nghttpx: Return 501 if invalid method is received on h1 frontend

integration-tests/nghttpx_http1_test.go

@@ -52,6 +52,27 @@ func TestH1H1PlainGETClose(t *testing.T) {
 	}
 }
 
+// TestH1H1InvalidMethod tests that server rejects invalid method with
+// 501 status code
+func TestH1H1InvalidMethod(t *testing.T) {
+	st := newServerTester(nil, t, func(w http.ResponseWriter, r *http.Request) {
+		t.Errorf("server should not forward this request")
+	})
+	defer st.Close()
+
+	res, err := st.http1(requestParam{
+		name:   "TestH1H1InvalidMethod",
+		method: "get",
+	})
+	if err != nil {
+		t.Fatalf("Error st.http1() = %v", err)
+	}
+
+	if got, want := res.status, 501; got != want {
+		t.Errorf("status = %v; want %v", got, want)
+	}
+}
+
 // TestH1H1MultipleRequestCL tests that server rejects request which
 // contains multiple Content-Length header fields.
 func TestH1H1MultipleRequestCL(t *testing.T) {

src/shrpx_https_upstream.cc

@@ -460,7 +460,9 @@ int HttpsUpstream::on_read() {
 
     unsigned int status_code;
 
-    if (downstream) {
+    if (htperr == HPE_INVALID_METHOD) {
+      status_code = 501;
+    } else if (downstream) {
       if (downstream->get_request_state() == Downstream::CONNECT_FAIL) {
         status_code = 503;
       } else if (downstream->get_request_state() ==