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.
## Summary
Session is the concept used for UDP flows. Therefore, to make
the session limiter ambiguous for both TCP and UDP, this commit
renames it to flow limiter.
Closes TUN-8861
## Summary
In order to make cloudflared behavior more predictable and
prevent an exhaustion of resources, we have decided to add
session limits that can be configured by the user. This first
commit introduces the session limiter and adds it to the UDP
handling path. For now the limiter is set to run only in
unlimited mode.
Luis Neto