Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Ben Hutchings]

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On Fri, 2011-05-06 at 13:12 -0700, Noah Meyerhans wrote:
> Package: linux-2.6
> Version: 2.6.38-3
> Severity: normal
> 
> Hi. I've got a system that hosts several kvm virtual hosts.  The VMs
> access the network via tap devices bridged with a physical interface.
> After upgrading to linux-image-2.6.38-2-amd64_2.6.38-4, I noticed that
> the virtualhosts were not autoconfiguring their IPv6 interfaces.
> Debugging revealed that no multicast was passing over the bridge.
> 
> The bridge configuration is:
> bridge name     bridge id               STP enabled     interfaces
> br0             8000.0002e3080eb5       no              eth1
>                                                         tap0
>                                                         tap1
>                                                         tap2
> 
> If I attach tcpdump to br0, I can see multicast (e.g. IPv6 Neighbor
> Solicitation) packets.  However, if I attach tcpdump to eth1, I do not
> see multicast packets sourced from one of the VMs.
> 
> Downgrading to 2.6.38-3 solves the problem.

This is pretty weird.  Debian version 2.6.38-3 has a few bridging
changes from stable 2.6.38.3 and 2.6.38.4, but they don't look like they
would cause this.

Ben.

-- 
Ben Hutchings
Once a job is fouled up, anything done to improve it makes it worse.

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Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Stephen Hemminger]

On Tue, 10 May 2011 03:38:44 +0100
Ben Hutchings <ben@decadent.org.uk> wrote:

> On Fri, 2011-05-06 at 13:12 -0700, Noah Meyerhans wrote:
> > Package: linux-2.6
> > Version: 2.6.38-3
> > Severity: normal
> > 
> > Hi. I've got a system that hosts several kvm virtual hosts.  The VMs
> > access the network via tap devices bridged with a physical interface.
> > After upgrading to linux-image-2.6.38-2-amd64_2.6.38-4, I noticed that
> > the virtualhosts were not autoconfiguring their IPv6 interfaces.
> > Debugging revealed that no multicast was passing over the bridge.
> > 
> > The bridge configuration is:
> > bridge name     bridge id               STP enabled     interfaces
> > br0             8000.0002e3080eb5       no              eth1
> >                                                         tap0
> >                                                         tap1
> >                                                         tap2
> > 
> > If I attach tcpdump to br0, I can see multicast (e.g. IPv6 Neighbor
> > Solicitation) packets.  However, if I attach tcpdump to eth1, I do not
> > see multicast packets sourced from one of the VMs.
> > 
> > Downgrading to 2.6.38-3 solves the problem.
> 
> This is pretty weird.  Debian version 2.6.38-3 has a few bridging
> changes from stable 2.6.38.3 and 2.6.38.4, but they don't look like they
> would cause this.
> 
> Ben.

There are two possible explainations:
  1. In 2.6.37 and kernels the bridge uses IGMP snooping, there were several
     fixes to that in the stable kernel; especially related to IPv6.

  2. There was also a recent change to block link local multicast
     address. But that should impact what you are doing.

Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Noah Meyerhans]

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On Tue, May 10, 2011 at 03:38:44AM +0100, Ben Hutchings wrote:
> This is pretty weird.  Debian version 2.6.38-3 has a few bridging
> changes from stable 2.6.38.3 and 2.6.38.4, but they don't look like they
> would cause this.

I have apparently filed the bug against the wrong version of Debian's
kernel.  2.6.38-3 is not affected, and works as expected.  The change
was introduced in -4.  That may have been clear from the report itself,
but the report was filed against -3.  I've fixed that in the BTS.

I've also confirmed that -5 is affected, to no great surprise.

I'll investigate further.

noah


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Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Ben Hutchings]

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On Mon, 2011-05-09 at 21:38 -0700, Noah Meyerhans wrote:
> On Tue, May 10, 2011 at 03:38:44AM +0100, Ben Hutchings wrote:
> > This is pretty weird.  Debian version 2.6.38-3 has a few bridging
> > changes from stable 2.6.38.3 and 2.6.38.4, but they don't look like they
> > would cause this.
> 
> I have apparently filed the bug against the wrong version of Debian's
> kernel.  2.6.38-3 is not affected, and works as expected.  The change
> was introduced in -4.  That may have been clear from the report itself,
> but the report was filed against -3.  I've fixed that in the BTS.

