lib/setup.php

   1 <?php
   2 /**
   3  * setup.php - Sets up sessions, connects to databases and so on
   4  *
   5  * Normally this is only called by the main config.php file
   6  * Normally this file does not need to be edited.
   7  * @author Martin Dougiamas
   8  * @version $Id$
   9  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  10  * @package moodlecore
  11  */
  12
  13 ////// DOCUMENTATION IN PHPDOC FORMAT FOR MOODLE GLOBALS AND COMMON OBJECT TYPES /////////////
  14 /**
  15  * $USER is a global instance of a typical $user record.
  16  *
  17  * Items found in the user record:
  18  *  - $USER->emailstop - Does the user want email sent to them?
  19  *  - $USER->email - The user's email address.
  20  *  - $USER->id - The unique integer identified of this user in the 'user' table.
  21  *  - $USER->email - The user's email address.
  22  *  - $USER->firstname - The user's first name.
  23  *  - $USER->lastname - The user's last name.
  24  *  - $USER->username - The user's login username.
  25  *  - $USER->secret - The user's ?.
  26  *  - $USER->lang - The user's language choice.
  27  *
  28  * @global object(user) $USER
  29  */
  30 global $USER;
  31 /**
  32  * This global variable is read in from the 'config' table.
  33  *
  34  * Some typical settings in the $CFG global:
  35  *  - $CFG->wwwroot - Path to moodle index directory in url format.
  36  *  - $CFG->dataroot - Path to moodle index directory on server's filesystem.
  37  *  - $CFG->libdir  - Path to moodle's library folder on server's filesystem.
  38  *
  39  * @global object(cfg) $CFG
  40  */
  41 global $CFG;
  42 /**
  43  * Definition of session type
  44  * @global object(session) $SESSION
  45  */
  46 global $SESSION;
  47 /**
  48  * Definition of shared memory cache
  49  */
  50 global $MCACHE;
  51 /**
  52  * Definition of course type
  53  * @global object(course) $COURSE
  54  */
  55 global $COURSE;
  56 /**
  57  * Definition of db type
  58  * @global object(db) $db
  59  */
  60 global $db;
  61 /**
  62  * $THEME is a global that defines the site theme.
  63  *
  64  * Items found in the theme record:
  65  *  - $THEME->cellheading - Cell colors.
  66  *  - $THEME->cellheading2 - Alternate cell colors.
  67  *
  68  * @global object(theme) $THEME
  69  */
  70 global $THEME;
  71
  72 /**
  73  * HTTPSPAGEREQUIRED is a global to define if the page being displayed must run under HTTPS.
  74  *
  75  * It's primary goal is to allow 100% HTTPS pages when $CFG->loginhttps is enabled. Default to false.
  76  * It's enabled only by the httpsrequired() function and used in some pages to update some URLs
  77 */
  78 global $HTTPSPAGEREQUIRED;
  79
  80
  81 /// First try to detect some attacks on older buggy PHP versions
  82     if (isset($_REQUEST['GLOBALS']) || isset($_COOKIE['GLOBALS']) || isset($_FILES['GLOBALS'])) {
  83         die('Fatal: Illegal GLOBALS overwrite attempt detected!');
  84     }
  85
  86
  87     if (!isset($CFG->wwwroot)) {
  88         trigger_error('Fatal: $CFG->wwwroot is not configured! Exiting.');
  89         die;
  90     }
  91
  92 /// store settings from config.php in array in $CFG - we can use it later to detect problems and overrides
  93     $CFG->config_php_settings = (array)$CFG;
  94
  95 /// Set httpswwwroot default value (this variable will replace $CFG->wwwroot
  96 /// inside some URLs used in HTTPSPAGEREQUIRED pages.
  97     $CFG->httpswwwroot = $CFG->wwwroot;
  98
  99     $CFG->libdir   = $CFG->dirroot .'/lib';
 100
 101     require_once($CFG->libdir .'/setuplib.php');        // Functions that MUST be loaded first
 102
 103 /// Time to start counting
 104     init_performance_info();
 105
 106
 107 /// If there are any errors in the standard libraries we want to know!
