[patch net-next V2 0/4] net: allow to change carrier from userspace

[patch net-next V2 0/4] net: allow to change carrier from userspace

[Jiri Pirko]

This is basically a V2 of a repost of my previous patchset:
"[patch net-next-2.6 0/2] net: allow to change carrier via sysfs" from Aug 30

The way net-sysfs stores values changed and this patchset reflects it.
Also, I exposed carrier via rtnetlink iface.

So far, only dummy driver uses carrier change ndo. In very near future
team driver will use that as well.

V1->v2:
 - added bigger comment to ndo and also note to operstate.txt documentation
   stating the clear purpose of this iface

Jiri Pirko (4):
  net: add change_carrier netdev op
  net: allow to change carrier via sysfs
  rtnl: expose carrier value with possibility to set it
  dummy: implement carrier change

 Documentation/networking/operstates.txt |  4 ++++
 drivers/net/dummy.c                     | 10 ++++++++++
 include/linux/netdevice.h               |  9 +++++++++
 include/uapi/linux/if_link.h            |  1 +
 net/core/dev.c                          | 19 +++++++++++++++++++
 net/core/net-sysfs.c                    | 15 ++++++++++++++-
 net/core/rtnetlink.c                    | 10 ++++++++++
 7 files changed, 67 insertions(+), 1 deletion(-)

-- 
1.8.0

[patch net-next 1/4] net: add change_carrier netdev op

[Jiri Pirko]

This allows a driver to register change_carrier callback which will be
called whenever user will like to change carrier state. This is useful
for devices like dummy, gre, team and so on.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 include/linux/netdevice.h |  9 +++++++++
 net/core/dev.c            | 19 +++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 02e0f6b..8047330 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -891,6 +891,11 @@ struct netdev_fcoe_hbainfo {
  * int (*ndo_bridge_setlink)(struct net_device *dev, struct nlmsghdr *nlh)
  * int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
  *			     struct net_device *dev)
+ *
+ * int (*ndo_change_carrier)(struct net_device *dev, bool new_carrier);
+ *	Called to update device carrier. Soft-devices which do not manage
+ *	real hardware like dummy, team, etc. can define this to provide
+ *	possibility to set their carrier state.
  */
 struct net_device_ops {
 	int			(*ndo_init)(struct net_device *dev);
@@ -1008,6 +1013,8 @@ struct net_device_ops {
 	int			(*ndo_bridge_getlink)(struct sk_buff *skb,
 						      u32 pid, u32 seq,
 						      struct net_device *dev);
+	int			(*ndo_change_carrier)(struct net_device *dev,
+						      bool new_carrier);
 };
 
 /*
@@ -2194,6 +2201,8 @@ extern int		dev_set_mtu(struct net_device *, int);
 extern void		dev_set_group(struct net_device *, int);
 extern int		dev_set_mac_address(struct net_device *,
 					    struct sockaddr *);
+extern int		dev_change_carrier(struct net_device *,
+					   bool new_carrier);
 extern int		dev_hard_start_xmit(struct sk_buff *skb,
 					    struct net_device *dev,
 					    struct netdev_queue *txq);
diff --git a/net/core/dev.c b/net/core/dev.c
index d0cbc93..268a714 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5027,6 +5027,25 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
 }
 EXPORT_SYMBOL(dev_set_mac_address);
 
+/**
+ *	dev_change_carrier - Change device carrier
+ *	@dev: device
+ *	@new_carries: new value
+ *
+ *	Change device carrier
+ */
+int dev_change_carrier(struct net_device *dev, bool new_carrier)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_change_carrier)
+		return -EOPNOTSUPP;
+	if (!netif_device_present(dev))
+		return -ENODEV;
+	return ops->ndo_change_carrier(dev, new_carrier);
+}
+EXPORT_SYMBOL(dev_change_carrier);
+
 /*
  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
  */
-- 
1.8.0

Re: [patch net-next 1/4] net: add change_carrier netdev op

[Dan Williams]

