the target host has only A records, it automatically falls back to an
AF_INET lookup and gives you the A results. However, if the target host has
a CNAME record, this behaviour is defeated since the original query does
return some data even though ares_parse_aaa_reply() doesn't consider it
relevant. Here's a small patch to make it behave the same with and without
the CNAME.
Changelog for the c-ares project
+* Jul 3 2008 (Daniel Stenberg)
+- Phil Blundell: If you ask ares_gethostbyname() to do an AF_INET6 lookup and
+ the target host has only A records, it automatically falls back to an
+ AF_INET lookup and gives you the A results. However, if the target host has
+ a CNAME record, this behaviour is defeated since the original query does
+ return some data even though ares_parse_aaa_reply() doesn't consider it
+ relevant. Here's a small patch to make it behave the same with and without
+ the CNAME.
+
* Jul 2 2008 (Yang Tse)
- Fallback to gettimeofday when monotonic clock is unavailable at run-time.
else if (hquery->family == AF_INET6)
{
status = ares_parse_aaaa_reply(abuf, alen, &host, NULL, NULL);
+ if (status == ARES_ENODATA)
+ {
+ /* The query returned something (e.g. CNAME) but there were no
+ AAAA records. Try looking up A instead. */
+ hquery->family = AF_INET;
+ ares_search(hquery->channel, hquery->name, C_IN, T_A, host_callback,
+ hquery);
+ return;
+ }
if (host && channel->nsort)
sort6_addresses(host, channel->sortlist, channel->nsort);
}