note 112063 deleted from function.fsockopen by cmb

Note Submitter: Charles Torvalds ---- Rewrite/Update of king dot macro's DNS lookups function. <?php function gethostbyaddr_timeout( $ip, $dns, $timeout = 3 ) { // src: http://www.askapache.com/php/php-fsockopen-dns-udp.html // random transaction number (for routers etc to get the reply back) $data = rand( 10, 77 ) . "\1\0\0\1\0\0\0\0\0\0"; // octals in the array, keys are strlen of bit $bitso = array("","\1","\2","\3" ); foreach( array_reverse( explode( '.', $ip ) ) as $bit ) { $l=strlen($bit); $data.="{$bitso[$l]}".$bit; } // and the final bit of the request $data .= "\7in-addr\4arpa\0\0\x0C\0\1"; // create UDP socket $errno = $errstr = 0; $fp = fsockopen( "udp://{$dns}", 53, $errno, $errstr, $timeout ); if( ! $fp || ! is_resource( $fp ) ) return $errno; if( function_exists( 'socket_set_timeout' ) ) { socket_set_timeout( $fp, $timeout ); } elseif ( function_exists( 'stream_set_timeout' ) ) { stream_set_timeout( $fp, $timeout ); } // send our request (and store request size so we can cheat later) $requestsize = fwrite( $fp, $data ); $max_rx = $requestsize * 3; $start = time(); $responsesize = 0; while ( $rxed < $max_rx && ( ( time() - $start ) < $timeout ) && ($b = fread( $fp, 1 ) ) !== false ) { $responsesize++; $response .= $b; } echo "[tx: $requestsize bytes] [rx: {$responsesize} bytes]"; // hope we get a reply if ( is_resource( $fp ) ) fclose( $fp ); // if empty response or bad response, return original ip if ( empty( $response ) || bin2hex( substr( $response, $requestsize + 2, 2 ) ) != '000c' ) return $ip; // set up our variables $host = ''; $len = $loops = 0; // set our pointer at the beginning of the hostname uses the request size from earlier rather than work it out $pos = $requestsize + 12; do { // get segment size $len = unpack( 'c', substr( $response, $pos, 1 ) ); // null terminated string, so length 0 = finished - return the hostname, without the trailing . if ( $len[1] == 0 ) return substr( $host, 0, -1 ); // add segment to our host $host .= substr( $response, $pos + 1, $len[1] ) . '.'; // move pointer on to the next segment $pos += $len[1] + 1; // recursion protection $loops++; } while ( $len[1] != 0 && $loops < 20 ); // return the ip in case return $ip; } ?>