[PATCH net-next v4 18/22] ethtool: provide link state in GET_SETTINGS request

From: Michal Kubecek
Date: Thu Mar 21 2019 - 09:41:20 EST

Add information about device link state (as provided by ETHTOOL_GLINK ioctl
command) into the GET_SETTINGS reply when ETH_SETTINGS_IM_LINKSTATE flag is
set in the request.

Note: we cannot use NLA_FLAG for link state as we need three states: off,
on and unknown. The attribute is also encapsulated in a nest to allow
future extensions.

Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
---
Documentation/networking/ethtool-netlink.txt | 5 ++-
include/uapi/linux/ethtool_netlink.h | 13 ++++++-
net/ethtool/common.c | 8 +++++
net/ethtool/common.h | 1 +
net/ethtool/ioctl.c | 8 ++---
net/ethtool/settings.c | 37 ++++++++++++++++++++
6 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/Documentation/networking/ethtool-netlink.txt b/Documentation/networking/ethtool-netlink.txt
index e79ae9fe01be..ebd1a0404828 100644
--- a/Documentation/networking/ethtool-netlink.txt
+++ b/Documentation/networking/ethtool-netlink.txt
@@ -277,6 +277,7 @@ Info mask bits meaning:

ETH_SETTINGS_IM_LINKINFO link settings
ETH_SETTINGS_IM_LINKMODES link modes and related
+ ETH_SETTINGS_IM_LINKSTATE link state

Response contents:

@@ -293,6 +294,8 @@ Response contents:
ETHA_LINKMODES_PEER (bitset) partner link modes
ETHA_LINKMODES_SPEED (u32) link speed (Mb/s)
ETHA_LINKMODES_DUPLEX (u8) duplex mode
+ ETHA_SETTINGS_LINK_STATE (nested) link state
+ ETHA_LINKSTATE_LINK (u8) link on/off/unknown

Most of the attributes and their values have the same meaning as matching
members of the corresponding ioctl structures. For ETHA_LINKMODES_OURS,
@@ -350,7 +353,7 @@ ETHTOOL_SWOL n/a
ETHTOOL_GMSGLVL n/a
ETHTOOL_SMSGLVL n/a
ETHTOOL_NWAY_RST n/a
-ETHTOOL_GLINK n/a
+ETHTOOL_GLINK ETHNL_CMD_GET_SETTINGS
ETHTOOL_GEEPROM n/a
ETHTOOL_SEEPROM n/a
ETHTOOL_GCOALESCE n/a
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 895ba9cd8924..45c27c7291d0 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -196,6 +196,7 @@ enum {
ETHA_SETTINGS_COMPACT, /* flag */
ETHA_SETTINGS_LINK_INFO, /* nest - ETHA_LINKINFO_* */
ETHA_SETTINGS_LINK_MODES, /* nest - ETHA_LINKMODES_* */
+ ETHA_SETTINGS_LINK_STATE, /* nest - ETHA_LINKSTATE_* */

__ETHA_SETTINGS_CNT,
ETHA_SETTINGS_MAX = (__ETHA_SETTINGS_CNT - 1)
@@ -203,9 +204,11 @@ enum {

#define ETH_SETTINGS_IM_LINKINFO (1U << 0)
#define ETH_SETTINGS_IM_LINKMODES (1U << 1)
+#define ETH_SETTINGS_IM_LINKSTATE (1U << 2)

#define ETH_SETTINGS_IM_ALL (ETH_SETTINGS_IM_LINKINFO | \
- ETH_SETTINGS_IM_LINKMODES)
+ ETH_SETTINGS_IM_LINKMODES | \
+ ETH_SETTINGS_IM_LINKSTATE)

enum {
ETHA_LINKINFO_UNSPEC,
@@ -231,6 +234,14 @@ enum {
ETHA_LINKMODES_MAX = (__ETHA_LINKMODES_CNT - 1)
};

+enum {
+ ETHA_LINKSTATE_UNSPEC,
+ ETHA_LINKSTATE_LINK, /* u8 */
+
+ __ETHA_LINKSTATE_CNT,
+ ETHA_LINKSTATE_MAX = (__ETHA_LINKSTATE_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 a91a4f00d275..dc907d8b6e43 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -205,3 +205,11 @@ convert_legacy_settings_to_link_ksettings(
= legacy_settings->eth_tp_mdix_ctrl;
return retval;
}
+
+int __ethtool_get_link(struct net_device *dev)
+{
+ if (!dev->ethtool_ops->get_link)
+ return -EOPNOTSUPP;
+
+ return netif_running(dev) && dev->ethtool_ops->get_link(dev);
+}
diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index 7a3e0b10e69a..a5ddd7f5cfce 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_link(struct net_device *dev);

