Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle 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 3 of the License, or

// (at your option) any later version.

//

// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Scheduled task class.

 *

 * @package    core

 * @copyright  2013 onwards Martin Dougiamas  http://dougiamas.com

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace core\task;

/**

 * Simple task to send notifications about failed login attempts.

 */

class send_failed_login_notifications_task extends scheduled_task {

    /** The maximum time period to look back (30 days = 30 * 24 * 3600) */

    const NOTIFY_MAXIMUM_TIME = 2592000;

    /**

     * Get a descriptive name for this task (shown to admins).

     *

     * @return string

     */

    public function get_name() {

        return get_string('tasksendfailedloginnotifications', 'admin');

    }

    /**

     * Do the job.

     * Throw exceptions on errors (the job will be retried).

     */

    public function execute() {

        global $CFG, $DB;

        if (empty($CFG->notifyloginfailures)) {

            return;

        }

        $recip = get_users_from_config($CFG->notifyloginfailures, 'moodle/site:config');

        // Do not look back more than 1 month to avoid crashes due to huge number of records.

        $maximumlastnotifytime = time() - self::NOTIFY_MAXIMUM_TIME;

        if (empty($CFG->lastnotifyfailure) || ($CFG->lastnotifyfailure < $maximumlastnotifytime)) {

            $CFG->lastnotifyfailure = $maximumlastnotifytime;

        }

        // If it has been less than an hour, or if there are no recipients, don't execute.

        if (((time() - HOURSECS) < $CFG->lastnotifyfailure) || !is_array($recip) || count($recip) <= 0) {

            return;

        }

        // We need to deal with the threshold stuff first.

        if (empty($CFG->notifyloginthreshold)) {

            $CFG->notifyloginthreshold = 10; // Default to something sensible.

        }

        // Get all the IPs with more than notifyloginthreshold failures since lastnotifyfailure

        // and insert them into the cache_flags temp table.

        $logmang = get_log_manager();

        /** @var \core\log\sql_internal_table_reader[] $readers */

        $readers = $logmang->get_readers('\core\log\sql_internal_table_reader');

        $reader = reset($readers);

        $readername = key($readers);

        if (empty($reader) || empty($readername)) {

            // No readers, no processing.

            return true;

        }

        $logtable = $reader->get_internal_log_table_name();

        $sql = "SELECT ip, COUNT(*)

                  FROM {" . $logtable . "}

                 WHERE eventname = ?

                       AND timecreated > ?

               GROUP BY ip

                 HAVING COUNT(*) >= ?";

        $params = array('\core\event\user_login_failed', $CFG->lastnotifyfailure, $CFG->notifyloginthreshold);

        $rs = $DB->get_recordset_sql($sql, $params);

        foreach ($rs as $iprec) {

            if (!empty($iprec->ip)) {

                set_cache_flag('login_failure_by_ip', $iprec->ip, '1', 0);

            }

        }

        $rs->close();

        // Get all the INFOs with more than notifyloginthreshold failures since lastnotifyfailure

        // and insert them into the cache_flags temp table.

        $sql = "SELECT userid, count(*)

                  FROM {" . $logtable . "}

                 WHERE eventname = ?

                       AND timecreated > ?

              GROUP BY userid

                HAVING count(*) >= ?";

        $params = array('\core\event\user_login_failed', $CFG->lastnotifyfailure, $CFG->notifyloginthreshold);

        $rs = $DB->get_recordset_sql($sql, $params);

        foreach ($rs as $inforec) {

            if (!empty($inforec->info)) {

                set_cache_flag('login_failure_by_id', $inforec->userid, '1', 0);

            }

        }

        $rs->close();

        // Now, select all the login error logged records belonging to the ips and infos

        // since lastnotifyfailure, that we have stored in the cache_flags table.

        $userfieldsapi = \core_user\fields::for_name();

        $namefields = $userfieldsapi->get_sql('u', false, '', '', false)->selects;

        $sql = "SELECT * FROM (

                        SELECT l.*, u.username, $namefields

                          FROM {" . $logtable . "} l

                          JOIN {cache_flags} cf ON l.ip = cf.name

                     LEFT JOIN {user} u         ON l.userid = u.id

                         WHERE l.eventname = ?

                               AND l.timecreated > ?

                               AND cf.flagtype = 'login_failure_by_ip'

                    UNION ALL

                        SELECT l.*, u.username, $namefields

                          FROM {" . $logtable . "} l

                          JOIN {cache_flags} cf ON l.userid = " . $DB->sql_cast_char2int('cf.name') . "

                     LEFT JOIN {user} u         ON l.userid = u.id

                         WHERE l.eventname = ?

                               AND l.timecreated > ?

                               AND cf.flagtype = 'login_failure_by_info') t

             ORDER BY t.timecreated DESC";

        $params = array('\core\event\user_login_failed', $CFG->lastnotifyfailure, '\core\event\user_login_failed', $CFG->lastnotifyfailure);

        // Init some variables.

        $count = 0;

        $messages = '';

        // Iterate over the logs recordset.

        $rs = $DB->get_recordset_sql($sql, $params);

        foreach ($rs as $log) {

            $a = new \stdClass();

            $a->time = userdate($log->timecreated);

            if (empty($log->username)) {

                // Entries with no valid username. We get attempted username from the event's other field.

                $other = \tool_log\local\privacy\helper::decode_other($log->other);

                $a->info = empty($other['username']) ? '' : $other['username'];

                $a->name = get_string('unknownuser');

            } else {

                $a->info = $log->username;

                $a->name = fullname($log);

            }

            $a->ip = $log->ip;

            $messages .= get_string('notifyloginfailuresmessage', '', $a)."\n";

            $count++;

        }

        $rs->close();

        // If we have something useful to report.

        if ($count > 0) {

            $site = get_site();

            $subject = get_string('notifyloginfailuressubject', '', format_string($site->fullname));

            // Calculate the complete body of notification (start + messages + end).

            $params = array('id' => 0, 'modid' => 'site_errors', 'chooselog' => '1', 'logreader' => $readername);

            $url = new \moodle_url('/report/log/index.php', $params);

            $body = get_string('notifyloginfailuresmessagestart', '', $CFG->wwwroot) .

                    (($CFG->lastnotifyfailure != 0) ? '('.userdate($CFG->lastnotifyfailure).')' : '')."\n\n" .

                    $messages .

                    "\n\n".get_string('notifyloginfailuresmessageend', '',  $url->out(false).' ')."\n\n";

            // For each destination, send mail.

            mtrace('Emailing admins about '. $count .' failed login attempts');

            foreach ($recip as $admin) {

                // Emailing the admins directly rather than putting these through the messaging system.

                email_to_user($admin, \core_user::get_noreply_user(), $subject, $body);

            }

        }

        // Update lastnotifyfailure with current time.

        set_config('lastnotifyfailure', time());

        // Finally, delete all the temp records we have created in cache_flags.

        $DB->delete_records_select('cache_flags', "flagtype IN ('login_failure_by_ip', 'login_failure_by_info')");

    }

}