956bbbfd91
IPv6 treats fragmentation and MTU errors differently than IPv4. Rather than requiring fragmentation on each hop of a routing path, fragmentation needs to happen at the packet source and failure to route a packet triggers an ICMPv6 `PacketTooBig` error. These need to be translated back through our NAT64 implementation of the Gateway. Due to the size difference in the headers of IPv4 and IPv6, the available MTU to the IPv4 packet is 20 bytes _less_ than the MTU reported by the ICMP error. IPv6 headers are always 40 bytes, meaning if the MTU is reported as e.g. 1200 on the IPv6 side, we need to only offer 1180 to the IPv4 end of the application. Once the new MTU is then honored, the packets translated by our NAT64 implementation will still conform to the required MTU of 1200, despite the overhead introduced by the translation. Resolves: #7515.
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.