On Tue, 2012-12-18 at 23:14 +0100, Jiri Pirko wrote:
> This allows a driver to register change_carrier callback which will be
> called whenever user will like to change carrier state. This is useful
> for devices like dummy, gre, team and so on.
> 
> Signed-off-by: Jiri Pirko <jiri@resnulli.us>
> ---
>  include/linux/netdevice.h |  9 +++++++++
>  net/core/dev.c            | 19 +++++++++++++++++++
>  2 files changed, 28 insertions(+)
> 
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 02e0f6b..8047330 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -891,6 +891,11 @@ struct netdev_fcoe_hbainfo {
>   * int (*ndo_bridge_setlink)(struct net_device *dev, struct nlmsghdr *nlh)
>   * int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
>   *			     struct net_device *dev)
> + *
> + * int (*ndo_change_carrier)(struct net_device *dev, bool new_carrier);
> + *	Called to update device carrier. Soft-devices which do not manage
> + *	real hardware like dummy, team, etc. can define this to provide
> + *	possibility to set their carrier state.

How about something like:

---
Called to change device carrier.  Virtual devices (like dummy, team,
etc) which do not represent real hardware may define this to allow their
userspace components to manage their virtual carrier state.  Devices
that determine carrier state from physical hardware properties (eg
network cables) or protocol-dependent mechanisms (eg
USB_CDC_NOTIFY_NETWORK_CONNECTION) should NOT implement this function.
---

I'm just worried that without some clearer wording, somebody will end up
implementing the function for an actual hardware driver down the road
and expect things to work when they change the carrier to "on" but the
protocol isn't set up or cable isn't plugged in.  I'm also worried that
it might be used to simply work around bugs in the drivers that should
be fixed in the drivers instead.

Dan

>  struct net_device_ops {
>  	int			(*ndo_init)(struct net_device *dev);
> @@ -1008,6 +1013,8 @@ struct net_device_ops {
>  	int			(*ndo_bridge_getlink)(struct sk_buff *skb,
>  						      u32 pid, u32 seq,
>  						      struct net_device *dev);
> +	int			(*ndo_change_carrier)(struct net_device *dev,
> +						      bool new_carrier);
>  };
>  
>  /*
> @@ -2194,6 +2201,8 @@ extern int		dev_set_mtu(struct net_device *, int);
>  extern void		dev_set_group(struct net_device *, int);
>  extern int		dev_set_mac_address(struct net_device *,
>  					    struct sockaddr *);
> +extern int		dev_change_carrier(struct net_device *,
> +					   bool new_carrier);
>  extern int		dev_hard_start_xmit(struct sk_buff *skb,
>  					    struct net_device *dev,
>  					    struct netdev_queue *txq);
> diff --git a/net/core/dev.c b/net/core/dev.c
> index d0cbc93..268a714 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -5027,6 +5027,25 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
>  }
>  EXPORT_SYMBOL(dev_set_mac_address);
>  
> +/**
> + *	dev_change_carrier - Change device carrier
> + *	@dev: device
> + *	@new_carries: new value
> + *
> + *	Change device carrier
> + */
> +int dev_change_carrier(struct net_device *dev, bool new_carrier)
> +{
> +	const struct net_device_ops *ops = dev->netdev_ops;
> +
> +	if (!ops->ndo_change_carrier)
> +		return -EOPNOTSUPP;
> +	if (!netif_device_present(dev))
> +		return -ENODEV;
> +	return ops->ndo_change_carrier(dev, new_carrier);
> +}
> +EXPORT_SYMBOL(dev_change_carrier);
> +
>  /*
>   *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
>   */

Re: [patch net-next 1/4] net: add change_carrier netdev op

[Jiri Pirko]

