dp-packet: Use memcpy on dp_packet elements.

memcpy replaces the several single copies inside dp_packet_clone_with_headroom(). Signed-off-by: Antonio Fischetti <[email protected]> Signed-off-by: Darrell Ball <[email protected]>
orimanabu · Aug 25, 2017 · 84b7057 · 84b7057
1 parent 94053e6
commit 84b7057
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Showing 2 changed files with 14 additions and 10 deletions.
diff --git a/lib/dp-packet.c b/lib/dp-packet.c
@@ -160,8 +160,9 @@ dp_packet_clone(const struct dp_packet *buffer)
     return dp_packet_clone_with_headroom(buffer, 0);
 }
 
-/* Creates and returns a new dp_packet whose data are copied from 'buffer'.   The
- * returned dp_packet will additionally have 'headroom' bytes of headroom. */
+/* Creates and returns a new dp_packet whose data are copied from 'buffer'.
+ * The returned dp_packet will additionally have 'headroom' bytes of
+ * headroom. */
 struct dp_packet *
 dp_packet_clone_with_headroom(const struct dp_packet *buffer, size_t headroom)
 {
@@ -170,13 +171,12 @@ dp_packet_clone_with_headroom(const struct dp_packet *buffer, size_t headroom)
     new_buffer = dp_packet_clone_data_with_headroom(dp_packet_data(buffer),
                                                  dp_packet_size(buffer),
                                                  headroom);
-    new_buffer->l2_pad_size = buffer->l2_pad_size;
-    new_buffer->l2_5_ofs = buffer->l2_5_ofs;
-    new_buffer->l3_ofs = buffer->l3_ofs;
-    new_buffer->l4_ofs = buffer->l4_ofs;
-    new_buffer->md = buffer->md;
-    new_buffer->cutlen = buffer->cutlen;
-    new_buffer->packet_type = buffer->packet_type;
+    /* Copy the following fields into the returned buffer: l2_pad_size,
+     * l2_5_ofs, l3_ofs, l4_ofs, cutlen, packet_type and md. */
+    memcpy(&new_buffer->l2_pad_size, &buffer->l2_pad_size,
+            sizeof(struct dp_packet) -
+            offsetof(struct dp_packet, l2_pad_size));
+
 #ifdef DPDK_NETDEV
     new_buffer->mbuf.ol_flags = buffer->mbuf.ol_flags;
 #else

diff --git a/lib/dp-packet.h b/lib/dp-packet.h
@@ -40,7 +40,8 @@ enum OVS_PACKED_ENUM dp_packet_source {
     DPBUF_STACK,               /* Un-movable stack space or static buffer. */
     DPBUF_STUB,                /* Starts on stack, may expand into heap. */
     DPBUF_DPDK,                /* buffer data is from DPDK allocated memory.
-                                * ref to dp_packet_init_dpdk() in dp-packet.c. */
+                                * ref to dp_packet_init_dpdk() in dp-packet.c.
+                                */
 };
 
 #define DP_PACKET_CONTEXT_SIZE 64
@@ -61,6 +62,9 @@ struct dp_packet {
     bool rss_hash_valid;        /* Is the 'rss_hash' valid? */
 #endif
     enum dp_packet_source source;  /* Source of memory allocated as 'base'. */
+
+    /* All the following elements of this struct are copied in a single call
+     * of memcpy in dp_packet_clone_with_headroom. */
     uint8_t l2_pad_size;           /* Detected l2 padding size.
                                     * Padding is non-pullable. */
     uint16_t l2_5_ofs;             /* MPLS label stack offset, or UINT16_MAX */