Temporary integrated OSPF commit.

13 files changed, 772 insertions, 687 deletions

diff --git a/proto/ospf/dbdes.c b/proto/ospf/dbdes.c
index 1f37965c..62b330ed 100644
--- a/proto/ospf/dbdes.c
+++ b/proto/ospf/dbdes.c
@@ -200,15 +200,11 @@ ospf_do_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
  * of the buffer.
  */
 void
-ospf_send_dbdes(struct ospf_neighbor *n, int next)
+ospf_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n, int next)
 {
-  struct ospf_iface *ifa = n->ifa;
-  struct ospf_area *oa = ifa->oa;
-  struct ospf_proto *p = oa->po;
-
   /* RFC 2328 10.8 */
 
-  if (oa->rt == NULL)
+  if (n->ifa->oa->rt == NULL)
     return;
 
   switch (n->state)
@@ -312,6 +308,7 @@ ospf_process_dbdes(struct ospf_proto *p, struct ospf_packet *pkt, struct ospf_ne
 	s_add_tail(&n->lsrql, SNODE req);
 
       req->lsa = lsa;
+      req->lsa_body = LSA_BODY_DUMMY;
     }
   }
 
@@ -394,7 +391,7 @@ ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa,
       n->imms = rcv_imms;
       OSPF_TRACE(D_PACKETS, "I'm slave to %I", n->ip);
       ospf_neigh_sm(n, INM_NEGDONE);
-      ospf_send_dbdes(n, 1);
+      ospf_send_dbdes(p, n, 1);
       break;
     }
 
@@ -426,7 +423,7 @@ ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa,
       if (!(n->myimms & DBDES_MS))
       {
 	/* Slave should retransmit dbdes packet */
-	ospf_send_dbdes(n, 0);
+	ospf_send_dbdes(p, n, 0);
       }
       return;
     }
@@ -472,7 +469,7 @@ ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa,
       if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M))
 	ospf_neigh_sm(n, INM_EXDONE);
       else
-	ospf_send_dbdes(n, 1);
+	ospf_send_dbdes(p, n, 1);
     }
     else
     {
@@ -489,7 +486,7 @@ ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa,
       if (ospf_process_dbdes(p, pkt, n) < 0)
 	return;
 
-      ospf_send_dbdes(n, 1);
+      ospf_send_dbdes(p, n, 1);
     }
     break;
 
@@ -504,7 +501,7 @@ ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa,
       if (!(n->myimms & DBDES_MS))
       {
 	/* Slave should retransmit dbdes packet */
-	ospf_send_dbdes(n, 0);
+	ospf_send_dbdes(p, n, 0);
       }
       return;
     }
diff --git a/proto/ospf/hello.c b/proto/ospf/hello.c
index 376eac3c..50cd8609 100644
--- a/proto/ospf/hello.c
+++ b/proto/ospf/hello.c
@@ -275,7 +275,7 @@ ospf_receive_hello(struct ospf_packet *pkt, struct ospf_iface *ifa,
   /* Check consistency of existing neighbor entry */
   if (n)
   {
-    unsigned t = ifa->type;
+    uint t = ifa->type;
     if (ospf_is_v2(p) && ((t == OSPF_IT_BCAST) || (t == OSPF_IT_NBMA) || (t == OSPF_IT_PTMP)))
     {
       /* Neighbor identified by IP address; Router ID may change */
diff --git a/proto/ospf/iface.c b/proto/ospf/iface.c
index 5e17371d..312e626a 100644
--- a/proto/ospf/iface.c
+++ b/proto/ospf/iface.c
@@ -620,18 +620,11 @@ ospf_iface_new(struct ospf_area *oa, struct ifa *addr, struct ospf_iface_patt *i
 
   add_tail(&oa->po->iface_list, NODE ifa);
 
-  /*
-   * In some cases we allow more ospf_ifaces on one physical iface.
-   * In OSPFv2, if they use different IP address prefix.
-   * In OSPFv3, if they use different instance_id.
-   * Therefore, we store such info to lock->addr field.
-   */
-
-  // XXXX review
   struct object_lock *lock = olock_new(pool);
-  lock->addr = ospf_is_v2(p) ? ifa->addr->prefix : _MI6(0,0,0,ifa->instance_id);
+  lock->addr = ospf_is_v2(p) ? ifa->addr->prefix : IPA_NONE;
   lock->type = OBJLOCK_IP;
   lock->port = OSPF_PROTO;
+  lock->inst = ifa->instance_id;
   lock->iface = iface;
   lock->data = ifa;
   lock->hook = ospf_iface_add;
@@ -997,7 +990,7 @@ ospf_walk_matching_iface_patts(struct ospf_proto *p, struct ospf_mip_walk *s)
 	BIT32_SET(s->ignore, id);
 
 	/* If we already found it in previous areas, ignore it and add warning */
-	if (!BIT32_TEST(s->active, id))
+	if (BIT32_TEST(s->active, id))
 	  { s->warn = 1; continue; }
 
 	BIT32_SET(s->active, id);
@@ -1046,7 +1039,7 @@ ospf_ifa_notify2(struct proto *P, uint flags, struct ifa *a)
   {
     struct ospf_mip_walk s = { .iface = a->iface, .a = a };
     while (ospf_walk_matching_iface_patts(p, &s))
-      ospf_iface_new(s.oa, s.a, s.ip);
+      ospf_iface_new(s.oa, a, s.ip);
   }
 
   if (flags & IF_CHANGE_DOWN)
@@ -1078,7 +1071,7 @@ ospf_ifa_notify3(struct proto *P, uint flags, struct ifa *a)
     {
       struct ospf_mip_walk s = { .iface = a->iface };
       while (ospf_walk_matching_iface_patts(p, &s))
-	ospf_iface_new(s.oa, s.a, s.ip);
+	ospf_iface_new(s.oa, a, s.ip);
     }
 
     if (flags & IF_CHANGE_DOWN)
diff --git a/proto/ospf/lsack.c b/proto/ospf/lsack.c
index aefddfb8..5cac3f69 100644
--- a/proto/ospf/lsack.c
+++ b/proto/ospf/lsack.c
@@ -79,10 +79,9 @@ ospf_reset_lsack_queue(struct ospf_neighbor *n)
 }
 
 static inline void
-ospf_send_lsack(struct ospf_neighbor *n, int queue)
+ospf_send_lsack_(struct ospf_proto *p, struct ospf_neighbor *n, int queue)
 {
   struct ospf_iface *ifa = n->ifa;
-  struct ospf_proto *p = ifa->oa->po;
   struct ospf_lsa_header *lsas;
   struct ospf_packet *pkt;
   struct lsa_node *no;
@@ -121,10 +120,10 @@ ospf_send_lsack(struct ospf_neighbor *n, int queue)
 }
 
 void
-ospf_lsack_send(struct ospf_neighbor *n, int queue)
+ospf_send_lsack(struct ospf_proto *p, struct ospf_neighbor *n, int queue)
 {
   while (!EMPTY_LIST(n->ackl[queue]))
-    ospf_send_lsack(n, queue);
+    ospf_send_lsack_(p, n, queue);
 }
 
 void
@@ -160,9 +159,6 @@ ospf_receive_lsack(struct ospf_packet *pkt, struct ospf_iface *ifa,
 
     if (lsa_comp(&lsa, &ret->lsa) != CMP_SAME)
     {
-      if ((lsa.sn == LSA_MAXSEQNO) && (lsa.age == LSA_MAXAGE))
-	continue;
-
       OSPF_TRACE(D_PACKETS, "Strange LSACK from %I", n->ip);
       OSPF_TRACE(D_PACKETS, "Type: %04x, Id: %R, Rt: %R",
 		 lsa_type, lsa.id, lsa.rt);
diff --git a/proto/ospf/lsreq.c b/proto/ospf/lsreq.c
index 8888f88e..1685ef13 100644
--- a/proto/ospf/lsreq.c
+++ b/proto/ospf/lsreq.c
@@ -71,7 +71,8 @@ ospf_send_lsreq(struct ospf_proto *p, struct ospf_neighbor *n)
   ospf_pkt_fill_hdr(ifa, pkt, LSREQ_P);
   ospf_lsreq_body(p, pkt, &lsrs, &lsr_max);
 
-  //  for (i = 0; i < lsr_max; i++)
+  /* We send smaller LSREQ to prevent multiple LSACKs as answer */
+  lsr_max = lsr_max / 4;
 
   i = 0;
   WALK_SLIST(en, n->lsrql)
diff --git a/proto/ospf/lsupd.c b/proto/ospf/lsupd.c
index b0bf21cd..37c89a24 100644
--- a/proto/ospf/lsupd.c
+++ b/proto/ospf/lsupd.c
@@ -115,7 +115,8 @@ ospf_lsa_lsrt_up(struct top_hash_entry *en, struct ospf_neighbor *n)
     s_add_tail(&n->lsrtl, SNODE ret);
   }
 
-  memcpy(&ret->lsa, &en->lsa, sizeof(struct ospf_lsa_header));
+  ret->lsa = en->lsa;
+  ret->lsa_body = LSA_BODY_DUMMY;
 }
 
 static inline int
@@ -134,25 +135,37 @@ ospf_lsa_lsrt_down(struct top_hash_entry *en, struct ospf_neighbor *n)
   return 0;
 }
 
+void
+ospf_add_flushed_to_lsrt(struct ospf_proto *p, struct ospf_neighbor *n)
+{
+  struct top_hash_entry *en;
+
+  WALK_SLIST(en, p->lsal)
+    if ((en->lsa.age == LSA_MAXAGE) && (en->lsa_body != NULL) &&
+	lsa_flooding_allowed(en->lsa_type, en->domain, n->ifa))
+      ospf_lsa_lsrt_up(en, n);
+}
+
 
-static void ospf_lsupd_flood_ifa(struct ospf_proto *p, struct ospf_iface *ifa, struct top_hash_entry *en);
+static void ospf_send_lsupd_to_ifa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_iface *ifa);
 
 
 /**
- * ospf_lsupd_flood - send received or generated LSA to the neighbors
- * @p: OSPF protocol
+ * ospf_flood_lsa - send LSA to the neighbors
+ * @p: OSPF protocol instance
  * @en: LSA entry
  * @from: neighbor than sent this LSA (or NULL if LSA is local)
  *
  * return value - was the LSA flooded back?
  */
-
 int
-ospf_lsupd_flood(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_neighbor *from)
+ospf_flood_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_neighbor *from)
 {
   struct ospf_iface *ifa;
   struct ospf_neighbor *n;
 
+  /* RFC 2328 13.3 */
+
   int back = 0;
   WALK_LIST(ifa, p->iface_list)
   {
@@ -185,6 +198,8 @@ ospf_lsupd_flood(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_ne
 	  {
 	    s_rem_node(SNODE req);
 	    ospf_hash_delete(n->lsrqh, req);
+	    n->want_lsreq = 1;
+
 	    if ((EMPTY_SLIST(n->lsrql)) && (n->state == NEIGHBOR_LOADING))
 	      ospf_neigh_sm(n, INM_LOADDONE);
 	  }
@@ -227,7 +242,7 @@ ospf_lsupd_flood(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_ne
     }
 
     /* 13.3 (5) - finally flood the packet */
-    ospf_lsupd_flood_ifa(p, ifa, en);
+    ospf_send_lsupd_to_ifa(p, en, ifa);
   }
 
   return back;
@@ -288,7 +303,7 @@ ospf_prepare_lsupd(struct ospf_proto *p, struct ospf_iface *ifa,
 
 
 static void
-ospf_lsupd_flood_ifa(struct ospf_proto *p, struct ospf_iface *ifa, struct top_hash_entry *en)
+ospf_send_lsupd_to_ifa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_iface *ifa)
 {
   uint c = ospf_prepare_lsupd(p, ifa, &en, 1);
 
@@ -384,7 +399,8 @@ ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa,
 
   /* RFC 2328 13. */
 
-  int sendreq = 1;	  /* XXXX: review sendreq */
+  int skip_lsreq = 0;
+  n->want_lsreq = 0;
 
   uint plen = ntohs(pkt->length);
   if (plen < (ospf_lsupd_hdrlen(p) + sizeof(struct ospf_lsa_header)))
@@ -436,7 +452,7 @@ ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa,
     u16 chsum = lsa_n->checksum;
     if (chsum != lsasum_check(lsa_n, NULL))
     {
-      log(L_WARN "%s: Received LSA from %I with bad checskum: %x %x",
+      log(L_WARN "%s: Received LSA from %I with bad checksum: %x %x",
 	  p->p.name, n->ip, chsum, lsa_n->checksum);
       continue;
     }
@@ -501,7 +517,7 @@ ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa,
       if (en && ((now - en->inst_time) < MINLSARRIVAL))
       {
 	OSPF_TRACE(D_EVENTS, "Skipping LSA received in less that MinLSArrival");
-	sendreq = 0;
+	skip_lsreq = 1;
 	continue;
       }
 
@@ -514,7 +530,6 @@ ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa,
       {
 	log(L_WARN "%s: Received invalid LSA from %I", p->p.name, n->ip);
 	mb_free(body);
-	sendreq = 0;
 	continue;
       }
 
@@ -528,22 +543,27 @@ ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa,
       }
 
       /* 13. (5c) - remove old LSA from all retransmission lists */
-      /* Must be done before (5b), otherwise it also removes the new entries from (5b) */
-
+      /*
+       * We only need to remove it from the retransmission list of the neighbor
+       * that send us the new LSA. The old LSA is automatically replaced in
+       * retransmission lists by the new LSA.
+       */
       if (en)
 	ospf_lsa_lsrt_down(en, n);
 
+#if 0
       /*
-      {
-	struct ospf_iface *ifi;
-	struct ospf_neighbor *ni;
-
-	WALK_LIST(ifi, p->iface_list)
-	  WALK_LIST(ni, ifi->neigh_list)
-	    if (ni->state > NEIGHBOR_EXSTART)
-	      ospf_lsa_lsrt_down(en, ni);
-      }
-      */
+       * Old code for removing LSA from all retransmission lists. Must be done
+       * before (5b), otherwise it also removes the new entries from (5b).
+       */
+      struct ospf_iface *ifi;
+      struct ospf_neighbor *ni;
+
+      WALK_LIST(ifi, p->iface_list)
+	WALK_LIST(ni, ifi->neigh_list)
+	if (ni->state > NEIGHBOR_EXSTART)
+	  ospf_lsa_lsrt_down(en, ni);
+#endif
 
       /* 13. (5d) - install new LSA into database */
       en = ospf_install_lsa(p, &lsa, lsa_type, lsa_domain, body);
@@ -553,7 +573,7 @@ ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa,
 	ospf_notify_net_lsa(ifa);
 
