From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lucas Nussbaum Subject: [PATCH] [NET_SCHED] sch_prio.c: remove duplicate call of tc_classify() Date: Thu, 30 Aug 2007 09:28:17 +0200 Message-ID: <20070830072817.GA9617@xanadu.blop.info> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Patrick McHardy To: netdev@vger.kernel.org Return-path: Received: from xanadu.blop.info ([80.248.208.235]:42572 "EHLO xanadu.blop.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753201AbXH3IGP (ORCPT ); Thu, 30 Aug 2007 04:06:15 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hi, When CONFIG_NET_CLS_ACT is enabled, tc_classify() is called twice in prio_classify(). This causes "interesting" behaviour: with the setup below, packets are duplicated, sent twice to ifb0, and then loop in and out of ifb0. The patch uses the previously calculated return value in the switch, which is probably what Patrick had in mind in commit bdba91ec70fb5ccbdeb1c7068319adc6ea9e1a7d -- maybe Patrick can double-check this? -- example setup -- ifconfig ifb0 up tc qdisc add dev ifb0 root netem delay 2s tc qdisc add dev $ETH root handle 1: prio tc filter add dev $ETH parent 1: protocol ip prio 10 u32 \ match ip dst 172.24.110.6/32 flowid 1:1 \ action mirred egress redirect dev ifb0 ping -c1 172.24.110.6 Signed-off-by: Lucas Nussbaum --- net/sched/sch_prio.c.orig 2007-08-30 07:36:41.000000000 +0200 +++ net/sched/sch_prio.c 2007-08-30 07:37:24.000000000 +0200 @@ -42,11 +42,11 @@ *qerr = NET_XMIT_BYPASS; if (TC_H_MAJ(skb->priority) != sch->handle) { err = tc_classify(skb, q->filter_list, &res); #ifdef CONFIG_NET_CLS_ACT - switch (tc_classify(skb, q->filter_list, &res)) { + switch (err) { case TC_ACT_STOLEN: case TC_ACT_QUEUED: *qerr = NET_XMIT_SUCCESS; case TC_ACT_SHOT: return NULL; -- | Lucas Nussbaum PhD student | | lucas.nussbaum@imag.fr LIG / Projet MESCAL | | jabber: lucas@nussbaum.fr +33 (0)6 64 71 41 65 | | homepage: http://www-id.imag.fr/~nussbaum/ |