diff options
| -rw-r--r-- | phpBB/includes/functions_download.php | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/phpBB/includes/functions_download.php b/phpBB/includes/functions_download.php index 87bf7a91a6..6d52e92e7c 100644 --- a/phpBB/includes/functions_download.php +++ b/phpBB/includes/functions_download.php @@ -226,6 +226,16 @@ function send_file_to_browser($attachment, $upload_dir, $category) if ($fp !== false) { + // Deliver file partially if requested + if ($range = http_byte_range($size)) + { + fseek($fp, $range['byte_pos_start']); + + send_status_line(206, 'Partial Content'); + header('Content-Range: bytes ' . $range['byte_pos_start'] . '-' . $range['byte_pos_end'] . '/' . $range['bytes_total']); + header('Content-Length: ' . $range['bytes_requested']); + } + while (!feof($fp)) { echo fread($fp, 8192); @@ -407,3 +417,107 @@ function file_gc() $db->sql_close(); exit; } + +/** +* HTTP range support (RFC 2616 Section 14.35) +* +* Allows browsers to request partial file content +* in case a download has been interrupted. +* +* A range request can contain multiple ranges, +* we however only handle the first request and +* only support requests from a given byte to the end of the file. +* +* @param int $filesize the size of the file in bytes we are about to deliver +* +* @return mixed false if the whole file has to be delivered +* associative array on success +* +* @author bantu +*/ +function http_byte_range($filesize) +{ + if (!$filesize) + { + return false; + } + + foreach (array($_SERVER, $_ENV) as $global) + { + if (isset($global['HTTP_RANGE'])) + { + $http_range = $global['HTTP_RANGE']; + break; + } + } + + // Return if no range requested + // Make sure range request starts with "bytes=" + if (empty($http_range) || strpos($http_range, 'bytes=') !== 0) + { + return false; + } + + // Strip leading 'bytes=' + // Multiple ranges can be separated by a comma + foreach (explode(',', substr($http_range, 6)) as $range_string) + { + $range = explode('-', trim($range_string)); + + // "-" is invalid, "0-0" however is valid and means the very first byte. + if (sizeof($range) != 2 || $range[0] === '' && $range[1] === '') + { + continue; + } + + if ($range[0] === '') + { + // Return last $range[1] bytes. + + if (!$range[1]) + { + continue; + } + + if ($range[1] >= $filesize) + { + return false; + } + + $first_byte_pos = $filesize - (int) $range[1]; + $last_byte_pos = $filesize - 1; + } + else + { + // Return bytes from $range[0] to $range[1] + + $first_byte_pos = (int) $range[0]; + $last_byte_pos = (int) $range[1]; + + if ($last_byte_pos && $last_byte_pos < $first_byte_pos) + { + // The requested range contains 0 bytes. + continue; + } + + if ($first_byte_pos >= $filesize) + { + // Requested range not satisfiable + return false; + } + + // Adjust last-byte-pos if it is absent or greater than the content. + if ($range[1] === '' || $last_byte_pos >= $filesize) + { + $last_byte_pos = $filesize - 1; + } + } + + return array( + 'byte_pos_start' => $first_byte_pos, + 'byte_pos_end' => $last_byte_pos, + 'bytes_requested' => $last_byte_pos - $first_byte_pos + 1, + 'bytes_total' => $filesize, + ); + } +} |