From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752847AbaCMBoG (ORCPT ); Wed, 12 Mar 2014 21:44:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45571 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752522AbaCMBoD (ORCPT ); Wed, 12 Mar 2014 21:44:03 -0400 Subject: Re: [PATCH 2/2] net: Implement SO_PEERCGROUP From: Simo Sorce To: Andy Lutomirski Cc: Vivek Goyal , "linux-kernel@vger.kernel.org" , cgroups@vger.kernel.org, Network Development , "David S. Miller" , Tejun Heo , jkaluza@redhat.com, lpoetter@redhat.com, kay@redhat.com In-Reply-To: References: <1394657163-7472-1-git-send-email-vgoyal@redhat.com> <1394657163-7472-3-git-send-email-vgoyal@redhat.com> <5320CAEC.6030008@amacapital.net> <1394658983.32465.203.camel@willson.li.ssimo.org> <1394673476.32465.215.camel@willson.li.ssimo.org> Content-Type: text/plain; charset="UTF-8" Date: Wed, 12 Mar 2014 21:43:58 -0400 Message-ID: <1394675038.32465.223.camel@willson.li.ssimo.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2014-03-12 at 18:21 -0700, Andy Lutomirski wrote: > On Wed, Mar 12, 2014 at 6:17 PM, Simo Sorce wrote: > > On Wed, 2014-03-12 at 14:19 -0700, Andy Lutomirski wrote: > >> On Wed, Mar 12, 2014 at 2:16 PM, Simo Sorce wrote: > >> > >> > > >> > Connection time is all we do and can care about. > >> > >> You have not answered why. > > > > We are going to disclose information to the peer based on policy that > > depends on the cgroup the peer is part of. All we care for is who opened > > the connection, if the peer wants to pass on that information after it > > has obtained it there is nothing we can do, so connection time is all we > > really care about. > > Can you give a realistic example? > > I could say that I'd like to disclose information to processes based > on their rlimits at the time they connected, but I don't think that > would carry much weight. We want to be able to show different user's list from SSSD based on the docker container that is asking for it. This works by having libnsss_sss.so from the containerized application connect to an SSSD daemon running on the host or in another container. The only way to distinguish between containers "from the outside" is to lookup the cgroup of the requesting process. It has a unique container ID, and can therefore be mapped to the appropriate policy that will let us decide which 'user domain' to serve to the container. Simo.