lib/cronlib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Cron functions.
  19  *
  20  * @package    core
  21  * @subpackage admin
  22  * @copyright  1999 onwards Martin Dougiamas  http://dougiamas.com
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26 /**
  27  * Execute cron tasks
  28  */
  29 function cron_run() {
  30     global $DB, $CFG, $OUTPUT;
  31
  32     if (CLI_MAINTENANCE) {
  33         echo "CLI maintenance mode active, cron execution suspended.\n";
  34         exit(1);
  35     }
  36
  37     if (moodle_needs_upgrading()) {
  38         echo "Moodle upgrade pending, cron execution suspended.\n";
  39         exit(1);
  40     }
  41
  42     require_once($CFG->libdir.'/adminlib.php');
  43     require_once($CFG->libdir.'/gradelib.php');
  44
  45     if (!empty($CFG->showcronsql)) {
  46         $DB->set_debug(true);
  47     }
  48     if (!empty($CFG->showcrondebugging)) {
  49         $CFG->debug = DEBUG_DEVELOPER;
  50         $CFG->debugdisplay = true;
  51     }
  52
  53     set_time_limit(0);
  54     $starttime = microtime();
  55
  56     // Increase memory limit
  57     raise_memory_limit(MEMORY_EXTRA);
  58
  59     // Emulate normal session - we use admin accoutn by default
  60     cron_setup_user();
  61
  62     // Start output log
  63     $timenow  = time();
  64     mtrace("Server Time: ".date('r',$timenow)."\n\n");
  65
  66
  67     // Run cleanup core cron jobs, but not every time since they aren't too important.
  68     // These don't have a timer to reduce load, so we'll use a random number
  69     // to randomly choose the percentage of times we should run these jobs.
  70     srand ((double) microtime() * 10000000);
  71     $random100 = rand(0,100);
  72     if ($random100 < 20) {     // Approximately 20% of the time.
  73         mtrace("Running clean-up tasks...");
  74
  75         // Delete users who haven't confirmed within required period
  76         if (!empty($CFG->deleteunconfirmed)) {
  77             $cuttime = $timenow - ($CFG->deleteunconfirmed * 3600);
  78             $rs = $DB->get_recordset_sql ("SELECT *
  79                                              FROM {user}
  80                                             WHERE confirmed = 0 AND firstaccess > 0
  81                                                   AND firstaccess < ?", array($cuttime));
  82             foreach ($rs as $user) {
  83                 delete_user($user); // we MUST delete user properly first
  84                 $DB->delete_records('user', array('id'=>$user->id)); // this is a bloody hack, but it might work
  85                 mtrace(" Deleted unconfirmed user for ".fullname($user, true)." ($user->id)");
  86             }
  87             $rs->close();
  88         }
  89
  90
  91         // Delete users who haven't completed profile within required period
  92         if (!empty($CFG->deleteincompleteusers)) {
  93             $cuttime = $timenow - ($CFG->deleteincompleteusers * 3600);
  94             $rs = $DB->get_recordset_sql ("SELECT *
  95                                              FROM {user}
  96                                             WHERE confirmed = 1 AND lastaccess > 0
  97                                                   AND lastaccess < ? AND deleted = 0
  98                                                   AND (lastname = '' OR firstname = '' OR email = '')",
  99                                           array($cuttime));
 100             foreach ($rs as $user) {
 101                 delete_user($user);
 102                 mtrace(" Deleted not fully setup user $user->username ($user->id)");
 103             }
 104             $rs->close();
 105         }
 106
 107
 108         // Delete old logs to save space (this might need a timer to slow it down...)
 109         if (!empty($CFG->loglifetime)) {  // value in days
 110             $loglifetime = $timenow - ($CFG->loglifetime * 3600 * 24);
 111             $DB->delete_records_select("log", "time < ?", array($loglifetime));
 112             mtrace(" Deleted old log records");
 113         }
 114
 115
 116         // Delete old backup_controllers and logs.
 117         $loglifetime = get_config('backup', 'loglifetime');
 118         if (!empty($loglifetime)) {  // Value in days.
 119             $loglifetime = $timenow - ($loglifetime * 3600 * 24);
 120             // Delete child records from backup_logs.
