From 54d94f4b1a5b9d8f2943236323d789290bb7bb2f Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Thu, 16 Jun 2022 12:39:08 +0200
Subject: [PATCH 01/20] Showing the nexthop resolution target in import tables

---
 nest/rt-show.c  | 16 ++++++++++++++--
 proto/bgp/bgp.h |  3 +++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/nest/rt-show.c b/nest/rt-show.c
index f3852d17..35036fe6 100644
--- a/nest/rt-show.c
+++ b/nest/rt-show.c
@@ -71,8 +71,13 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
   if (d->last_table != d->tab)
     rt_show_table(c, d);
 
-  cli_printf(c, -1007, "%-20s %s [%s %s%s]%s%s", ia, 
-      net_is_flow(e->net) ? flowspec_valid_name(flowspec_valid) : rta_dest_name(dest),
+  eattr *heea;
+  struct hostentry_adata *had = NULL;
+  if (!net_is_flow(e->net) && (dest == RTD_NONE) && (heea = ea_find(a, &ea_gen_hostentry)))
+    had = (struct hostentry_adata *) heea->u.ptr;
+
+  cli_printf(c, -1007, "%-20s %s [%s %s%s]%s%s", ia,
+      net_is_flow(e->net) ? flowspec_valid_name(flowspec_valid) : had ? "recursive" : rta_dest_name(dest),
       e->src->proto->name, tm, from, primary ? (sync_error ? " !" : " *") : "", info);
 
   if (dest == RTD_UNICAST)
@@ -100,6 +105,13 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
 	cli_printf(c, -1007, "\tdev %s%s%s",
 		   nh->iface->name, mpls,  onlink, weight);
     }
+  else if (had)
+    {
+      if (ipa_nonzero(had->he->link) && !ipa_equal(had->he->link, had->he->addr))
+	cli_printf(c, -1007, "\tvia %I %I table %s", had->he->addr, had->he->link, had->he->tab->name);
+      else
+	cli_printf(c, -1007, "\tvia %I table %s", had->he->addr, had->he->tab->name);
+    }
 
   if (d->verbose)
     ea_show_list(c, a);
diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h
index b3966bc3..cca7873a 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -520,6 +520,9 @@ static inline int
 rte_resolvable(const rte *rt)
 {
   eattr *nhea = ea_find(rt->attrs, &ea_gen_nexthop);
+  if (!nhea)
+    return 0;
+
   struct nexthop_adata *nhad = (void *) nhea->u.ptr;
   return NEXTHOP_IS_REACHABLE(nhad) || (nhad->dest != RTD_UNREACHABLE);
 }

From 8c92f47ac77f267368b6d6bd161689a0c0bc5e5a Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Thu, 16 Jun 2022 23:24:53 +0200
Subject: [PATCH 02/20] Route attribute storage keeps the previous layers

---
 lib/attrs.h       |  2 +-
 lib/route.h       |  4 +--
 nest/rt-attr.c    | 74 ++++++++++++++++++++++++++++++-----------------
 nest/rt-show.c    |  2 +-
 proto/bgp/attrs.c |  4 +--
 proto/mrt/mrt.c   |  2 +-
 6 files changed, 54 insertions(+), 34 deletions(-)

diff --git a/lib/attrs.h b/lib/attrs.h
index 79b7b14a..a75abcd3 100644
--- a/lib/attrs.h
+++ b/lib/attrs.h
@@ -42,7 +42,7 @@ lp_store_adata(struct linpool *pool, const void *buf, uint len)
 #define tmp_copy_adata(ad)	  tmp_store_adata((ad)->data, (ad)->length)
 
 static inline int adata_same(const struct adata *a, const struct adata *b)
-{ return (a->length == b->length && !memcmp(a->data, b->data, a->length)); }
+{ return (!a && !b) || (a->length == b->length && !memcmp(a->data, b->data, a->length)); }
 
 
 
diff --git a/lib/route.h b/lib/route.h
index 1b2f4de6..7e28b91e 100644
--- a/lib/route.h
+++ b/lib/route.h
@@ -237,7 +237,7 @@ ea_list *ea_append(ea_list *to, ea_list *what);
 void ea_format_bitfield(const struct eattr *a, byte *buf, int bufsize, const char **names, int min, int max);
 
 /* Normalize ea_list; allocates the result from tmp_linpool */
-ea_list *ea_normalize(const ea_list *e);
+ea_list *ea_normalize(ea_list *e, int overlay);
 
 uint ea_list_size(ea_list *);
 void ea_list_copy(ea_list *dest, ea_list *src, uint size);
@@ -414,7 +414,7 @@ static inline int rte_dest(const rte *r)
 
 void rta_init(void);
 ea_list *ea_lookup(ea_list *);		/* Get a cached (and normalized) variant of this attribute list */
-static inline int ea_is_cached(ea_list *r) { return r->flags & EALF_CACHED; }
+static inline int ea_is_cached(const ea_list *r) { return r->flags & EALF_CACHED; }
 static inline ea_list *ea_clone(ea_list *r) { r->uc++; return r; }
 void ea__free(ea_list *r);
 static inline void ea_free(ea_list *r) { if (r && !--r->uc) ea__free(r); }
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index 31e2057e..c0f81b9d 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -726,8 +726,8 @@ ea_do_prune(ea_list *e)
 	s++;
 
       /* Now s0 is the most recent version, s[-1] the oldest one */
-      /* Drop undefs */
-      if (s0->undef)
+      /* Drop undefs unless this is a true overlay */
+      if (s0->undef && !e->next)
 	continue;
 
       /* Copy the newest version to destination */
@@ -760,18 +760,15 @@ ea_do_prune(ea_list *e)
 static void
 ea_sort(ea_list *e)
 {
-  while (e)
-    {
-      if (!(e->flags & EALF_SORTED))
-	{
-	  ea_do_sort(e);
-	  ea_do_prune(e);
-	  e->flags |= EALF_SORTED;
-	}
-      if (e->count > 5)
-	e->flags |= EALF_BISECT;
-      e = e->next;
-    }
+  if (!(e->flags & EALF_SORTED))
+  {
+    ea_do_sort(e);
+    ea_do_prune(e);
+    e->flags |= EALF_SORTED;
+  }
+
+  if (e->count > 5)
+    e->flags |= EALF_BISECT;
 }
 
 /**
@@ -782,7 +779,7 @@ ea_sort(ea_list *e)
  * a given &ea_list after merging with ea_merge().
  */
 static unsigned
-ea_scan(const ea_list *e)
+ea_scan(const ea_list *e, int overlay)
 {
   unsigned cnt = 0;
 
@@ -790,6 +787,8 @@ ea_scan(const ea_list *e)
     {
       cnt += e->count;
       e = e->next;
+      if (e && overlay && ea_is_cached(e))
+	break;
     }
   return sizeof(ea_list) + sizeof(eattr)*cnt;
 }
@@ -809,27 +808,32 @@ ea_scan(const ea_list *e)
  * by calling ea_sort().
  */
 static void
-ea_merge(const ea_list *e, ea_list *t)
+ea_merge(ea_list *e, ea_list *t, int overlay)
 {
   eattr *d = t->attrs;
 
   t->flags = 0;
   t->count = 0;
-  t->next = NULL;
+
   while (e)
     {
       memcpy(d, e->attrs, sizeof(eattr)*e->count);
       t->count += e->count;
       d += e->count;
       e = e->next;
+
+      if (e && overlay && ea_is_cached(e))
+	break;
     }
+
+  t->next = e;
 }
 
 ea_list *
-ea_normalize(const ea_list *e)
+ea_normalize(ea_list *e, int overlay)
 {
-  ea_list *t = tmp_alloc(ea_scan(e));
-  ea_merge(e, t);
+  ea_list *t = tmp_alloc(ea_scan(e, overlay));
+  ea_merge(e, t, overlay);
   ea_sort(t);
 
   return t->count ? t : NULL;
@@ -850,7 +854,8 @@ ea_same(ea_list *x, ea_list *y)
 
   if (!x || !y)
     return x == y;
-  ASSERT(!x->next && !y->next);
+  if (x->next != y->next)
+    return 0;
   if (x->count != y->count)
     return 0;
   for(c=0; c<x->count; c++)
@@ -876,13 +881,12 @@ ea_list_size(ea_list *o)
   unsigned i, elen;
 
   ASSERT_DIE(o);
-  ASSERT_DIE(!o->next);
   elen = BIRD_CPU_ALIGN(sizeof(ea_list) + sizeof(eattr) * o->count);
 
   for(i=0; i<o->count; i++)
     {
       eattr *a = &o->attrs[i];
-      if (!(a->type & EAF_EMBEDDED))
+      if (!a->undef && !(a->type & EAF_EMBEDDED))
 	elen += ADATA_SIZE(a->u.ptr->length);
     }
 
@@ -899,7 +903,7 @@ ea_list_copy(ea_list *n, ea_list *o, uint elen)
   for(uint i=0; i<o->count; i++)
     {
       eattr *a = &n->attrs[i];
-      if (!(a->type & EAF_EMBEDDED))
+      if (!a->undef && !(a->type & EAF_EMBEDDED))
 	{
 	  unsigned size = ADATA_SIZE(a->u.ptr->length);
 	  ASSERT_DIE(adpos + size <= elen);
@@ -923,12 +927,21 @@ ea_list_ref(ea_list *l)
       eattr *a = &l->attrs[i];
       ASSERT_DIE(a->id < ea_class_max);
 
+      if (a->undef)
+	continue;
+
       struct ea_class *cl = ea_class_global[a->id];
       ASSERT_DIE(cl && cl->uc);
 
       CALL(cl->stored, a);
       cl->uc++;
     }
+
+  if (l->next)
+  {
+    ASSERT_DIE(ea_is_cached(l->next));
+    ea_clone(l->next);
+  }
 }
 
 static void
@@ -939,6 +952,9 @@ ea_list_unref(ea_list *l)
       eattr *a = &l->attrs[i];
       ASSERT_DIE(a->id < ea_class_max);
 
+      if (a->undef)
+	continue;
+
       struct ea_class *cl = ea_class_global[a->id];
       ASSERT_DIE(cl && cl->uc);
 
@@ -946,6 +962,9 @@ ea_list_unref(ea_list *l)
       if (!--cl->uc)
 	ea_class_free(cl);
     }
+
+  if (l->next)
+    ea_free(l->next);
 }
 
 void
@@ -1183,11 +1202,13 @@ ea_hash(ea_list *e)
 
   if (e)			/* Assuming chain of length 1 */
     {
-      ASSERT_DIE(!e->next);
+      h ^= mem_hash(&e->next, sizeof(e->next));
       for(i=0; i<e->count; i++)
 	{
 	  struct eattr *a = &e->attrs[i];
 	  h ^= a->id; h *= mul;
+	  if (a->undef)
+	    continue;
 	  if (a->type & EAF_EMBEDDED)
 	    h ^= a->u.data;
 	  else
@@ -1295,7 +1316,7 @@ ea_lookup(ea_list *o)
   uint h;
 
   ASSERT(!ea_is_cached(o));
-  o = ea_normalize(o);
+  o = ea_normalize(o, 1);
   h = ea_hash(o);
 
   for(r=rta_hash_table[h & rta_cache_mask]; r; r=r->next_hash)
@@ -1328,7 +1349,6 @@ ea__free(ea_list *a)
   if (a->next_hash)
     a->next_hash->pprev_hash = a->pprev_hash;
 
-  ASSERT(!a->next);
   ea_list_unref(a);
   mb_free(a);
 }
diff --git a/nest/rt-show.c b/nest/rt-show.c
index 35036fe6..8bf74754 100644
--- a/nest/rt-show.c
+++ b/nest/rt-show.c
@@ -60,7 +60,7 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
 
   /* Need to normalize the extended attributes */
   if (d->verbose && !rta_is_cached(a) && a)
-    a = ea_normalize(a);
+    a = ea_normalize(a, 0);
 
   get_route_info = e->src->proto->proto->get_route_info;
   if (get_route_info)
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 6d33ef2e..46e949bf 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -1253,10 +1253,10 @@ bgp_export_attr(struct bgp_export_state *s, eattr *a, ea_list *to)
  * Result: one sorted attribute list segment, or NULL if attributes are unsuitable.
  */
 static inline ea_list *
-bgp_export_attrs(struct bgp_export_state *s, const ea_list *a)
+bgp_export_attrs(struct bgp_export_state *s, ea_list *a)
 {
   /* Merge the attribute list */
-  ea_list *new = ea_normalize(a);
+  ea_list *new = ea_normalize(a, 0);
   ASSERT_DIE(new);
 
   uint i, count;
diff --git a/proto/mrt/mrt.c b/proto/mrt/mrt.c
index fcc1dcfe..fcbe317b 100644
--- a/proto/mrt/mrt.c
+++ b/proto/mrt/mrt.c
@@ -431,7 +431,7 @@ mrt_rib_table_entry_bgp_attrs(struct mrt_table_dump_state *s, rte *r)
 
   /* Attribute list must be normalized for bgp_encode_attrs() */
   if (!rta_is_cached(r->attrs))
-    eattrs = ea_normalize(eattrs);
+    eattrs = ea_normalize(eattrs, 0);
 
   mrt_buffer_need(b, MRT_ATTR_BUFFER_SIZE);
   byte *pos = b->pos;

From becab5072d6d84d6f9c9402387a9e1c14dcc384d Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Thu, 16 Jun 2022 23:24:56 +0200
Subject: [PATCH 03/20] Import tables are stored as an attribute layer inside
 the main tables.

The separate import tables were too memory-greedy, there is no need for
them being stored as full-sized tables.
---
 lib/route.h         |   3 +-
 nest/config.Y       |  13 +++-
 nest/proto.c        |  77 ++++++++++---------
 nest/protocol.h     |  16 ++--
 nest/rt-attr.c      |   4 +-
 nest/rt-show.c      |  12 ++-
 nest/rt-table.c     | 181 ++++++--------------------------------------
 nest/rt.h           |   1 +
 proto/bgp/bgp.c     |  12 +--
 proto/bgp/packets.c |   2 +-
 proto/ospf/rt.c     |   2 +-
 proto/perf/perf.c   |   2 +-
 proto/pipe/pipe.c   |   2 +-
 13 files changed, 101 insertions(+), 226 deletions(-)

diff --git a/lib/route.h b/lib/route.h
index 7e28b91e..f7b089d9 100644
--- a/lib/route.h
+++ b/lib/route.h
@@ -161,6 +161,7 @@ typedef struct ea_list {
 #define EALF_SORTED 1			/* Attributes are sorted by code */
 #define EALF_BISECT 2			/* Use interval bisection for searching */
 #define EALF_CACHED 4			/* List is cached */
+#define EALF_OVERLAY  8			/* List is an overlay in the same table */
 
 struct ea_class {
 #define EA_CLASS_INSIDE \
@@ -413,7 +414,7 @@ static inline int rte_dest(const rte *r)
 }
 
 void rta_init(void);
-ea_list *ea_lookup(ea_list *);		/* Get a cached (and normalized) variant of this attribute list */
+ea_list *ea_lookup(ea_list *, int overlay);		/* Get a cached (and normalized) variant of this attribute list */
 static inline int ea_is_cached(const ea_list *r) { return r->flags & EALF_CACHED; }
 static inline ea_list *ea_clone(ea_list *r) { r->uc++; return r; }
 void ea__free(ea_list *r);
diff --git a/nest/config.Y b/nest/config.Y
index 2d73b4c7..ea7e1266 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -311,7 +311,14 @@ channel_item_:
  | IMPORT LIMIT limit_spec { this_channel->in_limit = $3; }
  | EXPORT LIMIT limit_spec { this_channel->out_limit = $3; }
  | PREFERENCE expr { this_channel->preference = $2; check_u16($2); }
- | IMPORT KEEP FILTERED bool { this_channel->in_keep_filtered = $4; }
+ | IMPORT KEEP FILTERED bool {
+     if ($4)
+       this_channel->in_keep |= RIK_REJECTED;
+     else if ((this_channel->in_keep & RIK_PREFILTER) == RIK_PREFILTER)
+       cf_error("Import keep filtered is implied by the import table.");
+     else
+       this_channel->in_keep &= ~RIK_REJECTED;
+   }
  | RPKI RELOAD bool { this_channel->rpki_reload = $3; }
  ;
 
@@ -674,8 +681,8 @@ r_args:
      $$->tables_defined_by = RSD_TDB_ALL;
    }
  | r_args IMPORT TABLE channel_arg {
-     if (!$4->in_table) cf_error("No import table in channel %s.%s", $4->proto->name, $4->name);
-     rt_show_add_table($$, $4->in_table);
+     if (!($4->in_keep & RIK_PREFILTER)) cf_error("No import table in channel %s.%s", $4->proto->name, $4->name);
+     rt_show_add_table($$, $4->table)->prefilter = $4;
      $$->tables_defined_by = RSD_TDB_DIRECT;
    }
  | r_args EXPORT TABLE channel_arg {
diff --git a/nest/proto.c b/nest/proto.c
index 77817888..5e67d940 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -224,7 +224,7 @@ proto_add_channel(struct proto *p, struct channel_config *cf)
   c->preference = cf->preference;
   c->debug = cf->debug;
   c->merge_limit = cf->merge_limit;
-  c->in_keep_filtered = cf->in_keep_filtered;
+  c->in_keep = cf->in_keep;
   c->rpki_reload = cf->rpki_reload;
 
   c->channel_state = CS_DOWN;
@@ -294,7 +294,7 @@ static void
 channel_roa_in_changed(struct rt_subscription *s)
 {
   struct channel *c = s->data;
-  int active = c->reload_event && ev_active(c->reload_event);
+  int active = !!c->reload_req.hook;
 
   CD(c, "Reload triggered by RPKI change%s", active ? " - already active" : "");
 
@@ -379,7 +379,7 @@ channel_roa_subscribe_filter(struct channel *c, int dir)
 #ifdef CONFIG_BGP
   /* No automatic reload for BGP channels without in_table / out_table */
   if (c->channel == &channel_bgp)
-    valid = dir ? !!c->in_table : !!c->out_table;
+    valid = dir ? ((c->in_keep & RIK_PREFILTER) == RIK_PREFILTER) : !!c->out_table;
 #endif
 
   struct filter_iterator fit;
@@ -534,9 +534,6 @@ channel_import_stopped(struct rt_import_request *req)
 
   req->hook = NULL;
 
-  if (c->in_table)
-    rt_prune_sync(c->in_table, 1);
-
   mb_free(c->in_req.name);
   c->in_req.name = NULL;
 
@@ -603,43 +600,48 @@ channel_schedule_reload(struct channel *c)
 {
   ASSERT(c->in_req.hook);
 
-  rt_reload_channel_abort(c);
-  ev_schedule_work(c->reload_event);
+  rt_request_export(c->table, &c->reload_req);
 }
 
 static void
-channel_reload_loop(void *ptr)
+channel_reload_stopped(struct rt_export_request *req)
 {
-  struct channel *c = ptr;
-
-  /* Start reload */
-  if (!c->reload_active)
-    c->reload_pending = 0;
-
-  if (!rt_reload_channel(c))
-  {
-    ev_schedule_work(c->reload_event);
-    return;
-  }
+  struct channel *c = SKIP_BACK(struct channel, reload_req, req);
 
   /* Restart reload */
   if (c->reload_pending)
     channel_request_reload(c);
 }
 
+static void
+channel_reload_log_state_change(struct rt_export_request *req, u8 state)
+{
+  if (state == TES_READY)
+    rt_stop_export(req, channel_reload_stopped);
+}
+
+static void
+channel_reload_dump_req(struct rt_export_request *req)
+{
+  struct channel *c = SKIP_BACK(struct channel, reload_req, req);
+  debug("  Channel %s.%s import reload request %p\n", c->proto->name, c->name, req);
+}
+
+void channel_reload_export_bulk(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *rpe, rte **feed, uint count);
+
 /* Called by protocol to activate in_table */
 void
 channel_setup_in_table(struct channel *c)
 {
-  struct rtable_config *cf = mb_allocz(c->proto->pool, sizeof(struct rtable_config));
+  c->reload_req = (struct rt_export_request) {
+    .name = mb_sprintf(c->proto->pool, "%s.%s.import", c->proto->name, c->name),
+    .trace_routes = c->debug | c->proto->debug,
+    .export_bulk = channel_reload_export_bulk,
+    .dump_req = channel_reload_dump_req,
+    .log_state_change = channel_reload_log_state_change,
+  };
 
-  cf->name = "import";
-  cf->addr_type = c->net_type;
-  cf->internal = 1;
-
-  c->in_table = rt_setup(c->proto->pool, cf);
-
-  c->reload_event = ev_new_init(c->proto->pool, channel_reload_loop, c);
+  c->in_keep |= RIK_PREFILTER;
 }
 
 /* Called by protocol to activate out_table */
@@ -680,10 +682,10 @@ static void
 channel_do_pause(struct channel *c)
 {
   /* Need to abort feeding */
-  if (c->reload_event)
+  if (c->reload_req.hook)
   {
-    ev_postpone(c->reload_event);
-    rt_reload_channel_abort(c);
+    c->reload_pending = 0;
+    rt_stop_export(&c->reload_req, channel_reload_stopped);
   }
 
   /* Stop export */
@@ -710,15 +712,13 @@ channel_do_stop(struct channel *c)
   CALL(c->channel->shutdown, c);
 
   /* This have to be done in here, as channel pool is freed before channel_do_down() */
-  c->in_table = NULL;
-  c->reload_event = NULL;
   c->out_table = NULL;
 }
 
 static void
 channel_do_down(struct channel *c)
 {
-  ASSERT(!c->reload_active);
+  ASSERT(!c->reload_req.hook);
 
   c->proto->active_channels--;
 
@@ -726,8 +726,6 @@ channel_do_down(struct channel *c)
   memset(&c->import_stats, 0, sizeof(struct channel_import_stats));
   memset(&c->export_stats, 0, sizeof(struct channel_export_stats));
 
-  c->in_table = NULL;
-  c->reload_event = NULL;
   c->out_table = NULL;
 
   /* The in_table and out_table are going to be freed by freeing their resource pools. */
@@ -922,7 +920,9 @@ int
 channel_reconfigure(struct channel *c, struct channel_config *cf)
 {
   /* FIXME: better handle these changes, also handle in_keep_filtered */
-  if ((c->table != cf->table->table) || (cf->ra_mode && (c->ra_mode != cf->ra_mode)))
+  if ((c->table != cf->table->table) ||
+      (cf->ra_mode && (c->ra_mode != cf->ra_mode)) ||
+      (cf->in_keep != c->in_keep))
     return 0;
 
   /* Note that filter_same() requires arguments in (new, old) order */
@@ -949,7 +949,6 @@ channel_reconfigure(struct channel *c, struct channel_config *cf)
   c->preference = cf->preference;
   c->debug = cf->debug;
   c->in_req.trace_routes = c->out_req.trace_routes = c->debug | c->proto->debug;
-  c->in_keep_filtered = cf->in_keep_filtered;
   c->rpki_reload = cf->rpki_reload;
 
   /* Execute channel-specific reconfigure hook */
@@ -2099,7 +2098,7 @@ channel_show_stats(struct channel *c)
   u32 in_routes = c->in_limit.count;
   u32 out_routes = c->out_limit.count;
 
-  if (c->in_keep_filtered)
+  if (c->in_keep)
     cli_msg(-1006, "    Routes:         %u imported, %u filtered, %u exported, %u preferred",
 	    in_routes, (rx_routes - in_routes), out_routes, SRI(pref));
   else
diff --git a/nest/protocol.h b/nest/protocol.h
index aeb60ac6..b482ed99 100644
--- a/nest/protocol.h
+++ b/nest/protocol.h
@@ -454,7 +454,7 @@ struct channel_config {
   const struct filter *in_filter, *out_filter; /* Attached filters */
 
   struct channel_limit rx_limit;	/* Limit for receiving routes from protocol
-					   (relevant when in_keep_filtered is active) */
+					   (relevant when in_keep & RIK_REJECTED) */
   struct channel_limit in_limit;	/* Limit for importing routes from protocol */
   struct channel_limit out_limit;	/* Limit for exporting routes to protocol */
 
