struct in6_addr in6;
};
-int in_addr_null(int family, const union in_addr_union *u);
+int in_addr_is_null(int family, const union in_addr_union *u);
+int in_addr_is_link_local(int family, const union in_addr_union *u);
int in_addr_equal(int family, const union in_addr_union *a, const union in_addr_union *b);
int in_addr_prefix_intersect(int family, const union in_addr_union *a, unsigned aprefixlen, const union in_addr_union *b, unsigned bprefixlen);
int in_addr_prefix_next(int family, union in_addr_union *u, unsigned prefixlen);