 121             $DB->execute("DELETE FROM {backup_logs}
 122                            WHERE EXISTS (
 123                                SELECT 'x'
 124                                  FROM {backup_controllers} bc
 125                                 WHERE bc.backupid = {backup_logs}.backupid
 126                                   AND bc.timecreated < ?)", array($loglifetime));
 127             // Delete records from backup_controllers.
 128             $DB->execute("DELETE FROM {backup_controllers}
 129                           WHERE timecreated < ?", array($loglifetime));
 130             mtrace(" Deleted old backup records");
 131         }
 132
 133
 134         // Delete old cached texts
 135         if (!empty($CFG->cachetext)) {   // Defined in config.php
 136             $cachelifetime = time() - $CFG->cachetext - 60;  // Add an extra minute to allow for really heavy sites
 137             $DB->delete_records_select('cache_text', "timemodified < ?", array($cachelifetime));
 138             mtrace(" Deleted old cache_text records");
 139         }
 140
 141
 142         if (!empty($CFG->usetags)) {
 143             require_once($CFG->dirroot.'/tag/lib.php');
 144             tag_cron();
 145             mtrace(' Executed tag cron');
 146         }
 147
 148
 149         // Context maintenance stuff
 150         context_helper::cleanup_instances();
 151         mtrace(' Cleaned up context instances');
 152         context_helper::build_all_paths(false);
 153         // If you suspect that the context paths are somehow corrupt
 154         // replace the line below with: context_helper::build_all_paths(true);
 155         mtrace(' Built context paths');
 156
 157
 158         // Remove expired cache flags
 159         gc_cache_flags();
 160         mtrace(' Cleaned cache flags');
 161
 162
 163         // Cleanup messaging
 164         if (!empty($CFG->messagingdeletereadnotificationsdelay)) {
 165             $notificationdeletetime = time() - $CFG->messagingdeletereadnotificationsdelay;
 166             $DB->delete_records_select('message_read', 'notification=1 AND timeread<:notificationdeletetime', array('notificationdeletetime'=>$notificationdeletetime));
 167             mtrace(' Cleaned up read notifications');
 168         }
 169
 170         mtrace("...finished clean-up tasks");
 171
 172     } // End of occasional clean-up tasks
 173
 174
 175     // Send login failures notification - brute force protection in moodle is weak,
 176     // we should at least send notices early in each cron execution
 177     if (notify_login_failures()) {
 178         mtrace(' Notified login failures');
 179     }
 180
 181
 182     // Make sure all context instances are properly created - they may be required in auth, enrol, etc.
 183     context_helper::create_instances();
 184     mtrace(' Created missing context instances');
 185
 186
 187     // Session gc
 188     session_gc();
 189     mtrace("Cleaned up stale user sessions");
 190
 191
 192     // Run the auth cron, if any before enrolments
 193     // because it might add users that will be needed in enrol plugins
 194     $auths = get_enabled_auth_plugins();
 195     mtrace("Running auth crons if required...");
 196     foreach ($auths as $auth) {
 197         $authplugin = get_auth_plugin($auth);
 198         if (method_exists($authplugin, 'cron')) {
 199             mtrace("Running cron for auth/$auth...");
 200             $authplugin->cron();
 201             if (!empty($authplugin->log)) {
 202                 mtrace($authplugin->log);
 203             }
 204         }
 205         unset($authplugin);
 206     }
 207     // Generate new password emails for users - ppl expect these generated asap
 208     if ($DB->count_records('user_preferences', array('name'=>'create_password', 'value'=>'1'))) {
 209         mtrace('Creating passwords for new users...');
 210         $newusers = $DB->get_recordset_sql("SELECT u.id as id, u.email, u.firstname,
 211                                                  u.lastname, u.username, u.lang,
 212                                                  p.id as prefid
 213                                             FROM {user} u
 214                                             JOIN {user_preferences} p ON u.id=p.userid
 215                                            WHERE p.name='create_password' AND p.value='1' AND u.email !='' AND u.suspended = 0 AND u.auth != 'nologin' AND u.deleted = 0");
 216
 217         // note: we can not send emails to suspended accounts
 218         foreach ($newusers as $newuser) {
 219             if (setnew_password_and_mail($newuser)) {
 220                 unset_user_preference('create_password', $newuser);
 221                 set_user_preference('auth_forcepasswordchange', 1, $newuser);
 222             } else {
 223                 trigger_error("Could not create and mail new user password!");
 224             }
 225         }
 226         $newusers->close();
 227     }
 228
 229
 230     // It is very important to run enrol early
 231     // because other plugins depend on correct enrolment info.
