ospfd: Fix maxage/flush to not try flood twice, remember maxages for longer

2006-05-30 Paul Jakma <paul.jakma@sun.com>

	* (general) Fix confusion around MaxAge-ing and problem with
	  high-latency networks. Analysis and suggested fixes by
	  Phillip Spagnolo, in [quagga-dev 4132], on which this commit
	  expands slightly.
	* ospf_flood.{c,h}: (ospf_lsa_flush) new function.
	  Scope-general form of existing flush functions, essentially
	  the dormant ospf_maxage_flood() but without the ambiguity of
	  whether it is responsible for flooding.
	* ospf_lsa.c: (ospf_lsa_maxage) Role minimised to simply setup
	  LSA on the Maxage list and schedule removal - no more.
	  ospf_lsa_flush* being the primary way to kick-off flushes
	  of LSAs.
	  Don't hardcode the remover-timer value, which was too
	  short for very high-latency networks.
	  (ospf_maxage_lsa_remover) Just do what needs to be done to
	  remove maxage LSAs from the maxage list, remove the call
	  to ospf_flood_through().
	  Don't hardcode remove-timer value.
	  (ospf_lsa_{install,flush_schedule}) ospf_lsa_flush is the correct
	  entrypoint to flushing maxaged LSAs.
	  (lsa_header_set) Use a define for the initial age, useful for
	  testing.
	* ospf_opaque.c: (ospf_opaque_lsa_refresh) ditto.
	  (ospf_opaque_lsa_flush_schedule) ditto.
	* ospfd.h: ({struct ospf,ospf_new}) Add maxage_delay parameter,
	  interval to wait before running the maxage_remover. Supply a
	  suitable default.
	  Add a define for OSPF_LSA_INITIAL_AGE, see lsa_header_set().

6 files changed, 53 insertions, 44 deletions

diff --git a/ospfd/ospf_flood.c b/ospfd/ospf_flood.c
index 06d75740..77f2e161 100644
--- a/ospfd/ospf_flood.c
+++ b/ospfd/ospf_flood.c
@@ -991,3 +991,33 @@ ospf_lsa_flush_as (struct ospf *ospf, struct ospf_lsa *lsa)
   ospf_flood_through_as (ospf, NULL, lsa);
   ospf_lsa_maxage (ospf, lsa);
 }
+
+void
+ospf_lsa_flush (struct ospf *ospf, struct ospf_lsa *lsa)
+{
+  lsa->data->ls_age = htons (OSPF_LSA_MAXAGE);
+  
+  switch (lsa->data->type)
+    {
+      case OSPF_ROUTER_LSA:
+      case OSPF_NETWORK_LSA:
+      case OSPF_SUMMARY_LSA:
+      case OSPF_ASBR_SUMMARY_LSA:
+      case OSPF_AS_NSSA_LSA:
+#ifdef HAVE_OPAQUE_LSA
+      case OSPF_OPAQUE_LINK_LSA:
+      case OSPF_OPAQUE_AREA_LSA:
+#endif /* HAVE_OPAQUE_LSA */
+        ospf_lsa_flush_area (lsa, lsa->area);
+        break;
+      case OSPF_AS_EXTERNAL_LSA:
+#ifdef HAVE_OPAQUE_LSA
+      case OSPF_OPAQUE_AS_LSA:
+#endif /* HAVE_OPAQUE_LSA */
+        ospf_lsa_flush_as (ospf, lsa);
+        break;
+      default:
+        zlog_info ("%s: Unknown LSA type %u", __func__, lsa->data->type);
+        break;
+    }
+}
diff --git a/ospfd/ospf_flood.h b/ospfd/ospf_flood.h
index 5382e8fe..1ab11b88 100644
--- a/ospfd/ospf_flood.h
+++ b/ospfd/ospf_flood.h
@@ -66,6 +66,7 @@ extern void ospf_flood_lsa_area (struct ospf_lsa *, struct ospf_area *);
 extern void ospf_flood_lsa_as (struct ospf_lsa *);
 extern void ospf_lsa_flush_area (struct ospf_lsa *, struct ospf_area *);
 extern void ospf_lsa_flush_as (struct ospf *, struct ospf_lsa *);
+extern void ospf_lsa_flush (struct ospf *, struct ospf_lsa *);
 extern struct external_info *ospf_external_info_check (struct ospf_lsa *);
 
 extern void ospf_lsdb_init (struct ospf_lsdb *);
diff --git a/ospfd/ospf_lsa.c b/ospfd/ospf_lsa.c
index bdc40151..6f5ee3db 100644
--- a/ospfd/ospf_lsa.c
+++ b/ospfd/ospf_lsa.c
@@ -372,7 +372,7 @@ lsa_header_set (struct stream *s, u_char options,
 
   lsah = (struct lsa_header *) STREAM_DATA (s);
 
