diff options
Diffstat (limited to 'delete_lz.cc')
| -rw-r--r-- | delete_lz.cc | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/delete_lz.cc b/delete_lz.cc new file mode 100644 index 0000000..2e536e3 --- /dev/null +++ b/delete_lz.cc @@ -0,0 +1,139 @@ +/* Tarlz - Archiver with multimember lzip compression + Copyright (C) 2013-2022 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 <cstdio> +#include <cstdlib> +#include <stdint.h> // for lzlib.h +#include <unistd.h> +#include <lzlib.h> + +#include "tarlz.h" +#include "arg_parser.h" +#include "lzip_index.h" +#include "archive_reader.h" + + +/* Deleting from a corrupt archive must not worsen the corruption. Stop and + tail-copy as soon as corruption is found. +*/ +int delete_members_lz( const Cl_options & cl_opts, + const Archive_descriptor & ad, + std::vector< char > & name_pending, + const int outfd ) + { + Archive_reader_i ar( ad ); // indexed reader + Resizable_buffer rbuf; + if( !rbuf.size() || ar.fatal() ) { show_error( mem_msg ); return 1; } + + long long istream_pos = 0; // source of next data move + int retval = 0, retval2 = 0; + for( long i = 0; i < ad.lzip_index.members(); ++i ) + { + if( ad.lzip_index.dblock( i ).size() == 0 ) continue; // empty lzip member + long long member_begin = 0; // first pos of current tar member + Extended extended; // metadata from extended records + bool prev_extended = false; // prev header was extended + ar.set_member( i ); // prepare for new member + while( true ) // process one tar header per iteration + { + if( ar.data_pos() >= ar.mdata_end() ) + { + if( ar.at_member_end() && !prev_extended ) break; + // member end exceeded or ends in extended + show_file_error( ad.namep, "Member misalignment found." ); + retval = 2; goto done; + } + if( !prev_extended ) member_begin = ar.data_pos(); + Tar_header header; + if( ( retval = ar.read( header, header_size ) ) != 0 ) + { show_file_error( ad.namep, ar.e_msg(), ar.e_code() ); goto done; } + if( !verify_ustar_chksum( header ) ) // error or EOA + { + if( block_is_zero( header, header_size ) ) // EOA + { + if( prev_extended && !cl_opts.permissive ) + { show_file_error( ad.namep, fv_msg1 ); retval = 2; } + goto done; + } + // indexed archive reader does not verify posix format + show_file_error( ad.namep, ( ar.data_pos() > header_size ) ? + bad_hdr_msg : posix_lz_msg ); + retval = 2; + goto done; + } + + const Typeflag typeflag = (Typeflag)header[typeflag_o]; + if( typeflag == tf_global ) + { + if( prev_extended && !cl_opts.permissive ) + { show_file_error( ad.namep, fv_msg2 ); retval = 2; goto done; } + Extended dummy; // global headers are parsed and ignored + retval = ar.parse_records( dummy, header, rbuf, gblrec_msg, true ); + if( retval ) + { show_file_error( ad.namep, ar.e_msg(), ar.e_code() ); goto done; } + continue; + } + if( typeflag == tf_extended ) + { + if( prev_extended && !cl_opts.permissive ) + { show_file_error( ad.namep, fv_msg3 ); retval = 2; goto done; } + if( ( retval = ar.parse_records( extended, header, rbuf, extrec_msg, + cl_opts.permissive ) ) != 0 ) + { show_file_error( ad.namep, ar.e_msg(), ar.e_code() ); goto done; } + if( !extended.crc_present() && cl_opts.missing_crc ) + { show_file_error( ad.namep, miscrc_msg ); retval = 2; goto done; } + prev_extended = true; continue; + } + prev_extended = false; + + extended.fill_from_ustar( header ); // copy metadata from header + + if( ( retval = ar.skip_member( extended ) ) != 0 ) goto done; + + // delete tar member + if( !check_skip_filename( cl_opts, name_pending, extended.path().c_str() ) ) + { + print_removed_prefix( extended.removed_prefix ); + // verify that members match + if( member_begin != ad.lzip_index.dblock( i ).pos() || !ar.at_member_end() ) + { show_file_error( extended.path().c_str(), + "Can't delete: not compressed individually." ); + retval2 = 2; extended.reset(); continue; } + if( !show_member_name( extended, header, 1, rbuf ) ) + { retval = 1; goto done; } + const long long size = ad.lzip_index.mblock( i ).pos() - 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; goto done; } } + else if( !safe_seek( ad.infd, istream_pos ) || + !copy_file( ad.infd, outfd, size ) ) { retval = 1; goto done; } + } + istream_pos = ad.lzip_index.mblock( i ).end(); // member end + } + extended.reset(); + } + } +done: + if( retval < retval2 ) retval = retval2; + // tail copy keeps trailing data + return tail_copy( cl_opts.parser, ad, name_pending, istream_pos, outfd, retval ); + } |