@@ -463,7 +463,7 @@ struct channel_config {
   u16 preference;			/* Default route preference */
   u32 debug;				/* Debugging flags (D_*) */
   u8 merge_limit;			/* Maximal number of nexthops for RA_MERGED */
-  u8 in_keep_filtered;			/* Routes rejected in import filter are kept */
+  u8 in_keep;				/* Which states of routes to keep (RIK_*) */
   u8 rpki_reload;			/* RPKI changes trigger channel reload */
 };
 
@@ -480,7 +480,7 @@ struct channel {
   struct bmap export_map;		/* Keeps track which routes were really exported */
   struct bmap export_reject_map;	/* Keeps track which routes were rejected by export filter */
 
-  struct limit rx_limit;		/* Receive limit (for in_keep_filtered) */
+  struct limit rx_limit;		/* Receive limit (for in_keep & RIK_REJECTED) */
   struct limit in_limit;		/* Input limit */
   struct limit out_limit;		/* Output limit */
 
@@ -517,7 +517,7 @@ struct channel {
   u16 preference;			/* Default route preference */
   u32 debug;				/* Debugging flags (D_*) */
   u8 merge_limit;			/* Maximal number of nexthops for RA_MERGED */
-  u8 in_keep_filtered;			/* Routes rejected in import filter are kept */
+  u8 in_keep;				/* Which states of routes to keep (RIK_*) */
   u8 disabled;
   u8 stale;				/* Used in reconfiguration */
 
@@ -529,11 +529,7 @@ struct channel {
 
   btime last_state_change;		/* Time of last state transition */
 
-  struct rtable *in_table;		/* Internal table for received routes */
-  struct event *reload_event;		/* Event responsible for reloading from in_table */
-  struct fib_iterator reload_fit;	/* FIB iterator in in_table used during reloading */
-  struct rte_storage *reload_next_rte;	/* Route iterator in in_table used during reloading */
-  u8 reload_active;			/* Iterator reload_fit is linked */
+  struct rt_export_request reload_req;	/* Feeder for import reload */
 
   u8 reload_pending;			/* Reloading and another reload is scheduled */
   u8 refeed_pending;			/* Refeeding and another refeed is scheduled */
@@ -544,6 +540,8 @@ struct channel {
   list roa_subscriptions;		/* List of active ROA table subscriptions based on filters roa_check() */
 };
 
+#define RIK_REJECTED	1			/* Routes rejected in import filter are kept */
+#define RIK_PREFILTER	(2 | RIK_REJECTED)	/* All routes' attribute state before import filter is kept */
 
 /*
  * Channel states
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index c0f81b9d..35f85274 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -1310,13 +1310,13 @@ rta_rehash(void)
  * converted to the normalized form.
  */
 ea_list *
-ea_lookup(ea_list *o)
+ea_lookup(ea_list *o, int overlay)
 {
   ea_list *r;
   uint h;
 
   ASSERT(!ea_is_cached(o));
-  o = ea_normalize(o, 1);
+  o = ea_normalize(o, overlay);
   h = ea_hash(o);
 
   for(r=rta_hash_table[h & rta_cache_mask]; r; r=r->next_hash)
diff --git a/nest/rt-show.c b/nest/rt-show.c
index 8bf74754..12ddc816 100644
--- a/nest/rt-show.c
+++ b/nest/rt-show.c
@@ -26,7 +26,8 @@ rt_show_table(struct cli *c, struct rt_show_data *d)
     return;
 
   if (d->last_table) cli_printf(c, -1007, "");
-  cli_printf(c, -1007, "Table %s:", d->tab->table->name);
+  cli_printf(c, -1007, "Table %s:",
+      d->tab->prefilter ? "import" : d->tab->table->name);
   d->last_table = d->tab;
 }
 
@@ -156,7 +157,7 @@ rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
 
   for (struct rte_storage *er = n->routes; er; er = er->next)
     {
-      if (rte_is_filtered(&er->rte) != d->filtered)
+      if (!d->tab->prefilter && (rte_is_filtered(&er->rte) != d->filtered))
 	continue;
 
       d->rt_counter++;
@@ -167,6 +168,11 @@ rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
 	continue;
 
       struct rte e = er->rte;
+      if (d->tab->prefilter)
+	if (e.sender != d->tab->prefilter->in_req.hook)
+	  continue;
+	else while (e.attrs->next)
+	  e.attrs = e.attrs->next;
 
       /* Export channel is down, do not try to export routes to it */
       if (ec && !ec->out_req.hook)
@@ -239,7 +245,7 @@ rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
 	else
 	  ia[0] = 0;
 
-	rt_show_rte(c, ia, &e, d, (n->routes == er));
+	rt_show_rte(c, ia, &e, d, !d->tab->prefilter && (n->routes == er));
 	first_show = 0;
       }
 
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 1631e00f..975da363 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -606,7 +606,7 @@ rte_store(const rte *r, net *net, rtable *tab)
   if (ea_is_cached(e->rte.attrs))
     e->rte.attrs = rta_clone(e->rte.attrs);
   else
-    e->rte.attrs = rta_lookup(e->rte.attrs);
+    e->rte.attrs = rta_lookup(e->rte.attrs, 1);
 
   return e;
 }
@@ -1513,7 +1513,7 @@ channel_preimport(struct rt_import_request *req, rte *new, rte *old)
 
   if (new_in && !old_in)
     if (CHANNEL_LIMIT_PUSH(c, IN))
-      if (c->in_keep_filtered)
+      if (c->in_keep & RIK_REJECTED)
       {
 	new->flags |= REF_FILTERED;
 	return new;
@@ -1527,8 +1527,6 @@ channel_preimport(struct rt_import_request *req, rte *new, rte *old)
   return new;
 }
 
-static void rte_update_direct(struct channel *c, const net_addr *n, rte *new, struct rte_src *src);
-
 void
 rte_update(struct channel *c, const net_addr *n, rte *new, struct rte_src *src)
 {
@@ -1537,15 +1535,13 @@ rte_update(struct channel *c, const net_addr *n, rte *new, struct rte_src *src)
 
   ASSERT(c->channel_state == CS_UP);
 
-  if (c->in_table && !rte_update_in(c, n, new, src))
-    return;
+  /* The import reloader requires prefilter routes to be the first layer */
+  if (new && (c->in_keep & RIK_PREFILTER))
+    if (ea_is_cached(new->attrs) && !new->attrs->next)
+      new->attrs = ea_clone(new->attrs);
+    else
+      new->attrs = ea_lookup(new->attrs, 0);
 
-  return rte_update_direct(c, n, new, src);
-}
-
-static void
-rte_update_direct(struct channel *c, const net_addr *n, rte *new, struct rte_src *src)
-{
   const struct filter *filter = c->in_filter;
   struct channel_import_stats *stats = &c->import_stats;
 
@@ -1563,7 +1559,7 @@ rte_update_direct(struct channel *c, const net_addr *n, rte *new, struct rte_src
 	  stats->updates_filtered++;
 	  channel_rte_trace_in(D_FILTERS, c, new, "filtered out");
 
-	  if (c->in_keep_filtered)
+	  if (c->in_keep & RIK_REJECTED)
 	    new->flags |= REF_FILTERED;
 	  else
 	    new = NULL;
@@ -1588,6 +1584,11 @@ rte_update_direct(struct channel *c, const net_addr *n, rte *new, struct rte_src
 
   rte_import(&c->in_req, n, new, src);
 
+  /* Now the route attributes are kept by the in-table cached version
+   * and we may drop the local handle */
+  if (new && (c->in_keep & RIK_PREFILTER))
+    ea_free(new->attrs);
+
   rte_update_unlock();
 }
 
@@ -3183,154 +3184,22 @@ done:
  *	Import table
  */
 
-int
-rte_update_in(struct channel *c, const net_addr *n, rte *new, struct rte_src *src)
+
+void channel_reload_export_bulk(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *rpe UNUSED, rte **feed, uint count)
 {
-  struct rtable *tab = c->in_table;
-  net *net;
+  struct channel *c = SKIP_BACK(struct channel, reload_req, req);
 
-  if (new)
-    net = net_get(tab, n);
-  else
-  {
-    net = net_find(tab, n);
-
-    if (!net)
-      goto drop_withdraw;
-  }
-
-  /* Find the old rte */
-  struct rte_storage **pos = rte_find(net, src);
-  if (*pos)
+  for (uint i=0; i<count; i++)
+    if (feed[i]->sender == c->in_req.hook)
     {
-      rte *old = &(*pos)->rte;
-      if (new && rte_same(old, new))
-      {
-	/* Refresh the old rte, continue with update to main rtable */
-	if (old->flags & (REF_STALE | REF_DISCARD | REF_MODIFY))
-	{
-	  old->flags &= ~(REF_STALE | REF_DISCARD | REF_MODIFY);
-	  return 1;
-	}
+      /* Strip the later attribute layers */
+      rte new = *feed[i];
+      while (new.attrs->next)
+	new.attrs = new.attrs->next;
 
-	goto drop_update;
-      }
-
-      if (!new)
-	CHANNEL_LIMIT_POP(c, RX);
-
-      /* Move iterator if needed */
-      if (*pos == c->reload_next_rte)
-	c->reload_next_rte = (*pos)->next;
-
-      /* Remove the old rte */
-      struct rte_storage *del = *pos;
-      *pos = (*pos)->next;
-      rte_free(del);
-      tab->rt_count--;
+      /* And reload the route */
+      rte_update(c, net, &new, new.src);
     }
-  else if (new)
-    {
-      if (CHANNEL_LIMIT_PUSH(c, RX))
-      {
-	/* Required by rte_trace_in() */
-	new->net = n;
-
-	channel_rte_trace_in(D_FILTERS, c, new, "ignored [limit]");
-	goto drop_update;
-      }
-    }
-  else
-    goto drop_withdraw;
-
-  if (!new)
-  {
-    if (!net->routes)
-      fib_delete(&tab->fib, net);
-
-    return 1;
-  }
-
-  /* Insert the new rte */
-  struct rte_storage *e = rte_store(new, net, tab);
-  e->rte.lastmod = current_time();
-  e->next = *pos;
-  *pos = e;
-  tab->rt_count++;
-  return 1;
-
-drop_update:
-  c->import_stats.updates_received++;
-  c->in_req.hook->stats.updates_ignored++;
-
-  if (!net->routes)
-    fib_delete(&tab->fib, net);
-
-  return 0;
-
-drop_withdraw:
-  c->import_stats.withdraws_received++;
-  c->in_req.hook->stats.withdraws_ignored++;
-  return 0;
-}
-
-int
-rt_reload_channel(struct channel *c)
-{
-  struct rtable *tab = c->in_table;
-  struct fib_iterator *fit = &c->reload_fit;
-  int max_feed = 64;
-
-  ASSERT(c->channel_state == CS_UP);
-
-  if (!c->reload_active)
-  {
-    FIB_ITERATE_INIT(fit, &tab->fib);
-    c->reload_active = 1;
-  }
-
-  do {
-    for (struct rte_storage *e = c->reload_next_rte; e; e = e->next)
-    {
-      if (max_feed-- <= 0)
-      {
-	c->reload_next_rte = e;
-	debug("%s channel reload burst split (max_feed=%d)", c->proto->name, max_feed);
-	return 0;
-      }
-
-      rte r = e->rte;
-      rte_update_direct(c, r.net, &r, r.src);
-    }
-
-    c->reload_next_rte = NULL;
-
-    FIB_ITERATE_START(&tab->fib, fit, net, n)
-    {
-      if (c->reload_next_rte = n->routes)
-      {
-	FIB_ITERATE_PUT_NEXT(fit, &tab->fib);
-	break;
-      }
-    }
-    FIB_ITERATE_END;
-  }
-  while (c->reload_next_rte);
-
-  c->reload_active = 0;
-  return 1;
-}
-
-void
-rt_reload_channel_abort(struct channel *c)
-{
-  if (c->reload_active)
-  {
-    /* Unlink the iterator */
-    fit_get(&c->in_table->fib, &c->reload_fit);
-    c->reload_next_rte = NULL;
-    c->reload_active = 0;
-  }
 }
 
 void
diff --git a/nest/rt.h b/nest/rt.h
index 32bba6a6..d5e28cb6 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -387,6 +387,7 @@ struct rt_show_data_rtable {
   node n;
   rtable *table;
   struct channel *export_channel;
+  struct channel *prefilter;
 };
 
 struct rt_show_data {
diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c
index 84430287..8df99420 100644
--- a/proto/bgp/bgp.c
+++ b/proto/bgp/bgp.c
@@ -900,9 +900,6 @@ bgp_refresh_begin(struct bgp_channel *c)
 
   c->load_state = BFS_REFRESHING;
   rt_refresh_begin(c->c.table, &c->c.in_req);
-
-  if (c->c.in_table)
-    rt_refresh_begin(c->c.in_table, &c->c.in_req);
 }
 
 /**
@@ -924,9 +921,6 @@ bgp_refresh_end(struct bgp_channel *c)
 
   c->load_state = BFS_NONE;
   rt_refresh_end(c->c.table, &c->c.in_req);
-
-  if (c->c.in_table)
-    rt_prune_sync(c->c.in_table, 0);
 }
 
 
@@ -1393,9 +1387,9 @@ bgp_reload_routes(struct channel *C)
   struct bgp_proto *p = (void *) C->proto;
   struct bgp_channel *c = (void *) C;
 
-  ASSERT(p->conn && (p->route_refresh || c->c.in_table));
+  ASSERT(p->conn && (p->route_refresh || (C->in_keep & RIK_PREFILTER)));
 
-  if (c->c.in_table)
+  if (C->in_keep & RIK_PREFILTER)
     channel_schedule_reload(C);
   else
     bgp_schedule_packet(p->conn, c, PKT_ROUTE_REFRESH);
@@ -2153,7 +2147,7 @@ bgp_channel_reconfigure(struct channel *C, struct channel_config *CC, int *impor
       (new->cost != old->cost))
   {
     /* import_changed itself does not force ROUTE_REFRESH when import_table is active */
-    if (c->c.in_table && (c->c.channel_state == CS_UP))
+    if ((c->c.in_keep & RIK_PREFILTER) && (c->c.channel_state == CS_UP))
       bgp_schedule_packet(p->conn, c, PKT_ROUTE_REFRESH);
 
     *import_changed = 1;
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index 45ee4ed2..c2e98340 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -1392,7 +1392,7 @@ bgp_rte_update(struct bgp_parse_state *s, const net_addr *n, u32 path_id, ea_lis
 
   /* Prepare cached route attributes */
   if (s->cached_ea == NULL)
-    s->cached_ea = ea_lookup(a0);
+    s->cached_ea = ea_lookup(a0, 0);
 
   rte e0 = {
     .attrs = s->cached_ea,
diff --git a/proto/ospf/rt.c b/proto/ospf/rt.c
index aedf3df6..69c2907d 100644
--- a/proto/ospf/rt.c
+++ b/proto/ospf/rt.c
@@ -2086,7 +2086,7 @@ again1:
 
 	ASSERT_DIE(ARRAY_SIZE(eattrs.a) >= eattrs.l.count);
 
-	ea_list *eal = ea_lookup(&eattrs.l);
+	ea_list *eal = ea_lookup(&eattrs.l, 0);
 	ea_free(nf->old_ea);
 	nf->old_ea = eal;
 
diff --git a/proto/perf/perf.c b/proto/perf/perf.c
index 67ad2ada..d82ac8aa 100644
--- a/proto/perf/perf.c
+++ b/proto/perf/perf.c
@@ -156,7 +156,7 @@ perf_loop(void *data)
       ea_set_attr_data(&ea, &ea_gen_nexthop, 0,
 	  &nhad.ad.data, sizeof nhad - sizeof nhad.ad);
 
-      p->data[i].a = rta_lookup(ea);
+      p->data[i].a = rta_lookup(ea, 0);
     }
     else
       p->data[i].a = rta_clone(p->data[i-1].a);
diff --git a/proto/pipe/pipe.c b/proto/pipe/pipe.c
index 99d4b737..d12e6731 100644
--- a/proto/pipe/pipe.c
+++ b/proto/pipe/pipe.c
@@ -126,7 +126,7 @@ pipe_postconfig(struct proto_config *CF)
   if (cc->rx_limit.action)
     cf_error("Pipe protocol does not support receive limits");
 
-  if (cc->in_keep_filtered)
+  if (cc->in_keep)
     cf_error("Pipe protocol prohibits keeping filtered routes");
 
   cc->debug = cf->c.debug;

From 050b4b4e5e6d4c05345bed2ec62c865258b4e7ee Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 20 Jun 2022 21:29:10 +0200
Subject: [PATCH 04/20] Table export generalized to allow for exporting from
 non-tables

---
 nest/proto.c    |  6 ++--
 nest/rt-table.c | 90 ++++++++++++++++++++++++++++++++++---------------
 nest/rt.h       | 17 +++++++---
 3 files changed, 79 insertions(+), 34 deletions(-)

diff --git a/nest/proto.c b/nest/proto.c
index 5e67d940..8513b9cb 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -498,7 +498,7 @@ channel_start_export(struct channel *c)
   }
 
   DBG("%s.%s: Channel start export req=%p\n", c->proto->name, c->name, &c->out_req);
-  rt_request_export(c->table, &c->out_req);
+  rt_request_export(&c->table->exporter, &c->out_req);
 }
 
 static void
@@ -552,7 +552,7 @@ channel_export_stopped(struct rt_export_request *req)
   {
     c->refeeding = 1;
     c->refeed_pending = 0;
-    rt_request_export(c->table, req);
+    rt_request_export(&c->table->exporter, req);
     return;
   }
 
@@ -600,7 +600,7 @@ channel_schedule_reload(struct channel *c)
 {
   ASSERT(c->in_req.hook);
 
-  rt_request_export(c->table, &c->reload_req);
+  rt_request_export(&c->table->exporter, &c->reload_req);
 }
 
 static void
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 975da363..14c80138 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -139,7 +139,6 @@ const char *rt_import_state_name_array[TIS_MAX] = {
 
 const char *rt_export_state_name_array[TES_MAX] = {
   [TES_DOWN] = "DOWN",
-  [TES_HUNGRY] = "HUNGRY",
   [TES_FEEDING] = "FEEDING",
   [TES_READY] = "READY",
   [TES_STOP] = "STOP"
@@ -1183,7 +1182,7 @@ rte_announce(rtable *tab, net *net, struct rte_storage *new, struct rte_storage
   }
 
   struct rt_export_hook *eh;
-  WALK_LIST(eh, tab->exports)
+  WALK_LIST(eh, tab->exporter.hooks)
   {
     if (eh->export_state == TES_STOP)
       continue;
@@ -1677,11 +1676,21 @@ rt_examine(rtable *t, net_addr *a, struct channel *c, const struct filter *filte
   return v > 0;
 }
 
+static void
+rt_table_export_done(struct rt_export_hook *hook)
+{
+  struct rt_exporter *re = hook->table;
+  struct rtable *tab = SKIP_BACK(struct rtable, exporter, re);
+
+  rt_unlock_table(tab);
+  DBG("Export hook %p in table %s finished uc=%u\n", hook, tab->name, tab->use_count);
+}
+
 static void
 rt_export_stopped(void *data)
 {
   struct rt_export_hook *hook = data;
-  rtable *tab = hook->table;
+  struct rt_exporter *tab = hook->table;
 
   /* Unlist */
   rem_node(&hook->n);
@@ -1689,14 +1698,13 @@ rt_export_stopped(void *data)
   /* Reporting the channel as stopped. */
   hook->stopped(hook->req);
 
+  /* Reporting the hook as finished. */
+  tab->done(hook);
+
   /* Freeing the hook together with its coroutine. */
   rfree(hook->pool);
-  rt_unlock_table(tab);
-
-  DBG("Export hook %p in table %s finished uc=%u\n", hook, tab->name, tab->use_count);
 }
 
-
 static inline void
 rt_set_import_state(struct rt_import_hook *hook, u8 state)
 {
@@ -1748,54 +1756,73 @@ rt_stop_import(struct rt_import_request *req, void (*stopped)(struct rt_import_r
   hook->stopped = stopped;
 }
 
-void
-rt_request_export(rtable *tab, struct rt_export_request *req)
+static struct rt_export_hook *
+rt_table_export_start(struct rt_exporter *re, struct rt_export_request *req)
 {
+  rtable *tab = SKIP_BACK(rtable, exporter, re);
   rt_lock_table(tab);
 
   pool *p = rp_new(tab->rp, "Export hook");
-  struct rt_export_hook *hook = req->hook = mb_allocz(p, sizeof(struct rt_export_hook));
+  struct rt_export_hook *hook = mb_allocz(p, sizeof(struct rt_export_hook));
   hook->pool = p;
   hook->lp = lp_new_default(p);
-  
-  hook->req = req;
-  hook->table = tab;
 
   /* stats zeroed by mb_allocz */
 
-  rt_set_export_state(hook, TES_HUNGRY);
-
-  hook->n = (node) {};
-  add_tail(&tab->exports, &hook->n);
-
   FIB_ITERATE_INIT(&hook->feed_fit, &tab->fib);
 
   DBG("New export hook %p req %p in table %s uc=%u\n", hook, req, tab->name, tab->use_count);
 
+  hook->event = ev_new_init(p, rt_feed_channel, hook);
+
+  return hook;
+}
+
+void
+rt_request_export(struct rt_exporter *re, struct rt_export_request *req)
+{
+  struct rt_export_hook *hook = req->hook = re->start(re, req);
+
+  hook->req = req;
+  hook->table = re;
+
+  hook->n = (node) {};
+  add_tail(&re->hooks, &hook->n);
+
   rt_set_export_state(hook, TES_FEEDING);
 
-  hook->event = ev_new_init(p, rt_feed_channel, hook);
   ev_schedule_work(hook->event);
 }
 
+static void
+rt_table_export_stop(struct rt_export_hook *hook)
+{
+  rtable *tab = SKIP_BACK(rtable, exporter, hook->table);
+
+  if (hook->export_state == TES_FEEDING)
+    fit_get(&tab->fib, &hook->feed_fit);
+}
+
 void
 rt_stop_export(struct rt_export_request *req, void (*stopped)(struct rt_export_request *))
 {
   ASSERT_DIE(req->hook);
   struct rt_export_hook *hook = req->hook;
 
-  rtable *tab = hook->table;
-
-  /* Stop feeding */
+  /* Cancel the feeder event */
   ev_postpone(hook->event);
 
-  if (hook->export_state == TES_FEEDING)
-    fit_get(&tab->fib, &hook->feed_fit);
+  /* Stop feeding from the exporter */
+  hook->table->stop(hook);
 
+  /* Reset the event as the stopped event */
   hook->event->hook = rt_export_stopped;
   hook->stopped = stopped;
 
+  /* Update export state */
   rt_set_export_state(hook, TES_STOP);
+
+  /* Run the stopped event */
   ev_schedule(hook->event);
 }
 
@@ -1948,7 +1975,7 @@ rt_dump_hooks(rtable *tab)
   }
 
   struct rt_export_hook *eh;
-  WALK_LIST(eh, tab->exports)
+  WALK_LIST(eh, tab->exporter.hooks)
   {
     eh->req->dump_req(eh->req);
     debug("  Export hook %p requested by %p:"
@@ -2252,10 +2279,17 @@ rt_setup(pool *pp, struct rtable_config *cf)
 
   init_list(&t->flowspec_links);
 
+  t->exporter = (struct rt_exporter) {
+    .start = rt_table_export_start,
+    .stop = rt_table_export_stop,
+    .done = rt_table_export_done,
+  };
+  init_list(&t->exporter.hooks);
+
   if (!(t->internal = cf->internal))
   {
     init_list(&t->imports);
-    init_list(&t->exports);
+
     hmap_init(&t->id_map, p, 1024);
     hmap_set(&t->id_map, 0);
 
@@ -3138,7 +3172,9 @@ rt_feed_channel(void *data)
 
   ASSERT(c->export_state == TES_FEEDING);
 
-  FIB_ITERATE_START(&c->table->fib, fit, net, n)
+  rtable *tab = SKIP_BACK(rtable, exporter, c->table);
+
+  FIB_ITERATE_START(&tab->fib, fit, net, n)
     {
       if (max_feed <= 0)
 	{
diff --git a/nest/rt.h b/nest/rt.h
index d5e28cb6..0f5a5ba7 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -56,6 +56,16 @@ struct rtable_config {
   btime max_settle_time;		/* Maximum settle time for notifications */
 };
 
+struct rt_export_hook;
+struct rt_export_request;
+
+struct rt_exporter {
+  list hooks;				/* Registered route export hooks */
+  struct rt_export_hook *(*start)(struct rt_exporter *, struct rt_export_request *);
+  void (*stop)(struct rt_export_hook *);
+  void (*done)(struct rt_export_hook *);
+};
+
 typedef struct rtable {
   resource r;
   node n;				/* Node in list of all tables */
@@ -69,7 +79,7 @@ typedef struct rtable {
   u32 rt_count;				/* Number of routes in the table */
 
   list imports;				/* Registered route importers */
-  list exports;				/* Registered route exporters */
+  struct rt_exporter exporter;		/* Exporter API structure */
 
   struct hmap id_map;
   struct hostcache *hostcache;
@@ -221,7 +231,7 @@ struct rt_export_request {
 
 struct rt_export_hook {
   node n;
-  rtable *table;			/* The connected table */
+  struct rt_exporter *table;		/* The connected table */
 
   pool *pool;
   linpool *lp;
@@ -255,14 +265,13 @@ struct rt_export_hook {
 #define TIS_MAX		6
 
 #define TES_DOWN	0
-#define TES_HUNGRY	1
 #define TES_FEEDING	2
 #define TES_READY	3
 #define TES_STOP	4
 #define TES_MAX		5
 
 void rt_request_import(rtable *tab, struct rt_import_request *req);
-void rt_request_export(rtable *tab, struct rt_export_request *req);
+void rt_request_export(struct rt_exporter *tab, struct rt_export_request *req);
 
 void rt_stop_import(struct rt_import_request *, void (*stopped)(struct rt_import_request *));
 void rt_stop_export(struct rt_export_request *, void (*stopped)(struct rt_export_request *));

From 9c9059fd172dcc2f8805529de4b3174f280c109c Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Wed, 22 Jun 2022 12:45:42 +0200
Subject: [PATCH 05/20] Allowed optimized exporting of a subprefix tree

Added an option for export filter to allow for prefiltering based on the
prefix. Routes outside the given prefix are completely ignored. Config
is simple:

	export in <net> <filter>;
---
 doc/bird.sgml       |  8 ++--
 nest/config.Y       |  6 +++
 nest/proto.c        |  8 +++-
 nest/protocol.h     |  2 +
 nest/rt-table.c     | 89 +++++++++++++++++++++++++++++++++++++--------
 nest/rt.h           |  3 ++
 proto/pipe/config.Y |  6 +++
 proto/pipe/pipe.c   |  8 ++++
 proto/pipe/pipe.h   |  1 +
 9 files changed, 111 insertions(+), 20 deletions(-)

diff --git a/doc/bird.sgml b/doc/bird.sgml
index d17de23f..c9ce670b 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -914,10 +914,12 @@ inherited from templates can be updated by new definitions.
 	<cf/none/ is for dropping all routes. Default: <cf/all/ (except for
 	EBGP).
 
