[Lib] Add the implementation of AsFd

Signed-off-by: csh <[email protected]>

src/lib.rs

@@ -8,7 +8,7 @@ pub use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, Shutdown, SocketAddr};
 use std::{
     io::{self, Read, Write},
     net::{SocketAddrV4, SocketAddrV6},
-    os::wasi::prelude::{AsRawFd, FromRawFd, IntoRawFd},
+    os::fd::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd},
 };
 
 #[derive(Debug)]
@@ -28,6 +28,12 @@ impl AsMut<socket::Socket> for TcpStream {
     }
 }
 
+impl AsFd for TcpStream {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        unsafe { BorrowedFd::borrow_raw(self.as_raw_fd()) }
+    }
+}
+
 #[derive(Debug)]
 pub struct TcpListener {
     s: socket::Socket,
@@ -47,6 +53,12 @@ impl AsMut<socket::Socket> for TcpListener {
     }
 }
 
+impl AsFd for TcpListener {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        unsafe { BorrowedFd::borrow_raw(self.as_raw_fd()) }
+    }
+}
+
 #[derive(Debug)]
 pub struct UdpSocket {
     s: socket::Socket,
@@ -64,6 +76,12 @@ impl AsMut<socket::Socket> for UdpSocket {
     }
 }
 
+impl AsFd for UdpSocket {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        unsafe { BorrowedFd::borrow_raw(self.as_raw_fd()) }
+    }
+}
+
 impl TcpStream {
     /// Create TCP socket and connect to the given address.
     ///

src/socket.rs

@@ -1,7 +1,7 @@
 use std::io;
 use std::mem::MaybeUninit;
 use std::net::{Ipv4Addr, Ipv6Addr, Shutdown, SocketAddr, SocketAddrV4, SocketAddrV6};
-use std::os::wasi::prelude::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
+use std::os::fd::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, RawFd};
 
 #[derive(Copy, Clone, Debug)]
 #[repr(u8, align(1))]
@@ -1307,6 +1307,12 @@ impl AsRawFd for Socket {
     }
 }
 
+impl AsFd for Socket {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        unsafe { BorrowedFd::borrow_raw(self.as_raw_fd()) }
+    }
+}
+
 impl IntoRawFd for Socket {
     fn into_raw_fd(self) -> RawFd {
         let fd = self.fd;