From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: [PATCH 3/3] [NET_DOC] Document some simple rules for actions Date: Tue, 16 Oct 2007 09:09:42 -0400 Message-ID: <1192540182.4480.99.camel@localhost> References: <1192538011.4480.84.camel@localhost> <20071016125134.GA11319@gondor.apana.org.au> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: David Miller , Alexey Kuznetsov , Patrick McHardy , netdev@vger.kernel.org To: Herbert Xu Return-path: Received: from rv-out-0910.google.com ([209.85.198.189]:7763 "EHLO rv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932091AbXJPNLD (ORCPT ); Tue, 16 Oct 2007 09:11:03 -0400 Received: by rv-out-0910.google.com with SMTP id k20so1419702rvb for ; Tue, 16 Oct 2007 06:11:02 -0700 (PDT) In-Reply-To: <20071016125134.GA11319@gondor.apana.org.au> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, 2007-16-10 at 20:51 +0800, Herbert Xu wrote: > But I still think the distinction between skb_clone and > skb_copy_header is wrong. > > When you munge a packet, it's still going to go back up > the stack and be processed along the same path. Therefore > you should be calling pskb_expand_head. Dang, just noticed i said skb_expand() in the doc - is that the issue? I will resend that one patch. We do call pskb_expand_head() - example look at act_pedit.c > In other words, this does not explain why skb_copy/pskb_copy > and skb_copy_expand should differ from skb_clone. As far as > I can see all these functions should behave in the same manner > with respect to tc_verd We need to avoid actions from infinetely looping (eg when they ask for being reclassified) in a directed graph. That loop ttl count must be reset to zero if we branch, because that is a new directed path. This is always true and therefore that field must always be reset. I have a feeling i am going on a tangent if that doesnt respond to your comment above. cheers, jamal