[Pdns-users] exception building answer packet

[Steve Atkins]

> On Mar 25, 2016, at 7:15 AM, Peter van Dijk <peter.van.dijk at powerdns.com> wrote:
> 
> Hello Steve,
> 
> do you still have the ‘broken’ database contents from before your rectify? Those would be useful in figuring out whether there’s a bug!

I have several backups that might have that data. I'm planning on building a test server and loading them up to see if I can replicate the problem. If I get a test case I'll share.

Cheers,
  Steve

> 
> Kind regards,
> -- 
> Peter van Dijk
> PowerDNS.COM BV - https://www.powerdns.com/
> 
> On 25 Mar 2016, at 4:07, Steve Atkins wrote:
> 
>> pdnssec rectify-zone makes the problem go away, which fixes it for me.
>> 
>> It feels like there's still an underlying bug somewhere in the dnssec sql or surrounding code, though.
>> 
>> Cheers,
>>  Steve
>> 
>>> On Mar 24, 2016, at 7:54 PM, Steve Atkins <steve at blighty.com> wrote:
>>> 
>>> I'm using a postgresql backend, and I have several zones configured to use dnssec.
>>> 
>>> Queries for resource records that exist work perfectly. The verisign online checker says my dnssec is good.
>>> 
>>> If I query for a resource record that doesn't exist without using dnssec - either one where there are no RRs with a matching name or one where there are RRs with a matching name but none also have a matching type - I get the expected NXDOMAIN or NOERROR result.
>>> 
>>> If I run the same query with dnssec then I get a servfail.
>>> 
>>> With log level 9, and log-dns-details and log-dns-queries on, I get this in the log:
>>> 
>>> Mar 24 19:35:49 ns pdns[30538]: Remote 184.105.179.144 wants 'foo.blighty.com|A', do = 1, bufsize = 1680: packetcache MISS
>>> Mar 24 19:35:49 ns pdns[30538]: Exception building answer packet (Unknown DNS type '.blighty.com') sending out servfail
>>> 
>>> I see this with version 3.4.6 and 3.4.8. It looks like someone else had a similar issue here: https://mailman.powerdns.com/pipermail/pdns-users/2015-October/011747.html
>>> 
>>> It's a new installation, but the data has been around for a few years. There are no custom SQL queries.
>>> 
>>> There is no record in the database with type '.blighty.com' - all non-null types are expected A, TXT, PTR, etc. There are some records where the type is null, though.
>>> 
>>> Clearly it's getting garbage from the database, but only when building a dnssec response where there are no matching RRs.
>>> 
>>> Before I set up a testbed server to work out what's going on, does any of this ring any bells with anyone?
>>> 
>>> Cheers,
>>> Steve
>>> 
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>> 
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