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Diffstat (limited to 'vendor/rustix/src/ioctl/mod.rs')
| -rw-r--r-- | vendor/rustix/src/ioctl/mod.rs | 357 |
1 files changed, 0 insertions, 357 deletions
diff --git a/vendor/rustix/src/ioctl/mod.rs b/vendor/rustix/src/ioctl/mod.rs deleted file mode 100644 index 494cdc8..0000000 --- a/vendor/rustix/src/ioctl/mod.rs +++ /dev/null @@ -1,357 +0,0 @@ -//! Unsafe `ioctl` API. -//! -//! Unix systems expose a number of `ioctl`'s. `ioctl`s have been adopted as a -//! general purpose system call for making calls into the kernel. In addition -//! to the wide variety of system calls that are included by default in the -//! kernel, many drivers expose their own `ioctl`'s for controlling their -//! behavior, some of which are proprietary. Therefore it is impossible to make -//! a safe interface for every `ioctl` call, as they all have wildly varying -//! semantics. -//! -//! This module provides an unsafe interface to write your own `ioctl` API. To -//! start, create a type that implements [`Ioctl`]. Then, pass it to [`ioctl`] -//! to make the `ioctl` call. - -#![allow(unsafe_code)] - -use crate::backend::c; -use crate::fd::{AsFd, BorrowedFd}; -use crate::io::Result; - -#[cfg(any(linux_kernel, bsd))] -use core::mem; - -pub use patterns::*; - -mod patterns; - -#[cfg(linux_kernel)] -mod linux; - -#[cfg(bsd)] -mod bsd; - -#[cfg(linux_kernel)] -use linux as platform; - -#[cfg(bsd)] -use bsd as platform; - -/// Perform an `ioctl` call. -/// -/// `ioctl` was originally intended to act as a way of modifying the behavior -/// of files, but has since been adopted as a general purpose system call for -/// making calls into the kernel. In addition to the default calls exposed by -/// generic file descriptors, many drivers expose their own `ioctl` calls for -/// controlling their behavior, some of which are proprietary. -/// -/// This crate exposes many other `ioctl` interfaces with safe and idiomatic -/// wrappers, like [`ioctl_fionbio`] and [`ioctl_fionread`]. It is recommended -/// to use those instead of this function, as they are safer and more -/// idiomatic. For other cases, implement the [`Ioctl`] API and pass it to this -/// function. -/// -/// See documentation for [`Ioctl`] for more information. -/// -/// [`ioctl_fionbio`]: crate::io::ioctl_fionbio -/// [`ioctl_fionread`]: crate::io::ioctl_fionread -/// -/// # Safety -/// -/// While [`Ioctl`] takes much of the unsafety out of `ioctl` calls, it is -/// still unsafe to call this code with arbitrary device drivers, as it is up -/// to the device driver to implement the `ioctl` call correctly. It is on the -/// onus of the protocol between the user and the driver to ensure that the -/// `ioctl` call is safe to make. -/// -/// # References -/// - [Linux] -/// - [Winsock] -/// - [FreeBSD] -/// - [NetBSD] -/// - [OpenBSD] -/// - [Apple] -/// - [Solaris] -/// - [illumos] -/// -/// [Linux]: https://man7.org/linux/man-pages/man2/ioctl.2.html -/// [Winsock]: https://learn.microsoft.com/en-us/windows/win32/api/winsock/nf-winsock-ioctlsocket -/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=ioctl&sektion=2 -/// [NetBSD]: https://man.netbsd.org/ioctl.2 -/// [OpenBSD]: https://man.openbsd.org/ioctl.2 -/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/ioctl.2.html -/// [Solaris]: https://docs.oracle.com/cd/E23824_01/html/821-1463/ioctl-2.html -/// [illumos]: https://illumos.org/man/2/ioctl -#[inline] -pub unsafe fn ioctl<F: AsFd, I: Ioctl>(fd: F, mut ioctl: I) -> Result<I::Output> { - let fd = fd.as_fd(); - let request = I::OPCODE.raw(); - let arg = ioctl.as_ptr(); - - // SAFETY: The variant of `Ioctl` asserts that this is a valid IOCTL call - // to make. - let output = if I::IS_MUTATING { - _ioctl(fd, request, arg)? - } else { - _ioctl_readonly(fd, request, arg)? - }; - - // SAFETY: The variant of `Ioctl` asserts