[Pdns-users] HINFO records corrupted

[Volker Goetz]

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Hallo,

Am Montag, 5. April 2004 21:29 schrieb Volker Goetz:
> HINFO records are corrupted by PowerDNS (Version 2.9.16). Both the
> server (pdns_server) and the optional recursor (pdns_recursor) are
> affected.
>
> The content of HINFO records are not parsed correctly leading to garbage
> in a query to the resolver. When doing slave service for some zone with
> HINFO records in it, the database rejects the garbage in the content
> field (invalid unicode characters for PostgreSQL, other backends may
> give different errors). In case of the bind backend the garbage is
> written to the zone file, which in turn is unparseable.

I've investigatet further into this problem and found out that the contents 
are parsed wrong in DNSPacket::addHINFORecord. A rudimentary workaround 
for me is to change the generation of host's contents like that:

  if(offset==string::npos) {
    cpu=content;
  } else {
    cpu=content.substr(0,offset);
    host=content.substr(offset+2, (unsigned int)content[offset+1]);
  }

As far as I've seen, from some data dump, the host content ist prefixed 
with a lenght byte (which is at offset + 1). With this hack the cpu and 
host part of the hinfo content are displayed correctly. Unfortunately, it 
discards the additional and authority data and may have other impacts.

I have far too less knowledge on dns records and network packets, so I 
can't help with more patches/hacks.

Are there any plans to correct the bug? I'd like to be able to use pdns as 
slave server for zones with hinfo records, which is absolutely impossible 
at the moment.


- -- 

Best regards

Volker Götz

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section(one               Mail goetz at sectionone.de
Dipl.-Inform. Univ.       Web  http://www.sectionone.de/
Volker Götz               Tel. +49 30 / 40 00 67 9-0
Rosa-Luxemburg-Straße 15  Fax  +49 30 / 40 00 67 9-15
D-10178 Berlin            PGP  4FEB1C34 @ wwwkeys.de.pgp.net
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