Re: [PATCH v8 net-next 02/12] net: bridge: add blackhole fdb entry flag

[netdev]

On 2022-10-20 15:06, Ido Schimmel wrote:
> On Tue, Oct 18, 2022 at 06:56:09PM +0200, Hans J. Schultz wrote:
> > Add a 'blackhole' fdb flag, ensuring that no forwarding from any port
> > to a destination MAC that has a FDB entry with this flag on will 
> > occur.
> > The packets will thus be dropped.
> >
> > When the blackhole fdb flag is set, the 'local' flag will also be 
> > enabled
> > as blackhole entries are not associated with any port.
>
> It reads as if the kernel will enable the 'local' flag automatically,
> which is not true anymore. The bridge driver enforces that
> 'NUD_PERMANENT' is set if 'NTF_EXT_BLACKHOLE' is specified.
>
> > Thus the command will be alike to:
> > bridge fdb add MAC dev br0 local blackhole
> >
> > Signed-off-by: Hans J. Schultz <netdev@xxxxxxxxxxxxxxxxxxxx>
>
> Looks OK to me. See one comment below.
>
> Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxx>
>
> [...]
>
> > @@ -1140,7 +1148,7 @@ static int __br_fdb_add(struct ndmsg *ndm, 
> > struct net_bridge *br,
> >  		err = br_fdb_external_learn_add(br, p, addr, vid, true);
> >  	} else {
> >  		spin_lock_bh(&br->hash_lock);
> > -		err = fdb_add_entry(br, p, addr, ndm, nlh_flags, vid, nfea_tb);
> > +		err = fdb_add_entry(br, p, addr, ndm, nlh_flags, vid, ext_flags, 
> > nfea_tb);
>
> I believe the preference is to wrap to 80 columns when possible.

Ok, I only have knowledge of 100 columns as a limit.