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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 14:27:09 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 14:27:09 +0000
commit4caff76ff707b2d82726ef94872c3597fd62a4ae (patch)
treebea175e053890b150463151752b7a49dc49c436e /delete.cc
parentInitial commit. (diff)
downloadtarlz-4caff76ff707b2d82726ef94872c3597fd62a4ae.tar.xz
tarlz-4caff76ff707b2d82726ef94872c3597fd62a4ae.zip
Adding upstream version 0.23.upstream/0.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'delete.cc')
-rw-r--r--delete.cc190
1 files changed, 190 insertions, 0 deletions
diff --git a/delete.cc b/delete.cc
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--- /dev/null
+++ b/delete.cc
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+/* 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"
+
+
+bool safe_seek( const int fd, const long long pos )
+ {
+ if( lseek( fd, pos, SEEK_SET ) == pos ) return true;
+ show_error( seek_msg, errno ); return false;
+ }
+
+
+int tail_copy( const Arg_parser & parser, const Archive_descriptor & ad,
+ std::vector< char > & name_pending, const long long istream_pos,
+ const int outfd, int retval )
+ {
+ const long long rest = ad.lzip_index.file_size() - istream_pos;
+ if( istream_pos > 0 && rest > 0 &&
+ ( !safe_seek( ad.infd, istream_pos ) ||
+ !copy_file( ad.infd, outfd, rest ) ) )
+ { show_file_error( ad.namep, "Error during tail copy." );
+ return retval ? retval : 1; }
+ const long long ostream_pos = lseek( outfd, 0, SEEK_CUR );
+ if( ostream_pos < 0 )
+ { show_file_error( ad.namep, seek_msg, errno ); retval = 1; }
+ else if( ostream_pos > 0 && ostream_pos < ad.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( ad.namep, "Can't truncate archive", errno );
+ if( retval < 1 ) retval = 1;
+ }
+ }
+
+ if( ( close( outfd ) | close( ad.infd ) ) != 0 && retval == 0 )
+ { show_file_error( ad.namep, eclosa_msg, 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(), nfound_msg );
+ 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.num_files <= 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 Archive_descriptor ad( cl_opts.archive_name );
+ if( ad.infd < 0 ) return 1;
+ const int outfd = open_outstream( cl_opts.archive_name, false );
+ if( outfd < 0 ) { close( ad.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;
+
+ if( ad.indexed ) // archive is a compressed regular file
+ return delete_members_lz( cl_opts, ad, name_pending, outfd );
+ if( !ad.seekable )
+ { show_file_error( ad.namep, "Archive is not seekable." ); return 1; }
+ if( ad.lzip_index.file_size() < 3 * header_size )
+ { show_file_error( ad.namep, has_lz_ext( ad.name ) ? posix_lz_msg : posix_msg );
+ return 2; }
+ // archive is uncompressed seekable, unless compressed corrupt
+
+ Archive_reader ar( ad ); // serial reader
+ 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
+ if( !rbuf.size() ) { show_error( mem_msg ); return 1; }
+
+ while( true ) // process one tar header per iteration
+ {
+ if( !prev_extended && ( member_begin = lseek( ad.infd, 0, SEEK_CUR ) ) < 0 )
+ { show_file_error( ad.namep, seek_msg, errno ); retval = 1; break; }
+ Tar_header header;
+ if( ( retval = ar.read( header, header_size ) ) != 0 )
+ { show_file_error( ad.namep, ar.e_msg(), ar.e_code() ); break; }
+ 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; }
+ break;
+ }
+ // posix format already verified by archive reader
+ show_file_error( ad.namep, bad_hdr_msg );
+ retval = 2; break;
+ }
+
+ 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; break; }
+ 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() ); break; }
+ continue;
+ }
+ if( typeflag == tf_extended )
+ {
+ if( prev_extended && !cl_opts.permissive )
+ { show_file_error( ad.namep, fv_msg3 ); retval = 2; break; }
+ 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() ); break; }
+ if( !extended.crc_present() && cl_opts.missing_crc )
+ { show_file_error( ad.namep, miscrc_msg ); retval = 2; break; }
+ prev_extended = true; continue;
+ }
+ prev_extended = false;
+
+ extended.fill_from_ustar( header ); // copy metadata from header
+
+ if( ( retval = ar.skip_member( extended ) ) != 0 )
+ { show_file_error( ad.namep, seek_msg, errno ); break; }
+
+ // delete tar member
+ if( !check_skip_filename( cl_opts, name_pending, extended.path().c_str() ) )
+ {
+ print_removed_prefix( extended.removed_prefix );
+ if( !show_member_name( extended, header, 1, rbuf ) )
+ { retval = 1; break; }
+ const long long pos = lseek( ad.infd, 0, SEEK_CUR );
+ if( pos <= 0 || pos <= member_begin || member_begin < istream_pos )
+ { show_file_error( ad.namep, seek_msg, 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( ad.infd, istream_pos ) ||
+ !copy_file( ad.infd, outfd, size ) ||
+ !safe_seek( ad.infd, pos ) ) { retval = 1; break; }
+ }
+ istream_pos = pos;
+ }
+ extended.reset();
+ }
+
+ return tail_copy( cl_opts.parser, ad, name_pending, istream_pos, outfd, retval );
+ }