dbus-message.c

/* -*- 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
 *
 * SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */
 
#include <config.h>
#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"
#ifdef HAVE_UNIX_FD_PASSING
#include "dbus-sysdeps.h"
#include "dbus-sysdeps-unix.h"
#endif
 
#include <string.h>
 
#define _DBUS_TYPE_IS_STRINGLIKE(type) \
  (type == DBUS_TYPE_STRING || type == DBUS_TYPE_SIGNATURE || \
   type == DBUS_TYPE_OBJECT_PATH)
 
static void dbus_message_finalize (DBusMessage *message);
 
#ifdef DBUS_ENABLE_EMBEDDED_TESTS
static dbus_bool_t
_dbus_enable_message_cache (void)
{
  static int enabled = -1;
 
  if (enabled < 0)
    {
      const char *s = _dbus_getenv ("DBUS_MESSAGE_CACHE");
 
      enabled = TRUE;
 
      if (s && *s)
        {
          if (*s == '0')
            enabled = FALSE;
          else if (*s == '1')
            enabled = TRUE;
          else
            _dbus_warn ("DBUS_MESSAGE_CACHE should be 0 or 1 if set, not '%s'",
                s);
        }
    }
 
  return enabled;
}
#else
    /* constant expression, should be optimized away */
#   define _dbus_enable_message_cache() (TRUE)
#endif
 
#ifndef _dbus_message_trace_ref
void
_dbus_message_trace_ref (DBusMessage *message,
                         int          old_refcount,
                         int          new_refcount,
                         const char  *why)
{
  static int enabled = -1;
 
  _dbus_trace_ref ("DBusMessage", message, old_refcount, new_refcount, why,
      "DBUS_MESSAGE_TRACE", &enabled);
}
#endif
 
/* Not thread locked, but strictly const/read-only so should be OK
 */
_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 struct DBusMessageRealIter DBusMessageRealIter;
 
struct DBusMessageRealIter
{
  DBusMessage *message; 
  dbus_uint32_t changed_stamp : CHANGED_STAMP_BITS; 
  dbus_uint32_t iter_type : 3;      
  dbus_uint32_t sig_refcount : 8;   
  union
  {
    DBusTypeWriter writer; 
    DBusTypeReader reader; 
  } u; 
};
 
#if DBUS_SIZEOF_VOID_P > 8
/*
 * Architectures with 128-bit pointers were not supported in DBus 1.10, so we
 * do no check for DBus 1.10 structure layout compatibility for such
 * architectures (e.g. Arm Morello).
 */
#define CHECK_DBUS_1_10_BINARY_COMPATIBILITY 0
#else
#define CHECK_DBUS_1_10_BINARY_COMPATIBILITY 1
typedef struct
{
  void *dummy1;
  void *dummy2;
  dbus_uint32_t dummy3;
  int dummy4;
  int dummy5;
  int dummy6;
  int dummy7;
  int dummy8;
  int dummy9;
  int dummy10;
  int dummy11;
  int pad1;
  int pad2;
  void *pad3;
} DBusMessageIter_1_10_0;
#endif
 
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;
    }
}
 
static void
_dbus_message_byteswap (DBusMessage *message)
{
  const DBusString *type_str;
  int type_pos;
  char byte_order;
 
  byte_order = _dbus_header_get_byte_order (&message->header);
 
  if (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,
                          byte_order,
                          DBUS_COMPILER_BYTE_ORDER,
                          &message->body, 0);
 
  _dbus_header_byteswap (&message->header, DBUS_COMPILER_BYTE_ORDER);
  _dbus_assert (_dbus_header_get_byte_order (&message->header) ==
                DBUS_COMPILER_BYTE_ORDER);
}
 
#define ensure_byte_order(message) _dbus_message_byteswap (message)
 
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;
}
 
void _dbus_message_get_unix_fds(DBusMessage *message,
                                const int  **fds,
                                unsigned    *n_fds)
{
  _dbus_assert (message->locked);
 
#ifdef HAVE_UNIX_FD_PASSING
  *fds = message->unix_fds;
  *n_fds = message->n_unix_fds;
#else
  *fds = NULL;
  *n_fds = 0;
#endif
}
 
dbus_bool_t
_dbus_message_remove_unknown_fields (DBusMessage *message)
{
  return _dbus_header_remove_unknown_fields (&message->header);
}
 
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);
}
 
void
_dbus_message_add_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->counters == NULL)
    {
      message->size_counter_delta =
        _dbus_string_get_length (&message->header.data) +
        _dbus_string_get_length (&message->body);
 
#ifdef HAVE_UNIX_FD_PASSING
      message->unix_fd_counter_delta = message->n_unix_fds;
#endif
 
#if 0
      _dbus_verbose ("message has size %ld\n",
                     message->size_counter_delta);
#endif
    }
 
  _dbus_list_append_link (&message->counters, link);
 
  _dbus_counter_adjust_size (link->data, message->size_counter_delta);
 
#ifdef HAVE_UNIX_FD_PASSING
  _dbus_counter_adjust_unix_fd (link->data, message->unix_fd_counter_delta);
#endif
}
 
dbus_bool_t
_dbus_message_add_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_counter_link (message, link);
 
  return TRUE;
}
 
void
_dbus_message_remove_counter (DBusMessage  *message,
                              DBusCounter  *counter)
{
  DBusList *link;
 
  link = _dbus_list_find_last (&message->counters,
                               counter);
  _dbus_assert (link != NULL);
 
  _dbus_list_remove_link (&message->counters, link);
 
  _dbus_counter_adjust_size (counter, - message->size_counter_delta);
 
#ifdef HAVE_UNIX_FD_PASSING
  _dbus_counter_adjust_unix_fd (counter, - message->unix_fd_counter_delta);
#endif
 
  _dbus_counter_notify (counter);
  _dbus_counter_unref (counter);
}
 
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);
}
 
/* 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).
 */
 
#define MAX_MESSAGE_SIZE_TO_CACHE 10 * _DBUS_ONE_KILOBYTE
 
#define MAX_MESSAGE_CACHE_SIZE    5
 
/* Protected by _DBUS_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;
 
  if (!_DBUS_LOCK (message_cache))
    _dbus_assert_not_reached ("we would have initialized global locks "
        "before registering a shutdown function");
 
  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);
}
 
static DBusMessage*
dbus_message_get_cached (void)
{
  DBusMessage *message;
  int i;
 
  message = NULL;
 
  if (!_DBUS_LOCK (message_cache))
    {
      /* we'd have initialized global locks before caching anything,
       * so there can't be anything in the cache */
      return NULL;
    }
 
  _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 (_dbus_atomic_get (&message->refcount) == 0);
 
  _dbus_assert (message->counters == NULL);
  
  _DBUS_UNLOCK (message_cache);
 
  return message;
}
 
#ifdef HAVE_UNIX_FD_PASSING
static void
close_unix_fds(int *fds, unsigned *n_fds)
{
  DBusError e;
  unsigned int i;
 
  if (*n_fds <= 0)
    return;
 
  dbus_error_init(&e);
 
  for (i = 0; i < *n_fds; i++)
    {
      if (!_dbus_close(fds[i], &e))
        {
          _dbus_warn("Failed to close file descriptor: %s", e.message);
          dbus_error_free(&e);
        }
    }
 
  *n_fds = 0;
 
  /* We don't free the array here, in case we can recycle it later */
}
#endif
 
static void
free_counter (void *element,
              void *data)
{
  DBusCounter *counter = element;
  DBusMessage *message = data;
 
  _dbus_counter_adjust_size (counter, - message->size_counter_delta);
#ifdef HAVE_UNIX_FD_PASSING
  _dbus_counter_adjust_unix_fd (counter, - message->unix_fd_counter_delta);
#endif
 