Wed, Dec 19, 2012 at 12:02:51AM CET, dcbw@redhat.com wrote:
>On Tue, 2012-12-18 at 23:14 +0100, Jiri Pirko wrote:
>> This allows a driver to register change_carrier callback which will be
>> called whenever user will like to change carrier state. This is useful
>> for devices like dummy, gre, team and so on.
>> 
>> Signed-off-by: Jiri Pirko <jiri@resnulli.us>
>> ---
>>  include/linux/netdevice.h |  9 +++++++++
>>  net/core/dev.c            | 19 +++++++++++++++++++
>>  2 files changed, 28 insertions(+)
>> 
>> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>> index 02e0f6b..8047330 100644
>> --- a/include/linux/netdevice.h
>> +++ b/include/linux/netdevice.h
>> @@ -891,6 +891,11 @@ struct netdev_fcoe_hbainfo {
>>   * int (*ndo_bridge_setlink)(struct net_device *dev, struct nlmsghdr *nlh)
>>   * int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
>>   *			     struct net_device *dev)
>> + *
>> + * int (*ndo_change_carrier)(struct net_device *dev, bool new_carrier);
>> + *	Called to update device carrier. Soft-devices which do not manage
>> + *	real hardware like dummy, team, etc. can define this to provide
>> + *	possibility to set their carrier state.
>
>How about something like:
>
>---
>Called to change device carrier.  Virtual devices (like dummy, team,
>etc) which do not represent real hardware may define this to allow their
>userspace components to manage their virtual carrier state.  Devices
>that determine carrier state from physical hardware properties (eg
>network cables) or protocol-dependent mechanisms (eg
>USB_CDC_NOTIFY_NETWORK_CONNECTION) should NOT implement this function.
>---
>
>I'm just worried that without some clearer wording, somebody will end up
>implementing the function for an actual hardware driver down the road
>and expect things to work when they change the carrier to "on" but the
>protocol isn't set up or cable isn't plugged in.  I'm also worried that
>it might be used to simply work around bugs in the drivers that should
>be fixed in the drivers instead.

Okay - I'll repost this single patch with your text as comment.
Thanks.

>
>Dan
>
>>  struct net_device_ops {
>>  	int			(*ndo_init)(struct net_device *dev);
>> @@ -1008,6 +1013,8 @@ struct net_device_ops {
>>  	int			(*ndo_bridge_getlink)(struct sk_buff *skb,
>>  						      u32 pid, u32 seq,
>>  						      struct net_device *dev);
>> +	int			(*ndo_change_carrier)(struct net_device *dev,
>> +						      bool new_carrier);
>>  };
>>  
>>  /*
>> @@ -2194,6 +2201,8 @@ extern int		dev_set_mtu(struct net_device *, int);
>>  extern void		dev_set_group(struct net_device *, int);
>>  extern int		dev_set_mac_address(struct net_device *,
>>  					    struct sockaddr *);
>> +extern int		dev_change_carrier(struct net_device *,
>> +					   bool new_carrier);
>>  extern int		dev_hard_start_xmit(struct sk_buff *skb,
>>  					    struct net_device *dev,
>>  					    struct netdev_queue *txq);
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index d0cbc93..268a714 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -5027,6 +5027,25 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
>>  }
>>  EXPORT_SYMBOL(dev_set_mac_address);
>>  
>> +/**
>> + *	dev_change_carrier - Change device carrier
>> + *	@dev: device
>> + *	@new_carries: new value
>> + *
>> + *	Change device carrier
>> + */
>> +int dev_change_carrier(struct net_device *dev, bool new_carrier)
>> +{
>> +	const struct net_device_ops *ops = dev->netdev_ops;
>> +
>> +	if (!ops->ndo_change_carrier)
>> +		return -EOPNOTSUPP;
>> +	if (!netif_device_present(dev))
>> +		return -ENODEV;
>> +	return ops->ndo_change_carrier(dev, new_carrier);
>> +}
>> +EXPORT_SYMBOL(dev_change_carrier);
>> +
>>  /*
>>   *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
>>   */
>
>

Re: [patch net-next 1/4] net: add change_carrier netdev op

[David Miller]

From: Jiri Pirko <jiri@resnulli.us>
Date: Wed, 19 Dec 2012 09:20:50 +0100

> Okay - I'll repost this single patch with your text as comment.

Please always repost an entire series, rather than just part of
it.

Re: [patch net-next 1/4] net: add change_carrier netdev op

[Jiri Pirko]

Wed, Dec 19, 2012 at 10:28:25AM CET, davem@davemloft.net wrote:
>From: Jiri Pirko <jiri@resnulli.us>
>Date: Wed, 19 Dec 2012 09:20:50 +0100
>
>> Okay - I'll repost this single patch with your text as comment.
>
>Please always repost an entire series, rather than just part of
>it.

