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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 12:57:29 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 12:57:29 +0000
commit29146f385a524ad6a4b1b127cc3d9641a8fe0adc (patch)
tree1caea11496a3d9e0333cdf649d9f9be6d5a67b78 /decode.cc
parentInitial commit. (diff)
downloadtarlz-upstream.tar.xz
tarlz-upstream.zip
Adding upstream version 0.25.upstream/0.25upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'decode.cc')
-rw-r--r--decode.cc533
1 files changed, 533 insertions, 0 deletions
diff --git a/decode.cc b/decode.cc
new file mode 100644
index 0000000..bcac4c8
--- /dev/null
+++ b/decode.cc
@@ -0,0 +1,533 @@
+/* Tarlz - Archiver with multimember lzip compression
+ Copyright (C) 2013-2024 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 <algorithm>
+#include <cctype>
+#include <cerrno>
+#include <cstdio>
+#include <fcntl.h>
+#include <stdint.h> // for lzlib.h
+#include <unistd.h>
+#include <utime.h>
+#include <sys/stat.h>
+#if !defined __FreeBSD__ && !defined __OpenBSD__ && !defined __NetBSD__ && \
+ !defined __DragonFly__ && !defined __APPLE__ && !defined __OS2__
+#include <sys/sysmacros.h> // for major, minor, makedev
+#else
+#include <sys/types.h> // for major, minor, makedev
+#endif
+#include <lzlib.h>
+
+#include "tarlz.h"
+#include "arg_parser.h"
+#include "lzip_index.h"
+#include "archive_reader.h"
+#include "decode.h"
+
+#ifndef O_DIRECTORY
+#define O_DIRECTORY 0
+#endif
+
+namespace {
+
+Resizable_buffer grbuf;
+
+bool skip_warn( const bool reset = false ) // avoid duplicate warnings
+ {
+ static bool skipping = false;
+
+ if( reset ) skipping = false;
+ else if( !skipping )
+ { skipping = true; show_error( "Skipping to next header." ); return true; }
+ return false;
+ }
+
+
+void read_error( const Archive_reader & ar )
+ {
+ show_file_error( ar.ad.namep, ar.e_msg(), ar.e_code() );
+ if( ar.e_skip() ) skip_warn();
+ }
+
+
+int skip_member( Archive_reader & ar, const Extended & extended,
+ const Typeflag typeflag )
+ {
+ if( data_may_follow( typeflag ) )
+ { const int ret = ar.skip_member( extended );
+ if( ret != 0 ) { read_error( ar ); if( ar.fatal() ) return ret; } }
+ return 0;
+ }
+
+
+int compare_member( const Cl_options & cl_opts, Archive_reader & ar,
+ const Extended & extended, const Tar_header header )
+ {
+ if( !show_member_name( extended, header, 1, grbuf ) ) return 1;
+ std::string estr, ostr;
+ const bool stat_differs =
+ !compare_file_type( estr, ostr, cl_opts, extended, header );
+ if( estr.size() ) std::fputs( estr.c_str(), stderr );
+ if( ostr.size() ) { std::fputs( ostr.c_str(), stdout ); std::fflush( stdout ); }
+ if( extended.file_size() <= 0 ) return 0;
+ const Typeflag typeflag = (Typeflag)header[typeflag_o];
+ if( ( typeflag != tf_regular && typeflag != tf_hiperf ) || stat_differs )
+ return skip_member( ar, extended, typeflag );
+ // else compare file contents
+ const char * const filename = extended.path().c_str();
+ const int infd2 = open_instream( filename );
+ if( infd2 < 0 )
+ { set_error_status( 1 ); return skip_member( ar, extended, typeflag ); }
+ int retval = compare_file_contents( estr, ostr, ar, extended.file_size(),
