[PATCH net-next v8 07/14] ethtool: provide link settings with LINKINFO_GET request

From: Michal Kubecek
Date: Sun Dec 22 2019 - 18:45:55 EST

Implement LINKINFO_GET netlink request to get basic link settings provided
by ETHTOOL_GLINKSETTINGS and ETHTOOL_GSET ioctl commands.

This request provides settings not directly related to autonegotiation and
link mode selection: physical port, phy MDIO address, MDI(-X) status,
MDI(-X) control and transceiver.

LINKINFO_GET request can be used with NLM_F_DUMP (without device
identification) to request the information for all devices in current
network namespace providing the data.

Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
---
Documentation/networking/ethtool-netlink.rst | 37 +++++++-
include/uapi/linux/ethtool_netlink.h | 18 ++++
net/ethtool/Makefile | 2 +-
net/ethtool/common.c | 48 ++++++++++
net/ethtool/common.h | 4 +
net/ethtool/ioctl.c | 48 ----------
net/ethtool/linkinfo.c | 94 ++++++++++++++++++++
net/ethtool/netlink.c | 8 ++
net/ethtool/netlink.h | 1 +
9 files changed, 209 insertions(+), 51 deletions(-)
create mode 100644 net/ethtool/linkinfo.c

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index afe0ee2ba138..3460d6e31b82 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -170,12 +170,14 @@ Userspace to kernel:

===================================== ================================
``ETHTOOL_MSG_STRSET_GET`` get string set
+ ``ETHTOOL_MSG_LINKINFO_GET`` get link settings
===================================== ================================

Kernel to userspace:

===================================== ================================
``ETHTOOL_MSG_STRSET_GET_REPLY`` string set contents
+ ``ETHTOOL_MSG_LINKINFO_GET_REPLY`` link settings
===================================== ================================

``GET`` requests are sent by userspace applications to retrieve device
@@ -268,6 +270,37 @@ Flag ``ETHTOOL_A_STRSET_COUNTS_ONLY`` tells kernel to only return string
counts of the sets, not the actual strings.


+LINKINFO_GET
+============
+
+Requests link settings as provided by ``ETHTOOL_GLINKSETTINGS`` except for
+link modes and autonegotiation related information. The request does not use
+any attributes.
+
+Request contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_LINKINFO_HEADER`` nested request header
+ ==================================== ====== ==========================
+
+Kernel response contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_LINKINFO_HEADER`` nested reply header
+ ``ETHTOOL_A_LINKINFO_PORT`` u8 physical port
+ ``ETHTOOL_A_LINKINFO_PHYADDR`` u8 phy MDIO address
+ ``ETHTOOL_A_LINKINFO_TP_MDIX`` u8 MDI(-X) status
+ ``ETHTOOL_A_LINKINFO_TP_MDIX_CTRL`` u8 MDI(-X) control
+ ``ETHTOOL_A_LINKINFO_TRANSCEIVER`` u8 transceiver
+ ==================================== ====== ==========================
+
+Attributes and their values have the same meaning as matching members of the
+corresponding ioctl structures.
+
+``LINKINFO_GET`` allows dump requests (kernel returns reply message for all
+devices supporting the request).
+
+
Request translation
===================

@@ -278,7 +311,7 @@ have their netlink replacement yet.
=================================== =====================================
ioctl command netlink command
=================================== =====================================
- ``ETHTOOL_GSET`` n/a
+ ``ETHTOOL_GSET`` ``ETHTOOL_MSG_LINKINFO_GET``
``ETHTOOL_SSET`` n/a
``ETHTOOL_GDRVINFO`` n/a
``ETHTOOL_GREGS`` n/a
@@ -352,7 +385,7 @@ have their netlink replacement yet.
``ETHTOOL_STUNABLE`` n/a
``ETHTOOL_GPHYSTATS`` n/a
``ETHTOOL_PERQUEUE`` n/a
- ``ETHTOOL_GLINKSETTINGS`` n/a
+ ``ETHTOOL_GLINKSETTINGS`` ``ETHTOOL_MSG_LINKINFO_GET``
``ETHTOOL_SLINKSETTINGS`` n/a
``ETHTOOL_PHY_GTUNABLE`` n/a
``ETHTOOL_PHY_STUNABLE`` n/a
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index cabef1fec42a..1966532993e5 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -15,6 +15,7 @@
enum {
ETHTOOL_MSG_USER_NONE,
ETHTOOL_MSG_STRSET_GET,
+ ETHTOOL_MSG_LINKINFO_GET,