I gathered that, and then made the same mistake in writing the above!
The version with the regression, 2.6.38-4, includes the changes from
stable 2.6.38.3 and 2.6.38.4

Ben.

> I've also confirmed that -5 is affected, to no great surprise.
> 
> I'll investigate further.
> 
> noah
> 

-- 
Ben Hutchings
Once a job is fouled up, anything done to improve it makes it worse.

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Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Noah Meyerhans]

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On Tue, May 10, 2011 at 01:42:49PM +0100, Ben Hutchings wrote:
> > > This is pretty weird.  Debian version 2.6.38-3 has a few bridging
> > > changes from stable 2.6.38.3 and 2.6.38.4, but they don't look like they
> > > would cause this.
> > 
> > I have apparently filed the bug against the wrong version of Debian's
> > kernel.  2.6.38-3 is not affected, and works as expected.  The change
> > was introduced in -4.  That may have been clear from the report itself,
> > but the report was filed against -3.  I've fixed that in the BTS.
> 
> I gathered that, and then made the same mistake in writing the above!
> The version with the regression, 2.6.38-4, includes the changes from
> stable 2.6.38.3 and 2.6.38.4

With a little help from git bisect, I've tracked this regression down to
the following commit to the stable-2.6.38.y tree:

commit 5f1c356a3fadc0c19922d660da723b79bcc9aad7
Author: Herbert Xu <herbert@gondor.apana.org.au>
Date:   Fri Mar 18 05:27:28 2011 +0000

    bridge: Reset IPCB when entering IP stack on NF_FORWARD
    
    [ Upstream commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e ]
    
    Whenever we enter the IP stack proper from bridge netfilter we
    need to ensure that the skb is in a form the IP stack expects
    it to be in.
    
    The entry point on NF_FORWARD did not meet the requirements of
    the IP stack, therefore leading to potential crashes/panics.
    
    This patch fixes the problem.
    
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
    Acked-by: Stephen Hemminger <shemminger@vyatta.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The diff is
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 4b5b66d..49d50ea 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -741,6 +741,9 @@ static unsigned int br_nf_forward_ip(unsigned int
hook, struct sk_buff *skb,
                nf_bridge->mask |= BRNF_PKT_TYPE;
        }
 
+       if (br_parse_ip_options(skb))
+               return NF_DROP;
+
        /* The physdev module checks on this */
        nf_bridge->mask |= BRNF_BRIDGED;
        nf_bridge->physoutdev = skb->dev;

If I revert this change, network connectivity functions as expected for
the VMs on this host.

I don't know enough about this change or the problem it was supposed to
solve to be able to guess about what's going wrong.

noah


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Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Stephen Hemminger]

On Tue, 10 May 2011 11:05:40 -0700
Noah Meyerhans <noahm@debian.org> wrote:

> On Tue, May 10, 2011 at 01:42:49PM +0100, Ben Hutchings wrote:
> > > > This is pretty weird.  Debian version 2.6.38-3 has a few bridging
> > > > changes from stable 2.6.38.3 and 2.6.38.4, but they don't look like they
> > > > would cause this.
> > > 
> > > I have apparently filed the bug against the wrong version of Debian's
> > > kernel.  2.6.38-3 is not affected, and works as expected.  The change
> > > was introduced in -4.  That may have been clear from the report itself,
> > > but the report was filed against -3.  I've fixed that in the BTS.
> > 
> > I gathered that, and then made the same mistake in writing the above!
> > The version with the regression, 2.6.38-4, includes the changes from
> > stable 2.6.38.3 and 2.6.38.4
> 
> With a little help from git bisect, I've tracked this regression down to
> the following commit to the stable-2.6.38.y tree:
> 
> commit 5f1c356a3fadc0c19922d660da723b79bcc9aad7
> Author: Herbert Xu <herbert@gondor.apana.org.au>
> Date:   Fri Mar 18 05:27:28 2011 +0000
> 
>     bridge: Reset IPCB when entering IP stack on NF_FORWARD
>     
>     [ Upstream commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e ]
>     
>     Whenever we enter the IP stack proper from bridge netfilter we
>     need to ensure that the skb is in a form the IP stack expects
>     it to be in.
>     
>     The entry point on NF_FORWARD did not meet the requirements of
>     the IP stack, therefore leading to potential crashes/panics.
>     
>     This patch fixes the problem.
>     
>     Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
>     Acked-by: Stephen Hemminger <shemminger@vyatta.com>
>     Signed-off-by: David S. Miller <davem@davemloft.net>
>     Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
> 
> The diff is
> diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
> index 4b5b66d..49d50ea 100644
> --- a/net/bridge/br_netfilter.c
> +++ b/net/bridge/br_netfilter.c
> @@ -741,6 +741,9 @@ static unsigned int br_nf_forward_ip(unsigned int
> hook, struct sk_buff *skb,
>                 nf_bridge->mask |= BRNF_PKT_TYPE;
>         }
>  
> +       if (br_parse_ip_options(skb))
> +               return NF_DROP;
> +
>         /* The physdev module checks on this */
>         nf_bridge->mask |= BRNF_BRIDGED;
>         nf_bridge->physoutdev = skb->dev;
> 
> If I revert this change, network connectivity functions as expected for
> the VMs on this host.
> 
> I don't know enough about this change or the problem it was supposed to
> solve to be able to guess about what's going wrong.
> 
> noah
> 

