* [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
@ 2010-12-25 13:41 Changli Gao
2010-12-31 19:10 ` David Miller
0 siblings, 1 reply; 8+ messages in thread
From: Changli Gao @ 2010-12-25 13:41 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: David S. Miller, bridge, netdev, Changli Gao
Since nf_bridge_maybe_copy_header() may change the length of skb,
we should check the length of skb after it to handle the ppoe skbs.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
---
net/bridge/br_forward.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 2bd11ec..ee64287 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -41,17 +41,13 @@ static inline unsigned packet_length(const struct sk_buff *skb)
int br_dev_queue_push_xmit(struct sk_buff *skb)
{
- /* drop mtu oversized packets except gso */
- if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
+ /* ip_fragment doesn't copy the MAC header */
+ if (nf_bridge_maybe_copy_header(skb) ||
+ (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))) {
kfree_skb(skb);
- else {
- /* ip_fragment doesn't copy the MAC header */
- if (nf_bridge_maybe_copy_header(skb))
- kfree_skb(skb);
- else {
- skb_push(skb, ETH_HLEN);
- dev_queue_xmit(skb);
- }
+ } else {
+ skb_push(skb, ETH_HLEN);
+ dev_queue_xmit(skb);
}
return 0;
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
2010-12-25 13:41 [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header() Changli Gao
@ 2010-12-31 19:10 ` David Miller
2011-01-03 10:44 ` Changli Gao
0 siblings, 1 reply; 8+ messages in thread
From: David Miller @ 2010-12-31 19:10 UTC (permalink / raw)
To: xiaosuo; +Cc: shemminger, bridge, netdev
From: Changli Gao <xiaosuo@gmail.com>
Date: Sat, 25 Dec 2010 21:41:30 +0800
> Since nf_bridge_maybe_copy_header() may change the length of skb,
> we should check the length of skb after it to handle the ppoe skbs.
>
> Signed-off-by: Changli Gao <xiaosuo@gmail.com>
This is really strange.
packet_length() subtracts VLAN_HLEN from the value it returns, so the
correct fix seems to be to make this function handle the PPPOE case
too.
Otherwise I suspect you have many other functions to fix as well.
I'm not applying this patch.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
2010-12-31 19:10 ` David Miller
@ 2011-01-03 10:44 ` Changli Gao
2011-01-03 17:22 ` David Miller
0 siblings, 1 reply; 8+ messages in thread
From: Changli Gao @ 2011-01-03 10:44 UTC (permalink / raw)
To: David Miller; +Cc: shemminger, bridge, netdev
On Sat, Jan 1, 2011 at 3:10 AM, David Miller <davem@davemloft.net> wrote:
> From: Changli Gao <xiaosuo@gmail.com>
> Date: Sat, 25 Dec 2010 21:41:30 +0800
>
>> Since nf_bridge_maybe_copy_header() may change the length of skb,
>> we should check the length of skb after it to handle the ppoe skbs.
>>
>> Signed-off-by: Changli Gao <xiaosuo@gmail.com>
>
> This is really strange.
>
> packet_length() subtracts VLAN_HLEN from the value it returns, so the
> correct fix seems to be to make this function handle the PPPOE case
> too.
>
It is correct. The actual MTU of 802.1q frame is 4 bytes larger. For
example, the MTU of ethernet is normally 1500, however the actual MTU
of the 802.1Q is 1504.
Please see this patch:
http://git.kernel.org/?p=linux/kernel/git/davem/net-next-2.6.git;a=commitdiff;h=c893b8066c7bf6156e4d760e5acaf4c148e37190;hp=3c0fef0b7d36e5f8d3ea3731a8228102274e3c23
> Otherwise I suspect you have many other functions to fix as well.
>
> I'm not applying this patch.
>
--
Regards,
Changli Gao(xiaosuo@gmail.com)
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
2011-01-03 10:44 ` Changli Gao
@ 2011-01-03 17:22 ` David Miller
2011-01-03 18:15 ` Stephen Hemminger
0 siblings, 1 reply; 8+ messages in thread
From: David Miller @ 2011-01-03 17:22 UTC (permalink / raw)
To: xiaosuo; +Cc: shemminger, bridge, netdev
From: Changli Gao <xiaosuo@gmail.com>
Date: Mon, 3 Jan 2011 18:44:59 +0800
> On Sat, Jan 1, 2011 at 3:10 AM, David Miller <davem@davemloft.net> wrote:
>> From: Changli Gao <xiaosuo@gmail.com>
>> Date: Sat, 25 Dec 2010 21:41:30 +0800
>>
>>> Since nf_bridge_maybe_copy_header() may change the length of skb,
>>> we should check the length of skb after it to handle the ppoe skbs.
>>>
>>> Signed-off-by: Changli Gao <xiaosuo@gmail.com>
>>
>> This is really strange.
>>
>> packet_length() subtracts VLAN_HLEN from the value it returns, so the
>> correct fix seems to be to make this function handle the PPPOE case
>> too.
>>
>
> It is correct. The actual MTU of 802.1q frame is 4 bytes larger. For
> example, the MTU of ethernet is normally 1500, however the actual MTU
> of the 802.1Q is 1504.
