module.archive.gzip.php

Go to the documentation of this file.

<?php
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
// See readme.txt for more details                             //
//                                                             //
// module.archive.gzip.php                                     //
// written by Mike Mozolin <teddybearØmail*ru>                 //
// module for analyzing GZIP files                             //
// dependencies: NONE                                          //
//                                                            ///

class getid3_gzip {

        // public: Optional file list - disable for speed.
        var $option_gzip_parse_contents = false; // decode gzipped files, if possible, and parse recursively (.tar.gz for example)

        function getid3_gzip(&$fd, &$ThisFileInfo) {
                $ThisFileInfo['fileformat'] = 'gzip';

                $start_length = 10;
                $unpack_header = 'a1id1/a1id2/a1cmethod/a1flags/a4mtime/a1xflags/a1os';
                //+---+---+---+---+---+---+---+---+---+---+
                //|ID1|ID2|CM |FLG|     MTIME     |XFL|OS |
                //+---+---+---+---+---+---+---+---+---+---+
                @fseek($fd, 0);
                $buffer = @fread($fd, $ThisFileInfo['filesize']);

                $arr_members = explode("\x1F\x8B\x08", $buffer);
                while (true) {
                        $is_wrong_members = false;
                        $num_members = intval(count($arr_members));
                        for ($i = 0; $i < $num_members; $i++) {
                                if (strlen($arr_members[$i]) == 0) {
                                        continue;
                                }
                                $buf = "\x1F\x8B\x08".$arr_members[$i];

                                $attr = unpack($unpack_header, substr($buf, 0, $start_length));
                                if (!$this->get_os_type(ord($attr['os']))) {
                                        // Merge member with previous if wrong OS type
                                        $arr_members[$i - 1] .= $buf;
                                        $arr_members[$i] = '';
                                        $is_wrong_members = true;
                                        continue;
                                }
                        }
                        if (!$is_wrong_members) {
                                break;
                        }
                }

                $ThisFileInfo['gzip']['files'] = array();

                $fpointer = 0;
                $idx = 0;
                for ($i = 0; $i < $num_members; $i++) {
                        if (strlen($arr_members[$i]) == 0) {
                                continue;
                        }
                        $thisThisFileInfo = &$ThisFileInfo['gzip']['member_header'][++$idx];

                        $buff = "\x1F\x8B\x08".$arr_members[$i];

                        $attr = unpack($unpack_header, substr($buff, 0, $start_length));
                        $thisThisFileInfo['filemtime']      = getid3_lib::LittleEndian2Int($attr['mtime']);
                        $thisThisFileInfo['raw']['id1']     = ord($attr['cmethod']);
                        $thisThisFileInfo['raw']['id2']     = ord($attr['cmethod']);
                        $thisThisFileInfo['raw']['cmethod'] = ord($attr['cmethod']);
                        $thisThisFileInfo['raw']['os']      = ord($attr['os']);
                        $thisThisFileInfo['raw']['xflags']  = ord($attr['xflags']);
                        $thisThisFileInfo['raw']['flags']   = ord($attr['flags']);

                        $thisThisFileInfo['flags']['crc16']    = (bool) ($thisThisFileInfo['raw']['flags'] & 0x02);
                        $thisThisFileInfo['flags']['extra']    = (bool) ($thisThisFileInfo['raw']['flags'] & 0x04);
                        $thisThisFileInfo['flags']['filename'] = (bool) ($thisThisFileInfo['raw']['flags'] & 0x08);
                        $thisThisFileInfo['flags']['comment']  = (bool) ($thisThisFileInfo['raw']['flags'] & 0x10);

                        $thisThisFileInfo['compression'] = $this->get_xflag_type($thisThisFileInfo['raw']['xflags']);

                        $thisThisFileInfo['os'] = $this->get_os_type($thisThisFileInfo['raw']['os']);
                        if (!$thisThisFileInfo['os']) {
                                $ThisFileInfo['error'][] = 'Read error on gzip file';
                                return false;
                        }

                        $fpointer = 10;
                        $arr_xsubfield = array();
                        // bit 2 - FLG.FEXTRA
                        //+---+---+=================================+
                        //| XLEN  |...XLEN bytes of "extra field"...|
                        //+---+---+=================================+
                        if ($thisThisFileInfo['flags']['extra']) {
                                $w_xlen = substr($buff, $fpointer, 2);
                                $xlen = getid3_lib::LittleEndian2Int($w_xlen);
                                $fpointer += 2;

