* Re: [Bugme-new] [Bug 8756] New: Route advmss copied to ALL routes when interface MTU changes
[not found] <bug-8756-10286@http.bugzilla.kernel.org/>
@ 2007-07-15 4:48 ` Andrew Morton
2007-07-15 8:07 ` Simon Arlott
0 siblings, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2007-07-15 4:48 UTC (permalink / raw)
To: netdev; +Cc: bugme-daemon@kernel-bugs.osdl.org, bugzilla
On Sat, 14 Jul 2007 15:34:31 -0700 (PDT) bugme-daemon@bugzilla.kernel.org wrote:
> http://bugzilla.kernel.org/show_bug.cgi?id=8756
It is unclear which kernel version this applies to?
> Summary: Route advmss copied to ALL routes when interface MTU
> changes
> Product: Networking
> Version: 2.5
> Platform: All
> OS/Version: Linux
> Tree: Mainline
> Status: NEW
> Severity: normal
> Priority: P1
> Component: IPV6
> AssignedTo: yoshfuji@linux-ipv6.org
> ReportedBy: bugzilla@fire.lp0.eu
>
>
> Steps to reproduce:
> 1. Have multiple network devices and routes for them with standard (low, i.e.
> 1500) MTUs and default ADVMSS (e.g. 1440)
> 2. Change the MTU on one of them to something high (e.g. 7200)
> 3. The ADVMSS is incorrectly set for ALL routes based on the new MTU of the
> interface that changed.
>
> Note: if addrconf is running then the ADVMSS will be reset on the next RA, so
> this will impede attempts to reproduce.
>
> # ip -6 r
> fe80::/64 dev sit0 metric 256 expires 4481744sec mtu 1480 advmss 1440
> hoplimit 4294967295
> fe80::/64 dev ppp0 metric 256 expires 19071345sec mtu 1500 advmss 1440
> hoplimit 4294967295
> fe80::/64 dev eth0 metric 256 expires 19072430sec mtu 1500 advmss 1440
> hoplimit 4294967295
> default dev ppp0 metric 1024 expires 19071347sec mtu 1500 advmss 1440
> hoplimit 4294967295
>
> # ifconfig eth0 mtu 7200
>
> # ip -6 r
> fe80::/64 dev sit0 metric 256 expires 4481732sec mtu 1480 advmss 7140
> hoplimit 4294967295 <-- wrong
> fe80::/64 dev ppp0 metric 256 expires 19071334sec mtu 1500 advmss 7140
> hoplimit 4294967295 <-- wrong
> fe80::/64 dev eth0 metric 256 expires 19072419sec mtu 7200 advmss 7140
> hoplimit 4294967295 <-- correct
>
> Explicitly setting the MTU on these other routes (although this is not possible
> without having to add another route due to bug 8755) automatically sets ADVMSS
> appropriately.
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [Bugme-new] [Bug 8756] New: Route advmss copied to ALL routes when interface MTU changes
2007-07-15 4:48 ` [Bugme-new] [Bug 8756] New: Route advmss copied to ALL routes when interface MTU changes Andrew Morton
@ 2007-07-15 8:07 ` Simon Arlott
2007-07-23 19:25 ` [PATCH [Bug 8756]] IPv6: Don't update ADVMSS on routes where the MTU is not also updated Simon Arlott
0 siblings, 1 reply; 4+ messages in thread
From: Simon Arlott @ 2007-07-15 8:07 UTC (permalink / raw)
To: netdev; +Cc: Andrew Morton, bugme-daemon@kernel-bugs.osdl.org
On 15/07/07 05:48, Andrew Morton wrote:
> On Sat, 14 Jul 2007 15:34:31 -0700 (PDT) bugme-daemon@bugzilla.kernel.org wrote:
>
>> http://bugzilla.kernel.org/show_bug.cgi?id=8756
>
> It is unclear which kernel version this applies to?
Linus' 2.6 tree, as of Mon Jul 9 15:50:56 2007 -0700
For some reason it says "Version: 2.5" on the email and "Version: " on
the website...