       /* 13. (5b) - flood new LSA */
-      int flood_back = ospf_lsupd_flood(p, en, n);
+      int flood_back = ospf_flood_lsa(p, en, n);
 
       /* 13.5. - schedule ACKs (tbl 19, cases 1+2) */ 
       if (! flood_back)
@@ -582,7 +602,7 @@ ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa,
       else
 	ospf_enqueue_lsack(n, lsa_n, ACKL_DIRECT);
 
-      sendreq = 0;
+      skip_lsreq = 1;
       continue;
     }
 
@@ -598,11 +618,17 @@ ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa,
     }
   }
 
-  /* Send direct LSAs */
-  ospf_lsack_send(n, ACKL_DIRECT);
-
-  /* If loading, ask for another part of neighbor's database */
-  if (sendreq && (n->state == NEIGHBOR_LOADING))
+  /* Send direct LSACKs */
+  ospf_send_lsack(p, n, ACKL_DIRECT);
+
+  /*
+   * In loading state, we should ask for another batch of LSAs. This is only
+   * vaguely mentioned in RFC 2328. We send a new LSREQ only if the current
+   * LSUPD actually removed some entries from LSA request list (want_lsreq) and
+   * did not contain duplicate or early LSAs (skip_lsreq). The first condition
+   * prevents endless floods, the second condition helps with flow control.
+   */
+  if ((n->state == NEIGHBOR_LOADING) && n->want_lsreq && !skip_lsreq)
     ospf_send_lsreq(p, n);
 }
 
diff --git a/proto/ospf/neighbor.c b/proto/ospf/neighbor.c
index 392f1d64..c182f0d2 100644
--- a/proto/ospf/neighbor.c
+++ b/proto/ospf/neighbor.c
@@ -33,13 +33,26 @@ static void rxmt_timer_hook(timer * timer);
 static void ackd_timer_hook(timer * t);
 
 static void
-init_lists(struct ospf_neighbor *n)
+init_lists(struct ospf_proto *p, struct ospf_neighbor *n)
 {
   s_init_list(&(n->lsrql));
-  n->lsrqh = ospf_top_new(n->pool);
+  n->lsrqh = ospf_top_new(p, n->pool);
 
   s_init_list(&(n->lsrtl));
-  n->lsrth = ospf_top_new(n->pool);
+  n->lsrth = ospf_top_new(p, n->pool);
+}
+
+static void
+release_lsrtl(struct ospf_proto *p, struct ospf_neighbor *n)
+{
+  struct top_hash_entry *ret, *en;
+
+  WALK_SLIST(ret, n->lsrtl)
+  {
+    en = ospf_hash_find_entry(p->gr, ret);
+    if (en)
+      en->ret_count--;
+  }
 }
 
 /* Resets LSA request and retransmit lists.
@@ -47,11 +60,12 @@ init_lists(struct ospf_neighbor *n)
  * it is reset during entering EXCHANGE state.
  */
 static void
-reset_lists(struct ospf_neighbor *n)
+reset_lists(struct ospf_proto *p, struct ospf_neighbor *n)
 {
+  release_lsrtl(p,n);
   ospf_top_free(n->lsrqh);
   ospf_top_free(n->lsrth);
-  init_lists(n);
+  init_lists(p, n);
 }
 
 struct ospf_neighbor *
@@ -68,7 +82,7 @@ ospf_neighbor_new(struct ospf_iface *ifa)
   n->csn = 0;
   n->state = NEIGHBOR_DOWN;
 
-  init_lists(n);
+  init_lists(p, n);
   s_init(&(n->dbsi), &(p->lsal));
 
   n->inactim = tm_new(pool);
@@ -360,6 +374,10 @@ ospf_neigh_sm(struct ospf_neighbor *n, int event)
       s_get(&(n->dbsi));
       s_init(&(n->dbsi), &p->lsal);
 
+      /* Add MaxAge LSA entries to retransmission list */
+      ospf_add_flushed_to_lsrt(p, n);
+
+      /* FIXME: Why is this here ? */
       ospf_reset_lsack_queue(n);
     }
     else
@@ -388,7 +406,7 @@ ospf_neigh_sm(struct ospf_neighbor *n, int event)
       if (n->state >= NEIGHBOR_EXSTART)
 	if (!can_do_adj(n))
 	{
-	  reset_lists(n);
+	  reset_lists(p,n);
 	  neigh_chstate(n, NEIGHBOR_2WAY);
 	}
       break;
@@ -399,7 +417,7 @@ ospf_neigh_sm(struct ospf_neighbor *n, int event)
   case INM_BADLSREQ:
     if (n->state >= NEIGHBOR_EXCHANGE)
     {
-      reset_lists(n);
+      reset_lists(p, n);
       neigh_chstate(n, NEIGHBOR_EXSTART);
     }
     break;
@@ -407,12 +425,12 @@ ospf_neigh_sm(struct ospf_neighbor *n, int event)
   case INM_KILLNBR:
   case INM_LLDOWN:
   case INM_INACTTIM:
-    reset_lists(n);
+    reset_lists(p, n);
     neigh_chstate(n, NEIGHBOR_DOWN);
     break;
 
   case INM_1WAYREC:
-    reset_lists(n);
+    reset_lists(p, n);
     neigh_chstate(n, NEIGHBOR_INIT);
     break;
 
@@ -552,8 +570,10 @@ ospf_neigh_remove(struct ospf_neighbor *n)
       nn->found = 0;
   }
 
-  s_get(&(n->dbsi));
   neigh_chstate(n, NEIGHBOR_DOWN);
+
+  s_get(&(n->dbsi));
+  release_lsrtl(p, n);
   rem_node(NODE n);
   rfree(n->pool);
   OSPF_TRACE(D_EVENTS, "Deleting neigbor %R", n->rid);
@@ -620,9 +640,9 @@ ospf_sh_neigh_info(struct ospf_neighbor *n)
 }
 
 static void
-rxmt_timer_hook(timer * timer)
+rxmt_timer_hook(timer *t)
 {
-  struct ospf_neighbor *n = (struct ospf_neighbor *) timer->data;
+  struct ospf_neighbor *n = t->data;
   struct ospf_proto *p = n->ifa->oa->po;
 
   DBG("%s: RXMT timer fired on interface %s for neigh %I\n",
@@ -631,12 +651,12 @@ rxmt_timer_hook(timer * timer)
   switch (n->state)
   {
   case NEIGHBOR_EXSTART:
-    ospf_send_dbdes(n, 1);
+    ospf_send_dbdes(p, n, 1);
     return;
 
   case NEIGHBOR_EXCHANGE:
   if (n->myimms & DBDES_MS)
-    ospf_send_dbdes(n, 0);
+    ospf_send_dbdes(p, n, 0);
   case NEIGHBOR_LOADING:
     ospf_send_lsreq(p, n);
     return;
@@ -653,8 +673,13 @@ rxmt_timer_hook(timer * timer)
 }
 
 static void
-ackd_timer_hook(timer * t)
+ackd_timer_hook(timer *t)
 {
   struct ospf_neighbor *n = t->data;
-  ospf_lsack_send(n, ACKL_DELAY);
+  struct ospf_proto *p = n->ifa->oa->po;
+
+  DBG("%s: ACKD timer fired on interface %s for neigh %I\n",
+      p->p.name, n->ifa->ifname, n->ip);
+
+  ospf_send_lsack(p, n, ACKL_DELAY);
 }
diff --git a/proto/ospf/ospf.c b/proto/ospf/ospf.c
index abcd527a..df5fe472 100644
--- a/proto/ospf/ospf.c
+++ b/proto/ospf/ospf.c
@@ -11,93 +11,81 @@
 /**
  * DOC: Open Shortest Path First (OSPF)
  * 
- * The OSPF protocol is quite complicated and its complex implemenation is
- * split to many files. In |ospf.c|, you will find mainly the interface
- * for communication with the core (e.g., reconfiguration hooks, shutdown
- * and initialisation and so on). In |packet.c|, you will find various
- * functions for sending and receiving generic OSPF packets. There are
- * also routines for authentication and checksumming. File |iface.c| contains
- * the interface state machine and functions for allocation and deallocation of OSPF's
- * interface data structures. Source |neighbor.c| includes the neighbor state
- * machine and functions for election of Designated Router and Backup
- * Designated router. In |hello.c|, there are routines for sending
- * and receiving of hello packets as well as functions for maintaining
- * wait times and the inactivity timer. Files |lsreq.c|, |lsack.c|, |dbdes.c|
- * contain functions for sending and receiving of link-state requests,
- * link-state acknowledgements and database descriptions respectively.
- * In |lsupd.c|, there are functions for sending and receiving
- * of link-state updates and also the flooding algorithm. Source |topology.c| is
- * a place where routines for searching LSAs in the link-state database,
- * adding and deleting them reside, there also are functions for originating
- * of various types of LSAs (router LSA, net LSA, external LSA). File |rt.c|
- * contains routines for calculating the routing table. |lsalib.c| is a set
- * of various functions for working with the LSAs (endianity conversions,
- * calculation of checksum etc.).
+ * The OSPF protocol is quite complicated and its complex implemenation is split
+ * to many files. In |ospf.c|, you will find mainly the interface for
+ * communication with the core (e.g., reconfiguration hooks, shutdown and
+ * initialisation and so on). File |iface.c| contains the interface state
+ * machine and functions for allocation and deallocation of OSPF's interface
+ * data structures. Source |neighbor.c| includes the neighbor state machine and
+ * functions for election of Designated Router and Backup Designated router. In
+ * |packet.c|, you will find various functions for sending and receiving generic
+ * OSPF packets. There are also routines for authentication and checksumming.
+ * In |hello.c|, there are routines for sending and receiving of hello packets
+ * as well as functions for maintaining wait times and the inactivity timer.
+ * Files |lsreq.c|, |lsack.c|, |dbdes.c| contain functions for sending and
+ * receiving of link-state requests, link-state acknowledgements and database
+ * descriptions respectively.  In |lsupd.c|, there are functions for sending and
+ * receiving of link-state updates and also the flooding algorithm. Source
+ * |topology.c| is a place where routines for searching LSAs in the link-state
+ * database, adding and deleting them reside, there also are functions for
+ * originating of various types of LSAs (router LSA, net LSA, external LSA).
+ * File |rt.c| contains routines for calculating the routing table. |lsalib.c|
+ * is a set of various functions for working with the LSAs (endianity
+ * conversions, calculation of checksum etc.).
  *
- * One instance of the protocol is able to hold LSA databases for
- * multiple OSPF areas, to exchange routing information between
- * multiple neighbors and to calculate the routing tables. The core
- * structure is &ospf_proto to which multiple &ospf_area and
- * &ospf_iface structures are connected. &ospf_area is also connected to
- * &top_hash_graph which is a dynamic hashing structure that
- * describes the link-state database. It allows fast search, addition
- * and deletion. Each LSA is kept in two pieces: header and body. Both of them are
+ * One instance of the protocol is able to hold LSA databases for multiple OSPF
+ * areas, to exchange routing information between multiple neighbors and to
+ * calculate the routing tables. The core structure is &ospf_proto to which
+ * multiple &ospf_area and &ospf_iface structures are connected. &ospf_proto is
+ * also connected to &top_hash_graph which is a dynamic hashing structure that
+ * describes the link-state database. It allows fast search, addition and
+ * deletion. Each LSA is kept in two pieces: header and body. Both of them are
  * kept in the endianity of the CPU.
  *
- * In OSPFv2 specification, it is implied that there is one IP prefix
- * for each physical network/interface (unless it is an ptp link). But
- * in modern systems, there might be more independent IP prefixes
- * associated with an interface.  To handle this situation, we have
- * one &ospf_iface for each active IP prefix (instead for each active
- * iface); This behaves like virtual interface for the purpose of OSPF.
- * If we receive packet, we associate it with a proper virtual interface
- * mainly according to its source address.
+ * In OSPFv2 specification, it is implied that there is one IP prefix for each
+ * physical network/interface (unless it is an ptp link). But in modern systems,
+ * there might be more independent IP prefixes associated with an interface.  To
+ * handle this situation, we have one &ospf_iface for each active IP prefix
+ * (instead for each active iface); This behaves like virtual interface for the
+ * purpose of OSPF.  If we receive packet, we associate it with a proper virtual
+ * interface mainly according to its source address.
  *
- * OSPF keeps one socket per &ospf_iface. This allows us (compared to
- * one socket approach) to evade problems with a limit of multicast
- * groups per socket and with sending multicast packets to appropriate
- * interface in a portable way. The socket is associated with
- * underlying physical iface and should not receive packets received
- * on other ifaces (unfortunately, this is not true on
- * BSD). Generally, one packet can be received by more sockets (for
- * example, if there are more &ospf_iface on one physical iface),
- * therefore we explicitly filter received packets according to
- * src/dst IP address and received iface.
+ * OSPF keeps one socket per &ospf_iface. This allows us (compared to one socket
+ * approach) to evade problems with a limit of multicast groups per socket and
+ * with sending multicast packets to appropriate interface in a portable way.
+ * The socket is associated with underlying physical iface and should not
+ * receive packets received on other ifaces (unfortunately, this is not true on
+ * BSD). Generally, one packet can be received by more sockets (for example, if
+ * there are more &ospf_iface on one physical iface), therefore we explicitly
+ * filter received packets according to src/dst IP address and received iface.
  *
- * Vlinks are implemented using particularly degenerate form of
- * &ospf_iface, which has several exceptions: it does not have its
- * iface or socket (it copies these from 'parent' &ospf_iface) and it
- * is present in iface list even when down (it is not freed in
- * ospf_iface_down()).
+ * Vlinks are implemented using particularly degenerate form of &ospf_iface,
+ * which has several exceptions: it does not have its iface or socket (it copies
+ * these from 'parent' &ospf_iface) and it is present in iface list even when
+ * down (it is not freed in ospf_iface_down()).
  *
  * The heart beat of ospf is ospf_disp(). It is called at regular intervals
- * (&ospf_proto->tick). It is responsible for aging and flushing of LSAs in
- * the database, for routing table calculaction and it call area_disp() of every
- * ospf_area.
+ * (&ospf_proto->tick). It is responsible for aging and flushing of LSAs in the
+ * database, updating topology information in LSAs and for routing table
+ * calculation.
  * 
- * The function area_disp() is
- * responsible for late originating of router LSA and network LSA
- * and for cleanup before routing table calculation process in
- * the area.
- * To every &ospf_iface, we connect one or more
- * &ospf_neighbor's -- a structure containing many timers and queues
- * for building adjacency and for exchange of routing messages.
+ * To every &ospf_iface, we connect one or more &ospf_neighbor's -- a structure
+ * containing many timers and queues for building adjacency and for exchange of
+ * routing messages.
  *
- * BIRD's OSPF implementation respects RFC2328 in every detail, but
- * some of internal algorithms do differ. The RFC recommends making a snapshot
- * of the link-state database when a new adjacency is forming and sending
- * the database description packets based on the information in this 
- * snapshot. The database can be quite large in some networks, so
- * rather we walk through a &slist structure which allows us to
- * continue even if the actual LSA we were working with is deleted. New
- * LSAs are added at the tail of this &slist.
+ * BIRD's OSPF implementation respects RFC2328 in every detail, but some of
+ * internal algorithms do differ. The RFC recommends making a snapshot of the
+ * link-state database when a new adjacency is forming and sending the database
+ * description packets based on the information in this snapshot. The database
+ * can be quite large in some networks, so rather we walk through a &slist
+ * structure which allows us to continue even if the actual LSA we were working
+ * with is deleted. New LSAs are added at the tail of this &slist.
  *
- * We also don't keep a separate OSPF routing table, because the core
- * helps us by being able to recognize when a route is updated
- * to an identical one and it suppresses the update automatically.
- * Due to this, we can flush all the routes we've recalculated and
- * also those we've deleted to the core's routing table and the
- * core will take care of the rest. This simplifies the process
+ * We also do not keep a separate OSPF routing table, because the core helps us
+ * by being able to recognize when a route is updated to an identical one and it
+ * suppresses the update automatically. Due to this, we can flush all the routes
+ * we have recalculated and also those we have deleted to the core's routing
+ * table and the core will take care of the rest. This simplifies the process
  * and conserves memory.
  */
 
