On 9/8/20 3:10 AM, Ido Schimmel wrote:
> From: Ido Schimmel <ido...@nvidia.com>
>
> 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 <ido...@nvidia.com>
> ---
> 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 b40c343ca969..6505a0a28df2 100644
> --- a/net/ipv4/nexthop.c
> +++ b/net/ipv4/nexthop.c
> @@ -156,6 +156,27 @@ 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;
> @@ -2116,11 +2137,40 @@ 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);
can the unlock be moved here? register function below should not need it.
> + if (err)
> + goto unlock;
> + err = blocking_notifier_chain_register(&net->nexthop.notifier_chain,
> + nb);
> +unlock:
> + rtnl_unlock();
> + return err;
> }
> EXPORT_SYMBOL(register_nexthop_notifier);
>
>
