--- openflow-2009-10-14.h	2015-07-23 09:54:15.780479306 -0700
+++ openflow-2009-12-03-2.h	2015-07-23 09:54:15.788479306 -0700
@@ -692,7 +692,7 @@
     OFPST_TABLE,
 
     /* Physical port statistics.
-     * The request body is empty.
+     * The request body is struct ofp_port_stats_request.
      * The reply body is an array of struct ofp_port_stats. */
     OFPST_PORT,
 
@@ -805,6 +805,16 @@
 };
 OFP_ASSERT(sizeof(struct ofp_table_stats) == 64);
 
+/* Body for ofp_stats_request of type OFPST_PORT. */
+struct ofp_port_stats_request {
+    uint16_t port_no;        /* OFPST_PORT message must request statistics
+                              * either for a single port (specified in
+                              * port_no) or for all ports (if port_no ==
+                              * OFPP_NONE). */
+    uint8_t pad[6];
+};
+OFP_ASSERT(sizeof(struct ofp_port_stats_request) == 8);
+
 /* Body of reply to OFPST_PORT request. If a counter is unsupported, set
  * the field to all ones. */
 struct ofp_port_stats {