From mboxrd@z Thu Jan  1 00:00:00 1970
From: "David S. Miller" <davem@redhat.com>
Subject: Re: [IPCOMP] Exclude IPCOMP header from props.header_len
Date: Tue, 6 Jul 2004 14:11:05 -0700
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To: Herbert Xu <herbert@gondor.apana.org.au>
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On Tue, 6 Jul 2004 22:31:27 +1000
Herbert Xu <herbert@gondor.apana.org.au> wrote:

> This patch changes the value of props.header_len for IPCOMP to
> exclude the IPCOMP header.  The reason is that the IPCOMP header
> is added only if the packet is compressible.  That is, if the
> size of the compressed payload plus the size of the IPCOMP header
> is less than that of the original payload.
> 
> This means that the IPCOMP encapsulation does not impose any
> overhead at all as far as the MTU is concerned.  The current
> code incorrectly reduces the MTU by the size of the IPCOMP
> header.
> 
> As a side-effect, this means that we don't have to move the
> IP header around when IPCOMP is used.

Very nice patch Herbert, applied.