[blechschmidt]

I have not heard about tindydns before but it seems to be a DNS server, not a client.

The tool has mainly been tested on a Hetzner EX41 server. (Ubuntu, Intel® Core™ i7-6700, 32 GB RAM)

[otterley]

Have you tried c-ares? http://c-ares.haxx.se/

[blechschmidt]

Not yet. I have had a quick look at ldns (https://www.nlnetlabs.nl/projects/ldns/) which supports parsing DNS packets from wire. I will probably replace the DNS implementation with either libldns or c-ares.

[otterley]

ldns is synchronous so all your queries will block. libunbound (https://www.unbound.net/documentation/libunbound.html), like c-ares, is an async C resolver library from the authors of ldns.

[blechschmidt]

Ah, that would mean that I would have the libraries handle the resolving. I was currently only thinking about keeping the single socket which is used in order to only use the parsing functions from the libraries.

[otterley]

Ah, you are correct. There is also dnscache, which is part of the same suite. However, it does not do what you are attempting to do.