From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Vitaly E. Lavrov" Subject: [RFC PATCH] tc filter not show last u32 filter Date: Tue, 21 Apr 2015 20:53:03 +0300 Message-ID: <55368E7F.4030005@guap.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: jhs@mojatatu.com To: netdev@vger.kernel.org Return-path: Received: from mail.guap.ru ([91.151.188.3]:17517 "EHLO mail.guap.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753369AbbDUSIg (ORCPT ); Tue, 21 Apr 2015 14:08:36 -0400 Sender: netdev-owner@vger.kernel.org List-ID: "tc filter show" does not show last U32 filter on 32-bit systems (tested on x86). Additional condition: filter does not have action and CONFIG_NET_CLS_ACT=y Example: tc filter add dev eth0 parent 1:0 protocol ip prio 100 u32 match ip dst 10.200.2.2 flowid 1:20 Function tcf_action_copy_stats() returns an error because the (struct tc_action *)a->priv is NULL (for 32bit systems). The sequence of calls: u32_dump() cls_u32.c:1009 if (tcf_exts_dump_stats(skb, &n->exts) < 0) goto nla_put_failure; tcf_exts_dump_stats() cls_api.c:606 if (tcf_action_copy_stats(skb, a, 1) < 0) return -1; tcf_action_copy_stats() act_api.c:604 struct tcf_common *p = a->priv; act_api.c:606 if (p == NULL) goto errout; // return -1; One of variants correcting this error is a verify the existence of action before calling tcf_action_copy_stats(). Patch for kernel 3.18.10 diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index aad6a67..8e7ad61 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -602,9 +602,11 @@ EXPORT_SYMBOL(tcf_exts_dump); int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts) { #ifdef CONFIG_NET_CLS_ACT - struct tc_action *a = tcf_exts_first_act(exts); - if (tcf_action_copy_stats(skb, a, 1) < 0) - return -1; + if(tcf_exts_is_available(exts)) { + struct tc_action *a = tcf_exts_first_act(exts); + if (tcf_action_copy_stats(skb, a, 1) < 0) + return -1; + } #endif return 0; } This will fix the bug 84661 https://bugzilla.kernel.org/show_bug.cgi?id=84661 In 64bit system a->priv is not NULL, but is not a valid pointer, but because of a->type == 0 and compat_mode == 1 returns a value 0. "tc filter show dev eth0". ------------------------ tc filter add dev eth0 parent 1:0 protocol ip prio 100 u32 match ip dst 10.200.2.2 flowid 1:20 tc filter add dev eth0 parent 1:0 protocol ip prio 100 u32 match ip dst 10.200.2.3 flowid 1:30 tc filter show dev eth0 .... (1) filter parent 1: protocol ip pref 100 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:20 match 0ac80202/ffffffff at 16 (2) filter parent 1: protocol ip pref 100 u32 fh 800::801 order 2049 key ht 800 bkt 0 flowid 1:30 match 0ac80203/ffffffff at 16 ------------------------ 64bit system (1) a->priv == 0x80000800 (2) a->priv == 0x80000801 32bit system (1) a->priv == 0x0 (2) a->priv == 0x0 I could not understand the reason for this difference between 32-bit and 64-bit systems.