[RFC PATCH net-next v3 16/21] ethtool: provide WoL information in GET_SETTINGS request

From: Michal Kubecek <mkubecek@suse.cz>
To: netdev@vger.kernel.org
Cc: David Miller <davem@davemloft.net>, Andrew Lunn <andrew@lunn.ch>,
	Jakub Kicinski <jakub.kicinski@netronome.com>,
	Jiri Pirko <jiri@resnulli.us>,
	linux-kernel@vger.kernel.org
Subject: [RFC PATCH net-next v3 16/21] ethtool: provide WoL information in GET_SETTINGS request
Date: Mon, 18 Feb 2019 19:22:44 +0100 (CET)	[thread overview]
Message-ID: <245dea0700fe52a3430958c1eab97f21a964c6ee.1550513384.git.mkubecek@suse.cz> (raw)
In-Reply-To: <cover.1550513384.git.mkubecek@suse.cz>

Add information about supported and enabled wake on LAN modes into the
GET_SETTINGS reply when ETH_SETTINGS_IM_WOLINFO flag is set in the request.

The GET_SETTINGS request can be still sent by unprivileged users but in
such case the SecureOn password (if any) is not included in the reply.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
---
 Documentation/networking/ethtool-netlink.txt | 13 ++++-
 include/uapi/linux/ethtool_netlink.h         | 13 ++++-
 net/ethtool/common.c                         | 10 ++++
 net/ethtool/common.h                         |  1 +
 net/ethtool/ioctl.c                          |  8 +--
 net/ethtool/settings.c                       | 61 ++++++++++++++++++++
 6 files changed, 100 insertions(+), 6 deletions(-)

diff --git a/Documentation/networking/ethtool-netlink.txt b/Documentation/networking/ethtool-netlink.txt
index 0ea7d89c6052..913df35cb762 100644
--- a/Documentation/networking/ethtool-netlink.txt
+++ b/Documentation/networking/ethtool-netlink.txt
@@ -283,6 +283,7 @@ Info mask bits meaning:
 
     ETH_SETTINGS_IM_LINKINFO		link_ksettings except link modes
     ETH_SETTINGS_IM_LINKMODES		link modes from link_ksettings
+    ETH_SETTINGS_IM_WOLINFO		struct ethtool_wolinfo
 
 Response contents:
 
@@ -298,12 +299,22 @@ Response contents:
         ETHA_LINKINFO_TRANSCEIVER	(u8)		transceiver
     ETHA_SETTINGS_LINK_MODES	(bitset)	device link modes
     ETHA_SETTINGS_PEER_MODES	(bitset)	link partner link modes
+    ETHA_SETTINGS_WOL		(nested)	wake on LAN settings
+        ETHA_WOL_MODES			(bitfield32)	wake on LAN modes
+        ETHA_WOL_SOPASS			(binary)	SecureOn(tm) password
 
 Most of the attributes and their values have the same meaning as matching
 members of the corresponding ioctl structures. For ETHA_SETTINGS_LINK_MODES,
 value represents advertised modes and mask represents supported modes.
 ETHA_SETTINGS_PEER_MODES in the reply is a bit list.
 
+For ETHA_WOL_MODES, selector reports wake on LAN modes supported by the
+device and value enabled modes.
+
+GET_SETTINGS request is allowed for unprivileged user but ETHA_SETTINGS_SOPASS
+is only provided by kernel in response to privileged (netns CAP_NET_ADMIN)
+requests.
+
 GET_SETTINGS requests allow dumps and messages in the same format as response
 to them are broadcasted as notifications on change of these settings using
 netlink or ioctl ethtool interface.
@@ -322,7 +333,7 @@ ETHTOOL_GSET			ETHNL_CMD_GET_SETTINGS
 ETHTOOL_SSET			n/a
 ETHTOOL_GDRVINFO		ETHNL_CMD_GET_INFO
 ETHTOOL_GREGS			n/a
-ETHTOOL_GWOL			n/a
+ETHTOOL_GWOL			ETHNL_CMD_GET_SETTINGS
 ETHTOOL_SWOL			n/a
 ETHTOOL_GMSGLVL			n/a
 ETHTOOL_SMSGLVL			n/a
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 4e1fa4a06aac..ce9d6b48f814 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -201,6 +201,7 @@ enum {
 	ETHA_SETTINGS_LINK_INFO,		/* nested */
 	ETHA_SETTINGS_LINK_MODES,		/* bitset */
 	ETHA_SETTINGS_PEER_MODES,		/* bitset */
+	ETHA_SETTINGS_WOL,			/* nested */
 
