1 files changed, 456 insertions, 0 deletions
diff --git a/vendor/rustix/src/imp/libc/io/syscalls.rs b/vendor/rustix/src/imp/libc/io/syscalls.rs
new file mode 100644
index 000000000..4fafbfd66
--- /dev/null
+++ b/vendor/rustix/src/imp/libc/io/syscalls.rs
@@ -0,0 +1,456 @@
+//! libc syscalls supporting `rustix::io`.
+
+use super::super::c;
+#[cfg(any(target_os = "android", target_os = "linux"))]
+use super::super::conv::syscall_ret_owned_fd;
+use super::super::conv::{
+    borrowed_fd, ret, ret_c_int, ret_discarded_fd, ret_owned_fd, ret_ssize_t,
+};
+use super::super::offset::{libc_pread, libc_pwrite};
+#[cfg(not(target_os = "redox"))]
+use super::super::offset::{libc_preadv, libc_pwritev};
+#[cfg(all(target_os = "linux", target_env = "gnu"))]
+use super::super::offset::{libc_preadv2, libc_pwritev2};
+use crate::fd::{AsFd, BorrowedFd, RawFd};
+#[cfg(not(target_os = "wasi"))]
+use crate::io::DupFlags;
+#[cfg(not(any(target_os = "ios", target_os = "macos", target_os = "wasi")))]
+use crate::io::PipeFlags;
+use crate::io::{self, IoSlice, IoSliceMut, OwnedFd, PollFd};
+#[cfg(any(target_os = "android", target_os = "linux"))]
+use crate::io::{EventfdFlags, ReadWriteFlags};
+use core::cmp::min;
+use core::convert::TryInto;
+use core::mem::MaybeUninit;
+#[cfg(feature = "net")]
+use libc_errno::errno;
+
+pub(crate) fn read(fd: BorrowedFd<'_>, buf: &mut [u8]) -> io::Result<usize> {
+    let nread = unsafe {
+        ret_ssize_t(c::read(
+            borrowed_fd(fd),
+            buf.as_mut_ptr().cast(),
+            min(buf.len(), READ_LIMIT),
+        ))?
+    };
+    Ok(nread as usize)
+}
+
+pub(crate) fn write(fd: BorrowedFd<'_>, buf: &[u8]) -> io::Result<usize> {
+    let nwritten = unsafe {
+        ret_ssize_t(c::write(
+            borrowed_fd(fd),
+            buf.as_ptr().cast(),
+            min(buf.len(), READ_LIMIT),
+        ))?
+    };
+    Ok(nwritten as usize)
+}
+
+pub(crate) fn pread(fd: BorrowedFd<'_>, buf: &mut [u8], offset: u64) -> io::Result<usize> {
+    let len = min(buf.len(), READ_LIMIT);
+
+    // Silently cast; we'll get `EINVAL` if the value is negative.
+    let offset = offset as i64;
+
+    let nread = unsafe {
+        ret_ssize_t(libc_pread(
+            borrowed_fd(fd),
+            buf.as_mut_ptr().cast(),
+            len,
+            offset,
+        ))?
+    };
+    Ok(nread as usize)
+}
+
+pub(crate) fn pwrite(fd: BorrowedFd<'_>, buf: &[u8], offset: u64) -> io::Result<usize> {
+    let len = min(buf.len(), READ_LIMIT);
+
+    // Silently cast; we'll get `EINVAL` if the value is negative.
+    let offset = offset as i64;
+
+    let nwritten = unsafe {
+        ret_ssize_t(libc_pwrite(
+            borrowed_fd(fd),
+            buf.as_ptr().cast(),
+            len,
+            offset,
+        ))?
+    };
+    Ok(nwritten as usize)
+}
+
+pub(crate) fn readv(fd: BorrowedFd<'_>, bufs: &mut [IoSliceMut]) -> io::Result<usize> {
+    let nread = unsafe {
+        ret_ssize_t(c::readv(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), max_iov()) as c::c_int,
+        ))?
+    };
+    Ok(nread as usize)
+}
+
+pub(crate) fn writev(fd: BorrowedFd<'_>, bufs: &[IoSlice]) -> io::Result<usize> {
+    let nwritten = unsafe {
+        ret_ssize_t(c::writev(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), max_iov()) as c::c_int,
+        ))?