that this is a valid pointer to - // the output data. - I::output_from_ptr(output, arg) -} - -unsafe fn _ioctl( - fd: BorrowedFd<'_>, - request: RawOpcode, - arg: *mut c::c_void, -) -> Result<IoctlOutput> { - crate::backend::io::syscalls::ioctl(fd, request, arg) -} - -unsafe fn _ioctl_readonly( - fd: BorrowedFd<'_>, - request: RawOpcode, - arg: *mut c::c_void, -) -> Result<IoctlOutput> { - crate::backend::io::syscalls::ioctl_readonly(fd, request, arg) -} - -/// A trait defining the properties of an `ioctl` command. -/// -/// Objects implementing this trait can be passed to [`ioctl`] to make an -/// `ioctl` call. The contents of the object represent the inputs to the -/// `ioctl` call. The inputs must be convertible to a pointer through the -/// `as_ptr` method. In most cases, this involves either casting a number to a -/// pointer, or creating a pointer to the actual data. The latter case is -/// necessary for `ioctl` calls that modify userspace data. -/// -/// # Safety -/// -/// This trait is unsafe to implement because it is impossible to guarantee -/// that the `ioctl` call is safe. The `ioctl` call may be proprietary, or it -/// may be unsafe to call in certain circumstances. -/// -/// By implementing this trait, you guarantee that: -/// -/// - The `ioctl` call expects the input provided by `as_ptr` and produces the -/// output as indicated by `output`. -/// - That `output_from_ptr` can safely take the pointer from `as_ptr` and cast -/// it to the correct type, *only* after the `ioctl` call. -/// - That `OPCODE` uniquely identifies the `ioctl` call. -/// - That, for whatever platforms you are targeting, the `ioctl` call is safe -/// to make. -/// - If `IS_MUTATING` is false, that no userspace data will be modified by the -/// `ioctl` call. -pub unsafe trait Ioctl { - /// The type of the output data. - /// - /// Given a pointer, one should be able to construct an instance of this - /// type. - type Output; - - /// The opcode used by this `ioctl` command. - /// - /// There are different types of opcode depending on the operation. See - /// documentation for the [`Opcode`] struct for more information. - const OPCODE: Opcode; - - /// Does the `ioctl` mutate any data in the userspace? - /// - /// If the `ioctl` call does not mutate any data in the userspace, then - /// making this `false` enables optimizations that can make the call - /// faster. When in doubt, set this to `true`. - /// - /// # Safety - /// - /// This should only be set to `false` if the `ioctl` call does not mutate - /// any data in the userspace. Undefined behavior may occur if this is set - /// to `false` when it should be `true`. - const IS_MUTATING: bool; - - /// Get a pointer to the data to be passed to the `ioctl` command. - /// - /// See trait-level documentation for more information. - fn as_ptr(&mut self) -> *mut c::c_void; - - /// Cast the output data to the correct type. - /// - /// # Safety - /// - /// The `extract_output` value must be the resulting value after a - /// successful `ioctl` call, and `out` is the direct return value of an - /// `ioctl` call that did not fail. In this case `extract_output` is the - /// pointer that was passed to the `ioctl` call. - unsafe fn output_from_ptr( - out: IoctlOutput, - extract_output: *mut c::c_void, - ) -> Result<Self::Output>; -} - -/// The opcode used by an `Ioctl`. -#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] -pub struct Opcode { - /// The raw opcode. - raw: RawOpcode, -} - -impl Opcode { - /// Create a new old `Opcode` from a raw opcode. - /// - /// Rather than being a composition of several attributes, old opcodes are - /// just numbers. In general most drivers follow stricter conventions, but - /// older drivers may still use this strategy. - #[inline] - pub const fn old(raw: RawOpcode) -> Self { - Self { raw } - } - - /// Create a new opcode from a direction, group, number, and size. - /// - /// This corresponds to the C macro `_IOC(direction, group, number, size)` - #[cfg(any(linux_kernel, bsd))] - #[inline] - pub const fn from_components( - direction: Direction, - group: u8, - number: u8, - data_size: usize, - ) -> Self { - if data_size > RawOpcode::MAX as usize { - panic!