From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: [PATCH net-next] tc: cls_bpf: make ingress and egress qdiscs consistent Date: Sat, 04 Apr 2015 00:54:12 +0200 Message-ID: <551F1A14.7080205@iogearbox.net> References: <1428095784-7091-1-git-send-email-ast@plumgrid.com> <551F0A1B.3000100@iogearbox.net> <551F0B96.2090403@plumgrid.com> <551F0FE2.8000502@iogearbox.net> <551F1177.7090902@plumgrid.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <551F1177.7090902@plumgrid.com> Sender: netdev-owner@vger.kernel.org To: Alexei Starovoitov , "David S. Miller" Cc: Jiri Pirko , Jamal Hadi Salim , linux-api@vger.kernel.org, netdev@vger.kernel.org List-Id: linux-api@vger.kernel.org On 04/04/2015 12:17 AM, Alexei Starovoitov wrote: ... > 1. there shouldn't be a choice at all for bpf. Because not pulling l2 > means it's bug. Yep, correct. You would also loose context for a possible dissection, at best you only have skb->protocol. > 2. adding a flag means adding it to iproute2 with default off and making > users forgetting it from time to time and have no way of knowing why > their programs all of a sudden stopped working. > > classic falls under the same rules. It doesn't make sense at all to run > a program on packet without L2 header. It's very odd both for classic > and extended programs. Yep. > Two 'if' conditions in critical path is bogus argument, since these > checks would be there in ingress as well. Same critical path. Why bogus? There would be no such test on the normal egress path, where this is irrelevant. I wasn't talking about ingress here. I see the point regarding the user option. So, why not adding a flag to tcf_proto_ops a la `.flags = CLS_REQUIRES_L2` that gets propagated to tcf_proto, and only ingress_enqueue() would need to test if the classifier imposes that requirement, so it can push/pull.