android: sets socket protect path from env var

leaf/src/lib.rs

@@ -333,9 +333,6 @@ pub struct StartOptions {
     // Enable auto reload, take effect only when "auto-reload" feature is enabled.
     #[cfg(feature = "auto-reload")]
     pub auto_reload: bool,
-    // The service path to protect outbound sockets on Android.
-    #[cfg(target_os = "android")]
-    pub socket_protect_path: Option<String>,
     // Tokio runtime options.
     pub runtime_opt: RuntimeOption,
 }
@@ -370,11 +367,6 @@ pub fn start(rt_id: RuntimeId, opts: StartOptions) -> Result<(), Error> {
     let rt = new_runtime(&opts.runtime_opt)?;
     let _g = rt.enter();
 
-    #[cfg(target_os = "android")]
-    if let Some(p) = opts.socket_protect_path.as_ref() {
-        rt.block_on(proxy::set_socket_protect_path(p.to_owned()));
-    }
-
     let mut tasks: Vec<Runner> = Vec::new();
     let mut runners = Vec::new();
 

leaf/src/option/mod.rs

@@ -131,6 +131,15 @@ lazy_static! {
         outbound_binds
     };
 
+    /// Sets the RPC service endpoint for protecting outbound sockets on Android to
+    /// avoid infinite loop. The `path` is treated as a Unix domain socket endpoint.
+    /// The RPC service simply listens for incoming connections, reads an int32 on
+    /// each connection, treats it as the file descriptor to protect, writes back 0
+    /// on success.
+    pub static ref SOCKET_PROTECT_PATH: String = {
+        get_env_var_or("SOCKET_PROTECT_PATH", "".to_string())
+    };
+
     pub static ref GATEWAY_MODE: bool = {
         get_env_var_or("GATEWAY_MODE", false)
     };

leaf/src/proxy/mod.rs

@@ -106,32 +106,18 @@ pub trait Color {
     fn color(&self) -> colored::Color;
 }
 
-#[cfg(target_os = "android")]
-lazy_static! {
-    static ref SOCKET_PROTECT_PATH: Mutex<Option<String>> = Mutex::new(None);
-}
-
 #[derive(Debug)]
 pub enum OutboundBind {
     Ip(SocketAddr),
     Interface(String),
 }
 
-// Sets the RPC service endpoint for protecting outbound sockets on Android to
-// avoid infinite loop. The `path` is treated as a Unix domain socket endpoint.
-// The RPC service simply listens for incoming connections, reads an int32 on
-// each connection, treats it as the file descriptor to protect, writes back 0
-// on success.
-#[cfg(target_os = "android")]
-pub async fn set_socket_protect_path(path: String) {
-    SOCKET_PROTECT_PATH.lock().await.replace(path);
-}
-
 #[cfg(target_os = "android")]
-async fn protect_socket<S: AsRawFd>(socket: S) -> io::Result<()> {
-    if let Some(path) = SOCKET_PROTECT_PATH.lock().await.as_ref() {
-        let mut stream = UnixStream::connect(path).await?;
-        stream.write_i32(socket.as_raw_fd() as i32).await?;
+async fn protect_socket(fd: RawFd) -> io::Result<()> {
+    // TODO Warns about empty protect path?
+    if !option::SOCKET_PROTECT_PATH.is_empty() {
+        let mut stream = UnixStream::connect(&*option::SOCKET_PROTECT_PATH).await?;
+        stream.write_i32(fd as i32).await?;
         if stream.read_i32().await? != 0 {
             return Err(io::Error::new(
                 io::ErrorKind::Other,
@@ -295,7 +281,7 @@ pub async fn new_udp_socket(indicator: &SocketAddr) -> io::Result<UdpSocket> {
     bind_socket(&socket, indicator).await?;
 
     #[cfg(target_os = "android")]
-    protect_socket(&socket).await?;
+    protect_socket(socket.as_raw_fd()).await?;
 
     UdpSocket::from_std(socket.into())
 }
@@ -326,7 +312,7 @@ async fn tcp_dial_task(dial_addr: SocketAddr) -> io::Result<(AnyStream, SocketAd
     bind_socket(&socket, &dial_addr).await?;
 
     #[cfg(target_os = "android")]
-    protect_socket(&socket).await?;
+    protect_socket(socket.as_raw_fd()).await?;
 
     trace!("tcp dialing {}", &dial_addr);
     let stream = timeout(

leaf/src/util.rs

@@ -24,8 +24,6 @@ fn get_start_options(
             config: crate::Config::File(config_path),
             #[cfg(feature = "auto-reload")]
             auto_reload,
-            #[cfg(target_os = "android")]
-            socket_protect_path: None,
             runtime_opt: crate::RuntimeOption::SingleThread,
         };
     }
@@ -34,17 +32,13 @@ fn get_start_options(
             config: crate::Config::File(config_path),
             #[cfg(feature = "auto-reload")]
             auto_reload,
-            #[cfg(target_os = "android")]
-            socket_protect_path: None,
             runtime_opt: crate::RuntimeOption::MultiThreadAuto(stack_size),
         };
     }
     crate::StartOptions {
         config: crate::Config::File(config_path),
         #[cfg(feature = "auto-reload")]
         auto_reload,
-        #[cfg(target_os = "android")]
-        socket_protect_path: None,
         runtime_opt: crate::RuntimeOption::MultiThread(threads, stack_size),
     }
 }