BUG/MAJOR: dns: don't treat Authority records as an error
Support for DNS Service Discovery by means of SRV records was enhanced with
commit 13a9232eb ("MEDIUM: dns: use Additional records from SRV responses")
to use the content of the answers Additional records when present.
If there are Authority records before the Additional records we mistakenly
treat that as an invalid response. To fix this, just ignore the Authority
section if it exist and skip to the Additional records.
As 13a9232eb was introduced during 2.2-dev, it must be backported to 2.2.
This is a fix for issue #778
diff --git a/src/dns.c b/src/dns.c
index 6a8ab83..f5bce42 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -1044,6 +1044,34 @@
if (dns_query->type != DNS_RTYPE_SRV)
goto skip_parsing_additional_records;
+ /* if we find Authority records, just skip them */
+ for (i = 0; i < dns_p->header.nscount; i++) {
+ offset = 0;
+ len = dns_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE,
+ &offset, 0);
+ if (len == 0)
+ continue;
+
+ if (reader + offset + 10 >= bufend)
+ goto invalid_resp;
+
+ reader += offset;
+ /* skip 2 bytes for class */
+ reader += 2;
+ /* skip 2 bytes for type */
+ reader += 2;
+ /* skip 4 bytes for ttl */
+ reader += 4;
+ /* read data len */
+ len = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ if (reader + len >= bufend)
+ goto invalid_resp;
+
+ reader += len;
+ }
+
nb_saved_records = 0;
for (i = 0; i < dns_p->header.arcount; i++) {
if (reader >= bufend)