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/* Lziprecover - Data recovery tool for the lzip format
Copyright (C) 2009-2024 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 <sys/stat.h>
#include "lzip.h"
#include "mtester.h"
#include "lzip_index.h"
namespace {
bool pending_newline = false;
void print_pending_newline( const char terminator )
{ if( pending_newline && terminator != '\n' ) std::fputc( '\n', stdout );
pending_newline = false; }
bool gross_damage( const uint8_t * const mbuffer, const long msize )
{
enum { maxlen = 7 }; // max number of consecutive identical bytes
long i = Lzip_header::size;
const long end = msize - Lzip_trailer::size - maxlen;
while( i < end )
{
const uint8_t byte = mbuffer[i];
int len = 0; // does not count the first byte
while( mbuffer[++i] == byte ) if( ++len >= maxlen ) return true;
}
return false;
}
// Return value: 0 = no change, 5 = repaired pos
int repair_dictionary_size( uint8_t * const mbuffer, const long msize )
{
Lzip_header & header = *(Lzip_header *)mbuffer;
unsigned dictionary_size = header.dictionary_size();
const Lzip_trailer & trailer =
*(const Lzip_trailer *)( mbuffer + msize - trailer.size );
const unsigned long long data_size = trailer.data_size();
const bool valid_ds = isvalid_ds( dictionary_size );
if( valid_ds && dictionary_size >= data_size ) return 0; // can't be bad
const unsigned long long dict_size_9 = 1 << 25; // dict size of opt -9
if( !valid_ds || dictionary_size < dict_size_9 )
{
dictionary_size = std::min( data_size, dict_size_9 );
if( dictionary_size < min_dictionary_size )
dictionary_size = min_dictionary_size;
LZ_mtester mtester( mbuffer, msize, dictionary_size );
const int result = mtester.test_member();
if( result == 0 )
{ header.dictionary_size( dictionary_size ); return 5; } // fix DS
if( result != 1 || mtester.max_distance() <= dictionary_size ||
mtester.max_distance() > max_dictionary_size ) return 0;
}
if( data_size > dict_size_9 )
{
dictionary_size =
std::min( data_size, (unsigned long long)max_dictionary_size );
LZ_mtester mtester( mbuffer, msize, dictionary_size );
if( mtester.test_member() == 0 )
{ header.dictionary_size( dictionary_size ); return 5; } // fix DS
}
return 0;
}
const LZ_mtester * prepare_master( const uint8_t * const buffer,
const long buffer_size,
const unsigned long pos_limit,
const unsigned 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, uint8_t * const buffer2,
long * const failure_posp = 0 )
{
LZ_mtester mtester( master ); // tester with external buffer
mtester.duplicate_buffer( buffer2 );
if( mtester.test_member() == 0 && mtester.finished() ) return true;
if( failure_posp ) *failure_posp = mtester.member_position();
return false;
}
// Return value: -1 = master failed, 0 = begin reached, > 0 = repaired pos
long repair_member( uint8_t * const mbuffer, const long long mpos,
const long msize, const long begin, const long end,
const unsigned dictionary_size, const char terminator )
{
uint8_t * const buffer2 = new uint8_t[dictionary_size];
for( long pos = end; pos >= begin && pos > end - 50000; )
{
const long min_pos = std::max( begin, pos - 100 );
const unsigned long pos_limit = std::max( min_pos - 16, 0L );
const LZ_mtester * master =
prepare_master( mbuffer, msize, pos_limit, dictionary_size );
if( !master ) { delete[] buffer2; return -1; }
for( ; pos >= min_pos; --pos )
{
if( verbosity >= 2 )
{
std::printf( " Trying position %llu %c", mpos + pos, terminator );
std::fflush( stdout ); pending_newline = true;
}
for( int j = 0; j < 255; ++j )
{
++mbuffer[pos];
if( test_member_rest( *master, buffer2 ) )
{ delete master; delete[] buffer2; return pos; }
}
++mbuffer[pos];
}
delete master;
}
delete[] buffer2;
return 0;
}
} // end namespace
long seek_write( const int fd, const uint8_t * const buf, const long size,
const long long pos )
{
if( lseek( fd, pos, SEEK_SET ) == pos )
return writeblock( fd, buf, size );
return 0;
}
uint8_t * read_member( const int infd, const long long mpos,
const long long msize, const char * const filename )
{
if( msize <= 0 || msize > LONG_MAX )
{ show_file_error( filename,
"Input file contains member larger than LONG_MAX." ); return 0; }
if( !safe_seek( infd, mpos, filename ) ) return 0;
uint8_t * const buffer = new uint8_t[msize];
if( readblock( infd, buffer, msize ) != msize )
{ show_file_error( filename, read_error_msg, errno );