+    };
+    Ok(nwritten as usize)
+}
+
+#[cfg(not(target_os = "redox"))]
+pub(crate) fn preadv(
+    fd: BorrowedFd<'_>,
+    bufs: &mut [IoSliceMut],
+    offset: u64,
+) -> io::Result<usize> {
+    // Silently cast; we'll get `EINVAL` if the value is negative.
+    let offset = offset as i64;
+    let nread = unsafe {
+        ret_ssize_t(libc_preadv(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), max_iov()) as c::c_int,
+            offset,
+        ))?
+    };
+    Ok(nread as usize)
+}
+
+#[cfg(not(target_os = "redox"))]
+pub(crate) fn pwritev(fd: BorrowedFd<'_>, bufs: &[IoSlice], offset: u64) -> io::Result<usize> {
+    // Silently cast; we'll get `EINVAL` if the value is negative.
+    let offset = offset as i64;
+    let nwritten = unsafe {
+        ret_ssize_t(libc_pwritev(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), max_iov()) as c::c_int,
+            offset,
+        ))?
+    };
+    Ok(nwritten as usize)
+}
+
+#[cfg(all(target_os = "linux", target_env = "gnu"))]
+pub(crate) fn preadv2(
+    fd: BorrowedFd<'_>,
+    bufs: &mut [IoSliceMut],
+    offset: u64,
+    flags: ReadWriteFlags,
+) -> io::Result<usize> {
+    // Silently cast; we'll get `EINVAL` if the value is negative.
+    let offset = offset as i64;
+    let nread = unsafe {
+        ret_ssize_t(libc_preadv2(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), max_iov()) as c::c_int,
+            offset,
+            flags.bits(),
+        ))?
+    };
+    Ok(nread as usize)
+}
+
+/// At present, `libc` only has `preadv2` defined for glibc. On other
+/// ABIs, `ReadWriteFlags` has no flags defined, and we use plain `preadv`.
+#[cfg(any(
+    target_os = "android",
+    all(target_os = "linux", not(target_env = "gnu")),
+))]
+#[inline]
+pub(crate) fn preadv2(
+    fd: BorrowedFd<'_>,
+    bufs: &mut [IoSliceMut],
+    offset: u64,
+    flags: ReadWriteFlags,
+) -> io::Result<usize> {
+    assert!(flags.is_empty());
+    preadv(fd, bufs, offset)
+}
+
+#[cfg(all(target_os = "linux", target_env = "gnu"))]
+pub(crate) fn pwritev2(
+    fd: BorrowedFd<'_>,
+    bufs: &[IoSlice],
+    offset: u64,
+    flags: ReadWriteFlags,
+) -> io::Result<usize> {
+    // Silently cast; we'll get `EINVAL` if the value is negative.
+    let offset = offset as i64;
+    let nwritten = unsafe {
+        ret_ssize_t(libc_pwritev2(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), max_iov()) as c::c_int,
+            offset,
+            flags.bits(),
+        ))?
+    };
+    Ok(nwritten as usize)
+}
+
+/// At present, `libc` only has `pwritev2` defined for glibc. On other
+/// ABIs, `ReadWriteFlags` has no flags defined, and we use plain `pwritev`.
+#[cfg(any(
+    target_os = "android",
+    all(target_os = "linux", not(target_env = "gnu")),
+))]
+#[inline]
+pub(crate) fn pwritev2(
+    fd: BorrowedFd<'_>,
+    bufs: &[IoSlice],
+    offset: u64,
+    flags: ReadWriteFlags,
+) -> io::Result<usize> {
+    assert!(flags.is_empty());
+    pwritev(fd, bufs, offset)
+}
+
+// These functions are derived from Rust's library/std/src/sys/unix/fd.rs at
+// revision a77da2d454e6caa227a85b16410b95f93495e7e0.
+
+// The maximum read limit on most POSIX-like systems is `SSIZE_MAX`, with the
+// man page quoting that if the count of bytes to read is greater than
+// `SSIZE_MAX` the result is "unspecified".
+//
+// On macOS, however, apparently the 64-bit libc is either buggy or
+// intentionally showing odd behavior by rejecting any read with a size larger
+// than or equal to `INT_MAX`. To handle both of these the read size is capped
+// on both platforms.
