+ /*
+ * Fields for Tx offloading of tunnels.
+ * These are undefined for packets which don't request
+ * any tunnel offloads (outer IP or UDP checksum,
+ * tunnel TSO).
+ *
+ * PMDs should not use these fields unconditionally
+ * when calculating offsets.
+ *
+ * Applications are expected to set appropriate tunnel
+ * offload flags when they fill in these fields.
+ */