[patch net-next-2.6] dummy: allow report link status and change it via sysfs

[patch net-next-2.6] dummy: allow report link status and change it via sysfs

[Jiri Pirko]

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
---
 drivers/net/dummy.c |   54 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 54 insertions(+), 0 deletions(-)

diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
index 39cf9b9..fc39c24 100644
--- a/drivers/net/dummy.c
+++ b/drivers/net/dummy.c
@@ -37,9 +37,57 @@
 #include <linux/rtnetlink.h>
 #include <net/rtnetlink.h>
 #include <linux/u64_stats_sync.h>
+#include <linux/ethtool.h>
 
 static int numdummies = 1;
 
+static ssize_t dummy_show_link(struct device *d,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	struct net_device *dev = to_net_dev(d);
+
+	return sprintf(buf, "%d\n", netif_carrier_ok(dev) ? 1 : 0);
+}
+
+static ssize_t dummy_store_link(struct device *d,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct net_device *dev = to_net_dev(d);
+	int new_value;
+
+	if (sscanf(buf, "%d", &new_value) != 1) {
+		pr_err("%s: no link value specified.\n", dev->name);
+		return -EINVAL;
+	}
+	switch (new_value) {
+	case 0:
+		netif_carrier_off(dev);
+		break;
+	case 1:
+		netif_carrier_on(dev);
+		break;
+	default:
+		pr_info("%s: Ignoring invalid link value %d.\n",
+			dev->name, new_value);
+	}
+	return count;
+}
+
+static DEVICE_ATTR(link, S_IRUGO | S_IWUSR,
+		   dummy_show_link, dummy_store_link);
+
+static struct attribute *per_dummy_attrs[] = {
+	&dev_attr_link.attr,
+	NULL,
+};
+
+static struct attribute_group dummy_group = {
+	.name = "dummy",
+	.attrs = per_dummy_attrs,
+};
+
 static int dummy_set_address(struct net_device *dev, void *p)
 {
 	struct sockaddr *sa = p;
@@ -103,6 +151,7 @@ static int dummy_dev_init(struct net_device *dev)
 	if (!dev->dstats)
 		return -ENOMEM;
 
+	dev->sysfs_groups[0] = &dummy_group;
 	return 0;
 }
 
@@ -121,12 +170,17 @@ static const struct net_device_ops dummy_netdev_ops = {
 	.ndo_get_stats64	= dummy_get_stats64,
 };
 
+static const struct ethtool_ops dummy_ethtool_ops = {
+	.get_link		= ethtool_op_get_link,
+};
+
 static void dummy_setup(struct net_device *dev)
 {
 	ether_setup(dev);
 
 	/* Initialize the device structure. */
 	dev->netdev_ops = &dummy_netdev_ops;
+	dev->ethtool_ops = &dummy_ethtool_ops;
 	dev->destructor = dummy_dev_free;
 
 	/* Fill in device structure with ethernet-generic values. */
-- 
1.7.6

Re: [patch net-next-2.6] dummy: allow report link status and change it via sysfs

[Ben Hutchings]

On Fri, 2011-07-29 at 17:27 +0200, Jiri Pirko wrote:
> Signed-off-by: Jiri Pirko <jpirko@redhat.com>
> ---
>  drivers/net/dummy.c |   54 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 54 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
> index 39cf9b9..fc39c24 100644
> --- a/drivers/net/dummy.c
> +++ b/drivers/net/dummy.c
> @@ -37,9 +37,57 @@
>  #include <linux/rtnetlink.h>
>  #include <net/rtnetlink.h>
>  #include <linux/u64_stats_sync.h>
> +#include <linux/ethtool.h>
>  
>  static int numdummies = 1;
>  
> +static ssize_t dummy_show_link(struct device *d,
> +			       struct device_attribute *attr,
> +			       char *buf)
> +{
> +	struct net_device *dev = to_net_dev(d);
> +
> +	return sprintf(buf, "%d\n", netif_carrier_ok(dev) ? 1 : 0);
> +}
[...]

Net devices already have the 'carrier' attribute.  You should make that
attribute writable for dummy devices, rather than adding another one.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [patch net-next-2.6] dummy: allow report link status and change it via sysfs

[Stephen Hemminger]

On Fri, 29 Jul 2011 18:03:09 +0200
Ben Hutchings <bhutchings@solarflare.com> wrote:

> On Fri, 2011-07-29 at 17:27 +0200, Jiri Pirko wrote:
> > Signed-off-by: Jiri Pirko <jpirko@redhat.com>
> > ---
> >  drivers/net/dummy.c |   54 +++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 54 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
> > index 39cf9b9..fc39c24 100644
> > --- a/drivers/net/dummy.c
> > +++ b/drivers/net/dummy.c
> > @@ -37,9 +37,57 @@
> >  #include <linux/rtnetlink.h>
> >  #include <net/rtnetlink.h>
> >  #include <linux/u64_stats_sync.h>
> > +#include <linux/ethtool.h>
> >  
> >  static int numdummies = 1;
> >  
> > +static ssize_t dummy_show_link(struct device *d,
> > +			       struct device_attribute *attr,
> > +			       char *buf)
> > +{
> > +	struct net_device *dev = to_net_dev(d);
> > +
> > +	return sprintf(buf, "%d\n", netif_carrier_ok(dev) ? 1 : 0);
> > +}
> [...]
> 
> Net devices already have the 'carrier' attribute.  You should make that
> attribute writable for dummy devices, rather than adding another one.
> 

And adding ethtool support is unnecessary since carrier is already
reported by tools like 'ip link'