-  lsah->ls_age = htons (0);
+  lsah->ls_age = htons (OSPF_LSA_INITIAL_AGE);
   lsah->options = options;
   lsah->type = type;
   lsah->id = id;
@@ -2762,7 +2762,7 @@ ospf_lsa_install (struct ospf *ospf, struct ospf_interface *oi,
                    new->data->type, 
                    inet_ntoa (new->data->id), 
                    lsa);
-      ospf_lsa_maxage (ospf, lsa);
+      ospf_lsa_flush (ospf, lsa);
     }
 
   return new;
@@ -2794,35 +2794,6 @@ ospf_check_nbr_status (struct ospf *ospf)
 }
 
 
-#ifdef ORIGINAL_CODING
-/* This function flood the maxaged LSA to DR. */
-void
-ospf_maxage_flood (struct ospf_lsa *lsa)
-{
-  switch (lsa->data->type)
-    {
-    case OSPF_ROUTER_LSA:
-    case OSPF_NETWORK_LSA:
-    case OSPF_SUMMARY_LSA:
-    case OSPF_ASBR_SUMMARY_LSA:
-    case OSPF_AS_NSSA_LSA:
-#ifdef HAVE_OPAQUE_LSA
-    case OSPF_OPAQUE_LINK_LSA:
-    case OSPF_OPAQUE_AREA_LSA:
-#endif /* HAVE_OPAQUE_LSA */
-      ospf_flood_through_area (lsa->area, NULL, lsa);
-      break;
-    case OSPF_AS_EXTERNAL_LSA:
-#ifdef HAVE_OPAQUE_LSA
-    case OSPF_OPAQUE_AS_LSA:
-#endif /* HAVE_OPAQUE_LSA */
-      ospf_flood_through_as (NULL, lsa);
-      break;
-    default:
-      break;
-    }
-}
-#endif /* ORIGINAL_CODING */
 
 static int
 ospf_maxage_lsa_remover (struct thread *thread)
@@ -2862,13 +2833,6 @@ ospf_maxage_lsa_remover (struct thread *thread)
           zlog_debug ("LSA[Type%d:%s]: MaxAge LSA removed from list",
                      lsa->data->type, inet_ntoa (lsa->data->id));
 
-	/* Flood max age LSA. */
-#ifdef ORIGINAL_CODING
-	ospf_maxage_flood (lsa);
-#else /* ORIGINAL_CODING */
-        ospf_flood_through (ospf, NULL, lsa);
-#endif /* ORIGINAL_CODING */
-
 	if (CHECK_FLAG (lsa->flags, OSPF_LSA_PREMATURE_AGE))
           {
             if (IS_DEBUG_OSPF (lsa, LSA_FLOODING))
@@ -2892,7 +2856,8 @@ ospf_maxage_lsa_remover (struct thread *thread)
         neighbor Link state retransmission lists and b) none of the router's
         neighbors are in states Exchange or Loading. */
   if (reschedule)
-    OSPF_TIMER_ON (ospf->t_maxage, ospf_maxage_lsa_remover, 2);
+    OSPF_TIMER_ON (ospf->t_maxage, ospf_maxage_lsa_remover,
+                   ospf->maxage_delay);
 
   return 0;
 }
@@ -2910,6 +2875,11 @@ ospf_lsa_maxage_delete (struct ospf *ospf, struct ospf_lsa *lsa)
     }
 }
 
+/* Add LSA onto the MaxAge list, and schedule for removal.
+ * This does *not* lead to the LSA being flooded, that must be taken
+ * care of elsewhere, see, e.g., ospf_lsa_flush* (which are callers of this
+ * function).
+ */
 void
 ospf_lsa_maxage (struct ospf *ospf, struct ospf_lsa *lsa)
 {
@@ -2929,7 +2899,8 @@ ospf_lsa_maxage (struct ospf *ospf, struct ospf_lsa *lsa)
   if (IS_DEBUG_OSPF (lsa, LSA_FLOODING))
     zlog_debug ("LSA[%s]: MaxAge LSA remover scheduled.", dump_lsa_key (lsa));
 
