the message destination (should not be freed) or #NULL + */ +const char* +dbus_message_get_destination (DBusMessage *message) +{ + const char *v; + + _dbus_return_val_if_fail (message != NULL, NULL); + + v = NULL; /* in case field doesn't exist */ + _dbus_header_get_field_basic (&message->header, + DBUS_HEADER_FIELD_DESTINATION, + DBUS_TYPE_STRING, + &v); + return v; +} + +/** + * Sets the message sender. + * + * The sender must be a valid bus name as defined in the D-Bus + * specification. + * + * Usually you don't want to call this. The message bus daemon will + * call it to set the origin of each message. If you aren't implementing + * a message bus daemon you shouldn't need to set the sender. + * + * @param message the message + * @param sender the sender or #NULL to unset + * @returns #FALSE if not enough memory + */ +dbus_bool_t +dbus_message_set_sender (DBusMessage *message, + const char *sender) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (!message->locked, FALSE); + _dbus_return_val_if_fail (sender == NULL || + _dbus_check_is_valid_bus_name (sender), + FALSE); + + return set_or_delete_string_field (message, + DBUS_HEADER_FIELD_SENDER, + DBUS_TYPE_STRING, + sender); +} + +/** + * Gets the unique name of the connection which originated this + * message, or #NULL if unknown or inapplicable. The sender is filled + * in by the message bus. + * + * Note, the returned sender is always the unique bus name. + * Connections may own multiple other bus names, but those + * are not found in the sender field. + * + * The returned string becomes invalid if the message is + * modified, since it points into the wire-marshaled message data. + * + * @param message the message + * @returns the unique name of the sender or #NULL + */ +const char* +dbus_message_get_sender (DBusMessage *message) +{ + const char *v; + + _dbus_return_val_if_fail (message != NULL, NULL); + + v = NULL; /* in case field doesn't exist */ + _dbus_header_get_field_basic (&message->header, + DBUS_HEADER_FIELD_SENDER, + DBUS_TYPE_STRING, + &v); + return v; +} + +/** + * Gets the type signature of the message, i.e. the arguments in the + * message payload. The signature includes only "in" arguments for + * #DBUS_MESSAGE_TYPE_METHOD_CALL and only "out" arguments for + * #DBUS_MESSAGE_TYPE_METHOD_RETURN, so is slightly different from + * what you might expect (that is, it does not include the signature of the + * entire C++-style method). + * + * The signature is a string made up of type codes such as + * #DBUS_TYPE_INT32. The string is terminated with nul (nul is also + * the value of #DBUS_TYPE_INVALID). + * + * The returned string becomes invalid if the message is + * modified, since it points into the wire-marshaled message data. + * + * @param message the message + * @returns the type signature + */ +const char* +dbus_message_get_signature (DBusMessage *message) +{ + const DBusString *type_str; + int type_pos; + + _dbus_return_val_if_fail (message != NULL, NULL); + + get_const_signature (&message->header, &type_str, &type_pos); + + return _dbus_string_get_const_data_len (type_str, type_pos, 0); +} + +static dbus_bool_t +_dbus_message_has_type_interface_member (DBusMessage *message, + int type, + const char *interface, + const char *member) +{ + const char *n; + + _dbus_assert (message != NULL); + _dbus_assert (interface != NULL); + _dbus_assert (member != NULL); + + if (dbus_message_get_type (message) != type) + return FALSE; + + /* Optimize by checking the short member name first + * instead of the longer interface name + */ + + n = dbus_message_get_member (message); + + if (n && strcmp (n, member) == 0) + { + n = dbus_message_get_interface (message); + + if (n == NULL || strcmp (n, interface) == 0) + return TRUE; + } + + return FALSE; +} + +/** + * Checks whether the message is a method call with the given + * interface and member fields. If the message is not + * #DBUS_MESSAGE_TYPE_METHOD_CALL, or has a different interface or + * member