 108     error_reporting(E_ALL);
 109
 110 /// Just say no to link prefetching (Moz prefetching, Google Web Accelerator, others)
 111 /// http://www.google.com/webmasters/faq.html#prefetchblock
 112     if (!empty($_SERVER['HTTP_X_moz']) && $_SERVER['HTTP_X_moz'] === 'prefetch'){
 113         header($_SERVER['SERVER_PROTOCOL'] . ' 404 Prefetch Forbidden');
 114         trigger_error('Prefetch request forbidden.');
 115         exit;
 116     }
 117
 118 /// Connect to the database using adodb
 119
 120 /// Set $CFG->dbfamily global
 121 /// and configure some other specific variables for each db BEFORE attempting the connection
 122     preconfigure_dbconnection();
 123
 124     require_once($CFG->libdir .'/adodb/adodb.inc.php'); // Database access functions
 125
 126     $db = &ADONewConnection($CFG->dbtype);
 127
 128     // See MDL-6760 for why this is necessary. In Moodle 1.8, once we start using NULLs properly,
 129     // we probably want to change this value to ''.
 130     $db->null2null = 'A long random string that will never, ever match something we want to insert into the database, I hope. \'';
 131
 132     error_reporting(0);  // Hide errors
 133
 134     if (!isset($CFG->dbpersist) or !empty($CFG->dbpersist)) {    // Use persistent connection (default)
 135         $dbconnected = $db->PConnect($CFG->dbhost,$CFG->dbuser,$CFG->dbpass,$CFG->dbname);
 136     } else {                                                     // Use single connection
 137         $dbconnected = $db->Connect($CFG->dbhost,$CFG->dbuser,$CFG->dbpass,$CFG->dbname);
 138     }
 139     if (! $dbconnected) {
 140         // In the name of protocol correctness, monitoring and performance
 141         // profiling, set the appropriate error headers for machine comsumption
 142         if (isset($_SERVER['SERVER_PROTOCOL'])) {
 143             // Avoid it with cron.php. Note that we assume it's HTTP/1.x
 144             header($_SERVER['SERVER_PROTOCOL'] . ' 503 Service Unavailable');
 145         }
 146         // and then for human consumption...
 147         echo '<html><body>';
 148         echo '<table align="center"><tr>';
 149         echo '<td style="color:#990000; text-align:center; font-size:large; border-width:1px; '.
 150              '    border-color:#000000; border-style:solid; border-radius: 20px; border-collapse: collapse; '.
 151              '    -moz-border-radius: 20px; padding: 15px">';
 152         echo '<p>Error: Database connection failed.</p>';
 153         echo '<p>It is possible that the database is overloaded or otherwise not running properly.</p>';
 154         echo '<p>The site administrator should also check that the database details have been correctly specified in config.php</p>';
 155         echo '</td></tr></table>';
 156         echo '</body></html>';
 157
 158         error_log('ADODB Error: '.$db->ErrorMsg()); // see MDL-14628
 159
 160         if (empty($CFG->noemailever) and !empty($CFG->emailconnectionerrorsto)) {
 161             if (file_exists($CFG->dataroot.'/emailcount')){
 162                 $fp = fopen($CFG->dataroot.'/emailcount', 'r');
 163                 $content = fread($fp, 24);
 164                 fclose($fp);
 165                 if((time() - (int)$content) > 600){
 166                     mail($CFG->emailconnectionerrorsto,
 167                         'WARNING: Database connection error: '.$CFG->wwwroot,
 168                         'Connection error: '.$CFG->wwwroot);
 169                     $fp = fopen($CFG->dataroot.'/emailcount', 'w');
 170                     fwrite($fp, time());
 171                 }
 172             } else {
 173                mail($CFG->emailconnectionerrorsto,
 174                     'WARNING: Database connection error: '.$CFG->wwwroot,
 175                     'Connection error: '.$CFG->wwwroot);
 176                $fp = fopen($CFG->dataroot.'/emailcount', 'w');
 177                fwrite($fp, time());
 178             }
 179         }
 180         die;
 181     }
 182
 183 /// Forcing ASSOC mode for ADOdb (some DBs default to FETCH_BOTH)
 184     $db->SetFetchMode(ADODB_FETCH_ASSOC);
 185
 186 /// Starting here we have a correct DB conection but me must avoid
 187 /// to execute any DB transaction until "set names" has been executed
 188 /// some lines below!
