service.go

@@ -32,6 +32,10 @@ type ResolveAddressResult struct {
 	Addresses []string `json:"addresses"`
 }
 
+type ReverseLookupResult struct {
+	Names []string `json:"names"`
+}
+
 type Service struct {
 	mu                           sync.RWMutex
 	records                      map[string]NameRecords
@@ -355,6 +359,14 @@ func (service *Service) Health() map[string]any {
 	}
 }
 
+func (service *Service) ResolveReverseNames(ip string) (ReverseLookupResult, bool) {
+	names, ok := service.ResolveReverse(ip)
+	if !ok {
+		return ReverseLookupResult{}, false
+	}
+	return ReverseLookupResult{Names: names}, true
+}
+
 func (service *Service) findRecord(name string) (NameRecords, bool) {
 	service.mu.RLock()
 	defer service.mu.RUnlock()

service_test.go

@@ -140,6 +140,24 @@ func TestServiceResolveReverseUsesARecords(t *testing.T) {
 	}
 }
 
+func TestServiceResolveReverseNamesReturnsNamedField(t *testing.T) {
+	service := NewService(ServiceOptions{
+		Records: map[string]NameRecords{
+			"gateway.charon.lthn": {
+				A: []string{"10.10.10.10"},
+			},
+		},
+	})
+
+	result, ok := service.ResolveReverseNames("10.10.10.10")
+	if !ok {
+		t.Fatal("expected named reverse result")
+	}
+	if len(result.Names) != 1 || result.Names[0] != "gateway.charon.lthn" {
+		t.Fatalf("unexpected reverse names result: %#v", result)
+	}
+}
+
 func TestServiceResolveReverseFallsBackToFalseWhenUnknown(t *testing.T) {
 	service := NewService(ServiceOptions{
 		Records: map[string]NameRecords{