2020-03-11 21:41:43

by Michal Kubecek

Subject: [PATCH net-next 06/15] ethtool: add FEATURES_NTF notification

Send ETHTOOL_MSG_FEATURES_NTF notification whenever network device features
are modified using ETHTOOL_MSG_FEATURES_SET netlink message, ethtool ioctl
request or any other way resulting in call to netdev_update_features() or
netdev_change_features()

Signed-off-by: Michal Kubecek <[email protected]>
---
Documentation/networking/ethtool-netlink.rst | 6 ++++
include/uapi/linux/ethtool_netlink.h | 1 +
net/ethtool/features.c | 4 +++
net/ethtool/netlink.c | 29 +++++++++++++++++++-
4 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index d6706c4aa972..47542f042e9d 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -208,6 +208,7 @@ Kernel to userspace:
``ETHTOOL_MSG_WOL_NTF`` wake-on-lan settings notification
``ETHTOOL_MSG_FEATURES_GET_REPLY`` device features
``ETHTOOL_MSG_FEATURES_SET_REPLY`` optional reply to FEATURES_SET
+ ``ETHTOOL_MSG_FEATURES_NTF`` netdev features notification
===================================== =================================

``GET`` requests are sent by userspace applications to retrieve device
@@ -591,6 +592,11 @@ reports the difference between old and new dev->features: mask consists of
bits which have changed, values are their values in new dev->features (after
the operation).

+``ETHTOOL_MSG_FEATURES_NTF`` notification is sent not only if device features
+are modified using ``ETHTOOL_MSG_FEATURES_SET`` request or on of ethtool ioctl
+request but also each time features are modified with netdev_update_features()
+or netdev_change_features().
+

Request translation
===================
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 6f7aaa6b7f42..3d0204cf96a6 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -47,6 +47,7 @@ enum {
ETHTOOL_MSG_WOL_NTF,
ETHTOOL_MSG_FEATURES_GET_REPLY,
ETHTOOL_MSG_FEATURES_SET_REPLY,
+ ETHTOOL_MSG_FEATURES_NTF,

/* add new constants above here */
__ETHTOOL_MSG_KERNEL_CNT,
diff --git a/net/ethtool/features.c b/net/ethtool/features.c
index a12e73db4452..cf00751067c6 100644
--- a/net/ethtool/features.c
+++ b/net/ethtool/features.c
@@ -233,6 +233,7 @@ int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
struct nlattr *tb[ETHTOOL_A_FEATURES_MAX + 1];
struct ethnl_req_info req_info = {};
struct net_device *dev;
+ bool mod;
int ret;

ret = nlmsg_parse(info->nlhdr, GENL_HDRLEN, tb,
@@ -275,6 +276,7 @@ int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
dev->wanted_features = ethnl_bitmap_to_features(req_wanted);
__netdev_update_features(dev);
ethnl_features_to_bitmap(new_active, dev->features);
+ mod = !bitmap_equal(old_active, new_active, NETDEV_FEATURE_COUNT);

ret = 0;
if (!(req_info.flags & ETHTOOL_FLAG_OMIT_REPLY)) {
@@ -295,6 +297,8 @@ int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
wanted_diff_mask, new_active,
active_diff_mask, compact);
}
+ if (mod)
+ ethtool_notify(dev, ETHTOOL_MSG_FEATURES_NTF, NULL);

out_rtnl:
rtnl_unlock();
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 757ea3fc98a0..5c0e361bfd66 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -528,6 +528,7 @@ ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = {
[ETHTOOL_MSG_LINKMODES_NTF] = &ethnl_linkmodes_request_ops,
[ETHTOOL_MSG_DEBUG_NTF] = &ethnl_debug_request_ops,
[ETHTOOL_MSG_WOL_NTF] = &ethnl_wol_request_ops,
+ [ETHTOOL_MSG_FEATURES_NTF] = &ethnl_features_request_ops,
};

/* default notification handler */
@@ -613,6 +614,7 @@ static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
[ETHTOOL_MSG_LINKMODES_NTF] = ethnl_default_notify,
[ETHTOOL_MSG_DEBUG_NTF] = ethnl_default_notify,
[ETHTOOL_MSG_WOL_NTF] = ethnl_default_notify,
+ [ETHTOOL_MSG_FEATURES_NTF] = ethnl_default_notify,
};

void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
@@ -630,6 +632,29 @@ void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
}
EXPORT_SYMBOL(ethtool_notify);

+static void ethnl_notify_features(struct netdev_notifier_info *info)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(info);
+
+ ethtool_notify(dev, ETHTOOL_MSG_FEATURES_NTF, NULL);
+}
+
+static int ethnl_netdev_event(struct notifier_block *this, unsigned long event,
+ void *ptr)
+{
+ switch (event) {
+ case NETDEV_FEAT_CHANGE:
+ ethnl_notify_features(ptr);
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block ethnl_netdev_notifier = {
+ .notifier_call = ethnl_netdev_event,
+};
+
/* genetlink setup */

static const struct genl_ops ethtool_genl_ops[] = {
@@ -736,7 +761,9 @@ static int __init ethnl_init(void)
return ret;
ethnl_ok = true;

- return 0;
+ ret = register_netdevice_notifier(&ethnl_netdev_notifier);
+ WARN(ret < 0, "ethtool: net device notifier registration failed");
+ return ret;
}

subsys_initcall(ethnl_init);
--
2.25.1