Bump version 0.7.8

.github/workflows/auto-merge.yaml

@@ -15,6 +15,6 @@ jobs:
       - name: Auto approve pull request, then squash and merge
         uses: ahmadnassri/action-dependabot-auto-merge@v2
         with:
-          target: minor
+          # target: minor
           # here `PAT_REPO_ADMIN` is a user's passkey provided by github.
           github-token: ${{ secrets.PAT_REPO_ADMIN }}

.github/workflows/publish-exe.yml

@@ -34,7 +34,7 @@ jobs:
 
         include:
           - target: x86_64-unknown-linux-gnu
-            host_os: ubuntu-latest
+            host_os: ubuntu-22.04
           - target: x86_64-unknown-linux-musl
             host_os: ubuntu-latest
           - target: i686-unknown-linux-musl
@@ -73,7 +73,7 @@ jobs:
             rustup target add ${{ matrix.target }}
           fi
           cargo install cbindgen
-          if [[ "${{ matrix.host_os }}" == "ubuntu-latest" ]]; then
+          if [[ "${{ contains(matrix.host_os, 'ubuntu') }}" == "true" && "${{ matrix.host_os }}" != "ubuntu-22.04" ]]; then
             sudo .github/workflows/install-cross.sh
           fi
 
@@ -81,7 +81,7 @@ jobs:
         if: ${{ !cancelled() }}
         shell: bash
         run: |
-          if [[ "${{ matrix.host_os }}" == "ubuntu-latest" ]]; then
+          if [[ "${{ contains(matrix.host_os, 'ubuntu') }}" == "true" && "${{ matrix.host_os }}" != "ubuntu-22.04" ]]; then
             cross build --all-features --release --target ${{ matrix.target }}
           else
             if [[ "${{ matrix.target }}" == "x86_64-win7-windows-msvc" || "${{ matrix.target }}" == "i686-win7-windows-msvc" ]]; then
@@ -105,7 +105,7 @@ jobs:
               ./build-apple.sh
               zip -r mypubdir4/tun2proxy-apple-xcframework.zip ./tun2proxy.xcframework/
             fi
-          elif [[ "${{ matrix.host_os }}" == "ubuntu-latest" ]]; then
+          elif [[ "${{ contains(matrix.host_os, 'ubuntu') }}" == "true" ]]; then
             zip -j mypubdir4/tun2proxy-${{ matrix.target }}.zip target/${{ matrix.target }}/release/tun2proxy-bin target/${{ matrix.target }}/release/udpgw-server README.md target/tun2proxy.h target/${{ matrix.target }}/release/libtun2proxy.so
             if [[ "${{ matrix.target }}" == "x86_64-unknown-linux-gnu" ]]; then
               ./build-android.sh

.github/workflows/rust.yml

@@ -77,6 +77,7 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+    - uses: dtolnay/rust-toolchain@stable
     - name: Install cargo lipo and rust compiler for ios target
       if: ${{ !cancelled() }}
       run: |

Cargo.toml

@@ -1,14 +1,14 @@
 [package]
 name = "tun2proxy"
-version = "0.7.2"
-edition = "2021"
+version = "0.7.8"
+edition = "2024"
 license = "MIT"
 repository = "https://github.com/tun2proxy/tun2proxy"
 homepage = "https://github.com/tun2proxy/tun2proxy"
 authors = ["B. Blechschmidt", "ssrlive"]
 description = "Tunnel interface to proxy"
 readme = "README.md"
-rust-version = "1.80"
+rust-version = "1.85"
 
 [lib]
 crate-type = ["staticlib", "cdylib", "lib"]
@@ -36,12 +36,13 @@ digest_auth = "0.3"
 dotenvy = "0.15"
 env_logger = "0.11"
 hashlink = "0.10"
-hickory-proto = "0.24"
+hickory-proto = "0.25"
 httparse = "1"
-ipstack = { version = "0.1" }
+ipstack = { version = "0.3", git = "https://github.com/ssrlive/ipstack.git", rev = "53c648e" }
 log = { version = "0.4", features = ["std"] }
 mimalloc = { version = "0.1", default-features = false, optional = true }
 percent-encoding = "2"
+shlex = "1.3.0"
 socks5-impl = { version = "0.6", default-features = false, features = [
     "tokio",
 ] }
@@ -55,14 +56,15 @@ unicase = "2"
 url = "2"
 
 [build-dependencies]
+chrono = "0.4"
 serde_json = "1"
 
 [target.'cfg(target_os="linux")'.dependencies]
 serde = { version = "1", features = ["derive"] }
-bincode = "1"
+bincode = "2"
 
 [target.'cfg(target_os="android")'.dependencies]
-android_logger = "0.14"
+android_logger = "0.15"
 jni = { version = "0.21", default-features = false }
 
