Fix bug where connection close aborts the peer handler if it's not in Established state.

crates/server/src/peer.rs

@@ -640,20 +640,17 @@ where
         // Close the TCP stream.
         if let Some(stream) = self.tcp_stream.as_mut() {
             match stream.shutdown().await {
-                Ok(_) => info!("Closed TCP stream with peer: {}", self.config.name),
+                Ok(_) => trace!("Closed TCP stream with peer: {}", self.config.name),
-                Err(e) => warn!(
+                Err(_) => { /* Ignore errors since the connection is already defunct. */ }
-                    "Failed to close TCP stream with peer {}: {}",
-                    self.config.name,
-                    e.to_string()
-                ),
             }
         }
 
-        let peer_id = match &self.peer_open_msg {
+        // If the state is open, then we cleanup the routes from this peer.
-            Some(peer_open_msg) => peer_open_msg.identifier,
+        // TODO: This should only be done after the hold timer has expired but for
-            None => bail!("Missing peer open msg"),
+        // simplicity we do it here now.
-        };
+        if matches!(self.state, BGPState::Established) {
-
+            if let Some(peer_open_msg) = &self.peer_open_msg {
+                let peer_id = peer_open_msg.identifier;
                 // Iterate over every route that we've announced to the route manager
                 // and withdraw it.
                 let mut route_withdraw = RouteWithdraw {
@@ -669,12 +666,16 @@ where
                     .send(RouteManagerCommands::Update(RouteUpdate::Withdraw(
                         route_withdraw,
                     )))
-            .map_err(|e| std::io::Error::new(std::io::ErrorKind::BrokenPipe, e.to_string()))?;
+                    .map_err(|e| {
+                        std::io::Error::new(std::io::ErrorKind::BrokenPipe, e.to_string())
+                    })?;
 
                 // Clear prefixes_in.
                 self.prefixes_in = IpLookupTable::new();
+            }
+        }
 
-        // Set the state machine back to the expected.
+        // On any connection close we reset the state back to Active, regardless of the state we were in before.
         self.state = BGPState::Active;
         self.established_time = None;