There were two more follow on commits in stable related to this.
I recommend merging 2.6.38.6 which includes these.


-- 

Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Noah Meyerhans]

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On Tue, May 10, 2011 at 03:11:00PM -0700, Stephen Hemminger wrote:
> There were two more follow on commits in stable related to this.
> I recommend merging 2.6.38.6 which includes these.

The problem still exists in the current 2.6.38.6.  Backing out 5f1c356a
still solves the problem there.

I have not yet tried anything outside the stable-2.6.38.y tree, but it
seems like these same changes are present there, and it's unlikely that
other releases will work any better.

noah


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Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[David Miller]

From: Noah Meyerhans <noahm@debian.org>
Date: Tue, 10 May 2011 16:35:40 -0700

> On Tue, May 10, 2011 at 03:11:00PM -0700, Stephen Hemminger wrote:
>> There were two more follow on commits in stable related to this.
>> I recommend merging 2.6.38.6 which includes these.
> 
> The problem still exists in the current 2.6.38.6.  Backing out 5f1c356a
> still solves the problem there.
> 
> I have not yet tried anything outside the stable-2.6.38.y tree, but it
> seems like these same changes are present there, and it's unlikely that
> other releases will work any better.

So the issue is that if we back out that change, we get crashes.

Aparently there is a code path where whatever is existing in the
SKB ip options block matters, and needs to be maintained.

Someone needs to audit all of this and figure out how to fix the
problem properly.

Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Stephen Hemminger]

On Thu, 12 May 2011 15:59:16 -0700 (PDT)
David Miller <davem@davemloft.net> wrote:

> From: Noah Meyerhans <noahm@debian.org>
> Date: Tue, 10 May 2011 16:35:40 -0700
> 
> > On Tue, May 10, 2011 at 03:11:00PM -0700, Stephen Hemminger wrote:
> >> There were two more follow on commits in stable related to this.
> >> I recommend merging 2.6.38.6 which includes these.
> > 
> > The problem still exists in the current 2.6.38.6.  Backing out 5f1c356a
> > still solves the problem there.
> > 
> > I have not yet tried anything outside the stable-2.6.38.y tree, but it
> > seems like these same changes are present there, and it's unlikely that
> > other releases will work any better.
> 
> So the issue is that if we back out that change, we get crashes.
> 
> Aparently there is a code path where whatever is existing in the
> SKB ip options block matters, and needs to be maintained.
> 
> Someone needs to audit all of this and figure out how to fix the
> problem properly.
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

I suspect tuntap is part of the problem. The skb may not be
allocated with enough padding or something like that. No guarantees
but will do some investigation.


-- 

Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Stephen Hemminger]

On Tue, 10 May 2011 16:35:40 -0700
Noah Meyerhans <noahm@debian.org> wrote:

> On Tue, May 10, 2011 at 03:11:00PM -0700, Stephen Hemminger wrote:
> > There were two more follow on commits in stable related to this.
> > I recommend merging 2.6.38.6 which includes these.
> 
> The problem still exists in the current 2.6.38.6.  Backing out 5f1c356a
> still solves the problem there.
> 
> I have not yet tried anything outside the stable-2.6.38.y tree, but it
> seems like these same changes are present there, and it's unlikely that
> other releases will work any better.

