/*

 * Block allocation table functions

 *

 * Copyright (C) 2012-2024, 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 <memory.h>

#include <types.h>

#include "libvhdi_block_allocation_table.h"

#include "libvhdi_block_descriptor.h"

#include "libvhdi_definitions.h"

#include "libvhdi_libbfio.h"

#include "libvhdi_libcerror.h"

#include "libvhdi_libcnotify.h"

#include "libvhdi_libfdata.h"

#include "libvhdi_unused.h"

/* Creates a block allocation table

 * Make sure the value block_allocation_table is referencing, is set to NULL

 * Returns 1 if successful or -1 on error

 */

int libvhdi_block_allocation_table_initialize(

     libvhdi_block_allocation_table_t **block_allocation_table,

     uint32_t number_of_entries,

     libcerror_error_t **error )

{

  static char *function = "libvhdi_block_allocation_table_initialize";

  if( block_allocation_table == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid block allocation table.",

     function );

    return( -1 );

  }

  if( *block_allocation_table != NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,

     "%s: invalid block allocation table value already set.",

     function );

    return( -1 );

  }

  if( number_of_entries == 0 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,

     "%s: invalid number of entries: %" PRIu32 " value out of bounds.",

     function,

     number_of_entries );

    return( -1 );

  }

  *block_allocation_table = memory_allocate_structure(

                             libvhdi_block_allocation_table_t );

  if( *block_allocation_table == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,

     "%s: unable to create block allocation table.",

     function );

    goto on_error;

  }

  if( memory_set(

       *block_allocation_table,

       0,

       sizeof( libvhdi_block_allocation_table_t ) ) == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_SET_FAILED,

     "%s: unable to clear block allocation table.",

     function );

    memory_free(

     *block_allocation_table );

    *block_allocation_table = NULL;

    return( -1 );

  }

  ( *block_allocation_table )->number_of_entries = number_of_entries;

  return( 1 );

on_error:

  if( *block_allocation_table != NULL )

  {

    memory_free(

     *block_allocation_table );

    *block_allocation_table = NULL;

  }

  return( -1 );

}

/* Frees a block allocation table

 * Returns 1 if successful or -1 on error

 */

int libvhdi_block_allocation_table_free(

     libvhdi_block_allocation_table_t **block_allocation_table,

     libcerror_error_t **error )

{

  static char *function = "libvhdi_block_allocation_table_free";

  if( block_allocation_table == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid block allocation table.",

     function );

    return( -1 );

  }

  if( *block_allocation_table != NULL )

  {

    memory_free(

     *block_allocation_table );

    *block_allocation_table = NULL;

  }

  return( 1 );

}

/* Reads the block allocation table

 * Returns 1 if successful or -1 on error

 */

int libvhdi_block_allocation_table_read_file_io_handle(

     libvhdi_block_allocation_table_t *block_allocation_table,

     libbfio_handle_t *file_io_handle,

     int file_type,

     uint32_t disk_type,

     off64_t file_offset,

     uint32_t block_size,

     uint32_t bytes_per_sector,

     libcerror_error_t **error )

{

  static char *function                        = "libvhdi_block_allocation_table_read_file_io_handle";

  uint64_t entries_per_chunk                   = 0;

  uint32_t sector_bitmap_size                  = 0;

#if defined( HAVE_DEBUG_OUTPUT )

  uint8_t empty_table_entry_data[ 8 ] = {

    0, 0, 0, 0, 0, 0, 0, 0 };

  libvhdi_block_descriptor_t *block_descriptor = NULL;

  uint8_t *data                                = NULL;

  size_t data_offset                           = 0;

  size_t read_size                             = 0;

  ssize_t read_count                           = 0;

  uint64_t table_entries_size                  = 0;

#endif

  if( block_allocation_table == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid block allocation table.",

     function );

    return( -1 );

  }

  if( ( file_type != LIBVHDI_FILE_TYPE_VHD )

   && ( file_type != LIBVHDI_FILE_TYPE_VHDX ) )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,

     "%s: unsupported file type.",

     function );

    return( -1 );

  }

  if( block_size == 0 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,

     "%s: invalid number of block size: %" PRIu32 " value out of bounds.",

     function,

     block_size );

    return( -1 );

  }

  if( ( bytes_per_sector != 512 )

   && ( bytes_per_sector != 4096 ) )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,

     "%s: unsupported bytes per sector.",

     function );

    return( -1 );

  }

  block_allocation_table->file_type        = file_type;

  block_allocation_table->disk_type        = disk_type;

  block_allocation_table->file_offset      = file_offset;

  block_allocation_table->block_size       = block_size;

  block_allocation_table->bytes_per_sector = bytes_per_sector;

  if( file_type == LIBVHDI_FILE_TYPE_VHD )

