(no subject)

>From listmaster  Fri Dec 16 21:37:31 1994
To: uri@bunyip.com
Subject: ftp URLs
Date: Fri, 16 Dec 1994 18:36:21 -0800
From: "Roy T. Fielding" <fielding@avron.ICS.UCI.EDU>
Sender: owner-uri@bunyip.com
Precedence: bulk

Since most people on this list don't subscribe to www-proxy, I thought
I'd forward this message here.  I think it demonstrates the problem
of describing ftp as a sequence of CWD commands without also saying that
the client should first attempt RETR /full-path and only attempt the separate
CWD commands if the RETR fails.

In this case, the proxy is following the URL spec's behavior and failing,
but it works just fine with XMosaic.

......Roy Fielding   ICS Grad Student, University of California, Irvine  USA
                                     <fielding@ics.uci.edu>
                     <URL:http://www.ics.uci.edu/dir/grad/Software/fielding>

------- Forwarded Message

Date: Fri, 16 Dec 1994 23:47:20 +0100
Message-Id: <9412162233.AA13092@godot.pa.dec.com>
Reply-To: steveg@pa.dec.com
Sender: www-proxy@www0.cern.ch
Precedence: bulk
From: steveg@pa.dec.com
To: Multiple recipients of list <www-proxy@www0.cern.ch>
Subject: proxies and FTP


We are having difficulties with our proxy when we try to get to 
the url:
  ftp://reports.adm.cs.cmu.edu/usr/anon/1994/CMU-CS-94-100.ps
or
  ftp://reports.adm.cs.cmu.edu/%2fusr/anon/1994/CMU-CS-94-100.ps
or
  ftp://reports.adm.cs.cmu.edu//usr/anon/1994/CMU-CS-94-100.ps

We are running a CERN 3.0 proxy on our external corporate firewall.

The problem occurs because "reports.adm.cs.cmu.edu" automatically 
cd's to /usr/anon on anonymous ftp connections.  A cd to "/usr/anon/1994" 
succeeds but a "cwd /; cwd usr; cwd 1994;" style FTP command sequence 
is forbidden for security reasons. 

The URL - ftp://reports.adm.cs.cmu.edu/1994/CMU-CS-94-100.ps - does 
work, but I doubt it works for non-proxied browsers.

So the questions are:

1) According to the URL spec 
(http://ds.internic.net/internet-drafts/draft-ietf-uri-url-08.txt)
the second of the 3 methods given above should work.  Does the request 
fail because the proxy is going through a series of FTP "cwd" commands 
rather than a single "cwd"?

2) Do "standard" browsers do the right thing with FTP requests?  
i.e. does ftp://reports.adm.cs.cmu.edu/1994/CMU-CS-94-100.ps work 
is you are not going through a firewall?  Or do other browsers "cwd 
/1994" rather than "cwd 1994" (as the spec claims?).

3) Is there some other way out of this mess?

Steve
steveg@pa.dec.com

------- End of Forwarded Message

Received on Saturday, 17 December 1994 01:47:23 UTC