@@ -145,7 +133,7 @@ add_area_nets(struct ospf_area *oa, struct ospf_area_config *ac)
 }
 
 static void
-ospf_area_add(struct ospf_proto *p, struct ospf_area_config *ac, int reconf)
+ospf_area_add(struct ospf_proto *p, struct ospf_area_config *ac)
 {
   struct ospf_area *oa;
 
@@ -169,6 +157,8 @@ ospf_area_add(struct ospf_proto *p, struct ospf_area_config *ac, int reconf)
     oa->options = ac->type;
   else
     oa->options = ac->type | OPT_V6 | (p->stub_router ? 0 : OPT_R);
+
+  ospf_notify_rt_lsa(oa);
 }
 
 static void
@@ -252,11 +242,11 @@ ospf_start(struct proto *P)
   init_list(&(p->area_list));
   fib_init(&p->rtf, P->pool, sizeof(ort), 0, ospf_rt_initort);
   p->areano = 0;
-  p->gr = ospf_top_new(P->pool);
+  p->gr = ospf_top_new(p, P->pool);
   s_init_list(&(p->lsal));
 
   WALK_LIST(ac, c->area_list)
-    ospf_area_add(p, ac, 0);
+    ospf_area_add(p, ac);
 
   if (c->abr)
     ospf_open_vlink_sk(p);
@@ -382,7 +372,7 @@ ospf_build_attrs(ea_list * next, struct linpool *pool, u32 m1, u32 m2,
 
 
 void
-schedule_rtcalc(struct ospf_proto *p)
+ospf_schedule_rtcalc(struct ospf_proto *p)
 {
   if (p->calcrt)
     return;
@@ -418,7 +408,7 @@ ospf_disp(timer * timer)
   /* Originate or flush local topology LSAs */
   ospf_update_topology(p);
 
-  /* Age LSA DB */
+  /* Process LSA DB */
   ospf_update_lsadb(p);
 
   /* Calculate routing table */
@@ -429,7 +419,7 @@ ospf_disp(timer * timer)
 
 /**
  * ospf_import_control - accept or reject new route from nest's routing table
- * @p: current instance of protocol
+ * @P: OSPF protocol instance
  * @new: the new route
  * @attrs: list of attributes
  * @pool: pool for allocation of attributes
@@ -475,7 +465,7 @@ ospf_store_tmp_attrs(struct rte *rt, struct ea_list *attrs)
 
 /**
  * ospf_shutdown - Finish of OSPF instance
- * @p: current instance of protocol
+ * @P: OSPF protocol instance
  *
  * RFC does not define any action that should be taken before router
  * shutdown. To make my neighbors react as fast as possible, I send
@@ -619,7 +609,7 @@ ospf_area_reconfigure(struct ospf_area *oa, struct ospf_area_config *nac)
 
 /**
  * ospf_reconfigure - reconfiguration hook
- * @p: current instance of protocol (with old configuration)
+ * @P: current instance of protocol (with old configuration)
  * @c: new configuration requested by user
  *
  * This hook tries to be a little bit intelligent. Instance of OSPF
@@ -669,7 +659,7 @@ ospf_reconfigure(struct proto *P, struct proto_config *c)
     if (oa)
       ospf_area_reconfigure(oa, nac);
     else
-      ospf_area_add(p, nac, 1);
+      ospf_area_add(p, nac);
   }
 
   /* Add and update interfaces */
@@ -697,7 +687,7 @@ ospf_reconfigure(struct proto *P, struct proto_config *c)
     if (oa->marked)
       ospf_area_remove(oa);
 
-  schedule_rtcalc(p);
+  ospf_schedule_rtcalc(p);
   
   return 1;
 }
@@ -1009,7 +999,7 @@ show_lsa_router(struct ospf_proto *p, struct top_hash_entry *he, int verbose)
 	/* In OSPFv2, we try to find network-LSA to get prefix/pxlen */
 	struct top_hash_entry *net_he = ospf_hash_find_net2(p->gr, he->domain, rtl.id);
 
-	if (net_he)
+	if (net_he && (net_he->lsa.age < LSA_MAXAGE))
 	{
 	  struct ospf_lsa_header *net_lsa = &(net_he->lsa);
 	  struct ospf_lsa_net *net_ln = net_he->lsa_body;
@@ -1367,8 +1357,8 @@ void
 ospf_sh_lsadb(struct lsadb_show_data *ld)
 {
   struct ospf_proto *p = (struct ospf_proto *) proto_get_named(ld->name, &proto_ospf);
-  int num = p->gr->hash_entries;
-  unsigned int i, j;
+  uint num = p->gr->hash_entries;
+  uint i, j;
   int last_dscope = -1;
   u32 last_domain = 0;
   u16 type_mask = ospf_is_v2(p) ?  0x00ff : 0xffff;	/* see lsa_etype() */
diff --git a/proto/ospf/ospf.h b/proto/ospf/ospf.h
index 34c26b47..e5713628 100644
--- a/proto/ospf/ospf.h
+++ b/proto/ospf/ospf.h
@@ -102,7 +102,7 @@ do { if ((p->p.debug & D_PACKETS) || OSPF_FORCE_DEBUG) \
 struct ospf_config
 {
   struct proto_config c;
-  unsigned tick;
+  uint tick;
   byte ospf2;
   byte rfc1583;
   byte stub_router;
@@ -110,16 +110,26 @@ struct ospf_config
   byte abr;
   byte asbr;
   int ecmp;
-  list area_list;		/* list of struct ospf_area_config */
-  list vlink_list;		/* list of struct ospf_iface_patt */
+  list area_list;		/* list of area configs (struct ospf_area_config) */
+  list vlink_list;		/* list of configured vlinks (struct ospf_iface_patt) */
 };
 
-struct nbma_node
+struct ospf_area_config
 {
   node n;
-  ip_addr ip;
-  byte eligible;
-  byte found; 
+  u32 areaid;
+  u32 default_cost;		/* Cost of default route for stub areas
+				   (With possible LSA_EXT3_EBIT for NSSA areas) */
+  u8 type;			/* Area type (standard, stub, NSSA), represented
+				   by option flags (OPT_E, OPT_N) */
+  u8 summary;			/* Import summaries to this stub/NSSA area, valid for ABR */
+  u8 default_nssa;		/* Generate default NSSA route for NSSA+summary area */
+  u8 translator;		/* Translator role, for NSSA ABR */
+  u32 transint;			/* Translator stability interval */
+  list patt_list;		/* List of iface configs (struct ospf_iface_patt) */
+  list net_list;	      	/* List of aggregate networks for that area */
+  list enet_list;	      	/* List of aggregate external (NSSA) networks */
+  list stubnet_list;		/* List of stub networks added to Router LSA */
 };
 
 struct area_net_config
@@ -148,65 +158,54 @@ struct ospf_stubnet_config
   u8 summary;
 };
 
-struct ospf_area_config
+struct nbma_node
 {
   node n;
-  u32 areaid;
-  u32 default_cost;		/* Cost of default route for stub areas
-				   (With possible LSA_EXT3_EBIT for NSSA areas) */
-  u8 type;			/* Area type (standard, stub, NSSA), represented
-				   by option flags (OPT_E, OPT_N) */
-  u8 summary;			/* Import summaries to this stub/NSSA area, valid for ABR */
-  u8 default_nssa;		/* Generate default NSSA route for NSSA+summary area */
-  u8 translator;		/* Translator role, for NSSA ABR */
-  u32 transint;			/* Translator stability interval */
-  list patt_list;
-  list net_list;	      	/* List of aggregate networks for that area */
-  list enet_list;	      	/* List of aggregate external (NSSA) networks */
-  list stubnet_list;		/* List of stub networks added to Router LSA */
+  ip_addr ip;
+  byte eligible;
+  byte found; 
 };
 
+struct ospf_iface_patt
+{
+  struct iface_patt i;
+  u32 type;
+  u32 stub;
+  u32 cost;
+  u32 helloint;
+  u32 rxmtint;
+  u32 pollint;
+  u32 waitint;
+  u32 deadc;
+  u32 deadint;
+  u32 inftransdelay;
+  list nbma_list;
+  u32 priority;
+  u32 voa;
+  u32 vid;
+  int tx_tos;
+  int tx_priority;
+  u16 tx_length;
+  u16 rx_buffer;
 
-/* Generic option flags */
-#define OPT_V6	0x01		/* OSPFv3, LSA relevant for IPv6 routing calculation */
-#define OPT_E	0x02		/* Related to AS-external LSAs */
-#define OPT_MC	0x04		/* Related to MOSPF, not used and obsolete */
-#define OPT_N	0x08		/* Related to NSSA */
-#define OPT_P	0x08		/* OSPFv2, flags P and N share position, see NSSA RFC */
-#define OPT_EA	0x10		/* OSPFv2, external attributes, not used and obsolete */
-#define OPT_R	0x10		/* OSPFv3, originator is active router */
-#define OPT_DC	0x20		/* Related to demand circuits, not used */
-
-/* Router-LSA VEB flags are are stored together with links (OSPFv2) or options (OSPFv3) */
-#define OPT_RT_B  (0x01 << 24)
-#define OPT_RT_E  (0x02 << 24)
-#define OPT_RT_V  (0x04 << 24)
-#define OPT_RT_NT (0x10 << 24)
-
-/* Prefix flags, specific for OSPFv3 */
-#define OPT_PX_NU 0x01
-#define OPT_PX_LA 0x02
-#define OPT_PX_P  0x08
-#define OPT_PX_DN 0x10
-
-
-/* OSPF interface types */
-#define OSPF_IT_BCAST	0
-#define OSPF_IT_NBMA	1
-#define OSPF_IT_PTP	2
-#define OSPF_IT_PTMP	3
-#define OSPF_IT_VLINK	4
-#define OSPF_IT_UNDEF	5
-
-/* OSPF interface states */
-#define OSPF_IS_DOWN	0	/* Not active */
-#define OSPF_IS_LOOP	1	/* Iface with no link */
-#define OSPF_IS_WAITING	2	/* Waiting for Wait timer */
-#define OSPF_IS_PTP	3	/* PTP operational */
-#define OSPF_IS_DROTHER	4	/* I'm on BCAST or NBMA and I'm not DR */
-#define OSPF_IS_BACKUP	5	/* I'm BDR */
-#define OSPF_IS_DR	6	/* I'm DR */
-
+#define OSPF_RXBUF_MINSIZE 256	/* Minimal allowed size */
+  u8 instance_id;
+  u8 autype;			/* Not really used in OSPFv3 */
+#define OSPF_AUTH_NONE 0
+#define OSPF_AUTH_SIMPLE 1
+#define OSPF_AUTH_CRYPT 2
+#define OSPF_AUTH_CRYPT_SIZE 16
+  u8 strictnbma;
+  u8 check_link;
+  u8 ecmp_weight;
+  u8 link_lsa_suppression;
+  u8 real_bcast;		/* Not really used in OSPFv3 */
+  u8 ptp_netmask;		/* bool + 2 for unspecified */
+  u8 ttl_security;		/* bool + 2 for TX only */
+  u8 bfd;
+  u8 bsd_secondary;
+  list *passwords;
+};
 
 /* Default values for interface parameters */
 #define COST_D 10
@@ -220,6 +219,58 @@ struct ospf_area_config
   /* Value of Wait timer - not found it in RFC * - using 4*HELLO */
 
 
+
+struct ospf_proto
+{
+  struct proto p;
+  timer *disp_timer;		/* OSPF proto dispatcher */
+  uint tick;
+  struct top_graph *gr;		/* LSA graph */
+  slist lsal;			/* List of all LSA's */
+  int calcrt;			/* Routing table calculation scheduled?
+				   0=no, 1=normal, 2=forced reload */
+  list iface_list;		/* List of OSPF interfaces (struct ospf_iface) */
+  list area_list;		/* List of OSPF areas (struct ospf_area) */
+  int areano;			/* Number of area I belong to */
+  int padj;			/* Number of neighbors in Exchange or Loading state */
+  struct fib rtf;		/* Routing table */
+  byte ospf2;			/* OSPF v2 or v3 */
+  byte rfc1583;			/* RFC1583 compatibility */
+  byte stub_router;		/* Do not forward transit traffic */
+  byte merge_external;		/* Should i merge external routes? */
+  byte asbr;			/* May i originate any ext/NSSA lsa? */
+  byte ecmp;			/* Maximal number of nexthops in ECMP route, or 0 */
+  struct ospf_area *backbone;	/* If exists */
+  void *lsab;			/* LSA buffer used when originating router LSAs */
+  int lsab_size, lsab_used;
+  linpool *nhpool;		/* Linpool used for next hops computed in SPF */
+  sock *vlink_sk;		/* IP socket used for vlink TX */
+  u32 router_id;
+  u32 last_vlink_id;		/* Interface IDs for vlinks (starts at 0x80000000) */
+};
+
+struct ospf_area
+{
+  node n;
+  u32 areaid;
+  struct ospf_area_config *ac;	/* Related area config */
+  struct top_hash_entry *rt;	/* My own router LSA */
+  struct top_hash_entry *pxr_lsa; /* Originated prefix LSA */
+  list cand;			/* List of candidates for RT calc. */
+  struct fib net_fib;		/* Networks to advertise or not */
+  struct fib enet_fib;		/* External networks for NSSAs */
+  u32 options;			/* Optional features */
+  u8 update_rt_lsa;		/* Rt lsa origination scheduled? */
+  u8 trcap;			/* Transit capability? */
+  u8 marked;			/* Used in OSPF reconfigure */
+  u8 translate;			/* Translator state (TRANS_*), for NSSA ABR  */
+  timer *translator_timer;	/* For NSSA translator switch */
+  struct ospf_proto *po;
+  struct fib rtr;		/* Routing tables for routers */
+};
+
+
+
 struct ospf_iface
 {
   node n;
@@ -231,7 +282,7 @@ struct ospf_iface
 
   pool *pool;
   sock *sk;			/* IP socket */
-  list neigh_list;		/* List of neigbours */
+  list neigh_list;		/* List of neigbours (struct ospf_neighbor) */
   u32 cost;			/* Cost of iface */
   u32 waitint;			/* number of sec before changing state from wait */
   u32 rxmtint;			/* number of seconds between LSA retransmissions */
@@ -295,6 +346,153 @@ struct ospf_iface
   u8 bfd;			/* Use BFD on iface */
 };
 
