From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: ICMP packets - ll_temac with Microblaze
Date: Wed, 21 Dec 2011 17:05:43 +0100
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Cc: monstr@monstr.eu, David Miller <davem@davemloft.net>,
	John Williams <john.williams@petalogix.com>,
	netdev@vger.kernel.org
To: Jun Zhao <mypopydev@gmail.com>
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Le jeudi 22 d=C3=A9cembre 2011 =C3=A0 00:01 +0800, Jun Zhao a =C3=A9cri=
t :

> Why receive buffer size MUST bigger than the jumbo frames size even i=
f
> the packet size is small?

Thats the way it is in linux.

We count the memory size used by the packet.

If not, a malicious attacker could send 1-byte frames and exhaust your
kernel memory.

If you want to reduce it, you might use copybreak : Some drivers copy
the data into a small skb instead of providing a jumbo frame to upper
stack.

tg3 for example.