From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-2.6.22-rc7] xfrm beet interfamily support Date: Wed, 18 Jul 2007 02:18:14 -0700 (PDT) Message-ID: <20070718.021814.99458359.davem@davemloft.net> References: <200707161506.47915.joakim.koskela@hiit.fi> <39e6f6c70707160556m37137161odec6d01cc200524c@mail.gmail.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: joakim.koskela@hiit.fi, netdev@vger.kernel.org To: acme@ghostprotocols.net Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:50843 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756119AbXGRJSQ (ORCPT ); Wed, 18 Jul 2007 05:18:16 -0400 In-Reply-To: <39e6f6c70707160556m37137161odec6d01cc200524c@mail.gmail.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: "Arnaldo Carvalho de Melo" Date: Mon, 16 Jul 2007 09:56:59 -0300 > Sorry for not commented that the code you were using (and David said > it was invalid) is in fact valid: > > skb->transport_header = skb->network_header; > > This works for both offsets and pointers, i.e. both transport_header > and network_header are in the same "address space". > > > skb_set_transport_header(skb, skb_network_offset(skb)); > > Also works, but its too convoluted IMHO, for pointers it would reduce to: > > skb->transport_header = skb->data + skb->network_header > - skb->data; > > for offsets: > > skb->transport_header = skb->data - skb->head; > skb->transport_header += skb->head + skb->network_header > - skb->data; > > I.e. both reduce to: > > skb->transport_header = skb->network_header; > > Some more comments below, but I think this time, sans the above > possible cleanup, your patch is OK wrt offsets/pointers. Thanks for the correction, indeed you are correct :)