/*

 * Fix-up values functions

 *

 * Copyright (C) 2010-2024, Joachim Metz <joachim.metz@gmail.com>

 *

 * Refer to AUTHORS for acknowledgements.

 *

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

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

 * the Free Software Foundation, either version 3 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 Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 */

#include <common.h>

#include <byte_stream.h>

#include <types.h>

#include "libfsntfs_fixup_values.h"

#include "libfsntfs_libcerror.h"

#include "libfsntfs_libcnotify.h"

/* Applies the fix-up values to the data

 * Returns 1 if successful or -1 on error

 */

int libfsntfs_fixup_values_apply(

     uint8_t *data,

     size_t data_size,

     uint16_t fixup_values_offset,

     uint16_t number_of_fixup_values,

     libcerror_error_t **error )

{

  static char *function           = "libfsntfs_fixup_values_apply";

  size_t data_offset              = 0;

  size_t fixup_placeholder_offset = 0;

  size_t fixup_value_offset       = 0;

  size_t fixup_values_size        = 0;

  uint16_t fixup_value_index      = 0;

#if defined( HAVE_DEBUG_OUTPUT )

  uint16_t value_16bit            = 0;

#endif

  if( data == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid MFT entry.",

     function );

    return( -1 );

  }

  if( data_size > (size_t) SSIZE_MAX )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

     "%s: invalid data size value out of bounds.",

     function );

    return( -1 );

  }

  if( fixup_values_offset >= data_size )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,

     "%s: invalid fix-up values offset value out of bounds.",

     function );

    return( -1 );

  }

  fixup_values_size = 2 + ( (size_t) number_of_fixup_values * 2 );

  if( ( number_of_fixup_values == 0 )

   || ( fixup_values_size > ( data_size - fixup_values_offset ) ) )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,

     "%s: invalide number of fix-up values value out of bounds.",

     function );

    return( -1 );

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: fix-up values data:\n",

     function );

    libcnotify_print_data(

     &( data[ fixup_values_offset ] ),

     fixup_values_size,

     0 );

  }

#endif

  fixup_placeholder_offset = (size_t) fixup_values_offset;

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    byte_stream_copy_to_uint16_little_endian(

     &( data[ fixup_placeholder_offset ] ),

     value_16bit );

    libcnotify_printf(

     "%s: fix-up placeholder value\t\t\t: 0x%04" PRIx16 "\n",

     function,

     value_16bit );

  }

#endif

  fixup_value_offset = fixup_placeholder_offset + 2;

  data_offset        = 510;

  for( fixup_value_index = 0;

       fixup_value_index < number_of_fixup_values;

       fixup_value_index++ )

  {

#if defined( HAVE_DEBUG_OUTPUT )

    if( libcnotify_verbose != 0 )

    {

      byte_stream_copy_to_uint16_little_endian(

       &( data[ fixup_value_offset ] ),

       value_16bit );

      libcnotify_printf(

       "%s: fix-up value: %" PRIu16 "\t\t\t\t: 0x%04" PRIx16 "\n",

       function,

       fixup_value_index,

       value_16bit );

    }

#endif

    if( ( data_offset + 1 ) < data_size )

    {

      if( ( data[ data_offset ] != data[ fixup_placeholder_offset ] )

       && ( data[ data_offset + 1 ] != data[ fixup_placeholder_offset + 1 ] ) )

      {

#if defined( HAVE_DEBUG_OUTPUT )

        if( libcnotify_verbose != 0 )

        {

          byte_stream_copy_to_uint16_little_endian(

           &( data[ data_offset ] ),

           value_16bit );

          libcnotify_printf(

           "%s: corruption detected - mismatch between placeholder and value at offset: %" PRIzd " (0x%04" PRIx16 ")\n",

           function,

           data_offset,

           value_16bit );

        }

#endif

/* TODO handle error */

      }

#if defined( HAVE_DEBUG_OUTPUT )

      if( libcnotify_verbose != 0 )

      {

        libcnotify_printf(

         "%s: applying fix-up value: %" PRIu16 "\t\t\t: (offset: %" PRIzd ") 0x%02" PRIx8 "%02" PRIx8 " => (offset: %" PRIzd ") 0x%02" PRIx8 "%02" PRIx8 "\n",

         function,

         fixup_value_index,

         data_offset,

         data[ data_offset + 1 ],

         data[ data_offset ],

         fixup_value_offset,

         data[ fixup_value_offset + 1 ],

         data[ fixup_value_offset ] );

      }

#endif

      data[ data_offset ]     = data[ fixup_value_offset ];

      data[ data_offset + 1 ] = data[ fixup_value_offset + 1 ];

    }

    fixup_value_offset += 2;

    data_offset        += 512;

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "\n" );

  }

#endif

  return( 1 );

}