From: Eric Dumazet <eric.dumazet@gmail.com>
To: Alexei Starovoitov <ast@fb.com>,
Eric Dumazet <eric.dumazet@gmail.com>, Yonghong Song <yhs@fb.com>,
Steffen Klassert <steffen.klassert@secunet.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
netdev <netdev@vger.kernel.org>, Martin Lau <kafai@fb.com>,
saeedm@mellanox.com, diptanu@fb.com
Subject: Re: BUG_ON triggered in skb_segment
Date: Tue, 13 Mar 2018 16:27:03 -0700 [thread overview]
Message-ID: <39a56b2c-6ea8-02f7-9e9c-968b16b9aa7a@gmail.com> (raw)
In-Reply-To: <cce5fa43-eac6-1074-fe34-356c4b6a4321@fb.com>
On 03/13/2018 04:09 PM, Alexei Starovoitov wrote:
> we have bpf_skb_proto_6_to_4() that was used by cilium for long time.
> It's not clear why it's not crashing there, but we cannot just
> reject changing proto in bpf programs now.
> We have to fix whatever needs to be fixed in skb_segment
> (if bug is there) or fix whatever necessary on mlx5 side.
> In bpf helper we mark it as SKB_GSO_DODGY just like packets coming
> through virtio would do, so if skb_segment() needs to do something
> special with skb the SKB_GSO_DODGY flag is already there.
'Fixing' skb_segment(), I did that a long time ago and Herbert Xu was
not happy with the fix and provided something else.
GSO_DODGY has nothing to do with the problem really.
Changing gso_size is breaking GRO since it ends up changing the number
of segments on the wire. TCP is not going to be happy, so you'll also
have to fix TCP eventually.
next prev parent reply other threads:[~2018-03-13 23:27 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 5:45 BUG_ON triggered in skb_segment Yonghong Song
2018-03-13 6:04 ` Eric Dumazet
2018-03-13 6:08 ` Yonghong Song
2018-03-13 6:25 ` Eric Dumazet
2018-03-13 8:44 ` Steffen Klassert
2018-03-13 22:37 ` Yonghong Song
2018-03-13 22:47 ` Eric Dumazet
2018-03-13 23:09 ` Alexei Starovoitov
2018-03-13 23:18 ` Daniel Borkmann
2018-03-13 23:27 ` Eric Dumazet [this message]
2018-03-14 0:04 ` Alexei Starovoitov
2018-03-14 0:26 ` Eric Dumazet
2018-03-14 0:35 ` Eric Dumazet
2018-03-14 1:15 ` Eric Dumazet
2018-03-16 22:37 ` Yonghong Song
2018-03-16 23:03 ` Eric Dumazet
2018-03-17 4:44 ` Yonghong Song
2018-03-13 6:18 ` Yunsheng Lin
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=39a56b2c-6ea8-02f7-9e9c-968b16b9aa7a@gmail.com \
--to=eric.dumazet@gmail.com \
--cc=ast@fb.com \
--cc=daniel@iogearbox.net \
--cc=diptanu@fb.com \
--cc=kafai@fb.com \
--cc=netdev@vger.kernel.org \
--cc=saeedm@mellanox.com \
--cc=steffen.klassert@secunet.com \
--cc=yhs@fb.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).