  {

    sector_bitmap_size = block_size / ( 512 * 8 );

    if( ( sector_bitmap_size % 512 ) != 0 )

    {

      sector_bitmap_size /= 512;

      sector_bitmap_size += 1;

      sector_bitmap_size *= 512;

    }

    block_allocation_table->sector_bitmap_size = sector_bitmap_size;

  }

  else if( file_type == LIBVHDI_FILE_TYPE_VHDX )

  {

    entries_per_chunk = ( ( (uint64_t) 1UL << 23 ) * bytes_per_sector ) / block_size;

#if defined( HAVE_DEBUG_OUTPUT )

    if( libcnotify_verbose != 0 )

    {

      libcnotify_printf(

       "%s: bytes per sector\t: %" PRIu32 "\n",

       function,

       bytes_per_sector );

      libcnotify_printf(

       "%s: entries per chunk\t: %" PRIu64 "\n",

       function,

       entries_per_chunk );

    }

#endif

    if( ( 1048576 % entries_per_chunk ) != 0 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,

       "%s: unsupported entries per chunk.",

       function );

      return( -1 );

    }

    block_allocation_table->entries_per_chunk  = (uint32_t) entries_per_chunk;

    block_allocation_table->sector_bitmap_size = 1048576 / entries_per_chunk;

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: sector bitmap size\t: %" PRIu32 "\n",

     function,

     block_allocation_table->sector_bitmap_size );

  }

#endif

  if( file_type == LIBVHDI_FILE_TYPE_VHD )

  {

    block_allocation_table->table_entry_size = 4;

  }

  else if( file_type == LIBVHDI_FILE_TYPE_VHDX )

  {

    block_allocation_table->table_entry_size = 8;

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: table entry size\t: %" PRIzd "\n",

     function,

     block_allocation_table->table_entry_size );

    libcnotify_printf(

     "\n" );

  }

#endif

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    if( ( file_type == LIBVHDI_FILE_TYPE_VHDX )

     && ( disk_type != LIBVHDI_DISK_TYPE_FIXED ) )

    {

      table_entries_size = block_allocation_table->number_of_entries / entries_per_chunk;

      if( ( block_allocation_table->number_of_entries % entries_per_chunk ) != 0 )

      {

        table_entries_size += 1;

      }

      table_entries_size *= entries_per_chunk + 1;

    }

    else

    {

      table_entries_size = block_allocation_table->number_of_entries;

    }

    table_entries_size *= block_allocation_table->table_entry_size;

    libcnotify_printf(

     "%s: table entries size\t: %" PRIu64 "\n",

     function,

     table_entries_size );

    file_offset += sector_bitmap_size;

    libcnotify_printf(

     "%s: reading block allocation table at offset: %" PRIi64 " (0x%08" PRIx64 ")\n",

     function,

     file_offset,

     file_offset );

    if( libbfio_handle_seek_offset(

         file_io_handle,

         file_offset,

         SEEK_SET,

         error ) == -1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_IO,

       LIBCERROR_IO_ERROR_SEEK_FAILED,

       "%s: unable to block allocation table at offset: %" PRIi64 " (0x%08" PRIx64 ").",

       function,

       file_offset,

       file_offset );

      goto on_error;

    }

    data = (uint8_t *) memory_allocate(

                        sizeof( uint8_t ) * 64 * 1024 );

    if( data == NULL )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_MEMORY,

       LIBCERROR_MEMORY_ERROR_INSUFFICIENT,

       "%s: unable to create block allocation table entries data.",

       function );

      goto on_error;

    }

    if( libvhdi_block_descriptor_initialize(

         &block_descriptor,

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,

       "%s: unable to create block descriptor.",

       function );

      goto on_error;

    }

    while( table_entries_size > 0 )

    {

      read_size = 64 * 1024;

      if( read_size > table_entries_size )

      {

        read_size = table_entries_size;

      }

      read_count = libbfio_handle_read_buffer(

                    file_io_handle,

                    data,

                    read_size,

                    error );

      if( read_count != (ssize_t) read_size )

      {

        libcerror_error_set(

         error,

         LIBCERROR_ERROR_DOMAIN_IO,

         LIBCERROR_IO_ERROR_READ_FAILED,

         "%s: unable to read block allocation table entries data.",

         function );

        goto on_error;

      }

      libcnotify_print_data(

       data,

       read_size,

       LIBCNOTIFY_PRINT_DATA_FLAG_GROUP_DATA );

      data_offset = 0;

      while( data_offset < read_size )

      {

        if( memory_compare(

             &( data[ data_offset ] ),

             empty_table_entry_data,

             block_allocation_table->table_entry_size ) != 0 )

