- /* pathes with errors are not eligible */
- if (asp1 == NULL || asp1->flags & F_ATTR_PARSE_ERR)
- return -1;
- if (asp2 == NULL || asp2->flags & F_ATTR_PARSE_ERR)
- return 1;
-
- /* only loop free pathes are eligible */
- if (asp1->flags & F_ATTR_LOOP)
- return -1;
- if (asp2->flags & F_ATTR_LOOP)
- return 1;
-
- /*
- * 1. check if prefix is eligible a.k.a reachable
- * A NULL nexthop is eligible since it is used for locally
- * announced networks.
- */
- if (prefix_nexthop(p2) != NULL &&
- prefix_nexthop(p2)->state != NEXTHOP_REACH)
+ /* 1. check if prefix is eligible a.k.a reachable */
+ if (!prefix_eligible(p2))
return 1;
- if (prefix_nexthop(p1) != NULL &&
- prefix_nexthop(p1)->state != NEXTHOP_REACH)
+ if (!prefix_eligible(p1))
return -1;
/* 2. local preference of prefix, bigger is better */
@@ -416,16 +398,13 @@ int
prefix_eligible(struct prefix *p)
{
struct rde_aspath *asp = prefix_aspath(p);
- struct nexthop *nh = prefix_nexthop(p);
/* The aspath needs to be loop and error free */
if (asp == NULL || asp->flags & (F_ATTR_LOOP|F_ATTR_PARSE_ERR))
return 0;
- /*
- * If the nexthop exists it must be reachable.
- * It is OK if the nexthop does not exist (local announcement).
- */
- if (nh != NULL && nh->state != NEXTHOP_REACH)
+
+ /* The nexthop must be valid. */
+ if (!prefix_nhvalid(p))
return 0;
active = prefix_best(re);
-
if (old != NULL)
prefix_remove(old, re);
-
if (new != NULL)
prefix_insert(new, NULL, re);
-
- xp = TAILQ_FIRST(&re->prefix_h);
- if (xp != NULL && !prefix_eligible(xp))
- xp = NULL;
+ xp = prefix_best(re);
/*
* If the active prefix changed or the active prefix was removed
@@ -506,5 +480,76 @@ prefix_evaluate(struct rib_entry *re, st
*/
if (rde_evaluate_all())
if ((new != NULL && prefix_eligible(new)) || old != NULL)
- rde_generate_updates(rib, prefix_best(re), NULL, 1);
+ rde_generate_updates(rib, xp, NULL, 1);
}
+
+void
+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 rib *rib;
+
+ /* Skip non local-RIBs or RIBs that are flagged as noeval. */
+ rib = re_rib(re);
+ if (rib->flags & F_RIB_NOEVALUATE) {
+ log_warnx("%s: prefix with F_RIB_NOEVALUATE hit", __func__);
+ return;
+ }
+
+ if (oldstate == state) {
+ /*
+ * The state of the nexthop did not change. The only
+ * thing that may have changed is the true_nexthop
+ * or other internal infos. This will not change
+ * the routing decision so shortcut here.
+ * XXX needs to be changed for ECMP
+ */
+ if (state == NEXTHOP_REACH) {
+ if ((rib->flags & F_RIB_NOFIB) == 0 &&
+ p == prefix_best(re))
+ rde_send_kroute(rib, p, NULL);
+ }
+ return;
+ }
+
+ /*
+ * Re-evaluate the prefix by removing the prefix then updating the
+ * nexthop state and reinserting the prefix again.
+ */
+ oldbest = prefix_best(re);
+ prefix_remove(p, re);
+
+ if (state == NEXTHOP_REACH)
+ p->nhflags |= NEXTHOP_VALID;
+ else
+ p->nhflags &= ~NEXTHOP_VALID;
+
+ prefix_insert(p, NULL, re);
+ newbest = prefix_best(re);
+
+ /*
+ * If the active prefix changed or the active prefix was removed
+ * and added again then generate an update.
