+/**
+ * skb_clone_writable - is the header of a clone writable
+ * @skb: buffer to check
+ * @len: length up to which to write
+ *
+ * Returns true if modifying the header part of the cloned buffer
+ * does not requires the data to be copied.
+ */
+static inline int skb_clone_writable(struct sk_buff *skb, int len)
+{
+ return !skb_header_cloned(skb) &&
+ skb_headroom(skb) + len <= skb->hdr_len;
+}
+