From 2d3b479df41a10e2f41f9259fcba775bd34de6e4 Mon Sep 17 00:00:00 2001 From: david decotigny Date: Sat, 29 Mar 2014 09:48:35 -0700 Subject: 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 Signed-off-by: David S. Miller --- include/linux/netdevice.h | 3 +++ include/uapi/linux/if_link.h | 1 + net/core/net-sysfs.c | 11 +++++++++++ net/core/rtnetlink.c | 6 +++++- net/sched/sch_generic.c | 2 ++ 5 files changed, 22 insertions(+), 1 deletion(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 34cae3ee74f1..45537ed7a5b3 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1308,6 +1308,9 @@ struct net_device { atomic_long_t rx_dropped; atomic_long_t tx_dropped; + /* Stats to monitor carrier on<->off transitions */ + atomic_t carrier_changes; + #ifdef CONFIG_WIRELESS_EXT /* List of functions to handle Wireless Extensions (instead of ioctl). * See for details. Jean II */ diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h index 16410b6e7819..9a7f7ace6649 100644 --- a/include/uapi/linux/if_link.h +++ b/include/uapi/linux/if_link.h @@ -144,6 +144,7 @@ enum { IFLA_NUM_RX_QUEUES, IFLA_CARRIER, IFLA_PHYS_PORT_ID, + IFLA_CARRIER_CHANGES, __IFLA_MAX }; 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] = { diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index e82e43b69c33..e1543b03e39d 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -310,6 +310,7 @@ 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); linkwatch_fire_event(dev); if (netif_running(dev)) __netdev_watchdog_up(dev); @@ -328,6 +329,7 @@ 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); linkwatch_fire_event(dev); } } -- cgit v1.2.3