diff options
Diffstat (limited to 'vendor/rustix/src/ioctl')
| -rw-r--r-- | vendor/rustix/src/ioctl/bsd.rs | 27 | ||||
| -rw-r--r-- | vendor/rustix/src/ioctl/linux.rs | 118 | ||||
| -rw-r--r-- | vendor/rustix/src/ioctl/mod.rs | 357 | ||||
| -rw-r--r-- | vendor/rustix/src/ioctl/patterns.rs | 256 | 
4 files changed, 758 insertions, 0 deletions
diff --git a/vendor/rustix/src/ioctl/bsd.rs b/vendor/rustix/src/ioctl/bsd.rs new file mode 100644 index 0000000..2639d81 --- /dev/null +++ b/vendor/rustix/src/ioctl/bsd.rs @@ -0,0 +1,27 @@ +//! `ioctl` opcode behavior for BSD platforms. + +use super::{Direction, RawOpcode}; + +pub(super) const fn compose_opcode( +    dir: Direction, +    group: RawOpcode, +    num: RawOpcode, +    size: RawOpcode, +) -> RawOpcode { +    let dir = match dir { +        Direction::None => NONE, +        Direction::Read => READ, +        Direction::Write => WRITE, +        Direction::ReadWrite => READ | WRITE, +    }; + +    dir | num | (group << 8) | ((size & IOCPARAM_MASK) << 16) +} + +// `IOC_VOID` +pub const NONE: RawOpcode = 0x2000_0000; +// `IOC_OUT` ("out" is from the perspective of the kernel) +pub const READ: RawOpcode = 0x4000_0000; +// `IOC_IN` +pub const WRITE: RawOpcode = 0x8000_0000; +pub const IOCPARAM_MASK: RawOpcode = 0x1FFF; diff --git a/vendor/rustix/src/ioctl/linux.rs b/vendor/rustix/src/ioctl/linux.rs new file mode 100644 index 0000000..2f3599f --- /dev/null +++ b/vendor/rustix/src/ioctl/linux.rs @@ -0,0 +1,118 @@ +//! `ioctl` opcode behavior for Linux platforms. + +use super::{Direction, RawOpcode}; +use consts::*; + +/// Compose an opcode from its component parts. +pub(super) const fn compose_opcode( +    dir: Direction, +    group: RawOpcode, +    num: RawOpcode, +    size: RawOpcode, +) -> RawOpcode { +    macro_rules! mask_and_shift { +        ($val:expr, $shift:expr, $mask:expr) => {{ +            ($val & $mask) << $shift +        }}; +    } + +    let dir = match dir { +        Direction::None => NONE, +        Direction::Read => READ, +        Direction::Write => WRITE, +        Direction::ReadWrite => READ | WRITE, +    }; + +    mask_and_shift!(group, GROUP_SHIFT, GROUP_MASK) +        | mask_and_shift!(num, NUM_SHIFT, NUM_MASK) +        | mask_and_shift!(size, SIZE_SHIFT, SIZE_MASK) +        | mask_and_shift!(dir, DIR_SHIFT, DIR_MASK) +} + +const NUM_BITS: RawOpcode = 8; +const GROUP_BITS: RawOpcode = 8; + +const NUM_SHIFT: RawOpcode = 0; +const GROUP_SHIFT: RawOpcode = NUM_SHIFT + NUM_BITS; +const SIZE_SHIFT: RawOpcode = GROUP_SHIFT + GROUP_BITS; +const DIR_SHIFT: RawOpcode = SIZE_SHIFT + SIZE_BITS; + +const NUM_MASK: RawOpcode = (1 << NUM_BITS) - 1; +const GROUP_MASK: RawOpcode = (1 << GROUP_BITS) - 1; +const SIZE_MASK: RawOpcode = (1 << SIZE_BITS) - 1; +const DIR_MASK: RawOpcode = (1 << DIR_BITS) - 1; + +#[cfg(any( +    target_arch = "x86", +    target_arch = "arm", +    target_arch = "s390x", +    target_arch = "x86_64", +    target_arch = "aarch64", +    target_arch = "riscv32", +    target_arch = "riscv64", +    target_arch = "loongarch64", +    target_arch = "csky" +))] +mod consts { +    use super::RawOpcode; + +    pub(super) const NONE: RawOpcode = 0; +    pub(super) const