extern void subnet_del(subnet_t *);
extern char *net2str(subnet_t *);
extern subnet_t *str2net(char *);
extern subnet_t *lookup_subnet_mac(mac_t);
extern subnet_t *lookup_subnet_ipv4(ipv4_t);
extern subnet_t *lookup_subnet_ipv6(ipv6_t);
extern void subnet_del(subnet_t *);
extern char *net2str(subnet_t *);
extern subnet_t *str2net(char *);
extern subnet_t *lookup_subnet_mac(mac_t);
extern subnet_t *lookup_subnet_ipv4(ipv4_t);
extern subnet_t *lookup_subnet_ipv6(ipv6_t);