+/* Registers 'cb' to be called with auxiliary data 'aux' with network device
+ * change notifications. The notifier is stored in 'notifier', which the
+ * caller must not modify or free.
+ *
+ * This is probably not the function that you want. You should probably be
+ * using dpif_port_poll() or netdev_monitor_create(), which unlike this
+ * function are not Linux-specific.
+ *
+ * Returns 0 if successful, otherwise a positive errno value. */