 189
 190     error_reporting(E_ALL);       // Show errors from now on.
 191
 192     if (!isset($CFG->prefix)) {   // Just in case it isn't defined in config.php
 193         $CFG->prefix = '';
 194     }
 195
 196
 197 /// Define admin directory
 198
 199     if (!isset($CFG->admin)) {   // Just in case it isn't defined in config.php
 200         $CFG->admin = 'admin';   // This is relative to the wwwroot and dirroot
 201     }
 202
 203 /// Increase memory limits if possible
 204     raise_memory_limit('96M');    // We should never NEED this much but just in case...
 205
 206 /// Load up standard libraries
 207
 208     require_once($CFG->libdir .'/textlib.class.php');   // Functions to handle multibyte strings
 209     require_once($CFG->libdir .'/weblib.php');          // Functions for producing HTML
 210     require_once($CFG->libdir .'/dmllib.php');          // Functions to handle DB data (DML)
 211     require_once($CFG->libdir .'/datalib.php');         // Legacy lib with a big-mix of functions.
 212     require_once($CFG->libdir .'/accesslib.php');       // Access control functions
 213     require_once($CFG->libdir .'/deprecatedlib.php');   // Deprecated functions included for backward compatibility
 214     require_once($CFG->libdir .'/moodlelib.php');       // Other general-purpose functions
 215     require_once($CFG->libdir .'/eventslib.php');       // Events functions
 216     require_once($CFG->libdir .'/grouplib.php');        // Groups functions
 217
 218     //point pear include path to moodles lib/pear so that includes and requires will search there for files before anywhere else
 219     //the problem is that we need specific version of quickforms and hacked excel files :-(
 220     ini_set('include_path', $CFG->libdir.'/pear' . PATH_SEPARATOR . ini_get('include_path'));
 221
 222 /// Disable errors for now - needed for installation when debug enabled in config.php
 223     if (isset($CFG->debug)) {
 224         $originalconfigdebug = $CFG->debug;
 225         unset($CFG->debug);
 226     } else {
 227         $originalconfigdebug = -1;
 228     }
 229
 230 /// Set the client/server and connection to utf8
 231 /// and configure some other specific variables for each db
 232     configure_dbconnection();
 233
 234 /// Load up any configuration from the config table
 235     $CFG = get_config();
 236
 237 /// Turn on SQL logging if required
 238     if (!empty($CFG->logsql)) {
 239         $db->LogSQL();
 240     }
 241
 242 /// Prevent warnings from roles when upgrading with debug on
 243     if (isset($CFG->debug)) {
 244         $originaldatabasedebug = $CFG->debug;
 245         unset($CFG->debug);
 246     } else {
 247         $originaldatabasedebug = -1;
 248     }
 249
 250
 251 /// For now, only needed under apache (and probably unstable in other contexts)
 252     if (function_exists('register_shutdown_function')) {
 253         register_shutdown_function('moodle_request_shutdown');
 254     }
 255
 256 /// Defining the site
 257     if ($SITE = get_site()) {
 258         /**
 259          * If $SITE global from {@link get_site()} is set then SITEID to $SITE->id, otherwise set to 1.
 260          */
 261         define('SITEID', $SITE->id);
 262         /// And the 'default' course
 263         $COURSE = clone($SITE);   // For now.  This will usually get reset later in require_login() etc.
 264     } else {
 265         /**
 266          * @ignore
 267          */
 268         define('SITEID', 1);
 269         /// And the 'default' course
 270         $COURSE = new object;  // no site created yet
 271         $COURSE->id = 1;
 272     }
 273
 274     // define SYSCONTEXTID in config.php if you want to save some queries (after install or upgrade!)
