class.ilAccessHandler.php

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<?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("Services/AccessControl/classes/class.ilAccessInfo.php");

class ilAccessHandler
{
        function ilAccessHandler()
        {
                global $rbacsystem;

                $this->rbacsystem =& $rbacsystem;
                $this->results = array();
                $this->current_info = new ilAccessInfo();
                
                // use function enable to switch on/off tests (only cache is used so far)
                $this->cache = true;
                $this->rbac = true;
                $this->tree = true;
                $this->condition = true;
                $this->path = true;
                $this->status = true;
                $this->obj_id_cache = array();
                $this->obj_type_cache = array();
        $this->obj_tree_cache=array();
        }

        function storeAccessResult($a_permission, $a_cmd, $a_ref_id, $a_access_granted, $a_user_id = "",$a_info = "")
        {
                global $ilUser;

                if ($a_user_id == "")
                {
                        $a_user_id = $ilUser->getId();
                }
                
                if ($a_info == "")
                {
                        $a_info = $this->current_info;
                }

                //var_dump("<pre>",$a_permission,"</pre>");

                if ($this->cache)
                {
                        $this->results[$a_ref_id][$a_permission][$a_cmd][$a_user_id] = 
                                        array("granted" => $a_access_granted, "info" => $a_info);
//echo "<br>write-$a_ref_id-$a_permission-$a_cmd-$a_user_id-$a_access_granted-";
                        $this->current_result_element = array($a_access_granted,$a_ref_id,$a_permission,$a_cmd,$a_user_id);                     
                        $this->last_result = $this->results[$a_ref_id][$a_permission][$a_cmd][$a_user_id];
                        $this->last_info = $a_info;
                }

                // get new info object
                $this->current_info = new ilAccessInfo();

        }


        function getStoredAccessResult($a_permission, $a_cmd, $a_ref_id, $a_user_id = "")
        {
                global $ilUser;

                if ($a_user_id == "")
                {
                        $a_user_id = $ilUser->getId();
                }
                
                /*if (is_object($this->results[$a_ref_id][$a_permission][$a_cmd][$a_user_id]['info']))
                {
                        $this->current_info = $this->results[$a_ref_id][$a_permission][$a_cmd][$a_user_id]['info'];
                }*/

                return $this->results[$a_ref_id][$a_permission][$a_cmd][$a_user_id];
        }

        function storeCache()
        {
                global $ilDB, $ilUser;
                
                $q = "REPLACE INTO acc_cache (user_id, time, result) VALUES ".
                        "(".$ilDB->quote($ilUser->getId()).",".time().",".
                        $ilDB->quote(serialize($this->results)).")";
                $ilDB->query($q);
        }
        
        function readCache($a_secs = 0)
        {
                global $ilUser, $ilDB;
                
                if ($a_secs > 0)
                {
                        $q = "SELECT * FROM acc_cache WHERE user_id = ".
                                $ilDB->quote($ilUser->getId());
                        $set = $ilDB->query($q);
                        $rec = $set->fetchRow(DB_FETCHMODE_ASSOC);
                        if ((time() - $rec["time"]) < $a_secs)
                        {
                                $this->results = unserialize($rec["result"]);
//var_dump($this->results);
                                return true;
                        }
                }
                return false;
        }

        function getResults()
        {
                return $this->results;
        }
        
        function setResults($a_results)
        {
                $this->results = $a_results;
        }
        
        function addInfoItem($a_type, $a_text, $a_data = "")
        {
                $this->current_info->addInfoItem($a_type, $a_text, $a_data);
        }

        function checkAccess($a_permission, $a_cmd, $a_ref_id, $a_type = "", $a_obj_id = "", $a_tree_id="")
        {
                global $ilUser;

                return $this->checkAccessOfUser($ilUser->getId(),$a_permission, $a_cmd, $a_ref_id, $a_type, $a_obj_id, $a_tree_id);
        }

        function checkAccessOfUser($a_user_id,$a_permission, $a_cmd, $a_ref_id, $a_type = "", $a_obj_id = "", $a_tree_id="")
        {
                global $ilBench, $lng;
                
