From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB5DEC43461 for ; Wed, 16 Sep 2020 00:19:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7AC0D20575 for ; Wed, 16 Sep 2020 00:19:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726269AbgIPATE (ORCPT ); Tue, 15 Sep 2020 20:19:04 -0400 Received: from mail.hallyn.com ([178.63.66.53]:42412 "EHLO mail.hallyn.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726858AbgIOOWN (ORCPT ); Tue, 15 Sep 2020 10:22:13 -0400 Received: by mail.hallyn.com (Postfix, from userid 1001) id EEC1BC38; Tue, 15 Sep 2020 09:19:46 -0500 (CDT) Date: Tue, 15 Sep 2020 09:19:46 -0500 From: "Serge E. Hallyn" To: "Michael Kerrisk (man-pages)" Cc: Stephen Smalley , linux-man , linux-security-module , selinux@vger.kernel.org, smcv@collabora.com, James Morris , "Serge E. Hallyn" Subject: Re: [PATCH v2] socket.7,unix.7: add initial description for SO_PEERSEC Message-ID: <20200915141946.GA19979@mail.hallyn.com> References: <20200914180700.11003-1-stephen.smalley.work@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Tue, Sep 15, 2020 at 10:56:18AM +0200, Michael Kerrisk (man-pages) wrote: > Hello Stephen, > > On Mon, 14 Sep 2020 at 20:07, Stephen Smalley > wrote: > > > > SO_PEERSEC was introduced for AF_UNIX stream sockets connected via > > connect(2) in Linux 2.6.2 [1] and later augmented to support AF_UNIX stream > > and datagram sockets created via socketpair(2) in Linux 4.18 [2]. Document > > SO_PEERSEC in the socket.7 and unix.7 man pages following the example > > of the existing SO_PEERCRED descriptions. SO_PEERSEC is also supported > > on AF_INET sockets when using labeled IPSEC or NetLabel but defer > > adding a description of that support to a separate patch. > > > > The module-independent description of the security context returned > > by SO_PEERSEC is from Simon McVittie . > > Thanks for the patch, The text looks in reasonable shape to me. I'm > just hanging off applying for a bit in case some Reviewed/Acked-by > comes in. > fwiw just as someone who's used this, Reviewed-by: Serge Hallyn Thanks Stephen, thanks Michael. > Cheers, > > Michael > > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=da6e57a2e6bd7939f610d957afacaf6a131e75ed > > > > [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0b811db2cb2aabc910e53d34ebb95a15997c33e7 > > > > Signed-off-by: Stephen Smalley > > --- > > v2 adds kernel commit info to the description and man page and uses > > the suggested text from Simon McVittie for the description of > > the security context string in a module-neutral way. > > > > man7/socket.7 | 5 +++++ > > man7/unix.7 | 46 ++++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 51 insertions(+) > > > > diff --git a/man7/socket.7 b/man7/socket.7 > > index 21e891791..c3635f95b 100644 > > --- a/man7/socket.7 > > +++ b/man7/socket.7 > > @@ -690,6 +690,11 @@ Return the credentials of the peer process connected to this socket. > > For further details, see > > .BR unix (7). > > .TP > > +.BR SO_PEERSEC " (since Linux 2.6.2)" > > +Return the security context of the peer socket connected to this socket. > > +For further details, see > > +.BR unix (7). > > +.TP > > .B SO_PRIORITY > > Set the protocol-defined priority for all packets to be sent on > > this socket. > > diff --git a/man7/unix.7 b/man7/unix.7 > > index 50828a5bc..298521d4a 100644 > > --- a/man7/unix.7 > > +++ b/man7/unix.7 > > @@ -349,6 +349,52 @@ stream sockets and for > > .B AF_UNIX > > stream and datagram socket pairs created using > > .BR socketpair (2). > > +.TP > > +.B SO_PEERSEC > > +This read-only socket option returns the > > +security context of the peer socket connected to this socket. > > +By default, this will be the same as the security context of > > +the process that created the peer socket unless overridden > > +by the policy or by a process with the required permissions. > > +.IP > > +The argument to > > +.BR getsockopt (2) > > +is a pointer to a > > +buffer of the specified length in bytes > > +into which the security context string will be copied. > > +If the buffer length is less than the length of the security > > +context string, then > > +.BR getsockopt (2) > > +will return the required length > > +via > > +.I optlen > > +and return \-1 and sets > > +.I errno > > +to > > +.BR ERANGE . > > +The caller should allocate at least > > +.BR NAME_MAX > > +bytes for the buffer initially although this is not guaranteed > > +to be sufficient. Resizing the buffer to the returned length > > +and retrying may be necessary. > > +.IP > > +The security context string may include a terminating null character > > +in the returned length, but is not guaranteed to do so: a security > > +context "foo" might be represented as either {'f','o','o'} of length 3 > > +or {'f','o','o','\\0'} of length 4, which are considered to be > > +interchangeable. It is printable, does not contain non-terminating > > +null characters, and is in an unspecified encoding (in particular it > > +is not guaranteed to be ASCII or UTF-8). > > +.IP > > +The use of this option for sockets in the > > +.B AF_UNIX > > +address family > > +is supported since Linux 2.6.2 for connected stream sockets and > > +since Linux 4.18, > > +.\" commit 0b811db2cb2aabc910e53d34ebb95a15997c33e7 > > +also for stream and datagram socket pairs created > > +using > > +.BR socketpair (2). > > .\" > > .SS Autobind feature > > If a > > -- > > 2.25.1 > > > > > -- > Michael Kerrisk > Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ > Linux/UNIX System Programming Training: http://man7.org/training/