 [target.'cfg(unix)'.dependencies]
@@ -74,7 +76,7 @@ nix = { version = "0.29", default-features = false, features = [
 ] }
 
 [target.'cfg(target_os = "windows")'.dependencies]
-windows-service = "0.7"
+windows-service = "0.8"
 
-[profile.release]
-strip = "symbols"
+# [profile.release]
+# strip = "symbols"

build.rs

@@ -1,4 +1,13 @@
 fn main() -> Result<(), Box<dyn std::error::Error>> {
+    if let Ok(git_hash) = get_git_hash() {
+        // Set the environment variables
+        println!("cargo:rustc-env=GIT_HASH={}", git_hash.trim());
+    }
+
+    // Get the build time
+    let build_time = chrono::Utc::now().format("%Y-%m-%d %H:%M:%S").to_string();
+    println!("cargo:rustc-env=BUILD_TIME={}", build_time);
+
     #[cfg(target_os = "windows")]
     if let Ok(cargo_target_dir) = get_cargo_target_dir() {
         let mut f = std::fs::File::create(cargo_target_dir.join("build.log"))?;
@@ -85,3 +94,10 @@ fn get_crate_dir(crate_name: &str) -> Result<std::path::PathBuf, Box<dyn std::er
     }
     Ok(crate_dir.ok_or("crate_dir")?)
 }
+
+fn get_git_hash() -> std::io::Result<String> {
+    use std::process::Command;
+    let git_hash = Command::new("git").args(["rev-parse", "--short", "HEAD"]).output()?.stdout;
+    let git_hash = String::from_utf8(git_hash).map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
+    Ok(git_hash)
+}

src/android.rs

@@ -1,14 +1,14 @@
 #![cfg(target_os = "android")]
 
 use crate::{
+    Args,
     args::ArgProxy,
     error::{Error, Result},
-    Args,
 };
 use jni::{
+    JNIEnv,
     objects::{JClass, JString},
     sys::{jboolean, jchar, jint},
-    JNIEnv,
 };
 
 /// # Safety
@@ -21,7 +21,7 @@ use jni::{
 /// - tun_mtu: the tun mtu
 /// - dns_strategy: the dns strategy, see ArgDns enum
 /// - verbosity: the verbosity level, see ArgVerbosity enum
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn Java_com_github_shadowsocks_bg_Tun2proxy_run(
     mut env: JNIEnv,
     _clazz: JClass,
@@ -58,7 +58,7 @@ pub unsafe extern "C" fn Java_com_github_shadowsocks_bg_Tun2proxy_run(
 /// # Safety
 ///
 /// Shutdown tun2proxy
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn Java_com_github_shadowsocks_bg_Tun2proxy_stop(_env: JNIEnv, _: JClass) -> jint {
     crate::general_api::tun2proxy_stop_internal()
 }

src/args.rs

@@ -9,7 +9,7 @@ use std::net::{IpAddr, SocketAddr, ToSocketAddrs};
 use std::str::FromStr;
 
 #[derive(Debug, Clone, clap::Parser)]
-#[command(author, version, about = "Tunnel interface to proxy.", long_about = None)]
+#[command(author, version = version_info(), about = "Tunnel interface to proxy.", long_about = None)]
 pub struct Args {
     /// Proxy URL in the form proto://[username[:password]@]host:port,
     /// where proto is one of socks4, socks5, http.
@@ -127,6 +127,10 @@ pub struct Args {
     pub udpgw_keepalive: Option<u64>,
 }
 
+fn version_info() -> &'static str {
+    concat!(env!("CARGO_PKG_VERSION"), " (", env!("GIT_HASH"), " ", env!("BUILD_TIME"), ")")
+}
+
 fn validate_tun(p: &str) -> Result<String> {
     #[cfg(target_os = "macos")]
     if p.len() <= 4 || &p[..4] != "utun" {

src/bin/main.rs

@@ -1,5 +1,4 @@
-use tun::DEFAULT_MTU as MTU;
-use tun2proxy::{Args, BoxError};
+use tun2proxy::{ArgVerbosity, Args, BoxError};
 
 fn main() -> Result<(), BoxError> {
     dotenvy::dotenv().ok();
@@ -29,11 +28,16 @@ fn main() -> Result<(), BoxError> {
 }
 
 async fn main_async(args: Args) -> Result<(), BoxError> {
-    let default = format!("{:?},hickory_proto=warn", args.verbosity);
+    let ipstack = match args.verbosity {
+        ArgVerbosity::Trace => ArgVerbosity::Debug,
+        _ => args.verbosity,
+    };
+    let default = format!("{:?},hickory_proto=warn,ipstack={:?}", args.verbosity, ipstack);
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or(default)).init();
 
