[ovs-dev] [branch-2.9 3/3] conntrack: Replace structure copy by memcpy().

Darrell Ball dlu998 at gmail.com
Fri May 3 00:29:16 UTC 2019


There are a few cases where structure copy can be replaced by
memcpy(), for possible portability benefit.  This is because
the structures involved have padding and elements of the
structure are used to generate hashes.

Signed-off-by: Darrell Ball <dlu998 at gmail.com>
---
 lib/conntrack.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/lib/conntrack.c b/lib/conntrack.c
index 042b94e..0d71195 100644
--- a/lib/conntrack.c
+++ b/lib/conntrack.c
@@ -934,7 +934,7 @@ conn_not_found(struct conntrack *ct, struct dp_packet *pkt,
         nc = &connl;
         memset(nc, 0, sizeof *nc);
         memcpy(&nc->key, &ctx->key, sizeof nc->key);
-        nc->rev_key = nc->key;
+        memcpy(&nc->rev_key, &nc->key, sizeof nc->rev_key);
         conn_key_reverse(&nc->rev_key);
 
         if (ct_verify_helper(helper, ct_alg_ctl)) {
@@ -985,7 +985,7 @@ conn_not_found(struct conntrack *ct, struct dp_packet *pkt,
 
                 /* Update nc with nat adjustments made to
                  * conn_for_un_nat_copy by nat_select_range_tuple(). */
-                *nc = *conn_for_un_nat_copy;
+                memcpy(nc, conn_for_un_nat_copy, sizeof *nc);
             }
             conn_for_un_nat_copy->conn_type = CT_CONN_TYPE_UN_NAT;
             conn_for_un_nat_copy->nat_info = NULL;
@@ -1076,8 +1076,8 @@ create_un_nat_conn(struct conntrack *ct, struct conn *conn_for_un_nat_copy,
                    long long now, bool alg_un_nat)
 {
     struct conn *nc = xmemdup(conn_for_un_nat_copy, sizeof *nc);
-    nc->key = conn_for_un_nat_copy->rev_key;
-    nc->rev_key = conn_for_un_nat_copy->key;
+    memcpy(&nc->key, &conn_for_un_nat_copy->rev_key, sizeof nc->key);
+    memcpy(&nc->rev_key, &conn_for_un_nat_copy->key, sizeof nc->rev_key);
     uint32_t un_nat_hash = conn_key_hash(&nc->key, ct->hash_basis);
     unsigned un_nat_conn_bucket = hash_to_bucket(un_nat_hash);
     ct_lock_lock(&ct->buckets[un_nat_conn_bucket].lock);
@@ -1266,7 +1266,7 @@ process_one(struct conntrack *ct, struct dp_packet *pkt,
 
             struct conn_lookup_ctx ctx2;
             ctx2.conn = NULL;
-            ctx2.key = conn->rev_key;
+            memcpy(&ctx2.key, &conn->rev_key, sizeof ctx2.key);
             ctx2.hash = conn_key_hash(&conn->rev_key, ct->hash_basis);
 
             ct_lock_unlock(&ct->buckets[bucket].lock);
@@ -1352,7 +1352,7 @@ process_one(struct conntrack *ct, struct dp_packet *pkt,
 
     struct conn conn_for_expectation;
     if (OVS_UNLIKELY((ct_alg_ctl != CT_ALG_CTL_NONE) && conn)) {
-        conn_for_expectation = *conn;
+        memcpy(&conn_for_expectation, conn, sizeof conn_for_expectation);
     }
 
     ct_lock_unlock(&ct->buckets[bucket].lock);
@@ -2334,8 +2334,10 @@ nat_conn_keys_insert(struct hmap *nat_conn_keys, const struct conn *nat_conn,
 
     if (!nat_conn_key_node) {
         struct nat_conn_key_node *nat_conn_key = xzalloc(sizeof *nat_conn_key);
-        nat_conn_key->key = nat_conn->rev_key;
-        nat_conn_key->value = nat_conn->key;
+        memcpy(&nat_conn_key->key, &nat_conn->rev_key,
+               sizeof nat_conn_key->key);
+        memcpy(&nat_conn_key->value, &nat_conn->key,
+               sizeof nat_conn_key->value);
         hmap_insert(nat_conn_keys, &nat_conn_key->node,
                     conn_key_hash(&nat_conn_key->key, basis));
         return true;
@@ -2741,7 +2743,8 @@ expectation_create(struct conntrack *ct, ovs_be16 dst_port,
     alg_exp_node->key.dst.port = dst_port;
     alg_exp_node->master_mark = master_conn->mark;
     alg_exp_node->master_label = master_conn->label;
-    alg_exp_node->master_key = master_conn->key;
+    memcpy(&alg_exp_node->master_key, &master_conn->key,
+           sizeof alg_exp_node->master_key);
     /* Take the write lock here because it is almost 100%
      * likely that the lookup will fail and
      * expectation_create() will be called below. */
-- 
1.9.1



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