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/*
* Bit stream functions
*
* Copyright (C) 2009-2017, Joachim Metz <joachim.metz@gmail.com>
*
* Refer to AUTHORS for acknowledgements.
*
* This software 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 software 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 software. If not, see <http://www.gnu.org/licenses/>.
*/
#include <common.h>
#include <byte_stream.h>
#include <memory.h>
#include <types.h>
#include "libfwnt_bit_stream.h"
#include "libfwnt_libcerror.h"
#include "libfwnt_libcnotify.h"
/* Creates a bit stream
* Make sure the value bit_stream is referencing, is set to NULL
* Returns 1 if successful or -1 on error
*/
int libfwnt_bit_stream_initialize(
libfwnt_bit_stream_t **bit_stream,
const uint8_t *byte_stream,
size_t byte_stream_size,
libcerror_error_t **error )
{
static char *function = "libfwnt_bit_stream_initialize";
if( bit_stream == NULL )
{
libcerror_error_set(
error,
LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
"%s: invalid bit stream.",
function );
return( -1 );
}
if( *bit_stream != NULL )
{
libcerror_error_set(
error,
LIBCERROR_ERROR_DOMAIN_RUNTIME,
LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,
"%s: invalid bit stream value already set.",
function );
return( -1 );
}
*bit_stream = memory_allocate_structure(
libfwnt_bit_stream_t );
if( *bit_stream == NULL )
{
libcerror_error_set(
error,
LIBCERROR_ERROR_DOMAIN_MEMORY,
LIBCERROR_MEMORY_ERROR_INSUFFICIENT,
"%s: unable to create bit stream.",
function );
goto on_error;
}
if( memory_set(
*bit_stream,
0,
sizeof( libfwnt_bit_stream_t ) ) == NULL )
{
libcerror_error_set(
error,
LIBCERROR_ERROR_DOMAIN_MEMORY,
LIBCERROR_MEMORY_ERROR_SET_FAILED,
"%s: unable to clear bit stream.",
function );
goto on_error;
}
( *bit_stream )->byte_stream = byte_stream;
( *bit_stream )->byte_stream_size = byte_stream_size;
return( 1 );
on_error:
if( *bit_stream != NULL )
{
memory_free(
*bit_stream );
*bit_stream = NULL;
}
return( -1 );
}
/* Frees a bit stream
* Returns 1 if successful or -1 on error
*/
int libfwnt_bit_stream_free(
libfwnt_bit_stream_t **bit_stream,
libcerror_error_t **error )
{
static char *function = "libfwnt_bit_stream_free";
if( bit_stream == NULL )
{
libcerror_error_set(
error,
LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
"%s: invalid bit stream.",
function );
return( -1 );
}
if( *bit_stream != NULL )
{
memory_free(
*bit_stream );
*bit_stream = NULL;
}
return( 1 );
}
/* Reads bits from the underlying byte stream
* Returns the number of bytes read, 0 if no data available or -1 on error
*/
ssize_t libfwnt_bit_stream_read(
libfwnt_bit_stream_t *bit_stream,
size_t read_size,
libcerror_error_t **error )
{
uint32_t bits = 0;
static char *function = "libfwnt_bit_stream_read";
uint8_t number_of_bits = 0;
if( bit_stream == NULL )
{
libcerror_error_set(
error,
LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
"%s: invalid bit stream.",
function );
return( -1 );
}
if( read_size > (size_t) SSIZE_MAX )
{
libcerror_error_set(
error,
LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,
"%s: invalid read size value exceeds maximum.",
function );
return( -1 );
}
if( ( read_size != 2 )
&& ( read_size != 4 ) )
{
libcerror_error_set(
error,
LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,
"%s: read size value out of bounds.",
function );
return( -1 );
}
if( bit_stream->byte_stream_offset >= bit_stream->byte_stream_size )
{
return( 0 );
}
if( ( bit_stream->byte_stream_offset + read_size ) > bit_stream->byte_stream_size )
{
read_size = bit_stream->byte_stream_size - bit_stream->byte_stream_offset;
}
if( read_size == 0 )
{
return( 0 );
}
number_of_bits = (uint8_t) ( read_size << 3 );
if( ( number_of_bits + bit_stream->number_of_bits ) > 32 )
{
libcerror_error_set(
error,
LIBCERROR_ERROR_DOMAIN_RUNTIME,
LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,
"%s: number of bits value out of bounds.",
function );
return( -1 );
}
/* TODO optimize the read for the maximum number of available bytes. ? */
/* TODO what about handling intermediate read size values ? */
while( number_of_bits >= 16 )
{
bit_stream->bits <<= 16;
byte_stream_copy_to_uint16_little_endian(
&( bit_stream->byte_stream[ bit_stream->byte_stream_offset ] ),
bits );
bit_stream->bits |= bits;
bit_stream->byte_stream_offset += 2;
bit_stream->number_of_bits += 16;
number_of_bits -= 16;
}
return( (ssize_t) read_size );
}
|
