Collaboration diagram for ilSessionControl:

Static Public Member Functions
static	checkExpiredSession ()
	checks for possibly expired session should be called from ilAuthUtils::__initAuth() so it's called before session_start() is called
static	initSession ()
	mark session with type regarding to the context.
static	handleLoginEvent ($a_login, $a_auth)
	when current session is allowed to be created it marks it with type regarding to the sessions user context.
static	handleLogoutEvent ()
	reset sessions type to unknown
static	getExistingSessionCount (array $a_types)
	returns number of valid sessions relating to given session types
static	getSettingFields ()
	returns the array of setting fields

Data Fields
const	INTERNAL_DEBUG = false
	this controls the debuggin into a separate logfile (.
const	DEFAULT_MAX_COUNT = 0
	default value for settings that have not been defined in setup or administration yet
const	DEFAULT_MIN_IDLE = 15
const	DEFAULT_MAX_IDLE = 30
const	DEFAULT_MAX_IDLE_AFTER_FIRST_REQUEST = 1
const	DEFAULT_ALLOW_CLIENT_MAINTENANCE = 1
const	SESSION_TYPE_UNKNOWN = 0
	session types from which one is assigned to each session
const	SESSION_TYPE_SYSTEM = 1
const	SESSION_TYPE_ADMIN = 2
const	SESSION_TYPE_USER = 3
const	SESSION_TYPE_ANONYM = 4

Static Public Attributes
static	$session_types_controlled

Static Private Member Functions
static	checkCurrentSessionIsAllowed (Auth $a_auth, $a_user_id)
	checks wether the current session exhaust the limit of sessions when limit is reached it deletes "firstRequestAbidencer" and checks again when limit is still reached it deletes "oneMinIdleSession" and checks again when limit is still reached the current session will be logged out
static	kickOneMinIdleSession (array $a_types)
	if sessions exist that relates to given session types and idled longer than min idle parameter, this method deletes one of these sessions
static	kickFirstRequestAbidencer (array $a_types)
	kicks sessions of users that abidence after login so people could not login and go for coffe break ;-)
static	isValidSession ($a_sid)
	checks if session exists for given id and if it is still valid
static	removeSessionCookie ()
	removes a session cookie, so it is not sent by browser anymore
static	checkAdministrationPermission ($a_user_id)
	checks wether a given user login relates to an user with administrative permissions
static	debug ($a_debug_log_message)
	logs the given debug message in ilLog

Static Private Attributes
static	$setting_fields
	all fieldnames that are saved in settings table
static	$session_types_not_controlled
	all session types that will be involved when count of sessions will be determined or when idleing sessions will be destroyed

Detailed Description

Author: Bjoern Heyser bheys.nosp@m.er@d.nosp@m.ataba.nosp@m.y.de

Version

Id:: class.ilSessionControl.php 35242 2012-06-27 13:22:15Z bheyser

Definition at line 11 of file class.ilSessionControl.php.

Member Function Documentation

static ilSessionControl::checkAdministrationPermission ( $a_user_id )

staticprivate

checks wether a given user login relates to an user with administrative permissions

ilRbacSystem $rbacsystem

Parameters

integer $a_user_id

Returns: boolean access

Definition at line 480 of file class.ilSessionControl.php.

Referenced by handleLoginEvent().

        {
                if( !(int)$a_user_id ) return false;
                global $rbacsystem;
                $access = $rbacsystem->checkAccessOfUser(
                        $a_user_id, 'read,visible', SYSTEM_FOLDER_ID
                );
                return $access;
        }

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static ilSessionControl::checkCurrentSessionIsAllowed	(	Auth	$a_auth,
			$a_user_id
	)

staticprivate

checks wether the current session exhaust the limit of sessions when limit is reached it deletes "firstRequestAbidencer" and checks again when limit is still reached it deletes "oneMinIdleSession" and checks again when limit is still reached the current session will be logged out

ilSetting $ilSetting ilAppEventHandler $ilAppEventHandler

Parameters

Auth $a_auth

Definition at line 234 of file class.ilSessionControl.php.

