feat: modularized proxy

src/main.rs

@@ -1,47 +1,11 @@
-use std::sync::Arc;
+mod netutils;
-use std::fmt;
+
-use tokio::io;
-use tokio::net::{TcpListener, TcpStream};
-use tokio::sync::Mutex;
 use anywho::Error;
+use netutils::{Backend, proxy, proxy_connection};
+use std::sync::Arc;
 
-#[derive(Clone, Debug)]
+use tokio::net::TcpListener;
-struct Backend {
+use tokio::sync::Mutex;
-    address: String,
-}
-
-impl fmt::Display for Backend {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", self.address)
-    }
-}
-
-impl Backend {
-    fn new(address: String) -> Self {
-        Backend { address }
-    }
-}
-
-async fn proxy_connection(client_stream: TcpStream, backend: &Backend) -> Result<(), io::Error> {
-    let log_error = |e| { eprintln!("error: something went wrong {}", e); e };
-
-    println!("info: connecting to backend {}", backend);
-    let backend_stream = TcpStream::connect(&backend.address).await.map_err(log_error)?;
-    println!("info: the bluetooth device is connected successfully {}", backend);
-
-    let (mut client_read, mut client_write) = client_stream.into_split();
-    let (mut backend_read, mut backend_write) = backend_stream.into_split();
-
-    let client_to_backend = io::copy(&mut client_read, &mut backend_write);
-    let backend_to_client = io::copy(&mut backend_read, &mut client_write);
-
-    let _ = tokio::select! {
-        res_a = client_to_backend => res_a.map_err(log_error)?,
-        res_b = backend_to_client => res_b.map_err(log_error)?,
-    };
-
-    Ok(())
-}
 
 #[tokio::main]
 async fn main() -> Result<(), Error> {
@@ -80,4 +44,4 @@ async fn main() -> Result<(), Error> {
             }
         });
     }
-}
+}

src/netutils.rs

@@ -0,0 +1,77 @@
+use std::fmt;
+use tokio::io;
+use tokio::net::{TcpListener, TcpStream};
+
+use std::error::Error;
+
+#[derive(Clone, Debug)]
+pub struct Backend {
+    address: String,
+}
+
+impl Backend {
+    pub fn new(address: String) -> Self {
+        Backend { address }
+    }
+}
+
+impl fmt::Display for Backend {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.address)
+    }
+}
+
+pub async fn proxy(client_addr: String, server_addr: String) -> Result<(), Box<dyn Error>> {
+    let listener = TcpListener::bind(client_addr.clone()).await?;
+    println!("Opened {client_addr} -> {server_addr}");
+    loop {
+        let server_addr = server_addr.clone();
+        let (client, _) = listener.accept().await?;
+        tokio::spawn(async move {
+            let server = TcpStream::connect(server_addr).await.unwrap();
+
+            let (mut read_client, mut write_client) = client.into_split();
+            let (mut read_server, mut write_server) = server.into_split();
+
+            let forward_to_server =
+                tokio::spawn(async move { io::copy(&mut read_client, &mut write_server).await });
+
+            let forward_to_client =
+                tokio::spawn(async move { io::copy(&mut read_server, &mut write_client).await });
+
+            let _ = tokio::join!(forward_to_server, forward_to_client);
+        });
+    }
+}
+
+pub async fn proxy_connection(
+    client_stream: TcpStream,
+    backend: &Backend,
+) -> Result<(), io::Error> {
+    let log_error = |e| {
+        eprintln!("error: something went wrong {}", e);
+        e
+    };
+
+    println!("info: connecting to backend {}", backend);
+    let backend_stream = TcpStream::connect(&backend.address)
+        .await
+        .map_err(log_error)?;
+    println!(
+        "info: the bluetooth device is connected successfully {}",
+        backend
+    );
+
+    let (mut client_read, mut client_write) = client_stream.into_split();
+    let (mut backend_read, mut backend_write) = backend_stream.into_split();
+
+    let client_to_backend = io::copy(&mut client_read, &mut backend_write);
+    let backend_to_client = io::copy(&mut backend_read, &mut client_write);
+
+    let _ = tokio::select! {
+        res_a = client_to_backend => res_a.map_err(log_error)?,
+        res_b = backend_to_client => res_b.map_err(log_error)?,
+    };
+
+    Ok(())
+}