Make close_fd_on_drop configurable (#132)

src/args.rs

@@ -23,9 +23,17 @@ pub struct Args {
     pub tun: Option<String>,
 
     /// File descriptor of the tun interface
+    #[cfg(unix)]
     #[arg(long, value_name = "fd", conflicts_with = "tun")]
     pub tun_fd: Option<i32>,
 
+    /// Set whether to close the received raw file descriptor on drop or not.
+    /// This setting is passed to the tun2 crate.
+    /// See [tun2::Configuration::close_fd_on_drop].
+    #[cfg(unix)]
+    #[arg(long, conflicts_with = "tun")]
+    pub close_fd_on_drop: Option<bool>,
+
     /// Create a tun interface in a newly created unprivileged namespace
     /// while maintaining proxy connectivity via the global network namespace.
     #[cfg(target_os = "linux")]
@@ -104,7 +112,10 @@ impl Default for Args {
         Args {
             proxy: ArgProxy::default(),
             tun: None,
+            #[cfg(unix)]
             tun_fd: None,
+            #[cfg(unix)]
+            close_fd_on_drop: None,
             #[cfg(target_os = "linux")]
             unshare: false,
             #[cfg(target_os = "linux")]
@@ -148,11 +159,18 @@ impl Args {
         self
     }
 
+    #[cfg(unix)]
     pub fn tun_fd(&mut self, tun_fd: Option<i32>) -> &mut Self {
         self.tun_fd = tun_fd;
         self
     }
 
+    #[cfg(unix)]
+    pub fn close_fd_on_drop(&mut self, close_fd_on_drop: bool) -> &mut Self {
+        self.close_fd_on_drop = Some(close_fd_on_drop);
+        self
+    }
+
     pub fn verbosity(&mut self, verbosity: ArgVerbosity) -> &mut Self {
         self.verbosity = verbosity;
         self

src/desktop_api.rs

@@ -86,11 +86,19 @@ pub async fn desktop_run_async(args: Args, shutdown_token: tokio_util::sync::Can
     let mut tun_config = tun2::Configuration::default();
     tun_config.address(TUN_IPV4).netmask(TUN_NETMASK).mtu(MTU).up();
     tun_config.destination(TUN_GATEWAY);
-    if let Some(tun_fd) = args.tun_fd {
-        tun_config.raw_fd(tun_fd);
+    #[cfg(unix)]
+    if let Some(fd) = args.tun_fd {
+        tun_config.raw_fd(fd);
+        if let Some(v) = args.close_fd_on_drop {
+            tun_config.close_fd_on_drop(v);
+        };
     } else if let Some(ref tun) = args.tun {
         tun_config.tun_name(tun);
     }
+    #[cfg(windows)]
+    if let Some(ref tun) = args.tun {
+        tun_config.tun_name(tun);
+    }
 
     #[cfg(target_os = "linux")]
     tun_config.platform_config(|cfg| {

src/mobile_api.rs

@@ -33,6 +33,9 @@ pub fn mobile_run(args: Args, tun_mtu: u16, _packet_information: bool) -> c_int
         #[cfg(unix)]
         if let Some(fd) = args.tun_fd {
             config.raw_fd(fd);
+            if let Some(v) = args.close_fd_on_drop {
+                config.close_fd_on_drop(v);
+            };
         } else if let Some(ref tun) = args.tun {
             config.tun_name(tun);
         }