field, returns #FALSE. If the interface field is missing, + * then it will be assumed equal to the provided interface. The D-Bus + * protocol allows method callers to leave out the interface name. + * + * @param message the message + * @param interface the name to check (must not be #NULL) + * @param method the name to check (must not be #NULL) + * + * @returns #TRUE if the message is the specified method call + */ +dbus_bool_t +dbus_message_is_method_call (DBusMessage *message, + const char *interface, + const char *method) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (interface != NULL, FALSE); + _dbus_return_val_if_fail (method != NULL, FALSE); + /* don't check that interface/method are valid since it would be + * expensive, and not catch many common errors + */ + + return _dbus_message_has_type_interface_member (message, + DBUS_MESSAGE_TYPE_METHOD_CALL, + interface, method); +} + +/** + * Checks whether the message is a signal with the given interface and + * member fields. If the message is not #DBUS_MESSAGE_TYPE_SIGNAL, or + * has a different interface or member field, returns #FALSE. + * + * @param message the message + * @param interface the name to check (must not be #NULL) + * @param signal_name the name to check (must not be #NULL) + * + * @returns #TRUE if the message is the specified signal + */ +dbus_bool_t +dbus_message_is_signal (DBusMessage *message, + const char *interface, + const char *signal_name) +{ + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (interface != NULL, FALSE); + _dbus_return_val_if_fail (signal_name != NULL, FALSE); + /* don't check that interface/name are valid since it would be + * expensive, and not catch many common errors + */ + + return _dbus_message_has_type_interface_member (message, + DBUS_MESSAGE_TYPE_SIGNAL, + interface, signal_name); +} + +/** + * Checks whether the message is an error reply with the given error + * name. If the message is not #DBUS_MESSAGE_TYPE_ERROR, or has a + * different name, returns #FALSE. + * + * @param message the message + * @param error_name the name to check (must not be #NULL) + * + * @returns #TRUE if the message is the specified error + */ +dbus_bool_t +dbus_message_is_error (DBusMessage *message, + const char *error_name) +{ + const char *n; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (error_name != NULL, FALSE); + /* don't check that error_name is valid since it would be expensive, + * and not catch many common errors + */ + + if (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_ERROR) + return FALSE; + + n = dbus_message_get_error_name (message); + + if (n && strcmp (n, error_name) == 0) + return TRUE; + else + return FALSE; +} + +/** + * Checks whether the message was sent to the given name. If the + * message has no destination specified or has a different + * destination, returns #FALSE. + * + * @param message the message + * @param name the name to check (must not be #NULL) + * + * @returns #TRUE if the message has the given destination name + */ +dbus_bool_t +dbus_message_has_destination (DBusMessage *message, + const char *name) +{ + const char *s; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (name != NULL, FALSE); + /* don't check that name is valid since it would be expensive, and + * not catch many common errors + */ + + s = dbus_message_get_destination (message); + + if (s && strcmp (s, name) == 0) + return TRUE; + else + return FALSE; +} + +/** + * Checks whether the message has the given unique name as its sender. + * If the message has no sender specified or has a different sender, + * returns #FALSE. Note that a peer application will always have the + * unique name of the connection as the sender. So you can't use this + * function to see whether a sender owned a well-known name. + * + * Messages from the bus itself will have #DBUS_SERVICE_DBUS + * as the sender. + * + * @param message the message + * @param name the name to check (must not be #NULL) + * + * @returns #TRUE