[libvirt] [PATCH] Fix error report from nl_recvmsg

[Daniel P. Berrange]

On Thu, Feb 28, 2013 at 11:11:53AM -0500, Laine Stump wrote:
> On 02/28/2013 08:37 AM, Daniel P. Berrange wrote:
> > From: "Daniel P. Berrange" <berrange at redhat.com>
> >
> > The nl_recvmsg does not always set errno. Instead it returns
> > its own custom set of error codes. Thus we were reporting the
> > wrong data.
> > ---
> >  src/util/virnetlink.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/src/util/virnetlink.c b/src/util/virnetlink.c
> > index 0b36fdc..8b47ede 100644
> > --- a/src/util/virnetlink.c
> > +++ b/src/util/virnetlink.c
> > @@ -335,8 +335,9 @@ virNetlinkEventCallback(int watch,
> >      if (length == 0)
> >          return;
> >      if (length < 0) {
> > -        virReportSystemError(errno,
> > -                             "%s", _("nl_recv returned with error"));
> > +        virReportError(VIR_ERR_INTERNAL_ERROR,
> > +                       _("nl_recv returned with error: %s"),
> > +                       nl_geterror(length));
> 
> My recollection is that we specifically avoided calling nl_geterror()
> because it isn't threadsafe.
> 
> I'll go take another look to verify.

I did check this, but only for libnl3 which merely does a static
string table lookup:

const char *nl_geterror(int error)
{
        error = abs(error);

        if (error > NLE_MAX)
                error = NLE_FAILURE;

        return errmsg[error];
}


Daniel
-- 
|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|