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/* Lziprecover - Data recovery tool for lzip files
Copyright (C) 2009, 2010, 2011, 2012, 2013, 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 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 General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <algorithm>
#include <cerrno>
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>
#include <stdint.h>
#include <unistd.h>
#include "lzip.h"
#include "file_index.h"
int seek_read( const int fd, uint8_t * const buf, const int size,
const long long pos )
{
if( lseek( fd, pos, SEEK_SET ) == pos )
return readblock( fd, buf, size );
return 0;
}
Block Block::split( const long long pos )
{
if( pos > pos_ && pos < end() )
{
const Block b( pos_, pos - pos_ );
pos_ = pos; size_ -= b.size_;
return b;
}
return Block( 0, 0 );
}
void File_index::set_errno_error( const char * const msg )
{
error_ = msg; error_ += std::strerror( errno ); error_ += '.';
retval_ = 1;
}
void File_index::set_num_error( const char * const msg1, unsigned long long num,
const char * const msg2 )
{
char buf[80];
snprintf( buf, sizeof buf, "%s%llu%s", msg1, num, msg2 );
error_ = buf;
retval_ = 2;
}
File_index::File_index( const int infd )
: isize( lseek( infd, 0, SEEK_END ) ), retval_( 0 )
{
if( isize < 0 )
{ set_errno_error( "Input file is not seekable :" ); return; }
if( isize < min_member_size )
{ error_ = "Input file is too short."; retval_ = 2; return; }
if( isize > INT64_MAX )
{ error_ = "Input file is too long (2^63 bytes or more).";
retval_ = 2; return; }
File_header header;
if( seek_read( infd, header.data, File_header::size, 0 ) != File_header::size )
{ set_errno_error( "Error reading member header :" ); return; }
if( !header.verify_magic() )
{ error_ = "Bad magic number (file not in lzip format).";
retval_ = 2; return; }
if( !header.verify_version() )
{ set_num_error( "Version ", header.version(),
" member format not supported." ); return; }
long long pos = isize; // always points to a header or to EOF
while( pos >= min_member_size )
{
File_trailer trailer;
if( seek_read( infd, trailer.data, File_trailer::size,
pos - File_trailer::size ) != File_trailer::size )
{ set_errno_error( "Error reading member trailer :" ); break; }
const long long member_size = trailer.member_size();
if( member_size < min_member_size || member_size > pos )
{
if( member_vector.empty() ) // maybe trailing garbage
{ --pos; continue; }
set_num_error( "Member size in trailer is corrupt at pos ", pos - 8 );
break;
}
if( seek_read( infd, header.data, File_header::size,
pos - member_size ) != File_header::size )
{ set_errno_error( "Error reading member header :" ); break; }
if( !header.verify_magic() || !header.verify_version() )
{
if( member_vector.empty() ) // maybe trailing garbage
{ --pos; continue; }
set_num_error( "Bad header at pos ", pos - member_size );
break;
}
if( member_vector.empty() && isize - pos > File_header::size &&
seek_read( infd, header.data, File_header::size, pos ) == File_header::size &&
header.verify_magic() && header.verify_version() )
{
error_ = "Last member in input file is truncated or corrupt.";
retval_ = 2; break;
}
pos -= member_size;
member_vector.push_back( Member( 0, trailer.data_size(),
pos, member_size ) );
}
if( pos != 0 || member_vector.empty() )
{
member_vector.clear();
if( retval_ == 0 ) { error_ = "Can't create file index."; retval_ = 2; }
return;
}
std::reverse( member_vector.begin(), member_vector.end() );
for( unsigned long i = 0; i < member_vector.size() - 1; ++i )
{
const long long end = member_vector[i].dblock.end();
if( end < 0 || end > INT64_MAX )
{
member_vector.clear();
error_ = "Data in input file is too long (2^63 bytes or more).";
retval_ = 2; return;
}
member_vector[i+1].dblock.pos( end );
}
}
// All files in 'infd_vector' must be at least 'fsize' bytes long.
File_index::File_index( const std::vector< int > & infd_vector,
const long long fsize )
: isize( fsize ), retval_( 0 )
{
if( isize < 0 )
{ set_errno_error( "Input file is not seekable :" ); return; }
if( isize < min_member_size )
{ error_ = "Input file is too short."; retval_ = 2; return; }
if( isize > INT64_MAX )
{ error_ = "Input file is too long (2^63 bytes or more).";
retval_ = 2; return; }
const int files = infd_vector.size();
File_header header;
bool done = false;
for( int i = 0; i < files && !done; ++i )
{
const int infd = infd_vector[i];
if( seek_read( infd, header.data, File_header::size, 0 ) != File_header::size )
{ set_errno_error( "Error reading member header :" ); return; }
if( header.verify_magic() && header.verify_version() ) done = true;
}
if( !done )
{ error_ = "Bad magic number (file not in lzip format).";
retval_ = 2; return; }
long long pos = isize; // always points to a header or to EOF
while( pos >= min_member_size )
{
long long member_size;
File_trailer trailer;
done = false;
for( int it = 0; it < files && !done; ++it )
{
const int tfd = infd_vector[it];
if( seek_read( tfd, trailer.data, File_trailer::size,
pos - File_trailer::size ) != File_trailer::size )
{ set_errno_error( "Error reading member trailer :" ); goto error; }
member_size = trailer.member_size();
if( member_size >= min_member_size && member_size <= pos )
for( int ih = 0; ih < files && !done; ++ih )
{
const int hfd = infd_vector[ih];
if( seek_read( hfd, header.data, File_header::size,
pos - member_size ) != File_header::size )
{ set_errno_error( "Error reading member header :" ); goto error; }
if( header.verify_magic() && header.verify_version() ) done = true;
}
}
if( !done )
{
if( member_vector.empty() ) // maybe trailing garbage
{ --pos; continue; }
set_num_error( "Member size in trailer may be corrupt at pos ", pos - 8 );
break;
}
if( member_vector.empty() && isize - pos > File_header::size )
for( int i = 0; i < files; ++i )
{
const int infd = infd_vector[i];
if( seek_read( infd, header.data, File_header::size, pos ) == File_header::size &&
header.verify_magic() && header.verify_version() )
{
error_ = "Last member in input file is truncated or corrupt.";
retval_ = 2; goto error;
}
}
pos -= member_size;
member_vector.push_back( Member( 0, trailer.data_size(),
pos, member_size ) );
}
error:
if( pos != 0 || member_vector.empty() )
{
member_vector.clear();
if( retval_ == 0 ) { error_ = "Can't create file index."; retval_ = 2; }
return;
}
std::reverse( member_vector.begin(), member_vector.end() );
for( unsigned long i = 0; i < member_vector.size() - 1; ++i )
{
const long long end = member_vector[i].dblock.end();
if( end < 0 || end > INT64_MAX )
{
member_vector.clear();
error_ = "Data in input file is too long (2^63 bytes or more).";
retval_ = 2; return;
}
member_vector[i+1].dblock.pos( end );
}
}
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