sgx_tstd/src/os/fd/owned.rs - incubator-teaclave-sgx-sdk - Git at Google

 // Licensed to the Apache Software Foundation (ASF) under one
 // or more contributor license agreements.  See the NOTICE file
 // distributed with this work for additional information
 // regarding copyright ownership.  The ASF licenses this file
 // to you under the Apache License, Version 2.0 (the
 // "License"); you may not use this file except in compliance
 // with the License.  You may obtain a copy of the License at
 //
 //   http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing,
 // software distributed under the License is distributed on an
 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 // KIND, either express or implied.  See the License for the
 // specific language governing permissions and limitations
 // under the License..

 //! Owned and borrowed Unix-like file descriptors.

 #![deny(unsafe_op_in_unsafe_fn)]

 use super::raw::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
 use crate::fmt;
 use crate::fs;
 use crate::marker::PhantomData;
 use crate::mem::forget;
 use crate::sys::cvt_ocall;
 use crate::sys_common::{AsInner, FromInner, IntoInner};

 /// A borrowed file descriptor.
 ///
 /// This has a lifetime parameter to tie it to the lifetime of something that
 /// owns the file descriptor.
 ///
 /// This uses `repr(transparent)` and has the representation of a host file
 /// descriptor, so it can be used in FFI in places where a file descriptor is
 /// passed as an argument, it is not captured or consumed, and it never has the
 /// value `-1`.
 #[derive(Copy, Clone)]
 #[repr(transparent)]
 #[rustc_layout_scalar_valid_range_start(0)]
 // libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
 // 32-bit c_int. Below is -2, in two's complement, but that only works out
 // because c_int is 32 bits.
 #[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
 pub struct BorrowedFd<'fd> {
     fd: RawFd,
     _phantom: PhantomData<&'fd OwnedFd>,
 }

 /// An owned file descriptor.
 ///
 /// This closes the file descriptor on drop.
 ///
 /// This uses `repr(transparent)` and has the representation of a host file
 /// descriptor, so it can be used in FFI in places where a file descriptor is
 /// passed as a consumed argument or returned as an owned value, and it never
 /// has the value `-1`.
 #[repr(transparent)]
 #[rustc_layout_scalar_valid_range_start(0)]
 // libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
 // 32-bit c_int. Below is -2, in two's complement, but that only works out
 // because c_int is 32 bits.
 #[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
 pub struct OwnedFd {
     fd: RawFd,
 }

 impl BorrowedFd<'_> {
     /// Return a `BorrowedFd` holding the given raw file descriptor.
     ///
     /// # Safety
     ///
     /// The resource pointed to by `fd` must remain open for the duration of
     /// the returned `BorrowedFd`, and it must not have the value `-1`.
     #[inline]
     pub unsafe fn borrow_raw_fd(fd: RawFd) -> Self {
         assert_ne!(fd, u32::MAX as RawFd);
         // SAFETY: we just asserted that the value is in the valid range and isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
         unsafe { Self { fd, _phantom: PhantomData } }
     }
 }

 impl OwnedFd {
     /// Creates a new `OwnedFd` instance that shares the same underlying file handle
     /// as the existing `OwnedFd` instance.
     pub fn try_clone(&self) -> crate::io::Result<Self> {
         // We want to atomically duplicate this file descriptor and set the
         // CLOEXEC flag, and currently that's done via F_DUPFD_CLOEXEC. This
         // is a POSIX flag that was added to Linux in 2.6.24.
         let cmd = libc::F_DUPFD_CLOEXEC;

         let fd = cvt_ocall(unsafe { libc::fcntl_arg1(self.as_raw_fd(), cmd, 0) })?;
         Ok(unsafe { Self::from_raw_fd(fd) })
     }