delete[] buffer; return 0; }
return buffer;
}
int byte_repair( const std::string & input_filename,
const std::string & default_output_filename,
const Cl_options & cl_opts,
const char terminator, const bool force )
{
const char * const filename = input_filename.c_str();
struct stat in_stats;
const int infd = open_instream( filename, &in_stats, false, true );
if( infd < 0 ) return 1;
const Lzip_index lzip_index( infd, cl_opts, true );
if( lzip_index.retval() != 0 )
{ show_file_error( filename, lzip_index.error().c_str() );
return lzip_index.retval(); }
const bool to_file = default_output_filename.size();
output_filename =
to_file ? default_output_filename : insert_fixed( input_filename );
if( !force && output_file_exists() ) return 1;
outfd = -1;
for( long i = 0; i < lzip_index.members(); ++i )
{
const long long mpos = lzip_index.mblock( i ).pos();
const long long msize = lzip_index.mblock( i ).size();
if( !safe_seek( infd, mpos, filename ) ) cleanup_and_fail( 1 );
long long failure_pos = 0;
if( test_member_from_file( infd, msize, &failure_pos ) == 0 ) continue;
if( failure_pos < Lzip_header::size ) // End Of File
{ show_error( "Can't repair error in input file." );
cleanup_and_fail( 2 ); }
if( failure_pos >= msize - 8 ) failure_pos = msize - 8 - 1;
if( verbosity >= 2 ) // damaged member found
{
std::printf( "Repairing member %ld of %ld (failure pos = %llu)\n",
i + 1, lzip_index.members(), mpos + failure_pos );
std::fflush( stdout );
}
uint8_t * const mbuffer = read_member( infd, mpos, msize, filename );
if( !mbuffer ) cleanup_and_fail( 1 );
const Lzip_header & header = *(const Lzip_header *)mbuffer;
const unsigned dictionary_size = header.dictionary_size();
long pos = 0;
if( !gross_damage( mbuffer, msize ) )
{
pos = repair_dictionary_size( mbuffer, msize );
if( pos == 0 )
pos = repair_member( mbuffer, mpos, msize, header.size + 1,
header.size + 6, dictionary_size, terminator );
if( pos == 0 )
pos = repair_member( mbuffer, mpos, msize, header.size + 7,
failure_pos, dictionary_size, terminator );
print_pending_newline( terminator );
}
if( pos < 0 )
{ show_error( "Can't prepare master." ); cleanup_and_fail( 1 ); }
if( pos > 0 )
{
if( outfd < 0 ) // first damaged member repaired
{
if( !safe_seek( infd, 0, filename ) ) return 1;
set_signal_handler();
if( !open_outstream( true, true, false, true, to_file ) ) return 1;
if( !copy_file( infd, outfd ) ) // copy whole file
cleanup_and_fail( 1 );
}
if( seek_write( outfd, mbuffer + pos, 1, mpos + pos ) != 1 )
{ show_error( "Error writing output file", errno );
cleanup_and_fail( 1 ); }
}
delete[] mbuffer;
if( pos == 0 )
{
show_error( "Can't repair input file. Error is probably larger than 1 byte." );
cleanup_and_fail( 2 );
}
}
if( outfd < 0 )
{
if( verbosity >= 1 )
std::fputs( "Input file has no errors. Recovery is not needed.\n", stdout );
return 0;
}
if( !close_outstream( &in_stats ) ) return 1;
if( verbosity >= 1 )
std::printf( "Repaired copy of '%s' written to '%s'\n",
filename, output_filename.c_str() );
return 0;
}
int debug_delay( const char * const input_filename,
const Cl_options & cl_opts, Block range,
const char terminator )
{
struct stat in_stats; // not used
const int infd = open_instream( input_filename, &in_stats, false, true );
if( infd < 0 ) return 1;
const Lzip_index lzip_index( infd, cl_opts );
if( lzip_index.retval() != 0 )
{ show_file_error( input_filename, lzip_index.error().c_str() );
return lzip_index.retval(); }
if( range.end() > lzip_index.cdata_size() )
range.size( std::max( 0LL, lzip_index.cdata_size() - range.pos() ) );
if( range.size() <= 0 )
{ show_file_error( input_filename, "Nothing to do; range is empty." );
return 0; }
for( long i = 0; i < lzip_index.members(); ++i )
{
const Block & mb = lzip_index.mblock( i );
if( !range.overlaps( mb ) ) continue;
const long long mpos = lzip_index.mblock( i ).pos();
const long long msize = lzip_index.mblock( i ).size();
const unsigned dictionary_size = lzip_index.dictionary_size( i );
if( verbosity >= 2 )
{
std::printf( "Finding max delay in member %ld of %ld (mpos = %llu, msize = %llu)\n",
i + 1, lzip_index.members(), mpos, msize );
std::fflush( stdout );
}
uint8_t * const mbuffer = read_member( infd, mpos, msize, input_filename );
if( !mbuffer ) return 1;
uint8_t * const buffer2 = new uint8_t[dictionary_size];
long pos = std::max( range.pos() - mpos, Lzip_header::size + 1LL );
