4 files changed, 48 insertions, 0 deletions
diff --git a/include/linux/ethtool_netlink.h b/include/linux/ethtool_netlink.h
index f27e92b5f344..c98f6852c8eb 100644
--- a/include/linux/ethtool_netlink.h
+++ b/include/linux/ethtool_netlink.h
@@ -5,5 +5,10 @@
 
 #include <uapi/linux/ethtool_netlink.h>
 #include <linux/ethtool.h>
+#include <linux/netdevice.h>
+
+enum ethtool_multicast_groups {
+	ETHNL_MCGRP_MONITOR,
+};
 
 #endif /* _LINUX_ETHTOOL_NETLINK_H_ */
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 469a297b58c0..f007155ae8f4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4393,6 +4393,15 @@ struct netdev_notifier_bonding_info {
 void netdev_bonding_info_change(struct net_device *dev,
 				struct netdev_bonding_info *bonding_info);
 
+#if IS_ENABLED(CONFIG_ETHTOOL_NETLINK)
+void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data);
+#else
+static inline void ethtool_notify(struct net_device *dev, unsigned int cmd,
+				  const void *data)
+{
+}
+#endif
+
 static inline
 struct sk_buff *skb_gso_segment(struct sk_buff *skb, netdev_features_t features)
 {
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 951203049615..d530ccb6f7e6 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -89,4 +89,6 @@ enum {
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1
 
+#define ETHTOOL_MCGRP_MONITOR_NAME "monitor"
+
 #endif /* _UAPI_LINUX_ETHTOOL_NETLINK_H_ */
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index aef882e0c3f5..c0f25c8f3565 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -6,6 +6,8 @@
 
 static struct genl_family ethtool_genl_family;
 
+static bool ethnl_ok __read_mostly;
+
 static const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_MAX + 1] = {
 	[ETHTOOL_A_HEADER_UNSPEC]	= { .type = NLA_REJECT },
 	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
@@ -169,11 +171,38 @@ err:
 	return NULL;
 }
 
+/* notifications */
+
+typedef void (*ethnl_notify_handler_t)(struct net_device *dev, unsigned int cmd,
+				       const void *data);
+
+static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
+};
+
+void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
+{
+	if (unlikely(!ethnl_ok))
+		return;
+	ASSERT_RTNL();
+
+	if (likely(cmd < ARRAY_SIZE(ethnl_notify_handlers) &&
+		   ethnl_notify_handlers[cmd]))
+		ethnl_notify_handlers[cmd](dev, cmd, data);
+	else
+		WARN_ONCE(1, "notification %u not implemented (dev=%s)\n",
+			  cmd, netdev_name(dev));
+}
+EXPORT_SYMBOL(ethtool_notify);
+
 /* genetlink setup */
 
 static const struct genl_ops ethtool_genl_ops[] = {
 };
 
+static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
+	[ETHNL_MCGRP_MONITOR] = { .name = ETHTOOL_MCGRP_MONITOR_NAME },
+};
+
 static struct genl_family ethtool_genl_family = {
 	.name		= ETHTOOL_GENL_NAME,
 	.version	= ETHTOOL_GENL_VERSION,
@@ -181,6 +210,8 @@ static struct genl_family ethtool_genl_family = {
 	.parallel_ops	= true,
 	.ops		= ethtool_genl_ops,
 	.n_ops		= ARRAY_SIZE(ethtool_genl_ops),
+	.mcgrps		= ethtool_nl_mcgrps,
+	.n_mcgrps	= ARRAY_SIZE(ethtool_nl_mcgrps),
 };
 
 /* module setup */
@@ -192,6 +223,7 @@ static int __init ethnl_init(void)
 	ret = genl_register_family(&ethtool_genl_family);
 	if (WARN(ret < 0, "ethtool: genetlink family registration failed"))
 		return ret;
+	ethnl_ok = true;
 
 	return 0;
 }