 }

 impl AsRawFd for BorrowedFd<'_> {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
         self.fd
     }
 }

 impl AsRawFd for OwnedFd {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
         self.fd
     }
 }

 impl IntoRawFd for OwnedFd {
     #[inline]
     fn into_raw_fd(self) -> RawFd {
         let fd = self.fd;
         forget(self);
         fd
     }
 }

 impl FromRawFd for OwnedFd {
     /// Constructs a new instance of `Self` from the given raw file descriptor.
     ///
     /// # Safety
     ///
     /// The resource pointed to by `fd` must be open and suitable for assuming
     /// ownership. The resource must not require any cleanup other than `close`.
     #[inline]
     unsafe fn from_raw_fd(fd: RawFd) -> Self {
         assert_ne!(fd, u32::MAX as RawFd);
         // SAFETY: we just asserted that the value is in the valid range and isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
         unsafe { Self { fd } }
     }
 }

 impl Drop for OwnedFd {
     #[inline]
     fn drop(&mut self) {
         unsafe {
             // Note that errors are ignored when closing a file descriptor. The
             // reason for this is that if an error occurs we don't actually know if
             // the file descriptor was closed or not, and if we retried (for
             // something like EINTR), we might close another valid file descriptor
             // opened after we closed ours.
             let _ = libc::close(self.fd);
         }
     }
 }

 impl fmt::Debug for BorrowedFd<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("BorrowedFd").field("fd", &self.fd).finish()
     }
 }

 impl fmt::Debug for OwnedFd {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("OwnedFd").field("fd", &self.fd).finish()
     }
 }

 /// A trait to borrow the file descriptor from an underlying object.
 ///
 /// This is only available on unix platforms and must be imported in order to
 /// call the method. Windows platforms have a corresponding `AsHandle` and
 /// `AsSocket` set of traits.
 pub trait AsFd {
     /// Borrows the file descriptor.
     ///
     /// # Example
     ///
     /// ```rust,no_run
     /// # #![feature(io_safety)]
     /// use std::fs::File;
     /// # use std::io;
     /// # #[cfg(target_os = "wasi")]
     /// # use std::os::wasi::io::{AsFd, BorrowedFd};
     /// # #[cfg(unix)]
     /// # use std::os::unix::io::{AsFd, BorrowedFd};
     ///
     /// let mut f = File::open("foo.txt")?;
     /// # #[cfg(any(unix, target_os = "wasi"))]
     /// let borrowed_fd: BorrowedFd<'_> = f.as_fd();
     /// # Ok::<(), io::Error>(())
     /// ```
     fn as_fd(&self) -> BorrowedFd<'_>;
 }

 impl<T: AsFd> AsFd for &T {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
         T::as_fd(self)
     }
 }

 impl<T: AsFd> AsFd for &mut T {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
         T::as_fd(self)
     }
 }

 impl AsFd for BorrowedFd<'_> {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
         *self
     }
 }

 impl AsFd for OwnedFd {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
         // Safety: `OwnedFd` and `BorrowedFd` have the same validity
         // invariants, and the `BorrowdFd` is bounded by the lifetime
         // of `&self`.
         unsafe { BorrowedFd::borrow_raw_fd(self.as_raw_fd()) }
     }
 }

 impl AsFd for fs::File {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.as_inner().as_fd()
     }
 }

 impl From<fs::File> for OwnedFd {
     #[inline]
     fn from(file: fs::File) -> OwnedFd {
         file.into_inner().into_inner().into_inner()
     }
 }

 impl From<OwnedFd> for fs::File {
     #[inline]
     fn from(owned_fd: OwnedFd) -> Self {
         Self::from_inner(FromInner::from_inner(FromInner::from_inner(owned_fd)))
     }
 }

 #[cfg(feature = "net")]
 impl AsFd for crate::net::TcpStream {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.as_inner().socket().as_fd()
     }
 }

 #[cfg(feature = "net")]
 impl From<crate::net::TcpStream> for OwnedFd {
     #[inline]
     #[allow(clippy::useless_conversion)]
     fn from(tcp_stream: crate::net::TcpStream) -> OwnedFd {
         tcp_stream.into_inner().into_socket().into_inner().into_inner().into()
     }
 }

 #[cfg(feature = "net")]
 impl From<OwnedFd> for crate::net::TcpStream {
     #[inline]
     fn from(owned_fd: OwnedFd) -> Self {
         Self::from_inner(FromInner::from_inner(FromInner::from_inner(FromInner::from_inner(
             owned_fd,
         ))))
     }
 }