if the message has the given sender + */ +dbus_bool_t +dbus_message_has_sender (DBusMessage *message, + const char *name) +{ + const char *s; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (name != NULL, FALSE); + /* don't check that name is valid since it would be expensive, and + * not catch many common errors + */ + + s = dbus_message_get_sender (message); + + if (s && strcmp (s, name) == 0) + return TRUE; + else + return FALSE; +} + +/** + * Checks whether the message has the given signature; see + * dbus_message_get_signature() for more details on what the signature + * looks like. + * + * @param message the message + * @param signature typecode array + * @returns #TRUE if message has the given signature +*/ +dbus_bool_t +dbus_message_has_signature (DBusMessage *message, + const char *signature) +{ + const char *s; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (signature != NULL, FALSE); + /* don't check that signature is valid since it would be expensive, + * and not catch many common errors + */ + + s = dbus_message_get_signature (message); + + if (s && strcmp (s, signature) == 0) + return TRUE; + else + return FALSE; +} + +/** + * Sets a #DBusError based on the contents of the given + * message. The error is only set if the message + * is an error message, as in #DBUS_MESSAGE_TYPE_ERROR. + * The name of the error is set to the name of the message, + * and the error message is set to the first argument + * if the argument exists and is a string. + * + * The return value indicates whether the error was set (the error is + * set if and only if the message is an error message). So you can + * check for an error reply and convert it to DBusError in one go: + * @code + * if (dbus_set_error_from_message (error, reply)) + * return error; + * else + * process reply; + * @endcode + * + * @param error the error to set + * @param message the message to set it from + * @returns #TRUE if the message had type #DBUS_MESSAGE_TYPE_ERROR + */ +dbus_bool_t +dbus_set_error_from_message (DBusError *error, + DBusMessage *message) +{ + const char *str; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_error_is_set (error, FALSE); + + if (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_ERROR) + return FALSE; + + str = NULL; + dbus_message_get_args (message, NULL, + DBUS_TYPE_STRING, &str, + DBUS_TYPE_INVALID); + + dbus_set_error (error, dbus_message_get_error_name (message), + str ? "%s" : NULL, str); + + return TRUE; +} + +/** @} */ + +/** + * @addtogroup DBusMessageInternals + * + * @{ + */ + +/** + * The initial buffer size of the message loader. + * + * @todo this should be based on min header size plus some average + * body size, or something. Or rather, the min header size only, if we + * want to try to read only the header, store that in a DBusMessage, + * then read only the body and store that, etc., depends on + * how we optimize _dbus_message_loader_get_buffer() and what + * the exact message format is. + */ +#define INITIAL_LOADER_DATA_LEN 32 + +/** + * Creates a new message loader. Returns #NULL if memory can't + * be allocated. + * + * @returns new loader, or #NULL. + */ +DBusMessageLoader* +_dbus_message_loader_new (void) +{ + DBusMessageLoader *loader; + + loader = dbus_new0 (DBusMessageLoader, 1); + if (loader == NULL) + return NULL; + + loader->refcount = 1; + + loader->corrupted = FALSE; + loader->corruption_reason = DBUS_VALID; + + /* this can be configured by the app, but defaults to the protocol max */ + loader->max_message_size = DBUS_MAXIMUM_MESSAGE_LENGTH; + + if (!