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use crate::ffi::CStr;
use crate::backend::fs::syscalls::{open, unlink};
use crate::backend::fs::types::{Mode, OFlags};
use crate::fd::OwnedFd;
use crate::io;
use crate::shm::ShmOFlags;
const NAME_MAX: usize = 255;
const SHM_DIR: &[u8] = b"/dev/shm/";
fn get_shm_name(name: &CStr) -> io::Result<([u8; NAME_MAX + SHM_DIR.len() + 1], usize)> {
let name = name.to_bytes();
if name.len() > NAME_MAX {
return Err(io::Errno::NAMETOOLONG);
}
let num_slashes = name.iter().take_while(|x| **x == b'/').count();
let after_slashes = &name[num_slashes..];
if after_slashes.is_empty()
|| after_slashes == b"."
|| after_slashes == b".."
|| after_slashes.contains(&b'/')
{
return Err(io::Errno::INVAL);
}
let mut path = [0; NAME_MAX + SHM_DIR.len() + 1];
path[..SHM_DIR.len()].copy_from_slice(SHM_DIR);
path[SHM_DIR.len()..SHM_DIR.len() + name.len()].copy_from_slice(name);
Ok((path, SHM_DIR.len() + name.len() + 1))
}
pub(crate) fn shm_open(name: &CStr, oflags: ShmOFlags, mode: Mode) -> io::Result<OwnedFd> {
let (path, len) = get_shm_name(name)?;
open(
CStr::from_bytes_with_nul(&path[..len]).unwrap(),
OFlags::from_bits(oflags.bits()).unwrap() | OFlags::CLOEXEC,
mode,
)
}
pub(crate) fn shm_unlink(name: &CStr) -> io::Result<()> {
let (path, len) = get_shm_name(name)?;
unlink(CStr::from_bytes_with_nul(&path[..len]).unwrap())
}