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Diffstat (limited to '')
| -rw-r--r-- | common_decode.cc | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/common_decode.cc b/common_decode.cc new file mode 100644 index 0000000..a0ff89d --- /dev/null +++ b/common_decode.cc @@ -0,0 +1,255 @@ +/* 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 <cerrno> +#include <cstdio> +#include <ctime> +#include <unistd.h> +#include <sys/stat.h> + +#include "tarlz.h" +#include "arg_parser.h" +#include "decode.h" + + +namespace { + +enum { mode_string_size = 10, + group_string_size = 1 + uname_l + 1 + gname_l + 1 }; // 67 + +void format_mode_string( const Tar_header header, char buf[mode_string_size] ) + { + const Typeflag typeflag = (Typeflag)header[typeflag_o]; + + std::memcpy( buf, "----------", mode_string_size ); + switch( typeflag ) + { + case tf_regular: break; + case tf_link: buf[0] = 'h'; break; + case tf_symlink: buf[0] = 'l'; break; + case tf_chardev: buf[0] = 'c'; break; + case tf_blockdev: buf[0] = 'b'; break; + case tf_directory: buf[0] = 'd'; break; + case tf_fifo: buf[0] = 'p'; break; + case tf_hiperf: buf[0] = 'C'; break; + default: buf[0] = '?'; + } + const mode_t mode = parse_octal( header + mode_o, mode_l ); // 12 bits + const bool setuid = mode & S_ISUID; + const bool setgid = mode & S_ISGID; + const bool sticky = mode & S_ISVTX; + if( mode & S_IRUSR ) buf[1] = 'r'; + if( mode & S_IWUSR ) buf[2] = 'w'; + if( mode & S_IXUSR ) buf[3] = setuid ? 's' : 'x'; + else if( setuid ) buf[3] = 'S'; + if( mode & S_IRGRP ) buf[4] = 'r'; + if( mode & S_IWGRP ) buf[5] = 'w'; + if( mode & S_IXGRP ) buf[6] = setgid ? 's' : 'x'; + else if( setgid ) buf[6] = 'S'; + if( mode & S_IROTH ) buf[7] = 'r'; + if( mode & S_IWOTH ) buf[8] = 'w'; + if( mode & S_IXOTH ) buf[9] = sticky ? 't' : 'x'; + else if( sticky ) buf[9] = 'T'; + } + + +int format_user_group_string( const Extended & extended, + const Tar_header header, + char buf[group_string_size] ) + { + int len; + if( header[uname_o] && header[gname_o] ) + len = snprintf( buf, group_string_size, + " %.32s/%.32s", header + uname_o, header + gname_o ); + else + len = snprintf( buf, group_string_size, " %llu/%llu", + extended.get_uid(), extended.get_gid() ); + return len; + } + + +// return true if dir is a parent directory of name +bool compare_prefix_dir( const char * const dir, const char * const name ) + { + int len = 0; + while( dir[len] && dir[len] == name[len] ) ++len; + return ( !dir[len] && len > 0 && ( dir[len-1] == '/' || name[len] == '/' ) ); + } + + +// compare two file names ignoring trailing slashes +bool compare_tslash( const char * const name1, const char * const name2 ) + { + const char * p = name1; + const char * q = name2; + while( *p && *p == *q ) { ++p; ++q; } + while( *p == '/' ) ++p; + while( *q == '/' ) ++q; + return ( !*p && !*q ); + } + +} // end namespace + + +bool block_is_zero( const uint8_t * const buf, const int size ) + { + for( int i = 0; i < size; ++i ) if( buf[i] != 0 ) return false; + return true; + } + + +bool format_member_name( const Extended & extended, const Tar_header header, + Resizable_buffer & rbuf, const bool long_format ) + { + if( long_format ) + { + format_mode_string( header, rbuf() ); + const int group_string_len = + format_user_group_string( extended, header, rbuf() + mode_string_size ); + int offset = mode_string_size + group_string_len; + const time_t mtime = extended.mtime().sec(); + struct tm t; + if( !localtime_r( &mtime, &t ) ) // if local time fails + { time_t z = 0; if( !gmtime_r( &z, &t ) ) // use UTC, the epoch + { t.tm_year = 70; t.tm_mon = t.tm_hour = t.tm_min = 0; t.tm_mday = 1; } } + const Typeflag typeflag = (Typeflag)header[typeflag_o]; + const bool islink = ( typeflag == tf_link || typeflag == tf_symlink ); + const char * const link_string = !islink ? "" : + ( ( typeflag == tf_link ) ? " link to " : " -> " ); + // print "user/group size" in a field of width 19 with 8 or more for size + if( typeflag == tf_chardev || typeflag == tf_blockdev ) + { + const