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+FROM rust:alpine as builder
+WORKDIR /usr/src/app
+COPY . .
+RUN cargo install --path .
+
+FROM alpine
+RUN apk --no-cache add libgcc libstdc++ bash iproute2 iptables ipset netcat-openbsd
+COPY --from=builder /usr/local/cargo/bin/tun1 /usr/local/bin/tun
+COPY ./entrypoint.sh /entrypoint.sh
+
+ENTRYPOINT ["/entrypoint.sh"]
+CMD ["tun"]

src/main.rs

 use pnet::packet::ipv4::Ipv4Packet;
-use pnet::packet::Packet;
-use socket2::{Domain, Protocol, SockAddr, Socket, Type};
+use socket2::{Domain, Protocol, Socket, Type};
 use std::error::Error;
-use std::io::{BufRead, Read, Write};
-use std::mem::{transmute, MaybeUninit};
-use std::sync::{Arc, Mutex};
+use std::io::{Read, Write};
+use std::mem::{size_of, MaybeUninit};
+use std::net::ToSocketAddrs;
+use std::process::Command;
+use std::sync::{Arc, RwLock};
 use std::{env, thread};
-use std::net::{SocketAddr, SocketAddrV4};
-
-use std::net::UdpSocket;
-
 
 #[repr(C)]
 pub struct Meta {
@@ -23,17 +20,16 @@ struct Secret {
 }
 
 impl Secret {
-    fn new(key: &String) -> Secret {
-        Secret {
+    fn new(key: &str) -> Self {
+        Self {
             key: key.as_bytes().to_vec(),
         }
     }
     fn encrypt(&self, data: &mut [u8]) {
-        for (i, byte) in data.iter_mut().enumerate() {
-            *byte ^= self.key[i % self.key.len()];
+        for (i, b) in data.iter_mut().enumerate() {
+            *b ^= self.key[i % self.key.len()];
         }
     }
-
     fn decrypt(&self, data: &mut [u8]) {
         self.encrypt(data);
     }
@@ -44,108 +40,136 @@ fn main() -> Result<(), Box<dyn Error>> {
     let remote_id: u8 = env::var("REMOTE_ID")?.parse()?;
     let local_secret = Secret::new(&env::var("LOCAL_SECRET")?);
     let remote_secret = Secret::new(&env::var("REMOTE_SECRET")?);
-    let remote_addr: Arc<Mutex<Option<SockAddr>>> = Arc::new(Mutex::new(
-        match env::var("REMOTE_ADDR") {
-            Ok(addr_str) => {
-                let parsed = addr_str.parse::<SocketAddr>()?;
-                Some(parsed.into())
-            }
-            Err(_) => None,
+    let proto: i32 = env::var("PROTO")?.parse()?;
+    let up = env::var("UP_SCRIPT")?;
+    let dev = env::var("DEV")?;
+    let family = if env::var("FAMILY")?.parse::<u8>()? == 6 {
+        Domain::IPV6
+    } else {
+        Domain::IPV4
+    };
+
+    let endpoint = Arc::new(RwLock::new(match env::var("ENDPOINT") {
+        Ok(addr_str) => {
+            let parsed = addr_str.to_socket_addrs()?.next().unwrap();
+            Some(parsed.into())
         }
-    ));
+        Err(_) => None,
+    }));
 
     let mut config = tun::Configuration::default();
-    config
-        .address((10, 0, 0, local_id))
-        .netmask((255, 255, 255, 0))
-        .destination((10, 0, 0, remote_id))
-        .up();
-
-    #[cfg(target_os = "linux")]
-    config.platform_config(|config| {
-        config.ensure_root_privileges(true);
-    });
+    config.tun_name(dev).up();
 
     let dev = tun::create(&config)?;
     let (mut reader, mut writer) = dev.split();
 