+ filename, infd2 );
+ if( retval ) { read_error( ar ); if( !ar.fatal() ) retval = 0; }
+ else { if( estr.size() ) std::fputs( estr.c_str(), stderr );
+ if( ostr.size() )
+ { std::fputs( ostr.c_str(), stdout ); std::fflush( stdout ); } }
+ return retval;
+ }
+
+
+int list_member( Archive_reader & ar,
+ const Extended & extended, const Tar_header header )
+ {
+ if( !show_member_name( extended, header, 0, grbuf ) ) return 1;
+ return skip_member( ar, extended, (Typeflag)header[typeflag_o] );
+ }
+
+
+int extract_member( const Cl_options & cl_opts, Archive_reader & ar,
+ const Extended & extended, const Tar_header header )
+ {
+ const char * const filename = extended.path().c_str();
+ const Typeflag typeflag = (Typeflag)header[typeflag_o];
+ if( contains_dotdot( filename ) )
+ {
+ show_file_error( filename, dotdot_msg );
+ return skip_member( ar, extended, typeflag );
+ }
+ mode_t mode = parse_octal( header + mode_o, mode_l ); // 12 bits
+ if( geteuid() != 0 && !cl_opts.preserve_permissions ) mode &= ~get_umask();
+ int outfd = -1;
+
+ if( !show_member_name( extended, header, 1, grbuf ) ) return 1;
+ // remove file (or empty dir) before extraction to prevent following links
+ std::remove( filename );
+ if( !make_dirs( filename ) )
+ {
+ show_file_error( filename, intdir_msg, errno );
+ set_error_status( 1 );
+ return skip_member( ar, extended, typeflag );
+ }
+
+ switch( typeflag )
+ {
+ case tf_regular:
+ case tf_hiperf:
+ outfd = open_outstream( filename );
+ if( outfd < 0 )
+ { set_error_status( 1 ); return skip_member( ar, extended, typeflag ); }
+ break;
+ case tf_link:
+ case tf_symlink:
+ {
+ const char * const linkname = extended.linkpath().c_str();
+ const bool hard = typeflag == tf_link;
+ if( ( hard && link( linkname, filename ) != 0 ) ||
+ ( !hard && symlink( linkname, filename ) != 0 ) )
+ {
+ print_error( errno, cantln_msg, hard ? "" : "sym", linkname, filename );
+ set_error_status( 1 );
+ }
+ } break;
+ case tf_directory:
+ if( mkdir( filename, mode ) != 0 && errno != EEXIST )
+ {
+ show_file_error( filename, mkdir_msg, errno );
+ set_error_status( 1 );
+ }
+ break;
+ case tf_chardev:
+ case tf_blockdev:
+ {
+ const unsigned dev =
+ makedev( parse_octal( header + devmajor_o, devmajor_l ),
+ parse_octal( header + devminor_o, devminor_l ) );
+ const int dmode = ( typeflag == tf_chardev ? S_IFCHR : S_IFBLK ) | mode;
+ if( mknod( filename, dmode, dev ) != 0 )
+ {
+ show_file_error( filename, mknod_msg, errno );
+ set_error_status( 1 );
+ }
+ break;
+ }
+ case tf_fifo:
+ if( mkfifo( filename, mode ) != 0 )
+ {
+ show_file_error( filename, mkfifo_msg, errno );
+ set_error_status( 1 );
+ }
+ break;
+ default:
+ print_error( 0, uftype_msg, filename, typeflag );
+ set_error_status( 2 );
+ return skip_member( ar, extended, typeflag );
+ }
+
+ const bool islink = ( typeflag == tf_link || typeflag == tf_symlink );
+ errno = 0;
+ if( !islink &&
+ ( !uid_gid_in_range( extended.get_uid(), extended.get_gid() ) ||
+ chown( filename, extended.get_uid(), extended.get_gid() ) != 0 ) )
+ {
+ if( outfd >= 0 ) mode &= ~( S_ISUID | S_ISGID | S_ISVTX );
+ // chown in many cases returns with EPERM, which can be safely ignored.
