091d5b56e0
When encrypting IP packets, `snownet` needs to prepare a buffer where the encrypted packet is going to end up. Depending on whether we are sending data via a relayed connection or direct, this buffer needs to be offset by 4 bytes to allow for the 4-byte channel-data header of the TURN protocol. At present, we always first encrypt the packet and then on-demand move the packet by 4-bytes to the left if we **don't** need to send it via a relay. Internally, this translates to a `memmove` instruction which actually turns out to be very cheap (I couldn't measure a speed difference between this and `main`). All of this code has grown historically though so I figured, it is better to clean it up a bit to first evaluate, whether we have a direct or relayed connection and based on that, write the encrypted packet directly to the front of the buffer or offset it by 4 bytes.
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:
- Ensure the binary you are profiling is compiled with the
releaseprofile. sudo perf record -g --freq 10000 --pid $(pgrep <your-binary>).- Run the speed test or whatever load-inducing task you want to measure.
sudo perf script > profile.perf- 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.