From: "Linus Lüssing" <linus.luessing@c0d3.blue>
To: Kevin Mitchell <kevmitch@arista.com>
Cc: Matthias Schiffer <mschiffer@universe-factory.net>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
netdev@vger.kernel.org, gal@nvidia.com,
bridge@lists.linux-foundation.org,
Florian Westphal <fw@strlen.de>,
linux-kernel@vger.kernel.org,
Jozsef Kadlecsik <kadlec@netfilter.org>,
coreteam@netfilter.org, netfilter-devel@vger.kernel.org,
Nikolay Aleksandrov <nikolay@nvidia.com>,
Roopa Prabhu <roopa@nvidia.com>, Jakub Kicinski <kuba@kernel.org>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
"David S. Miller" <davem@davemloft.net>,
Pablo Neira Ayuso <pablo@netfilter.org>
Subject: Re: [Bridge] [PATCH v2 0/1] UDP traceroute packets with no checksum
Date: Wed, 4 May 2022 12:06:00 +0200 [thread overview]
Message-ID: <YnJQCIKgriI3kjFc@sellars> (raw)
In-Reply-To: <20220405235117.269511-1-kevmitch@arista.com>
On Tue, Apr 05, 2022 at 04:51:15PM -0700, Kevin Mitchell via Bridge wrote:
> This is v2 of https://lkml.org/lkml/2022/1/14/1060
>
> That patch was discovered to cause problems with UDP tunnels as
> described here:
>
> https://lore.kernel.org/netdev/7eed8111-42d7-63e1-d289-346a596fc933@nvidia.com/
>
> This version addresses the issue by instead explicitly handling zero UDP
> checksum in the nf_reject_verify_csum() helper function.
>
> Unlike the previous patch, this one only allows zero UDP checksum in
> IPv4. I discovered that the non-netfilter IPv6 path would indeed drop
> zero UDP checksum packets, so it's probably best to remain consistent.
Are you sure that a UDP zero checksum is not working for IPv6
packets? We are using it here without any issues with VXLAN
tunnels.
Yes, the original RFC did not allow UDP zero checksums in IPv6
packets, but I believe this has changed:
https://www.rfc-editor.org/rfc/rfc6936
(https://www.ietf.org/archive/id/draft-ietf-6man-udpzero-01.html)
Regards, Linus
prev parent reply other threads:[~2022-05-04 10:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-05 23:51 [PATCH v2 0/1] UDP traceroute packets with no checksum Kevin Mitchell
2022-04-05 23:51 ` [PATCH 1/1] netfilter: conntrack: skip verification of zero UDP checksum Kevin Mitchell
2022-05-04 10:06 ` Linus Lüssing [this message]
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=YnJQCIKgriI3kjFc@sellars \
--to=linus.luessing@c0d3.blue \
--cc=bridge@lists.linux-foundation.org \
--cc=coreteam@netfilter.org \
--cc=davem@davemloft.net \
--cc=fw@strlen.de \
--cc=gal@nvidia.com \
--cc=kadlec@netfilter.org \
--cc=kevmitch@arista.com \
--cc=kuba@kernel.org \
--cc=kuznet@ms2.inr.ac.ru \
--cc=linux-kernel@vger.kernel.org \
--cc=mschiffer@universe-factory.net \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=nikolay@nvidia.com \
--cc=pablo@netfilter.org \
--cc=roopa@nvidia.com \
--cc=yoshfuji@linux-ipv6.org \
/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).