  _dbus_counter_notify (counter);
  _dbus_counter_unref (counter);
}
 
static void
dbus_message_cache_or_finalize (DBusMessage *message)
{
  dbus_bool_t was_cached;
  int i;
 
  _dbus_assert (_dbus_atomic_get (&message->refcount) == 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->counters,
                      free_counter, message);
  _dbus_list_clear (&message->counters);
 
#ifdef HAVE_UNIX_FD_PASSING
  close_unix_fds(message->unix_fds, &message->n_unix_fds);
#endif
 
  was_cached = FALSE;
 
  if (!_DBUS_LOCK (message_cache))
    {
      /* The only way to get a non-null message goes through
       * dbus_message_get_cached() which takes the lock. */
      _dbus_assert_not_reached ("we would have initialized global locks "
          "the first time we constructed a message");
    }
 
  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_enable_message_cache ())
    goto out;
 
  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 (_dbus_atomic_get (&message->refcount) == 0);
 
  _DBUS_UNLOCK (message_cache);
  
  if (!was_cached)
    dbus_message_finalize (message);
}
 
/*
 * Arrange for iter to be something that _dbus_message_iter_check() would
 * reject as not a valid iterator.
 */
static void
_dbus_message_real_iter_zero (DBusMessageRealIter *iter)
{
  _dbus_assert (iter != NULL);
  _DBUS_ZERO (*iter);
  /* NULL is not, strictly speaking, guaranteed to be all-bits-zero */
  iter->message = NULL;
}
 
void
dbus_message_iter_init_closed (DBusMessageIter *iter)
{
  _dbus_return_if_fail (iter != NULL);
  _dbus_message_real_iter_zero ((DBusMessageRealIter *) iter);
}
 
static dbus_bool_t
_dbus_message_real_iter_is_zeroed (DBusMessageRealIter *iter)
{
  return (iter != NULL && iter->message == NULL && iter->changed_stamp == 0 &&
          iter->iter_type == 0 && iter->sig_refcount == 0);
}
 
#if defined(DBUS_ENABLE_CHECKS) || defined(DBUS_ENABLE_ASSERT)
static dbus_bool_t
_dbus_message_iter_check (DBusMessageRealIter *iter)
{
  char byte_order;
 
  if (iter == NULL)
    {
      _dbus_warn_check_failed ("dbus message iterator is NULL");
      return FALSE;
    }
 
  if (iter->message == NULL || iter->iter_type == 0)
    {
      _dbus_warn_check_failed ("dbus message iterator has already been "
                               "closed, or is uninitialized or corrupt");
      return FALSE;
    }
 
  byte_order = _dbus_header_get_byte_order (&iter->message->header);
 
  if (iter->iter_type == DBUS_MESSAGE_ITER_TYPE_READER)
    {
      if (iter->u.reader.byte_order != byte_order)
        {
          _dbus_warn_check_failed ("dbus message changed byte order since iterator was created");
          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 != byte_order)
        {
          _dbus_warn_check_failed ("dbus message changed byte order since append iterator was created");
          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");
      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)");
      return FALSE;
    }
 
  return TRUE;
}
#endif /* DBUS_ENABLE_CHECKS || DBUS_ENABLE_ASSERT */
 
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, j;
  dbus_bool_t retval;
  va_list copy_args;
 
  _dbus_assert (_dbus_message_iter_check (real));
 
  retval = FALSE;
 
  spec_type = first_arg_type;
  i = 0;
 
  /* copy var_args first, then we can do another iteration over it to
   * free memory and close unix fds if parse failed at some point.
   */
  va_copy (copy_args, var_args);
 
  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 (spec_type == DBUS_TYPE_UNIX_FD)
        {
#ifdef HAVE_UNIX_FD_PASSING
          DBusBasicValue idx;
          int *pfd, nfd;
 
          pfd = va_arg (var_args, int*);
          _dbus_assert(pfd);
 
          _dbus_type_reader_read_basic(&real->u.reader, &idx);
 
          if (idx.u32 >= real->message->n_unix_fds)
            {
              dbus_set_error (error, DBUS_ERROR_INCONSISTENT_MESSAGE,
                              "Message refers to file descriptor at index %i,"
                              "but has only %i descriptors attached.\n",
                              idx.u32,
                              real->message->n_unix_fds);
              goto out;
            }
 
          if ((nfd = _dbus_dup(real->message->unix_fds[idx.u32], error)) < 0)
            goto out;
 
          *pfd = nfd;
#else
          dbus_set_error (error, DBUS_ERROR_NOT_SUPPORTED,
                          "Platform does not support file desciptor passing.\n");
          goto out;
#endif
        }
      else if (dbus_type_is_basic (spec_type))
        {
          void *ptr;
 
          ptr = va_arg (var_args, void *);
 
          _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 void **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) &&
              element_type != DBUS_TYPE_UNIX_FD)
            {
              ptr = va_arg (var_args, const void **);
              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 (_DBUS_TYPE_IS_STRINGLIKE (spec_element_type))
            {
              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);
 
              j = 0;
              while (j < n_elements)
                {
                  const char *s;
                  _dbus_type_reader_read_basic (&array,
                                                (void *) &s);
                  
                  str_array[j] = _dbus_strdup (s);
                  if (str_array[j] == NULL)
                    {
                      dbus_free_string_array (str_array);
                      _DBUS_SET_OOM (error);
                      goto out;
                    }
                  
                  ++j;
                  
                  if (!_dbus_type_reader_next (&array))
                    _dbus_assert (j == n_elements);
                }
 
              _dbus_assert (_dbus_type_reader_get_current_type (&array) == DBUS_TYPE_INVALID);
              _dbus_assert (j == n_elements);
              _dbus_assert (str_array[j] == 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",
                          _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",
                      _DBUS_FUNCTION_NAME);
          goto out;
        }
#endif
 
      /* how many arguments already handled */
      i++;
 
      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;
        }
    }
 
  retval = TRUE;
 
 out:
  /* there may memory or unix fd leak in the above iteration if parse failed.
   * so we have another iteration over copy_args to free memory and close
   * unix fds.
   */
  if (!retval)
    {
      spec_type = first_arg_type;
      j = 0;
 
      while (j < i)
        {
          if (spec_type == DBUS_TYPE_UNIX_FD)
            {
#ifdef HAVE_UNIX_FD_PASSING
              int *pfd;
 
              pfd = va_arg (copy_args, int *);
              _dbus_assert(pfd);
              if (*pfd >= 0)
                {
                  _dbus_close (*pfd, NULL);
                  *pfd = -1;
                }
#endif
            }
          else if (dbus_type_is_basic (spec_type))
            {
              /* move the index forward */
              va_arg (copy_args, const void *);
            }
          else if (spec_type == DBUS_TYPE_ARRAY)
            {
              int spec_element_type;
 
              spec_element_type = va_arg (copy_args, int);
              if (dbus_type_is_fixed (spec_element_type))
                {
                  /* move the index forward */
                  va_arg (copy_args, const void **);
                  va_arg (copy_args, int *);
                }
              else if (_DBUS_TYPE_IS_STRINGLIKE (spec_element_type))
                {
                  char ***str_array_p;
 
                  str_array_p = va_arg (copy_args, char ***);
                  /* move the index forward */
                  va_arg (copy_args, int *);
                  _dbus_assert (str_array_p != NULL);
                  dbus_free_string_array (*str_array_p);
                  *str_array_p = NULL;
                }
            }
 
          spec_type = va_arg (copy_args, int);
          j++;
        }
    }
 
  va_end (copy_args);
  return retval;
}
 
dbus_uint32_t
dbus_message_get_serial (DBusMessage *message)
{
  _dbus_return_val_if_fail (message != NULL, 0);
 
  return _dbus_header_get_serial (&message->header);
}
 
dbus_bool_t
dbus_message_set_reply_serial (DBusMessage   *message,
                               dbus_uint32_t  reply_serial)
{
  DBusBasicValue value;
 
