[net-next] IFLA_STATS64, tcp cong modules

[net-next] IFLA_STATS64, tcp cong modules

[Jan Engelhardt]

Hi!


Here are three simple patches for net-next aka to-be-2.6.35.

The following changes since commit 3a5b27bf6f29574d667230c7e76e4b83fe3014e0:
  Linus Torvalds (1):
        Merge branch 'for-linus' of git://gitorious.org/linux-omap-dss2/linux

are available in the git repository at:

  git://dev.medozas.de/linux net

Jan Engelhardt (3):
      net: tcp: make hybla selectable as default congestion module
      net: tcp: make veno selectable as default congestion module
      net: core: add IFLA_STATS64 support

 include/linux/if_link.h |   33 +++++++++++++++++++++++++++++++++
 net/core/rtnetlink.c    |   42 +++++++++++++++++++++++++++++++++++++++++-
 net/ipv4/Kconfig        |    8 ++++++++
 3 files changed, 82 insertions(+), 1 deletions(-)

[PATCH 1/3] net: tcp: make hybla selectable as default congestion module

[Jan Engelhardt]

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 net/ipv4/Kconfig |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 0c94a1a..731c47b 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -587,6 +587,9 @@ choice
 	config DEFAULT_HTCP
 		bool "Htcp" if TCP_CONG_HTCP=y
 
+	config DEFAULT_HYBLA
+		bool "Hybla" if TCP_CONG_HYBLA=y
+
 	config DEFAULT_VEGAS
 		bool "Vegas" if TCP_CONG_VEGAS=y
 
@@ -610,6 +613,7 @@ config DEFAULT_TCP_CONG
 	default "bic" if DEFAULT_BIC
 	default "cubic" if DEFAULT_CUBIC
 	default "htcp" if DEFAULT_HTCP
+	default "hybla" if DEFAULT_HYBLA
 	default "vegas" if DEFAULT_VEGAS
 	default "westwood" if DEFAULT_WESTWOOD
 	default "reno" if DEFAULT_RENO
-- 
1.7.0

[PATCH 2/3] net: tcp: make veno selectable as default congestion module

[Jan Engelhardt]

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 net/ipv4/Kconfig |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 731c47b..c9a1c68 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -593,6 +593,9 @@ choice
 	config DEFAULT_VEGAS
 		bool "Vegas" if TCP_CONG_VEGAS=y
 
+	config DEFAULT_VENO
+		bool "Veno" if TCP_CONG_VENO=y
+
 	config DEFAULT_WESTWOOD
 		bool "Westwood" if TCP_CONG_WESTWOOD=y
 
@@ -616,6 +619,7 @@ config DEFAULT_TCP_CONG
 	default "hybla" if DEFAULT_HYBLA
 	default "vegas" if DEFAULT_VEGAS
 	default "westwood" if DEFAULT_WESTWOOD
+	default "veno" if DEFAULT_VENO
 	default "reno" if DEFAULT_RENO
 	default "cubic"
 
-- 
1.7.0

[PATCH 3/3] net: core: add IFLA_STATS64 support

[Jan Engelhardt]

`ip -s link` shows interface counters truncated to 32 bit. This is
because interface statistics are transported only in 32-bit quantity
to userspace. This commit adds a new IFLA_STATS64 attribute that
exports them in full 64 bit.

References: http://lkml.indiana.edu/hypermail/linux/kernel/0307.3/0215.html
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
---
 include/linux/if_link.h |   33 +++++++++++++++++++++++++++++++++
 net/core/rtnetlink.c    |   42 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 74 insertions(+), 1 deletions(-)

diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index c9bf92c..cfd420b 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -37,6 +37,38 @@ struct rtnl_link_stats {
 	__u32	tx_compressed;
 };
 
