ethtool: provide link state with LINKSTATE_GET request

Implement LINKSTATE_GET netlink request to get link state information.

At the moment, only link up flag as provided by ETHTOOL_GLINK ioctl command
is returned.

LINKSTATE_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@suse.cz>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 9d96d51..c60afba 100644 (file)
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -184,6 +184,7 @@ Userspace to kernel:
   ``ETHTOOL_MSG_LINKINFO_SET``          set link settings
   ``ETHTOOL_MSG_LINKMODES_GET``         get link modes info
   ``ETHTOOL_MSG_LINKMODES_SET``         set link modes info
+  ``ETHTOOL_MSG_LINKSTATE_GET``         get link state
   ===================================== ================================
 
 Kernel to userspace:
@@ -194,6 +195,7 @@ Kernel to userspace:
   ``ETHTOOL_MSG_LINKINFO_NTF``          link settings notification
   ``ETHTOOL_MSG_LINKMODES_GET_REPLY``   link modes info
   ``ETHTOOL_MSG_LINKMODES_NTF``         link modes notification
+  ``ETHTOOL_MSG_LINKSTATE_GET_REPLY``   link state info
   ===================================== ================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
@@ -392,6 +394,35 @@ is supposed to allow requesting changes without knowing what exactly kernel
 supports.
 
 
+LINKSTATE_GET
+=============
+
+Requests link state information. At the moment, only link up/down flag (as
+provided by ``ETHTOOL_GLINK`` ioctl command) is provided but some future
+extensions are planned (e.g. link down reason). This request does not have any
+attributes.
+
+Request contents:
+
+  ====================================  ======  ==========================
+  ``ETHTOOL_A_LINKSTATE_HEADER``        nested  request header
+  ====================================  ======  ==========================
+
+Kernel response contents:
+
+  ====================================  ======  ==========================
+  ``ETHTOOL_A_LINKSTATE_HEADER``        nested  reply header
+  ``ETHTOOL_A_LINKSTATE_LINK``          bool    link state (up/down)
+  ====================================  ======  ==========================
+
+For most NIC drivers, the value of ``ETHTOOL_A_LINKSTATE_LINK`` returns
+carrier flag provided by ``netif_carrier_ok()`` but there are drivers which
+define their own handler.
+
+``LINKSTATE_GET`` allows dump requests (kernel returns reply messages for all
+devices supporting the request).
+
+
 Request translation
 ===================
 
@@ -413,7 +444,7 @@ have their netlink replacement yet.
   ``ETHTOOL_GMSGLVL``                 n/a
   ``ETHTOOL_SMSGLVL``                 n/a
   ``ETHTOOL_NWAY_RST``                n/a
-  ``ETHTOOL_GLINK``                   n/a
+  ``ETHTOOL_GLINK``                   ``ETHTOOL_MSG_LINKSTATE_GET``
   ``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 35948df..02f82f4 100644 (file)
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -19,6 +19,7 @@ enum {
        ETHTOOL_MSG_LINKINFO_SET,
        ETHTOOL_MSG_LINKMODES_GET,
        ETHTOOL_MSG_LINKMODES_SET,
+       ETHTOOL_MSG_LINKSTATE_GET,
 
        /* add new constants above here */
        __ETHTOOL_MSG_USER_CNT,
@@ -33,6 +34,7 @@ enum {
        ETHTOOL_MSG_LINKINFO_NTF,
        ETHTOOL_MSG_LINKMODES_GET_REPLY,
        ETHTOOL_MSG_LINKMODES_NTF,
+       ETHTOOL_MSG_LINKSTATE_GET_REPLY,
 
        /* add new constants above here */
        __ETHTOOL_MSG_KERNEL_CNT,
@@ -181,6 +183,18 @@ enum {
        ETHTOOL_A_LINKMODES_MAX = __ETHTOOL_A_LINKMODES_CNT - 1
 };
 
+/* LINKSTATE */
+
+enum {
+       ETHTOOL_A_LINKSTATE_UNSPEC,
+       ETHTOOL_A_LINKSTATE_HEADER,             /* nest - _A_HEADER_* */
+       ETHTOOL_A_LINKSTATE_LINK,               /* u8 */
+
+       /* add new constants above here */
+       __ETHTOOL_A_LINKSTATE_CNT,
+       ETHTOOL_A_LINKSTATE_MAX = __ETHTOOL_A_LINKSTATE_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 8023da6..9a1332f 100644 (file)
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -4,4 +4,5 @@ obj-y                           += ioctl.o common.o
 
 obj-$(CONFIG_ETHTOOL_NETLINK)  += ethtool_nl.o
 
-ethtool_nl-y   := netlink.o bitset.o strset.o linkinfo.o linkmodes.o
+ethtool_nl-y   := netlink.o bitset.o strset.o linkinfo.o linkmodes.o \
+                  linkstate.o

diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 1d4a0ae..e621b16 100644 (file)
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -217,3 +217,11 @@ 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 c8a2374..5c5f7dc 100644 (file)
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -3,6 +3,7 @@
 #ifndef _ETHTOOL_COMMON_H
 #define _ETHTOOL_COMMON_H
 
