Mooncell

A DNS over HTTPS proxy/bridge.

It receives DNS requests (over UDP and TCP) and resolves them using a user selected provider.

Requirements for 1.0

• [x] Full end-to-end resolution
• [x] Configurable port to listen on
• [x] Support for UDP requests
• [ ] Support for TCP requests
• [x] Built in list of providers to pick from
• [x] DNS-over-HTTPS via JSON
• [ ] Handle resolution errors by returning an empty response
• [x] Switch to Rust 2018

Follow-up features

• [ ] Adopt Rust official tooling for code formatting/styling (rustfmt, clippy, ...)
• [ ] A configurable, local cache (in memory to begin with, then look into file backed)
• [ ] DNS-over-HTTPS via binary message
• [ ] User-configurable provider
• [ ] Reach providers via IP, not via FQDN (i.e. resolve at launch, then send Host header)

Related documentation

IETF

• IETF draft
• IETF draft tracker

(Stable) Providers of DNS-over-HTTPS

• Google
• Cloudflare
• Quad9
• Rubyfish
• BlahDNS

DNS protocol

• Protocol and format
• Message Header and Question Section Format
• Let's hand write DNS messages

Other

• curl DoH wiki/tracker
• Rust doh-proxy (similar project to this one)

Compiling

Windows (x64)

1. Install OpenSSL for Windows 64 bit via the large dev binaries, or in one of the other possible, painful ways
2. Set varialbe set OPENSSL_DIR=c:\OpenSSL-Win64 (assuming you installed it in the default path)
3. cargo build should now work

Personal notes

• ~~Both Processor and Server are services (similar to Guava services): you are suppose to start them, stop them and (optionally) wait for them to terminate. I think there is a good case here for implementing a tiny crate that provides Trait(s) for services a la Guava.~~ UPDATE: Created srvzio and now Mooncell's services are based on it.
• I made everything with Threads, but by the end I expect to rewrite everything using proper Rust async/await. I just could not surmount the Tokio + Hyper learning curve while also doing the same for the Rust language itself.