+#[cfg(target_os = "macos")]
+const READ_LIMIT: usize = c::c_int::MAX as usize - 1;
+#[cfg(not(target_os = "macos"))]
+const READ_LIMIT: usize = c::ssize_t::MAX as usize;
+
+#[cfg(any(
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "netbsd",
+    target_os = "openbsd",
+))]
+const fn max_iov() -> usize {
+    c::IOV_MAX as usize
+}
+
+#[cfg(any(target_os = "android", target_os = "emscripten", target_os = "linux"))]
+const fn max_iov() -> usize {
+    c::UIO_MAXIOV as usize
+}
+
+#[cfg(not(any(
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "emscripten",
+    target_os = "freebsd",
+    target_os = "ios",
+    target_os = "linux",
+    target_os = "macos",
+    target_os = "netbsd",
+    target_os = "openbsd",
+)))]
+const fn max_iov() -> usize {
+    16 // The minimum value required by POSIX.
+}
+
+pub(crate) unsafe fn close(raw_fd: RawFd) {
+    let _ = c::close(raw_fd as c::c_int);
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+pub(crate) fn eventfd(initval: u32, flags: EventfdFlags) -> io::Result<OwnedFd> {
+    unsafe { syscall_ret_owned_fd(c::syscall(c::SYS_eventfd2, initval, flags.bits())) }
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[inline]
+pub(crate) fn ioctl_blksszget(fd: BorrowedFd) -> io::Result<u32> {
+    let mut result = MaybeUninit::<c::c_uint>::uninit();
+    unsafe {
+        ret(c::ioctl(borrowed_fd(fd), c::BLKSSZGET, result.as_mut_ptr()))?;
+        Ok(result.assume_init() as u32)
+    }
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[inline]
+pub(crate) fn ioctl_blkpbszget(fd: BorrowedFd) -> io::Result<u32> {
+    let mut result = MaybeUninit::<c::c_uint>::uninit();
+    unsafe {
+        ret(c::ioctl(
+            borrowed_fd(fd),
+            c::BLKPBSZGET,
+            result.as_mut_ptr(),
+        ))?;
+        Ok(result.assume_init() as u32)
+    }
+}
+
+#[cfg(not(target_os = "redox"))]
+pub(crate) fn ioctl_fionread(fd: BorrowedFd<'_>) -> io::Result<u64> {
+    let mut nread = MaybeUninit::<c::c_int>::uninit();
+    unsafe {
+        ret(c::ioctl(borrowed_fd(fd), c::FIONREAD, nread.as_mut_ptr()))?;
+        // `FIONREAD` returns the number of bytes silently casted to a `c_int`,
+        // even when this is lossy. The best we can do is convert it back to a
+        // `u64` without sign-extending it back first.
+        Ok(u64::from(nread.assume_init() as c::c_uint))
+    }
+}
+
+pub(crate) fn ioctl_fionbio(fd: BorrowedFd<'_>, value: bool) -> io::Result<()> {
+    unsafe {
+        let data = value as c::c_int;
+        ret(c::ioctl(borrowed_fd(fd), c::FIONBIO, &data))
+    }
+}
+
+#[cfg(not(any(target_os = "redox", target_os = "wasi")))]
+#[cfg(feature = "net")]
+pub(crate) fn is_read_write(fd: BorrowedFd<'_>) -> io::Result<(bool, bool)> {
+    let (mut read, mut write) = crate::fs::fd::_is_file_read_write(fd)?;
+    let mut not_socket = false;
+    if read {
+        // Do a `recv` with `PEEK` and `DONTWAIT` for 1 byte. A 0 indicates
+        // the read side is shut down; an `EWOULDBLOCK` indicates the read
+        // side is still open.
+        match unsafe {
+            c::recv(
+                borrowed_fd(fd),
+                MaybeUninit::<[u8; 1]>::uninit()
+                    .as_mut_ptr()
+                    .cast::<c::c_void>(),
+                1,
+                c::MSG_PEEK | c::MSG_DONTWAIT,
+            )
+        } {
+            0 => read = false,
+            -1 => {
+                #[allow(unreachable_patterns)] // `EAGAIN` may equal `EWOULDBLOCK`
+                match errno().0 {
+                    c::EAGAIN | c::EWOULDBLOCK => (),
+                    c::ENOTSOCK => not_socket = true,
+                    err => return Err(io::Errno(err)),
+                }
+            }
+            _ => (),
+        }
+    }
+    if write && !not_socket {
+        // Do a `send` with `DONTWAIT` for 0 bytes. An `EPIPE` indicates
+        // the write side is shut down.