_dbus_string_init (&loader->data)) + { + dbus_free (loader); + return NULL; + } + + /* preallocate the buffer for speed, ignore failure */ + _dbus_string_set_length (&loader->data, INITIAL_LOADER_DATA_LEN); + _dbus_string_set_length (&loader->data, 0); + + return loader; +} + +/** + * Increments the reference count of the loader. + * + * @param loader the loader. + * @returns the loader + */ +DBusMessageLoader * +_dbus_message_loader_ref (DBusMessageLoader *loader) +{ + loader->refcount += 1; + + return loader; +} + +/** + * Decrements the reference count of the loader and finalizes the + * loader when the count reaches zero. + * + * @param loader the loader. + */ +void +_dbus_message_loader_unref (DBusMessageLoader *loader) +{ + loader->refcount -= 1; + if (loader->refcount == 0) + { + _dbus_list_foreach (&loader->messages, + (DBusForeachFunction) dbus_message_unref, + NULL); + _dbus_list_clear (&loader->messages); + _dbus_string_free (&loader->data); + dbus_free (loader); + } +} + +/** + * Gets the buffer to use for reading data from the network. Network + * data is read directly into an allocated buffer, which is then used + * in the DBusMessage, to avoid as many extra memcpy's as possible. + * The buffer must always be returned immediately using + * _dbus_message_loader_return_buffer(), even if no bytes are + * successfully read. + * + * @todo this function can be a lot more clever. For example + * it can probably always return a buffer size to read exactly + * the body of the next message, thus avoiding any memory wastage + * or reallocs. + * + * @todo we need to enforce a max length on strings in header fields. + * + * @param loader the message loader. + * @param buffer the buffer + */ +void +_dbus_message_loader_get_buffer (DBusMessageLoader *loader, + DBusString **buffer) +{ + _dbus_assert (!loader->buffer_outstanding); + + *buffer = &loader->data; + + loader->buffer_outstanding = TRUE; +} + +/** + * Returns a buffer obtained from _dbus_message_loader_get_buffer(), + * indicating to the loader how many bytes of the buffer were filled + * in. This function must always be called, even if no bytes were + * successfully read. + * + * @param loader the loader. + * @param buffer the buffer. + * @param bytes_read number of bytes that were read into the buffer. + */ +void +_dbus_message_loader_return_buffer (DBusMessageLoader *loader, + DBusString *buffer, + int bytes_read) +{ + _dbus_assert (loader->buffer_outstanding); + _dbus_assert (buffer == &loader->data); + + loader->buffer_outstanding = FALSE; +} + +/* + * FIXME when we move the header out of the buffer, that memmoves all + * buffered messages. Kind of crappy. + * + * Also we copy the header and body, which is kind of crappy. To + * avoid this, we have to allow header and body to be in a single + * memory block, which is good for messages we read and bad for + * messages we are creating. But we could move_len() the buffer into + * this single memory block, and move_len() will just swap the buffers + * if you're moving the entire buffer replacing the dest string. + * + * We could also have the message loader tell the transport how many + * bytes to read; so it would first ask for some arbitrary number like + * 256, then if the message was incomplete it would use the + * header/body len to ask for exactly the size of the message (or + * blocks the size of a typical kernel buffer for the socket). That + * way we don't get trailing bytes in the buffer that have to be + * memmoved. Though I suppose we also don't have a chance of reading a + * bunch of small messages at once, so the optimization may be stupid. + * + * Another approach would be to keep a "start" index into + * loader->data and only delete it occasionally, instead of after + * each message is loaded. + * + * load_message() returns FALSE if not enough memory OR the loader was corrupted + */ +static dbus_bool_t +load_message (DBusMessageLoader *loader, + DBusMessage *message, + int byte_order, + int fields_array_len, + int header_len, + int body_len) +{ + dbus_bool_t oom; + DBusValidity validity; + const DBusString *type_str; + int type_pos; + DBusValidationMode mode; + + mode = DBUS_VALIDATION_MODE_DATA_IS_UNTRUSTED; + + oom = FALSE; + +#if 0 + _dbus_verbose_bytes_of_string (&loader->data, 0, header_len /* + body_len */); +#endif + + /* 1. VALIDATE AND COPY OVER HEADER */ + _dbus_assert (_dbus_string_get_length (&message->header.data) == 0); + _dbus_assert ((header_len + body_len) <= _dbus_string_get_length (&loader->data)); + + if (!