References $_SESSION, $ilSetting, ilSessionStatistics\createRawEntry(), debug(), DEFAULT_MAX_COUNT, getExistingSessionCount(), kickFirstRequestAbidencer(), kickOneMinIdleSession(), Auth\logout(), ilUtil\redirect(), ilSession\SESSION_CLOSE_LIMIT, and ilSession\setClosingContext().

Referenced by handleLoginEvent().

        {
                global $ilSetting;
                
                $max_sessions = (int)$ilSetting->get('session_max_count', DEFAULT_MAX_COUNT);
                if($max_sessions > 0)
                {
                        // get total number of sessions
                        $num_sessions = self::getExistingSessionCount(self::$session_types_controlled);
                        self::debug(__METHOD__."--> total existing sessions (".$num_sessions.")");
                        if(($num_sessions + 1) > $max_sessions)
                        {
                                self::debug(__METHOD__.' --> limit for session pool reached, but try kicking some first request abidencer');
                                self::kickFirstRequestAbidencer(self::$session_types_controlled);
                                // get total number of sessions again
                                $num_sessions = self::getExistingSessionCount(self::$session_types_controlled);
                                if(($num_sessions + 1) > $max_sessions)
                                {
                                        self::debug(__METHOD__.' --> limit for session pool still reached so try kick one min idle session');
                                        self::kickOneMinIdleSession(self::$session_types_controlled);
                                        // get total number of sessions again
                                        $num_sessions = self::getExistingSessionCount(self::$session_types_controlled);
                                        if(($num_sessions + 1) > $max_sessions)
                                        {
                                                self::debug(__METHOD__.' --> limit for session pool still reached so logout session ('.session_id().') and trigger event');
                                                ilSession::setClosingContext(ilSession::SESSION_CLOSE_LIMIT);                                   
                                                
                                                // as the session is opened and closed in one request, there
                                                // is no proper session yet and we have to do this ourselves
                                                ilSessionStatistics::createRawEntry(session_id(), $_SESSION['SessionType'], 
                                                        time(), $a_user_id);
                                                
                                                $a_auth->logout();
                                                
                                                // Trigger reachedSessionPoolLimit Event
                                                global $ilAppEventHandler;
                                                $ilAppEventHandler->raise(
                                                        'Services/Authentication', 'reachedSessionPoolLimit', array()
                                                );
                                                // auth won't do this, we need to close session properly
                                                session_destroy();
                                                ilUtil::redirect('login.php?reached_session_limit=true');
                                        }
                                        else
                                        {
                                                self::debug(__METHOD__.' --> limit of session pool not reached anymore after kicking one min idle session');
                                        }
                                }
                                else
                                {
                                        self::debug(__METHOD__.' --> limit of session pool not reached anymore after kicking some first request abidencer');
                                }
                        }
                        else
                        {
                                self::debug(__METHOD__.' --> limit for session pool not reached yet');
                        }
                }
                else
                {
                        self::debug(__METHOD__.' --> limit for session pool not set so check is bypassed');
                }
        }

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static ilSessionControl::checkExpiredSession ( )

static

checks for possibly expired session should be called from ilAuthUtils::__initAuth() so it's called before session_start() is called

ilSetting $ilSetting ilLanguage $lng ilAppEventHandler $ilAppEventHandler

Definition at line 85 of file class.ilSessionControl.php.

References $_COOKIE, $_GET, $ilSetting, $lng, debug(), isValidSession(), ilUtil\redirect(), and removeSessionCookie().

Referenced by ilAuthUtils\_initAuth().

        {
                global $ilSetting;
                
                // do not check session in fixed duration mode
                if( $ilSetting->get('session_handling_type', 0) != 1 )
                        return;
                // check for expired sessions makes sense
                // only when public section is not enabled
                // because it is not possible to determine
                // wether the sid cookie relates to a session of an
                // authenticated user or a anonymous user
                // when the session dataset has allready been deleted
                if(!$ilSetting->get("pub_section"))
                {
                        global $lng;
                        $sid = null;
                        if( !isset($_COOKIE[session_name()]) || !strlen($_COOKIE[session_name()]) )
                        {
                                self::debug('Browser did not send a sid cookie');
                        }
                        else
                        {
                                $sid = $_COOKIE[session_name()];
                                self::debug('Browser sent sid cookie with value ('.$sid.')');
                                if(!self::isValidSession($sid))
                                {
                                        self::debug('remove session cookie for ('.$sid.') and trigger event');
                                        // raw data will be updated (later) with garbage collection [destroyExpired()]
                                        