        {

          if( libvhdi_block_descriptor_read_table_entry_data(

               block_descriptor,

               &( data[ data_offset ] ),

               block_allocation_table->table_entry_size,

               file_type,

               block_allocation_table->sector_bitmap_size,

               error ) != 1 )

          {

            libcerror_error_set(

             error,

             LIBCERROR_ERROR_DOMAIN_IO,

             LIBCERROR_IO_ERROR_READ_FAILED,

             "%s: unable to read allocation table entry.",

             function );

            goto on_error;

          }

        }

        data_offset += block_allocation_table->table_entry_size;

      }

      table_entries_size -= read_size;

    }

    if( libvhdi_block_descriptor_free(

         &block_descriptor,

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,

       "%s: unable to free block descriptor.",

       function );

      goto on_error;

    }

    memory_free(

     data );

  }

#endif /* defined( HAVE_DEBUG_OUTPUT ) */

  return( 1 );

#if defined( HAVE_DEBUG_OUTPUT )

on_error:

  if( block_descriptor != NULL )

  {

    libvhdi_block_descriptor_free(

     &block_descriptor,

     NULL );

  }

  if( data != NULL )

  {

    memory_free(

     data );

  }

  return( -1 );

#endif

}

/* Reads a block allocation table entry

 * Callback function for the data block vector

 * Returns 1 if successful or -1 on error

 */

int libvhdi_block_allocation_table_read_element_data(

     libvhdi_block_allocation_table_t *block_allocation_table,

     libbfio_handle_t *file_io_handle,

     libfdata_vector_t *vector,

     libfdata_cache_t *cache,

     int element_index,

     int element_data_file_index LIBVHDI_ATTRIBUTE_UNUSED,

     off64_t element_data_offset LIBVHDI_ATTRIBUTE_UNUSED,

     size64_t element_data_size LIBVHDI_ATTRIBUTE_UNUSED,

     uint32_t element_data_flags LIBVHDI_ATTRIBUTE_UNUSED,

     uint8_t read_flags LIBVHDI_ATTRIBUTE_UNUSED,

     libcerror_error_t **error )

{

  libvhdi_block_descriptor_t *block_descriptor               = NULL;

  libvhdi_block_descriptor_t *sector_bitmap_block_descriptor = NULL;

  static char *function                                      = "libvhdi_block_allocation_table_read_element_data";

  off64_t sector_bitmap_offset                               = 0;

  off64_t table_entry_offset                                 = 0;

  LIBVHDI_UNREFERENCED_PARAMETER( element_data_file_index );

  LIBVHDI_UNREFERENCED_PARAMETER( element_data_offset );

  LIBVHDI_UNREFERENCED_PARAMETER( element_data_size );

  LIBVHDI_UNREFERENCED_PARAMETER( element_data_flags );

  LIBVHDI_UNREFERENCED_PARAMETER( read_flags );

  if( block_allocation_table == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid block allocation table.",

     function );

    return( -1 );

  }

  if( libvhdi_block_descriptor_initialize(

       &block_descriptor,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,

     "%s: unable to create block descriptor.",

     function );

    goto on_error;

  }

  table_entry_offset = element_index;

  if( ( block_allocation_table->file_type == LIBVHDI_FILE_TYPE_VHDX )

   && ( block_allocation_table->disk_type != LIBVHDI_DISK_TYPE_FIXED ) )

  {

    table_entry_offset /= block_allocation_table->entries_per_chunk;

    table_entry_offset *= block_allocation_table->entries_per_chunk + 1;

    table_entry_offset += element_index % block_allocation_table->entries_per_chunk;

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: table entry index\t: %" PRIi64 "\n",

     function,

     table_entry_offset );

  }

#endif

  table_entry_offset *= block_allocation_table->table_entry_size;

  table_entry_offset += block_allocation_table->file_offset;

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: table entry offset\t: %" PRIi64 "\n",

     function,

     table_entry_offset );

    libcnotify_printf(

     "\n" );

  }

#endif

  if( libvhdi_block_descriptor_read_table_entry_file_io_handle(

       block_descriptor,

       file_io_handle,

       block_allocation_table->file_type,

       table_entry_offset,

       block_allocation_table->sector_bitmap_size,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_IO,

     LIBCERROR_IO_ERROR_READ_FAILED,

     "%s: unable to read block allocation table entry: %d.",

     function,

     element_index );

    goto on_error;

  }

  if( block_allocation_table->file_type == LIBVHDI_FILE_TYPE_VHD )

  {

    sector_bitmap_offset = block_descriptor->file_offset;

    if( sector_bitmap_offset != -1 )

