From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: [PATCH net-next v2 1/2] bpf: Allow CGROUP_SKB eBPF program to access sk_buff Date: Tue, 06 Jun 2017 18:40:38 +0200 Message-ID: <5936DB06.5070601@iogearbox.net> References: <1496279760-20996-1-git-send-email-chenbofeng.kernel@gmail.com> <59369A30.1060301@iogearbox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: Lorenzo Colitti , Chenbo Feng , ast@fb.com To: Chenbo Feng , netdev@vger.kernel.org, David Miller Return-path: Received: from www62.your-server.de ([213.133.104.62]:55962 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751200AbdFFQkl (ORCPT ); Tue, 6 Jun 2017 12:40:41 -0400 In-Reply-To: <59369A30.1060301@iogearbox.net> Sender: netdev-owner@vger.kernel.org List-ID: On 06/06/2017 02:04 PM, Daniel Borkmann wrote: > On 06/01/2017 03:15 AM, Chenbo Feng wrote: >> From: Chenbo Feng >> >> This allows cgroup eBPF program to classify packet based on their >> protocol or other detail information. Currently program need >> CAP_NET_ADMIN privilege to attach a cgroup eBPF program, and A >> process with CAP_NET_ADMIN can already see all packets on the system, >> for example, by creating an iptables rules that causes the packet to >> be passed to userspace via NFLOG. >> >> Signed-off-by: Chenbo Feng > > Sorry, but I am puzzled what above change log has to do with the > below diff?! Back then we decided not to add BPF_PROG_TYPE_CGROUP_SKB > to may_access_skb(), since one can already use bpf_skb_load_bytes() > helper to access pkt data, which is a much more flexible interface. > Mind to elaborate why you cannot use bpf_skb_load_bytes() instead? See my other email [1], this one is also problematic wrt SKF_LL_OFF. [1] http://patchwork.ozlabs.org/patch/771946/