request: add match function (#1615)

2 files changed, 38 insertions, 0 deletions

diff --git a/request/request.go b/request/request.go
index 0ce341a1b..0bca1a405 100644
--- a/request/request.go
+++ b/request/request.go
@@ -361,6 +361,24 @@ func (r *Request) Clear() {
 	r.name = ""
 }
 
+// Match checks if the reply matches the qname and qtype from the request, it returns
+// false when they don't match.
+func (r *Request) Match(reply *dns.Msg) bool {
+	if len(reply.Question) != 1 {
+		return false
+	}
+
+	if strings.ToLower(reply.Question[0].Name) != r.Name() {
+		return false
+	}
+
+	if reply.Question[0].Qtype != r.QType() {
+		return false
+	}
+
+	return true
+}
+
 const (
 	// TODO(miek): make this less awkward.
 	doTrue  = 1
diff --git a/request/request_test.go b/request/request_test.go
index e6fcf6935..ff9efcfd0 100644
--- a/request/request_test.go
+++ b/request/request_test.go
@@ -109,6 +109,26 @@ func TestRequestScrubExtra(t *testing.T) {
 	}
 }
 
+func TestRequestMatch(t *testing.T) {
+	st := testRequest()
+	reply := new(dns.Msg)
+
+	reply.SetQuestion("example.com.", dns.TypeMX)
+	if b := st.Match(reply); b {
+		t.Errorf("failed to match %s %d, got %t, expected %t", "example.com.", dns.TypeMX, b, false)
+	}
+
+	reply.SetQuestion("example.com.", dns.TypeA)
+	if b := st.Match(reply); !b {
+		t.Errorf("failed to match %s %d, got %t, expected %t", "example.com.", dns.TypeA, b, true)
+	}
+
+	reply.SetQuestion("example.org.", dns.TypeA)
+	if b := st.Match(reply); b {
+		t.Errorf("failed to match %s %d, got %t, expected %t", "example.org.", dns.TypeA, b, false)
+	}
+}
+
 func BenchmarkRequestDo(b *testing.B) {
 	st := testRequest()