From: Ben Pfaff <blp@nicira.com>
Date: Wed, 2 Mar 2011 21:25:10 +0000 (-0800)
Subject: odp-util: Replace ODPUTIL_FLOW_KEY_U32S by new struct odputil_keybuf.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=19cf40693da2e6e7612268fc6708fc6c879ebdff;p=openvswitch

odp-util: Replace ODPUTIL_FLOW_KEY_U32S by new struct odputil_keybuf.

This seems to me to better encapsulate the inherent ugliness.
---

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 035ceaed..762d24b3 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 4020660b..a88c7eec 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 *);
 
diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index dc5c9156..e6ea69dd 100644
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -1603,7 +1603,7 @@ facet_put__(struct ofproto *ofproto, struct facet *facet,
             const struct nlattr *actions, size_t actions_len,
             struct dpif_flow_stats *stats)
 {
-    uint32_t keybuf[ODPUTIL_FLOW_KEY_U32S];
+    struct odputil_keybuf keybuf;
     enum dpif_flow_put_flags flags;
     struct ofpbuf key;
 
@@ -1614,9 +1614,9 @@ facet_put__(struct ofproto *ofproto, struct facet *facet,
         facet->dp_byte_count = 0;
     }
 
-    ofpbuf_use_stack(&key, keybuf, sizeof keybuf);
+    ofpbuf_use_stack(&key, &keybuf, sizeof keybuf);
     odp_flow_key_from_flow(&key, &facet->flow);
-    assert(key.base == keybuf);
+    assert(key.base == &keybuf);
 
     return dpif_flow_put(ofproto->dpif, flags, key.data, key.size,
                          actions, actions_len, stats);
@@ -1660,13 +1660,13 @@ static void
 facet_uninstall(struct ofproto *p, struct facet *facet)
 {
     if (facet->installed) {
-        uint32_t keybuf[ODPUTIL_FLOW_KEY_U32S];
+        struct odputil_keybuf keybuf;
         struct dpif_flow_stats stats;
         struct ofpbuf key;
 
-        ofpbuf_use_stack(&key, keybuf, sizeof keybuf);
+        ofpbuf_use_stack(&key, &keybuf, sizeof keybuf);
         odp_flow_key_from_flow(&key, &facet->flow);
-        assert(key.base == keybuf);
+        assert(key.base == &keybuf);
 
         if (!dpif_flow_del(p->dpif, key.data, key.size, &stats)) {
             facet_update_stats(p, facet, &stats);