ietf-nntp POST and IHAVE responses (was: Commetns on draft-15.pdf)

[Russ Allbery]

Charles Lindsey <chl at clw.cs.man.ac.uk> writes:

> P33. S9.3.1.1 (POST responses)

> If an article is POSTed, and the server can discover, in real time, that
> it is syntactically invalid, or breached site policy, or whatever, does it
> return 441, or do we need to invent a 541 response (there would surely be
> no point in trying to send it again)?

As discussed in the other thread, I think that POST's response codes
should be left alone.

> There is also a remark in S9.3.2 (IHAVE) that some servers may not be
> able to provide such responses in real-time. Should that remark not
> appear here also, since it seems to apply equally to POST?

The IHAVE comment is somewhat confusingly worded; it assumes that servers
work like C News.  It's not a significant problem, but I think it could be
worded better.  And looking at it more closely, this issue is dealt with
in a couple of places in 9.3.2 and the latter comment is much clearer.

I propose simply removing this portion of section 9.3.2:

    However, the server MAY elect not to post or forward the article if
    after further examination of the article it deems it inappropriate to
    do so. Reasons for such subsequent rejection of an article may include
    such problems as inappropriate newsgroups or distributions, disk space
    limitations, article lengths, garbled headers, and the like. These are
    typically restrictions enforced by the server host's news software and
    not necessarily the NNTP server itself.

because the end of the last paragraph says the same thing more succinctly.

With IHAVE, generally the other server doesn't particularly care whether
or not the article was posted, but with POST, it's actually important to
let the client know that the article is invalid.  The exception is
generally only for dealing with spam, where the intention is to make the
server be deceptive to try to fool a spammer.

This sounds like a textbook example of a case where SHOULD is the
appropriate term, since there are reasons why a server may not want to
follow the constraint.  I propose adding to the end of the third paragraph
after:

    Note that response codes 340 and 440 are used in direct response to
    the POST command. Others are returned following the sending of the
    article.

the following new text:

    A response of 240 SHOULD indicate that barring unforseen server errors
    the posted article will be made available on the server and/or
    transferred to other servers as appropriate.  In other words, articles
    not wanted by the server SHOULD be rejected with a 411 response and
    not accepted and silently discarded.

Intentionally deceptive spam filters can then be left as a conscious
decision to not abide by SHOULD, which is explicitly allowed in the
definition of SHOULD.

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>