 	__ETHA_SETTINGS_CNT,
 	ETHA_SETTINGS_MAX = (__ETHA_SETTINGS_CNT - 1)
@@ -208,8 +209,9 @@ enum {
 
 #define ETH_SETTINGS_IM_LINKINFO		0x01
 #define ETH_SETTINGS_IM_LINKMODES		0x02
+#define ETH_SETTINGS_IM_WOLINFO			0x04
 
-#define ETH_SETTINGS_IM_ALL			0x03
+#define ETH_SETTINGS_IM_ALL			0x07
 
 enum {
 	ETHA_LINKINFO_UNSPEC,
@@ -226,6 +228,15 @@ enum {
 	ETHA_LINKINFO_MAX = (__ETHA_LINKINFO_CNT - 1)
 };
 
+enum {
+	ETHA_WOL_UNSPEC,
+	ETHA_WOL_MODES,				/* bitfield32 */
+	ETHA_WOL_SOPASS,			/* binary */
+
+	__ETHA_WOL_CNT,
+	ETHA_WOL_MAX = (__ETHA_WOL_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 3316e9e403c9..9fba57f554dd 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -207,3 +207,13 @@ convert_legacy_settings_to_link_ksettings(
 		= legacy_settings->eth_tp_mdix_ctrl;
 	return retval;
 }
+
+int __ethtool_get_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
+{
+	if (!dev->ethtool_ops->get_wol)
+		return -EOPNOTSUPP;
+
+	dev->ethtool_ops->get_wol(dev, wol);
+
+	return 0;
+}
diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index 7a3e0b10e69a..ed3f1ca54660 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -17,6 +17,7 @@ phy_tunable_strings[__ETHTOOL_PHY_TUNABLE_COUNT][ETH_GSTRING_LEN];
 
 int __ethtool_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info);
 int __ethtool_get_ts_info(struct net_device *dev, struct ethtool_ts_info *info);
+int __ethtool_get_wol(struct net_device *dev, struct ethtool_wolinfo *wol);
 
 bool convert_legacy_settings_to_link_ksettings(
 	struct ethtool_link_ksettings *link_ksettings,
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 5e878cf6f418..945eaf551a4c 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1230,11 +1230,11 @@ static int ethtool_reset(struct net_device *dev, char __user *useraddr)
 static int ethtool_get_wol(struct net_device *dev, char __user *useraddr)
 {
 	struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
+	int rc;
 
-	if (!dev->ethtool_ops->get_wol)
-		return -EOPNOTSUPP;
-
-	dev->ethtool_ops->get_wol(dev, &wol);
+	rc = __ethtool_get_wol(dev, &wol);
+	if (rc < 0)
+		return rc;
 
 	if (copy_to_user(useraddr, &wol, sizeof(wol)))
 		return -EFAULT;
diff --git a/net/ethtool/settings.c b/net/ethtool/settings.c
index 4f2858fe1a7d..d296625edb2b 100644
--- a/net/ethtool/settings.c
+++ b/net/ethtool/settings.c
@@ -6,11 +6,13 @@
 
 struct settings_data {
 	struct common_req_info		reqinfo_base;
+	bool				privileged;
 
 	/* everything below here will be reset for each device in dumps */
 	struct common_reply_data	repdata_base;
 	struct ethtool_link_ksettings	ksettings;
 	struct ethtool_link_settings	*lsettings;
+	struct ethtool_wolinfo		wolinfo;
 	bool				lpm_empty;
 };
 
@@ -22,15 +24,20 @@ static const struct nla_policy get_settings_policy[ETHA_SETTINGS_MAX + 1] = {
 	[ETHA_SETTINGS_LINK_INFO]	= { .type = NLA_REJECT },
 	[ETHA_SETTINGS_LINK_MODES]	= { .type = NLA_REJECT },
 	[ETHA_SETTINGS_PEER_MODES]	= { .type = NLA_REJECT },
+	[ETHA_SETTINGS_WOL]		= { .type = NLA_REJECT },
 };
 
 static int parse_settings(struct common_req_info *req_info,
 			  struct sk_buff *skb, struct genl_info *info,
 			  const struct nlmsghdr *nlhdr)
 {
+	struct settings_data *data =
+		container_of(req_info, struct settings_data, reqinfo_base);
 	struct nlattr *tb[ETHA_SETTINGS_MAX + 1];
 	int ret;
 