Does this fix the problem?  The tap driver allocates an skb and throws
it into the receive path, but the skb does not have the same padding
as normal skb's received.

--- a/drivers/net/tun.c	2011-05-12 16:36:15.231347935 -0700
+++ b/drivers/net/tun.c	2011-05-12 16:36:38.503464573 -0700
@@ -614,7 +614,7 @@ static __inline__ ssize_t tun_get_user(s
 	}
 
 	if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
-		align = NET_IP_ALIGN;
+		align = NET_IP_ALIGN + NET_SKB_PAD;
 		if (unlikely(len < ETH_HLEN ||
 			     (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
 			return -EINVAL;

-- 

Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Noah Meyerhans]

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On Thu, May 12, 2011 at 04:43:22PM -0700, Stephen Hemminger wrote:
> > > There were two more follow on commits in stable related to this.
> > > I recommend merging 2.6.38.6 which includes these.
> > 
> > The problem still exists in the current 2.6.38.6.  Backing out 5f1c356a
> > still solves the problem there.
> > 
> > I have not yet tried anything outside the stable-2.6.38.y tree, but it
> > seems like these same changes are present there, and it's unlikely that
> > other releases will work any better.
> 
> Does this fix the problem?  The tap driver allocates an skb and throws
> it into the receive path, but the skb does not have the same padding
> as normal skb's received.
> 
> --- a/drivers/net/tun.c	2011-05-12 16:36:15.231347935 -0700
> +++ b/drivers/net/tun.c	2011-05-12 16:36:38.503464573 -0700
> @@ -614,7 +614,7 @@ static __inline__ ssize_t tun_get_user(s
>  	}
>  
>  	if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
> -		align = NET_IP_ALIGN;
> +		align = NET_IP_ALIGN + NET_SKB_PAD;
>  		if (unlikely(len < ETH_HLEN ||
>  			     (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
>  			return -EINVAL;
> 

Sorry, this does not fix the problem.

noah


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Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4

[Stephen Hemminger]

On Tue, 10 May 2011 16:35:40 -0700
Noah Meyerhans <noahm@debian.org> wrote:

> On Tue, May 10, 2011 at 03:11:00PM -0700, Stephen Hemminger wrote:
> > There were two more follow on commits in stable related to this.
> > I recommend merging 2.6.38.6 which includes these.
> 
> The problem still exists in the current 2.6.38.6.  Backing out 5f1c356a
> still solves the problem there.
> 
> I have not yet tried anything outside the stable-2.6.38.y tree, but it
> seems like these same changes are present there, and it's unlikely that
> other releases will work any better.
> 
> noah
> 

Is this unique to the tap interfaces or does bridging multicast
not work for all devices?


-- 

[Bridge] [PATCH] bridge: fix forwarding of IPv6

[Stephen Hemminger]

The commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e
    bridge: Reset IPCB when entering IP stack on NF_FORWARD
broke forwarding of IPV6 packets in bridge because it would
call bp_parse_ip_options with an IPV6 packet.

Reported-by: Noah Meyerhans <noahm@debian.org>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

---
Patch against net-next-2.6 but must be applied to net-2.6
and stable as well

--- a/net/bridge/br_netfilter.c	2011-05-13 12:37:30.289646958 -0700
+++ b/net/bridge/br_netfilter.c	2011-05-13 12:38:07.820333938 -0700
@@ -737,7 +737,7 @@ static unsigned int br_nf_forward_ip(uns
 		nf_bridge->mask |= BRNF_PKT_TYPE;
 	}
 
-	if (br_parse_ip_options(skb))
+	if (pf == PF_INET && br_parse_ip_options(skb))
 		return NF_DROP;
 
 	/* The physdev module checks on this */


-- 

Re: [Bridge] [PATCH] bridge: fix forwarding of IPv6

[Eric Dumazet]

Le vendredi 13 mai 2011 à 12:53 -0700, Stephen Hemminger a écrit :
> The commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e
>     bridge: Reset IPCB when entering IP stack on NF_FORWARD
> broke forwarding of IPV6 packets in bridge because it would
> call bp_parse_ip_options with an IPV6 packet.
> 
> Reported-by: Noah Meyerhans <noahm@debian.org>
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> 
> ---
> Patch against net-next-2.6 but must be applied to net-2.6
> and stable as well
> 