+ if( errno != EPERM && errno != EINVAL )
+ { show_file_error( filename, chown_msg, errno ); set_error_status( 1 ); }
+ }
+
+ if( outfd >= 0 ) fchmod( outfd, mode ); // ignore errors
+
+ if( data_may_follow( typeflag ) )
+ {
+ const int bufsize = 32 * header_size;
+ uint8_t buf[bufsize];
+ long long rest = extended.file_size();
+ const int rem = rest % header_size;
+ const int padding = rem ? header_size - rem : 0;
+ while( rest > 0 )
+ {
+ const int rsize = ( rest >= bufsize ) ? bufsize : rest + padding;
+ const int ret = ar.read( buf, rsize );
+ if( ret != 0 )
+ {
+ read_error( ar );
+ if( outfd >= 0 )
+ {
+ if( cl_opts.keep_damaged )
+ { writeblock( outfd, buf, std::min( rest, (long long)ar.e_size() ) );
+ close( outfd ); }
+ else { close( outfd ); std::remove( filename ); }
+ }
+ if( ar.fatal() ) return ret; else return 0;
+ }
+ const int wsize = ( rest >= bufsize ) ? bufsize : rest;
+ if( outfd >= 0 && writeblock( outfd, buf, wsize ) != wsize )
+ { show_file_error( filename, werr_msg, errno ); return 1; }
+ rest -= wsize;
+ }
+ }
+ if( outfd >= 0 && close( outfd ) != 0 )
+ { show_file_error( filename, eclosf_msg, errno ); return 1; }
+ if( !islink )
+ {
+ struct utimbuf t;
+ t.actime = extended.atime().sec();
+ t.modtime = extended.mtime().sec();
+ utime( filename, &t ); // ignore errors
+ }
+ return 0;
+ }
+
+
+void format_file_diff( std::string & ostr, const char * const filename,
+ const char * const msg )
+ { if( verbosity >= 0 )
+ { ostr += filename; ostr += ": "; ostr += msg; ostr += '\n'; } }
+
+
+bool option_C_present( const Arg_parser & parser )
+ {
+ for( int i = 0; i < parser.arguments(); ++i )
+ if( parser.code( i ) == 'C' ) return true;
+ return false;
+ }
+
+
+bool option_C_after_filename( const Arg_parser & parser )
+ {
+ for( int i = 0; i < parser.arguments(); ++i )
+ if( nonempty_arg( parser, i ) )
+ while( ++i < parser.arguments() )
+ if( parser.code( i ) == 'C' ) return true;
+ return false;
+ }
+
+} // end namespace
+
+
+mode_t get_umask()
+ {
+ static mode_t mask = 0; // read once, cache the result
+ static bool first_call = true;
+ if( first_call ) { first_call = false; mask = umask( 0 ); umask( mask );
+ mask &= S_IRWXU | S_IRWXG | S_IRWXO; }
+ return mask;
+ }
+
+
+bool compare_file_type( std::string & estr, std::string & ostr,
+ const Cl_options & cl_opts,
+ const Extended & extended, const Tar_header header )
+ {
+ const char * const filename = extended.path().c_str();
+ const Typeflag typeflag = (Typeflag)header[typeflag_o];
+ struct stat st;
+ bool diff = false, size_differs = false, type_differs = true;
+ if( hstat( filename, &st, cl_opts.dereference ) != 0 )
+ format_file_error( estr, filename, "warning: can't stat", errno );
+ else if( ( typeflag == tf_regular || typeflag == tf_hiperf ) &&
+ !S_ISREG( st.st_mode ) )
+ format_file_diff( ostr, filename, "Is not a regular file" );
+ else if( typeflag == tf_symlink && !S_ISLNK( st.st_mode ) )
+ format_file_diff( ostr, filename, "Is not a symlink" );
+ else if( typeflag == tf_chardev && !S_ISCHR( st.st_mode ) )
+ format_file_diff( ostr, filename, "Is not a character device" );
+ else if( typeflag == tf_blockdev && !S_ISBLK( st.st_mode ) )
+ format_file_diff( ostr, filename, "Is not a block device" );
+ else if( typeflag == tf_directory && !S_ISDIR( st.st_mode ) )
+ format_file_diff( ostr, filename, "Is not a directory" );
+ else if( typeflag == tf_fifo && !S_ISFIFO( st.st_mode ) )
+ format_file_diff( ostr, filename, "Is not a FIFO" );
+ else
+ {
+ type_differs = false;
+ if( typeflag != tf_symlink && !cl_opts.ignore_metadata )
+ {
+ const mode_t mode = parse_octal( header + mode_o, mode_l ); // 12 bits
+ if( mode != ( st.st_mode & ( S_ISUID | S_ISGID | S_ISVTX |
+ S_IRWXU | S_IRWXG | S_IRWXO ) ) )
+ { format_file_diff( ostr, filename, "Mode differs" ); diff = true; }
+ }
+ if( !cl_opts.ignore_ids && !cl_opts.ignore_metadata )
+ {
+ if( extended.get_uid() != (long long)st.st_uid )
