dns

commit 3a23ded8a9048c791d17b7cc06e978412c4c4973
parent 3b6333ee3bb41ffb8165a098957014d84fe3d565
Author: Oliver Lowe <o@olowe.co>
Date:   Tue, 14 Dec 2021 12:37:30 +1100

cmd/recursor: early return on authoritative flag

Because we have an authoritative answer, so that means it's time to
stop the lookup and return the result!

Diffstat:
M
cmd/recursor/recursor.go
 | 
5
+----

1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/cmd/recursor/recursor.go b/cmd/recursor/recursor.go
@@ -59,7 +59,7 @@ func resolve(q dnsmessage.Question, next []net.IP) (dnsmessage.Message, error) {
 		}
 		fmt.Fprintf(os.Stderr, "asking %s about %s\n", ip, q.Name)
 		rmsg, err = dns.Exchange(qmsg, ip2dial(ip))
-		if rmsg.Header.RCode == dnsmessage.RCodeNameError {
+		if rmsg.Header.Authoritative {
 			return rmsg, err
 		} else if rmsg.Header.RCode == dnsmessage.RCodeSuccess && err == nil {
 			break
@@ -68,9 +68,6 @@ func resolve(q dnsmessage.Question, next []net.IP) (dnsmessage.Message, error) {
 	if err != nil {
 		return dnsmessage.Message{}, fmt.Errorf("resolve %s: %w", q.Name, err)
 	}
-	if len(rmsg.Answers) > 0 {
-		return rmsg, nil
-	}
 
 	fmt.Fprintf(os.Stderr, "no answer for %s %s, checking additionals\n", q.Name, q.Type)
 	if len(rmsg.Additionals) > 0 {