Services/WebAccessChecker/classes/class.ilWebAccessChecker.php

Go to the documentation of this file.

<?php
/*
        +-----------------------------------------------------------------------------+
        | ILIAS open source                                                           |
        +-----------------------------------------------------------------------------+
        | Copyright (c) 1998-2001 ILIAS open source, University of Cologne            |
        |                                                                             |
        | This program is free software; you can redistribute it and/or               |
        | modify it under the terms of the GNU General Public License                 |
        | as published by the Free Software Foundation; either version 2              |
        | of the License, or (at your option) any later version.                      |
        |                                                                             |
        | This program is distributed in the hope that it will be useful,             |
        | but WITHOUT ANY WARRANTY; without even the implied warranty of              |
        | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               |
        | GNU General Public License for more details.                                |
        |                                                                             |
        | You should have received a copy of the GNU General Public License           |
        | along with this program; if not, write to the Free Software                 |
        | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. |
        +-----------------------------------------------------------------------------+
*/

require_once "./include/inc.header.php";
require_once "./Services/Utilities/classes/class.ilUtil.php";
require_once "./classes/class.ilObject.php";
require_once "./Services/MediaObjects/classes/class.ilObjMediaObject.php";

class ilWebAccessChecker
{
        var $lng;
        var $ilAccess;
        var $checked_list;
        
        var $subpath;

        var $file;

        var $params;


        var $disposition = "inline";


        var $mimetype;      

        var $errorcode;

            
        var $errortext;


        function ilWebAccessChecker()
        {
                global $ilAccess, $lng, $ilLog;

                $this->lng =& $lng;
                $this->ilAccess =& $ilAccess;
                $this->checked_list = & $_SESSION["WebAccessChecked"];
                $this->params = array();

                // get the requested file and its type
                $uri = parse_url($_SERVER["REQUEST_URI"]);
                parse_str($uri["query"], $this->params);

                $pattern = ILIAS_WEB_DIR . "/" . CLIENT_ID;
                $this->subpath = urldecode(substr($uri["path"], strpos($uri["path"], $pattern)));
                $this->file = realpath(ILIAS_ABSOLUTE_PATH . "/". $this->subpath);
                
                /* debugging
                echo "<pre>";
                echo "REQUEST_URI:         ". $_SERVER["REQUEST_URI"]. "\n";
                echo "Parsed URI:          ". $uri["path"]. "\n";
                echo "DOCUMENT_ROOT:       ". $_SERVER["DOCUMENT_ROOT"]. "\n";
                echo "PHP_SELF:            ". $_SERVER["PHP_SELF"]. "\n";
                echo "SCRIPT_NAME:         ". $_SERVER["SCRIPT_NAME"]. "\n";
                echo "SCRIPT_FILENAME:     ". $_SERVER["SCRIPT_FILENAME"]. "\n";
                echo "PATH_TRANSLATED:     ". $_SERVER["PATH_TRANSLATED"]. "\n";
                echo "ILIAS_WEB_DIR:       ". ILIAS_WEB_DIR. "\n";
                echo "ILIAS_HTTP_PATH:     ". ILIAS_HTTP_PATH. "\n";
                echo "ILIAS_ABSOLUTE_PATH: ". ILIAS_ABSOLUTE_PATH. "\n";
                echo "CLIENT_ID:           ". CLIENT_ID. "\n";
                echo "CLIENT_WEB_DIR:      ". CLIENT_WEB_DIR. "\n";
                echo "subpath:             ". $this->subpath. "\n";
                echo "file:                ". $this->file. "\n";
                echo "</pre>";
                exit;
                */

                if (file_exists($this->file))
                {
                        $this->mimetype = ilObjMediaObject::getMimeType($this->file);
                }
                else
                {
                        $this->errorcode = 404;
                        $this->errortext = $this->lng->txt("url_not_found");
                        return false;
                }
        }

        function checkAccess()
        {
                global $ilLog;
                
