ospf: suppress delete using replacement

After a SPF run, OSPF deletes routes that have changed in terms of any
metric, type, and/or next-hops and re-adds them. Given that the Zebra-RIB
already support replacement semantics, we suppress deletes for routes
that will be added back again.

This has the following advantages. It reduces the number of IPC messages
between OSPF/Zebra. Also, in the current flow, a batch of route deletes
were followed by a batch of adds even for say a metric change.

With the change, routes are sent as "add" when they are modified. Zebra
already implicitly deletes older routes.

Signed-off-by: Ayan Banerjee <ayan@cumulusnetworks.com>
Reviewed-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Reviewed-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
This commit is contained in:
Ayan Banerjee 2012-12-03 10:48:46 -08:00 committed by Scott Feldman
parent e1a555b67c
commit 16a86b3e2f

View File

@ -126,6 +126,31 @@ ospf_route_table_free (struct route_table *rt)
route_table_finish (rt);
}
/* If a prefix exists in the new routing table, then return 1,
otherwise return 0. Since the ZEBRA-RIB does an implicit
withdraw, it is not necessary to send a delete, an add later
will act like an implicit delete. */
static int
ospf_route_exist_new_table (struct route_table *rt, struct prefix_ipv4 *prefix)
{
struct route_node *rn;
assert (rt);
assert (prefix);
rn = route_node_lookup (rt, (struct prefix *) prefix);
if (!rn) {
return 0;
}
route_unlock_node (rn);
if (!rn->info) {
return 0;
}
return 1;
}
/* If a prefix and a nexthop match any route in the routing table,
then return 1, otherwise return 0. */
int
@ -223,13 +248,13 @@ ospf_route_delete_uniq (struct route_table *rt, struct route_table *cmprt)
{
if (or->type == OSPF_DESTINATION_NETWORK)
{
if (! ospf_route_match_same (cmprt,
(struct prefix_ipv4 *) &rn->p, or))
if (! ospf_route_exist_new_table (cmprt,
(struct prefix_ipv4 *) &rn->p))
ospf_zebra_delete ((struct prefix_ipv4 *) &rn->p, or);
}
else if (or->type == OSPF_DESTINATION_DISCARD)
if (! ospf_route_match_same (cmprt,
(struct prefix_ipv4 *) &rn->p, or))
if (! ospf_route_exist_new_table (cmprt,
(struct prefix_ipv4 *) &rn->p))
ospf_zebra_delete_discard ((struct prefix_ipv4 *) &rn->p);
}
}