ofproto: Use NULL "desc" values to indicate defaults.

This saves a small amount of memory.  It should also save a small amount of
time for reconfiguration starting with an upcoming commit where it becomes
possible to change the dp_desc away from the default (because it will not
be necessary to compare the current value against the default).

Signed-off-by: Ben Pfaff <blp@nicira.com>

diff --git a/ofproto/ofproto-provider.h b/ofproto/ofproto-provider.h
index bc0105f..f2274ef 100644 (file)
--- a/ofproto/ofproto-provider.h
+++ b/ofproto/ofproto-provider.h
@@ -52,11 +52,11 @@ struct ofproto {
                                        * ofproto-dpif implementation */
     bool forward_bpdu;          /* Option to allow forwarding of BPDU frames
                                  * when NORMAL action is invoked. */
-    char *mfr_desc;             /* Manufacturer. */
-    char *hw_desc;              /* Hardware. */
-    char *sw_desc;              /* Software version. */
-    char *serial_desc;          /* Serial number. */
-    char *dp_desc;              /* Datapath description. */
+    char *mfr_desc;             /* Manufacturer (NULL for default)b. */
+    char *hw_desc;              /* Hardware (NULL for default). */
+    char *sw_desc;              /* Software version (NULL for default). */
+    char *serial_desc;          /* Serial number (NULL for default). */
+    char *dp_desc;              /* Datapath description (NULL for default). */
     enum ofp_config_flags frag_handling; /* One of OFPC_*.  */
 
     /* Datapath. */

diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 00b7274..939ad20 100644 (file)
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -407,11 +407,11 @@ ofproto_create(const char *datapath_name, const char *datapath_type,
                                         OFPROTO_FLOW_EVICTION_THRESHOLD_DEFAULT);
     ofproto->forward_bpdu = false;
     ofproto->fallback_dpid = pick_fallback_dpid();
-    ofproto->mfr_desc = xstrdup(DEFAULT_MFR_DESC);
-    ofproto->hw_desc = xstrdup(DEFAULT_HW_DESC);
-    ofproto->sw_desc = xstrdup(DEFAULT_SW_DESC);
-    ofproto->serial_desc = xstrdup(DEFAULT_SERIAL_DESC);
-    ofproto->dp_desc = xstrdup(DEFAULT_DP_DESC);
+    ofproto->mfr_desc = NULL;
+    ofproto->hw_desc = NULL;
+    ofproto->sw_desc = NULL;
+    ofproto->serial_desc = NULL;
+    ofproto->dp_desc = NULL;
     ofproto->frag_handling = OFPC_FRAG_NORMAL;
     hmap_init(&ofproto->ports);
     shash_init(&ofproto->port_by_name);
@@ -2393,17 +2393,29 @@ static enum ofperr
 handle_desc_stats_request(struct ofconn *ofconn,
                           const struct ofp_header *request)
 {
+    static const char *default_mfr_desc = "Nicira, Inc.";
+    static const char *default_hw_desc = "Open vSwitch";
+    static const char *default_sw_desc = VERSION;
+    static const char *default_serial_desc = "None";
+    static const char *default_dp_desc = "None";
+
     struct ofproto *p = ofconn_get_ofproto(ofconn);
     struct ofp_desc_stats *ods;
     struct ofpbuf *msg;
 
     msg = ofpraw_alloc_stats_reply(request, 0);
     ods = ofpbuf_put_zeros(msg, sizeof *ods);
-    ovs_strlcpy(ods->mfr_desc, p->mfr_desc, sizeof ods->mfr_desc);
-    ovs_strlcpy(ods->hw_desc, p->hw_desc, sizeof ods->hw_desc);
-    ovs_strlcpy(ods->sw_desc, p->sw_desc, sizeof ods->sw_desc);
-    ovs_strlcpy(ods->serial_num, p->serial_desc, sizeof ods->serial_num);
-    ovs_strlcpy(ods->dp_desc, p->dp_desc, sizeof ods->dp_desc);
+    ovs_strlcpy(ods->mfr_desc, p->mfr_desc ? p->mfr_desc : default_mfr_desc,
+                sizeof ods->mfr_desc);
+    ovs_strlcpy(ods->hw_desc, p->hw_desc ? p->hw_desc : default_hw_desc,
+                sizeof ods->hw_desc);
+    ovs_strlcpy(ods->sw_desc, p->sw_desc ? p->sw_desc : default_sw_desc,
+                sizeof ods->sw_desc);
+    ovs_strlcpy(ods->serial_num,
+                p->serial_desc ? p->serial_desc : default_serial_desc,
+                sizeof ods->serial_num);
+    ovs_strlcpy(ods->dp_desc, p->dp_desc ? p->dp_desc : default_dp_desc,
+                sizeof ods->dp_desc);
     ofconn_send_reply(ofconn, msg);
 
     return 0;

diff --git a/ofproto/ofproto.h b/ofproto/ofproto.h
index 27a55e9..cedb2cd 100644 (file)
--- a/ofproto/ofproto.h
+++ b/ofproto/ofproto.h
@@ -132,12 +132,6 @@ struct ofproto_controller {
     uint8_t dscp;               /* DSCP value for controller connection. */
 };
 
-#define DEFAULT_MFR_DESC "Nicira, Inc."
-#define DEFAULT_HW_DESC "Open vSwitch"
-#define DEFAULT_SW_DESC VERSION
-#define DEFAULT_SERIAL_DESC "None"
-#define DEFAULT_DP_DESC "None"
-
 void ofproto_enumerate_types(struct sset *types);
 const char *ofproto_normalize_type(const char *);