Milter-greylist

reschauzier wrote:
 > Oliver Fromme wrote:
 > > Furthermore, a lot of internet access providers use the
 > > hexadecimal IP (instead of decimal) for the reverse look-
 > > up of their pools.  So it's probably a good idea to add
 > > a similar regular expression that matches IP addresses
 > > expressed in hexadecimal, for example:
 > > 
 > > [0-9a-f]{2,2}[-.]?[0-9a-f]{2,2}[-.]?[0-9a-f]{2,2}[-.]?[0-9a-f]{2,2}
 > > 
 > > (Note that milter-greylist uses case-insensitive matches,
 > > so it's not necessary to say "[0-9A-Za-z]".)
 > > 
 > > That will match things like 5f-8b-23-cd.dsl.example.com,
 > > 5f8b23cd.cable.foo.net, and even 5f-8b.23-cd.dyn.bar.org
 > > or 5f8b-23cd.pool.baz.biz.
 > 
 > Unfortunately, it will also match web307045.mail.mud.yahoo.com, which
 > is a very valid mailer.

Is it?

$ host web307045.mail.mud.yahoo.com
Host web307045.mail.mud.yahoo.com not found: 3(NXDOMAIN)

I'm also not too worried about greylisting Yahoo, but
that's another story.  :-)

 > In order to reliably detect hex addresses
 > without separators, you'd need two passes of regexes: the first to
 > identify a string of 8 hex numbers, and then a second one to make sure
 > there is at least one non-decimal number in that string.

I don't quite understand what you mean, could you please
explain?  What do you mean, "at least one non-decimal
number", and how does it apply to your example "web307045"?

I think it would make sense to whitelist hosts that contain
the word "mail" somewhere in the name, e.g. /mail.*\..*/.
That whitelist entry should be placed before the greylist
entry for decimal/hexadecimal matching of dynamic address
pools, so it is checked first for a match.  It would help
in the case of "web307045.mail.mud.yahoo.com".  Usually
the names of dynamic address pools don't contain the word
"mail".

 > I don't think
 > this is possible with milter-greylist at this time.

I think a lot of things are possible with milter-greylist.
:-)

Best regards
   Oliver

-- 
Oliver Fromme,  secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
Dienstleistungen mit Schwerpunkt FreeBSD: http://www.secnetix.de/bsd
Any opinions expressed in this message may be personal to the author
and may not necessarily reflect the opinions of secnetix in any way.

PI:
int f[9814],b,c=9814,g,i;long a=1e4,d,e,h;
main(){for(;b=c,c-=14;i=printf("%04d",e+d/a),e=d%a)
while(g=--b*2)d=h*b+a*(i?f[b]:a/5),h=d/--g,f[b]=d%g;}