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authordavid decotigny <decot@googlers.com>2014-03-29 09:48:35 -0700
committerDavid S. Miller <davem@davemloft.net>2014-03-31 16:24:52 -0400
commit2d3b479df41a10e2f41f9259fcba775bd34de6e4 (patch)
tree517291066c35188a41b005e81904e69865643e76 /net/core
parent9c76a114bbef10b4d44bd258006721dd896695dd (diff)
downloadlinux-2d3b479df41a10e2f41f9259fcba775bd34de6e4.tar.gz
net-sysfs: expose number of carrier on/off changes
This allows to monitor carrier on/off transitions and detect link
flapping issues:
 - new /sys/class/net/X/carrier_changes
 - new rtnetlink IFLA_CARRIER_CHANGES (getlink)

Tested:
  - grep . /sys/class/net/*/carrier_changes
    + ip link set dev X down/up
    + plug/unplug cable
  - updated iproute2: prints IFLA_CARRIER_CHANGES
  - iproute2 20121211-2 (debian): unchanged behavior

Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/net-sysfs.c11
-rw-r--r--net/core/rtnetlink.c6
2 files changed, 16 insertions, 1 deletions
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index daed9a64c6f6..462396278484 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -253,6 +253,16 @@ static ssize_t operstate_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(operstate);
 
+static ssize_t carrier_changes_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_changes));
+}
+static DEVICE_ATTR_RO(carrier_changes);
+
 /* read-write attributes */
 
 static int change_mtu(struct net_device *net, unsigned long new_mtu)
@@ -386,6 +396,7 @@ static struct attribute *net_class_attrs[] = {
 	&dev_attr_duplex.attr,
 	&dev_attr_dormant.attr,
 	&dev_attr_operstate.attr,
+	&dev_attr_carrier_changes.attr,
 	&dev_attr_ifalias.attr,
 	&dev_attr_carrier.attr,
 	&dev_attr_mtu.attr,
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index e7c6006bc3ea..d4ff41739b0f 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -822,6 +822,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + nla_total_size(4) /* IFLA_NUM_RX_QUEUES */
 	       + nla_total_size(1) /* IFLA_OPERSTATE */
 	       + nla_total_size(1) /* IFLA_LINKMODE */
+	       + nla_total_size(4) /* IFLA_CARRIER_CHANGES */
 	       + nla_total_size(ext_filter_mask
 			        & RTEXT_FILTER_VF ? 4 : 0) /* IFLA_NUM_VF */
 	       + rtnl_vfinfo_size(dev, ext_filter_mask) /* IFLA_VFINFO_LIST */
@@ -970,7 +971,9 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 	    (dev->qdisc &&
 	     nla_put_string(skb, IFLA_QDISC, dev->qdisc->ops->id)) ||
 	    (dev->ifalias &&
-	     nla_put_string(skb, IFLA_IFALIAS, dev->ifalias)))
+	     nla_put_string(skb, IFLA_IFALIAS, dev->ifalias)) ||
+	    nla_put_u32(skb, IFLA_CARRIER_CHANGES,
+			atomic_read(&dev->carrier_changes)))
 		goto nla_put_failure;
 
 	if (1) {
@@ -1147,6 +1150,7 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_NUM_TX_QUEUES]	= { .type = NLA_U32 },
 	[IFLA_NUM_RX_QUEUES]	= { .type = NLA_U32 },
 	[IFLA_PHYS_PORT_ID]	= { .type = NLA_BINARY, .len = MAX_PHYS_PORT_ID_LEN },
+	[IFLA_CARRIER_CHANGES]	= { .type = NLA_U32 },  /* ignored */
 };
 
 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {