Revision control
Copy as Markdown
Other Tools
//! libc syscalls supporting `rustix::termios`.
//!
//! # Safety
//!
//! See the `rustix::backend::syscalls` module documentation for details.
use crate::backend::c;
#[cfg(not(target_os = "wasi"))]
use crate::backend::conv::ret_pid_t;
use crate::backend::conv::{borrowed_fd, ret};
use crate::fd::BorrowedFd;
#[cfg(all(feature = "alloc", feature = "procfs"))]
#[cfg(not(any(target_os = "fuchsia", target_os = "wasi")))]
use crate::ffi::CStr;
#[cfg(any(
not(target_os = "espidf"),
all(
feature = "procfs",
not(any(target_os = "fuchsia", target_os = "wasi"))
)
))]
use core::mem::MaybeUninit;
#[cfg(not(target_os = "wasi"))]
use {crate::io, crate::pid::Pid};
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
use {
crate::termios::{Action, OptionalActions, QueueSelector, Termios, Winsize},
crate::utils::as_mut_ptr,
};
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
pub(crate) fn tcgetattr(fd: BorrowedFd<'_>) -> io::Result<Termios> {
// If we have `TCGETS2`, use it, so that we fill in the `c_ispeed` and
// `c_ospeed` fields.
#[cfg(linux_kernel)]
{
use crate::termios::{ControlModes, InputModes, LocalModes, OutputModes, SpecialCodes};
use crate::utils::default_array;
let termios2 = unsafe {
let mut termios2 = MaybeUninit::<c::termios2>::uninit();
// QEMU's `TCGETS2` doesn't currently set `input_speed` or
// `output_speed` on PowerPC, so zero out the fields ourselves.
#[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
{
termios2.write(core::mem::zeroed());
}
ret(c::ioctl(
borrowed_fd(fd),
c::TCGETS2 as _,
termios2.as_mut_ptr(),
))?;
termios2.assume_init()
};
// Convert from the Linux `termios2` to our `Termios`.
let mut result = Termios {
input_modes: InputModes::from_bits_retain(termios2.c_iflag),
output_modes: OutputModes::from_bits_retain(termios2.c_oflag),
control_modes: ControlModes::from_bits_retain(termios2.c_cflag),
local_modes: LocalModes::from_bits_retain(termios2.c_lflag),
line_discipline: termios2.c_line,
special_codes: SpecialCodes(default_array()),
input_speed: termios2.c_ispeed,
output_speed: termios2.c_ospeed,
};
// QEMU's `TCGETS2` doesn't currently set `input_speed` or
// `output_speed` on PowerPC, so set them manually if we can.
#[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
{
use crate::termios::speed;
if result.output_speed == 0 && (termios2.c_cflag & c::CBAUD) != c::BOTHER {
if let Some(output_speed) = speed::decode(termios2.c_cflag & c::CBAUD) {
result.output_speed = output_speed;
}
}
if result.input_speed == 0
&& ((termios2.c_cflag & c::CIBAUD) >> c::IBSHIFT) != c::BOTHER
{
// For input speeds, `B0` is special-cased to mean the input
// speed is the same as the output speed.
if ((termios2.c_cflag & c::CIBAUD) >> c::IBSHIFT) == c::B0 {
result.input_speed = result.output_speed;
} else if let Some(input_speed) =
speed::decode((termios2.c_cflag & c::CIBAUD) >> c::IBSHIFT)
{
result.input_speed = input_speed;
}
}
}
result.special_codes.0[..termios2.c_cc.len()].copy_from_slice(&termios2.c_cc);
Ok(result)
}
#[cfg(not(linux_kernel))]
unsafe {
let mut result = MaybeUninit::<Termios>::uninit();
// `result` is a `Termios` which starts with the same layout as
// `libc::termios`, so we can cast the pointer.
ret(c::tcgetattr(borrowed_fd(fd), result.as_mut_ptr().cast()))?;
Ok(result.assume_init())
}
}
#[cfg(not(target_os = "wasi"))]
pub(crate) fn tcgetpgrp(fd: BorrowedFd<'_>) -> io::Result<Pid> {
unsafe {
let pid = ret_pid_t(c::tcgetpgrp(borrowed_fd(fd)))?;
// This doesn't appear to be documented, but on Linux, it appears
// `tcsetpgrp` can succceed and set the pid to 0 if we pass it a
// pseudo-terminal device fd. For now, translate it into `OPNOTSUPP`.
#[cfg(linux_kernel)]
if pid == 0 {
return Err(io::Errno::OPNOTSUPP);
}
Ok(Pid::from_raw_unchecked(pid))
}
}
#[cfg(not(target_os = "wasi"))]
pub(crate) fn tcsetpgrp(fd: BorrowedFd<'_>, pid: Pid) -> io::Result<()> {
unsafe { ret(c::tcsetpgrp(borrowed_fd(fd), pid.as_raw_nonzero().get())) }
}
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
pub(crate) fn tcsetattr(
fd: BorrowedFd<'_>,
optional_actions: OptionalActions,
termios: &Termios,
) -> io::Result<()> {
// If we have `TCSETS2`, use it, so that we use the `c_ispeed` and
// `c_ospeed` fields.