                $ilBench->start("AccessControl", "0400_clear_info");
                $this->current_info->clear();
                $ilBench->stop("AccessControl", "0400_clear_info");
                
        // get stored result
                $cached = $this->doCacheCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id);
                if ($cached["hit"])
                {
                        // Store access result
                        if (!$cached["granted"])
                        {
                                $this->current_info->addInfoItem(IL_NO_PERMISSION, $lng->txt("status_no_permission"));
                        }
                        return $cached["granted"];
                }

                $ilBench->start("AccessControl", "0500_lookup_id_and_type");
                // get object id if not provided
                if ($a_obj_id == "")
                {
                        if ($this->obj_id_cache[$a_ref_id] > 0)
                        {
                                $a_obj_id = $this->obj_id_cache[$a_ref_id];
                        }
                        else
                        {
                                $a_obj_id = ilObject::_lookupObjId($a_ref_id);
                                $this->obj_id_cache[$a_ref_id] = $a_obj_id;
                        }
                }
                if ($a_type == "")
                {
                        if ($this->obj_type_cache[$a_ref_id] != "")
                        {
                                $a_type = $this->obj_type_cache[$a_ref_id];
                        }
                        else
                        {
                                $a_type = ilObject::_lookupType($a_ref_id, true);
                                $this->obj_type_cache[$a_ref_id] = $a_type;
                        }
                }
                $ilBench->stop("AccessControl", "0500_lookup_id_and_type");

                // to do: payment handling

        // if supplied tree id is not = 1 (= repository main tree),
        // check if object is in tree and not deleted
                if ($a_tree_id != 1 &&
            !$this->doTreeCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id))
                {
                        $this->current_info->addInfoItem(IL_NO_PERMISSION, $lng->txt("status_no_permission"));
                        $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, false, $a_user_id);
                        return false;
                }

                // rbac check for current object
                if (!$this->doRBACCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id))
                {
                        $this->current_info->addInfoItem(IL_NO_PERMISSION, $lng->txt("status_no_permission"));
                        $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, false, $a_user_id);
                        return false;
                }

                // check read permission for all parents
                $par_check = $this->doPathCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id);
                if (!$par_check)
                {
                        $this->current_info->addInfoItem(IL_NO_PARENT_ACCESS, $lng->txt("no_parent_access"));
                        $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, false, $a_user_id);
                        return false;
                }

                // condition check (currently only implemented for read permission)
                if (!$this->doConditionCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id, $a_obj_id, $a_type))
                {
                        $this->current_info->addInfoItem(IL_NO_PERMISSION, $lng->txt("status_no_permission"));
                        $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, false, $a_user_id);
                        return false;
                }

                // object type specific check
                if (!$this->doStatusCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id, $a_obj_id, $a_type))
                {
                        $this->current_info->addInfoItem(IL_NO_PERMISSION, $lng->txt("status_no_permission"));
                        $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, false, $a_user_id);
                        return false;
                }

                // all checks passed
                $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, true, $a_user_id);
                return true;
        }

        function getInfo()
        {
                //return $this->last_result;
                //$this->last_info->setQueryData($this->current_result_element);
                //var_dump("<pre>",$this->results,"</pre>");
                return is_object($this->last_info) ? $this->last_info->getInfoItems() : array();
        }
        
        function getResultLast()
        {
                return $this->last_result;
        }
        
        function getResultAll($a_ref_id = "")
        {
                if ($a_ref_id == "")
                {
                        return $this->results;
                }
                
                return $this->results[$a_ref_id];
        }
        
        function doCacheCheck($a_permission, $a_cmd, $a_ref_id,$a_user_id)
        {
                global $ilBench;
                //echo "cacheCheck<br/>";

