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//! Provide helpers for making ioctl system calls. //! //! This library is pretty low-level and messy. `ioctl` is not fun. //! //! What is an `ioctl`? //! =================== //! //! The `ioctl` syscall is the grab-bag syscall on POSIX systems. Don't want to add a new //! syscall? Make it an `ioctl`! `ioctl` refers to both the syscall, and the commands that can be //! sent with it. `ioctl` stands for "IO control", and the commands are always sent to a file //! descriptor. //! //! It is common to see `ioctl`s used for the following purposes: //! //! * Provide read/write access to out-of-band data related to a device such as configuration //! (for instance, setting serial port options) //! * Provide a mechanism for performing full-duplex data transfers (for instance, xfer on SPI //! devices). //! * Provide access to control functions on a device (for example, on Linux you can send //! commands like pause, resume, and eject to the CDROM device. //! * Do whatever else the device driver creator thought made most sense. //! //! `ioctl`s are synchronous system calls and are similar to read and write calls in that regard. //! They operate on file descriptors and have an identifier that specifies what the ioctl is. //! Additionally they may read or write data and therefore need to pass along a data pointer. //! Besides the semantics of the ioctls being confusing, the generation of this identifer can also //! be difficult. //! //! Historically `ioctl` numbers were arbitrary hard-coded values. In Linux (before 2.6) and some //! unices this has changed to a more-ordered system where the ioctl numbers are partitioned into //! subcomponents (For linux this is documented in //! [`Documentation/ioctl/ioctl-number.rst`](https://elixir.bootlin.com/linux/latest/source/Documentation/userspace-api/ioctl/ioctl-number.rst)): //! //! * Number: The actual ioctl ID //! * Type: A grouping of ioctls for a common purpose or driver //! * Size: The size in bytes of the data that will be transferred //! * Direction: Whether there is any data and if it's read, write, or both //! //! Newer drivers should not generate complete integer identifiers for their `ioctl`s instead //! preferring to use the 4 components above to generate the final ioctl identifier. Because of //! how old `ioctl`s are, however, there are many hard-coded `ioctl` identifiers. These are //! commonly referred to as "bad" in `ioctl` documentation. //! //! Defining `ioctl`s //! ================= //! //! This library provides several `ioctl_*!` macros for binding `ioctl`s. These generate public //! unsafe functions that can then be used for calling the ioctl. This macro has a few different //! ways it can be used depending on the specific ioctl you're working with. //! //! A simple `ioctl` is `SPI_IOC_RD_MODE`. This ioctl works with the SPI interface on Linux. This //! specific `ioctl` reads the mode of the SPI device as a `u8`. It's declared in //! `/include/uapi/linux/spi/spidev.h` as `_IOR(SPI_IOC_MAGIC, 1, __u8)`. Since it uses the `_IOR` //! macro, we know it's a `read` ioctl and can use the `ioctl_read!` macro as follows: //! //! ``` //! # #[macro_use] extern crate nix; //! const SPI_IOC_MAGIC: u8 = b'k'; // Defined in linux/spi/spidev.h //! const SPI_IOC_TYPE_MODE: u8 = 1; //! ioctl_read!(spi_read_mode, SPI_IOC_MAGIC, SPI_IOC_TYPE_MODE, u8); //! # fn main() {} //! ``` //! //! This generates the function: //! //! ``` //! # #[macro_use] extern crate nix; //! # use std::mem; //! # use nix::{libc, Result}; //! # use nix::errno::Errno; //! # use nix::libc::c_int as c_int; //! # const SPI_IOC_MAGIC: u8 = b'k'; // Defined in linux/spi/spidev.h //! # const SPI_IOC_TYPE_MODE: u8 = 1; //! pub unsafe fn spi_read_mode(fd: c_int, data: *mut u8) -> Result<c_int> { //! let res = libc::ioctl(fd, request_code_read!(SPI_IOC_MAGIC, SPI_IOC_TYPE_MODE, mem::size_of::<u8>()), data); //! Errno::result(res) //! } //! # fn main() {} //! ``` //! //! The return value for the wrapper functions generated by the `ioctl_*!` macros are `nix::Error`s. //! These are generated by assuming the return value of the ioctl is `-1` on error and everything //! else is a valid return value. If this is not the case, `Result::map` can be used to map some //! of the range of "good" values (-Inf..-2, 0..Inf) into a smaller range in a helper function. //! //! Writing `ioctl`s generally use pointers as their data source and these should use the //! `ioctl_write_ptr!`. But in some cases an `int` is passed directly. For these `ioctl`s use the //! `ioctl_write_int!` macro. This variant does not take a type as the last argument: //! //! ``` //! # #[macro_use] extern crate nix; //! const HCI_IOC_MAGIC: u8 = b'k'; //! const HCI_IOC_HCIDEVUP: u8 = 1; //! ioctl_write_int!