From: Sowmini Varadhan <sowmini.varadhan@oracle.com>
To: Alexander Duyck <alexander.duyck@gmail.com>
Cc: David Miller <davem@davemloft.net>, Jiri Benc <jbenc@redhat.com>,
Netdev <netdev@vger.kernel.org>,
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: Fri, 23 Sep 2016 19:41:34 -0400 [thread overview]
Message-ID: <20160923234134.GA6397@oracle.com> (raw)
In-Reply-To: <CAKgT0UeB5n3g4f1v_2nenjcayAi=eOPFSC7132ihXTZOztHRkw@mail.gmail.com>
On (09/23/16 10:38), Alexander Duyck wrote:
>
> So basically what I was thinking is we do something like reserving
> NET_IP_ALIGN and continue writing headers to skb->data, but we force
> the tracking for the inner headers into frag[0] so that we can keep
> the inner headers aligned without messing up the alignment for outer
> headers. In theory the inner offset and all that would still be
> functional but might need a few tweaks. You could probably even use
> the skb->encapsulation bit to indicate you are doing this. You could
> almost think of it as us doing something like the inverse of
> pskb_pull_tail. The general idea here is we want to actually leave
> the data in skb->data, but just reference it from frag[0] so that we
> don't accidentally pull in the 2 byte padding for alignment when
> transmitting the frame.
yes, I think something along this line could do the trick.. I tried
hacking it a bit today for vxlan, and it could be extended for all
these encaps protocols. Let me fix/test this more next week, maybe
we can discuss in Tokyo.
--Sowmini
next prev parent reply other threads:[~2016-09-23 23:42 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
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 [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160923234134.GA6397@oracle.com \
--to=sowmini.varadhan@oracle.com \
--cc=aduyck@mirantis.com \
--cc=alexander.duyck@gmail.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=hannes@stressinduktion.org \
--cc=jbenc@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.