                                $thisThisFileInfo['raw']['xfield'] = substr($buff, $fpointer, $xlen);
                                // Extra SubFields
                                //+---+---+---+---+==================================+
                                //|SI1|SI2|  LEN  |... LEN bytes of subfield data ...|
                                //+---+---+---+---+==================================+
                                $idx = 0;
                                while (true) {
                                        if ($idx >= $xlen) {
                                                break;
                                        }
                                        $si1 = ord(substr($buff, $fpointer + $idx++, 1));
                                        $si2 = ord(substr($buff, $fpointer + $idx++, 1));
                                        if (($si1 == 0x41) && ($si2 == 0x70)) {
                                                $w_xsublen = substr($buff, $fpointer+$idx, 2);
                                                $xsublen = getid3_lib::LittleEndian2Int($w_xsublen);
                                                $idx += 2;
                                                $arr_xsubfield[] = substr($buff, $fpointer+$idx, $xsublen);
                                                $idx += $xsublen;
                                        } else {
                                                break;
                                        }
                                }
                                $fpointer += $xlen;
                        }
                        // bit 3 - FLG.FNAME
                        //+=========================================+
                        //|...original file name, zero-terminated...|
                        //+=========================================+
                        // GZIP files may have only one file, with no filename, so assume original filename is current filename without .gz
                        $thisThisFileInfo['filename'] = eregi_replace('.gz$', '', $ThisFileInfo['filename']);
                        if ($thisThisFileInfo['flags']['filename']) {
                                while (true) {
                                        if (ord($buff[$fpointer]) == 0) {
                                                $fpointer++;
                                                break;
                                        }
                                        $thisThisFileInfo['filename'] .= $buff[$fpointer];
                                        $fpointer++;
                                }
                        }
                        // bit 4 - FLG.FCOMMENT
                        //+===================================+
                        //|...file comment, zero-terminated...|
                        //+===================================+
                        if ($thisThisFileInfo['flags']['comment']) {
                                while (true) {
                                        if (ord($buff[$fpointer]) == 0) {
                                                $fpointer++;
                                                break;
                                        }
                                        $thisThisFileInfo['comment'] .= $buff[$fpointer];
                                        $fpointer++;
                                }
                        }
                        // bit 1 - FLG.FHCRC
                        //+---+---+
                        //| CRC16 |
                        //+---+---+
                        if ($thisThisFileInfo['flags']['crc16']) {
                                $w_crc = substr($buff, $fpointer, 2);
                                $thisThisFileInfo['crc16'] = getid3_lib::LittleEndian2Int($w_crc);
                                $fpointer += 2;
                        }
                        // bit 0 - FLG.FTEXT
                        //if ($thisThisFileInfo['raw']['flags'] & 0x01) {
                        //      Ignored...
                        //}
                        // bits 5, 6, 7 - reserved

                        $thisThisFileInfo['crc32']    = getid3_lib::LittleEndian2Int(substr($buff, strlen($buff) - 8, 4));
                        $thisThisFileInfo['filesize'] = getid3_lib::LittleEndian2Int(substr($buff, strlen($buff) - 4));

                        $ThisFileInfo['gzip']['files'] = getid3_lib::array_merge_clobber($ThisFileInfo['gzip']['files'], getid3_lib::CreateDeepArray($thisThisFileInfo['filename'], '/', $thisThisFileInfo['filesize']));

                        if ($this->option_gzip_parse_contents) {
                                // Try to inflate GZip
                                $csize = 0;
                                $inflated = '';
                                $chkcrc32 = '';
                                if (function_exists('gzinflate')) {
                                        $cdata = substr($buff, $fpointer);
                                        $cdata = substr($cdata, 0, strlen($cdata) - 8);
                                        $csize = strlen($cdata);
                                        $inflated = gzinflate($cdata);

                                        // Calculate CRC32 for inflated content
                                        $thisThisFileInfo['crc32_valid'] = (bool) (sprintf('%u', crc32($inflated)) == $thisThisFileInfo['crc32']);

                                        // determine format
                                        $formattest = substr($inflated, 0, 32774);
                                        $newgetID3 = new getID3();
                                        $determined_format = $newgetID3->GetFileFormat($formattest);
                                        unset($newgetID3);

                                // file format is determined
                                switch (@$determined_format['module']) {
                                        case 'tar':
                                                        // view TAR-file info
                                                        if (file_exists(GETID3_INCLUDEPATH.$determined_format['include']) && @include_once(GETID3_INCLUDEPATH.$determined_format['include'])) {
                                                                getid3_tar::read_tar($inflated, $ThisFileInfo['gzip']['member_header'][$idx]);
                                                        }
                                                        break;

                                        case '':
                                        default:
                                                // unknown or unhandled format
                                                break;
                                        }
                                }
                        }
                }
                return true;
        }

        // Converts the OS type
        function get_os_type($key) {
                static $os_type = array(
                        '0'   => 'FAT filesystem (MS-DOS, OS/2, NT/Win32)',
                        '1'   => 'Amiga',
                        '2'   => 'VMS (or OpenVMS)',
                        '3'   => 'Unix',
                        '4'   => 'VM/CMS',
                        '5'   => 'Atari TOS',
                        '6'   => 'HPFS filesystem (OS/2, NT)',
                        '7'   => 'Macintosh',
                        '8'   => 'Z-System',
                        '9'   => 'CP/M',
                        '10'  => 'TOPS-20',
                        '11'  => 'NTFS filesystem (NT)',
                        '12'  => 'QDOS',
                        '13'  => 'Acorn RISCOS',
                        '255' => 'unknown'
                );
                return @$os_type[$key];
        }

        // Converts the eXtra FLags
        function get_xflag_type($key) {
                static $xflag_type = array(
                        '0' => 'unknown',
                        '2' => 'maximum compression',
                        '4' => 'fastest algorithm'
                );
                return @$xflag_type[$key];
        }
}

?>