2017-09-04 08:36:29

by Haishuang Yan

Subject: [PATCH v3 1/2] ip_tunnel: fix ip tunnel lookup in collect_md mode

In collect_md mode, if the tun dev is down, it still can call
ip_tunnel_rcv to receive on packets, and the rx statistics increase
improperly.

Fixes: 2e15ea390e6f ("ip_gre: Add support to collect tunnel metadata.")
Cc: Pravin B Shelar <[email protected]>
Signed-off-by: Haishuang Yan <[email protected]>

---
Change since v3:
* Increment rx_dropped if tunnel device is not up, suggested by
Pravin B Shelar
* Fix wrong recipient addresss
---
net/ipv4/ip_tunnel.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index e1856bf..5b2e542 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -176,8 +176,11 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
return cand;

t = rcu_dereference(itn->collect_md_tun);
- if (t)
- return t;
+ if (t) {
+ if (t->dev->flags & IFF_UP)
+ return t;
+ t->dev->stats.rx_dropped++;
+ }

if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP)
return netdev_priv(itn->fb_tunnel_dev);
--
1.8.3.1

2017-09-04 08:36:37

by Haishuang Yan

Subject: [PATCH v3 2/2] ip6_tunnel: fix ip6 tunnel lookup in collect_md mode

In collect_md mode, if the tun dev is down, it still can call
__ip6_tnl_rcv to receive on packets, and the rx statistics increase
improperly.

Fixes: 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
Cc: Alexei Starovoitov <[email protected]>
Signed-off-by: Haishuang Yan <[email protected]>

---
Change since v3:
* Increment rx_dropped if tunnel device is not up, suggested by
Pravin B Shelar
* Fix wrong recipient address
---
net/ipv6/ip6_tunnel.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 10a693a..e91d3b6 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -171,8 +171,11 @@ static struct net_device_stats *ip6_get_stats(struct net_device *dev)
}

t = rcu_dereference(ip6n->collect_md_tun);
- if (t)
- return t;
+ if (t) {
+ if (t->dev->flags & IFF_UP)
+ return t;
+ t->dev->stats.rx_dropped++;
+ }

t = rcu_dereference(ip6n->tnls_wc[0]);
if (t && (t->dev->flags & IFF_UP))
--
1.8.3.1

2017-09-06 03:15:04

by Alexei Starovoitov

Subject: Re: [PATCH v3 2/2] ip6_tunnel: fix ip6 tunnel lookup in collect_md mode

On 9/4/17 1:36 AM, Haishuang Yan wrote:
> In collect_md mode, if the tun dev is down, it still can call
> __ip6_tnl_rcv to receive on packets, and the rx statistics increase
> improperly.
>
> Fixes: 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
> Cc: Alexei Starovoitov <[email protected]>
> Signed-off-by: Haishuang Yan <[email protected]>
>
> ---
> Change since v3:
> * Increment rx_dropped if tunnel device is not up, suggested by
> Pravin B Shelar
> * Fix wrong recipient address
> ---
> net/ipv6/ip6_tunnel.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
> index 10a693a..e91d3b6 100644
> --- a/net/ipv6/ip6_tunnel.c
> +++ b/net/ipv6/ip6_tunnel.c
> @@ -171,8 +171,11 @@ static struct net_device_stats *ip6_get_stats(struct net_device *dev)
> }
>
> t = rcu_dereference(ip6n->collect_md_tun);
> - if (t)
> - return t;
> + if (t) {
> + if (t->dev->flags & IFF_UP)
> + return t;
> + t->dev->stats.rx_dropped++;
> + }

Why increment the stats only for this drop case?
There are plenty of other conditions where packet
will be dropped in ip6 tunnel. I think it's important
to present consistent behavior to the users,
so I'd increment drop stats either for all drop cases
or for none. And today it's none.
The ! IFF_UP case should probably be return NULL too.

2017-09-06 06:39:14

by Haishuang Yan

Subject: Re: [PATCH v3 2/2] ip6_tunnel: fix ip6 tunnel lookup in collect_md mode

> On 2017??9??6??, at ????11:14, Alexei Starovoitov <[email protected]> wrote:
>
> On 9/4/17 1:36 AM, Haishuang Yan wrote:
>> In collect_md mode, if the tun dev is down, it still can call
>> __ip6_tnl_rcv to receive on packets, and the rx statistics increase
>> improperly.
>>
>> Fixes: 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
>> Cc: Alexei Starovoitov <[email protected]>
>> Signed-off-by: Haishuang Yan <[email protected]>
>>
>> ---
>> Change since v3:
>> * Increment rx_dropped if tunnel device is not up, suggested by
>> Pravin B Shelar
>> * Fix wrong recipient address
>> ---
>> net/ipv6/ip6_tunnel.c | 7 +++++--
>> 1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
>> index 10a693a..e91d3b6 100644
>> --- a/net/ipv6/ip6_tunnel.c
>> +++ b/net/ipv6/ip6_tunnel.c
>> @@ -171,8 +171,11 @@ static struct net_device_stats *ip6_get_stats(struct net_device *dev)
>> }
>>
>> t = rcu_dereference(ip6n->collect_md_tun);
>> - if (t)
>> - return t;
>> + if (t) {
>> + if (t->dev->flags & IFF_UP)
>> + return t;
>> + t->dev->stats.rx_dropped++;
>> + }
>
> Why increment the stats only for this drop case?
Because It was suggested by Pravin on v2 commit of the patch.

> There are plenty of other conditions where packet
> will be dropped in ip6 tunnel. I think it's important
> to present consistent behavior to the users,
> so I'd increment drop stats either for all drop cases
> or for none. And today it's none.
> The ! IFF_UP case should probably be return NULL too
>
>