+struct ospf_neighbor
+{
+  node n;
+  pool *pool;
+  struct ospf_iface *ifa;
+  u8 state;
+  timer *inactim;		/* Inactivity timer */
+  u8 imms;			/* I, M, Master/slave received */
+  u8 myimms;			/* I, M Master/slave */
+  u32 dds;			/* DD Sequence number being sent */
+  u32 ddr;			/* last Dat Des packet received */
+
+  u32 rid;			/* Router ID */
+  ip_addr ip;			/* IP of it's interface */
+  u8 priority;			/* Priority */
+  u8 adj;			/* built adjacency? */
+  u8 want_lsreq;		/* Set to 1 when lsrql was shortened during LSUPD */
+  u32 options;			/* Options received */
+
+  /* Entries dr and bdr store IP addresses in OSPFv2 and router IDs in
+     OSPFv3, we use the same type to simplify handling */
+  u32 dr;			/* Neigbour's idea of DR */
+  u32 bdr;			/* Neigbour's idea of BDR */
+  u32 iface_id;			/* ID of Neighbour's iface connected to common network */
+
+  /* Database summary list iterator, controls initial dbdes exchange.
+   * Advances in the LSA list as dbdes packets are sent.
+   */
+  siterator dbsi;		/* iterator of po->lsal */
+
+  /* Link state request list, controls initial LSA exchange.
+   * Entries added when received in dbdes packets, removed as sent in lsreq packets.
+   */
+  slist lsrql;			/* slist of struct top_hash_entry from n->lsrqh */
+  struct top_graph *lsrqh;
+
+  /* Link state retransmission list, controls LSA retransmission during flood.
+   * Entries added as sent in lsupd packets, removed when received in lsack packets.
+   * These entries hold ret_count in appropriate LSA entries.
+   */
+  slist lsrtl;			/* slist of struct top_hash_entry from n->lsrth */
+  struct top_graph *lsrth;
+  timer *rxmt_timer;		/* RXMT timer */
+  list ackl[2];
+#define ACKL_DIRECT 0
+#define ACKL_DELAY 1
+  timer *ackd_timer;		/* Delayed ack timer */
+  struct bfd_request *bfd_req;	/* BFD request, if BFD is used */
+  void *ldd_buffer;		/* Last database description packet */
+  u32 ldd_bsize;		/* Buffer size for ldd_buffer */
+  u32 csn;                      /* Last received crypt seq number (for MD5) */
+};
+
+
+/* OSPF interface types */
+#define OSPF_IT_BCAST	0
+#define OSPF_IT_NBMA	1
+#define OSPF_IT_PTP	2
+#define OSPF_IT_PTMP	3
+#define OSPF_IT_VLINK	4
+#define OSPF_IT_UNDEF	5
+
+/* OSPF interface states */
+#define OSPF_IS_DOWN	0	/* Not active */
+#define OSPF_IS_LOOP	1	/* Iface with no link */
+#define OSPF_IS_WAITING	2	/* Waiting for Wait timer */
+#define OSPF_IS_PTP	3	/* PTP operational */
+#define OSPF_IS_DROTHER	4	/* I'm on BCAST or NBMA and I'm not DR */
+#define OSPF_IS_BACKUP	5	/* I'm BDR */
+#define OSPF_IS_DR	6	/* I'm DR */
+
+/* Definitions for interface state machine */
+#define ISM_UP		0	/* Interface Up */
+#define ISM_WAITF	1	/* Wait timer fired */
+#define ISM_BACKS	2	/* Backup seen */
+#define ISM_NEICH	3	/* Neighbor change */
+#define ISM_LOOP	4	/* Link down */
+#define ISM_UNLOOP	5	/* Link up */
+#define ISM_DOWN	6	/* Interface down */
+
+
+/* OSPF neighbor states */
+#define NEIGHBOR_DOWN	0
+#define NEIGHBOR_ATTEMPT 1
+#define NEIGHBOR_INIT	2
+#define NEIGHBOR_2WAY	3
+#define NEIGHBOR_EXSTART 4
+#define NEIGHBOR_EXCHANGE 5
+#define NEIGHBOR_LOADING 6
+#define NEIGHBOR_FULL	7
+
+/* Definitions for neighbor state machine */
+#define INM_HELLOREC	0	/* Hello Received */
+#define INM_START	1	/* Neighbor start - for NBMA */
+#define INM_2WAYREC	2	/* 2-Way received */
+#define INM_NEGDONE	3	/* Negotiation done */
+#define INM_EXDONE	4	/* Exchange done */
+#define INM_BADLSREQ	5	/* Bad LS Request */
+#define INM_LOADDONE	6	/* Load done */
+#define INM_ADJOK	7	/* AdjOK? */
+#define INM_SEQMIS	8	/* Sequence number mismatch */
+#define INM_1WAYREC	9	/* 1-Way */
+#define INM_KILLNBR	10	/* Kill Neighbor */
+#define INM_INACTTIM	11	/* Inactivity timer */
+#define INM_LLDOWN	12	/* Line down */
+
+#define TRANS_OFF	0
+#define TRANS_ON	1
+#define TRANS_WAIT	2	/* Waiting before the end of translation */
+
+
+
+/* Generic option flags */
+#define OPT_V6		0x01	/* OSPFv3, LSA relevant for IPv6 routing calculation */
+#define OPT_E		0x02	/* Related to AS-external LSAs */
+#define OPT_MC		0x04	/* Related to MOSPF, not used and obsolete */
+#define OPT_N		0x08	/* Related to NSSA */
+#define OPT_P		0x08	/* OSPFv2, flags P and N share position, see NSSA RFC */
+#define OPT_EA		0x10	/* OSPFv2, external attributes, not used and obsolete */
+#define OPT_R		0x10	/* OSPFv3, originator is active router */
+#define OPT_DC		0x20	/* Related to demand circuits, not used */
+
+/* Router-LSA VEB flags are are stored together with links (OSPFv2) or options (OSPFv3) */
+#define OPT_RT_B	(0x01 << 24)
+#define OPT_RT_E	(0x02 << 24)
+#define OPT_RT_V	(0x04 << 24)
+#define OPT_RT_NT	(0x10 << 24)
+
+/* Prefix flags, specific for OSPFv3 */
+#define OPT_PX_NU	0x01
+#define OPT_PX_LA	0x02
+#define OPT_PX_P	0x08
+#define OPT_PX_DN	0x10
+
+
+struct ospf_packet
+{
+  u8 version;
+  u8 type;
+  u16 length;
+  u32 routerid;
+  u32 areaid;
+  u16 checksum;
+  u8 instance_id;		/* See RFC 6549 */
+  u8 autype;			/* Undefined for OSPFv3 */
+};
+
 struct ospf_md5
 {
   u16 zero;
@@ -309,7 +507,6 @@ union ospf_auth
   struct ospf_md5 md5;
 };
 
-
 /* Packet types */
 #define HELLO_P		1	/* Hello */
 #define DBDES_P		2	/* Database description */
@@ -317,8 +514,6 @@ union ospf_auth
 #define LSUPD_P		4	/* Link state update */
 #define LSACK_P		5	/* Link state acknowledgement */
 
-/* Area IDs */
-#define BACKBONE	0
 
 #define DBDES_I		4	/* Init bit */
 #define DBDES_M		2	/* More bit */
@@ -326,19 +521,6 @@ union ospf_auth
 #define DBDES_IMMS	(DBDES_I | DBDES_M | DBDES_MS)
 
 
-struct ospf_packet
-{
-  u8 version;
-  u8 type;
-  u16 length;
-  u32 routerid;
-  u32 areaid;
-  u16 checksum;
-  u8 instance_id;		/* See RFC 6549 */
-  u8 autype;			/* Undefined for OSPFv3 */
-};
-
-
 #define LSA_T_RT	0x2001
 #define LSA_T_NET	0x2002
 #define LSA_T_SUM_NET	0x2003
@@ -530,7 +712,7 @@ struct ospf_lsa_prefix
 };
 
 
-static inline unsigned
+static inline uint
 lsa_net_count(struct ospf_lsa_header *lsa)
 {
   return (lsa->length - sizeof(struct ospf_lsa_header) - sizeof(struct ospf_lsa_net))
@@ -558,6 +740,7 @@ lsa_get_ipv6_prefix(u32 *buf, ip_addr *addr, int *pxlen, u8 *pxopts, u16 *rest)
 
   *addr = IPA_NONE;
 
+#ifdef IPV6
   if (pxl > 0)
     _I0(*addr) = *buf++;
   if (pxl > 32)
@@ -570,6 +753,7 @@ lsa_get_ipv6_prefix(u32 *buf, ip_addr *addr, int *pxlen, u8 *pxopts, u16 *rest)
   /* Clean up remaining bits */
   if (pxl < 128)
     addr->addr[pxl / 32] &= u32_mkmask(pxl % 32);
+#endif
 
   return buf;
 }
@@ -613,183 +797,6 @@ struct ospf_lsreq_header
 };
 
 
-struct ospf_neighbor
-{
-  node n;
-  pool *pool;
-  struct ospf_iface *ifa;
-  u8 state;
-#define NEIGHBOR_DOWN 0
-#define NEIGHBOR_ATTEMPT 1
-#define NEIGHBOR_INIT 2
-#define NEIGHBOR_2WAY 3
-#define NEIGHBOR_EXSTART 4
-#define NEIGHBOR_EXCHANGE 5
-#define NEIGHBOR_LOADING 6
-#define NEIGHBOR_FULL 7
-  timer *inactim;		/* Inactivity timer */
-  u8 imms;			/* I, M, Master/slave received */
-  u8 myimms;			/* I, M Master/slave */
-  u32 dds;			/* DD Sequence number being sent */
-  u32 ddr;			/* last Dat Des packet received */
-
-  u32 rid;			/* Router ID */
-  ip_addr ip;			/* IP of it's interface */
-  u8 priority;			/* Priority */
-  u8 adj;			/* built adjacency? */
-  u32 options;			/* Options received */
-
-  /* Entries dr and bdr store IP addresses in OSPFv2 and router IDs in
-     OSPFv3, we use the same type to simplify handling */
-  u32 dr;			/* Neigbour's idea of DR */
-  u32 bdr;			/* Neigbour's idea of BDR */
-  u32 iface_id;			/* ID of Neighbour's iface connected to common network */
-
-  /* Database summary list iterator, controls initial dbdes exchange.
-   * Advances in the LSA list as dbdes packets are sent.
-   */
-  siterator dbsi;		/* iterator of po->lsal */
-
-  /* Link state request list, controls initial LSA exchange.
-   * Entries added when received in dbdes packets, removed as sent in lsreq packets.
-   */
-  slist lsrql;			/* slist of struct top_hash_entry from n->lsrqh */
-  struct top_graph *lsrqh;
-
-  /* Link state retransmission list, controls LSA retransmission during flood.
-   * Entries added as sent in lsupd packets, removed when received in lsack packets.
-   */
-  slist lsrtl;			/* slist of struct top_hash_entry from n->lsrth */
-  struct top_graph *lsrth;
-  timer *rxmt_timer;		/* RXMT timer */
-  list ackl[2];
-#define ACKL_DIRECT 0
-#define ACKL_DELAY 1
-  timer *ackd_timer;		/* Delayed ack timer */
-  struct bfd_request *bfd_req;	/* BFD request, if BFD is used */
-  void *ldd_buffer;		/* Last database description packet */
-  u32 ldd_bsize;		/* Buffer size for ldd_buffer */
-  u32 csn;                      /* Last received crypt seq number (for MD5) */
-};
-
-/* Definitions for interface state machine */
-#define ISM_UP 0		/* Interface Up */
-#define ISM_WAITF 1		/* Wait timer fired */
-#define ISM_BACKS 2		/* Backup seen */
-#define ISM_NEICH 3		/* Neighbor change */
-#define ISM_LOOP 4		/* Link down */
-#define ISM_UNLOOP 5		/* Link up */
-#define ISM_DOWN 6		/* Interface down */
-
-/* Definitions for neighbor state machine */
-#define INM_HELLOREC 0		/* Hello Received */
-#define INM_START 1		/* Neighbor start - for NBMA */
-#define INM_2WAYREC 2		/* 2-Way received */
-#define INM_NEGDONE 3		/* Negotiation done */
-#define INM_EXDONE 4		/* Exchange done */
-#define INM_BADLSREQ 5		/* Bad LS Request */
-#define INM_LOADDONE 6		/* Load done */
-#define INM_ADJOK 7		/* AdjOK? */
-#define INM_SEQMIS 8		/* Sequence number mismatch */
-#define INM_1WAYREC 9		/* 1-Way */
-#define INM_KILLNBR 10		/* Kill Neighbor */
-#define INM_INACTTIM 11		/* Inactivity timer */
-#define INM_LLDOWN 12		/* Line down */
-
-struct ospf_area
-{
-  node n;
-  u32 areaid;
-  struct ospf_area_config *ac;	/* Related area config */
-  struct top_hash_entry *rt;	/* My own router LSA */
-  struct top_hash_entry *pxr_lsa; /* Originated prefix LSA */
-  list cand;			/* List of candidates for RT calc. */
-  struct fib net_fib;		/* Networks to advertise or not */
-  struct fib enet_fib;		/* External networks for NSSAs */
-  u32 options;			/* Optional features */
-  u8 update_rt_lsa;		/* Rt lsa origination scheduled? */
-  u8 trcap;			/* Transit capability? */
-  u8 marked;			/* Used in OSPF reconfigure */
-  u8 translate;			/* Translator state (TRANS_*), for NSSA ABR  */
-  timer *translator_timer;	/* For NSSA translator switch */
-  struct ospf_proto *po;
-  struct fib rtr;		/* Routing tables for routers */
-};
-
-#define TRANS_OFF	0
-#define TRANS_ON	1
-#define TRANS_WAIT	2	/* Waiting before the end of translation */
-
-struct ospf_proto
-{
-  struct proto p;
-  timer *disp_timer;		/* OSPF proto dispatcher */
-  unsigned tick;
-  struct top_graph *gr;		/* LSA graph */
-  slist lsal;			/* List of all LSA's */
-  int calcrt;			/* Routing table calculation scheduled?
-				   0=no, 1=normal, 2=forced reload */
-  list iface_list;		/* Interfaces we really use */
-  list area_list;
-  int areano;			/* Number of area I belong to */
-  int padj;			/* Number of neighbors in Exchange or Loading state */
-  struct fib rtf;		/* Routing table */
-  byte ospf2;			/* OSPF v2 or v3 */
-  byte rfc1583;			/* RFC1583 compatibility */
-  byte stub_router;		/* Do not forward transit traffic */
-  byte merge_external;		/* Should i merge external routes? */
-  byte asbr;			/* May i originate any ext/NSSA lsa? */
-  byte ecmp;			/* Maximal number of nexthops in ECMP route, or 0 */
-  struct ospf_area *backbone;	/* If exists */
-  void *lsab;			/* LSA buffer used when originating router LSAs */
-  int lsab_size, lsab_used;
-  linpool *nhpool;		/* Linpool used for next hops computed in SPF */
-  sock *vlink_sk;		/* IP socket used for vlink TX */
-  u32 router_id;
-  u32 last_vlink_id;		/* Interface IDs for vlinks (starts at 0x80000000) */
-};
-
-struct ospf_iface_patt
-{
-  struct iface_patt i;
-  u32 type;
-  u32 stub;
-  u32 cost;
-  u32 helloint;
-  u32 rxmtint;
-  u32 pollint;
-  u32 waitint;
-  u32 deadc;
-  u32 deadint;
-  u32 inftransdelay;
-  list nbma_list;
-  u32 priority;
-  u32 voa;
-  u32 vid;
-  int tx_tos;
-  int tx_priority;
-  u16 tx_length;
-  u16 rx_buffer;
-
-#define OSPF_RXBUF_MINSIZE 256	/* Minimal allowed size */
-  u8 instance_id;
-  u8 autype;			/* Not really used in OSPFv3 */
-#define OSPF_AUTH_NONE 0
-#define OSPF_AUTH_SIMPLE 1
-#define OSPF_AUTH_CRYPT 2
-#define OSPF_AUTH_CRYPT_SIZE 16
-  u8 strictnbma;
-  u8 check_link;
-  u8 ecmp_weight;
-  u8 link_lsa_suppression;
-  u8 real_bcast;		/* Not really used in OSPFv3 */
-  u8 ptp_netmask;		/* bool + 2 for unspecified */
-  u8 ttl_security;		/* bool + 2 for TX only */
-  u8 bfd;
-  u8 bsd_secondary;
-  list *passwords;
-};
-
 
