Dnscache

Simple DNS proxy supporting one upstream. Designed for using slow and unreliable upstream DNS servers like Tor's DNS resolver. Trades consistency for availability. Not for serious use.

License = MIT or Apache 2.0

``` dnscache 0.1.0 Vitaly _Vi Shukela vi0oss@gmail.com Simple DNS cacher.

USAGE: dnscache [OPTIONS]

FLAGS: -h, --help Prints help information -V, --version Prints version information

OPTIONS: --neg-ttl Negative reply TTL, seconds [default: 30]

ARGS: Listen address and port Upstream DNS server address and port Path to LevelDB database directory ```

Features:

• IPv6 AAAA records
• Forwarding of trickier queries as is
• Multi-question queries
• Minimal protection from poisoning by filtering domain names in replies
• Always tries to immediately return some A or AAAA records for client to try, no waiting for refreshing.

Notes:

• It does not construct DNS requests on its own, it reuses client-constructed packets
• Uncached queries (non-A, non-AAAA or non-IN) are forwarded based in ID
• TTL may be 0 in replies
• Single threaded, single UDP socket

Concerns:

• ID field is handled inconsistently
• Entries are never deleted from cache
• If data is stale, it first replies with TTL 0, then re-checks in upstream
• The used LevelDB implementation is not recommended for serious use yet.
• The same socket used both for client and for upstream communication. Can't listen only on 127.0.0.1, but rely on 8.8.8.8.