Passive TCP connections on OS assigned ports

[GoogleCodeExporter]

The opentransport.lisp module does not support ports assigned by the OS for 
passive connections. 

Developers should be able to let the OS determine the port instead of always 
having to specify the 
port when opening a TCP stream.

Original issue reported on code.google.com by terje.norderhaug on 3 Jan 2010 at 9:36

[GoogleCodeExporter]

The patch below implements the enhancement, allowing passive tcp streams with 
the port determined by the 
OS. It can be implemented better by upgrading #'ot-conn-tcp-passive-connect.

(ccl:advise ot-conn-tcp-passive-connect
            (destructuring-bind (conn port &optional (allow-reuse t)) arglist
              (declare (ignore allow-reuse))
              (if (eql port #$kOTAnyInetAddress)
                ;; Avoids registering a proxy for port 0 but instead registers one for the true port:
                (multiple-value-bind (proxy result)
                 (let* ((*opentransport-class-proxies* NIL) ; makes ot-find-proxy return NIL 
                        (result (:do-it)) ;; pushes onto *opentransport-class-proxies*
                        (proxy (prog1
                                 (pop *opentransport-class-proxies*)
                                 (assert (not *opentransport-class-proxies*))))
                        (context (cdr proxy))
                        (tmpconn (make-ot-conn :context context 
                                               :endpoint (pref context :ot-context.ref)))
                        (localaddress (ot-conn-tcp-get-addresses tmpconn)))
                   (declare (dynamic-extent tmpconn))
                   ;; replace original set in body of function
                   (setf (ot-conn-local-address conn) localaddress)
                   (values
                    (cons localaddress context)                    
                    result))
                  ;; need to be outside local binding of *opentransport-class-proxies* 
                  (without-interrupts
                   (push proxy *opentransport-class-proxies*))
                  result) 
                (:do-it)))        
         :when :around :name 'ot-conn-tcp-passive-connect-any-address)

;; should not be zero after ot-conn-tcp-passive-connect-any-address advise:

(with-open-stream (stream (open-tcp-stream NIL #$kOTAnyInetAddress 
:reuse-local-port-p nil))
  (stream-local-port stream))

Original comment by terje.norderhaug on 3 Jan 2010 at 9:41