From: Sowmini Varadhan <sowmini.varadhan@oracle.com>
To: Tom Herbert <tom@herbertland.com>
Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Jiri Benc <jbenc@redhat.com>,
Hannes Frederic Sowa <hannes@stressinduktion.org>,
Alexander Duyck <aduyck@mirantis.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Paolo Abeni <pabeni@redhat.com>
Subject: Re: [PATCH net-next] net/vxlan: Avoid unaligned access in vxlan_build_skb()
Date: Tue, 20 Sep 2016 11:49:05 -0400 [thread overview]
Message-ID: <20160920154905.GN8920@oracle.com> (raw)
In-Reply-To: <CALx6S34c=Ftn1PfQ+YRDvbbWUmFW0R1zGC2jgkY0G7Fcx_SM7g@mail.gmail.com>
On (09/20/16 08:31), Tom Herbert wrote:
>
> On Tue, Sep 20, 2016 at 7:27 AM, Sowmini Varadhan
> <sowmini.varadhan@oracle.com> wrote:
> > The vxlan header is at offset (14 + 20 + 8) into the packet,
> > so the vxh is not aligned in vxlan_build_skb. Use [get/put]_unaligned
> > functions to modify flags and vni field in the vxh.
> >
> I'm wondering if VXLAN is just the tip of the iceberg. Wouldn't this
> is also be a problem in GRE and Geneve when they encapsulate Ethernet?
> What about the outer IP header, wouldn't that potentially have
> unaligned accesses also when creating it?
Indeed. All of the above are true, and we have to conquer
each unaligned access, one at a time.
There's also the over-arching problem of arbitrary encapsulations
introducing intervening headers that throw off alignment.
That would be a design discussion to be had with the ietf.
--Sowmini
next prev parent reply other threads:[~2016-09-20 15:49 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-20 14:27 [PATCH net-next] net/vxlan: Avoid unaligned access in vxlan_build_skb() Sowmini Varadhan
2016-09-20 15:31 ` Tom Herbert
2016-09-20 15:49 ` Sowmini Varadhan [this message]
2016-09-20 16:11 ` Jiri Benc
2016-09-20 16:31 ` Sowmini Varadhan
2016-09-20 16:43 ` Jiri Benc
2016-09-20 17:07 ` Sowmini Varadhan
2016-09-20 17:15 ` Jiri Benc
2016-09-20 17:09 ` Jiri Benc
2016-09-20 17:19 ` Tom Herbert
2016-09-20 17:24 ` Sowmini Varadhan
2016-09-22 5:52 ` David Miller
2016-09-22 21:30 ` Sowmini Varadhan
2016-09-23 12:06 ` David Miller
2016-09-23 14:17 ` Alexander Duyck
2016-09-23 17:20 ` Sowmini Varadhan
2016-09-23 17:38 ` Alexander Duyck
2016-09-23 23:41 ` Sowmini Varadhan
2016-09-24 0:43 ` Alexander Duyck
2016-09-28 17:03 ` Sowmini Varadhan
2016-09-28 18:08 ` Alexander Duyck
2016-09-28 19:56 ` Sowmini Varadhan
2016-09-20 16:45 ` Hannes Frederic Sowa
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