 275     if (!defined('SYSCONTEXTID')) {
 276         get_system_context();
 277     }
 278
 279 /// Set error reporting back to normal
 280     if ($originaldatabasedebug == -1) {
 281         $CFG->debug = DEBUG_MINIMAL;
 282     } else {
 283         $CFG->debug = $originaldatabasedebug;
 284     }
 285     if ($originalconfigdebug !== -1) {
 286         $CFG->debug = $originalconfigdebug;
 287     }
 288     unset($originalconfigdebug);
 289     unset($originaldatabasedebug);
 290     error_reporting($CFG->debug);
 291
 292
 293 /// find out if PHP cofigured to display warnings
 294     if (ini_get_bool('display_errors')) {
 295         define('WARN_DISPLAY_ERRORS_ENABLED', true);
 296     }
 297 /// If we want to display Moodle errors, then try and set PHP errors to match
 298     if (!isset($CFG->debugdisplay)) {
 299         //keep it as is during installation
 300     } else if (empty($CFG->debugdisplay)) {
 301         @ini_set('display_errors', '0');
 302         @ini_set('log_errors', '1');
 303     } else {
 304         @ini_set('display_errors', '1');
 305     }
 306 // Even when users want to see errors in the output,
 307 // some parts of Moodle cannot display them at all.
 308 // (Once we are XHTML strict compliant, debugdisplay
 309 //  _must_ go away).
 310     if (defined('MOODLE_SANE_OUTPUT')) {
 311         @ini_set('display_errors', '0');
 312         @ini_set('log_errors', '1');
 313     }
 314
 315 /// Shared-Memory cache init -- will set $MCACHE
 316 /// $MCACHE is a global object that offers at least add(), set() and delete()
 317 /// with similar semantics to the memcached PHP API http://php.net/memcache
 318 /// Ensure we define rcache - so we can later check for it
 319 /// with a really fast and unambiguous $CFG->rcache === false
 320     if (!empty($CFG->cachetype)) {
 321         if (empty($CFG->rcache)) {
 322             $CFG->rcache = false;
 323         } else {
 324             $CFG->rcache = true;
 325         }
 326
 327         // do not try to initialize if cache disabled
 328         if (!$CFG->rcache) {
 329             $CFG->cachetype = '';
 330         }
 331
 332         if ($CFG->cachetype === 'memcached' && !empty($CFG->memcachedhosts)) {
 333             if (!init_memcached()) {
 334                 debugging("Error initialising memcached");
 335                 $CFG->cachetype = '';
 336                 $CFG->rcache = false;
 337             }
 338         } else if ($CFG->cachetype === 'eaccelerator') {
 339             if (!init_eaccelerator()) {
 340                 debugging("Error initialising eaccelerator cache");
 341                 $CFG->cachetype = '';
 342                 $CFG->rcache = false;
 343             }
 344         }
 345
 346     } else { // just make sure it is defined
 347         $CFG->cachetype = '';
 348         $CFG->rcache    = false;
 349     }
 350
 351 /// Set a default enrolment configuration (see bug 1598)
 352     if (!isset($CFG->enrol)) {
 353         $CFG->enrol = 'manual';
 354     }
 355
 356 /// Set default enabled enrolment plugins
 357     if (!isset($CFG->enrol_plugins_enabled)) {
 358         $CFG->enrol_plugins_enabled = 'manual';
 359     }
 360
 361 /// File permissions on created directories in the $CFG->dataroot
 362
 363     if (empty($CFG->directorypermissions)) {
 364         $CFG->directorypermissions = 0777;      // Must be octal (that's why it's here)
 365     }
 366
 367 /// Calculate and set $CFG->ostype to be used everywhere. Possible values are:
 368 /// - WINDOWS: for any Windows flavour.
