issue with bridge handling

[Oliver, Jef]

I have narrowed down the cause. The issue arises when building the change request for the link and the special case of this being a bridge. On links, the request type needs to be RTM_NEWLINK. But, because this is a bridge, some operations require a change request of RTM_SETLINK. This is controlled by the ao_override_rtm that I introduced. (Spotted in af_request_type in lib/route/link.c)

The RTM_SETLINK only needs to be applied if bridge flags are being set. (IFLA_BRPORT_GUARD, IFLA_BRPORT_MODE, etc...) These flags are set with ao_fill_pi, which is called to fill IFLA_PROTINFO. (Nested attribute) I am working on a patch that will only set ao_override_rtm if ao_fill_pi needs to be run.

Thanks,
Jef 

> -----Original Message-----
> From: Thomas Haller [mailto:thaller at redhat.com]
> Sent: Tuesday, November 28, 2017 7:50 AM
> To: Oliver, Jef <jef.oliver at intel.com>; libnl at lists.infradead.org
> Subject: Re: issue with bridge handling
> 
> On Tue, 2017-11-28 at 14:55 +0000, Oliver, Jef wrote:
> > Thomas,
> >
> > I will investigate and send a patch if required. Can you provide the
> > kernel version you are using, or if this is happening on multiple
> > kernels?
> 
> Hi Jef,
> 
> Thanks, I'd be highly appreciated if you can find the time!!
> 
> I didn't look into it yet except a quick git-bisect.
> I only tested it on Fedora 27 kernel: 4.13.13-300.fc27.x86_64
> 
> 
> best,
> Thomas
> 
> 
> >
> > Thank You,
> > Jef
> >
> >
> > -------- Original message --------
> > From: Thomas Haller <thaller at redhat.com>
> > Date: 11/28/17 6:13 AM (GMT-08:00)
> > To: libnl at lists.infradead.org
> > Cc: "Oliver, Jef" <jef.oliver at intel.com>
> > Subject: issue with bridge handling
> >
> > Hi,
> >
> > seems something with bridge handling is broken since commit:
> >
> https://github.com/thom311/libnl/commit/55bc931a7272e6ac8f555bcc2a373
> > eb2b6b58377
> >
> >   ip link add name br0 type bridge
> >   ./src/nl-link-set -n br0 --state=up
> >
> > fails now with:
> > Error: Unable to change link: Operation not supported
> >
> >
> > Just a heads up. It needs investigation.
> > (as always, patches welcome ;-) )
> >
> > best
> > Thomas