1 files changed, 340 insertions, 0 deletions
diff --git a/vendor/rustix/src/backend/libc/io/syscalls.rs b/vendor/rustix/src/backend/libc/io/syscalls.rs
new file mode 100644
index 0000000..e28e6be
--- /dev/null
+++ b/vendor/rustix/src/backend/libc/io/syscalls.rs
@@ -0,0 +1,340 @@
+//! libc syscalls supporting `rustix::io`.
+
+use crate::backend::c;
+#[cfg(not(target_os = "wasi"))]
+use crate::backend::conv::ret_discarded_fd;
+use crate::backend::conv::{borrowed_fd, ret, ret_c_int, ret_owned_fd, ret_usize};
+use crate::fd::{AsFd, BorrowedFd, OwnedFd, RawFd};
+#[cfg(not(any(
+    target_os = "aix",
+    target_os = "espidf",
+    target_os = "nto",
+    target_os = "vita",
+    target_os = "wasi"
+)))]
+use crate::io::DupFlags;
+#[cfg(linux_kernel)]
+use crate::io::ReadWriteFlags;
+use crate::io::{self, FdFlags};
+use crate::ioctl::{IoctlOutput, RawOpcode};
+use core::cmp::min;
+#[cfg(all(feature = "fs", feature = "net"))]
+use libc_errno::errno;
+#[cfg(not(target_os = "espidf"))]
+use {
+    crate::backend::MAX_IOV,
+    crate::io::{IoSlice, IoSliceMut},
+};
+
+pub(crate) unsafe fn read(fd: BorrowedFd<'_>, buf: *mut u8, len: usize) -> io::Result<usize> {
+    ret_usize(c::read(borrowed_fd(fd), buf.cast(), min(len, READ_LIMIT)))
+}
+
+pub(crate) fn write(fd: BorrowedFd<'_>, buf: &[u8]) -> io::Result<usize> {
+    unsafe {
+        ret_usize(c::write(
+            borrowed_fd(fd),
+            buf.as_ptr().cast(),
+            min(buf.len(), READ_LIMIT),
+        ))
+    }
+}
+
+pub(crate) unsafe fn pread(
+    fd: BorrowedFd<'_>,
+    buf: *mut u8,
+    len: usize,
+    offset: u64,
+) -> io::Result<usize> {
+    let len = min(len, READ_LIMIT);
+
+    // Silently cast; we'll get `EINVAL` if the value is negative.
+    let offset = offset as i64;
+
+    // ESP-IDF and Vita don't support 64-bit offsets.
+    #[cfg(any(target_os = "espidf", target_os = "vita"))]
+    let offset: i32 = offset.try_into().map_err(|_| io::Errno::OVERFLOW)?;
+
+    ret_usize(c::pread(borrowed_fd(fd), buf.cast(), len, offset))
+}
+
+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;
+
+    // ESP-IDF and Vita don't support 64-bit offsets.
+    #[cfg(any(target_os = "espidf", target_os = "vita"))]
+    let offset: i32 = offset.try_into().map_err(|_| io::Errno::OVERFLOW)?;
+
+    unsafe { ret_usize(c::pwrite(borrowed_fd(fd), buf.as_ptr().cast(), len, offset)) }
+}
+
+#[cfg(not(target_os = "espidf"))]
+pub(crate) fn readv(fd: BorrowedFd<'_>, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+    unsafe {
+        ret_usize(c::readv(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), MAX_IOV) as c::c_int,
+        ))
+    }
+}
+
+#[cfg(not(target_os = "espidf"))]
+pub(crate) fn writev(fd: BorrowedFd<'_>, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+    unsafe {
+        ret_usize(c::writev(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), MAX_IOV) as c::c_int,
+        ))
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "haiku",
+    target_os = "nto",
+    target_os = "redox",
+    target_os = "solaris",
+    target_os = "vita"
+)))]
+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;
+    unsafe {
+        ret_usize(c::preadv(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), MAX_IOV) as c::c_int,
+            offset,
+        ))
+    }
+}
+
+#[cfg(not(any(
+    target_os = "espidf",
+    target_os = "haiku",
+    target_os = "nto",
+    target_os = "redox",
+    target_os = "solaris",
+    target_os = "vita"
+)))]
+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;
+    unsafe {
+        ret_usize(c::pwritev(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), MAX_IOV) as c::c_int,
+            offset,
+        ))
+    }
+}
+
+#[cfg(linux_kernel)]
+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;
+    unsafe {
+        ret_usize(c::preadv2(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), MAX_IOV) as c::c_int,
+            offset,
+            bitflags_bits!(flags),
+        ))
+    }
+}
+
+#[cfg(linux_kernel)]
+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;
+    unsafe {
+        ret_usize(c::pwritev2(
+            borrowed_fd(fd),
+            bufs.as_ptr().cast::<c::iovec>(),
+            min(bufs.len(), MAX_IOV) as c::c_int,
+            offset,
+            bitflags_bits!(flags),
+        ))
+    }
+}
+
+// These functions are derived from Rust's library/std/src/sys/unix/fd.rs at
+// revision 326ef470a8b379a180d6dc4bbef08990698a737a.
