From 8ce5e6a33ce4226d6749c5351020b550368d6d4b Mon Sep 17 00:00:00 2001
From: Donald Sharp <sharpd@cumulusnetworks.com>
Date: Tue, 7 Mar 2017 15:13:04 -0500
Subject: [PATCH] zebra: Notify all nexthops that we've changed

Zebra when it was scanning the tree would unset NEXTHOPS_CHANGED
after the first notification.  If the route we are notifying because
of covers multiple interesting nexthops then we would be unable
to know that we need to notify for that one as well because of
the flag removal.

Ticket: CM-15157
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
---
 zebra/zebra_rnh.c | 43 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/zebra/zebra_rnh.c b/zebra/zebra_rnh.c
index c4c11f98d9..edfe274922 100644
--- a/zebra/zebra_rnh.c
+++ b/zebra/zebra_rnh.c
@@ -620,9 +620,6 @@ zebra_rnh_eval_nexthop_entry (vrf_id_t vrfid, int family, int force,
    */
   if (!prefix_same(&rnh->resolved_route, &prn->p))
     {
-      if (rib)
-        UNSET_FLAG(rib->status, RIB_ENTRY_NEXTHOPS_CHANGED);
-
       if (prn)
         prefix_copy(&rnh->resolved_route, &prn->p);
       else
@@ -633,9 +630,6 @@ zebra_rnh_eval_nexthop_entry (vrf_id_t vrfid, int family, int force,
     }
   else if (compare_state(rib, rnh->state))
     {
-      if (rib)
-        UNSET_FLAG(rib->status, RIB_ENTRY_NEXTHOPS_CHANGED);
-
       copy_state(rnh, rib, nrn);
       state_changed = 1;
     }
@@ -692,6 +686,30 @@ zebra_rnh_evaluate_entry (vrf_id_t vrfid, int family, int force, rnh_type_t type
                                   nrn, rnh, prn, rib);
 }
 
+/*
+ * Clear the RIB_ENTRY_NEXTHOPS_CHANGED flag
+ * from the rib entries.
+ *
+ * Please note we are doing this *after* we have
+ * notified the world about each nexthop as that
+ * we can have a situation where one rib entry
+ * covers multiple nexthops we are interested in.
+ */
+static void
+zebra_rnh_clear_nhc_flag (vrf_id_t vrfid, int family, rnh_type_t type,
+                          struct route_node *nrn)
+{
+  struct rnh *rnh;
+  struct rib *rib;
+  struct route_node *prn;
+
+  rnh = nrn->info;
+
+  rib = zebra_rnh_resolve_entry (vrfid, family, type, nrn, rnh, &prn);
+
+  if (rib)
+    UNSET_FLAG (rib->status, RIB_ENTRY_NEXTHOPS_CHANGED);
+}
 
 /* Evaluate all tracked entries (nexthops or routes for import into BGP)
  * of a particular VRF and address-family or a specific prefix.
@@ -712,7 +730,11 @@ zebra_evaluate_rnh (vrf_id_t vrfid, int family, int force, rnh_type_t type,
       /* Evaluating a specific entry, make sure it exists. */
       nrn = route_node_lookup (rnh_table, p);
       if (nrn && nrn->info)
-        zebra_rnh_evaluate_entry (vrfid, family, force, type, nrn);
+        {
+          zebra_rnh_evaluate_entry (vrfid, family, force, type, nrn);
+          zebra_rnh_clear_nhc_flag (vrfid, family, type, nrn);
+        }
+
       if (nrn)
         route_unlock_node (nrn);
     }
@@ -726,6 +748,13 @@ zebra_evaluate_rnh (vrf_id_t vrfid, int family, int force, rnh_type_t type,
             zebra_rnh_evaluate_entry (vrfid, family, force, type, nrn);
           nrn = route_next(nrn); /* this will also unlock nrn */
         }
+      nrn = route_top (rnh_table);
+      while (nrn)
+        {
+          if (nrn->info)
+            zebra_rnh_clear_nhc_flag (vrfid, family, type, nrn);
+          nrn = route_next(nrn); /* this will also unlock nrn */
+        }
     }
 }
 
-- 
2.39.5