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#[cfg(not(any(solarish, target_os = "haiku", target_os = "nto", target_os = "vita")))]
use super::types::FileType;
use crate::backend::c;
use crate::backend::conv::owned_fd;
use crate::fd::{AsFd, BorrowedFd, OwnedFd};
use crate::ffi::{CStr, CString};
use crate::fs::{fcntl_getfl, openat, Mode, OFlags};
#[cfg(not(target_os = "vita"))]
use crate::fs::{fstat, Stat};
#[cfg(not(any(
solarish,
target_os = "haiku",
target_os = "netbsd",
target_os = "nto",
target_os = "redox",
target_os = "vita",
target_os = "wasi",
)))]
use crate::fs::{fstatfs, StatFs};
#[cfg(not(any(
solarish,
target_os = "haiku",
target_os = "redox",
target_os = "vita",
target_os = "wasi"
)))]
use crate::fs::{fstatvfs, StatVfs};
use crate::io;
#[cfg(not(any(target_os = "fuchsia", target_os = "vita", target_os = "wasi")))]
#[cfg(feature = "process")]
use crate::process::fchdir;
use alloc::borrow::ToOwned;
#[cfg(not(any(linux_like, target_os = "hurd")))]
use c::readdir as libc_readdir;
#[cfg(any(linux_like, target_os = "hurd"))]
use c::readdir64 as libc_readdir;
use core::fmt;
use core::ptr::NonNull;
use libc_errno::{errno, set_errno, Errno};
/// `DIR*`
pub struct Dir {
/// The `libc` `DIR` pointer.
libc_dir: NonNull<c::DIR>,
/// Have we seen any errors in this iteration?
any_errors: bool,
}
impl Dir {
/// Take ownership of `fd` and construct a `Dir` that reads entries from
/// the given directory file descriptor.
#[inline]
pub fn new<Fd: Into<OwnedFd>>(fd: Fd) -> io::Result<Self> {
Self::_new(fd.into())
}
#[inline]
fn _new(fd: OwnedFd) -> io::Result<Self> {
let raw = owned_fd(fd);
unsafe {
let libc_dir = c::fdopendir(raw);
if let Some(libc_dir) = NonNull::new(libc_dir) {
Ok(Self {
libc_dir,
any_errors: false,
})
} else {
let err = io::Errno::last_os_error();
let _ = c::close(raw);
Err(err)
}
}
}
/// Borrow `fd` and construct a `Dir` that reads entries from the given
/// directory file descriptor.
#[inline]
pub fn read_from<Fd: AsFd>(fd: Fd) -> io::Result<Self> {
Self::_read_from(fd.as_fd())
}
#[inline]
#[allow(unused_mut)]
fn _read_from(fd: BorrowedFd<'_>) -> io::Result<Self> {
let mut any_errors = false;
// Given an arbitrary `OwnedFd`, it's impossible to know whether the
// user holds a `dup`'d copy which could continue to modify the
// file description state, which would cause Undefined Behavior after
// our call to `fdopendir`. To prevent this, we obtain an independent
// `OwnedFd`.
let flags = fcntl_getfl(fd)?;
let fd_for_dir = match openat(fd, cstr!("."), flags | OFlags::CLOEXEC, Mode::empty()) {
Ok(fd) => fd,
#[cfg(not(target_os = "wasi"))]
Err(io::Errno::NOENT) => {
// If "." doesn't exist, it means the directory was removed.
// We treat that as iterating through a directory with no
// entries.
any_errors = true;
crate::io::dup(fd)?
}
Err(err) => return Err(err),
};
let raw = owned_fd(fd_for_dir);
unsafe {
let libc_dir = c::fdopendir(raw);
if let Some(libc_dir) = NonNull::new(libc_dir) {
Ok(Self {
libc_dir,
any_errors,
})
} else {
let err = io::Errno::last_os_error();
let _ = c::close(raw);
Err(err)
}
}
}
/// `rewinddir(self)`
#[inline]
pub fn rewind(&mut self) {
self.any_errors = false;
unsafe { c::rewinddir(self.libc_dir.as_ptr()) }
}
/// `readdir(self)`, where `None` means the end of the directory.
pub fn read(&mut self) -> Option<io::Result<DirEntry>> {
// If we've seen errors, don't continue to try to read anything further.
if self.any_errors {
return None;
}
set_errno(Errno(0));
let dirent_ptr = unsafe { libc_readdir(self.libc_dir.as_ptr()) };
if dirent_ptr.is_null() {
let curr_errno = errno().0;
if curr_errno == 0 {
// We successfully reached the end of the stream.
