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#[allow(dead_code)]
enum Priv {
Bind {
src: String,
rw: bool,
ignore_nonexist: bool,
recursive: bool,
},
Tmpfs {
rw: bool,
opts: Vec<String>,
},
Normal {
src: String,
rw: bool,
ignore_nonexist: bool,
opts: Vec<String>,
},
}
/// The description of a mount.
pub struct Mount(Priv);
impl Mount {
/// Create a new bind mount.
///
/// Read `BindPaths` and `BindReadOnlyPaths` in
/// [systemd.exec(5)](man:systemd.exec(5)) for details.
///
/// This setting is not available if the feature `systemd_233` is
/// disabled.
#[cfg(feature = "systemd_233")]
pub fn bind<T: AsRef<str>>(src: T) -> Self {
Self(Priv::Bind {
src: src.as_ref().to_owned(),
rw: false,
recursive: false,
ignore_nonexist: false,
})
}
/// Create a tmpfs mount.
///
/// Read `TemporaryFileSystem` in [systemd.exec(5)](man:systemd.exec(5))
/// for details.
///
/// This setting is not available if the feature `systemd_238` is
/// disabled.
#[cfg(feature = "systemd_238")]
pub fn tmpfs() -> Self {
Self(Priv::Tmpfs {
rw: false,
opts: vec![],
})
}
/// Create a normal mount.
///
/// Read `MountImages` in [systemd.exec(5)](man:systemd.exec(5)) for
/// details.
///
/// This setting is not available if the feature `systemd_247` is
/// disabled.
#[cfg(feature = "systemd_247")]
pub fn normal<T: AsRef<str>>(src: T) -> Self {
Self(Priv::Normal {
src: src.as_ref().to_owned(),
rw: false,
ignore_nonexist: false,
opts: vec![],
})
}
/// Make the [Mount] writable.
pub fn writable(self) -> Self {
match self {
Self(Priv::Bind {
src,
recursive,
ignore_nonexist,
..
}) => Self(Priv::Bind {
src,
recursive,
ignore_nonexist,
rw: true,
}),
Self(Priv::Tmpfs { opts, .. }) => Self(Priv::Tmpfs { opts, rw: true }),
Self(Priv::Normal {
opts,
src,
ignore_nonexist,
..
}) => Self(Priv::Normal {
opts,
src,
ignore_nonexist,
rw: true,
}),
}
}
/// Make the [Mount] recursive. It only makes a difference for a bind
/// mount.
pub fn recursive(self) -> Self {
match self {
Self(Priv::Bind { src, rw, .. }) => Self(Priv::Bind {
src,
rw,
recursive: true,
ignore_nonexist: true,
}),
_ => self,
}
}
/// Append a mount option. If the option contains a comma (`,`), or
/// it is `ro`, `rw`, or empty, or it's applied for a bind mount,
/// [None] will be returned. But the option will not be validated
/// further.
///
/// For `rw`, use [Self::writable] instead.
pub fn opt<T: AsRef<str>>(self, option: T) -> Option<Self> {
let o = option.as_ref();
if o.contains(',') {
return None;
}
match o {
"" | "ro" | "rw" => return None,
_ => {}
}
match self {
Self(Priv::Bind { .. }) => None,
Self(Priv::Tmpfs { rw, mut opts }) => {
opts.push(o.to_owned());
Some(Self(Priv::Tmpfs { rw, opts }))
}
Self(Priv::Normal {
src,
rw,
mut opts,
ignore_nonexist,
}) => {
opts.push(o.to_owned());
Some(Self(Priv::Normal {
src,
rw,
opts,
ignore_nonexist,
}))
}
}
}
/// Ignore the mount if the source does not exist. This does not make
/// any difference for tmpfs mounts.
pub fn ignore_nonexist(self) -> Self {
match self {
Self(Priv::Tmpfs { .. }) => self,
Self(Priv::Normal { src, rw, opts, .. }) => Self(Priv::Normal {
src,
rw,
opts,
ignore_nonexist: true,
}),
Self(Priv::Bind {
src, rw, recursive, ..
}) => Self(Priv::Bind {
src,
rw,
recursive,
ignore_nonexist: true,
}),
}
}
}
fn escape(s: &str) -> String {
s.replace('\\', "\\\\")
.replace(':', "\\:")
.replace(' ', "\\ ")
}
pub enum MarshaledMount {
/// src, dest, ignore_nonexist, flags (MS_REC or 0)
Bind(String, String, bool, u64),
/// src, dest, ignore_nonexist, flags (MS_REC or 0)
BindReadOnly(String, String, bool, u64),
/// src, dest, ignore_nonexist, `[(GPT label, flags)]`
/// Currently only `root` used as `GPT label`
Normal(String, String, bool, Vec<(&'static str, String)>),
/// dest, flags (joined with comma)
Tmpfs(String, String),
}
pub fn marshal<T: AsRef<str>>(mount_point: T, mount: Mount) -> MarshaledMount {
use MarshaledMount::*;
let mp = escape(mount_point.as_ref());
match mount {
Mount(Priv::Bind {
src,
rw,
ignore_nonexist,
recursive,
}) => {
let src = escape(&src);
let flags: u64 = match recursive {
true => 16384, // MS_REC
false => 0,
};
match rw {
true => Bind(src, mp, ignore_nonexist, flags),
false => BindReadOnly(src, mp, ignore_nonexist, flags),
}
}
Mount(Priv::Normal {
src,
rw,
ignore_nonexist,
mut opts,
}) => {
let src = escape(&src);
if !rw {
opts.push("ro".into());
}
let opts = opts.into_iter().map(|x| ("root", x)).collect();
Normal(src, mp, ignore_nonexist, opts)
}
Mount(Priv::Tmpfs { rw, mut opts }) => {
if !rw {
opts.push("ro".into());
}
Tmpfs(mp, opts.join(","))
}
}
}