lzip/tarlz
1
0
Fork 0
Code Issues Activity
tarlz/decode.cc
Daniel Baumann 5e422e043e
Merging upstream version 0.27. 
Signed-off-by: Daniel Baumann <daniel@debian.org>
2025-03-04 07:39:30 +01:00

538 lines
20 KiB
C++
Raw Permalink Blame History

/* Tarlz - Archiver with multimember lzip compression
Copyright (C) 2013-2025 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, const unsigned chksum = 0 )
{
static bool skipping = false; // avoid duplicate warnings
if( reset ) { skipping = false; return false; }
if( skipping ) return false;
skipping = true;
if( chksum != 0 )
{ if( verbosity < 1 ) show_error( "Corrupt header." );
else std::fprintf( stderr, "%s: Corrupt header: ustar chksum = %06o\n",
program_name, chksum ); }
show_error( "Skipping to next header." ); return true;
}
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;
if( !make_dirs( filename ) )
{
show_file_error( filename, intdir_msg, errno );
set_error_status( 1 );
return skip_member( ar, extended, typeflag );
}
// remove file or empty dir before extraction to prevent following links
std::remove( filename );
switch( typeflag )
{
case tf_regular:
case tf_hiperf:
outfd = open_outstream( filename, true, 0, false );
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 ); unlink( 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, wr_err_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, rd_err_msg, 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;
if( ad.name.size() && ad.indexed && ad.lzip_index.multi_empty() )
{ show_file_error( ad.namep, empty_msg ); close( ad.infd ); return 2; }
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 cwd_fd = c_after_name ? open( ".", O_RDONLY | O_DIRECTORY ) : -1;
if( c_after_name && cwd_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;
}
skip_warn( false, 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; }
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; }
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(),
cwd_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 );
}
View git blame Copy permalink