DNS server based on https://www.ietf.org/rfc/rfc1035.txt spec.
Notes:
- UDP used for connections.
- Each request is handled on a separate go routine.
- Local cache holds up to 10000 items, items are evicted based on TTL.
- Block urls using block.txt, exact match only, add each url on a separate line.
- Logs are written to dns-{date}.log in the exe path.