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/* Tarlz - Archiver with multimember lzip compression
Copyright (C) 2013-2020 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 <cctype>
#include <cerrno>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <vector>
#include <pthread.h>
#include <stdint.h>
#include <unistd.h>
#include <lzlib.h>
#include "arg_parser.h"
#include "tarlz.h"
#include "lzip_index.h"
namespace {
bool parse_records( const int infd, Extended & extended,
const Tar_header header, Resizable_buffer & rbuf,
const bool permissive )
{
const long long edsize = parse_octal( header + size_o, size_l );
const long long bufsize = round_up( edsize );
if( edsize <= 0 || edsize >= 1LL << 33 || bufsize >= INT_MAX )
return false; // overflow or no extended data
if( !rbuf.resize( bufsize ) ) return false; // extended records buffer
return ( readblock( infd, (uint8_t *)rbuf(), bufsize ) == bufsize &&
extended.parse( rbuf(), edsize, permissive ) );
}
} // end namespace
bool safe_seek( const int fd, const long long pos )
{
if( lseek( fd, pos, SEEK_SET ) == pos ) return true;
show_error( "Seek error", errno ); return false;
}
int tail_copy( const char * const archive_namep, const Arg_parser & parser,
std::vector< char > & name_pending,
const Lzip_index & lzip_index, const long long istream_pos,
const int infd, const int outfd, int retval )
{
const long long rest = lzip_index.file_size() - istream_pos;
if( istream_pos > 0 && rest > 0 &&
( !safe_seek( infd, istream_pos ) ||
!copy_file( infd, outfd, rest ) ) )
{ show_file_error( archive_namep, "Error during tail copy." );
return retval ? retval : 1; }
const long long ostream_pos = lseek( outfd, 0, SEEK_CUR );
if( ostream_pos < 0 ) { show_error( "Seek error", errno ); retval = 1; }
else if( ostream_pos > 0 && ostream_pos < lzip_index.file_size() )
{
int ret;
do ret = ftruncate( outfd, ostream_pos );
while( ret != 0 && errno == EINTR );
if( ret != 0 || lseek( outfd, 0, SEEK_END ) != ostream_pos )
{
show_file_error( archive_namep, "Can't truncate archive", errno );
if( retval < 1 ) retval = 1;
}
}
if( ( close( outfd ) != 0 || close( infd ) != 0 ) && !retval )
{ show_file_error( archive_namep, "Error closing archive", errno );
retval = 1; }
if( retval == 0 ) for( int i = 0; i < parser.arguments(); ++i )
if( nonempty_arg( parser, i ) && name_pending[i] )
{
show_file_error( parser.argument( i ).c_str(), "Not found in archive." );
retval = 1;
}
return retval;
}
/* Deleting from a corrupt archive must not worsen the corruption. Stop and
tail-copy as soon as corruption is found.
