int nl_sock_init(struct ctx *c);
unsigned int nl_get_ext_if(int *v4, int *v6);
void nl_route(int ns, unsigned int ifi, sa_family_t af, void *gw);
void nl_addr(int ns, unsigned int ifi, sa_family_t af,
	     void *addr, int prefix_len, void *addr_l);
void nl_link(int ns, unsigned int ifi, void *mac, int up, int mtu);