chore(API): Infrastructure to use endpoints with fd. passing

util/src/mio/mio.rs

@@ -0,0 +1,39 @@
+use mio::net::{UnixListener, UnixStream};
+use rustix::fd::RawFd;
+
+use crate::fd::claim_fd;
+
+pub mod interest {
+    use mio::Interest;
+    pub const R: Interest = Interest::READABLE;
+    pub const W: Interest = Interest::WRITABLE;
+    pub const RW: Interest = R.add(W);
+}
+
+pub trait UnixListenerExt: Sized {
+    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))
+    }
+}
+
+pub trait UnixStreamExt: Sized {
+    fn claim_fd(fd: RawFd) -> anyhow::Result<Self>;
+}
+
+impl UnixStreamExt for UnixStream {
+    fn claim_fd(fd: RawFd) -> anyhow::Result<Self> {
+        use std::os::unix::net::UnixStream as StdUnixStream;
+
+        let sock = StdUnixStream::from(claim_fd(fd)?);
+        sock.set_nonblocking(true)?;
+        Ok(UnixStream::from_std(sock))
+    }
+}