 #define SH_ROUTER_SELF 0xffffffff
 
@@ -810,7 +817,7 @@ struct lsadb_show_data {
 
 
 /* ospf.c */
-void schedule_rtcalc(struct ospf_proto *p);
+void ospf_schedule_rtcalc(struct ospf_proto *p);
 
 static inline void ospf_notify_rt_lsa(struct ospf_area *oa)
 { oa->update_rt_lsa = 1; }
@@ -822,12 +829,15 @@ static inline void ospf_notify_link_lsa(struct ospf_iface *ifa)
 { ifa->update_link_lsa = 1; }
 
 
+#define ospf_is_v2(X) OSPF_IS_V2
+#define ospf_is_v3(X) (!OSPF_IS_V2)
+/*
 static inline int ospf_is_v2(struct ospf_proto *p)
 { return p->ospf2; }
 
 static inline int ospf_is_v3(struct ospf_proto *p)
 { return ! p->ospf2; }
-
+*/
 static inline int ospf_get_version(struct ospf_proto *p)
 { return ospf_is_v2(p) ? 2 : 3; }
 
@@ -920,7 +930,7 @@ void ospf_send_hello(struct ospf_iface *ifa, int kind, struct ospf_neighbor *dir
 void ospf_receive_hello(struct ospf_packet *pkt, struct ospf_iface *ifa, struct ospf_neighbor *n, ip_addr faddr);
 
 /* dbdes.c */
-void ospf_send_dbdes(struct ospf_neighbor *n, int next);
+void ospf_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n, int next);
 void ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa, struct ospf_neighbor *n);
 
 /* lsreq.c */
@@ -930,7 +940,8 @@ void ospf_receive_lsreq(struct ospf_packet *pkt, struct ospf_iface *ifa, struct
 /* lsupd.c */
 void ospf_dump_lsahdr(struct ospf_proto *p, struct ospf_lsa_header *lsa_n);
 void ospf_dump_common(struct ospf_proto *p, struct ospf_packet *pkt);
-int ospf_lsupd_flood(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_neighbor *from);
+void ospf_add_flushed_to_lsrt(struct ospf_proto *p, struct ospf_neighbor *n);
+int ospf_flood_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_neighbor *from);
 int ospf_send_lsupd(struct ospf_proto *p, struct top_hash_entry **lsa_list, uint lsa_count, struct ospf_neighbor *n);
 void ospf_rxmt_lsupd(struct ospf_proto *p, struct ospf_neighbor *n);
 void ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa, struct ospf_neighbor *n);
@@ -938,7 +949,7 @@ void ospf_receive_lsupd(struct ospf_packet *pkt, struct ospf_iface *ifa, struct
 /* lsack.c */
 void ospf_enqueue_lsack(struct ospf_neighbor *n, struct ospf_lsa_header *h_n, int queue);
 void ospf_reset_lsack_queue(struct ospf_neighbor *n);
-void ospf_lsack_send(struct ospf_neighbor *n, int queue);
+void ospf_send_lsack(struct ospf_proto *p, struct ospf_neighbor *n, int queue);
 void ospf_receive_lsack(struct ospf_packet *pkt, struct ospf_iface *ifa, struct ospf_neighbor *n);
 
 
diff --git a/proto/ospf/rt.c b/proto/ospf/rt.c
index c4340ee5..9d146ce2 100644
--- a/proto/ospf/rt.c
+++ b/proto/ospf/rt.c
@@ -557,7 +557,7 @@ spfa_process_rt(struct ospf_proto *p, struct ospf_area *oa, struct top_hash_entr
 
   /* Errata 2078 to RFC 5340 4.8.1 - skip links from non-routing nodes */
   if (ospf_is_v3(p) && (act != oa->rt) && !(rt->options & OPT_R))
-    break;
+    return;
 
   /* Now process Rt links */
   for (lsa_walk_rt_init(p, act, &rtl), i = 0; lsa_walk_rt(&rtl); i++)
@@ -688,6 +688,8 @@ ospf_rt_spfa(struct ospf_area *oa)
 
   if (oa->rt == NULL)
     return;
+  if (oa->rt->lsa.age == LSA_MAXAGE)
+    return;
 
   OSPF_TRACE(D_EVENTS, "Starting routing table calculation for area %R", oa->areaid);
 
@@ -1087,8 +1089,7 @@ check_sum_net_lsa(struct ospf_proto *p, ort *nf)
   struct area_net *anet = NULL;
   struct ospf_area *anet_oa = NULL;
 
-  /* RT entry marked as area network */
-  if (nf->fn.flags & OSPF_RT_PERSISTENT)
+  if (nf->area_net)
   {
     /* It is a default route for stub areas, handled entirely in ospf_rt_abr() */
     if (nf->fn.pxlen == 0)
@@ -1162,8 +1163,7 @@ check_nssa_lsa(struct ospf_proto *p, ort *nf)
   if (nf->external_rte)
     return;
 
-  /* RT entry marked as area network */
-  if (nf->fn.flags & OSPF_RT_PERSISTENT)
+  if (nf->area_net)
   {
     /* Find that area network */
     WALK_LIST(oa, p->area_list)
@@ -1176,12 +1176,12 @@ check_nssa_lsa(struct ospf_proto *p, ort *nf)
 
   /* RFC 3103 3.2 (3) - originate the aggregated address range */
   if (anet && anet->active && !anet->hidden && oa->translate)
-    ospf_originate_ext_lsa(p, NULL, nf, LSA_RTCALC, anet->metric,
+    ospf_originate_ext_lsa(p, NULL, nf, LSA_M_RTCALC, anet->metric,
 			   (anet->metric & LSA_EXT3_EBIT), IPA_NONE, anet->tag, 0);
 
   /* RFC 3103 3.2 (2) - originate the same network */
   else if (decide_nssa_lsa(p, nf, &rt))
-    ospf_originate_ext_lsa(p, NULL, nf, LSA_RTCALC, rt.metric, rt.ebit, rt.fwaddr, rt.tag, 0);
+    ospf_originate_ext_lsa(p, NULL, nf, LSA_M_RTCALC, rt.metric, rt.ebit, rt.fwaddr, rt.tag, 0);
 }
 
 /* RFC 2328 16.7. p2 - find new/lost vlink endpoints */
@@ -1273,7 +1273,7 @@ ospf_rt_abr1(struct ospf_proto *p)
 
 	  /* Get a RT entry and mark it to know that it is an area network */
 	  ort *nfi = (ort *) fib_get(&p->rtf, &anet->fn.prefix, anet->fn.pxlen);
-	  nfi->fn.flags |= OSPF_RT_PERSISTENT; /* mark persistent, to have stable UID */
+	  nfi->area_net = 1;
 
 	  /* 16.2. (3) */
 	  if (nfi->n.type == RTS_OSPF_IA)
@@ -1289,7 +1289,7 @@ ospf_rt_abr1(struct ospf_proto *p)
 
   ip_addr addr = IPA_NONE;
   default_nf = (ort *) fib_get(&p->rtf, &addr, 0);
-  default_nf->fn.flags |= OSPF_RT_PERSISTENT; /* keep persistent */
+  default_nf->area_net = 1;
 
   struct ospf_area *oa;
   WALK_LIST(oa, p->area_list)
@@ -1309,7 +1309,7 @@ ospf_rt_abr1(struct ospf_proto *p)
      */
 
     if (oa_is_nssa(oa) && oa->ac->default_nssa)
-      ospf_originate_ext_lsa(p, oa, default_nf, LSA_RTCALC, oa->ac->default_cost,
+      ospf_originate_ext_lsa(p, oa, default_nf, LSA_M_RTCALC, oa->ac->default_cost,
 			     (oa->ac->default_cost & LSA_EXT3_EBIT), IPA_NONE, 0, 0);
 
     /* RFC 2328 16.4. (3) - precompute preferred ASBR entries */
@@ -1348,7 +1348,7 @@ translator_timer_hook(timer *timer)
     return;
 
   oa->translate = TRANS_OFF;
-  schedule_rtcalc(oa->po);
+  ospf_schedule_rtcalc(oa->po);
 }
 
 static void
@@ -1431,7 +1431,7 @@ ospf_rt_abr2(struct ospf_proto *p)
 
 	  /* Get a RT entry and mark it to know that it is an area network */
 	  nf2 = (ort *) fib_get(&p->rtf, &anet->fn.prefix, anet->fn.pxlen);
-	  nf2->fn.flags |= OSPF_RT_PERSISTENT; /* keep persistent */
+	  nf2->area_net = 1;
 	}
 
 	u32 metric = (nf->n.type == RTS_OSPF_EXT1) ?
@@ -1634,7 +1634,7 @@ ospf_rt_reset(struct ospf_proto *p)
   FIB_WALK(&p->rtf, nftmp)
   {
     ri = (ort *) nftmp;
-    ri->fn.flags &= ~OSPF_RT_PERSISTENT;
+    ri->area_net = 0;
     reset_ri(ri);
   }
   FIB_WALK_END;
@@ -1647,8 +1647,8 @@ ospf_rt_reset(struct ospf_proto *p)
     en->nhs = NULL;
     en->lb = IPA_NONE;
 
-    if (en->rtcalc == LSA_RTCALC)
-      en->rtcalc = LSA_STALE;
+    if (en->mode == LSA_M_RTCALC)
+      en->mode = LSA_M_STALE;
   }
 
   WALK_LIST(oa, p->area_list)
@@ -1683,14 +1683,9 @@ ospf_rt_reset(struct ospf_proto *p)
   }
 }
 
-static void
-ospf_flush_stale(struct ospf_proto *p)
-{
-}
-
 /**
  * ospf_rt_spf - calculate internal routes
- * @p: OSPF protocol
+ * @p: OSPF protocol instance
  *
  * Calculation of internal paths in an area is described in 16.1 of RFC 2328.
  * It's based on Dijkstra's shortest path tree algorithms.
@@ -2064,8 +2059,8 @@ again1:
       rte_update(&p->p, ne, NULL);
     }
 
-    /* Remove unused rt entry. Entries with any flags are persistent. */
-    if (!nf->n.type && !nf->external_rte) // XXXX
+    /* Remove unused rt entry, some special entries are persistent */
+    if (!nf->n.type && !nf->external_rte && !nf->area_net)
     {
       FIB_ITERATE_PUT(&fit, nftmp);
       fib_delete(fib, nftmp);
@@ -2096,6 +2091,6 @@ again2:
 
   /* Cleanup stale LSAs */
   WALK_SLIST(en, p->lsal)
-    if (en->rtcalc == LSA_STALE)
+    if (en->mode == LSA_M_STALE)
       ospf_flush_lsa(p, en);
 }
diff --git a/proto/ospf/rt.h b/proto/ospf/rt.h
index 77d7080b..61936f3c 100644
--- a/proto/ospf/rt.h
+++ b/proto/ospf/rt.h
@@ -2,9 +2,10 @@
  *      BIRD -- OSPF
  *
  *      (c) 2000--2004 Ondrej Filip <feela@network.cz>
+ *	(c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
+ *	(c) 2009--2014 CZ.NIC z.s.p.o.
  *
  *      Can be freely distributed and used under the terms of the GNU GPL.
- *
  */
 