_dbus_header_load (&message->header, + mode, + &validity, + byte_order, + fields_array_len, + header_len, + body_len, + &loader->data, 0, + _dbus_string_get_length (&loader->data))) + { + _dbus_verbose ("Failed to load header for new message code %d\n", validity); + + /* assert here so we can catch any code that still uses DBUS_VALID to indicate + oom errors. They should use DBUS_VALIDITY_UNKNOWN_OOM_ERROR instead */ + _dbus_assert (validity != DBUS_VALID); + + if (validity == DBUS_VALIDITY_UNKNOWN_OOM_ERROR) + oom = TRUE; + else + { + loader->corrupted = TRUE; + loader->corruption_reason = validity; + } + goto failed; + } + + _dbus_assert (validity == DBUS_VALID); + + message->byte_order = byte_order; + + /* 2. VALIDATE BODY */ + if (mode != DBUS_VALIDATION_MODE_WE_TRUST_THIS_DATA_ABSOLUTELY) + { + get_const_signature (&message->header, &type_str, &type_pos); + + /* Because the bytes_remaining arg is NULL, this validates that the + * body is the right length + */ + validity = _dbus_validate_body_with_reason (type_str, + type_pos, + byte_order, + NULL, + &loader->data, + header_len, + body_len); + if (validity != DBUS_VALID) + { + _dbus_verbose ("Failed to validate message body code %d\n", validity); + + loader->corrupted = TRUE; + loader->corruption_reason = validity; + + goto failed; + } + } + + /* 3. COPY OVER BODY AND QUEUE MESSAGE */ + + if (!_dbus_list_append (&loader->messages, message)) + { + _dbus_verbose ("Failed to append new message to loader queue\n"); + oom = TRUE; + goto failed; + } + + _dbus_assert (_dbus_string_get_length (&message->body) == 0); + _dbus_assert (_dbus_string_get_length (&loader->data) >= + (header_len + body_len)); + + if (!_dbus_string_copy_len (&loader->data, header_len, body_len, &message->body, 0)) + { + _dbus_verbose ("Failed to move body into new message\n"); + oom = TRUE; + goto failed; + } + + _dbus_string_delete (&loader->data, 0, header_len + body_len); + + /* don't waste more than 2k of memory */ + _dbus_string_compact (&loader->data, 2048); + + _dbus_assert (_dbus_string_get_length (&message->header.data) == header_len); + _dbus_assert (_dbus_string_get_length (&message->body) == body_len); + + _dbus_verbose ("Loaded message %p\n", message); + + _dbus_assert (!oom); + _dbus_assert (!loader->corrupted); + _dbus_assert (loader->messages != NULL); + _dbus_assert (_dbus_list_find_last (&loader->messages, message) != NULL); + + return TRUE; + + failed: + + /* Clean up */ + + /* does nothing if the message isn't in the list */ + _dbus_list_remove_last (&loader->messages, message); + + if (oom) + _dbus_assert (!loader->corrupted); + else + _dbus_assert (loader->corrupted); + + _dbus_verbose_bytes_of_string (&loader->data, 0, _dbus_string_get_length (&loader->data)); + + return FALSE; +} + +/** + * Converts buffered data into messages, if we have enough data. If + * we don't have enough data, does nothing. + * + * @todo we need to check that the proper named header fields exist + * for each message type. + * + * @todo If a message has unknown type, we should probably eat it + * right here rather than passing it out to applications. However + * it's not an error to see messages of unknown type. + * + * @param loader the loader. + * @returns #TRUE if we had enough memory to finish. + */ +dbus_bool_t +_dbus_message_loader_queue_messages (DBusMessageLoader *loader) +{ + while (!loader->corrupted && + _dbus_string_get_length (&loader->data) >= DBUS_MINIMUM_HEADER_SIZE) + { + DBusValidity validity; + int byte_order, fields_array_len, header_len, body_len; + + if (_dbus_header_have_message_untrusted (loader->max_message_size, + &validity, + &byte_order, + &fields_array_len, + &header_len, + &body_len, + &loader->data, 0, + _dbus_string_get_length (&loader->data))) + { + DBusMessage *message; + + _dbus_assert (validity == DBUS_VALID); + + message = dbus_message_new_empty_header (); + if (message == NULL) + return FALSE; + + if (!load_message (loader, message, + byte_order, fields_array_len, + header_len, body_len)) + { + dbus_message_unref (message); + /* load_message() returns false if corrupted or OOM; if + * corrupted then return TRUE for not OOM + */ + return loader->corrupted; + } + + _dbus_assert (loader->messages != NULL); + _dbus_assert (_dbus_list_find_last (&loader->messages, message) != NULL); + } + else + { + _dbus_verbose ("Initial peek at header says we don't have a whole message yet, or data broken with invalid code %d\n", + validity); + if (validity != DBUS_VALID) + { + loader->corrupted = TRUE; + loader->corruption_reason = validity; + } + return TRUE; + } + } + + return TRUE; +} + +/** + * Peeks at first loaded message, returns #NULL if no messages have + * been queued. + * + * @param loader the loader. + * @returns the next message, or #NULL if none. + */ +DBusMessage* +_dbus_message_loader_peek_message (DBusMessageLoader *loader) +{ + if (loader->messages) + return loader->messages->data; + else + return NULL; +} + +/** + * Pops a loaded message (passing ownership of the message + * to the caller). Returns #NULL if no messages have been + * queued. + * + * @param loader the loader. + * @returns the next message, or #NULL if none. + */ +DBusMessage* +_dbus_message_loader_pop_message (DBusMessageLoader *loader) +{ + return _dbus_list_pop_first (&loader->messages); +} + +/** + * Pops a loaded message inside a list link (passing ownership of the + * message and link to the caller). Returns #NULL if no messages have + * been loaded. + * + * @param loader the loader. + * @returns the next message link, or #NULL if none. + */ +DBusList* +_dbus_message_loader_pop_message_link (DBusMessageLoader *loader) +{ + return _dbus_list_pop_first_link (&loader->messages); +} + +/** + * Returns a popped message link, used to undo a pop. + * + * @param loader the loader + * @param link the link with a message in it + */ +void +_dbus_message_loader_putback_message_link (DBusMessageLoader *loader, + DBusList *link) +{ + _dbus_list_prepend_link (&loader->messages, link); +} + +/** + * Checks whether the loader is confused due to bad data. + * If messages are received that are invalid, the + * loader gets confused and gives up permanently. + * This state is called "corrupted." + * + * @param loader the loader + * @returns #TRUE if the loader is hosed. + */ +dbus_bool_t +_dbus_message_loader_get_is_corrupted (DBusMessageLoader *loader) +{ + _dbus_assert ((loader->corrupted && loader->corruption_reason != DBUS_VALID) || + (!loader->corrupted && loader->corruption_reason == DBUS_VALID)); + return loader->corrupted; +} + +/** + * Sets the maximum size message we allow. + * + * @param loader the loader + * @param size the max message size in bytes + */ +void +_dbus_message_loader_set_max_message_size (DBusMessageLoader *loader, + long size) +{ + if (size > DBUS_MAXIMUM_MESSAGE_LENGTH) + { + _dbus_verbose ("clamping requested max message size %ld to %d\n", + size, DBUS_MAXIMUM_MESSAGE_LENGTH); + size = DBUS_MAXIMUM_MESSAGE_LENGTH; + } + loader->max_message_size = size; +} + +/** + * Gets the maximum allowed message size in bytes. + * + * @param loader the loader + * @returns max size in bytes + */ +long +_dbus_message_loader_get_max_message_size (DBusMessageLoader *loader) +{ + return loader->max_message_size; +} + +static DBusDataSlotAllocator slot_allocator; +_DBUS_DEFINE_GLOBAL_LOCK (message_slots); + +/** + * Allocates an integer ID to be used for storing application-specific + * data on any DBusMessage. The allocated ID may then be used + * with dbus_message_set_data() and dbus_message_get_data(). + * The passed-in slot must be initialized to -1, and is filled in + * with the slot ID. If the passed-in slot is not -1, it's assumed + * to be already allocated, and its refcount is incremented. + * + * The allocated slot is global, i.e. all DBusMessage