/**
   * Initializes this network address manager service implementation and starts all
   * processes/threads associated with this address manager, such as a stun firewall/nat detector,
   * keep alive threads, binding lifetime discovery threads and etc. The method may also be used
   * after a call to stop() as a reinitialization technique.
   */
  public void start() {
    // init stun
    String stunAddressStr = null;
    int port = -1;
    stunAddressStr = NetaddrActivator.getConfigurationService().getString(PROP_STUN_SERVER_ADDRESS);
    String portStr = NetaddrActivator.getConfigurationService().getString(PROP_STUN_SERVER_PORT);

    this.localHostFinderSocket = initRandomPortSocket();

    if (stunAddressStr == null || portStr == null) {
      useStun = false;
      // we use the default stun server address only for chosing a public
      // route and not for stun queries.
      stunServerAddress = new StunAddress(DEFAULT_STUN_SERVER_ADDRESS, DEFAULT_STUN_SERVER_PORT);
      logger.info(
          "Stun server address("
              + stunAddressStr
              + ")/port("
              + portStr
              + ") not set (or invalid). Disabling STUN.");

    } else {
      try {
        port = Integer.valueOf(portStr).intValue();
      } catch (NumberFormatException ex) {
        logger.error(portStr + " is not a valid port number. " + "Defaulting to 3478", ex);
        port = 3478;
      }

      stunServerAddress = new StunAddress(stunAddressStr, port);
      detector = new SimpleAddressDetector(stunServerAddress);

      if (logger.isDebugEnabled()) {
        logger.debug(
            "Created a STUN Address detector for the following "
                + "STUN server: "
                + stunAddressStr
                + ":"
                + port);
      }
      detector.start();
      logger.debug("STUN server detector started;");

      // make sure that someone doesn't set invalid stun address and port
      NetaddrActivator.getConfigurationService()
          .addVetoableChangeListener(PROP_STUN_SERVER_ADDRESS, this);
      NetaddrActivator.getConfigurationService()
          .addVetoableChangeListener(PROP_STUN_SERVER_PORT, this);

      // now start a thread query to the stun server and only set the
      // useStun flag to true if it succeeds.
      launchStunServerTest();
    }
  }
 /**
  * The method queries a Stun server for a binding for the specified port.
  *
  * @param port the port to resolve (the stun message gets sent trhough that port)
  * @return StunAddress the address returned by the stun server or null if an error occurred or no
  *     address was returned
  * @throws IOException if an error occurs while stun4j is using sockets.
  * @throws BindException if the port is already in use.
  */
 private StunAddress queryStunServer(int port) throws IOException, BindException {
   StunAddress mappedAddress = null;
   if (detector != null && useStun) {
     mappedAddress = detector.getMappingFor(port);
     if (logger.isDebugEnabled())
       logger.debug(
           "For port:"
               + port
               + "a Stun server returned the "
               + "following mapping ["
               + mappedAddress);
   }
   return mappedAddress;
 }
 /**
  * The method queries a Stun server for a binding for the port and address that <tt>sock</tt> is
  * bound on.
  *
  * @param sock the socket whose port and address we'dlike to resolve (the stun message gets sent
  *     trhough that socket)
  * @return StunAddress the address returned by the stun server or null if an error occurred or no
  *     address was returned
  * @throws IOException if an error occurs while stun4j is using sockets.
  * @throws BindException if the port is already in use.
  */
 private StunAddress queryStunServer(DatagramSocket sock) throws IOException, BindException {
   StunAddress mappedAddress = null;
   if (detector != null && useStun) {
     mappedAddress = detector.getMappingFor(sock);
     if (logger.isTraceEnabled()) {
       logger.trace(
           "For socket with address "
               + sock.getLocalAddress().getHostAddress()
               + " and port "
               + sock.getLocalPort()
               + " the stun server returned the "
               + "following mapping ["
               + mappedAddress
               + "]");
     }
   }
   return mappedAddress;
 }
  /**
   * Kills all threads/processes lauched by this thread and prepares it for shutdown. You may use
   * this method as a reinitialization technique ( you'll have to call start afterwards)
   */
  public void stop() {
    try {
      try {
        detector.shutDown();
      } catch (Exception ex) {
        logger.debug("Failed to properly shutdown a stun detector: " + ex.getMessage());
      }
      detector = null;
      useStun = false;

      // remove the listeners
      NetaddrActivator.getConfigurationService()
          .removeVetoableChangeListener(PROP_STUN_SERVER_ADDRESS, this);

      NetaddrActivator.getConfigurationService()
          .removeVetoableChangeListener(PROP_STUN_SERVER_PORT, this);

    } finally {
      logger.logExit();
    }
  }