-	<tag><label id="proto-export">export <m/filter/</tag>
+	<tag><label id="proto-export">export [ in <m/prefix/ ] <m/filter/</tag>
 	This is similar to the <cf>import</cf> keyword, except that it works in
-	the direction from the routing table to the protocol. Default: <cf/none/
-	(except for EBGP).
+	the direction from the routing table to the protocol. If <cf/in/ keyword is used,
+	only routes inside the given prefix are exported. Other routes are completely
+	ignored (e.g. no logging and no statistics).
+	Default: <cf/none/ (except for EBGP).
 
 	<tag><label id="proto-import-keep-filtered">import keep filtered <m/switch/</tag>
 	Usually, if an import filter rejects a route, the route is forgotten.
diff --git a/nest/config.Y b/nest/config.Y
index ea7e1266..c3f2532f 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -306,6 +306,12 @@ channel_item_:
      this_channel->table = $2;
    }
  | IMPORT imexport { this_channel->in_filter = $2; }
+ | EXPORT IN net_any imexport {
+     if (this_channel->net_type && ($3->type != this_channel->net_type))
+       cf_error("Incompatible export prefilter type");
+     this_channel->out_subprefix = $3;
+     this_channel->out_filter = $4;
+   }
  | EXPORT imexport { this_channel->out_filter = $2; }
  | RECEIVE LIMIT limit_spec { this_channel->rx_limit = $3; }
  | IMPORT LIMIT limit_spec { this_channel->in_limit = $3; }
diff --git a/nest/proto.c b/nest/proto.c
index 8513b9cb..3792fde4 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -214,6 +214,7 @@ proto_add_channel(struct proto *p, struct channel_config *cf)
 
   c->in_filter = cf->in_filter;
   c->out_filter = cf->out_filter;
+  c->out_subprefix = cf->out_subprefix;
 
   channel_init_limit(c, &c->rx_limit, PLD_RX, &cf->rx_limit);
   channel_init_limit(c, &c->in_limit, PLD_IN, &cf->in_limit);
@@ -467,6 +468,7 @@ channel_start_export(struct channel *c)
 
   c->out_req = (struct rt_export_request) {
     .name = rn,
+    .addr_in = c->out_subprefix,
     .trace_routes = c->debug | c->proto->debug,
     .dump_req = channel_dump_export_req,
     .log_state_change = channel_export_log_state_change,
@@ -922,7 +924,10 @@ channel_reconfigure(struct channel *c, struct channel_config *cf)
   /* FIXME: better handle these changes, also handle in_keep_filtered */
   if ((c->table != cf->table->table) ||
       (cf->ra_mode && (c->ra_mode != cf->ra_mode)) ||
-      (cf->in_keep != c->in_keep))
+      (cf->in_keep != c->in_keep) ||
+      cf->out_subprefix && c->out_subprefix &&
+	  !net_equal(cf->out_subprefix, c->out_subprefix) ||
+      (!cf->out_subprefix != !c->out_subprefix))
     return 0;
 
   /* Note that filter_same() requires arguments in (new, old) order */
@@ -947,6 +952,7 @@ channel_reconfigure(struct channel *c, struct channel_config *cf)
   // c->ra_mode = cf->ra_mode;
   c->merge_limit = cf->merge_limit;
   c->preference = cf->preference;
+  c->out_req.addr_in = c->out_subprefix = cf->out_subprefix;
   c->debug = cf->debug;
   c->in_req.trace_routes = c->out_req.trace_routes = c->debug | c->proto->debug;
   c->rpki_reload = cf->rpki_reload;
diff --git a/nest/protocol.h b/nest/protocol.h
index b482ed99..a1701a7e 100644
--- a/nest/protocol.h
+++ b/nest/protocol.h
@@ -452,6 +452,7 @@ struct channel_config {
   struct proto_config *parent;		/* Where channel is defined (proto or template) */
   struct rtable_config *table;		/* Table we're attached to */
   const struct filter *in_filter, *out_filter; /* Attached filters */
+  const net_addr *out_subprefix;	/* Export only subprefixes of this net */
 
   struct channel_limit rx_limit;	/* Limit for receiving routes from protocol
 					   (relevant when in_keep & RIK_REJECTED) */
@@ -477,6 +478,7 @@ struct channel {
   struct rtable *table;
   const struct filter *in_filter;	/* Input filter */
   const struct filter *out_filter;	/* Output filter */
+  const net_addr *out_subprefix;	/* Export only subprefixes of this net */
   struct bmap export_map;		/* Keeps track which routes were really exported */
   struct bmap export_reject_map;	/* Keeps track which routes were rejected by export filter */
 
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 14c80138..afafef62 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -126,7 +126,9 @@ static inline void rt_flowspec_resolve_rte(rte *r, struct channel *c);
 static inline void rt_prune_table(rtable *tab);
 static inline void rt_schedule_notify(rtable *tab);
 static void rt_flowspec_notify(rtable *tab, net *net);
-static void rt_feed_channel(void *);
+static void rt_feed_by_fib(void *);
+static void rt_feed_by_trie(void *);
+static uint rt_feed_net(struct rt_export_hook *c, net *n);
 
 const char *rt_import_state_name_array[TIS_MAX] = {
   [TIS_DOWN] = "DOWN",
@@ -1187,6 +1189,9 @@ rte_announce(rtable *tab, net *net, struct rte_storage *new, struct rte_storage
     if (eh->export_state == TES_STOP)
       continue;
 
+    if (eh->req->addr_in && !net_in_netX(net->n.addr, eh->req->addr_in))
+      continue;
+
     if (new)
       eh->stats.updates_received++;
     else
@@ -1768,13 +1773,21 @@ rt_table_export_start(struct rt_exporter *re, struct rt_export_request *req)
   hook->lp = lp_new_default(p);
 
   /* stats zeroed by mb_allocz */
-
-  FIB_ITERATE_INIT(&hook->feed_fit, &tab->fib);
+  if (tab->trie && req->addr_in && net_val_match(tab->addr_type, NB_IP))
+  {
+    hook->walk_state = mb_allocz(p, sizeof (struct f_trie_walk_state));
+    hook->walk_lock = rt_lock_trie(tab);
+    trie_walk_init(hook->walk_state, tab->trie, req->addr_in);
+    hook->event = ev_new_init(p, rt_feed_by_trie, hook);
+  }
+  else
+  {
+    FIB_ITERATE_INIT(&hook->feed_fit, &tab->fib);
+    hook->event = ev_new_init(p, rt_feed_by_fib, hook);
+  }
 
   DBG("New export hook %p req %p in table %s uc=%u\n", hook, req, tab->name, tab->use_count);
 
-  hook->event = ev_new_init(p, rt_feed_channel, hook);
-
   return hook;
 }
 
@@ -3154,7 +3167,7 @@ rt_commit(struct config *new, struct config *old)
 }
 
 /**
- * rt_feed_channel - advertise all routes to a channel
+ * rt_feed_by_fib - advertise all routes to a channel by walking a fib
  * @c: channel to be fed
  *
  * This function performs one pass of advertisement of routes to a channel that
@@ -3163,7 +3176,7 @@ rt_commit(struct config *new, struct config *old)
  * order not to monopolize CPU time.)
  */
 static void
-rt_feed_channel(void *data)
+rt_feed_by_fib(void *data)
 {
   struct rt_export_hook *c = data;
 
@@ -3183,9 +3196,55 @@ rt_feed_channel(void *data)
 	  return;
 	}
 
-      if (c->export_state != TES_FEEDING)
-	goto done;
+      ASSERT(c->export_state == TES_FEEDING);
 
+      if (!c->req->addr_in || net_in_netX(n->n.addr, c->req->addr_in))
+	max_feed -= rt_feed_net(c, n);
+    }
+  FIB_ITERATE_END;
+
+  rt_set_export_state(c, TES_READY);
+}
+
+static void
+rt_feed_by_trie(void *data)
+{
+  struct rt_export_hook *c = data;
+  rtable *tab = SKIP_BACK(rtable, exporter, c->table);
+
+  ASSERT_DIE(c->walk_state);
+  struct f_trie_walk_state *ws = c->walk_state;
+
+  int max_feed = 256;
+
+  ASSERT_DIE(c->export_state == TES_FEEDING);
+
+  net_addr addr;
+  while (trie_walk_next(ws, &addr))
+  {
+    net *n = net_find(tab, &addr);
+    if (!n)
+      continue;
+
+    if ((max_feed -= rt_feed_net(c, n)) <= 0)
+      return;
+
+    ASSERT_DIE(c->export_state == TES_FEEDING);
+  }
+
+  rt_unlock_trie(tab, c->walk_lock);
+  c->walk_lock = NULL;
+
+  mb_free(c->walk_state);
+  c->walk_state = NULL;
+
+  rt_set_export_state(c, TES_READY);
+}
+
+
+static uint
+rt_feed_net(struct rt_export_hook *c, net *n)
+{
       if (c->req->export_bulk)
       {
 	uint count = rte_feed_count(n);
@@ -3196,23 +3255,21 @@ rt_feed_channel(void *data)
 	  rte_feed_obtain(n, feed, count);
 	  struct rt_pending_export rpe = { .new_best = n->routes };
 	  c->req->export_bulk(c->req, n->n.addr, &rpe, feed, count);
-	  max_feed -= count;
 	  rte_update_unlock();
 	}
+	return count;
       }
-      else if (n->routes && rte_is_valid(&n->routes->rte))
+
+      if (n->routes && rte_is_valid(&n->routes->rte))
       {
 	rte_update_lock();
 	struct rt_pending_export rpe = { .new = n->routes, .new_best = n->routes };
 	c->req->export_one(c->req, n->n.addr, &rpe);
-	max_feed--;
 	rte_update_unlock();
+	return 1;
       }
-    }
-  FIB_ITERATE_END;
 
-done:
-  rt_set_export_state(c, TES_READY);
+      return 0;
 }
 
 
diff --git a/nest/rt.h b/nest/rt.h
index 0f5a5ba7..57e117da 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -212,6 +212,7 @@ struct rt_pending_export {
 
 struct rt_export_request {
   struct rt_export_hook *hook;		/* Table part of the export */
+  const net_addr *addr_in;		/* Subnet export request */
   char *name;
   u8 trace_routes;
 
@@ -245,6 +246,8 @@ struct rt_export_hook {
   } 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 */
 
   btime last_state_change;		/* Time of last state transition */
 
diff --git a/proto/pipe/config.Y b/proto/pipe/config.Y
index c869de9f..0990168e 100644
--- a/proto/pipe/config.Y
+++ b/proto/pipe/config.Y
@@ -41,6 +41,12 @@ pipe_proto:
    pipe_proto_start '{'
  | pipe_proto proto_item ';'
  | pipe_proto channel_item_ ';'
+ | pipe_proto IMPORT IN net_any imexport ';' {
+    if (this_channel->net_type && ($4->type != this_channel->net_type))
+      cf_error("Incompatible export prefilter type");
+    PIPE_CFG->in_subprefix = $4;
+    this_channel->in_filter = $5;
+  }
  | pipe_proto PEER TABLE rtable ';' { PIPE_CFG->peer = $4; }
  | pipe_proto MAX GENERATION expr ';' {
     if (($4 < 1) || ($4 > 254)) cf_error("Max generation must be in range 1..254, got %u", $4);
diff --git a/proto/pipe/pipe.c b/proto/pipe/pipe.c
index d12e6731..351db36b 100644
--- a/proto/pipe/pipe.c
+++ b/proto/pipe/pipe.c
@@ -123,6 +123,12 @@ pipe_postconfig(struct proto_config *CF)
   if (cc->table->addr_type != cf->peer->addr_type)
     cf_error("Primary table and peer table must have the same type");
 
+  if (cc->out_subprefix && (cc->table->addr_type != cc->out_subprefix->type))
+    cf_error("Export subprefix must match table type");
+
+  if (cf->in_subprefix && (cc->table->addr_type != cf->in_subprefix->type))
+    cf_error("Import subprefix must match table type");
+
   if (cc->rx_limit.action)
     cf_error("Pipe protocol does not support receive limits");
 
@@ -142,6 +148,7 @@ pipe_configure_channels(struct pipe_proto *p, struct pipe_config *cf)
     .channel = cc->channel,
     .table = cc->table,
     .out_filter = cc->out_filter,
+    .out_subprefix = cc->out_subprefix,
     .in_limit = cc->in_limit,
     .ra_mode = RA_ANY,
     .debug = cc->debug,
@@ -153,6 +160,7 @@ pipe_configure_channels(struct pipe_proto *p, struct pipe_config *cf)
     .channel = cc->channel,
     .table = cf->peer,
     .out_filter = cc->in_filter,
+    .out_subprefix = cf->in_subprefix,
     .in_limit = cc->out_limit,
     .ra_mode = RA_ANY,
     .debug = cc->debug,
diff --git a/proto/pipe/pipe.h b/proto/pipe/pipe.h
index 60c857eb..a6534e1c 100644
--- a/proto/pipe/pipe.h
+++ b/proto/pipe/pipe.h
@@ -12,6 +12,7 @@
 struct pipe_config {
   struct proto_config c;
   struct rtable_config *peer;		/* Table we're connected to */
+  const net_addr *in_subprefix;
   u8 max_generation;
 };
 

From 5c1ebe012e1bbfec52b4fba8b59edd355a7dff91 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Sun, 26 Jun 2022 14:11:08 +0200
Subject: [PATCH 06/20] Fixed forgotten preference handling in filters

---
 conf/confbase.Y  | 2 +-
 filter/test.conf | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/conf/confbase.Y b/conf/confbase.Y
index 9a83083c..58890cd6 100644
--- a/conf/confbase.Y
+++ b/conf/confbase.Y
@@ -173,7 +173,7 @@ expr_us:
  | expr US { $$ = $1 US_; }
  ;
 
-toksym: FROM ;
+toksym: FROM | PREFERENCE ;
 symbol: CF_SYM_UNDEFINED | CF_SYM_KNOWN | toksym ;
 symbol_known: CF_SYM_KNOWN | toksym ;
 
diff --git a/filter/test.conf b/filter/test.conf
index 21e7330f..eb9cc30c 100644
--- a/filter/test.conf
+++ b/filter/test.conf
@@ -1445,6 +1445,8 @@ bool t;
 	rip_metric = 14;
 	unset(rip_metric);
 
+	preference = 1234;
+
 	test_ca_int1 = 42;
 	test_ca_ip2 = 1.3.5.7;
 	test_ca_quad3 = 2.4.6.8;

From 13ef5e53dd4a98c80261139b4c9ce4b1074cac40 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Fri, 24 Jun 2022 15:27:26 +0200
Subject: [PATCH 07/20] The show-route CLI command now uses the route export
 API

In the multithreaded environment, it is not supposed that anybody
traverses the routing table as the CLI show-route was doing. Now the
routing table traversal is gone and CLI won't hold the table locked
while computing filters.
---
 nest/cli.c      |   8 +-
 nest/cli.h      |   4 +-
 nest/config.Y   |   1 +
 nest/rt-show.c  | 279 +++++++++++++++++++++++++-----------------------
 nest/rt-table.c |  11 +-
 nest/rt.h       |   8 +-
 proto/mrt/mrt.c |   7 +-
 7 files changed, 169 insertions(+), 149 deletions(-)

diff --git a/nest/cli.c b/nest/cli.c
index b54a0d76..31deef03 100644
--- a/nest/cli.c
+++ b/nest/cli.c
@@ -319,7 +319,6 @@ cli_new(void *priv)
   c->event->data = c;
   c->cont = cli_hello;
   c->parser_pool = lp_new_default(c->pool);
-  c->show_pool = lp_new_default(c->pool);
   c->rx_buf = mb_alloc(c->pool, CLI_RX_BUF_SIZE);
   ev_schedule(c->event);
   return c;
@@ -409,11 +408,14 @@ void
 cli_free(cli *c)
 {
   cli_set_log_echo(c, 0, 0);
+  int defer = 0;
   if (c->cleanup)
-    c->cleanup(c);
+    defer = c->cleanup(c);
   if (c == cmd_reconfig_stored_cli)
     cmd_reconfig_stored_cli = NULL;
-  rfree(c->pool);
+
+  if (!defer)
+    rfree(c->pool);
 }
 
 /**
diff --git a/nest/cli.h b/nest/cli.h
index 8a3294c5..92572968 100644
--- a/nest/cli.h
+++ b/nest/cli.h
@@ -33,12 +33,12 @@ typedef struct cli {
   struct cli_out *tx_buf, *tx_pos, *tx_write;
   event *event;
   void (*cont)(struct cli *c);
-  void (*cleanup)(struct cli *c);
+  int (*cleanup)(struct cli *c);	/* Return 0 if finished and cli may be freed immediately.
+					   Otherwise return 1 and call rfree(c->pool) when appropriate. */
   void *rover;				/* Private to continuation routine */
   int last_reply;
   int restricted;			/* CLI is restricted to read-only commands */
   struct linpool *parser_pool;		/* Pool used during parsing */
-  struct linpool *show_pool;		/* Pool used during route show */
   byte *ring_buf;			/* Ring buffer for asynchronous messages */
   byte *ring_end, *ring_read, *ring_write;	/* Pointers to the ring buffer */
   uint ring_overflow;			/* Counter of ring overflows */
diff --git a/nest/config.Y b/nest/config.Y
index c3f2532f..ec10dd69 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -653,6 +653,7 @@ r_args:
      init_list(&($$->tables));
      $$->filter = FILTER_ACCEPT;
      $$->running_on_config = config;
+     $$->cli = this_cli;
    }
  | r_args net_any {
      $$ = $1;
diff --git a/nest/rt-show.c b/nest/rt-show.c
index 12ddc816..1404f7e6 100644
--- a/nest/rt-show.c
+++ b/nest/rt-show.c
@@ -19,8 +19,10 @@
 #include "sysdep/unix/krt.h"
 
 static void
-rt_show_table(struct cli *c, struct rt_show_data *d)
+rt_show_table(struct rt_show_data *d)
 {
+  struct cli *c = d->cli;
+
   /* No table blocks in 'show route count' */
   if (d->stats == 2)
     return;
@@ -70,7 +72,7 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
     bsprintf(info, " (%d)", rt_get_preference(e));
 
   if (d->last_table != d->tab)
-    rt_show_table(c, d);
+    rt_show_table(d);
 
   eattr *heea;
   struct hostentry_adata *had = NULL;
@@ -118,32 +120,10 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
     ea_show_list(c, a);
 }
 
-static uint
-rte_feed_count(net *n)
-{
-  uint count = 0;
-  for (struct rte_storage *e = n->routes; e; e = e->next)
-    if (rte_is_valid(RTE_OR_NULL(e)))
-      count++;
-  return count;
-}
-
 static void
-rte_feed_obtain(net *n, rte **feed, uint count)
-{
-  uint i = 0;
-  for (struct rte_storage *e = n->routes; e; e = e->next)
-    if (rte_is_valid(RTE_OR_NULL(e)))
-    {
-      ASSERT_DIE(i < count);
-      feed[i++] = &e->rte;
-    }
-  ASSERT_DIE(i == count);
-}
-
-static void
-rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
+rt_show_net(struct rt_show_data *d, const net_addr *n, rte **feed, uint count)
 {
+  struct cli *c = d->cli;
   byte ia[NET_MAX_TEXT_LENGTH+1];
   struct channel *ec = d->tab->export_channel;
 
@@ -155,9 +135,9 @@ rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
   int first_show = 1;
   int pass = 0;
 
-  for (struct rte_storage *er = n->routes; er; er = er->next)
+  for (uint i = 0; i < count; i++)
     {
-      if (!d->tab->prefilter && (rte_is_filtered(&er->rte) != d->filtered))
+      if (!d->tab->prefilter && (rte_is_filtered(feed[i]) != d->filtered))
 	continue;
 
       d->rt_counter++;
@@ -167,7 +147,7 @@ rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
       if (pass)
 	continue;
 
-      struct rte e = er->rte;
+      struct rte e = *feed[i];
       if (d->tab->prefilter)
 	if (e.sender != d->tab->prefilter->in_req.hook)
 	  continue;
@@ -190,13 +170,7 @@ rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
 	{
 	  /* Special case for merged export */
 	  pass = 1;
-	  uint count = rte_feed_count(n);
-	  if (!count)
-	    goto skip;
-
-	  rte **feed = alloca(count * sizeof(rte *));
-	  rte_feed_obtain(n, feed, count);
-	  rte *em = rt_export_merged(ec, feed, count, c->show_pool, 1);
+	  rte *em = rt_export_merged(ec, feed, count, tmp_linpool, 1);
 
 	  if (em)
 	    e = *em;
@@ -241,159 +215,166 @@ rt_show_net(struct cli *c, net *n, struct rt_show_data *d)
       if (d->stats < 2)
       {
 	if (first_show)
-	  net_format(n->n.addr, ia, sizeof(ia));
+	  net_format(n, ia, sizeof(ia));
 	else
 	  ia[0] = 0;
 
