| //! linux_raw syscalls supporting `rustix::termios`. |
| //! |
| //! # Safety |
| //! |
| //! See the `rustix::backend` module documentation for details. |
| #![allow(unsafe_code)] |
| #![allow(clippy::undocumented_unsafe_blocks)] |
| |
| use crate::backend::c; |
| use crate::backend::conv::{by_ref, c_uint, ret}; |
| use crate::fd::BorrowedFd; |
| use crate::io; |
| use crate::pid::Pid; |
| #[cfg(feature = "procfs")] |
| use crate::procfs; |
| use crate::termios::{ |
| Action, ControlModes, InputModes, LocalModes, OptionalActions, OutputModes, QueueSelector, |
| SpecialCodeIndex, Termios, Winsize, |
| }; |
| #[cfg(feature = "procfs")] |
| use crate::{ffi::CStr, fs::FileType, path::DecInt}; |
| use core::mem::MaybeUninit; |
| use linux_raw_sys::general::IBSHIFT; |
| use linux_raw_sys::ioctl::{ |
| TCFLSH, TCSBRK, TCXONC, TIOCEXCL, TIOCGPGRP, TIOCGSID, TIOCGWINSZ, TIOCNXCL, TIOCSPGRP, |
| TIOCSWINSZ, |
| }; |
| |
| #[inline] |
| pub(crate) fn tcgetwinsize(fd: BorrowedFd<'_>) -> io::Result<Winsize> { |
| unsafe { |
| let mut result = MaybeUninit::<Winsize>::uninit(); |
| ret(syscall!(__NR_ioctl, fd, c_uint(TIOCGWINSZ), &mut result))?; |
| Ok(result.assume_init()) |
| } |
| } |
| |
| #[inline] |
| pub(crate) fn tcgetattr(fd: BorrowedFd<'_>) -> io::Result<Termios> { |
| unsafe { |
| let mut result = MaybeUninit::<Termios>::uninit(); |
| ret(syscall!(__NR_ioctl, fd, c_uint(c::TCGETS2), &mut result))?; |
| Ok(result.assume_init()) |
| } |
| } |
| |
| #[inline] |
| pub(crate) fn tcgetpgrp(fd: BorrowedFd<'_>) -> io::Result<Pid> { |
| unsafe { |
| let mut result = MaybeUninit::<c::pid_t>::uninit(); |
| ret(syscall!(__NR_ioctl, fd, c_uint(TIOCGPGRP), &mut result))?; |
| let pid = result.assume_init(); |
| Ok(Pid::from_raw_unchecked(pid)) |
| } |
| } |
| |
| #[inline] |
| pub(crate) fn tcsetattr( |
| fd: BorrowedFd, |
| optional_actions: OptionalActions, |
| termios: &Termios, |
| ) -> io::Result<()> { |
| // Translate from `optional_actions` into an ioctl request code. On MIPS, |
| // `optional_actions` already has `TCGETS` added to it. |
| let request = linux_raw_sys::ioctl::TCSETS2 |
| + if cfg!(any( |
| target_arch = "mips", |
| target_arch = "mips32r6", |
| target_arch = "mips64", |
| target_arch = "mips64r6" |
| )) { |
| optional_actions as u32 - linux_raw_sys::ioctl::TCSETS |
| } else { |
| optional_actions as u32 |
| }; |
| unsafe { |
| ret(syscall_readonly!( |
| __NR_ioctl, |
| fd, |
| c_uint(request), |
| by_ref(termios) |
| )) |
| } |
| } |
| |
| #[inline] |
| pub(crate) fn tcsendbreak(fd: BorrowedFd) -> io::Result<()> { |
| unsafe { ret(syscall_readonly!(__NR_ioctl, fd, c_uint(TCSBRK), c_uint(0))) } |
| } |
| |
| #[inline] |
| pub(crate) fn tcdrain(fd: BorrowedFd) -> io::Result<()> { |
| unsafe { ret(syscall_readonly!(__NR_ioctl, fd, c_uint(TCSBRK), c_uint(1))) } |
| } |
| |
| #[inline] |
| pub(crate) fn tcflush(fd: BorrowedFd, queue_selector: QueueSelector) -> io::Result<()> { |
| unsafe { |
| ret(syscall_readonly!( |
| __NR_ioctl, |
| fd, |
| c_uint(TCFLSH), |
| c_uint(queue_selector as u32) |
| )) |
| } |
| } |
| |
| #[inline] |
| pub(crate) fn tcflow(fd: BorrowedFd, action: Action) -> io::Result<()> { |
| unsafe { |
| ret(syscall_readonly!( |
| __NR_ioctl, |
| fd, |
| c_uint(TCXONC), |
| c_uint(action as u32) |
| )) |
| } |
| } |
| |
| #[inline] |
| pub(crate) fn tcgetsid(fd: BorrowedFd) -> io::Result<Pid> { |
| unsafe { |
| let mut result = MaybeUninit::<c::pid_t>::uninit(); |
| ret(syscall!(__NR_ioctl, fd, c_uint(TIOCGSID), &mut result))?; |
| let pid = result.assume_init(); |
| Ok(Pid::from_raw_unchecked(pid)) |
| } |
| } |
| |
| #[inline] |
| pub(crate) fn tcsetwinsize(fd: BorrowedFd, winsize: Winsize) -> io::Result<()> { |
| unsafe { |
| ret(syscall!( |
| __NR_ioctl, |
| fd, |
| c_uint(TIOCSWINSZ), |
| by_ref(&winsize) |
| )) |
| } |
| } |
| |
| #[inline] |
| pub(crate) fn tcsetpgrp(fd: BorrowedFd<'_>, pid: Pid) -> io::Result<()> { |
| unsafe { ret(syscall!(__NR_ioctl, fd, c_uint(TIOCSPGRP), pid)) } |
| } |
| |
| #[inline] |
| pub(crate) fn ioctl_tiocexcl(fd: BorrowedFd<'_>) -> io::Result<()> { |
| unsafe { ret(syscall_readonly!(__NR_ioctl, fd, c_uint(TIOCEXCL))) } |
| } |
| |
| #[inline] |
| pub(crate) fn ioctl_tiocnxcl(fd: BorrowedFd<'_>) -> io::Result<()> { |
