/* -*- mode: C; c-file-style: "gnu" -*- */

/* dbus-marshal-byteswap.c  Swap a block of marshaled data

 *

 * Copyright (C) 2005 Red Hat, Inc.

 * Portion Copyright © 2008 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.

 * Licensed under the Academic Free License version 2.1

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#include "dbus-marshal-byteswap.h"

#include "dbus-marshal-basic.h"

#include "dbus-signature.h"

/**

 * @addtogroup DBusMarshal

 * @{

 */

static void

byteswap_body_helper (DBusTypeReader       *reader,

                      dbus_bool_t           walk_reader_to_end,

                      int                   old_byte_order,

                      int                   new_byte_order,

                      unsigned char        *p,

                      unsigned char       **new_p)

{

  int current_type;

  while ((current_type = _dbus_type_reader_get_current_type (reader)) != DBUS_TYPE_INVALID)

    {

      switch (current_type)

        {

        case DBUS_TYPE_BYTE:

          ++p;

          break;

        case DBUS_TYPE_INT16:

        case DBUS_TYPE_UINT16:

          {

            p = _DBUS_ALIGN_ADDRESS (p, 2);

            *((dbus_uint16_t*)p) = DBUS_UINT16_SWAP_LE_BE (*((dbus_uint16_t*)p));

            p += 2;

          }

          break;

        case DBUS_TYPE_BOOLEAN:

        case DBUS_TYPE_INT32:

        case DBUS_TYPE_UINT32:

          {

            p = _DBUS_ALIGN_ADDRESS (p, 4);

            *((dbus_uint32_t*)p) = DBUS_UINT32_SWAP_LE_BE (*((dbus_uint32_t*)p));

            p += 4;

          }

          break;

        case DBUS_TYPE_INT64:

        case DBUS_TYPE_UINT64:

        case DBUS_TYPE_DOUBLE:

          {

            p = _DBUS_ALIGN_ADDRESS (p, 8);

#ifdef DBUS_HAVE_INT64

            *((dbus_uint64_t*)p) = DBUS_UINT64_SWAP_LE_BE (*((dbus_uint64_t*)p));

#else

            _dbus_swap_array (p, 1, 8);

#endif

            p += 8;

          }

          break;

        case DBUS_TYPE_ARRAY:

        case DBUS_TYPE_STRING:

        case DBUS_TYPE_OBJECT_PATH:

          {

            dbus_uint32_t array_len;

            p = _DBUS_ALIGN_ADDRESS (p, 4);

            array_len = _dbus_unpack_uint32 (old_byte_order, p);

            *((dbus_uint32_t*)p) = DBUS_UINT32_SWAP_LE_BE (*((dbus_uint32_t*)p));

            p += 4;

            if (current_type == DBUS_TYPE_ARRAY)

              {

                int elem_type;

                int alignment;

                elem_type = _dbus_type_reader_get_element_type (reader);

                alignment = _dbus_type_get_alignment (elem_type);

		_dbus_assert ((array_len / alignment) < DBUS_MAXIMUM_ARRAY_LENGTH);

                p = _DBUS_ALIGN_ADDRESS (p, alignment);

                if (dbus_type_is_fixed (elem_type))

                  {

                    if (alignment > 1)

		      _dbus_swap_array (p, array_len / alignment, alignment);

		    p += array_len;

                  }

                else

                  {

                    DBusTypeReader sub;

                    const unsigned char *array_end;

                    array_end = p + array_len;

                    _dbus_type_reader_recurse (reader, &sub);

                    while (p < array_end)

                      {

                        byteswap_body_helper (&sub,

                                              FALSE,

                                              old_byte_order,

                                              new_byte_order,

                                              p, &p);

                      }

                  }

              }

            else

              {

                _dbus_assert (current_type == DBUS_TYPE_STRING ||

                              current_type == DBUS_TYPE_OBJECT_PATH);

                p += (array_len + 1); /* + 1 for nul */

              }

          }

          break;

        case DBUS_TYPE_SIGNATURE:

          {

            dbus_uint32_t sig_len;

            sig_len = *p;

            p += (sig_len + 2); /* +2 for len and nul */

          }

          break;

        case DBUS_TYPE_VARIANT:

          {

            /* 1 byte sig len, sig typecodes, align to

             * contained-type-boundary, values.

             */

            dbus_uint32_t sig_len;

            DBusString sig;

            DBusTypeReader sub;

            int contained_alignment;

            sig_len = *p;

            ++p;

#ifndef __SYMBIAN32__

            _dbus_string_init_const_len (&sig, p, sig_len);

#else

            _dbus_string_init_const_len (&sig, (const char *)p, sig_len);

#endif            

            p += (sig_len + 1); /* 1 for nul */

            contained_alignment = _dbus_type_get_alignment (_dbus_first_type_in_signature (&sig, 0));

            p = _DBUS_ALIGN_ADDRESS (p, contained_alignment);

            _dbus_type_reader_init_types_only (&sub, &sig, 0);

            byteswap_body_helper (&sub, FALSE, old_byte_order, new_byte_order, p, &p);

          }

          break;

        case DBUS_TYPE_STRUCT:

        case DBUS_TYPE_DICT_ENTRY:

          {

            DBusTypeReader sub;

            p = _DBUS_ALIGN_ADDRESS (p, 8);

            _dbus_type_reader_recurse (reader, &sub);

            byteswap_body_helper (&sub, TRUE, old_byte_order, new_byte_order, p, &p);

          }

          break;

        default:

          _dbus_assert_not_reached ("invalid typecode in supposedly-validated signature");

          break;

        }

      if (walk_reader_to_end)

        _dbus_type_reader_next (reader);

      else

        break;

    }

  if (new_p)

    *new_p = p;

}

/**

 * Byteswaps the marshaled data in the given value_str.

 *

 * @param signature the types in the value_str

 * @param signature_start where in signature is the signature

 * @param old_byte_order the old byte order

 * @param new_byte_order the new byte order

 * @param value_str the string containing the body

 * @param value_pos where the values start

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

_dbus_marshal_byteswap (const DBusString *signature,

                        int               signature_start,

                        int               old_byte_order,

                        int               new_byte_order,

                        DBusString       *value_str,

                        int               value_pos)

{

  DBusTypeReader reader;

  _dbus_assert (value_pos >= 0);

  _dbus_assert (value_pos <= _dbus_string_get_length (value_str));

  if (old_byte_order == new_byte_order)

    return;

  _dbus_type_reader_init_types_only (&reader,

                                     signature, signature_start);

#ifndef __SYMBIAN32__

  byteswap_body_helper (&reader, TRUE,

                        old_byte_order, new_byte_order,

                        _dbus_string_get_data_len (value_str, value_pos, 0),

                        NULL);

#else

  byteswap_body_helper (&reader, TRUE,

                        old_byte_order, new_byte_order,

                        (unsigned char *)_dbus_string_get_data_len (value_str, value_pos, 0),

                        NULL);

#endif

}

/** @} */

/* Tests in dbus-marshal-byteswap-util.c */