From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757934AbbJVTnz (ORCPT ); Thu, 22 Oct 2015 15:43:55 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:60161 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757354AbbJVTnx (ORCPT ); Thu, 22 Oct 2015 15:43:53 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Daniel Borkmann Cc: Alexei Starovoitov , Hannes Frederic Sowa , davem@davemloft.net, viro@ZenIV.linux.org.uk, tgraf@suug.ch, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Alexei Starovoitov References: <562301F9.1030702@plumgrid.com> <5623B4B4.2010703@iogearbox.net> <5623CD8D.7000500@iogearbox.net> <56240814.8020105@plumgrid.com> <1445240171.3728424.413797809.230D716F@webmail.messagingengine.com> <5624BD0C.3070404@iogearbox.net> <5624FCDF.3090601@iogearbox.net> <562518B8.2070401@plumgrid.com> <56252A43.3000706@iogearbox.net> <56253335.9000206@plumgrid.com> <1445280385.602530.414418777.63627F89@webmail.messagingengine.com> <562545AA.2080207@plumgrid.com> <1445284997.621186.414538017.6E35B341@webmail.messagingengine.com> <56255714.2070800@plumgrid.com> <56256BF9.1090500@iogearbox.net> <56258B11.9080505@plumgrid.com> <5625FF71.8020304@iogearbox.net> <56267FAF.60206@plumgrid.com> <87io61fjx3.fsf@x220.int.ebiederm.org> <5627AC79.5000704@iogearbox.net> Date: Thu, 22 Oct 2015 14:35:14 -0500 In-Reply-To: <5627AC79.5000704@iogearbox.net> (Daniel Borkmann's message of "Wed, 21 Oct 2015 17:17:13 +0200") Message-ID: <87a8rabsst.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-AID: U2FsdGVkX1+y6HAa7NozNLKzFthWWzZuYqY3RAlW1ns= X-SA-Exim-Connect-IP: 67.3.201.231 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 TVD_RCVD_IP Message was received from an IP address * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Daniel Borkmann X-Spam-Relay-Country: X-Spam-Timing: total 2209 ms - load_scoreonly_sql: 0.06 (0.0%), signal_user_changed: 4.0 (0.2%), b_tie_ro: 2.8 (0.1%), parse: 1.08 (0.0%), extract_message_metadata: 15 (0.7%), get_uri_detail_list: 1.44 (0.1%), tests_pri_-1000: 6 (0.3%), tests_pri_-950: 1.25 (0.1%), tests_pri_-900: 1.07 (0.0%), tests_pri_-400: 21 (0.9%), check_bayes: 20 (0.9%), b_tokenize: 5 (0.2%), b_tok_get_all: 6 (0.3%), b_comp_prob: 2.7 (0.1%), b_tok_touch_all: 3.1 (0.1%), b_finish: 0.74 (0.0%), tests_pri_0: 220 (10.0%), tests_pri_500: 1936 (87.7%), poll_dns_idle: 1921 (87.0%), rewrite_mail: 0.00 (0.0%) Subject: Re: [PATCH net-next 3/4] bpf: add support for persistent maps/progs X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 24 Sep 2014 11:00:52 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Daniel Borkmann writes: > On 10/20/2015 08:56 PM, Eric W. Biederman wrote: > ... >> Just FYI: Using a device for this kind of interface is pretty >> much a non-starter as that quickly gets you into situations where >> things do not work in containers. If someone gets a version of device >> namespaces past GregKH it might be up for discussion to use character >> devices. > > Okay, you are referring to this discussion here: > > http://thread.gmane.org/gmane.linux.kernel.containers/26760 That is a piece of it. It is an old old discussion (which generally has been handled poorly). For the forseeable future device namespaces have a firm NACK by GregKH. Which means that dynamic character device based interfaces do not work in containers. Which means if you are not talking about physical hardware, character devices are a poor fit. Making a character based interface for eBPF not workable. Eric p.s. There are plenty of reasons (even if privilege remains a requirement) to ask how can this functionality be used in a container. If for no other reason than sandboxing privileged applications is typically a good idea.