-	rt_show_rte(c, ia, &e, d, !d->tab->prefilter && (n->routes == er));
+	rt_show_rte(c, ia, &e, d, !d->tab->prefilter && !i);
 	first_show = 0;
       }
 
       d->show_counter++;
 
     skip:
-      lp_flush(c->show_pool);
-
       if (d->primary_only)
 	break;
     }
+
+  if ((d->show_counter - d->show_counter_last_flush) > 64)
+  {
+    d->show_counter_last_flush = d->show_counter;
+    cli_write_trigger(d->cli);
+  }
 }
 
 static void
+rt_show_net_export_bulk(struct rt_export_request *req, const net_addr *n,
+    struct rt_pending_export *rpe UNUSED, rte **feed, uint count)
+{
+  struct rt_show_data *d = SKIP_BACK(struct rt_show_data, req, req);
+  return rt_show_net(d, n, feed, count);
+}
+
+static void
+rt_show_export_stopped_cleanup(struct rt_export_request *req)
+{
+  struct rt_show_data *d = SKIP_BACK(struct rt_show_data, req, req);
+
+  /* The hook is now invalid */
+  req->hook = NULL;
+
+  /* Unlock referenced tables */
+  struct rt_show_data_rtable *tab;
+  WALK_LIST(tab, d->tables)
+    rt_unlock_table(tab->table);
+
+  /* And free the CLI (deferred) */
+  rfree(d->cli->pool);
+}
+
+static int
 rt_show_cleanup(struct cli *c)
 {
   struct rt_show_data *d = c->rover;
-  struct rt_show_data_rtable *tab;
 
-  /* Unlink the iterator */
-  if (d->table_open && !d->trie_walk)
-    fit_get(&d->tab->table->fib, &d->fit);
+  /* Cancel the feed */
+  if (d->req.hook)
+  {
+    rt_stop_export(&d->req, rt_show_export_stopped_cleanup);
+    return 1;
+  }
+  else
+    return 0;
+}
 
-  if (d->walk_lock)
-    rt_unlock_trie(d->tab->table, d->walk_lock);
+static void rt_show_export_stopped(struct rt_export_request *req);
 
-  /* Unlock referenced tables */
-  WALK_LIST(tab, d->tables)
-    rt_unlock_table(tab->table);
+static void
+rt_show_log_state_change(struct rt_export_request *req, u8 state)
+{
+  if (state == TES_READY)
+    rt_stop_export(req, rt_show_export_stopped);
 }
 
 static void
-rt_show_cont(struct cli *c)
+rt_show_dump_req(struct rt_export_request *req)
 {
-  struct rt_show_data *d = c->rover;
-  struct rtable *tab = d->tab->table;
-#ifdef DEBUGGING
-  unsigned max = 4;
-#else
-  unsigned max = 64;
-#endif
-  struct fib *fib = &tab->fib;
-  struct fib_iterator *it = &d->fit;
+  debug("  CLI Show Route Feed %p\n", req);
+}
+
+static void
+rt_show_cont(struct rt_show_data *d)
+{
+  struct cli *c = d->cli;
 
   if (d->running_on_config && (d->running_on_config != config))
   {
     cli_printf(c, 8004, "Stopped due to reconfiguration");
-    goto done;
+
+    /* Unlock referenced tables */
+    struct rt_show_data_rtable *tab;
+    WALK_LIST(tab, d->tables)
+      rt_unlock_table(tab->table);
+
+    /* No more action */
+    c->cleanup = NULL;
+    c->cont = NULL;
+    c->rover = NULL;
+    cli_write_trigger(c);
+    return;
   }
 
-  if (!d->table_open)
-  {
-    /* We use either trie-based walk or fib-based walk */
-    d->trie_walk = tab->trie &&
-      (d->addr_mode == RSD_ADDR_IN) &&
-      net_val_match(tab->addr_type, NB_IP);
+  d->req = (struct rt_export_request) {
+    .addr_in = (d->addr_mode == RSD_ADDR_IN) ? d->addr : NULL,
+    .name = "CLI Show Route",
+    .export_bulk = rt_show_net_export_bulk,
+    .dump_req = rt_show_dump_req,
+    .log_state_change = rt_show_log_state_change,
+  };
 
-    if (d->trie_walk && !d->walk_state)
-      d->walk_state = lp_allocz(c->parser_pool, sizeof (struct f_trie_walk_state));
+  d->table_counter++;
+  d->kernel = rt_show_get_kernel(d);
 
-    if (d->trie_walk)
-    {
-      d->walk_lock = rt_lock_trie(tab);
-      trie_walk_init(d->walk_state, tab->trie, d->addr);
-    }
-    else
-      FIB_ITERATE_INIT(&d->fit, &tab->fib);
+  d->show_counter_last = d->show_counter;
+  d->rt_counter_last   = d->rt_counter;
+  d->net_counter_last  = d->net_counter;
 
-    d->table_open = 1;
-    d->table_counter++;
-    d->kernel = rt_show_get_kernel(d);
+  if (d->tables_defined_by & RSD_TDB_SET)
+    rt_show_table(d);
 
-    d->show_counter_last = d->show_counter;
-    d->rt_counter_last   = d->rt_counter;
-    d->net_counter_last  = d->net_counter;
+  rt_request_export(&d->tab->table->exporter, &d->req);
+}
 
-    if (d->tables_defined_by & RSD_TDB_SET)
-      rt_show_table(c, d);
-  }
+static void
+rt_show_export_stopped(struct rt_export_request *req)
+{
+  struct rt_show_data *d = SKIP_BACK(struct rt_show_data, req, req);
 
-  if (d->trie_walk)
-  {
-    /* Trie-based walk */
-    net_addr addr;
-    while (trie_walk_next(d->walk_state, &addr))
-    {
-      net *n = net_find(tab, &addr);
-      if (!n)
-	continue;
-
-      rt_show_net(c, n, d);
-
-      if (!--max)
-	return;
-    }
-
-    rt_unlock_trie(tab, d->walk_lock);
-    d->walk_lock = NULL;
-  }
-  else
-  {
-    /* fib-based walk */
-    FIB_ITERATE_START(fib, it, net, n)
-    {
-      if ((d->addr_mode == RSD_ADDR_IN) && (!net_in_netX(n->n.addr, d->addr)))
-	goto next;
-
-      if (!max--)
-      {
-	FIB_ITERATE_PUT(it);
-	return;
-      }
-      rt_show_net(c, n, d);
-
-    next:;
-    }
-    FIB_ITERATE_END;
-  }
+  /* The hook is now invalid */
+  req->hook = NULL;
 
   if (d->stats)
   {
     if (d->last_table != d->tab)
-      rt_show_table(c, d);
+      rt_show_table(d);
 
-    cli_printf(c, -1007, "%d of %d routes for %d networks in table %s",
+    cli_printf(d->cli, -1007, "%d of %d routes for %d networks in table %s",
 	       d->show_counter - d->show_counter_last, d->rt_counter - d->rt_counter_last,
-	       d->net_counter - d->net_counter_last, tab->name);
+	       d->net_counter - d->net_counter_last, d->tab->table->name);
   }
 
   d->kernel = NULL;
-  d->table_open = 0;
   d->tab = NODE_NEXT(d->tab);
 
   if (NODE_VALID(d->tab))
-    return;
+    return rt_show_cont(d);
 
+  /* Unlock referenced tables */
+  struct rt_show_data_rtable *tab;
+  WALK_LIST(tab, d->tables)
+    rt_unlock_table(tab->table);
+
+  /* Printout total stats */
   if (d->stats && (d->table_counter > 1))
   {
-    if (d->last_table) cli_printf(c, -1007, "");
-    cli_printf(c, 14, "Total: %d of %d routes for %d networks in %d tables",
+    if (d->last_table) cli_printf(d->cli, -1007, "");
+    cli_printf(d->cli, 14, "Total: %d of %d routes for %d networks in %d tables",
 	       d->show_counter, d->rt_counter, d->net_counter, d->table_counter);
   }
   else
-    cli_printf(c, 0, "");
+    cli_printf(d->cli, 0, "");
 
-done:
-  rt_show_cleanup(c);
-  c->cont = c->cleanup = NULL;
+  cli_write_trigger(d->cli);
 }
 
 struct rt_show_data_rtable *
@@ -491,6 +472,12 @@ rt_show_prepare_tables(struct rt_show_data *d)
     cf_error("No valid tables");
 }
 
+static void
+rt_show_dummy_cont(struct cli *c UNUSED)
+{
+  /* Explicitly do nothing to prevent CLI from trying to parse another command. */
+}
+
 void
 rt_show(struct rt_show_data *d)
 {
@@ -510,12 +497,16 @@ rt_show(struct rt_show_data *d)
 
     /* There is at least one table */
     d->tab = HEAD(d->tables);
-    this_cli->cont = rt_show_cont;
     this_cli->cleanup = rt_show_cleanup;
     this_cli->rover = d;
+    this_cli->cont = rt_show_dummy_cont;
+    rt_show_cont(d);
   }
   else
   {
+    uint max = 64;
+    rte **feed = mb_alloc(d->cli->pool, sizeof(rte *) * max);
+
     WALK_LIST(tab, d->tables)
     {
       d->tab = tab;
@@ -526,8 +517,24 @@ rt_show(struct rt_show_data *d)
       else
 	n = net_find(tab->table, d->addr);
 
-      if (n)
-	rt_show_net(this_cli, n, d);
+      uint count = 0;
+      for (struct rte_storage *e = n->routes; e; e = e->next)
+	count++;
+
+      if (!count)
+	continue;
+
+      if (count > max)
+      {
+	do max *= 2; while (count > max);
+	feed = mb_realloc(feed, sizeof(rte *) * max);
+      }
+
+      uint i = 0;
+      for (struct rte_storage *e = n->routes; e; e = e->next)
+	feed[i++] = &e->rte;
+
+      rt_show_net(d, n->n.addr, feed, count);
     }
 
     if (d->rt_counter)
diff --git a/nest/rt-table.c b/nest/rt-table.c
index afafef62..ed0132ca 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -1813,7 +1813,16 @@ rt_table_export_stop(struct rt_export_hook *hook)
   rtable *tab = SKIP_BACK(rtable, exporter, hook->table);
 
   if (hook->export_state == TES_FEEDING)
-    fit_get(&tab->fib, &hook->feed_fit);
+    if (hook->walk_lock)
+    {
+      rt_unlock_trie(tab, hook->walk_lock);
+      hook->walk_lock = NULL;
+
+      mb_free(hook->walk_state);
+      hook->walk_state = NULL;
+    }
+    else
+      fit_get(&tab->fib, &hook->feed_fit);
 }
 
 void
diff --git a/nest/rt.h b/nest/rt.h
index 57e117da..c959d358 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -403,13 +403,12 @@ struct rt_show_data_rtable {
 };
 
 struct rt_show_data {
+  struct cli *cli;			/* Pointer back to the CLI */
   net_addr *addr;
   list tables;
   struct rt_show_data_rtable *tab;	/* Iterator over table list */
   struct rt_show_data_rtable *last_table; /* Last table in output */
-  struct fib_iterator fit;		/* Iterator over networks in table */
-  struct f_trie_walk_state *walk_state;	/* Iterator over networks in trie */
-  struct f_trie *walk_lock;		/* Locked trie for walking */
+  struct rt_export_request req;		/* Export request in use */
   int verbose, tables_defined_by;
   const struct filter *filter;
   struct proto *show_protocol;
@@ -420,10 +419,9 @@ struct rt_show_data {
   struct rt_export_hook *kernel_export_hook;
   int export_mode, addr_mode, primary_only, filtered, stats;
 
-  int table_open;			/* Iteration (fit) is open */
-  int trie_walk;			/* Current table is iterated using trie */
   int net_counter, rt_counter, show_counter, table_counter;
   int net_counter_last, rt_counter_last, show_counter_last;
+  int show_counter_last_flush;
 };
 
 void rt_show(struct rt_show_data *);
diff --git a/proto/mrt/mrt.c b/proto/mrt/mrt.c
index fcbe317b..5ef4cd44 100644
--- a/proto/mrt/mrt.c
+++ b/proto/mrt/mrt.c
@@ -703,14 +703,17 @@ mrt_dump_cont(struct cli *c)
 
   cli_printf(c, 0, "");
   mrt_table_dump_free(c->rover);
-  c->cont = c->cleanup = c->rover = NULL;
+  c->cont = NULL;
+  c->cleanup = NULL;
+  c->rover = NULL;
 }
 
-static void
+static int
 mrt_dump_cleanup(struct cli *c)
 {
   mrt_table_dump_free(c->rover);
   c->rover = NULL;
+  return 0;
 }
 
 void

From dfb61dfceaa72dda477a5433a193da316dccef7f Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Sun, 26 Jun 2022 14:48:55 +0200
Subject: [PATCH 08/20] Fixed undefined attribute handling

---
 nest/rt-attr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index 35f85274..ed3aaf01 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -727,7 +727,7 @@ ea_do_prune(ea_list *e)
 
       /* Now s0 is the most recent version, s[-1] the oldest one */
       /* Drop undefs unless this is a true overlay */
-      if (s0->undef && !e->next)
+      if (s0->undef && (s[-1].undef || !e->next))
 	continue;
 
       /* Copy the newest version to destination */
@@ -1081,7 +1081,7 @@ ea_show(struct cli *c, const eattr *e)
   *pos++ = ' ';
 
   if (e->undef)
-    bsprintf(pos, "undefined (should not happen)");
+    return;
   else if (cls->format)
     cls->format(e, buf, end - buf);
   else

From 0f2f5ac58c8bc487ad62d153bfc5ebdb97d54fbd Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 27 Jun 2022 11:04:57 +0200
Subject: [PATCH 09/20] Fixed minor bugs in handling some route attributes

---
 filter/config.Y | 11 +++++++----
 filter/f-inst.c | 12 ++++++++++++
 nest/rt-attr.c  |  9 ++-------
 3 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/filter/config.Y b/filter/config.Y
index ca792593..8cecf936 100644
--- a/filter/config.Y
+++ b/filter/config.Y
@@ -27,6 +27,9 @@ static inline u32 pair_b(u32 p) { return p & 0xFFFF; }
     cf_error("Can't empty %s: not an attribute", sym->name); \
   f_generate_complex(fi_code, sym->attribute, arg); \
 })
+
+#define f_generate_complex_default(fi_code, da, arg, def) \
+  f_new_inst(FI_EA_SET, f_new_inst(fi_code, f_new_inst(FI_DEFAULT, f_new_inst(FI_EA_GET, da), f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_INT, .val.i = def })), arg), da)
   
 
 /*
@@ -902,10 +905,10 @@ cmd:
    }
  | attr_bit '=' term ';' {
      $$ = f_new_inst(FI_CONDITION, $3,
-	f_generate_complex(FI_BITOR, $1.class,
-	      f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_INT, .val.i = (1U << $1.bit)})),
-	f_generate_complex(FI_BITAND, $1.class,
-	      f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_INT, .val.i = ~(1U << $1.bit)}))
+	f_generate_complex_default(FI_BITOR, $1.class,
+	      f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_INT, .val.i = (1U << $1.bit)}), 0),
+	f_generate_complex_default(FI_BITAND, $1.class,
+	      f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_INT, .val.i = ~(1U << $1.bit)}), 0)
      );
    }
  | break_command print_list ';' {
diff --git a/filter/f-inst.c b/filter/f-inst.c
index 9ff5f79a..e7b642ab 100644
--- a/filter/f-inst.c
+++ b/filter/f-inst.c
@@ -768,6 +768,18 @@
     ea_unset_attr(fs->eattrs, 1, da);
   }
 
+  INST(FI_DEFAULT, 2, 1) {
+    ARG_ANY(1);
+    ARG_ANY(2);
+
+    log(L_INFO "Type of arg 1 is: %d", v1.type);
+
+    if (v1.type == T_VOID)
+      RESULT_VAL(v2);
+    else
+      RESULT_VAL(v1);
+  }
+
   INST(FI_LENGTH, 1, 1) {	/* Get length of */
     ARG_ANY(1);
     switch(v1.type) {
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index ed3aaf01..cec1d7cf 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -836,7 +836,7 @@ ea_normalize(ea_list *e, int overlay)
   ea_merge(e, t, overlay);
   ea_sort(t);
 
-  return t->count ? t : NULL;
+  return t->count ? t : t->next;
 }
 
 /**
@@ -1075,11 +1075,6 @@ ea_show(struct cli *c, const eattr *e)
   struct ea_class *cls = ea_class_global[e->id];
   ASSERT_DIE(cls);
 
-  pos += bsprintf(pos, "%s", cls->name);
-
-  *pos++ = ':';
-  *pos++ = ' ';
-
   if (e->undef)
     return;
   else if (cls->format)
@@ -1115,7 +1110,7 @@ ea_show(struct cli *c, const eattr *e)
 	  bsprintf(pos, "<type %02x>", e->type);
       }
 
-  cli_printf(c, -1012, "\t%s", buf);
+  cli_printf(c, -1012, "\t%s: %s", cls->name, buf);
 }
 
 static void

From d2142ad4050c64991f856734bafadd527c28e74b Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 27 Jun 2022 12:14:05 +0200
Subject: [PATCH 10/20] Fixed displaying BGP and RIP attributes after recent
 reworks

---
 filter/test.conf  |  4 ----
 lib/route.h       |  1 +
 nest/rt-attr.c    | 41 +++++++++++++++++++++++------------------
 proto/bgp/attrs.c |  4 ++++
 proto/rip/rip.c   |  2 +-
 5 files changed, 29 insertions(+), 23 deletions(-)

diff --git a/filter/test.conf b/filter/test.conf
index eb9cc30c..cd2fa8db 100644
--- a/filter/test.conf
+++ b/filter/test.conf
@@ -1470,11 +1470,7 @@ bool t;
 	bgp_community = -empty-;
 	bgp_originator_id = 9.7.5.3;
 	bgp_cluster_list = -empty-;
-	t = defined(bgp_mp_reach_nlri);
-	t = defined(bgp_mp_unreach_nlri);
 	bgp_ext_community = --empty--;
-	bgp_as4_path = +empty+;
-	t = defined(bgp_as4_aggregator);
 	t = defined(bgp_aigp);
 	bgp_large_community = ---empty---;
 	t = defined(bgp_mpls_label_stack);
diff --git a/lib/route.h b/lib/route.h
index f7b089d9..130465f9 100644
--- a/lib/route.h
+++ b/lib/route.h
@@ -172,6 +172,7 @@ struct ea_class {
   btype type;				/* Data type ID */ \
   uint readonly:1;			/* This attribute can't be changed by filters */ \
   uint conf:1;				/* Requested by config */ \
+  uint hidden:1;			/* Technical attribute, do not show, do not expose to filters */ \
   void (*format)(const eattr *ea, byte *buf, uint size); \
   void (*stored)(const eattr *ea);	/* When stored into global hash */ \
   void (*freed)(const eattr *ea);	/* When released from global hash */ \
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index cec1d7cf..0881b61b 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -436,7 +436,8 @@ ea_class_free(struct ea_class *cl)
   /* No more ea class references. Unregister the attribute. */
   idm_free(&ea_class_idm, cl->id);
   ea_class_global[cl->id] = NULL;
-  ea_lex_unregister(cl);
+  if (!cl->hidden)
+    ea_lex_unregister(cl);
 }
 
 static void
@@ -492,7 +493,8 @@ ea_register(pool *p, struct ea_class *def)
   ASSERT_DIE(def->id < ea_class_max);
   ea_class_global[def->id] = def;
 
-  ea_lex_register(def);
+  if (!def->hidden)
+    ea_lex_register(def);
 
   return ea_ref_class(p, def);
 }
@@ -1017,37 +1019,40 @@ opaque_format(const struct adata *ad, byte *buf, uint size)
 }
 
 static inline void
-ea_show_int_set(struct cli *c, const struct adata *ad, int way, byte *pos, byte *buf, byte *end)
+ea_show_int_set(struct cli *c, const char *name, const struct adata *ad, int way, byte *buf)
 {
-  int i = int_set_format(ad, way, 0, pos, end - pos);
-  cli_printf(c, -1012, "\t%s", buf);
+  int nlen = strlen(name);
+  int i = int_set_format(ad, way, 0, buf, CLI_MSG_SIZE - nlen - 3);
+  cli_printf(c, -1012, "\t%s: %s", name, buf);
   while (i)
     {
-      i = int_set_format(ad, way, i, buf, end - buf - 1);
+      i = int_set_format(ad, way, i, buf, CLI_MSG_SIZE - 1);
       cli_printf(c, -1012, "\t\t%s", buf);
     }
 }
 
 static inline void
-ea_show_ec_set(struct cli *c, const struct adata *ad, byte *pos, byte *buf, byte *end)
+ea_show_ec_set(struct cli *c, const char *name, const struct adata *ad, byte *buf)
 {
-  int i = ec_set_format(ad, 0, pos, end - pos);
-  cli_printf(c, -1012, "\t%s", buf);
+  int nlen = strlen(name);
+  int i = ec_set_format(ad, 0, buf, CLI_MSG_SIZE - nlen - 3);
+  cli_printf(c, -1012, "\t%s: %s", name, buf);
   while (i)
     {
-      i = ec_set_format(ad, i, buf, end - buf - 1);
+      i = ec_set_format(ad, i, buf, CLI_MSG_SIZE - 1);
       cli_printf(c, -1012, "\t\t%s", buf);
     }
 }
 
 static inline void
-ea_show_lc_set(struct cli *c, const struct adata *ad, byte *pos, byte *buf, byte *end)
+ea_show_lc_set(struct cli *c, const char *name, const struct adata *ad, byte *buf)
 {
-  int i = lc_set_format(ad, 0, pos, end - pos);
-  cli_printf(c, -1012, "\t%s", buf);
+  int nlen = strlen(name);
+  int i = lc_set_format(ad, 0, buf, CLI_MSG_SIZE - nlen - 3);
+  cli_printf(c, -1012, "\t%s: %s", name, buf);
   while (i)
     {
-      i = lc_set_format(ad, i, buf, end - buf - 1);
+      i = lc_set_format(ad, i, buf, CLI_MSG_SIZE - 1);
       cli_printf(c, -1012, "\t\t%s", buf);
     }
 }
@@ -1075,7 +1080,7 @@ ea_show(struct cli *c, const eattr *e)
   struct ea_class *cls = ea_class_global[e->id];
   ASSERT_DIE(cls);
 
-  if (e->undef)
+  if (e->undef || cls->hidden)
     return;
   else if (cls->format)
     cls->format(e, buf, end - buf);
@@ -1098,13 +1103,13 @@ ea_show(struct cli *c, const eattr *e)
 	  as_path_format(ad, pos, end - pos);
 	  break;
 	case T_CLIST:
-	  ea_show_int_set(c, ad, 1, pos, buf, end);
+	  ea_show_int_set(c, cls->name, ad, 1, buf);
 	  return;
 	case T_ECLIST:
-	  ea_show_ec_set(c, ad, pos, buf, end);
+	  ea_show_ec_set(c, cls->name, ad, buf);
 	  return;
 	case T_LCLIST:
-	  ea_show_lc_set(c, ad, pos, buf, end);
+	  ea_show_lc_set(c, cls->name, ad, buf);
 	  return;
 	default:
 	  bsprintf(pos, "<type %02x>", e->type);
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 46e949bf..22a53dce 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -1122,12 +1122,14 @@ static union bgp_attr_desc bgp_attr_table[BGP_ATTR_MAX] = {
   [BA_MP_REACH_NLRI] = {
     .name = "bgp_mp_reach_nlri",
     .type = T_OPAQUE,
+    .hidden = 1,
     .flags = BAF_OPTIONAL,
     .decode = bgp_decode_mp_reach_nlri,
   },
   [BA_MP_UNREACH_NLRI] = {
     .name = "bgp_mp_unreach_nlri",
     .type = T_OPAQUE,
+    .hidden = 1,
     .flags = BAF_OPTIONAL,
     .decode = bgp_decode_mp_unreach_nlri,
   },
@@ -1142,6 +1144,7 @@ static union bgp_attr_desc bgp_attr_table[BGP_ATTR_MAX] = {
   [BA_AS4_PATH] = {
     .name = "bgp_as4_path",
     .type = T_PATH,
+    .hidden = 1,
     .flags = BAF_OPTIONAL | BAF_TRANSITIVE,
     .encode = bgp_encode_raw,
     .decode = bgp_decode_as4_path,
@@ -1149,6 +1152,7 @@ static union bgp_attr_desc bgp_attr_table[BGP_ATTR_MAX] = {
   [BA_AS4_AGGREGATOR] = {
     .name = "bgp_as4_aggregator",
     .type = T_OPAQUE,
+    .hidden = 1,
     .flags = BAF_OPTIONAL | BAF_TRANSITIVE,
     .encode = bgp_encode_raw,
     .decode = bgp_decode_as4_aggregator,
diff --git a/proto/rip/rip.c b/proto/rip/rip.c
index d6edac14..f5c01380 100644
--- a/proto/rip/rip.c
+++ b/proto/rip/rip.c
@@ -1240,7 +1240,7 @@ rip_get_route_info(rte *rte, byte *buf)
 static void
 rip_tag_format(const eattr *a, byte *buf, uint buflen)
 {
-  bsnprintf(buf, buflen, "tag: %04x", a->u.data);
+  bsnprintf(buf, buflen, "%04x", a->u.data);
 }
 
 static struct ea_class ea_rip_metric = {

From c431d9c33c72203498133d7e2422423c37c4719d Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 27 Jun 2022 12:32:15 +0200
Subject: [PATCH 11/20] Fixed new route comparison

