1 files changed, 171 insertions, 44 deletions

diff --git a/proto/ospf/topology.h b/proto/ospf/topology.h
index cb876487..e2d6c773 100644
--- a/proto/ospf/topology.h
+++ b/proto/ospf/topology.h
@@ -2,6 +2,8 @@
  *	BIRD -- OSPF
  *
  *	(c) 1999--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.
  */
@@ -16,79 +18,204 @@ 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 (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;
-  void *lsa_body;
-  bird_clock_t inst_t;		/* Time of installation into DB */
+  void *lsa_body;		/* May be NULL if LSA was flushed but hash entry was kept */
+  void *next_lsa_body;		/* For postponed LSA origination */
+  u16 next_lsa_blen;		/* For postponed LSA origination */
+  u16 next_lsa_opts;		/* For postponed LSA origination */
+  bird_clock_t inst_time;	/* Time of installation into DB */
+  struct ort *nf;		/* Reference fibnode for sum and ext LSAs, NULL for otherwise */
   struct mpnh *nhs;		/* Computed nexthops - valid only in ospf_rt_spf() */
   ip_addr lb;			/* In OSPFv2, link back address. In OSPFv3, any global address in the area useful for vlinks */
-#ifdef OSPFv3
   u32 lb_id;			/* Interface ID of link back iface (for bcast or NBMA networks) */
-#endif
   u32 dist;			/* Distance from the root */
-  u16 ini_age;
+  int ret_count;		/* Number of retransmission lists referencing the entry */
   u8 color;
 #define OUTSPF 0
 #define CANDIDATE 1
 #define INSPF 2
+  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() */
 };
 
+
+/* 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
 {
   pool *pool;			/* Pool we allocate from */
   slab *hash_slab;		/* Slab for hash entries */
   struct top_hash_entry **hash_table;	/* Hashing (modelled a`la fib) */
-  unsigned int hash_size;
-  unsigned int hash_order;
-  unsigned int hash_mask;
-  unsigned int hash_entries;
-  unsigned int hash_entries_min, hash_entries_max;
+  uint ospf2;			/* Whether it is for OSPFv2 or OSPFv3 */
+  uint hash_size;
+  uint hash_order;
+  uint hash_mask;
+  uint hash_entries;
+  uint hash_entries_min, hash_entries_max;
+};
+
+struct ospf_new_lsa
+{
+  u16 type;
+  u8  mode;
+  u32 dom;
+  u32 id;
+  u16 opts;
+  u16 length;
+  struct ospf_iface *ifa;
+  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 *);
-u32 ospf_lsa_domain(u32 type, struct ospf_iface *ifa);
-struct top_hash_entry *ospf_hash_find_header(struct top_graph *f, u32 domain,
-					     struct ospf_lsa_header *h);
-struct top_hash_entry *ospf_hash_get_header(struct top_graph *f, u32 domain,
-					    struct ospf_lsa_header *h);
-
-struct top_hash_entry *ospf_hash_find(struct top_graph *, u32 domain, u32 lsa, u32 rtr,
-				      u32 type);
-struct top_hash_entry *ospf_hash_get(struct top_graph *, u32 domain, u32 lsa, u32 rtr,
-				     u32 type);
+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);
+void ospf_advance_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_lsa_header *lsa, u32 type, u32 domain, void *body);
+void ospf_flush_lsa(struct ospf_proto *p, struct top_hash_entry *en);
+void ospf_update_lsadb(struct ospf_proto *p);
+
+static inline void ospf_flush2_lsa(struct ospf_proto *p, struct top_hash_entry **en)
+{ if (*en) { ospf_flush_lsa(p, *en); *en = NULL; } }
+
+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 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);
+
+struct top_hash_entry *ospf_hash_find(struct top_graph *, u32 domain, u32 lsa, u32 rtr, u32 type);
+struct top_hash_entry *ospf_hash_get(struct top_graph *, u32 domain, u32 lsa, u32 rtr, u32 type);
 void ospf_hash_delete(struct top_graph *, struct top_hash_entry *);
-void originate_rt_lsa(struct ospf_area *oa);
-void update_rt_lsa(struct ospf_area *oa);
-void originate_net_lsa(struct ospf_iface *ifa);
-void update_net_lsa(struct ospf_iface *ifa);
-void update_link_lsa(struct ospf_iface *ifa);
-int can_flush_lsa(struct proto_ospf *po);
 
-void originate_sum_net_lsa(struct ospf_area *oa, struct fib_node *fn, int metric);
-void originate_sum_rt_lsa(struct ospf_area *oa, struct fib_node *fn, int metric, u32 options UNUSED);
-void flush_sum_lsa(struct ospf_area *oa, struct fib_node *fn, int type);
-void originate_ext_lsa(struct ospf_area *oa, struct fib_node *fn, int src, u32 metric, ip_addr fwaddr, u32 tag, int pbit);
-void flush_ext_lsa(struct ospf_area *oa, struct fib_node *fn, int nssa);
+static inline struct top_hash_entry * ospf_hash_find_entry(struct top_graph *f, struct top_hash_entry *en)
+{ return ospf_hash_find(f, en->domain, en->lsa.id, en->lsa.rt, en->lsa_type); }
 
+static inline struct top_hash_entry * ospf_hash_get_entry(struct top_graph *f, struct top_hash_entry *en)
+{ return ospf_hash_get(f, en->domain, en->lsa.id, en->lsa.rt, en->lsa_type); }
 
-#ifdef OSPFv2
-struct top_hash_entry * ospf_hash_find_net(struct top_graph *f, u32 domain, u32 lsa);
+struct top_hash_entry * ospf_hash_find_rt(struct top_graph *f, u32 domain, u32 rtr);
+struct top_hash_entry * ospf_hash_find_rt3_first(struct top_graph *f, u32 domain, u32 rtr);
+struct top_hash_entry * ospf_hash_find_rt3_next(struct top_hash_entry *e);
+
+struct top_hash_entry * ospf_hash_find_net2(struct top_graph *f, u32 domain, u32 id);
 
+/* In OSPFv2, id is network IP prefix (lsa.id) while lsa.rt field is unknown
+   In OSPFv3, id is lsa.rt of DR while nif is neighbor iface id (lsa.id) */
 static inline struct top_hash_entry *
-ospf_hash_find_rt(struct top_graph *f, u32 domain, u32 rtr)
+ospf_hash_find_net(struct top_graph *f, u32 domain, u32 id, u32 nif)
 {
-  return ospf_hash_find(f, domain, rtr, rtr, LSA_T_RT);
+  return f->ospf2 ?
+    ospf_hash_find_net2(f, domain, id) :
+    ospf_hash_find(f, domain, nif, id, LSA_T_NET);
 }
 
-#else /* OSPFv3 */
-struct top_hash_entry * ospf_hash_find_rt(struct top_graph *f, u32 domain, u32 rtr);
-struct top_hash_entry * ospf_hash_find_rt_first(struct top_graph *f, u32 domain, u32 rtr);
-struct top_hash_entry * ospf_hash_find_rt_next(struct top_hash_entry *e);
-#endif
-
 
 #endif /* _BIRD_OSPF_TOPOLOGY_H_ */