#[cfg(linux_kernel)]
{
use crate::termios::speed;
use crate::utils::default_array;
use linux_raw_sys::general::{termios2, BOTHER, CBAUD, IBSHIFT};
#[cfg(not(any(target_arch = "sparc", target_arch = "sparc64")))]
use linux_raw_sys::ioctl::{TCSETS, TCSETS2};
// linux-raw-sys' ioctl-generation script for sparc isn't working yet,
// so as a temporary workaround, declare these manually.
#[cfg(any(target_arch = "sparc", target_arch = "sparc64"))]
const TCSETS: u32 = 0x8024_5409;
#[cfg(any(target_arch = "sparc", target_arch = "sparc64"))]
const TCSETS2: u32 = 0x802c_540d;
// Translate from `optional_actions` into an ioctl request code. On
// MIPS, `optional_actions` already has `TCGETS` added to it.
let request = TCSETS2
+ if cfg!(any(
target_arch = "mips",
target_arch = "mips32r6",
target_arch = "mips64",
target_arch = "mips64r6"
)) {
optional_actions as u32 - TCSETS
} else {
optional_actions as u32
};
let input_speed = termios.input_speed();
let output_speed = termios.output_speed();
let mut termios2 = termios2 {
c_iflag: termios.input_modes.bits(),
c_oflag: termios.output_modes.bits(),
c_cflag: termios.control_modes.bits(),
c_lflag: termios.local_modes.bits(),
c_line: termios.line_discipline,
c_cc: default_array(),
c_ispeed: input_speed,
c_ospeed: output_speed,
};
// Ensure that our input and output speeds are set, as `libc`
// routines don't always support setting these separately.
termios2.c_cflag &= !CBAUD;
termios2.c_cflag |= speed::encode(output_speed).unwrap_or(BOTHER);
termios2.c_cflag &= !(CBAUD << IBSHIFT);
termios2.c_cflag |= speed::encode(input_speed).unwrap_or(BOTHER) << IBSHIFT;
let nccs = termios2.c_cc.len();
termios2
.c_cc
.copy_from_slice(&termios.special_codes.0[..nccs]);
unsafe { ret(c::ioctl(borrowed_fd(fd), request as _, &termios2)) }
}
#[cfg(not(linux_kernel))]
unsafe {
ret(c::tcsetattr(
borrowed_fd(fd),
optional_actions as _,
crate::utils::as_ptr(termios).cast(),
))
}
}
#[cfg(not(target_os = "wasi"))]
pub(crate) fn tcsendbreak(fd: BorrowedFd<'_>) -> io::Result<()> {
unsafe { ret(c::tcsendbreak(borrowed_fd(fd), 0)) }
}
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
pub(crate) fn tcdrain(fd: BorrowedFd<'_>) -> io::Result<()> {
unsafe { ret(c::tcdrain(borrowed_fd(fd))) }
}
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
pub(crate) fn tcflush(fd: BorrowedFd<'_>, queue_selector: QueueSelector) -> io::Result<()> {
unsafe { ret(c::tcflush(borrowed_fd(fd), queue_selector as _)) }
}
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
pub(crate) fn tcflow(fd: BorrowedFd<'_>, action: Action) -> io::Result<()> {
unsafe { ret(c::tcflow(borrowed_fd(fd), action as _)) }
}
#[cfg(not(target_os = "wasi"))]
pub(crate) fn tcgetsid(fd: BorrowedFd<'_>) -> io::Result<Pid> {
unsafe {
let pid = ret_pid_t(c::tcgetsid(borrowed_fd(fd)))?;
Ok(Pid::from_raw_unchecked(pid))
}
}
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
pub(crate) fn tcsetwinsize(fd: BorrowedFd<'_>, winsize: Winsize) -> io::Result<()> {
unsafe { ret(c::ioctl(borrowed_fd(fd), c::TIOCSWINSZ, &winsize)) }
}
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
pub(crate) fn tcgetwinsize(fd: BorrowedFd<'_>) -> io::Result<Winsize> {
unsafe {
let mut buf = MaybeUninit::<Winsize>::uninit();
ret(c::ioctl(
borrowed_fd(fd),
c::TIOCGWINSZ.into(),
buf.as_mut_ptr(),
))?;
Ok(buf.assume_init())
}
}
#[cfg(not(any(target_os = "espidf", target_os = "nto", target_os = "wasi")))]
#[inline]
pub(crate) fn set_speed(termios: &mut Termios, arbitrary_speed: u32) -> io::Result<()> {
#[cfg(bsd)]
let encoded_speed = arbitrary_speed;
#[cfg(not(bsd))]
let encoded_speed = match crate::termios::speed::encode(arbitrary_speed) {
Some(encoded_speed) => encoded_speed,
#[cfg(linux_kernel)]
None => c::BOTHER,
#[cfg(not(linux_kernel))]
None => return Err(io::Errno::INVAL),
};
#[cfg(not(linux_kernel))]
unsafe {
ret(c::cfsetspeed(
as_mut_ptr(termios).cast(),
encoded_speed.into(),
))
}
// Linux libc implementations don't support arbitrary speeds, so we encode
// the speed manually.