/* add new constants above here */
__ETHTOOL_MSG_USER_CNT,
@@ -25,6 +26,7 @@ enum {
enum {
ETHTOOL_MSG_KERNEL_NONE,
ETHTOOL_MSG_STRSET_GET_REPLY,
+ ETHTOOL_MSG_LINKINFO_GET_REPLY,

/* add new constants above here */
__ETHTOOL_MSG_KERNEL_CNT,
@@ -141,6 +143,22 @@ enum {
ETHTOOL_A_STRSET_MAX = __ETHTOOL_A_STRSET_CNT - 1
};

+/* LINKINFO */
+
+enum {
+ ETHTOOL_A_LINKINFO_UNSPEC,
+ ETHTOOL_A_LINKINFO_HEADER, /* nest - _A_HEADER_* */
+ ETHTOOL_A_LINKINFO_PORT, /* u8 */
+ ETHTOOL_A_LINKINFO_PHYADDR, /* u8 */
+ ETHTOOL_A_LINKINFO_TP_MDIX, /* u8 */
+ ETHTOOL_A_LINKINFO_TP_MDIX_CTRL, /* u8 */
+ ETHTOOL_A_LINKINFO_TRANSCEIVER, /* u8 */
+
+ /* add new constants above here */
+ __ETHTOOL_A_LINKINFO_CNT,
+ ETHTOOL_A_LINKINFO_MAX = __ETHTOOL_A_LINKINFO_CNT - 1
+};
+
/* generic netlink info */
#define ETHTOOL_GENL_NAME "ethtool"
#define ETHTOOL_GENL_VERSION 1
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index efcc42c34d62..765736ec52c0 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -4,4 +4,4 @@ obj-y += ioctl.o common.o

obj-$(CONFIG_ETHTOOL_NETLINK) += ethtool_nl.o

-ethtool_nl-y := netlink.o bitset.o strset.o
+ethtool_nl-y := netlink.o bitset.o strset.o linkinfo.o
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 0a8728565356..1d4a0aeff2cb 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -169,3 +169,51 @@ const char link_mode_names[][ETH_GSTRING_LEN] = {
__DEFINE_LINK_MODE_NAME(400000, CR8, Full),
};
static_assert(ARRAY_SIZE(link_mode_names) == __ETHTOOL_LINK_MODE_MASK_NBITS);
+
+/* return false if legacy contained non-0 deprecated fields
+ * maxtxpkt/maxrxpkt. rest of ksettings always updated
+ */
+bool
+convert_legacy_settings_to_link_ksettings(
+ struct ethtool_link_ksettings *link_ksettings,
+ const struct ethtool_cmd *legacy_settings)
+{
+ bool retval = true;
+
+ memset(link_ksettings, 0, sizeof(*link_ksettings));
+
+ /* This is used to tell users that driver is still using these
+ * deprecated legacy fields, and they should not use
+ * %ETHTOOL_GLINKSETTINGS/%ETHTOOL_SLINKSETTINGS
+ */
+ if (legacy_settings->maxtxpkt ||
+ legacy_settings->maxrxpkt)
+ retval = false;
+
+ ethtool_convert_legacy_u32_to_link_mode(
+ link_ksettings->link_modes.supported,
+ legacy_settings->supported);
+ ethtool_convert_legacy_u32_to_link_mode(
+ link_ksettings->link_modes.advertising,
+ legacy_settings->advertising);
+ ethtool_convert_legacy_u32_to_link_mode(
+ link_ksettings->link_modes.lp_advertising,
+ legacy_settings->lp_advertising);
+ link_ksettings->base.speed
+ = ethtool_cmd_speed(legacy_settings);
+ link_ksettings->base.duplex
+ = legacy_settings->duplex;
+ link_ksettings->base.port
+ = legacy_settings->port;
+ link_ksettings->base.phy_address
+ = legacy_settings->phy_address;
+ link_ksettings->base.autoneg
+ = legacy_settings->autoneg;
+ link_ksettings->base.mdio_support
+ = legacy_settings->mdio_support;
+ link_ksettings->base.eth_tp_mdix
+ = legacy_settings->eth_tp_mdix;
+ link_ksettings->base.eth_tp_mdix_ctrl
+ = legacy_settings->eth_tp_mdix_ctrl;
+ return retval;
+}
diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index bbb788908cb1..c8a237402729 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -19,4 +19,8 @@ extern const char
phy_tunable_strings[__ETHTOOL_PHY_TUNABLE_COUNT][ETH_GSTRING_LEN];
extern const char link_mode_names[][ETH_GSTRING_LEN];

