integrate to android

Cargo.toml

@@ -24,6 +24,10 @@ smoltcp = { version = "0.9", git = "https://github.com/blechschmidt/smoltcp", br
 thiserror = "1.0"
 url = "2.3"
 
+[target.'cfg(target_os="android")'.dependencies]
+android_logger = "0.13"
+jni = { version = "0.21", default-features = false }
+
 [dev-dependencies]
 ctor = "0.1"
 reqwest = { version = "0.11", features = ["blocking", "json"] }

src/android.rs

@@ -0,0 +1,74 @@
+#![cfg(target_os = "android")]
+
+use crate::{error::Error, main_entry, shutdown, NetworkInterface, Options, Proxy};
+use jni::{
+    objects::{JClass, JString},
+    sys::{jboolean, jint},
+    JNIEnv,
+};
+
+/// # Safety
+///
+/// Running tun2proxy
+#[no_mangle]
+pub unsafe extern "C" fn Java_com_github_shadowsocks_bg_Tun2proxy_run(
+    mut env: JNIEnv,
+    _clazz: JClass,
+    proxy_url: JString,
+    tun_fd: jint,
+    tun_mtu: jint,
+    verbose: jboolean,
+) -> jint {
+    let log_level = if verbose != 0 { "trace" } else { "info" };
+    let filter_str = &format!("off,tun2proxy={log_level}");
+    let filter = android_logger::FilterBuilder::new()
+        .parse(filter_str)
+        .build();
+    android_logger::init_once(
+        android_logger::Config::default()
+            .with_tag("tun2proxy")
+            .with_max_level(log::LevelFilter::Trace)
+            .with_filter(filter),
+    );
+
+    let mut block = || -> Result<(), Error> {
+        let proxy_url = get_java_string(&mut env, &proxy_url)?;
+        let proxy = Proxy::from_url(proxy_url)?;
+
+        let addr = proxy.addr;
+        let proxy_type = proxy.proxy_type;
+        log::info!("Proxy {proxy_type} server: {addr}");
+
+        let options = Options::new().with_virtual_dns().with_mtu(tun_mtu as usize);
+
+        let interface = NetworkInterface::Fd(tun_fd);
+        _ = main_entry(&interface, &proxy, options)?;
+        Ok::<(), Error>(())
+    };
+    if let Err(error) = block() {
+        log::error!("failed to run tun2proxy with error: {:?}", error);
+    }
+    0
+}
+
+/// # Safety
+///
+/// Shutdown tun2proxy
+#[no_mangle]
+pub unsafe extern "C" fn Java_com_github_shadowsocks_bg_Tun2proxy_stop(
+    _env: JNIEnv,
+    _clazz: JClass,
+) -> jint {
+    if let Err(e) = shutdown() {
+        log::error!("failed to shutdown tun2proxy with error: {:?}", e);
+        1
+    } else {
+        0
+    }
+}
+
+unsafe fn get_java_string<'a>(env: &'a mut JNIEnv, string: &'a JString) -> Result<&'a str, Error> {
+    let str_ptr = env.get_string(string)?.as_ptr();
+    let s: &str = std::ffi::CStr::from_ptr(str_ptr).to_str()?;
+    Ok(s)
+}

src/error.rs

@@ -27,6 +27,13 @@ pub enum Error {
     #[error("smoltcp::socket::tcp::SendError {0:?}")]
     Send(#[from] smoltcp::socket::tcp::SendError),
 
+    #[error("std::str::Utf8Error {0:?}")]
+    Utf8(#[from] std::str::Utf8Error),
+
+    #[cfg(target_os = "android")]
+    #[error("jni::errors::Error {0:?}")]
+    Jni(#[from] jni::errors::Error),
+
     #[error("&str {0}")]
     Str(String),
 

src/lib.rs

@@ -3,6 +3,7 @@ use crate::socks5::SocksVersion;
 use crate::{http::HttpManager, socks5::SocksManager, tun2proxy::TunToProxy};
 use std::net::{SocketAddr, ToSocketAddrs};
 
+mod android;
 pub mod error;
 mod http;
 pub mod setup;