Subject: Re: Negotiated noncompliance

From: Charles Lindsey <[email-masked]>
Date: Thu, 17 Aug 2000 10:01:10 +0100 (BST)

On Wed, 16 Aug 2000 16:41:38 -0700
	Dave Crocker <[email-masked]> said...

> 
> >  If an implementation receives protocol which is not
> >permitted by the specification and the specification does not mandate
> >the response to such illegal protocol, the implementation MAY consider
> >the peer to have negotiated a nonstandard protocol.
> 
> 
> In other words, a receiver is free to handle errors in any way it deems 
> appropriate, unless the specification explicitly defines the handling of 
> this particular effort.

That indeed seems a messy way to handle it. We know some implementations
are going to do this sort of thing, whether we like it or not.

In Netnews, we have the concept of a "cooperating subnet" who agree
amongst themselves to implement "some variant of the defined protocols".
It is a convenient bucket into which to sweep all those odd little
quirks which individual sites may adopt, and doing so without drawing
attention to them by verbiage visible in the text of the document. That
would be the real damage - drawing attention to possible loopholes will
only encourage people to open them up.

The most I would do is to say that you MUST generate proper stuff, and
you SHOULD NOT accept improper stuff (I agree that people who want to
say MUST NOT accept improper stuff are going too far).
> 
> Besides being on the wrong side of a slippery slope, this sort of language 
> will only serve to make the distinction between "in spec" and "out of spec" 
> more confused than it already is.

Exactly. I oppose the wording suggested, but have no problem with
opening up the discussion in more general terms.

Charles H. Lindsey ---------At Home, doing my own thing------------------------
Email:     [email-masked]  Web:   http://www.cs.man.ac.uk/~chl
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---

From: Charles Lindsey <[email-masked]>
Date: Thu, 17 Aug 2000 19:23:41 +0100 (BST)

On Thu, 17 Aug 2000 01:47:50 -0700
	Dave Crocker <[email-masked]> said...

> Absent the details of what constitutes "great care", what does a reader 
> learn that they did not already know?

Clueful readers learn nothing. However, it would not be wise to assume
all implementors are clueful, so a little hand holding may not come
amiss.

---

From: Barry Finkel <[email-masked]>
Date: Wed, 30 Aug 2000 15:56:08 -0500 (CDT)

Someone proposed this text:

> 
> An implementation which receives protocol which is not permitted
> by the specification SHOULD (if it is a client) abort the attempt
> to send the message and (if it is a server) reject the command
> with an appropriate status code (rather than assume that the
> non-complaint server will deliver the message). 

I would change the two occurrences of "which" in the first line to 
"that",
----------------------------------------------------------------------
Barry S. Finkel
Electronics and Computing Technologies Division
Argonne National Laboratory          Phone:    +1 (630) 252-7277
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