Re: [exim] Disk failure => 5xx error code

On Fri, 31 Mar 2006, John Rowe wrote:

> > I presume you are, however, using one or both of
> > those?
>
> Yes, tcpwrappers.

<snip>

> It must be a good sign that the question is "what is the best way to
> behave when there's a total system disk failure?"!

I have just looked into this a bit more. The only interface between Exim
and tcpwrappers is a call to the latter's hosts_ctl() function. This
function returns 0 when access is to be denied. This is what provokes
Exim into giving the 5xx error. There appears to be no interface for
getting back any other information. Therefore, I believe that the
original problem is a failing in the interface to tcpwrappers because it
can't say "unable to check at present, please give a temporary error".
(This is no doubt because in the uses for which it was designed, the
only requirement was for yes/no rather than yes/no/maybe.)

I don't think there is anything I can do about this in Exim -- unless
there are any tcpwrappers experts out there who know better...

Philip

--
Philip Hazel, University of Cambridge Computing Service.