From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: mac addresses of local interfaces do not obey setageing 0 Date: Tue, 15 Feb 2011 10:25:38 -0800 Message-ID: <20110215102538.5f24d62a@nehalam> References: <20110209181752.GA2042@darkmag.usersys.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, bridge@lists.linux-foundation.org To: Veaceslav Falico Return-path: Received: from mail.vyatta.com ([76.74.103.46]:51618 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755576Ab1BOSZl (ORCPT ); Tue, 15 Feb 2011 13:25:41 -0500 In-Reply-To: <20110209181752.GA2042@darkmag.usersys.redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 9 Feb 2011 19:17:52 +0100 Veaceslav Falico wrote: > Hello, > > I have a host and a VM inside this host bridged. I've set ageing_time and > forward_delay to 0 and trying to capture all the traffic that goes through that > bridge from my VM, but it fails to capture the traffic that has dst ether > address the same as the hosts address (i.e. I can't capture the traffic to the > host). > > From the code, I see that br->ageing_time doesn't really work with local mac > addresses - has_expired() function never says that a local interface mac address > is expired, because it verifies if fdb->is_static is set and returns right away. > > Is this the desired behaviour? If so, is there a way to capture packets with > destination to a local interface from another interface? > > I've also done a small patch and it seems to fix the situation, but I am not > sure if it's the right way to do it. > > > Regards, > Veaceslav > > --- > net/bridge/br_fdb.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c > index 88485cc..3d380c2 100644 > --- a/net/bridge/br_fdb.c > +++ b/net/bridge/br_fdb.c > @@ -61,8 +61,8 @@ static inline unsigned long hold_time(const struct net_bridge *br) > static inline int has_expired(const struct net_bridge *br, > const struct net_bridge_fdb_entry *fdb) > { > - return !fdb->is_static && > - time_before_eq(fdb->ageing_timer + hold_time(br), jiffies); > + return (br->ageing_time == 0) || (!fdb->is_static && > + time_before_eq(fdb->ageing_timer + hold_time(br), jiffies)); > } > No. Local addresses should never age. The proper way to capture packet is to us AF_PACKET or tc actions. --