landlock: Improve documentation of previous limitations

Improve consistency of previous limitations' subsection titles, and
expand a bit the IOCTL section.

This changes some HTML anchors and may break some external links though.

Cc: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Cc: Tahera Fahimi <fahimitahera@gmail.com>
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20241004153122.501775-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
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Mickaël Salaün 2024-10-04 17:31:20 +02:00
parent 8e929cb546
commit 9803787a23
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@ -8,7 +8,7 @@ Landlock: unprivileged access control
=====================================
:Author: Mickaël Salaün
:Date: September 2024
:Date: October 2024
The goal of Landlock is to enable to restrict ambient rights (e.g. global
filesystem or network access) for a set of processes. Because Landlock
@ -563,33 +563,34 @@ always allowed when using a kernel that only supports the first or second ABI.
Starting with the Landlock ABI version 3, it is now possible to securely control
truncation thanks to the new ``LANDLOCK_ACCESS_FS_TRUNCATE`` access right.
Network support (ABI < 4)
-------------------------
TCP bind and connect (ABI < 4)
------------------------------
Starting with the Landlock ABI version 4, it is now possible to restrict TCP
bind and connect actions to only a set of allowed ports thanks to the new
``LANDLOCK_ACCESS_NET_BIND_TCP`` and ``LANDLOCK_ACCESS_NET_CONNECT_TCP``
access rights.
IOCTL (ABI < 5)
---------------
Device IOCTL (ABI < 5)
----------------------
IOCTL operations could not be denied before the fifth Landlock ABI, so
:manpage:`ioctl(2)` is always allowed when using a kernel that only supports an
earlier ABI.
Starting with the Landlock ABI version 5, it is possible to restrict the use of
:manpage:`ioctl(2)` using the new ``LANDLOCK_ACCESS_FS_IOCTL_DEV`` right.
:manpage:`ioctl(2)` on character and block devices using the new
``LANDLOCK_ACCESS_FS_IOCTL_DEV`` right.
Abstract UNIX socket scoping (ABI < 6)
--------------------------------------
Abstract UNIX socket (ABI < 6)
------------------------------
Starting with the Landlock ABI version 6, it is possible to restrict
connections to an abstract :manpage:`unix(7)` socket by setting
``LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET`` to the ``scoped`` ruleset attribute.
Signal scoping (ABI < 6)
------------------------
Signal (ABI < 6)
----------------
Starting with the Landlock ABI version 6, it is possible to restrict
:manpage:`signal(7)` sending by setting ``LANDLOCK_SCOPE_SIGNAL`` to the