cfm: update remote opstate only when a CCM is received.

The remote opstate for a CFM interface is presumed to be up unless a CCM is
received which signals opstate down. This means than an interface configured
for CFM demand mode may incorrectly appear to be opstate up if it has not
received a CCM within the last fault interval.

We should remember the last remote opstate for a CFM interface and only
change it when a CCM arrives signaling a change.

Bug #18806
Signed-off-by: Paul Ingram <pingram@nicira.com>
Signed-off-by: Ethan Jackson <ethan@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/lib/cfm.c b/lib/cfm.c
index 0277fe623..0bd41bf96 100644
--- a/lib/cfm.c
+++ b/lib/cfm.c
@@ -390,6 +390,8 @@ cfm_run(struct cfm *cfm) OVS_EXCLUDED(mutex)
         struct remote_mp *rmp, *rmp_next;
         bool old_cfm_fault = cfm->fault;
         bool demand_override;
+        bool rmp_set_opup = false;
+        bool rmp_set_opdown = false;
 
         cfm->fault = cfm->recv_fault;
         cfm->recv_fault = 0;
@@ -399,7 +401,6 @@ cfm_run(struct cfm *cfm) OVS_EXCLUDED(mutex)
         cfm->rmps_array = xmalloc(hmap_count(&cfm->remote_mps) *
                                   sizeof *cfm->rmps_array);
 
-        cfm->remote_opup = true;
         if (cfm->health_interval == CFM_HEALTH_INTERVAL) {
             /* Calculate the cfm health of the interface.  If the number of
              * remote_mpids of a cfm interface is > 1, the cfm health is
@@ -451,14 +452,23 @@ cfm_run(struct cfm *cfm) OVS_EXCLUDED(mutex)
             } else {
                 rmp->recv = false;
 
-                if (!rmp->opup) {
-                    cfm->remote_opup = rmp->opup;
+                if (rmp->opup) {
+                    rmp_set_opup = true;
+                } else {
+                    rmp_set_opdown = true;
                 }
 
                 cfm->rmps_array[cfm->rmps_array_len++] = rmp->mpid;
             }
         }
 
+        if (rmp_set_opdown) {
+            cfm->remote_opup = false;
+        }
+        else if (rmp_set_opup) {
+            cfm->remote_opup = true;
+        }
+
         if (hmap_is_empty(&cfm->remote_mps)) {
             cfm->fault |= CFM_FAULT_RECV;
         }