int netdev_add_router(struct netdev *, struct in_addr router);
int netdev_get_next_hop(const struct netdev *, const struct in_addr *host,
struct in_addr *next_hop, char **);
int netdev_add_router(struct netdev *, struct in_addr router);
int netdev_get_next_hop(const struct netdev *, const struct in_addr *host,
struct in_addr *next_hop, char **);