Struct SealedDevice 

pub struct SealedDevice {
    pub name: &'static str,
    pub path: &'static str,
    pub major: u32,
    pub minor: u32,
    pub mode: u32,
    pub writable: bool,
}

One entry of the private /dev tmpfs.

major/minor/mode are recorded for the record and for the manual-verification document to assert against — they are not used to create the node. Device nodes cannot be mknoded from inside a non-initial user namespace at all (the kernel refuses regardless of CAP_MKNOD), so each entry is created as an empty file in the tmpfs and the host’s node is bind-mounted over it. This is what bubblewrap and rootless podman do, and it means the numbers a capsule actually sees are the host’s — which on every mainstream distribution are exactly the ones below.

Fields

name: &'static str

Name under /dev, without the directory.

path: &'static str

The host path bind-mounted over the tmpfs entry — /dev/ + Self::name, spelled out because it is also what the composed root’s Landlock rule set is built from.

major: u32

minor: u32

mode: u32

writable: bool

Whether the composed root’s Landlock rule for this device carries WriteFile on top of ReadFile.

Landlock still mediates inside a composed root — that is the whole point of keeping it as defence in depth — so a device present in /dev but absent from the rule set would exist and be unopenable, which is worse than not being there. The read-only pair is the two entropy sources, where nothing legitimate writes; the rest carry write because their write side is defined to discard (null, zero), to report ENOSPC (full), or to be a terminal (tty).

Trait Implementations

impl Clone for SealedDevice

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for SealedDevice

impl Debug for SealedDevice

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for SealedDevice

impl PartialEq for SealedDevice

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SealedDevice