mirror of
https://github.com/outbackdingo/firezone.git
synced 2026-01-27 10:18:54 +00:00
When looking through customer logs, we see a lot of "Resolved best route outside of tunnel" messages. Those get logged every time we need to rerun our re-implementation of Windows' weighting algorithm as to which source interface / IP a packet should be sent from. Currently, this gets cached in every socket instance so for the peer-to-peer socket, this is only computed once per destination IP. However, for DNS queries, we make a new socket for every query. Using a new source port DNS queries is recommended to avoid fingerprinting of DNS queries. Using a new socket also means that we need to re-run this algorithm every time we make a DNS query which is why we see this log so often. To fix this, we need to share this cache across all UDP sockets. Cache invalidation is one of the hardest problems in computer science and this instance is no different. This cache needs to be reset every time we roam as that changes the weighting of which source interface to use. To achieve this, we extend the `SocketFactory` trait with a `reset` method. This method is called whenever we roam and can then reset a shared cache inside the `UdpSocketFactory`. The "source IP resolver" function that is passed to the UDP socket now simply accesses this shared cache and inserts a new entry when it needs to resolve the IP. As an added benefit, this may speed up DNS queries on Windows a bit (although I haven't benchmarked it). It should certainly drastically reduce the amount of syscalls we make on Windows.
gateway
This crate houses the Firezone gateway.
Building
You can build the gateway using: cargo build --release --bin firezone-gateway
You should then find a binary in target/release/firezone-gateway.
Running
The Firezone Gateway supports Linux only. To run the Gateway binary on your Linux host:
- Generate a new Gateway token from the "Gateways" section of the admin portal and save it in your secrets manager.
- Ensure the
FIREZONE_TOKEN=<gateway_token>environment variable is set securely in your Gateway's shell environment. The Gateway requires this variable at startup. - Set
FIREZONE_IDto a unique string to identify this gateway in the portal, e.g.export FIREZONE_ID=$(head -c 32 /dev/urandom | sha256sum | cut -d' ' -f1). The Gateway requires this variable at startup. We recommend this to be a 64 character hex string. - Now, you can start the Gateway with:
firezone-gateway
If you're running as a non-root user, you'll need the CAP_NET_ADMIN capability
to open /dev/net/tun. You can add this to the gateway binary with:
sudo setcap 'cap_net_admin+eip' /path/to/firezone-gateway
Ports
The gateway requires no open ports. Connections automatically traverse NAT with STUN/TURN via the relay.