 232     mtrace("Running enrol crons if required...");
 233     $enrols = enrol_get_plugins(true);
 234     foreach($enrols as $ename=>$enrol) {
 235         // do this for all plugins, disabled plugins might want to cleanup stuff such as roles
 236         if (!$enrol->is_cron_required()) {
 237             continue;
 238         }
 239         mtrace("Running cron for enrol_$ename...");
 240         $enrol->cron();
 241         $enrol->set_config('lastcron', time());
 242     }
 243
 244
 245     // Run all cron jobs for each module
 246     mtrace("Starting activity modules");
 247     get_mailer('buffer');
 248     if ($mods = $DB->get_records_select("modules", "cron > 0 AND ((? - lastcron) > cron) AND visible = 1", array($timenow))) {
 249         foreach ($mods as $mod) {
 250             $libfile = "$CFG->dirroot/mod/$mod->name/lib.php";
 251             if (file_exists($libfile)) {
 252                 include_once($libfile);
 253                 $cron_function = $mod->name."_cron";
 254                 if (function_exists($cron_function)) {
 255                     mtrace("Processing module function $cron_function ...", '');
 256                     $pre_dbqueries = null;
 257                     $pre_dbqueries = $DB->perf_get_queries();
 258                     $pre_time      = microtime(1);
 259                     if ($cron_function()) {
 260                         $DB->set_field("modules", "lastcron", $timenow, array("id"=>$mod->id));
 261                     }
 262                     if (isset($pre_dbqueries)) {
 263                         mtrace("... used " . ($DB->perf_get_queries() - $pre_dbqueries) . " dbqueries");
 264                         mtrace("... used " . (microtime(1) - $pre_time) . " seconds");
 265                     }
 266                     // Reset possible changes by modules to time_limit. MDL-11597
 267                     @set_time_limit(0);
 268                     mtrace("done.");
 269                 }
 270             }
 271         }
 272     }
 273     get_mailer('close');
 274     mtrace("Finished activity modules");
 275
 276
 277     mtrace("Starting blocks");
 278     if ($blocks = $DB->get_records_select("block", "cron > 0 AND ((? - lastcron) > cron) AND visible = 1", array($timenow))) {
 279         // We will need the base class.
 280         require_once($CFG->dirroot.'/blocks/moodleblock.class.php');
 281         foreach ($blocks as $block) {
 282             $blockfile = $CFG->dirroot.'/blocks/'.$block->name.'/block_'.$block->name.'.php';
 283             if (file_exists($blockfile)) {
 284                 require_once($blockfile);
 285                 $classname = 'block_'.$block->name;
 286                 $blockobj = new $classname;
 287                 if (method_exists($blockobj,'cron')) {
 288                     mtrace("Processing cron function for ".$block->name.'....','');
 289                     if ($blockobj->cron()) {
 290                         $DB->set_field('block', 'lastcron', $timenow, array('id'=>$block->id));
 291                     }
 292                     // Reset possible changes by blocks to time_limit. MDL-11597
 293                     @set_time_limit(0);
 294                     mtrace('done.');
 295                 }
 296             }
 297
 298         }
 299     }
 300     mtrace('Finished blocks');
 301
 302
 303     mtrace('Starting admin reports');
 304     cron_execute_plugin_type('report');
 305     mtrace('Finished admin reports');
 306
 307
