From mboxrd@z Thu Jan  1 00:00:00 1970
From: Harald Welte <laforge@netfilter.org>
Subject: Re: [PATCH]: 1st step to remove skb_linearize() in ip6_tables.c and optimization
Date: Sun, 1 Aug 2004 20:11:50 +0200
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Cc: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>,
	kadlec@blackhole.kfki.hu, netfilter-devel@lists.netfilter.org,
	kisza@securityaudit.hu, usagi-core@linux-ipv6.org
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To: Patrick McHardy <kaber@trash.net>
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On Sun, Aug 01, 2004 at 07:08:59PM +0200, Patrick McHardy wrote:

> >>	struct tcphdr hdr;
> >>	struct tcphdr *tcph
> >>
> >>	tcph =3D skb_get_bits(skb, &hdr, skb->nh.iph->ihl*4, sizeof(hdr));
> >>
> >>If skb is neither shared nor cloned, this function linearize up to tcp=
=20
> >>header and returns the pointer to tcp header in skb.
> >>Otherwise, copies tcp header to "hdr" and return the pointer to it.
> >>If error, return NULL.
>
> The number of copies will still depend on the ruleset with non-linear skb=
s.
> skb_linearize_partial sounds like a much better idea to me.

Oh yes, indeed.  I somehow mis-interpreted Yasuyiki's approach.  We
should linearize with the first call, so that every 2nd, 3rd, ... call
do nothing but immediately return.

> Regards
> Patrick

--=20
- Harald Welte <laforge@netfilter.org>             http://www.netfilter.org/
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=3D
  "Fragmentation is like classful addressing -- an interesting early
   architectural error that shows how much experimentation was going
   on while IP was being designed."                    -- Paul Vixie

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