9caca475dc
Currently, `tunnel_test` uses a rather naive approach when dispatching `Transmit`s. In particular, it checks client, gateway and relay separately whether they "want" a certain packet. In a real network, these packets are routed based on their IP. To mimic something similar, we introduce a `Host` abstraction that wraps each component: client, gateway and relay. Additionally, we introduce a `RoutingTable` where we can add and remove hosts. With these things in place, routing a `Transmit` is as easy as looking up the destination IP in the routing table and dispatching to the corresponding host. Our hosts are type-safe: client, gateway and relay have different types. Thus, we abstract over them using a `HostId` in order to know, which host a certain message is for. Following these patches, we can easily introduce multiple gateways and relays to this test by simply making more entries in this routing table. This will increase the test coverage of connlib. Lastly, this patch massively increases the performance of `tunnel_test`. It turns out that previously, we spent a lot of CPU cycles accessing "random" IPs from very large iterators. With this patch, we take a limited range of 100 IPs that we sample from, thus drastically increasing performance of this test. The configured 1000 testcases execute in 3s on my machine now (with opt-level 1 which is what we use in CI). --------- Signed-off-by: Thomas Eizinger <thomas@eizinger.io>
relay
This crate houses a minimalistic STUN & TURN server.
Features
We aim to support the following feature set:
- STUN binding requests
- TURN allocate requests
- TURN refresh requests
- TURN channel bind requests
- TURN channel data requests
Relaying of data through other means such as DATA frames is not supported.
Building
You can build the relay using: cargo build --release --bin firezone-relay
You should then find a binary in target/release/firezone-relay.
Running
The Firezone Relay supports Linux only. To run the Relay binary on your Linux host:
- Generate a new Relay token from the "Relays" section of the admin portal and save it in your secrets manager.
- Ensure the
FIREZONE_TOKEN=<relay_token>environment variable is set securely in your Relay's shell environment. The Relay expects this variable at startup. - Now, you can start the Firezone Relay with:
firezone-relay
To view more advanced configuration options pass the --help flag:
firezone-relay --help
Ports
By default, the relay listens on port udp/3478. This is the standard port for
STUN/TURN. Additionally, the relay needs to have access to the port range
49152 - 65535 for the allocations.
Portal Connection
When given a token, the relay will connect to the Firezone portal and wait for
an init message before commencing relay operations.
Design
The relay is designed in a sans-IO fashion, meaning the core components do not cause side effects but operate as pure, synchronous state machines. They take in data and emit commands: wake me at this point in time, send these bytes to this peer, etc.
This allows us to very easily unit-test all kinds of scenarios because all inputs are simple values.
The main server runs in a single task and spawns one additional task for each allocation. Incoming data that needs to be relayed is forwarded to the main task where it gets authenticated and relayed on success.