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/* Lziprecover - Data recovery tool for the lzip format
Copyright (C) 2009-2014 Antonio Diaz Diaz.
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, see <http://www.gnu.org/licenses/>.
*/
#define _FILE_OFFSET_BITS 64
#include <algorithm>
#include <cerrno>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <vector>
#include <stdint.h>
#include <unistd.h>
#include "lzip.h"
#include "mtester.h"
void LZ_mtester::flush_data()
{
if( pos > stream_pos )
{
const int size = pos - stream_pos;
crc32.update_buf( crc_, buffer + stream_pos, size );
if( pos >= buffer_size ) { partial_data_pos += pos; pos = 0; }
stream_pos = pos;
}
}
bool LZ_mtester::verify_trailer()
{
const File_trailer * trailer = rdec.get_trailer();
if( !trailer ) return false;
return ( rdec.code_is_zero() &&
trailer->data_crc() == crc() &&
trailer->data_size() == data_position() &&
trailer->member_size() == (unsigned long)member_position() );
}
void LZ_mtester::duplicate_buffer()
{
uint8_t * const tmp = new uint8_t[buffer_size];
if( data_position() > 0 )
std::memcpy( tmp, buffer, std::min( data_position(),
(unsigned long long)buffer_size ) );
else tmp[buffer_size-1] = 0; // prev_byte of first byte
buffer = tmp;
}
/* Return value: 0 = OK, 1 = decoder error, 2 = unexpected EOF,
3 = trailer error, 4 = unknown marker found,
-1 = pos_limit reached. */
int LZ_mtester::test_member( const long pos_limit )
{
if( pos_limit < File_header::size + 5 ) return -1;
if( member_position() == File_header::size ) rdec.load();
while( !rdec.finished() )
{
if( member_position() >= pos_limit ) { flush_data(); return -1; }
const int pos_state = data_position() & pos_state_mask;
if( rdec.decode_bit( bm_match[state()][pos_state] ) == 0 ) // 1st bit
{
const uint8_t prev_byte = get_prev_byte();
if( state.is_char() )
{
state.set_char1();
put_byte( rdec.decode_tree8( bm_literal[get_lit_state(prev_byte)] ) );
}
else
{
state.set_char2();
put_byte( rdec.decode_matched( bm_literal[get_lit_state(prev_byte)],
get_byte( rep0 ) ) );
}
}
else
{
int len;
if( rdec.decode_bit( bm_rep[state()] ) != 0 ) // 2nd bit
{
if( rdec.decode_bit( bm_rep0[state()] ) != 0 ) // 3rd bit
{
unsigned distance;
if( rdec.decode_bit( bm_rep1[state()] ) == 0 ) // 4th bit
distance = rep1;
else
{
if( rdec.decode_bit( bm_rep2[state()] ) == 0 ) // 5th bit
distance = rep2;
else
{ distance = rep3; rep3 = rep2; }
rep2 = rep1;
}
rep1 = rep0;
rep0 = distance;
}
else
{
if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit
{ state.set_short_rep(); put_byte( get_byte( rep0 ) ); continue; }
}
state.set_rep();
len = min_match_len + rdec.decode_len( rep_len_model, pos_state );
}
else
{
const unsigned rep0_saved = rep0;
len = min_match_len + rdec.decode_len( match_len_model, pos_state );
const int dis_slot = rdec.decode_tree6( bm_dis_slot[get_len_state(len)] );
if( dis_slot < start_dis_model ) rep0 = dis_slot;
else
{
const int direct_bits = ( dis_slot >> 1 ) - 1;
rep0 = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
if( dis_slot < end_dis_model )
rep0 += rdec.decode_tree_reversed( bm_dis + rep0 - dis_slot - 1,
direct_bits );
else
{
rep0 += rdec.decode( direct_bits - dis_align_bits ) << dis_align_bits;
rep0 += rdec.decode_tree_reversed4( bm_align );
if( rep0 == 0xFFFFFFFFU ) // marker found
{
rep0 = rep0_saved;
rdec.normalize();
flush_data();
if( len == min_match_len ) // End Of Stream marker
{
if( verify_trailer() ) return 0; else return 3;
}
return 4;
}
}
}
rep3 = rep2; rep2 = rep1; rep1 = rep0_saved;
state.set_match();
if( rep0 >= dictionary_size || rep0 >= data_position() )
{ flush_data(); return 1; }
}
copy_block( rep0, len );
}
}
flush_data();
return 2;
}
uint8_t * read_member( const int infd, const long long mpos,
const long long msize )
{
if( msize <= 0 || msize > LONG_MAX )
{ show_error( "Member is larger than LONG_MAX." ); return 0; }
if( !safe_seek( infd, mpos ) ) return 0;
uint8_t * const buffer = new uint8_t[msize];
if( readblock( infd, buffer, msize ) != msize )
{ show_error( "Error reading input file", errno );
delete[] buffer; return 0; }
return buffer;
}
const LZ_mtester * prepare_master( const uint8_t * const buffer,
const long buffer_size,
const long pos_limit )
{
File_header & header = *(File_header *)buffer;
const unsigned dictionary_size = header.dictionary_size();
if( header.verify_magic() && header.verify_version() &&
dictionary_size >= min_dictionary_size &&
dictionary_size <= max_dictionary_size )
{
LZ_mtester * const master =
new LZ_mtester( buffer, buffer_size, dictionary_size );
if( master->test_member( pos_limit ) == -1 ) return master;
delete master;
}
return 0;
}
bool test_member_rest( const LZ_mtester & master, long * const failure_posp )
{
LZ_mtester mtester( master );
mtester.duplicate_buffer();
if( mtester.test_member() == 0 && mtester.finished() ) return true;
if( failure_posp ) *failure_posp = mtester.member_position();
return false;
}
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