 #[cfg(feature = "net")]
 impl AsFd for crate::net::TcpListener {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.as_inner().socket().as_fd()
     }
 }

 #[cfg(feature = "net")]
 impl From<crate::net::TcpListener> for OwnedFd {
     #[inline]
     #[allow(clippy::useless_conversion)]
     fn from(tcp_listener: crate::net::TcpListener) -> OwnedFd {
         tcp_listener.into_inner().into_socket().into_inner().into_inner().into()
     }
 }

 #[cfg(feature = "net")]
 impl From<OwnedFd> for crate::net::TcpListener {
     #[inline]
     fn from(owned_fd: OwnedFd) -> Self {
         Self::from_inner(FromInner::from_inner(FromInner::from_inner(FromInner::from_inner(
             owned_fd,
         ))))
     }
 }

 #[cfg(feature = "net")]
 impl AsFd for crate::net::UdpSocket {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.as_inner().socket().as_fd()
     }
 }

 #[cfg(feature = "net")]
 impl From<crate::net::UdpSocket> for OwnedFd {
     #[inline]
     #[allow(clippy::useless_conversion)]
     fn from(udp_socket: crate::net::UdpSocket) -> OwnedFd {
         udp_socket.into_inner().into_socket().into_inner().into_inner().into()
     }
 }

 #[cfg(feature = "net")]
 impl From<OwnedFd> for crate::net::UdpSocket {
     #[inline]
     fn from(owned_fd: OwnedFd) -> Self {
         Self::from_inner(FromInner::from_inner(FromInner::from_inner(FromInner::from_inner(
             owned_fd,
         ))))
     }
 }

 mod libc {
     pub use sgx_oc::F_DUPFD_CLOEXEC;
     pub use sgx_oc::ocall::{close, fcntl_arg1};
 }
	// Licensed to the Apache Software Foundation (ASF) under one
	// or more contributor license agreements. See the NOTICE file
	// distributed with this work for additional information
	// regarding copyright ownership. The ASF licenses this file
	// to you under the Apache License, Version 2.0 (the
	// "License"); you may not use this file except in compliance
	// with the License. You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing,
	// software distributed under the License is distributed on an
	// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	// KIND, either express or implied. See the License for the
	// specific language governing permissions and limitations
	// under the License..

	//! Owned and borrowed Unix-like file descriptors.

	#![deny(unsafe_op_in_unsafe_fn)]

	use super::raw::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
	use crate::fmt;
	use crate::fs;
	use crate::marker::PhantomData;
	use crate::mem::forget;
	use crate::sys::cvt_ocall;
	use crate::sys_common::{AsInner, FromInner, IntoInner};

	/// A borrowed file descriptor.
	///
	/// This has a lifetime parameter to tie it to the lifetime of something that
	/// owns the file descriptor.
	///
	/// This uses `repr(transparent)` and has the representation of a host file
	/// descriptor, so it can be used in FFI in places where a file descriptor is
	/// passed as an argument, it is not captured or consumed, and it never has the
	/// value `-1`.
	#[derive(Copy, Clone)]
	#[repr(transparent)]
	#[rustc_layout_scalar_valid_range_start(0)]
	// libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
	// 32-bit c_int. Below is -2, in two's complement, but that only works out
	// because c_int is 32 bits.
	#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
	pub struct BorrowedFd<'fd> {
	fd: RawFd,
	_phantom: PhantomData<&'fd OwnedFd>,
	}

	/// An owned file descriptor.
	///
	/// This closes the file descriptor on drop.
	///
	/// This uses `repr(transparent)` and has the representation of a host file
	/// descriptor, so it can be used in FFI in places where a file descriptor is
	/// passed as a consumed argument or returned as an owned value, and it never
	/// has the value `-1`.
	#[repr(transparent)]
	#[rustc_layout_scalar_valid_range_start(0)]
	// libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
	// 32-bit c_int. Below is -2, in two's complement, but that only works out
	// because c_int is 32 bits.
	#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
	pub struct OwnedFd {
	fd: RawFd,
	}