 369 /// - UNIX: for the rest
 370 /// Also, $CFG->os can continue being used if more specialization is required
 371     if (stristr(PHP_OS, 'win') && !stristr(PHP_OS, 'darwin')) {
 372         $CFG->ostype = 'WINDOWS';
 373     } else {
 374         $CFG->ostype = 'UNIX';
 375     }
 376     $CFG->os = PHP_OS;
 377
 378 /// Set up default frame target string, based on $CFG->framename
 379     $CFG->frametarget = frametarget();
 380
 381 /// Setup cache dir for Smarty and others
 382     if (!file_exists($CFG->dataroot .'/cache')) {
 383         make_upload_directory('cache');
 384     }
 385
 386 /// Set up smarty template system
 387     //require_once($CFG->libdir .'/smarty/Smarty.class.php');
 388     //$smarty = new Smarty;
 389     //$smarty->template_dir = $CFG->dirroot .'/templates/'. $CFG->template;
 390     //if (!file_exists($CFG->dataroot .'/cache/smarty')) {
 391     //    make_upload_directory('cache/smarty');
 392     //}
 393     //$smarty->compile_dir = $CFG->dataroot .'/cache/smarty';
 394
 395 /// Set up session handling
 396     if(empty($CFG->respectsessionsettings)) {
 397         if (empty($CFG->dbsessions)) {   /// File-based sessions
 398
 399             // Some distros disable GC by setting probability to 0
 400             // overriding the PHP default of 1
 401             // (gc_probability is divided by gc_divisor, which defaults to 1000)
 402             if (ini_get('session.gc_probability') == 0) {
 403                 ini_set('session.gc_probability', 1);
 404             }
 405
 406             if (!empty($CFG->sessiontimeout)) {
 407                 ini_set('session.gc_maxlifetime', $CFG->sessiontimeout);
 408             }
 409
 410             if (!file_exists($CFG->dataroot .'/sessions')) {
 411                 make_upload_directory('sessions');
 412             }
 413             ini_set('session.save_path', $CFG->dataroot .'/sessions');
 414
 415         } else {                         /// Database sessions
 416             ini_set('session.save_handler', 'user');
 417
 418             $ADODB_SESSION_DRIVER  = $CFG->dbtype;
 419             $ADODB_SESSION_CONNECT = $CFG->dbhost;
 420             $ADODB_SESSION_USER    = $CFG->dbuser;
 421             $ADODB_SESSION_PWD     = $CFG->dbpass;
 422             $ADODB_SESSION_DB      = $CFG->dbname;
 423             $ADODB_SESSION_TBL     = $CFG->prefix.'sessions2';
 424             if (!empty($CFG->sessiontimeout)) {
 425                 $ADODB_SESS_LIFE   = $CFG->sessiontimeout;
 426             }
 427
 428             require_once($CFG->libdir. '/adodb/session/adodb-session2.php');
 429         }
 430     }
 431 /// Set sessioncookie and sessioncookiepath variable if it isn't already
 432     if (!isset($CFG->sessioncookie)) {
 433         $CFG->sessioncookie = '';
 434     }
 435     if (!isset($CFG->sessioncookiepath)) {
 436         $CFG->sessioncookiepath = '/';
 437     }
 438
 439 /// Configure ampersands in URLs
 440
 441     @ini_set('arg_separator.output', '&amp;');
 442
 443 /// Work around for a PHP bug   see MDL-11237
 444
 445     @ini_set('pcre.backtrack_limit', 20971520);  // 20 MB
 446
 447 /// Location of standard files
 448
 449     $CFG->wordlist    = $CFG->libdir .'/wordlist.txt';
 450     $CFG->javascript  = $CFG->libdir .'/javascript.php';
 451     $CFG->moddata     = 'moddata';
 452
 453 // Alas, in some cases we cannot deal with magic_quotes.
 454     if (defined('MOODLE_SANE_INPUT') && ini_get_bool('magic_quotes_gpc')) {
 455         mdie("Facilities that require MOODLE_SANE_INPUT "
 456              . "cannot work with magic_quotes_gpc. Please disable "
 457              . "magic_quotes_gpc.");
 458     }
 459 /// A hack to get around magic_quotes_gpc being turned off
 460 /// It is strongly recommended to enable "magic_quotes_gpc"!
 461     if (!ini_get_bool('magic_quotes_gpc') && !defined('MOODLE_SANE_INPUT') ) {
 462         function addslashes_deep($value) {
 463             $value = is_array($value) ?
