Re: [Sbcl-help] socket-send

[Alexey D. <ade...@to...>]

Patrick May <pj...@sp...> writes:

> A recent post on Usenet described a problem with socket-send and  
> broadcast messages.  I've been playing around with it, but can't seem  
> to crack it.  Here's what I've got:
>
> (defparameter *broadcast-ip-address* #(192 168 0 255))
> (defparameter *broadcast-port* 1234)
>
> (defmacro with-udp-broadcast-socket (socket ip-address port &body body)
>    "Create and close a UDP socket configured for broadcast around the  
> body."
>    `(let ((,socket (make-instance 'inet-socket
>                                   :type :datagram
>                                   :protocol :udp)))
>       (setf (sockopt-broadcast ,socket) t)
>       (socket-bind ,socket ,ip-address ,port)
>       (unwind-protect (progn ,@body)
>         (socket-close ,socket))))
[...]
> with-udp-broadcast-socket socket *broadcast-ip-address* *broadcast-port*
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                      These should be local address and port, not destination.
>    (socket-send socket "test" nil
>                 :address '(*broadcast-ip-address* *broadcast-port*)))
>
> fails with the message:  *BROADCAST-IP-ADDRESS* can't be converted to  
> type (SIMPLE-ARRAY (UNSIGNED-BYTE 8) (4)).

A symbol is not an array :-)

(with-udp-broadcast-socket socket *broadcast-ip-address* *broadcast-port*
    (socket-send socket "test" nil
                 :address (list *broadcast-ip-address* *broadcast-port*)))


-- 
Regards,
Alexey Dejneka

"Alas, the spheres of truth are less transparent than those of
illusion." -- L.E.J. Brouwer