| // 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::marker::PhantomData; |
| use crate::mem::forget; |
| use crate::sys_common::{AsInner, FromInner, IntoInner}; |
| use crate::untrusted::fs; |
| |
| /// 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 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 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_libc::ocall::close; |
| } |