Fix CPU reporting: MikroTik uses 0x80|pct encoding, add CPU to CSV

- MikroTik encodes CPU as 0x80 | percentage (high bit flag)
- Deserialize: mask with 0x7F and cap at 100
- Serialize: set high bit (0x80 | cpu) to match MikroTik format
- CSV now includes local_cpu_pct and remote_cpu_pct columns
- Both client and server write CPU to CSV

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

src/csv_output.rs

@@ -12,7 +12,7 @@ use std::time::SystemTime;
 static CSV_FILE: Mutex<Option<String>> = Mutex::new(None);
 static QUIET: std::sync::atomic::AtomicBool = std::sync::atomic::AtomicBool::new(false);
 
-const HEADER: &str = "timestamp,host,port,protocol,direction,duration_s,tx_avg_mbps,rx_avg_mbps,tx_bytes,rx_bytes,lost_packets,auth_type";
+const HEADER: &str = "timestamp,host,port,protocol,direction,duration_s,tx_avg_mbps,rx_avg_mbps,tx_bytes,rx_bytes,lost_packets,local_cpu_pct,remote_cpu_pct,auth_type";
 
 /// Initialize CSV output. Creates file with headers if needed.
 pub fn init(path: &str) -> std::io::Result<()> {
@@ -45,6 +45,8 @@ pub fn write_result(
     tx_bytes: u64,
     rx_bytes: u64,
     lost_packets: u64,
+    local_cpu: u8,
+    remote_cpu: u8,
     auth_type: &str,
 ) {
     let guard = CSV_FILE.lock().unwrap();
@@ -66,9 +68,10 @@ pub fn write_result(
             .as_secs();
 
         let row = format!(
-            "{},{},{},{},{},{},{:.2},{:.2},{},{},{},{}",
+            "{},{},{},{},{},{},{:.2},{:.2},{},{},{},{},{},{}",
             now, host, port, protocol, direction, duration_secs,
-            tx_mbps, rx_mbps, tx_bytes, rx_bytes, lost_packets, auth_type,
+            tx_mbps, rx_mbps, tx_bytes, rx_bytes, lost_packets,
+            local_cpu, remote_cpu, auth_type,
         );
 
         if let Ok(mut f) = OpenOptions::new().append(true).open(path) {

src/main.rs

@@ -226,9 +226,11 @@ async fn main() -> anyhow::Result<()> {
         // Write CSV if enabled
         if csv_output::is_enabled() {
             let auth_type = if cli.auth_user.is_some() { "auth" } else { "none" };
+            let local_cpu = cpu::get();
+            let remote_cpu = shared_state.remote_cpu.load(std::sync::atomic::Ordering::Relaxed);
             csv_output::write_result(
                 &host, cli.port, proto_str, dir_str,
-                elapsed, total_tx, total_rx, total_lost, auth_type,
+                elapsed, total_tx, total_rx, total_lost, local_cpu, remote_cpu, auth_type,
             );
         }
     } else {

src/protocol.rs

@@ -144,8 +144,8 @@ impl StatusMessage {
     pub fn serialize(&self) -> [u8; STATUS_MSG_SIZE] {
         let mut buf = [0u8; STATUS_MSG_SIZE];
         buf[0] = STATUS_MSG_TYPE;
-        // Byte 1: CPU load percentage (0-100)
-        buf[1] = self.cpu_load;
+        // Byte 1: CPU load with high bit set (MikroTik format: 0x80 | percentage)
+        buf[1] = 0x80 | (self.cpu_load & 0x7F);
         buf[2] = 0;
         buf[3] = 0;
         // Bytes 4-7: sequence number (LE)
@@ -156,8 +156,11 @@ impl StatusMessage {
     }
 
     pub fn deserialize(buf: &[u8; STATUS_MSG_SIZE]) -> Self {
+        // MikroTik encodes CPU with high bit set: actual = byte & 0x7F
+        let raw_cpu = buf[1];
+        let cpu = if raw_cpu > 128 { raw_cpu & 0x7F } else { raw_cpu };
         Self {
-            cpu_load: buf[1],
+            cpu_load: cpu.min(100),
             seq: u32::from_le_bytes([buf[4], buf[5], buf[6], buf[7]]),
             bytes_received: u32::from_le_bytes([buf[8], buf[9], buf[10], buf[11]]),
         }

src/server.rs

@@ -357,7 +357,8 @@ async fn handle_client(
     if crate::csv_output::is_enabled() {
         crate::csv_output::write_result(
             &peer.ip().to_string(), peer.port(), proto_str, dir_str,
-            intervals as u64, total_tx, total_rx, total_lost, auth_type,
+            intervals as u64, total_tx, total_rx, total_lost,
+            crate::cpu::get(), 0, auth_type,
         );
     }
     result.map(|_| ())

tests/full_integration_test.rs

@@ -242,7 +242,7 @@ async fn test_csv_created_client() {
     // Write result like main.rs does
     btest_rs::csv_output::write_result(
         "127.0.0.1", port, "TCP", "receive",
-        2, tx, rx, lost, "none",
+        2, tx, rx, lost, 0, 0, "none",
     );
 
     // Verify CSV exists and has data
@@ -251,7 +251,12 @@ async fn test_csv_created_client() {
     assert!(lines.len() >= 2, "CSV should have header + at least 1 row, got {} lines", lines.len());
     assert!(lines[0].starts_with("timestamp,"), "CSV header missing");
     assert!(lines[1].contains("TCP"), "CSV row should contain protocol");
-    assert!(!lines[1].contains(",0,0,0,"), "CSV should have non-zero bytes");
+    // Check that tx or rx bytes are non-zero (the 7th or 8th CSV field)
+    let fields: Vec<&str> = lines[1].split(',').collect();
+    assert!(fields.len() >= 10, "CSV row should have enough fields");
+    let tx_bytes: u64 = fields[8].parse().unwrap_or(0);
+    let rx_bytes: u64 = fields[9].parse().unwrap_or(0);
+    assert!(tx_bytes > 0 || rx_bytes > 0, "CSV should have non-zero bytes: tx={} rx={}", tx_bytes, rx_bytes);
 
     let _ = std::fs::remove_file(&csv_path);
 }