fix #4040 : patch : ospf6d: fix infinite loop when adding ASBR route

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
This commit is contained in:
Alexandre Derumier 2023-04-13 13:48:03 +02:00 committed by Thomas Lamprecht
parent f7d7d4c8df
commit 9ec952bb8a
2 changed files with 77 additions and 0 deletions

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@ -0,0 +1,76 @@
From 4dfe15200ab1a84a8d77fcbc33085c373d556eae Mon Sep 17 00:00:00 2001
From: Renato Westphal <renato@opensourcerouting.org>
Date: Wed, 23 Nov 2022 22:14:51 -0300
Subject: [PATCH] ospf6d: fix infinite loop when adding ASBR route
Commit 8f359e1593c414322 removed a check that prevented the same route
from being added twice. In certain topologies, that change resulted in
the following infinite loop when adding an ASBR route:
ospf6_route_add
ospf6_top_brouter_hook_add
ospf6_abr_examin_brouter
ospf6_abr_examin_summary
ospf6_route_add
(repeat until stack overflow)
Revert the offending commit and update `ospf6_route_is_identical()` to
not do comparison using `memcmp()`.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
---
ospf6d/ospf6_route.c | 21 +++++++++++++++++++++
ospf6d/ospf6_route.h | 8 ++++++++
2 files changed, 29 insertions(+)
diff --git a/ospf6d/ospf6_route.c b/ospf6d/ospf6_route.c
index db94b85b1b5..1cc1fcb47b3 100644
--- a/ospf6d/ospf6_route.c
+++ b/ospf6d/ospf6_route.c
@@ -702,6 +702,27 @@ struct ospf6_route *ospf6_route_add(struct ospf6_route *route,
}
if (old) {
+ /* if route does not actually change, return unchanged */
+ if (ospf6_route_is_identical(old, route)) {
+ if (IS_OSPF6_DEBUG_ROUTE(MEMORY))
+ zlog_debug(
+ "%s %p: route add %p: needless update of %p old cost %u",
+ ospf6_route_table_name(table),
+ (void *)table, (void *)route,
+ (void *)old, old->path.cost);
+ else if (IS_OSPF6_DEBUG_ROUTE(TABLE))
+ zlog_debug("%s: route add: needless update",
+ ospf6_route_table_name(table));
+
+ ospf6_route_delete(route);
+ SET_FLAG(old->flag, OSPF6_ROUTE_ADD);
+ ospf6_route_table_assert(table);
+
+ /* to free the lookup lock */
+ route_unlock_node(node);
+ return old;
+ }
+
if (IS_OSPF6_DEBUG_ROUTE(MEMORY))
zlog_debug(
"%s %p: route add %p cost %u paths %u nh %u: update of %p cost %u paths %u nh %u",
diff --git a/ospf6d/ospf6_route.h b/ospf6d/ospf6_route.h
index bb5827a1766..c8411c015f8 100644
--- a/ospf6d/ospf6_route.h
+++ b/ospf6d/ospf6_route.h
@@ -297,6 +297,14 @@ extern const char *const ospf6_path_type_substr[OSPF6_PATH_TYPE_MAX];
&& (ra)->path.origin.type == (rb)->path.origin.type \
&& (ra)->path.origin.id == (rb)->path.origin.id \
&& (ra)->path.origin.adv_router == (rb)->path.origin.adv_router)
+#define ospf6_route_is_identical(ra, rb) \
+ ((ra)->type == (rb)->type && \
+ prefix_same(&(ra)->prefix, &(rb)->prefix) && \
+ (ra)->path.type == (rb)->path.type && \
+ (ra)->path.cost == (rb)->path.cost && \
+ (ra)->path.u.cost_e2 == (rb)->path.u.cost_e2 && \
+ listcount(ra->paths) == listcount(rb->paths) && \
+ ospf6_route_cmp_nexthops(ra, rb) == 0)
#define ospf6_route_is_best(r) (CHECK_FLAG ((r)->flag, OSPF6_ROUTE_BEST))

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@ -3,3 +3,4 @@ pve/0002-bgpd-add-an-option-for-RT-auto-derivation-to-force-A.patch
frr/0001-zebra-buffering.patch
frr/0002-zebra-buffering.patch
frr/0003-zebra-buffering.patch
frr/ospf6d-fix-infinite-loop.patch