+u32 flow_hash(const struct sw_flow_key *);
+int flow_cmp(const struct tbl_node *, void *target);
+
+/* Upper bound on the length of a nlattr-formatted flow key. The longest
+ * nlattr-formatted flow key would be:
+ *
+ * struct pad nl hdr total
+ * ------ --- ------ -----
+ * ODP_KEY_ATTR_TUN_ID 8 -- 4 12
+ * ODP_KEY_ATTR_IN_PORT 4 -- 4 8
+ * ODP_KEY_ATTR_ETHERNET 12 -- 4 16
+ * ODP_KEY_ATTR_8021Q 4 -- 4 8
+ * ODP_KEY_ATTR_ETHERTYPE 2 2 4 8
+ * ODP_KEY_ATTR_IPV6 34 2 4 40
+ * ODP_KEY_ATTR_ICMPV6 2 2 4 8
+ * ODP_KEY_ATTR_ND 28 -- 4 32
+ * -------------------------------------------------
+ * total 132
+ */
+#define FLOW_BUFSIZE 132
+
+int flow_to_nlattrs(const struct sw_flow_key *, struct sk_buff *);
+int flow_from_nlattrs(struct sw_flow_key *swkey, const struct nlattr *);
+
+static inline struct sw_flow *flow_cast(const struct tbl_node *node)
+{
+ return container_of(node, struct sw_flow, tbl_node);
+}