1 //! User and Group ID types.
2
3 #![allow(unsafe_code)]
4
5 use crate::backend::c;
6
7 /// A group identifier as a raw integer.
8 #[cfg(not(target_os = "wasi"))]
9 pub type RawGid = c::gid_t;
10 /// A user identifier as a raw integer.
11 #[cfg(not(target_os = "wasi"))]
12 pub type RawUid = c::uid_t;
13
14 /// `uid_t`—A Unix user ID.
15 #[repr(transparent)]
16 #[derive(Copy, Clone, Eq, PartialEq, Debug, Hash)]
17 pub struct Uid(RawUid);
18
19 /// `gid_t`—A Unix group ID.
20 #[repr(transparent)]
21 #[derive(Copy, Clone, Eq, PartialEq, Debug, Hash)]
22 pub struct Gid(RawGid);
23
24 impl 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]
from_raw(raw: RawUid) -> Self34 pub const unsafe fn from_raw(raw: RawUid) -> Self {
35 Self(raw)
36 }
37
38 /// Converts a `Uid` into a `RawUid`.
39 #[inline]
as_raw(self) -> RawUid40 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]
is_root(self) -> bool46 pub const fn is_root(self) -> bool {
47 self.0 == Self::ROOT.0
48 }
49 }
50
51 impl 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]
from_raw(raw: RawGid) -> Self61 pub const unsafe fn from_raw(raw: RawGid) -> Self {
62 Self(raw)
63 }
64
65 /// Converts a `Gid` into a `RawGid`.
66 #[inline]
as_raw(self) -> RawGid67 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]
is_root(self) -> bool73 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.
translate_fchown_args(owner: Option<Uid>, group: Option<Gid>) -> (RawUid, RawGid)80 pub(crate) fn translate_fchown_args(owner: Option<Uid>, group: Option<Gid>) -> (RawUid, RawGid) {
81 let ow = match owner {
82 Some(o) => o.as_raw(),
83 None => !0,
84 };
85
86 let gr = match group {
87 Some(g) => g.as_raw(),
88 None => !0,
89 };
90
91 (ow, gr)
92 }
93
94 #[test]
test_sizes()95 fn test_sizes() {
96 assert_eq_size!(RawUid, u32);
97 assert_eq_size!(RawGid, u32);
98 }
99