     let shutdown_token = tokio_util::sync::CancellationToken::new();
     let main_loop_handle = tokio::spawn({
+        let args = args.clone();
         let shutdown_token = shutdown_token.clone();
         async move {
             #[cfg(target_os = "linux")]
@@ -41,18 +45,20 @@ async fn main_async(args: Args) -> Result<(), BoxError> {
                 if let Err(err) = namespace_proxy_main(args, shutdown_token).await {
                     log::error!("namespace proxy error: {}", err);
                 }
-                return;
+                return Ok(0);
             }
 
             unsafe extern "C" fn traffic_cb(status: *const tun2proxy::TrafficStatus, _: *mut std::ffi::c_void) {
-                let status = &*status;
+                let status = unsafe { &*status };
                 log::debug!("Traffic: ▲ {} : ▼ {}", status.tx, status.rx);
             }
             unsafe { tun2proxy::tun2proxy_set_traffic_status_callback(1, Some(traffic_cb), std::ptr::null_mut()) };
 
-            if let Err(err) = tun2proxy::general_run_async(args, MTU, false, shutdown_token).await {
-                log::error!("main loop error: {}", err);
+            let ret = tun2proxy::general_run_async(args, tun::DEFAULT_MTU, cfg!(target_os = "macos"), shutdown_token).await;
+            if let Err(err) = &ret {
+                log::error!("main loop error: {err}");
             }
+            ret
         }
     });
 
@@ -65,13 +71,19 @@ async fn main_async(args: Args) -> Result<(), BoxError> {
     })
     .await;
 
-    main_loop_handle.await?;
+    let tasks = main_loop_handle.await??;
 
     if ctrlc_fired.load(std::sync::atomic::Ordering::SeqCst) {
         log::info!("Ctrl-C fired, waiting the handler to finish...");
         ctrlc_handel.await.map_err(|err| err.to_string())?;
     }
 
+    if args.exit_on_fatal_error && tasks >= args.max_sessions {
+        // Because `main_async` function perhaps stuck in `await` state, so we need to exit the process forcefully
+        log::info!("Internal fatal error, max sessions reached ({tasks}/{})", args.max_sessions);
+        std::process::exit(-1);
+    }
+
     Ok(())
 }
 
@@ -80,7 +92,7 @@ async fn namespace_proxy_main(
     _args: Args,
     _shutdown_token: tokio_util::sync::CancellationToken,
 ) -> Result<std::process::ExitStatus, tun2proxy::Error> {
-    use nix::fcntl::{open, OFlag};
+    use nix::fcntl::{OFlag, open};
     use nix::sys::stat::Mode;
     use std::os::fd::AsRawFd;
 

src/bin/udpgw_server.rs

@@ -3,14 +3,14 @@ use std::net::SocketAddr;
 use tokio::{
     io::AsyncWriteExt,
     net::{
-        tcp::{ReadHalf, WriteHalf},
         UdpSocket,
+        tcp::{ReadHalf, WriteHalf},
     },
     sync::mpsc::{Receiver, Sender},
 };
 use tun2proxy::{
-    udpgw::{Packet, UdpFlag},
     ArgVerbosity, BoxError, Error, Result,
+    udpgw::{Packet, UdpFlag},
 };
 
 pub(crate) const CLIENT_DISCONNECT_TIMEOUT: tokio::time::Duration = std::time::Duration::from_secs(60);

src/dns.rs

@@ -1,21 +1,16 @@
 use hickory_proto::{
     op::{Message, MessageType, ResponseCode},
-    rr::{record_type::RecordType, Name, RData, Record},
+    rr::{
+        Name, RData, Record,
+        rdata::{A, AAAA},
+    },
 };
 use std::{net::IpAddr, str::FromStr};
 
 pub fn build_dns_response(mut request: Message, domain: &str, ip: IpAddr, ttl: u32) -> Result<Message, String> {
     let record = match ip {
-        IpAddr::V4(ip) => {
-            let mut record = Record::with(Name::from_str(domain)?, RecordType::A, ttl);
-            record.set_data(Some(RData::A(ip.into())));
-            record
-        }
-        IpAddr::V6(ip) => {
-            let mut record = Record::with(Name::from_str(domain)?, RecordType::AAAA, ttl);
-            record.set_data(Some(RData::AAAA(ip.into())));
-            record
-        }
+        IpAddr::V4(ip) => Record::from_rdata(Name::from_str(domain)?, ttl, RData::A(A(ip))),
+        IpAddr::V6(ip) => Record::from_rdata(Name::from_str(domain)?, ttl, RData::AAAA(AAAA(ip))),
     };
 
