tunnel_group_drv_id
tunnel_group_drv_id(drv_group_id) & ((1 << DP_GROUP_ID_BITS) - 1),
tunnel_group_drv_id(drv_group_id) & ((1 << DP_GROUP_ID_BITS) - 1),
tunnel_group_drv_id(tunnel->group->drv_group_id),
tunnel_group_drv_id(new_drv_group_id),