(hci_dev_up, HCI_IOC_MAGIC, HCI_IOC_HCIDEVUP); //! # fn main() {} //! ``` //! //! Some `ioctl`s don't transfer any data, and those should use `ioctl_none!`. This macro //! doesn't take a type and so it is declared similar to the `write_int` variant shown above. //! //! The mode for a given `ioctl` should be clear from the documentation if it has good //! documentation. Otherwise it will be clear based on the macro used to generate the `ioctl` //! number where `_IO`, `_IOR`, `_IOW`, and `_IOWR` map to "none", "read", "write_*", and "readwrite" //! respectively. To determine the specific `write_` variant to use you'll need to find //! what the argument type is supposed to be. If it's an `int`, then `write_int` should be used, //! otherwise it should be a pointer and `write_ptr` should be used. On Linux the //! [`ioctl_list` man page](https://man7.org/linux/man-pages/man2/ioctl_list.2.html) describes a //! large number of `ioctl`s and describes their argument data type. //! //! Using "bad" `ioctl`s //! -------------------- //! //! As mentioned earlier, there are many old `ioctl`s that do not use the newer method of //! generating `ioctl` numbers and instead use hardcoded values. These can be used with the //! `ioctl_*_bad!` macros. This naming comes from the Linux kernel which refers to these //! `ioctl`s as "bad". These are a different variant as they bypass calling the macro that generates //! the ioctl number and instead use the defined value directly. //! //! For example the `TCGETS` `ioctl` reads a `termios` data structure for a given file descriptor. //! It's defined as `0x5401` in `ioctls.h` on Linux and can be implemented as: //! //! ``` //! # #[macro_use] extern crate nix; //! # #[cfg(any(target_os = "android", target_os = "linux"))] //! # use nix::libc::TCGETS as TCGETS; //! # #[cfg(any(target_os = "android", target_os = "linux"))] //! # use nix::libc::termios as termios; //! # #[cfg(any(target_os = "android", target_os = "linux"))] //! ioctl_read_bad!(tcgets, TCGETS, termios); //! # fn main() {} //! ``` //! //! The generated function has the same form as that generated by `ioctl_read!`: //! //! ```text //! pub unsafe fn tcgets(fd: c_int, data: *mut termios) -> Result<c_int>; //! ``` //! //! Working with Arrays //! ------------------- //! //! Some `ioctl`s work with entire arrays of elements. These are supported by the `ioctl_*_buf` //! family of macros: `ioctl_read_buf`, `ioctl_write_buf`, and `ioctl_readwrite_buf`. Note that //! there are no "bad" versions for working with buffers. The generated functions include a `len` //! argument to specify the number of elements (where the type of each element is specified in the //! macro). //! //! Again looking to the SPI `ioctl`s on Linux for an example, there is a `SPI_IOC_MESSAGE` `ioctl` //! that queues up multiple SPI messages by writing an entire array of `spi_ioc_transfer` structs. //! `linux/spi/spidev.h` defines a macro to calculate the `ioctl` number like: //! //! ```C //! #define SPI_IOC_MAGIC 'k' //! #define SPI_MSGSIZE(N) ... //! #define SPI_IOC_MESSAGE(N) _IOW(SPI_IOC_MAGIC, 0, char[SPI_MSGSIZE(N)]) //! ``` //! //! The `SPI_MSGSIZE(N)` calculation is already handled by the `ioctl_*!` macros, so all that's //! needed to define this `ioctl` is: //! //! ``` //! # #[macro_use] extern crate nix; //! const SPI_IOC_MAGIC: u8 = b'k'; // Defined in linux/spi/spidev.h //! const SPI_IOC_TYPE_MESSAGE: u8 = 0; //! # pub struct spi_ioc_transfer(u64); //! ioctl_write_buf!(spi_transfer, SPI_IOC_MAGIC, SPI_IOC_TYPE_MESSAGE, spi_ioc_transfer); //! # fn main() {} //! ``` //! //! This generates a function like: //! //! ``` //! # #[macro_use] extern crate nix; //! # use std::mem; //! # use nix::{libc, Result}; //! # use nix::errno::Errno; //! # use nix::libc::c_int as c_int; //! # const SPI_IOC_MAGIC: u8 = b'k'; //! # const SPI_IOC_TYPE_MESSAGE: u8 = 0; //! # pub struct spi_ioc_transfer(u64); //! pub unsafe fn spi_message(fd: c_int, data: &mut [spi_ioc_transfer]) -> Result<c_int> { //! let res = libc::ioctl(fd, //! request_code_write!(SPI_IOC_MAGIC, SPI_IOC_TYPE_MESSAGE, data.len() * mem::size_of::<spi_ioc_transfer>()), //! data); //! Errno::result(res) //! } //! # fn main() {} //! ``` //! //! Finding `ioctl` Documentation //! ----------------------------- //! //! For Linux, look at your system's headers. For example, `/usr/include/linux/input.h` has a lot //! of lines defining macros which use `_IO`, `_IOR`, `_IOW`, `_IOC`, and `_IOWR`. Some `ioctl`s are //! documented directly in the headers defining their constants, but others have more extensive //! documentation in man pages (like termios' `ioctl`s which are in `tty_ioctl(4)`). //! //! Documenting the Generated Functions //! =================================== //! //! In many cases, users will wish for the functions generated by the `ioctl` //! macro to be public and documented. For this reason, the generated functions //! are public by default. If you wish to hide the ioctl, you will need to put //! them in a private module. //! //! For documentation, it is possible to use doc comments inside the `ioctl_*!