/* Lunzip - Decompressor for the lzip format
Copyright (C) 2010-2016 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 <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "lzip.h"
#include "decoder.h"
CRC32 crc32;
void Pp_show_msg( struct Pretty_print * const pp, const char * const msg )
{
if( verbosity >= 0 )
{
if( pp->first_post )
{
unsigned i;
pp->first_post = false;
fprintf( stderr, " %s: ", pp->name );
for( i = strlen( pp->name ); i < pp->longest_name; ++i )
fputc( ' ', stderr );
if( !msg ) fflush( stderr );
}
if( msg ) fprintf( stderr, "%s\n", msg );
}
}
/* Returns the number of bytes really read.
If (returned value < size) and (errno == 0), means EOF was reached.
*/
static int readblock( const int fd, uint8_t * const buf, const int size )
{
int sz = 0;
errno = 0;
while( sz < size )
{
const int n = read( fd, buf + sz, size - sz );
if( n > 0 ) sz += n;
else if( n == 0 ) break; /* EOF */
else if( errno != EINTR ) break;
errno = 0;
}
return sz;
}
/* Returns the number of bytes really written.
If (returned value < size), it is always an error.
*/
static int writeblock( const int fd, const uint8_t * const buf, const int size )
{
int sz = 0;
errno = 0;
while( sz < size )
{
const int n = write( fd, buf + sz, size - sz );
if( n > 0 ) sz += n;
else if( n < 0 && errno != EINTR ) break;
errno = 0;
}
return sz;
}
int seek_read( const int fd, uint8_t * const buf, const int size,
const int offset )
{
if( lseek( fd, offset, SEEK_END ) >= 0 )
return readblock( fd, buf, size );
return 0;
}
bool Rd_read_block( struct Range_decoder * const rdec )
{
if( !rdec->at_stream_end )
{
rdec->stream_pos = readblock( rdec->infd, rdec->buffer, rd_buffer_size );
if( rdec->stream_pos != rd_buffer_size && errno )
{ show_error( "Read error", errno, false ); cleanup_and_fail( 1 ); }
rdec->at_stream_end = ( rdec->stream_pos < rd_buffer_size );
rdec->partial_member_pos += rdec->pos;
rdec->pos = 0;
}
return rdec->pos < rdec->stream_pos;
}
void LZd_flush_data( struct LZ_decoder * const d )
{
if( d->pos > d->stream_pos )
{
const int size = d->pos - d->stream_pos;
CRC32_update_buf( &d->crc, d->buffer + d->stream_pos, size );
if( d->outfd >= 0 &&
writeblock( d->outfd, d->buffer + d->stream_pos, size ) != size )
{ show_error( "Write error", errno, false ); cleanup_and_fail( 1 ); }
if( d->pos >= d->buffer_size )
{ d->partial_data_pos += d->pos; d->pos = 0;
if( d->partial_data_pos >= d->dictionary_size ) d->pos_wrapped = true; }
d->stream_pos = d->pos;
}
}
static bool LZd_verify_trailer( struct LZ_decoder * const d,
struct Pretty_print * const pp )
{
File_trailer trailer;
int size = Rd_read_data( d->rdec, trailer, Ft_size );
const unsigned long long data_size = LZd_data_position( d );
const unsigned long long member_size = Rd_member_position( d->rdec );
bool error = false;
if( size < Ft_size )
{
error = true;
if( verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "Trailer truncated at trailer position %d;"
" some checks may fail.\n", size );
}
while( size < Ft_size ) trailer[size++] = 0;
}
if( Ft_get_data_crc( trailer ) != LZd_crc( d ) )
{
error = true;
if( verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "CRC mismatch; trailer says %08X, data CRC is %08X\n",
Ft_get_data_crc( trailer ), LZd_crc( d ) );
}
}
if( Ft_get_data_size( trailer ) != data_size )
{
error = true;
if( verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "Data size mismatch; trailer says %llu, data size is %llu (0x%llX)\n",
Ft_get_data_size( trailer ), data_size, data_size );
}
}
if( Ft_get_member_size( trailer ) != member_size )
{
error = true;
if( verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "Member size mismatch; trailer says %llu, member size is %llu (0x%llX)\n",
Ft_get_member_size( trailer ), member_size, member_size );
}
}
if( !error && verbosity >= 2 && data_size > 0 && member_size > 0 )
fprintf( stderr, "%6.3f:1, %6.3f bits/byte, %5.2f%% saved. ",
(double)data_size / member_size,
( 8.0 * member_size ) / data_size,
100.0 * ( 1.0 - ( (double)member_size / data_size ) ) );
if( !error && verbosity >= 4 )
fprintf( stderr, "data CRC %08X, data size %9llu, member size %8llu. ",
LZd_crc( d ), data_size, member_size );
return !error;
}
/* Return value: 0 = OK, 1 = decoder error, 2 = unexpected EOF,
3 = trailer error, 4 = unknown marker found. */
int LZd_decode_member( struct LZ_decoder * const d,
struct Pretty_print * const pp )
{
struct Range_decoder * const rdec = d->rdec;
void (* const copy_block)
( struct LZ_decoder * const d, const int distance, int len ) =
( (unsigned)d->buffer_size >= d->dictionary_size ) ?
