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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 <cerrno>
#include <csignal>
#include <cstdio>
#include <cstdlib>
#include <stdint.h> // for lzlib.h
#include <unistd.h>
#include <utime.h>
#include <sys/stat.h>
#include <lzlib.h>
#include "tarlz.h"
#include "arg_parser.h"
namespace {
/* Variables used in signal handler context.
They are not declared volatile because the handler never returns. */
std::string output_filename;
int outfd = -1;
bool delete_output_on_interrupt = false;
void set_signals( void (*action)(int) )
{
std::signal( SIGHUP, action );
std::signal( SIGINT, action );
std::signal( SIGTERM, action );
}
void cleanup_and_fail( const int retval )
{
set_signals( SIG_IGN ); // ignore signals
if( delete_output_on_interrupt )
{
delete_output_on_interrupt = false;
if( verbosity >= 0 )
std::fprintf( stderr, "%s: Deleting output file '%s', if it exists.\n",
program_name, output_filename.c_str() );
if( outfd >= 0 ) { close( outfd ); outfd = -1; }
if( std::remove( output_filename.c_str() ) != 0 && errno != ENOENT )
show_error( "WARNING: deletion of output file (apparently) failed." );
}
std::exit( retval );
}
extern "C" void signal_handler( int )
{
show_error( "Control-C or similar caught, quitting." );
cleanup_and_fail( 1 );
}
const char * ne_output_filename() // non-empty output file name
{
return output_filename.size() ? output_filename.c_str() : "(stdout)";
}
bool check_tty_in( const char * const input_filename, const int infd )
{
if( isatty( infd ) ) // for example /dev/tty
{ show_file_error( input_filename,
"I won't read archive data from a terminal." );
close( infd ); return false; }
return true;
}
bool check_tty_out()
{
if( isatty( outfd ) ) // for example /dev/tty
{ show_file_error( ne_output_filename(),
"I won't write compressed data to a terminal." );
return false; }
return true;
}
// Set permissions, owner, and times.
void close_and_set_permissions( const struct stat * const in_statsp )
{
bool warning = false;
if( in_statsp )
{
const mode_t mode = in_statsp->st_mode;
// fchown will in many cases return with EPERM, which can be safely ignored.
if( fchown( outfd, in_statsp->st_uid, in_statsp->st_gid ) == 0 )
{ if( fchmod( outfd, mode ) != 0 ) warning = true; }
else
if( errno != EPERM ||
fchmod( outfd, mode & ~( S_ISUID | S_ISGID | S_ISVTX ) ) != 0 )
warning = true;
}
if( close( outfd ) != 0 )
{
show_error( "Error closing output file", errno );
cleanup_and_fail( 1 );
}
outfd = -1;
delete_output_on_interrupt = false;
if( in_statsp )
{
struct utimbuf t;
t.actime = in_statsp->st_atime;
t.modtime = in_statsp->st_mtime;
if( utime( output_filename.c_str(), &t ) != 0 ) warning = true;
}
if( warning && verbosity >= 1 )
show_error( "Can't change output file attributes." );
}
bool archive_write( const uint8_t * const buf, const long long size,
LZ_Encoder * const encoder )
{
static bool flushed = true; // avoid flushing empty lzip members
if( size <= 0 && flushed ) return true;
flushed = ( size <= 0 );
enum { obuf_size = 65536 };
uint8_t obuf[obuf_size];
long long sz = 0;
if( flushed ) LZ_compress_finish( encoder ); // flush encoder
while( sz < size || flushed )
{
if( sz < size )
{ const int wr = LZ_compress_write( encoder, buf + sz,
std::min( size - sz, (long long)max_dictionary_size ) );
if( wr < 0 ) internal_error( "library error (LZ_compress_write)." );
sz += wr; }
if( sz >= size && !flushed ) break; // minimize dictionary size
const int rd = LZ_compress_read( encoder, obuf, obuf_size );
if( rd < 0 ) internal_error( "library error (LZ_compress_read)." );
if( rd == 0 && sz >= size ) break;
if( writeblock( outfd, obuf, rd ) != rd )
{ show_file_error( ne_output_filename(), werr_msg, errno ); return false; }
}
if( LZ_compress_finished( encoder ) == 1 &&
LZ_compress_restart_member( encoder, LLONG_MAX ) < 0 )
internal_error( "library error (LZ_compress_restart_member)." );
return true;
}
bool tail_compress( const Cl_options & cl_opts,
