From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: Re: [PATCH net-next] bridge: ebtables: Avoid resetting limit rule state Date: Tue, 28 Nov 2017 00:30:08 +0100 Message-ID: <20171127233008.GA1418@salvia> References: <20171125074418.16537-1-linus.luessing@c0d3.blue> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Cc: netfilter-devel@vger.kernel.org, Jozsef Kadlecsik , Florian Westphal , Stephen Hemminger , "David S . Miller" , coreteam@netfilter.org, bridge@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Linus =?iso-8859-1?Q?L=FCssing?= Return-path: Content-Disposition: inline In-Reply-To: <20171125074418.16537-1-linus.luessing@c0d3.blue> Sender: linux-kernel-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org Hi Linus, On Sat, Nov 25, 2017 at 08:44:18AM +0100, Linus Lüssing wrote: > So far any changes with ebtables will reset the state of limit rules, > leading to spikes in traffic. This is especially noticeable if changes > are done frequently, for instance via a daemon. > > This patch fixes this by bailing out from (re)setting if the limit > rule was initialized before. > > When sending packets every 250ms for 600s, with a > "--limit 1/sec --limit-burst 50" rule and a command like this > in the background: > > $ ebtables -N VOIDCHAIN > $ while true; do ebtables -F VOIDCHAIN; sleep 30; done > > The results are: > > Before: ~1600 packets > After: 650 packets > > Signed-off-by: Linus Lüssing > --- > net/bridge/netfilter/ebt_limit.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/bridge/netfilter/ebt_limit.c b/net/bridge/netfilter/ebt_limit.c > index 61a9f1be1263..f74b48633feb 100644 > --- a/net/bridge/netfilter/ebt_limit.c > +++ b/net/bridge/netfilter/ebt_limit.c > @@ -69,6 +69,10 @@ static int ebt_limit_mt_check(const struct xt_mtchk_param *par) > { > struct ebt_limit_info *info = par->matchinfo; > > + /* Do not reset state on unrelated table changes */ > + if (info->prev) > + return 0; What kernel version are you using? I suspect you don't have this applied? commit ec23189049651b16dc2ffab35a4371dc1f491aca Author: Willem de Bruijn Date: Mon Jan 2 17:19:46 2017 -0500 xtables: extend matches and targets with .usersize