                                        self::removeSessionCookie();
                                        // Trigger expiredSessionDetected  Event
                                        global $ilAppEventHandler;
                                        $ilAppEventHandler->raise(
                                                'Services/Authentication', 'expiredSessionDetected', array()
                                        );
                                        ilUtil::redirect('login.php?expired=true'.'&target='.$_GET['target']);
                                }
                        }
                }
        }

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static ilSessionControl::debug ( $a_debug_log_message )

staticprivate

logs the given debug message in ilLog

ilLog $ilLog

Parameters

string $a_debug_log_message

Definition at line 499 of file class.ilSessionControl.php.

References $ilLog.

Referenced by checkCurrentSessionIsAllowed(), checkExpiredSession(), handleLoginEvent(), handleLogoutEvent(), initSession(), isValidSession(), kickFirstRequestAbidencer(), kickOneMinIdleSession(), and removeSessionCookie().

        {
                global $ilLog;
                if(DEVMODE) $ilLog->write($a_debug_log_message, 'message');
                if(self::INTERNAL_DEBUG) error_log($a_debug_log_message."\n", 3, 'session.log');
        }

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static ilSessionControl::getExistingSessionCount ( array $a_types )

static

returns number of valid sessions relating to given session types

ilDB $ilDB

Parameters

array $a_types

Returns: integer num_sessions

Definition at line 317 of file class.ilSessionControl.php.

References $ilDB, $query, $res, $row, and DB_FETCHMODE_OBJECT.

Referenced by checkCurrentSessionIsAllowed(), and ilSessionStatisticsGUI\renderCurrentBasics().

        {
                global $ilDB;
                $ts = time();
                $query = "SELECT count(session_id) AS num_sessions FROM usr_session ".
                                        "WHERE expires > %s ".
                                        "AND ".$ilDB->in('type', $a_types, false, 'integer');
        
                $res = $ilDB->queryF($query, array('integer'), array($ts));
                $row = $res->fetchRow(DB_FETCHMODE_OBJECT);
                return $row->num_sessions;
        }

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static ilSessionControl::getSettingFields ( )

static

returns the array of setting fields

Returns: array setting_fields

Definition at line 513 of file class.ilSessionControl.php.

References $setting_fields.

Referenced by ilSetup\checkClientSessionSettings(), ilSetupGUI\displaySessions(), ilSetup\getSessionSettings(), and ilSetup\setSessionSettings().

        {
                return self::$setting_fields;
        }

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static ilSessionControl::handleLoginEvent	(	$a_login,
		$a_auth
	)

static

when current session is allowed to be created it marks it with type regarding to the sessions user context.

when session is not allowed to be created it will be destroyed.

Definition at line 164 of file class.ilSessionControl.php.

References $_SESSION, $ilSetting, ilObjUser\_lookupId(), checkAdministrationPermission(), checkCurrentSessionIsAllowed(), debug(), SESSION_TYPE_ADMIN, SESSION_TYPE_ANONYM, SESSION_TYPE_SYSTEM, and SESSION_TYPE_USER.

Referenced by ilAuthBase\loginObserver().

        {
                global $ilSetting;
                
                require_once 'Services/User/classes/class.ilObjUser.php';
                $user_id = ilObjUser::_lookupId($a_login);
                // we need the session type for the session statistics
                // regardless of the current session handling type
                switch(true)
                {
                        case isset($_ENV['SHELL']):
                                $type = self::SESSION_TYPE_SYSTEM;                              
                                break;
                        case $user_id == ANONYMOUS_USER_ID:
                                $type = self::SESSION_TYPE_ANONYM;
                                break;
                        case self::checkAdministrationPermission($user_id):
                                $type = self::SESSION_TYPE_ADMIN;
                                break;
                        default:
                                $type = self::SESSION_TYPE_USER;                                
                                break;
                }
                
                $_SESSION['SessionType'] = $type;
                self::debug(__METHOD__." --> update sessions type to (".$type.")");
                                
                // do not handle login event in fixed duration mode
                if( $ilSetting->get('session_handling_type', 0) != 1 )
                        return;
                                
                if(in_array($type, self::$session_types_controlled))
                {
                        self::checkCurrentSessionIsAllowed($a_auth, $user_id);
                }
        }

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static ilSessionControl::handleLogoutEvent ( )

static

reset sessions type to unknown

Definition at line 208 of file class.ilSessionControl.php.

