-void encap_init(void);
-void encap4_input(struct mbuf *, int);
-int encap6_input(struct mbuf **, int *);
+struct protosw;
+struct ip6protosw;
+struct domain;
+
+__BEGIN_DECLS
+void encap4_init(struct protosw *, struct domain *);
+void encap6_init(struct ip6protosw *, struct domain *);
+void encap4_input(struct mbuf *, int);
+int encap6_input(struct mbuf **, int *, int);