Add netlink handlers for the per-VLAN neigh_forward_grat option via BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT attribute. The per-VLAN option provides fine-grained control, allowing different VLANs on the same port to have different gratuitous ARP/unsolicited NA forwarding behavior. This enables control via 'bridge' commands: # bridge vlan set dev eth0 vid 10 neigh_suppress on # bridge vlan set dev eth0 vid 10 neigh_forward_grat on Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Danielle Ratson <danieller@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20260511065936.4173106-6-danieller@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>