Re: [PATCH] [BZ #20900] Call __res_vinit if _PATH_RESCONF is changed

[Florian Weimer <fweimer at redhat dot com>]

On 12/01/2016 07:56 PM, H.J. Lu wrote:
> The content of _PATH_RESCONF may change over time with DHCP.
> __res_maybe_init should check if _PATH_RESCONF is changed.  Otherwise
> a long-running process will get wrong DNS results if _PATH_RESCONF is
> changed by DHCP.
>
> Any comments?

This is not the correct approach.  You need a pristine copy of _res and 
check if the application hasn't made any changes because this is a 
public interface and such changes are expected (and in one case, even 
encouraged).  The existing behavior (re-init all threads if we re-init 
one) is buggy for the same reason.

I'm working on a new resolv.conf parser which will address these issues 
and also eliminate the search path limit.

Florian