---
 nest/proto.c    |  2 +-
 nest/rt-table.c | 35 +++++++++++++++++++++++++----------
 nest/rt.h       |  2 +-
 3 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/nest/proto.c b/nest/proto.c
index 3792fde4..0daf59f4 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -177,7 +177,7 @@ proto_find_channel_by_name(struct proto *p, const char *n)
   return NULL;
 }
 
-rte * channel_preimport(struct rt_import_request *req, rte *new, rte *old);
+int channel_preimport(struct rt_import_request *req, rte *new, rte *old);
 
 void rt_notify_optimal(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *rpe);
 void rt_notify_any(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *rpe);
diff --git a/nest/rt-table.c b/nest/rt-table.c
index ed0132ca..41b6337e 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -1282,6 +1282,14 @@ rte_recalculate(struct rt_import_hook *c, net *net, rte *new, struct rte_src *sr
   rte *old_best = old_best_stored ? &old_best_stored->rte : NULL;
   rte *old = NULL;
 
+  /* If the new route is identical to the old one, we find the attributes in
+   * cache and clone these with no performance drop. OTOH, if we were to lookup
+   * the attributes, such a route definitely hasn't been anywhere yet,
+   * therefore it's definitely worth the time. */
+  struct rte_storage *new_stored = NULL;
+  if (new)
+    new = &(new_stored = rte_store(new, net, table))->rte;
+
   /* Find and remove original route from the same protocol */
   struct rte_storage **before_old = rte_find(net, src);
 
@@ -1304,7 +1312,7 @@ rte_recalculate(struct rt_import_hook *c, net *net, rte *new, struct rte_src *sr
 		c->table->name, net->n.addr, old->src->proto->name, old->src->private_id, old->src->global_id);
 	}
 
-	  if (new && rte_same(old, new))
+	  if (new && rte_same(old, &new_stored->rte))
 	    {
 	      /* No changes, ignore the new route and refresh the old one */
 
@@ -1315,6 +1323,10 @@ rte_recalculate(struct rt_import_hook *c, net *net, rte *new, struct rte_src *sr
 		  stats->updates_ignored++;
 		  rt_rte_trace_in(D_ROUTES, req, new, "ignored");
 		}
+
+	      /* We need to free the already stored route here before returning */
+	      rte_free(new_stored);
+	      return;
 	  }
 
 	*before_old = (*before_old)->next;
@@ -1327,8 +1339,13 @@ rte_recalculate(struct rt_import_hook *c, net *net, rte *new, struct rte_src *sr
       return;
     }
 
-  if (req->preimport)
-    new = req->preimport(req, new, old);
+  /* If rejected by import limit, we need to pretend there is no route */
+  if (req->preimport && (req->preimport(req, new, old) == 0))
+  {
+    rte_free(new_stored);
+    new_stored = NULL;
+    new = NULL;
+  }
 
   int new_ok = rte_is_ok(new);
   int old_ok = rte_is_ok(old);
@@ -1343,8 +1360,6 @@ rte_recalculate(struct rt_import_hook *c, net *net, rte *new, struct rte_src *sr
   if (old_ok || new_ok)
     table->last_rt_change = current_time();
 
-  struct rte_storage *new_stored = new ? rte_store(new, net, table) : NULL;
-
   if (table->config->sorted)
     {
       /* If routes are sorted, just insert new route to appropriate position */
@@ -1500,14 +1515,14 @@ rte_update_unlock(void)
     lp_flush(rte_update_pool);
 }
 
-rte *
+int
 channel_preimport(struct rt_import_request *req, rte *new, rte *old)
 {
   struct channel *c = SKIP_BACK(struct channel, in_req, req);
 
   if (new && !old)
     if (CHANNEL_LIMIT_PUSH(c, RX))
-      return NULL;
+      return 0;
 
   if (!new && old)
     CHANNEL_LIMIT_POP(c, RX);
@@ -1520,15 +1535,15 @@ channel_preimport(struct rt_import_request *req, rte *new, rte *old)
       if (c->in_keep & RIK_REJECTED)
       {
 	new->flags |= REF_FILTERED;
-	return new;
+	return 1;
       }
       else
-	return NULL;
+	return 0;
 
   if (!new_in && old_in)
     CHANNEL_LIMIT_POP(c, IN);
 
-  return new;
+  return 1;
 }
 
 void
diff --git a/nest/rt.h b/nest/rt.h
index c959d358..70e0283f 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -181,7 +181,7 @@ struct rt_import_request {
   void (*log_state_change)(struct rt_import_request *req, u8 state);
   /* Preimport is called when the @new route is just-to-be inserted, replacing @old.
    * Return a route (may be different or modified in-place) to continue or NULL to withdraw. */
-  struct rte *(*preimport)(struct rt_import_request *req, struct rte *new, struct rte *old);
+  int (*preimport)(struct rt_import_request *req, struct rte *new, struct rte *old);
   struct rte *(*rte_modify)(struct rte *, struct linpool *);
 };
 

From d5cac1a4ef49f4159f3b95f53a405f81d785711b Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 27 Jun 2022 12:44:11 +0200
Subject: [PATCH 12/20] Route attribute display now normalizes ea_lists.

This is needed to display every attribute only once with overlay
attribute lists recently introduced.
---
 nest/rt-attr.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index 0881b61b..049dc72a 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -1376,9 +1376,9 @@ ea_dump_all(void)
 void
 ea_show_list(struct cli *c, ea_list *eal)
 {
-  for( ; eal; eal=eal->next)
-    for(int i=0; i<eal->count; i++)
-      ea_show(c, &eal->attrs[i]);
+  ea_list *n = ea_normalize(eal, 0);
+  for (int i  =0; i < n->count; i++)
+    ea_show(c, &n->attrs[i]);
 }
 
 /**

From bdd6f728399a7601eaeff7165645fb0c597d309d Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 27 Jun 2022 13:39:28 +0200
Subject: [PATCH 13/20] Moved nexthop + hostentry display to other eattrs

---
 nest/rt-attr.c        | 59 +++++++++++++++++++++++++++++++++++++++++--
 nest/rt-show.c        | 41 ++++++------------------------
 nest/rt.h             |  2 ++
 proto/static/static.c |  2 +-
 4 files changed, 68 insertions(+), 36 deletions(-)

diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index 049dc72a..ba036cd2 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -1057,6 +1057,49 @@ ea_show_lc_set(struct cli *c, const char *name, const struct adata *ad, byte *bu
     }
 }
 
+void
+ea_show_nexthop_list(struct cli *c, struct nexthop_adata *nhad)
+{
+  if (!NEXTHOP_IS_REACHABLE(nhad))
+    return;
+
+  NEXTHOP_WALK(nh, nhad)
+  {
+    char mpls[MPLS_MAX_LABEL_STACK*12 + 5], *lsp = mpls;
+    char *onlink = (nh->flags & RNF_ONLINK) ? " onlink" : "";
+    char weight[16] = "";
+
+    if (nh->labels)
+    {
+      lsp += bsprintf(lsp, " mpls %d", nh->label[0]);
+      for (int i=1;i<nh->labels; i++)
+	lsp += bsprintf(lsp, "/%d", nh->label[i]);
+    }
+    *lsp = '\0';
+
+    if (!NEXTHOP_ONE(nhad))
+      bsprintf(weight, " weight %d", nh->weight + 1);
+
+    if (ipa_nonzero(nh->gw))
+      cli_printf(c, -1007, "\tvia %I on %s%s%s%s",
+	  nh->gw, nh->iface->name, mpls, onlink, weight);
+    else
+      cli_printf(c, -1007, "\tdev %s%s%s",
+	  nh->iface->name, mpls,  onlink, weight);
+  }
+}
+
+void
+ea_show_hostentry(const struct adata *ad, byte *buf, uint size)
+{
+  const struct hostentry_adata *had = (const struct hostentry_adata *) ad;
+
+  if (ipa_nonzero(had->he->link) && !ipa_equal(had->he->link, had->he->addr))
+    bsnprintf(buf, size, "via %I %I table %s", had->he->addr, had->he->link, had->he->tab->name);
+  else
+    bsnprintf(buf, size, "via %I table %s", had->he->addr, had->he->tab->name);
+}
+
 /**
  * ea_show - print an &eattr to CLI
  * @c: destination CLI
@@ -1088,6 +1131,9 @@ ea_show(struct cli *c, const eattr *e)
     switch (e->type)
       {
 	case T_INT:
+	  if ((cls == &ea_gen_igp_metric) && e->u.data >= IGP_METRIC_UNKNOWN)
+	    return;
+
 	  bsprintf(pos, "%u", e->u.data);
 	  break;
 	case T_OPAQUE:
@@ -1111,6 +1157,12 @@ ea_show(struct cli *c, const eattr *e)
 	case T_LCLIST:
 	  ea_show_lc_set(c, cls->name, ad, buf);
 	  return;
+	case T_NEXTHOP_LIST:
+	  ea_show_nexthop_list(c, (struct nexthop_adata *) e->u.ptr);
+	  return;
+	case T_HOSTENTRY:
+	  ea_show_hostentry(ad, pos, end - pos);
+	  break;
 	default:
 	  bsprintf(pos, "<type %02x>", e->type);
       }
@@ -1396,12 +1448,15 @@ rta_init(void)
   rte_src_init();
   ea_class_init();
 
+  /* These attributes are required to be first for nice "show route" output */
+  ea_register_init(&ea_gen_nexthop);
+  ea_register_init(&ea_gen_hostentry);
+
+  /* Other generic route attributes */
   ea_register_init(&ea_gen_preference);
   ea_register_init(&ea_gen_igp_metric);
   ea_register_init(&ea_gen_from);
   ea_register_init(&ea_gen_source);
-  ea_register_init(&ea_gen_nexthop);
-  ea_register_init(&ea_gen_hostentry);
   ea_register_init(&ea_gen_flowspec_valid);
 }
 
diff --git a/nest/rt-show.c b/nest/rt-show.c
index 1404f7e6..ac6653ec 100644
--- a/nest/rt-show.c
+++ b/nest/rt-show.c
@@ -83,41 +83,16 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
       net_is_flow(e->net) ? flowspec_valid_name(flowspec_valid) : had ? "recursive" : rta_dest_name(dest),
       e->src->proto->name, tm, from, primary ? (sync_error ? " !" : " *") : "", info);
 
-  if (dest == RTD_UNICAST)
-    NEXTHOP_WALK(nh, nhad)
-    {
-      char mpls[MPLS_MAX_LABEL_STACK*12 + 5], *lsp = mpls;
-      char *onlink = (nh->flags & RNF_ONLINK) ? " onlink" : "";
-      char weight[16] = "";
-
-      if (nh->labels)
-	{
-	  lsp += bsprintf(lsp, " mpls %d", nh->label[0]);
-	  for (int i=1;i<nh->labels; i++)
-	    lsp += bsprintf(lsp, "/%d", nh->label[i]);
-	}
-      *lsp = '\0';
-
-      if (!NEXTHOP_ONE(nhad))
-	bsprintf(weight, " weight %d", nh->weight + 1);
-
-      if (ipa_nonzero(nh->gw))
-	cli_printf(c, -1007, "\tvia %I on %s%s%s%s",
-		   nh->gw, nh->iface->name, mpls, onlink, weight);
-      else
-	cli_printf(c, -1007, "\tdev %s%s%s",
-		   nh->iface->name, mpls,  onlink, weight);
-    }
-  else if (had)
-    {
-      if (ipa_nonzero(had->he->link) && !ipa_equal(had->he->link, had->he->addr))
-	cli_printf(c, -1007, "\tvia %I %I table %s", had->he->addr, had->he->link, had->he->tab->name);
-      else
-	cli_printf(c, -1007, "\tvia %I table %s", had->he->addr, had->he->tab->name);
-    }
-
   if (d->verbose)
     ea_show_list(c, a);
+  else if (dest == RTD_UNICAST)
+    ea_show_nexthop_list(c, nhad);
+  else if (had)
+  {
+    char hetext[256];
+    ea_show_hostentry(&had->ad, hetext, sizeof hetext);
+    cli_printf(c, -1007, "\t%s", hetext);
+  }
 }
 
 static void
diff --git a/nest/rt.h b/nest/rt.h
index 70e0283f..745f96ef 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -459,6 +459,8 @@ struct hostentry_adata {
 void
 ea_set_hostentry(ea_list **to, struct rtable *dep, struct rtable *tab, ip_addr gw, ip_addr ll, u32 lnum, u32 labels[lnum]);
 
+void ea_show_hostentry(const struct adata *ad, byte *buf, uint size);
+void ea_show_nexthop_list(struct cli *c, struct nexthop_adata *nhad);
 
 /*
  *	Default protocol preferences
diff --git a/proto/static/static.c b/proto/static/static.c
index d1d5b92b..f0a514f7 100644
--- a/proto/static/static.c
+++ b/proto/static/static.c
@@ -695,7 +695,7 @@ static_get_route_info(rte *rte, byte *buf)
 {
   eattr *a = ea_find(rte->attrs, &ea_gen_igp_metric);
   u32 pref = rt_get_preference(rte);
-  if (a)
+  if (a && (a->u.data < IGP_METRIC_UNKNOWN))
     buf += bsprintf(buf, " (%d/%u)", pref, a->u.data);
   else
     buf += bsprintf(buf, " (%d)", pref);

From dc720a085f0f805891eb086bf96dac99c8a1b7da Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 27 Jun 2022 19:53:06 +0200
Subject: [PATCH 14/20] Show route uses the export request also for one-net
 queries

---
 nest/config.Y   |  10 ++--
 nest/proto.c    |   5 +-
 nest/rt-show.c  | 118 ++++++++++++++---------------------------------
 nest/rt-table.c | 119 ++++++++++++++++++++++++++++++++++++++----------
 nest/rt.h       |  26 +++++++----
 5 files changed, 153 insertions(+), 125 deletions(-)

diff --git a/nest/config.Y b/nest/config.Y
index ec10dd69..7c163f74 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -659,20 +659,20 @@ r_args:
      $$ = $1;
      if ($$->addr) cf_error("Only one prefix expected");
      $$->addr = $2;
-     $$->addr_mode = RSD_ADDR_EQUAL;
+     $$->addr_mode = TE_ADDR_EQUAL;
    }
  | r_args FOR r_args_for {
      $$ = $1;
      if ($$->addr) cf_error("Only one prefix expected");
      $$->addr = $3;
-     $$->addr_mode = RSD_ADDR_FOR;
+     $$->addr_mode = TE_ADDR_FOR;
    }
  | r_args IN net_any {
      $$ = $1;
      if ($$->addr) cf_error("Only one prefix expected");
      if (!net_type_match($3, NB_IP)) cf_error("Only IP networks accepted for 'in' argument");
      $$->addr = $3;
-     $$->addr_mode = RSD_ADDR_IN;
+     $$->addr_mode = TE_ADDR_IN;
    }
 | r_args TABLE symbol_known {
      cf_assert_symbol($3, SYM_TABLE);
@@ -689,12 +689,12 @@ r_args:
    }
  | r_args IMPORT TABLE channel_arg {
      if (!($4->in_keep & RIK_PREFILTER)) cf_error("No import table in channel %s.%s", $4->proto->name, $4->name);
-     rt_show_add_table($$, $4->table)->prefilter = $4;
+     rt_show_add_exporter($$, &$4->table->exporter, "import")->prefilter = $4;
      $$->tables_defined_by = RSD_TDB_DIRECT;
    }
  | r_args EXPORT TABLE channel_arg {
      if (!$4->out_table) cf_error("No export table in channel %s.%s", $4->proto->name, $4->name);
-     rt_show_add_table($$, $4->out_table);
+     rt_show_add_exporter($$, &$4->out_table->exporter, "export");
      $$->tables_defined_by = RSD_TDB_DIRECT;
    }
  | r_args FILTER filter {
diff --git a/nest/proto.c b/nest/proto.c
index 0daf59f4..e7be8001 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -468,7 +468,8 @@ channel_start_export(struct channel *c)
 
   c->out_req = (struct rt_export_request) {
     .name = rn,
-    .addr_in = c->out_subprefix,
+    .addr = c->out_subprefix,
+    .addr_mode = c->out_subprefix ? TE_ADDR_IN : TE_ADDR_NONE,
     .trace_routes = c->debug | c->proto->debug,
     .dump_req = channel_dump_export_req,
     .log_state_change = channel_export_log_state_change,
@@ -952,7 +953,7 @@ channel_reconfigure(struct channel *c, struct channel_config *cf)
   // c->ra_mode = cf->ra_mode;
   c->merge_limit = cf->merge_limit;
   c->preference = cf->preference;
-  c->out_req.addr_in = c->out_subprefix = cf->out_subprefix;
+  c->out_req.addr = c->out_subprefix = cf->out_subprefix;
   c->debug = cf->debug;
   c->in_req.trace_routes = c->out_req.trace_routes = c->debug | c->proto->debug;
   c->rpki_reload = cf->rpki_reload;
diff --git a/nest/rt-show.c b/nest/rt-show.c
index ac6653ec..c3294518 100644
--- a/nest/rt-show.c
+++ b/nest/rt-show.c
@@ -29,24 +29,17 @@ rt_show_table(struct rt_show_data *d)
 
   if (d->last_table) cli_printf(c, -1007, "");
   cli_printf(c, -1007, "Table %s:",
-      d->tab->prefilter ? "import" : d->tab->table->name);
+      d->tab->name);
   d->last_table = d->tab;
 }
 
-static inline struct krt_proto *
-rt_show_get_kernel(struct rt_show_data *d)
-{
-  struct proto_config *krt = d->tab->table->config->krt_attached;
-  return krt ? (struct krt_proto *) krt->proto : NULL;
-}
-
 static void
 rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary)
 {
   byte from[IPA_MAX_TEXT_LENGTH+8];
   byte tm[TM_DATETIME_BUFFER_SIZE], info[256];
   ea_list *a = e->attrs;
-  int sync_error = d->kernel ? krt_get_sync_error(d->kernel, e) : 0;
+  int sync_error = d->tab->kernel ? krt_get_sync_error(d->tab->kernel, e) : 0;
   void (*get_route_info)(struct rte *, byte *buf);
   eattr *nhea = net_type_match(e->net, NB_DEST) ?
     ea_find(a, &ea_gen_nexthop) : NULL;
@@ -228,11 +221,6 @@ rt_show_export_stopped_cleanup(struct rt_export_request *req)
   /* The hook is now invalid */
   req->hook = NULL;
 
-  /* Unlock referenced tables */
-  struct rt_show_data_rtable *tab;
-  WALK_LIST(tab, d->tables)
-    rt_unlock_table(tab->table);
-
   /* And free the CLI (deferred) */
   rfree(d->cli->pool);
 }
@@ -276,11 +264,6 @@ rt_show_cont(struct rt_show_data *d)
   {
     cli_printf(c, 8004, "Stopped due to reconfiguration");
 
-    /* Unlock referenced tables */
-    struct rt_show_data_rtable *tab;
-    WALK_LIST(tab, d->tables)
-      rt_unlock_table(tab->table);
-
     /* No more action */
     c->cleanup = NULL;
     c->cont = NULL;
@@ -290,15 +273,15 @@ rt_show_cont(struct rt_show_data *d)
   }
 
   d->req = (struct rt_export_request) {
-    .addr_in = (d->addr_mode == RSD_ADDR_IN) ? d->addr : NULL,
+    .addr = d->addr,
     .name = "CLI Show Route",
     .export_bulk = rt_show_net_export_bulk,
     .dump_req = rt_show_dump_req,
     .log_state_change = rt_show_log_state_change,
+    .addr_mode = d->addr_mode,
   };
 
   d->table_counter++;
-  d->kernel = rt_show_get_kernel(d);
 
   d->show_counter_last = d->show_counter;
   d->rt_counter_last   = d->rt_counter;
@@ -307,7 +290,7 @@ rt_show_cont(struct rt_show_data *d)
   if (d->tables_defined_by & RSD_TDB_SET)
     rt_show_table(d);
 
-  rt_request_export(&d->tab->table->exporter, &d->req);
+  rt_request_export(d->tab->table, &d->req);
 }
 
 static void
@@ -325,19 +308,14 @@ rt_show_export_stopped(struct rt_export_request *req)
 
     cli_printf(d->cli, -1007, "%d of %d routes for %d networks in table %s",
 	       d->show_counter - d->show_counter_last, d->rt_counter - d->rt_counter_last,
-	       d->net_counter - d->net_counter_last, d->tab->table->name);
+	       d->net_counter - d->net_counter_last, d->tab->name);
   }
 
-  d->kernel = NULL;
   d->tab = NODE_NEXT(d->tab);
 
   if (NODE_VALID(d->tab))
     return rt_show_cont(d);
 
-  /* Unlock referenced tables */
-  struct rt_show_data_rtable *tab;
-  WALK_LIST(tab, d->tables)
-    rt_unlock_table(tab->table);
 
   /* Printout total stats */
   if (d->stats && (d->table_counter > 1))
@@ -346,6 +324,8 @@ rt_show_export_stopped(struct rt_export_request *req)
     cli_printf(d->cli, 14, "Total: %d of %d routes for %d networks in %d tables",
 	       d->show_counter, d->rt_counter, d->net_counter, d->table_counter);
   }
+  else if (!d->rt_counter && ((d->addr_mode == TE_ADDR_EQUAL) || (d->addr_mode == TE_ADDR_FOR)))
+    cli_printf(d->cli, 8001, "Network not found");
   else
     cli_printf(d->cli, 0, "");
 
@@ -353,14 +333,27 @@ rt_show_export_stopped(struct rt_export_request *req)
 }
 
 struct rt_show_data_rtable *
-rt_show_add_table(struct rt_show_data *d, rtable *t)
+rt_show_add_exporter(struct rt_show_data *d, struct rt_exporter *t, const char *name)
 {
   struct rt_show_data_rtable *tab = cfg_allocz(sizeof(struct rt_show_data_rtable));
   tab->table = t;
+  tab->name = name;
   add_tail(&(d->tables), &(tab->n));
   return tab;
 }
 
+struct rt_show_data_rtable *
+rt_show_add_table(struct rt_show_data *d, struct rtable *t)
+{
+  struct rt_show_data_rtable *rsdr = rt_show_add_exporter(d, &t->exporter, t->name);
+
+  struct proto_config *krt = t->config->krt_attached;
+  if (krt)
+    rsdr->kernel = (struct krt_proto *) krt->proto;
+
+  return rsdr;
+}
+
 static inline void
 rt_show_get_default_tables(struct rt_show_data *d)
 {
@@ -415,16 +408,16 @@ rt_show_prepare_tables(struct rt_show_data *d)
     if (d->export_mode)
     {
       if (!tab->export_channel && d->export_channel &&
-	  (tab->table == d->export_channel->table))
+	  (tab->table == &d->export_channel->table->exporter))
 	tab->export_channel = d->export_channel;
 
       if (!tab->export_channel && d->export_protocol)
-	tab->export_channel = proto_find_channel_by_table(d->export_protocol, tab->table);
+	tab->export_channel = proto_find_channel_by_table(d->export_protocol, SKIP_BACK(rtable, exporter, tab->table));
 
       if (!tab->export_channel)
       {
 	if (d->tables_defined_by & RSD_TDB_NMN)
-	  cf_error("No export channel for table %s", tab->table->name);
+	  cf_error("No export channel for table %s", tab->name);
 
 	rem_node(&(tab->n));
 	continue;
@@ -435,7 +428,7 @@ rt_show_prepare_tables(struct rt_show_data *d)
     if (d->addr && (tab->table->addr_type != d->addr->type))
     {
       if (d->tables_defined_by & RSD_TDB_NMN)
-	cf_error("Incompatible type of prefix/ip for table %s", tab->table->name);
+	cf_error("Incompatible type of prefix/ip for table %s", tab->name);
 
       rem_node(&(tab->n));
       continue;
@@ -456,65 +449,20 @@ rt_show_dummy_cont(struct cli *c UNUSED)
 void
 rt_show(struct rt_show_data *d)
 {
-  struct rt_show_data_rtable *tab;
-  net *n;
-
   /* Filtered routes are neither exported nor have sensible ordering */
   if (d->filtered && (d->export_mode || d->primary_only))
     cf_error("Incompatible show route options");
 
   rt_show_prepare_tables(d);
 
