new file to add ACL checks on media files #204 (incomplete yet)

darcs-hash:20050413200438-9977f-7b75da8fcdd239f3ef9658e8c487e998e619e9d2.gz

fetch.php

+<?php
+/**
+ * DokuWiki media passthrough file
+ *
+ * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
+ * @author     Andreas Gohr <andi@splitbrain.org>
+ */
+
+
+	if(!defined('DOKU_INC')) define('DOKU_INC',realpath(dirname(__FILE__)).'/');
+	require_once(DOKU_INC.'inc/init.php');
+	require_once(DOKU_INC.'inc/common.php');
+  require_once(DOKU_INC.'inc/auth.php');
+
+	//get input
+	$MEDIA  = $_REQUEST['media'];
+	$CACHE  = calc_cache($_REQUEST['cache']);
+	$WIDTH  = $_REQUEST['w'];
+	$HEIGHT = $_REQUEST['h'];
+  $EXT    = media_extension($MEDIA);
+
+	//media to local file
+	if(preg_match('#^(https?|ftp)://#i',$MEDIA)){
+    //handle external media
+  	$FILE = get_from_URL($MEDIA,$EXT,$CACHE);
+    if(!$FILE){
+      //download failed - redirect to original URL
+      header('Location: '.$MEDIA);
+      exit;
+    }
+  }else{
+    $MEDIA = cleanID($MEDIA);
+    if(empty($MEDIA)){
+      header("HTTP/1.0 400 Bad Request");
+      print 'Bad request';
+      exit;
+    }
+
+    //check permissions (namespace only)
+    if(auth_quickaclcheck(getNS($MEDIA).':X') < AUTH_READ){
+      header("HTTP/1.0 401 Unauthorized");
+      //fixme add some image for imagefiles else display login message
+      exit;
+    }
+    $FILE  = mediaFN($MEDIA);
+  } 
+  
+  //check file existance
+  if(!@file_exists($FILE)){
+    header("HTTP/1.0 404 Not Found");
+    //FIXME add some default broken image or display message
+    exit;
+  }
+
+
+
+  //FIXME handle image resizing
+
+
+  //FIXME add correct mimetype
+  //FIXME send Size header
+  //FIXME send Lastmod Handler
+  //FIXME cache headers??
+  //FIXME handle conditional and partial requests
+
+  //send file
+  passthru($FILE) ;
+
+
+/* ----------- */
+
+/**
+ * Returns the wanted cachetime in seconds
+ *
+ * Resolves named constants
+ *
+ * @author  Andreas Gohr <andi@splitbrain.org>
+ */
+function calc_cache($cache){
+  global $conf;
+
+  if(strtolower($cache) == 'nocache') return 0; //never cache
+  if(strtolower($cache) == 'recache') return $conf['cachetime']; //use standard cache
+  return -1; //cache endless
+}
+
+/**
+ * Download a remote file and return local filename
+ *
+ * returns false if download fails. Uses cached file if available and
+ * wanted
+ *
+ * @author  Andreas Gohr <andi@splitbrain.org>
+ */
+function get_from_URL($url,$ext,$cache){
+  global $conf;
+
+  $url = strtolower($url);
+  $md5 = md5($url);
+
+  $local = $conf['mediadir']."/_cache/$md5.$ext";
+  $mtime = @filemtime($local); // 0 if not exists
+
+  //decide if download needed:
+
+  //  never cache     exists but no endless cache     not exists or expired
+  if( $cache == 0 || ($mtime != 0 && $cache != -1) || $mtime < time()-$cache ){
+    if(download($url,$local)){
+      return $local;
+    }else{
+      return false;
+    }
+  }
+      
+  //if cache exists use it else
+  if($mtime) return $local;
+
+  //else return false
+  return false;
+}
+
+
+
+
+//Setup VIM: ex: et ts=2 enc=utf-8 :
+?>

inc/common.php

@@ -415,6 +415,21 @@ function wikiFN($id,$rev=''){
   return $fn;
 }
 
+/**
+ * returns the full path to the mediafile specified by ID
+ *
+ * The filename is URL encoded to protect Unicode chars
+ *
+ * @author Andreas Gohr <andi@splitbrain.org>
+ */
+function mediaFN($id){
+  global $conf;
+  $id = cleanID($id);
+  $id = str_replace(':','/',$id);
+    $fn = $conf['datadir'].'/'.utf8_encodeFN($id);
+  return $fn;
+}
+
 /**
  * Returns the full filepath to a localized textfile if local
  * version isn't found the english one is returned