const long end = std::min( range.end() - mpos, msize );
long max_delay = 0;
while( pos < end )
{
const unsigned long pos_limit = std::max( pos - 16, 0L );
const LZ_mtester * master =
prepare_master( mbuffer, msize, pos_limit, dictionary_size );
if( !master ) { show_error( "Can't prepare master." );
delete[] buffer2; delete[] mbuffer; return 1; }
const long partial_end = std::min( pos + 100, end );
for( ; pos < partial_end; ++pos )
{
if( verbosity >= 2 )
{
std::printf( " Delays at position %llu %c", mpos + pos, terminator );
std::fflush( stdout ); pending_newline = true;
}
int value = -1;
for( int j = 0; j < 256; ++j )
{
++mbuffer[pos];
if( j == 255 ) break;
long failure_pos = 0;
if( test_member_rest( *master, buffer2, &failure_pos ) ) continue;
const long delay = failure_pos - pos;
if( delay > max_delay ) { max_delay = delay; value = mbuffer[pos]; }
}
if( value >= 0 && verbosity >= 2 )
{
std::printf( " New max delay %lu at position %llu (0x%02X)\n",
max_delay, mpos + pos, value );
std::fflush( stdout ); pending_newline = false;
}
if( pos + max_delay >= msize ) { pos = end; break; }
}
delete master;
}
delete[] buffer2;
delete[] mbuffer;
print_pending_newline( terminator );
}
if( verbosity >= 1 ) std::fputs( "Done.\n", stdout );
return 0;
}
int debug_byte_repair( const char * const input_filename,
const Cl_options & cl_opts, const Bad_byte & bad_byte,
const char terminator )
{
struct stat in_stats; // not used
const int infd = open_instream( input_filename, &in_stats, false, true );
if( infd < 0 ) return 1;
const Lzip_index lzip_index( infd, cl_opts );
if( lzip_index.retval() != 0 )
{ show_file_error( input_filename, lzip_index.error().c_str() );
return lzip_index.retval(); }
long idx = 0;
for( ; idx < lzip_index.members(); ++idx )
if( lzip_index.mblock( idx ).includes( bad_byte.pos ) ) break;
if( idx >= lzip_index.members() )
{ show_file_error( input_filename, "Nothing to do; byte is beyond EOF." );
return 0; }
const long long mpos = lzip_index.mblock( idx ).pos();
const long long msize = lzip_index.mblock( idx ).size();
{
long long failure_pos = 0;
if( !safe_seek( infd, mpos, input_filename ) ) return 1;
if( test_member_from_file( infd, msize, &failure_pos ) != 0 )
{
if( verbosity >= 0 )
std::fprintf( stderr, "Member %ld of %ld already damaged (failure pos = %llu)\n",
idx + 1, lzip_index.members(), mpos + failure_pos );
return 2;
}
}
uint8_t * const mbuffer = read_member( infd, mpos, msize, input_filename );
if( !mbuffer ) return 1;
const Lzip_header & header = *(const Lzip_header *)mbuffer;
const unsigned dictionary_size = header.dictionary_size();
const uint8_t good_value = mbuffer[bad_byte.pos-mpos];
const uint8_t bad_value = bad_byte( good_value );
mbuffer[bad_byte.pos-mpos] = bad_value;
long failure_pos = 0;
if( bad_byte.pos != 5 || isvalid_ds( header.dictionary_size() ) )
{
LZ_mtester mtester( mbuffer, msize, header.dictionary_size() );
if( mtester.test_member() == 0 && mtester.finished() )
{
if( verbosity >= 1 )
std::fputs( "Member decompressed with no errors.\n", stdout );
delete[] mbuffer;
return 0;
}
failure_pos = mtester.member_position();
}
if( verbosity >= 2 )
{
std::printf( "Test repairing member %ld of %ld (mpos = %llu, msize = %llu)\n"
" (damage pos = %llu (0x%02X->0x%02X), failure pos = %llu, delay = %lld )\n",
idx + 1, lzip_index.members(), mpos, msize,
bad_byte.pos, good_value, bad_value, mpos + failure_pos,
mpos + failure_pos - bad_byte.pos );
std::fflush( stdout );
}
if( failure_pos >= msize ) failure_pos = msize - 1;
long pos = repair_dictionary_size( mbuffer, msize );
if( pos == 0 )
pos = repair_member( mbuffer, mpos, msize, header.size + 1,
header.size + 6, dictionary_size, terminator );
if( pos == 0 )
pos = repair_member( mbuffer, mpos, msize, header.size + 7,
failure_pos, dictionary_size, terminator );
print_pending_newline( terminator );
delete[] mbuffer;
if( pos < 0 ) { show_error( "Can't prepare master." ); return 1; }
if( pos == 0 ) internal_error( "can't repair input file." );
if( verbosity >= 1 ) std::fputs( "Member repaired successfully.\n", stdout );
return 0;
}
/* If show_packets is true, print to stdout descriptions of the decoded LZMA
packets. Print also some global values; total number of packets in
member, max distance (rep0) and its file position, max LZMA packet size
in each member and the file position of these packets.