     // We must indicate that this message is a response. Otherwise, implementations may not
@@ -27,9 +22,7 @@ pub fn build_dns_response(mut request: Message, domain: &str, ip: IpAddr, ttl: u
 }
 
 pub fn remove_ipv6_entries(message: &mut Message) {
-    message
-        .answers_mut()
-        .retain(|answer| !matches!(answer.data(), Some(RData::AAAA(_))));
+    message.answers_mut().retain(|answer| !matches!(answer.data(), RData::AAAA(_)));
 }
 
 pub fn extract_ipaddr_from_dns_message(message: &Message) -> Result<IpAddr, String> {
@@ -38,7 +31,7 @@ pub fn extract_ipaddr_from_dns_message(message: &Message) -> Result<IpAddr, Stri
     }
     let mut cname = None;
     for answer in message.answers() {
-        match answer.data().ok_or("DNS response not contains answer data")? {
+        match answer.data() {
             RData::A(addr) => {
                 return Ok(IpAddr::V4((*addr).into()));
             }

src/dump_logger.rs

@@ -9,7 +9,7 @@ pub(crate) static DUMP_CALLBACK: Mutex<Option<DumpCallback>> = Mutex::new(None);
 /// # Safety
 ///
 /// set dump log info callback.
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn tun2proxy_set_log_callback(
     callback: Option<unsafe extern "C" fn(ArgVerbosity, *const c_char, *mut c_void)>,
     ctx: *mut c_void,
@@ -23,7 +23,7 @@ pub struct DumpCallback(Option<unsafe extern "C" fn(ArgVerbosity, *const c_char,
 impl DumpCallback {
     unsafe fn call(self, dump_level: ArgVerbosity, info: *const c_char) {
         if let Some(cb) = self.0 {
-            cb(dump_level, info, self.1);
+            unsafe { cb(dump_level, info, self.1) };
         }
     }
 }

src/error.rs

@@ -26,7 +26,7 @@ pub enum Error {
     IpStack(#[from] ipstack::IpStackError),
 
     #[error("DnsProtoError {0:?}")]
-    DnsProto(#[from] hickory_proto::error::ProtoError),
+    DnsProto(#[from] hickory_proto::ProtoError),
 
     #[error("httparse::Error {0:?}")]
     Httparse(#[from] httparse::Error),
@@ -43,10 +43,6 @@ pub enum Error {
 
     #[error("std::num::ParseIntError {0:?}")]
     IntParseError(#[from] std::num::ParseIntError),
-
-    #[cfg(target_os = "linux")]
-    #[error("bincode::Error {0:?}")]
-    BincodeError(#[from] bincode::Error),
 }
 
 impl From<&str> for Error {

src/general_api.rs

@@ -1,6 +1,6 @@
 use crate::{
-    args::{ArgDns, ArgProxy},
     ArgVerbosity, Args,
+    args::{ArgDns, ArgProxy},
 };
 use std::os::raw::{c_char, c_int, c_ushort};
 
@@ -16,7 +16,7 @@ static TUN_QUIT: std::sync::Mutex<Option<tokio_util::sync::CancellationToken>> =
 /// - dns_strategy: the dns strategy, see ArgDns enum
 /// - root_privilege: whether to run with root privilege
 /// - verbosity: the verbosity level, see ArgVerbosity enum
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn tun2proxy_with_name_run(
     proxy_url: *const c_char,
     tun: *const c_char,
@@ -25,12 +25,12 @@ pub unsafe extern "C" fn tun2proxy_with_name_run(
     _root_privilege: bool,
     verbosity: ArgVerbosity,
 ) -> c_int {
-    let proxy_url = std::ffi::CStr::from_ptr(proxy_url).to_str().unwrap();
+    let proxy_url = unsafe { std::ffi::CStr::from_ptr(proxy_url) }.to_str().unwrap();
     let proxy = ArgProxy::try_from(proxy_url).unwrap();
-    let tun = std::ffi::CStr::from_ptr(tun).to_str().unwrap().to_string();
+    let tun = unsafe { std::ffi::CStr::from_ptr(tun) }.to_str().unwrap().to_string();
 
     let mut args = Args::default();
-    if let Ok(bypass) = std::ffi::CStr::from_ptr(bypass).to_str() {
+    if let Ok(bypass) = unsafe { std::ffi::CStr::from_ptr(bypass) }.to_str() {
         args.bypass(bypass.parse().unwrap());
     }
     args.proxy(proxy).tun(tun).dns(dns_strategy).verbosity(verbosity);
@@ -53,7 +53,7 @@ pub unsafe extern "C" fn tun2proxy_with_name_run(
 /// - dns_strategy: the dns strategy, see ArgDns enum
 /// - verbosity: the verbosity level, see ArgVerbosity enum
 #[cfg(unix)]
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn tun2proxy_with_fd_run(
     proxy_url: *const c_char,
     tun_fd: c_int,
@@ -63,7 +63,7 @@ pub unsafe extern "C" fn tun2proxy_with_fd_run(
     dns_strategy: ArgDns,
     verbosity: ArgVerbosity,
 ) -> c_int {
-    let proxy_url = std::ffi::CStr::from_ptr(proxy_url).to_str().unwrap();
+    let proxy_url = unsafe { std::ffi::CStr::from_ptr(proxy_url) }.to_str().unwrap();
     let proxy = ArgProxy::try_from(proxy_url).unwrap();
 
