From a49050db2058b92d1b902c74ded2f41cbcdd8c50 Mon Sep 17 00:00:00 2001
From: Roman Manz <rmanz@amadeus.com>
Date: Wed, 31 May 2023 15:40:08 +0000
Subject: [PATCH] adding support for deprecated SPDY/3.1 websocket upgrades

---
 websocket.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/websocket.go b/websocket.go
index 522b88e3..fcc72fc5 100644
--- a/websocket.go
+++ b/websocket.go
@@ -22,7 +22,8 @@ func headerContains(header http.Header, name string, value string) bool {
 
 func isWebSocketRequest(r *http.Request) bool {
 	return headerContains(r.Header, "Connection", "upgrade") &&
-		headerContains(r.Header, "Upgrade", "websocket")
+		( headerContains(r.Header, "Upgrade", "websocket") ||
+			headerContains(r.Header, "Upgrade", "SPDY/3.1"))
 }
 
 func (proxy *ProxyHttpServer) serveWebsocketTLS(ctx *ProxyCtx, w http.ResponseWriter, req *http.Request, tlsConfig *tls.Config, clientConn *tls.Conn) {