int device_handler_discover(struct device_handler *handler,
struct discover_device *dev);
int device_handler_dhcp(struct device_handler *handler,
struct discover_device *dev, struct event *event);
int device_handler_discover(struct device_handler *handler,
struct discover_device *dev);
int device_handler_dhcp(struct device_handler *handler,
struct discover_device *dev, struct event *event);