*/
int delete_members( const Cl_options & cl_opts )
{
if( cl_opts.filenames <= 0 )
{ if( verbosity >= 1 ) show_error( "Nothing to delete." ); return 0; }
if( cl_opts.archive_name.empty() )
{ show_error( "Deleting from stdin not implemented yet." ); return 1; }
const char * const archive_namep = cl_opts.archive_name.c_str();
const int infd = open_instream( cl_opts.archive_name );
if( infd < 0 ) return 1;
const int outfd = open_outstream( cl_opts.archive_name, false );
if( outfd < 0 ) { close( infd ); return 1; }
// mark member names to be deleted
std::vector< char > name_pending( cl_opts.parser.arguments(), false );
for( int i = 0; i < cl_opts.parser.arguments(); ++i )
if( nonempty_arg( cl_opts.parser, i ) &&
!Exclude::excluded( cl_opts.parser.argument( i ).c_str() ) )
name_pending[i] = true;
const Lzip_index lzip_index( infd, true, false ); // only regular files
if( lzip_index.retval() == 0 ) // compressed
return delete_members_lz( cl_opts, archive_namep, name_pending, lzip_index,
infd, outfd );
if( lseek( infd, 0, SEEK_SET ) != 0 )
{ show_file_error( archive_namep, "Archive is not seekable." ); return 1; }
if( lzip_index.file_size() < 3 * header_size )
{ show_file_error( archive_namep, posix_msg ); return 2; }
// archive is uncompressed seekable, unless compressed corrupt
Resizable_buffer rbuf;
long long istream_pos = 0; // source of next data move
long long member_begin = 0; // first pos of current tar member
Extended extended; // metadata from extended records
int retval = 0;
bool prev_extended = false; // prev header was extended
while( true ) // process one tar header per iteration
{
if( !prev_extended && ( member_begin = lseek( infd, 0, SEEK_CUR ) ) < 0 )
{ show_error( "Seek error", errno ); retval = 1; break; }
Tar_header header;
const int rd = readblock( infd, header, header_size );
if( rd == 0 && errno == 0 ) // missing EOF blocks
{ show_file_error( archive_namep, end_msg ); retval = 2; break; }
if( rd != header_size )
{ show_file_error( archive_namep, "Read error", errno );
retval = 2; break; }
if( !verify_ustar_chksum( header ) )
{
if( block_is_zero( header, header_size ) ) // EOF
{
if( prev_extended && !cl_opts.permissive )
{ show_file_error( archive_namep, fv_msg1 ); retval = 2; }
break;
}
show_file_error( archive_namep, "Corrupt header in archive." );
retval = 2; break;
}
const Typeflag typeflag = (Typeflag)header[typeflag_o];
if( typeflag == tf_global )
{
if( prev_extended && !cl_opts.permissive )
{ show_file_error( archive_namep, fv_msg2 ); retval = 2; break; }
Extended dummy; // global headers are parsed and ignored
if( !parse_records( infd, dummy, header, rbuf, true ) )
{ show_file_error( archive_namep, gblrec_msg ); retval = 2; break; }
continue;
}
if( typeflag == tf_extended )
{
if( prev_extended && !cl_opts.permissive )
{ show_file_error( archive_namep, fv_msg3 ); retval = 2; break; }
if( !parse_records( infd, extended, header, rbuf, cl_opts.permissive ) )
{ show_file_error( archive_namep, extrec_msg ); retval = 2; break; }
else if( !extended.crc_present() && cl_opts.missing_crc )
{ show_file_error( archive_namep, mcrc_msg ); retval = 2; break; }
prev_extended = true;
continue;
}
prev_extended = false;
extended.fill_from_ustar( header ); // copy metadata from header
{ // skip member
long long rest = round_up( extended.file_size() ); // size + padding
if( lseek( infd, rest, SEEK_CUR ) <= 0 )
{ show_file_error( archive_namep, "Seek error", errno );
retval = 1; break; }
}
// delete tar member
if( !check_skip_filename( cl_opts, name_pending, extended.path().c_str() ) )
{
if( !show_member_name( extended, header, 1, rbuf ) )
{ retval = 1; break; }
const long long pos = lseek( infd, 0, SEEK_CUR );
if( pos <= 0 || pos <= member_begin || member_begin < istream_pos )
{ show_file_error( archive_namep, "Seek error", errno );
retval = 1; break; }
const long long size = member_begin - istream_pos;
if( size > 0 ) // move pending data each time a member is deleted
{
if( istream_pos == 0 )
{ if( !safe_seek( outfd, size ) ) { retval = 1; break; } }
else if( !safe_seek( infd, istream_pos ) ||
!copy_file( infd, outfd, size ) ||
!safe_seek( infd, pos ) ) { retval = 1; break; }
}
istream_pos = pos;
}
extended.reset();
}
return tail_copy( archive_namep, cl_opts.parser, name_pending, lzip_index,
istream_pos, infd, outfd, retval );
}
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