On Wed, Dec 08, 2010 at 04:21:24PM -0800, William Ahern wrote:
>> This would be ???OpenBSD just wants to be difficult???. :-)
> You get the same behavior on KAME stacks when net.inet6.ip6.v6only is 1,
> which is the default value on NetBSD and, I think, FreeBSD.
That's just a default; there's an ioctl to put it back to supporting
dual-stack sockets.
> There's a difference between doing the Right Thing with default settings and
> shoe-horning policy into an interface lacking the ability to select the
> setting or to even know that a response has been manufactured.
Sure, but this interface has been set a long time ago. Regardless of what you
may think or not about the usefulness of mapped-v4 sockets, c-ares should not
unilaterally decide that its gethostbyname() should suddenly behave
differently from everybody else wrt. AAAA fallbacks.
You're of course free to make some sort of interface, or flag, that specifies
no fallback. I'm sure it has its own use (for instance in implementing
parallel A/AAAA lookup yourself).
/* Steinar */
-- Software Engineer, Google SwitzerlandReceived on 2010-12-13