Files
firezone/rust
Thomas Eizinger 0c5ca66f57 fix(connlib): override query ID of DoH response (#10931)
As per the RFC, queries to DoH servers should always set their query ID
to 0. This is more cache-friendly because two queries for the same
domain end up being byte-for-byte equivalent in the HTTP request. When
transported over HTTP, the query ID is obsolete because the response can
be unambiguously mapped back to the request already.

Connlib's DoH feature zeros out the query ID in the IO layer. To
correctly test this functionality, we therefore extend the test-suite to
do the same and restore the original query ID before sending back the
response on the original transport.

This fixes a bug where all DNS queries that were forwarded to a DoH
server incorrectly had their query ID set to 0.
2025-11-24 07:45:53 +00:00
..
2023-05-10 07:58:32 -07:00
2025-11-19 05:10:52 +00:00

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.