-  OSPF_TIMER_ON (ospf->t_maxage, ospf_maxage_lsa_remover, 2);
+  OSPF_TIMER_ON (ospf->t_maxage, ospf_maxage_lsa_remover,
+                 ospf->maxage_delay);
 }
 
 static int
@@ -3296,6 +3267,7 @@ ospf_lsa_flush_schedule (struct ospf *ospf, struct ospf_lsa *lsa)
   switch (lsa->data->type)
     {
 #ifdef HAVE_OPAQUE_LSA
+    /* Opaque wants to be notified of flushes */
     case OSPF_OPAQUE_LINK_LSA:
     case OSPF_OPAQUE_AREA_LSA:
     case OSPF_OPAQUE_AS_LSA:
@@ -3303,7 +3275,7 @@ ospf_lsa_flush_schedule (struct ospf *ospf, struct ospf_lsa *lsa)
       break;
 #endif /* HAVE_OPAQUE_LSA */
     default:
-      ospf_lsa_maxage (ospf, lsa);
+      ospf_lsa_flush (ospf, lsa);
       break;
     }
 
diff --git a/ospfd/ospf_opaque.c b/ospfd/ospf_opaque.c
index 0b6ac4cb..6e90011e 100644
--- a/ospfd/ospf_opaque.c
+++ b/ospfd/ospf_opaque.c
@@ -1630,7 +1630,7 @@ ospf_opaque_lsa_refresh (struct ospf_lsa *lsa)
         zlog_debug ("LSA[Type%d:%s]: Flush stray Opaque-LSA", lsa->data->type, inet_ntoa (lsa->data->id));
 
       lsa->data->ls_age = htons (OSPF_LSA_MAXAGE);
-      ospf_lsa_maxage (ospf, lsa);
+      ospf_lsa_flush (ospf, lsa);
     }
   else
     (* functab->lsa_refresher)(lsa);
@@ -2108,7 +2108,7 @@ ospf_opaque_lsa_flush_schedule (struct ospf_lsa *lsa0)
     zlog_debug ("Schedule Type-%u Opaque-LSA to FLUSH: [opaque-type=%u, opaque-id=%x]", lsa->data->type, GET_OPAQUE_TYPE (ntohl (lsa->data->id.s_addr)), GET_OPAQUE_ID (ntohl (lsa->data->id.s_addr)));
 
   /* This lsa will be flushed and removed eventually. */
-  ospf_lsa_maxage (lsa0->area->ospf, lsa);
+  ospf_lsa_flush (lsa0->area->ospf, lsa);
 
 out:
   return;
diff --git a/ospfd/ospfd.c b/ospfd/ospfd.c
index 7db81cea..0188ffda 100644
--- a/ospfd/ospfd.c
+++ b/ospfd/ospfd.c
@@ -199,6 +199,7 @@ ospf_new (void)
   new->spf_hold_multiplier = 1;
 
   /* MaxAge init. */
+  new->maxage_delay = OSFP_LSA_MAXAGE_REMOVE_DELAY_DEFAULT;
   new->maxage_lsa = list_new ();
   new->t_maxage_walker =
     thread_add_timer (master, ospf_lsa_maxage_walker,
diff --git a/ospfd/ospfd.h b/ospfd/ospfd.h
index b7dc6762..0e57c452 100644
--- a/ospfd/ospfd.h
+++ b/ospfd/ospfd.h
@@ -58,6 +58,7 @@
 #endif
 #define OSPF_MIN_LS_INTERVAL                     5
 #define OSPF_MIN_LS_ARRIVAL                      1
+#define OSPF_LSA_INITIAL_AGE                     0	/* useful for debug */
 #define OSPF_LSA_MAXAGE                       3600
 #define OSPF_CHECK_AGE                         300
 #define OSPF_LSA_MAXAGE_DIFF                   900
@@ -66,7 +67,6 @@
 #define OSPF_INITIAL_SEQUENCE_NUMBER    0x80000001
 #define OSPF_MAX_SEQUENCE_NUMBER        0x7fffffff
 
-#define OSPF_LSA_MAXAGE_CHECK_INTERVAL          30
 #define OSPF_NSSA_TRANS_STABLE_DEFAULT		40
 
 #define OSPF_ALLSPFROUTERS              0xe0000005      /* 224.0.0.5 */
@@ -260,8 +260,13 @@ struct ospf
 #ifdef HAVE_OPAQUE_LSA
   struct thread *t_opaque_lsa_self;	/* Type-11 Opaque-LSAs origin event. */
 #endif /* HAVE_OPAQUE_LSA */
+
+#define OSFP_LSA_MAXAGE_REMOVE_DELAY_DEFAULT	60
+  unsigned int maxage_delay;		/* Delay on Maxage remover timer, sec */
   struct thread *t_maxage;              /* MaxAge LSA remover timer. */
+#define OSPF_LSA_MAXAGE_CHECK_INTERVAL		30
   struct thread *t_maxage_walker;       /* MaxAge LSA checking timer. */
+
   struct thread *t_deferred_shutdown;	/* deferred/stub-router shutdown timer*/
 
   struct thread *t_write;