 #ifndef _BIRD_OSPF_RT_H_
@@ -28,12 +29,17 @@ typedef struct orta
 #define ORTA_ASBR OPT_RT_E
 #define ORTA_ABR  OPT_RT_B
   /*
-   * For ORT_NET routes, the field is almost unused with one
-   * exception: ORTA_PREF for external routes means that the route is
-   * preferred in AS external route selection according to 16.4.1. -
-   * it is intra-area path using non-backbone area. In other words,
-   * the forwarding address (or ASBR if forwarding address is zero) is
-   * intra-area (type == RTS_OSPF) and its area is not a backbone.
+   * For ORT_NET routes, there are just several flags for external routes:
+   *
+   * ORTA_PREF for external routes means that the route is preferred in AS
+   * external route selection according to 16.4.1. - it is intra-area path using
+   * non-backbone area. In other words, the forwarding address (or ASBR if
+   * forwarding address is zero) is intra-area (type == RTS_OSPF) and its area
+   * is not a backbone.
+   *
+   * ORTA_NSSA means that the entry represents an NSSA route, and ORTA_PROP
+   * means that the NSSA route has propagate-bit set. These flags are used in
+   * NSSA translation.
    */
 #define ORTA_PREF 0x80000000
 #define ORTA_NSSA 0x40000000
@@ -51,41 +57,38 @@ typedef struct orta
 }
 orta;
 
-
-/* Values for fn.flags in struct ort */
-#define OSPF_RT_PERSISTENT	0x01
-
 typedef struct ort
 {
   /*
-   * We use OSPF_RT_PERSISTENT to mark persistent rt entries, that are
-   * needed for summary LSAs that don't have 'proper' rt entry (area
-   * networks + default to stubs) to keep uid stable (used for LSA ID
-   * in OSPFv3 - see fibnode_to_lsaid()).
-   *
-   * We use ORT_RT_EXPORT and ORT_RT_NSSA to note whether the
-   * external/NSSA route was originated from the route export (in
-   * ospf_rt_notify()) or from the NSSA route translation (in
-   * check_nssa_lsa()).
+   * Most OSPF routing table entries are for computed OSPF routes, these have
+   * defined n.type. There are also few other cases: entries for configured area
+   * networks (these have area_net field set) and entries for external routes
+   * exported to OSPF (these have external_rte field set). These entries are
+   * kept even if they do not contain 'proper' rt entry. That is needed to keep
+   * allocated stable UID numbers (fn.uid), which are used as LSA IDs in OSPFv3
+   * (see fibnode_to_lsaid()) for related LSAs (network summary LSAs in the
+   * first case, external or NSSA LSAs in the second case). Entries for external
+   * routes also have a second purpose - to prevent NSSA translation of received
+   * NSSA routes if regular external routes were already originated for the same
+   * network (see check_nssa_lsa()).
    *
-   * old_* values are here to represent the last route update. old_rta
-   * is cached (we keep reference), mainly for multipath nexthops.
-   * old_rta == NULL means route was not in the last update, in that
-   * case other old_* values are not valid.
+   * old_* values are here to represent the last route update. old_rta is cached
+   * (we keep reference), mainly for multipath nexthops.  old_rta == NULL means
+   * route was not in the last update, in that case other old_* values are not
+   * valid.
    */
   struct fib_node fn;
   orta n;
   u32 old_metric1, old_metric2, old_tag, old_rid;
   rta *old_rta;
   u8 external_rte;
+  u8 area_net;
 }
 ort;
 
 static inline int rt_is_nssa(ort *nf)
 { return nf->n.options & ORTA_NSSA; }
 
-#define EXT_EXPORT 1
-#define EXT_NSSA 2
 
 /*
  * Invariants for structs top_hash_entry (nodes of LSA db)
@@ -97,7 +100,7 @@ static inline int rt_is_nssa(ort *nf)
  * - beware, nhs is not valid after SPF calculation
  *
  * Invariants for structs orta nodes of fib tables po->rtf, oa->rtr:
- * - nodes may be invalid (fn.type == 0), in that case other invariants don't hold
+ * - nodes may be invalid (n.type == 0), in that case other invariants don't hold
  * - n.metric1 may be at most a small multiple of LSINFINITY,
  *   therefore sums do not overflow
  * - n.oa is always non-NULL
diff --git a/proto/ospf/topology.c b/proto/ospf/topology.c
index 5ed3cf7a..bc2de79f 100644
--- a/proto/ospf/topology.c
+++ b/proto/ospf/topology.c
@@ -40,11 +40,13 @@ static inline void lsab_reset(struct ospf_proto *p);
  * new routing table calculation is necessary. This is described in 13.2 of RFC
  * 2328. This function is for received LSA only, locally originated LSAs are
  * installed by ospf_originate_lsa().
+ *
+ * The LSA body in @body is expected to be mb_allocated by the caller and its
+ * ownership is transferred to the LSA entry structure.
  */
 struct top_hash_entry *
 ospf_install_lsa(struct ospf_proto *p, struct ospf_lsa_header *lsa, u32 type, u32 domain, void *body)
 {
-  /* LSA can be temporary, but body must be mb_allocated. */
   struct top_hash_entry *en;
   int change = 0;
 
@@ -61,8 +63,8 @@ ospf_install_lsa(struct ospf_proto *p, struct ospf_lsa_header *lsa, u32 type, u3
       memcmp(en->lsa_body, body, lsa->length - sizeof(struct ospf_lsa_header)))
     change = 1;
 
-  DBG("Inst lsa: Id: %R, Rt: %R, Type: %u, Age: %u, Sum: %u, Sn: 0x%x\n",
-      lsa->id, lsa->rt, lsa->type, lsa->age, lsa->checksum, lsa->sn);
+  if ((en->lsa.age == LSA_MAXAGE) && (lsa->age == LSA_MAXAGE))
+    change = 0;
 
   mb_free(en->lsa_body);
   en->lsa_body = body;
@@ -70,16 +72,43 @@ ospf_install_lsa(struct ospf_proto *p, struct ospf_lsa_header *lsa, u32 type, u3
   en->init_age = en->lsa.age;
   en->inst_time = now;
 
+  /*
+   * We do not set en->mode. It is either default LSA_M_BASIC, or in a special
+   * case when en is local but flushed, there is postponed LSA, self-originated
+   * LSA is received and ospf_install_lsa() is called from ospf_advance_lse(),
+   * then we have en->mode from the postponed LSA origination.
+   */
+
+  OSPF_TRACE(D_EVENTS, "Installing LSA: Type: %04x, Id: %R, Rt: %R, Seq: %08x, Age: %u",
+	     en->lsa_type, en->lsa.id, en->lsa.rt, en->lsa.sn, en->lsa.age);
+
   if (change)
-    schedule_rtcalc(p);
+    ospf_schedule_rtcalc(p);
 
   return en;
 }
 
+/**
+ * ospf_advance_lsa - handle received unexpected self-originated LSA
+ * @p: OSPF protocol instance
+ * @en: current LSA entry or NULL
+ * @lsa: new LSA header
+ * @type: type of LSA 
+ * @domain: domain of LSA
+ * @body: pointer to LSA body
+ *
+ * This function handles received unexpected self-originated LSA (@lsa, @body)
+ * by either advancing sequence number of the local LSA instance (@en) and
+ * propagating it, or installing the received LSA and immediately flushing it
+ * (if there is no local LSA; i.e., @en is NULL or MaxAge).
+ *
+ * The LSA body in @body is expected to be mb_allocated by the caller and its
+ * ownership is transferred to the LSA entry structure or it is freed.
+ */
 void
 ospf_advance_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_lsa_header *lsa, u32 type, u32 domain, void *body)
 {
-  // OSPF_TRACE(D_EVENTS, "Reflooding new self-originated LSA with newer sequence number");
+  /* RFC 2328 13.4 */
 
   if (en && (en->lsa.age < LSA_MAXAGE))
   {
@@ -101,6 +130,9 @@ ospf_advance_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_ls
       en->init_age = 0;
       en->inst_time = now;
       lsasum_calculate(&en->lsa, en->lsa_body);
+
+      OSPF_TRACE(D_EVENTS, "Advancing LSA: Type: %04x, Id: %R, Rt: %R, Seq: %08x",
+		 en->lsa_type, en->lsa.id, en->lsa.rt, en->lsa.sn);
     }
     else
     {
@@ -129,6 +161,11 @@ ospf_advance_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_ls
       en->lsa.age = LSA_MAXAGE;
       en->init_age = lsa->age;
       en->inst_time = now;
+
+      OSPF_TRACE(D_EVENTS, "Resetting LSA:  Type: %04x, Id: %R, Rt: %R, Seq: %08x",
+		 en->lsa_type, en->lsa.id, en->lsa.rt, en->lsa.sn);
+      OSPF_TRACE(D_EVENTS, "Postponing LSA: Type: %04x, Id: %R, Rt: %R",
+		 en->lsa_type, en->lsa.id, en->lsa.rt);
     }
   }
   else
@@ -137,6 +174,7 @@ ospf_advance_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_ls
      * We do not have received LSA in the database. We have to flush the
      * received LSA. It has to be installed in the database to secure
      * retransmissions. Note that the received LSA may already be MaxAge.
+     * Also note that en->next_lsa_* may be defined.
      */
 
     lsa->age = LSA_MAXAGE;
@@ -150,7 +188,7 @@ ospf_advance_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_ls
    * the neighbor we received it from), we cheat a bit here.
    */
 
-  ospf_lsupd_flood(p, en, NULL);
+  ospf_flood_lsa(p, en, NULL);
 }
 
 
@@ -167,11 +205,11 @@ ospf_do_originate_lsa(struct ospf_proto *p, struct top_hash_entry *en, void *lsa
     /* Prepare to flush old LSA */
     if (en->lsa.age != LSA_MAXAGE)
     {
-      OSPF_TRACE(D_EVENTS, "Resetting LSA: Type: %04x, Id: %R, Rt: %R",
-		 en->lsa_type, en->lsa.id, en->lsa.rt);
+      OSPF_TRACE(D_EVENTS, "Resetting LSA:  Type: %04x, Id: %R, Rt: %R, Seq: %08x",
+		 en->lsa_type, en->lsa.id, en->lsa.rt, en->lsa.sn);
 
       en->lsa.age = LSA_MAXAGE;
-      ospf_lsupd_flood(p, en, NULL);
+      ospf_flood_lsa(p, en, NULL);
       return 0;
     }
 
@@ -183,9 +221,6 @@ ospf_do_originate_lsa(struct ospf_proto *p, struct top_hash_entry *en, void *lsa
     en->lsa.sn = LSA_ZEROSEQNO;
   }
 
-  OSPF_TRACE(D_EVENTS, "Originating LSA: Type: %04x, Id: %R, Rt: %R",
-	     en->lsa_type, en->lsa.id, en->lsa.rt);
-
   /*
    * lsa.type_raw is initialized by ospf_hash_get() to OSPFv3 LSA type.
    * lsa_set_options() implicitly converts it to OSPFv2 LSA type, assuming that
@@ -205,7 +240,13 @@ ospf_do_originate_lsa(struct ospf_proto *p, struct top_hash_entry *en, void *lsa
   en->inst_time = now;
   lsasum_calculate(&en->lsa, en->lsa_body);
 
-  ospf_lsupd_flood(p, en, NULL);
+  OSPF_TRACE(D_EVENTS, "Originating LSA: Type: %04x, Id: %R, Rt: %R, Seq: %08x",
+	     en->lsa_type, en->lsa.id, en->lsa.rt, en->lsa.sn);
+
+  ospf_flood_lsa(p, en, NULL);
+
+  if (en->mode == LSA_M_BASIC)
+    ospf_schedule_rtcalc(p);
 
   return 1;
 }
@@ -244,15 +285,20 @@ ospf_originate_lsa(struct ospf_proto *p, struct ospf_new_lsa *lsa)
   {
     log(L_ERR "%s: LSA ID collision for %I/%d",
 	p->p.name, lsa->nf->fn.prefix, lsa->nf->fn.pxlen);
+
+    en = NULL;
     goto drop;
   }
 
-  /* XXXX check for maxage or opts change */
+  if (en->mode != lsa->mode)
+    en->mode = lsa->mode;
 
   if (en->next_lsa_body)
   {
     /* Ignore the new LSA if it is the same as the scheduled one */
-    if ((lsa_blen == en->next_lsa_blen) && !memcmp(lsa_body, en->next_lsa_body, lsa_blen))
+    if ((lsa_blen == en->next_lsa_blen) &&
+	!memcmp(lsa_body, en->next_lsa_body, lsa_blen) &&
+	(!ospf_is_v2(p) || (lsa->opts == en->next_lsa_opts)))
       goto drop;
 
     /* Free scheduled LSA */
@@ -263,13 +309,19 @@ ospf_originate_lsa(struct ospf_proto *p, struct ospf_new_lsa *lsa)
   }
 
   /* Ignore the the new LSA if is the same as the current one */
-  if ((lsa_length == en->lsa.length) && !memcmp(lsa_body, en->lsa_body, lsa_blen))
+  if ((en->lsa.age < LSA_MAXAGE) &&
+      (lsa_length == en->lsa.length) &&
+      !memcmp(lsa_body, en->lsa_body, lsa_blen) &&
+      (!ospf_is_v2(p) || (lsa->opts == lsa_get_options(&en->lsa))))
     goto drop;
 
   lsa_body = lsab_flush(p);
 
   if (! ospf_do_originate_lsa(p, en, lsa_body, lsa_blen, lsa->opts))
   {
+    OSPF_TRACE(D_EVENTS, "Postponing LSA: Type: %04x, Id: %R, Rt: %R",
+	       en->lsa_type, en->lsa.id, en->lsa.rt);
+
     en->next_lsa_body = lsa_body;
     en->next_lsa_blen = lsa_blen;
     en->next_lsa_opts = lsa->opts;
@@ -293,8 +345,6 @@ ospf_originate_next_lsa(struct ospf_proto *p, struct top_hash_entry *en)
   en->next_lsa_body = NULL;
   en->next_lsa_blen = 0;
   en->next_lsa_opts = 0;
-
-  // XXXX:  schedule_rtcalc(p);
 }
 
 static void
@@ -309,8 +359,8 @@ ospf_refresh_lsa(struct ospf_proto *p, struct top_hash_entry *en)
    * switched lsa.age to LSA_MAXAGE.
    */
 
-  OSPF_TRACE(D_EVENTS, "Refreshing LSA: Type: %04x, Id: %R, Rt: %R",
-	     en->lsa_type, en->lsa.id, en->lsa.rt);
+  OSPF_TRACE(D_EVENTS, "Refreshing LSA: Type: %04x, Id: %R, Rt: %R, Seq: %08x",
+	     en->lsa_type, en->lsa.id, en->lsa.rt, en->lsa.sn);
 
   ASSERT(en->next_lsa_body == NULL);
 
