The Relayed connection setup is optimistic. It does not have any confirmation of an established end-to-end connection. Peers start sending WireGuard handshake packets immediately after the successful offer-answer handshake.
Meanwhile, for successful P2P connection negotiation, we change the WireGuard endpoint address, but this change does not trigger new handshake initiation. Because the peer switched from Relayed connection to P2P, the packets from the Relay server are dropped and must wait for the next WireGuard handshake via P2P.
To avoid this scenario, the relayed WireGuard proxy no longer drops the packets. Instead, it rewrites the source address to the new P2P endpoint and continues forwarding the packets.
We still have one corner case: if the Relayed server negotiation chooses a server that has not been used before. In this case, one side of the peer connection will be slower to reach the Relay server, and the Relay server will drop the handshake packet.
If everything goes well we should see exactly 5 seconds improvements between the WireGuard configuration time and the handshake time.
- Move `util/grpc` and `util/net` to `client` so `internal` packages can be accessed
- Add methods to return the next best interface after the NetBird interface.
- Use `IP_UNICAST_IF` sock opt to force the outgoing interface for the NetBird `net.Dialer` and `net.ListenerConfig` to avoid routing loops. The interface is picked by the new route lookup method.
- Some refactoring to avoid import cycles
- Old behavior is available through `NB_USE_LEGACY_ROUTING=true` env var
Deduplicate STUN package sending.
Originally, because every peer shared the same UDP address, the library could not distinguish which STUN message was associated with which candidate. As a result, the Pion library responded from all candidates for every STUN message.
This PR introduces a new inactivity package responsible for monitoring peer activity and notifying when peers become inactive.
Introduces a new Signal message type to close the peer connection after the idle timeout is reached.
Periodically checks the last activity of registered peers via a Bind interface.
Notifies via a channel when peers exceed a configurable inactivity threshold.
Default settings
DefaultInactivityThreshold is set to 15 minutes, with a minimum allowed threshold of 1 minute.
Limitations
This inactivity check does not support kernel WireGuard integration. In kernel–user space communication, the user space side will always be responsible for closing the connection.
- When a peer is connected with TURN and a Relay connection is established, do not force switching to Relay. Keep using TURN until disconnection.
-In the proxy preparation phase, the Bind Proxy does not set the remote conn as a fake address for Bind. When running the Work() function, the proper proxy instance updates the conn inside the Bind.
In the case of user space WireGuard mode, use in-memory proxy between the TURN/Relay connection and the WireGuard Bind. We keep the UDP proxy and eBPF proxy for kernel mode.
The key change is the new wgproxy/bind and the iface/bind/ice_bind changes. Everything else is just to fulfill the dependencies.