objects will + * have a slot with the given integer ID reserved. + * + * @param slot_p address of a global variable storing the slot + * @returns #FALSE on failure (no memory) + */ +dbus_bool_t +dbus_message_allocate_data_slot (dbus_int32_t *slot_p) +{ + return _dbus_data_slot_allocator_alloc (&slot_allocator, + &_DBUS_LOCK_NAME (message_slots), + slot_p); +} + +/** + * Deallocates a global ID for message data slots. + * dbus_message_get_data() and dbus_message_set_data() may no + * longer be used with this slot. Existing data stored on existing + * DBusMessage objects will be freed when the message is + * finalized, but may not be retrieved (and may only be replaced if + * someone else reallocates the slot). When the refcount on the + * passed-in slot reaches 0, it is set to -1. + * + * @param slot_p address storing the slot to deallocate + */ +void +dbus_message_free_data_slot (dbus_int32_t *slot_p) +{ + _dbus_return_if_fail (*slot_p >= 0); + + _dbus_data_slot_allocator_free (&slot_allocator, slot_p); +} + +/** + * Stores a pointer on a DBusMessage, along + * with an optional function to be used for freeing + * the data when the data is set again, or when + * the message is finalized. The slot number + * must have been allocated with dbus_message_allocate_data_slot(). + * + * @param message the message + * @param slot the slot number + * @param data the data to store + * @param free_data_func finalizer function for the data + * @returns #TRUE if there was enough memory to store the data + */ +dbus_bool_t +dbus_message_set_data (DBusMessage *message, + dbus_int32_t slot, + void *data, + DBusFreeFunction free_data_func) +{ + DBusFreeFunction old_free_func; + void *old_data; + dbus_bool_t retval; + + _dbus_return_val_if_fail (message != NULL, FALSE); + _dbus_return_val_if_fail (slot >= 0, FALSE); + + retval = _dbus_data_slot_list_set (&slot_allocator, + &message->slot_list, + slot, data, free_data_func, + &old_free_func, &old_data); + + if (retval) + { + /* Do the actual free outside the message lock */ + if (old_free_func) + (* old_free_func) (old_data); + } + + return retval; +} + +/** + * Retrieves data previously set with dbus_message_set_data(). + * The slot must still be allocated (must not have been freed). + * + * @param message the message + * @param slot the slot to get data from + * @returns the data, or #NULL if not found + */ +void* +dbus_message_get_data (DBusMessage *message, + dbus_int32_t slot) +{ + void *res; + + _dbus_return_val_if_fail (message != NULL, NULL); + + res = _dbus_data_slot_list_get (&slot_allocator, + &message->slot_list, + slot); + + return res; +} + +/** + * Utility function to convert a machine-readable (not translated) + * string into a D-Bus message type. + * + * @code + * "method_call" -> DBUS_MESSAGE_TYPE_METHOD_CALL + * "method_return" -> DBUS_MESSAGE_TYPE_METHOD_RETURN + * "signal" -> DBUS_MESSAGE_TYPE_SIGNAL + * "error" -> DBUS_MESSAGE_TYPE_ERROR + * anything else -> DBUS_MESSAGE_TYPE_INVALID + * @endcode + * + */ +int +dbus_message_type_from_string (const char *type_str) +{ + if (strcmp (type_str, "method_call") == 0) + return DBUS_MESSAGE_TYPE_METHOD_CALL; + if (strcmp (type_str, "method_return") == 0) + return DBUS_MESSAGE_TYPE_METHOD_RETURN; + else if (strcmp (type_str, "signal") == 0) + return DBUS_MESSAGE_TYPE_SIGNAL; + else if (strcmp (type_str, "error") == 0) + return DBUS_MESSAGE_TYPE_ERROR; + else + return DBUS_MESSAGE_TYPE_INVALID; +} + +/** + * Utility function to convert a D-Bus message type into a + * machine-readable string (not translated). + * + * @code + * DBUS_MESSAGE_TYPE_METHOD_CALL -> "method_call" + * DBUS_MESSAGE_TYPE_METHOD_RETURN -> "method_return" + * DBUS_MESSAGE_TYPE_SIGNAL -> "signal" + * DBUS_MESSAGE_TYPE_ERROR -> "error" + * DBUS_MESSAGE_TYPE_INVALID -> "invalid" + * @endcode + * + */ +const char * +dbus_message_type_to_string (int type) +{ + switch (type) + { + case DBUS_MESSAGE_TYPE_METHOD_CALL: + return "method_call"; + case