node: fix websocket connection header check (ethereum#21646)

Author: gzliudan

node/rpcstack.go

@@ -166,5 +166,5 @@ func NewWebsocketUpgradeHandler(h http.Handler, ws http.Handler) http.Handler {
 // isWebsocket checks the header of an http request for a websocket upgrade request.
 func isWebsocket(r *http.Request) bool {
 	return strings.ToLower(r.Header.Get("Upgrade")) == "websocket" &&
-		strings.ToLower(r.Header.Get("Connection")) == "upgrade"
+		strings.Contains(strings.ToLower(r.Header.Get("Connection")), "upgrade")
 }

node/rpcstack_test.go

@@ -36,3 +36,18 @@ func TestNewWebsocketUpgradeHandler_websocket(t *testing.T) {
 	response := <-responses
 	assert.Equal(t, "websocket", response.Header.Get("Upgrade"))
 }
+
+// TestIsWebsocket tests if an incoming websocket upgrade request is handled properly.
+func TestIsWebsocket(t *testing.T) {
+	r, _ := http.NewRequest("GET", "/", nil)
+
+	assert.False(t, isWebsocket(r))
+	r.Header.Set("upgrade", "websocket")
+	assert.False(t, isWebsocket(r))
+	r.Header.Set("connection", "upgrade")
+	assert.True(t, isWebsocket(r))
+	r.Header.Set("connection", "upgrade,keep-alive")
+	assert.True(t, isWebsocket(r))
+	r.Header.Set("connection", " UPGRADE,keep-alive")
+	assert.True(t, isWebsocket(r))
+}