From owner-svn-src-head@FreeBSD.ORG Wed Jan 28 00:35:47 2015 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id CF3D861B; Wed, 28 Jan 2015 00:35:47 +0000 (UTC) Received: from mail-wi0-x229.google.com (mail-wi0-x229.google.com [IPv6:2a00:1450:400c:c05::229]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 5DCD5381; Wed, 28 Jan 2015 00:35:47 +0000 (UTC) Received: by mail-wi0-f169.google.com with SMTP id h11so5811549wiw.0; Tue, 27 Jan 2015 16:35:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=ZoTDrEFMtj83Ln7+NquW2141+F/B6q041RyL8BVMBxM=; b=qwu7hhLySrFscyGE4vBlwUrhGaffic/rr/hWZGPwY8vVM7A/skgQO0mIDSeduf/+CK YHCQkpP9qBVNceCorCZ1tcanC0LzZEWidJFluAvE4aLLlQI+BtjISN3ZUnoXfByAGK0+ A6d0YMH/65Lmti4VqHunnFj4CM2ZiIoDeAe8GV6Xkxh+LwLUEEFQckeaX5aG41s/+/// uOC04YUYtDm1n82QxaRvAZ/wU6smAfZJhGvlVdSruBoKAZ8kEMw3jFpqUwTI9JgbV1wI 8ubINIOqd4H92VGHueQhEWVAFP3tnlKnl569HVm+4jMK9idu1fdAA3YUoiEPLPa0Vq0Z OkEg== X-Received: by 10.181.12.112 with SMTP id ep16mr1542058wid.38.1422405345870; Tue, 27 Jan 2015 16:35:45 -0800 (PST) Received: from ivaldir.etoilebsd.net ([2001:41d0:8:db4c::1]) by mx.google.com with ESMTPSA id ej10sm20243066wib.1.2015.01.27.16.35.44 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Jan 2015 16:35:45 -0800 (PST) Sender: Baptiste Daroussin Date: Wed, 28 Jan 2015 01:35:42 +0100 From: Baptiste Daroussin To: Devin Teske Subject: Re: svn commit: r277652 - in head/usr.sbin/pw: . tests Message-ID: <20150128003542.GC84622@ivaldir.etoilebsd.net> References: <201501241913.t0OJD4xT039188@svn.freebsd.org> <20150125155254.V1007@besplex.bde.org> <20150125142148.GA76051@zxy.spb.ru> <20150126014336.P2572@besplex.bde.org> <5D58B34B-8647-4B69-8D90-E7D37C98D4AD@FreeBSD.org> <20150127234420.GB84622@ivaldir.etoilebsd.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="/3yNEOqWowh/8j+e" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Bruce Evans , Slawa Olhovchenkov X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Jan 2015 00:35:48 -0000 --/3yNEOqWowh/8j+e Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jan 27, 2015 at 04:08:28PM -0800, Devin Teske wrote: >=20 > > On Jan 27, 2015, at 3:44 PM, Baptiste Daroussin wrot= e: > >=20 > > On Mon, Jan 26, 2015 at 01:20:28PM -0800, Devin Teske wrote: > >>=20 > >>> On Jan 25, 2015, at 7:31 AM, Bruce Evans wrote: > >>>=20 > >>> On Sun, 25 Jan 2015, Slawa Olhovchenkov wrote: > >>>=20 > >>>> On Sun, Jan 25, 2015 at 04:56:24PM +1100, Bruce Evans wrote: > >>>>=20 > >>>>> Negative ids have historical abuses in places like mountd. > >>=20 > >> Which paves the way for the =E2=80=9Caccepted practice=E2=80=9D argume= nt > >> and backed up by =E2=80=9Cin-the-field usage=E2=80=9D statement(s). > >>=20 > >>=20 > >>=20 > >>>>> mountd still > >>>>> hard-codes -2 and -2 for the default uid and gid of an unprivileged= user. > >>>>> It at least casts these values to uid_t and gid_t before using them. > >>>>> This gives the ids the non-random values of UINT32_MAX-1 if uid_t a= nd > >>>>> gid_t are uint32_t. (If uid_t and gid_t were signed, then it would > >>>>> leave the values as negative, so invalid.) These magic values may = work > >>>>> better than when ids were 16 bits, since there is less risk of them > >>>>> conflicting with a normal id. However, the non-conflict is probably > >>>>> a bug. FreeBSD