91c6242ccc
Currently - because we know all our upstream DNS servers at the time of initialisation - we configure them on the TCP DNS client in `connlib` upfront. This allocates the necessary ports and sockets to emit TCP packets for queries that we want to send to upstream DNS servers, e.g. if the Internet Resource is active or if the Firezone-configured upstream DNS server is also a CIDR resource. In order to resolve SRV and TXT records within the DNS context of a site (#8221), we need to send DNS queries to the Gateway's TUN device which now hosts a DNS server on port 53535 (#8285). The IPs of Gateway's aren't known until we connect to them, meaning we cannot include them in the set of upstream resolver IPs that we want our DNS-over-TCP client to connect to. To be able to reuse the same library, we refactor the `dns_over_tcp::Client` implementation to dynamically allocate sockets for upstream resolvers. With that in place, we will be able to send DNS-over-TCP queries to Gateway's in case the application requests SRV or TXT records for a DNS resource. Related: #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.