+struct ip_comp_hdr;
+struct sk_buff;
+struct xfrm_state;
+
+int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb);
+int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb);
+void ipcomp_destroy(struct xfrm_state *x);
+int ipcomp_init_state(struct xfrm_state *x);
+
+static inline struct ip_comp_hdr *ip_comp_hdr(const struct sk_buff *skb)
+{
+ return (struct ip_comp_hdr *)skb_transport_header(skb);
+}
+