     let mut args = Args::default();
@@ -83,12 +83,17 @@ pub unsafe extern "C" fn tun2proxy_with_fd_run(
 ///   e.g. `tun2proxy-bin --setup --proxy socks5://127.0.0.1:1080 --bypass 98.76.54.0/24 --dns over-tcp --verbosity trace`
 /// - tun_mtu: The MTU of the TUN device, e.g. 1500
 /// - packet_information: Whether exists packet information in packet from TUN device
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn tun2proxy_run_with_cli_args(cli_args: *const c_char, tun_mtu: c_ushort, packet_information: bool) -> c_int {
-    let Ok(cli_args) = std::ffi::CStr::from_ptr(cli_args).to_str() else {
+    let Ok(cli_args) = unsafe { std::ffi::CStr::from_ptr(cli_args) }.to_str() else {
+        log::error!("Failed to convert CLI arguments to string");
         return -5;
     };
-    let args = <Args as ::clap::Parser>::parse_from(cli_args.split_whitespace());
+    let Some(args) = shlex::split(cli_args) else {
+        log::error!("Failed to split CLI arguments");
+        return -6;
+    };
+    let args = <Args as ::clap::Parser>::parse_from(args);
     general_run_for_api(args, tun_mtu, packet_information)
 }
 
@@ -115,11 +120,18 @@ pub fn general_run_for_api(args: Args, tun_mtu: u16, packet_information: bool) -
         return -3;
     };
     match rt.block_on(async move {
-        if let Err(err) = general_run_async(args, tun_mtu, packet_information, shutdown_token).await {
-            log::error!("main loop error: {}", err);
-            return Err(err);
+        let ret = general_run_async(args.clone(), tun_mtu, packet_information, shutdown_token).await;
+        match &ret {
+            Ok(sessions) => {
+                if args.exit_on_fatal_error && *sessions >= args.max_sessions {
+                    log::error!("Forced exit due to max sessions reached ({sessions}/{})", args.max_sessions);
+                    std::process::exit(-1);
+                }
+                log::debug!("tun2proxy exited normally, current sessions: {sessions}");
+            }
+            Err(err) => log::error!("main loop error: {err}"),
         }
-        Ok(())
+        ret
     }) {
         Ok(_) => 0,
         Err(e) => {
@@ -135,7 +147,7 @@ pub async fn general_run_async(
     tun_mtu: u16,
     _packet_information: bool,
     shutdown_token: tokio_util::sync::CancellationToken,
-) -> std::io::Result<()> {
+) -> std::io::Result<usize> {
     let mut tun_config = tun::Configuration::default();
 
     #[cfg(any(target_os = "linux", target_os = "windows", target_os = "macos"))]
@@ -241,7 +253,7 @@ pub async fn general_run_async(
 /// # Safety
 ///
 /// Shutdown the tun2proxy component.
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn tun2proxy_stop() -> c_int {
     tun2proxy_stop_internal()
 }

src/http.rs

@@ -7,7 +7,7 @@ use crate::{
 use httparse::Response;
 use socks5_impl::protocol::UserKey;
 use std::{
-    collections::{hash_map::RandomState, HashMap, VecDeque},
+    collections::{HashMap, VecDeque, hash_map::RandomState},
     iter::FromIterator,
     net::SocketAddr,
     str,

src/lib.rs

@@ -22,18 +22,18 @@ use std::{
 use tokio::{
     io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt},
     net::{TcpSocket, TcpStream, UdpSocket},
-    sync::{mpsc::Receiver, Mutex},
+    sync::{Mutex, mpsc::Receiver},
 };
 pub use tokio_util::sync::CancellationToken;
 use tproxy_config::is_private_ip;
 use udp_stream::UdpStream;
 #[cfg(feature = "udpgw")]
-use udpgw::{UdpGwClientStream, UdpGwResponse, UDPGW_KEEPALIVE_TIME, UDPGW_MAX_CONNECTIONS};
+use udpgw::{UDPGW_KEEPALIVE_TIME, UDPGW_MAX_CONNECTIONS, UdpGwClientStream, UdpGwResponse};
 
 pub use {
     args::{ArgDns, ArgProxy, ArgVerbosity, Args, ProxyType},
     error::{BoxError, Error, Result},
-    traffic_status::{tun2proxy_set_traffic_status_callback, TrafficStatus},
+    traffic_status::{TrafficStatus, tun2proxy_set_traffic_status_callback},
 };
 
 #[cfg(feature = "mimalloc")]
@@ -64,12 +64,15 @@ pub mod win_svc;
 
 const DNS_PORT: u16 = 53;
 
