[Pdns-users] Recursor : Lua & udpQueryResponse questions

GAVARRET, David david.gavarret at sfr.com
Tue Jun 4 21:38:21 UTC 2019


I'm playing around the "udpQueryResponse" feature of the Recursor to implement an automatic domain search for short hostnames (on dedicated internal resolvers used by our operational teams). 
I have implemented it in the "nxdomain" hook.

Everything works great, but I have 2 questions :

1/ what is the timeout of a "udpQueryResponse" call via dq.followUpFunction ? is there any relationship with the "network-timeout" parameter ?

2/ my answer is a CNAME (with the FQDN found) with a specific TTL ("cnameTTL=345600") and with a followCNAMERecords follow-up function :
        dq:addAnswer(pdns.CNAME, dq.udpAnswer, cnameTTL)
        dq.rcode = 0

But it seems that the response is only cached in the Packet Cache, because 1 hour after the first udp server call, the resolver executes the udp server call again, and 1H is my default "packetcache-ttl" value.
Maybe it's the wanted behaviour because I use the "nxdomain" hook ?
Is there an implementation that may put my answer in the Record Cache (with respect of my TTL) ?

Thanks in advance for your explanations.

Best regards,
David Gavarret

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