serve rDNS if there is no fDNS

[SkyperTHC]

Serve rDNS (in-PTR) if there is no fDNS.

Can we store BOTH value in DB?
Can we store TIMESTAMP and should be just store the LAST rDNS or historical value.

...or also scan and serve TLS CN & SAN. Perhaps even scan unresolved domains with:

echo 185.199.108.153 | tlsx -san -cn -nc -retry 1

or (in real-time; for every requests for which we dont have an answer), forward the request to host.io/ipinfo.io (??).

Can we log how often we 'fail to serve an answer' and then deal with the "most IPs for which we cant serve data" either manually or host.io/ipinfo.io?

[messede-degod]

failed requests (RDNS/Subdomains/CNAMEs) are now being logged.