[PATCH] resolv: Enable full ICMP errors for UDP DNS sockets [BZ #24047]

[Zack Weinberg]

On Thu, Mar 7, 2019 at 7:08 AM Zack Weinberg <zackw@panix.com> wrote:
>
> On Thu, Mar 7, 2019 at 6:21 AM Florian Weimer <fweimer@redhat.com> wrote:
> >
> > * Florian Weimer:
> >
> > > The Linux kernel suppresses some ICMP error messages by default for
> > > UDP sockets.  This commit enables full ICMP error reporting,
> > > hopefully resulting in faster failover to working name servers.
> ...
>
> The documentation makes it sound like IP_RECVERR doesn't do anything
> by itself, you need to call recvmsg(MSG_ERRQUEUE) to actually see the
> errors.  As far as I can tell, res_send.c doesn't do that, either
> before or after this patch.  Is the documentation wrong?

er, by "the documentation" I am referring to the ip(7) manpage.

zw