__be16 id;
__be16 frag_off;
+ /* IP header length (excluding options or extension headers). */
+ u8 ihl;
+
/* TOS for IPv4, class for IPv6. */
u8 tos;
/* Protocol for IPv4, NH for IPv6. */
u8 protocol;
+ /* Option length for IPv4, zero for IPv6. */
+ u8 optlen;
+
/* Used by IPv6 only, zero for IPv4. */
u8 flow_lbl[3];
};