READ: RawOpcode = 2; +    pub(super) const WRITE: RawOpcode = 1; +    pub(super) const SIZE_BITS: RawOpcode = 14; +    pub(super) const DIR_BITS: RawOpcode = 2; +} + +#[cfg(any( +    target_arch = "mips", +    target_arch = "mips32r6", +    target_arch = "mips64", +    target_arch = "mips64r6", +    target_arch = "powerpc", +    target_arch = "powerpc64", +    target_arch = "sparc", +    target_arch = "sparc64" +))] +mod consts { +    use super::RawOpcode; + +    pub(super) const NONE: RawOpcode = 1; +    pub(super) const READ: RawOpcode = 2; +    pub(super) const WRITE: RawOpcode = 4; +    pub(super) const SIZE_BITS: RawOpcode = 13; +    pub(super) const DIR_BITS: RawOpcode = 3; +} + +#[cfg(not(any( +    // These have no ioctl opcodes defined in linux_raw_sys +    // so can't use that as a known-good value for this test. +    target_arch = "sparc", +    target_arch = "sparc64" +)))] +#[test] +fn check_known_opcodes() { +    use crate::backend::c::{c_long, c_uint}; +    use core::mem::size_of; + +    // _IOR('U', 15, unsigned int) +    assert_eq!( +        compose_opcode( +            Direction::Read, +            b'U' as RawOpcode, +            15, +            size_of::<c_uint>() as RawOpcode +        ), +        linux_raw_sys::ioctl::USBDEVFS_CLAIMINTERFACE as RawOpcode +    ); + +    // _IOW('v', 2, long) +    assert_eq!( +        compose_opcode( +            Direction::Write, +            b'v' as RawOpcode, +            2, +            size_of::<c_long>() as RawOpcode +        ), +        linux_raw_sys::ioctl::FS_IOC_SETVERSION as RawOpcode +    ); +} diff --git a/vendor/rustix/src/ioctl/mod.rs b/vendor/rustix/src/ioctl/mod.rs new file mode 100644 index 0000000..494cdc8 --- /dev/null +++ b/vendor/rustix/src/ioctl/mod.rs @@ -0,0 +1,357 @@ +//! 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; diff --git a/vendor/rustix/src/ioctl/patterns.rs b/vendor/rustix/src/ioctl/patterns.rs new file mode 100644 index 0000000..6cf7ebd --- /dev/null +++ b/vendor/rustix/src/ioctl/patterns.rs @@ -0,0 +1,256 @@ +//! Implements typical patterns for `ioctl` usage. + +use super::{Ioctl, IoctlOutput, Opcode, RawOpcode}; + +use crate::backend::c; +use crate::io::Result; + +use core::marker::PhantomData; +use core::ptr::addr_of_mut; +use core::{fmt, mem}; + +/// Implements an `ioctl` with no real arguments. +pub struct NoArg<Opcode> { +    /// The opcode. +    _opcode: PhantomData<Opcode>, +} + +impl<Opcode: CompileTimeOpcode> fmt::Debug for NoArg<Opcode> { +    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { +        f.debug_tuple("NoArg").field(&Opcode::OPCODE).finish() +    } +} + +impl<Opcode: CompileTimeOpcode> NoArg<Opcode> { +    /// Create a new no-argument `ioctl` object. +    /// +    /// # Safety +    /// +    /// - `Opcode` must provide a valid opcode. +    #[inline] +    pub unsafe fn new() -> Self { +        Self { +            _opcode: PhantomData, +        } +    } +} + +unsafe impl<Opcode: CompileTimeOpcode> Ioctl for NoArg<Opcode> { +    type Output = (); + +    const IS_MUTATING: bool = false; +    const OPCODE: self::Opcode = Opcode::OPCODE; + +    fn as_ptr(&mut self) -> *mut c::c_void { +        core::ptr::null_mut() +    } + +    unsafe fn output_from_ptr(_: IoctlOutput, _: *mut c::c_void) -> Result<Self::Output> { +        Ok(()) +    } +} + +/// Implements the traditional “getter” pattern for `ioctl`s. +/// +/// Some `ioctl`s just read data into the userspace. As this is a popular +/// pattern this structure implements it. +pub struct Getter<Opcode, Output> { +    /// The output data. +    output: mem::MaybeUninit<Output>, + +    /// The opcode. +    _opcode: PhantomData<Opcode>, +} + +impl<Opcode: CompileTimeOpcode, Output> fmt::Debug for Getter<Opcode, Output> { +    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { +        f.debug_tuple("Getter").field(&Opcode::OPCODE).finish() +    } +} + +impl<Opcode: CompileTimeOpcode, Output> Getter<Opcode, Output> { +    /// Create a new getter-style `ioctl` object. +    /// +    /// # Safety +    /// +    /// - `Opcode` must provide a valid opcode. +    /// - For this opcode, `Output` must be the type that the kernel expects to +    ///   write into. +    #[inline] +    pub unsafe fn new() -> Self { +        Self { +            output: mem::MaybeUninit::uninit(), +            _opcode: PhantomData, +        } +    } +} + +unsafe impl<Opcode: CompileTimeOpcode, Output> Ioctl for Getter<Opcode, Output> { +    type Output = Output; + +    const IS_MUTATING: bool = true; +    const OPCODE: self::Opcode = Opcode::OPCODE; + +    fn as_ptr(&mut self) -> *mut c::c_void { +        self.output.as_mut_ptr().cast() +    } + +    unsafe fn output_from_ptr(_: IoctlOutput, ptr: *mut c::c_void) -> Result<Self::Output> { +        Ok(ptr.cast::<Output>().read()) +    } +} + +/// Implements the pattern for `ioctl`s where a pointer argument is given to +/// the `ioctl`. +/// +/// The opcode must be read-only. +pub struct Setter<Opcode, Input> { +    /// The input data. +    input: Input, + +    /// The opcode. +    _opcode: PhantomData<Opcode>, +} + +impl<Opcode: CompileTimeOpcode, Input: fmt::Debug> fmt::Debug for Setter<Opcode, Input> { +    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { +        f.debug_tuple("Setter") +            .field(&Opcode::OPCODE) +            .field(&self.input) +            .finish() +    } +} + +impl<Opcode: CompileTimeOpcode, Input> Setter<Opcode, Input> { +    /// Create a new pointer setter-style `ioctl` object. +    /// +    /// # Safety +    /// +    /// - `Opcode` must provide a valid opcode. +    /// - For this opcode, `Input` must be the type that the kernel expects to +    ///   get. +    #[inline] +    pub unsafe fn new(input: Input) -> Self { +        Self { +            input, +            _opcode: PhantomData, +        } +    } +} + +unsafe impl<Opcode: CompileTimeOpcode, Input> Ioctl for Setter<Opcode, Input> { +    type Output = (); + +    const IS_MUTATING: bool = false; +    const OPCODE: self::Opcode = Opcode::OPCODE; + +    fn as_ptr(&mut self) -> *mut c::c_void { +        addr_of_mut!