Vrouter to return error for invalid flow op

If a flow operation is requested for an index which
is not active, vrouter should return an ENOENT error
for such operation

Closes-Bug: 1548678
Change-Id: I42bbd58f41a868b1ce630046ae40e911df0d9491
(cherry picked from commit 1cf3761)

dp-core/vr_flow.c

@@ -1587,6 +1587,15 @@ vr_flow_set_req_is_invalid(struct vrouter *router, vr_flow_req *req,
                 goto invalid_req;
             }
         }
+    } else {
+        /*
+         * flow set request received with an index which is
+         * not active anymore, return ENOENT error
+         */
+        if ((req->fr_flags & VR_FLOW_FLAG_ACTIVE) && !(req->fr_index < 0)) {
+            error = -ENOENT;
+            goto invalid_req;
+        }
     }
 
     if (req->fr_flags & VR_FLOW_FLAG_VRFT) {