In case the 53 UDP port is not an option to bind then we hijack the DNS traffic with eBPF, and we forward the traffic to the listener on a custom port. With this implementation, we should be able to listen to DNS queries on any address and still set the local host system to send queries to the custom address on port 53.
Because we tried to attach multiple XDP programs to the same interface, I did a refactor in the WG traffic forward code also.
* Move ebpf code to its own package to avoid crash issues in Android
Older versions of android crashes because of the bytecode files
Even when they aren't loaded as it was our case
* move c file to own folder
* fix lint
EBPF proxy between TURN (relay) and WireGuard to reduce number of used ports used by the NetBird agent.
- Separate the wg configuration from the proxy logic
- In case if eBPF type proxy has only one single proxy instance
- In case if the eBPF is not supported fallback to the original proxy Implementation
Between the signature of eBPF type proxy and original proxy has
differences so this is why the factory structure exists