` macros. Here is an //! example : //! //! ``` //! # #[macro_use] extern crate nix; //! # use nix::libc::c_int; //! ioctl_read! { //! /// Make the given terminal the controlling terminal of the calling process. The calling //! /// process must be a session leader and not have a controlling terminal already. If the //! /// terminal is already the controlling terminal of a different session group then the //! /// ioctl will fail with **EPERM**, unless the caller is root (more precisely: has the //! /// **CAP_SYS_ADMIN** capability) and arg equals 1, in which case the terminal is stolen //! /// and all processes that had it as controlling terminal lose it. //! tiocsctty, b't', 19, c_int //! } //! //! # fn main() {} //! ``` use cfg_if::cfg_if; #[cfg(any(target_os = "android", target_os = "linux", target_os = "redox"))] #[macro_use] mod linux; #[cfg(any(target_os = "android", target_os = "linux", target_os = "redox"))] pub use self::linux::*; #[cfg(any(target_os = "dragonfly", target_os = "freebsd", target_os = "illumos", target_os = "ios", target_os = "macos", target_os = "netbsd", target_os = "openbsd"))] #[macro_use] mod bsd; #[cfg(any(target_os = "dragonfly", target_os = "freebsd", target_os = "illumos", target_os = "ios", target_os = "macos", target_os = "netbsd", target_os = "openbsd"))] pub use self::bsd::*; /// Convert raw ioctl return value to a Nix result #[macro_export] #[doc(hidden)] macro_rules! convert_ioctl_res { ($w:expr) => ( { $crate::errno::Errno::result($w) } ); } /// Generates a wrapper function for an ioctl that passes no data to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl identifier /// * The ioctl sequence number /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Example /// /// The `videodev2` driver on Linux defines the `log_status` `ioctl` as: /// /// ```C /// #define VIDIOC_LOG_STATUS _IO('V', 70) /// ``` /// /// This can be implemented in Rust like: /// /// ```no_run /// # #[macro_use] extern crate nix; /// ioctl_none!(log_status, b'V', 70); /// fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_none { ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, request_code_none!($ioty, $nr) as $crate::sys::ioctl::ioctl_num_type)) } ) } /// Generates a wrapper function for a "bad" ioctl that passes no data to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl request code /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Example /// /// ```no_run /// # #[macro_use] extern crate nix; /// # use libc::TIOCNXCL; /// # use std::fs::File; /// # use std::os::unix::io::AsRawFd; /// ioctl_none_bad!(tiocnxcl, TIOCNXCL); /// fn main() { /// let file = File::open("/dev/ttyUSB0").unwrap(); /// unsafe { tiocnxcl(file.as_raw_fd()) }.unwrap(); /// } /// ``` // TODO: add an example using request_code_*!() #[macro_export(local_inner_macros)] macro_rules! ioctl_none_bad { ($(#[$attr:meta])* $name:ident, $nr:expr) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, $nr as $crate::sys::ioctl::ioctl_num_type)) } ) } /// Generates a wrapper function for an ioctl that reads data from the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl identifier /// * The ioctl sequence number /// * The data type passed by this ioctl /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: *mut DATA_TYPE) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Example /// /// ``` /// # #[macro_use] extern crate nix; /// const SPI_IOC_MAGIC: u8 = b'k'; // Defined in linux/spi/spidev.h /// const SPI_IOC_TYPE_MODE: u8 = 1; /// ioctl_read!(spi_read_mode, SPI_IOC_MAGIC, SPI_IOC_TYPE_MODE, u8); /// # fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_read { ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr, $ty:ty) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: *mut $ty) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, request_code_read!($ioty, $nr, ::std::mem::size_of::<$ty>()) as $crate::sys::ioctl::ioctl_num_type, data)) } ) } /// Generates a wrapper function for a "bad" ioctl that reads data from the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl request code /// * The data type passed by this ioctl /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: *mut DATA_TYPE) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Example /// /// ``` /// # #[macro_use] extern crate nix; /// # #[cfg(any(target_os = "android", target_os = "linux"))] /// ioctl_read_bad!