(self.input).cast::<c::c_void>() +    } + +    unsafe fn output_from_ptr(_: IoctlOutput, _: *mut c::c_void) -> Result<Self::Output> { +        Ok(()) +    } +} + +/// Implements an “updater” pattern for `ioctl`s. +/// +/// The ioctl takes a reference to a struct that it reads its input from, +/// then writes output to the same struct. +pub struct Updater<'a, Opcode, Value> { +    /// Reference to input/output data. +    value: &'a mut Value, + +    /// The opcode. +    _opcode: PhantomData<Opcode>, +} + +impl<'a, Opcode: CompileTimeOpcode, Value> Updater<'a, Opcode, Value> { +    /// Create a new pointer updater-style `ioctl` object. +    /// +    /// # Safety +    /// +    /// - `Opcode` must provide a valid opcode. +    /// - For this opcode, `Value` must be the type that the kernel expects to +    ///   get. +    #[inline] +    pub unsafe fn new(value: &'a mut Value) -> Self { +        Self { +            value, +            _opcode: PhantomData, +        } +    } +} + +unsafe impl<'a, Opcode: CompileTimeOpcode, T> Ioctl for Updater<'a, Opcode, T> { +    type Output = (); + +    const IS_MUTATING: bool = true; +    const OPCODE: self::Opcode = Opcode::OPCODE; + +    fn as_ptr(&mut self) -> *mut c::c_void { +        (self.value as *mut T).cast() +    } + +    unsafe fn output_from_ptr(_output: IoctlOutput, _ptr: *mut c::c_void) -> Result<()> { +        Ok(()) +    } +} + +/// Trait for something that provides an `ioctl` opcode at compile time. +pub trait CompileTimeOpcode { +    /// The opcode. +    const OPCODE: Opcode; +} + +/// Provides a bad opcode at compile time. +pub struct BadOpcode<const OPCODE: RawOpcode>; + +impl<const OPCODE: RawOpcode> CompileTimeOpcode for BadOpcode<OPCODE> { +    const OPCODE: Opcode = Opcode::old(OPCODE); +} + +/// Provides a read code at compile time. +/// +/// This corresponds to the C macro `_IOR(GROUP, NUM, Data)`. +#[cfg(any(linux_kernel, bsd))] +pub struct ReadOpcode<const GROUP: u8, const NUM: u8, Data>(Data); + +#[cfg(any(linux_kernel, bsd))] +impl<const GROUP: u8, const NUM: u8, Data> CompileTimeOpcode for ReadOpcode<GROUP, NUM, Data> { +    const OPCODE: Opcode = Opcode::read::<Data>(GROUP, NUM); +} + +/// Provides a write code at compile time. +/// +/// This corresponds to the C macro `_IOW(GROUP, NUM, Data)`. +#[cfg(any(linux_kernel, bsd))] +pub struct WriteOpcode<const GROUP: u8, const NUM: u8, Data>(Data); + +#[cfg(any(linux_kernel, bsd))] +impl<const GROUP: u8, const NUM: u8, Data> CompileTimeOpcode for WriteOpcode<GROUP, NUM, Data> { +    const OPCODE: Opcode = Opcode::write::<Data>(GROUP, NUM); +} + +/// Provides a read/write code at compile time. +/// +/// This corresponds to the C macro `_IOWR(GROUP, NUM, Data)`. +#[cfg(any(linux_kernel, bsd))] +pub struct ReadWriteOpcode<const GROUP: u8, const NUM: u8, Data>(Data); + +#[cfg(any(linux_kernel, bsd))] +impl<const GROUP: u8, const NUM: u8, Data> CompileTimeOpcode for ReadWriteOpcode<GROUP, NUM, Data> { +    const OPCODE: Opcode = Opcode::read_write::<Data>(GROUP, NUM); +} + +/// Provides a `None` code at compile time. +/// +/// This corresponds to the C macro `_IO(GROUP, NUM)` when `Data` is zero +/// sized. +#[cfg(any(linux_kernel, bsd))] +pub struct NoneOpcode<const GROUP: u8, const NUM: u8, Data>(Data); + +#[cfg(any(linux_kernel, bsd))] +impl<const GROUP: u8, const NUM: u8, Data> CompileTimeOpcode for NoneOpcode<GROUP, NUM, Data> { +    const OPCODE: Opcode = Opcode::none::<Data>(GROUP, NUM); +}  | 
