+#ifndef DCCP_SOCKOPT_TX_CCID
+#define DCCP_SOCKOPT_TX_CCID 14 /**< Set/get the TX CCID. */
+#endif
+
+/**
+ * Flowopts: Transport-layer independent encapsulation of socket options
+ * that need to be registered prior to setting up a connection.
+ */
+struct flowopts;
+
+extern struct flowopts *flowopt_new(void);
+extern void flowopt_add(struct flowopts *fo, int level, int opt,
+ const char *name, const void *val, int len);
+extern void flowopt_add_bool(struct flowopts *fo, int lev, int opt,
+ const char *optname, bool on_or_off);
+/** Flowopt shortcut macros */
+#define OPT_ADD(fo, lev, opt, val, len) flowopt_add(fo, lev, opt, #opt, val, len)
+#define OPT_ENABLE(fo, lev, opt) flowopt_add_bool(fo, lev, opt, #opt, 1)
+#define OPT_DISABLE(fo, lev, opt) flowopt_add_bool(fo, lev, opt, #opt, 0)