-static TASK_COUNT: std::sync::atomic::AtomicU64 = std::sync::atomic::AtomicU64::new(0);
+static TASK_COUNT: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
 use std::sync::atomic::Ordering::Relaxed;
 
 #[allow(unused)]
 #[derive(Hash, Copy, Clone, Eq, PartialEq, Debug)]
-#[cfg_attr(target_os = "linux", derive(serde::Serialize, serde::Deserialize))]
+#[cfg_attr(
+    target_os = "linux",
+    derive(bincode::Encode, bincode::Decode, serde::Serialize, serde::Deserialize)
+)]
 pub enum SocketProtocol {
     Tcp,
     Udp,
@@ -77,7 +80,10 @@ pub enum SocketProtocol {
 
 #[allow(unused)]
 #[derive(Hash, Copy, Clone, Eq, PartialEq, Debug)]
-#[cfg_attr(target_os = "linux", derive(serde::Serialize, serde::Deserialize))]
+#[cfg_attr(
+    target_os = "linux",
+    derive(bincode::Encode, bincode::Decode, serde::Serialize, serde::Deserialize)
+)]
 pub enum SocketDomain {
     IpV4,
     IpV6,
@@ -148,7 +154,9 @@ async fn create_udp_stream(socket_queue: &Option<Arc<SocketQueue>>, peer: Socket
 /// * `mtu` - The MTU of the network device
 /// * `args` - The arguments to use
 /// * `shutdown_token` - The token to exit the server
-pub async fn run<D>(device: D, mtu: u16, args: Args, shutdown_token: CancellationToken) -> crate::Result<()>
+/// # Returns
+/// * The number of sessions while exiting
+pub async fn run<D>(device: D, mtu: u16, args: Args, shutdown_token: CancellationToken) -> crate::Result<usize>
 where
     D: AsyncRead + AsyncWrite + Unpin + Send + 'static,
 {
@@ -259,10 +267,10 @@ where
                 ip_stack_stream?
             }
         };
-        let max_sessions = args.max_sessions as u64;
+        let max_sessions = args.max_sessions;
         match ip_stack_stream {
             IpStackStream::Tcp(tcp) => {
-                if TASK_COUNT.load(Relaxed) > max_sessions {
+                if TASK_COUNT.load(Relaxed) >= max_sessions {
                     if args.exit_on_fatal_error {
                         log::info!("Too many sessions that over {max_sessions}, exiting...");
                         break;
@@ -270,7 +278,7 @@ where
                     log::warn!("Too many sessions that over {max_sessions}, dropping new session");
                     continue;
                 }
-                log::trace!("Session count {}", TASK_COUNT.fetch_add(1, Relaxed) + 1);
+                log::trace!("Session count {}", TASK_COUNT.fetch_add(1, Relaxed).saturating_add(1));
                 let info = SessionInfo::new(tcp.local_addr(), tcp.peer_addr(), IpProtocol::Tcp);
                 let domain_name = if let Some(virtual_dns) = &virtual_dns {
                     let mut virtual_dns = virtual_dns.lock().await;
@@ -285,11 +293,11 @@ where
                     if let Err(err) = handle_tcp_session(tcp, proxy_handler, socket_queue).await {
                         log::error!("{} error \"{}\"", info, err);
                     }
-                    log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed) - 1);
+                    log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed).saturating_sub(1));
                 });
             }
             IpStackStream::Udp(udp) => {
-                if TASK_COUNT.load(Relaxed) > max_sessions {
+                if TASK_COUNT.load(Relaxed) >= max_sessions {
                     if args.exit_on_fatal_error {
                         log::info!("Too many sessions that over {max_sessions}, exiting...");
                         break;
@@ -297,7 +305,7 @@ where
                     log::warn!("Too many sessions that over {max_sessions}, dropping new session");
                     continue;
                 }
-                log::trace!("Session count {}", TASK_COUNT.fetch_add(1, Relaxed) + 1);
+                log::trace!("Session count {}", TASK_COUNT.fetch_add(1, Relaxed).saturating_add(1));
                 let mut info = SessionInfo::new(udp.local_addr(), udp.peer_addr(), IpProtocol::Udp);
                 if info.dst.port() == DNS_PORT {
                     if is_private_ip(info.dst.ip()) {
@@ -311,7 +319,7 @@ where
                             if let Err(err) = handle_dns_over_tcp_session(udp, proxy_handler, socket_queue, ipv6_enabled).await {
                                 log::error!("{} error \"{}\"", info, err);
                             }
-                            log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed) - 1);
+                            log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed).saturating_sub(1));
                         });
                         continue;
                     }
@@ -322,7 +330,7 @@ where
                                     log::error!("{} error \"{}\"", info, err);
                                 }
                             }
-                            log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed) - 1);
+                            log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed).saturating_sub(1));
                         });
                         continue;
                     }
@@ -353,7 +361,7 @@ where
                         if let Err(e) = handle_udp_gateway_session(udp, udpgw, &dst_addr, proxy_handler, queue, ipv6_enabled).await {
                             log::info!("Ending {} with \"{}\"", info, e);
                         }
-                        log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed) - 1);
+                        log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed).saturating_sub(1));
                     });
                     continue;
                 }
@@ -365,7 +373,7 @@ where
                             if let Err(err) = handle_udp_associate_session(udp, ty, proxy_handler, socket_queue, ipv6_enabled).await {
                                 log::info!("Ending {} with \"{}\"", info, err);
                             }
-                            log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed) - 1);
+                            log::trace!("Session count {}", TASK_COUNT.fetch_sub(1, Relaxed).saturating_sub(1));
                         });
                     }
                     Err(e) => {
@@ -375,7 +383,7 @@ where
             }
             IpStackStream::UnknownTransport(u) => {
                 let len = u.payload().len();
-                log::info!("#0 unhandled transport - Ip Protocol 0x{:02X}, length {}", u.ip_protocol(), len);
+                log::info!("#0 unhandled transport - Ip Protocol {:?}, length {}", u.ip_protocol(), len);
                 continue;
             }
             IpStackStream::UnknownNetwork(pkt) => {
@@ -384,7 +392,7 @@ where
             }
         }
     }
-    Ok(())
+    Ok(TASK_COUNT.load(Relaxed))
 }
 
