Files
rosenpass/util/src/mio/mio.rs
2024-12-16 22:29:01 +01:00

110 lines
4.0 KiB
Rust

use mio::net::{UnixListener, UnixStream};
use std::os::fd::{OwnedFd, RawFd};
use crate::{
fd::{claim_fd, claim_fd_inplace},
result::OkExt,
};
/// Module containing I/O interest flags for Unix operations (see also: [mio::Interest])
pub mod interest {
use mio::Interest;
/// Interest flag indicating readability
pub const R: Interest = Interest::READABLE;
/// Interest flag indicating writability
pub const W: Interest = Interest::WRITABLE;
/// Interest flag indicating both readability and writability
pub const RW: Interest = R.add(W);
}
/// Extension trait providing additional functionality for a Unix listener
///
/// # Example
///
/// ```rust
/// use mio::net::{UnixListener, UnixStream};
/// use rosenpass_util::mio::{UnixListenerExt, UnixStreamExt};
///
/// use std::os::unix::io::{AsRawFd, IntoRawFd, RawFd};
/// use std::path::Path;
///
/// // This would be the UDS created by an external source
/// let socket_path = "/tmp/rp_mio_uds_test_socket";
/// if Path::new(socket_path).exists() {
/// std::fs::remove_file(socket_path).expect("Failed to remove existing socket");
/// }
///
/// // An extended MIO listener can then be created by claiming the existing socket
/// // Note that the original descriptor is not reused, but copied before claiming it here
/// let listener = UnixListener::bind(socket_path).unwrap();
/// let listener_fd: RawFd = listener.as_raw_fd();
/// let ext_listener = <UnixListener as UnixListenerExt>
/// ::claim_fd(listener_fd).expect("Failed to claim_fd for ext_listener socket");
///
/// // Similarly, "client" connections can be established by claiming existing sockets
/// // Note that in this case, the file descriptor will be reused (safety implications!)
/// let stream = UnixStream::connect(socket_path).unwrap();
/// let stream_fd = stream.into_raw_fd();
/// let ext_stream = <UnixStream as UnixStreamExt>
/// ::claim_fd_inplace(stream_fd).expect("Failed to claim_fd_inplace for ext_stream socket");
///
/// // Handle accepted connections...
/// ext_listener.accept().expect("Failed to accept incoming connection");
///
/// // Send or receive messages ...
///
/// // Cleanup, shutdown etc. goes here ...
/// std::fs::remove_file(socket_path).unwrap();
/// ```
pub trait UnixListenerExt: Sized {
/// Creates a new Unix listener by claiming ownership of a raw file descriptor
/// (see [fd::claim_fd](crate::fd::claim_fd))
fn claim_fd(fd: RawFd) -> anyhow::Result<Self>;
}
impl UnixListenerExt for UnixListener {
fn claim_fd(fd: RawFd) -> anyhow::Result<Self> {
use std::os::unix::net::UnixListener as StdUnixListener;
let sock = StdUnixListener::from(claim_fd(fd)?);
sock.set_nonblocking(true)?;
Ok(UnixListener::from_std(sock))
}
}
/// Extension trait providing additional functionality for a Unix stream
pub trait UnixStreamExt: Sized {
/// Creates a new Unix stream from an owned file descriptor
fn from_fd(fd: OwnedFd) -> anyhow::Result<Self>;
/// Claims ownership of a raw file descriptor and creates a new Unix stream
/// (see [fd::claim_fd](crate::fd::claim_fd))
fn claim_fd(fd: RawFd) -> anyhow::Result<Self>;
/// Claims ownership of a raw file descriptor in place and creates a new Unix stream
/// (see [fd::claim_fd_inplace](crate::fd::claim_fd_inplace))
fn claim_fd_inplace(fd: RawFd) -> anyhow::Result<Self>;
}
impl UnixStreamExt for UnixStream {
fn from_fd(fd: OwnedFd) -> anyhow::Result<Self> {
use std::os::unix::net::UnixStream as StdUnixStream;
#[cfg(target_os = "linux")] // TODO: We should support this on other plattforms
crate::fd::GetUnixSocketType::demand_unix_stream_socket(&fd)?;
let sock = StdUnixStream::from(fd);
sock.set_nonblocking(true)?;
UnixStream::from_std(sock).ok()
}
fn claim_fd(fd: RawFd) -> anyhow::Result<Self> {
Self::from_fd(claim_fd(fd)?)
}
fn claim_fd_inplace(fd: RawFd) -> anyhow::Result<Self> {
Self::from_fd(claim_fd_inplace(fd)?)
}
}