eacf67f2bc
The DNS server added in #8285 was only a dummy DNS server that added infrastructure to actually receive DNS queries on the IP of the TUN device at port 53535 and it returns SERVFAIL for all queries. For this DNS server to be useful, we need to take those queries and replay them towards a DNS server that is configured locally on the Gateway. To achieve this, we parse `/etc/resolv.conf` during startup of the Gateway and pass the contained nameservers into the tunnel. From there, the Gateway's event-loop can receive the queries, feed them into the already existing machinery for performing recursive DNS queries that we use on the Client and resolve the records. In its current implementation, we only use the first nameserver defined in `/etc/resolv.conf`. If the lookup fails, we send back a SERVFAIL error and log a message. Resolves: #8221
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.