-  if (!d->addr || (d->addr_mode == RSD_ADDR_IN))
-  {
-    WALK_LIST(tab, d->tables)
-      rt_lock_table(tab->table);
+  if (EMPTY_LIST(d->tables))
+    cf_error("No suitable tables found");
 
-    /* There is at least one table */
-    d->tab = HEAD(d->tables);
-    this_cli->cleanup = rt_show_cleanup;
-    this_cli->rover = d;
-    this_cli->cont = rt_show_dummy_cont;
-    rt_show_cont(d);
-  }
-  else
-  {
-    uint max = 64;
-    rte **feed = mb_alloc(d->cli->pool, sizeof(rte *) * max);
+  d->tab = HEAD(d->tables);
 
-    WALK_LIST(tab, d->tables)
-    {
-      d->tab = tab;
-      d->kernel = rt_show_get_kernel(d);
+  this_cli->cleanup = rt_show_cleanup;
+  this_cli->rover = d;
+  this_cli->cont = rt_show_dummy_cont;
 
-      if (d->addr_mode == RSD_ADDR_FOR)
-	n = net_route(tab->table, d->addr);
-      else
-	n = net_find(tab->table, d->addr);
-
-      uint count = 0;
-      for (struct rte_storage *e = n->routes; e; e = e->next)
-	count++;
-
-      if (!count)
-	continue;
-
-      if (count > max)
-      {
-	do max *= 2; while (count > max);
-	feed = mb_realloc(feed, sizeof(rte *) * max);
-      }
-
-      uint i = 0;
-      for (struct rte_storage *e = n->routes; e; e = e->next)
-	feed[i++] = &e->rte;
-
-      rt_show_net(d, n->n.addr, feed, count);
-    }
-
-    if (d->rt_counter)
-      cli_msg(0, "");
-    else
-      cli_msg(8001, "Network not found");
-  }
+  rt_show_cont(d);
 }
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 41b6337e..7fcc43af 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -128,6 +128,8 @@ static inline void rt_schedule_notify(rtable *tab);
 static void rt_flowspec_notify(rtable *tab, net *net);
 static void rt_feed_by_fib(void *);
 static void rt_feed_by_trie(void *);
+static void rt_feed_equal(void *);
+static void rt_feed_for(void *);
 static uint rt_feed_net(struct rt_export_hook *c, net *n);
 
 const char *rt_import_state_name_array[TIS_MAX] = {
@@ -1189,8 +1191,27 @@ rte_announce(rtable *tab, net *net, struct rte_storage *new, struct rte_storage
     if (eh->export_state == TES_STOP)
       continue;
 
-    if (eh->req->addr_in && !net_in_netX(net->n.addr, eh->req->addr_in))
-      continue;
+    switch (eh->req->addr_mode)
+    {
+      case TE_ADDR_NONE:
+	break;
+
+      case TE_ADDR_IN:
+	if (!net_in_netX(net->n.addr, eh->req->addr))
+	  continue;
+	break;
+
+      case TE_ADDR_EQUAL:
+	if (!net_equal(net->n.addr, eh->req->addr))
+	  continue;
+	break;
+
+      case TE_ADDR_FOR:
+	bug("Continuos export of best prefix match not implemented yet.");
+
+      default:
+	bug("Strange table export address mode: %d", eh->req->addr_mode);
+    }
 
     if (new)
       eh->stats.updates_received++;
@@ -1788,17 +1809,33 @@ rt_table_export_start(struct rt_exporter *re, struct rt_export_request *req)
   hook->lp = lp_new_default(p);
 
   /* stats zeroed by mb_allocz */
-  if (tab->trie && req->addr_in && net_val_match(tab->addr_type, NB_IP))
+  switch (req->addr_mode)
   {
-    hook->walk_state = mb_allocz(p, sizeof (struct f_trie_walk_state));
-    hook->walk_lock = rt_lock_trie(tab);
-    trie_walk_init(hook->walk_state, tab->trie, req->addr_in);
-    hook->event = ev_new_init(p, rt_feed_by_trie, hook);
-  }
-  else
-  {
-    FIB_ITERATE_INIT(&hook->feed_fit, &tab->fib);
-    hook->event = ev_new_init(p, rt_feed_by_fib, hook);
+    case TE_ADDR_IN:
+      if (tab->trie && net_val_match(tab->addr_type, NB_IP))
+      {
+	hook->walk_state = mb_allocz(p, sizeof (struct f_trie_walk_state));
+	hook->walk_lock = rt_lock_trie(tab);
+	trie_walk_init(hook->walk_state, tab->trie, req->addr);
+	hook->event = ev_new_init(p, rt_feed_by_trie, hook);
+	break;
+      }
+      /* fall through */
+    case TE_ADDR_NONE:
+      FIB_ITERATE_INIT(&hook->feed_fit, &tab->fib);
+      hook->event = ev_new_init(p, rt_feed_by_fib, hook);
+      break;
+
+    case TE_ADDR_EQUAL:
+      hook->event = ev_new_init(p, rt_feed_equal, hook);
+      break;
+
+    case TE_ADDR_FOR:
+      hook->event = ev_new_init(p, rt_feed_for, hook);
+      break;
+
+    default:
+      bug("Requested an unknown export address mode");
   }
 
   DBG("New export hook %p req %p in table %s uc=%u\n", hook, req, tab->name, tab->use_count);
@@ -1817,8 +1854,8 @@ rt_request_export(struct rt_exporter *re, struct rt_export_request *req)
   hook->n = (node) {};
   add_tail(&re->hooks, &hook->n);
 
+  /* Regular export */
   rt_set_export_state(hook, TES_FEEDING);
-
   ev_schedule_work(hook->event);
 }
 
@@ -1827,17 +1864,19 @@ rt_table_export_stop(struct rt_export_hook *hook)
 {
   rtable *tab = SKIP_BACK(rtable, exporter, hook->table);
 
-  if (hook->export_state == TES_FEEDING)
-    if (hook->walk_lock)
-    {
-      rt_unlock_trie(tab, hook->walk_lock);
-      hook->walk_lock = NULL;
+  if (hook->export_state != TES_FEEDING)
+    return;
 
-      mb_free(hook->walk_state);
-      hook->walk_state = NULL;
-    }
-    else
-      fit_get(&tab->fib, &hook->feed_fit);
+  if (hook->walk_lock)
+  {
+    rt_unlock_trie(tab, hook->walk_lock);
+    hook->walk_lock = NULL;
+
+    mb_free(hook->walk_state);
+    hook->walk_state = NULL;
+  }
+  else
+    fit_get(&tab->fib, &hook->feed_fit);
 }
 
 void
@@ -2317,6 +2356,7 @@ rt_setup(pool *pp, struct rtable_config *cf)
   init_list(&t->flowspec_links);
 
   t->exporter = (struct rt_exporter) {
+    .addr_type = t->addr_type,
     .start = rt_table_export_start,
     .stop = rt_table_export_stop,
     .done = rt_table_export_done,
@@ -3222,7 +3262,7 @@ rt_feed_by_fib(void *data)
 
       ASSERT(c->export_state == TES_FEEDING);
 
-      if (!c->req->addr_in || net_in_netX(n->n.addr, c->req->addr_in))
+      if ((c->req->addr_mode == TE_ADDR_NONE) || net_in_netX(n->n.addr, c->req->addr))
 	max_feed -= rt_feed_net(c, n);
     }
   FIB_ITERATE_END;
@@ -3265,6 +3305,37 @@ rt_feed_by_trie(void *data)
   rt_set_export_state(c, TES_READY);
 }
 
+static void
+rt_feed_equal(void *data)
+{
+  struct rt_export_hook *c = data;
+  rtable *tab = SKIP_BACK(rtable, exporter, c->table);
+
+  ASSERT_DIE(c->export_state == TES_FEEDING);
+  ASSERT_DIE(c->req->addr_mode == TE_ADDR_EQUAL);
+
+  net *n = net_find(tab, c->req->addr);
+  if (n)
+    rt_feed_net(c, n);
+
+  rt_set_export_state(c, TES_READY);
+}
+
+static void
+rt_feed_for(void *data)
+{
+  struct rt_export_hook *c = data;
+  rtable *tab = SKIP_BACK(rtable, exporter, c->table);
+
+  ASSERT_DIE(c->export_state == TES_FEEDING);
+  ASSERT_DIE(c->req->addr_mode == TE_ADDR_FOR);
+
+  net *n = net_route(tab, c->req->addr);
+  if (n)
+    rt_feed_net(c, n);
+
+  rt_set_export_state(c, TES_READY);
+}
 
 static uint
 rt_feed_net(struct rt_export_hook *c, net *n)
diff --git a/nest/rt.h b/nest/rt.h
index 745f96ef..3ed56fcc 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -61,6 +61,7 @@ struct rt_export_request;
 
 struct rt_exporter {
   list hooks;				/* Registered route export hooks */
+  uint addr_type;			/* Type of address data exported (NET_*) */
   struct rt_export_hook *(*start)(struct rt_exporter *, struct rt_export_request *);
   void (*stop)(struct rt_export_hook *);
   void (*done)(struct rt_export_hook *);
@@ -212,9 +213,10 @@ struct rt_pending_export {
 
 struct rt_export_request {
   struct rt_export_hook *hook;		/* Table part of the export */
-  const net_addr *addr_in;		/* Subnet export request */
   char *name;
+  const net_addr *addr;			/* Network prefilter address */
   u8 trace_routes;
+  u8 addr_mode;				/* Network prefilter mode (TE_ADDR_*) */
 
   /* There are two methods of export. You can either request feeding every single change
    * or feeding the whole route feed. In case of regular export, &export_one is preferred.
@@ -273,9 +275,18 @@ struct rt_export_hook {
 #define TES_STOP	4
 #define TES_MAX		5
 
+/* Value of addr_mode */
+#define TE_ADDR_NONE	0		/* No address matching */
+#define TE_ADDR_EQUAL	1		/* Exact query - show route <addr> */
+#define TE_ADDR_FOR	2		/* Longest prefix match - show route for <addr> */
+#define TE_ADDR_IN	3		/* Interval query - show route in <addr> */
+
+
 void rt_request_import(rtable *tab, struct rt_import_request *req);
 void rt_request_export(struct rt_exporter *tab, struct rt_export_request *req);
 
+void rt_export_once(struct rt_exporter *tab, struct rt_export_request *req);
+
 void rt_stop_import(struct rt_import_request *, void (*stopped)(struct rt_import_request *));
 void rt_stop_export(struct rt_export_request *, void (*stopped)(struct rt_export_request *));
 
@@ -397,9 +408,11 @@ extern const int rt_default_ecmp;
 
 struct rt_show_data_rtable {
   node n;
-  rtable *table;
+  const char *name;
+  struct rt_exporter *table;
   struct channel *export_channel;
   struct channel *prefilter;
+  struct krt_proto *kernel;
 };
 
 struct rt_show_data {
@@ -415,7 +428,6 @@ struct rt_show_data {
   struct proto *export_protocol;
   struct channel *export_channel;
   struct config *running_on_config;
-  struct krt_proto *kernel;
   struct rt_export_hook *kernel_export_hook;
   int export_mode, addr_mode, primary_only, filtered, stats;
 
@@ -425,7 +437,8 @@ struct rt_show_data {
 };
 
 void rt_show(struct rt_show_data *);
-struct rt_show_data_rtable * rt_show_add_table(struct rt_show_data *d, rtable *t);
+struct rt_show_data_rtable * rt_show_add_exporter(struct rt_show_data *d, struct rt_exporter *t, const char *name);
+struct rt_show_data_rtable * rt_show_add_table(struct rt_show_data *d, struct rtable *t);
 
 /* Value of table definition mode in struct rt_show_data */
 #define RSD_TDB_DEFAULT	  0		/* no table specified */
@@ -436,11 +449,6 @@ struct rt_show_data_rtable * rt_show_add_table(struct rt_show_data *d, rtable *t
 #define RSD_TDB_SET	  0x1		/* internal: show empty tables */
 #define RSD_TDB_NMN	  0x2		/* internal: need matching net */
 
-/* Value of addr_mode */
-#define RSD_ADDR_EQUAL	1		/* Exact query - show route <addr> */
-#define RSD_ADDR_FOR	2		/* Longest prefix match - show route for <addr> */
-#define RSD_ADDR_IN	3		/* Interval query - show route in <addr> */
-
 /* Value of export_mode in struct rt_show_data */
 #define RSEM_NONE	0		/* Export mode not used */
 #define RSEM_PREEXPORT	1		/* Routes ready for export, before filtering */

From fd72c696784ba74e793db1fb7c44668c47a383b2 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Tue, 28 Jun 2022 10:51:00 +0200
Subject: [PATCH 15/20] Attribute lists split to storage headers and data to
 save BGP memory

---
 lib/route.h    | 29 +++++++++++++++++++++--------
 nest/rt-attr.c | 39 ++++++++++++++++++++-------------------
 2 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/lib/route.h b/lib/route.h
index 130465f9..30be7c4e 100644
--- a/lib/route.h
+++ b/lib/route.h
@@ -147,10 +147,6 @@ typedef struct eattr {
 #define EA_BIT_GET(ea) ((ea) >> 24)
 
 typedef struct ea_list {
-  struct ea_list *next_hash;		/* Next in hash chain */
-  struct ea_list **pprev_hash;		/* Previous in hash chain */
-  u32 uc;				/* Use count */
-  u32 hash_key;				/* List hash */
   struct ea_list *next;			/* In case we have an override list */
   byte flags;				/* Flags: EALF_... */
   byte rfu;
@@ -158,10 +154,17 @@ typedef struct ea_list {
   eattr attrs[0];			/* Attribute definitions themselves */
 } ea_list;
 
+struct ea_storage {
+  struct ea_storage *next_hash;		/* Next in hash chain */
+  struct ea_storage **pprev_hash;	/* Previous in hash chain */
+  u32 uc;				/* Use count */
+  u32 hash_key;				/* List hash */
+  ea_list l[0];				/* The list itself */
+};
+
 #define EALF_SORTED 1			/* Attributes are sorted by code */
 #define EALF_BISECT 2			/* Use interval bisection for searching */
 #define EALF_CACHED 4			/* List is cached */
-#define EALF_OVERLAY  8			/* List is an overlay in the same table */
 
 struct ea_class {
 #define EA_CLASS_INSIDE \
@@ -417,9 +420,19 @@ static inline int rte_dest(const rte *r)
 void rta_init(void);
 ea_list *ea_lookup(ea_list *, int overlay);		/* Get a cached (and normalized) variant of this attribute list */
 static inline int ea_is_cached(const ea_list *r) { return r->flags & EALF_CACHED; }
-static inline ea_list *ea_clone(ea_list *r) { r->uc++; return r; }
-void ea__free(ea_list *r);
-static inline void ea_free(ea_list *r) { if (r && !--r->uc) ea__free(r); }
+static inline struct ea_storage *ea_get_storage(ea_list *r)
+{
+  ASSERT_DIE(ea_is_cached(r));
+  return SKIP_BACK(struct ea_storage, l, r);
+}
+
+static inline ea_list *ea_clone(ea_list *r) { ea_get_storage(r)->uc++; return r; }
+void ea__free(struct ea_storage *r);
+static inline void ea_free(ea_list *l) {
+  if (!l) return;
+  struct ea_storage *r = ea_get_storage(l);
+  if (!--r->uc) ea__free(r);
+}
 
 void ea_dump(ea_list *);
 void ea_dump_all(void);
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index ba036cd2..a66d4c6e 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -1206,11 +1206,12 @@ ea_dump(ea_list *e)
     }
   while (e)
     {
+      struct ea_storage *s = ea_is_cached(e) ? ea_get_storage(e) : NULL;
       debug("[%c%c%c] uc=%d h=%08x",
 	    (e->flags & EALF_SORTED) ? 'S' : 's',
 	    (e->flags & EALF_BISECT) ? 'B' : 'b',
 	    (e->flags & EALF_CACHED) ? 'C' : 'c',
-	    e->uc, e->hash_key);
+	    s ? s->uc : 0, s ? s->hash_key : 0);
       for(i=0; i<e->count; i++)
 	{
 	  eattr *a = &e->attrs[i];
@@ -1304,12 +1305,12 @@ static uint rta_cache_count;
 static uint rta_cache_size = 32;
 static uint rta_cache_limit;
 static uint rta_cache_mask;
-static ea_list **rta_hash_table;
+static struct ea_storage **rta_hash_table;
 
 static void
 rta_alloc_hash(void)
 {
-  rta_hash_table = mb_allocz(rta_pool, sizeof(ea_list *) * rta_cache_size);
+  rta_hash_table = mb_allocz(rta_pool, sizeof(struct ea_storage *) * rta_cache_size);
   if (rta_cache_size < 32768)
     rta_cache_limit = rta_cache_size * 2;
   else
@@ -1318,7 +1319,7 @@ rta_alloc_hash(void)
 }
 
 static inline void
-rta_insert(ea_list *r)
+rta_insert(struct ea_storage *r)
 {
   uint h = r->hash_key & rta_cache_mask;
   r->next_hash = rta_hash_table[h];
@@ -1333,8 +1334,8 @@ rta_rehash(void)
 {
   uint ohs = rta_cache_size;
   uint h;
-  ea_list *r, *n;
-  ea_list **oht = rta_hash_table;
+  struct ea_storage *r, *n;
+  struct ea_storage **oht = rta_hash_table;
 
   rta_cache_size = 2*rta_cache_size;
   DBG("Rehashing rta cache from %d to %d entries.\n", ohs, rta_cache_size);
@@ -1364,7 +1365,7 @@ rta_rehash(void)
 ea_list *
 ea_lookup(ea_list *o, int overlay)
 {
-  ea_list *r;
+  struct ea_storage *r;
   uint h;
 
   ASSERT(!ea_is_cached(o));
@@ -1372,15 +1373,15 @@ ea_lookup(ea_list *o, int overlay)
   h = ea_hash(o);
 
   for(r=rta_hash_table[h & rta_cache_mask]; r; r=r->next_hash)
-    if (r->hash_key == h && ea_same(r, o))
-      return ea_clone(r);
+    if (r->hash_key == h && ea_same(r->l, o))
+      return ea_clone(r->l);
 
   uint elen = ea_list_size(o);
-  r = mb_alloc(rta_pool, elen);
-  ea_list_copy(r, o, elen);
-  ea_list_ref(r);
+  r = mb_alloc(rta_pool, elen + sizeof(struct ea_storage));
+  ea_list_copy(r->l, o, elen);
+  ea_list_ref(r->l);
 
-  r->flags |= EALF_CACHED;
+  r->l->flags |= EALF_CACHED;
   r->hash_key = h;
   r->uc = 1;
 
@@ -1389,19 +1390,19 @@ ea_lookup(ea_list *o, int overlay)
   if (++rta_cache_count > rta_cache_limit)
     rta_rehash();
 
-  return r;
+  return r->l;
 }
 
 void
-ea__free(ea_list *a)
+ea__free(struct ea_storage *a)
 {
-  ASSERT(rta_cache_count && ea_is_cached(a));
+  ASSERT(rta_cache_count);
   rta_cache_count--;
   *a->pprev_hash = a->next_hash;
   if (a->next_hash)
     a->next_hash->pprev_hash = a->pprev_hash;
 
-  ea_list_unref(a);
+  ea_list_unref(a->l);
   mb_free(a);
 }
 
@@ -1416,10 +1417,10 @@ ea_dump_all(void)
 {
   debug("Route attribute cache (%d entries, rehash at %d):\n", rta_cache_count, rta_cache_limit);
   for (uint h=0; h < rta_cache_size; h++)
-    for (ea_list *a = rta_hash_table[h]; a; a = a->next_hash)
+    for (struct ea_storage *a = rta_hash_table[h]; a; a = a->next_hash)
       {
 	debug("%p ", a);
-	ea_dump(a);
+	ea_dump(a->l);
 	debug("\n");
       }
   debug("\n");

From 61842ff3157d323f4d13b92effeca1c56c1dd262 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Tue, 28 Jun 2022 12:57:18 +0200
Subject: [PATCH 16/20] Fixed bad import table attributes freeing

---
 nest/rt-table.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/nest/rt-table.c b/nest/rt-table.c
index 7fcc43af..afa0ec5c 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -1627,7 +1627,14 @@ rte_update(struct channel *c, const net_addr *n, rte *new, struct rte_src *src)
   /* Now the route attributes are kept by the in-table cached version
    * and we may drop the local handle */
   if (new && (c->in_keep & RIK_PREFILTER))
-    ea_free(new->attrs);
+  {
+    /* There may be some updates on top of the original attribute block */
+    ea_list *a = new->attrs;
+    while (a->next)
+      a = a->next;
+
+    ea_free(a);
+  }
 
   rte_update_unlock();
 }

From b06911f6ef1b4cd3f7ea541b062187e80a934dd8 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Wed, 29 Jun 2022 12:51:07 +0200
Subject: [PATCH 17/20] Do not try to check flowspec validity for piped routes

---
 nest/rt-table.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nest/rt-table.c b/nest/rt-table.c
index afa0ec5c..5adf6346 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -2925,7 +2925,7 @@ static struct rte_storage *
 rt_flowspec_update_rte(rtable *tab, net *n, rte *r)
 {
 #ifdef CONFIG_BGP
-  if (rt_get_source_attr(r) != RTS_BGP)
+  if (r->generation || (rt_get_source_attr(r) != RTS_BGP))
     return NULL;
 
   struct bgp_channel *bc = (struct bgp_channel *) SKIP_BACK(struct channel, in_req, r->sender->req);

From d5e3272f3d9b1bad7ceb6d0d5897a7269e28a537 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Wed, 29 Jun 2022 13:22:40 +0200
Subject: [PATCH 18/20] Hash: iterable now per partes by an iterator

It's now possible to pause iteration through hash. This requires
struct hash_iterator to be allocated somewhere handy.

