ofproto: fix compile warning of ofproto/ofproto.c

[openvswitch] / ofproto / ofproto.c

diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 0ee69effbe6f978a149582b01001f3587ccd6518..41977874b8a5a9ab4e236000eaf8fb4755319930 100644 (file)
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -963,25 +963,47 @@ process_port_change(struct ofproto *ofproto, int error, char *devname)
     }
 }
 
+/* Returns a "preference level" for snooping 'ofconn'.  A higher return value
+ * means that 'ofconn' is more interesting for monitoring than a lower return
+ * value. */
+static int
+snoop_preference(const struct ofconn *ofconn)
+{
+    switch (ofconn->role) {
+    case NX_ROLE_MASTER:
+        return 3;
+    case NX_ROLE_OTHER:
+        return 2;
+    case NX_ROLE_SLAVE:
+        return 1;
+    default:
+        /* Shouldn't happen. */
+        return 0;
+    }
+}
+
 /* One of ofproto's "snoop" pvconns has accepted a new connection on 'vconn'.
  * Connects this vconn to a controller. */
 static void
 add_snooper(struct ofproto *ofproto, struct vconn *vconn)
 {
-    struct ofconn *ofconn;
+    struct ofconn *ofconn, *best;
 
-    /* Arbitrarily pick the first controller in the list for monitoring.  We
-     * could do something smarter or more flexible later, if it ever proves
-     * useful. */
+    /* Pick a controller for monitoring. */
+    best = NULL;
     LIST_FOR_EACH (ofconn, struct ofconn, node, &ofproto->all_conns) {
-        if (ofconn->type == OFCONN_CONTROLLER) {
-            rconn_add_monitor(ofconn->rconn, vconn);
-            return;
+        if (ofconn->type == OFCONN_CONTROLLER
+            && (!best || snoop_preference(ofconn) > snoop_preference(best))) {
+            best = ofconn;
         }
+    }
 
+    if (best) {
+        rconn_add_monitor(best->rconn, vconn);
+    } else {
+        VLOG_INFO_RL(&rl, "no controller connection to snoop");
+        vconn_close(vconn);
     }
-    VLOG_INFO_RL(&rl, "no controller connection to monitor");
-    vconn_close(vconn);
 }
 
 int
@@ -3518,7 +3540,7 @@ handle_role_request(struct ofproto *ofproto,
     uint32_t role;
 
     if (ntohs(msg->header.length) != sizeof *nrr) {
-        VLOG_WARN_RL(&rl, "received role request of length %zu (expected %zu)",
+        VLOG_WARN_RL(&rl, "received role request of length %u (expected %zu)",
                      ntohs(msg->header.length), sizeof *nrr);
         return ofp_mkerr(OFPET_BAD_REQUEST, OFPBRC_BAD_LEN);
     }
@@ -3568,7 +3590,7 @@ handle_vendor(struct ofproto *p, struct ofconn *ofconn, void *msg)
     struct nicira_header *nh;
 
     if (ntohs(ovh->header.length) < sizeof(struct ofp_vendor_header)) {
-        VLOG_WARN_RL(&rl, "received vendor message of length %zu "
+        VLOG_WARN_RL(&rl, "received vendor message of length %u "
                           "(expected at least %zu)",
                    ntohs(ovh->header.length), sizeof(struct ofp_vendor_header));
         return ofp_mkerr(OFPET_BAD_REQUEST, OFPBRC_BAD_LEN);
@@ -3577,7 +3599,7 @@ handle_vendor(struct ofproto *p, struct ofconn *ofconn, void *msg)
         return ofp_mkerr(OFPET_BAD_REQUEST, OFPBRC_BAD_VENDOR);
     }
     if (ntohs(ovh->header.length) < sizeof(struct nicira_header)) {
-        VLOG_WARN_RL(&rl, "received Nicira vendor message of length %zu "
+        VLOG_WARN_RL(&rl, "received Nicira vendor message of length %u "
                           "(expected at least %zu)",
                      ntohs(ovh->header.length), sizeof(struct nicira_header));
         return ofp_mkerr(OFPET_BAD_REQUEST, OFPBRC_BAD_LEN);