tinydns runs chrooted in the directory specified by the $ROOT environment variable, under the uid and gid specified by the $UID and $GID environment variables.
tinydns listens for incoming UDP packets addressed to port 53 of $IP. It discards packets from low ports other than 53. It does not listen for TCP queries.
tinydns rejects inverse queries, non-Internet-class queries, truncated packets, and packets that contain anything other than a single query. It looks up other queries inside data.cdb, a binary file created by tinydns-data.