 308     mtrace('Starting main gradebook job...');
 309     grade_cron();
 310     mtrace('done.');
 311
 312
 313     mtrace('Starting processing the event queue...');
 314     events_cron();
 315     mtrace('done.');
 316
 317
 318     if ($CFG->enablecompletion) {
 319         // Completion cron
 320         mtrace('Starting the completion cron...');
 321         require_once($CFG->dirroot.'/completion/cron.php');
 322         completion_cron();
 323         mtrace('done');
 324     }
 325
 326
 327     if ($CFG->enableportfolios) {
 328         // Portfolio cron
 329         mtrace('Starting the portfolio cron...');
 330         require_once($CFG->libdir . '/portfoliolib.php');
 331         portfolio_cron();
 332         mtrace('done');
 333     }
 334
 335
 336     //now do plagiarism checks
 337     require_once($CFG->libdir.'/plagiarismlib.php');
 338     plagiarism_cron();
 339
 340
 341     mtrace('Starting course reports');
 342     cron_execute_plugin_type('coursereport');
 343     mtrace('Finished course reports');
 344
 345
 346     // run gradebook import/export/report cron
 347     mtrace('Starting gradebook plugins');
 348     cron_execute_plugin_type('gradeimport');
 349     cron_execute_plugin_type('gradeexport');
 350     cron_execute_plugin_type('gradereport');
 351     mtrace('Finished gradebook plugins');
 352
 353     // run calendar cron
 354     require_once "{$CFG->dirroot}/calendar/lib.php";
 355     calendar_cron();
 356
 357     // Run external blog cron if needed
 358     if (!empty($CFG->enableblogs) && $CFG->useexternalblogs) {
 359         require_once($CFG->dirroot . '/blog/lib.php');
 360         mtrace("Fetching external blog entries...", '');
 361         $sql = "timefetched < ? OR timefetched = 0";
 362         $externalblogs = $DB->get_records_select('blog_external', $sql, array(time() - $CFG->externalblogcrontime));
 363
 364         foreach ($externalblogs as $eb) {
 365             blog_sync_external_entries($eb);
 366         }
 367         mtrace('done.');
 368     }
 369     // Run blog associations cleanup
 370     if (!empty($CFG->enableblogs) && $CFG->useblogassociations) {
 371         require_once($CFG->dirroot . '/blog/lib.php');
 372         // delete entries whose contextids no longer exists
 373         mtrace("Deleting blog associations linked to non-existent contexts...", '');
 374         $DB->delete_records_select('blog_association', 'contextid NOT IN (SELECT id FROM {context})');
 375         mtrace('done.');
 376     }
 377
 378
 379     // Run question bank clean-up.
 380     mtrace("Starting the question bank cron...", '');
 381     require_once($CFG->libdir . '/questionlib.php');
 382     question_bank::cron();
 383     mtrace('done.');
 384
 385
 386     //Run registration updated cron
 387     mtrace(get_string('siteupdatesstart', 'hub'));
 388     require_once($CFG->dirroot . '/' . $CFG->admin . '/registration/lib.php');
 389     $registrationmanager = new registration_manager();
 390     $registrationmanager->cron();
 391     mtrace(get_string('siteupdatesend', 'hub'));
 392
 393     // If enabled, fetch information about available updates and eventually notify site admins
 394     if (empty($CFG->disableupdatenotifications)) {
 395         require_once($CFG->libdir.'/pluginlib.php');
 396         $updateschecker = available_update_checker::instance();
 397         $updateschecker->cron();
 398     }
 399
 400     //cleanup old session linked tokens
 401     //deletes the session linked tokens that are over a day old.
