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//! linux_raw syscalls supporting `rustix::pipe`.
//!
//! # Safety
//!
//! See the `rustix::backend` module documentation for details.
#![allow(unsafe_code, clippy::undocumented_unsafe_blocks)]
use crate::backend::conv::{c_int, c_uint, opt_mut, pass_usize, ret, ret_usize, slice};
use crate::backend::{c, MAX_IOV};
use crate::fd::{BorrowedFd, OwnedFd};
use crate::io;
use crate::pipe::{IoSliceRaw, PipeFlags, SpliceFlags};
use core::cmp;
use core::mem::MaybeUninit;
use linux_raw_sys::general::{F_GETPIPE_SZ, F_SETPIPE_SZ};
#[inline]
pub(crate) fn pipe() -> io::Result<(OwnedFd, OwnedFd)> {
// aarch64 and risc64 omit `__NR_pipe`. On mips, `__NR_pipe` uses a special
// calling convention, but using it is not worth complicating our syscall
// wrapping infrastructure at this time.
#[cfg(any(
target_arch = "aarch64",
target_arch = "mips",
target_arch = "mips32r6",
target_arch = "mips64",
target_arch = "mips64r6",
target_arch = "riscv64",
))]
{
pipe_with(PipeFlags::empty())
}
#[cfg(not(any(
target_arch = "aarch64",
target_arch = "mips",
target_arch = "mips32r6",
target_arch = "mips64",
target_arch = "mips64r6",
target_arch = "riscv64",
)))]
unsafe {
let mut result = MaybeUninit::<[OwnedFd; 2]>::uninit();
ret(syscall!(__NR_pipe, &mut result))?;
let [p0, p1] = result.assume_init();
Ok((p0, p1))
}
}
#[inline]
pub(crate) fn pipe_with(flags: PipeFlags) -> io::Result<(OwnedFd, OwnedFd)> {
unsafe {
let mut result = MaybeUninit::<[OwnedFd; 2]>::uninit();
ret(syscall!(__NR_pipe2, &mut result, flags))?;
let [p0, p1] = result.assume_init();
Ok((p0, p1))
}
}
#[inline]
pub fn splice(
fd_in: BorrowedFd<'_>,
off_in: Option<&mut u64>,
fd_out: BorrowedFd<'_>,
off_out: Option<&mut u64>,
len: usize,
flags: SpliceFlags,
) -> io::Result<usize> {
unsafe {
ret_usize(syscall!(
__NR_splice,
fd_in,
opt_mut(off_in),
fd_out,
opt_mut(off_out),
pass_usize(len),
flags
))
}
}
#[inline]
pub unsafe fn vmsplice(
fd: BorrowedFd<'_>,
bufs: &[IoSliceRaw<'_>],
flags: SpliceFlags,
) -> io::Result<usize> {
let (bufs_addr, bufs_len) = slice(&bufs[..cmp::min(bufs.len(), MAX_IOV)]);
ret_usize(syscall!(__NR_vmsplice, fd, bufs_addr, bufs_len, flags))
}
#[inline]
pub fn tee(
fd_in: BorrowedFd<'_>,
fd_out: BorrowedFd<'_>,
len: usize,
flags: SpliceFlags,
) -> io::Result<usize> {
unsafe { ret_usize(syscall!(__NR_tee, fd_in, fd_out, pass_usize(len), flags)) }
}
#[inline]
pub(crate) fn fcntl_getpipe_sz(fd: BorrowedFd<'_>) -> io::Result<usize> {
#[cfg(target_pointer_width = "32")]
unsafe {
ret_usize(syscall_readonly!(__NR_fcntl64, fd, c_uint(F_GETPIPE_SZ)))
}
#[cfg(target_pointer_width = "64")]
unsafe {
ret_usize(syscall_readonly!(__NR_fcntl, fd, c_uint(F_GETPIPE_SZ)))
}
}
#[inline]
pub(crate) fn fcntl_setpipe_sz(fd: BorrowedFd<'_>, size: usize) -> io::Result<()> {
let size: c::c_int = size.try_into().map_err(|_| io::Errno::PERM)?;
#[cfg(target_pointer_width = "32")]
unsafe {
ret(syscall_readonly!(
__NR_fcntl64,
fd,
c_uint(F_SETPIPE_SZ),
c_int(size)
))
}
#[cfg(target_pointer_width = "64")]
unsafe {
ret(syscall_readonly!(
__NR_fcntl,
fd,
c_uint(F_SETPIPE_SZ),
c_int(size)
))
}
}