ospfd: NSSA area should not exchange Type-4 LSAs in DD

Problem Statement:
==================
OSPF Peer gets stuck in EXSTART with ARISTA Device.

Root Cause:
=================
First peer is form with Arista device in normal area and then
the area type is changed to NSSA. Due to this Type-4 and Type-5
LSAs advertised by Arista router is still present in
the OSPF DB. While DD exchange the Type-5 LSAs are omitted but
the Type-4 LSAs are not omitted due to which Arista device gets
stuck in EXSTART and it keeps moving between EXCHANGE And EXSTART.

Fix:
=================
When the area is NSSA, we should not send Type-4 LSAs in DD
exchange packet.

Signed-off-by: Mobashshera Rasool <mrasool@vmware.com>

diff --git a/ospfd/ospf_nsm.c b/ospfd/ospf_nsm.c
index 892d264a2d5e3ca59f6947f5d0de13c53d49fd6b..268fb81e52a9fd97d5c7b30e6d302f655df041a0 100644 (file)
--- a/ospfd/ospf_nsm.c
+++ b/ospfd/ospf_nsm.c
@@ -298,8 +298,6 @@ static int nsm_negotiation_done(struct ospf_neighbor *nbr)
                ospf_db_summary_add(nbr, lsa);
        LSDB_LOOP (SUMMARY_LSDB(area), rn, lsa)
                ospf_db_summary_add(nbr, lsa);
-       LSDB_LOOP (ASBR_SUMMARY_LSDB(area), rn, lsa)
-               ospf_db_summary_add(nbr, lsa);
 
        /* Process only if the neighbor is opaque capable. */
        if (CHECK_FLAG(nbr->options, OSPF_OPTION_O)) {
@@ -314,10 +312,14 @@ static int nsm_negotiation_done(struct ospf_neighbor *nbr)
                        ospf_db_summary_add(nbr, lsa);
        }
 
+       /* For Stub/NSSA area, we should not send Type-4 and Type-5 LSAs */
        if (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK
-           && area->external_routing == OSPF_AREA_DEFAULT)
+           && area->external_routing == OSPF_AREA_DEFAULT) {
+               LSDB_LOOP (ASBR_SUMMARY_LSDB(area), rn, lsa)
+                       ospf_db_summary_add(nbr, lsa);
                LSDB_LOOP (EXTERNAL_LSDB(nbr->oi->ospf), rn, lsa)
                        ospf_db_summary_add(nbr, lsa);
+       }
 
        if (CHECK_FLAG(nbr->options, OSPF_OPTION_O)
            && (nbr->oi->type != OSPF_IFTYPE_VIRTUALLINK