Well, stable is not needed, since faulty commit is not in 2.6.38

Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>

Re: [Bridge] [PATCH] bridge: fix forwarding of IPv6

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 13 May 2011 22:00:44 +0200

> Le vendredi 13 mai 2011 à 12:53 -0700, Stephen Hemminger a écrit :
>> The commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e
>>     bridge: Reset IPCB when entering IP stack on NF_FORWARD
>> broke forwarding of IPV6 packets in bridge because it would
>> call bp_parse_ip_options with an IPV6 packet.
>> 
>> Reported-by: Noah Meyerhans <noahm@debian.org>
>> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
>> 
>> ---
>> Patch against net-next-2.6 but must be applied to net-2.6
>> and stable as well
>> 
> 
> Well, stable is not needed, since faulty commit is not in 2.6.38
> 
> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>

I do need to queue it up for -stable because the faulty commit is
also queued up there :-)

Re: [Bridge] [PATCH] bridge: fix forwarding of IPv6

[Eric Dumazet]

Le vendredi 13 mai 2011 à 16:02 -0400, David Miller a écrit :

> I do need to queue it up for -stable because the faulty commit is
> also queued up there :-)

okay ;)

Re: [Bridge] [PATCH] bridge: fix forwarding of IPv6

[Stephen Hemminger]

On Fri, 13 May 2011 16:02:32 -0400 (EDT)
David Miller <davem@davemloft.net> wrote:

> From: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Fri, 13 May 2011 22:00:44 +0200
> 
> > Le vendredi 13 mai 2011 à 12:53 -0700, Stephen Hemminger a écrit :
> >> The commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e
> >>     bridge: Reset IPCB when entering IP stack on NF_FORWARD
> >> broke forwarding of IPV6 packets in bridge because it would
> >> call bp_parse_ip_options with an IPV6 packet.
> >> 
> >> Reported-by: Noah Meyerhans <noahm@debian.org>
> >> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> >> 
> >> ---
> >> Patch against net-next-2.6 but must be applied to net-2.6
> >> and stable as well
> >> 
> > 
> > Well, stable is not needed, since faulty commit is not in 2.6.38
> > 
> > Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
> 
> I do need to queue it up for -stable because the faulty commit is
> also queued up there :-)

The faulty commit was in 2.6.38.4

Re: [Bridge] [PATCH] bridge: fix forwarding of IPv6

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Fri, 13 May 2011 12:53:14 -0700

> The commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e
>     bridge: Reset IPCB when entering IP stack on NF_FORWARD
> broke forwarding of IPV6 packets in bridge because it would
> call bp_parse_ip_options with an IPV6 packet.
> 
> Reported-by: Noah Meyerhans <noahm@debian.org>
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> 
> ---
> Patch against net-next-2.6 but must be applied to net-2.6
> and stable as well

Applied and queued up for -stable, thanks!

Re: [Bridge] [PATCH] bridge: fix forwarding of IPv6

[Noah Meyerhans]

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On Fri, May 13, 2011 at 12:53:14PM -0700, Stephen Hemminger wrote:
> The commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e
>     bridge: Reset IPCB when entering IP stack on NF_FORWARD
> broke forwarding of IPV6 packets in bridge because it would
> call bp_parse_ip_options with an IPV6 packet.
> 
> Reported-by: Noah Meyerhans <noahm@debian.org>
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> 
> ---
> Patch against net-next-2.6 but must be applied to net-2.6
> and stable as well
> 
> --- a/net/bridge/br_netfilter.c	2011-05-13 12:37:30.289646958 -0700
> +++ b/net/bridge/br_netfilter.c	2011-05-13 12:38:07.820333938 -0700
> @@ -737,7 +737,7 @@ static unsigned int br_nf_forward_ip(uns
>  		nf_bridge->mask |= BRNF_PKT_TYPE;
>  	}
>  
> -	if (br_parse_ip_options(skb))
> +	if (pf == PF_INET && br_parse_ip_options(skb))
>  		return NF_DROP;
>  
>  	/* The physdev module checks on this */
> 

I can confirm that this patch fixes the behavior I've been seeing in the
stable-2.6.38.y tree.  Thank you, Stephen!

noah



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