dnsx/resolver: send original prefs in onUpstreamAnswer

Author: ignoramous

intra/backend/dnsx_listener.go

@@ -88,6 +88,20 @@ type DNSOpts struct {
 	NOBLOCK bool
 }
 
+func (o *DNSOpts) Copy() *DNSOpts {
+	if o == nil {
+		return nil
+	}
+	return &DNSOpts{
+		UID:       o.UID,
+		PIDCSV:    o.PIDCSV,
+		IPCSV:     o.IPCSV,
+		TIDCSV:    o.TIDCSV,
+		TIDSECCSV: o.TIDSECCSV,
+		NOBLOCK:   o.NOBLOCK,
+	}
+}
+
 // String implements fmt.Stringer.
 func (s *DNSSummary) String() string {
 	if s == nil {
@@ -107,7 +121,7 @@ type DNSListener interface {
 	// The listener may return DNSOpts to specify if another upstream should override that answer.
 	// Another round of OnQuery is NOT called in this case, and OnResponse is called once after processing
 	// DNSOpts returned by OnUpstreamAnswer if it has a non-empty TIDCSV (overriding the original TIDCSV).
-	OnUpstreamAnswer(smm *DNSSummary, unmodifiedipcsv string) *DNSOpts
+	OnUpstreamAnswer(smm *DNSSummary, forPref *DNSOpts, unmodifiedipcsv string) *DNSOpts
 	// OnResponse is called when a DNS response is received. May be called twice for the same query,
 	// for instance, when different options are requested through OnUpstreamAnswer.
 	OnResponse(*DNSSummary)

intra/dnsx/transport.go

@@ -720,7 +720,7 @@ runagain:
 
 	if run == 1 {
 		pref2, ouacompleted := core.Grx("r.onUA."+qname, func(_ context.Context) (*x.DNSOpts, error) {
-			return r.listener.OnUpstreamAnswer(smm, realips), nil
+			return r.listener.OnUpstreamAnswer(smm, pref.Copy(), realips), nil
 		}, listenerTimeout)
 		if !ouacompleted {
 			log.W("dns: fwd: for %s[%s]; preferences2 missing for %s:%d; ips? %s", smm.ID, uid, qname, qtyp, realips)