  _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 */
 
  value.u32 = reply_serial;
 
  return _dbus_header_set_field_basic (&message->header,
                                       DBUS_HEADER_FIELD_REPLY_SERIAL,
                                       DBUS_TYPE_UINT32,
                                       &value);
}
 
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 (_dbus_atomic_get (&message->refcount) == 0);
 
  /* This calls application callbacks! */
  _dbus_data_slot_list_free (&message->slot_list);
 
  _dbus_list_foreach (&message->counters,
                      free_counter, message);
  _dbus_list_clear (&message->counters);
 
  _dbus_header_free (&message->header);
  _dbus_string_free (&message->body);
 
#ifdef HAVE_UNIX_FD_PASSING
  close_unix_fds(message->unix_fds, &message->n_unix_fds);
  dbus_free(message->unix_fds);
#endif
 
  _dbus_assert (_dbus_atomic_get (&message->refcount) == 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_new0 (DBusMessage, 1);
      if (message == NULL)
        return NULL;
#ifndef DBUS_DISABLE_CHECKS
      message->generation = _dbus_current_generation;
#endif
 
#ifdef HAVE_UNIX_FD_PASSING
      message->unix_fds = NULL;
      message->n_unix_fds_allocated = 0;
#endif
    }
 
  _dbus_atomic_inc (&message->refcount);
 
  _dbus_message_trace_ref (message, 0, 1, "new_empty_header");
 
  message->locked = FALSE;
#ifndef DBUS_DISABLE_CHECKS
  message->in_cache = FALSE;
#endif
  message->counters = NULL;
  message->size_counter_delta = 0;
  message->changed_stamp = 0;
 
#ifdef HAVE_UNIX_FD_PASSING
  message->n_unix_fds = 0;
  message->n_unix_fds_allocated = 0;
  message->unix_fd_counter_delta = 0;
#endif
 
  if (!from_cache)
    _dbus_data_slot_list_init (&message->slot_list);
 
  if (from_cache)
    {
      _dbus_header_reinit (&message->header);
      _dbus_string_set_length (&message->body, 0);
    }
  else
    {
      if (!_dbus_header_init (&message->header))
        {
          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;
}
 
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,
                            DBUS_COMPILER_BYTE_ORDER,
                            message_type,
                            NULL, NULL, NULL, NULL, NULL))
    {
      dbus_message_unref (message);
      return NULL;
    }
 
  return message;
}
 
DBusMessage*
dbus_message_new_method_call (const char *destination,
                              const char *path,
                              const char *iface,
                              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 (iface == NULL ||
                            _dbus_check_is_valid_interface (iface), 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_COMPILER_BYTE_ORDER,
                            DBUS_MESSAGE_TYPE_METHOD_CALL,
                            destination, path, iface, method, NULL))
    {
      dbus_message_unref (message);
      return NULL;
    }
 
  return message;
}
 
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_COMPILER_BYTE_ORDER,
                            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;
}
 
DBusMessage*
dbus_message_new_signal (const char *path,
                         const char *iface,
                         const char *name)
{
  DBusMessage *message;
 
  _dbus_return_val_if_fail (path != NULL, NULL);
  _dbus_return_val_if_fail (iface != 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 (iface), 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_COMPILER_BYTE_ORDER,
                            DBUS_MESSAGE_TYPE_SIGNAL,
                            NULL, path, iface, name, NULL))
    {
      dbus_message_unref (message);
      return NULL;
    }
 
  dbus_message_set_no_reply (message, TRUE);
 
  return message;
}
 
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_COMPILER_BYTE_ORDER,
                            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;
}
 
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;
}
 
 
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;
 
  _dbus_atomic_inc (&retval->refcount);
 
  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;
 
#ifdef HAVE_UNIX_FD_PASSING
  retval->unix_fds = dbus_new(int, message->n_unix_fds);
  if (retval->unix_fds == NULL && message->n_unix_fds > 0)
    goto failed_copy;
 
  retval->n_unix_fds_allocated = message->n_unix_fds;
 
  for (retval->n_unix_fds = 0;
       retval->n_unix_fds < message->n_unix_fds;
       retval->n_unix_fds++)
    {
      retval->unix_fds[retval->n_unix_fds] = _dbus_dup(message->unix_fds[retval->n_unix_fds], NULL);
 
      if (retval->unix_fds[retval->n_unix_fds] < 0)
        goto failed_copy;
    }
 
#endif
 
  _dbus_message_trace_ref (retval, 0, 1, "copy");
  return retval;
 
 failed_copy:
  _dbus_header_free (&retval->header);
  _dbus_string_free (&retval->body);
 
#ifdef HAVE_UNIX_FD_PASSING
  close_unix_fds(retval->unix_fds, &retval->n_unix_fds);
  dbus_free(retval->unix_fds);
#endif
 
  dbus_free (retval);
 
  return NULL;
}
 
 
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);
  _dbus_message_trace_ref (message, old_refcount, old_refcount + 1, "ref");
 
  return message;
}
 
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 >= 1);
 
  _dbus_message_trace_ref (message, old_refcount, old_refcount - 1, "unref");
 
  if (old_refcount == 1)
    {
      /* Calls application callbacks! */
      dbus_message_cache_or_finalize (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);
}
 
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;
}
 
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 void *value;
          value = va_arg (var_args, const void *);
 
          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) &&
              element_type != DBUS_TYPE_UNIX_FD)
            {
              const void **value;
              int n_elements;
 
              value = va_arg (var_args, const void **);
              n_elements = va_arg (var_args, int);
              
              if (!dbus_message_iter_append_fixed_array (&array,
                                                         element_type,
                                                         value,
                                                         n_elements)) {
                dbus_message_iter_abandon_container (&iter, &array);
                goto failed;
              }
            }
          else if (_DBUS_TYPE_IS_STRINGLIKE (element_type))
            {
              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])) {
                    dbus_message_iter_abandon_container (&iter, &array);
                    goto failed;
                  }
                  ++i;
                }
            }
          else
            {
              _dbus_warn ("arrays of %s can't be appended with %s for now",
                          _dbus_type_to_string (element_type),
                          _DBUS_FUNCTION_NAME);
              dbus_message_iter_abandon_container (&iter, &array);
              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",
                      _dbus_type_to_string (type), _DBUS_FUNCTION_NAME);
          goto failed;
        }
#endif
 
      type = va_arg (var_args, int);
    }
 
  return TRUE;
 
 failed:
  return FALSE;
}
 
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;
}
 
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)
{
  /* If these static assertions fail on your platform, report it as a bug. */
  _DBUS_STATIC_ASSERT (sizeof (DBusMessageRealIter) <= sizeof (DBusMessageIter));
  _DBUS_STATIC_ASSERT (_DBUS_ALIGNOF (DBusMessageRealIter) <=
      _DBUS_ALIGNOF (DBusMessageIter));
#if CHECK_DBUS_1_10_BINARY_COMPATIBILITY
  /* A failure of these two assertions would indicate that we've broken
   * ABI on this platform since 1.10.0. */
  _DBUS_STATIC_ASSERT (sizeof (DBusMessageIter_1_10_0) ==
      sizeof (DBusMessageIter));
  _DBUS_STATIC_ASSERT (_DBUS_ALIGNOF (DBusMessageIter_1_10_0) ==
      _DBUS_ALIGNOF (DBusMessageIter));
#endif
  /* If this static assertion fails, it means the DBusMessageIter struct
   * is not "packed", which might result in "iter = other_iter" not copying
   * every byte. */
#if DBUS_SIZEOF_VOID_P > 8
  _DBUS_STATIC_ASSERT (sizeof (DBusMessageIter) == 16 * sizeof (void *));
#else
  _DBUS_STATIC_ASSERT (sizeof (DBusMessageIter) ==
      4 * sizeof (void *) + sizeof (dbus_uint32_t) + 9 * sizeof (int));
#endif
 
