[PATCH net-next v2] net: core: Expose number of link up/down transitions
From: Florian Fainelli
Date: Thu Jan 18 2018 - 13:00:20 EST
From: David Decotigny <decot@xxxxxxxxxxxx>
Expose the number of times the link has been going UP or DOWN, and
update the "carrier_changes" counter to be the sum of these two events.
While at it, also update the sysfs-class-net documentation to cover:
carrier_changes (3.15), carrier_up_count (4.16) and carrier_down_count
(4.16)
Signed-off-by: David Decotigny <decot@xxxxxxxxxxxx>
[Florian:
* rebase
* add documentation
* merge carrier_changes with up/down counters]
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
Changes in v2:
- fixed sysfs attributes to use <iface>
- renamed count_link_{up,down} to carrier_{up,down}_count to match
existing carrier_changes semantics
Documentation/ABI/testing/sysfs-class-net | 24 ++++++++++++++++++++++++
include/linux/netdevice.h | 6 ++++--
include/uapi/linux/if_link.h | 2 ++
net/core/net-sysfs.c | 25 ++++++++++++++++++++++++-
net/core/rtnetlink.c | 13 +++++++++++--
net/sched/sch_generic.c | 4 ++--
6 files changed, 67 insertions(+), 7 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-class-net b/Documentation/ABI/testing/sysfs-class-net
index 6856da99b6f7..2f1788111cd9 100644
--- a/Documentation/ABI/testing/sysfs-class-net
+++ b/Documentation/ABI/testing/sysfs-class-net
@@ -259,3 +259,27 @@ Contact: netdev@xxxxxxxxxxxxxxx
Description:
Symbolic link to the PHY device this network device is attached
to.
+
+What: /sys/class/net/<iface>/carrier_changes
+Date: Mar 2014
+KernelVersion: 3.15
+Contact: netdev@xxxxxxxxxxxxxxx
+Description:
+ 32-bit unsigned integer counting the number of times the link has
+ seen a change from UP to DOWN and vice versa
+
+What: /sys/class/net/<iface>/carrier_up_count
+Date: Jan 2018
+KernelVersion: 4.16
+Contact: netdev@xxxxxxxxxxxxxxx
+Description:
+ 32-bit unsigned integer counting the number of times the link has
+ been up
+
+What: /sys/class/net/<iface>/carrier_down_count
+Date: Jan 2018
+KernelVersion: 4.16
+Contact: netdev@xxxxxxxxxxxxxxx
+Description:
+ 32-bit unsigned integer counting the number of times the link has
+ been down
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ed0799a12bf2..837e9cb7e358 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1680,8 +1680,6 @@ struct net_device {
unsigned long base_addr;
int irq;
- atomic_t carrier_changes;
-
/*
* Some hardware also needs these fields (state,dev_list,
* napi_list,unreg_list,close_list) but they are not
@@ -1719,6 +1717,10 @@ struct net_device {
atomic_long_t tx_dropped;
atomic_long_t rx_nohandler;
+ /* Stats to monitor link on/off, flapping */
+ atomic_t carrier_up_count;
+ atomic_t carrier_down_count;
+
#ifdef CONFIG_WIRELESS_EXT
const struct iw_handler_def *wireless_handlers;
struct iw_public_data *wireless_data;
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index f8f04fed6186..8616131e2c61 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -161,6 +161,8 @@ enum {
IFLA_EVENT,
IFLA_NEW_NETNSID,
IFLA_IF_NETNSID,
+ IFLA_CARRIER_UP_COUNT,
+ IFLA_CARRIER_DOWN_COUNT,
__IFLA_MAX
};
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 7bf8b85ade16..c4a28f4667b6 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -295,10 +295,31 @@ static ssize_t carrier_changes_show(struct device *dev,
