[ovs-dev] [PATCH 1/5] vxlan: Group Policy extension

[Thomas Graf]

On 01/14/15 at 04:18pm, Tom Herbert wrote:
> > diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
> > index 99df0d7..06f7196 100644
> > --- a/drivers/net/vxlan.c
> > +++ b/drivers/net/vxlan.c
> > @@ -126,6 +126,7 @@ struct vxlan_dev {
> >         __u8              tos;          /* TOS override */
> >         __u8              ttl;
> >         u32               flags;        /* VXLAN_F_* in vxlan.h */
> > +       u32               exts;         /* Enabled extensions */
> >
> 
> Thomas, why not just make a VXAM_F_GPB flag? Then this setting can be
> saved in the flags for vxlan_dev and vxlan_sock so no exts field.

Because we need to compare enabled extensions in vxlan_find_sock() to
make sure we are not sharing a VXLAN socket with extensions enabled
with a user which does not have the same extensions enabled.

However, we do not want vxlan_find_sock() to compare all flags.

So we need a bitmap that is ignored during the share check (flags) and
a bitmap that must match to allow sharing (exts).

The RCO extension is currently suffering from this bug which is causing
a compatibility issue. I explained in the thread of your patch. I was
under the imrpession that you would either send a v2 or fix it in a
follow-up.