+struct rtnl_link_stats64 {
+	__u64	rx_packets;		/* total packets received	*/
+	__u64	tx_packets;		/* total packets transmitted	*/
+	__u64	rx_bytes;		/* total bytes received 	*/
+	__u64	tx_bytes;		/* total bytes transmitted	*/
+	__u64	rx_errors;		/* bad packets received		*/
+	__u64	tx_errors;		/* packet transmit problems	*/
+	__u64	rx_dropped;		/* no space in linux buffers	*/
+	__u64	tx_dropped;		/* no space available in linux	*/
+	__u64	multicast;		/* multicast packets received	*/
+	__u64	collisions;
+
+	/* detailed rx_errors: */
+	__u64	rx_length_errors;
+	__u64	rx_over_errors;		/* receiver ring buff overflow	*/
+	__u64	rx_crc_errors;		/* recved pkt with crc error	*/
+	__u64	rx_frame_errors;	/* recv'd frame alignment error */
+	__u64	rx_fifo_errors;		/* recv'r fifo overrun		*/
+	__u64	rx_missed_errors;	/* receiver missed packet	*/
+
+	/* detailed tx_errors */
+	__u64	tx_aborted_errors;
+	__u64	tx_carrier_errors;
+	__u64	tx_fifo_errors;
+	__u64	tx_heartbeat_errors;
+	__u64	tx_window_errors;
+
+	/* for cslip etc */
+	__u64	rx_compressed;
+	__u64	tx_compressed;
+};
+
 /* The struct should be in sync with struct ifmap */
 struct rtnl_link_ifmap {
 	__u64	mem_start;
@@ -83,6 +115,7 @@ enum {
 	IFLA_VF_VLAN,
 	IFLA_VF_TX_RATE,	/* TX Bandwidth Allocation */
 	IFLA_VFINFO,
+	IFLA_STATS64,
 	__IFLA_MAX
 };
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 4568120..e1121f0 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -600,7 +600,39 @@ static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
 
 	a->rx_compressed = b->rx_compressed;
 	a->tx_compressed = b->tx_compressed;
-};
+}
+
+static void copy_rtnl_link_stats64(struct rtnl_link_stats64 *a,
+				   const struct net_device_stats *b)
+{
+	a->rx_packets = b->rx_packets;
+	a->tx_packets = b->tx_packets;
+	a->rx_bytes = b->rx_bytes;
+	a->tx_bytes = b->tx_bytes;
+	a->rx_errors = b->rx_errors;
+	a->tx_errors = b->tx_errors;
+	a->rx_dropped = b->rx_dropped;
+	a->tx_dropped = b->tx_dropped;
+
+	a->multicast = b->multicast;
+	a->collisions = b->collisions;
+
+	a->rx_length_errors = b->rx_length_errors;
+	a->rx_over_errors = b->rx_over_errors;
+	a->rx_crc_errors = b->rx_crc_errors;
+	a->rx_frame_errors = b->rx_frame_errors;
+	a->rx_fifo_errors = b->rx_fifo_errors;
+	a->rx_missed_errors = b->rx_missed_errors;
+
+	a->tx_aborted_errors = b->tx_aborted_errors;
+	a->tx_carrier_errors = b->tx_carrier_errors;
+	a->tx_fifo_errors = b->tx_fifo_errors;
+	a->tx_heartbeat_errors = b->tx_heartbeat_errors;
+	a->tx_window_errors = b->tx_window_errors;
+
+	a->rx_compressed = b->rx_compressed;
+	a->tx_compressed = b->tx_compressed;
+}
 
 static inline int rtnl_vfinfo_size(const struct net_device *dev)
 {
@@ -698,6 +730,14 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 	stats = dev_get_stats(dev);
 	copy_rtnl_link_stats(nla_data(attr), stats);
 
+	attr = nla_reserve(skb, IFLA_STATS64,
+			sizeof(struct rtnl_link_stats64));
+	if (attr == NULL)
+		goto nla_put_failure;
+
+	stats = dev_get_stats(dev);
+	copy_rtnl_link_stats64(nla_data(attr), stats);
+
 	if (dev->netdev_ops->ndo_get_vf_config && dev->dev.parent) {
 		int i;
 		struct ifla_vf_info ivi;
-- 
1.7.0

Re: [PATCH 1/3] net: tcp: make hybla selectable as default congestion module

[Stephen Hemminger]

On Thu, 11 Mar 2010 20:57:27 +0100
Jan Engelhardt <jengelh@medozas.de> wrote:

> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
> ---
>  net/ipv4/Kconfig |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
> index 0c94a1a..731c47b 100644
> --- a/net/ipv4/Kconfig
> +++ b/net/ipv4/Kconfig
> @@ -587,6 +587,9 @@ choice
>  	config DEFAULT_HTCP
>  		bool "Htcp" if TCP_CONG_HTCP=y
>  
> +	config DEFAULT_HYBLA
> +		bool "Hybla" if TCP_CONG_HYBLA=y
> +
>  	config DEFAULT_VEGAS
>  		bool "Vegas" if TCP_CONG_VEGAS=y
>  
> @@ -610,6 +613,7 @@ config DEFAULT_TCP_CONG
>  	default "bic" if DEFAULT_BIC
>  	default "cubic" if DEFAULT_CUBIC
>  	default "htcp" if DEFAULT_HTCP
> +	default "hybla" if DEFAULT_HYBLA
>  	default "vegas" if DEFAULT_VEGAS
>  	default "westwood" if DEFAULT_WESTWOOD
>  	default "reno" if DEFAULT_RENO

Hybla seems too experimental to be made default.