	impl BorrowedFd<'_> {
	/// Return a `BorrowedFd` holding the given raw file descriptor.
	///
	/// # Safety
	///
	/// The resource pointed to by `fd` must remain open for the duration of
	/// the returned `BorrowedFd`, and it must not have the value `-1`.
	#[inline]
	pub unsafe fn borrow_raw_fd(fd: RawFd) -> Self {
	assert_ne!(fd, u32::MAX as RawFd);
	// SAFETY: we just asserted that the value is in the valid range and isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
	unsafe { Self { fd, _phantom: PhantomData } }
	}
	}

	impl OwnedFd {
	/// Creates a new `OwnedFd` instance that shares the same underlying file handle
	/// as the existing `OwnedFd` instance.
	pub fn try_clone(&self) -> crate::io::Result<Self> {
	// We want to atomically duplicate this file descriptor and set the
	// CLOEXEC flag, and currently that's done via F_DUPFD_CLOEXEC. This
	// is a POSIX flag that was added to Linux in 2.6.24.
	let cmd = libc::F_DUPFD_CLOEXEC;

	let fd = cvt_ocall(unsafe { libc::fcntl_arg1(self.as_raw_fd(), cmd, 0) })?;
	Ok(unsafe { Self::from_raw_fd(fd) })
	}

	}

	impl AsRawFd for BorrowedFd<'_> {
	#[inline]
	fn as_raw_fd(&self) -> RawFd {
	self.fd
	}
	}

	impl AsRawFd for OwnedFd {
	#[inline]
	fn as_raw_fd(&self) -> RawFd {
	self.fd
	}
	}

	impl IntoRawFd for OwnedFd {
	#[inline]
	fn into_raw_fd(self) -> RawFd {
	let fd = self.fd;
	forget(self);
	fd
	}
	}

	impl FromRawFd for OwnedFd {
	/// Constructs a new instance of `Self` from the given raw file descriptor.
	///
	/// # Safety
	///
	/// The resource pointed to by `fd` must be open and suitable for assuming
	/// ownership. The resource must not require any cleanup other than `close`.
	#[inline]
	unsafe fn from_raw_fd(fd: RawFd) -> Self {
	assert_ne!(fd, u32::MAX as RawFd);
	// SAFETY: we just asserted that the value is in the valid range and isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
	unsafe { Self { fd } }
	}
	}

	impl Drop for OwnedFd {
	#[inline]
	fn drop(&mut self) {
	unsafe {
	// Note that errors are ignored when closing a file descriptor. The
	// reason for this is that if an error occurs we don't actually know if
	// the file descriptor was closed or not, and if we retried (for
	// something like EINTR), we might close another valid file descriptor
	// opened after we closed ours.
	let _ = libc::close(self.fd);
	}
	}
	}

	impl fmt::Debug for BorrowedFd<'_> {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
	f.debug_struct("BorrowedFd").field("fd", &self.fd).finish()
	}
	}

	impl fmt::Debug for OwnedFd {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
	f.debug_struct("OwnedFd").field("fd", &self.fd).finish()
	}
	}

	/// A trait to borrow the file descriptor from an underlying object.
	///
	/// This is only available on unix platforms and must be imported in order to
	/// call the method. Windows platforms have a corresponding `AsHandle` and
	/// `AsSocket` set of traits.
	pub trait AsFd {
	/// Borrows the file descriptor.
	///
	/// # Example
	///
	/// ```rust,no_run
	/// # #![feature(io_safety)]
	/// use std::fs::File;
	/// # use std::io;
	/// # #[cfg(target_os = "wasi")]
	/// # use std::os::wasi::io::{AsFd, BorrowedFd};
	/// # #[cfg(unix)]
	/// # use std::os::unix::io::{AsFd, BorrowedFd};
	///
	/// let mut f = File::open("foo.txt")?;
	/// # #[cfg(any(unix, target_os = "wasi"))]
	/// let borrowed_fd: BorrowedFd<'_> = f.as_fd();
	/// # Ok::<(), io::Error>(())
	/// ```
	fn as_fd(&self) -> BorrowedFd<'_>;
	}

	impl<T: AsFd> AsFd for &T {
	#[inline]
	fn as_fd(&self) -> BorrowedFd<'_> {
	T::as_fd(self)
	}
	}