uses the magic ids of 65534 for user nobody: group > >>>>> nobody. These would have been (id_t)-2 with 16-bit ids. They no > >>>>> longer match, so ls displays (id_t)-2 numerically. FreeBSD also has > >>>>> a group nogroup =3D 65553 that doesn't match the nfs usage. Howeve= r2, > >>>>> in FreeBSD-1 wher ids were 16-bits, nobody was 32767 and nogroup was > >>>>> 32766. so they didn't match nfs for other reasons. The 2 non-groups > >>>>> now seem to be just a bug -- FreeBSD-1 didn't have group nobody. > >>>>> 4.4BSD-Lite2 has the same values as FreeBSD-1. > >>>>=20 > >>>> This is not full true for ZFS case. > >>>> On ZFS nobody is 2^32-2. > >>>=20 > >>> File systems don't get to decide this. > >>=20 > >> +1 (and thanks for the historical account, bruce =E2=80=94 sincerely) > >>=20 > >> However, I still want to make the argument that: > >>=20 > >> a. Because we=E2=80=99ve supported mapping negative inputs to unsigned= values in pw *for over a decade*, that=E2=80=A6 > >>=20 > >> b. We should either revert or make a relnotes submission to note that = we=E2=80=99re changing the long-standing accepted practice. > >>=20 > >> Changing the accepted practice broke code internally, it would have li= kely broken some external code as well =E2=80=94 and people deserve to know= about said change else we should continue to support accepted practice tha= t is decade(s) old. > >=20 > > It has never been accepted by pw(8) it was just not checked >=20 > Those are indistinguishable from each other by an end-user (someone not > reading the code; and even still there is the =E2=80=9Cspirit=E2=80=9D of= the code and the =E2=80=9Cletter > of the code"). >=20 >=20 > > as a result it was > > accepting *anything* and passed it unchecked directly to atoi(3) result= ing in > > for example pw groupdel -u plop removing wheel... or pw userdel -u some= thing > > trying to delete root. (was this an accepted behaviour for a decade as = well?) > >=20 >=20 > The erroneous deletion was inherently wrong. I do not want to see that bug > resurface (and I thank you very much for fixing it). >=20 > However, I=E2=80=99m sure you know that said erroneous deletion was a sid= e-effect of > lacking error-checks. >=20 > Again, thank you fixing the PR itemizing the erroneous deletion of users/= groups. > Please note that Bruce sent me a private e-mail with some historical back= ground, > to which I replied and we=E2=80=99re working out some logic on the side. = There shouldn=E2=80=99t > be much more to this thread =E2=80=94 I envision that we=E2=80=99ll be ap= proaching a solid agree- > meant that should lead to some commits (can=E2=80=99t say yet what direct= ion it will go as > I=E2=80=99m looking forward to Bruce=E2=80=99s touch-points). Well you may have not noticed but I revert my fix and will let someone else handle this (feel free to revert my revert if you think it has to be done, = but still negative uid looked wrong to me hence my revert). That said I have spent too much time in pw(8) this thing should be entirely rewritten this is a terrible can of worm. Bapt --/3yNEOqWowh/8j+e Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlTILt4ACgkQ8kTtMUmk6Ew9+gCfe7mO6nCG8vPA8EKMbW7gRlXD PrQAn2rIXXeU1pXsAkKlOUrqD8NRGCzJ =ChUi -----END PGP SIGNATURE----- --/3yNEOqWowh/8j+e--