rebase from live enviornment

wp/plugins/wordfence/lib/wfScanMonitor.php

@@ -0,0 +1,131 @@
+<?php
+
+class wfScanMonitor {
+
+	const CRON_INTERVAL_NAME = 'wf_scan_monitor_interval';
+	const CRON_INTERVAL_AMOUNT = 60; //Seconds
+	const CRON_HOOK = 'wf_scan_monitor';
+
+	const CONFIG_LAST_ATTEMPT = 'scanMonitorLastAttempt';
+	const CONFIG_LAST_ATTEMPT_WAS_FORK = 'scanMonitorLastAttemptWasFork';
+	const CONFIG_LAST_ATTEMPT_MODE = 'scanMonitorLastAttemptMode';
+	const CONFIG_LAST_SUCCESS = 'scanMonitorLastSuccess';
+	const CONFIG_MAX_RESUME_ATTEMPTS = 'scan_max_resume_attempts';
+	const CONFIG_REMAINING_RESUME_ATTEMPTS = 'scanMonitorRemainingResumeAttempts';
+
+	const DEFAULT_RESUME_ATTEMPTS = 2;
+	const MAX_RESUME_ATTEMPTS = 5;
+	const SCAN_START_TIMEOUT = 30; //Seconds
+
+	public static function beginMonitoring() {
+		if (wp_next_scheduled(self::CRON_HOOK))
+			return;
+		wp_schedule_event(time(), self::CRON_INTERVAL_NAME, self::CRON_HOOK);
+	}
+
+	public static function endMonitoring() {
+		$timestamp = wp_next_scheduled(self::CRON_HOOK);
+		if ($timestamp !== false)
+			wp_unschedule_event($timestamp, self::CRON_HOOK);
+	}
+
+	public static function validateResumeAttempts($attempts, &$valid = null) {
+		if ($attempts < 0 || $attempts > self::MAX_RESUME_ATTEMPTS) {
+			$valid = false;
+			return self::DEFAULT_RESUME_ATTEMPTS;
+		}
+		$valid = true;
+		return $attempts;
+	}
+
+	private static function setRemainingResumeAttempts($attempts) {
+		wfConfig::set(self::CONFIG_REMAINING_RESUME_ATTEMPTS, $attempts);
+	}
+
+	public static function getConfiguredResumeAttempts() {
+		$attempts = (int) wfConfig::get(self::CONFIG_MAX_RESUME_ATTEMPTS, self::DEFAULT_RESUME_ATTEMPTS);
+		return self::validateResumeAttempts($attempts);
+	}
+
+	private static function resetResumeAttemptCounter() {
+		$attempts = self::getConfiguredResumeAttempts();
+		self::setRemainingResumeAttempts($attempts);
+		return $attempts;
+	}
+
+	private static function getRemainingResumeAttempts() {
+		$attempts = (int) wfConfig::get(self::CONFIG_REMAINING_RESUME_ATTEMPTS, 0);
+		return self::validateResumeAttempts($attempts);
+	}
+
+	public static function handleScanStart($mode) {
+		wfConfig::set(self::CONFIG_LAST_ATTEMPT_MODE, $mode);
+		$maxAttempts = self::resetResumeAttemptCounter();
+		if ($maxAttempts > 0)
+			self::beginMonitoring();
+	}
+
+	public static function monitorScan() {
+		$remainingAttempts = self::getRemainingResumeAttempts();
+		if ($remainingAttempts > 0) {
+			$now = time();
+			$lastAttempt = wfConfig::get(self::CONFIG_LAST_ATTEMPT);
+			if ($lastAttempt === null || $now - $lastAttempt < self::SCAN_START_TIMEOUT)
+				return;
+			$lastSuccess = wfConfig::get(self::CONFIG_LAST_SUCCESS);
+			self::setRemainingResumeAttempts(--$remainingAttempts);
+			if ($lastSuccess === null || $lastAttempt > $lastSuccess) {
+				wordfence::status(2, 'info', sprintf(__('Attempting to resume scan stage (%d attempt(s) remaining)...', 'wordfence'), $remainingAttempts));
+				self::resumeScan();
+			}
+		}
+		else {
+			self::endMonitoring();
+		}
+	}
+
+	private static function resumeScan() {
+		$mode = wfConfig::get(self::CONFIG_LAST_ATTEMPT_MODE);
+		if (!wfScanner::isValidScanType($mode))
+			$mode = false;
+		wfScanEngine::startScan(wfConfig::get(self::CONFIG_LAST_ATTEMPT_WAS_FORK), $mode, true);
+	}
+
+	private static function logTimestamp($key) {
+		wfConfig::set($key, time());
+	}
+
+	public static function logLastAttempt($fork) {
+		self::logTimestamp(self::CONFIG_LAST_ATTEMPT);
+		wfConfig::set(self::CONFIG_LAST_ATTEMPT_WAS_FORK, $fork);
+	}
+
+	public static function logLastSuccess() {
+		self::logTimestamp(self::CONFIG_LAST_SUCCESS);
+	}
+
+	public static function handleStageStart($fork) {
+		if ($fork)
+			self::resetResumeAttemptCounter();
+	}
+
+	public static function registerCronInterval($schedules) {
+		if (!array_key_exists(self::CRON_INTERVAL_NAME, $schedules)) {
+			$schedules[self::CRON_INTERVAL_NAME] = array(
+				'interval' => self::CRON_INTERVAL_AMOUNT,
+				'display' => 'Wordfence Scan Monitor'
+			);
+		}
+		return $schedules;
+	}
+
+	public static function registerActions() {
+		add_filter('cron_schedules', array(self::class, 'registerCronInterval'));
+		add_action(self::CRON_HOOK, array(self::class, 'monitorScan'));
+	}
+
+	public static function handleDeactivation() {
+		self::endMonitoring();
+	}
+
+}