Yes, I understand this, but I don't see why packet_length() cannot
simply account for PPPOE's encapsulation overhead just as it does for
VLAN's special MTU considerations.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
2011-01-03 17:22 ` David Miller
@ 2011-01-03 18:15 ` Stephen Hemminger
2011-01-03 20:13 ` David Miller
0 siblings, 1 reply; 8+ messages in thread
From: Stephen Hemminger @ 2011-01-03 18:15 UTC (permalink / raw)
To: David Miller; +Cc: xiaosuo, bridge, netdev
On Mon, 03 Jan 2011 09:22:14 -0800 (PST)
David Miller <davem@davemloft.net> wrote:
> From: Changli Gao <xiaosuo@gmail.com>
> Date: Mon, 3 Jan 2011 18:44:59 +0800
>
> > On Sat, Jan 1, 2011 at 3:10 AM, David Miller <davem@davemloft.net> wrote:
> >> From: Changli Gao <xiaosuo@gmail.com>
> >> Date: Sat, 25 Dec 2010 21:41:30 +0800
> >>
> >>> Since nf_bridge_maybe_copy_header() may change the length of skb,
> >>> we should check the length of skb after it to handle the ppoe skbs.
> >>>
> >>> Signed-off-by: Changli Gao <xiaosuo@gmail.com>
> >>
> >> This is really strange.
> >>
> >> packet_length() subtracts VLAN_HLEN from the value it returns, so the
> >> correct fix seems to be to make this function handle the PPPOE case
> >> too.
> >>
> >
> > It is correct. The actual MTU of 802.1q frame is 4 bytes larger. For
> > example, the MTU of ethernet is normally 1500, however the actual MTU
> > of the 802.1Q is 1504.
>
> Yes, I understand this, but I don't see why packet_length() cannot
> simply account for PPPOE's encapsulation overhead just as it does for
> VLAN's special MTU considerations.
Because PPPOE happens afterwards and is not part the calculation.
The check should be moved until after skb has reached final form.
--
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
2011-01-03 18:15 ` Stephen Hemminger
@ 2011-01-03 20:13 ` David Miller
2011-01-05 13:37 ` Changli Gao
0 siblings, 1 reply; 8+ messages in thread
From: David Miller @ 2011-01-03 20:13 UTC (permalink / raw)
To: shemminger; +Cc: xiaosuo, bridge, netdev
From: Stephen Hemminger <shemminger@linux-foundation.org>
Date: Mon, 3 Jan 2011 10:15:33 -0800
> On Mon, 03 Jan 2011 09:22:14 -0800 (PST)
> David Miller <davem@davemloft.net> wrote:
>
>> From: Changli Gao <xiaosuo@gmail.com>
>> Date: Mon, 3 Jan 2011 18:44:59 +0800
>>
>> > On Sat, Jan 1, 2011 at 3:10 AM, David Miller <davem@davemloft.net> wrote:
>> >> From: Changli Gao <xiaosuo@gmail.com>
>> >> Date: Sat, 25 Dec 2010 21:41:30 +0800
>> >>
>> >>> Since nf_bridge_maybe_copy_header() may change the length of skb,
>> >>> we should check the length of skb after it to handle the ppoe skbs.
>> >>>
>> >>> Signed-off-by: Changli Gao <xiaosuo@gmail.com>
>> >>
>> >> This is really strange.
>> >>
>> >> packet_length() subtracts VLAN_HLEN from the value it returns, so the
>> >> correct fix seems to be to make this function handle the PPPOE case
>> >> too.
>> >>
>> >
>> > It is correct. The actual MTU of 802.1q frame is 4 bytes larger. For
>> > example, the MTU of ethernet is normally 1500, however the actual MTU
>> > of the 802.1Q is 1504.
>>
>> Yes, I understand this, but I don't see why packet_length() cannot
>> simply account for PPPOE's encapsulation overhead just as it does for
>> VLAN's special MTU considerations.
>
> Because PPPOE happens afterwards and is not part the calculation.
> The check should be moved until after skb has reached final form.
That works for me.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
2011-01-03 20:13 ` David Miller
@ 2011-01-05 13:37 ` Changli Gao
2011-01-06 19:33 ` David Miller
0 siblings, 1 reply; 8+ messages in thread
From: Changli Gao @ 2011-01-05 13:37 UTC (permalink / raw)
To: David Miller; +Cc: shemminger, bridge, netdev
On Tue, Jan 4, 2011 at 4:13 AM, David Miller <davem@davemloft.net> wrote:
> From: Stephen Hemminger <shemminger@linux-foundation.org>
>>
>> Because PPPOE happens afterwards and is not part the calculation.
>> The check should be moved until after skb has reached final form.
>
> That works for me.
>
So, is my patch acceptable?
--
Regards,
Changli Gao(xiaosuo@gmail.com)
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
2011-01-05 13:37 ` Changli Gao
@ 2011-01-06 19:33 ` David Miller
0 siblings, 0 replies; 8+ messages in thread
From: David Miller @ 2011-01-06 19:33 UTC (permalink / raw)
To: xiaosuo; +Cc: shemminger, bridge, netdev
From: Changli Gao <xiaosuo@gmail.com>
Date: Wed, 5 Jan 2011 21:37:28 +0800
> On Tue, Jan 4, 2011 at 4:13 AM, David Miller <davem@davemloft.net> wrote:
>> From: Stephen Hemminger <shemminger@linux-foundation.org>
>>>
>>> Because PPPOE happens afterwards and is not part the calculation.
>>> The check should be moved until after skb has reached final form.
>>
>> That works for me.
>>
>
> So, is my patch acceptable?
Yes, I've applied it, thank you.
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2011-01-06 19:32 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
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2010-12-25 13:41 [PATCH] net: bridge: check the length of skb after nf_bridge_maybe_copy_header() Changli Gao
2010-12-31 19:10 ` David Miller
2011-01-03 10:44 ` Changli Gao
2011-01-03 17:22 ` David Miller
2011-01-03 18:15 ` Stephen Hemminger
2011-01-03 20:13 ` David Miller
2011-01-05 13:37 ` Changli Gao
2011-01-06 19:33 ` David Miller
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