svn commit: r367280 - head/lib/libc/gen

[Emmanuel Vadot]

On Mon, 2 Nov 2020 23:24:34 +0100
Stefan Esser <se at freebsd.org> wrote:

> Am 02.11.20 um 22:49 schrieb Emmanuel Vadot:
> > On Mon, 2 Nov 2020 22:41:38 +0100
> > Stefan Esser <se at freebsd.org> wrote:
> > 
> >> Am 02.11.20 um 20:20 schrieb Oliver Pinter:> On Monday, November 2,
> >> 2020, Stefan Eßer <se at freebsd.org
> >>> <mailto:se at freebsd.org>> wrote:
> >>>
> >>>      Author: se
> >>>      Date: Mon Nov  2 18:48:06 2020
> >>>      New Revision: 367280
> >>>      URL: https://svnweb.freebsd.org/changeset/base/367280
> >>>      <https://svnweb.freebsd.org/changeset/base/367280>
> >>>
> >>>      Log:
> >>>         Re-arrange some of the code to separate writable user tree
> >>>      variables from
> >>>         R/O variables.
> >>>
> >>>         While here fix some nearby style. No functional change intended.
> >>>
> >>>         MFC after:    1 month
> >>>
> >>>
> >>> Is there any phabricator reference for this / these commit(s) + reviewer
> >>> lists?
> >>
> >> The previous commit that has been refined in this one has been
> >> discussed in D27009.
> >>
> >> I had added the new R/W sysctl variable to a switch statement that
> >> contained one R/O string value, and excluded the OID from causing
> >> an error return when a new value had been passed.
> >>
> >> This was functionally OK, but I have decided to move handling of
> >> the new writable variable to before the check for a write attempt
> >> and thus need to test specifically for its OID.
> >>
> >> This sysctl variable is referenced in Scott Longs proposed
> >> getlocalbase() function (D27022), but also in the change to make
> >> it define defaults paths in /etc/defaults/rc.conf (D27014).
> >>
> >> I do not support to make LOCALBASE dynamic for a broad range of
> >> programs, since this could lead to severe security issues (e.g.
> >> when a program is restricted by policy settings LOCALBASE/etc and
> >> an user-defined LOCALBASE could be used to circumvent them.
> >>
> >> There are already programs that respect a LOCALBASE environment
> >> variable, e.g. the pkg program, to allow it to e.g. operate with
> >> a DESTDIR prefix other than "/". This is a program that could
> >> instead use getlocalbase(), IMHO.
> >>
> >> But for security reasons all files that determine policies and
> >> exist in LOCALBASE since they are not distributed as part of the
> >> base system, should be located in a secure way, and that is by
> >> referring to a compiled in trusted path, IMHO.
> >>
> >> Even if the sysctl variable "user.localbase" can only be written to
> >> by root, the use of getlocalbase() provided by a shared library could
> >> allow to perform a LD_PRELOAD attack (provide a getlocalbase() that
> >> leadsto a user provided policy file instead of the admin controlled
> >> one).
> >>
> >> Regards, STefan
> > 
> >   I think that the first question we want to ask is : Do we want to
> > support LOCALBASE being different than /usr/local
> 
> The big majority of users will keep the default value, and I do not
> see a good reason for a change, except if there is a large installed
> base that traditionally uses another prefix (I have seen /vol/local
> and /opt, but also OS and architecture-specific prefixes, for example).

 I'd still like to see some arguments for such installs.

> >   I honestly don't see any advantages of making it !=/usr/local/ and
> > before we start putting a lot of new/useless(for I guess 99% of our
> > user base) in the tree we should here why people are using /usr/pkg or
> > whatever weird location.
> 
> No, why should we [assess] (assuming that word is to be implied in
> your sentence) why people want to be able to easily use a different
> prefix? That would be a waste of time, IMHO.
> 
> I know that there are legitimate reasons to want a different prefix,
> and we had requests to make it easier to support it.

 What are thoses ?

> We have literal uses of /usr/local in a lot of files in the FreeBSD
> base system (more than 1700) and this is not going to change.
> 
> But it was easy to replace a number of such literal pathes in base
> system binaries, and we can make it easier for those that need a
> different prefix to get it consistently used.
> 
> >   If they have some good argument, then we should proceed further.
> 
> You do not have to participate in this effort 

 I do have to participate, it's a common project.
 Also since I also participate in pkg(8) and in ports/Mk lua/blah stuff
there might be some stuff to do there so yes I need to participate.
 And since you never really started a conversation on a ml (that I know
of) my only mean to start this participation is answering a commit
email.

> - there are so many
> other areas to work on (and I know you are very active in one).

 Only one ? Damn, I should work more then.

> But please do not ask those that have started to reduce the use of
> literal /usr/local in the base system to justify this work.

 Seriously ? I have every right to ask you to justify this when it was
not talked about in a public forum.

> If you are happy with /usr/local, then you are not affected at all.
> And if you need to configure your system to use a different prefix,
> you are welcome to let us know which steps are still causing much
> effort and should be worked on to make it easier ...
> 
> Do you have any reason to be against removal of literal /usr/local
> from the base system in favor of using a symbolic name for it?

 Do you have any reason to remove them at all ?

> Regards, STefan


-- 
Emmanuel Vadot <manu at bidouilliste.com>