Function tcp4or6

midway/relay/proxy.go:197–207

always "tcp" for now, because for web properties that are ipv4-only cause connect-timeouts from incoming ipv6 connections. Instead of specifically returning "tcp6", we now let it be "tcp".

(a net.Addr)

// cause connect-timeouts from incoming ipv6 connections. Instead of
// specifically returning "tcp6", we now let it be "tcp".
func tcp4or6(a net.Addr) (string, error) {
	if addrport, err := netip.ParseAddrPort(a.String()); err == nil {
		if addrport.Addr().Is6() || addrport.Addr().Is4In6() {
			return /*tcp6*/ "tcp", nil
		} else {
			return /*tcp4*/ "tcp", nil
		}
	} else {
		return "tcp", err
	}
}

func underlyingConn(c net.Conn) net.Conn {
	if wrap, ok := c.(*Conn); ok {