BMP: Refactor route monitoring

 - Manage BMP state through bmp_peer, bmp_stream, bmp_table structures
 - Use channels and rt_notify() hook for route announcements
 - Add support for post-policy monitoring
 - Send End-of-RIB even when there is no routes
 - Remove rte_update_in_notify() hook from import tables
 - Update import tables to support channels
 - Add bmp_hack (no feed / no flush) flag to channels

3 files changed, 52 insertions, 35 deletions

diff --git a/nest/proto.c b/nest/proto.c
index 885a0b75..16245dca 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -179,6 +179,7 @@ proto_add_channel(struct proto *p, struct channel_config *cf)
   c->merge_limit = cf->merge_limit;
   c->in_keep_filtered = cf->in_keep_filtered;
   c->rpki_reload = cf->rpki_reload;
+  c->bmp_hack = cf->bmp_hack;
 
   c->channel_state = CS_DOWN;
   c->export_state = ES_DOWN;
@@ -450,7 +451,10 @@ channel_start_export(struct channel *c)
   ASSERT(c->channel_state == CS_UP);
   ASSERT(c->export_state == ES_DOWN);
 
-  channel_schedule_feed(c, 1);	/* Sets ES_FEEDING */
+  if (!c->bmp_hack)
+    channel_schedule_feed(c, 1);	/* Sets ES_FEEDING */
+  else
+    c->export_state = ES_READY;
 }
 
 static void
@@ -523,7 +527,7 @@ channel_setup_in_table(struct channel *c)
   cf->addr_type = c->net_type;
   cf->internal = 1;
 
-  c->in_table = rt_setup(c->proto->pool, cf);
+  c->in_table = cf->table = rt_setup(c->proto->pool, cf);
 
   c->reload_event = ev_new_init(c->proto->pool, channel_reload_loop, c);
 }
@@ -574,7 +578,8 @@ channel_do_up(struct channel *c)
 static void
 channel_do_flush(struct channel *c)
 {
-  rt_schedule_prune(c->table);
+  if (!c->bmp_hack)
+    rt_schedule_prune(c->table);
 
   c->gr_wait = 0;
   if (c->gr_lock)
diff --git a/nest/protocol.h b/nest/protocol.h
index da6d434e..d94a11bc 100644
--- a/nest/protocol.h
+++ b/nest/protocol.h
@@ -214,7 +214,6 @@ struct proto {
   void (*if_notify)(struct proto *, unsigned flags, struct iface *i);
   void (*ifa_notify)(struct proto *, unsigned flags, struct ifa *a);
   void (*rt_notify)(struct proto *, struct channel *, struct network *net, struct rte *new, struct rte *old);
-  void (*rte_update_in_notify)(struct channel *, const net_addr *, const struct rte *, const struct rte_src *);
   void (*neigh_notify)(struct neighbor *neigh);
   int (*preexport)(struct channel *, struct rte *rt);
   void (*reload_routes)(struct channel *);
@@ -477,7 +476,8 @@ struct channel_class {
 #endif
 };
 
-extern struct channel_class channel_bgp;
+extern const struct channel_class channel_basic;
+extern const struct channel_class channel_bgp;
 
 struct channel_config {
   node n;
@@ -500,6 +500,7 @@ struct channel_config {
   u8 merge_limit;			/* Maximal number of nexthops for RA_MERGED */
   u8 in_keep_filtered;			/* Routes rejected in import filter are kept */
   u8 rpki_reload;			/* RPKI changes trigger channel reload */
+  u8 bmp_hack;				/* No feed, no flush */
 };
 
 struct channel {
@@ -552,6 +553,7 @@ struct channel {
   u8 reload_pending;			/* Reloading and another reload is scheduled */
   u8 refeed_pending;			/* Refeeding and another refeed is scheduled */
   u8 rpki_reload;			/* RPKI changes trigger channel reload */
+  u8 bmp_hack;				/* No feed, no flush */
 
   struct rtable *out_table;		/* Internal table for exported routes */
 
@@ -620,6 +622,7 @@ static inline struct channel_config *proto_cf_main_channel(struct proto_config *
 struct channel *proto_find_channel_by_table(struct proto *p, struct rtable *t);
 struct channel *proto_find_channel_by_name(struct proto *p, const char *n);
 struct channel *proto_add_channel(struct proto *p, struct channel_config *cf);
+void proto_remove_channel(struct proto *p, struct channel *c);
 int proto_configure_channel(struct proto *p, struct channel **c, struct channel_config *cf);
 
 void channel_set_state(struct channel *c, uint state);
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 2b065032..e8478c36 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -3063,6 +3063,23 @@ rt_feed_channel_abort(struct channel *c)
  *	Import table
  */
 
+static void
+rte_announce_in(struct rtable *tab, struct network *net, struct rte *new, struct rte *old)
+{
+  struct channel *c; node *n;
+  WALK_LIST2(c, n, tab->channels, table_node)
+  {
+    if (c->export_state == ES_DOWN)
+      continue;
+
+    if (c->ra_mode != RA_ANY)
+      continue;
+
+    struct proto *p = c->proto;
+    p->rt_notify(p, c, net, new, old);
+  }
+}
+
 int
 rte_update_in(struct channel *c, const net_addr *n, rte *new, struct rte_src *src)
 {
@@ -3096,9 +3113,6 @@ rte_update_in(struct channel *c, const net_addr *n, rte *new, struct rte_src *sr
 	{
 	  old->flags &= ~(REF_STALE | REF_DISCARD | REF_MODIFY);
 
-	  if (c->proto->rte_update_in_notify)
-	    c->proto->rte_update_in_notify(c, n, old, src);
-
 	  return 1;
 	}
 
@@ -3111,28 +3125,15 @@ rte_update_in(struct channel *c, const net_addr *n, rte *new, struct rte_src *sr
 
       /* Remove the old rte */
       *pos = old->next;
-      rte_free_quick(old);
       tab->rt_count--;
-
       break;
     }
 
-  if (!new)
-  {
-    if (!old)
-      goto drop_withdraw;
-
-    if (!net->routes)
-      fib_delete(&tab->fib, net);
-
-    if (c->proto->rte_update_in_notify)
-      c->proto->rte_update_in_notify(c, n, NULL, src);
-
-    return 1;
-  }
+  if (!old && !new)
+    goto drop_withdraw;
 
   struct channel_limit *l = &c->rx_limit;
-  if (l->action && !old)
+  if (l->action && !old && new)
   {
     if (tab->rt_count >= l->limit)
       channel_notify_limit(c, l, PLD_RX, tab->rt_count);
@@ -3147,18 +3148,26 @@ rte_update_in(struct channel *c, const net_addr *n, rte *new, struct rte_src *sr
     }
   }
 
-  /* Insert the new rte */
-  rte *e = rte_do_cow(new);
-  e->flags |= REF_COW;
-  e->net = net;
-  e->sender = c;
-  e->lastmod = current_time();
-  e->next = *pos;
-  *pos = e;
-  tab->rt_count++;
+  if (new)
+  {
+    /* Insert the new rte */
+    rte *e = rte_do_cow(new);
+    e->flags |= REF_COW;
+    e->net = net;
+    e->sender = c;
+    e->lastmod = current_time();
+    e->next = *pos;
+    *pos = new = e;
+    tab->rt_count++;
+  }
 
-  if (c->proto->rte_update_in_notify)
-    c->proto->rte_update_in_notify(c, n, e, src);
+  rte_announce_in(tab, net, new, old);
+
+  if (old)
+    rte_free_quick(old);
+
+  if (!net->routes)
+    fib_delete(&tab->fib, net);
 
   return 1;