xattr/sys/
linux_macos.rs

Help
1use std::ffi::{OsStr, OsString};
2use std::io;
3use std::mem;
4use std::os::unix::ffi::OsStrExt;
5use std::os::unix::io::BorrowedFd;
6use std::path::Path;
7
8use rustix::fs as rfs;
9use rustix::path::Arg;
10
11use crate::util::allocate_loop;
12
13use std::os::raw::c_char;
14
15#[cfg(not(target_os = "macos"))]
16pub const ENOATTR: i32 = rustix::io::Errno::NODATA.raw_os_error();
17
18#[cfg(target_os = "macos")]
19pub const ENOATTR: i32 = rustix::io::Errno::NOATTR.raw_os_error();
20
21// Convert an `&mut [u8]` to an `&mut [c_char]`
22#[inline]
23fn as_listxattr_buffer(buf: &mut [u8]) -> &mut [c_char] {
24    // SAFETY: u8 and i8 have the same size and alignment
25    unsafe { &mut *(buf as *mut [u8] as *mut [c_char]) }
26}
27
28/// An iterator over a set of extended attributes names.
29#[derive(Default)]
30pub struct XAttrs {
31    data: Box<[u8]>,
32    offset: usize,
33}
34
35impl Clone for XAttrs {
36    fn clone(&self) -> Self {
37        XAttrs {
38            data: Vec::from(&*self.data).into_boxed_slice(),
39            offset: self.offset,
40        }
41    }
42    fn clone_from(&mut self, other: &XAttrs) {
43        self.offset = other.offset;
44
45        let mut data = mem::replace(&mut self.data, Box::new([])).into_vec();
46        data.extend(other.data.iter().cloned());
47        self.data = data.into_boxed_slice();
48    }
49}
50
51// Yes, I could avoid these allocations on linux/macos. However, if we ever want to be freebsd
52// compatible, we need to be able to prepend the namespace to the extended attribute names.
53// Furthermore, borrowing makes the API messy.
54impl Iterator for XAttrs {
55    type Item = OsString;
56    fn next(&mut self) -> Option<OsString> {
57        let data = &self.data[self.offset..];
58        if data.is_empty() {
59            None
60        } else {
61            // always null terminated (unless empty).
62            let end = data.iter().position(|&b| b == 0u8).unwrap();
63            self.offset += end + 1;
64            Some(OsStr::from_bytes(&data[..end]).to_owned())
65        }
66    }
67
68    fn size_hint(&self) -> (usize, Option<usize>) {
69        if self.data.len() == self.offset {
70            (0, Some(0))
71        } else {
72            (1, None)
73        }
74    }
75}
76
77pub fn get_fd(fd: BorrowedFd<'_>, name: &OsStr) -> io::Result<Vec<u8>> {
78    allocate_loop(|buf| rfs::fgetxattr(fd, name, buf))
79}
80
81pub fn set_fd(fd: BorrowedFd<'_>, name: &OsStr, value: &[u8]) -> io::Result<()> {
82    rfs::fsetxattr(fd, name, value, rfs::XattrFlags::empty())?;
83    Ok(())
84}
85
86pub fn remove_fd(fd: BorrowedFd<'_>, name: &OsStr) -> io::Result<()> {
87    rfs::fremovexattr(fd, name)?;
88    Ok(())
89}
90
91pub fn list_fd(fd: BorrowedFd<'_>) -> io::Result<XAttrs> {
92    let vec = allocate_loop(|buf| rfs::flistxattr(fd, as_listxattr_buffer(buf)))?;
93    Ok(XAttrs {
94        data: vec.into_boxed_slice(),
95        offset: 0,
96    })
97}
98
99pub fn get_path(path: &Path, name: &OsStr, deref: bool) -> io::Result<Vec<u8>> {
100    let path = path.into_c_str()?;
101    let name = name.into_c_str()?;
102
103    allocate_loop(|buf| {
104        let getxattr_func = if deref { rfs::getxattr } else { rfs::lgetxattr };
105        let size = getxattr_func(&*path, &*name, buf)?;
106        io::Result::Ok(size)
107    })
108}
109
110pub fn set_path(path: &Path, name: &OsStr, value: &[u8], deref: bool) -> io::Result<()> {
111    let setxattr_func = if deref { rfs::setxattr } else { rfs::lsetxattr };
112    setxattr_func(path, name, value, rfs::XattrFlags::empty())?;
113    Ok(())
114}
115
116pub fn remove_path(path: &Path, name: &OsStr, deref: bool) -> io::Result<()> {
117    let removexattr_func = if deref {
118        rfs::removexattr
119    } else {
120        rfs::lremovexattr
121    };
122    removexattr_func(path, name)?;
123    Ok(())
124}
125
126pub fn list_path(path: &Path, deref: bool) -> io::Result<XAttrs> {
127    let listxattr_func = if deref {
128        rfs::listxattr
129    } else {
130        rfs::llistxattr
131    };
132    let path = path.as_cow_c_str()?;
133    let vec = allocate_loop(|buf| listxattr_func(&*path, as_listxattr_buffer(buf)))?;
134    Ok(XAttrs {
135        data: vec.into_boxed_slice(),
136        offset: 0,
137    })
138}
xattr/sys/linux_macos.rs

xattr/sys/
linux_macos.rs
