Merge pull request #4044 from annando/ejabberd-lock

Prevent the running of multiple xmpp auth daemons at a time

doc/htconfig.md

@@ -19,6 +19,7 @@ Example: To set the directory value please add this line to your .htconfig.php:
 
 ## jabber ##
 * **debug** (Boolean) - Enable debug level for the jabber account synchronisation.
+* **lockpath** - Must be writable by the ejabberd process. if set then it will prevent the running of multiple processes.
 
 ## system ##
 

src/Util/ExAuth.php

@@ -45,6 +45,7 @@ require_once 'include/dba.php';
 class ExAuth
 {
 	private $bDebug;
+	private $host;
 
 	/**
 	 * @brief Create the class
@@ -133,6 +134,10 @@ class ExAuth
 			return;
 		}
 
+		// We only allow one process per hostname. So we set a lock file
+		// Problem: We get the firstname after the first auth - not before
+		$this->setHost($aCommand[2]);
+
 		// Now we check if the given user is valid
 		$sUser = str_replace(array('%20', '(a)'), array(' ', '@'), $aCommand[1]);
 
@@ -209,6 +214,10 @@ class ExAuth
 			return;
 		}
 
+		// We only allow one process per hostname. So we set a lock file
+		// Problem: We get the firstname after the first auth - not before
+		$this->setHost($aCommand[2]);
+
 		// We now check if the password match
 		$sUser = str_replace(array('%20', '(a)'), array(' ', '@'), $aCommand[1]);
 
@@ -260,7 +269,9 @@ class ExAuth
 	 */
 	private function checkCredentials($host, $user, $password, $ssl)
 	{
-		$url = ($ssl ? 'https' : 'http') . '://' . $host . '/api/account/verify_credentials.json';
+		$this->writeLog(LOG_INFO, 'external credential check for ' . $user . '@' . $host);
+
+		$url = ($ssl ? 'https' : 'http') . '://' . $host . '/api/account/verify_credentials.json?skip_status=true';
 
 		$ch = curl_init();
 		curl_setopt($ch, CURLOPT_URL, $url);
@@ -281,6 +292,40 @@ class ExAuth
 		return $http_code == 200;
 	}
 
+	/**
+	 * @brief Set the hostname for this process
+	 *
+	 * @param string $host The hostname
+	 */
+	private function setHost($host)
+	{
+		if (!empty($this->host)) {
+			return;
+		}
+
+		$this->writeLog(LOG_INFO, 'Hostname for process ' . getmypid() . ' is ' . $host);
+
+		$this->host = $host;
+
+		$lockpath = Config::get('jabber', 'lockpath');
+		if (is_null($lockpath)) {
+			return;
+		}
+
+		$file = $lockpath . DIRECTORY_SEPARATOR . $host;
+		if (Pidfile::isRunningProcess($file)) {
+			if (PidFile::killProcess($file)) {
+				$this->writeLog(LOG_INFO, 'Old process was successfully killed');
+			} else {
+				$this->writeLog(LOG_ERR, "The old Process wasn't killed in time. We now quit our process.");
+				die();
+			}
+		}
+
+		// Now it is safe to create the pid file
+		Pidfile::create($file);
+	}
+
 	/**
 	 * @brief write data to the syslog
 	 *

src/Util/Pidfile.php

@@ -9,64 +9,100 @@ namespace Friendica\Util;
  */
 class Pidfile
 {
-	private $file;
-	private $running;
-
 	/**
-	 * @param string $dir  path
-	 * @param string $name filename
-	 * @return void
+	 * @brief Read the pid from a given pid file
+	 *
+	 * @param string $file Filename of pid file
+	 *
+	 * @return boolean|string PID or "false" if not existent
 	 */
-	public function __construct($dir, $name)
-	{
-		$this->_file = "$dir/$name.pid";
-
-		if (file_exists($this->_file)) {
-			$pid = trim(@file_get_contents($this->file));
-			if (($pid != "") && posix_kill($pid, 0)) {
-				$this->running = true;
-			}
+	static private function pidFromFile($file) {
+		if (!file_exists($file)) {
+			return false;
 		}
 
-		if (! $this->running) {
-			$pid = getmypid();
-			file_put_contents($this->file, $pid);
-		}
+		return trim(@file_get_contents($file));
 	}
 
 	/**
-	 * @return void
+	 * @brief Is there a running process with the given pid file
+	 *
+	 * @param string $file Filename of pid file
+	 *
+	 * @return boolean Is it running?
 	 */
-	public function __destruct()
-	{
-		if ((! $this->running) && file_exists($this->file)) {
-			@unlink($this->file);
+	static public function isRunningProcess($file) {
+		$pid = self::pidFromFile($file);
+
+		if (!$pid) {
+			return false;
 		}
-	}
 
-	/**
-	 * @return boolean
-	 */
-	public static function isRunning()
-	{
-		return self::$running;
-	}
+		// Is the process running?
+		$running = posix_kill($pid, 0);
 
-	/**
-	 * @return object
-	 */
-	public static function runningTime()
-	{
-		return time() - @filectime(self::$file);
-	}
-
-	/**
-	 * @return boolean
-	 */
-	public static function kill()
-	{
-		if (file_exists(self::$file)) {
-			return posix_kill(file_get_contents(self::$file), SIGTERM);
+		// If not, then we will kill the stale file
+		if (!$running) {
+			self::delete($file);
 		}
+		return $running;
+	}
+
+	/**
+	 * @brief Kills a process from a given pid file
+	 *
+	 * @param string $file Filename of pid file
+	 *
+	 * @return boolean Was it killed successfully?
+	 */
+	static public function killProcess($file) {
+		$pid = self::pidFromFile($file);
+
+		// We don't have a process id? then we quit
+		if (!$pid) {
+			return false;
+		}
+
+		// We now kill the process
+		$killed = posix_kill($pid, SIGTERM);
+
+		// If we killed the process successfully, we can remove the pidfile
+		if ($killed) {
+			self::delete($file);
+		}
+		return $killed;
+	}
+
+	/**
+	 * @brief Creates a pid file
+	 *
+	 * @param string $file Filename of pid file
+	 *
+	 * @return boolean|string PID or "false" if not created
+	 */
+	static public function create($file) {
+		$pid = self::pidFromFile($file);
+
+		// We have a process id? then we quit
+		if ($pid) {
+			return false;
+		}
+
+		$pid = getmypid();
+		file_put_contents($file, $pid);
+
+		// Now we check if everything is okay
+		return self::pidFromFile($file);
+	}
+
+	/**
+	 * @brief Deletes a given pid file
+	 *
+	 * @param string $file Filename of pid file
+	 *
+	 * @return boolean Is it running?
+	 */
+	static public function delete($file) {
+		return @unlink($file);
 	}
 }