References $_SESSION, $ilSetting, debug(), removeSessionCookie(), and SESSION_TYPE_UNKNOWN.

Referenced by ilAuthBase\logoutObserver().

        {
                global $ilSetting;
                
                // do not handle logout event in fixed duration mode
                if( $ilSetting->get('session_handling_type', 0) != 1 )
                        return;
                
                $_SESSION['SessionType'] = self::SESSION_TYPE_UNKNOWN;
                self::debug(__METHOD__." --> reset sessions type to (".$_SESSION['SessionType'].")");
                
                // session_destroy() is called in auth, so raw data will be updated
                self::removeSessionCookie();
        }

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static ilSessionControl::initSession ( )

static

mark session with type regarding to the context.

should be called from ilAuthBase::initAuth()

Definition at line 140 of file class.ilSessionControl.php.

References $_SESSION, $ilSetting, debug(), and SESSION_TYPE_UNKNOWN.

Referenced by ilAuthBase\initAuth().

        {
                global $ilSetting;
                
                // do not init session type in fixed duration mode
                if( $ilSetting->get('session_handling_type', 0) != 1 )
                        return;
                
                if( !isset($_SESSION['SessionType']) )
                {
                        $_SESSION['SessionType'] = self::SESSION_TYPE_UNKNOWN;
                        self::debug(__METHOD__." --> init session with type (".$_SESSION['SessionType'].")");
                }
                else
                {
                        self::debug(__METHOD__." --> keep sessions type on (".$_SESSION['SessionType'].")");
                }
        }

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static ilSessionControl::isValidSession ( $a_sid )

staticprivate

checks if session exists for given id and if it is still valid

ilDB $ilDB ilSetting $ilSetting

Parameters

string $a_sid

Returns: boolean session_valid

Definition at line 421 of file class.ilSessionControl.php.

References $ilDB, $ilSetting, $query, $res, $row, and debug().

        {
                global $ilDB, $ilSetting;
                $query = "SELECT session_id, expires FROM usr_session ".
                                        "WHERE session_id = %s";
                $res = $ilDB->queryF($query, array('text'), array($a_sid));
                $ts = time();
                $sessions = array();
                while( $row = $ilDB->fetchAssoc($res) )
                {
                        if( $row['expires'] > $ts )
                        {
                                self::debug(__METHOD__.' --> Found a valid session with id ('.$a_sid.')');
                                $sessions[] = $row;
                        }
                        else
                        {
                                self::debug(__METHOD__.' --> Found an expired session with id ('.$a_sid.')');
                        }
                }
                if(count($sessions) == 1)
                {
                        self::debug(__METHOD__.' --> Exact one valid session found for session id ('.$a_sid.')');
                        return true;
                }
                else
                {
                        if(count($sessions) > 1)
                                        self::debug(__METHOD__.' --> Strange!!! More than one sessions found for given session id! ('.$a_sid.')');
                        else    self::debug(__METHOD__.' --> No valid session found for session id ('.$a_sid.')');
                        return false;
                }
        }

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static ilSessionControl::kickFirstRequestAbidencer ( array $a_types )

staticprivate

kicks sessions of users that abidence after login so people could not login and go for coffe break ;-)

ilDB $ilDB ilSetting $ilSetting

Returns: <type>

Definition at line 384 of file class.ilSessionControl.php.

References $ilDB, $ilSetting, $query, $res, $row, ilSession\_destroy(), DB_FETCHMODE_OBJECT, debug(), and ilSession\SESSION_CLOSE_FIRST.

Referenced by checkCurrentSessionIsAllowed().

