Whole bunch of async code and preparation to fork.

[pve-lxc-syscalld.git] / src / pidfd.rs

//! pidfd helper functionality

use std::ffi::CString;
use std::io;
use std::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};

use crate::nsfd::{ns_type, NsFd};
use crate::tools::Fd;
use crate::{file_descriptor_type, libc_try};

file_descriptor_type!(PidFd);

impl PidFd {
    pub fn open(pid: libc::pid_t) -> io::Result<Self> {
        let path = CString::new(format!("/proc/{}", pid)).unwrap();

        let fd =
            libc_try!(unsafe { libc::open(path.as_ptr(), libc::O_DIRECTORY | libc::O_CLOEXEC) });

        Ok(Self(fd))
    }

    pub fn mount_namespace(&self) -> io::Result<NsFd<ns_type::Mount>> {
        NsFd::openat(self.0, "ns/mnt")
    }

    pub fn cgroup_namespace(&self) -> io::Result<NsFd<ns_type::Cgroup>> {
        NsFd::openat(self.0, "ns/cgroup")
    }

    pub fn user_namespace(&self) -> io::Result<NsFd<ns_type::User>> {
        NsFd::openat(self.0, "ns/user")
    }

    pub fn cwd_fd(&self) -> io::Result<Fd> {
        Ok(Fd(libc_try!(unsafe {
            libc::openat(
                self.as_raw_fd(),
                b"cwd".as_ptr() as *const _,
                libc::O_DIRECTORY,
            )
        })))
    }
}