Export tables merged with BGP prefix hash

Until now, if export table was enabled, Nest was storing exactly the
route before rt_notify() was called on it. This was quite sloppy and
spooky and it also wasn't reflecting the changes BGP does before
sending. And as BGP is storing the routes to be sent anyway, we are
simply keeping the already-sent routes in there to better rule out
unneeded reexports.

Some of the route attributes (IGP metric, preference) make no sense in
BGP, therefore these will be probably replaced by something sensible.
Also the nexthop shown in the short output is the BGP nexthop.

1 files changed, 15 insertions, 5 deletions

diff --git a/nest/rt.h b/nest/rt.h
index 3ed56fcc..5a8c5a19 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -247,14 +247,20 @@ struct rt_export_hook {
     u32 withdraws_received;		/* Number of route withdraws received */
   } stats;
 
-  struct fib_iterator feed_fit;		/* Routing table iterator used during feeding */
-  struct f_trie_walk_state *walk_state;	/* Iterator over networks in trie */
-  struct f_trie *walk_lock;		/* Locked trie for walking */
+  union {
+    struct fib_iterator feed_fit;		/* Routing table iterator used during feeding */
+    struct {
+      struct f_trie_walk_state *walk_state;	/* Iterator over networks in trie */
+      struct f_trie *walk_lock;			/* Locked trie for walking */
+    };
+    u32 hash_iter;				/* Iterator over hash */
+  };
 
   btime last_state_change;		/* Time of last state transition */
 
   u8 refeed_pending;			/* Refeeding and another refeed is scheduled */
   u8 export_state;			/* Route export state (TES_*, see below) */
+  u8 feed_type;				/* Which feeding method is used (TFT_*, see below) */
 
   struct event *event;			/* Event running all the export operations */
 
@@ -282,6 +288,10 @@ struct rt_export_hook {
 #define TE_ADDR_IN	3		/* Interval query - show route in <addr> */
 
 
+#define TFT_FIB		1
+#define TFT_TRIE	2
+#define TFT_HASH	3
+
 void rt_request_import(rtable *tab, struct rt_import_request *req);
 void rt_request_export(struct rt_exporter *tab, struct rt_export_request *req);
 
@@ -296,6 +306,8 @@ const char *rt_export_state_name(u8 state);
 static inline u8 rt_import_get_state(struct rt_import_hook *ih) { return ih ? ih->import_state : TIS_DOWN; }
 static inline u8 rt_export_get_state(struct rt_export_hook *eh) { return eh ? eh->export_state : TES_DOWN; }
 
+void rt_set_export_state(struct rt_export_hook *hook, u8 state);
+
 void rte_import(struct rt_import_request *req, const net_addr *net, rte *new, struct rte_src *src);
 
 /* Types of route announcement, also used as flags */
@@ -386,8 +398,6 @@ int rt_reload_channel(struct channel *c);
 void rt_reload_channel_abort(struct channel *c);
 void rt_refeed_channel(struct channel *c);
 void rt_prune_sync(rtable *t, int all);
-int rte_update_in(struct channel *c, const net_addr *n, rte *new, struct rte_src *src);
-int rte_update_out(struct channel *c, const net_addr *n, rte *new, const rte *old, struct rte_storage **old_exported);
 struct rtable_config *rt_new_table(struct symbol *s, uint addr_type);
 
 static inline int rt_is_ip(rtable *tab)