+/* Converts a service name (a string) to a port number
+ * (in the range [1-65535]). Returns less than zero on error. */
+int service_name_to_port_number (const char *service_name);
+
+/** Parse a string to a derive_t value. Returns zero on success or non-zero on
+ * failure. If failure is returned, ret_value is not touched. */
+int strtoderive (const char *string, derive_t *ret_value);
+