  /* 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;
}
 
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,
                          _dbus_header_get_byte_order (&message->header),
                          type_str, type_pos,
                          &message->body,
                          0);
 
  return _dbus_type_reader_get_current_type (&real->u.reader) != DBUS_TYPE_INVALID;
}
 
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);
}
 
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);
}
 
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);
}
 
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);
}
 
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);
}
 
char *
dbus_message_iter_get_signature (DBusMessageIter *iter)
{
  const DBusString *sig;
  DBusString retstr;
  char *ret = NULL;
  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))
    goto oom;
 
  /* This is correct whether it succeeds or fails: on success it sets `ret`,
   * and on failure it leaves `ret` set to NULL. */
  _dbus_string_steal_data (&retstr, &ret);
 
oom:
  _dbus_string_free (&retstr);
  return ret;
}
 
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);
 
  if (dbus_message_iter_get_arg_type (iter) == DBUS_TYPE_UNIX_FD)
    {
#ifdef HAVE_UNIX_FD_PASSING
      DBusBasicValue idx;
 
      _dbus_type_reader_read_basic(&real->u.reader, &idx);
 
      if (idx.u32 >= real->message->n_unix_fds) {
        /* Hmm, we cannot really signal an error here, so let's make
           sure to return an invalid fd. */
        *((int*) value) = -1;
        return;
      }
 
      *((int*) value) = _dbus_dup(real->message->unix_fds[idx.u32], NULL);
#else
      *((int*) value) = -1;
#endif
    }
  else
    {
      _dbus_type_reader_read_basic (&real->u.reader,
                                    value);
    }
}
 
int
dbus_message_iter_get_element_count (DBusMessageIter *iter)
{
  DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
  DBusTypeReader array;
  int element_type;
  int n_elements = 0;
 
  _dbus_return_val_if_fail (_dbus_message_iter_check (real), 0);
  _dbus_return_val_if_fail (_dbus_type_reader_get_current_type (&real->u.reader)
                            == DBUS_TYPE_ARRAY, 0);
 
  element_type = _dbus_type_reader_get_element_type (&real->u.reader);
  _dbus_type_reader_recurse (&real->u.reader, &array);
  if (dbus_type_is_fixed (element_type))
    {
      int alignment = _dbus_type_get_alignment (element_type);
      int total_len = _dbus_type_reader_get_array_length (&array);
      n_elements = total_len / alignment;
    }
  else
    {
      while (_dbus_type_reader_get_current_type (&array) != DBUS_TYPE_INVALID)
        {
          ++n_elements;
          _dbus_type_reader_next (&array);
        }
    }
 
   return n_elements;
}
 
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);
}
 
void
dbus_message_iter_get_fixed_array (DBusMessageIter  *iter,
                                   void             *value,
                                   int              *n_elements)
{
  DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
#ifndef DBUS_DISABLE_CHECKS
  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) && subtype != DBUS_TYPE_UNIX_FD));
#endif
 
  _dbus_type_reader_read_fixed_multi (&real->u.reader,
                                      value, n_elements);
}
 
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,
                                        _dbus_header_get_byte_order (&message->header),
                                        &message->body,
                                        _dbus_string_get_length (&message->body));
}
 
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,
                                   &current_sig, &current_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;
 
  /* If this assertion failed, then str would be neither stored in u.writer
   * nor freed by this function, resulting in a memory leak. */
  _dbus_assert (real->u.writer.type_str == NULL);
  _dbus_type_writer_add_types (&real->u.writer,
                               str, _dbus_string_get_length (str));
  return TRUE;
}
 
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;
}
 
static void
_dbus_message_iter_abandon_signature (DBusMessageRealIter *real)
{
  DBusString *str;
 
  _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;
  _dbus_assert (real->sig_refcount == 0);
 
  str = real->u.writer.type_str;
 
  _dbus_type_writer_remove_types (&real->u.writer);
  _dbus_string_free (str);
  dbus_free (str);
}
 
#if defined(DBUS_ENABLE_CHECKS) || defined(DBUS_ENABLE_ASSERT)
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)");
      return FALSE;
    }
 
  return TRUE;
}
#endif
 
#ifdef HAVE_UNIX_FD_PASSING
static int *
expand_fd_array(DBusMessage *m,
                unsigned     n)
{
  _dbus_assert(m);
 
  /* This makes space for adding n new fds to the array and returns a
     pointer to the place were the first fd should be put. */
 
  if (m->n_unix_fds + n > m->n_unix_fds_allocated)
    {
      unsigned k;
      int *p;
 
      /* Make twice as much space as necessary */
      k = (m->n_unix_fds + n) * 2;
 
      /* Allocate at least four */
      if (k < 4)
        k = 4;
 
      p = dbus_realloc(m->unix_fds, k * sizeof(int));
      if (p == NULL)
        return NULL;
 
      m->unix_fds = p;
      m->n_unix_fds_allocated = k;
    }
 
  return m->unix_fds + m->n_unix_fds;
}
#endif
 
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);
 
#ifndef DBUS_DISABLE_CHECKS
  switch (type)
    {
      DBusString str;
      DBusValidity signature_validity;
      const char * const *string_p;
      const dbus_bool_t *bool_p;
 
      case DBUS_TYPE_STRING:
        string_p = value;
        _dbus_return_val_if_fail (_dbus_check_is_valid_utf8 (*string_p), FALSE);
        break;
 
      case DBUS_TYPE_OBJECT_PATH:
        string_p = value;
        _dbus_return_val_if_fail (_dbus_check_is_valid_path (*string_p), FALSE);
        break;
 
      case DBUS_TYPE_SIGNATURE:
        string_p = value;
        _dbus_string_init_const (&str, *string_p);
        signature_validity = _dbus_validate_signature_with_reason (&str,
                                                                   0,
                                                                   _dbus_string_get_length (&str));
 
        if (signature_validity == DBUS_VALIDITY_UNKNOWN_OOM_ERROR)
          return FALSE;
 
        _dbus_return_val_if_fail (signature_validity == DBUS_VALID, FALSE);
        break;
 
      case DBUS_TYPE_BOOLEAN:
        bool_p = value;
        _dbus_return_val_if_fail (*bool_p == 0 || *bool_p == 1, FALSE);
        break;
 
      default:
          {
            /* nothing to check, all possible values are allowed */
          }
    }
#endif
 
  if (!_dbus_message_iter_open_signature (real))
    return FALSE;
 
  if (type == DBUS_TYPE_UNIX_FD)
    {
#ifdef HAVE_UNIX_FD_PASSING
      int *fds;
      dbus_uint32_t u;
 
      ret = FALSE;
 
      /* First step, include the fd in the fd list of this message */
      if (!(fds = expand_fd_array(real->message, 1)))
        goto out;
 
      *fds = _dbus_dup(*(int*) value, NULL);
      if (*fds < 0)
        goto out;
 
      u = real->message->n_unix_fds;
 
      /* Second step, write the index to the fd */
      if (!(ret = _dbus_type_writer_write_basic (&real->u.writer, DBUS_TYPE_UNIX_FD, &u))) {
        _dbus_close(*fds, NULL);
        goto out;
      }
 
      real->message->n_unix_fds += 1;
      u += 1;
 
