Re: [PATCH]: 1st step to remove skb_linearize() in ip6_tables.c and optimization

[Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>]

Hi,

From: Harald Welte <laforge@netfilter.org>
Date: Sun, 1 Aug 2004 20:11:50 +0200

> On Sun, Aug 01, 2004 at 07:08:59PM +0200, Patrick McHardy wrote:
> 
> > >>	struct tcphdr hdr;
> > >>	struct tcphdr *tcph
> > >>
> > >>	tcph = 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 
> > >>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 skbs.
> > 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.

Oh, sorry. I misstook about pskb_may_pull(). And please forget my patch
because it's inefficient.


> 
> > Regards
> > Patrick
> 
> -- 
> - Harald Welte <laforge@netfilter.org>             http://www.netfilter.org/
> ============================================================================
>   "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