@@ -324,7 +374,7 @@ ospf_refresh_lsa(struct ospf_proto *p, struct top_hash_entry *en)
     en->next_lsa_opts = ospf_is_v2(p) ? lsa_get_options(&en->lsa) : 0;
 
     en->lsa.age = LSA_MAXAGE;
-    ospf_lsupd_flood(p, en, NULL);
+    ospf_flood_lsa(p, en, NULL);
     return;
   }
 
@@ -333,7 +383,7 @@ ospf_refresh_lsa(struct ospf_proto *p, struct top_hash_entry *en)
   en->init_age = 0;
   en->inst_time = now;
   lsasum_calculate(&en->lsa, en->lsa_body);
-  ospf_lsupd_flood(p, en, NULL);
+  ospf_flood_lsa(p, en, NULL);
 }
 
 /**
@@ -349,16 +399,13 @@ ospf_refresh_lsa(struct ospf_proto *p, struct top_hash_entry *en)
  * immediately removed when being flushed, the caller may assume that @en still
  * exists after the call. The function is the opposite of ospf_originate_lsa()
  * and is supposed to do the right thing even in cases of postponed
- * origination. Note that this function do not schedule routing table
- * calculation, the caller is responsible to do it if necessary.
+ * origination.
  */
 void
 ospf_flush_lsa(struct ospf_proto *p, struct top_hash_entry *en)
 {
-  OSPF_TRACE(D_EVENTS, "Flushing LSA: Type: %04x, Id: %R, Rt: %R",
-	     en->lsa_type, en->lsa.id, en->lsa.rt);
-
-  en->rtcalc = 0;
+  OSPF_TRACE(D_EVENTS, "Flushing LSA: Type: %04x, Id: %R, Rt: %R, Seq: %08x",
+	     en->lsa_type, en->lsa.id, en->lsa.rt, en->lsa.sn);
 
   if (en->next_lsa_body)
   {
@@ -372,7 +419,12 @@ ospf_flush_lsa(struct ospf_proto *p, struct top_hash_entry *en)
     return;
 
   en->lsa.age = LSA_MAXAGE;
-  ospf_lsupd_flood(p, en, NULL);
+  ospf_flood_lsa(p, en, NULL);
+
+  if (en->mode == LSA_M_BASIC)
+    ospf_schedule_rtcalc(p);
+
+  en->mode = LSA_M_BASIC;
 }
 
 static void
@@ -450,7 +502,6 @@ ospf_update_lsadb(struct ospf_proto *p)
     if (real_age >= LSA_MAXAGE)
     {
       ospf_flush_lsa(p, en);
-      schedule_rtcalc(p);
       continue;
     }
 
@@ -510,9 +561,9 @@ ort_to_lsaid(struct ospf_proto *p, ort *nf)
 
 
 static void *
-lsab_alloc(struct ospf_proto *p, unsigned size)
+lsab_alloc(struct ospf_proto *p, uint size)
 {
-  unsigned offset = p->lsab_used;
+  uint offset = p->lsab_used;
   p->lsab_used += size;
   if (p->lsab_used > p->lsab_size)
   {
@@ -524,7 +575,7 @@ lsab_alloc(struct ospf_proto *p, unsigned size)
 }
 
 static inline void *
-lsab_allocz(struct ospf_proto *p, unsigned size)
+lsab_allocz(struct ospf_proto *p, uint size)
 {
   void *r = lsab_alloc(p, size);
   bzero(r, size);
@@ -547,7 +598,7 @@ lsab_reset(struct ospf_proto *p)
 }
 
 static inline void *
-lsab_offset(struct ospf_proto *p, unsigned offset)
+lsab_offset(struct ospf_proto *p, uint offset)
 {
   return ((byte *) p->lsab) + offset;
 }
@@ -815,15 +866,6 @@ prepare_rt3_lsa_body(struct ospf_proto *p, struct ospf_area *oa)
   rt->options = get_rt_options(p, oa, bitv) | (oa->options & LSA_OPTIONS_MASK);
 }
 
-/**
- * ospf_originate_rt_lsa - build new instance of router LSA
- * @oa: ospf_area which is LSA built to
- *
- * It builds router LSA walking through all OSPF interfaces in
- * specified OSPF area. This function is mostly called from
- * area_disp(). Builds new LSA, increases sequence number (if old
- * instance exists) and sets age of LSA to zero.
- */
 static void
 ospf_originate_rt_lsa(struct ospf_proto *p, struct ospf_area *oa)
 {
@@ -834,6 +876,8 @@ ospf_originate_rt_lsa(struct ospf_proto *p, struct ospf_area *oa)
     .opts = oa->options
   };
 
+  OSPF_TRACE(D_EVENTS, "Updating router state for area %R", oa->areaid);
+
   if (ospf_is_v2(p))
     prepare_rt2_lsa_body(p, oa);
   else
@@ -908,15 +952,6 @@ prepare_net3_lsa_body(struct ospf_proto *p, struct ospf_iface *ifa)
   net->optx = options & LSA_OPTIONS_MASK;
 }
 
-/**
- * ospf_originate_net_lsa - originates of deletes network LSA
- * @ifa: interface which is LSA originated for
- *
- * Interface counts number of adjacent neighbors. If this number is
- * lower than one or interface is not in state %OSPF_IS_DR it deletes
- * and premature ages instance of network LSA for specified interface.
- * In other case, new instance of network LSA is originated.
- */
 static void
 ospf_originate_net_lsa(struct ospf_proto *p, struct ospf_iface *ifa)
 {
@@ -928,6 +963,8 @@ ospf_originate_net_lsa(struct ospf_proto *p, struct ospf_iface *ifa)
     .ifa  = ifa
   };
 
+  OSPF_TRACE(D_EVENTS, "Updating network state for %s (Id: %R)", ifa->ifname, lsa.id);
+
   if (ospf_is_v2(p))
     prepare_net2_lsa_body(p, ifa);
   else
@@ -977,10 +1014,9 @@ prepare_sum3_rt_lsa_body(struct ospf_proto *p, u32 drid, u32 metric, u32 options
 void
 ospf_originate_sum_net_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, int metric)
 {
-  struct top_hash_entry *en;
-
   struct ospf_new_lsa lsa = {
     .type = LSA_T_SUM_NET,
+    .mode = LSA_M_RTCALC,
     .dom  = oa->areaid,
     .id   = ort_to_lsaid(p, nf),
     .opts = oa->options,
@@ -992,32 +1028,26 @@ ospf_originate_sum_net_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf,
   else
     prepare_sum3_net_lsa_body(p, nf, metric);
 
-  en = ospf_originate_lsa(p, &lsa);
-  en->rtcalc = LSA_RTCALC;
+  ospf_originate_lsa(p, &lsa);
 }
 
 void
 ospf_originate_sum_rt_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, int metric, u32 options)
 {
-  struct top_hash_entry *en;
-  u32 rid = ipa_to_rid(nf->fn.prefix);
-
-  /* In OSPFv3, LSA ID is meaningless, but we still use Router ID of ASBR */
-
   struct ospf_new_lsa lsa = {
     .type = LSA_T_SUM_RT,
+    .mode = LSA_M_RTCALC,
     .dom  = oa->areaid,
-    .id   = rid,
+    .id   = ipa_to_rid(nf->fn.prefix),	/* Router ID of ASBR, irrelevant for OSPFv3 */
     .opts = oa->options
   };
 
   if (ospf_is_v2(p))
     prepare_sum2_lsa_body(p, 0, metric);
   else
-    prepare_sum3_rt_lsa_body(p, rid, metric, options & LSA_OPTIONS_MASK);
+    prepare_sum3_rt_lsa_body(p, lsa.id, metric, options & LSA_OPTIONS_MASK);
 
-  en = ospf_originate_lsa(p, &lsa);
-  en->rtcalc = LSA_RTCALC;
+  ospf_originate_lsa(p, &lsa);
 }
 
 
@@ -1076,13 +1106,15 @@ prepare_ext3_lsa_body(struct ospf_proto *p, ort *nf,
 
 /**
  * originate_ext_lsa - new route received from nest and filters
+ * @p: OSPF protocol instance
  * @oa: ospf_area for which LSA is originated
  * @nf: network prefix and mask
- * @src: the source of origination of the LSA (EXT_EXPORT/EXT_NSSA)
- * @metric: the metric of a route (possibly with appropriate E-bit)
+ * @mode: the mode of the LSA (LSA_M_EXPORT or LSA_M_RTCALC)
+ * @metric: the metric of a route
+ * @ebit: E-bit for route metric (bool)
  * @fwaddr: the forwarding address
  * @tag: the route tag
- * @pbit: P-bit for NSSA LSAs, ignored for external LSAs
+ * @pbit: P-bit for NSSA LSAs (bool), ignored for external LSAs
  *
  * If I receive a message that new route is installed, I try to originate an
  * external LSA. If @oa is an NSSA area, NSSA-LSA is originated instead.
@@ -1091,13 +1123,12 @@ prepare_ext3_lsa_body(struct ospf_proto *p, ort *nf,
  * the export from ospf_rt_notify(), or the NSSA-EXT translation.
  */
 void
-ospf_originate_ext_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, u8 rtcalc,
+ospf_originate_ext_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, u8 mode,
 		       u32 metric, u32 ebit, ip_addr fwaddr, u32 tag, int pbit)
 {
-  struct top_hash_entry *en;
-
   struct ospf_new_lsa lsa = {
     .type = oa ? LSA_T_NSSA : LSA_T_EXT,
+    .mode = mode, /* LSA_M_EXPORT or LSA_M_RTCALC */
     .dom  = oa ? oa->areaid : 0,
     .id   = ort_to_lsaid(p, nf),
     .opts = oa ? (pbit ? OPT_P : 0) : OPT_E,
@@ -1109,8 +1140,7 @@ ospf_originate_ext_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, u8 r
   else
     prepare_ext3_lsa_body(p, nf, metric, ebit, fwaddr, tag, oa && pbit);
 
-  en = ospf_originate_lsa(p, &lsa);
-  en->rtcalc = rtcalc;
+  ospf_originate_lsa(p, &lsa);
 }
 
 static void
@@ -1228,7 +1258,7 @@ ospf_rt_notify(struct proto *P, rtable *tbl UNUSED, net *n, rte *new, rte *old U
 
     /* Old external route might blocked some NSSA translation */
     if ((p->areano > 1) && rt_is_nssa(nf) && nf->n.oa->translate)
-      schedule_rtcalc(p);
+      ospf_schedule_rtcalc(p);
 
     return;
   }
@@ -1262,7 +1292,7 @@ ospf_rt_notify(struct proto *P, rtable *tbl UNUSED, net *n, rte *new, rte *old U
   }
 
   nf = (ort *) fib_get(&p->rtf, &n->n.prefix, n->n.pxlen);
-  ospf_originate_ext_lsa(p, oa, nf, 0, metric, ebit, fwd, tag, 1);
+  ospf_originate_ext_lsa(p, oa, nf, LSA_M_EXPORT, metric, ebit, fwd, tag, 1);
   nf->external_rte = 1;
 }
 
@@ -1320,6 +1350,8 @@ ospf_originate_link_lsa(struct ospf_proto *p, struct ospf_iface *ifa)
     .ifa  = ifa
   };
 
+  OSPF_TRACE(D_EVENTS, "Updating link state for %s (Id: %R)", ifa->ifname, lsa.id);
+
   prepare_link_lsa_body(p, ifa);
 
   ifa->link_lsa = ospf_originate_lsa(p, &lsa);
@@ -1576,6 +1608,8 @@ ospf_originate_prefix_net_lsa(struct ospf_proto *p, struct ospf_iface *ifa)
   ifa->pxn_lsa = ospf_originate_lsa(p, &lsa);
 }
 
+static inline int breaks_minlsinterval(struct top_hash_entry *en)
+{ return en && (en->lsa.age < LSA_MAXAGE) && ((en->inst_time + MINLSINTERVAL) > now); }
 
 void
 ospf_update_topology(struct ospf_proto *p)
@@ -1587,6 +1621,25 @@ ospf_update_topology(struct ospf_proto *p)
   {
     if (oa->update_rt_lsa)
     {
+      /*
+       * Generally, MinLSInterval is enforced in ospf_do_originate_lsa(), but
+       * origination of (prefix) router LSA is a special case. We do not want to
+       * prepare a new router LSA body and then postpone it in en->next_lsa_body
+       * for later origination, because there are side effects (updates of
+       * rt_pos_* and px_pos_* in ospf_iface structures) during that, which may
+       * confuse routing table calculation if executed after LSA body
+       * preparation but before final LSA origination (as rtcalc would use
+       * current rt_pos_* indexes but the old router LSA body).
+       *
+       * Here, we ensure that MinLSInterval is observed and we do not even try
+       * to originate these LSAs if it is not. Therefore, origination, when
+       * requested, will succeed unless there is also a seqnum wrapping, which
+       * is not a problem because in that case rtcalc is blocked by MaxAge.
+       */
+
+      if (breaks_minlsinterval(oa->rt) || breaks_minlsinterval(oa->pxr_lsa))
+	continue;
+
       ospf_originate_rt_lsa(p, oa);
       ospf_originate_prefix_rt_lsa(p, oa);
       oa->update_rt_lsa = 0;
@@ -1624,8 +1677,6 @@ ospf_update_topology(struct ospf_proto *p)
       ifa->update_net_lsa = 0;
     }
   }
-
-  // XXXX schedule_rtcalc(p);
 }
 
 
@@ -1664,7 +1715,7 @@ ospf_top_hash_u32(u32 a)
   return a;
 }
 
-static unsigned
+static uint
 ospf_top_hash(struct top_graph *f, u32 domain, u32 lsaid, u32 rtrid, u32 type)
 {
   /* In OSPFv2, we don't know Router ID when looking for network LSAs.
@@ -1685,12 +1736,14 @@ ospf_top_hash(struct top_graph *f, u32 domain, u32 lsaid, u32 rtrid, u32 type)
 /**
  * ospf_top_new - allocated new topology database
  * @p: OSPF protocol instance
+ * @pool: pool for allocation
  *
- * this dynamically hashed structure is often used for keeping lsas. mainly
- * its used in @ospf_area structure.
+ * This dynamically hashed structure is used for keeping LSAs. Mainly it is used
+ * for the LSA database of the OSPF protocol, but also for LSA retransmission
+ * and request lists of OSPF neighbors.
  */
 struct top_graph *
-ospf_top_new(pool *pool)
+ospf_top_new(struct ospf_proto *p, pool *pool)
 {
   struct top_graph *f;
 
@@ -1701,6 +1754,7 @@ ospf_top_new(pool *pool)
   ospf_top_ht_alloc(f);
   f->hash_entries = 0;
   f->hash_entries_min = 0;
+  f->ospf2 = ospf_is_v2(p);
   return f;
 }
 
