Before calling rde_generate_updates() with EVAL_ALL ensure that the new

path is actually eligible. If this is not the case pass NULL instead.
This is an optimisation to bypass extra work if both old and new path
were ineligible.
OK tb@

diff --git a/usr.sbin/bgpd/rde_decide.c b/usr.sbin/bgpd/rde_decide.c
index cf752b4..5ebe405 100644 (file)
--- a/usr.sbin/bgpd/rde_decide.c
+++ b/usr.sbin/bgpd/rde_decide.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rde_decide.c,v 1.101 2023/03/13 16:52:42 claudio Exp $ */
+/*     $OpenBSD: rde_decide.c,v 1.102 2023/10/12 14:22:08 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Claudio Jeker <claudio@openbsd.org>
@@ -568,9 +568,12 @@ prefix_evaluate(struct rib_entry *re, struct prefix *new, struct prefix *old)
         * to be passed on (not only a change of the best prefix).
         * rde_generate_updates() will then take care of distribution.
         */
-       if (rde_evaluate_all())
-               if ((new != NULL && prefix_eligible(new)) || old != NULL)
+       if (rde_evaluate_all()) {
+               if (new != NULL && !prefix_eligible(new))
+                       new = NULL;
+               if (new != NULL || old != NULL)
                        rde_generate_updates(re, new, old, EVAL_ALL);
+       }
 }
 
 void
@@ -578,7 +581,7 @@ prefix_evaluate_nexthop(struct prefix *p, enum nexthop_state state,
     enum nexthop_state oldstate)
 {
        struct rib_entry *re = prefix_re(p);
-       struct prefix   *newbest, *oldbest;
+       struct prefix   *newbest, *oldbest, *new, *old;
        struct rib      *rib;
 
        /* Skip non local-RIBs or RIBs that are flagged as noeval. */
@@ -608,6 +611,7 @@ prefix_evaluate_nexthop(struct prefix *p, enum nexthop_state state,
         * Re-evaluate the prefix by removing the prefix then updating the
         * nexthop state and reinserting the prefix again.
         */
+       old = p;
        oldbest = prefix_best(re);
        prefix_remove(p, re);
 
@@ -618,6 +622,9 @@ prefix_evaluate_nexthop(struct prefix *p, enum nexthop_state state,
 
        prefix_insert(p, NULL, re);
        newbest = prefix_best(re);
+       new = p;
+       if (!prefix_eligible(new))
+               new = NULL;
 
        /*
         * If the active prefix changed or the active prefix was removed
@@ -631,7 +638,7 @@ prefix_evaluate_nexthop(struct prefix *p, enum nexthop_state state,
                 */
                if ((rib->flags & F_RIB_NOFIB) == 0)
                        rde_send_kroute(rib, newbest, oldbest);
-               rde_generate_updates(re, p, p, EVAL_DEFAULT);
+               rde_generate_updates(re, new, old, EVAL_DEFAULT);
                return;
        }
 
@@ -641,5 +648,5 @@ prefix_evaluate_nexthop(struct prefix *p, enum nexthop_state state,
         * rde_generate_updates() will then take care of distribution.
         */
        if (rde_evaluate_all())
-               rde_generate_updates(re, p, p, EVAL_ALL);
+               rde_generate_updates(re, new, old, EVAL_ALL);
 }