Sorry, I thought that in this case where the change is in one patch and
only cosmethic it wouldn't be a problem. Reposting the whole patchset.

[patch net-next V3 1/4] net: add change_carrier netdev op

[Jiri Pirko]

This allows a driver to register change_carrier callback which will be
called whenever user will like to change carrier state. This is useful
for devices like dummy, gre, team and so on.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 include/linux/netdevice.h | 12 ++++++++++++
 net/core/dev.c            | 19 +++++++++++++++++++
 2 files changed, 31 insertions(+)

V2->V3: updated comment by Dan Williams

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 02e0f6b..22ca4a8 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -891,6 +891,14 @@ struct netdev_fcoe_hbainfo {
  * int (*ndo_bridge_setlink)(struct net_device *dev, struct nlmsghdr *nlh)
  * int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
  *			     struct net_device *dev)
+ *
+ * int (*ndo_change_carrier)(struct net_device *dev, bool new_carrier);
+ *	Called to change device carrier. Soft-devices (like dummy, team, etc)
+ *	which do not represent real hardware may define this to allow their
+ *	userspace components to manage their virtual carrier state. Devices
+ *	that determine carrier state from physical hardware properties (eg
+ *	network cables) or protocol-dependent mechanisms (eg
+ *	USB_CDC_NOTIFY_NETWORK_CONNECTION) should NOT implement this function.
  */
 struct net_device_ops {
 	int			(*ndo_init)(struct net_device *dev);
@@ -1008,6 +1016,8 @@ struct net_device_ops {
 	int			(*ndo_bridge_getlink)(struct sk_buff *skb,
 						      u32 pid, u32 seq,
 						      struct net_device *dev);
+	int			(*ndo_change_carrier)(struct net_device *dev,
+						      bool new_carrier);
 };
 
 /*
@@ -2194,6 +2204,8 @@ extern int		dev_set_mtu(struct net_device *, int);
 extern void		dev_set_group(struct net_device *, int);
 extern int		dev_set_mac_address(struct net_device *,
 					    struct sockaddr *);
+extern int		dev_change_carrier(struct net_device *,
+					   bool new_carrier);
 extern int		dev_hard_start_xmit(struct sk_buff *skb,
 					    struct net_device *dev,
 					    struct netdev_queue *txq);
diff --git a/net/core/dev.c b/net/core/dev.c
index d0cbc93..268a714 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5027,6 +5027,25 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
 }
 EXPORT_SYMBOL(dev_set_mac_address);
 
+/**
+ *	dev_change_carrier - Change device carrier
+ *	@dev: device
+ *	@new_carries: new value
+ *
+ *	Change device carrier
+ */
+int dev_change_carrier(struct net_device *dev, bool new_carrier)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_change_carrier)
+		return -EOPNOTSUPP;
+	if (!netif_device_present(dev))
+		return -ENODEV;
+	return ops->ndo_change_carrier(dev, new_carrier);
+}
+EXPORT_SYMBOL(dev_change_carrier);
+
 /*
  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
  */
-- 
1.8.0

[patch net-next 2/4] net: allow to change carrier via sysfs

[Jiri Pirko]

Make carrier writable

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 net/core/net-sysfs.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 334efd5..7eda40a 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -126,6 +126,19 @@ static ssize_t show_broadcast(struct device *dev,
 	return -EINVAL;
 }
 
+static int change_carrier(struct net_device *net, unsigned long new_carrier)
+{
+	if (!netif_running(net))
+		return -EINVAL;
+	return dev_change_carrier(net, (bool) new_carrier);
+}
+
+static ssize_t store_carrier(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t len)
+{
+	return netdev_store(dev, attr, buf, len, change_carrier);
+}
+
 static ssize_t show_carrier(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
@@ -331,7 +344,7 @@ static struct device_attribute net_class_attributes[] = {
 	__ATTR(link_mode, S_IRUGO, show_link_mode, NULL),
 	__ATTR(address, S_IRUGO, show_address, NULL),
 	__ATTR(broadcast, S_IRUGO, show_broadcast, NULL),
-	__ATTR(carrier, S_IRUGO, show_carrier, NULL),
+	__ATTR(carrier, S_IRUGO | S_IWUSR, show_carrier, store_carrier),
 	__ATTR(speed, S_IRUGO, show_speed, NULL),
 	__ATTR(duplex, S_IRUGO, show_duplex, NULL),
 	__ATTR(dormant, S_IRUGO, show_dormant, NULL),
-- 
1.8.0

