Fwd: [systemd-devel] socket activation selinux context on create

[Ted Toth <txtoth@gmail.com>]

I asked on the systemd-devel list about enabling systemd to set the
context of a socket and got the answer I've included below. I don't
know how a transition rule can be written to transition tcp sockets to
multiple different target contexts, is this possible and if so how?

---------- Forwarded message ---------
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, Aug 25, 2022 at 4:19 AM
Subject: Re: [systemd-devel] socket activation selinux context on create
To: Ted Toth <txtoth@gmail.com>
Cc: <systemd-devel@lists.freedesktop.org>


On Mi, 24.08.22 11:50, Ted Toth (txtoth@gmail.com) wrote:

> I don't see a way to set the context of the socket that systemd
> listens on. If there is a way to do this please tell me otherwise I'd
> like to see an option (SELinuxCreateContext?) added to be able to set
> the context (setsockcreatecon) to be used by systemd when creating the
> socket. Currently as an extra layer of security I add code called in
> the socket activation ExecStartPre process to check that the source
> context (peercon) can connect to the target context (getcon). If a
> sockets context was set by systemd I would have to perform this
> additional check as my SELinux policy would do it for me.

This was proposed before, but SELinux maintainers really want that the
loaded selinux policy picks the label, and not unit files.

i.e. as I understand their philosophy: how labels are assigned should
be encoded in the database and in the policy but not elsewhere,
i.e. in unit files. I think that philosophy does make sense.

Lennart

--
Lennart Poettering, Berlin