Deduplicate copy method

Signed-off-by: Jacob Kiers <code@kiers.eu>

src/servers/mod.rs

@@ -2,6 +2,8 @@ use log::{error, info};
 use std::collections::{HashMap, HashSet};
 use std::net::SocketAddr;
 use std::sync::Arc;
+use tokio::io;
+use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt};
 use tokio::task::JoinHandle;
 
 mod protocol;
@@ -210,3 +212,17 @@ mod tests {
         // conn.shutdown().await.unwrap();
     }
 }
+
+async fn copy<'a, R, W>(reader: &'a mut R, writer: &'a mut W) -> io::Result<u64>
+where
+    R: AsyncRead + Unpin + ?Sized,
+    W: AsyncWrite + Unpin + ?Sized,
+{
+    match io::copy(reader, writer).await {
+        Ok(u64) => {
+            let _ = writer.shutdown().await;
+            Ok(u64)
+        }
+        Err(_) => Ok(0),
+    }
+}