const int infd, Tar_header header,
LZ_Encoder * const encoder )
{
if( cl_opts.solidity != solid && !archive_write( 0, 0, encoder ) )
return false; // flush encoder before compressing EOA blocks
int size = header_size;
bool zero = true; // true until non-zero data found after EOA blocks
while( true )
{
if( size > 0 && !archive_write( header, size, encoder ) )
{ close( infd ); return false; }
if( size < header_size ) break; // EOF
size = readblock( infd, header, header_size );
if( errno ) return false;
if( zero && !block_is_zero( header, size ) )
{ zero = false; // flush encoder after compressing EOA blocks
if( cl_opts.solidity != solid && !archive_write( 0, 0, encoder ) )
return false; }
}
return true;
}
int compress_archive( const Cl_options & cl_opts,
const std::string & input_filename,
LZ_Encoder * const encoder,
const bool to_stdout, const bool to_file )
{
const bool one_to_one = !to_stdout && !to_file;
const bool from_stdin = input_filename == "-";
const char * const filename = from_stdin ? "(stdin)" : input_filename.c_str();
const int infd = from_stdin ? STDIN_FILENO : open_instream( filename );
if( infd < 0 || !check_tty_in( filename, infd ) ) return 1;
if( one_to_one )
{
if( from_stdin ) { outfd = STDOUT_FILENO; output_filename.clear(); }
else
{
output_filename = input_filename + ".lz";
outfd = open_outstream( output_filename, true, 0, false );
if( outfd < 0 ) { close( infd ); return 1; }
delete_output_on_interrupt = true;
}
if( !check_tty_out() ) { close( infd ); return 1; } // don't delete a tty
}
if( verbosity >= 1 ) std::fprintf( stderr, "%s\n", filename );
unsigned long long partial_data_size = 0; // size of current block
Extended extended; // metadata from extended records
Resizable_buffer rbuf; // headers and extended records buffer
if( !rbuf.size() ) { show_error( mem_msg ); return 1; }
const char * const rderr_msg = "Read error";
while( true ) // process one tar member per iteration
{
int total_header_size = header_size; // size of header(s) read
const int rd = readblock( infd, rbuf.u8(), header_size );
if( rd == 0 && errno == 0 ) break; // missing EOA blocks
if( rd != header_size )
{ show_file_error( filename, rderr_msg, errno ); close( infd ); return 1; }
if( to_file && outfd < 0 ) // open outfd after verifying infd
{
outfd = open_outstream( output_filename, true, 0, false );
// check tty only once and don't try to delete a tty
if( outfd < 0 || !check_tty_out() ) { close( infd ); return 1; }
delete_output_on_interrupt = true;
}
if( !verify_ustar_chksum( rbuf.u8() ) ) // maybe EOA block
{
if( block_is_zero( rbuf.u8(), header_size ) ) // first EOA block
{ tail_compress( cl_opts, infd, rbuf.u8(), encoder ); break; }
show_file_error( filename, bad_hdr_msg ); close( infd ); return 2;
}
const Typeflag typeflag = (Typeflag)rbuf()[typeflag_o];
if( typeflag == tf_extended || typeflag == tf_global )
{
const long long edsize = parse_octal( rbuf.u8() + size_o, size_l );
const long long bufsize = round_up( edsize );
// overflow or no extended data
if( edsize <= 0 || edsize >= 1LL << 33 || bufsize >= INT_MAX )
{ show_file_error( filename, bad_hdr_msg ); close( infd ); return 2; }
if( !rbuf.resize( total_header_size + bufsize ) )
{ show_file_error( filename, mem_msg ); close( infd ); return 1; }
if( readblock( infd, rbuf.u8() + total_header_size, bufsize ) != bufsize )
{ show_file_error( filename, rderr_msg, errno ); close( infd ); return 1; }
total_header_size += bufsize;
if( typeflag == tf_extended ) // do not parse global headers
{
if( !extended.parse( rbuf() + header_size, edsize, false ) )
{ show_file_error( filename, extrec_msg ); close( infd ); return 2; }
// read ustar header
if( !rbuf.resize( total_header_size + header_size ) )
{ show_file_error( filename, mem_msg ); close( infd ); return 1; }
if( readblock( infd, rbuf.u8() + total_header_size, header_size ) != header_size )
{ show_file_error( filename, errno ? rderr_msg : end_msg, errno );