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[Stephen Hemminger]

On Thu, 11 Mar 2010 20:57:29 +0100
Jan Engelhardt <jengelh@medozas.de> wrote:

> `ip -s link` shows interface counters truncated to 32 bit. This is
> because interface statistics are transported only in 32-bit quantity
> to userspace. This commit adds a new IFLA_STATS64 attribute that
> exports them in full 64 bit.
> 
> References: http://lkml.indiana.edu/hypermail/linux/kernel/0307.3/0215.html
> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
> 

What is the point since net_device_stats has only 32 bit counters.
The last time this came up the issue was is that is not possible
to atomically increment a 64 bit counter on most 32 bit platforms.

Re: [PATCH 1/3] net: tcp: make hybla selectable as default congestion module

[Jan Engelhardt]

On Thursday 2010-03-11 21:10, Stephen Hemminger wrote:
>> 
>> diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
>> index 0c94a1a..731c47b 100644
>> --- a/net/ipv4/Kconfig
>> +++ b/net/ipv4/Kconfig
>> @@ -587,6 +587,9 @@ choice
>>  	config DEFAULT_HTCP
>>  		bool "Htcp" if TCP_CONG_HTCP=y
>>  
>> +	config DEFAULT_HYBLA
>> +		bool "Hybla" if TCP_CONG_HYBLA=y
>> +
>>  	config DEFAULT_VEGAS
>>  		bool "Vegas" if TCP_CONG_VEGAS=y
>>  
>> @@ -610,6 +613,7 @@ config DEFAULT_TCP_CONG
>>  	default "bic" if DEFAULT_BIC
>>  	default "cubic" if DEFAULT_CUBIC
>>  	default "htcp" if DEFAULT_HTCP
>> +	default "hybla" if DEFAULT_HYBLA
>>  	default "vegas" if DEFAULT_VEGAS
>>  	default "westwood" if DEFAULT_WESTWOOD
>>  	default "reno" if DEFAULT_RENO
>
>Hybla seems too experimental to be made default.

I run Hybla since 2006 on anything that is not connected via
wireless and I did not notice any pressing issues.

Also, the patch does not make hybla the default default (reno remains),
just the default once explicitly selected in a two-step process:

1. CONFIG_TCP_CONG_HYBLA=y
*and*
2. choosing Hybla in CONFIG_DEFAULT_TCP_CONG

I think that is enough of a "safety measure" against any potential
unsuspecting users.

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[Eric Dumazet]

Le jeudi 11 mars 2010 à 20:57 +0100, Jan Engelhardt a écrit :
> `ip -s link` shows interface counters truncated to 32 bit. This is
> because interface statistics are transported only in 32-bit quantity
> to userspace. This commit adds a new IFLA_STATS64 attribute that
> exports them in full 64 bit.
> 
> References: http://lkml.indiana.edu/hypermail/linux/kernel/0307.3/0215.html

oh oh, back to  2003 :)

> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
> ---
>  
>  static inline int rtnl_vfinfo_size(const struct net_device *dev)
>  {
> @@ -698,6 +730,14 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
>  	stats = dev_get_stats(dev);

OK, stats is up2date with device stats

>  	copy_rtnl_link_stats(nla_data(attr), stats);
>  
> +	attr = nla_reserve(skb, IFLA_STATS64,
> +			sizeof(struct rtnl_link_stats64));
> +	if (attr == NULL)
> +		goto nla_put_failure;
> +
> +	stats = dev_get_stats(dev);

Why calling dev_get_stats(dev) a second time ?
Its can be pretty expensive on some devices.

> +	copy_rtnl_link_stats64(nla_data(attr), stats);
> +
>  	if (dev->netdev_ops->ndo_get_vf_config && dev->dev.parent) {
>  		int i;
>  		struct ifla_vf_info ivi;
> -- 

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Thu, 11 Mar 2010 12:12:39 -0800

> On Thu, 11 Mar 2010 20:57:29 +0100
> Jan Engelhardt <jengelh@medozas.de> wrote:
> 
>> `ip -s link` shows interface counters truncated to 32 bit. This is
>> because interface statistics are transported only in 32-bit quantity
>> to userspace. This commit adds a new IFLA_STATS64 attribute that
>> exports them in full 64 bit.
>> 
>> References: http://lkml.indiana.edu/hypermail/linux/kernel/0307.3/0215.html
>> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
>> 
> 
> What is the point since net_device_stats has only 32 bit counters.
> The last time this came up the issue was is that is not possible
> to atomically increment a 64 bit counter on most 32 bit platforms.