(tcgets, libc::TCGETS, libc::termios); /// # fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_read_bad { ($(#[$attr:meta])* $name:ident, $nr:expr, $ty:ty) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: *mut $ty) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, $nr as $crate::sys::ioctl::ioctl_num_type, data)) } ) } /// Generates a wrapper function for an ioctl that writes data through a pointer to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl identifier /// * The ioctl sequence number /// * The data type passed by this ioctl /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: *const DATA_TYPE) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Example /// /// ``` /// # #[macro_use] extern crate nix; /// # pub struct v4l2_audio {} /// ioctl_write_ptr!(s_audio, b'V', 34, v4l2_audio); /// # fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_write_ptr { ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr, $ty:ty) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: *const $ty) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, request_code_write!($ioty, $nr, ::std::mem::size_of::<$ty>()) as $crate::sys::ioctl::ioctl_num_type, data)) } ) } /// Generates a wrapper function for a "bad" ioctl that writes data through a pointer to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl request code /// * The data type passed by this ioctl /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: *const DATA_TYPE) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Example /// /// ``` /// # #[macro_use] extern crate nix; /// # #[cfg(any(target_os = "android", target_os = "linux"))] /// ioctl_write_ptr_bad!(tcsets, libc::TCSETS, libc::termios); /// # fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_write_ptr_bad { ($(#[$attr:meta])* $name:ident, $nr:expr, $ty:ty) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: *const $ty) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, $nr as $crate::sys::ioctl::ioctl_num_type, data)) } ) } cfg_if!{ if #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))] { /// Generates a wrapper function for a ioctl that writes an integer to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl identifier /// * The ioctl sequence number /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: nix::sys::ioctl::ioctl_param_type) -> Result<libc::c_int> /// ``` /// /// `nix::sys::ioctl::ioctl_param_type` depends on the OS: /// * BSD - `libc::c_int` /// * Linux - `libc::c_ulong` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Example /// /// ``` /// # #[macro_use] extern crate nix; /// ioctl_write_int!(vt_activate, b'v', 4); /// # fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_write_int { ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: $crate::sys::ioctl::ioctl_param_type) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, request_code_write_int!($ioty, $nr) as $crate::sys::ioctl::ioctl_num_type, data)) } ) } } else { /// Generates a wrapper function for a ioctl that writes an integer to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl identifier /// * The ioctl sequence number /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: nix::sys::ioctl::ioctl_param_type) -> Result<libc::c_int> /// ``` /// /// `nix::sys::ioctl::ioctl_param_type` depends on the OS: /// * BSD - `libc::c_int` /// * Linux - `libc::c_ulong` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Example /// /// ``` /// # #[macro_use] extern crate nix; /// const HCI_IOC_MAGIC: u8 = b'k'; /// const HCI_IOC_HCIDEVUP: u8 = 1; /// ioctl_write_int!(hci_dev_up, HCI_IOC_MAGIC, HCI_IOC_HCIDEVUP); /// # fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_write_int { ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: $crate::sys::ioctl::ioctl_param_type) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, request_code_write!($ioty, $nr, ::std::mem::size_of::<$crate::libc::c_int>()) as $crate::sys::ioctl::ioctl_num_type, data)) } ) } } } /// Generates a wrapper function for a "bad" ioctl that writes an integer to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl request code /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: libc::c_int) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Examples /// /// ``` /// # #[macro_use] extern crate nix; /// # #[cfg(any(target_os = "android", target_os = "linux"))] /// ioctl_write_int_bad!(tcsbrk, libc::TCSBRK); /// # fn main() {} /// ``` /// /// ```rust /// # #[macro_use] extern crate nix; /// const KVMIO: u8 = 0xAE; /// ioctl_write_int_bad!(kvm_create_vm, request_code_none!