+        if unsafe { c::send(borrowed_fd(fd), [].as_ptr(), 0, c::MSG_DONTWAIT) } == -1 {
+            #[allow(unreachable_patterns)] // `EAGAIN` may equal `EWOULDBLOCK`
+            match errno().0 {
+                c::EAGAIN | c::EWOULDBLOCK => (),
+                c::ENOTSOCK => (),
+                c::EPIPE => write = false,
+                err => return Err(io::Errno(err)),
+            }
+        }
+    }
+    Ok((read, write))
+}
+
+#[cfg(target_os = "wasi")]
+#[cfg(feature = "net")]
+pub(crate) fn is_read_write(_fd: BorrowedFd<'_>) -> io::Result<(bool, bool)> {
+    todo!("Implement is_read_write for WASI in terms of fd_fdstat_get");
+}
+
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn dup(fd: BorrowedFd<'_>) -> io::Result<OwnedFd> {
+    unsafe { ret_owned_fd(c::dup(borrowed_fd(fd))) }
+}
+
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn dup2(fd: BorrowedFd<'_>, new: &mut OwnedFd) -> io::Result<()> {
+    unsafe { ret_discarded_fd(c::dup2(borrowed_fd(fd), borrowed_fd(new.as_fd()))) }
+}
+
+#[cfg(not(any(
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "redox",
+    target_os = "wasi",
+)))]
+pub(crate) fn dup3(fd: BorrowedFd<'_>, new: &mut OwnedFd, flags: DupFlags) -> io::Result<()> {
+    unsafe {
+        ret_discarded_fd(c::dup3(
+            borrowed_fd(fd),
+            borrowed_fd(new.as_fd()),
+            flags.bits(),
+        ))
+    }
+}
+
+#[cfg(any(
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "redox",
+))]
+pub(crate) fn dup3(fd: BorrowedFd<'_>, new: &mut OwnedFd, _flags: DupFlags) -> io::Result<()> {
+    // Android 5.0 has `dup3`, but libc doesn't have bindings. Emulate it
+    // using `dup2`. We don't need to worry about the difference between
+    // `dup2` and `dup3` when the file descriptors are equal because we
+    // have an `&mut OwnedFd` which means `fd` doesn't alias it.
+    dup2(fd, new)
+}
+
+#[cfg(any(target_os = "ios", target_os = "macos"))]
+pub(crate) fn ioctl_fioclex(fd: BorrowedFd<'_>) -> io::Result<()> {
+    unsafe { ret(c::ioctl(borrowed_fd(fd), c::FIOCLEX)) }
+}
+
+#[cfg(not(any(target_os = "redox", target_os = "wasi")))]
+pub(crate) fn ioctl_tiocexcl(fd: BorrowedFd) -> io::Result<()> {
+    unsafe { ret(c::ioctl(borrowed_fd(fd), c::TIOCEXCL as _)) }
+}
+
+#[cfg(not(any(target_os = "redox", target_os = "wasi")))]
+pub(crate) fn ioctl_tiocnxcl(fd: BorrowedFd) -> io::Result<()> {
+    unsafe { ret(c::ioctl(borrowed_fd(fd), c::TIOCNXCL as _)) }
+}
+
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn pipe() -> io::Result<(OwnedFd, OwnedFd)> {
+    unsafe {
+        let mut result = MaybeUninit::<[OwnedFd; 2]>::uninit();
+        ret(c::pipe(result.as_mut_ptr().cast::<i32>()))?;
+        let [p0, p1] = result.assume_init();
+        Ok((p0, p1))
+    }
+}
+
+#[cfg(not(any(target_os = "ios", target_os = "macos", target_os = "wasi")))]
+pub(crate) fn pipe_with(flags: PipeFlags) -> io::Result<(OwnedFd, OwnedFd)> {
+    unsafe {
+        let mut result = MaybeUninit::<[OwnedFd; 2]>::uninit();
+        ret(c::pipe2(result.as_mut_ptr().cast::<i32>(), flags.bits()))?;
+        let [p0, p1] = result.assume_init();
+        Ok((p0, p1))
+    }
+}
+
+#[inline]
+pub(crate) fn poll(fds: &mut [PollFd<'_>], timeout: c::c_int) -> io::Result<usize> {
+    let nfds = fds
+        .len()
+        .try_into()
+        .map_err(|_convert_err| io::Errno::INVAL)?;
+
+    ret_c_int(unsafe { c::poll(fds.as_mut_ptr().cast(), nfds, timeout) })
+        .map(|nready| nready as usize)
+}