odp-util: Replace ODPUTIL_FLOW_KEY_U32S by new struct odputil_keybuf.

This seems to me to better encapsulate the inherent ugliness.

2 files changed, 9 insertions, 8 deletions

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 035ceaedd..762d24b39 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -872,7 +872,7 @@ struct dp_netdev_flow_state {
     uint32_t bucket;
     uint32_t offset;
     struct nlattr *actions;
-    uint32_t keybuf[ODPUTIL_FLOW_KEY_U32S];
+    struct odputil_keybuf keybuf;
     struct dpif_flow_stats stats;
 };
 
@@ -909,9 +909,9 @@ dpif_netdev_flow_dump_next(const struct dpif *dpif, void *state_,
     if (key) {
         struct ofpbuf buf;
 
-        ofpbuf_use_stack(&buf, state->keybuf, sizeof state->keybuf);
+        ofpbuf_use_stack(&buf, &state->keybuf, sizeof state->keybuf);
         odp_flow_key_from_flow(&buf, &flow->key);
-        assert(buf.base == state->keybuf);
+        assert(buf.base == &state->keybuf);
 
         *key = buf.data;
         *key_len = buf.size;
diff --git a/lib/odp-util.h b/lib/odp-util.h
index 4020660b4..a88c7eec8 100644
--- a/lib/odp-util.h
+++ b/lib/odp-util.h
@@ -86,11 +86,12 @@ void format_odp_actions(struct ds *, const struct nlattr *odp_actions,
  * key types are added. */
 BUILD_ASSERT_DECL(__ODP_KEY_ATTR_MAX == 14);
 
-/* 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_U32S DIV_ROUND_UP(ODPUTIL_FLOW_KEY_BYTES, 4)
+/* 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 *);