+ { format_file_diff( ostr, filename, "Uid differs" ); diff = true; }
+ if( extended.get_gid() != (long long)st.st_gid )
+ { format_file_diff( ostr, filename, "Gid differs" ); diff = true; }
+ }
+ if( typeflag != tf_symlink )
+ {
+ if( typeflag != tf_directory && !cl_opts.ignore_metadata &&
+ extended.mtime().sec() != (long long)st.st_mtime )
+ {
+ if( (time_t)extended.mtime().sec() == st.st_mtime )
+ { if( !cl_opts.ignore_overflow ) { diff = true;
+ format_file_diff( ostr, filename, "Mod time overflow" ); } }
+ else { diff = true;
+ format_file_diff( ostr, filename, "Mod time differs" ); }
+ }
+ if( ( typeflag == tf_regular || typeflag == tf_hiperf ) &&
+ extended.file_size() != st.st_size ) // don't compare contents
+ { format_file_diff( ostr, filename, "Size differs" ); size_differs = true; }
+ if( ( typeflag == tf_chardev || typeflag == tf_blockdev ) &&
+ ( parse_octal( header + devmajor_o, devmajor_l ) !=
+ (unsigned)major( st.st_rdev ) ||
+ parse_octal( header + devminor_o, devminor_l ) !=
+ (unsigned)minor( st.st_rdev ) ) )
+ { format_file_diff( ostr, filename, "Device number differs" ); diff = true; }
+ }
+ else
+ {
+ char * const buf = new char[st.st_size+1];
+ long len = readlink( filename, buf, st.st_size );
+ bool e = ( len != st.st_size );
+ if( !e )
+ {
+ while( len > 1 && buf[len-1] == '/' ) --len; // trailing '/'
+ buf[len] = 0;
+ if( extended.linkpath() != buf ) e = true;
+ }
+ delete[] buf;
+ if( e ) { format_file_diff( ostr, filename, "Symlink differs" ); diff = true; }
+ }
+ }
+ if( diff || size_differs || type_differs ) set_error_status( 1 );
+ return !( size_differs || type_differs );
+ }
+
+
+bool compare_file_contents( std::string & estr, std::string & ostr,
+ Archive_reader_base & ar, const long long file_size,
+ const char * const filename, const int infd2 )
+ {
+ long long rest = file_size;
+ const int rem = rest % header_size;
+ const int padding = rem ? header_size - rem : 0;
+ const int bufsize = 32 * header_size;
+ uint8_t buf1[bufsize];
+ uint8_t buf2[bufsize];
+ int retval = 0;
+ bool diff = false;
+ estr.clear(); ostr.clear();
+ while( rest > 0 )
+ {
+ const int rsize1 = ( rest >= bufsize ) ? bufsize : rest + padding;
+ const int rsize2 = ( rest >= bufsize ) ? bufsize : rest;
+ if( ( retval = ar.read( buf1, rsize1 ) ) != 0 ) { diff = true; break; }
+ if( !diff )
+ {
+ const int rd = readblock( infd2, buf2, rsize2 );
+ if( rd != rsize2 )
+ {
+ if( errno ) format_file_error( estr, filename, "Read error", errno );
+ else format_file_diff( ostr, filename, "EOF found in file" );
+ diff = true;
+ }
+ else
+ {
+ int i = 0; while( i < rsize2 && buf1[i] == buf2[i] ) ++i;
+ if( i < rsize2 )
+ { format_file_diff( ostr, filename, "Contents differ" ); diff = true; }
+ }
+ }
+ if( rest < bufsize ) break;
+ rest -= rsize1;
+ }
+ close( infd2 );
+ if( diff ) set_error_status( 1 );
+ return retval;
+ }
+
+
+int decode( const Cl_options & cl_opts )
+ {
+ if( !grbuf.size() ) { show_error( mem_msg ); return 1; }
+ // open archive before changing working directory
+ const Archive_descriptor ad( cl_opts.archive_name );
+ if( ad.infd < 0 ) return 1;
+
+ const bool c_present = option_C_present( cl_opts.parser ) &&
+ cl_opts.program_mode != m_list;
+ const bool c_after_name = c_present &&
+ option_C_after_filename( cl_opts.parser );
+ // save current working directory for sequential decoding
+ const int chdir_fd = c_after_name ? open( ".", O_RDONLY | O_DIRECTORY ) : -1;
+ if( c_after_name && chdir_fd < 0 )
+ { show_error( "Can't save current working directory", errno ); return 1; }
+ if( c_present && !c_after_name ) // execute all -C options
+ for( int i = 0; i < cl_opts.parser.arguments(); ++i )
+ {
+ if( cl_opts.parser.code( i ) != 'C' ) continue;
+ const char * const dir = cl_opts.parser.argument( i ).c_str();
+ if( chdir( dir ) != 0 )
+ { show_file_error( dir, chdir_msg, errno ); return 1; }
+ }
+ /* Mark filenames to be compared, extracted or listed.
