* transmission through this interface. This function may be set to null
* if it would always return EOPNOTSUPP anyhow. (This will prevent the
* network device from being usefully used by the netdev-based "userspace
* transmission through this interface. This function may be set to null
* if it would always return EOPNOTSUPP anyhow. (This will prevent the
* network device from being usefully used by the netdev-based "userspace