1 files changed, 64 insertions, 0 deletions

diff --git a/src/resolve/resolved-dns-answer.c b/src/resolve/resolved-dns-answer.c
index b50558e280..f74e440531 100644
--- a/src/resolve/resolved-dns-answer.c
+++ b/src/resolve/resolved-dns-answer.c
@@ -320,6 +320,33 @@ int dns_answer_contains_nsec_or_nsec3(DnsAnswer *a) {
         return false;
 }
 
+int dns_answer_contains_zone_nsec3(DnsAnswer *answer, const char *zone) {
+        DnsResourceRecord *rr;
+        int r;
+
+        /* Checks whether the specified answer contains at least one NSEC3 RR in the specified zone */
+
+        DNS_ANSWER_FOREACH(rr, answer) {
+                const char *p;
+
+                if (rr->key->type != DNS_TYPE_NSEC3)
+                        continue;
+
+                p = DNS_RESOURCE_KEY_NAME(rr->key);
+                r = dns_name_parent(&p);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        continue;
+
+                r = dns_name_equal(p, zone);
+                if (r != 0)
+                        return r;
+        }
+
+        return false;
+}
+
 int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags) {
         DnsResourceRecord *rr, *soa = NULL;
         DnsAnswerFlags rr_flags, soa_flags = 0;
@@ -794,3 +821,40 @@ void dns_answer_dump(DnsAnswer *answer, FILE *f) {
                 fputc('\n', f);
         }
 }
+
+bool dns_answer_has_dname_for_cname(DnsAnswer *a, DnsResourceRecord *cname) {
+        DnsResourceRecord *rr;
+        int r;
+
+        assert(cname);
+
+        /* Checks whether the answer contains a DNAME record that indicates that the specified CNAME record is
+         * synthesized from it */
+
+        if (cname->key->type != DNS_TYPE_CNAME)
+                return 0;
+
+        DNS_ANSWER_FOREACH(rr, a) {
+                _cleanup_free_ char *n = NULL;
+
+                if (rr->key->type != DNS_TYPE_DNAME)
+                        continue;
+                if (rr->key->class != cname->key->class)
+                        continue;
+
+                r = dns_name_change_suffix(cname->cname.name, rr->dname.name, DNS_RESOURCE_KEY_NAME(rr->key), &n);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        continue;
+
+                r = dns_name_equal(n, DNS_RESOURCE_KEY_NAME(cname->key));
+                if (r < 0)
+                        return r;
+                if (r > 0)
+                        return 1;
+
+        }
+
+        return 0;
+}