Do not allow agent to modify a "NEW" flow

The "NEW" flag is set whenever a flow becomes active and is in the transient state. If agent tries to modify the entry in that state, a possibility because of reuse of an entry due to eviction, a condition could happen where the flags used by datapath could come from the flags set by agent, more specifically the Modified flag, and thus be in a state where nothing can be done in the entry. Hence, prevent agent from acting upon NEW flows. Change-Id: I017fd7d32f0488cef90a17c491c6021bbdd181c7 Closes-BUG: #1580855
Juniper · Jul 19, 2016 · 4a5554e · 4a5554e
1 parent ad180ee
commit 4a5554e
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/dp-core/vr_flow.c b/dp-core/vr_flow.c
@@ -343,7 +343,8 @@ vr_flow_start_modify(struct vrouter *router, struct vr_flow_entry *fe)
     unsigned short flags;
 
     flags = fe->fe_flags;
-    if (!(flags & (VR_FLOW_FLAG_MODIFIED | VR_FLOW_FLAG_EVICTED))) {
+    if (!(flags & (VR_FLOW_FLAG_MODIFIED | VR_FLOW_FLAG_EVICTED |
+                    VR_FLOW_FLAG_NEW_FLOW))) {
         if (__sync_bool_compare_and_swap(&fe->fe_flags, flags,
                     flags | VR_FLOW_FLAG_MODIFIED)) {
             return true;

diff --git a/include/vr_flow.h b/include/vr_flow.h
@@ -34,7 +34,8 @@ typedef enum {
 
 #define VR_FLOW_FLAG_DP_FLAGS           (VR_FLOW_FLAG_EVICT_CANDIDATE |\
                                             VR_FLOW_FLAG_EVICTED |\
-                                            VR_FLOW_FLAG_NEW_FLOW)
+                                            VR_FLOW_FLAG_NEW_FLOW |\
+                                            VR_FLOW_FLAG_MODIFIED)
 
 #define VR_FLOW_FLAG_DP_BITS(fe)        (((fe)->fe_flags) &\
                                             (VR_FLOW_FLAG_DP_FLAGS))