[patch net-next 3/4] rtnl: expose carrier value with possibility to set it

[Jiri Pirko]

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 Documentation/networking/operstates.txt |  4 ++++
 include/uapi/linux/if_link.h            |  1 +
 net/core/rtnetlink.c                    | 10 ++++++++++
 3 files changed, 15 insertions(+)

diff --git a/Documentation/networking/operstates.txt b/Documentation/networking/operstates.txt
index 1a77a3c..9769457 100644
--- a/Documentation/networking/operstates.txt
+++ b/Documentation/networking/operstates.txt
@@ -88,6 +88,10 @@ set this flag. On netif_carrier_off(), the scheduler stops sending
 packets. The name 'carrier' and the inversion are historical, think of
 it as lower layer.
 
+Note that for certain kind of soft-devices, which are not managing any
+real hardware, there is possible to set this bit from userpsace.
+One should use TVL IFLA_CARRIER to do so.
+
 netif_carrier_ok() can be used to query that bit.
 
 __LINK_STATE_DORMANT, maps to IFF_DORMANT:
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 60f3b6b..c4edfe1 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -142,6 +142,7 @@ enum {
 #define IFLA_PROMISCUITY IFLA_PROMISCUITY
 	IFLA_NUM_TX_QUEUES,
 	IFLA_NUM_RX_QUEUES,
+	IFLA_CARRIER,
 	__IFLA_MAX
 };
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 1868625..2ef7a56 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -780,6 +780,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + nla_total_size(4) /* IFLA_MTU */
 	       + nla_total_size(4) /* IFLA_LINK */
 	       + nla_total_size(4) /* IFLA_MASTER */
+	       + nla_total_size(1) /* IFLA_CARRIER */
 	       + nla_total_size(4) /* IFLA_PROMISCUITY */
 	       + nla_total_size(4) /* IFLA_NUM_TX_QUEUES */
 	       + nla_total_size(4) /* IFLA_NUM_RX_QUEUES */
@@ -909,6 +910,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 	     nla_put_u32(skb, IFLA_LINK, dev->iflink)) ||
 	    (dev->master &&
 	     nla_put_u32(skb, IFLA_MASTER, dev->master->ifindex)) ||
+	    nla_put_u8(skb, IFLA_CARRIER, netif_carrier_ok(dev)) ||
 	    (dev->qdisc &&
 	     nla_put_string(skb, IFLA_QDISC, dev->qdisc->ops->id)) ||
 	    (dev->ifalias &&
@@ -1108,6 +1110,7 @@ const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_MTU]		= { .type = NLA_U32 },
 	[IFLA_LINK]		= { .type = NLA_U32 },
 	[IFLA_MASTER]		= { .type = NLA_U32 },
+	[IFLA_CARRIER]		= { .type = NLA_U8 },
 	[IFLA_TXQLEN]		= { .type = NLA_U32 },
 	[IFLA_WEIGHT]		= { .type = NLA_U32 },
 	[IFLA_OPERSTATE]	= { .type = NLA_U8 },
@@ -1438,6 +1441,13 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
 		modified = 1;
 	}
 
+	if (tb[IFLA_CARRIER]) {
+		err = dev_change_carrier(dev, nla_get_u8(tb[IFLA_CARRIER]));
+		if (err)
+			goto errout;
+		modified = 1;
+	}
+
 	if (tb[IFLA_TXQLEN])
 		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
 
-- 
1.8.0

[patch net-next 4/4] dummy: implement carrier change

[Jiri Pirko]

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 drivers/net/dummy.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
index c260af5..42aa54a 100644
--- a/drivers/net/dummy.c
+++ b/drivers/net/dummy.c
@@ -100,6 +100,15 @@ static void dummy_dev_uninit(struct net_device *dev)
 	free_percpu(dev->dstats);
 }
 