None
} else {
// `errno` is unknown or non-zero, so an error occurred.
self.any_errors = true;
Some(Err(io::Errno(curr_errno)))
}
} else {
// We successfully read an entry.
unsafe {
let dirent = &*dirent_ptr;
// We have our own copy of OpenBSD's dirent; check that the
// layout minimally matches libc's.
#[cfg(target_os = "openbsd")]
check_dirent_layout(dirent);
let result = DirEntry {
#[cfg(not(any(
solarish,
target_os = "aix",
target_os = "haiku",
target_os = "nto",
target_os = "vita"
)))]
d_type: dirent.d_type,
#[cfg(not(any(freebsdlike, netbsdlike, target_os = "vita")))]
d_ino: dirent.d_ino,
#[cfg(any(freebsdlike, netbsdlike))]
d_fileno: dirent.d_fileno,
name: CStr::from_ptr(dirent.d_name.as_ptr()).to_owned(),
};
Some(Ok(result))
}
}
}
/// `fstat(self)`
#[cfg(not(target_os = "vita"))]
#[inline]
pub fn stat(&self) -> io::Result<Stat> {
fstat(unsafe { BorrowedFd::borrow_raw(c::dirfd(self.libc_dir.as_ptr())) })
}
/// `fstatfs(self)`
#[cfg(not(any(
solarish,
target_os = "haiku",
target_os = "netbsd",
target_os = "nto",
target_os = "redox",
target_os = "vita",
target_os = "wasi",
)))]
#[inline]
pub fn statfs(&self) -> io::Result<StatFs> {
fstatfs(unsafe { BorrowedFd::borrow_raw(c::dirfd(self.libc_dir.as_ptr())) })
}
/// `fstatvfs(self)`
#[cfg(not(any(
solarish,
target_os = "haiku",
target_os = "redox",
target_os = "vita",
target_os = "wasi"
)))]
#[inline]
pub fn statvfs(&self) -> io::Result<StatVfs> {
fstatvfs(unsafe { BorrowedFd::borrow_raw(c::dirfd(self.libc_dir.as_ptr())) })
}
/// `fchdir(self)`
#[cfg(feature = "process")]
#[cfg(not(any(target_os = "fuchsia", target_os = "vita", target_os = "wasi")))]
#[cfg_attr(doc_cfg, doc(cfg(feature = "process")))]
#[inline]
pub fn chdir(&self) -> io::Result<()> {
fchdir(unsafe { BorrowedFd::borrow_raw(c::dirfd(self.libc_dir.as_ptr())) })
}
}
/// `Dir` implements `Send` but not `Sync`, because we use `readdir` which is
/// not guaranteed to be thread-safe. Users can wrap this in a `Mutex` if they
/// need `Sync`, which is effectively what'd need to do to implement `Sync`
/// ourselves.
unsafe impl Send for Dir {}
impl Drop for Dir {
#[inline]
fn drop(&mut self) {
unsafe { c::closedir(self.libc_dir.as_ptr()) };
}
}
impl Iterator for Dir {
type Item = io::Result<DirEntry>;
#[inline]
fn next(&mut self) -> Option<Self::Item> {
Self::read(self)
}
}
impl fmt::Debug for Dir {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut s = f.debug_struct("Dir");
#[cfg(not(target_os = "vita"))]
s.field("fd", unsafe { &c::dirfd(self.libc_dir.as_ptr()) });
s.finish()
}
}
/// `struct dirent`
#[derive(Debug)]
pub struct DirEntry {
#[cfg(not(any(
solarish,
target_os = "aix",
target_os = "haiku",
target_os = "nto",
target_os = "vita"
)))]
d_type: u8,
#[cfg(not(any(freebsdlike, netbsdlike, target_os = "vita")))]
d_ino: c::ino_t,
#[cfg(any(freebsdlike, netbsdlike))]
d_fileno: c::ino_t,
name: CString,
}
impl DirEntry {
/// Returns the file name of this directory entry.