struct net_device *netdev = to_net_dev(dev);
return sprintf(buf, fmt_dec,
- atomic_read(&netdev->carrier_changes));
+ atomic_read(&netdev->carrier_up_count) +
+ atomic_read(&netdev->carrier_down_count));
}
static DEVICE_ATTR_RO(carrier_changes);
+static ssize_t carrier_up_count_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct net_device *netdev = to_net_dev(dev);
+
+ return sprintf(buf, fmt_dec, atomic_read(&netdev->carrier_up_count));
+}
+static DEVICE_ATTR_RO(carrier_up_count);
+
+static ssize_t carrier_down_count_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct net_device *netdev = to_net_dev(dev);
+
+ return sprintf(buf, fmt_dec, atomic_read(&netdev->carrier_down_count));
+}
+static DEVICE_ATTR_RO(carrier_down_count);
+
/* read-write attributes */
static int change_mtu(struct net_device *dev, unsigned long new_mtu)
@@ -547,6 +568,8 @@ static struct attribute *net_class_attrs[] __ro_after_init = {
&dev_attr_phys_port_name.attr,
&dev_attr_phys_switch_id.attr,
&dev_attr_proto_down.attr,
+ &dev_attr_carrier_up_count.attr,
+ &dev_attr_carrier_down_count.attr,
NULL,
};
ATTRIBUTE_GROUPS(net_class);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 16d644a4f974..97874daa1336 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -990,6 +990,8 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
+ nla_total_size(4) /* IFLA_NEW_NETNSID */
+ nla_total_size(1) /* IFLA_PROTO_DOWN */
+ nla_total_size(4) /* IFLA_IF_NETNSID */
+ + nla_total_size(4) /* IFLA_CARRIER_UP_COUNT */
+ + nla_total_size(4) /* IFLA_CARRIER_DOWN_COUNT */
+ 0;
}
@@ -1551,8 +1553,13 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
nla_put_string(skb, IFLA_QDISC, dev->qdisc->ops->id)) ||
nla_put_ifalias(skb, dev) ||
nla_put_u32(skb, IFLA_CARRIER_CHANGES,
- atomic_read(&dev->carrier_changes)) ||
- nla_put_u8(skb, IFLA_PROTO_DOWN, dev->proto_down))
+ atomic_read(&dev->carrier_up_count) +
+ atomic_read(&dev->carrier_down_count)) ||
+ nla_put_u8(skb, IFLA_PROTO_DOWN, dev->proto_down) ||
+ nla_put_u32(skb, IFLA_CARRIER_UP_COUNT,
+ atomic_read(&dev->carrier_up_count)) ||
+ nla_put_u32(skb, IFLA_CARRIER_DOWN_COUNT,
+ atomic_read(&dev->carrier_down_count)))
goto nla_put_failure;
if (event != IFLA_EVENT_NONE) {
@@ -1656,6 +1663,8 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
[IFLA_EVENT] = { .type = NLA_U32 },
[IFLA_GROUP] = { .type = NLA_U32 },
[IFLA_IF_NETNSID] = { .type = NLA_S32 },
+ [IFLA_CARRIER_UP_COUNT] = { .type = NLA_U32 },
+ [IFLA_CARRIER_DOWN_COUNT] = { .type = NLA_U32 },
};
static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index ef8b4ecde2ac..1816bde47256 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -510,7 +510,7 @@ void netif_carrier_on(struct net_device *dev)
if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
if (dev->reg_state == NETREG_UNINITIALIZED)
return;
- atomic_inc(&dev->carrier_changes);
+ atomic_inc(&dev->carrier_up_count);
linkwatch_fire_event(dev);
if (netif_running(dev))
__netdev_watchdog_up(dev);
@@ -529,7 +529,7 @@ void netif_carrier_off(struct net_device *dev)
if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
if (dev->reg_state == NETREG_UNINITIALIZED)
return;
- atomic_inc(&dev->carrier_changes);
+ atomic_inc(&dev->carrier_down_count);
linkwatch_fire_event(dev);
}
}
--
2.14.1