+ */
+ if (oldbest != newbest || newbest == p) {
+ /*
+ * Send update withdrawing oldbest and adding newbest
+ * but remember that newbest may be NULL aka ineligible.
+ * Additional decision may be made by the called functions.
+ */
+ rde_generate_updates(rib, newbest, oldbest, 0);
+ if ((rib->flags & F_RIB_NOFIB) == 0)
+ rde_send_kroute(rib, newbest, oldbest);
+ return;
+ }
+
+ /*
+ * If there are peers with 'rde evaluate all' every update needs
+ * 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())
+ rde_generate_updates(rib, newbest, NULL, 1);
+ }
Index: usr.sbin/bgpd/rde_rib.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/rde_rib.c,v
retrieving revision 1.237
diff -u -p -r1.237 rde_rib.c
--- usr.sbin/bgpd/rde_rib.c 22 Mar 2022 10:53:08 -0000 1.237
+++ usr.sbin/bgpd/rde_rib.c 25 Jul 2022 12:54:13 -0000
@@ -1502,37 +1502,6 @@ prefix_bypeer(struct rib_entry *re, stru
return (NULL);
}
-static void
-prefix_evaluate_all(struct prefix *p, enum nexthop_state state,
- enum nexthop_state oldstate)
-{
- struct rib_entry *re = prefix_re(p);
-
- /* Skip non local-RIBs or RIBs that are flagged as noeval. */
- if (re_rib(re)->flags & F_RIB_NOEVALUATE) {
- log_warnx("%s: prefix with F_RIB_NOEVALUATE hit", __func__);
- return;
- }
-
- if (oldstate == state) {
- /*
- * The state of the nexthop did not change. The only
- * thing that may have changed is the true_nexthop
- * or other internal infos. This will not change
- * the routing decision so shortcut here.
- */
- if (state == NEXTHOP_REACH) {
- if ((re_rib(re)->flags & F_RIB_NOFIB) == 0 &&
- p == prefix_best(re))
- rde_send_kroute(re_rib(re), p, NULL);
- }
- return;
- }
-
- /* redo the route decision */
- prefix_evaluate(prefix_re(p), p, p);
-}
-
/* kill a prefix. */
void
prefix_destroy(struct prefix *p)
@@ -1704,7 +1673,7 @@ nexthop_runner(void)
p = nh->next_prefix;
for (j = 0; p != NULL && j < RDE_RUNNER_ROUNDS; j++) {
- prefix_evaluate_all(p, nh->state, nh->oldstate);
+ prefix_evaluate_nexthop(p, nh->state, nh->oldstate);
p = LIST_NEXT(p, entry.list.nexthop);
}
@@ -1806,15 +1775,24 @@ nexthop_modify(struct nexthop *setnh, en
void
nexthop_link(struct prefix *p)
{
- if (p->nexthop == NULL)
- return;
- if (p->flags & PREFIX_FLAG_ADJOUT)
+ p->nhflags &= ~NEXTHOP_VALID;
+
+ if (p->flags & PREFIX_FLAG_ADJOUT) {
+ /* All nexthops are valid in Adj-RIB-Out */
+ p->nhflags |= NEXTHOP_VALID;
return;
+ }
/* no need to link prefixes in RIBs that have no decision process */
if (re_rib(prefix_re(p))->flags & F_RIB_NOEVALUATE)
return;
+ /* self-announce networks use nexthop NULL and are valid as well */
+ if (p->nexthop == NULL || p->nexthop->state == NEXTHOP_REACH)
+ p->nhflags |= NEXTHOP_VALID;
+
+ if (p->nexthop == NULL)
+ return;
p->flags |= PREFIX_NEXTHOP_LINKED;
LIST_INSERT_HEAD(&p->nexthop->prefix_h, p, entry.list.nexthop);
}
@@ -1822,6 +1800,8 @@ nexthop_link(struct prefix *p)
void
nexthop_unlink(struct prefix *p)
{
+ p->nhflags &= ~NEXTHOP_VALID;
+
if (p->nexthop == NULL || (p->flags & PREFIX_NEXTHOP_LINKED) == 0)
return;
