On Fri, 30 May 2003, Christian Balzer wrote:
> What I'm looking at (and a search in the archives didn't reveal a
> past discussion about it) is that when you have a host list that
> includes (wildcard) host names, those host names will NOT be matched
> based on the result of the reverse lookup alone. Seems like when there
> is no forward entry for result of the reverse lookup at all, it will
> fail completely.
Depending on your operating system, this may be happening internally
inside the gethostbyaddr() (or equivalent) function. I certainly came
across some examples of this at some stage. The code of Exim contains
this comment:
/* This code was present in versions of Exim before 3.20. At that point
I took it out because I thought that gethostbyaddr() did the check
anyway. It turns out that this isn't always the case, so it's coming
back in at 4.01. This version is actually better, because it also checks
aliases. */
> Could we please (with sugar and cream on top) have something along
> the lines of a "+reverse_only" option for host lists?
I do not like this idea because of the fact that it would work only on
some operating systems. And knowing the way things change, it might stop
working for a new OS release.
Maybe you can use the dnsdb lookup type to build your own checks?
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
Get the Exim 4 book: http://www.uit.co.uk/exim-book
