From: Jesper Juhl <juhl-lkml@dif.dk>
The patch adds a new sysfs attribute called carrier for net devices that
exposes the result of netif_carrier_ok(). This allows a user to quickly
and easily determine if a given netdevice has carrier or not. Reading
/sys/class/net/<interface>/carrier yields a '1' when there is a carrier and
a '0' when there is not.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/net/core/net-sysfs.c | 11 +++++++++++
1 files changed, 11 insertions(+)
diff -puN net/core/net-sysfs.c~add-new-sysfs-attribute-carrier-for-net-devices net/core/net-sysfs.c
--- 25/net/core/net-sysfs.c~add-new-sysfs-attribute-carrier-for-net-devices 2004-10-03 16:30:07.086832216 -0700
+++ 25-akpm/net/core/net-sysfs.c 2004-10-03 16:30:07.090831608 -0700
@@ -126,8 +126,18 @@ static ssize_t show_broadcast(struct cla
return -EINVAL;
}
+static ssize_t show_carrier(struct class_device *dev, char *buf)
+{
+ struct net_device *netdev = to_net_dev(dev);
+ if (netif_running(netdev)) {
+ return sprintf(buf, fmt_dec, !!netif_carrier_ok(netdev));
+ }
+ return -EINVAL;
+}
+
static CLASS_DEVICE_ATTR(address, S_IRUGO, show_address, NULL);
static CLASS_DEVICE_ATTR(broadcast, S_IRUGO, show_broadcast, NULL);
+static CLASS_DEVICE_ATTR(carrier, S_IRUGO, show_carrier, NULL);
/* read-write attributes */
NETDEVICE_SHOW(mtu, fmt_dec);
@@ -186,6 +196,7 @@ static struct class_device_attribute *ne
&class_device_attr_type,
&class_device_attr_address,
&class_device_attr_broadcast,
+ &class_device_attr_carrier,
NULL
};
_