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 be3e34ac8cc7..58669dafeaf9 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1318,12 +1318,12 @@ static int ethtool_nway_reset(struct net_device *dev)
static int ethtool_get_link(struct net_device *dev, char __user *useraddr)
{
struct ethtool_value edata = { .cmd = ETHTOOL_GLINK };
+ int link = __ethtool_get_link(dev);

- if (!dev->ethtool_ops->get_link)
- return -EOPNOTSUPP;
-
- edata.data = netif_running(dev) && dev->ethtool_ops->get_link(dev);
+ if (link < 0)
+ return link;

+ edata.data = link;
if (copy_to_user(useraddr, &edata, sizeof(edata)))
return -EFAULT;
return 0;
diff --git a/net/ethtool/settings.c b/net/ethtool/settings.c
index 2e0f425029ef..7a2729f01f79 100644
--- a/net/ethtool/settings.c
+++ b/net/ethtool/settings.c
@@ -11,6 +11,7 @@ struct settings_data {
struct common_reply_data repdata_base;
struct ethtool_link_ksettings ksettings;
struct ethtool_link_settings *lsettings;
+ int link;
bool lpm_empty;
};

@@ -112,6 +113,7 @@ static const struct nla_policy get_settings_policy[ETHA_SETTINGS_MAX + 1] = {
[ETHA_SETTINGS_COMPACT] = { .type = NLA_FLAG },
[ETHA_SETTINGS_LINK_INFO] = { .type = NLA_REJECT },
[ETHA_SETTINGS_LINK_MODES] = { .type = NLA_REJECT },
+ [ETHA_SETTINGS_LINK_STATE] = { .type = NLA_REJECT },
};

static int parse_settings(struct common_req_info *req_info,
@@ -168,6 +170,7 @@ static int prepare_settings(struct common_req_info *req_info,

data->lsettings = &data->ksettings.base;
data->lpm_empty = true;
+ data->link = -EOPNOTSUPP;

ret = ethnl_before_ops(dev);
if (ret < 0)
@@ -189,6 +192,8 @@ 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_LINKSTATE)
+ data->link = __ethtool_get_link(dev);
ethnl_after_ops(dev);

data->repdata_base.info_mask = req_mask;
@@ -237,6 +242,13 @@ static int link_modes_size(const struct ethtool_link_ksettings *ksettings,
return nla_total_size(len);
}

+static int link_state_size(int link)
+{
+ if (link < 0)
+ return nla_total_size(0);
+ return nla_total_size(nla_total_size(sizeof(u8)));
+}
+
/* 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
@@ -258,6 +270,8 @@ static int settings_size(const struct common_req_info *req_info)
return ret;
len += ret;
}
+ if (info_mask & ETH_SETTINGS_IM_LINKSTATE)
+ len += link_state_size(data->link);

return len;
}
@@ -330,6 +344,23 @@ static int fill_link_modes(struct sk_buff *skb,
return -EMSGSIZE;
}

+static int fill_link_state(struct sk_buff *skb, u8 link)
+{
+ struct nlattr *nest;
+
+ nest = ethnl_nest_start(skb, ETHA_SETTINGS_LINK_STATE);
+ if (!nest)
+ return -EMSGSIZE;
+ if (link >=0 && nla_put_u8(skb, ETHA_LINKSTATE_LINK, link))
+ 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)
{
@@ -350,6 +381,11 @@ static int fill_settings(struct sk_buff *skb,
if (ret < 0)
return ret;
}
+ if (info_mask & ETH_SETTINGS_IM_LINKSTATE) {
+ ret = fill_link_state(skb, data->link);
+ if (ret < 0)
+ return ret;
+ }

return 0;
}
@@ -394,6 +430,7 @@ static const struct nla_policy set_settings_policy[ETHA_SETTINGS_MAX + 1] = {
[ETHA_SETTINGS_COMPACT] = { .type = NLA_FLAG },
[ETHA_SETTINGS_LINK_INFO] = { .type = NLA_NESTED },
[ETHA_SETTINGS_LINK_MODES] = { .type = NLA_NESTED },
+ [ETHA_SETTINGS_LINK_STATE] = { .type = NLA_REJECT },
};

static int ethnl_set_link_ksettings(struct genl_info *info,
--
2.21.0