@@ -1715,8 +1769,8 @@ ospf_top_free(struct top_graph *f)
 static void
 ospf_top_rehash(struct top_graph *f, int step)
 {
-  unsigned int oldn, oldh;
   struct top_hash_entry **n, **oldt, **newt, *e, *x;
+  uint oldn, oldh;
 
   oldn = f->hash_size;
   oldt = f->hash_table;
@@ -1752,7 +1806,7 @@ ospf_hash_find(struct top_graph *f, u32 domain, u32 lsa, u32 rtr, u32 type)
     e = e->next;
 
   /* Hide hash entry with empty lsa_body */
-  return e->lsa_body ? e : NULL;
+  return (e && e->lsa_body) ? e : NULL;
 }
 
 /* In OSPFv2, lsa.id is the same as lsa.rt for router LSA. In OSPFv3, we don't know
@@ -1780,11 +1834,15 @@ ospf_hash_find_rt(struct top_graph *f, u32 domain, u32 rtr)
   return rv;
 }
 
+/*
+ * ospf_hash_find_rt3_first() and ospf_hash_find_rt3_next() are used exclusively
+ * for lsa_walk_rt_init(), lsa_walk_rt(), therefore they skip MaxAge entries.
+ */
 static inline struct top_hash_entry *
 find_matching_rt3(struct top_hash_entry *e, u32 domain, u32 rtr)
 {
   while (e && (e->lsa.rt != rtr || e->lsa_type != LSA_T_RT ||
-	       e->domain != domain || e->lsa_body == NULL))
+	       e->domain != domain || e->lsa.age == LSA_MAXAGE))
     e = e->next;
   return e;
 }
@@ -1917,7 +1975,7 @@ ospf_dump_lsa(struct top_hash_entry *he, struct proto *p)
 void
 ospf_top_dump(struct top_graph *f, struct proto *p)
 {
-  unsigned int i;
+  uint i;
   OSPF_TRACE(D_EVENTS, "Hash entries: %d", f->hash_entries);
 
   for (i = 0; i < f->hash_size; i++)
@@ -1928,115 +1986,3 @@ ospf_top_dump(struct top_graph *f, struct proto *p)
   }
 }
 */
-
-
-
-#if 0
-
-void
-update_rt_lsa(struct ospf_area *oa)
-{
-  struct ospf_proto *po = oa->po;
-
-  if ((oa->rt) && ((oa->rt->inst_t + MINLSINTERVAL)) > now)
-    return;
-
-  originate_rt_lsa(oa);
-  if (ospf_is_v3(p))
-    originate_prefix_rt_lsa(oa);
-
-  schedule_rtcalc(p);
-  oa->origrt = 0;
-}
-
-
-
-
-static inline int
-check_sum2_net_lsa(struct top_hash_entry *en, struct fib_node *fn, u32 metric)
-{
-  struct ospf_lsa_sum2 *sum = en->lsa_body;
-
-  if (fn->pxlen != ip4_masklen(sum->netmask))
-    return -1;
-
-  return (en->lsa.sn != LSA_MAXSEQNO) && (sum->metric == metric);
-}
-
-static inline int
-check_sum3_net_lsa(struct top_hash_entry *en, struct fib_node *fn, u32 metric)
-{
-  struct ospf_lsa_sum3_net *sum = en->lsa_body;
-  ip6_addr prefix;
-  int pxlen;
-  u8 pxopts;
-  u16 rest;
-  lsa_get_ipv6_prefix(sum->prefix, &prefix, &pxlen, &pxopts, &rest);
-
-
-  if ((fn->pxlen != pxlen) || !ip6_equal(fn->prefix, prefix))
-    return -1;
-
-  return (en->lsa.sn != LSA_MAXSEQNO) && (sum->metric == metric);
-}
-
-
-static int
-check_sum_net_lsa(struct ospf_proto *po, struct top_hash_entry *en, struct fib_node *fn, u32 metric)
-{
-  int rv = ospf_is_v2(po) ?
-    check_sum2_net_lsa(en, fn, metric) :
-    check_sum3_net_lsa(en, fn, metric);
-
-  if (rv < 0)
-    log(L_ERR "%s: LSAID collision for %I/%d", p->p.name, fn->prefix, fn->pxlen);
-
-  return rv;
-}
-
-static int
-check_sum_rt_lsa(struct ospf_proto *po, struct top_hash_entry *en, u32 drid, u32 metric, u32 options)
-{
-  if (en->lsa.sn == LSA_MAXSEQNO)
-    return 0;
-
-  if (ospf_is_v2(po))
-  {
-    struct ospf_lsa_sum2 *sum = en->lsa_body;
-    return (sum->metric == metric);
-  }
-  else
-  {
-    struct ospf_lsa_sum3_rt *sum = en->lsa_body;
-    return (sum->options == options) && (sum->metric == metric) && (sum->drid == drid);
-  }
-}
-
-
-
-
-
-
-
-  OSPF_TRACE(D_EVENTS, "Originating router-LSA for area %R", oa->areaid);
-  OSPF_TRACE(D_EVENTS, "Originating network-LSA for iface %s", ifa->ifname);
-  OSPF_TRACE(D_EVENTS, "Originating net-summary-LSA for %I/%d (metric %d)", fn->prefix, fn->pxlen, metric);
-  OSPF_TRACE(D_EVENTS, "Originating rt-summary-LSA for %R (metric %d)", rid, metric);
-  OSPF_TRACE(D_EVENTS, "Originating %s-LSA for %I/%d",
-	     nssa ? "NSSA" : "AS-external", fn->prefix, fn->pxlen);
-  OSPF_TRACE(D_EVENTS, "Originating link-LSA for iface %s", ifa->ifname);
-  OSPF_TRACE(D_EVENTS, "Originating router prefix-LSA for area %R", oa->areaid);
-  OSPF_TRACE(D_EVENTS, "Originating network prefix-LSA for iface %s", ifa->ifname);
-
-
-  en = ospf_hash_find(po->gr, lsa.dom, lsa.id, po->router_id, lsa.type);
-  if (en && check_ext_lsa(po, en, fn, metric, fwaddr, tag))
-    return;
-
-  *length = sizeof(struct ospf_lsa_header) + po->lsab_used;
-  return lsab_flush(po);
-
-  *length = po->lsab_used + sizeof(struct ospf_lsa_header);
-  return lsab_flush(po);
-
-#endif
diff --git a/proto/ospf/topology.h b/proto/ospf/topology.h
index e4ea79f7..b34689e2 100644
--- a/proto/ospf/topology.h
+++ b/proto/ospf/topology.h
@@ -18,7 +18,7 @@ struct top_hash_entry
 				   in intra-area routing table calculation */
   struct top_hash_entry *next;	/* Next in hash chain */
   struct ospf_lsa_header lsa;
-  u16 lsa_type;			/* lsa.type processed and converted to common values */	
+  u16 lsa_type;			/* lsa.type processed and converted to common values (LSA_T_*) */	
   u16 init_age;			/* Initial value for lsa.age during inst_time */
   u32 domain;			/* Area ID for area-wide LSAs, Iface ID for link-wide LSAs */
   //  struct ospf_area *oa;
@@ -37,13 +37,115 @@ struct top_hash_entry
 #define OUTSPF 0
 #define CANDIDATE 1
 #define INSPF 2
-  u8 rtcalc;			/* LSA generated during RT calculation (LSA_RTCALC or LSA_STALE)*/
+  u8 mode;			/* LSA generated during RT calculation (LSA_RTCALC or LSA_STALE)*/
   u8 nhs_reuse;			/* Whether nhs nodes can be reused during merging.
 				   See a note in rt.c:merge_nexthops() */
 };
 
-#define LSA_RTCALC	1
-#define LSA_STALE	2
+
+/* Prevents ospf_hash_find() to ignore the entry, for p->lsrqh and p->lsrth */
+#define LSA_BODY_DUMMY ((void *) 1)
+
+/*
+ * LSA entry life cycle
+ *
+ * LSA entries are created by ospf_originate_lsa() (for locally originated LSAs)
+ * or ospf_install_lsa() (for LSAs received from neighbors). A regular (like
+ * newly originated) LSA entry has defined lsa_body nad lsa.age < %LSA_MAXAGE.
+ * When the LSA is requested to be flushed by ospf_flush_lsa(), the lsa.age is
+ * set to %LSA_MAXAGE and flooded. Flush process is finished asynchronously,
+ * when (at least) flooding is acknowledged by neighbors. This is detected in
+ * ospf_update_lsadb(), then ospf_clear_lsa() is called to free the LSA body but
+ * the LSA entry is kept. Such LSA does not formally exist, we keep an empty
+ * entry (until regular timeout) to know inst_time and lsa.sn in the case of
+ * later reorigination. After the timeout, LSA is removed by ospf_remove_lsa().
+ *
+ * When LSA origination is requested (by ospf_originate_lsa()). but it is not
+ * possible to do that immediately (because of MinLSInterval or because the
+ * sequence number is wrapping), The new LSA is scheduled for later origination
+ * in next_lsa_* fields of the LSA entry. The later origination is handled by
+ * ospf_originate_next_lsa() called from ospf_update_lsadb(). We can see that
+ * both real origination and final flush is asynchronous to ospf_originate_lsa()
+ * and ospf_flush_lsa().
+ *
+ * LSA entry therefore could be in three basic states:
+ * R - regular (lsa.age < %LSA_MAXAGE, lsa_body != NULL)
+ * F - flushing (lsa.age == %LSA_MAXAGE, lsa_body != NULL)
+ * E - empty (lsa.age == %LSA_MAXAGE, lsa_body == NULL)
+ *
+ * And these states are doubled based on whether the next LSA is scheduled
+ * (next_lsa_body != NULL, -n suffix) or not (next_lsa_body == NULL). We also
+ * use X for a state of non-existentce. We have this basic state graph
+ * (transitions from any state to R are omitted for clarity):
+ *
+ *  X --> R ---> F ---> E --> X
+ *        | \  / |      |
+ *        |  \/  |      |
+ *        |  /\  |      |
+ *        | /  \ |      |
+ *        Rn --> Fn --> En
+ *
+ * The transitions are:
+ *
+ * any state -> R		- new LSA origination requested and executed
+ * R -> Rn, F -> Fn, E -> En	- new LSA origination requested and postponed
+ * R -> Fn			- new LSA origination requested, seqnum wrapping
+ * Rn,Fn,En -> R		- postponed LSA finally originated
+ * R -> R			- LSA refresh done
+ * R -> Fn			- LSA refresh with seqnum wrapping
+ * R -> F, Rn -> Fn		- LSA age timeout
+ * R,Rn,Fn -> F, En -> E	- LSA flush requested
+ * F -> E, Fn -> En		- LSA flush done (acknowledged)
+ * E -> X			- LSA real age timeout (or immediate for received LSA)
+ *
+ * The 'origination requested' and 'flush requested' transitions are triggered
+ * and done by ospf_originate_lsa() and ospf_flush_lsa(), the rest is handled
+ * asynchronously by ospf_update_lsadb().
+ *
+ * The situation is significantly simpler for non-local (received) LSAs - there
+ * is no postponed origination and after flushing is done, LSAs are immediately
+ * removed, so it is just X -> R -> F -> X, or X -> F -> X (when MaxAge LSA is
+ * received).
+ *
+ * There are also some special cases related to handling of received unknown
+ * self-originated LSAs in ospf_advance_lsa():
+ * X -> F		- LSA is received and immediately flushed
+ * R,Rn -> Fn		- LSA with MaxSeqNo received and flushed, current LSA scheduled
+ */
+
+
+#define LSA_M_BASIC	0
+#define LSA_M_EXPORT	1
+#define LSA_M_RTCALC	2
+#define LSA_M_STALE	3
+
+/*
+ * LSA entry modes:
+ *
+ * LSA_M_BASIC - The LSA is explicitly originated using ospf_originate_lsa() and
+ * explicitly flushed using ospf_flush_lsa(). When the LSA is changed, the
+ * routing table calculation is scheduled. This is also the mode used for LSAs
+ * received from neighbors. Example: Router-LSAs, Network-LSAs.
+ *
+ * LSA_M_EXPORT - like LSA_M_BASIC, but the routing table calculation does not
+ * depend on the LSA. Therefore, the calculation is not scheduled when the LSA
+ * is changed. Example: AS-external-LSAs for exported routes.
+ *
+ * LSA_M_RTCALC - The LSA has to be requested using ospf_originate_lsa() during
+ * each routing table calculation, otherwise it is flushed automatically at the
+ * end of the calculation. The LSA is a result of the calculation and not a
+ * source for it. Therefore, the calculation is not scheduled when the LSA is
+ * changed. Example: Summary-LSAs.
+ *
+ * LSA_M_STALE - Temporary state for LSA_M_RTCALC that is not requested during
+ * the current routing table calculation.
+ *
+ *
+ * Note that we do not schedule the routing table calculation when the age of
+ * LSA_M_BASIC LSA is changed to MaxAge because of the sequence number wrapping,
+ * As it will be switched back to a regular one ASAP.
+ */
+
 
 struct top_graph
 {
@@ -61,6 +163,7 @@ struct top_graph
 struct ospf_new_lsa
 {
   u16 type;
+  u8  mode;
   u32 dom;
   u32 id;
   u16 opts;
@@ -69,9 +172,8 @@ struct ospf_new_lsa
   struct ort *nf;
 };
 
-struct top_graph *ospf_top_new(pool *);
-void ospf_top_free(struct top_graph *);
-void ospf_top_dump(struct top_graph *, struct proto *);
+struct top_graph *ospf_top_new(struct ospf_proto *p, pool *pool);
+void ospf_top_free(struct top_graph *f);
 
 struct top_hash_entry * ospf_install_lsa(struct ospf_proto *p, struct ospf_lsa_header *lsa, u32 type, u32 domain, void *body);
 struct top_hash_entry * ospf_originate_lsa(struct ospf_proto *p, struct ospf_new_lsa *lsa);
@@ -84,7 +186,7 @@ static inline void ospf_flush2_lsa(struct ospf_proto *p, struct top_hash_entry *
 
 void ospf_originate_sum_net_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, int metric);
 void ospf_originate_sum_rt_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, int metric, u32 options);
-void ospf_originate_ext_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, u8 rtcalc, u32 metric, u32 ebit, ip_addr fwaddr, u32 tag, int pbit);
+void ospf_originate_ext_lsa(struct ospf_proto *p, struct ospf_area *oa, ort *nf, u8 mode, u32 metric, u32 ebit, ip_addr fwaddr, u32 tag, int pbit);
 
 void ospf_rt_notify(struct proto *P, rtable *tbl, net *n, rte *new, rte *old, ea_list *attrs);
 void ospf_update_topology(struct ospf_proto *p);