fix relay half-close data loss (closes #6)

Author: therealaleph

src/relay.rs

@@ -1,29 +1,8 @@
-use tokio::io;
+use tokio::io::copy_bidirectional;
 use tokio::net::TcpStream;
 
-pub async fn relay(client: TcpStream, upstream: TcpStream) -> Result<(), std::io::Error> {
-    let (mut cr, mut cw) = io::split(client);
-    let (mut ur, mut uw) = io::split(upstream);
-
-    let c2u = tokio::spawn(async move { io::copy(&mut cr, &mut uw).await });
-    let u2c = tokio::spawn(async move { io::copy(&mut ur, &mut cw).await });
-
-    tokio::select! {
-        r = c2u => {
-            match r {
-                Ok(Ok(n)) => tracing::debug!(bytes = n, "client->upstream finished"),
-                Ok(Err(e)) => tracing::debug!("client->upstream error: {}", e),
-                Err(e) => tracing::debug!("client->upstream task panicked: {}", e),
-            }
-        }
-        r = u2c => {
-            match r {
-                Ok(Ok(n)) => tracing::debug!(bytes = n, "upstream->client finished"),
-                Ok(Err(e)) => tracing::debug!("upstream->client error: {}", e),
-                Err(e) => tracing::debug!("upstream->client task panicked: {}", e),
-            }
-        }
-    }
-
+pub async fn relay(mut client: TcpStream, mut upstream: TcpStream) -> Result<(), std::io::Error> {
+    let (c2u, u2c) = copy_bidirectional(&mut client, &mut upstream).await?;
+    tracing::debug!(c2u, u2c, "relay finished");
     Ok(())
 }