refractor into smaller modules

src/proxy.rs

@@ -0,0 +1,29 @@
+use std::error::Error;
+use tokio::io::copy_bidirectional;
+use tokio::net::{TcpListener, TcpStream};
+
+pub async fn run_proxy(listen_addr: String, server_addr: String) -> Result<(), Box<dyn Error>> {
+    println!("Listening on {}", listen_addr);
+    println!("Proxying to {}", server_addr);
+
+    let listener = TcpListener::bind(&listen_addr).await?;
+
+    while let Ok((mut inbound, _)) = listener.accept().await {
+        let server_addr = server_addr.clone();
+
+        tokio::spawn(async move {
+            match TcpStream::connect(&server_addr).await {
+                Ok(mut outbound) => {
+                    if let Err(e) = copy_bidirectional(&mut inbound, &mut outbound).await {
+                        println!("Failed to transfer; error={e}");
+                    }
+                }
+                Err(e) => {
+                    println!("Failed to connect to server; error={e}");
+                }
+            }
+        });
+    }
+
+    Ok(())
+}