xattr/sys/
linux_macos.rs

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 {
26        &mut *(buf as *mut [u8] as *mut [c_char])
27    }
28}
29
30/// An iterator over a set of extended attributes names.
31pub struct XAttrs {
32    data: Box<[u8]>,
33    offset: usize,
34}
35
36impl Clone for XAttrs {
37    fn clone(&self) -> Self {
38        XAttrs {
39            data: Vec::from(&*self.data).into_boxed_slice(),
40            offset: self.offset,
41        }
42    }
43    fn clone_from(&mut self, other: &XAttrs) {
44        self.offset = other.offset;
45
46        let mut data = mem::replace(&mut self.data, Box::new([])).into_vec();
47        data.extend(other.data.iter().cloned());
48        self.data = data.into_boxed_slice();
49    }
50}
51
52// Yes, I could avoid these allocations on linux/macos. However, if we ever want to be freebsd
53// compatible, we need to be able to prepend the namespace to the extended attribute names.
54// Furthermore, borrowing makes the API messy.
55impl Iterator for XAttrs {
56    type Item = OsString;
57    fn next(&mut self) -> Option<OsString> {
58        let data = &self.data[self.offset..];
59        if data.is_empty() {
60            None
61        } else {
62            // always null terminated (unless empty).
63            let end = data.iter().position(|&b| b == 0u8).unwrap();
64            self.offset += end + 1;
65            Some(OsStr::from_bytes(&data[..end]).to_owned())
66        }
67    }
68
69    fn size_hint(&self) -> (usize, Option<usize>) {
70        if self.data.len() == self.offset {
71            (0, Some(0))
72        } else {
73            (1, None)
74        }
75    }
76}
77
78pub fn get_fd(fd: BorrowedFd<'_>, name: &OsStr) -> io::Result<Vec<u8>> {
79    allocate_loop(|buf| {
80        rfs::fgetxattr(fd, name, buf)
81    })
82}
83
84pub fn set_fd(fd: BorrowedFd<'_>, name: &OsStr, value: &[u8]) -> io::Result<()> {
85    rfs::fsetxattr(fd, name, value, rfs::XattrFlags::empty())?;
86    Ok(())
87}
88
89pub fn remove_fd(fd: BorrowedFd<'_>, name: &OsStr) -> io::Result<()> {
90    rfs::fremovexattr(fd, name)?;
91    Ok(())
92}
93
94pub fn list_fd(fd: BorrowedFd<'_>) -> io::Result<XAttrs> {
95    let vec = allocate_loop(|buf| {
96        rfs::flistxattr(fd, as_listxattr_buffer(buf))
97    })?;
98    Ok(XAttrs {
99        data: vec.into_boxed_slice(),
100        offset: 0,
101    })
102}
103
104pub fn get_path(path: &Path, name: &OsStr, deref: bool) -> io::Result<Vec<u8>> {
105    let path = path.into_c_str()?;
106    let name = name.into_c_str()?;
107
108    allocate_loop(|buf| {
109        let getxattr_func = if deref { rfs::getxattr } else { rfs::lgetxattr };
110        let size = getxattr_func(&*path, &*name, buf)?;
111        io::Result::Ok(size)
112    })
113}
114
115pub fn set_path(path: &Path, name: &OsStr, value: &[u8], deref: bool) -> io::Result<()> {
116    let setxattr_func = if deref { rfs::setxattr } else { rfs::lsetxattr };
117    setxattr_func(path, name, value, rfs::XattrFlags::empty())?;
118    Ok(())
119}
120
121pub fn remove_path(path: &Path, name: &OsStr, deref: bool) -> io::Result<()> {
122    let removexattr_func = if deref { rfs::removexattr } else { rfs::lremovexattr };
123    removexattr_func(path, name)?;
124    Ok(())
125}
126
127pub fn list_path(path: &Path, deref: bool) -> io::Result<XAttrs> {
128    let listxattr_func = if deref { rfs::listxattr } else { rfs::llistxattr };
129    let path = path.as_cow_c_str()?;
130    let vec = allocate_loop(|buf| {
131        listxattr_func(&*path, as_listxattr_buffer(buf))
132    })?;
133    Ok(XAttrs {
134        data: vec.into_boxed_slice(),
135        offset: 0,
136    })
137}
xattr/sys/linux_macos.rs

xattr/sys/
linux_macos.rs