#[cfg(linux_kernel)]
{
use crate::termios::ControlModes;
debug_assert_eq!(encoded_speed & !c::CBAUD, 0);
termios.control_modes -= ControlModes::from_bits_retain(c::CBAUD | c::CIBAUD);
termios.control_modes |=
ControlModes::from_bits_retain(encoded_speed | (encoded_speed << c::IBSHIFT));
termios.input_speed = arbitrary_speed;
termios.output_speed = arbitrary_speed;
Ok(())
}
}
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
#[inline]
pub(crate) fn set_output_speed(termios: &mut Termios, arbitrary_speed: u32) -> io::Result<()> {
#[cfg(bsd)]
let encoded_speed = arbitrary_speed;
#[cfg(not(bsd))]
let encoded_speed = match crate::termios::speed::encode(arbitrary_speed) {
Some(encoded_speed) => encoded_speed,
#[cfg(linux_kernel)]
None => c::BOTHER,
#[cfg(not(linux_kernel))]
None => return Err(io::Errno::INVAL),
};
#[cfg(not(linux_kernel))]
unsafe {
ret(c::cfsetospeed(
as_mut_ptr(termios).cast(),
encoded_speed.into(),
))
}
// Linux libc implementations don't support arbitrary speeds or setting the
// input and output speeds separately, so we encode the speed manually.
#[cfg(linux_kernel)]
{
use crate::termios::ControlModes;
debug_assert_eq!(encoded_speed & !c::CBAUD, 0);
termios.control_modes -= ControlModes::from_bits_retain(c::CBAUD);
termios.control_modes |= ControlModes::from_bits_retain(encoded_speed);
termios.output_speed = arbitrary_speed;
Ok(())
}
}
#[cfg(not(any(target_os = "espidf", target_os = "wasi")))]
#[inline]
pub(crate) fn set_input_speed(termios: &mut Termios, arbitrary_speed: u32) -> io::Result<()> {
#[cfg(bsd)]
let encoded_speed = arbitrary_speed;
#[cfg(not(bsd))]
let encoded_speed = match crate::termios::speed::encode(arbitrary_speed) {
Some(encoded_speed) => encoded_speed,
#[cfg(linux_kernel)]
None => c::BOTHER,
#[cfg(not(linux_kernel))]
None => return Err(io::Errno::INVAL),
};
#[cfg(not(linux_kernel))]
unsafe {
ret(c::cfsetispeed(
as_mut_ptr(termios).cast(),
encoded_speed.into(),
))
}
// Linux libc implementations don't support arbitrary speeds or setting the
// input and output speeds separately, so we encode the speed manually.
#[cfg(linux_kernel)]
{
use crate::termios::ControlModes;
debug_assert_eq!(encoded_speed & !c::CBAUD, 0);
termios.control_modes -= ControlModes::from_bits_retain(c::CIBAUD);
termios.control_modes |= ControlModes::from_bits_retain(encoded_speed << c::IBSHIFT);
termios.input_speed = arbitrary_speed;
Ok(())
}
}
#[cfg(not(any(target_os = "espidf", target_os = "nto", target_os = "wasi")))]
#[inline]
pub(crate) fn cfmakeraw(termios: &mut Termios) {
unsafe { c::cfmakeraw(as_mut_ptr(termios).cast()) }
}
pub(crate) fn isatty(fd: BorrowedFd<'_>) -> bool {
// Use the return value of `isatty` alone. We don't check `errno` because
// we return `bool` rather than `io::Result<bool>`, because we assume
// `BorrowedFd` protects us from `EBADF`, and any other reasonably
// anticipated `errno` value would end up interpreted as “assume it's not a
// terminal” anyway.
unsafe { c::isatty(borrowed_fd(fd)) != 0 }
}
#[cfg(all(feature = "alloc", feature = "procfs"))]
#[cfg(not(any(target_os = "fuchsia", target_os = "wasi")))]
pub(crate) fn ttyname(dirfd: BorrowedFd<'_>, buf: &mut [MaybeUninit<u8>]) -> io::Result<usize> {
unsafe {
// `ttyname_r` returns its error status rather than using `errno`.
match c::ttyname_r(borrowed_fd(dirfd), buf.as_mut_ptr().cast(), buf.len()) {
0 => Ok(CStr::from_ptr(buf.as_ptr().cast()).to_bytes().len()),
err => Err(io::Errno::from_raw_os_error(err)),
}
}
}