From 975ff7f3324af33e218e3d0abf5797c2b67f97d7 Mon Sep 17 00:00:00 2001
From: Ido Schimmel <idosch@nvidia.com>
Date: Wed, 4 Nov 2020 15:30:35 +0200
Subject: [PATCH] nexthop: Replay nexthops when registering a notifier
When registering a new notifier to the nexthop notification chain,
replay all the existing nexthops to the new notifier so that it will
have a complete picture of the available nexthops.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
net/ipv4/nexthop.c | 54 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 52 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 9a235d5c56701..5e1b22d4f939f 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -157,6 +157,27 @@ static int call_nexthop_notifiers(struct net *net,
return notifier_to_errno(err);
}
+static int call_nexthop_notifier(struct notifier_block *nb, struct net *net,
+ enum nexthop_event_type event_type,
+ struct nexthop *nh,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_notifier_info info = {
+ .net = net,
+ .extack = extack,
+ };
+ int err;
+
+ err = nh_notifier_info_init(&info, nh);
+ if (err)
+ return err;
+
+ err = nb->notifier_call(nb, event_type, &info);
+ nh_notifier_info_fini(&info);
+
+ return notifier_to_errno(err);
+}
+
static unsigned int nh_dev_hashfn(unsigned int val)
{
unsigned int mask = NH_DEV_HASHSIZE - 1;
@@ -2118,11 +2139,40 @@ static struct notifier_block nh_netdev_notifier = {
.notifier_call = nh_netdev_event,
};
+static int nexthops_dump(struct net *net, struct notifier_block *nb,
+ struct netlink_ext_ack *extack)
+{
+ struct rb_root *root = &net->nexthop.rb_root;
+ struct rb_node *node;
+ int err = 0;
+
+ for (node = rb_first(root); node; node = rb_next(node)) {
+ struct nexthop *nh;
+
+ nh = rb_entry(node, struct nexthop, rb_node);
+ err = call_nexthop_notifier(nb, net, NEXTHOP_EVENT_REPLACE, nh,
+ extack);
+ if (err)
+ break;
+ }
+
+ return err;
+}
+
int register_nexthop_notifier(struct net *net, struct notifier_block *nb,
struct netlink_ext_ack *extack)
{
- return blocking_notifier_chain_register(&net->nexthop.notifier_chain,
- nb);
+ int err;
+
+ rtnl_lock();
+ err = nexthops_dump(net, nb, extack);
+ if (err)
+ goto unlock;
+ err = blocking_notifier_chain_register(&net->nexthop.notifier_chain,
+ nb);
+unlock:
+ rtnl_unlock();
+ return err;
}
EXPORT_SYMBOL(register_nexthop_notifier);