[rbldnsd] multiple TXT element answers?

[Kai Schlichting]

On Wed 05/17/06 at 4:20 AM, "Michael Tokarev" <mjt at corpit.ru> wrote:

> Kai Schlichting wrote:
>> $ dig  1.55.5.12.asn.routeviews.org txt
>> [...]
>> ;; ANSWER SECTION:
>> 1.55.5.12.asn.routeviews.org. 84426 IN  TXT     "12163" "12.5.48.0" "21"
>> 1.55.5.12.asn.routeviews.org. 84426 IN  TXT     "12163" "12.5.54.0" "23"
>> 
>> (the zone returns all hits, not just "patricia trie"-like longest prefix match)

> It's ip4set.  So far so good.  I wonder what's the right-hand 'value' and why
> the digits are different.. but that's another question.

sorry, I wasn't clear enough. The above 3 TXT fields are, in order:
- origin ASN
- network number
- prefix length

e.g: 12.5.55.1 lives in 12.5.48.0/21 (and 12.5.54.0/23), with both prefixes
announced by AS 12163

Have a look at http://linuxmafia.com/~karsten/Download/procmail-asn-header for
some rather simplistic use.

>> Is there a way to get what I need in order to be a mirror for this zone?

> Not currently.  Oh well.

> It's not difficult to add the code to do so, but I've two questions
> before:

>  1) is it really needed?  See above - I don't know what those numbers
>    mean, and if the structure is really necessary (maybe just space-
>    separating list is sufficient.. modulo the historical stuff and
>    existing users).

it would be a novel use for rbldnsd - possibly opening the door to
more creative DNS uses than strictly for DNSBLs.

When the routeviews.org-guys designed this DNS-based service (not a DNSBL,
by any means), it was designed with the limitations of BIND - unfortunately
users tend to follow and program code that makes use of the data as
presented, so yes: this is essentially to accommodate an established,
yet inconvenient format due to current use.


>  2) how to specify those chunks in the data files, preserving
>     existing usage/users?  One idea comes to mind: if TXT template
>     starts with double-quote, treat it as a series of chunks...

what level of effort would be required for this on your part?

I am still investigating and in the process of 'selling' this idea
(to use rbldnsd instead of the BIND-clunk) to the routeviews.org folks -
so you indicating "yeah, I can hack that into the code in the next 2 hrs"
would certainly give me proper direction....

Thanks,
bye,Kai