(Packet sizes are a fractionary number of bytes. The packet and marker
sizes shown by option -X are the number of extra bytes required to decode
the packet, not counting the data present in the range decoder before and
after the decoding. The max marker size of a 'Sync Flush marker' does not
include the 5 bytes read by rdec.load).
if bad_byte.pos >= cdata_size, bad_byte is ignored.
*/
int debug_decompress( const char * const input_filename,
const Cl_options & cl_opts, const Bad_byte & bad_byte,
const bool show_packets )
{
struct stat in_stats;
const int infd = open_instream( input_filename, &in_stats, false, true );
if( infd < 0 ) return 1;
const Lzip_index lzip_index( infd, cl_opts );
if( lzip_index.retval() != 0 )
{ show_file_error( input_filename, lzip_index.error().c_str() );
return lzip_index.retval(); }
outfd = show_packets ? -1 : STDOUT_FILENO;
int retval = 0;
for( long i = 0; i < lzip_index.members(); ++i )
{
const long long dpos = lzip_index.dblock( i ).pos();
const long long mpos = lzip_index.mblock( i ).pos();
const long long msize = lzip_index.mblock( i ).size();
const unsigned dictionary_size = lzip_index.dictionary_size( i );
if( verbosity >= 1 && show_packets )
std::printf( "Decoding LZMA packets in member %ld of %ld (mpos = %llu, msize = %llu)\n"
" mpos dpos\n",
i + 1, lzip_index.members(), mpos, msize );
if( !isvalid_ds( dictionary_size ) )
{ show_error( bad_dict_msg ); retval = 2; break; }
uint8_t * const mbuffer = read_member( infd, mpos, msize, input_filename );
if( !mbuffer ) { retval = 1; break; }
if( bad_byte.pos >= 0 && lzip_index.mblock( i ).includes( bad_byte.pos ) )
{
const uint8_t good_value = mbuffer[bad_byte.pos-mpos];
const uint8_t bad_value = bad_byte( good_value );
mbuffer[bad_byte.pos-mpos] = bad_value;
if( verbosity >= 1 && show_packets )
std::printf( "Byte at pos %llu changed from 0x%02X to 0x%02X\n",
bad_byte.pos, good_value, bad_value );
}
LZ_mtester mtester( mbuffer, msize, dictionary_size, outfd );
const int result = mtester.debug_decode_member( dpos, mpos, show_packets );
delete[] mbuffer;
if( show_packets )
{
const std::vector< unsigned long long > & mppv = mtester.max_packet_posv();
const unsigned mpackets = mppv.size();
std::printf( "Total packets in member = %llu\n"
"Max distance in any match = %u at file position %llu\n"
"Max marker size found = %u\n"
"Max packet size found = %u (%u packets)%s",
mtester.total_packets(), mtester.max_distance(),
mtester.max_distance_pos(), mtester.max_marker_size(),
mtester.max_packet_size(), mpackets,
mpackets ? " at file positions" : "" );
for( unsigned i = 0; i < mpackets; ++i )
std::printf( " %llu", mppv[i] );
std::fputc( '\n', stdout );
}
if( result != 0 )
{
if( verbosity >= 0 && result <= 2 && show_packets )
std::printf( "%s at pos %llu\n", ( result == 2 ) ?
"File ends unexpectedly" : "Decoder error",
mpos + mtester.member_position() );
retval = 2;
if( result != 3 || !mtester.finished() || mtester.data_position() !=
(unsigned long long)lzip_index.dblock( i ).size() ) break;
}
if( i + 1 < lzip_index.members() && show_packets )
std::fputc( '\n', stdout );
}
if( !close_outstream( &in_stats ) && retval == 0 ) retval = 1;
if( verbosity >= 1 && show_packets && retval == 0 )
std::fputs( "Done.\n", stdout );
return retval;
}
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