From cee0cd148c9b71bf47d007c850193b5fbf9486c1 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Sat, 20 Mar 2021 21:16:12 +0100
Subject: [PATCH] Export table: Delay freeing of old stored route.

This is needed to provide the protocols the full old route after filters
when export table is enabled.
---
 nest/route.h    |  2 +-
 nest/rt-table.c | 58 ++++++++++++++++++++++++++++---------------------
 2 files changed, 34 insertions(+), 26 deletions(-)

diff --git a/nest/route.h b/nest/route.h
index f5fc9e31..227a5f5e 100644
--- a/nest/route.h
+++ b/nest/route.h
@@ -353,7 +353,7 @@ int rte_update_in(struct channel *c, const net_addr *n, rte *new, struct rte_src
 int rt_reload_channel(struct channel *c);
 void rt_reload_channel_abort(struct channel *c);
 void rt_prune_sync(rtable *t, int all);
-int rte_update_out(struct channel *c, const net_addr *n, rte *new, rte *old0, int refeed);
+int rte_update_out(struct channel *c, const net_addr *n, rte *new, rte *old, rte **old_exported, int refeed);
 struct rtable_config *rt_new_table(struct symbol *s, uint addr_type);
 
 
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 13209dd7..b1e3ab70 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -333,6 +333,26 @@ rte_cow_rta(rte *r, linpool *lp)
   return r;
 }
 
+/**
+ * rte_free - delete a &rte
+ * @e: &rte to be deleted
+ *
+ * rte_free() deletes the given &rte from the routing table it's linked to.
+ */
+void
+rte_free(rte *e)
+{
+  if (rta_is_cached(e->attrs))
+    rta_free(e->attrs);
+  sl_free(rte_slab, e);
+}
+
+static inline void
+rte_free_quick(rte *e)
+{
+  rta_free(e->attrs);
+  sl_free(rte_slab, e);
+}
 
 /**
  * rte_init_tmp_attrs - initialize temporary ea_list for route
@@ -661,8 +681,14 @@ do_rt_notify(struct channel *c, net *net, rte *new, rte *old, int refeed)
   }
 
   /* Apply export table */
-  if (c->out_table && !rte_update_out(c, net->n.addr, new, old, refeed))
-    return;
+  struct rte *old_exported = NULL;
+  if (c->out_table)
+  {
+    if (!rte_update_out(c, net->n.addr, new, old, &old_exported, refeed))
+      return;
+  }
+  else if (c->out_filter == FILTER_ACCEPT)
+    old_exported = old;
 
   if (new)
     stats->exp_updates_accepted++;
@@ -692,6 +718,9 @@ do_rt_notify(struct channel *c, net *net, rte *new, rte *old, int refeed)
   }
 
   p->rt_notify(p, c, net, new, old);
+
+  if (c->out_table && old_exported)
+    rte_free_quick(old_exported);
 }
 
 static void
@@ -1044,27 +1073,6 @@ rte_validate(rte *e)
   return 1;
 }
 
-/**
- * rte_free - delete a &rte
- * @e: &rte to be deleted
- *
- * rte_free() deletes the given &rte from the routing table it's linked to.
- */
-void
-rte_free(rte *e)
-{
-  if (rta_is_cached(e->attrs))
-    rta_free(e->attrs);
-  sl_free(rte_slab, e);
-}
-
-static inline void
-rte_free_quick(rte *e)
-{
-  rta_free(e->attrs);
-  sl_free(rte_slab, e);
-}
-
 static int
 rte_same(rte *x, rte *y)
 {
@@ -2762,7 +2770,7 @@ again:
  */
 
 int
-rte_update_out(struct channel *c, const net_addr *n, rte *new, rte *old0, int refeed)
+rte_update_out(struct channel *c, const net_addr *n, rte *new, rte *old0, rte **old_exported, int refeed)
 {
   struct rtable *tab = c->out_table;
   struct rte_src *src;
@@ -2808,7 +2816,7 @@ rte_update_out(struct channel *c, const net_addr *n, rte *new, rte *old0, int re
 
       /* Remove the old rte */
       *pos = old->next;
-      rte_free_quick(old);
+      *old_exported = old;
       tab->rt_count--;
 
       break;