Add TCP status for bidirectional mode

In BOTH direction, the TX loop now injects 12-byte status messages
every 1 second between data packets, reporting rx_bytes to the client.
Multi-connection mode also updated with same logic for all 3 cases:
- TX only: pure data
- RX only: status sender on writer
- BOTH: TX data + interleaved status messages

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/server.rs

@@ -303,13 +303,18 @@ async fn run_tcp_test_server(stream: TcpStream, cmd: Command) -> Result<()> {
     let mut _reader_keepalive = None;
 
     let state_tx = state.clone();
-    let tx_handle = if server_should_tx {
+    let tx_handle = if server_should_tx && server_should_rx {
+        // BOTH mode: TX data + inject status messages for the RX direction
+        Some(tokio::spawn(async move {
+            tcp_tx_with_status(writer, tx_size, tx_speed, state_tx).await
+        }))
+    } else if server_should_tx {
+        // TX only
         Some(tokio::spawn(async move {
             tcp_tx_loop(writer, tx_size, tx_speed, state_tx).await
         }))
     } else if server_should_rx {
-        // Server receives: use the writer to send periodic status messages
-        // back to the client (MikroTik needs this to show speed)
+        // RX only: use writer for status messages
         let st = state.clone();
         Some(tokio::spawn(async move {
             tcp_status_sender(writer, st).await
@@ -329,19 +334,26 @@ async fn run_tcp_test_server(stream: TcpStream, cmd: Command) -> Result<()> {
         None
     };
 
-    if !server_should_rx || server_should_tx {
-        // Normal status loop (TX-only or BOTH modes)
+    if server_should_tx && !server_should_rx {
+        // TX-only: normal status loop reports TX stats
         status_report_loop(&cmd, &state).await;
+    } else if server_should_tx && server_should_rx {
+        // BOTH: TX loop injects status + prints RX. Just report TX here.
+        let mut seq: u32 = 0;
+        let mut tick = tokio::time::interval(Duration::from_secs(1));
+        loop {
+            tick.tick().await;
+            if !state.running.load(Ordering::Relaxed) { break; }
+            seq += 1;
+            let tx = state.tx_bytes.swap(0, Ordering::Relaxed);
+            bandwidth::print_status(seq, "TX", tx, Duration::from_secs(1), None);
+        }
     } else {
-        // RX-only: tcp_status_sender handles both status sending and printing.
-        // Just wait for it and the RX loop to finish.
-        if tx_handle.is_some() {
-            // tx_handle is the status sender in this case
+        // RX-only: tcp_status_sender handles everything. Just wait.
         while state.running.load(Ordering::Relaxed) {
             tokio::time::sleep(Duration::from_millis(500)).await;
         }
     }
-    }
 
     state.running.store(false, Ordering::SeqCst);
     if let Some(h) = tx_handle { let _ = h.await; }
@@ -365,11 +377,21 @@ async fn run_tcp_multiconn_server(streams: Vec<TcpStream>, cmd: Command) -> Resu
     for tcp_stream in streams {
         let (reader, writer) = tcp_stream.into_split();
 
-        if server_should_tx {
+        if server_should_tx && server_should_rx {
+            let st = state.clone();
+            tx_handles.push(tokio::spawn(async move {
+                tcp_tx_with_status(writer, tx_size, tx_speed, st).await
+            }));
+        } else if server_should_tx {
             let st = state.clone();
             tx_handles.push(tokio::spawn(async move {
                 tcp_tx_loop(writer, tx_size, tx_speed, st).await
             }));
+        } else if server_should_rx {
+            let st = state.clone();
+            tx_handles.push(tokio::spawn(async move {
+                tcp_status_sender(writer, st).await
+            }));
         } else {
             _writer_keepalives.push(writer);
         }
@@ -404,14 +426,53 @@ async fn tcp_tx_loop(
     tx_size: usize,
     tx_speed: u32,
     state: Arc<BandwidthState>,
+) {
+    tcp_tx_loop_inner(&mut writer, tx_size, tx_speed, &state, false).await;
+}
+
+/// TCP TX loop that also sends status messages when `send_status` is true.
+/// Used in bidirectional mode where the writer handles both data and status.
+async fn tcp_tx_with_status(
+    mut writer: tokio::net::tcp::OwnedWriteHalf,
+    tx_size: usize,
+    tx_speed: u32,
+    state: Arc<BandwidthState>,
+) {
+    tcp_tx_loop_inner(&mut writer, tx_size, tx_speed, &state, true).await;
+}
+
+async fn tcp_tx_loop_inner(
+    writer: &mut tokio::net::tcp::OwnedWriteHalf,
+    tx_size: usize,
+    tx_speed: u32,
+    state: &Arc<BandwidthState>,
+    send_status: bool,
 ) {
     tokio::time::sleep(Duration::from_millis(100)).await;
 
-    let packet = vec![0u8; tx_size]; // TCP data is all zeros (no 0x07 header)
+    let packet = vec![0u8; tx_size];
     let mut interval = bandwidth::calc_send_interval(tx_speed, tx_size as u16);
     let mut next_send = Instant::now();
+    let mut next_status = Instant::now() + Duration::from_secs(1);
+    let mut status_seq: u32 = 0;
 
     while state.running.load(Ordering::Relaxed) {
+        // Inject status message every ~1 second if in bidirectional mode
+        if send_status && Instant::now() >= next_status {
+            status_seq += 1;
+            let rx_bytes = state.rx_bytes.swap(0, Ordering::Relaxed);
+            let status = StatusMessage {
+                seq: status_seq,
+                bytes_received: rx_bytes as u32,
+            };
+            if writer.write_all(&status.serialize()).await.is_err() {
+                state.running.store(false, Ordering::SeqCst);
+                break;
+            }
+            bandwidth::print_status(status_seq, "RX", rx_bytes, Duration::from_secs(1), None);
+            next_status = Instant::now() + Duration::from_secs(1);
+        }
+
         if writer.write_all(&packet).await.is_err() {
             state.running.store(false, Ordering::SeqCst);
             break;