On 64-bit it has 64-bit counters, yet we only report 32-bit
counters to userspace via netlink even in that case.

That's what Jan is fixing here.

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[Jan Engelhardt]

On Thursday 2010-03-11 21:26, David Miller wrote:
>> On Thu, 11 Mar 2010 20:57:29 +0100
>> Jan Engelhardt <jengelh@medozas.de> wrote:
>> 
>>> `ip -s link` shows interface counters truncated to 32 bit. This is
>>> because interface statistics are transported only in 32-bit quantity
>>> to userspace. This commit adds a new IFLA_STATS64 attribute that
>>> exports them in full 64 bit.
>>> 
>>> References: http://lkml.indiana.edu/hypermail/linux/kernel/0307.3/0215.html
>>> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
>>> 
>> 
>> What is the point since net_device_stats has only 32 bit counters.
>> The last time this came up the issue was is that is not possible
>> to atomically increment a 64 bit counter on most 32 bit platforms.
>
>On 64-bit it has 64-bit counters, yet we only report 32-bit
>counters to userspace via netlink even in that case.
>
>That's what Jan is fixing here.

On a side note, is it perhaps possible to use jiffies-like magic to
also have 64-bit counters on 32-bit, or is that still too expensive?

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[David Miller]

From: Jan Engelhardt <jengelh@medozas.de>
Date: Thu, 11 Mar 2010 22:07:07 +0100 (CET)

> On a side note, is it perhaps possible to use jiffies-like magic to
> also have 64-bit counters on 32-bit, or is that still too expensive?

I think there might still be atomicity issues.

We've been telling people to poll periodically in userspace to avoid
these problems, but that has limitations as network speeds increase.

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[Stephen Hemminger]

On Thu, 11 Mar 2010 12:26:39 -0800 (PST)
David Miller <davem@davemloft.net> wrote:

> From: Stephen Hemminger <shemminger@vyatta.com>
> Date: Thu, 11 Mar 2010 12:12:39 -0800
> 
> > On Thu, 11 Mar 2010 20:57:29 +0100
> > Jan Engelhardt <jengelh@medozas.de> wrote:
> > 
> >> `ip -s link` shows interface counters truncated to 32 bit. This is
> >> because interface statistics are transported only in 32-bit quantity
> >> to userspace. This commit adds a new IFLA_STATS64 attribute that
> >> exports them in full 64 bit.
> >> 
> >> References: http://lkml.indiana.edu/hypermail/linux/kernel/0307.3/0215.html
> >> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
> >> 
> > 
> > What is the point since net_device_stats has only 32 bit counters.
> > The last time this came up the issue was is that is not possible
> > to atomically increment a 64 bit counter on most 32 bit platforms.
> 
> On 64-bit it has 64-bit counters, yet we only report 32-bit
> counters to userspace via netlink even in that case.

That make sense, but maybe we shouldn't send IFLA_STATS64 on
32bit platforms.

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[Jan Engelhardt]

On Thursday 2010-03-11 23:04, Stephen Hemminger wrote:
>> >> `ip -s link` shows interface counters truncated to 32 bit. This is
>> >> because interface statistics are transported only in 32-bit quantity
>> >> to userspace. This commit adds a new IFLA_STATS64 attribute that
>> >> exports them in full 64 bit.
>> 
>> On 64-bit it has 64-bit counters, yet we only report 32-bit
>> counters to userspace via netlink even in that case.
>
>That make sense, but maybe we shouldn't send IFLA_STATS64 on
>32bit platforms.

Somehow I'd prefer to have consistency. Platform-specific 
actions and/or payload I think we already were plagued enough by 
syscalls and iptables. (Just to name two.)

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Thu, 11 Mar 2010 14:04:06 -0800

> That make sense, but maybe we shouldn't send IFLA_STATS64 on
> 32bit platforms.