+	data->privileged = ethnl_is_privileged(skb);
+
 	ret = genlmsg_parse(nlhdr, &ethtool_genl_family, tb,
 			    ETHA_SETTINGS_MAX, get_settings_policy,
 			    info ? info->extack : NULL);
@@ -68,6 +75,16 @@ static int ethnl_get_link_ksettings(struct genl_info *info,
 	return ret;
 }
 
+static int ethnl_get_wol(struct genl_info *info, struct net_device *dev,
+			 struct ethtool_wolinfo *wolinfo)
+{
+	int ret = __ethtool_get_wol(dev, wolinfo);
+
+	if (ret < 0)
+		ETHNL_SET_ERRMSG(info, "failed to retrieve wol info");
+	return ret;
+}
+
 static int prepare_settings(struct common_req_info *req_info,
 			    struct genl_info *info)
 {
@@ -100,6 +117,11 @@ static int prepare_settings(struct common_req_info *req_info,
 		ethnl_bitmap_to_u32(data->ksettings.link_modes.lp_advertising,
 				    __ETHTOOL_LINK_MODE_MASK_NWORDS);
 	}
+	if (req_mask & ETH_SETTINGS_IM_WOLINFO) {
+		ret = ethnl_get_wol(info, dev, &data->wolinfo);
+		if (ret < 0)
+			req_mask &= ~ETH_SETTINGS_IM_WOLINFO;
+	}
 	ethnl_after_ops(dev);
 
 	data->repdata_base.info_mask = req_mask;
@@ -147,6 +169,12 @@ static int link_modes_size(const struct ethtool_link_ksettings *ksettings,
 	return len;
 }
 
+static int wol_size(void)
+{
+	return nla_total_size(nla_total_size(sizeof(struct nla_bitfield32)) +
+			      nla_total_size(SOPASS_MAX));
+}
+
 /* To keep things simple, reserve space for some attributes which may not
  * be added to the message (e.g. ETHA_SETTINGS_SOPASS); therefore the length
  * returned may be bigger than the actual length of the message sent
@@ -168,6 +196,8 @@ static int settings_size(const struct common_req_info *req_info)
 			return ret;
 		len += ret;
 	}
+	if (info_mask & ETH_SETTINGS_IM_WOLINFO)
+		len += wol_size();
 
 	return len;
 }
@@ -227,6 +257,32 @@ static int fill_link_modes(struct sk_buff *skb,
 	return 0;
 }
 
+static int fill_wolinfo(struct sk_buff *skb,
+			const struct ethtool_wolinfo *wolinfo, bool privileged)
+{
+	struct nlattr *nest = ethnl_nest_start(skb, ETHA_SETTINGS_WOL);
+
+	if (!nest)
+		return -EMSGSIZE;
+	if (nla_put_bitfield32(skb, ETHA_WOL_MODES, wolinfo->wolopts,
+			       wolinfo->supported))
+		goto err;
+	/* ioctl() restricts read access to wolinfo but the actual
+	 * reason is to hide sopass from unprivileged users; netlink
+	 * can show wol modes without sopass
+	 */
+	if (privileged &&
+	    nla_put(skb, ETHA_WOL_SOPASS, sizeof(wolinfo->sopass),
+		    wolinfo->sopass))
+		goto err;
+	nla_nest_end(skb, nest);
+	return 0;
+
+err:
+	nla_nest_cancel(skb, nest);
+	return -EMSGSIZE;
+}
+
 static int fill_settings(struct sk_buff *skb,
 			 const struct common_req_info *req_info)
 {
@@ -247,6 +303,11 @@ static int fill_settings(struct sk_buff *skb,
 		if (ret < 0)
 			return ret;
 	}
+	if (info_mask & ETH_SETTINGS_IM_WOLINFO) {
+		ret = fill_wolinfo(skb, &data->wolinfo, data->privileged);
+		if (ret < 0)
+			return ret;
+	}
 
 	return 0;
 }
-- 
2.20.1

