From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [Bugme-new] [Bug 14875] New: iproute2: problems with "tc filter replace" and u32 hashing filters Date: Mon, 4 Jan 2010 12:33:14 -0800 Message-ID: <20100104123314.a8e1de57.akpm@linux-foundation.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: bugzilla-daemon@bugzilla.kernel.org, bugme-daemon@bugzilla.kernel.org, stas@crypt.org.ru To: netdev@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:46451 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752260Ab0ADUdY (ORCPT ); Mon, 4 Jan 2010 15:33:24 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: (switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Fri, 25 Dec 2009 02:24:00 GMT bugzilla-daemon@bugzilla.kernel.org wrote: > http://bugzilla.kernel.org/show_bug.cgi?id=14875 > > Summary: iproute2: problems with "tc filter replace" and u32 > hashing filters > Product: Networking > Version: 2.5 > Kernel Version: 2.6.32 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: low > Priority: P1 > Component: Other > AssignedTo: acme@ghostprotocols.net > ReportedBy: stas@crypt.org.ru > Regression: No > > > I'm using u32 hashing filters and have some issues with "tc filter replace" > command. > > Issue 1: "tc filter replace" command does not replace filters inside u32 hash > tables and works like "tc filter add" command. > > Consider the following scenario: > > 1. Create qdisc and hashing filters for 10.0.0.0/24 network > > tc qdisc add dev eth1 root handle 1: htb > tc filter add dev eth1 parent 1:0 pref 10 protocol ip u32 > tc filter add dev eth1 parent 1:0 pref 10 handle 100: protocol ip \ > u32 divisor 256 > tc filter add dev eth1 parent 1:0 pref 10 protocol ip u32 ht 800:: \ > match ip src 10.0.0.0/24 hashkey mask 0x000000ff at 12 link 100: > tc filter add dev eth1 parent 1:0 protocol ip pref 30 u32 \ > match u32 0x0 0x0 at 0 police mtu 1 action drop > > 2. Add filter for IP-address 10.0.0.1 > > tc class add dev eth1 parent 1: classid 1:3 htb rate 256kibit ceil 256kibit > tc qdisc add dev eth1 parent 1:3 handle 3:0 pfifo limit 50 > tc filter add dev eth1 parent 1: pref 20 u32 ht 100:1: \ > match ip src 10.0.0.1 flowid 1:3 > > 3. Try to replace filter for 10.0.0.1 with a new one for 10.0.0.2 > > tc filter replace dev eth1 parent 1: pref 20 u32 ht 100:1: \ > match ip src 10.0.0.2 flowid 1:3 > > I expect that filter for 10.0.0.1 in hash table 100:1: have been replaced by > new > rule for 10.0.0.2. But "tc -p filter show dev eth1" outputs two filters for > both 10.0.0.1 and 10.0.0.2: > > filter parent 1: protocol ip pref 10 u32 fh 100:1:800 order 2048 key ht 100 > bkt 1 flowid 1:3 > match IP src 10.0.0.1/32 > filter parent 1: protocol ip pref 10 u32 fh 100:1:801 order 2049 key ht 100 > bkt 1 flowid 1:3 > match IP dst 10.0.0.2/32 > > It means that "tc filter replace" command did not delete the filter 100:1:800, > but attached a new one with handle 100:1:801, just like the "tc filter add" > command. I think it is a wrong behaviour for "replace" command. > > > Issue 2: It seems that tc does not provide any syntax to replace a single > filter > inside the hash table. The command with explicit handle number > > tc filter replace dev eth1 parent 1: pref 20 u32 ht 100:1:800 \ > match ip dst 10.0.0.3 flowid 1:3 > > gives the error message: "ht" must be a hash table. > > The similar command with "handle 100:1:800" prints "What is "handle"?" and > usage information. > > The following sequence of "del" and "add" commands works: > > tc filter del dev eth1 parent 1: pref 10 handle 100:1:800 u32 > tc filter add dev eth1 parent 1: pref 20 u32 ht 100:1: \ > match ip src 10.0.0.1 flowid 1:3 > > Note, that "del" command works only when I use "pref 10" (preference value > for hashing filter 100:), but in "add" command I specified "pref 20" > (preference for 100:1:800 filter). This is little counterintuitive, but not > very important. > > > My suggestions about fixing of "tc filter replace" behaviour. > > 1. The "replace" command with "ht" argument > > tc filter replace dev eth1 parent 1: pref 20 u32 ht 100:1: match ... > > should empty the whole table 100:1: and add a new filter with handle 100:1:800. > > 2. The command with "handle" argument > > tc filter replace dev eth1 parent 1: pref 20 u32 handle 100:1:800 match ... > > should replace only one filter with handle 100:1:800. > > Thanks for attention.