+#include <linux/netdevice.h>
 #include <linux/ethtool.h>
 
 /* compose link mode index from speed, type and duplex */
@@ -19,6 +20,8 @@ extern const char
 phy_tunable_strings[__ETHTOOL_PHY_TUNABLE_COUNT][ETH_GSTRING_LEN];
 extern const char link_mode_names[][ETH_GSTRING_LEN];
 
+int __ethtool_get_link(struct net_device *dev);
+
 bool convert_legacy_settings_to_link_ksettings(
        struct ethtool_link_ksettings *link_ksettings,
        const struct ethtool_cmd *legacy_settings);

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 36e2ef2..182bffb 100644 (file)
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1365,12 +1365,12 @@ 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/linkstate.c b/net/ethtool/linkstate.c
new file mode 100644 (file)
index 0000000..2740cde
--- /dev/null
+++ b/net/ethtool/linkstate.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "netlink.h"
+#include "common.h"
+
+struct linkstate_req_info {
+       struct ethnl_req_info           base;
+};
+
+struct linkstate_reply_data {
+       struct ethnl_reply_data         base;
+       int                             link;
+};
+
+#define LINKSTATE_REPDATA(__reply_base) \
+       container_of(__reply_base, struct linkstate_reply_data, base)
+
+static const struct nla_policy
+linkstate_get_policy[ETHTOOL_A_LINKSTATE_MAX + 1] = {
+       [ETHTOOL_A_LINKSTATE_UNSPEC]            = { .type = NLA_REJECT },
+       [ETHTOOL_A_LINKSTATE_HEADER]            = { .type = NLA_NESTED },
+       [ETHTOOL_A_LINKSTATE_LINK]              = { .type = NLA_REJECT },
+};
+
+static int linkstate_prepare_data(const struct ethnl_req_info *req_base,
+                                 struct ethnl_reply_data *reply_base,
+                                 struct genl_info *info)
+{
+       struct linkstate_reply_data *data = LINKSTATE_REPDATA(reply_base);
+       struct net_device *dev = reply_base->dev;
+       int ret;
+
+       ret = ethnl_ops_begin(dev);
+       if (ret < 0)
+               return ret;
+       data->link = __ethtool_get_link(dev);
+       ethnl_ops_complete(dev);
+
+       return 0;
+}
+
+static int linkstate_reply_size(const struct ethnl_req_info *req_base,
+                               const struct ethnl_reply_data *reply_base)
+{
+       return nla_total_size(sizeof(u8)) /* LINKSTATE_LINK */
+               + 0;
+}
+
+static int linkstate_fill_reply(struct sk_buff *skb,
+                               const struct ethnl_req_info *req_base,
+                               const struct ethnl_reply_data *reply_base)
+{
+       struct linkstate_reply_data *data = LINKSTATE_REPDATA(reply_base);
+
+       if (data->link >= 0 &&
+           nla_put_u8(skb, ETHTOOL_A_LINKSTATE_LINK, !!data->link))
+               return -EMSGSIZE;
+
+       return 0;
+}
+
+const struct ethnl_request_ops ethnl_linkstate_request_ops = {
+       .request_cmd            = ETHTOOL_MSG_LINKSTATE_GET,
+       .reply_cmd              = ETHTOOL_MSG_LINKSTATE_GET_REPLY,
+       .hdr_attr               = ETHTOOL_A_LINKSTATE_HEADER,
+       .max_attr               = ETHTOOL_A_LINKSTATE_MAX,
+       .req_info_size          = sizeof(struct linkstate_req_info),
+       .reply_data_size        = sizeof(struct linkstate_reply_data),
+       .request_policy         = linkstate_get_policy,
+
+       .prepare_data           = linkstate_prepare_data,
+       .reply_size             = linkstate_reply_size,
+       .fill_reply             = linkstate_fill_reply,
+};

diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 1b5e1bd..4ca96c7 100644 (file)
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -210,6 +210,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
        [ETHTOOL_MSG_STRSET_GET]        = &ethnl_strset_request_ops,
        [ETHTOOL_MSG_LINKINFO_GET]      = &ethnl_linkinfo_request_ops,
        [ETHTOOL_MSG_LINKMODES_GET]     = &ethnl_linkmodes_request_ops,
+       [ETHTOOL_MSG_LINKSTATE_GET]     = &ethnl_linkstate_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -645,6 +646,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
                .flags  = GENL_UNS_ADMIN_PERM,
                .doit   = ethnl_set_linkmodes,
        },
+       {
+               .cmd    = ETHTOOL_MSG_LINKSTATE_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 1269cca..da9d652 100644 (file)
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -333,6 +333,7 @@ struct ethnl_request_ops {
 extern const struct ethnl_request_ops ethnl_strset_request_ops;
 extern const struct ethnl_request_ops ethnl_linkinfo_request_ops;
 extern const struct ethnl_request_ops ethnl_linkmodes_request_ops;
+extern const struct ethnl_request_ops ethnl_linkstate_request_ops;
 
 int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info);