Files
firezone/rust
Thomas Eizinger 2841fd0017 chore(connlib): spawn dedicated tasks for UDP send/recv (#10147)
At the moment, `connlib`'s UDP thread spawns a single task for reading
and writing to the UDP socket. It will always first try to write data
before reading new data. To avoid scheduling issues, we split this into
two dedicated tasks and insert

```rust
tokio::task::yield_now().await;
```

into each loop. This allows the `tokio` runtime to schedule each of the
tasks fairly even if one of them is very busy.

For example, if we are very busy writing data (because we are receiving
a lot of IP traffic), this ensures that we will occasionally also read
from our socket to receive STUN control messages from our peers.
2025-08-06 07:38:01 +00:00
..
2023-05-10 07:58:32 -07:00

Rust development guide

Firezone uses Rust for all data plane components. This directory contains the Linux and Windows clients, and low-level networking implementations related to STUN/TURN.

We target the last stable release of Rust using rust-toolchain.toml. If you are using rustup, that is automatically handled for you. Otherwise, ensure you have the latest stable version of Rust installed.

Reading Client logs

The Client logs are written as JSONL for machine-readability.

To make them more human-friendly, pipe them through jq like this:

cd path/to/logs  # e.g. `$HOME/.cache/dev.firezone.client/data/logs` on Linux
cat *.log | jq -r '"\(.time) \(.severity) \(.message)"'

Resulting in, e.g.

2024-04-01T18:25:47.237661392Z INFO started log
2024-04-01T18:25:47.238193266Z INFO GIT_VERSION = 1.0.0-pre.11-35-gcc0d43531
2024-04-01T18:25:48.295243016Z INFO No token / actor_name on disk, starting in signed-out state
2024-04-01T18:25:48.295360641Z INFO null

Benchmarking on Linux

The recommended way for benchmarking any of the Rust components is Linux' perf utility. For example, to attach to a running application, do:

  1. Ensure the binary you are profiling is compiled with the release profile.
  2. sudo perf record -g --freq 10000 --pid $(pgrep <your-binary>).
  3. Run the speed test or whatever load-inducing task you want to measure.
  4. sudo perf script > profile.perf
  5. Open profiler.firefox.com and load profile.perf

Instead of attaching to a process with --pid, you can also specify the path to executable directly. That is useful if you want to capture perf data for a test or a micro-benchmark.