hsr: broadcast netlink notifications in the device's net namespace

The HSR generic netlink family sets .netnsok = true. HSR devices can
live in network namespaces other than init_net.

Two async notifiers broadcast events with genlmsg_multicast(). They
are hsr_nl_ringerror() and hsr_nl_nodedown(). That helper delivers
only on the default genl socket in init_net. So the events always land
in init_net. The network namespace of the device does not matter.

This has two effects. A listener in the device's own namespace never
sees its own ring error and node down events. A privileged listener in
init_net receives events from HSR devices in other namespaces. The
payload carries the peer node MAC (HSR_A_NODE_ADDR) and the slave port
ifindex (HSR_A_IFINDEX).

Switch both callers to genlmsg_multicast_netns(). Other families with
.netnsok = true already do this. Examples are gtp, ovpn, team,
batman-adv, netdev-genl, ethtool and handshake.

hsr_nl_ringerror() already has the slave port. It uses
dev_net(port->dev). hsr_nl_nodedown() takes the namespace from the
master port via hsr_port_get_hsr().

Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Link: https://patch.msgid.link/20260604054949.2999304-1-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c
index f0ca23da3ab99cea7563aaa1fddf1c64ba706641..8099f2069a748eb32684232acddf46b646b1a69a 100644 (file)
--- a/net/hsr/hsr_netlink.c
+++ b/net/hsr/hsr_netlink.c
@@ -252,7 +252,8 @@ void hsr_nl_ringerror(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN],
                goto nla_put_failure;
 
        genlmsg_end(skb, msg_head);
-       genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);
+       genlmsg_multicast_netns(&hsr_genl_family, dev_net(port->dev),
+                               skb, 0, 0, GFP_ATOMIC);
 
        return;
 
@@ -288,8 +289,12 @@ void hsr_nl_nodedown(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN])
        if (res < 0)
                goto nla_put_failure;
 
+       rcu_read_lock();
+       master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
        genlmsg_end(skb, msg_head);
-       genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);
+       genlmsg_multicast_netns(&hsr_genl_family, dev_net(master->dev),
+                               skb, 0, 0, GFP_ATOMIC);
+       rcu_read_unlock();
 
        return;