From: "Ilya V. Matveychikov" <i.matveychikov@securitycode.ru>
To: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: <netdev@vger.kernel.org>
Subject: Re: question: update_pmtu doesn't update dst mtu
Date: Thu, 3 Apr 2014 16:07:21 +0400 [thread overview]
Message-ID: <533D4EF9.60608@securitycode.ru> (raw)
In-Reply-To: <20140403115809.GA13354@order.stressinduktion.org>
On 03.04.2014 15:58, Hannes Frederic Sowa wrote:
> On Thu, Apr 03, 2014 at 03:37:33PM +0400, Ilya V. Matveychikov wrote:
>> Looking through the code gives me that rt_pmtu is always 0 for the skb->dst
>> entry and ipv4_mtu that called via the dst->ops->mtu() uses dev->mtu :(
>
> At this point you have to drop skb_dst and have to relookup the route. During
> that a new dst will be created which gets the mtu value from the next hop
> exception, which got created by update_pmtu.
>
> Normally routes are checked with dst_check if they are still valid
> and a relookup should happen. In your example just do the relookup
> unconditionally.
>
Does it mean that the next packet must have an updated route without any
problems? I meant that if the first packet xmitting leads to updating the route
PMTU via the exception creating (or updating) so the next packets must have an
updated route? Am I right?
next prev parent reply other threads:[~2014-04-03 12:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-03 11:37 question: update_pmtu doesn't update dst mtu Ilya V. Matveychikov
2014-04-03 11:58 ` Hannes Frederic Sowa
2014-04-03 12:07 ` Ilya V. Matveychikov [this message]
2014-04-03 12:14 ` Hannes Frederic Sowa
2014-04-03 12:27 ` Ilya V. Matveychikov
2014-04-08 9:03 ` Ilya V. Matveychikov
2014-04-08 14:57 ` Hannes Frederic Sowa
2014-04-09 8:17 ` Ilya V. Matveychikov
2014-04-09 20:30 ` Hannes Frederic Sowa
2014-04-10 8:28 ` Ilya V. Matveychikov
-- strict thread matches above, loose matches on Subject: below --
2014-04-03 11:57 Ilya V. Matveychikov
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