 464                     array_map('addslashes_deep', $value) :
 465                     addslashes($value);
 466             return $value;
 467         }
 468         $_POST = array_map('addslashes_deep', $_POST);
 469         $_GET = array_map('addslashes_deep', $_GET);
 470         $_COOKIE = array_map('addslashes_deep', $_COOKIE);
 471         $_REQUEST = array_map('addslashes_deep', $_REQUEST);
 472         if (!empty($_SERVER['REQUEST_URI'])) {
 473             $_SERVER['REQUEST_URI'] = addslashes($_SERVER['REQUEST_URI']);
 474         }
 475         if (!empty($_SERVER['QUERY_STRING'])) {
 476             $_SERVER['QUERY_STRING'] = addslashes($_SERVER['QUERY_STRING']);
 477         }
 478         if (!empty($_SERVER['HTTP_REFERER'])) {
 479             $_SERVER['HTTP_REFERER'] = addslashes($_SERVER['HTTP_REFERER']);
 480         }
 481        if (!empty($_SERVER['PATH_INFO'])) {
 482             $_SERVER['PATH_INFO'] = addslashes($_SERVER['PATH_INFO']);
 483         }
 484         if (!empty($_SERVER['PHP_SELF'])) {
 485             $_SERVER['PHP_SELF'] = addslashes($_SERVER['PHP_SELF']);
 486         }
 487         if (!empty($_SERVER['PATH_TRANSLATED'])) {
 488             $_SERVER['PATH_TRANSLATED'] = addslashes($_SERVER['PATH_TRANSLATED']);
 489         }
 490     }
 491
 492
 493 /// The following code can emulate "register globals" if required.
 494 /// This hack is no longer being applied as of Moodle 1.6 unless you really
 495 /// really want to use it (by defining  $CFG->enableglobalshack = true)
 496
 497     if (!empty($CFG->enableglobalshack) && !defined('MOODLE_SANE_INPUT')) {
 498         if (!empty($CFG->detect_unchecked_vars)) {
 499             global $UNCHECKED_VARS;
 500             $UNCHECKED_VARS->url = $_SERVER['PHP_SELF'];
 501             $UNCHECKED_VARS->vars = array();
 502         }
 503         if (isset($_GET)) {
 504             extract($_GET, EXTR_SKIP);    // Skip existing variables, ie CFG
 505             if (!empty($CFG->detect_unchecked_vars)) {
 506                 foreach ($_GET as $key => $val) {
 507                     $UNCHECKED_VARS->vars[$key]=$val;
 508                 }
 509             }
 510         }
 511         if (isset($_POST)) {
 512             extract($_POST, EXTR_SKIP);   // Skip existing variables, ie CFG
 513             if (!empty($CFG->detect_unchecked_vars)) {
 514                 foreach ($_POST as $key => $val) {
 515                     $UNCHECKED_VARS->vars[$key]=$val;
 516                 }
 517             }
 518         }
 519         if (isset($_SERVER)) {
 520             extract($_SERVER);
 521         }
 522     }
 523
 524
 525 /// Load up global environment variables
 526
 527     if (!isset($CFG->cookiesecure) or strpos($CFG->wwwroot, 'https://') !== 0) {
 528         $CFG->cookiesecure = false;
 529     }
 530
 531     if (!isset($CFG->cookiehttponly)) {
 532         $CFG->cookiehttponly = false;
 533     }
 534
 535     //discard session ID from POST, GET and globals to tighten security,
 536     //this session fixation prevention can not be used in cookieless mode
 537     if (empty($CFG->usesid) && !defined('MOODLE_SANE_INPUT')) {
 538         unset(${'MoodleSession'.$CFG->sessioncookie});
 539         unset($_GET['MoodleSession'.$CFG->sessioncookie]);
 540         unset($_POST['MoodleSession'.$CFG->sessioncookie]);
 541     }
 542     //compatibility hack for Moodle Cron, cookies not deleted, but set to "deleted" - should not be needed with $nomoodlecookie in cron.php now
 543     if (!empty($_COOKIE['MoodleSession'.$CFG->sessioncookie]) && $_COOKIE['MoodleSession'.$CFG->sessioncookie] == "deleted") {
 544         unset($_COOKIE['MoodleSession'.$CFG->sessioncookie]);
 545     }
 546     if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] == "deleted") {
 547         unset($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]);
 548     }
 549     if (!empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 550         require_once("$CFG->dirroot/lib/cookieless.php");
 551         sid_start_ob();
 552     }
 553
 554     if (empty($nomoodlecookie)) {
