Wed, Oct 09, 2019 at 10:59:43PM CEST, mkubecek@suse.cz wrote:

Implement LINKINFO_SET netlink request to set link settings queried by
LINKINFO_GET message.

Only physical port, phy MDIO address and MDI(-X) control can be set,
attempt to modify MDI(-X) status and transceiver is rejected.

When any data is modified, ETHTOOL_MSG_LINKINFO_NTF message in the same
format as reply to LINKINFO_GET request is sent to notify userspace about
the changes. The same notification is also sent when these settings are
modified using the ioctl interface.

It is a bit confusing and harder to follow when you have set and notify
code in the same patch. Could you please split?

[...]

+/* LINKINFO_SET */
+
+static const struct nla_policy linkinfo_hdr_policy[ETHTOOL_A_HEADER_MAX + 1] = {
+	[ETHTOOL_A_HEADER_UNSPEC]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_HEADER_DEV_INDEX]		= { .type = NLA_U32 },
+	[ETHTOOL_A_HEADER_DEV_NAME]		= { .type = NLA_NUL_STRING,
+						    .len = IFNAMSIZ - 1 },
+	[ETHTOOL_A_HEADER_GFLAGS]		= { .type = NLA_U32 },
+	[ETHTOOL_A_HEADER_RFLAGS]		= { .type = NLA_REJECT },
+};

This is what I was talking about in the other email. These common attrs
should have common policy and should be parsed by generic netlink code
by default and be available for ethnl_set_linkinfo() in info->attrs.

+
+static const struct nla_policy
+linkinfo_set_policy[ETHTOOL_A_LINKINFO_MAX + 1] = {
+	[ETHTOOL_A_LINKINFO_UNSPEC]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_LINKINFO_HEADER]		= { .type = NLA_NESTED },
+	[ETHTOOL_A_LINKINFO_PORT]		= { .type = NLA_U8 },
+	[ETHTOOL_A_LINKINFO_PHYADDR]		= { .type = NLA_U8 },
+	[ETHTOOL_A_LINKINFO_TP_MDIX]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_LINKINFO_TP_MDIX_CTRL]	= { .type = NLA_U8 },
+	[ETHTOOL_A_LINKINFO_TRANSCEIVER]	= { .type = NLA_REJECT },
+};
+
+int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *tb[ETHTOOL_A_LINKINFO_MAX + 1];
+	struct ethtool_link_ksettings ksettings = {};
+	struct ethtool_link_settings *lsettings;
+	struct ethnl_req_info req_info = {};
+	struct net_device *dev;
+	bool mod = false;
+	int ret;
+
+	ret = nlmsg_parse(info->nlhdr, GENL_HDRLEN, tb,
+			  ETHTOOL_A_LINKINFO_MAX, linkinfo_set_policy,
+			  info->extack);

Yeah, genl code should do this parse..

+	if (ret < 0)
+		return ret;
+	ret = ethnl_parse_header(&req_info, tb[ETHTOOL_A_LINKINFO_HEADER],
+				 genl_info_net(info), info->extack,
+				 linkinfo_hdr_policy, true);

and pre_doit should do this one.

+	if (ret < 0)
+		return ret;
+	dev = req_info.dev;
+	if (!dev->ethtool_ops->get_link_ksettings ||
+	    !dev->ethtool_ops->set_link_ksettings)
+		return -EOPNOTSUPP;
+
+	rtnl_lock();
+	ret = ethnl_before_ops(dev);
+	if (ret < 0)
+		goto out_rtnl;
+
+	ret = __ethtool_get_link_ksettings(dev, &ksettings);
+	if (ret < 0) {
+		if (info)
+			GENL_SET_ERR_MSG(info, "failed to retrieve link settings");
+		goto out_ops;
+	}
+	lsettings = &ksettings.base;
+
+	ethnl_update_u8(&lsettings->port, tb[ETHTOOL_A_LINKINFO_PORT], &mod);
+	ethnl_update_u8(&lsettings->phy_address, tb[ETHTOOL_A_LINKINFO_PHYADDR],
+			&mod);
+	ethnl_update_u8(&lsettings->eth_tp_mdix_ctrl,
+			tb[ETHTOOL_A_LINKINFO_TP_MDIX_CTRL], &mod);
+
+	ret = 0;
+	if (mod) {

	if (!mod)
		goto out_ops;

?

Correct me if I'm wrong, but this is the only notification I found in
this patchset. Do you expect other then ethnl_std_notify() handler?
Bacause otherwise this can ba simplified down to just a single table
similar you have for GET.