fix HTTP Host header

http.go

@@ -128,14 +128,14 @@ func (h *httpHandler) handleRequest(conn net.Conn, req *http.Request) {
 		return
 	}
 
-	host := req.Host
 	// try to get the actual host.
 	if v := req.Header.Get("Gost-Target"); v != "" {
 		if h, err := decodeServerName(v); err == nil {
-			host = h
+			req.Host = h
 		}
 	}
 
+	host := req.Host
 	if _, port, _ := net.SplitHostPort(host); port == "" {
 		host = net.JoinHostPort(host, "80")
 	}
@@ -152,7 +152,6 @@ func (h *httpHandler) handleRequest(conn net.Conn, req *http.Request) {
 		log.Logf("[http] %s -> %s\n%s", conn.RemoteAddr(), conn.LocalAddr(), string(dump))
 	}
 
-	req.Host = host
 	req.Header.Del("Gost-Target")
 
 	resp := &http.Response{
@@ -305,6 +304,8 @@ func (h *httpHandler) authenticate(conn net.Conn, req *http.Request, resp *http.
 
 	// probing resistance is enabled
 	if ss := strings.SplitN(h.options.ProbeResist, ":", 2); len(ss) == 2 {
+		resp.StatusCode = http.StatusServiceUnavailable // default status code
+
 		switch ss[0] {
 		case "code":
 			resp.StatusCode, _ = strconv.Atoi(ss[1])