+static int dummy_change_carrier(struct net_device *dev, bool new_carrier)
+{
+	if (new_carrier)
+		netif_carrier_on(dev);
+	else
+		netif_carrier_off(dev);
+	return 0;
+}
+
 static const struct net_device_ops dummy_netdev_ops = {
 	.ndo_init		= dummy_dev_init,
 	.ndo_uninit		= dummy_dev_uninit,
@@ -108,6 +117,7 @@ static const struct net_device_ops dummy_netdev_ops = {
 	.ndo_set_rx_mode	= set_multicast_list,
 	.ndo_set_mac_address	= eth_mac_addr,
 	.ndo_get_stats64	= dummy_get_stats64,
+	.ndo_change_carrier	= dummy_change_carrier,
 };
 
 static void dummy_setup(struct net_device *dev)
-- 
1.8.0

[patch net-next V3,repost 0/4] net: allow to change carrier from userspace

[Jiri Pirko]

This is basically a V3 of a repost of my previous patchset:
"[patch net-next-2.6 0/2] net: allow to change carrier via sysfs" from Aug 30

The way net-sysfs stores values changed and this patchset reflects it.
Also, I exposed carrier via rtnetlink iface.

So far, only dummy driver uses carrier change ndo. In very near future
team driver will use that as well.

V2->V3:
 - updated ndo_change_carrier comment by Dan Williams

V1->v2:
 - added bigger comment to ndo and also note to operstate.txt documentation
   stating the clear purpose of this iface

Jiri Pirko (4):
  net: add change_carrier netdev op
  net: allow to change carrier via sysfs
  rtnl: expose carrier value with possibility to set it
  dummy: implement carrier change

 Documentation/networking/operstates.txt |  4 ++++
 drivers/net/dummy.c                     | 10 ++++++++++
 include/linux/netdevice.h               | 12 ++++++++++++
 include/uapi/linux/if_link.h            |  1 +
 net/core/dev.c                          | 19 +++++++++++++++++++
 net/core/net-sysfs.c                    | 15 ++++++++++++++-
 net/core/rtnetlink.c                    | 10 ++++++++++
 7 files changed, 70 insertions(+), 1 deletion(-)

-- 
1.8.0

[patch net-next 1/4] net: add change_carrier netdev op

[Jiri Pirko]

This allows a driver to register change_carrier callback which will be
called whenever user will like to change carrier state. This is useful
for devices like dummy, gre, team and so on.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 include/linux/netdevice.h | 12 ++++++++++++
 net/core/dev.c            | 19 +++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c599e47..0e1b92a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -891,6 +891,14 @@ struct netdev_fcoe_hbainfo {
  * int (*ndo_bridge_setlink)(struct net_device *dev, struct nlmsghdr *nlh)
  * int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
  *			     struct net_device *dev)
+ *
+ * int (*ndo_change_carrier)(struct net_device *dev, bool new_carrier);
+ *	Called to change device carrier. Soft-devices (like dummy, team, etc)
+ *	which do not represent real hardware may define this to allow their
+ *	userspace components to manage their virtual carrier state. Devices
+ *	that determine carrier state from physical hardware properties (eg
+ *	network cables) or protocol-dependent mechanisms (eg
+ *	USB_CDC_NOTIFY_NETWORK_CONNECTION) should NOT implement this function.
  */
 struct net_device_ops {
 	int			(*ndo_init)(struct net_device *dev);
@@ -1008,6 +1016,8 @@ struct net_device_ops {
 	int			(*ndo_bridge_getlink)(struct sk_buff *skb,
 						      u32 pid, u32 seq,
 						      struct net_device *dev);
+	int			(*ndo_change_carrier)(struct net_device *dev,
+						      bool new_carrier);
 };
 
 /*
@@ -2194,6 +2204,8 @@ extern int		dev_set_mtu(struct net_device *, int);
 extern void		dev_set_group(struct net_device *, int);
 extern int		dev_set_mac_address(struct net_device *,
 					    struct sockaddr *);
+extern int		dev_change_carrier(struct net_device *,
+					   bool new_carrier);
 extern int		dev_hard_start_xmit(struct sk_buff *skb,
 					    struct net_device *dev,
 					    struct netdev_queue *txq);
diff --git a/net/core/dev.c b/net/core/dev.c
index 515473e..21c5b97 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5027,6 +5027,25 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
 }
 EXPORT_SYMBOL(dev_set_mac_address);
 
