resolved: add dns_answer_is_empty() and dns_question_is_empty() helpers

And make use of them at a few places.

3 files changed, 12 insertions, 4 deletions

diff --git a/src/resolve/resolved-dns-answer.h b/src/resolve/resolved-dns-answer.h
index b2b86d1772..4a92bd1150 100644
--- a/src/resolve/resolved-dns-answer.h
+++ b/src/resolve/resolved-dns-answer.h
@@ -87,6 +87,10 @@ static inline unsigned dns_answer_size(DnsAnswer *a) {
         return a ? a->n_rrs : 0;
 }
 
+static inline bool dns_answer_isempty(DnsAnswer *a) {
+        return dns_answer_size(a) <= 0;
+}
+
 void dns_answer_dump(DnsAnswer *answer, FILE *f);
 
 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsAnswer*, dns_answer_unref);
diff --git a/src/resolve/resolved-dns-question.h b/src/resolve/resolved-dns-question.h
index ea41478975..a9a1863b1e 100644
--- a/src/resolve/resolved-dns-question.h
+++ b/src/resolve/resolved-dns-question.h
@@ -56,6 +56,10 @@ static inline unsigned dns_question_size(DnsQuestion *q) {
         return q ? q->n_keys : 0;
 }
 
+static inline bool dns_question_isempty(DnsQuestion *q) {
+        return dns_question_size(q) <= 0;
+}
+
 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuestion*, dns_question_unref);
 
 #define _DNS_QUESTION_FOREACH(u, key, q)                                \
diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 9d484d0a48..6f56148732 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -610,9 +610,9 @@ static int dns_scope_make_reply_packet(
         assert(s);
         assert(ret);
 
-        if ((!q || q->n_keys <= 0)
-            && (!answer || answer->n_rrs <= 0)
-            && (!soa || soa->n_rrs <= 0))
+        if (dns_question_isempty(q) &&
+            dns_answer_isempty(answer) &&
+            dns_answer_isempty(soa))
                 return -EINVAL;
 
         r = dns_packet_new(&p, s->protocol, 0);
@@ -718,7 +718,7 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) {
                 return;
         }
 
-        assert(p->question->n_keys == 1);
+        assert(dns_question_size(p->question) == 1);
         key = p->question->keys[0];
 
         r = dns_zone_lookup(&s->zone, key, 0, &answer, &soa, &tentative);