Re: [PATCH net-next 0/3] Add SCM_PIDFD and SO_PEERPIDFD

[Luca Boccassi]

On Mon, 20 Mar 2023 at 14:35, Luca Boccassi <bluca@xxxxxxxxxx> wrote:
>
> On Thu, 2023-03-16 at 14:15 +0100, Alexander Mikhalitsyn wrote:
> > 1. Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS,
> > but it contains pidfd instead of plain pid, which allows programmers not
> > to care about PID reuse problem.
> >
> > 2. Add SO_PEERPIDFD which allows to get pidfd of peer socket holder pidfd.
> > This thing is direct analog of SO_PEERCRED which allows to get plain PID.
> >
> > 3. Add SCM_PIDFD / SO_PEERPIDFD kselftest
> >
> > Idea comes from UAPI kernel group:
> > https://uapi-group.org/kernel-features/
> >
> > Big thanks to Christian Brauner and Lennart Poettering for productive
> > discussions about this.
> >
> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> > Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> > Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> > Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
> > Cc: Leon Romanovsky <leon@xxxxxxxxxx>
> > Cc: David Ahern <dsahern@xxxxxxxxxx>
> > Cc: Arnd Bergmann <arnd@xxxxxxxx>
> > Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> > Cc: Christian Brauner <brauner@xxxxxxxxxx>
> >
> > Alexander Mikhalitsyn (3):
> >   scm: add SO_PASSPIDFD and SCM_PIDFD
> >   net: core: add getsockopt SO_PEERPIDFD
> >   selftests: net: add SCM_PIDFD / SO_PEERPIDFD test
>
> I've implemented support for this in dbus-daemon:
>
> https://gitlab.freedesktop.org/dbus/dbus/-/merge_requests/398
>
> It's working very well. I am also working on the dbus-broker and polkit
> side of things, will share the links here once they are in a reviewable
> state. But the dbus-daemon implementation is enough to meaningfully
> test this.
>
> For the series:
>
> Tested-by: Luca Boccassi <bluca@xxxxxxxxxx>

Polkit changes:

https://gitlab.freedesktop.org/polkit/polkit/-/merge_requests/154