 402     mtrace("Deleting session linked tokens more than one day old...", '');
 403     $DB->delete_records_select('external_tokens', 'lastaccess < :onedayago AND tokentype = :tokentype',
 404                     array('onedayago' => time() - DAYSECS, 'tokentype' => EXTERNAL_TOKEN_EMBEDDED));
 405     mtrace('done.');
 406
 407
 408     // all other plugins
 409     cron_execute_plugin_type('message', 'message plugins');
 410     cron_execute_plugin_type('filter', 'filters');
 411     cron_execute_plugin_type('editor', 'editors');
 412     cron_execute_plugin_type('format', 'course formats');
 413     cron_execute_plugin_type('profilefield', 'profile fields');
 414     cron_execute_plugin_type('webservice', 'webservices');
 415     cron_execute_plugin_type('repository', 'repository plugins');
 416     cron_execute_plugin_type('qbehaviour', 'question behaviours');
 417     cron_execute_plugin_type('qformat', 'question import/export formats');
 418     cron_execute_plugin_type('qtype', 'question types');
 419     cron_execute_plugin_type('plagiarism', 'plagiarism plugins');
 420     cron_execute_plugin_type('theme', 'themes');
 421     cron_execute_plugin_type('tool', 'admin tools');
 422
 423
 424     // and finally run any local cronjobs, if any
 425     if ($locals = get_plugin_list('local')) {
 426         mtrace('Processing customized cron scripts ...', '');
 427         // new cron functions in lib.php first
 428         cron_execute_plugin_type('local');
 429         // legacy cron files are executed directly
 430         foreach ($locals as $local => $localdir) {
 431             if (file_exists("$localdir/cron.php")) {
 432                 include("$localdir/cron.php");
 433             }
 434         }
 435         mtrace('done.');
 436     }
 437
 438
 439     // Run automated backups if required - these may take a long time to execute
 440     require_once($CFG->dirroot.'/backup/util/includes/backup_includes.php');
 441     require_once($CFG->dirroot.'/backup/util/helper/backup_cron_helper.class.php');
 442     backup_cron_automated_helper::run_automated_backup();
 443
 444
 445     // Run stats as at the end because they are known to take very long time on large sites
 446     if (!empty($CFG->enablestats) and empty($CFG->disablestatsprocessing)) {
 447         require_once($CFG->dirroot.'/lib/statslib.php');
 448         // check we're not before our runtime
 449         $timetocheck = stats_get_base_daily() + $CFG->statsruntimestarthour*60*60 + $CFG->statsruntimestartminute*60;
 450
 451         if (time() > $timetocheck) {
 452             // process configured number of days as max (defaulting to 31)
 453             $maxdays = empty($CFG->statsruntimedays) ? 31 : abs($CFG->statsruntimedays);
 454             if (stats_cron_daily($maxdays)) {
 455                 if (stats_cron_weekly()) {
 456                     if (stats_cron_monthly()) {
 457                         stats_clean_old();
 458                     }
 459                 }
 460             }
 461             @set_time_limit(0);
 462         } else {
 463             mtrace('Next stats run after:'. userdate($timetocheck));
 464         }
 465     }
 466
 467
 468     // cleanup file trash - not very important
 469     $fs = get_file_storage();
 470     $fs->cron();
 471
 472     mtrace("Cron script completed correctly");
 473
 474     $difftime = microtime_diff($starttime, microtime());
 475     mtrace("Execution took ".$difftime." seconds");
 476 }
 477
 478 /**
 479  * Executes cron functions for a specific type of plugin.
 480  *
 481  * @param string $plugintype Plugin type (e.g. 'report')
 482  * @param string $description If specified, will display 'Starting (whatever)'
 483  *   and 'Finished (whatever)' lines, otherwise does not display
 484  */
 485 function cron_execute_plugin_type($plugintype, $description = null) {
 486     global $DB;
 487
 488     // Get list from plugin => function for all plugins
 489     $plugins = get_plugin_list_with_function($plugintype, 'cron');
 490
 491     // Modify list for backward compatibility (different files/names)
 492     $plugins = cron_bc_hack_plugin_functions($plugintype, $plugins);
 493
 494     // Return if no plugins with cron function to process
 495     if (!$plugins) {
 496         return;
 497     }
 498
 499     if ($description) {
 500         mtrace('Starting '.$description);
 501     }
 502
 503     foreach ($plugins as $component=>$cronfunction) {
 504         $dir = get_component_directory($component);
 505
 506         // Get cron period if specified in version.php, otherwise assume every cron
 507         $cronperiod = 0;
 508         if (file_exists("$dir/version.php")) {
 509             $plugin = new stdClass();
 510             include("$dir/version.php");
 511             if (isset($plugin->cron)) {
 512                 $cronperiod = $plugin->cron;
 513             }
 514         }
 515
 516         // Using last cron and cron period, don't run if it already ran recently
 517         $lastcron = get_config($component, 'lastcron');
 518         if ($cronperiod && $lastcron) {
 519             if ($lastcron + $cronperiod > time()) {
 520                 // do not execute cron yet
 521                 continue;
 522             }
 523         }
 524
 525         mtrace('Processing cron function for ' . $component . '...');
 526         $pre_dbqueries = $DB->perf_get_queries();
 527         $pre_time = microtime(true);
 528
 529         $cronfunction();
 530
 531         mtrace("done. (" . ($DB->perf_get_queries() - $pre_dbqueries) . " dbqueries, " .