Let's at least be optimistic that we'll be able to support 64-bit
stats on 32-bit at some point :-)

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[Jan Engelhardt]

On Thursday 2010-03-11 23:13, David Miller wrote:
>
>> That make sense, but maybe we shouldn't send IFLA_STATS64 on
>> 32bit platforms.
>
>Let's at least be optimistic that we'll be able to support 64-bit
>stats on 32-bit at some point :-)

I was about to say. There is hope: whenever you least expect it, 
academia comes up with a perfectly foundated theory and plan to solve 
the problem. (N.B.: But the initial implementation generally sucks ;-)

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[Stephen Hemminger]

On Thu, 11 Mar 2010 23:13:18 +0100 (CET)
Jan Engelhardt <jengelh@medozas.de> wrote:

> On Thursday 2010-03-11 23:04, Stephen Hemminger wrote:
> >> >> `ip -s link` shows interface counters truncated to 32 bit. This is
> >> >> because interface statistics are transported only in 32-bit quantity
> >> >> to userspace. This commit adds a new IFLA_STATS64 attribute that
> >> >> exports them in full 64 bit.
> >> 
> >> On 64-bit it has 64-bit counters, yet we only report 32-bit
> >> counters to userspace via netlink even in that case.
> >
> >That make sense, but maybe we shouldn't send IFLA_STATS64 on
> >32bit platforms.
> 
> Somehow I'd prefer to have consistency. Platform-specific 
> actions and/or payload I think we already were plagued enough by 
> syscalls and iptables. (Just to name two.)

But if you send 32bit truncated values when 64 bit is expected
then users are going to complain

-- 

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Thu, 11 Mar 2010 14:50:59 -0800

> But if you send 32bit truncated values when 64 bit is expected
> then users are going to complain

They already complain, a lot.

This isn't going to change the situation at all, and
I agree with Jan that consistency is the trumping factor
here.

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[Stephen Hemminger]

On Thu, 11 Mar 2010 14:54:12 -0800 (PST)
David Miller <davem@davemloft.net> wrote:

> From: Stephen Hemminger <shemminger@vyatta.com>
> Date: Thu, 11 Mar 2010 14:50:59 -0800
> 
> > But if you send 32bit truncated values when 64 bit is expected
> > then users are going to complain
> 
> They already complain, a lot.
> 
> This isn't going to change the situation at all, and
> I agree with Jan that consistency is the trumping factor
> here.

But if non utilities will already adapt to new/old kernel, so
just don't put out 64 bit values if the platform is 32 bit.
When/if 32 bit platforms support it, great add the extra stats.

-- 

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Thu, 11 Mar 2010 15:10:50 -0800

> But if non utilities will already adapt to new/old kernel, so
> just don't put out 64 bit values if the platform is 32 bit.
> When/if 32 bit platforms support it, great add the extra stats.

How about we just make userland ready for it and:

1) Emitting it now will get it tested even on 32-bit

2) They'll be ready when the drivers can keep track of
   64-bit stats too.

Stephen I've heard your side of the story, I just don't
agree with it :-)

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[Stephen Hemminger]

On Thu, 11 Mar 2010 15:15:29 -0800 (PST)
David Miller <davem@davemloft.net> wrote:

> From: Stephen Hemminger <shemminger@vyatta.com>
> Date: Thu, 11 Mar 2010 15:10:50 -0800
> 
> > But if non utilities will already adapt to new/old kernel, so
> > just don't put out 64 bit values if the platform is 32 bit.
> > When/if 32 bit platforms support it, great add the extra stats.
> 
> How about we just make userland ready for it and:
> 
> 1) Emitting it now will get it tested even on 32-bit
> 
> 2) They'll be ready when the drivers can keep track of
>    64-bit stats too.
> 
> Stephen I've heard your side of the story, I just don't
> agree with it :-)

I'm okay with it. just raising the issue.

-- 

Re: [PATCH 1/3] net: tcp: make hybla selectable as default congestion module

[David Miller]

From: Jan Engelhardt <jengelh@medozas.de>
Date: Thu, 11 Mar 2010 20:57:27 +0100

> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

Applied.

Re: [PATCH 2/3] net: tcp: make veno selectable as default congestion module

[David Miller]

From: Jan Engelhardt <jengelh@medozas.de>
Date: Thu, 11 Mar 2010 20:57:28 +0100

> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

Applied.

Re: [PATCH 3/3] net: core: add IFLA_STATS64 support

[David Miller]

From: Jan Engelhardt <jengelh@medozas.de>
Date: Thu, 11 Mar 2010 20:57:29 +0100

> `ip -s link` shows interface counters truncated to 32 bit. This is
> because interface statistics are transported only in 32-bit quantity
> to userspace. This commit adds a new IFLA_STATS64 attribute that
> exports them in full 64 bit.
> 
> References: http://lkml.indiana.edu/hypermail/linux/kernel/0307.3/0215.html
> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

Applied.