      /* Final step, update the header accordingly */
      ret = _dbus_header_set_field_basic (&real->message->header,
                                          DBUS_HEADER_FIELD_UNIX_FDS,
                                          DBUS_TYPE_UINT32,
                                          &u);
 
      /* If any of these operations fail the message is
         hosed. However, no memory or fds should be leaked since what
         has been added to message has been added to the message, and
         can hence be accounted for when the message is being
         freed. */
#else
      ret = FALSE;
      /* This is redundant (we could just fall through), but it avoids
       * -Wunused-label in builds that don't HAVE_UNIX_FD_PASSING */
      goto out;
#endif
    }
  else
    {
      ret = _dbus_type_writer_write_basic (&real->u.writer, type, value);
    }
 
out:
  if (!_dbus_message_iter_close_signature (real))
    ret = FALSE;
 
  return ret;
}
 
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) && element_type != DBUS_TYPE_UNIX_FD, 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);
 
#ifndef DBUS_DISABLE_CHECKS
  if (element_type == DBUS_TYPE_BOOLEAN)
    {
      const dbus_bool_t * const *bools = value;
      int i;
 
      for (i = 0; i < n_elements; i++)
        {
          _dbus_return_val_if_fail ((*bools)[i] == 0 || (*bools)[i] == 1, FALSE);
        }
    }
#endif
 
  ret = _dbus_type_writer_write_fixed_multi (&real->u.writer, element_type, value, n_elements);
 
  return ret;
}
 
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;
  DBusValidity contained_signature_validity;
  dbus_bool_t ret;
 
  _dbus_return_val_if_fail (sub != NULL, FALSE);
  /* Do our best to make sure the sub-iterator doesn't contain something
   * valid-looking on failure */
  _dbus_message_real_iter_zero (real_sub);
 
  _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 ((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)
   */
  if (contained_signature != NULL)
    {
      _dbus_string_init_const (&contained_str, contained_signature);
      contained_signature_validity = _dbus_validate_signature_with_reason (&contained_str,
          0,
          _dbus_string_get_length (&contained_str));
 
      if (contained_signature_validity == DBUS_VALIDITY_UNKNOWN_OOM_ERROR)
        return FALSE;
    }
  else
    {
      /* just some placeholder value */
      contained_signature_validity = DBUS_VALID_BUT_INCOMPLETE;
    }
 
  _dbus_return_val_if_fail ((type == DBUS_TYPE_ARRAY && contained_signature && *contained_signature == DBUS_DICT_ENTRY_BEGIN_CHAR) ||
                            contained_signature == NULL ||
                            contained_signature_validity == DBUS_VALID,
                            FALSE);
 
  if (!_dbus_message_iter_open_signature (real))
    return FALSE;
 
  ret = FALSE;
  *real_sub = *real;
 
  if (contained_signature != NULL)
    {
      _dbus_string_init_const (&contained_str, contained_signature);
 
      ret = _dbus_type_writer_recurse (&real->u.writer,
                                       type,
                                       &contained_str, 0,
                                       &real_sub->u.writer);
    }
  else
    {
      ret = _dbus_type_writer_recurse (&real->u.writer,
                                       type,
                                       NULL, 0,
                                       &real_sub->u.writer);
    }
 
  if (!ret)
    _dbus_message_iter_abandon_signature (real);
 
  return ret;
}
 
 
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);
  _dbus_message_real_iter_zero (real_sub);
 
  if (!_dbus_message_iter_close_signature (real))
    ret = FALSE;
 
  return ret;
}
 
void
dbus_message_iter_abandon_container (DBusMessageIter *iter,
                                     DBusMessageIter *sub)
{
  DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
  DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub;
 
#ifndef DBUS_DISABLE_CHECKS
  _dbus_return_if_fail (_dbus_message_iter_append_check (real));
  _dbus_return_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
  _dbus_return_if_fail (_dbus_message_iter_append_check (real_sub));
  _dbus_return_if_fail (real_sub->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
#endif
 
  _dbus_message_iter_abandon_signature (real);
  _dbus_message_real_iter_zero (real_sub);
}
 
void
dbus_message_iter_abandon_container_if_open (DBusMessageIter *iter,
                                             DBusMessageIter *sub)
{
  DBusMessageRealIter *real = (DBusMessageRealIter *)iter;
  DBusMessageRealIter *real_sub = (DBusMessageRealIter *)sub;
 
  /* If both the parent and the child are zeroed out, then either we didn't
   * even get as far as successfully recursing into the parent, or we already
   * closed both the child and the parent. For example, in the code sample
   * in the doc-comment above, this happens for
   * abandon_container_if_open (&outer, &inner) if the first open_container
   * call failed, or if we reached result = TRUE and fell through. */
  if (_dbus_message_real_iter_is_zeroed (real) &&
      _dbus_message_real_iter_is_zeroed (real_sub))
    return;
 
#ifndef DBUS_DISABLE_CHECKS
  /* If the child is not zeroed out, but the parent is, then something has
   * gone horribly wrong (in practice that would probably mean both are
   * uninitialized or corrupt, and the parent happens to have ended up
   * all-bytes-zero). */
  _dbus_return_if_fail (_dbus_message_iter_append_check (real));
  _dbus_return_if_fail (real->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
#endif
 
  /* If the parent is not zeroed out, but the child is, then either we did
   * not successfully open the child, or we already closed the child. This
   * means we do not own a reference to the parent's signature, so it would
   * be wrong to release it; so we must not call abandon_signature() here.
   * In the code sample in the doc-comment above, this happens for
   * abandon_container_if_open (&outer, &inner) if the second open_container
   * call failed, or if the second close_container call failed. */
  if (_dbus_message_real_iter_is_zeroed (real_sub))
    return;
 
#ifndef DBUS_DISABLE_CHECKS
  _dbus_return_if_fail (_dbus_message_iter_append_check (real_sub));
  _dbus_return_if_fail (real_sub->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
#endif
 
  /* If neither the parent nor the child is zeroed out, then we genuinely
   * have an open container; close it. In the code sample in the doc-comment,
   * this happens for abandon_container_if_open (&outer, &inner) if the
   * append_basic call failed. */
  _dbus_message_iter_abandon_signature (real);
  _dbus_message_real_iter_zero (real_sub);
}
 
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);
}
 
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);
}
 
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);
}
 
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);
}
 
 
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);
}
 
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,
                                (void *) &v);
  return v;
}
 
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;
}
 
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;
}
 
dbus_bool_t
dbus_message_set_interface (DBusMessage  *message,
                            const char   *iface)
{
  _dbus_return_val_if_fail (message != NULL, FALSE);
  _dbus_return_val_if_fail (!message->locked, FALSE);
  _dbus_return_val_if_fail (iface == NULL ||
                            _dbus_check_is_valid_interface (iface),
                            FALSE);
 
  return set_or_delete_string_field (message,
                                     DBUS_HEADER_FIELD_INTERFACE,
                                     DBUS_TYPE_STRING,
                                     iface);
}
 
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,
                                (void *) &v);
  return v;
}
 
dbus_bool_t
dbus_message_has_interface (DBusMessage   *message,
                            const char    *iface)
{
  const char *msg_interface;
  msg_interface = dbus_message_get_interface (message);
   
  if (msg_interface == NULL)
    {
      if (iface == NULL)
        return TRUE;
      else
        return FALSE;
    }
 
  if (iface == NULL)
    return FALSE;
     
  if (strcmp (msg_interface, iface) == 0)
    return TRUE;
 
  return FALSE;
 
}
 
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);
}
 
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,
                                (void *) &v);
  return v;
}
 
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;
 
}
 
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);
}
 
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,
                                (void *) &v);
  return v;
}
 
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);
}
 
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,
                                (void *) &v);
  return v;
}
 