 532                 round(microtime(true) - $pre_time, 2) . " seconds)");
 533
 534         set_config('lastcron', time(), $component);
 535         @set_time_limit(0);
 536     }
 537
 538     if ($description) {
 539         mtrace('Finished ' . $description);
 540     }
 541 }
 542
 543 /**
 544  * Used to add in old-style cron functions within plugins that have not been converted to the
 545  * new standard API. (The standard API is frankenstyle_name_cron() in lib.php; some types used
 546  * cron.php and some used a different name.)
 547  *
 548  * @param string $plugintype Plugin type e.g. 'report'
 549  * @param array $plugins Array from plugin name (e.g. 'report_frog') to function name (e.g.
 550  *   'report_frog_cron') for plugin cron functions that were already found using the new API
 551  * @return array Revised version of $plugins that adds in any extra plugin functions found by
 552  *   looking in the older location
 553  */
 554 function cron_bc_hack_plugin_functions($plugintype, $plugins) {
 555     global $CFG; // mandatory in case it is referenced by include()d PHP script
 556
 557     if ($plugintype === 'report') {
 558         // Admin reports only - not course report because course report was
 559         // never implemented before, so doesn't need BC
 560         foreach (get_plugin_list($plugintype) as $pluginname=>$dir) {
 561             $component = $plugintype . '_' . $pluginname;
 562             if (isset($plugins[$component])) {
 563                 // We already have detected the function using the new API
 564                 continue;
 565             }
 566             if (!file_exists("$dir/cron.php")) {
 567                 // No old style cron file present
 568                 continue;
 569             }
 570             include_once("$dir/cron.php");
 571             $cronfunction = $component . '_cron';
 572             if (function_exists($cronfunction)) {
 573                 $plugins[$component] = $cronfunction;
 574             } else {
 575                 debugging("Invalid legacy cron.php detected in $component, " .
 576                         "please use lib.php instead");
 577             }
 578         }
 579     } else if (strpos($plugintype, 'grade') === 0) {
 580         // Detect old style cron function names
 581         // Plugin gradeexport_frog used to use grade_export_frog_cron() instead of
 582         // new standard API gradeexport_frog_cron(). Also applies to gradeimport, gradereport
 583         foreach(get_plugin_list($plugintype) as $pluginname=>$dir) {
 584             $component = $plugintype.'_'.$pluginname;
 585             if (isset($plugins[$component])) {
 586                 // We already have detected the function using the new API
 587                 continue;
 588             }
 589             if (!file_exists("$dir/lib.php")) {
 590                 continue;
 591             }
 592             include_once("$dir/lib.php");
 593             $cronfunction = str_replace('grade', 'grade_', $plugintype) . '_' .
 594                     $pluginname . '_cron';
 595             if (function_exists($cronfunction)) {
 596                 $plugins[$component] = $cronfunction;
 597             }
 598         }
 599     }
 600
 601     return $plugins;
 602 }
 603
 604
 605 /**
 606  * Notify admin users or admin user of any failed logins (since last notification).
 607  *
 608  * Note that this function must be only executed from the cron script
 609  * It uses the cache_flags system to store temporary records, deleting them
 610  * by name before finishing
 611  *
 612  * @return bool True if executed, false if not
 613  */
 614 function notify_login_failures() {
 615     global $CFG, $DB, $OUTPUT;
 616
 617     if (empty($CFG->notifyloginfailures)) {
 618         return false;
 619     }
 620
 621     $recip = get_users_from_config($CFG->notifyloginfailures, 'moodle/site:config');
 622
 623     if (empty($CFG->lastnotifyfailure)) {
 624         $CFG->lastnotifyfailure=0;
 625     }
 626
 627     // If it has been less than an hour, or if there are no recipients, don't execute.
 628     if (((time() - HOURSECS) < $CFG->lastnotifyfailure) || !is_array($recip) || count($recip) <= 0) {
 629         return false;
 630     }
 631
 632     // we need to deal with the threshold stuff first.
 633     if (empty($CFG->notifyloginthreshold)) {
 634         $CFG->notifyloginthreshold = 10; // default to something sensible.