+bool convert_legacy_settings_to_link_ksettings(
+ struct ethtool_link_ksettings *link_ksettings,
+ const struct ethtool_cmd *legacy_settings);
+
#endif /* _ETHTOOL_COMMON_H */
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index aed2c2cf1623..eca7462e6263 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -358,54 +358,6 @@ bool ethtool_convert_link_mode_to_legacy_u32(u32 *legacy_u32,
}
EXPORT_SYMBOL(ethtool_convert_link_mode_to_legacy_u32);

-/* return false if legacy contained non-0 deprecated fields
- * maxtxpkt/maxrxpkt. rest of ksettings always updated
- */
-static bool
-convert_legacy_settings_to_link_ksettings(
- struct ethtool_link_ksettings *link_ksettings,
- const struct ethtool_cmd *legacy_settings)
-{
- bool retval = true;
-
- memset(link_ksettings, 0, sizeof(*link_ksettings));
-
- /* This is used to tell users that driver is still using these
- * deprecated legacy fields, and they should not use
- * %ETHTOOL_GLINKSETTINGS/%ETHTOOL_SLINKSETTINGS
- */
- if (legacy_settings->maxtxpkt ||
- legacy_settings->maxrxpkt)
- retval = false;
-
- ethtool_convert_legacy_u32_to_link_mode(
- link_ksettings->link_modes.supported,
- legacy_settings->supported);
- ethtool_convert_legacy_u32_to_link_mode(
- link_ksettings->link_modes.advertising,
- legacy_settings->advertising);
- ethtool_convert_legacy_u32_to_link_mode(
- link_ksettings->link_modes.lp_advertising,
- legacy_settings->lp_advertising);
- link_ksettings->base.speed
- = ethtool_cmd_speed(legacy_settings);
- link_ksettings->base.duplex
- = legacy_settings->duplex;
- link_ksettings->base.port
- = legacy_settings->port;
- link_ksettings->base.phy_address
- = legacy_settings->phy_address;
- link_ksettings->base.autoneg
- = legacy_settings->autoneg;
- link_ksettings->base.mdio_support
- = legacy_settings->mdio_support;
- link_ksettings->base.eth_tp_mdix
- = legacy_settings->eth_tp_mdix;
- link_ksettings->base.eth_tp_mdix_ctrl
- = legacy_settings->eth_tp_mdix_ctrl;
- return retval;
-}
-
/* return false if ksettings link modes had higher bits
* set. legacy_settings always updated (best effort)
*/
diff --git a/net/ethtool/linkinfo.c b/net/ethtool/linkinfo.c
new file mode 100644
index 000000000000..f52a31af6fff
--- /dev/null
+++ b/net/ethtool/linkinfo.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "netlink.h"
+#include "common.h"
+
+struct linkinfo_req_info {
+ struct ethnl_req_info base;
+};
+
+struct linkinfo_reply_data {
+ struct ethnl_reply_data base;
+ struct ethtool_link_ksettings ksettings;
+ struct ethtool_link_settings *lsettings;
+};
+
+#define LINKINFO_REPDATA(__reply_base) \
+ container_of(__reply_base, struct linkinfo_reply_data, base)
+
+static const struct nla_policy
+linkinfo_get_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_REJECT },
+ [ETHTOOL_A_LINKINFO_PHYADDR] = { .type = NLA_REJECT },
+ [ETHTOOL_A_LINKINFO_TP_MDIX] = { .type = NLA_REJECT },
+ [ETHTOOL_A_LINKINFO_TP_MDIX_CTRL] = { .type = NLA_REJECT },
+ [ETHTOOL_A_LINKINFO_TRANSCEIVER] = { .type = NLA_REJECT },
+};
+
+static int linkinfo_prepare_data(const struct ethnl_req_info *req_base,
+ struct ethnl_reply_data *reply_base,
+ struct genl_info *info)