 async fn handle_virtual_dns_session(mut udp: IpStackUdpStream, dns: Arc<Mutex<VirtualDns>>) -> crate::Result<()> {

src/socket_transfer.rs

@@ -1,10 +1,10 @@
 #![cfg(target_os = "linux")]
 
-use crate::{error, SocketDomain, SocketProtocol};
+use crate::{SocketDomain, SocketProtocol, error};
 use nix::{
     errno::Errno,
     fcntl::{self, FdFlag},
-    sys::socket::{cmsg_space, getsockopt, recvmsg, sendmsg, sockopt, ControlMessage, ControlMessageOwned, MsgFlags, SockType},
+    sys::socket::{ControlMessage, ControlMessageOwned, MsgFlags, SockType, cmsg_space, getsockopt, recvmsg, sendmsg, sockopt},
 };
 use serde::{Deserialize, Serialize};
 use std::{
@@ -16,14 +16,14 @@ use tokio::net::{TcpSocket, UdpSocket, UnixDatagram};
 
 const REQUEST_BUFFER_SIZE: usize = 64;
 
-#[derive(Hash, Copy, Clone, Eq, PartialEq, Debug, Serialize, Deserialize)]
+#[derive(bincode::Encode, bincode::Decode, Hash, Copy, Clone, Eq, PartialEq, Debug, Serialize, Deserialize)]
 struct Request {
     protocol: SocketProtocol,
     domain: SocketDomain,
     number: u32,
 }
 
-#[derive(Hash, Copy, Clone, Eq, PartialEq, Debug, Serialize, Deserialize)]
+#[derive(bincode::Encode, bincode::Decode, PartialEq, Debug, Hash, Copy, Clone, Eq, Serialize, Deserialize)]
 enum Response {
     Ok,
 }
@@ -135,14 +135,21 @@ where
     // Borrow socket as mut to prevent multiple simultaneous requests
     let socket = socket.deref_mut();
 
-    // Send request
-    let request = bincode::serialize(&Request {
-        protocol: T::domain(),
-        domain,
-        number,
-    })?;
+    let mut request = [0u8; 1000];
 
-    socket.send(&request[..]).await?;
+    // Send request
+    let size = bincode::encode_into_slice(
+        Request {
+            protocol: T::domain(),
+            domain,
+            number,
+        },
+        &mut request,
+        bincode::config::standard(),
+    )
+    .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidInput, e))?;
+
+    socket.send(&request[..size]).await?;
 
     // Receive response
     loop {
@@ -161,7 +168,9 @@ where
 
         // Parse response
         let response = &msg.iovs().next().unwrap()[..msg.bytes];
-        let response: Response = bincode::deserialize(response)?;
+        let response: Response = bincode::decode_from_slice(response, bincode::config::standard())
+            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidInput, e))?
+            .0;
         if !matches!(response, Response::Ok) {
             return Err("Request for new sockets failed".into());
         }
@@ -194,10 +203,14 @@ pub async fn process_socket_requests(socket: &UnixDatagram) -> error::Result<()>
 
         let len = socket.recv(&mut buf[..]).await?;
 
