[PATCH net-next v7 14/17] ethtool: set link settings with LINKINFO_SET request

Michal Kubecek
2019-10-09T20:59:49Z

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.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
---
Documentation/networking/ethtool-netlink.rst | 25 +++++-
include/uapi/linux/ethtool_netlink.h | 2 +
net/ethtool/ioctl.c | 12 ++-
net/ethtool/linkinfo.c | 83 ++++++++++++++++++++
net/ethtool/netlink.c | 11 +++
net/ethtool/netlink.h | 2 +
6 files changed, 131 insertions(+), 4 deletions(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 0d21469debec..48833b6092d9 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -168,6 +168,7 @@ Userspace to kernel:
===================================== ================================
``ETHTOOL_MSG_STRSET_GET`` get string set
``ETHTOOL_MSG_LINKINFO_GET`` get link settings
+ ``ETHTOOL_MSG_LINKINFO_SET`` set link settings
===================================== ================================

Kernel to userspace:
@@ -175,6 +176,7 @@ Kernel to userspace:
===================================== ================================
``ETHTOOL_MSG_STRSET_GET_REPLY`` string set contents
``ETHTOOL_MSG_LINKINFO_GET_REPLY`` link settings
+ ``ETHTOOL_MSG_LINKINFO_NTF`` link settings notification
===================================== ================================

``GET`` requests are sent by userspace applications to retrieve device
@@ -300,6 +302,25 @@ corresponding ioctl structures.
devices supporting the request).

+LINKINFO_SET
+============
+
+``LINKINFO_SET`` request allows setting some of the attributes reported by
+``LINKINFO_GET``. and The request has no request specific flags.
+
+Request contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_LINKINFO_HEADER`` nested request header
+ ``ETHTOOL_A_LINKINFO_PORT`` u8 physical port
+ ``ETHTOOL_A_LINKINFO_PHYADDR`` u8 phy MDIO address
+ ``ETHTOOL_A_LINKINFO_TP_MDIX_CTRL`` u8 MDI(-X) control
+ ==================================== ====== ==========================
+
+MDI(-X) status and transceiver cannot be set, request with the corresponding
+attributes is rejected.
+
+
Request translation
===================

@@ -311,7 +332,7 @@ have their netlink replacement yet.
ioctl command netlink command
=================================== =====================================
``ETHTOOL_GSET`` ``ETHTOOL_MSG_LINKINFO_GET``
- ``ETHTOOL_SSET`` n/a
+ ``ETHTOOL_SSET`` ``ETHTOOL_MSG_LINKINFO_SET``
``ETHTOOL_GDRVINFO`` n/a
``ETHTOOL_GREGS`` n/a
``ETHTOOL_GWOL`` n/a
@@ -385,7 +406,7 @@ have their netlink replacement yet.
``ETHTOOL_GPHYSTATS`` n/a
``ETHTOOL_PERQUEUE`` n/a
``ETHTOOL_GLINKSETTINGS`` ``ETHTOOL_MSG_LINKINFO_GET``
- ``ETHTOOL_SLINKSETTINGS`` n/a
+ ``ETHTOOL_SLINKSETTINGS`` ``ETHTOOL_MSG_LINKINFO_SET``
``ETHTOOL_PHY_GTUNABLE`` n/a
``ETHTOOL_PHY_STUNABLE`` n/a
``ETHTOOL_GFECPARAM`` n/a
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 56ab2a530d22..78ee5584d5da 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -16,6 +16,7 @@ enum {
ETHTOOL_MSG_USER_NONE,
ETHTOOL_MSG_STRSET_GET,
ETHTOOL_MSG_LINKINFO_GET,
+ ETHTOOL_MSG_LINKINFO_SET,

/* add new constants above here */
__ETHTOOL_MSG_USER_CNT,
@@ -27,6 +28,7 @@ enum {
ETHTOOL_MSG_KERNEL_NONE,
ETHTOOL_MSG_STRSET_GET_REPLY,
ETHTOOL_MSG_LINKINFO_GET_REPLY,
+ ETHTOOL_MSG_LINKINFO_NTF,