+/**
+ *	dev_change_carrier - Change device carrier
+ *	@dev: device
+ *	@new_carries: new value
+ *
+ *	Change device carrier
+ */
+int dev_change_carrier(struct net_device *dev, bool new_carrier)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_change_carrier)
+		return -EOPNOTSUPP;
+	if (!netif_device_present(dev))
+		return -ENODEV;
+	return ops->ndo_change_carrier(dev, new_carrier);
+}
+EXPORT_SYMBOL(dev_change_carrier);
+
 /*
  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
  */
-- 
1.8.0

[patch net-next V3 0/4] net: allow to change carrier from userspace

[Jiri Pirko]

This is basically a V3 of a repost of my previous patchset:
"[patch net-next-2.6 0/2] net: allow to change carrier via sysfs" from Aug 30

The way net-sysfs stores values changed and this patchset reflects it.
Also, I exposed carrier via rtnetlink iface.

So far, only dummy driver uses carrier change ndo. In very near future
team driver will use that as well.

V2->V3:
 - updated ndo_change_carrier comment by Dan Williams

V1->v2:
 - added bigger comment to ndo and also note to operstate.txt documentation
   stating the clear purpose of this iface

Jiri Pirko (4):
  net: add change_carrier netdev op
  net: allow to change carrier via sysfs
  rtnl: expose carrier value with possibility to set it
  dummy: implement carrier change

 Documentation/networking/operstates.txt |  4 ++++
 drivers/net/dummy.c                     | 10 ++++++++++
 include/linux/netdevice.h               | 12 ++++++++++++
 include/uapi/linux/if_link.h            |  1 +
 net/core/dev.c                          | 19 +++++++++++++++++++
 net/core/net-sysfs.c                    | 15 ++++++++++++++-
 net/core/rtnetlink.c                    | 10 ++++++++++
 7 files changed, 70 insertions(+), 1 deletion(-)

-- 
1.8.0

[patch net-next 1/4] net: add change_carrier netdev op

[Jiri Pirko]

This allows a driver to register change_carrier callback which will be
called whenever user will like to change carrier state. This is useful
for devices like dummy, gre, team and so on.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 include/linux/netdevice.h | 12 ++++++++++++
 net/core/dev.c            | 19 +++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 02e0f6b..22ca4a8 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -891,6 +891,14 @@ struct netdev_fcoe_hbainfo {
  * int (*ndo_bridge_setlink)(struct net_device *dev, struct nlmsghdr *nlh)
  * int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
  *			     struct net_device *dev)
+ *
+ * int (*ndo_change_carrier)(struct net_device *dev, bool new_carrier);
+ *	Called to change device carrier. Soft-devices (like dummy, team, etc)
+ *	which do not represent real hardware may define this to allow their
+ *	userspace components to manage their virtual carrier state. Devices
+ *	that determine carrier state from physical hardware properties (eg
+ *	network cables) or protocol-dependent mechanisms (eg
+ *	USB_CDC_NOTIFY_NETWORK_CONNECTION) should NOT implement this function.
  */
 struct net_device_ops {
 	int			(*ndo_init)(struct net_device *dev);
@@ -1008,6 +1016,8 @@ struct net_device_ops {
 	int			(*ndo_bridge_getlink)(struct sk_buff *skb,
 						      u32 pid, u32 seq,
 						      struct net_device *dev);
+	int			(*ndo_change_carrier)(struct net_device *dev,
+						      bool new_carrier);
 };
 
 /*
@@ -2194,6 +2204,8 @@ extern int		dev_set_mtu(struct net_device *, int);
 extern void		dev_set_group(struct net_device *, int);
 extern int		dev_set_mac_address(struct net_device *,
 					    struct sockaddr *);
+extern int		dev_change_carrier(struct net_device *,
+					   bool new_carrier);
 extern int		dev_hard_start_xmit(struct sk_buff *skb,
 					    struct net_device *dev,
 					    struct netdev_queue *txq);
diff --git a/net/core/dev.c b/net/core/dev.c
index d0cbc93..268a714 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5027,6 +5027,25 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
 }
 EXPORT_SYMBOL(dev_set_mac_address);
 