+
+// The maximum read limit on most POSIX-like systems is `SSIZE_MAX`, with the
+// manual 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;
+
+pub(crate) unsafe fn close(raw_fd: RawFd) {
+    let _ = c::close(raw_fd as c::c_int);
+}
+
+#[inline]
+pub(crate) unsafe fn ioctl(
+    fd: BorrowedFd<'_>,
+    request: RawOpcode,
+    arg: *mut c::c_void,
+) -> io::Result<IoctlOutput> {
+    ret_c_int(c::ioctl(borrowed_fd(fd), request, arg))
+}
+
+#[inline]
+pub(crate) unsafe fn ioctl_readonly(
+    fd: BorrowedFd<'_>,
+    request: RawOpcode,
+    arg: *mut c::c_void,
+) -> io::Result<IoctlOutput> {
+    ioctl(fd, request, arg)
+}
+
+#[cfg(not(any(target_os = "redox", target_os = "wasi")))]
+#[cfg(all(feature = "fs", feature = "net"))]
+pub(crate) fn is_read_write(fd: BorrowedFd<'_>) -> io::Result<(bool, bool)> {
+    use core::mem::MaybeUninit;
+
+    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(all(feature = "fs", 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");
+}
+
+pub(crate) fn fcntl_getfd(fd: BorrowedFd<'_>) -> io::Result<FdFlags> {
+    let flags = unsafe { ret_c_int(c::fcntl(borrowed_fd(fd), c::F_GETFD))? };
+    Ok(FdFlags::from_bits_retain(bitcast!(flags)))
+}
+
+pub(crate) fn fcntl_setfd(fd: BorrowedFd<'_>, flags: FdFlags) -> io::Result<()> {
+    unsafe { ret(c::fcntl(borrowed_fd(fd), c::F_SETFD, flags.bits())) }
+}
+
+#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
+pub(crate) fn fcntl_dupfd_cloexec(fd: BorrowedFd<'_>, min: RawFd) -> io::Result<OwnedFd> {
+    unsafe { ret_owned_fd(c::fcntl(borrowed_fd(fd), c::F_DUPFD_CLOEXEC, min)) }
+}
+
+#[cfg(target_os = "espidf")]
+pub(crate) fn fcntl_dupfd(fd: BorrowedFd<'_>, min: RawFd) -> io::Result<OwnedFd> {
+    unsafe { ret_owned_fd(c::fcntl(borrowed_fd(fd), c::F_DUPFD, min)) }
+}
+
+#[cfg(not(target_os = "wasi"))]
+pub(crate) fn dup(fd: BorrowedFd<'_>) -> io::Result<OwnedFd> {
+    unsafe { ret_owned_fd(c::dup(borrowed_fd(fd))) }
+}
+
+#[allow(clippy::needless_pass_by_ref_mut)]
+#[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()))) }
+}
+
+#[allow(clippy::needless_pass_by_ref_mut)]
+#[cfg(not(any(
+    apple,
+    target_os = "aix",
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "espidf",
+    target_os = "haiku",
+    target_os = "nto",
+    target_os = "redox",
+    target_os = "vita",
+    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()),
+            bitflags_bits!(flags),
+        ))
+    }
+}
+
+#[cfg(any(
+    apple,
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "haiku",
+    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)
+}