1 files changed, 19 insertions, 0 deletions

diff --git a/bind/config.go b/bind/config.go
index 584b1ee..42b97cf 100644
--- a/bind/config.go
+++ b/bind/config.go
@@ -54,6 +54,25 @@ func (c *BINDConfig) Zone(view, name string) *Zone {
         return z
 }
 
+// Find the closest zone that we manage by striping dotted components off the
+// front of the domain until one matches. If there is a match return the zone
+// that matched and any prefix components, if any, as a dotted string. If none
+// match then return nil.
+func (c *BINDConfig) FindClosestZone(zoneIn, view string) (*Zone, string) {
+        suffix := ""
+        prefix := []string{}
+
+        zc := strings.Split(zoneIn, ".")
+        for i := 0; i <= len(zc)-2; i++ {
+                prefix, suffix = zc[:i], strings.Join(zc[i:], ".")
+                if zone := c.Zone(view, suffix); zone != nil {
+                        return zone, strings.Join(prefix, ".")
+                }
+        }
+
+        return nil, ""
+}
+
 func (c *BINDConfig) AddKey(k *Key) {
         c.keys[k.Name] = k
 }