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);
}
 
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,
                                (void *) &v);
  return v;
}
 
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  *iface,
                                         const char  *member)
{
  const char *n;
 
  _dbus_assert (message != NULL);
  _dbus_assert (iface != 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, iface) == 0)
        return TRUE;
    }
 
  return FALSE;
}
 
dbus_bool_t
dbus_message_is_method_call (DBusMessage *message,
                             const char  *iface,
                             const char  *method)
{
  _dbus_return_val_if_fail (message != NULL, FALSE);
  _dbus_return_val_if_fail (iface != 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,
                                                  iface, method);
}
 
dbus_bool_t
dbus_message_is_signal (DBusMessage *message,
                        const char  *iface,
                        const char  *signal_name)
{
  _dbus_return_val_if_fail (message != NULL, FALSE);
  _dbus_return_val_if_fail (iface != 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,
                                                  iface, signal_name);
}
 
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;
}
 
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;
}
 
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;
}
 
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;
}
 
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;
}
 
dbus_bool_t
dbus_message_contains_unix_fds(DBusMessage *message)
{
#ifdef HAVE_UNIX_FD_PASSING
  _dbus_assert(message);
 
  return message->n_unix_fds > 0;
#else
  return FALSE;
#endif
}
 
dbus_bool_t
dbus_message_set_container_instance (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_CONTAINER_INSTANCE,
                                     DBUS_TYPE_OBJECT_PATH,
                                     object_path);
}
 
const char *
dbus_message_get_container_instance (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_CONTAINER_INSTANCE,
                                DBUS_TYPE_OBJECT_PATH,
                                (void *) &v);
  return v;
}
 
#define INITIAL_LOADER_DATA_LEN 32
 
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;
 
  /* We set a very relatively conservative default here since due to how
  SCM_RIGHTS works we need to preallocate an fd array of the maximum
  number of unix fds we want to receive in advance. A
  try-and-reallocate loop is not possible. */
  loader->max_message_unix_fds = DBUS_DEFAULT_MESSAGE_UNIX_FDS;
 
  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);
 
#ifdef HAVE_UNIX_FD_PASSING
  loader->unix_fds = NULL;
  loader->n_unix_fds = loader->n_unix_fds_allocated = 0;
  loader->unix_fds_outstanding = FALSE;
#endif
 
  return loader;
}
 
DBusMessageLoader *
_dbus_message_loader_ref (DBusMessageLoader *loader)
{
  loader->refcount += 1;
 
  return loader;
}
 
void
_dbus_message_loader_unref (DBusMessageLoader *loader)
{
  loader->refcount -= 1;
  if (loader->refcount == 0)
    {
#ifdef HAVE_UNIX_FD_PASSING
      close_unix_fds(loader->unix_fds, &loader->n_unix_fds);
      dbus_free(loader->unix_fds);
#endif
      _dbus_list_clear_full (&loader->messages,
                             (DBusFreeFunction) dbus_message_unref);
      _dbus_string_free (&loader->data);
      dbus_free (loader);
    }
}
 
void
_dbus_message_loader_get_buffer (DBusMessageLoader  *loader,
                                 DBusString        **buffer,
                                 int                *max_to_read,
                                 dbus_bool_t        *may_read_fds)
{
  _dbus_assert (!loader->buffer_outstanding);
 
  *buffer = &loader->data;
 
  loader->buffer_outstanding = TRUE;
 
  if (max_to_read != NULL)
    {
#ifdef HAVE_UNIX_FD_PASSING
      int offset = 0;
      int remain;
      int byte_order;
      int fields_array_len;
      int header_len;
      int body_len;
#endif
 
      *max_to_read = DBUS_MAXIMUM_MESSAGE_LENGTH;
      *may_read_fds = TRUE;
 
#ifdef HAVE_UNIX_FD_PASSING
      /* If we aren't holding onto any fds, we can read as much as we want
       * (fast path). */
      if (loader->n_unix_fds == 0)
        return;
 
      /* Slow path: we have a message with some fds in it. We don't want
       * to start on the next message until this one is out of the way;
       * otherwise a legitimate sender can keep us processing messages
       * containing fds, until we disconnect it for having had fds pending
       * for too long, a limit that is in place to stop malicious senders
       * from setting up recursive fd-passing that takes up our quota and
       * will never go away. */
 
      remain = _dbus_string_get_length (&loader->data);
 
      while (remain > 0)
        {
          DBusValidity validity = DBUS_VALIDITY_UNKNOWN;
          int needed;
 
          /* If 0 < remain < DBUS_MINIMUM_HEADER_SIZE, then we've had at
           * least the first byte of a message, but we don't know how
           * much more to read. Only read the rest of the
           * DBUS_MINIMUM_HEADER_SIZE for now; then we'll know. */
          if (remain < DBUS_MINIMUM_HEADER_SIZE)
            {
              *max_to_read = DBUS_MINIMUM_HEADER_SIZE - remain;
              *may_read_fds = FALSE;
              return;
            }
 
          if (!_dbus_header_have_message_untrusted (loader->max_message_size,
                                                    &validity,
                                                    &byte_order,
                                                    &fields_array_len,
                                                    &header_len,
                                                    &body_len,
                                                    &loader->data,
                                                    offset,
                                                    remain))
            {
              /* If a message in the buffer is invalid, we're going to
               * disconnect the sender anyway, so reading an arbitrary amount
               * is fine. */
              if (validity != DBUS_VALID)
                return;
 
              /* We have a partial message, with the
               * DBUS_MINIMUM_HEADER_SIZE-byte fixed part of the header (which
               * lets us work out how much more we need), but no more. Read
               * the rest of the message. */
              needed = header_len + body_len;
              _dbus_assert (needed > remain);
              *max_to_read = needed - remain;
              *may_read_fds = FALSE;
              return;
            }
 
          /* Skip over entire messages until we have less than a message
           * remaining. */
          needed = header_len + body_len;
          _dbus_assert (needed > DBUS_MINIMUM_HEADER_SIZE);
          _dbus_assert (remain >= needed);
          remain -= needed;
          offset += needed;
        }
#endif
    }
}
 
void
_dbus_message_loader_return_buffer (DBusMessageLoader  *loader,
                                    DBusString         *buffer)
{
  _dbus_assert (loader->buffer_outstanding);
  _dbus_assert (buffer == &loader->data);
 
  loader->buffer_outstanding = FALSE;
}
 
#ifdef HAVE_UNIX_FD_PASSING
dbus_bool_t
_dbus_message_loader_get_unix_fds(DBusMessageLoader  *loader,
                                  int               **fds,
                                  unsigned           *max_n_fds)
{
  _dbus_assert (!loader->unix_fds_outstanding);
 
  /* Allocate space where we can put the fds we read. We allocate
     space for max_message_unix_fds since this is an
     upper limit how many fds can be received within a single
     message. Since SCM_RIGHTS doesn't allow a reallocate+retry logic
     we are allocating the maximum possible array size right from the
     beginning. This sucks a bit, however unless SCM_RIGHTS is fixed
     there is no better way. */
 
  if (loader->n_unix_fds_allocated < loader->max_message_unix_fds)
    {
      int *a = dbus_realloc(loader->unix_fds,
                            loader->max_message_unix_fds * sizeof(loader->unix_fds[0]));
 
      if (!a)
        return FALSE;
 
      loader->unix_fds = a;
      loader->n_unix_fds_allocated = loader->max_message_unix_fds;
    }
 
