anchor.diff:  
   (defclass tcp-connection ()
     ((%state :accessor tcp-connection-%state :initarg :%state)
  -   (direction :accessor tcp-connection-direction :initarg :direction)
      (local-port :accessor tcp-connection-local-port :initarg :local-port)
      (local-ip :accessor tcp-connection-local-ip :initarg :local-ip)
      (remote-port :accessor tcp-connection-remote-port :initarg :remote-port)
  
positive.code:                (t
                  ;; Aborting connection
                  (tcp4-send-packet connection ack seq nil :rst-p t)
                  (setf (tcp-connection-state connection) :connection-aborted
                        (tcp-connection-direction connection) nil)
                  (detach-tcp-connection connection))))
          (:syn-received
           ;; Pasive open
  
negative.code:                         (logtest flags +tcp4-flag-fin+))
                 ;; Remote have sended FIN and waiting for ACK
                 (setf (tcp-connection-state connection) :close-wait
                       (tcp-connection-r-next connection)
                       (logand (+ (tcp-connection-r-next connection) 1)
                               #xFFFFFFFF))
  