<?php
/**
* Functions used by lib/exe/fetch.php
* (not included by other parts of dokuwiki)
*/
/**
* Set headers and send the file to the client
*
* The $cache parameter influences how long files may be kept in caches, the $public parameter
* influences if this caching may happen in public proxis or in the browser cache only FS#2734
*
* This function will abort the current script when a 304 is sent or file sending is handled
* through x-sendfile
*
* @author Andreas Gohr <andi@splitbrain.org>
* @author Ben Coburn <btcoburn@silicodon.net>
* @author Gerry Weissbach <dokuwiki@gammaproduction.de>
*
* @param string $file local file to send
* @param string $mime mime type of the file
* @param bool $dl set to true to force a browser download
* @param int $cache remaining cache time in seconds (-1 for $conf['cache'], 0 for no-cache)
* @param bool $public is this a public ressource or a private one?
* @param string $orig original file to send - the file name will be used for the Content-Disposition
*/
function sendFile($file, $mime, $dl, $cache, $public = false, $orig = null) {
global $conf;
// send mime headers
header("Content-Type: $mime");
// calculate cache times
if($cache == -1) {
$maxage = max($conf['cachetime'], 3600); // cachetime or one hour
$expires = time() + $maxage;
} else if($cache > 0) {
$maxage = $cache; // given time
$expires = time() + $maxage;
} else { // $cache == 0
$maxage = 0;
$expires = 0; // 1970-01-01
}
// smart http caching headers
if($maxage) {
if($public) {
// cache publically
header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
header('Cache-Control: public, proxy-revalidate, no-transform, max-age='.$maxage);
} else {
// cache in browser
header('Expires: '.gmdate("D, d M Y H:i:s", $expires).' GMT');
header('Cache-Control: private, no-transform, max-age='.$maxage);
}
} else {
// no cache at all
header('Expires: Thu, 01 Jan 1970 00:00:00 GMT');
header('Cache-Control: no-cache, no-transform');
}
//send important headers first, script stops here if '304 Not Modified' response
$fmtime = @filemtime($file);
http_conditionalRequest($fmtime);
// Use the current $file if is $orig is not set.
if ( $orig == null ) {
$orig = $file;
}
//download or display?
if($dl) {
header('Content-Disposition: attachment;'.rfc2231_encode('filename', utf8_basename($orig)).';');
} else {
header('Content-Disposition: inline;'.rfc2231_encode('filename', utf8_basename($orig)).';');
}
//use x-sendfile header to pass the delivery to compatible webservers
http_sendfile($file);
// send file contents
$fp = @fopen($file, "rb");
if($fp) {
http_rangeRequest($fp, filesize($file), $mime);
} else {
http_status(500);
print "Could not read $file - bad permissions?";
}
}
/**
* Try an rfc2231 compatible encoding. This ensures correct
* interpretation of filenames outside of the ASCII set.
* This seems to be needed for file names with e.g. umlauts that
* would otherwise decode wrongly in IE.
*
* There is no additional checking, just the encoding and setting the key=value for usage in headers
*
* @author Gerry Weissbach <gerry.w@gammaproduction.de>
* @param string $name name of the field to be set in the header() call
* @param string $value value of the field to be set in the header() call
* @param string $charset used charset for the encoding of value
* @param string $lang language used.
* @return string in the format " name=value" for values WITHOUT special characters
* @return string in the format " name*=charset'lang'value" for values WITH special characters
*/
function rfc2231_encode($name, $value, $charset='utf-8', $lang='en') {
$internal = preg_replace_callback('/[\x00-\x20*\'%()<>@,;:\\\\"\/[\]?=\x80-\xFF]/', function($match) { return rawurlencode($match[0]); }, $value);
if ( $value != $internal ) {
return ' '.$name.'*='.$charset."'".$lang."'".$internal;
} else {
return ' '.$name.'="'.$value.'"';
}
}
/**
* Check for media for preconditions and return correct status code
*
* READ: MEDIA, MIME, EXT, CACHE
* WRITE: MEDIA, FILE, array( STATUS, STATUSMESSAGE )
*
* @author Gerry Weissbach <gerry.w@gammaproduction.de>
*
* @param string $media reference to the media id
* @param string $file reference to the file variable
* @param string $rev
* @param int $width
* @param int $height
* @return array as array(STATUS, STATUSMESSAGE)
*/
function checkFileStatus(&$media, &$file, $rev = '', $width=0, $height=0) {
global $MIME, $EXT, $CACHE, $INPUT;
//media to local file
if(media_isexternal($media)) {
//check token for external image and additional for resized and cached images
if(media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
return array(412, 'Precondition Failed');
}
//handle external images
if(strncmp($MIME, 'image/', 6) == 0) $file = media_get_from_URL($media, $EXT, $CACHE);
if(!$file) {
//download failed - redirect to original URL
return array(302, $media);
}
} else {
$media = cleanID($media);
if(empty($media)) {
return array(400, 'Bad request');
}
// check token for resized images
if (($width || $height) && media_get_token($media, $width, $height) !== $INPUT->str('tok')) {
return array(412, 'Precondition Failed');
}
//check permissions (namespace only)
if(auth_quickaclcheck(getNS($media).':X') < AUTH_READ) {
return array(403, 'Forbidden');
}
$file = mediaFN($media, $rev);
}
//check file existance
if(!file_exists($file)) {
return array(404, 'Not Found');
}
return array(200, null);
}
/**
* Returns the wanted cachetime in seconds
*
* Resolves named constants
*
* @author Andreas Gohr <andi@splitbrain.org>
*
* @param string $cache
* @return int cachetime in seconds
*/
function calc_cache($cache) {
global $conf;
if(strtolower($cache) == 'nocache') return 0; //never cache
if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
return -1; //cache endless
}