QUIC proxy works like kcp proxy, it can proxy TCP streams and transfer data with QUIC.
QUIC has better congestion algorithm (BBR) for network with both high loss rate and high bandwidth.
QUIC proxy can be enabled by passing `--enable-quic-proxy` to easytier in the client side. The proxy status can be viewed by `easytier-cli proxy`.
Some devices have ipv6 but don't allow input connection, this patch add hole punching for these devices.
- **add v6 hole punch msg to udp tunnel**
- **send hole punch packet when do ipv6 direct connect**
1. dns resolver should be global unique so dns cache can work. avoid dns query influence hole punching.
2. when system dns failed, fallback to hickory dns.
This patch removes Tarpc & Tonic GRPC and implements a customized rpc framework, which can be used by peer rpc and cli interface.
web config server can also use this rpc framework.
moreover, rewrite the public server logic, use ospf route to implement public server based networking. this make public server mesh possible.