kanidm_utils_users/
unix.rs

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1use libc::passwd as c_passwd;
2use libc::{gid_t, uid_t};
3use std::ffi::{CStr, OsStr, OsString};
4use std::os::unix::ffi::OsStrExt;
5use std::{mem, ptr};
6
7pub fn get_current_uid() -> uid_t {
8    unsafe { libc::getuid() }
9}
10
11pub fn get_effective_uid() -> uid_t {
12    unsafe { libc::geteuid() }
13}
14
15pub fn get_current_gid() -> gid_t {
16    unsafe { libc::getgid() }
17}
18
19pub fn get_effective_gid() -> gid_t {
20    unsafe { libc::getegid() }
21}
22
23pub fn get_user_name_by_uid(uid: uid_t) -> Option<OsString> {
24    let mut passwd = unsafe { mem::zeroed::<c_passwd>() };
25    let mut buf = vec![0; 2048];
26    let mut result = ptr::null_mut::<c_passwd>();
27
28    loop {
29        let r =
30            unsafe { libc::getpwuid_r(uid, &mut passwd, buf.as_mut_ptr(), buf.len(), &mut result) };
31
32        if r != libc::ERANGE {
33            break;
34        }
35
36        let newsize = buf.len().checked_mul(2)?;
37        buf.resize(newsize, 0);
38    }
39
40    if result.is_null() {
41        // There is no such user, or an error has occurred.
42        // errno gets set if there’s an error.
43        return None;
44    }
45
46    if result != &mut passwd {
47        // The result of getpwuid_r should be its input passwd.
48        return None;
49    }
50
51    let name = unsafe {
52        OsStr::from_bytes(CStr::from_ptr(result.read().pw_name).to_bytes()).to_os_string()
53    };
54
55    Some(name)
56}
57
58#[test]
59/// just testing these literally don't panic
60fn test_get_effective_uid() {
61    let euid = get_effective_uid();
62    assert!(euid > 0);
63    let egid = get_effective_gid();
64    assert!(egid > 0);
65
66    let username = get_user_name_by_uid(get_current_uid());
67    assert!(username.is_some());
68}
kanidm_utils_users/unix.rs

kanidm_utils_users/
unix.rs
