[rbldnsd] Extracting 'hidden' TXT records

[furio ercolessi]

[ For the series 'weird questions' ]

I illustrate the point with an example taken from SBL.
61.143.182.145 is currently contained three times in SBL:

http://www.spamhaus.org/sbl/sbl.lasso?query=SBL13628  for 61.143.182.145/32
http://www.spamhaus.org/sbl/sbl.lasso?query=SBL14180  for 61.143.182.144/28
http://www.spamhaus.org/SBL/sbl.lasso?query=SBL12684  for 61.143.176.0/20

That is quite common: it is a hierarchy of escalations.

Now, a TXT query returns only the first two:
;; ANSWER SECTION:
145.182.143.61.sbl.spamhaus.org.  2H IN TXT  "http://www.spamhaus.org/SBL/sbl.lasso?query=SBL14180"
145.182.143.61.sbl.spamhaus.org.  2H IN TXT  "http://www.spamhaus.org/SBL/sbl.lasso?query=SBL13628"

This happens also for Bind nameservers, and it is perfectly understandable:
the /20 listing really is sixteen /24 listings, and a /24 listing is 
overridden by a /32 listing.

Good.  Now suppose that I want to build an application that tries to
return all listings relative to a given IP, possibly by performing
multiple queries.  How to check explicitly for the presence of 
a /24 (or larger) listing?

With Bind, it can be done:

% dig txt '*.182.143.61.sbl.spamhaus.org' @204.152.184.189
;; ANSWER SECTION:
*.182.143.61.sbl.spamhaus.org.  2H IN TXT  "http://www.spamhaus.org/SBL/sbl.lasso?query=SBL12684"

but if I try to do the same with rbldnsd I get no answer.  I tried
fooling it with '256.182.143.61.sbl.spamhaus.org' but rbldnsd is too
smart to be tricked, and still get no response.

The question is: is there any trick to extract this information 
(presence of /24 listing when /32 listings are present) out of rbldnsd?

furio