From 03bc071774d7b1474d0d5a14c9734c1379988e55 Mon Sep 17 00:00:00 2001
From: Miek Gieben <miek@miek.nl>
Date: Mon, 17 Oct 2016 10:26:24 +0000
Subject: [PATCH] Check for empty message in typify

---
 middleware/pkg/response/typify.go      | 4 ++++
 middleware/pkg/response/typify_test.go | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/middleware/pkg/response/typify.go b/middleware/pkg/response/typify.go
index 20ec13453..f121ecccf 100644
--- a/middleware/pkg/response/typify.go
+++ b/middleware/pkg/response/typify.go
@@ -58,6 +58,10 @@ func TypeFromString(s string) (Type, error) {
 
 // Typify classifies a message, it returns the Type.
 func Typify(m *dns.Msg) (Type, *dns.OPT) {
+	if m == nil {
+		return OtherError, nil
+	}
+
 	opt := m.IsEdns0()
 
 	if len(m.Answer) > 0 && m.Rcode == dns.RcodeSuccess {
diff --git a/middleware/pkg/response/typify_test.go b/middleware/pkg/response/typify_test.go
index dbd11c129..8d0644e3b 100644
--- a/middleware/pkg/response/typify_test.go
+++ b/middleware/pkg/response/typify_test.go
@@ -8,6 +8,15 @@ import (
 	"github.com/miekg/dns"
 )
 
+func TestTypifyNilMsg(t *testing.T) {
+	var m *dns.Msg = nil
+
+	ty, _ := Typify(m)
+	if ty != OtherError {
+		t.Errorf("message wrongly typified, expected OtherError, got %d", ty)
+	}
+}
+
 func TestClassifyDelegation(t *testing.T) {
 	m := delegationMsg()
 	mt, _ := Typify(m)