OSPF: Fix net-summary origination combined with stubnet option

Stubnet nodes in OSPF FIB were removed during rt_sync(), but the pointer
remained in top_hash_entry.nf, so net-summary LSA origination was
confused, reported 'LSA ID collision' and net-summary LSAs were not
originated properly.

Thanks to Naveen Chowdary Yerramneni for bugreport and analysis.

2 files changed, 11 insertions, 7 deletions

diff --git a/proto/ospf/rt.c b/proto/ospf/rt.c
index 19f2d074..21aaf144 100644
--- a/proto/ospf/rt.c
+++ b/proto/ospf/rt.c
@@ -429,10 +429,9 @@ add_network(struct ospf_area *oa, ip_addr px, int pxlen, int metric, struct top_
   if (en == oa->rt)
   {
     /*
-     * Local stub networks does not have proper iface in en->nhi
-     * (because they all have common top_hash_entry en).
-     * We have to find iface responsible for that stub network.
-     * Configured stubnets does not have any iface. They will
+     * Local stub networks do not have proper iface in en->nhi (because they all
+     * have common top_hash_entry en). We have to find iface responsible for
+     * that stub network. Configured stubnets do not have any iface. They will
      * be removed in rt_sync().
      */
 
@@ -1560,6 +1559,7 @@ ospf_rt_reset(struct ospf_proto *p)
   {
     ri = (ort *) nftmp;
     ri->area_net = 0;
+    ri->keep = 0;
     reset_ri(ri);
   }
   FIB_WALK_END;
@@ -1929,9 +1929,12 @@ again1:
 	}
     }
 
-    /* Remove configured stubnets */
-    if (!nf->n.nhs)
+    /* Remove configured stubnets but keep the entries */
+    if (nf->n.type && !nf->n.nhs)
+    {
       reset_ri(nf);
+      nf->keep = 1;
+    }
 
     if (nf->n.type) /* Add the route */
     {
@@ -1991,7 +1994,7 @@ again1:
     }
 
     /* Remove unused rt entry, some special entries are persistent */
-    if (!nf->n.type && !nf->external_rte && !nf->area_net)
+    if (!nf->n.type && !nf->external_rte && !nf->area_net && !nf->keep)
     {
       FIB_ITERATE_PUT(&fit, nftmp);
       fib_delete(fib, nftmp);
diff --git a/proto/ospf/rt.h b/proto/ospf/rt.h
index 30332f3b..73b28375 100644
--- a/proto/ospf/rt.h
+++ b/proto/ospf/rt.h
@@ -84,6 +84,7 @@ typedef struct ort
   rta *old_rta;
   u8 external_rte;
   u8 area_net;
+  u8 keep;
 }
 ort;