search

PowerDNS / pdns

PowerDNS Authoritative, PowerDNS Recursor, dnsdist
https://www.powerdns.com/
GNU General Public License v2.0
3.7k stars 908 forks source link

DNSAction.Spoof TTL #9307

Open jonlmcdonald opened 4 years ago

jonlmcdonald commented 4 years ago

Short description

Allow DNSAction.Spoof to specify TTL. This would be similar to recursor's dq:addAnswer.

Usecase

I have lists in a database that are used for allow/block. When blocked, a spoofed response is returned. Setting TTL=1 would allow changes (allowlist) to be made without delay.

Description

Add a TTL setting to DNSAction.Spoof.

rgacogne commented 4 years ago

This has been implemented in https://github.com/PowerDNS/pdns/pull/8722 and will be available in 1.5.0 (available as 1.5.0-rc4 at the moment), as documented at 1.

jonlmcdonald commented 4 years ago

How would this be used in Lua? Where would the TTL be specified in the following example?

return DNSAction.Spoof, "some.domain.com"

Habbie commented 4 years ago

Hi, you're commenting on a closed ticket. Such comments tend to get ignored if they are not noticed immediately.

I also don't have the answer for you right now. Best to come back to IRC :)

rgacogne commented 4 years ago

I read that report too quickly and incorrectly assumed it was about SpoofAction, please accept my apologies!

rgacogne commented 4 years ago

It's a bit complicated by the fact that Lua rules can only return a single string, and changing that would be a bit cumbersome. Since we support returning a list of IP addresses separated by a comma, we would need to find a way to pass the TTL in that string without making the parsing too brittle. Perhaps something like "<IP 1>, <IP 2>, ... <IP N> - <TTL>".