unsigned devmajor = parse_octal( header + devmajor_o, devmajor_l ); + const unsigned devminor = parse_octal( header + devminor_o, devminor_l ); + const int width = std::max( 1, + std::max( 8, 19 - group_string_len ) - 1 - decimal_digits( devminor ) ); + offset += snprintf( rbuf() + offset, rbuf.size() - offset, " %*u,%u", + width, devmajor, devminor ); + } + else + { + const int width = std::max( 8, 19 - group_string_len ); + offset += snprintf( rbuf() + offset, rbuf.size() - offset, " %*llu", + width, extended.file_size() ); + } + for( int i = 0; i < 2; ++i ) // resize rbuf if not large enough + { + const int len = snprintf( rbuf() + offset, rbuf.size() - offset, + " %4d-%02u-%02u %02u:%02u %s%s%s\n", + 1900 + t.tm_year, 1 + t.tm_mon, t.tm_mday, t.tm_hour, + t.tm_min, extended.path().c_str(), link_string, + islink ? extended.linkpath().c_str() : "" ); + if( len + offset < (int)rbuf.size() ) break; + if( !rbuf.resize( len + offset + 1 ) ) return false; + } + } + else + { + if( rbuf.size() < extended.path().size() + 2 && + !rbuf.resize( extended.path().size() + 2 ) ) return false; + snprintf( rbuf(), rbuf.size(), "%s\n", extended.path().c_str() ); + } + return true; + } + + +bool show_member_name( const Extended & extended, const Tar_header header, + const int vlevel, Resizable_buffer & rbuf ) + { + if( verbosity >= vlevel ) + { + if( !format_member_name( extended, header, rbuf, verbosity > vlevel ) ) + { show_error( mem_msg ); return false; } + std::fputs( rbuf(), stdout ); + std::fflush( stdout ); + } + return true; + } + + +bool check_skip_filename( const Cl_options & cl_opts, + std::vector< char > & name_pending, + const char * const filename, const int chdir_fd ) + { + static int c_idx = -1; // parser index of last -C executed + if( Exclude::excluded( filename ) ) return true; // skip excluded files + if( cl_opts.num_files <= 0 ) return false; // no files specified, no skip + bool skip = true; // else skip all but the files (or trees) specified + bool chdir_pending = false; + + for( int i = 0; i < cl_opts.parser.arguments(); ++i ) + { + if( cl_opts.parser.code( i ) == 'C' ) { chdir_pending = true; continue; } + if( !nonempty_arg( cl_opts.parser, i ) ) continue; // skip opts, empty names + std::string removed_prefix; + const char * const name = remove_leading_dotslash( + cl_opts.parser.argument( i ).c_str(), &removed_prefix ); + if( compare_prefix_dir( name, filename ) || + compare_tslash( name, filename ) ) + { + print_removed_prefix( removed_prefix ); + skip = false; name_pending[i] = false; + if( chdir_pending && chdir_fd >= 0 ) + { + if( c_idx > i ) + { if( fchdir( chdir_fd ) != 0 ) + { show_error( "Error changing to initial working directory", errno ); + throw Chdir_error(); } c_idx = -1; } + for( int j = c_idx + 1; j < i; ++j ) + { + if( cl_opts.parser.code( j ) != 'C' ) continue; + const char * const dir = cl_opts.parser.argument( j ).c_str(); + if( chdir( dir ) != 0 ) + { show_file_error( dir, chdir_msg, errno ); throw Chdir_error(); } + c_idx = j; + } + } + break; + } + } + return skip; + } + + +bool make_dirs( const std::string & name ) + { + int i = name.size(); + while( i > 0 && name[i-1] == '/' ) --i; // remove trailing slashes + while( i > 0 && name[i-1] != '/' ) --i; // remove last component + while( i > 0 && name[i-1] == '/' ) --i; // remove more slashes + const int dirsize = i; // first slash before last component + + for( i = 0; i < dirsize; ) // if dirsize == 0, dirname is '/' or empty + { + while( i < dirsize && name[i] == '/' ) ++i; + const int first = i; + while( i < dirsize && name[i] != '/' ) ++i; + if( first < i ) + { + const std::string partial( name, 0, i ); + const mode_t mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH; + struct stat st; + if( lstat( partial.c_str(), &st ) == 0 ) + { if( !S_ISDIR( st.st_mode ) ) { errno = ENOTDIR; return false; } } + else if( mkdir( partial.c_str(), mode ) != 0 && errno != EEXIST ) + return false; // if EEXIST, another thread or process created the dir + } + } + return true; + } |