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From: Shmulik Ladkani <shmulik.ladkani@gmail.com>
To: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Lance Richardson <lrichard@redhat.com>,
	fw@strlen.de, netdev@vger.kernel.org, jtluka@redhat.com
Subject: Re: [PATCH net v3] ipv4: allow local fragmentation in ip_finish_output_gso()
Date: Fri, 4 Nov 2016 11:40:14 +0200	[thread overview]
Message-ID: <20161104114014.3dbb8684@halley> (raw)
In-Reply-To: <ce29c141-65d1-c1b2-dc45-a9752fb614d8@stressinduktion.org>

On Thu, 3 Nov 2016 22:34:34 +0100 Hannes Frederic Sowa <hannes@stressinduktion.org> wrote:
> Correct, but we should maybe redefine the code a bit. From my
> understanding we can now create an ICMP storm in case every fragment gets.

Yes, you are right.

Each segment gets into ip_fragment, and due to outer DF being set,
ICMP_FRAG_NEEDED is sent per segment.

BTW, suppose GRO is off, and sender actually did send a burst of
(non-gso) packets with outer DF set, and each was tunnel encapsulated,
resulting in oversized frames.

Would'nt the stack just send the ICMP_FRAG_NEEDED per encapsulated
frame?

If so, then the GRO behaviour is aligned, and there's nothing to fix.

Best,
Shmulik

  reply	other threads:[~2016-11-04  9:40 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-02 20:36 [PATCH net v3] ipv4: allow local fragmentation in ip_finish_output_gso() Lance Richardson
2016-11-03  7:42 ` Shmulik Ladkani
2016-11-03  9:44   ` Hannes Frederic Sowa
2016-11-03 13:06   ` Lance Richardson
2016-11-04  9:24     ` Shmulik Ladkani
2016-11-04 13:48       ` Lance Richardson
2016-11-03  9:42 ` Hannes Frederic Sowa
2016-11-03 20:12 ` David Miller
2016-11-03 20:40   ` Shmulik Ladkani
2016-11-03 20:56     ` David Miller
2016-11-03 20:27 ` Shmulik Ladkani
2016-11-03 21:05   ` Lance Richardson
2016-11-03 21:34     ` Hannes Frederic Sowa
2016-11-04  9:40       ` Shmulik Ladkani [this message]
2016-11-04 13:49         ` Lance Richardson
2016-11-04  8:02     ` Shmulik Ladkani

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