>
>> Summary: Route advmss copied to ALL routes when interface MTU
>> changes
>> Product: Networking
>> Version: 2.5
>> Platform: All
>> OS/Version: Linux
>> Tree: Mainline
>> Status: NEW
>> Severity: normal
>> Priority: P1
>> Component: IPV6
>> AssignedTo: yoshfuji@linux-ipv6.org
>> ReportedBy: bugzilla@fire.lp0.eu
>>
>>
>> Steps to reproduce:
>> 1. Have multiple network devices and routes for them with standard (low, i.e.
>> 1500) MTUs and default ADVMSS (e.g. 1440)
>> 2. Change the MTU on one of them to something high (e.g. 7200)
>> 3. The ADVMSS is incorrectly set for ALL routes based on the new MTU of the
>> interface that changed.
>>
>> Note: if addrconf is running then the ADVMSS will be reset on the next RA, so
>> this will impede attempts to reproduce.
>>
>> # ip -6 r
>> fe80::/64 dev sit0 metric 256 expires 4481744sec mtu 1480 advmss 1440
>> hoplimit 4294967295
>> fe80::/64 dev ppp0 metric 256 expires 19071345sec mtu 1500 advmss 1440
>> hoplimit 4294967295
>> fe80::/64 dev eth0 metric 256 expires 19072430sec mtu 1500 advmss 1440
>> hoplimit 4294967295
>> default dev ppp0 metric 1024 expires 19071347sec mtu 1500 advmss 1440
>> hoplimit 4294967295
>>
>> # ifconfig eth0 mtu 7200
>>
>> # ip -6 r
>> fe80::/64 dev sit0 metric 256 expires 4481732sec mtu 1480 advmss 7140
>> hoplimit 4294967295 <-- wrong
>> fe80::/64 dev ppp0 metric 256 expires 19071334sec mtu 1500 advmss 7140
>> hoplimit 4294967295 <-- wrong
>> fe80::/64 dev eth0 metric 256 expires 19072419sec mtu 7200 advmss 7140
>> hoplimit 4294967295 <-- correct
>>
>> Explicitly setting the MTU on these other routes (although this is not possible
>> without having to add another route due to bug 8755) automatically sets ADVMSS
>> appropriately.
>>
--
Simon Arlott
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH [Bug 8756]] IPv6: Don't update ADVMSS on routes where the MTU is not also updated
2007-07-15 8:07 ` Simon Arlott
@ 2007-07-23 19:25 ` Simon Arlott
2007-07-26 7:10 ` David Miller
0 siblings, 1 reply; 4+ messages in thread
From: Simon Arlott @ 2007-07-23 19:25 UTC (permalink / raw)
To: netdev; +Cc: bugme-daemon, David Miller
The ADVMSS value was incorrectly updated for ALL routes when the MTU
is updated because it's outside the effect of the if statement's
condition.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
---
This fixes http://bugzilla.kernel.org/show_bug.cgi?id=8756
net/ipv6/route.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 919de68..55ea80f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1983,9 +1983,10 @@ static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
!dst_metric_locked(&rt->u.dst, RTAX_MTU) &&
(dst_mtu(&rt->u.dst) > arg->mtu ||
(dst_mtu(&rt->u.dst) < arg->mtu &&
- dst_mtu(&rt->u.dst) == idev->cnf.mtu6)))
+ dst_mtu(&rt->u.dst) == idev->cnf.mtu6))) {
rt->u.dst.metrics[RTAX_MTU-1] = arg->mtu;
- rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(arg->mtu);
+ rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(arg->mtu);
+ }
return 0;
}
--
1.5.0.1
--
Simon Arlott
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2007-07-26 7:10 UTC | newest]
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[not found] <bug-8756-10286@http.bugzilla.kernel.org/>
2007-07-15 4:48 ` [Bugme-new] [Bug 8756] New: Route advmss copied to ALL routes when interface MTU changes Andrew Morton
2007-07-15 8:07 ` Simon Arlott
2007-07-23 19:25 ` [PATCH [Bug 8756]] IPv6: Don't update ADVMSS on routes where the MTU is not also updated Simon Arlott
2007-07-26 7:10 ` David Miller
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