("data size is too large"); - } - - Self::old(platform::compose_opcode( - direction, - group as RawOpcode, - number as RawOpcode, - data_size as RawOpcode, - )) - } - - /// Create a new non-mutating opcode from a group, a number, and the type - /// of data. - /// - /// This corresponds to the C macro `_IO(group, number)` when `T` is zero - /// sized. - #[cfg(any(linux_kernel, bsd))] - #[inline] - pub const fn none<T>(group: u8, number: u8) -> Self { - Self::from_components(Direction::None, group, number, mem::size_of::<T>()) - } - - /// Create a new reading opcode from a group, a number and the type of - /// data. - /// - /// This corresponds to the C macro `_IOR(group, number, T)`. - #[cfg(any(linux_kernel, bsd))] - #[inline] - pub const fn read<T>(group: u8, number: u8) -> Self { - Self::from_components(Direction::Read, group, number, mem::size_of::<T>()) - } - - /// Create a new writing opcode from a group, a number and the type of - /// data. - /// - /// This corresponds to the C macro `_IOW(group, number, T)`. - #[cfg(any(linux_kernel, bsd))] - #[inline] - pub const fn write<T>(group: u8, number: u8) -> Self { - Self::from_components(Direction::Write, group, number, mem::size_of::<T>()) - } - - /// Create a new reading and writing opcode from a group, a number and the - /// type of data. - /// - /// This corresponds to the C macro `_IOWR(group, number, T)`. - #[cfg(any(linux_kernel, bsd))] - #[inline] - pub const fn read_write<T>(group: u8, number: u8) -> Self { - Self::from_components(Direction::ReadWrite, group, number, mem::size_of::<T>()) - } - - /// Get the raw opcode. - #[inline] - pub fn raw(self) -> RawOpcode { - self.raw - } -} - -/// The direction that an `ioctl` is going. -/// -/// Note that this is relative to userspace. `Read` means reading data from the -/// kernel, and write means the kernel writing data to userspace. -#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] -pub enum Direction { - /// None of the above. - None, - - /// Read data from the kernel. - Read, - - /// Write data to the kernel. - Write, - - /// Read and write data to the kernel. - ReadWrite, -} - -/// The type used by the `ioctl` to signify the output. -pub type IoctlOutput = c::c_int; - -/// The type used by the `ioctl` to signify the command. -pub type RawOpcode = _RawOpcode; - -// Under raw Linux, this is an `unsigned int`. -#[cfg(linux_raw)] -type _RawOpcode = c::c_uint; - -// On libc Linux with GNU libc or uclibc, this is an `unsigned long`. -#[cfg(all( - not(linux_raw), - target_os = "linux", - any(target_env = "gnu", target_env = "uclibc") -))] -type _RawOpcode = c::c_ulong; - -// Musl uses `c_int`. -#[cfg(all( - not(linux_raw), - target_os = "linux", - not(target_env = "gnu"), - not(target_env = "uclibc") -))] -type _RawOpcode = c::c_int; - -// Android uses `c_int`. -#[cfg(all(not(linux_raw), target_os = "android"))] -type _RawOpcode = c::c_int; - -// BSD, Haiku, Hurd, Redox, and Vita use `unsigned long`. -#[cfg(any( - bsd, - target_os = "redox", - target_os = "haiku", - target_os = "hurd", - target_os = "vita" -))] -type _RawOpcode = c::c_ulong; - -// AIX, Emscripten, Fuchsia, Solaris, and WASI use a `int`. -#[cfg(any( - solarish, - target_os = "aix", - target_os = "fuchsia", - target_os = "emscripten", - target_os = "wasi", - target_os = "nto" -))] -type _RawOpcode = c::c_int; - -// ESP-IDF uses a `c_uint`. -#[cfg(target_os = "espidf")] -type _RawOpcode = c::c_uint; - -// Windows has `ioctlsocket`, which uses `i32`. -#[cfg(windows)] -type _RawOpcode = i32; |