(KVMIO, 0x03)); /// # fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_write_int_bad { ($(#[$attr:meta])* $name:ident, $nr:expr) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: $crate::libc::c_int) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, $nr as $crate::sys::ioctl::ioctl_num_type, data)) } ) } /// Generates a wrapper function for an ioctl that reads and writes data to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl identifier /// * The ioctl sequence number /// * The data type passed by this ioctl /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: *mut DATA_TYPE) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Example /// /// ``` /// # #[macro_use] extern crate nix; /// # pub struct v4l2_audio {} /// ioctl_readwrite!(enum_audio, b'V', 65, v4l2_audio); /// # fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_readwrite { ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr, $ty:ty) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: *mut $ty) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, request_code_readwrite!($ioty, $nr, ::std::mem::size_of::<$ty>()) as $crate::sys::ioctl::ioctl_num_type, data)) } ) } /// Generates a wrapper function for a "bad" ioctl that reads and writes data to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl request code /// * The data type passed by this ioctl /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: *mut DATA_TYPE) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). // TODO: Find an example for ioctl_readwrite_bad #[macro_export(local_inner_macros)] macro_rules! ioctl_readwrite_bad { ($(#[$attr:meta])* $name:ident, $nr:expr, $ty:ty) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: *mut $ty) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, $nr as $crate::sys::ioctl::ioctl_num_type, data)) } ) } /// Generates a wrapper function for an ioctl that reads an array of elements from the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl identifier /// * The ioctl sequence number /// * The data type passed by this ioctl /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: &mut [DATA_TYPE]) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). // TODO: Find an example for ioctl_read_buf #[macro_export(local_inner_macros)] macro_rules! ioctl_read_buf { ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr, $ty:ty) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: &mut [$ty]) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, request_code_read!($ioty, $nr, data.len() * ::std::mem::size_of::<$ty>()) as $crate::sys::ioctl::ioctl_num_type, data)) } ) } /// Generates a wrapper function for an ioctl that writes an array of elements to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl identifier /// * The ioctl sequence number /// * The data type passed by this ioctl /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: &[DATA_TYPE]) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). /// /// # Examples /// /// ``` /// # #[macro_use] extern crate nix; /// const SPI_IOC_MAGIC: u8 = b'k'; // Defined in linux/spi/spidev.h /// const SPI_IOC_TYPE_MESSAGE: u8 = 0; /// # pub struct spi_ioc_transfer(u64); /// ioctl_write_buf!(spi_transfer, SPI_IOC_MAGIC, SPI_IOC_TYPE_MESSAGE, spi_ioc_transfer); /// # fn main() {} /// ``` #[macro_export(local_inner_macros)] macro_rules! ioctl_write_buf { ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr, $ty:ty) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: &[$ty]) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, request_code_write!($ioty, $nr, data.len() * ::std::mem::size_of::<$ty>()) as $crate::sys::ioctl::ioctl_num_type, data)) } ) } /// Generates a wrapper function for an ioctl that reads and writes an array of elements to the kernel. /// /// The arguments to this macro are: /// /// * The function name /// * The ioctl identifier /// * The ioctl sequence number /// * The data type passed by this ioctl /// /// The generated function has the following signature: /// /// ```rust,ignore /// pub unsafe fn FUNCTION_NAME(fd: libc::c_int, data: &mut [DATA_TYPE]) -> Result<libc::c_int> /// ``` /// /// For a more in-depth explanation of ioctls, see [`::sys::ioctl`](sys/ioctl/index.html). // TODO: Find an example for readwrite_buf #[macro_export(local_inner_macros)] macro_rules! ioctl_readwrite_buf { ($(#[$attr:meta])* $name:ident, $ioty:expr, $nr:expr, $ty:ty) => ( $(#[$attr])* pub unsafe fn $name(fd: $crate::libc::c_int, data: &mut [$ty]) -> $crate::Result<$crate::libc::c_int> { convert_ioctl_res!($crate::libc::ioctl(fd, request_code_readwrite!($ioty, $nr, data.len() * ::std::mem::size_of::<$ty>()) as $crate::sys::ioctl::ioctl_num_type, data)) } ) }