From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Miroslaw Subject: Re: [PATCH 04/13] acl: allow zero verdict Date: Tue, 13 Dec 2016 15:53:08 +0100 Message-ID: <20161213145308.lqqnm6ivryjfxih7@rere.qmqm.pl> References: <2601191342CEEE43887BDE71AB9772583F0E6E0B@irsmsx105.ger.corp.intel.com> <20161213135443.ovmlunbh67dr4tew@rere.qmqm.pl> <2601191342CEEE43887BDE71AB9772583F0E7008@irsmsx105.ger.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: 8bit Cc: "dev@dpdk.org" To: "Ananyev, Konstantin" Return-path: Received: from rere.qmqm.pl (rere.qmqm.pl [84.10.57.10]) by dpdk.org (Postfix) with ESMTP id 088DC282 for ; Tue, 13 Dec 2016 15:53:09 +0100 (CET) Content-Disposition: inline In-Reply-To: <2601191342CEEE43887BDE71AB9772583F0E7008@irsmsx105.ger.corp.intel.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Dec 13, 2016 at 02:14:19PM +0000, Ananyev, Konstantin wrote: > > -----Original Message----- > > From: Michal Miroslaw [mailto:mirq-linux@rere.qmqm.pl] > > Sent: Tuesday, December 13, 2016 1:55 PM > > To: Ananyev, Konstantin > > Cc: dev@dpdk.org > > Subject: Re: [dpdk-dev] [PATCH 04/13] acl: allow zero verdict > > > > On Tue, Dec 13, 2016 at 10:36:16AM +0000, Ananyev, Konstantin wrote: > > > Hi Michal, > > > > > > > -----Original Message----- > > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Michal Miroslaw > > > > Sent: Tuesday, December 13, 2016 1:08 AM > > > > To: dev@dpdk.org > > > > Subject: [dpdk-dev] [PATCH 04/13] acl: allow zero verdict > > > > > > > > Signed-off-by: Michał Mirosław > > > > --- > > > > lib/librte_acl/rte_acl.c | 3 +-- > > > > lib/librte_acl/rte_acl.h | 2 -- > > > > lib/librte_table/rte_table_acl.c | 2 +- > > > > 3 files changed, 2 insertions(+), 5 deletions(-) > > > > > > > > diff --git a/lib/librte_acl/rte_acl.c b/lib/librte_acl/rte_acl.c > > > > index 8b7e92c..d1f40be 100644 > > > > --- a/lib/librte_acl/rte_acl.c > > > > +++ b/lib/librte_acl/rte_acl.c > > > > @@ -313,8 +313,7 @@ acl_check_rule(const struct rte_acl_rule_data *rd) > > > > if ((RTE_LEN2MASK(RTE_ACL_MAX_CATEGORIES, typeof(rd->category_mask)) & > > > > rd->category_mask) == 0 || > > > > rd->priority > RTE_ACL_MAX_PRIORITY || > > > > - rd->priority < RTE_ACL_MIN_PRIORITY || > > > > - rd->userdata == RTE_ACL_INVALID_USERDATA) > > > > + rd->priority < RTE_ACL_MIN_PRIORITY) > > > > return -EINVAL; > > > > return 0; > > > > } > > > > > > I am not sure, how it supposed to work properly? > > > Zero value is reserved and ifnicates that no match were found for that input. > > > > This is actually in use by us. In our use we don't need to differentiate > > matching a rule with zero verdict vs not matching a rule at all. I also > > have a patch that changes the value returned in non-matching case, but > > it's in "dirty hack" state, as of yet. > > With that chane rte_acl_classify() might produce invalid results. > Even if you don't need it (I still don't understand how) , it doesn't mean other people > don't need it either and it is ok to change it. > > > > > The ACL code does not treat zero userdata specially, so this is only > > a policy choice and as such would be better to be made by the user. > > I believe it does. > userdata==0 is a reserved value. > When rte_acl_clasify() returns 0 for that particular input, it means 'no matches were found'. Dear Konstantin, Can you describe how the ACL code treats zero specially? I could not find anything, really. The only thing I found is that iff I use zero userdata in a rule I won't be able to differentiate a case where it matched from a case where no rule matched. If I all my rules have non-zero userdata, then this patch changes nothing. But if I have a table where 0 means drop (default-drop policy) then being able to use zero userdata in DROP rules makes the ACLs just that more useful. Best Regards, Michał Mirosław