+{
+ struct linkinfo_reply_data *data = LINKINFO_REPDATA(reply_base);
+ struct net_device *dev = reply_base->dev;
+ int ret;
+
+ data->lsettings = &data->ksettings.base;
+
+ ret = ethnl_ops_begin(dev);
+ if (ret < 0)
+ return ret;
+ ret = __ethtool_get_link_ksettings(dev, &data->ksettings);
+ if (ret < 0 && info)
+ GENL_SET_ERR_MSG(info, "failed to retrieve link settings");
+ ethnl_ops_complete(dev);
+
+ return ret;
+}
+
+static int linkinfo_reply_size(const struct ethnl_req_info *req_base,
+ const struct ethnl_reply_data *reply_base)
+{
+ return nla_total_size(sizeof(u8)) /* LINKINFO_PORT */
+ + nla_total_size(sizeof(u8)) /* LINKINFO_PHYADDR */
+ + nla_total_size(sizeof(u8)) /* LINKINFO_TP_MDIX */
+ + nla_total_size(sizeof(u8)) /* LINKINFO_TP_MDIX_CTRL */
+ + nla_total_size(sizeof(u8)) /* LINKINFO_TRANSCEIVER */
+ + 0;
+}
+
+static int linkinfo_fill_reply(struct sk_buff *skb,
+ const struct ethnl_req_info *req_base,
+ const struct ethnl_reply_data *reply_base)
+{
+ const struct linkinfo_reply_data *data = LINKINFO_REPDATA(reply_base);
+
+ if (nla_put_u8(skb, ETHTOOL_A_LINKINFO_PORT, data->lsettings->port) ||
+ nla_put_u8(skb, ETHTOOL_A_LINKINFO_PHYADDR,
+ data->lsettings->phy_address) ||
+ nla_put_u8(skb, ETHTOOL_A_LINKINFO_TP_MDIX,
+ data->lsettings->eth_tp_mdix) ||
+ nla_put_u8(skb, ETHTOOL_A_LINKINFO_TP_MDIX_CTRL,
+ data->lsettings->eth_tp_mdix_ctrl) ||
+ nla_put_u8(skb, ETHTOOL_A_LINKINFO_TRANSCEIVER,
+ data->lsettings->transceiver))
+ return -EMSGSIZE;
+
+ return 0;
+}
+
+const struct ethnl_request_ops ethnl_linkinfo_request_ops = {
+ .request_cmd = ETHTOOL_MSG_LINKINFO_GET,
+ .reply_cmd = ETHTOOL_MSG_LINKINFO_GET_REPLY,
+ .hdr_attr = ETHTOOL_A_LINKINFO_HEADER,
+ .max_attr = ETHTOOL_A_LINKINFO_MAX,
+ .req_info_size = sizeof(struct linkinfo_req_info),
+ .reply_data_size = sizeof(struct linkinfo_reply_data),
+ .request_policy = linkinfo_get_policy,
+
+ .prepare_data = linkinfo_prepare_data,
+ .reply_size = linkinfo_reply_size,
+ .fill_reply = linkinfo_fill_reply,
+};
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 7dc082bde670..ce86d97c922e 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -195,6 +195,7 @@ struct ethnl_dump_ctx {
static const struct ethnl_request_ops *
ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
[ETHTOOL_MSG_STRSET_GET] = &ethnl_strset_request_ops,
+ [ETHTOOL_MSG_LINKINFO_GET] = &ethnl_linkinfo_request_ops,
};

static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -526,6 +527,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
.dumpit = ethnl_default_dumpit,
.done = ethnl_default_done,
},
+ {
+ .cmd = ETHTOOL_MSG_LINKINFO_GET,
+ .doit = ethnl_default_doit,
+ .start = ethnl_default_start,
+ .dumpit = ethnl_default_dumpit,
+ .done = ethnl_default_done,
+ },
};

static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index c11b31dffd14..b2f4a49ae837 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -329,5 +329,6 @@ struct ethnl_request_ops {
/* request handlers */

extern const struct ethnl_request_ops ethnl_strset_request_ops;
+extern const struct ethnl_request_ops ethnl_linkinfo_request_ops;

#endif /* _NET_ETHTOOL_NETLINK_H */
--
2.24.1