net: export device speed and duplex via sysfs (d519e17e) · Commits · 戴 / test

This patch exports the link-speed (in Mbps) and duplex of an interface via sysfs. This eliminates the need to use ethtool just to check the link-speed. Not requiring 'ethtool' and not relying on the SIOCETHTOOL ioctl should be helpful in an embedded environment where space is at a premium as well. NOTE: This patch also intentionally allows non-root users to check the link speed and duplex -- something not possible with ethtool. Here's some sample output: # cat /sys/class/net/eth0/speed 100 # cat /sys/class/net/eth0/duplex half # ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: Not reported Advertised auto-negotiation: No Speed: 100Mb/s Duplex: Half Port: Twisted Pair PHYAD: 1 Transceiver: internal Auto-negotiation: off Supports Wake-on: g Wake-on: g Current message level: 0x000000ff (255) Link detected: yes Signed-off-by:

David S. Miller <davem@davemloft.net>

net/core/net-sysfs.c

+40 −0

Original line number	Diff line number	Diff line
		@@ -130,6 +130,44 @@ static ssize_t show_carrier(struct device *dev,
		return -EINVAL;
		}

		static ssize_t show_speed(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct net_device *netdev = to_net_dev(dev);
		int ret = -EINVAL;

		if (!rtnl_trylock())
		return restart_syscall();

		if (netif_running(netdev) && netdev->ethtool_ops->get_settings) {
		struct ethtool_cmd cmd = { ETHTOOL_GSET };

		if (!netdev->ethtool_ops->get_settings(netdev, &cmd))
		ret = sprintf(buf, fmt_dec, ethtool_cmd_speed(&cmd));
		}
		rtnl_unlock();
		return ret;
		}

		static ssize_t show_duplex(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct net_device *netdev = to_net_dev(dev);
		int ret = -EINVAL;

		if (!rtnl_trylock())
		return restart_syscall();

		if (netif_running(netdev) && netdev->ethtool_ops->get_settings) {
		struct ethtool_cmd cmd = { ETHTOOL_GSET };

		if (!netdev->ethtool_ops->get_settings(netdev, &cmd))
		ret = sprintf(buf, "%s\n", cmd.duplex ? "full" : "half");
		}
		rtnl_unlock();
		return ret;
		}

		static ssize_t show_dormant(struct device *dev,
		struct device_attribute attr, char buf)
		{
		@@ -259,6 +297,8 @@ static struct device_attribute net_class_attributes[] = {
		__ATTR(address, S_IRUGO, show_address, NULL),
		__ATTR(broadcast, S_IRUGO, show_broadcast, NULL),
		__ATTR(carrier, S_IRUGO, show_carrier, NULL),
		__ATTR(speed, S_IRUGO, show_speed, NULL),
		__ATTR(duplex, S_IRUGO, show_duplex, NULL),
		__ATTR(dormant, S_IRUGO, show_dormant, NULL),
		__ATTR(operstate, S_IRUGO, show_operstate, NULL),
		__ATTR(mtu, S_IRUGO \| S_IWUSR, show_mtu, store_mtu),

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