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/* Lziprecover - Data recovery tool for lzipped files
Copyright (C) 2009, 2010, 2011, 2012, 2013 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"
const char * format_num( unsigned long long num,
unsigned long long limit,
const int set_prefix )
{
const char * const si_prefix[8] =
{ "k", "M", "G", "T", "P", "E", "Z", "Y" };
const char * const binary_prefix[8] =
{ "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi", "Yi" };
static bool si = true;
static char buf[32];
if( set_prefix ) si = ( set_prefix > 0 );
const unsigned factor = ( si ? 1000 : 1024 );
const char * const * prefix = ( si ? si_prefix : binary_prefix );
const char * p = "";
bool exact = ( num % factor == 0 );
for( int i = 0; i < 8 && ( num > limit || ( exact && num >= factor ) ); ++i )
{ num /= factor; if( num % factor != 0 ) exact = false; p = prefix[i]; }
snprintf( buf, sizeof buf, "%llu %s", num, p );
return buf;
}
File_index::File_index( const int infd ) : retval_( 0 )
{
const long long isize = lseek( infd, 0, SEEK_END );
if( isize < 0 )
{ error_ = "Input file is not seekable :";
error_ += std::strerror( errno ); retval_ = 1; return; }
if( isize > INT64_MAX )
{ error_ = "Input file is too long (2^63 bytes or more).";
retval_ = 2; return; }
long long pos = isize; // always points to a header or EOF
File_header header;
File_trailer trailer;
if( isize < min_member_size )
{ error_ = "Input file is too short."; retval_ = 2; return; }
if( seek_read( infd, header.data, File_header::size, 0 ) != File_header::size )
{ error_ = "Error reading member header :";
error_ += std::strerror( errno ); retval_ = 1; return; }
if( !header.verify_magic() )
{ error_ = "Bad magic number (file not in lzip format).";
retval_ = 2; return; }
if( !header.verify_version() )
{ error_ = "Version "; error_ += format_num( header.version() );
error_ += "member format not supported."; retval_ = 2; return; }
while( pos >= min_member_size )
{
if( seek_read( infd, trailer.data, File_trailer::size(),
pos - File_trailer::size() ) != File_trailer::size() )
{ error_ = "Error reading member trailer :";
error_ += std::strerror( errno ); retval_ = 1; break; }
const long long member_size = trailer.member_size();
if( member_size < min_member_size || member_size > pos )
{
if( member_vector.size() == 0 ) // maybe trailing garbage
{ --pos; continue; }
error_ = "Member size in trailer is corrupt at pos ";
error_ += format_num( pos - 8 ); retval_ = 2; break;
}
if( seek_read( infd, header.data, File_header::size,
pos - member_size ) != File_header::size )
{ error_ = "Error reading member header :";
error_ += std::strerror( errno ); retval_ = 1; break; }
if( !header.verify_magic() || !header.verify_version() )
{
if( member_vector.size() == 0 ) // maybe trailing garbage
{ --pos; continue; }
error_ = "Bad header at pos ";
error_ += format_num( pos - member_size ); retval_ = 2; break;
}
if( member_vector.size() == 0 && isize - pos > File_header::size &&
seek_read( infd, header.data, File_header::size, pos ) == File_header::size &&
header.verify_magic() && header.verify_version() )
{ // last trailer is corrupt
error_ = "Member size in trailer is corrupt at pos ";
error_ += format_num( isize - 8 ); retval_ = 2; break;
}
pos -= member_size;
member_vector.push_back( Member( 0, trailer.data_size(),
pos, member_size ) );
}
if( pos != 0 || member_vector.size() == 0 )
{
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 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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