From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luis Carlos Cobo" Subject: Re: Proposed interface for per-packet mesh-ttl Date: Thu, 16 Aug 2007 12:21:14 -0700 Message-ID: <8e8340660708161221t1c0bee01g9d0cb1835f7026f0@mail.gmail.com> References: <445f43ac0707031149o2b50fc0en48aef4130b4b60ec@mail.gmail.com> <445f43ac0707031229m4ed60e0cg7960437c3e373c8e@mail.gmail.com> <20070727195616.GA31510@infradead.org> <1185574942.17934.9.camel@xo-13-A4-25.localdomain> <20070728073145.57155e03@oldman> <445f43ac0707301337l2f7d62ebx6955a12cd89c6bd3@mail.gmail.com> <20070730215316.5c236e18@oldman> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Javier Cardona" , "Dan Williams" , "Christoph Hellwig" , netdev@vger.kernel.org To: "Stephen Hemminger" Return-path: Received: from ik-out-1112.google.com ([66.249.90.179]:20054 "EHLO ik-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753613AbXHPTVR (ORCPT ); Thu, 16 Aug 2007 15:21:17 -0400 Received: by ik-out-1112.google.com with SMTP id b32so77986ika for ; Thu, 16 Aug 2007 12:21:15 -0700 (PDT) In-Reply-To: <20070730215316.5c236e18@oldman> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 7/30/07, Stephen Hemminger wrote: > it would need an IP ttl to mesh mapping. The fundamental thing is to try > and avoid topology specific options bleeding all the way up the socket layer, > especially since the network layer is involved and may need to multipath. I think the cleanest way would be to add a ll_ttl (ll for link layer) field to struct sock and a SO_LL_TTL socket option that sets both the field and a flag in sk->flags. This way it is useful for any driver that can do mesh or any other protocol that involves a ttl at link layer (not that I'm aware of any). However I guess you are not supposed to add new socket options nor modify struct socket too often so I'd appreciate feedback on whether this would be considered a good approach. -- Luis Carlos Cobo Rus GnuPG ID: 44019B60 cozybit Inc.