Russ Allbery | 7 Apr 2009 21:41
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Re: Question about rejects by serving agents


Julien ÉLIE <julien <at> trigofacile.com> writes:

> In 3.7, a serving agent "MUST reject any article that does not include
> all the mandatory header fields or any article which contains header
> fields that do not have valid contents".
>
> Is there a reason why a serving agent MUST reject such articles?

If it served out such a message, it would be violating the protocol.
Clients should be able to assume that the serving agent won't give them
malformed articles.  (This is kind of true of relaying agents as well, but
since they only talk to serving agents, it's less critical.)

> I understand that injecting agents MUST (because it happens at the
> beginning) but what surprises me is that it is a SHOULD for relaying
> agents.

Relaying agents are often very stupid and don't really look at the
article.  We wrote the standard to allow for this because they're
speed-critical and some implementors don't like doing a full validation at
that stage.

--

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

Julien ÉLIE | 7 Apr 2009 23:39
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Re: Question about rejects by serving agents


Hi Russ,

>> In 3.7, a serving agent "MUST reject any article that does not include
>> all the mandatory header fields or any article which contains header
>> fields that do not have valid contents".
>>
>> Is there a reason why a serving agent MUST reject such articles?
>
> Clients should be able to assume that the serving agent won't give them
> malformed articles.  (This is kind of true of relaying agents as well, but
> since they only talk to serving agents, it's less critical.)

OK.

> Relaying agents are often very stupid and don't really look at the
> article.  We wrote the standard to allow for this because they're
> speed-critical and some implementors don't like doing a full validation at
> that stage.

That makes sense.  Thanks Russ.

--

-- 
Julien ÉLIE

« Ô temps suspends ton vol ! Et vous heures propices,
  Suspendez votre cours. » (Alphonse de Lamartine)


Gmane