                // extract the object id (html/scorm learning modules)
                $pos1 = strpos($this->subpath, "lm_data/lm_") + 11;
                $pos2 = strpos($this->subpath, "/", $pos1);

                if ($pos1 == 11 or $pos2 === false)
                {
                        // media object
                        $pos1 = strpos($this->subpath, "mobs/mm_") + 8;
                        $pos2 = strpos($this->subpath, "/", $pos1);
                        if ($pos1 === false or $pos2 === false)
                        {
                                $this->errorcode = 404;
                                $this->errortext = $this->lng->txt("url_not_found");
                                return false;
                        }
                        else
                        {
                                $mob_id = substr($this->subpath, $pos1, $pos2-$pos1);
                                include_once("./Services/MediaObjects/classes/class.ilObjMediaObject.php");
                                $usages = ilObjMediaObject::lookupUsages($mob_id);
                                foreach($usages as $usage)
                                {
                                        //var_dump($usage);
                                        $oid = ilObjMediaObject::getParentObjectIdForUsage($usage, true);
                                        //var_dump($oid);
                                        if ($oid > 0)
                                        {
                                                $obj_ids[] = $oid;
                                        
                                                // media objects in news (media casts)
                                                if ($usage["type"] == "news")
                                                {
                                                        include_once("./Modules/MediaCast/classes/class.ilObjMediaCastAccess.php");
                                                        include_once("./Services/News/classes/class.ilNewsItem.php");
                                                        
                                                        if (ilObjMediaCastAccess::_lookupPublicFiles($oid) &&
                                                                ilNewsItem::_lookupVisibility($usage["id"]) == NEWS_PUBLIC)
                                                        {
                                                                return true;
                                                        }
                                                }
                                        }
                                }
                        }
                }
                $obj_ids[] = substr($this->subpath, $pos1, $pos2-$pos1);
                foreach($obj_ids as $obj_id)
                {
                        if (!is_numeric($obj_id))
                        {
                                $this->errorcode = 404;
                                $this->errortext = $this->lng->txt("obj_not_found");
                                return false;
                        }
        
                        // look in cache, if already checked
                        if (is_array($this->checked_list))
                        {
                                if (in_array($obj_id, $this->checked_list))
                                {
        //                              return true;
                                }
                        }
        
                        // find the object references
                        $obj_type = ilObject::_lookupType($obj_id);
                        $ref_ids  = ilObject::_getAllReferences($obj_id);
                        if (!$ref_ids)
                        {
                                $this->errorcode = 403;
                                $this->errortext = $this->lng->txt("permission_denied");
                                return false;
                        }
        
                        // check, if one of the references is readable
                        $readable = false;
        
                        foreach($ref_ids as $ref_id)
                        {
                                if ($this->ilAccess->checkAccess("read", "view", $ref_id, $obj_type, $obj_id))
                                {
                                        $readable = true;
                                        break;
                                }
                        }
                        if ($readable)
                        {
                                //add object to cache
                                $this->checked_list[] = $obj_id;
                                return true;
                        }
                }
                
                $this->errorcode = 403;
                $this->errortext = $this->lng->txt("permission_denied");
                return false;
        }
        
        
        function setDisposition($a_disposition = "inline")
        {
                $this->disposition = $a_disposition;
        }

        function getDisposition()
        {
                return $this->disposition;
        }

        
        function sendFile()
        {
                if ($this->getDisposition() == "attachment")
                {
                        ilUtil::deliverFile($this->file, basename($this->file));
                        exit;
                }
                else
                {
                        if (!isset($_SERVER["HTTPS"]))
                        {
                                header("Cache-Control: no-cache, must-revalidate");
                                header("Pragma: no-cache");
                        }
                        
                        header("Content-Type: " . $this->mimetype);
                        header("Content-Length: ".(string)(filesize($this->file)));
                        
                        if (isset($_SERVER["HTTPS"]))
                        {
                                header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
                                header('Pragma: public');
                        }

                        header("Connection: close");

                        ilUtil::readFile( $this->file);
                        exit;
                }
        }
        
        function sendError()
        {
                switch ($this->errorcode)
                {
                        case 403:
                                header("HTTP/1.0: 403 Forbidden");
                                break;
                        case 404:
                                header("HTTP/1.0: 404 Not Found");
                                break;
                }
                exit($this->errortext);
        }
}
?>