[ovs-dev] Datapath kern log msg key attribute error

[Jesse Gross]

On Thu, Apr 24, 2014 at 8:38 AM, Thomas F Herbert
<thomasfherbert at gmail.com> wrote:
> Hi,
>
> I think there is a problem with parsing out the OVS ATTRIBUTE nesting in the
> NL message in the datapath and I am having trouble finding the cause. I
> think the nl msg is built up wrong in the case of the vlan push action.
>
> I first saw the problem while testing my patch for 802.1ad. However, I also
> see the same problem WITHOUT the patch on commits in the master branch.
>
> The message appears in the kern log for commit dcbe78 and subsequent commits
> on the master branch. The message does NOT appear in the 2.1 release branch.
>
> Apr 23 07:50:11 lubuntu-12 kernel: [ 1009.493608] openvswitch: netlink: Key
> attribute has unexpected length (type=62, length=4, expected=0).
>
> Message is from line 300 in datapath/flow_netlink.c
>
> It is interesting that type 62 is the maximum key attribute value.
>
> The problem can be also  reproduced with the following command with commit
> f487a:
>
> ovs-ofctl -vdbg --protocols=OpenFlow11 add-flow br0
> in_port=1,actions=push_vlan:0x8100,load:0x64-\>OXM_OF_VLAN_VID[],output:2

This attribute is for MPLS, which userspace supports but the kernel
doesn't. This shouldn't be generated in any case but is there any MPLS
traffic here?

You could try bisecting since you have points in the code where it is
working and not. It might also be worth setting the log level to debug
to watch the upcalls and flow installations.