Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753322AbaGIAsG (ORCPT ); Tue, 8 Jul 2014 20:48:06 -0400 Received: from mail-la0-f54.google.com ([209.85.215.54]:43667 "EHLO mail-la0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751292AbaGIAsE (ORCPT ); Tue, 8 Jul 2014 20:48:04 -0400 Date: Wed, 9 Jul 2014 04:47:59 +0400 From: Dmitry Popov To: David Miller Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ip_tunnel: fix ip_tunnel_lookup Message-Id: <20140709044759.009fdce94cf1fb2d872a4a4f@qrator.net> In-Reply-To: <20140708.151210.1879376103263511218.davem@davemloft.net> References: <20140705022637.73152ff57309c468c1fdb563@qrator.net> <20140708.151210.1879376103263511218.davem@davemloft.net> X-Mailer: Sylpheed 3.4.2 (GTK+ 2.24.24; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 08 Jul 2014 15:12:10 -0700 (PDT) David Miller wrote: > From: Dmitry Popov > Date: Sat, 5 Jul 2014 02:26:37 +0400 > > > @@ -205,6 +207,8 @@ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, > > > > hlist_for_each_entry_rcu(t, head, hash_node) { > > if (t->parms.i_key != key || > > + t->parms.iph.saddr != 0 || > > + t->parms.iph.daddr != 0 || > > !(t->dev->flags & IFF_UP)) > > continue; > > > > I don't really understand the logic of these tests. > > Usually the canonical way to test these kinds of things is: > > if (parms->saddr && parms->saddr != saddr) > goto no_match; > > But you are signalling a non-match any time the address is not a > wildcard. > > Why? Because that's exactly what I want: to skip any non-wildcard tunnels. How I see ip_tunnel_lookup logic: 1) try to find exact match (and if found return this tunnel): tunnel.saddr == iph.daddr && tunnel.daddr == iph.saddr && key_matched() 2) try to find matched (local) wildcard tunnel: tunnel.saddr == any && tunnel.daddr == iph.saddr && key_matched() 3) try to find matched (remote) wildcard tunnel: tunnel.saddr == iph.daddr && tunnel.daddr == any && key_matched() (there is also a test for multicast tunnel, but let's skip it for simplicity) 4) try to find matched (full) wildcard tunnel: tunnel.saddr == any && tunnel.daddr == any && key_matched() 5) if nothing found return default tunnel. According to this logic, in 4th loop (the one you quoted) we have to test that tunnel.daddr == any && tunnel.saddr == any. In my opinion those two new lines are the best way to achieve it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/