From 6bbe9dea3a6bb1644a3b3b961d1a27dde9e49f15 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Sun, 11 Feb 2024 22:58:29 +0100
Subject: [PATCH] Flowspec links don't peruse the all-hooks list for lookup

---
 nest/route.h    |  9 ++-------
 nest/rt-table.c | 44 ++++++++++++++++++++++++++++++--------------
 2 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/nest/route.h b/nest/route.h
index 376df7b8..cc39cb92 100644
--- a/nest/route.h
+++ b/nest/route.h
@@ -11,6 +11,7 @@
 #define _BIRD_ROUTE_H_
 
 #include "lib/lists.h"
+#include "lib/tlists.h"
 #include "lib/bitmap.h"
 #include "lib/resource.h"
 #include "lib/net.h"
@@ -129,6 +130,7 @@ struct rtable_private {
 
   list imports;				/* Registered route importers */
   struct rt_exporter exporter;		/* Exporter API structure */
+  TLIST_STRUCT_DEF(rt_flowspec_link, struct rt_flowspec_link) flowspec_links;	/* Links serving flowspec reload */
 
   struct hmap id_map;
   struct hostcache *hostcache;
@@ -542,13 +544,6 @@ struct hostcache {
   struct rt_export_request req;		/* Notifier */
 };
 
-struct rt_flowspec_link {
-  rtable *src;
-  rtable *dst;
-  u32 uc;
-  struct rt_export_request req;
-};
-
 #define rte_update  channel_rte_import
 /**
  * rte_update - enter a new update to a routing table
diff --git a/nest/rt-table.c b/nest/rt-table.c
index ed65d351..b3809d24 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -2564,6 +2564,23 @@ rt_kick_prune_timer(struct rtable_private *tab)
   tm_start_in(tab->prune_timer, gc_period, tab->loop);
 }
 
+#define TLIST_PREFIX rt_flowspec_link
+#define TLIST_TYPE struct rt_flowspec_link
+#define TLIST_ITEM n
+#define TLIST_WANT_WALK
+#define TLIST_WANT_ADD_TAIL
+#define TLIST_DEFINED_BEFORE
+
+struct rt_flowspec_link {
+  TLIST_DEFAULT_NODE;
+  rtable *src;
+  rtable *dst;
+  u32 uc;
+  struct rt_export_request req;
+};
+
+#include "lib/tlists.h"
+
 
 static void
 rt_flowspec_export_one(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *first)
@@ -2618,20 +2635,15 @@ rt_flowspec_log_state_change(struct rt_export_request *req, u8 state)
 static struct rt_flowspec_link *
 rt_flowspec_find_link(struct rtable_private *src, rtable *dst)
 {
-  struct rt_export_hook *hook; node *n;
-  WALK_LIST2(hook, n, src->exporter.hooks, n)
-    switch (atomic_load_explicit(&hook->export_state, memory_order_acquire))
-    {
-      case TES_HUNGRY:
-      case TES_FEEDING:
-      case TES_READY:
-	if (hook->req->export_one == rt_flowspec_export_one)
-	{
-	  struct rt_flowspec_link *ln = SKIP_BACK(struct rt_flowspec_link, req, hook->req);
-	  if (ln->dst == dst)
-	    return ln;
-	}
-    }
+  WALK_TLIST(rt_flowspec_link, ln, &src->flowspec_links)
+    if (ln->dst == dst && ln->req.hook)
+      switch (atomic_load_explicit(&ln->req.hook->export_state, memory_order_acquire))
+      {
+	case TES_HUNGRY:
+	case TES_FEEDING:
+	case TES_READY:
+	  return ln;
+      }
 
   return NULL;
 }
@@ -2665,6 +2677,7 @@ rt_flowspec_link(rtable *src_pub, rtable *dst_pub)
 	.log_state_change = rt_flowspec_log_state_change,
 	.export_one = rt_flowspec_export_one,
       };
+      rt_flowspec_link_add_tail(&src->flowspec_links, ln);
 
       rt_table_export_start_locked(src, &ln->req);
 
@@ -2703,7 +2716,10 @@ rt_flowspec_unlink(rtable *src, rtable *dst)
     ASSERT(ln && (ln->uc > 0));
 
     if (!--ln->uc)
+    {
+      rt_flowspec_link_rem_node(&t->flowspec_links, ln);
       rt_stop_export(&ln->req, rt_flowspec_link_stopped);
+    }
   }
 
   birdloop_leave(dst->loop);