  *fds = loader->unix_fds + loader->n_unix_fds;
  *max_n_fds = loader->n_unix_fds_allocated - loader->n_unix_fds;
 
  loader->unix_fds_outstanding = TRUE;
  return TRUE;
}
 
void
_dbus_message_loader_return_unix_fds(DBusMessageLoader  *loader,
                                     int                *fds,
                                     unsigned            n_fds)
{
  _dbus_assert(loader->unix_fds_outstanding);
  _dbus_assert(loader->unix_fds + loader->n_unix_fds == fds);
  _dbus_assert(loader->n_unix_fds + n_fds <= loader->n_unix_fds_allocated);
 
  loader->n_unix_fds += n_fds;
  loader->unix_fds_outstanding = FALSE;
 
  if (n_fds && loader->unix_fds_change)
    loader->unix_fds_change (loader->unix_fds_change_data);
}
#endif
 
/*
 * 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;
  dbus_uint32_t n_unix_fds = 0;
 
  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))
    {
      _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);
 
  /* 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 UNIX FDS */
  _dbus_header_get_field_basic(&message->header,
                               DBUS_HEADER_FIELD_UNIX_FDS,
                               DBUS_TYPE_UINT32,
                               &n_unix_fds);
 
#ifdef HAVE_UNIX_FD_PASSING
 
  if (n_unix_fds > loader->n_unix_fds)
    {
      _dbus_verbose("Message contains references to more unix fds than were sent %u != %u\n",
                    n_unix_fds, loader->n_unix_fds);
 
      loader->corrupted = TRUE;
      loader->corruption_reason = DBUS_INVALID_MISSING_UNIX_FDS;
      goto failed;
    }
 
  /* If this was a recycled message there might still be
     some memory allocated for the fds */
  dbus_free(message->unix_fds);
 
  if (n_unix_fds > 0)
    {
      message->unix_fds = _dbus_memdup(loader->unix_fds, n_unix_fds * sizeof(message->unix_fds[0]));
      if (message->unix_fds == NULL)
        {
          _dbus_verbose ("Failed to allocate file descriptor array\n");
          oom = TRUE;
          goto failed;
        }
 
      message->n_unix_fds_allocated = message->n_unix_fds = n_unix_fds;
      loader->n_unix_fds -= n_unix_fds;
      memmove (loader->unix_fds, loader->unix_fds + n_unix_fds, loader->n_unix_fds * sizeof (loader->unix_fds[0]));
 
      if (loader->unix_fds_change)
        loader->unix_fds_change (loader->unix_fds_change_data);
    }
  else
    message->unix_fds = NULL;
 
#else
 
  if (n_unix_fds > 0)
    {
      _dbus_verbose ("Hmm, message claims to come with file descriptors "
                     "but that's not supported on our platform, disconnecting.\n");
 
      loader->corrupted = TRUE;
      loader->corruption_reason = DBUS_INVALID_MISSING_UNIX_FDS;
      goto failed;
    }
 
#endif
 
  /* 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;
}
 
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;
}
 
DBusMessage*
_dbus_message_loader_peek_message (DBusMessageLoader *loader)
{
  if (loader->messages)
    return loader->messages->data;
  else
    return NULL;
}
 
DBusMessage*
_dbus_message_loader_pop_message (DBusMessageLoader *loader)
{
  return _dbus_list_pop_first (&loader->messages);
}
 
DBusList*
_dbus_message_loader_pop_message_link (DBusMessageLoader *loader)
{
  return _dbus_list_pop_first_link (&loader->messages);
}
 
void
_dbus_message_loader_putback_message_link (DBusMessageLoader  *loader,
                                           DBusList           *link)
{
  _dbus_list_prepend_link (&loader->messages, link);
}
 
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;
}
 
DBusValidity
_dbus_message_loader_get_corruption_reason (DBusMessageLoader *loader)
{
  _dbus_assert ((loader->corrupted && loader->corruption_reason != DBUS_VALID) ||
                (!loader->corrupted && loader->corruption_reason == DBUS_VALID));
 
  return loader->corruption_reason;
}
 
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;
}
 
long
_dbus_message_loader_get_max_message_size (DBusMessageLoader  *loader)
{
  return loader->max_message_size;
}
 
void
_dbus_message_loader_set_max_message_unix_fds (DBusMessageLoader  *loader,
                                               long                n)
{
  if (n > DBUS_MAXIMUM_MESSAGE_UNIX_FDS)
    {
      _dbus_verbose ("clamping requested max message unix_fds %ld to %d\n",
                     n, DBUS_MAXIMUM_MESSAGE_UNIX_FDS);
      n = DBUS_MAXIMUM_MESSAGE_UNIX_FDS;
    }
  loader->max_message_unix_fds = n;
}
 
long
_dbus_message_loader_get_max_message_unix_fds (DBusMessageLoader  *loader)
{
  return loader->max_message_unix_fds;
}
 
int
_dbus_message_loader_get_pending_fds_count (DBusMessageLoader *loader)
{
#ifdef HAVE_UNIX_FD_PASSING
  return loader->n_unix_fds;
#else
  return 0;
#endif
}
 
void
_dbus_message_loader_set_pending_fds_function (DBusMessageLoader *loader,
                                               void (* callback) (void *),
                                               void *data)
{
#ifdef HAVE_UNIX_FD_PASSING
  loader->unix_fds_change = callback;
  loader->unix_fds_change_data = data;
#endif
}
 
static DBusDataSlotAllocator slot_allocator =
  _DBUS_DATA_SLOT_ALLOCATOR_INIT (_DBUS_LOCK_NAME (message_slots));
 
dbus_bool_t
dbus_message_allocate_data_slot (dbus_int32_t *slot_p)
{
  return _dbus_data_slot_allocator_alloc (&slot_allocator,
                                          slot_p);
}
 
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);
}
 
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;
}
 
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;
}
 
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;
}
 
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";
    }
}
 
dbus_bool_t
dbus_message_marshal (DBusMessage  *msg,
                      char        **marshalled_data_p,
                      int          *len_p)
{
  DBusString tmp;
  dbus_bool_t was_locked;
 
  _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;
 
  /* Ensure the message is locked, to ensure the length header is filled in. */
  was_locked = msg->locked;
 
  if (!was_locked)
    dbus_message_lock (msg);
 
  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);
 
  if (!was_locked)
    msg->locked = FALSE;
 
  return TRUE;
 
 fail:
  _dbus_string_free (&tmp);
 
  if (!was_locked)
    msg->locked = FALSE;
 
  return FALSE;
}
 
DBusMessage *
dbus_message_demarshal (const char *str,
                        int         len,
                        DBusError  *error)
{
  DBusMessageLoader *loader = NULL;
  DBusString *buffer;
  DBusMessage *msg;
 
  _dbus_return_val_if_fail (str != NULL, NULL);
 
  loader = _dbus_message_loader_new ();
 
  if (loader == NULL)
    goto fail_oom;
 
  _dbus_message_loader_get_buffer (loader, &buffer, NULL, NULL);
 
  if (!_dbus_string_append_len (buffer, str, len))
    goto fail_oom;
 
  _dbus_message_loader_return_buffer (loader, buffer);
 
  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:
  if (loader->corruption_reason == DBUS_VALIDITY_UNKNOWN_OOM_ERROR)
    goto fail_oom;
 
  dbus_set_error (error, DBUS_ERROR_INVALID_ARGS, "Message is corrupted (%s)",
                  _dbus_validity_to_error_message (loader->corruption_reason));
  _dbus_message_loader_unref (loader);
  return NULL;
 
 fail_oom:
  _DBUS_SET_OOM (error);
 
  if (loader != NULL)
    _dbus_message_loader_unref (loader);
 
  return NULL;
}
 
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 || (header_len + body_len) > len);
      (void) have_message; /* unused unless asserting */
      return header_len + body_len;
    }
  else
    {
      return -1; /* broken! */
    }
}
 
void
dbus_message_set_allow_interactive_authorization (DBusMessage *message,
                                                  dbus_bool_t  allow)
{
  _dbus_return_if_fail (message != NULL);
  _dbus_return_if_fail (!message->locked);
 
