not work

Cargo.lock

 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "async-channel"

src/main.rs

 use socket2::{Domain, Protocol, SockAddr, Socket, Type};
 use std::error::Error;
-use std::io::{BufRead, Write};
-use std::mem::{transmute, MaybeUninit};
+use std::io::{BufRead, Read, Write};
+use std::mem::MaybeUninit;
 use std::{env, thread};
+use std::net::SocketAddrV4;
 
 #[repr(C)]
 pub struct Meta {
@@ -34,9 +35,10 @@ impl Secret {
 
 fn main() -> Result<(), Box<dyn Error>> {
     let local_id: u8 = env::var("LOCAL_ID")?.parse()?;
-    let remote_id: u8 = env::var("LOCAL_ID")?.parse()?;
+    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 mut remote_address: &SockAddr;
 
     let mut config = tun::Configuration::default();
     config
@@ -50,13 +52,11 @@ fn main() -> Result<(), Box<dyn Error>> {
         config.ensure_root_privileges(true);
     });
 
-    let mut dev = tun::create(&config)?;
-    let (mut reader, mut writer) = dev.split();
+    let dev = tun::create(&config)?;
+    let (mut reader, 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 local_id = 0u8;
-    let remote_id = 0u8;
 
     let inbound = thread::spawn(move || {
         let mut recv_buf = [MaybeUninit::uninit(); 1500];
@@ -64,6 +64,7 @@ fn main() -> Result<(), Box<dyn Error>> {
         loop {
             match socket.recv_from(&mut recv_buf) {
                 Ok((len, addr1)) => {
+                    remote_address = &addr1;
                     println!("recv from {:?}", recv_buf);
                     // if let Some(packet) = Ipv4Packet::new(unsafe { transmute(&recv_buf[..len]) }) {
                     //     let (meta1, payload) = packet.payload().split_at_mut(size_of::<Meta>());
@@ -83,7 +84,22 @@ fn main() -> Result<(), Box<dyn Error>> {
         }
     });
 
+    let outbound = thread::spawn(move || {
+        let mut recv_buf = [0u8; 1500-20-4];
+        loop {
+            match reader.read(&mut recv_buf) {
+                Ok(len) => {
+                    println!("recv from {:?}", recv_buf);
+
+                    socket.send_to(&recv_buf, &remote_address);
+                }
+                Err(_) => {}
+            }
+        }
+    });
+
     inbound.join();
+    outbound.join();
     
     Ok(())
 }