diff --git a/vnt/tun/src/android/mod.rs b/vnt/tun/src/android/mod.rs
index d1d3f1c..d9c7957 100644
--- a/vnt/tun/src/android/mod.rs
+++ b/vnt/tun/src/android/mod.rs
@@ -13,6 +13,11 @@ impl Device {
         Ok(Self { fd: Fd::new(fd)? })
     }
 }
+impl Device {
+    pub fn as_tun_fd(&self) ->&Fd{
+        &self.fd
+    }
+}
 impl IFace for Device {
     fn version(&self) -> io::Result<String> {
         Ok(String::new())
diff --git a/vnt/tun/src/macos/device.rs b/vnt/tun/src/macos/device.rs
index 5b971af..b423632 100644
--- a/vnt/tun/src/macos/device.rs
+++ b/vnt/tun/src/macos/device.rs
@@ -224,6 +224,11 @@ impl Device {
         }
     }
 }
+impl Device {
+    pub fn as_tun_fd(&self) ->&Fd{
+        &self.tun
+    }
+}
 
 impl IFace for Device {
     fn version(&self) -> io::Result<String> {
diff --git a/vnt/tun/src/unix/fd.rs b/vnt/tun/src/unix/fd.rs
index c377870..bdb0098 100644
--- a/vnt/tun/src/unix/fd.rs
+++ b/vnt/tun/src/unix/fd.rs
@@ -1,5 +1,6 @@
 use std::io;
 use std::os::fd::{AsRawFd, IntoRawFd, RawFd};
+use libc::{F_GETFL, F_SETFL, fcntl, O_NONBLOCK};
 
 pub struct Fd(pub RawFd);
 
@@ -10,6 +11,12 @@ impl Fd {
         }
         Ok(Fd(value))
     }
+    pub fn set_nonblock(&self) -> io::Result<()> {
+        match unsafe { fcntl(self.0, F_SETFL, fcntl(self.0, F_GETFL) | O_NONBLOCK) } {
+            0 => Ok(()),
+            _ => Err(io::Error::last_os_error()),
+        }
+    }
 }
 
 impl Fd {
@@ -51,6 +58,7 @@ impl IntoRawFd for Fd {
     }
 }
 
+#[cfg(not(target_os = "android"))]
 impl Drop for Fd {
     fn drop(&mut self) {
         unsafe {
diff --git a/vnt/tun/src/unix/mod.rs b/vnt/tun/src/unix/mod.rs
index 8d4537a..9d99dda 100644
--- a/vnt/tun/src/unix/mod.rs
+++ b/vnt/tun/src/unix/mod.rs
@@ -1,6 +1,7 @@
 mod fd;
 
 pub use fd::Fd;
+#[cfg(any(target_os = "macos", target_os = "linux"))]
 use std::process::Output;
 #[cfg(any(target_os = "macos", target_os = "linux"))]
 mod sockaddr;