+void sk_init(void); /* called once at program startup */
+void sk_cleanup(void); /* called just before program exit */
+
+SockAddr sk_namelookup(const char *host, char **canonicalname);
+SockAddr sk_nonamelookup(const char *host);
+void sk_getaddr(SockAddr addr, char *buf, int buflen);
+int sk_hostname_is_local(char *name);
+int sk_address_is_local(SockAddr addr);
+enum { ADDRTYPE_IPV4, ADDRTYPE_IPV6, ADDRTYPE_NAME };
+int sk_addrtype(SockAddr addr);
+void sk_addrcopy(SockAddr addr, char *buf);