Date: Mon, 3 Oct 1994 10:17:38 +0100
Message-Id: <199410030916.KAA14958@wsinis10.win.tue.nl>
From: reinpost@win.tue.nl (Reinier Post)
To: Multiple recipients of list <www-proxy@www0.cern.ch>
Subject: proxy must tell client not to use it (was: security)
Jeroen Vanheste writes:
>What I meant was that I want *the server* to be able to decide that he will
>not be proxy-server for certain client-destinations combinations.
The client decides which proxy is called; at the moment this is not very
configurable, but even if it were, it would still be a matter of client
configuration. There is no way for a (proxy) server to tell the client
to get a document elsewhere. This would require a change in the HTTP
protocol, or a separate communication mechanism between client and (proxy)
server. The present Redirect response cannot be used by a proxy server to
indicate that it refuses to act as a gateway for the document. One
possibility would be to create a new type of redirection pointing to a
standard document on the proxy server describing which URLs are being served
to which clients. It may be sufficient to improve the level of detail
at which clients select various proxies for various URLs. This configuration
can then be done manually by the administrator of the client's site.
Or client software can be taught to fetch the document on the proxy and
reconfigure itself accordingly.
Anyhow, presently there is no way for the server to communicate the relevant
information to the client, or for the client to respond to it.
(Sorry, can't resist:
If you're really desperate for a workaround, teach the proxy server to
translate its links, instead of making the client call a proxy automatically.
In this way the server can control whether or not it is going to be called
for descendants of a document. This is the way my cache program used to work
before the proxy mechanism existed, and the functionality is still there. See
for details.)
-- Reinier Post reinpost@win.tue.nl a.k.a. <A HREF="http://www.win.tue.nl/win/cs/is/reinpost/">me</A>