- void (*build_header)(struct sk_buff *, const struct vport *,
- const struct tnl_mutable_config *);
+
+ /*
+ * Returns a linked list of SKBs with tunnel headers (multiple
+ * packets may be generated in the event of fragmentation). Space
+ * will have already been allocated at the start of the packet equal
+ * to sizeof(struct iphdr) + value returned by hdr_len(). The IP
+ * header will have already been constructed.
+ */
+ struct sk_buff *(*build_header)(struct sk_buff *,
+ const struct vport *,
+ const struct tnl_mutable_config *,
+ struct dst_entry *);