Files
RedBear-OS/src/header/sys_uio/mod.rs
T
2026-05-06 08:57:33 +01:00

92 lines
2.5 KiB
Rust

//! `sys/uio.h` implementation.
//!
//! See <https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/sys_uio.h.html>.
use core::slice;
use crate::{
header::{errno, unistd},
platform::{
self,
types::{c_int, c_void, off_t, ssize_t},
},
};
pub use crate::header::bits_iovec::{gather, iovec, scatter};
pub const IOV_MAX: c_int = 1024;
/// Non-POSIX, see <https://man7.org/linux/man-pages/man2/readv.2.html>.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn preadv(
fd: c_int,
iov: *const iovec,
iovcnt: c_int,
offset: off_t,
) -> ssize_t {
if !(0..=IOV_MAX).contains(&iovcnt) {
platform::ERRNO.set(errno::EINVAL);
return -1;
}
let iovs = unsafe { slice::from_raw_parts(iov, iovcnt as usize) };
let mut vec = unsafe { gather(iovs) };
let ret = unsafe { unistd::pread(fd, vec.as_mut_ptr().cast::<c_void>(), vec.len(), offset) };
unsafe { scatter(iovs, vec) };
ret
}
/// Non-POSIX, see <https://man7.org/linux/man-pages/man2/readv.2.html>.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn pwritev(
fd: c_int,
iov: *const iovec,
iovcnt: c_int,
offset: off_t,
) -> ssize_t {
if !(0..=IOV_MAX).contains(&iovcnt) {
platform::ERRNO.set(errno::EINVAL);
return -1;
}
let iovs = unsafe { slice::from_raw_parts(iov, iovcnt as usize) };
let vec = unsafe { gather(iovs) };
unsafe { unistd::pwrite(fd, vec.as_ptr().cast::<c_void>(), vec.len(), offset) }
}
/// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/readv.html>.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn readv(fd: c_int, iov: *const iovec, iovcnt: c_int) -> ssize_t {
if !(0..=IOV_MAX).contains(&iovcnt) {
platform::ERRNO.set(errno::EINVAL);
return -1;
}
let iovs = unsafe { slice::from_raw_parts(iov, iovcnt as usize) };
let mut vec = unsafe { gather(iovs) };
let ret = unsafe { unistd::read(fd, vec.as_mut_ptr().cast::<c_void>(), vec.len()) };
unsafe { scatter(iovs, vec) };
ret
}
/// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/writev.html>.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn writev(fd: c_int, iov: *const iovec, iovcnt: c_int) -> ssize_t {
if !(0..=IOV_MAX).contains(&iovcnt) {
platform::ERRNO.set(errno::EINVAL);
return -1;
}
let iovs = unsafe { slice::from_raw_parts(iov, iovcnt as usize) };
let vec = unsafe { gather(iovs) };
unsafe { unistd::write(fd, vec.as_ptr().cast::<c_void>(), vec.len()) }
}