| unsafe { ret(syscall_readonly!(__NR_ioctl, fd, c_uint(TIOCNXCL))) } |
| } |
| |
| /// A wrapper around a conceptual `cfsetspeed` which handles an arbitrary |
| /// integer speed value. |
| #[inline] |
| pub(crate) fn set_speed(termios: &mut Termios, arbitrary_speed: u32) -> io::Result<()> { |
| let encoded_speed = crate::termios::speed::encode(arbitrary_speed).unwrap_or(c::BOTHER); |
| |
| 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 << IBSHIFT)); |
| |
| termios.input_speed = arbitrary_speed; |
| termios.output_speed = arbitrary_speed; |
| |
| Ok(()) |
| } |
| |
| /// A wrapper around a conceptual `cfsetospeed` which handles an arbitrary |
| /// integer speed value. |
| #[inline] |
| pub(crate) fn set_output_speed(termios: &mut Termios, arbitrary_speed: u32) -> io::Result<()> { |
| let encoded_speed = crate::termios::speed::encode(arbitrary_speed).unwrap_or(c::BOTHER); |
| |
| 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(()) |
| } |
| |
| /// A wrapper around a conceptual `cfsetispeed` which handles an arbitrary |
| /// integer speed value. |
| #[inline] |
| pub(crate) fn set_input_speed(termios: &mut Termios, arbitrary_speed: u32) -> io::Result<()> { |
| let encoded_speed = crate::termios::speed::encode(arbitrary_speed).unwrap_or(c::BOTHER); |
| |
| 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 << IBSHIFT); |
| |
| termios.input_speed = arbitrary_speed; |
| |
| Ok(()) |
| } |
| |
| #[inline] |
| pub(crate) fn cfmakeraw(termios: &mut Termios) { |
| // From the Linux [`cfmakeraw` manual page]: |
| // |
| // [`cfmakeraw` manual page]: https://man7.org/linux/man-pages/man3/cfmakeraw.3.html |
| termios.input_modes -= InputModes::IGNBRK |
| | InputModes::BRKINT |
| | InputModes::PARMRK |
| | InputModes::ISTRIP |
| | InputModes::INLCR |
| | InputModes::IGNCR |
| | InputModes::ICRNL |
| | InputModes::IXON; |
| termios.output_modes -= OutputModes::OPOST; |
| termios.local_modes -= LocalModes::ECHO |
| | LocalModes::ECHONL |
| | LocalModes::ICANON |
| | LocalModes::ISIG |
| | LocalModes::IEXTEN; |
| termios.control_modes -= ControlModes::CSIZE | ControlModes::PARENB; |
| termios.control_modes |= ControlModes::CS8; |
| |
| // Musl and glibc also do these: |
| termios.special_codes[SpecialCodeIndex::VMIN] = 1; |
| termios.special_codes[SpecialCodeIndex::VTIME] = 0; |
| } |
| |
| #[inline] |
| pub(crate) fn isatty(fd: BorrowedFd<'_>) -> bool { |
| // On error, Linux will return either `EINVAL` (2.6.32) or `ENOTTY` |
| // (otherwise), because we assume we're never passing an invalid |
| // file descriptor (which would get `EBADF`). Either way, an error |
| // means we don't have a tty. |
| tcgetwinsize(fd).is_ok() |
| } |
| |
| #[cfg(feature = "procfs")] |
| #[allow(unsafe_code)] |
| pub(crate) fn ttyname(fd: BorrowedFd<'_>, buf: &mut [MaybeUninit<u8>]) -> io::Result<usize> { |
| let fd_stat = crate::backend::fs::syscalls::fstat(fd)?; |
| |
| // Quick check: if `fd` isn't a character device, it's not a tty. |
| if FileType::from_raw_mode(fd_stat.st_mode) != FileType::CharacterDevice { |
| return Err(io::Errno::NOTTY); |
| } |
| |
| // Check that `fd` is really a tty. |
| tcgetwinsize(fd)?; |
| |
| // Get a fd to '/proc/self/fd'. |
| let proc_self_fd = procfs::proc_self_fd()?; |
| |
| // Gather the ttyname by reading the 'fd' file inside 'proc_self_fd'. |
| let r = crate::backend::fs::syscalls::readlinkat( |
| proc_self_fd, |
| DecInt::from_fd(fd).as_c_str(), |
| buf, |
| )?; |
| |
| // If the number of bytes is equal to the buffer length, truncation may |
| // have occurred. This check also ensures that we have enough space for |
| // adding a NUL terminator. |
| if r == buf.len() { |
| return Err(io::Errno::RANGE); |
| } |
| |
| // `readlinkat` returns the number of bytes placed in the buffer. |
| // NUL-terminate the string at that offset. |
| buf[r].write(b'\0'); |
| |
| // Check that the path we read refers to the same file as `fd`. |
| { |
| // SAFETY: We just wrote the NUL byte above |
| let path = unsafe { CStr::from_ptr(buf.as_ptr().cast()) }; |
| |
| let path_stat = crate::backend::fs::syscalls::stat(path)?; |
| if path_stat.st_dev != fd_stat.st_dev || path_stat.st_ino != fd_stat.st_ino { |
| return Err(io::Errno::NODEV); |
| } |
| } |
| |
| Ok(r) |
| } |