 555         session_name('MoodleSession'.$CFG->sessioncookie);
 556         if (check_php_version('5.2.0')) {
 557             session_set_cookie_params(0, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
 558         } else {
 559             session_set_cookie_params(0, $CFG->sessioncookiepath, '', $CFG->cookiesecure);
 560         }
 561         @session_start();
 562         if (! isset($_SESSION['SESSION'])) {
 563             $_SESSION['SESSION'] = new object;
 564             $_SESSION['SESSION']->session_test = random_string(10);
 565             if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
 566                 $_SESSION['SESSION']->has_timed_out = true;
 567             }
 568             if (check_php_version('5.2.0')) {
 569                 setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
 570             } else {
 571                 setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, '', $CFG->cookiesecure);
 572             }
 573             $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] = $_SESSION['SESSION']->session_test;
 574         }
 575         if (! isset($_SESSION['USER']))    {
 576             $_SESSION['USER']    = new object;
 577         }
 578
 579         $SESSION = &$_SESSION['SESSION'];   // Makes them easier to reference
 580         $USER    = &$_SESSION['USER'];
 581         if (!isset($USER->id)) {
 582             $USER->id = 0; // to enable proper function of $CFG->notloggedinroleid hack
 583         }
 584     }
 585     else {
 586         $SESSION  = NULL;
 587         $USER     = new object();
 588         $USER->id = 0; // user not logged in when session disabled
 589         if (isset($CFG->mnet_localhost_id)) {
 590             $USER->mnethostid = $CFG->mnet_localhost_id;
 591         }
 592     }
 593
 594     if (defined('FULLME')) {     // Usually in command-line scripts like admin/cron.php
 595         $FULLME = FULLME;
 596         $ME = FULLME;
 597     } else {
 598         $FULLME = qualified_me();
 599         $ME = strip_querystring($FULLME);
 600     }
 601
 602 /// In VERY rare cases old PHP server bugs (it has been found on PHP 4.1.2 running
 603 /// as a CGI under IIS on Windows) may require that you uncomment the following:
 604 //  session_register("USER");
 605 //  session_register("SESSION");
 606
 607
 608
 609 /// Load up theme variables (colours etc)
 610
 611     if (!isset($CFG->themedir)) {
 612         $CFG->themedir = $CFG->dirroot.'/theme';
 613         $CFG->themewww = $CFG->wwwroot.'/theme';
 614     }
 615     $CFG->httpsthemewww = $CFG->themewww;
 616
 617     if (isset($_GET['theme'])) {
 618         if ($CFG->allowthemechangeonurl || confirm_sesskey()) {
 619             $themename = clean_param($_GET['theme'], PARAM_SAFEDIR);
 620             if (($themename != '') and file_exists($CFG->themedir.'/'.$themename)) {
 621                 $SESSION->theme = $themename;
 622             }
 623             unset($themename);
 624         }
 625     }
 626
 627     if (!isset($CFG->theme)) {
 628         $CFG->theme = 'standardwhite';
 629     }
 630
 631 /// now do a session test to prevent random user switching - observed on some PHP/Apache combinations,
 632 /// disable checks when working in cookieless mode
 633     if (empty($CFG->usesid) || !empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 634         if ($SESSION != NULL) {
 635             if (empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
 636                 report_session_error();
 637             } else if (isset($SESSION->session_test) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] != $SESSION->session_test) {
 638                 report_session_error();
 639             }
 640         }
 641     }
 642
 643
 644 /// Set language/locale of printed times.  If user has chosen a language that
 645 /// that is different from the site language, then use the locale specified
 646 /// in the language file.  Otherwise, if the admin hasn't specified a locale
 647 /// then use the one from the default language.  Otherwise (and this is the
 648 /// majority of cases), use the stored locale specified by admin.
