1//! User and Group ID types.
2
3#![allow(unsafe_code)]
4
5use crate::backend::c;
6
7/// A group identifier as a raw integer.
8#[cfg(not(target_os = "wasi"))]
9pub type RawGid = c::gid_t;
10/// A user identifier as a raw integer.
11#[cfg(not(target_os = "wasi"))]
12pub type RawUid = c::uid_t;
13
14/// `uid_t`—A Unix user ID.
15#[repr(transparent)]
16#[derive(Copy, Clone, Eq, PartialEq, Debug, Hash)]
17pub struct Uid(RawUid);
18
19/// `gid_t`—A Unix group ID.
20#[repr(transparent)]
21#[derive(Copy, Clone, Eq, PartialEq, Debug, Hash)]
22pub struct Gid(RawGid);
23
24impl Uid {
25 /// A `Uid` corresponding to the root user (uid 0).
26 pub const ROOT: Self = Self(0);
27
28 /// Converts a `RawUid` into a `Uid`.
29 ///
30 /// # Safety
31 ///
32 /// `raw` must be the value of a valid Unix user ID.
33 #[inline]
34 pub const unsafe fn from_raw(raw: RawUid) -> Self {
35 Self(raw)
36 }
37
38 /// Converts a `Uid` into a `RawUid`.
39 #[inline]
40 pub const fn as_raw(self) -> RawUid {
41 self.0
42 }
43
44 /// Test whether this uid represents the root user (uid 0).
45 #[inline]
46 pub const fn is_root(self) -> bool {
47 self.0 == Self::ROOT.0
48 }
49}
50
51impl Gid {
52 /// A `Gid` corresponding to the root group (gid 0).
53 pub const ROOT: Self = Self(0);
54
55 /// Converts a `RawGid` into a `Gid`.
56 ///
57 /// # Safety
58 ///
59 /// `raw` must be the value of a valid Unix group ID.
60 #[inline]
61 pub const unsafe fn from_raw(raw: RawGid) -> Self {
62 Self(raw)
63 }
64
65 /// Converts a `Gid` into a `RawGid`.
66 #[inline]
67 pub const fn as_raw(self) -> RawGid {
68 self.0
69 }
70
71 /// Test whether this gid represents the root group (gid 0).
72 #[inline]
73 pub const fn is_root(self) -> bool {
74 self.0 == Self::ROOT.0
75 }
76}
77
78// Return the raw value of the IDs. In case of `None` it returns `!0` since it
79// has the same bit pattern as `-1` indicating no change to the owner/group ID.
80pub(crate) fn translate_fchown_args(owner: Option<Uid>, group: Option<Gid>) -> (RawUid, RawGid) {
81 let ow: u32 = match owner {
82 Some(o: Uid) => o.as_raw(),
83 None => !0,
84 };
85
86 let gr: u32 = match group {
87 Some(g: Gid) => g.as_raw(),
88 None => !0,
89 };
90
91 (ow, gr)
92}
93
94#[test]
95fn test_sizes() {
96 assert_eq_size!(RawUid, u32);
97 assert_eq_size!(RawGid, u32);
98}
99