#[inline]
pub fn file_name(&self) -> &CStr {
&self.name
}
/// Returns the type of this directory entry.
#[cfg(not(any(
solarish,
target_os = "aix",
target_os = "haiku",
target_os = "nto",
target_os = "vita"
)))]
#[inline]
pub fn file_type(&self) -> FileType {
FileType::from_dirent_d_type(self.d_type)
}
/// Return the inode number of this directory entry.
#[cfg(not(any(freebsdlike, netbsdlike, target_os = "vita")))]
#[inline]
pub fn ino(&self) -> u64 {
self.d_ino as u64
}
/// Return the inode number of this directory entry.
#[cfg(any(freebsdlike, netbsdlike))]
#[inline]
pub fn ino(&self) -> u64 {
#[allow(clippy::useless_conversion)]
self.d_fileno.into()
}
}
/// libc's OpenBSD `dirent` has a private field so we can't construct it
/// directly, so we declare it ourselves to make all fields accessible.
#[cfg(target_os = "openbsd")]
#[repr(C)]
#[derive(Debug)]
struct libc_dirent {
d_fileno: c::ino_t,
d_off: c::off_t,
d_reclen: u16,
d_type: u8,
d_namlen: u8,
__d_padding: [u8; 4],
d_name: [c::c_char; 256],
}
/// We have our own copy of OpenBSD's dirent; check that the layout
/// minimally matches libc's.
#[cfg(target_os = "openbsd")]
fn check_dirent_layout(dirent: &c::dirent) {
use crate::utils::as_ptr;
// Check that the basic layouts match.
#[cfg(test)]
{
assert_eq_size!(libc_dirent, c::dirent);
assert_eq_size!(libc_dirent, c::dirent);
}
// Check that the field offsets match.
assert_eq!(
{
let z = libc_dirent {
d_fileno: 0_u64,
d_off: 0_i64,
d_reclen: 0_u16,
d_type: 0_u8,
d_namlen: 0_u8,
__d_padding: [0_u8; 4],
d_name: [0 as c::c_char; 256],
};
let base = as_ptr(&z) as usize;
(
(as_ptr(&z.d_fileno) as usize) - base,
(as_ptr(&z.d_off) as usize) - base,
(as_ptr(&z.d_reclen) as usize) - base,
(as_ptr(&z.d_type) as usize) - base,
(as_ptr(&z.d_namlen) as usize) - base,
(as_ptr(&z.d_name) as usize) - base,
)
},
{
let z = dirent;
let base = as_ptr(z) as usize;
(
(as_ptr(&z.d_fileno) as usize) - base,
(as_ptr(&z.d_off) as usize) - base,
(as_ptr(&z.d_reclen) as usize) - base,
(as_ptr(&z.d_type) as usize) - base,
(as_ptr(&z.d_namlen) as usize) - base,
(as_ptr(&z.d_name) as usize) - base,
)
}
);
}
#[test]
fn dir_iterator_handles_io_errors() {
// create a dir, keep the FD, then delete the dir
let tmp = tempfile::tempdir().unwrap();
let fd = crate::fs::openat(
crate::fs::CWD,
tmp.path(),
crate::fs::OFlags::RDONLY | crate::fs::OFlags::CLOEXEC,
crate::fs::Mode::empty(),
)
.unwrap();
let file_fd = crate::fs::openat(
&fd,
tmp.path().join("test.txt"),
crate::fs::OFlags::WRONLY | crate::fs::OFlags::CREATE,
crate::fs::Mode::RWXU,
)
.unwrap();
let mut dir = Dir::read_from(&fd).unwrap();
// Reach inside the `Dir` and replace its directory with a file, which
// will cause the subsequent `readdir` to fail.
unsafe {
let raw_fd = c::dirfd(dir.libc_dir.as_ptr());
let mut owned_fd: crate::fd::OwnedFd = crate::fd::FromRawFd::from_raw_fd(raw_fd);
crate::io::dup2(&file_fd, &mut owned_fd).unwrap();
core::mem::forget(owned_fd);
}
// FreeBSD and macOS seem to read some directory entries before we call
// `.next()`.
#[cfg(any(apple, freebsdlike))]
{
dir.rewind();
}
assert!(matches!(dir.next(), Some(Err(_))));
assert!(dir.next().is_none());
}