From 1c2851ecfa94f3d0b732a267c6c2db8b817c37f4 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Thu, 14 Jul 2022 11:09:23 +0200
Subject: [PATCH] Fixed invalid routes handling

The invalid routes were filtered out before they could ever get
exported, yet some of the routines need them available, e.g. for
display or import reload.

Now the invalid routes are properly exported and dropped in channel
export routines instead.
---
 nest/rt-table.c   | 51 ++++++++++++++++++++++++-----------------------
 nest/rt.h         |  6 ++++--
 proto/bgp/attrs.c | 10 ++++------
 3 files changed, 34 insertions(+), 33 deletions(-)

diff --git a/nest/rt-table.c b/nest/rt-table.c
index e7281b2e..5e07c129 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -726,8 +726,8 @@ 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++;
+    count++;
+
   return count;
 }
 
@@ -736,11 +736,11 @@ rte_feed_obtain(net *n, struct 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);
 }
 
@@ -1059,10 +1059,15 @@ void
 rt_notify_optimal(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *rpe)
 {
   struct channel *c = SKIP_BACK(struct channel, out_req, req);
-  rte n0;
 
   if (rpe->new_best != rpe->old_best)
-    rt_notify_basic(c, net, RTE_COPY(rpe->new_best, &n0), RTE_OR_NULL(rpe->old_best));
+  {
+    rte n0 = RTE_COPY_VALID(rpe->new_best);
+    rte *o = RTE_VALID_OR_NULL(rpe->old_best);
+
+    if (n0.src || o)
+      rt_notify_basic(c, net, n0.src ? &n0 : NULL, o);
+  }
 
   /* Drop the old stored rejection if applicable.
    * new->id == old->id happens when updating hostentries. */
@@ -1074,10 +1079,14 @@ void
 rt_notify_any(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *rpe)
 {
   struct channel *c = SKIP_BACK(struct channel, out_req, req);
-  rte n0;
 
   if (rpe->new != rpe->old)
-    rt_notify_basic(c, net, RTE_COPY(rpe->new, &n0), RTE_OR_NULL(rpe->old));
+  {
+    rte n0 = RTE_COPY_VALID(rpe->new);
+    rte *o = RTE_VALID_OR_NULL(rpe->old);
+    if (n0.src || o)
+      rt_notify_basic(c, net, n0.src ? &n0 : NULL, o);
+  }
 
   /* Drop the old stored rejection if applicable.
    * new->id == old->id happens when updating hostentries. */
@@ -1091,10 +1100,11 @@ rt_feed_any(struct rt_export_request *req, const net_addr *net, struct rt_pendin
   struct channel *c = SKIP_BACK(struct channel, out_req, req);
 
   for (uint i=0; i<count; i++)
-  {
-    rte n0 = *feed[i];
-    rt_notify_basic(c, net, &n0, NULL);
-  }
+    if (rte_is_valid(feed[i]))
+    {
+      rte n0 = *feed[i];
+      rt_notify_basic(c, net, &n0, NULL);
+    }
 }
 
 /**
@@ -1132,26 +1142,17 @@ static void
 rte_announce(rtable *tab, net *net, struct rte_storage *new, struct rte_storage *old,
 	     struct rte_storage *new_best, struct rte_storage *old_best)
 {
-  if (!rte_is_valid(RTE_OR_NULL(new)))
-    new = NULL;
-
-  if (!rte_is_valid(RTE_OR_NULL(old)))
-    old = NULL;
-
-  if (!rte_is_valid(RTE_OR_NULL(new_best)))
-    new_best = NULL;
-
-  if (!rte_is_valid(RTE_OR_NULL(old_best)))
-    old_best = NULL;
+  int new_best_valid = rte_is_valid(RTE_OR_NULL(new_best));
+  int old_best_valid = rte_is_valid(RTE_OR_NULL(old_best));
 
   if (!new && !old && !new_best && !old_best)
     return;
 
-  if (new_best != old_best)
+  if (new_best_valid || old_best_valid)
   {
-    if (new_best)
+    if (new_best_valid)
       new_best->rte.sender->stats.pref++;
-    if (old_best)
+    if (old_best_valid)
       old_best->rte.sender->stats.pref--;
 
     if (tab->hostcache)
diff --git a/nest/rt.h b/nest/rt.h
index b13c06be..bdbea05b 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -167,8 +167,10 @@ struct rte_storage {
   struct rte rte;			/* Route data */
 };
 
-#define RTE_COPY(r, l) ((r) ? (((*(l)) = (r)->rte), (l)) : NULL)
-#define RTE_OR_NULL(r) ((r) ? &((r)->rte) : NULL)
+#define RTE_COPY(r)		((r) ? (r)->rte : (rte) {})
+#define RTE_COPY_VALID(r)	(((r) && (rte_is_valid(&(r)->rte))) ? (r)->rte : (rte) {})
+#define RTE_OR_NULL(r)		((r) ? &((r)->rte) : NULL)
+#define RTE_VALID_OR_NULL(r)	(((r) && (rte_is_valid(&(r)->rte))) ? &((r)->rte) : NULL)
 
 /* Table-channel connections */
 
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 1ca77fd5..883a9746 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -2557,12 +2557,10 @@ bgp_rte_modify_stale(struct rt_export_request *req, const net_addr *n, struct rt
   {
     rte *r = feed[i];
 
-    /* Not our route */
-    if (r->sender != irh)
-      continue;
-
-    /* A new route, do not mark as stale */
-    if (r->stale_cycle == irh->stale_set)
+    if (
+	!rte_is_valid(r) ||			/* Not a valid route */
+	(r->sender != irh) ||			/* Not our route */
+	(r->stale_cycle == irh->stale_set))	/* A new route, do not mark as stale */
       continue;
 
     eattr *ea = ea_find(r->attrs, BGP_EA_ID(BA_COMMUNITY));