                $ilBench->start("AccessControl", "1000_checkAccess_get_cache_result");
                $stored_access = $this->getStoredAccessResult($a_permission, $a_cmd, $a_ref_id,$a_user_id);
                //var_dump($stored_access);
                if (is_array($stored_access))
                {
//echo "Hit";
                        $this->current_info = $stored_access["info"];
                        //var_dump("cache-treffer:");
                        $ilBench->stop("AccessControl", "1000_checkAccess_get_cache_result");
                        return array("hit" => true, "granted" => $stored_access["granted"]);
                }
                
                // not in cache
                $ilBench->stop("AccessControl", "1000_checkAccess_get_cache_result");
                return array("hit" => false, "granted" => false);
        }
        
        function doTreeCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id)
        {
                global $tree, $lng, $ilBench;
                //echo "treeCheck<br/>";

        // Get stored result
                $tree_cache_key = $a_user_id.':'.$a_ref_id;
        if (array_key_exists($tree_cache_key, $this->obj_tree_cache)) {
                        // Store access result
                        if (!$this->obj_tree_cache[$tree_cache_key])
                        {
                                $this->current_info->addInfoItem(IL_NO_PERMISSION, $lng->txt("status_no_permission"));
                        }
                        $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, $this->obj_tree_cache[$tree_cache_key], $a_user_id);

            return $this->obj_tree_cache[$tree_cache_key];
        }

                $ilBench->start("AccessControl", "2000_checkAccess_in_tree");

                if(!$tree->isInTree($a_ref_id) or $tree->isDeleted($a_ref_id))
                {
            // Store negative access results
                        
                        // Store in tree cache
            // Note, we only store up to 1000 results to avoid memory overflow.
            if (count($this->obj_tree_cache) < 1000) 
            {
                $this->obj_tree_cache[$tree_cache_key] = false;
            }

                        // Store in result cache
                        $this->current_info->addInfoItem(IL_DELETED, $lng->txt("object_deleted"));
                        $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, false, $a_user_id);

                        $ilBench->stop("AccessControl", "2000_checkAccess_in_tree");

                        return false;
                }

        // Store positive access result.

                // Store in tree cache
        // Note, we only store up to 1000 results to avoid memory overflow.
        if (count($this->obj_tree_cache) < 1000)
        {
            $this->obj_tree_cache[$tree_cache_key] = true;
        }

                // Store in result cache
                $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, true, $a_user_id);

                $ilBench->stop("AccessControl", "2000_checkAccess_in_tree");
                return true;
        }
        
        function doRBACCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id)
        {
                global $lng, $ilBench, $ilErr, $ilLog;

                $ilBench->start("AccessControl", "2500_checkAccess_rbac_check");
                
                if ($a_permission == "")
                {
                                $message = sprintf('%s::doRBACCheck(): No operations given! $a_ref_id: %s',
                                                                   get_class($this),
                                                                   $a_ref_id);
                                $ilLog->write($message,$ilLog->FATAL);
                                $ilErr->raiseError($message,$ilErr->MESSAGE);
                }
                
                $access = $this->rbacsystem->checkAccessOfUser($a_user_id, $a_permission, $a_ref_id);

                // Store in result cache
                if (!$access)
                {
                        $this->current_info->addInfoItem(IL_NO_PERMISSION, $lng->txt("status_no_permission"));
                }
                $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, true, $a_user_id);
                $ilBench->stop("AccessControl", "2500_checkAccess_rbac_check");

                return $access;
        }
        
        function doPathCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id, $a_all = false)
        {
                global $tree, $lng, $ilBench,$ilObjDataCache;
//echo "<br>dopathcheck";
                //echo "pathCheck<br/>";
        $ilBench->start("AccessControl", "3100_checkAccess_check_parents_get_path");
                $path = $tree->getPathId($a_ref_id);
                $ilBench->stop("AccessControl", "3100_checkAccess_check_parents_get_path");