	impl<T: AsFd> AsFd for &mut T {
	#[inline]
	fn as_fd(&self) -> BorrowedFd<'_> {
	T::as_fd(self)
	}
	}

	impl AsFd for BorrowedFd<'_> {
	#[inline]
	fn as_fd(&self) -> BorrowedFd<'_> {
	*self
	}
	}

	impl AsFd for OwnedFd {
	#[inline]
	fn as_fd(&self) -> BorrowedFd<'_> {
	// Safety: `OwnedFd` and `BorrowedFd` have the same validity
	// invariants, and the `BorrowdFd` is bounded by the lifetime
	// of `&self`.
	unsafe { BorrowedFd::borrow_raw_fd(self.as_raw_fd()) }
	}
	}

	impl AsFd for fs::File {
	#[inline]
	fn as_fd(&self) -> BorrowedFd<'_> {
	self.as_inner().as_fd()
	}
	}

	impl From<fs::File> for OwnedFd {
	#[inline]
	fn from(file: fs::File) -> OwnedFd {
	file.into_inner().into_inner().into_inner()
	}
	}

	impl From<OwnedFd> for fs::File {
	#[inline]
	fn from(owned_fd: OwnedFd) -> Self {
	Self::from_inner(FromInner::from_inner(FromInner::from_inner(owned_fd)))
	}
	}

	#[cfg(feature = "net")]
	impl AsFd for crate::net::TcpStream {
	#[inline]
	fn as_fd(&self) -> BorrowedFd<'_> {
	self.as_inner().socket().as_fd()
	}
	}

	#[cfg(feature = "net")]
	impl From<crate::net::TcpStream> for OwnedFd {
	#[inline]
	#[allow(clippy::useless_conversion)]
	fn from(tcp_stream: crate::net::TcpStream) -> OwnedFd {
	tcp_stream.into_inner().into_socket().into_inner().into_inner().into()
	}
	}

	#[cfg(feature = "net")]
	impl From<OwnedFd> for crate::net::TcpStream {
	#[inline]
	fn from(owned_fd: OwnedFd) -> Self {
	Self::from_inner(FromInner::from_inner(FromInner::from_inner(FromInner::from_inner(
	owned_fd,
	))))
	}
	}

	#[cfg(feature = "net")]
	impl AsFd for crate::net::TcpListener {
	#[inline]
	fn as_fd(&self) -> BorrowedFd<'_> {
	self.as_inner().socket().as_fd()
	}
	}

	#[cfg(feature = "net")]
	impl From<crate::net::TcpListener> for OwnedFd {
	#[inline]
	#[allow(clippy::useless_conversion)]
	fn from(tcp_listener: crate::net::TcpListener) -> OwnedFd {
	tcp_listener.into_inner().into_socket().into_inner().into_inner().into()
	}
	}

	#[cfg(feature = "net")]
	impl From<OwnedFd> for crate::net::TcpListener {
	#[inline]
	fn from(owned_fd: OwnedFd) -> Self {
	Self::from_inner(FromInner::from_inner(FromInner::from_inner(FromInner::from_inner(
	owned_fd,
	))))
	}
	}

	#[cfg(feature = "net")]
	impl AsFd for crate::net::UdpSocket {
	#[inline]
	fn as_fd(&self) -> BorrowedFd<'_> {
	self.as_inner().socket().as_fd()
	}
	}

	#[cfg(feature = "net")]
	impl From<crate::net::UdpSocket> for OwnedFd {
	#[inline]
	#[allow(clippy::useless_conversion)]
	fn from(udp_socket: crate::net::UdpSocket) -> OwnedFd {
	udp_socket.into_inner().into_socket().into_inner().into_inner().into()
	}
	}

	#[cfg(feature = "net")]
	impl From<OwnedFd> for crate::net::UdpSocket {
	#[inline]
	fn from(owned_fd: OwnedFd) -> Self {
	Self::from_inner(FromInner::from_inner(FromInner::from_inner(FromInner::from_inner(
	owned_fd,
	))))
	}
	}

	mod libc {
	pub use sgx_oc::F_DUPFD_CLOEXEC;
	pub use sgx_oc::ocall::{close, fcntl_arg1};
	}