&LZd_copy_block : &LZd_copy_block2;
unsigned rep0 = 0; /* rep[0-3] latest four distances */
unsigned rep1 = 0; /* used for efficient coding of */
unsigned rep2 = 0; /* repeated distances */
unsigned rep3 = 0;
State state = 0;
Rd_load( rdec );
while( !Rd_finished( rdec ) )
{
const int pos_state = LZd_data_position( d ) & pos_state_mask;
if( Rd_decode_bit( rdec, &d->bm_match[state][pos_state] ) == 0 ) /* 1st bit */
{
const uint8_t prev_byte = LZd_peek_prev( d );
if( St_is_char( state ) )
{
state -= ( state < 4 ) ? state : 3;
LZd_put_byte( d, Rd_decode_tree( rdec,
d->bm_literal[get_lit_state(prev_byte)], 8 ) );
}
else
{
state -= ( state < 10 ) ? 3 : 6;
LZd_put_byte( d, Rd_decode_matched( rdec,
d->bm_literal[get_lit_state(prev_byte)],
LZd_peek( d, rep0 ) ) );
}
}
else /* match or repeated match */
{
int len;
if( Rd_decode_bit( rdec, &d->bm_rep[state] ) != 0 ) /* 2nd bit */
{
if( Rd_decode_bit( rdec, &d->bm_rep0[state] ) != 0 ) /* 3rd bit */
{
unsigned distance;
if( Rd_decode_bit( rdec, &d->bm_rep1[state] ) == 0 ) /* 4th bit */
distance = rep1;
else
{
if( Rd_decode_bit( rdec, &d->bm_rep2[state] ) == 0 ) /* 5th bit */
distance = rep2;
else
{ distance = rep3; rep3 = rep2; }
rep2 = rep1;
}
rep1 = rep0;
rep0 = distance;
}
else
{
if( Rd_decode_bit( rdec, &d->bm_len[state][pos_state] ) == 0 ) /* 4th bit */
{ state = St_set_short_rep( state );
LZd_put_byte( d, LZd_peek( d, rep0 ) ); continue; }
}
state = St_set_rep( state );
len = min_match_len + Rd_decode_len( rdec, &d->rep_len_model, pos_state );
}
else /* match */
{
int dis_slot;
const unsigned rep0_saved = rep0;
len = min_match_len + Rd_decode_len( rdec, &d->match_len_model, pos_state );
dis_slot = Rd_decode_tree6( rdec, d->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 += Rd_decode_tree_reversed( rdec,
d->bm_dis + rep0 - dis_slot - 1, direct_bits );
else
{
rep0 += Rd_decode( rdec, direct_bits - dis_align_bits ) << dis_align_bits;
rep0 += Rd_decode_tree_reversed4( rdec, d->bm_align );
if( rep0 == 0xFFFFFFFFU ) /* marker found */
{
rep0 = rep0_saved;
Rd_normalize( rdec );
LZd_flush_data( d );
if( len == min_match_len ) /* End Of Stream marker */
{
if( LZd_verify_trailer( d, pp ) ) return 0; else return 3;
}
if( len == min_match_len + 1 ) /* Sync Flush marker */
{
Rd_load( rdec ); continue;
}
if( verbosity >= 0 )
{
Pp_show_msg( pp, 0 );
fprintf( stderr, "Unsupported marker code '%d'\n", len );
}
return 4;
}
}
}
rep3 = rep2; rep2 = rep1; rep1 = rep0_saved;
state = St_set_match( state );
if( rep0 >= d->dictionary_size ||
( rep0 >= LZd_data_position( d ) && !d->pos_wrapped ) )
{ LZd_flush_data( d ); return 1; }
}
copy_block( d, rep0, len );
}
}
LZd_flush_data( d );
return 2;
}