TUN-1893: Proxy requests to the origin based on tunnel hostname

h2mux/muxedstream.go

@@ -68,7 +68,8 @@ type MuxedStream struct {
 	sentEOF bool
 	// true if the peer sent us an EOF
 	receivedEOF bool
-
+	// If valid, tunnelHostname is used to identify which origin service is the intended recipient of the request
+	tunnelHostname TunnelHostname
 	// Compression-related fields
 	receivedUseDict bool
 	method          string
@@ -195,6 +196,25 @@ func (s *MuxedStream) WriteHeaders(headers []Header) error {
 	return nil
 }
 
+// IsRPCStream returns if the stream is used to transport RPC.
+func (s *MuxedStream) IsRPCStream() bool {
+	rpcHeaders := RPCHeaders()
+	if len(s.Headers) != len(rpcHeaders) {
+		return false
+	}
+	// The headers order matters, so RPC stream should be opened with OpenRPCStream method and let MuxWriter serializes the headers.
+	for i, rpcHeader := range rpcHeaders {
+		if s.Headers[i] != rpcHeader {
+			return false
+		}
+	}
+	return true
+}
+
+func (s *MuxedStream) TunnelHostname() TunnelHostname {
+	return s.tunnelHostname
+}
+
 func (s *MuxedStream) getReceiveWindow() uint32 {
 	s.writeLock.Lock()
 	defer s.writeLock.Unlock()