The iteration itself is surrounded by HASH_WALK_ITER and
HASH_WALK_ITER_END. Call HASH_WALK_ITER_PUT to ask for pausing; it may
still do some more iterations until it comes to a suitable pausing
point. The iterator must be initalized to an empty structure. No cleanup
is needed if iteration is abandoned inbetween.
---
 lib/hash.h      | 40 ++++++++++++++++++++++++++++++----------
 lib/hash_test.c | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 10 deletions(-)

diff --git a/lib/hash.h b/lib/hash.h
index 8febb33f..ebb2857a 100644
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -10,7 +10,7 @@
 #ifndef _BIRD_HASH_H_
 #define _BIRD_HASH_H_
 
-#define HASH(type)		struct { type **data; uint count, order; }
+#define HASH(type)		struct { type **data; uint count; u16 iterators; u8 order; u8 down_requested:1; }
 #define HASH_TYPE(v)		typeof(** (v).data)
 #define HASH_SIZE(v)		(1U << (v).order)
 
@@ -125,20 +125,26 @@
 
 #define HASH_MAY_STEP_DOWN_(v,pool,rehash_fn,args)			\
   ({                                                                    \
-    if (((v).count < (HASH_SIZE(v) REHASH_LO_MARK(args))) &&		\
-	((v).order > (REHASH_LO_BOUND(args))))				\
+    if ((v).iterators)							\
+      (v).down_requested = 1;						\
+    else if (((v).count < (HASH_SIZE(v) REHASH_LO_MARK(args))) &&	\
+	     ((v).order > (REHASH_LO_BOUND(args))))			\
       rehash_fn(&(v), pool, -(REHASH_LO_STEP(args)));			\
   })
 
 #define HASH_MAY_RESIZE_DOWN_(v,pool,rehash_fn,args)			\
   ({                                                                    \
-    uint _o = (v).order;							\
-    while (((v).count < ((1U << _o) REHASH_LO_MARK(args))) &&		\
-	   (_o > (REHASH_LO_BOUND(args))))				\
-      _o -= (REHASH_LO_STEP(args));					\
-    if (_o < (v).order)							\
-      rehash_fn(&(v), pool, _o - (v).order);				\
-  })
+    if ((v).iterators)							\
+      (v).down_requested = 1;						\
+    else {								\
+      uint _o = (v).order;						\
+      while (((v).count < ((1U << _o) REHASH_LO_MARK(args))) &&		\
+	     (_o > (REHASH_LO_BOUND(args))))				\
+	_o -= (REHASH_LO_STEP(args));					\
+      if (_o < (v).order)						\
+	rehash_fn(&(v), pool, _o - (v).order);				\
+    }									\
+   })
 
 
 #define HASH_INSERT2(v,id,pool,node)					\
@@ -195,6 +201,20 @@
 #define HASH_WALK_FILTER_END } while (0)
 
 
+#define HASH_WALK_ITER(v, id, n, iter)					\
+  do {									\
+    uint _hash_walk_iter_put = 0;					\
+    uint _shift = 32 - (v).order;					\
+    for ( ; !_hash_walk_iter_put; (iter) += (1U << _shift)) {		\
+      _hash_walk_iter_put = ((iter) + (1U << _shift) == 0);		\
+      for (HASH_TYPE(v) *n = (v).data[(iter) >> _shift]; n; n = id##_NEXT((n)))\
+	if (HASH_FN(v, id, id##_KEY(n)) >= ((iter) >> _shift))		\
+
+#define HASH_WALK_ITER_PUT	(_hash_walk_iter_put = 1)
+
+#define HASH_WALK_ITER_END } } while (0)
+
+
 static inline void
 mem_hash_init(u64 *h)
 {
diff --git a/lib/hash_test.c b/lib/hash_test.c
index 4bce7017..ecfcdd66 100644
--- a/lib/hash_test.c
+++ b/lib/hash_test.c
@@ -285,6 +285,46 @@ t_walk_filter(void)
   return 1;
 }
 
+static int
+t_walk_iter(void)
+{
+  init_hash();
+  fill_hash();
+
+  u32 hit = 0;
+
+  u32 prev_hash = ~0;
+  for (uint cnt = 0; cnt < MAX_NUM; )
+  {
+    u32 last_hash = ~0;
+//    printf("PUT!\n");
+    HASH_WALK_ITER(hash, TEST, n, hit)
+    {
+      cnt++;
+      u32 cur_hash = HASH_FN(hash, TEST, n->key);
+      /*
+      printf("C%08x L%08x P%08x K%08x H%08x N%p S%d I%ld\n",
+	  cur_hash, last_hash, prev_hash, n->key, hit, n, _shift, n - &nodes[0]);
+	  */
+
+      if (last_hash == ~0U)
+      {
+	if (prev_hash != ~0U)
+	  bt_assert(prev_hash < cur_hash);
+	last_hash = prev_hash = cur_hash;
+      }
+      else
+	bt_assert(last_hash == cur_hash);
+
+      if (cnt < MAX_NUM)
+	HASH_WALK_ITER_PUT;
+    }
+    HASH_WALK_ITER_END;
+  }
+
+  return 1;
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -299,6 +339,7 @@ main(int argc, char *argv[])
   bt_test_suite(t_walk_delsafe_remove, 	"HASH_WALK_DELSAFE and HASH_REMOVE");
   bt_test_suite(t_walk_delsafe_remove2,	"HASH_WALK_DELSAFE and HASH_REMOVE2. HASH_REMOVE2 is HASH_REMOVE and smart auto-resize function");
   bt_test_suite(t_walk_filter,		"HASH_WALK_FILTER");
+  bt_test_suite(t_walk_iter,		"HASH_WALK_ITER");
 
   return bt_exit_value();
 }

From 6b0368cc2c317d1acc0881a96b32ded291d82741 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 20 Jun 2022 19:10:49 +0200
Subject: [PATCH 19/20] 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.
---
 lib/route.h         |   2 +
 nest/config.Y       |   2 +-
 nest/proto.c        |  16 ---
 nest/protocol.h     |   3 +-
 nest/rt-attr.c      |  27 ++++-
 nest/rt-table.c     | 168 +++-------------------------
 nest/rt.h           |  20 +++-
 proto/bgp/attrs.c   | 266 ++++++++++++++++++++++++++++++++++++++++----
 proto/bgp/bgp.c     |   7 +-
 proto/bgp/bgp.h     |  19 +++-
 proto/bgp/packets.c |  32 +++---
 11 files changed, 342 insertions(+), 220 deletions(-)

diff --git a/lib/route.h b/lib/route.h
index 30be7c4e..68596316 100644
--- a/lib/route.h
+++ b/lib/route.h
@@ -35,6 +35,7 @@ typedef struct rte {
 #define REF_STALE	4		/* Route is stale in a refresh cycle */
 #define REF_DISCARD	8		/* Route is scheduled for discard */
 #define REF_MODIFY	16		/* Route is scheduled for modify */
+#define REF_PENDING	32		/* Route has not propagated completely yet */
 
 /* Route is valid for propagation (may depend on other flags in the future), accepts NULL */
 static inline int rte_is_valid(rte *r) { return r && !(r->flags & REF_FILTERED); }
@@ -53,6 +54,7 @@ struct rte_src {
 
 struct rte_src *rt_find_source(struct proto *p, u32 id);
 struct rte_src *rt_get_source(struct proto *p, u32 id);
+struct rte_src *rt_find_source_global(u32 id);
 static inline void rt_lock_source(struct rte_src *src) { src->uc++; }
 static inline void rt_unlock_source(struct rte_src *src) { src->uc--; }
 void rt_prune_sources(void);
diff --git a/nest/config.Y b/nest/config.Y
index 7c163f74..edddfc2b 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -694,7 +694,7 @@ r_args:
    }
  | r_args EXPORT TABLE channel_arg {
      if (!$4->out_table) cf_error("No export table in channel %s.%s", $4->proto->name, $4->name);
-     rt_show_add_exporter($$, &$4->out_table->exporter, "export");
+     rt_show_add_exporter($$, $4->out_table, "export");
      $$->tables_defined_by = RSD_TDB_DIRECT;
    }
  | r_args FILTER filter {
diff --git a/nest/proto.c b/nest/proto.c
index e7be8001..061205c1 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -559,10 +559,6 @@ channel_export_stopped(struct rt_export_request *req)
     return;
   }
 
-  /* Free the routes from out_table */
-  if (c->out_table)
-    rt_prune_sync(c->out_table, 1);
-
   mb_free(c->out_req.name);
   c->out_req.name = NULL;
 
@@ -647,18 +643,6 @@ channel_setup_in_table(struct channel *c)
   c->in_keep |= RIK_PREFILTER;
 }
 
-/* Called by protocol to activate out_table */
-void
-channel_setup_out_table(struct channel *c)
-{
-  struct rtable_config *cf = mb_allocz(c->proto->pool, sizeof(struct rtable_config));
-  cf->name = "export";
-  cf->addr_type = c->net_type;
-  cf->internal = 1;
-
-  c->out_table = rt_setup(c->proto->pool, cf);
-}
-
 
 static void
 channel_do_start(struct channel *c)
diff --git a/nest/protocol.h b/nest/protocol.h
index a1701a7e..3ccd364a 100644
--- a/nest/protocol.h
+++ b/nest/protocol.h
@@ -537,7 +537,7 @@ struct channel {
   u8 refeed_pending;			/* Refeeding and another refeed is scheduled */
   u8 rpki_reload;			/* RPKI changes trigger channel reload */
 
-  struct rtable *out_table;		/* Internal table for exported routes */
+  struct rt_exporter *out_table;	/* Internal table for exported routes */
 
   list roa_subscriptions;		/* List of active ROA table subscriptions based on filters roa_check() */
 };
@@ -610,7 +610,6 @@ int proto_configure_channel(struct proto *p, struct channel **c, struct channel_
 
 void channel_set_state(struct channel *c, uint state);
 void channel_setup_in_table(struct channel *c);
-void channel_setup_out_table(struct channel *c);
 void channel_schedule_reload(struct channel *c);
 
 static inline void channel_init(struct channel *c) { channel_set_state(c, CS_START); }
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index a66d4c6e..b31bc5cc 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -197,11 +197,14 @@ static struct idm src_ids;
 #define RSH_INIT_ORDER		6
 
 static HASH(struct rte_src) src_hash;
+static struct rte_src **rte_src_global;
+static uint rte_src_global_max = SRC_ID_INIT_SIZE;
 
 static void
 rte_src_init(void)
 {
   rte_src_slab = sl_new(rta_pool, sizeof(struct rte_src));
+  rte_src_global = mb_allocz(rta_pool, sizeof(struct rte_src *) * rte_src_global_max);
 
   idm_init(&src_ids, rta_pool, SRC_ID_INIT_SIZE);
 
@@ -232,10 +235,27 @@ rt_get_source(struct proto *p, u32 id)
   src->uc = 0;
 
   HASH_INSERT2(src_hash, RSH, rta_pool, src);
+  if (src->global_id >= rte_src_global_max)
+  {
+    rte_src_global = mb_realloc(rte_src_global, sizeof(struct rte_src *) * (rte_src_global_max *= 2));
+    memset(&rte_src_global[rte_src_global_max / 2], 0,
+	sizeof(struct rte_src *) * (rte_src_global_max / 2));
+  }
+
+  rte_src_global[src->global_id] = src;
 
   return src;
 }
 
+struct rte_src *
+rt_find_source_global(u32 id)
+{
+  if (id >= rte_src_global_max)
+    return NULL;
+  else
+    return rte_src_global[id];
+}
+
 void
 rt_prune_sources(void)
 {
@@ -1081,8 +1101,11 @@ ea_show_nexthop_list(struct cli *c, struct nexthop_adata *nhad)
       bsprintf(weight, " weight %d", nh->weight + 1);
 
     if (ipa_nonzero(nh->gw))
-      cli_printf(c, -1007, "\tvia %I on %s%s%s%s",
-	  nh->gw, nh->iface->name, mpls, onlink, weight);
+      if (nh->iface)
+	cli_printf(c, -1007, "\tvia %I on %s%s%s%s",
+	    nh->gw, nh->iface->name, mpls, onlink, weight);
+      else
+	cli_printf(c, -1007, "\tvia %I", nh->gw);
     else
       cli_printf(c, -1007, "\tdev %s%s%s",
 	  nh->iface->name, mpls,  onlink, weight);
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 5adf6346..29690414 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -820,17 +820,6 @@ do_rt_notify(struct channel *c, const net_addr *net, rte *new, const rte *old)
   if (!new && old)
     CHANNEL_LIMIT_POP(c, OUT);
 
-  /* Apply export table */
-  struct rte_storage *old_exported = NULL;
-  if (c->out_table)
-  {
-    if (!rte_update_out(c, net, new, old, &old_exported))
-    {
-      channel_rte_trace_out(D_ROUTES, c, new, "idempotent");
-      return;
-    }
-  }
-
   if (new)
     stats->updates_accepted++;
   else
@@ -852,10 +841,7 @@ do_rt_notify(struct channel *c, const net_addr *net, rte *new, const rte *old)
       channel_rte_trace_out(D_ROUTES, c, old, "removed");
   }
 
-  p->rt_notify(p, c, net, new, old_exported ? &old_exported->rte : old);
-
-  if (c->out_table && old_exported)
-    rte_free(old_exported);
+  p->rt_notify(p, c, net, new, old);
 }
 
 static void
@@ -1747,7 +1733,7 @@ rt_export_stopped(void *data)
   hook->stopped(hook->req);
 
   /* Reporting the hook as finished. */
-  tab->done(hook);
+  CALL(tab->done, hook);
 
   /* Freeing the hook together with its coroutine. */
   rfree(hook->pool);
@@ -1763,7 +1749,7 @@ rt_set_import_state(struct rt_import_hook *hook, u8 state)
     hook->req->log_state_change(hook->req, state);
 }
 
-static inline void
+void
 rt_set_export_state(struct rt_export_hook *hook, u8 state)
 {
   hook->last_state_change = current_time();
@@ -1874,16 +1860,22 @@ rt_table_export_stop(struct rt_export_hook *hook)
   if (hook->export_state != TES_FEEDING)
     return;
 
-  if (hook->walk_lock)
+  switch (hook->req->addr_mode)
   {
-    rt_unlock_trie(tab, hook->walk_lock);
-    hook->walk_lock = NULL;
-
-    mb_free(hook->walk_state);
-    hook->walk_state = NULL;
+    case TE_ADDR_IN:
+      if (hook->walk_lock)
+      {
+	rt_unlock_trie(tab, hook->walk_lock);
+	hook->walk_lock = NULL;
+	mb_free(hook->walk_state);
+	hook->walk_state = NULL;
+	break;
+      }
+      /* fall through */
+    case TE_ADDR_NONE:
+      fit_get(&tab->fib, &hook->feed_fit);
+      break;
   }
-  else
-    fit_get(&tab->fib, &hook->feed_fit);
 }
 
 void
@@ -1896,7 +1888,7 @@ rt_stop_export(struct rt_export_request *req, void (*stopped)(struct rt_export_r
   ev_postpone(hook->event);
 
   /* Stop feeding from the exporter */
-  hook->table->stop(hook);
+  CALL(hook->table->stop, hook);
 
   /* Reset the event as the stopped event */
   hook->event->hook = rt_export_stopped;
@@ -3397,130 +3389,6 @@ void channel_reload_export_bulk(struct rt_export_request *req, const net_addr *n
     }
 }
 
-void
-rt_prune_sync(rtable *t, int all)
-{
-  struct fib_iterator fit;
-
-  FIB_ITERATE_INIT(&fit, &t->fib);
-
-again:
-  FIB_ITERATE_START(&t->fib, &fit, net, n)
-  {
-    struct rte_storage *e, **ee = &n->routes;
-
-    while (e = *ee)
-    {
-      if (all || (e->rte.flags & (REF_STALE | REF_DISCARD)))
-      {
-	*ee = e->next;
-	rte_free(e);
-	t->rt_count--;
-      }
-      else
-	ee = &e->next;
-    }
-
-    if (all || !n->routes)
-    {
-      FIB_ITERATE_PUT(&fit);
-      fib_delete(&t->fib, n);
-      goto again;
-    }
-  }
-  FIB_ITERATE_END;
-}
-
-
-/*
- *	Export table
- */
-
-int
-rte_update_out(struct channel *c, const net_addr *n, rte *new, const rte *old0, struct rte_storage **old_exported)
-{
-  struct rtable *tab = c->out_table;
-  struct rte_src *src;
-  net *net;
-
-  if (new)
-  {
-    net = net_get(tab, n);
-    src = new->src;
-  }
-  else
-  {
-    net = net_find(tab, n);
-    src = old0->src;
-
-    if (!net)
-      goto drop;
-  }
-
-  /* Find the old rte */
-  struct rte_storage **pos = (c->ra_mode == RA_ANY) ? rte_find(net, src) : &net->routes;
-  struct rte_storage *old = NULL;
-
-  if (old = *pos)
-  {
-    if (new && rte_same(&(*pos)->rte, new))
-      goto drop;
-
-    /* Remove the old rte */
-    *pos = old->next;
-    *old_exported = old;
-    tab->rt_count--;
-  }
-
-  if (!new)
-  {
-    if (!old)
-      goto drop;
-
-    if (!net->routes)
-      fib_delete(&tab->fib, net);
-
-    return 1;
-  }
-
-  /* Insert the new rte */
-  struct rte_storage *e = rte_store(new, net, tab);
-  e->rte.lastmod = current_time();
-  e->next = *pos;
-  *pos = e;
-  tab->rt_count++;
-  return 1;
-
-drop:
-  return 0;
-}
-
-void
-rt_refeed_channel(struct channel *c)
-{
-  if (!c->out_table)
-  {
-    channel_request_feeding(c);
-    return;
-  }
-
-  ASSERT_DIE(c->ra_mode != RA_ANY);
-
-  c->proto->feed_begin(c, 0);
-
-  FIB_WALK(&c->out_table->fib, net, n)
-  {
-    if (!n->routes)
-      continue;
-
-    rte e = n->routes->rte;
-    c->proto->rt_notify(c->proto, c, n->n.addr, &e, NULL);
-  }
-  FIB_WALK_END;
-
-  c->proto->feed_end(c);
-}
-
 
 /*
  *	Hostcache
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)
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 22a53dce..084c9b63 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -1550,7 +1550,6 @@ bgp_free_bucket_table(struct bgp_channel *c)
 static struct bgp_bucket *
 bgp_get_bucket(struct bgp_channel *c, ea_list *new)
 {
-
   /* Hash and lookup */
   u32 hash = ea_hash(new);
   struct bgp_bucket *b = HASH_FIND(c->bucket_hash, RBH, new, hash);
@@ -1571,8 +1570,7 @@ bgp_get_bucket(struct bgp_channel *c, ea_list *new)
   /* Copy the ea_list */
   ea_list_copy(b->eattrs, new, ea_size);
 
-  /* Insert the bucket to send queue and bucket hash */
-  add_tail(&c->bucket_queue, &b->send_node);
+  /* Insert the bucket to bucket hash */
   HASH_INSERT2(c->bucket_hash, RBH, c->pool, b);
 
   return b;
@@ -1590,14 +1588,30 @@ bgp_get_withdraw_bucket(struct bgp_channel *c)
   return c->withdraw_bucket;
 }
 
-void
-bgp_free_bucket(struct bgp_channel *c, struct bgp_bucket *b)
+static void
+bgp_free_bucket_xx(struct bgp_channel *c, struct bgp_bucket *b)
 {
-  rem_node(&b->send_node);
   HASH_REMOVE2(c->bucket_hash, RBH, c->pool, b);
   mb_free(b);
 }
 
+int
+bgp_done_bucket(struct bgp_channel *c, struct bgp_bucket *b)
+{
+  /* Won't free the withdraw bucket */
+  if (b == c->withdraw_bucket)
+    return 0;
+
+  if (EMPTY_LIST(b->prefixes))
+    rem_node(&b->send_node);
+
+  if (b->px_uc || !EMPTY_LIST(b->prefixes))
+    return 0;
+
+  bgp_free_bucket_xx(c, b);
+  return 1;
+}
+
 void
 bgp_defer_bucket(struct bgp_channel *c, struct bgp_bucket *b)
 {
@@ -1617,8 +1631,8 @@ bgp_withdraw_bucket(struct bgp_channel *c, struct bgp_bucket *b)
     struct bgp_prefix *px = HEAD(b->prefixes);
 
     log(L_ERR "%s: - withdrawing %N", p->p.name, &px->net);
-    rem_node(&px->buck_node);
-    add_tail(&wb->prefixes, &px->buck_node);
+    rem_node(&px->buck_node_xx);
+    add_tail(&wb->prefixes, &px->buck_node_xx);
   }
 }
 
@@ -1629,7 +1643,7 @@ bgp_withdraw_bucket(struct bgp_channel *c, struct bgp_bucket *b)
 
 #define PXH_KEY(px)		px->net, px->path_id, px->hash
 #define PXH_NEXT(px)		px->next
-#define PXH_EQ(n1,i1,h1,n2,i2,h2) h1 == h2 && i1 == i2 && net_equal(n1, n2)
+#define PXH_EQ(n1,i1,h1,n2,i2,h2) h1 == h2 && (c->add_path_tx ? (i1 == i2) : 1) && net_equal(n1, n2)
 #define PXH_FN(n,i,h)		h
 
 #define PXH_REHASH		bgp_pxh_rehash
@@ -1659,15 +1673,13 @@ bgp_free_prefix_table(struct bgp_channel *c)
 static struct bgp_prefix *
 bgp_get_prefix(struct bgp_channel *c, const net_addr *net, u32 path_id)
 {
+  u32 path_id_hash = c->add_path_tx ? path_id : 0;
   /* We must use a different hash function than the rtable */
-  u32 hash = u32_hash(net_hash(net) ^ u32_hash(path_id));
-  struct bgp_prefix *px = HASH_FIND(c->prefix_hash, PXH, net, path_id, hash);
+  u32 hash = u32_hash(net_hash(net) ^ u32_hash(path_id_hash));
+  struct bgp_prefix *px = HASH_FIND(c->prefix_hash, PXH, net, path_id_hash, hash);
 
   if (px)
-  {
-    rem_node(&px->buck_node);
     return px;
-  }
 
   if (c->prefix_slab)
     px = sl_alloc(c->prefix_slab);
@@ -1684,10 +1696,64 @@ bgp_get_prefix(struct bgp_channel *c, const net_addr *net, u32 path_id)
   return px;
 }
 
-void
+static void bgp_free_prefix(struct bgp_channel *c, struct bgp_prefix *px);
+
+static inline int
+bgp_update_prefix(struct bgp_channel *c, struct bgp_prefix *px, struct bgp_bucket *b)
+{
+#define BPX_TRACE(what)	do { \
+  if (c->c.debug & D_ROUTES) log(L_TRACE "%s.%s < %s %N %uG %s", \
+      c->c.proto->name, c->c.name, what, \
+      px->net, px->path_id, (b == c->withdraw_bucket) ? "withdraw" : "update"); } while (0)
+  px->lastmod = current_time();
+
+  /* Already queued for the same bucket */
+  if (px->cur == b)
+  {
+    BPX_TRACE("already queued");
+    return 0;
+  }
+
+  /* Unqueue from the old bucket */
+  if (px->cur)
+  {
+    rem_node(&px->buck_node_xx);
+    bgp_done_bucket(c, px->cur);
+  }
+
+  /* The new bucket is the same as we sent before */
+  if ((px->last == b) || c->c.out_table && !px->last && (b == c->withdraw_bucket))
+  {
+    if (px->cur)
+      BPX_TRACE("reverted");
+    else
+      BPX_TRACE("already sent");
+
+    /* Well, we haven't sent anything yet */
+    if (!px->last)
+      bgp_free_prefix(c, px);
+
+    px->cur = NULL;
+    return 0;
+  }
+
+  /* Enqueue the bucket if it has been empty */
+  if ((b != c->withdraw_bucket) && EMPTY_LIST(b->prefixes))
+    add_tail(&c->bucket_queue, &b->send_node);
+
+  /* Enqueue to the new bucket and indicate the change */
+  add_tail(&b->prefixes, &px->buck_node_xx);
+  px->cur = b;
+
+  BPX_TRACE("queued");
+  return 1;
+
+#undef BPX_TRACE
+}
+
+static void
 bgp_free_prefix(struct bgp_channel *c, struct bgp_prefix *px)
 {
-  rem_node(&px->buck_node);
   HASH_REMOVE2(c->prefix_hash, PXH, c->pool, px);
 
   if (c->prefix_slab)
@@ -1696,6 +1762,167 @@ bgp_free_prefix(struct bgp_channel *c, struct bgp_prefix *px)
     mb_free(px);
 }
 
