The bump of the QUIC library introduces a cyclic dependency between the connection and quic modules hence it is necessary to break this coupling.
Right now, the connection module depends on the quic module for the datagram v2/v3 and to which a QUIC connection (currently an interface) is passed.
As it is there is no issue however, under the hood, interface is a wrapper around an UDP connection and a QUIC connection meaning this type must be exposed to the quic module since the QUIC Connection will no longer be a interface but a struct.
Given the above, these changes introduce an interface, QUICConnection, with the surface used today in cloudflared and a struct, ConnWithCloser, that implements said interface within the quic module.
Closes TUN-10563
This PR implements all the dialers and resolvers needed to make pre-checks happen. So this task focuses on the following:
1. Implement the DNS probe: call DNSResolver.Resolve(region)
2. Implement the QUIC probe: call QUICDialer.DialQuic (handshake only, no stream opened) and record the result.
3. Implement the HTTP/2 probe: call TCPDialer.DialEdge (TCP + TLS handshake only, no frames sent) and record the result.
4. Implement the Management API probe: call ManagementDialer.DialContext to api.cloudflare.com:443 and record the result.
5. Export edgeDiscovery as EdgeDiscovery in edgediscovery/allregions/discovery.go so the pre-check can reuse the production DNS path.
This sets up the main components to implement the checker.
Luis Neto
Miguel da Costa Martins Marcelino