 635     }
 636
 637     // Get all the IPs with more than notifyloginthreshold failures since lastnotifyfailure
 638     // and insert them into the cache_flags temp table
 639     $sql = "SELECT ip, COUNT(*)
 640               FROM {log}
 641              WHERE module = 'login' AND action = 'error'
 642                    AND time > ?
 643           GROUP BY ip
 644             HAVING COUNT(*) >= ?";
 645     $params = array($CFG->lastnotifyfailure, $CFG->notifyloginthreshold);
 646     $rs = $DB->get_recordset_sql($sql, $params);
 647     foreach ($rs as $iprec) {
 648         if (!empty($iprec->ip)) {
 649             set_cache_flag('login_failure_by_ip', $iprec->ip, '1', 0);
 650         }
 651     }
 652     $rs->close();
 653
 654     // Get all the INFOs with more than notifyloginthreshold failures since lastnotifyfailure
 655     // and insert them into the cache_flags temp table
 656     $sql = "SELECT info, count(*)
 657               FROM {log}
 658              WHERE module = 'login' AND action = 'error'
 659                    AND time > ?
 660           GROUP BY info
 661             HAVING count(*) >= ?";
 662     $params = array($CFG->lastnotifyfailure, $CFG->notifyloginthreshold);
 663     $rs = $DB->get_recordset_sql($sql, $params);
 664     foreach ($rs as $inforec) {
 665         if (!empty($inforec->info)) {
 666             set_cache_flag('login_failure_by_info', $inforec->info, '1', 0);
 667         }
 668     }
 669     $rs->close();
 670
 671     // Now, select all the login error logged records belonging to the ips and infos
 672     // since lastnotifyfailure, that we have stored in the cache_flags table
 673     $sql = "SELECT * FROM (
 674         SELECT l.*, u.firstname, u.lastname
 675               FROM {log} l
 676               JOIN {cache_flags} cf ON l.ip = cf.name
 677          LEFT JOIN {user} u         ON l.userid = u.id
 678              WHERE l.module = 'login' AND l.action = 'error'
 679                    AND l.time > ?
 680                    AND cf.flagtype = 'login_failure_by_ip'
 681         UNION ALL
 682             SELECT l.*, u.firstname, u.lastname
 683               FROM {log} l
 684               JOIN {cache_flags} cf ON l.info = cf.name
 685          LEFT JOIN {user} u         ON l.userid = u.id
 686              WHERE l.module = 'login' AND l.action = 'error'
 687                    AND l.time > ?
 688                    AND cf.flagtype = 'login_failure_by_info') t
 689         ORDER BY t.time DESC";
 690     $params = array($CFG->lastnotifyfailure, $CFG->lastnotifyfailure);
 691
 692     // Init some variables
 693     $count = 0;
 694     $messages = '';
 695     // Iterate over the logs recordset
 696     $rs = $DB->get_recordset_sql($sql, $params);
 697     foreach ($rs as $log) {
 698         $log->time = userdate($log->time);
 699         $messages .= get_string('notifyloginfailuresmessage','',$log)."\n";
 700         $count++;
 701     }
 702     $rs->close();
 703
 704     // If we have something useful to report.
 705     if ($count > 0) {
 706         $site = get_site();
 707         $subject = get_string('notifyloginfailuressubject', '', format_string($site->fullname));
 708         // Calculate the complete body of notification (start + messages + end)
 709         $body = get_string('notifyloginfailuresmessagestart', '', $CFG->wwwroot) .
 710                 (($CFG->lastnotifyfailure != 0) ? '('.userdate($CFG->lastnotifyfailure).')' : '')."\n\n" .
 711                 $messages .
 712                 "\n\n".get_string('notifyloginfailuresmessageend','',$CFG->wwwroot)."\n\n";
 713
 714         // For each destination, send mail
 715         mtrace('Emailing admins about '. $count .' failed login attempts');
 716         foreach ($recip as $admin) {
 717             //emailing the admins directly rather than putting these through the messaging system
 718             email_to_user($admin, generate_email_supportuser(), $subject, $body);
 719         }
 720     }
 721
 722     // Update lastnotifyfailure with current time
 723     set_config('lastnotifyfailure', time());
 724
 725     // Finally, delete all the temp records we have created in cache_flags
 726     $DB->delete_records_select('cache_flags', "flagtype IN ('login_failure_by_ip', 'login_failure_by_info')");
 727
 728     return true;
 729 }