+void
+bgp_done_prefix(struct bgp_channel *c, struct bgp_prefix *px, struct bgp_bucket *buck)
+{
+  /* Cleanup: We're called from bucket senders. */
+  ASSERT_DIE(px->cur == buck);
+  rem_node(&px->buck_node_xx);
+
+  /* We may want to store the updates */
+  if (c->c.out_table)
+  {
+    /* Nothing to be sent right now */
+    px->cur = NULL;
+
+    /* Unref the previous sent version */
+    if (px->last)
+      px->last->px_uc--;
+
+    /* Ref the current sent version */
+    if (buck != c->withdraw_bucket)
+    {
+      px->last = buck;
+      px->last->px_uc++;
+      return;
+    }
+
+    /* Prefixes belonging to the withdraw bucket are freed always */
+  }
+
+  bgp_free_prefix(c, px);
+}
+
+
+/*
+ *	Prefix hash table exporter
+ */
+
+static void
+bgp_out_table_feed(void *data)
+{
+  struct rt_export_hook *hook = data;
+  struct bgp_channel *c = SKIP_BACK(struct bgp_channel, prefix_exporter, hook->table);
+
+  int max = 512;
+
+  const net_addr *neq = (hook->req->addr_mode == TE_ADDR_EQUAL) ? hook->req->addr : NULL;
+  const net_addr *cand = NULL;
+
+  do {
+    HASH_WALK_ITER(c->prefix_hash, PXH, n, hook->hash_iter)
+    {
+      switch (hook->req->addr_mode)
+      {
+	case TE_ADDR_IN:
+	  if (!net_in_netX(n->net, hook->req->addr))
+	    continue;
+	  /* fall through */
+	case TE_ADDR_NONE:
+	  /* Splitting only for multi-net exports */
+	  if (--max <= 0)
+	    HASH_WALK_ITER_PUT;
+	  break;
+
+	case TE_ADDR_FOR:
+	  if (!neq)
+	  {
+	    if (net_in_netX(hook->req->addr, n->net) && (!cand || (n->net->length > cand->length)))
+	      cand = n->net;
+	    continue;
+	  }
+	  /* fall through */
+	case TE_ADDR_EQUAL:
+	  if (!net_equal(n->net, neq))
+	    continue;
+	  break;
+      }
+
+      struct bgp_bucket *buck = n->cur ?: n->last;
+      ea_list *ea = NULL;
+      if (buck == c->withdraw_bucket)
+	ea_set_dest(&ea, 0, RTD_UNREACHABLE);
+      else
+      {
+	ea = buck->eattrs;
+	eattr *eanh = bgp_find_attr(ea, BA_NEXT_HOP);
+	ASSERT_DIE(eanh);
+	const ip_addr *nh = (const void *) eanh->u.ptr->data;
+
+	struct nexthop_adata nhad = {
+	  .ad = { .length = sizeof (struct nexthop_adata) - sizeof (struct adata), },
+	  .nh = { .gw = nh[0], },
+	};
+
+	ea_set_attr(&ea, EA_LITERAL_DIRECT_ADATA(&ea_gen_nexthop, 0, tmp_copy_adata(&nhad.ad)));
+      }
+
+      struct rte_storage es = {
+	.rte = {
+	  .attrs = ea,
+	  .net = n->net,
+	  .src = rt_find_source_global(n->path_id),
+	  .sender = NULL,
+	  .lastmod = n->lastmod,
+	  .flags = n->cur ? REF_PENDING : 0,
+	},
+      };
+
+      struct rt_pending_export rpe = {
+	.new = &es, .new_best = &es,
+      };
+
+      if (hook->req->export_bulk)
+      {
+	rte *feed = &es.rte;
+	hook->req->export_bulk(hook->req, n->net, &rpe, &feed, 1);
+      }
+      else if (hook->req->export_one)
+	hook->req->export_one(hook->req, n->net, &rpe);
+      else
+	bug("No export method in export request");
+    }
+    HASH_WALK_ITER_END;
+
+    neq = cand;
+    cand = NULL;
+  } while (neq);
+
+  if (hook->hash_iter)
+    ev_schedule_work(hook->event);
+  else
+    rt_set_export_state(hook, TES_READY);
+}
+
+static struct rt_export_hook *
+bgp_out_table_export_start(struct rt_exporter *re, struct rt_export_request *req UNUSED)
+{
+  struct bgp_channel *c = SKIP_BACK(struct bgp_channel, prefix_exporter, re);
+  pool *p = rp_new(c->c.proto->pool, "Export hook");
+  struct rt_export_hook *hook = mb_allocz(p, sizeof(struct rt_export_hook));
+  hook->pool = p;
+  hook->lp = lp_new_default(p);
+  hook->event = ev_new_init(p, bgp_out_table_feed, hook);
+  hook->feed_type = TFT_HASH;
+
+  return hook;
+}
+
+void
+bgp_setup_out_table(struct bgp_channel *c)
+{
+  ASSERT_DIE(c->c.out_table == NULL);
+
+  c->prefix_exporter = (struct rt_exporter) {
+    .addr_type = c->c.table->addr_type,
+    .start = bgp_out_table_export_start,
+  };
+
+  init_list(&c->prefix_exporter.hooks);
+
+  c->c.out_table = &c->prefix_exporter;
+}
+
 
 /*
  *	BGP protocol glue
@@ -1894,7 +2121,6 @@ bgp_rt_notify(struct proto *P, struct channel *C, const net_addr *n, rte *new, c
   struct bgp_proto *p = (void *) P;
   struct bgp_channel *c = (void *) C;
   struct bgp_bucket *buck;
-  struct bgp_prefix *px;
   u32 path;
 
   if (new)
@@ -1915,10 +2141,8 @@ bgp_rt_notify(struct proto *P, struct channel *C, const net_addr *n, rte *new, c
     path = old->src->global_id;
   }
 
-  px = bgp_get_prefix(c, n, c->add_path_tx ? path : 0);
-  add_tail(&buck->prefixes, &px->buck_node);
-
-  bgp_schedule_packet(p->conn, c, PKT_UPDATE);
+  if (bgp_update_prefix(c, bgp_get_prefix(c, n, path), buck))
+    bgp_schedule_packet(p->conn, c, PKT_UPDATE);
 }
 
 
diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c
index 8df99420..6ffe8824 100644
--- a/proto/bgp/bgp.c
+++ b/proto/bgp/bgp.c
@@ -1740,14 +1740,15 @@ bgp_channel_start(struct channel *C)
   }
 
   c->pool = p->p.pool; // XXXX
-  bgp_init_bucket_table(c);
-  bgp_init_prefix_table(c);
 
   if (c->cf->import_table)
     channel_setup_in_table(C);
 
   if (c->cf->export_table)
-    channel_setup_out_table(C);
+    bgp_setup_out_table(c);
+
+  bgp_init_bucket_table(c);
+  bgp_init_prefix_table(c);
 
   c->stale_timer = tm_new_init(c->pool, bgp_long_lived_stale_timeout, c, 0, 0);
 
diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h
index cca7873a..003893e0 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -156,7 +156,7 @@ struct bgp_channel_config {
   u8 aigp_originate;			/* AIGP is originated automatically */
   u32 cost;				/* IGP cost for direct next hops */
   u8 import_table;			/* Use c.in_table as Adj-RIB-In */
-  u8 export_table;			/* Use c.out_table as Adj-RIB-Out */
+  u8 export_table;			/* Keep Adj-RIB-Out and export it */
 
   struct rtable_config *igp_table_ip4;	/* Table for recursive IPv4 next hop lookups */
   struct rtable_config *igp_table_ip6;	/* Table for recursive IPv6 next hop lookups */
@@ -357,6 +357,8 @@ struct bgp_channel {
   HASH(struct bgp_prefix) prefix_hash;	/* Prefixes to be sent */
   slab *prefix_slab;			/* Slab holding prefix nodes */
 
+  struct rt_exporter prefix_exporter;	/* Table-like exporter for prefix_hash */
+
   ip_addr next_hop_addr;		/* Local address for NEXT_HOP attribute */
   ip_addr link_addr;			/* Link-local version of next_hop_addr */
 
@@ -378,8 +380,11 @@ struct bgp_channel {
 };
 
 struct bgp_prefix {
-  node buck_node;			/* Node in per-bucket list */
+  node buck_node_xx;			/* Node in per-bucket list */
   struct bgp_prefix *next;		/* Node in prefix hash table */
+  struct bgp_bucket *last;		/* Last bucket sent with this prefix */
+  struct bgp_bucket *cur;		/* Current bucket (cur == last) if no update is required */
+  btime lastmod;			/* Last modification of this prefix */
   u32 hash;
   u32 path_id;
   net_addr net[0];
@@ -388,8 +393,9 @@ struct bgp_prefix {
 struct bgp_bucket {
   node send_node;			/* Node in send queue */
   struct bgp_bucket *next;		/* Node in bucket hash table */
-  list prefixes;			/* Prefixes in this bucket (struct bgp_prefix) */
+  list prefixes;			/* Prefixes to send in this bucket (struct bgp_prefix) */
   u32 hash;				/* Hash over extended attributes */
+  u32 px_uc;				/* How many prefixes are linking this bucket */
   ea_list eattrs[0];			/* Per-bucket extended attributes */
 };
 
@@ -556,15 +562,16 @@ int bgp_encode_attrs(struct bgp_write_state *s, ea_list *attrs, byte *buf, byte
 ea_list * bgp_decode_attrs(struct bgp_parse_state *s, byte *data, uint len);
 void bgp_finish_attrs(struct bgp_parse_state *s, ea_list **to);
 
+void bgp_setup_out_table(struct bgp_channel *c);
+
 void bgp_init_bucket_table(struct bgp_channel *c);
 void bgp_free_bucket_table(struct bgp_channel *c);
-void bgp_free_bucket(struct bgp_channel *c, struct bgp_bucket *b);
-void bgp_defer_bucket(struct bgp_channel *c, struct bgp_bucket *b);
 void bgp_withdraw_bucket(struct bgp_channel *c, struct bgp_bucket *b);
+int bgp_done_bucket(struct bgp_channel *c, struct bgp_bucket *b);
 
 void bgp_init_prefix_table(struct bgp_channel *c);
 void bgp_free_prefix_table(struct bgp_channel *c);
-void bgp_free_prefix(struct bgp_channel *c, struct bgp_prefix *bp);
+void bgp_done_prefix(struct bgp_channel *c, struct bgp_prefix *px, struct bgp_bucket *buck);
 
 int bgp_rte_better(struct rte *, struct rte *);
 int bgp_rte_mergable(rte *pri, rte *sec);
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index c2e98340..4d4ae3eb 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -1488,7 +1488,7 @@ bgp_encode_nlri_ip4(struct bgp_write_state *s, struct bgp_bucket *buck, byte *bu
     memcpy(pos, &a, b);
     ADVANCE(pos, size, b);
 
-    bgp_free_prefix(s->channel, px);
+    bgp_done_prefix(s->channel, px, buck);
   }
 
   return pos - buf;
@@ -1573,7 +1573,7 @@ bgp_encode_nlri_ip6(struct bgp_write_state *s, struct bgp_bucket *buck, byte *bu
     memcpy(pos, &a, b);
     ADVANCE(pos, size, b);
 
-    bgp_free_prefix(s->channel, px);
+    bgp_done_prefix(s->channel, px, buck);
   }
 
   return pos - buf;
@@ -1661,7 +1661,7 @@ bgp_encode_nlri_vpn4(struct bgp_write_state *s, struct bgp_bucket *buck, byte *b
     memcpy(pos, &a, b);
     ADVANCE(pos, size, b);
 
-    bgp_free_prefix(s->channel, px);
+    bgp_done_prefix(s->channel, px, buck);
   }
 
   return pos - buf;
@@ -1758,7 +1758,7 @@ bgp_encode_nlri_vpn6(struct bgp_write_state *s, struct bgp_bucket *buck, byte *b
     memcpy(pos, &a, b);
     ADVANCE(pos, size, b);
 
-    bgp_free_prefix(s->channel, px);
+    bgp_done_prefix(s->channel, px, buck);
   }
 
   return pos - buf;
@@ -1845,7 +1845,7 @@ bgp_encode_nlri_flow4(struct bgp_write_state *s, struct bgp_bucket *buck, byte *
     memcpy(pos, net->data, flen);
     ADVANCE(pos, size, flen);
 
-    bgp_free_prefix(s->channel, px);
+    bgp_done_prefix(s->channel, px, buck);
   }
 
   return pos - buf;
@@ -1933,7 +1933,7 @@ bgp_encode_nlri_flow6(struct bgp_write_state *s, struct bgp_bucket *buck, byte *
     memcpy(pos, net->data, flen);
     ADVANCE(pos, size, flen);
 
-    bgp_free_prefix(s->channel, px);
+    bgp_done_prefix(s->channel, px, buck);
   }
 
   return pos - buf;
@@ -2167,6 +2167,8 @@ bgp_create_ip_reach(struct bgp_write_state *s, struct bgp_bucket *buck, byte *bu
    *	var	IPv4 Network Layer Reachability Information
    */
 
+  ASSERT_DIE(s->channel->withdraw_bucket != buck);
+
   int lr, la;
 
   la = bgp_encode_attrs(s, buck->eattrs, buf+4, buf + MAX_ATTRS_LENGTH);
@@ -2188,6 +2190,8 @@ bgp_create_ip_reach(struct bgp_write_state *s, struct bgp_bucket *buck, byte *bu
 static byte *
 bgp_create_mp_reach(struct bgp_write_state *s, struct bgp_bucket *buck, byte *buf, byte *end)
 {
+  ASSERT_DIE(s->channel->withdraw_bucket != buck);
+
   /*
    *	2 B	IPv4 Withdrawn Routes Length (zero)
    *	---	IPv4 Withdrawn Routes NLRI (unused)
@@ -2341,9 +2345,8 @@ again: ;
     buck = HEAD(c->bucket_queue);
 
     /* Cleanup empty buckets */
-    if (EMPTY_LIST(buck->prefixes))
+    if (bgp_done_bucket(c, buck))
     {
-      bgp_free_bucket(c, buck);
       lp_restore(tmp_linpool, &tmpp);
       goto again;
     }
@@ -2352,10 +2355,7 @@ again: ;
       bgp_create_ip_reach(&s, buck, buf, end):
       bgp_create_mp_reach(&s, buck, buf, end);
 
-    if (EMPTY_LIST(buck->prefixes))
-      bgp_free_bucket(c, buck);
-    else
-      bgp_defer_bucket(c, buck);
+    bgp_done_bucket(c, buck);
 
     if (!res)
     {
@@ -2724,7 +2724,7 @@ bgp_rx_route_refresh(struct bgp_conn *conn, byte *pkt, uint len)
   {
   case BGP_RR_REQUEST:
     BGP_TRACE(D_PACKETS, "Got ROUTE-REFRESH");
-    rt_refeed_channel(&c->c);
+    channel_request_feeding(&c->c);
     break;
 
   case BGP_RR_BEGIN:
@@ -2903,7 +2903,11 @@ bgp_schedule_packet(struct bgp_conn *conn, struct bgp_channel *c, int type)
 {
   ASSERT(conn->sk);
 
-  DBG("BGP: Scheduling packet type %d\n", type);
+  struct bgp_proto *p = conn->bgp;
+  if (c)
+    BGP_TRACE(D_PACKETS, "Scheduling packet type %d for channel %s", type, c->c.name);
+  else
+    BGP_TRACE(D_PACKETS, "Scheduling packet type %d", type);
 
   if (c)
   {

From 9efaf6bafea1c69629e59c6504980fb2986287fe Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 11 Jul 2022 17:04:52 +0200
Subject: [PATCH 20/20] Dropped the internal kernel protocol table for learnt
 routes.

The learnt routes are now pushed all into the connected table, not only
the best one. This shouldn't do any damage in well managed setups, yet
it should be noted that it is a change of behavior.

If anybody misses a feature which they implemented by misusing this
internal learn table, let us know, we'll consider implementing it in a
better way.
---
 sysdep/linux/netlink.c |   3 +-
 sysdep/unix/krt.c      | 239 ++---------------------------------------
 sysdep/unix/krt.h      |   4 -
 3 files changed, 11 insertions(+), 235 deletions(-)

diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index d802d3e0..656202ac 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -2042,11 +2042,10 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
     s->net = lp_alloc(s->pool, net->length);
     net_copy(s->net, net);
 
-    s->attrs = ra;
-
     ea_set_attr_data(&ra, &ea_gen_nexthop, 0,
 	nhad.ad.data, nhad.ad.length);
 
+    s->attrs = ra;
     s->proto = p;
     s->new = new;
     s->krt_src = krt_src;
diff --git a/sysdep/unix/krt.c b/sysdep/unix/krt.c
index a37d3186..67d19cbb 100644
--- a/sysdep/unix/krt.c
+++ b/sysdep/unix/krt.c
@@ -302,236 +302,29 @@ krt_uptodate(rte *a, rte *b)
   return (a->attrs == b->attrs);
 }
 
-static void
-krt_learn_announce_update(struct krt_proto *p, rte *e)
-{
-  rte e0 = {
-    .attrs = ea_clone(e->attrs),
-    .src = p->p.main_source,
-  };
-
-  rte_update(p->p.main_channel, e->net, &e0, p->p.main_source);
-}
-
-static void
-krt_learn_announce_delete(struct krt_proto *p, net_addr *n)
-{
-  rte_update(p->p.main_channel, n, NULL, p->p.main_source);
-}
-
 /* Called when alien route is discovered during scan */
 static void
 krt_learn_scan(struct krt_proto *p, rte *e)
 {
-  net *n = net_get(p->krt_table, e->net);
-  struct rte_storage *m, **mm;
+  rte e0 = {
+    .attrs = e->attrs,
+    .src = rt_get_source(&p->p, krt_metric(e)),
+  };
 
-  struct rte_storage *ee = rte_store(e, n, p->krt_table);
+  ea_set_attr_u32(&e0.attrs, &ea_gen_preference, 0, p->p.main_channel->preference);
 
-  for(mm = &n->routes; m = *mm; mm = &m->next)
-    if (krt_same_key(&m->rte, e))
-      break;
-  if (m)
-    {
-      if (krt_uptodate(&m->rte, e))
-	{
-	  krt_trace_in_rl(&rl_alien, p, e, "[alien] seen");
-	  rte_free(ee);
-	  m->rte.pflags |= KRT_REF_SEEN;
-	}
-      else
-	{
-	  krt_trace_in(p, e, "[alien] updated");
-	  *mm = m->next;
-	  rte_free(m);
-	  m = NULL;
-	}
-    }
-  else
-    krt_trace_in(p, e, "[alien] created");
-
-  if (!m)
-    {
-      ee->next = n->routes;
-      n->routes = ee;
-      ee->rte.pflags |= KRT_REF_SEEN;
-    }
-}
-
-static void
-krt_learn_prune(struct krt_proto *p)
-{
-  struct fib *fib = &p->krt_table->fib;
-  struct fib_iterator fit;
-
-  KRT_TRACE(p, D_EVENTS, "Pruning inherited routes");
-
-  FIB_ITERATE_INIT(&fit, fib);
-again:
-  FIB_ITERATE_START(fib, &fit, net, n)
-    {
-      struct rte_storage *e, **ee, *best, **pbest, *old_best;
-
-      /*
-       * Note that old_best may be NULL even if there was an old best route in
-       * the previous step, because it might be replaced in krt_learn_scan().
-       * But in that case there is a new valid best route.
-       */
-
-      old_best = NULL;
-      best = NULL;
-      pbest = NULL;
-      ee = &n->routes;
-      while (e = *ee)
-	{
-	  if (e->rte.pflags & KRT_REF_BEST)
-	    old_best = e;
-
-	  if (!(e->rte.pflags & KRT_REF_SEEN))
-	    {
-	      *ee = e->next;
-	      rte_free(e);
-	      continue;
-	    }
-
-	  if (!best || krt_metric(&best->rte) > krt_metric(&e->rte))
-	    {
-	      best = e;
-	      pbest = ee;
-	    }
-
-	  e->rte.pflags &= ~(KRT_REF_SEEN | KRT_REF_BEST);
-	  ee = &e->next;
-	}
-      if (!n->routes)
-	{
-	  DBG("%I/%d: deleting\n", n->n.prefix, n->n.pxlen);
-	  if (old_best)
-	    krt_learn_announce_delete(p, n->n.addr);
-
-	  FIB_ITERATE_PUT(&fit);
-	  fib_delete(fib, n);
-	  goto again;
-	}
-
-      best->rte.pflags |= KRT_REF_BEST;
-      *pbest = best->next;
-      best->next = n->routes;
-      n->routes = best;
-
-      if ((best != old_best) || p->reload)
-	{
-	  DBG("%I/%d: announcing (metric=%d)\n", n->n.prefix, n->n.pxlen, krt_metric(&best->rte));
-	  krt_learn_announce_update(p, &best->rte);
-	}
-      else
-	DBG("%I/%d: uptodate (metric=%d)\n", n->n.prefix, n->n.pxlen, krt_metric(&best->rte));
-    }
-  FIB_ITERATE_END;
-
-  p->reload = 0;
+  rte_update(p->p.main_channel, e->net, &e0, e0.src);
 }
 
 static void
 krt_learn_async(struct krt_proto *p, rte *e, int new)
 {
-  net *n = net_get(p->krt_table, e->net);
-  struct rte_storage *g, **gg, *best, **bestp, *old_best;
-
-  ea_set_attr_u32(&e->attrs, &ea_gen_preference, 0, p->p.main_channel->preference);
-  struct rte_storage *ee = rte_store(e, n, p->krt_table);
-
-  old_best = n->routes;
-  for(gg=&n->routes; g = *gg; gg = &g->next)
-    if (krt_same_key(&g->rte, e))
-      break;
   if (new)
-    {
-      if (g)
-	{
-	  if (krt_uptodate(&g->rte, e))
-	    {
-	      krt_trace_in(p, e, "[alien async] same");
-	      rte_free(ee);
-	      return;
-	    }
-	  krt_trace_in(p, e, "[alien async] updated");
-	  *gg = g->next;
-	  rte_free(g);
-	}
-      else
-	krt_trace_in(p, e, "[alien async] created");
+    return krt_learn_scan(p, e);
 
-      ee->next = n->routes;
-      n->routes = ee;
-    }
-  else if (!g)
-    {
-      krt_trace_in(p, e, "[alien async] delete failed");
-      rte_free(ee);
-      return;
-    }
-  else
-    {
-      krt_trace_in(p, e, "[alien async] removed");
-      *gg = g->next;
-      rte_free(ee);
-      rte_free(g);
-    }
-  best = n->routes;
-  bestp = &n->routes;
-  for(gg=&n->routes; g=*gg; gg=&g->next)
-  {
-    if (krt_metric(&best->rte) > krt_metric(&g->rte))
-      {
-	best = g;
-	bestp = gg;
-      }
-
-    g->rte.pflags &= ~KRT_REF_BEST;
-  }
-
-  if (best)
-    {
-      best->rte.pflags |= KRT_REF_BEST;
-      *bestp = best->next;
-      best->next = n->routes;
-      n->routes = best;
-    }
-
-  if (best != old_best)
-    {
-      DBG("krt_learn_async: distributing change\n");
-      if (best)
-	krt_learn_announce_update(p, &best->rte);
-      else
-	krt_learn_announce_delete(p, n->n.addr);
-    }
-}
-
-static void
-krt_learn_init(struct krt_proto *p)
-{
-  if (KRT_CF->learn)
-  {
-    struct rtable_config *cf = mb_allocz(p->p.pool, sizeof(struct rtable_config));
-    cf->name = "Inherited";
-    cf->addr_type = p->p.net_type;
-    cf->internal = 1;
-
-    p->krt_table = rt_setup(p->p.pool, cf);
-  }
-}
-
-static void
-krt_dump(struct proto *P)
-{
-  struct krt_proto *p = (struct krt_proto *) P;
-
-  if (!KRT_CF->learn)
-    return;
-  debug("KRT: Table of inheritable routes\n");
-  rt_dump(p->krt_table);
+  struct rte_src *src = rt_find_source(&p->p, krt_metric(e));
+  if (src)
+    rte_update(p->p.main_channel, e->net, NULL, src);
 }
 
 #endif
@@ -738,11 +531,6 @@ krt_prune(struct krt_proto *p)
   }
   FIB_WALK_END;
 
-#ifdef KRT_ALLOW_LEARN
-  if (KRT_CF->learn)
-    krt_learn_prune(p);
-#endif
-
   if (p->ready)
     p->initialized = 1;
 }
@@ -1053,10 +841,6 @@ krt_start(struct proto *P)
   bmap_init(&p->seen_map, p->p.pool, 1024);
   add_tail(&krt_proto_list, &p->krt_node);
 
-#ifdef KRT_ALLOW_LEARN
-  krt_learn_init(p);
-#endif
-
   if (!krt_sys_start(p))
   {
     rem_node(&p->krt_node);
@@ -1172,9 +956,6 @@ struct protocol proto_unix_kernel = {
   .shutdown =		krt_shutdown,
   .reconfigure =	krt_reconfigure,
   .copy_config =	krt_copy_config,
-#ifdef KRT_ALLOW_LEARN
-  .dump =		krt_dump,
-#endif
 };
 
 void
diff --git a/sysdep/unix/krt.h b/sysdep/unix/krt.h
index 69fc9aa1..e0d60cbd 100644
--- a/sysdep/unix/krt.h
+++ b/sysdep/unix/krt.h
@@ -55,10 +55,6 @@ struct krt_proto {
   struct proto p;
   struct krt_state sys;		/* Sysdep state */
 
-#ifdef KRT_ALLOW_LEARN
-  struct rtable *krt_table;	/* Internal table of inherited routes */
-#endif
-
 #ifndef CONFIG_ALL_TABLES_AT_ONCE
   timer *scan_timer;
 #endif