    {

      sector_bitmap_offset -= block_allocation_table->sector_bitmap_size;

    }

  }

  else if( block_allocation_table->file_type == LIBVHDI_FILE_TYPE_VHDX )

  {

    if( block_allocation_table->disk_type != LIBVHDI_DISK_TYPE_DIFFERENTIAL )

    {

      sector_bitmap_offset = -1;

    }

    else

    {

      if( block_allocation_table->entries_per_chunk == 0 )

      {

        libcerror_error_set(

         error,

         LIBCERROR_ERROR_DOMAIN_RUNTIME,

         LIBCERROR_RUNTIME_ERROR_VALUE_MISSING,

         "%s: invalid block allocation table - missing entries per chunk.",

         function );

        goto on_error;

      }

      if( libvhdi_block_descriptor_initialize(

           &sector_bitmap_block_descriptor,

           error ) != 1 )

      {

        libcerror_error_set(

         error,

         LIBCERROR_ERROR_DOMAIN_RUNTIME,

         LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,

         "%s: unable to create sector bitmap block descriptor.",

         function );

        goto on_error;

      }

      table_entry_offset  = 1 + ( element_index / block_allocation_table->entries_per_chunk );

      table_entry_offset *= block_allocation_table->entries_per_chunk + 1;

      table_entry_offset -= 1;

#if defined( HAVE_DEBUG_OUTPUT )

      if( libcnotify_verbose != 0 )

      {

        libcnotify_printf(

         "%s: bitmap entry index\t: %" PRIi64 "\n",

         function,

         table_entry_offset );

      }

#endif

      table_entry_offset *= block_allocation_table->table_entry_size;

      table_entry_offset += block_allocation_table->file_offset;

#if defined( HAVE_DEBUG_OUTPUT )

      if( libcnotify_verbose != 0 )

      {

        libcnotify_printf(

         "%s: bitmap entry offset\t: %" PRIi64 "\n",

         function,

         table_entry_offset );

        libcnotify_printf(

         "\n" );

      }

#endif

      if( libvhdi_block_descriptor_read_table_entry_file_io_handle(

           sector_bitmap_block_descriptor,

           file_io_handle,

           block_allocation_table->file_type,

           table_entry_offset,

           block_allocation_table->sector_bitmap_size,

           error ) != 1 )

      {

        libcerror_error_set(

         error,

         LIBCERROR_ERROR_DOMAIN_IO,

         LIBCERROR_IO_ERROR_READ_FAILED,

         "%s: unable to read sector bitmap block allocation table entry.",

         function );

        goto on_error;

      }

      sector_bitmap_offset  = sector_bitmap_block_descriptor->file_offset;

      sector_bitmap_offset += ( element_index % block_allocation_table->entries_per_chunk ) * block_allocation_table->sector_bitmap_size;

      if( libvhdi_block_descriptor_free(

           &sector_bitmap_block_descriptor,

           error ) != 1 )

      {

        libcerror_error_set(

         error,

         LIBCERROR_ERROR_DOMAIN_RUNTIME,

         LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,

         "%s: unable to free sector bitmap block descriptor.",

         function );

        goto on_error;

      }

    }

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: sector bitmap offset\t: %" PRIi64 "\n",

     function,

     sector_bitmap_offset );

    libcnotify_printf(

     "\n" );

  }

#endif

  if( libvhdi_block_descriptor_read_sector_bitmap_file_io_handle(

       block_descriptor,

       file_io_handle,

       block_allocation_table->file_type,

       sector_bitmap_offset,

       block_allocation_table->block_size,

       block_allocation_table->sector_bitmap_size,

       block_allocation_table->bytes_per_sector,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_IO,

     LIBCERROR_IO_ERROR_READ_FAILED,

     "%s: unable to read block: %d sector bitmap.",

     function,

     element_index );

    goto on_error;

  }

  if( libfdata_vector_set_element_value_by_index(

       vector,

       (intptr_t *) file_io_handle,

       cache,

       element_index,

       (intptr_t *) block_descriptor,

       (int (*)(intptr_t **, libcerror_error_t **)) &libvhdi_block_descriptor_free,

       LIBFDATA_LIST_ELEMENT_VALUE_FLAG_MANAGED,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_SET_FAILED,

     "%s: unable to set block descriptor as element value.",

     function );

    goto on_error;

  }

  return( 1 );

on_error:

  if( sector_bitmap_block_descriptor != NULL )

  {

    libvhdi_block_descriptor_free(

     &sector_bitmap_block_descriptor,

     NULL );

  }

  if( block_descriptor != NULL )

  {

    libvhdi_block_descriptor_free(

     &block_descriptor,

     NULL );

  }

  return( 1 );

}