/* add new constants above here */
__ETHTOOL_MSG_KERNEL_CNT,
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 2cd04cb6b4b9..0747fe6b5f4c 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -26,6 +26,7 @@
#include <net/devlink.h>
#include <net/xdp_sock.h>
#include <net/flow_offload.h>
+#include <linux/ethtool_netlink.h>

#include "common.h"

@@ -565,7 +566,10 @@ static int ethtool_set_link_ksettings(struct net_device *dev,
!= link_ksettings.base.link_mode_masks_nwords)
return -EINVAL;

- return dev->ethtool_ops->set_link_ksettings(dev, &link_ksettings);
+ err = dev->ethtool_ops->set_link_ksettings(dev, &link_ksettings);
+ if (err >= 0)
+ ethtool_notify(dev, ETHTOOL_MSG_LINKINFO_NTF, NULL);
+ return err;
}

/* Query device for its ethtool_cmd settings.
@@ -614,6 +618,7 @@ static int ethtool_set_settings(struct net_device *dev, void __user *useraddr)
{
struct ethtool_link_ksettings link_ksettings;
struct ethtool_cmd cmd;
+ int ret;

ASSERT_RTNL();

@@ -626,7 +631,10 @@ static int ethtool_set_settings(struct net_device *dev, void __user *useraddr)
return -EINVAL;
link_ksettings.base.link_mode_masks_nwords =
__ETHTOOL_LINK_MODE_MASK_NU32;
- return dev->ethtool_ops->set_link_ksettings(dev, &link_ksettings);
+ ret = dev->ethtool_ops->set_link_ksettings(dev, &link_ksettings);
+ if (ret >= 0)
+ ethtool_notify(dev, ETHTOOL_MSG_LINKINFO_NTF, NULL);
+ return ret;
}

static noinline_for_stack int ethtool_get_drvinfo(struct net_device *dev,
diff --git a/net/ethtool/linkinfo.c b/net/ethtool/linkinfo.c
index c28ca4d9dd2a..ea1997b154f0 100644
--- a/net/ethtool/linkinfo.c
+++ b/net/ethtool/linkinfo.c
@@ -95,3 +95,86 @@ const struct get_request_ops linkinfo_request_ops = {
.reply_size = linkinfo_size,
.fill_reply = linkinfo_fill,
};
+
+/* 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 },
+};
+
+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);
+ 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);
+ 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) {
+ ret = dev->ethtool_ops->set_link_ksettings(dev, &ksettings);
+ if (ret < 0)
+ GENL_SET_ERR_MSG(info, "link settings update failed");
+ else
+ ethtool_notify(dev, ETHTOOL_MSG_LINKINFO_NTF, NULL);
+ }
+
+out_ops:
+ ethnl_after_ops(dev);
+out_rtnl:
+ rtnl_unlock();
+ dev_put(dev);
+ return ret;
+}
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index dc52d912e0dd..5b9d12656e97 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -603,6 +603,11 @@ static int ethnl_get_done(struct netlink_callback *cb)

static const struct get_request_ops *ethnl_std_notify_to_ops(unsigned int cmd)
{
+ switch (cmd) {
+ case ETHTOOL_MSG_LINKINFO_NTF:
+ return &linkinfo_request_ops;
+ };
+
WARN_ONCE(1, "unexpected notification type %u\n", cmd);
return NULL;
}
@@ -683,6 +688,7 @@ typedef void (*ethnl_notify_handler_t)(struct net_device *dev, unsigned int cmd,
const void *data);

static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
+ [ETHTOOL_MSG_LINKINFO_NTF] = ethnl_std_notify,
};

void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
@@ -717,6 +723,11 @@ static const struct genl_ops ethtool_genl_ops[] = {
.dumpit = ethnl_get_dumpit,
.done = ethnl_get_done,
},
+ {
+ .cmd = ETHTOOL_MSG_LINKINFO_SET,
+ .flags = GENL_UNS_ADMIN_PERM,
+ .doit = ethnl_set_linkinfo,
+ },
};

static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 23e82a4dd265..ca136dd7ea02 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -350,4 +350,6 @@ struct get_request_ops {
extern const struct get_request_ops strset_request_ops;
extern const struct get_request_ops linkinfo_request_ops;

+int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info);
+
#endif /* _NET_ETHTOOL_NETLINK_H */
--
2.23.0