middleware/caching: don't set TTL on OPT

When setting the TTL on all RR in the message we would also do this
for the OPT RR. This is wrong as the OPT RR does *not* have a TTL.

2 files changed, 8 insertions, 1 deletions

diff --git a/middleware/cache/cache.go b/middleware/cache/cache.go
index 6249b8faa..fd804d445 100644
--- a/middleware/cache/cache.go
+++ b/middleware/cache/cache.go
@@ -74,7 +74,7 @@ func (c *CachingResponseWriter) WriteMsg(res *dns.Msg) error {
 
 func (c *CachingResponseWriter) set(m *dns.Msg, key string, mt middleware.MsgType) {
 	if key == "" {
-		// logger the log? TODO(miek)
+		log.Printf("[ERROR] Caching called with empty cache key")
 		return
 	}
 
@@ -94,6 +94,10 @@ func (c *CachingResponseWriter) set(m *dns.Msg, key string, mt middleware.MsgTyp
 		i := newItem(m, duration)
 
 		c.cache.Set(key, i, duration)
+	case middleware.OtherError:
+		// don't cache these
+	default:
+		log.Printf("[WARNING] Caching called with unknown middleware MsgType: %d", mt)
 	}
 }
 
diff --git a/middleware/cache/item.go b/middleware/cache/item.go
index 6f0190c52..544de3c9a 100644
--- a/middleware/cache/item.go
+++ b/middleware/cache/item.go
@@ -74,6 +74,9 @@ func setCap(m *dns.Msg, ttl uint32) {
 		r.Header().Ttl = uint32(ttl)
 	}
 	for _, r := range m.Extra {
+		if r.Header().Rrtype == dns.TypeOPT {
+			continue
+		}
 		r.Header().Ttl = uint32(ttl)
 	}
 }