+extern int setsockopt(int socket, int level, int option_name, const void *option_value, socklen_t option_len);
+extern int getsockopt(int socket, int level, int option_name, void *option_value, socklen_t *option_len);
+
+extern int getsockname(int socket, struct sockaddr *addr, socklen_t *addrlen);
+extern int getpeername(int socket, struct sockaddr *addr, socklen_t *addrlen);
+
+extern struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type);
+extern void sethostent(int stayopen);
+extern void endhostent(void);
+extern void herror(const char *s);
+extern const char *hstrerror(int err);
+extern struct hostent *gethostent(void);
+
+#ifdef __cplusplus
+}
+#endif
+