From: Charles Lindsey (chl@clerew.man.ac.uk)
Date: Fri Feb 06 2004 - 06:10:04 CST
In <BC473F44.C717%planb@newsreaders.com> "J.B.Moreno" <planb@newsreaders.com> writes:
>On 2/4/04 8:43 AM, Charles Lindsey at <chl@clerew.man.ac.uk> wrote:
>> Russ Allbery <rra@stanford.edu> writes:
>>> No, if we're using injection-date for the staleness check, it may not ever
>>> be overwritten or modified, for the same reason that we require the server
>>> not modify the Date header. Doing anything else breaks Usenet's loop
>>> detection algorithm and potentially allows reinjection of stale messages.
>>
>> No, I don't think it is as simple as that. We need to analyze the reasons
>> why double injection occurs. My belief is that the commonest cause will be
>> because there is confusion or disagreement as to who is doing the actual
>> injection (and especially so since INN has implemented "IHAVE for anybody"
>> which either injects or relays according to how well it trusts the
>> client).
>That's a certainly a contributing cause, but fundamentally it's irrelevant
>-- the problem is accepting stale messages. The only way to see how fresh
>an article is is to have a header that contains a timestamp, replacing that
>timestamp with a newer one, for whatever reason, can result in double
>injection.
Hmmmmm! Maybe. That is certainly the safest option, insofar as it will
never go _wrong_. But that does not ensure that it always goes _right_.
Some otherwise safe articles are going to get lost / dropped / rejected /
poorly propagated.
My concern was the man with the broken posting agent which inserted an
Injection-Date-header when it shouldn't. Or maybe his machine really was
the injector and he normally had it connected permanently to the internet
and used IHAVE to his upstream. But now he is away from home. The article
is on his laptop and he carries it around for a couple of days until he
finds somewhere to plug it in (and that 'somewhere' does not accept his
IHAVE and regards itself as the true injecting agent). Or maybe he is
still at home, but his telephone line has been down for a couple of days.
So it seems that we just have to say to him "Tough! Usenet is like that".
-- Charles H. Lindsey ---------At Home, doing my own thing------------------------ Tel: +44 161 436 6131 Fax: +44 161 436 6133 Web: http://www.cs.man.ac.uk/~chl Email: chl@clerew.man.ac.uk Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K. PGP: 2C15F1A9 Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5