        {
                global $ilDB, $ilSetting;
                $max_idle_after_first_request = (int)$ilSetting->get('session_max_idle_after_first_request') * 60;
                if((int)$max_idle_after_first_request == 0) return;
                $query = "SELECT session_id,expires FROM usr_session WHERE " .
                                "(ctime - createtime) < %s " .
                                "AND (%s - createtime) > %s " .
                                "AND ".$ilDB->in('type', $a_types, false, 'integer');
                $res = $ilDB->queryF( $query,
                        array('integer', 'integer', 'integer'),
                        array($max_idle_after_first_request, time(), $max_idle_after_first_request)
                );
                
                $session_ids = array();
                while( $row = $res->fetchRow(DB_FETCHMODE_OBJECT) )
                {
                        $session_ids[$row->session_id] = $row->expires;                                 
                }               
                ilSession::_destroy($session_ids, ilSession::SESSION_CLOSE_FIRST, true);
                self::debug(__METHOD__.' --> Finished kicking first request abidencer');
        }

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static ilSessionControl::kickOneMinIdleSession ( array $a_types )

staticprivate

if sessions exist that relates to given session types and idled longer than min idle parameter, this method deletes one of these sessions

ilDB $ilDB ilSetting $ilSetting

Parameters

array $a_types

Returns: boolean $deletionSuccess

Definition at line 343 of file class.ilSessionControl.php.

References $ilDB, $ilSetting, $query, $res, $row, ilSession\_destroy(), DB_FETCHMODE_OBJECT, debug(), and ilSession\SESSION_CLOSE_IDLE.

Referenced by checkCurrentSessionIsAllowed().

        {
                global $ilDB, $ilSetting;
                $ts = time();
                $min_idle = (int)$ilSetting->get('session_min_idle', self::DEFAULT_MIN_IDLE) * 60;
                $max_idle = (int)$ilSetting->get('session_max_idle', self::DEFAULT_MAX_IDLE) * 60;
                $query = "SELECT session_id,expires FROM usr_session WHERE expires >= %s " .
                                "AND (expires - %s) < (%s - %s) " .
                                "AND ".$ilDB->in('type', $a_types, false, 'integer');
                                "ORDER BY expires";
                $res = $ilDB->queryF(
                                $query,
                                array('integer', 'integer', 'integer', 'integer'),
                                array($ts, $ts, $max_idle, $min_idle)
                );
                
                while( $row = $res->fetchRow(DB_FETCHMODE_OBJECT) )
                {
                        ilSession::_destroy($row->session_id, ilSession::SESSION_CLOSE_IDLE, $row->expires);
                        self::debug(__METHOD__.' --> successfully deleted one min idle session');
                        return true;
                }
                self::debug(__METHOD__.' --> no min idle session available for deletion');
                
                return false;
        }

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static ilSessionControl::removeSessionCookie ( )

staticprivate

removes a session cookie, so it is not sent by browser anymore

Definition at line 466 of file class.ilSessionControl.php.

References debug(), and ilUtil\setCookie().

Referenced by checkExpiredSession(), and handleLogoutEvent().

        {
                ilUtil::setCookie(session_name(),'deleted',true,true);
                self::debug('Session cookie has been removed');
        }

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Field Documentation

ilSessionControl::$session_types_controlled

static

Initial value:

 array(
                self::SESSION_TYPE_USER,
                self::SESSION_TYPE_ANONYM
        )

Definition at line 59 of file class.ilSessionControl.php.

Referenced by ilSession\_writeData(), ilSessionStatistics\getNumberOfActiveRawSessions(), ilSessionStatistics\getRawData(), and ilSessionStatisticsGUI\renderCurrentBasics().

array ilSessionControl::$session_types_not_controlled

staticprivate

Initial value:

 array(
                self::SESSION_TYPE_UNKNOWN,
                self::SESSION_TYPE_SYSTEM,
                self::SESSION_TYPE_ADMIN
        )

all session types that will be involved when count of sessions will be determined or when idleing sessions will be destroyed

all session types that will be ignored when count of sessions will be determined or when idleing sessions will be destroyed

Definition at line 70 of file class.ilSessionControl.php.

array ilSessionControl::$setting_fields

staticprivate

Initial value:

 array(
                'session_max_count',
                'session_min_idle',
                'session_max_idle',
                'session_max_idle_after_first_request',
                'session_allow_client_maintenance',
                'session_handling_type'
        )