DBUS_MESSAGE_TYPE_METHOD_RETURN: + return "method_return"; + case DBUS_MESSAGE_TYPE_SIGNAL: + return "signal"; + case DBUS_MESSAGE_TYPE_ERROR: + return "error"; + default: + return "invalid"; + } +} + +/** + * Turn a DBusMessage into the marshalled form as described in the D-Bus + * specification. + * + * Generally, this function is only useful for encapsulating D-Bus messages in + * a different protocol. + * + * @param msg the DBusMessage + * @param marshalled_data_p the location to save the marshalled form to + * @param len_p the location to save the length of the marshalled form to + * @returns #FALSE if there was not enough memory + */ +dbus_bool_t +dbus_message_marshal (DBusMessage *msg, + char **marshalled_data_p, + int *len_p) +{ + DBusString tmp; + + _dbus_return_val_if_fail (msg != NULL, FALSE); + _dbus_return_val_if_fail (marshalled_data_p != NULL, FALSE); + _dbus_return_val_if_fail (len_p != NULL, FALSE); + + if (!_dbus_string_init (&tmp)) + return FALSE; + + if (!_dbus_string_copy (&(msg->header.data), 0, &tmp, 0)) + goto fail; + + *len_p = _dbus_string_get_length (&tmp); + + if (!_dbus_string_copy (&(msg->body), 0, &tmp, *len_p)) + goto fail; + + *len_p = _dbus_string_get_length (&tmp); + + if (!_dbus_string_steal_data (&tmp, marshalled_data_p)) + goto fail; + + _dbus_string_free (&tmp); + return TRUE; + + fail: + _dbus_string_free (&tmp); + return FALSE; +} + +/** + * Demarshal a D-Bus message from the format described in the D-Bus + * specification. + * + * Generally, this function is only useful for encapsulating D-Bus messages in + * a different protocol. + * + * @param str the marshalled DBusMessage + * @param len the length of str + * @param error the location to save errors to + * @returns #NULL if there was an error + */ +DBusMessage * +dbus_message_demarshal (const char *str, + int len, + DBusError *error) +{ + DBusMessageLoader *loader; + DBusString *buffer; + DBusMessage *msg; + + _dbus_return_val_if_fail (str != NULL, NULL); + + loader = _dbus_message_loader_new (); + + if (loader == NULL) + return NULL; + + _dbus_message_loader_get_buffer (loader, &buffer); + _dbus_string_append_len (buffer, str, len); + _dbus_message_loader_return_buffer (loader, buffer, len); + + if (!_dbus_message_loader_queue_messages (loader)) + goto fail_oom; + + if (_dbus_message_loader_get_is_corrupted (loader)) + goto fail_corrupt; + + msg = _dbus_message_loader_pop_message (loader); + + if (!msg) + goto fail_oom; + + _dbus_message_loader_unref (loader); + return msg; + + fail_corrupt: + dbus_set_error (error, DBUS_ERROR_INVALID_ARGS, "Message is corrupted"); + _dbus_message_loader_unref (loader); + return NULL; + + fail_oom: + _DBUS_SET_OOM (error); + _dbus_message_loader_unref (loader); + return NULL; +} + +/** + * Returns the number of bytes required to be in the buffer to demarshal a + * D-Bus message. + * + * Generally, this function is only useful for encapsulating D-Bus messages in + * a different protocol. + * + * @param str data to be marshalled + * @param len the length of str + * @param error the location to save errors to + * @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 + * + */ +int +dbus_message_demarshal_bytes_needed(const char *buf, + int len) +{ + DBusString str; + int byte_order, fields_array_len, header_len, body_len; + DBusValidity validity = DBUS_VALID; + int have_message; + + if (!buf || len < DBUS_MINIMUM_HEADER_SIZE) + return 0; + + if (len > DBUS_MAXIMUM_MESSAGE_LENGTH) + len = DBUS_MAXIMUM_MESSAGE_LENGTH; + _dbus_string_init_const_len (&str, buf, len); + + validity = DBUS_VALID; + have_message + = _dbus_header_have_message_untrusted(DBUS_MAXIMUM_MESSAGE_LENGTH, + &validity, &byte_order, + &fields_array_len, + &header_len, + &body_len, + &str, 0, + len); + _dbus_string_free (&str); + + if (validity == DBUS_VALID) + { + _dbus_assert(have_message); + return header_len + body_len; + } + else + { + return -1; /* broken! */ + } +} + +/** @} */ + +/* tests in dbus-message-util.c */