                $tmp_info = $this->current_info;
                //var_dump($this->tmp_info);
                                        
                foreach ($path as $id)
                {
                        if ($a_ref_id == $id)
                        {
                                continue;
                        }

                        // Check course activation
                        if($ilObjDataCache->lookupType($ilObjDataCache->lookupObjId($id)) == 'crs')
                        {
                                if(!$this->doActivationCheck($a_permission,$a_cmd,$a_ref_id,$a_user_id,$a_all))
                                {
                                        return false;
                                }
                        }
                        
                        $access = $this->checkAccessOfUser($a_user_id, "read", "info", $id);

                        if ($access == false)
                        {
                                
                                //$this->doCacheCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id);
                                $tmp_info->addInfoItem(IL_NO_PARENT_ACCESS, $lng->txt("no_parent_access"),$id);

                                if ($a_all == false)
                                {
                                        return false;
                                }
                        }
                }
                
                return true;
        }

        function doActivationCheck($a_permission, $a_cmd, $a_ref_id, $a_user_id, $a_all = false)
        {
                global $ilBench,$ilObjDataCache;
                
                $ilBench->start("AccessControl", "3150_checkAccess_check_course_activation");

                $cache_perm = ($a_permission == "visible")
                        ? "visible"
                        : "other";
                        
//echo "<br>doActivationCheck-$cache_perm-$a_ref_id-$a_user_id-".$ilObjDataCache->lookupType($ilObjDataCache->lookupObjId($a_ref_id));

                if (isset($this->ac_cache[$cache_perm][$a_ref_id][$a_user_id]))
                {
                        $ilBench->stop("AccessControl", "3150_checkAccess_check_course_activation");
                        return $this->ac_cache[$cache_perm][$a_ref_id][$a_user_id];
                }
                
                // nothings needs to be done if current permission is write permission
                if($a_permission == 'write')
                {
                        $ilBench->stop("AccessControl", "3150_checkAccess_check_course_activation");
                        return true;
                }
                include_once 'Modules/Course/classes/class.ilCourseItems.php';
                
                $this->preloadActivationTimes(array($a_ref_id));
                if(isset($this->ac_times[$a_ref_id]))
                {
                        // read preloaded
                        $item_data = $this->ac_times[$a_ref_id];
                }
                else
                {
                        global $ilLog;
                        $ilLog->write(__METHOD__.': Error preloading activation times failed.');
                        $item_data = ilCourseItems::_readActivationTimes(array($a_ref_id));
                        $item_data = $item_data[$a_ref_id];
                }
                

                // if activation isn't enabled
                if($item_data['timing_type'] != IL_CRS_TIMINGS_ACTIVATION)
                {
                        $this->ac_cache[$cache_perm][$a_ref_id][$a_user_id] = true;
                        $ilBench->stop("AccessControl", "3150_checkAccess_check_course_activation");
                        return true;
                }
                
                // if within activation time
                if((time() >= $item_data['timing_start']) and
                   (time() <= $item_data['timing_end']))
                {
                        $this->ac_cache[$cache_perm][$a_ref_id][$a_user_id] = true;
                        $ilBench->stop("AccessControl", "3150_checkAccess_check_course_activation");
                        return true;
                }
                
                // if user has write permission
                if($this->checkAccessOfUser($a_user_id, "write", "", $a_ref_id))
                {
                        $this->ac_cache[$cache_perm][$a_ref_id][$a_user_id] = true;
                        $ilBench->stop("AccessControl", "3150_checkAccess_check_course_activation");
                        return true;
                }
                // if current permission is visible and visible is set in activation
                if($a_permission == 'visible' and $item_data['visible'])
                {
                        $this->ac_cache[$cache_perm][$a_ref_id][$a_user_id] = true;
                        $ilBench->stop("AccessControl", "3150_checkAccess_check_course_activation");
                        return true;
                }
                // no access
                $this->ac_cache[$cache_perm][$a_ref_id][$a_user_id] = false;
                $ilBench->stop("AccessControl", "3150_checkAccess_check_course_activation");
                return false;
        }
        
        public function preloadActivationTimes($a_ref_ids)
        {
                include_once('Modules/Course/classes/class.ilCourseItems.php');
                