close( infd ); return errno ? 1 : 2; }
if( !verify_ustar_chksum( rbuf.u8() ) )
{ show_file_error( filename, bad_hdr_msg ); close( infd ); return 2; }
const Typeflag typeflag2 = (Typeflag)(rbuf() + total_header_size)[typeflag_o];
if( typeflag2 == tf_extended || typeflag2 == tf_global )
{ const char * msg = ( typeflag2 == tf_global ) ? fv_msg2 : fv_msg3;
show_file_error( filename, msg ); close( infd ); return 2; }
total_header_size += header_size;
}
}
const long long file_size = round_up( extended.get_file_size_and_reset(
rbuf.u8() + total_header_size - header_size ) );
if( cl_opts.solidity == bsolid &&
block_is_full( total_header_size - header_size, file_size,
cl_opts.data_size, partial_data_size ) &&
!archive_write( 0, 0, encoder ) ) { close( infd ); return 1; }
if( !archive_write( rbuf.u8(), total_header_size, encoder ) )
{ close( infd ); return 1; }
if( file_size )
{
const long long bufsize = 32 * header_size;
uint8_t buf[bufsize];
long long rest = file_size; // file_size already rounded up
while( rest > 0 )
{
int size = std::min( rest, bufsize );
const int rd = readblock( infd, buf, size );
rest -= rd;
if( rd != size )
{
if( verbosity >= 0 )
std::fprintf( stderr, "'%s' ends unexpectedly at pos %llu\n",
filename, file_size - rest );
close( infd ); return 1;
}
if( !archive_write( buf, size, encoder ) ) { close( infd ); return 1; }
}
}
if( cl_opts.solidity == no_solid && !archive_write( 0, 0, encoder ) )
{ close( infd ); return 1; } // one tar member per lzip member
}
// flush and restart encoder (for next archive)
if( !archive_write( 0, 0, encoder ) ) { close( infd ); return 1; }
const bool need_close = delete_output_on_interrupt &&
( one_to_one || ( to_file && !from_stdin ) );
struct stat in_stats;
const struct stat * const in_statsp =
( need_close && fstat( infd, &in_stats ) == 0 ) ? &in_stats : 0;
if( close( infd ) != 0 )
{ show_file_error( filename, eclosf_msg, errno ); return 1; }
if( need_close ) close_and_set_permissions( in_statsp );
return 0;
}
} // end namespace
int compress( const Cl_options & cl_opts )
{
if( cl_opts.num_files > 1 && cl_opts.output_filename.size() )
{ show_file_error( cl_opts.output_filename.c_str(),
"Only can compress one archive when using '-o'." ); return 1; }
const bool to_stdout = cl_opts.output_filename == "-";
if( to_stdout ) // check tty only once
{ outfd = STDOUT_FILENO; if( !check_tty_out() ) return 1; }
else outfd = -1;
const bool to_file = !to_stdout && cl_opts.output_filename.size();
if( to_file ) output_filename = cl_opts.output_filename;
if( !to_stdout && ( cl_opts.filenames_given || to_file ) )
set_signals( signal_handler );
LZ_Encoder * encoder = LZ_compress_open(
option_mapping[cl_opts.level].dictionary_size,
option_mapping[cl_opts.level].match_len_limit, LLONG_MAX );
if( !encoder || LZ_compress_errno( encoder ) != LZ_ok )
{
if( !encoder || LZ_compress_errno( encoder ) == LZ_mem_error )
show_error( mem_msg2 );
else
internal_error( "invalid argument to encoder." );
return 1;
}
if( !cl_opts.filenames_given )
return compress_archive( cl_opts, "-", encoder, to_stdout, to_file );
int retval = 0;
bool stdin_used = false;
for( int i = 0; i < cl_opts.parser.arguments(); ++i )
if( nonempty_arg( cl_opts.parser, i ) ) // skip opts, empty names
{
if( cl_opts.parser.argument( i ) == "-" )
{ if( stdin_used ) continue; else stdin_used = true; }
const int tmp = compress_archive( cl_opts, cl_opts.parser.argument( i ),
encoder, to_stdout, to_file );
if( tmp )
{ set_retval( retval, tmp );
if( delete_output_on_interrupt ) cleanup_and_fail( retval ); }
}
// flush and close encoder if needed
if( outfd >= 0 && archive_write( 0, 0, encoder ) &&
LZ_compress_close( encoder ) < 0 )
{ show_error( "LZ_compress_close failed." ); set_retval( retval, 1 ); }
if( outfd >= 0 && close( outfd ) != 0 ) // to_stdout
{
show_error( "Error closing stdout", errno );
set_retval( retval, 1 );
}
return retval;
}
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