ospf6d: fix infinite loop when adding ASBR route

Commit 8f359e1593 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>
This commit is contained in:
Renato Westphal 2022-11-23 22:14:51 -03:00
parent d15c84fa22
commit 4dfe15200a
2 changed files with 29 additions and 0 deletions

View File

@ -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",

View File

@ -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))