+/**
+ *	dev_change_carrier - Change device carrier
+ *	@dev: device
+ *	@new_carries: new value
+ *
+ *	Change device carrier
+ */
+int dev_change_carrier(struct net_device *dev, bool new_carrier)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_change_carrier)
+		return -EOPNOTSUPP;
+	if (!netif_device_present(dev))
+		return -ENODEV;
+	return ops->ndo_change_carrier(dev, new_carrier);
+}
+EXPORT_SYMBOL(dev_change_carrier);
+
 /*
  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
  */
-- 
1.8.0

[patch net-next 0/4] net: allow to change carrier from userspace

[Jiri Pirko]

This is basically a repost of my previous patchset:
"[patch net-next-2.6 0/2] net: allow to change carrier via sysfs" from Aug 30

The way net-sysfs stores values changed and this patchset reflects it.
Also, I exposed carrier via rtnetlink iface.

So far, only dummy driver uses carrier change ndo. In very near future
team driver will use that as well.

Jiri Pirko (4):
  net: add change_carrier netdev op
  net: allow to change carrier via sysfs
  rtnl: expose carrier value with possibility to set it
  dummy: implement carrier change

 drivers/net/dummy.c          | 10 ++++++++++
 include/linux/netdevice.h    |  7 +++++++
 include/uapi/linux/if_link.h |  1 +
 net/core/dev.c               | 19 +++++++++++++++++++
 net/core/net-sysfs.c         | 15 ++++++++++++++-
 net/core/rtnetlink.c         | 10 ++++++++++
 6 files changed, 61 insertions(+), 1 deletion(-)

-- 
1.8.0

[patch net-next 1/4] net: add change_carrier netdev op

[Jiri Pirko]

This allows a driver to register change_carrier callback which will be
called whenever user will like to change carrier state. This is useful
for devices like dummy, gre, team and so on.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 include/linux/netdevice.h |  7 +++++++
 net/core/dev.c            | 19 +++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c6a14d4..e1a5c16 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -891,6 +891,9 @@ struct netdev_fcoe_hbainfo {
  * int (*ndo_bridge_setlink)(struct net_device *dev, struct nlmsghdr *nlh)
  * int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
  *			     struct net_device *dev)
+ *
+ * int (*ndo_change_carrier)(struct net_device *dev, bool new_carrier);
+ *	Called to update device carrier.
  */
 struct net_device_ops {
 	int			(*ndo_init)(struct net_device *dev);
@@ -1008,6 +1011,8 @@ struct net_device_ops {
 	int			(*ndo_bridge_getlink)(struct sk_buff *skb,
 						      u32 pid, u32 seq,
 						      struct net_device *dev);
+	int			(*ndo_change_carrier)(struct net_device *dev,
+						      bool new_carrier);
 };
 
 /*
@@ -2191,6 +2196,8 @@ extern int		dev_set_mtu(struct net_device *, int);
 extern void		dev_set_group(struct net_device *, int);
 extern int		dev_set_mac_address(struct net_device *,
 					    struct sockaddr *);
+extern int		dev_change_carrier(struct net_device *,
+					   bool new_carrier);
 extern int		dev_hard_start_xmit(struct sk_buff *skb,
 					    struct net_device *dev,
 					    struct netdev_queue *txq);
diff --git a/net/core/dev.c b/net/core/dev.c
index 4783850..cc6426b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5025,6 +5025,25 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
 }
 EXPORT_SYMBOL(dev_set_mac_address);
 
+/**
+ *	dev_change_carrier - Change device carrier
+ *	@dev: device
+ *	@new_carries: new value
+ *
+ *	Change device carrier
+ */
+int dev_change_carrier(struct net_device *dev, bool new_carrier)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_change_carrier)
+		return -EOPNOTSUPP;
+	if (!netif_device_present(dev))
+		return -ENODEV;
+	return ops->ndo_change_carrier(dev, new_carrier);
+}
+EXPORT_SYMBOL(dev_change_carrier);
+
 /*
  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
  */
-- 
1.8.0