From 0b815a1a6d43ab498674b8430c8c35ab08487a16 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Mon, 22 Sep 2008 21:28:11 -0700 Subject: net: network device name ifalias support This patch add support for keeping an additional character alias associated with an network interface. This is useful for maintaining the SNMP ifAlias value which is a user defined value. Routers use this to hold information like which circuit or line it is connected to. It is just an arbitrary text label on the network device. There are two exposed interfaces with this patch, the value can be read/written either via netlink or sysfs. This could be maintained just by the snmp daemon, but it is more generally useful for other management tools, and the kernel is good place to act as an agreed upon interface to store it. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/core/net-sysfs.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'net/core/net-sysfs.c') diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index c1f4e0d428c..92d6b946731 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -209,9 +209,44 @@ static ssize_t store_tx_queue_len(struct device *dev, return netdev_store(dev, attr, buf, len, change_tx_queue_len); } +static ssize_t store_ifalias(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct net_device *netdev = to_net_dev(dev); + size_t count = len; + ssize_t ret; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + /* ignore trailing newline */ + if (len > 0 && buf[len - 1] == '\n') + --count; + + rtnl_lock(); + ret = dev_set_alias(netdev, buf, count); + rtnl_unlock(); + + return ret < 0 ? ret : len; +} + +static ssize_t show_ifalias(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct net_device *netdev = to_net_dev(dev); + ssize_t ret = 0; + + rtnl_lock(); + if (netdev->ifalias) + ret = sprintf(buf, "%s\n", netdev->ifalias); + rtnl_unlock(); + return ret; +} + static struct device_attribute net_class_attributes[] = { __ATTR(addr_len, S_IRUGO, show_addr_len, NULL), __ATTR(dev_id, S_IRUGO, show_dev_id, NULL), + __ATTR(ifalias, S_IRUGO | S_IWUSR, show_ifalias, store_ifalias), __ATTR(iflink, S_IRUGO, show_iflink, NULL), __ATTR(ifindex, S_IRUGO, show_ifindex, NULL), __ATTR(features, S_IRUGO, show_features, NULL), @@ -418,6 +453,7 @@ static void netdev_release(struct device *d) BUG_ON(dev->reg_state != NETREG_RELEASED); + kfree(dev->ifalias); kfree((char *)dev - dev->padded); } -- cgit v1.2.3-70-g09d2