-        let request: Request = bincode::deserialize(&buf[..len])?;
+        let request: Request = bincode::decode_from_slice(&buf[..len], bincode::config::standard())
+            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidInput, e))?
+            .0;
 
         let response = Response::Ok;
-        let buf = bincode::serialize(&response)?;
+        let mut buf = [0u8; 1000];
+        let size = bincode::encode_into_slice(response, &mut buf, bincode::config::standard())
+            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidInput, e))?;
 
         let mut owned_fd_buf: Vec<OwnedFd> = Vec::with_capacity(request.number as usize);
         for _ in 0..request.number {
@@ -223,7 +236,7 @@ pub async fn process_socket_requests(socket: &UnixDatagram) -> error::Result<()>
 
         let raw_fd_buf: Vec<RawFd> = owned_fd_buf.iter().map(|fd| fd.as_raw_fd()).collect();
         let cmsg = ControlMessage::ScmRights(&raw_fd_buf[..]);
-        let iov = [IoSlice::new(&buf[..])];
+        let iov = [IoSlice::new(&buf[..size])];
 
         sendmsg::<()>(socket.as_raw_fd(), &iov, &[cmsg], MsgFlags::empty(), None)?;
     }

src/socks.rs

@@ -4,7 +4,7 @@ use crate::{
     proxy_handler::{ProxyHandler, ProxyHandlerManager},
     session_info::SessionInfo,
 };
-use socks5_impl::protocol::{self, handshake, password_method, Address, AuthMethod, StreamOperation, UserKey, Version};
+use socks5_impl::protocol::{self, Address, AuthMethod, StreamOperation, UserKey, Version, handshake, password_method};
 use std::{collections::VecDeque, net::SocketAddr, sync::Arc};
 use tokio::sync::Mutex;
 

src/traffic_status.rs

@@ -5,7 +5,7 @@ use std::sync::{LazyLock, Mutex};
 /// # Safety
 ///
 /// set traffic status callback.
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn tun2proxy_set_traffic_status_callback(
     send_interval_secs: u32,
     callback: Option<unsafe extern "C" fn(*const TrafficStatus, *mut c_void)>,
@@ -34,7 +34,7 @@ struct TrafficStatusCallback(Option<unsafe extern "C" fn(*const TrafficStatus, *
 impl TrafficStatusCallback {
     unsafe fn call(self, info: &TrafficStatus) {
         if let Some(cb) = self.0 {
-            cb(info, self.1);
+            unsafe { cb(info, self.1) };
         }
     }
 }

src/udpgw.rs

@@ -4,11 +4,11 @@ use std::{collections::VecDeque, hash::Hash, net::SocketAddr, sync::atomic::Orde
 use tokio::{
     io::{AsyncReadExt, AsyncWriteExt},
     net::{
-        tcp::{OwnedReadHalf, OwnedWriteHalf},
         TcpStream,
+        tcp::{OwnedReadHalf, OwnedWriteHalf},
     },
     sync::Mutex,
-    time::{sleep, Duration},
+    time::{Duration, sleep},
 };
 
 pub(crate) const UDPGW_LENGTH_FIELD_SIZE: usize = std::mem::size_of::<u16>();

src/virtual_dns.rs

@@ -1,5 +1,5 @@
 use crate::error::Result;
-use hashlink::{linked_hash_map::RawEntryMut, LruCache};
+use hashlink::{LruCache, linked_hash_map::RawEntryMut};
 use std::{
     collections::HashMap,
     convert::TryInto,

src/win_svc.rs

@@ -73,13 +73,21 @@ fn run_service(_arguments: Vec<std::ffi::OsString>) -> Result<(), crate::BoxErro
         let rt = tokio::runtime::Builder::new_multi_thread().enable_all().build()?;
         rt.block_on(async {
             unsafe extern "C" fn traffic_cb(status: *const crate::TrafficStatus, _: *mut std::ffi::c_void) {
-                let status = &*status;
+                let status = unsafe { &*status };
                 log::debug!("Traffic: ▲ {} : ▼ {}", status.tx, status.rx);
             }
             unsafe { crate::tun2proxy_set_traffic_status_callback(1, Some(traffic_cb), std::ptr::null_mut()) };
 
-            if let Err(err) = crate::general_run_async(args, tun::DEFAULT_MTU, false, shutdown_token).await {
-                log::error!("main loop error: {}", err);
+            let ret = crate::general_run_async(args.clone(), tun::DEFAULT_MTU, false, shutdown_token).await;
+            match &ret {
+                Ok(sessions) => {
+                    if args.exit_on_fatal_error && *sessions >= args.max_sessions {
+                        log::error!("Forced exit due to max sessions reached ({sessions}/{})", args.max_sessions);
+                        std::process::exit(-1);
+                    }
+                    log::debug!("tun2proxy exited normally, current sessions: {sessions}");
+                }
+                Err(err) => log::error!("main loop error: {err}"),
             }
             Ok::<(), crate::Error>(())
         })?;