On Thu, Aug 25, 2022 at 9:22 AM Ted Toth <txtoth@xxxxxxxxx> wrote: > 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? Ignoring setsockcreatecon(3) as that really isn't an option here, sockets created via socket(2) do check to see if there is a type transition defined in the policy. In the case of a TCP socket the type transition would look something like this: type_transition <domain> <domain>:tcp_socket <new_socket_type> ... so you can see there is not much one can select on other than the socket's object class. The reason is that the socket(2) call itself is rather spartan, with not even any clue as to if this is a client or server socket in the case of TCP. Taking a step back, what are you trying to do? Perhaps there is another approach that would get you where you want to go. > ---------- Forwarded message --------- > From: Lennart Poettering <lennart@xxxxxxxxxxxxxx> > Date: Thu, Aug 25, 2022 at 4:19 AM > Subject: Re: [systemd-devel] socket activation selinux context on create > To: Ted Toth <txtoth@xxxxxxxxx> > Cc: <systemd-devel@xxxxxxxxxxxxxxxxxxxxx> > > > On Mi, 24.08.22 11:50, Ted Toth (txtoth@xxxxxxxxx) 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 -- paul-moore.com