                $read_arr = array();
                foreach($a_ref_ids as $ref_id)
                {
                        if(!isset($this->ac_times[$ref_id]))
                        {
                                $read_arr[] = $ref_id;
                        }
                }
                if(count($read_arr))
                {
                        $this->ac_times = (array) $this->ac_times + ilCourseItems::_readActivationTimes($read_arr);
                }
        }
        
        function doConditionCheck($a_permission, $a_cmd, $a_ref_id,$a_user_id, $a_obj_id, $a_type)
        {
                //echo "conditionCheck<br/>";
                global $lng, $ilBench;

                if (($a_permission == "read" or $a_permission == 'join') &&
                        !$this->checkAccessOfUser($a_user_id, "write", "", $a_ref_id, $a_type, $a_obj_id))
                {
                        $ilBench->start("AccessControl", "4000_checkAccess_condition_check");
                        if(!ilConditionHandler::_checkAllConditionsOfTarget($a_ref_id,$a_obj_id,$a_type,$a_user_id))
                        {
                                $conditions = ilConditionHandler::_getConditionsOfTarget($a_ref_id,$a_obj_id, $a_type);
                                foreach ($conditions as $condition)
                                {
                                        $this->current_info->addInfoItem(IL_MISSING_PRECONDITION,
                                                $lng->txt("missing_precondition").": ".
                                                ilObject::_lookupTitle($condition["trigger_obj_id"])." ".
                                                $lng->txt("condition_".$condition["operator"])." ".
                                                $condition["value"], $condition);
                                }
                                $ilBench->stop("AccessControl", "4000_checkAccess_condition_check");
                                return false;
                        }
                        $ilBench->stop("AccessControl", "4000_checkAccess_condition_check");
                }

                return true;
        }
        
        function doStatusCheck($a_permission, $a_cmd, $a_ref_id,$a_user_id, $a_obj_id, $a_type)
        {
                global $objDefinition, $ilBench;
                //echo "statusCheck<br/>";
                $ilBench->start("AccessControl", "5000_checkAccess_object_check");

                $class = $objDefinition->getClassName($a_type);
                $location = $objDefinition->getLocation($a_type);
                $full_class = "ilObj".$class."Access";
                include_once($location."/class.".$full_class.".php");
                // static call to ilObj..::_checkAccess($a_cmd, $a_permission, $a_ref_id, $a_obj_id)

                $ilBench->start("AccessControl", "5001_checkAccess_".$full_class."_check");
                $obj_access = call_user_func(array($full_class, "_checkAccess"),
                        $a_cmd, $a_permission, $a_ref_id, $a_obj_id, $a_user_id);
                $ilBench->stop("AccessControl", "5001_checkAccess_".$full_class."_check");
                if (!($obj_access === true))
                {
                        //Note: We must not add an info item here, because one is going
                        //      to be added by the user function we just called a few
                        //      lines above.
                        //$this->current_info->addInfoItem(IL_NO_OBJECT_ACCESS, $obj_access);

                        $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, false, $a_user_id);
                        $ilBench->stop("AccessControl", "5000_checkAccess_object_check");
                        return false;
                }
                
                $this->storeAccessResult($a_permission, $a_cmd, $a_ref_id, true, $a_user_id);
                $ilBench->stop("AccessControl", "5000_checkAccess_object_check");
                return true;
        }
        
        function clear()
        {
                $this->results = array();
                $this->last_result = "";
                $this->current_info = new ilAccessInfo();
        }
        
        function enable($a_str,$a_bool)
        {
                $this->$a_str = $a_bool;
        }
}