2003-10-13 sowmini.varadhan@sun.com

	* ospf_lsa.h: Add OSPF_LSA_PREMATURE_AGE flag.
	* ospf_lsa.c: added better debug comments. check sequence number in
	  ospf_lsa_install. ospf_maxage_lsa_remover() checks for
 	  OSPF_LSA_PREMATURE_AGE and re-originates the lsa after ls_acks are
	  received.
	* ospf_flood.c: improve debug statement- print ls_seqnum.

3 files changed, 64 insertions, 11 deletions

diff --git a/ospfd/ospf_flood.c b/ospfd/ospf_flood.c
index fc6ab137..50cc9af2 100644
--- a/ospfd/ospf_flood.c
+++ b/ospfd/ospf_flood.c
@@ -119,8 +119,9 @@ ospf_process_self_originated_lsa (struct ospf *ospf,
   listnode node;
   
   if (IS_DEBUG_OSPF_EVENT)
-    zlog_info ("LSA[Type%d:%s]: Process self-originated LSA",
-	       new->data->type, inet_ntoa (new->data->id));
+    zlog_info ("LSA[Type%d:%s]: Process self-originated LSA seq 0x%lx",
+	       new->data->type, inet_ntoa (new->data->id), 
+	       (u_long)new->data->ls_seqnum);
 
   /* If we're here, we installed a self-originated LSA that we received
      from a neighbor, i.e. it's more recent.  We must see whether we want
diff --git a/ospfd/ospf_lsa.c b/ospfd/ospf_lsa.c
index 079eea54..4711f0fe 100644
--- a/ospfd/ospf_lsa.c
+++ b/ospfd/ospf_lsa.c
@@ -2380,8 +2380,9 @@ ospf_router_lsa_install (struct ospf *ospf,
       area->router_lsa_self = ospf_lsa_lock (new);
 
       if (IS_DEBUG_OSPF (lsa, LSA_INSTALL))
-        zlog_info("LSA[Type%d]: ID %s is self-originated",
-                  new->data->type, inet_ntoa (new->data->id));
+	zlog_info("LSA[Type%d]: ID %s seq 0x%x is self-originated",
+		  new->data->type, inet_ntoa (new->data->id), 
+		  new->data->ls_seqnum);
     }
 
   return new;
@@ -2641,6 +2642,44 @@ ospf_lsa_install (struct ospf *ospf, struct ospf_interface *oi,
   if (  old == NULL || ospf_lsa_different(old, lsa))
     rt_recalc = 1;
 
+  /*
+     Sequence number check (Section 14.1 of rfc 2328)
+     "Premature aging is used when it is time for a self-originated
+      LSA's sequence number field to wrap.  At this point, the current
+      LSA instance (having LS sequence number MaxSequenceNumber) must
+      be prematurely aged and flushed from the routing domain before a
+      new instance with sequence number equal to InitialSequenceNumber
+      can be originated. "
+   */
+
+  if (lsa->data->ls_seqnum - 1 == htonl(OSPF_MAX_SEQUENCE_NUMBER))
+    {
+      if (ospf_lsa_is_self_originated(ospf, lsa))
+        {
+	  lsa->data->ls_seqnum = htonl(OSPF_MAX_SEQUENCE_NUMBER);
+	  if (!IS_LSA_MAXAGE(lsa))
+            lsa->flags |= OSPF_LSA_PREMATURE_AGE;
+          lsa->data->ls_age = htons (OSPF_LSA_MAXAGE);
+      	
+          if (IS_DEBUG_OSPF (lsa, LSA_REFRESH))
+            {
+      	      zlog_info ("ospf_lsa_install() Premature Aging "
+		         "lsa 0x%lx", (u_long)lsa);
+      	      ospf_lsa_header_dump (lsa->data);
+            }
+        }
+      else
+        {
+          if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
+            {
+      	      zlog_info ("ospf_lsa_install() got an lsa with seq 0x80000000 "
+		         "that was not self originated. Ignoring\n");
+      	      ospf_lsa_header_dump (lsa->data);
+            }
+	  return old;
+        }
+    }
+
   /* discard old LSA from LSDB */
   if (old != NULL)
     ospf_discard_from_db (ospf, lsdb, lsa);
@@ -2722,12 +2761,16 @@ ospf_lsa_install (struct ospf *ospf, struct ospf_interface *oi,
         }
     }
 
-  /* If received LSA' ls_age is MaxAge, set LSA on MaxAge LSA list. */
-  if (IS_LSA_MAXAGE (new) && !IS_LSA_SELF (new))
+  /* 
+     If received LSA' ls_age is MaxAge, or lsa is being prematurely aged
+     (it's getting flushed out of the area), set LSA on MaxAge LSA list. 
+   */
+  if ((lsa->flags & OSPF_LSA_PREMATURE_AGE) ||
+      (IS_LSA_MAXAGE (new) && !IS_LSA_SELF (new)))
     {
-      if (IS_DEBUG_OSPF (lsa, LSA_FLOODING))
-	zlog_info ("LSA[Type%d:%s]: Install LSA, MaxAge",
-		   new->data->type, inet_ntoa (new->data->id));
+      if (IS_DEBUG_OSPF (lsa, LSA_INSTALL))
+	zlog_info ("LSA[Type%d:%s]: Install LSA 0x%lx, MaxAge",
+		   new->data->type, inet_ntoa (new->data->id), (u_long)lsa);
       ospf_lsa_maxage (ospf, lsa);
     }
 
@@ -2822,8 +2865,8 @@ ospf_maxage_lsa_remover (struct thread *thread)
         /* Remove LSA from the LSDB */
         if (CHECK_FLAG (lsa->flags, OSPF_LSA_SELF))
           if (IS_DEBUG_OSPF (lsa, LSA_FLOODING))
-            zlog_info ("LSA[Type%d:%s]: This LSA is self-originated: ",
-                       lsa->data->type, inet_ntoa (lsa->data->id));
+            zlog_info ("LSA[Type%d:%s]: LSA 0x%lx is self-oririnated: ",
+                       lsa->data->type, inet_ntoa (lsa->data->id), (u_long)lsa);
 
         if (IS_DEBUG_OSPF (lsa, LSA_FLOODING))
           zlog_info ("LSA[Type%d:%s]: MaxAge LSA removed from list",
@@ -2836,6 +2879,14 @@ ospf_maxage_lsa_remover (struct thread *thread)
         ospf_flood_through (ospf, NULL, lsa);
 #endif /* ORIGINAL_CODING */
 
+	if (lsa->flags & OSPF_LSA_PREMATURE_AGE)  
+          {
+            if (IS_DEBUG_OSPF (lsa, LSA_FLOODING))
+              zlog_info ("originating new router lsa for lsa 0x%lx \n", 
+                         (u_long)lsa);
+            ospf_router_lsa_originate(lsa->area);
+          }
+
 	/* Remove from lsdb. */
         ospf_discard_from_db (ospf, lsa->lsdb, lsa);
         ospf_lsdb_delete (lsa->lsdb, lsa);
diff --git a/ospfd/ospf_lsa.h b/ospfd/ospf_lsa.h
index c5541c85..021d6a48 100644
--- a/ospfd/ospf_lsa.h
+++ b/ospfd/ospf_lsa.h
@@ -80,6 +80,7 @@ struct ospf_lsa
 #ifdef HAVE_NSSA
 #define OSPF_LSA_LOCAL_XLT	  0x20
 #endif /* HAVE_NSSA */
+#define OSPF_LSA_PREMATURE_AGE	  0x40
 
   /* LSA data. */
   struct lsa_header *data;