  _dbus_header_toggle_flag (&message->header,
                            DBUS_HEADER_FLAG_ALLOW_INTERACTIVE_AUTHORIZATION,
                            allow);
}
 
dbus_bool_t
dbus_message_get_allow_interactive_authorization (DBusMessage *message)
{
  _dbus_return_val_if_fail (message != NULL, FALSE);
 
  return _dbus_header_get_flag (&message->header,
                                DBUS_HEADER_FLAG_ALLOW_INTERACTIVE_AUTHORIZATION);
}
 
struct DBusVariant
{
  DBusString data;
};
 
DBusVariant *
_dbus_variant_read (DBusMessageIter *reader)
{
  DBusVariant *self = NULL;
  /* Points to the single item we will read from the reader */
  DBusMessageRealIter *real_reader = (DBusMessageRealIter *) reader;
  /* The position in self at which we will write a single variant
   * (it is position 0) */
  DBusTypeWriter items_writer;
  /* The position in self at which we will write a copy of reader
   * (it is inside the variant) */
  DBusTypeWriter variant_writer;
  /* 'v' */
  DBusString variant_signature;
  /* Whatever is the signature of the item we will copy from the reader */
  DBusString contained_signature;
  /* TRUE if self->data needs to be freed */
  dbus_bool_t data_inited = FALSE;
  /* The type of the item we will read from the reader */
  int type;
  /* The string, start position within that string, and length of the signature
   * of the single complete type of the item reader points to */
  const DBusString *sig;
  int start, len;
 
  _dbus_assert (_dbus_message_iter_check (real_reader));
  _dbus_assert (real_reader->iter_type == DBUS_MESSAGE_ITER_TYPE_READER);
  _dbus_string_init_const (&variant_signature, DBUS_TYPE_VARIANT_AS_STRING);
  type = dbus_message_iter_get_arg_type (reader);
  _dbus_type_reader_get_signature (&real_reader->u.reader, &sig, &start, &len);
 
  if (!_dbus_string_init (&contained_signature))
    return NULL;
 
  if (!_dbus_string_copy_len (sig, start, len, &contained_signature, 0))
    goto oom;
 
  self = dbus_new0 (DBusVariant, 1);
 
  if (self == NULL)
    goto oom;
 
  if (!_dbus_string_init (&self->data))
    goto oom;
 
  data_inited = TRUE;
 
  _dbus_type_writer_init_values_only (&items_writer, DBUS_COMPILER_BYTE_ORDER,
                                      &variant_signature, 0, &self->data, 0);
 
  if (!_dbus_type_writer_recurse (&items_writer, DBUS_TYPE_VARIANT,
                                  &contained_signature, 0, &variant_writer))
    goto oom;
 
  if (type == DBUS_TYPE_ARRAY)
    {
      /* Points to each item in turn inside the array we are copying */
      DBusMessageIter array_reader;
      /* Same as array_reader */
      DBusMessageRealIter *real_array_reader = (DBusMessageRealIter *) &array_reader;
      /* The position inside the copied array at which we will write
       * the copy of array_reader */
      DBusTypeWriter array_writer;
 
      dbus_message_iter_recurse (reader, &array_reader);
 
      if (!_dbus_type_writer_recurse (&variant_writer, type,
                                      &contained_signature, 1, &array_writer))
        goto oom;
 
      if (!_dbus_type_writer_write_reader (&array_writer,
                                           &real_array_reader->u.reader))
        goto oom;
 
      if (!_dbus_type_writer_unrecurse (&variant_writer, &array_writer))
        goto oom;
    }
  else if (type == DBUS_TYPE_DICT_ENTRY || type == DBUS_TYPE_VARIANT ||
           type == DBUS_TYPE_STRUCT)
    {
      /* Points to each item in turn inside the container we are copying */
      DBusMessageIter inner_reader;
      /* Same as inner_reader */
      DBusMessageRealIter *real_inner_reader = (DBusMessageRealIter *) &inner_reader;
      /* The position inside the copied container at which we will write the
       * copy of inner_reader */
      DBusTypeWriter inner_writer;
 
      dbus_message_iter_recurse (reader, &inner_reader);
 
      if (!_dbus_type_writer_recurse (&variant_writer, type, NULL, 0,
                                      &inner_writer))
        goto oom;
 
      if (!_dbus_type_writer_write_reader (&inner_writer,
                                           &real_inner_reader->u.reader))
        goto oom;
 
      if (!_dbus_type_writer_unrecurse (&variant_writer, &inner_writer))
        goto oom;
    }
  else
    {
      DBusBasicValue value;
 
      /* We eliminated all the container types above */
      _dbus_assert (dbus_type_is_basic (type));
 
      dbus_message_iter_get_basic (reader, &value);
 
      if (!_dbus_type_writer_write_basic (&variant_writer, type, &value))
        goto oom;
    }
 
  _dbus_string_free (&contained_signature);
  return self;
 
oom:
  if (self != NULL)
    {
      if (data_inited)
        _dbus_string_free (&self->data);
 
      dbus_free (self);
    }
 
  _dbus_string_free (&contained_signature);
  return NULL;
}
 
const char *
_dbus_variant_get_signature (DBusVariant *self)
{
  const char *ret;
#ifndef DBUS_DISABLE_ASSERT
  unsigned char len;
#endif
 
  _dbus_assert (self != NULL);
 
#ifndef DBUS_DISABLE_ASSERT
  /* Here we make use of the fact that the serialization of a variant starts
   * with the 1-byte length, then that many bytes of signature, then \0. */
  len = _dbus_string_get_byte (&self->data, 0);
#endif
  ret = _dbus_string_get_const_data_len (&self->data, 1, len);
  _dbus_assert (strlen (ret) == len);
  return ret;
}
 
dbus_bool_t
_dbus_variant_write (DBusVariant *self,
                     DBusMessageIter *writer)
{
  /* 'v' */
  DBusString variant_signature;
  /* Points to the single item in self */
  DBusTypeReader variant_reader;
  /* Points to the single item (of whatever type) inside the variant */
  DBusTypeReader reader;
  /* The position at which we will copy reader */
  DBusMessageRealIter *real_writer = (DBusMessageRealIter *) writer;
  dbus_bool_t ret;
 
  _dbus_assert (self != NULL);
  _dbus_assert (_dbus_message_iter_append_check (real_writer));
  _dbus_assert (real_writer->iter_type == DBUS_MESSAGE_ITER_TYPE_WRITER);
 
  _dbus_string_init_const (&variant_signature, DBUS_TYPE_VARIANT_AS_STRING);
  _dbus_type_reader_init (&reader, DBUS_COMPILER_BYTE_ORDER,
                          &variant_signature, 0, &self->data, 0);
  _dbus_type_reader_recurse (&reader, &variant_reader);
 
  if (!_dbus_message_iter_open_signature (real_writer))
    return FALSE;
 
  ret = _dbus_type_writer_write_reader (&real_writer->u.writer,
                                        &variant_reader);
 
  if (!_dbus_message_iter_close_signature (real_writer))
    return FALSE;
 
  return ret;
}
 
int
_dbus_variant_get_length (DBusVariant *self)
{
  _dbus_assert (self != NULL);
  return _dbus_string_get_length (&self->data);
}
 
const DBusString *
_dbus_variant_peek (DBusVariant *self)
{
  _dbus_assert (self != NULL);
  return &self->data;
}
 
void
_dbus_variant_free (DBusVariant *self)
{
  _dbus_assert (self != NULL);
  _dbus_string_free (&self->data);
  dbus_free (self);
}
 
/* tests in dbus-message-util.c */