 649     if ($SESSION !== NULL && isset($_GET['lang']) && ($lang = clean_param($_GET['lang'], PARAM_SAFEDIR))) {
 650         if (file_exists($CFG->dataroot .'/lang/'. $lang) or file_exists($CFG->dirroot .'/lang/'. $lang)) {
 651             $SESSION->lang = $lang;
 652         } else if (file_exists($CFG->dataroot.'/lang/'.$lang.'_utf8') or
 653                    file_exists($CFG->dirroot .'/lang/'.$lang.'_utf8')) {
 654             $SESSION->lang = $lang.'_utf8';
 655         }
 656     }
 657
 658     setup_lang_from_browser();
 659
 660     unset($lang);
 661
 662     if (empty($CFG->lang)) {
 663         if (empty($SESSION->lang)) {
 664             $CFG->lang = 'en_utf8';
 665         } else {
 666             $CFG->lang = $SESSION->lang;
 667         }
 668     }
 669
 670     // set default locale and themes - might be changed again later from require_login()
 671     course_setup();
 672
 673     if (!empty($CFG->opentogoogle)) {
 674         if (empty($USER->id)) {  // Ignore anyone logged in
 675             if (!empty($_SERVER['HTTP_USER_AGENT'])) {
 676                 if (strpos($_SERVER['HTTP_USER_AGENT'], 'Googlebot') !== false ) {
 677                     $USER = guest_user();
 678                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], 'google.com') !== false ) { // Google
 679                     $USER = guest_user();
 680                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], 'Yahoo! Slurp') !== false ) {  // Yahoo
 681                     $USER = guest_user();
 682                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], '[ZSEBOT]') !== false ) {  // Zoomspider
 683                     $USER = guest_user();
 684                 } else if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSNBOT') !== false ) {  // MSN Search
 685                     $USER = guest_user();
 686                 }
 687             }
 688             if (empty($USER) && !empty($_SERVER['HTTP_REFERER'])) {
 689                 if (strpos($_SERVER['HTTP_REFERER'], 'google') !== false ) {
 690                     $USER = guest_user();
 691                 } else if (strpos($_SERVER['HTTP_REFERER'], 'altavista') !== false ) {
 692                     $USER = guest_user();
 693                 }
 694             }
 695             if (!empty($USER)) {
 696                 load_all_capabilities();
 697             }
 698         }
 699     }
 700
 701     if ($CFG->theme == 'standard' or $CFG->theme == 'standardwhite') {    // Temporary measure to help with XHTML validation
 702         if (isset($_SERVER['HTTP_USER_AGENT']) and empty($_SESSION['USER']->id)) {      // Allow W3CValidator in as user called w3cvalidator (or guest)
 703             if ((strpos($_SERVER['HTTP_USER_AGENT'], 'W3C_Validator') !== false) or
 704                 (strpos($_SERVER['HTTP_USER_AGENT'], 'Cynthia') !== false )) {
 705                 if ($USER = get_complete_user_data("username", "w3cvalidator")) {
 706                     $USER->ignoresesskey = true;
 707                 } else {
 708                     $USER = guest_user();
 709                 }
 710             }
 711         }
 712     }
 713
 714 /// Apache log intergration. In apache conf file one can use ${MOODULEUSER}n in
 715 /// LogFormat to get the current logged in username in moodle.
 716     if ($USER && function_exists('apache_note')
 717         && !empty($CFG->apacheloguser) && isset($USER->username)) {
 718         $apachelog_userid = $USER->id;
 719         $apachelog_username = clean_filename($USER->username);
 720         $apachelog_name = '';
 721         if (isset($USER->firstname)) {
 722             // We can assume both will be set
 723             // - even if to empty.
 724             $apachelog_name = clean_filename($USER->firstname . " " .
 725                                              $USER->lastname);
 726         }
 727         if (isset($USER->realuser)) {
 728             if ($realuser = get_record('user', 'id', $USER->realuser)) {
 729                 $apachelog_username = clean_filename($realuser->username." as ".$apachelog_username);
 730                 $apachelog_name = clean_filename($realuser->firstname." ".$realuser->lastname ." as ".$apachelog_name);
 731                 $apachelog_userid = clean_filename($realuser->id." as ".$apachelog_userid);
 732             }
 733         }
 734         switch ($CFG->apacheloguser) {
 735             case 3:
 736                 $logname = $apachelog_username;
 737                 break;
 738             case 2:
 739                 $logname = $apachelog_name;
 740                 break;
 741             case 1:
 742             default:
 743                 $logname = $apachelog_userid;
 744                 break;
 745         }
 746         apache_note('MOODLEUSER', $logname);
 747     }
 748
 749 /// Adjust ALLOWED_TAGS
 750     adjust_allowed_tags();
 751
 752
 753 /// Use a custom script replacement if one exists
 754     if (!empty($CFG->customscripts)) {
 755         if (($customscript = custom_script_path()) !== false) {
 756             require ($customscript);
 757         }
 758     }
 759
 760 /// note: we can not block non utf-8 installatrions here, because empty mysql database
 761 /// might be converted to utf-8 in admin/index.php during installation
 762 ?>