From mboxrd@z Thu Jan 1 00:00:00 1970 From: zhou peng Subject: Re: About ACL for IPC Object Date: Mon, 25 Jan 2010 23:21:44 +0800 Message-ID: <6fb445941001250721p73795fe2i9196bd3c77dd0fce@mail.gmail.com> References: <6fb445941001200112o2934f805l4eb4f78000e9527e@mail.gmail.com> <6fb445941001200120m3aa5e944j54a6f645ce82d76f@mail.gmail.com> <4B57C3C3.9010606@schaufler-ca.com> <20100121090510.GA908@infradead.org> <6fb445941001220115y6b99f7b4g306ea23d3202969@mail.gmail.com> <2375c9f91001220202m724e2ee2p2213b81a043ebd33@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Christoph Hellwig , Casey Schaufler , sds@tycho.nsa.gov, jra@samba.org, linux-security-module@vger.kernel.org, linux-next@vger.kernel.org, LKML , linux-fsdevel@vger.kernel.org To: =?ISO-8859-1?Q?Am=E9rico_Wang?= Return-path: Received: from mail-iw0-f186.google.com ([209.85.223.186]:62688 "EHLO mail-iw0-f186.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754124Ab0AYPVq convert rfc822-to-8bit (ORCPT ); Mon, 25 Jan 2010 10:21:46 -0500 In-Reply-To: <2375c9f91001220202m724e2ee2p2213b81a043ebd33@mail.gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: I have tested posix sem,posix shm and posix msg queue for ACL on fedora 12 with kernel 2.6.32. Posix sem and posix shm using tmpfs monted by default support ACL well = =2E Posix msg queue use mqueue fs mounted by manual but it seem not surpoort ACL well. It failed for setting named ACL item: { $ mkdir /dev/mqueue $ mount -o rw, acl -t mqueue none /dev/mqueue $cd /dev/mqueue "/mq" msg queue object created and used by processes properly $getfacl mq #file: mq #owner:root #group:root user:rw- group::--- other::--- $setfacl -m u:testuser:rw mq /* fail= ed here*/ $setfacl: mq :Operation not supported but mqueue fs works well for setting owner user and owner group items. } I am not sure whether mqueue don't support acl or I make mistake. 2010/1/22 Am=E9rico Wang : > (Top-posting fixed.) > > On Fri, Jan 22, 2010 at 5:15 PM, zhou peng wro= te: >> >> 2010/1/21 Christoph Hellwig : >>> On Wed, Jan 20, 2010 at 07:02:27PM -0800, Casey Schaufler wrote: >>>> zhou peng wrote: >>>> > Hi all, >>>> > >>>> > There are ACL in file system, but why there are no ACL implement= ation >>>> > in IPC object, eg. shm, message queue, FIFO? >>>> > >>>> >>>> Most people haven't noticed that IPC objects are even there, much = less >>>> that they have mode bits and not ACLs. Even when we were doing sec= urity >>>> evaluations on Unix boxes in the 1990's they were considered insuf= ficiently >>>> interesting to justify the additional work to do ACLs. >>>> >>>> If you really want ACLs on IPC objects it would make a dandy littl= e >>>> project for a summer. I would be happy to review patches. >> >> Thanks. It's interesting to add ACL over IPC objects. I want to have= a try. >> >>> >>> Or use the posix IPC mechanisms. =A0The Posix shared memory has ACL= by >>> using tmpfs as the backing store, and we could add similar support = to >>> Posix messages queues as they are also backed by a normal filesyste= m. >> >> Christoph Hellwig, This way may be convinent. Could you give some >> detailed message. :) >> I only find /proc/ipc/shm file which contain the info of shm objs,an= d >> tmpfs on /dev/shm which is empty. >> >>> >>> Adding this support to the old SYSV IPC mechanisms would be much ha= rder >>> as they do not fit into the file backed model we use everywhere els= e at >>> all. >> >> Just like file objects, the mode bits are implment over IPC objects >> without file backed, so I think adding ACL support to IPC objects ma= y >> be somewhat reasonable :) >> >> Thank you all for so many solutions. >> >> I want to control some IPC object (shm, msg queue, semphore) can be >> accessed by which named user or named group just like file objects A= CL >> do. >> >> I studied the solution you all referred, The SELinux is powerful but >> may be somewhat complicated. And I am confused with Christoph >> Hellwig=91s solution using tmpfs. > > Well, only posix semphores and posix share memory use tmpfs, I think, > posix msg queues use "mqueue" instead. > --=20 zhoupeng -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html