void format_odp_actions(struct ds *, const struct nlattr *odp_actions,
size_t actions_len);
-/* By my calculations currently the longest valid nlattr-formatted flow key is
- * 92 bytes long, so this leaves some safety margin.
+/* Upper bound on the length of a nlattr-formatted flow key. The longest
+ * nlattr-formatted flow key would be:
*
- * We allocate temporary on-stack buffers for flow keys as arrays of uint32_t
- * to ensure proper 32-bit alignment for Netlink attributes. (An array of
- * "struct nlattr" might not, in theory, be sufficiently aligned because it
- * only contains 16-bit types.) */
-#define ODPUTIL_FLOW_KEY_BYTES 112
-#define ODPUTIL_FLOW_KEY_U32S DIV_ROUND_UP(ODPUTIL_FLOW_KEY_BYTES, 4)
+ * 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 ODPUTIL_FLOW_KEY_BYTES 132
+
+/* This is an imperfect sanity-check that ODPUTIL_FLOW_KEY_BYTES doesn't
+ * need to be updated, but will at least raise awareness when new ODP
+ * key types are added. */
+BUILD_ASSERT_DECL(__ODP_KEY_ATTR_MAX == 14);
+
+/* A buffer with sufficient size and alignment to hold an nlattr-formatted flow
+ * key. An array of "struct nlattr" might not, in theory, be sufficiently
+ * aligned because it only contains 16-bit types. */
+struct odputil_keybuf {
+ uint32_t keybuf[DIV_ROUND_UP(ODPUTIL_FLOW_KEY_BYTES, 4)];
+};
void odp_flow_key_format(const struct nlattr *, size_t, struct ds *);