+ name_pending is of type char instead of bool to allow concurrent update. */
+ 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 ) && // skip opts, empty names
+ !Exclude::excluded( cl_opts.parser.argument( i ).c_str() ) )
+ name_pending[i] = true;
+
+ /* multi-threaded --list is faster even with 1 thread and 1 file in archive
+ but multi-threaded --diff and --extract probably need at least 2 of each.
+ CWD is not per-thread; multi-threaded decode can't be used if a
+ -C option appears after a file name in the command line. */
+ if( cl_opts.num_workers > 0 && !c_after_name && ad.indexed &&
+ ad.lzip_index.members() >= 2 ) // 2 lzip members may be 1 file + EOA
+ return decode_lz( cl_opts, ad, name_pending );
+
+ Archive_reader ar( ad ); // serial reader
+ 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
+ {
+ Tar_header header;
+ const int ret = ar.read( header, header_size );
+ if( ret != 0 ) { read_error( ar ); if( ar.fatal() ) { retval = ret; break; } }
+ if( ret != 0 || !check_ustar_chksum( header ) ) // error or EOA
+ {
+ if( ret == 0 && block_is_zero( header, header_size ) ) // EOA
+ {
+ if( !prev_extended || cl_opts.permissive ) break;
+ show_file_error( ad.namep, fv_msg1 );
+ retval = 2; break;
+ }
+ if( skip_warn() && verbosity >= 2 )
+ std::fprintf( stderr, "ustar chksum = %07o\n", ustar_chksum( header ) );
+ set_error_status( 2 ); continue;
+ }
+ skip_warn( true ); // reset warning
+
+ 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
+ const int ret = ar.parse_records( dummy, header, grbuf, gblrec_msg, true );
+ if( ret != 0 )
+ { show_file_error( ad.namep, ar.e_msg(), ar.e_code() );
+ if( ar.fatal() ) { retval = ret; break; }
+ skip_warn(); set_error_status( ret ); }
+ continue;
+ }
+ if( typeflag == tf_extended )
+ {
+ if( prev_extended && !cl_opts.permissive )
+ { show_file_error( ad.namep, fv_msg3 ); retval = 2; break; }
+ const int ret = ar.parse_records( extended, header, grbuf, extrec_msg,
+ cl_opts.permissive );
+ if( ret != 0 )
+ { show_file_error( ad.namep, ar.e_msg(), ar.e_code() );
+ if( ar.fatal() ) { retval = ret; break; }
+ skip_warn(); extended.reset(); set_error_status( ret ); }
+ else 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
+
+ try {
+ // members without name are skipped except when listing
+ if( check_skip_filename( cl_opts, name_pending, extended.path().c_str(),
+ chdir_fd ) ) retval = skip_member( ar, extended, typeflag );
+ else
+ {
+ print_removed_prefix( extended.removed_prefix );
+ if( cl_opts.program_mode == m_list )
+ retval = list_member( ar, extended, header );
+ else if( extended.path().empty() )
+ retval = skip_member( ar, extended, typeflag );
+ else if( cl_opts.program_mode == m_diff )
+ retval = compare_member( cl_opts, ar, extended, header );
+ else retval = extract_member( cl_opts, ar, extended, header );
+ }
+ }
+ catch( Chdir_error & ) { retval = 1; }
+ extended.reset();
+ if( retval )
+ { show_error( "Error is not recoverable: exiting now." ); break; }
+ }
+
+ if( close( ad.infd ) != 0 && retval == 0 )
+ { show_file_error( ad.namep, eclosa_msg, errno ); retval = 1; }
+
+ if( retval == 0 )
+ for( int i = 0; i < cl_opts.parser.arguments(); ++i )
+ if( nonempty_arg( cl_opts.parser, i ) && name_pending[i] )
+ { show_file_error( cl_opts.parser.argument( i ).c_str(), nfound_msg );
+ retval = 1; }
+ return final_exit_status( retval, cl_opts.program_mode != m_diff );
+ }