datapath: Fix build with backported skb_dst().

[sliver-openvswitch.git] / ofproto / ofproto.c

diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 2f105ec..dcf8683 100644 (file)
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -223,6 +223,8 @@ static struct ofconn *ofconn_create(struct ofproto *, struct rconn *,
 static void ofconn_destroy(struct ofconn *);
 static void ofconn_run(struct ofconn *, struct ofproto *);
 static void ofconn_wait(struct ofconn *);
+static bool ofconn_receives_async_msgs(const struct ofconn *);
+
 static void queue_tx(struct ofpbuf *msg, const struct ofconn *ofconn,
                      struct rconn_packet_counter *counter);
 
@@ -961,25 +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
@@ -1402,7 +1426,7 @@ send_port_status(struct ofproto *p, const struct ofport *ofport,
         struct ofp_port_status *ops;
         struct ofpbuf *b;
 
-        if (ofconn->role == NX_ROLE_SLAVE) {
+        if (!ofconn_receives_async_msgs(ofconn)) {
             continue;
         }
 
@@ -1651,6 +1675,22 @@ ofconn_wait(struct ofconn *ofconn)
         COVERAGE_INC(ofproto_ofconn_stuck);
     }
 }
+
+/* Returns true if 'ofconn' should receive asynchronous messages. */
+static bool
+ofconn_receives_async_msgs(const struct ofconn *ofconn)
+{
+    if (ofconn->type == OFCONN_CONTROLLER) {
+        /* Ordinary controllers always get asynchronous messages unless they
+         * have configured themselves as "slaves".  */
+        return ofconn->role != NX_ROLE_SLAVE;
+    } else {
+        /* Transient connections don't get asynchronous messages unless they
+         * have explicitly asked for them by setting a nonzero miss send
+         * length. */
+        return ofconn->miss_send_len > 0;
+    }
+}
 \f
 /* Caller is responsible for initializing the 'cr' member of the returned
  * rule. */
@@ -3864,7 +3904,7 @@ send_flow_removed(struct ofproto *p, struct rule *rule,
     prev = NULL;
     LIST_FOR_EACH (ofconn, struct ofconn, node, &p->all_conns) {
         if (rule->send_flow_removed && rconn_is_connected(ofconn->rconn)
-            && ofconn->role != NX_ROLE_SLAVE) {
+            && ofconn_receives_async_msgs(ofconn)) {
             if (prev) {
                 queue_tx(ofpbuf_clone(buf), prev, prev->reply_counter);
             } else {
@@ -4028,6 +4068,8 @@ schedule_packet_in(struct ofconn *ofconn, struct ofpbuf *packet, int max_len,
         buffer_id = UINT32_MAX;
     } else if (ofproto->fail_open && fail_open_is_active(ofproto->fail_open)) {
         buffer_id = pktbuf_get_null();
+    } else if (!ofconn->pktbuf) {
+        buffer_id = UINT32_MAX;
     } else {
         struct ofpbuf payload;
         payload.data = opi->data;
@@ -4124,7 +4166,7 @@ send_packet_in(struct ofproto *ofproto, struct ofpbuf *packet)
 
     prev = NULL;
     LIST_FOR_EACH (ofconn, struct ofconn, node, &ofproto->all_conns) {
-        if (ofconn->role != NX_ROLE_SLAVE) {
+        if (ofconn_receives_async_msgs(ofconn)) {
             if (prev) {
                 schedule_packet_in(prev, packet, max_len, true);
             }