+/**
+ * skb_availroom - bytes at buffer end
+ * @skb: buffer to check
+ *
+ * Return the number of bytes of free space at the tail of an sk_buff
+ * allocated by sk_stream_alloc()
+ */
+static inline int skb_availroom(const struct sk_buff *skb)
+{
+ if (skb_is_nonlinear(skb))
+ return 0;
+
+ return skb->end - skb->tail - skb->reserved_tailroom;
+}
+