TUN-3458: Upgrade to http2 when available, fallback to h2mux when we reach max retries

connection/connection.go

@@ -1,8 +1,6 @@
 package connection
 
 import (
-	"fmt"
-	"hash/fnv"
 	"io"
 	"net/http"
 	"strconv"
@@ -13,10 +11,6 @@ import (
 )
 
 const (
-	// edgeH2muxTLSServerName is the server name to establish h2mux connection with edge
-	edgeH2muxTLSServerName = "cftunnel.com"
-	// edgeH2TLSServerName is the server name to establish http2 connection with edge
-	edgeH2TLSServerName    = "h2.cftunnel.com"
 	lbProbeUserAgentPrefix = "Mozilla/5.0 (compatible; Cloudflare-Traffic-Manager/1.0; +https://www.cloudflare.com/traffic-manager/;"
 )
 
@@ -43,57 +37,6 @@ func (c *ClassicTunnelConfig) IsTrialZone() bool {
 	return c.Hostname == ""
 }
 
-type Protocol int64
-
-const (
-	H2mux Protocol = iota
-	HTTP2
-)
-
-func SelectProtocol(s string, accountTag string, http2Percentage uint32) (Protocol, bool) {
-	switch s {
-	case "h2mux":
-		return H2mux, true
-	case "http2":
-		return HTTP2, true
-	case "auto":
-		if tryHTTP2(accountTag, http2Percentage) {
-			return HTTP2, true
-		}
-		return H2mux, true
-	default:
-		return 0, false
-	}
-}
-
-func tryHTTP2(accountTag string, http2Percentage uint32) bool {
-	h := fnv.New32a()
-	h.Write([]byte(accountTag))
-	return h.Sum32()%100 < http2Percentage
-}
-
-func (p Protocol) ServerName() string {
-	switch p {
-	case H2mux:
-		return edgeH2muxTLSServerName
-	case HTTP2:
-		return edgeH2TLSServerName
-	default:
-		return ""
-	}
-}
-
-func (p Protocol) String() string {
-	switch p {
-	case H2mux:
-		return "h2mux"
-	case HTTP2:
-		return "http2"
-	default:
-		return fmt.Sprintf("unknown protocol")
-	}
-}
-
 type OriginClient interface {
 	Proxy(w ResponseWriter, req *http.Request, isWebsocket bool) error
 }