-    // 创建用于接收的原始套接字，协议号为 144
-    let socket = Socket::new(Domain::IPV4, Type::RAW, Some(Protocol::from(144)))?;
-    let socket_arc = Arc::new(Mutex::new(socket));
-    let socket_for_inbound = Arc::clone(&socket_arc);
-
-    let remote_addr_clone = Arc::clone(&remote_addr);
-
-    let inbound = thread::spawn(move || {
-        let mut recv_buf = [MaybeUninit::uninit(); 1500];
-        loop {
-            let sock_guard = socket_for_inbound.lock().unwrap();
-            match sock_guard.recv_from(&mut recv_buf) {
-                Ok((len, addr1)) => {
-                    println!("recv from {:?}", recv_buf);
-                    let recv_buf2: &mut [u8] = unsafe { transmute(&mut recv_buf[..len]) };
-                    if let Some(packet) = Ipv4Packet::new(recv_buf2) {
-                        let header_length = packet.get_header_length() as usize * 4;
-                        let (header, data) = recv_buf2.split_at_mut(header_length);
-                        let (meta1, payload) = data.split_at_mut(size_of::<Meta>());
-                        let meta: &Meta = unsafe { transmute(&meta1) };
-                        if meta.src_id == remote_id && meta.dst_id == local_id && meta.reversed == 0
-                        {
-                            let mut addr_lock = remote_addr_clone.lock().unwrap();
-                            *addr_lock = Some(addr1);
-                            local_secret.decrypt(payload);
-                            writer.write(payload);
+    // Create a raw socket with protocol number 144
+    let socket = Socket::new(family, Type::RAW, Some(Protocol::from(proto)))?;
+    #[cfg(target_os = "linux")]
+    socket.set_mark(env::var("MARK")?.parse()?);
+    let socket_clone = socket.try_clone()?;
+
+    match Command::new(up).status() {
+        Ok(status) => {
+            if !status.success() {
+                eprintln!("Script exited with non-zero status: {}", status);
+            }
+        }
+        Err(e) => eprintln!("Failed to run script '{}'", e),
+    }
+
+    // Thread for receiving from WAN (raw socket) and writing to TUN
+    let inbound = {
+        let remote_addr = Arc::clone(&endpoint);
+        let local_secret = local_secret;
+        thread::spawn(move || {
+            let mut recv_buf = [MaybeUninit::uninit(); 1500];
+            loop {
+                match socket.recv_from(&mut recv_buf) {
+                    Ok((len, addr)) => {
+                        // Safely interpret the uninit buffer up to `len` as bytes
+                        let data = unsafe {
+                            std::slice::from_raw_parts_mut(recv_buf.as_mut_ptr() as *mut u8, len)
+                        };
+
+                        if let Some(packet) = Ipv4Packet::new(data) {
+                            let header_len = packet.get_header_length() as usize * 4;
+                            let (_ip_header, rest) = data.split_at_mut(header_len);
+                            if rest.len() < size_of::<Meta>() {
+                                // Malformed packet
+                                continue;
+                            }
+                            let (meta_bytes, payload) = rest.split_at_mut(size_of::<Meta>());
+
+                            // Extract meta
+                            let meta = Meta {
+                                src_id: meta_bytes[0],
+                                dst_id: meta_bytes[1],
+                                reversed: u16::from_le_bytes([meta_bytes[2], meta_bytes[3]]),
+                            };
+
+                            // Check if it matches our expected IDs
+                            if meta.src_id == remote_id
+                                && meta.dst_id == local_id
+                                && meta.reversed == 0
+                            {
+                                // Update remote address for outbound
+                                *remote_addr.write().unwrap() = Some(addr);
+
+                                // Decrypt and push into TUN
+                                local_secret.decrypt(payload);
+                                let _ = writer.write_all(payload);
+                            } else {
+                                // eprintln!("Dropping unexpected packet");
+                            }
                         }
                     }
-                }
-                Err(e) => {
-                    eprintln!("接收数据包时出错: {:?}", e);
+                    Err(e) => eprintln!("Error receiving: {}", e),
                 }
             }
-        }
-    });
-
-    let outbound = thread::spawn(move || {
-        let mut recv_buf = [0u8; 1500 - 20];
-        let meta = Meta {
-            src_id: local_id,
-            dst_id: remote_id,
-            reversed: 0,
-        };
-        let meta_size = size_of::<Meta>();
-
-        unsafe {
+        })
+    };
+
+    // Thread for reading from TUN, encrypting, and sending to WAN
+    let outbound = {
+        let remote_addr = Arc::clone(&endpoint);
+        let remote_secret = remote_secret;
+        thread::spawn(move || {
+            let mut buffer = [0u8; 1500 - 20]; // minus typical IP header space
+            let meta_size = size_of::<Meta>();
+
+            // Pre-initialize with our Meta header (local -> remote)
+            let meta = Meta {
+                src_id: local_id,
+                dst_id: remote_id,
+                reversed: 0,
+            };
+            // Turn the Meta struct into bytes
             let meta_bytes =
-                std::slice::from_raw_parts(&meta as *const Meta as *const u8, meta_size);
-            recv_buf[..meta_size].copy_from_slice(meta_bytes);
-        }
-        loop {
-            match reader.read(&mut recv_buf[meta_size..]) {
-                Ok(len) => {
-                    println!("recv from {:?}", &recv_buf[meta_size..meta_size + len]);
-                    let maybe_remote = remote_addr.lock().unwrap().clone();
-                    println!("1");
-                    if let Some(ref remote) = maybe_remote {
-                        println!("2");
-                        let sock_guard = socket_arc.lock().unwrap();
-                        println!("3");
-                        remote_secret.encrypt(&mut recv_buf[meta_size..meta_size + len]);
-                        println!("4");
-                        if let Err(e) = sock_guard.send_to(&recv_buf[..meta_size + len], remote) {
-                            println!("5");
-                            eprintln!("Error sending packet: {:?}", e);
+                unsafe { std::slice::from_raw_parts(&meta as *const Meta as *const u8, meta_size) };
+            buffer[..meta_size].copy_from_slice(meta_bytes);
+
+            loop {
+                match reader.read(&mut buffer[meta_size..]) {
+                    Ok(n) if n > 0 => {
+                        // If we have a known remote address, encrypt and send
+                        if let Some(ref addr) = *remote_addr.read().unwrap() {
+                            remote_secret.encrypt(&mut buffer[meta_size..meta_size + n]);
+                            if let Err(e) = socket_clone.send_to(&buffer[..meta_size + n], addr) {
+                                eprintln!("Error sending packet: {}", e);
+                            }
+                        } else {
+                            eprintln!("No remote address set; packet dropped.");
                         }
-                    } else {
-                        eprintln!("No remote address available; packet discarded.");
                     }
+                    Err(e) => eprintln!("Error reading from TUN: {}", e),
+                    _ => {}
                 }
-                Err(_) => {}
             }
-        }
-    });
-
-    inbound.join();
-    outbound.join();
+        })
+    };
 
+    let _ = inbound.join();
+    let _ = outbound.join();
     Ok(())
 }