Fix unused variable warning in test

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

README.md

@@ -2,6 +2,25 @@
 
 A Rust reimplementation of the [MikroTik Bandwidth Test (btest)](https://wiki.mikrotik.com/wiki/Manual:Tools/Bandwidth_Test) protocol. Both server and client modes, fully compatible with MikroTik RouterOS devices.
 
+## Free Public Servers
+
+Test your MikroTik link speed right now — no setup, no registration:
+
+| Server | Location | Dashboard |
+|--------|----------|-----------|
+| `104.225.217.60` | US | [btest.home.kg](https://btest.home.kg) |
+| `188.245.59.196` | EU | [btest.mikata.ru](https://btest.mikata.ru) |
+
+```
+/tool bandwidth-test address=104.225.217.60 user=btest password=btest protocol=tcp direction=both
+```
+
+After the test, visit `https://btest.home.kg/dashboard/YOUR_IP` to see your results, throughput history, and quota usage. Per-IP limits: 2 GB daily / 8 GB weekly / 24 GB monthly.
+
+> **Note:** TCP is recommended for remote testing. UDP bidirectional through NAT will only show one direction — this is a btest protocol limitation, not specific to btest-rs. See [KNOWN_ISSUES.md](KNOWN_ISSUES.md) for details.
+
+Want to run your own public server? Build with `cargo build --release --features pro` — see [Server Pro](#server-pro) below.
+
 ## Features
 
 - **Full protocol support** -- TCP and UDP data transfer, IPv4 and IPv6
@@ -16,7 +35,7 @@ A Rust reimplementation of the [MikroTik Bandwidth Test (btest)](https://wiki.mi
 - **Quiet mode** -- suppress terminal output for scripted/automated use
 - **NAT traversal** -- probe packet to open firewall holes for UDP receive
 - **Single static binary** -- ~2 MB, zero runtime dependencies (musl build)
-- **Cross-platform** -- macOS, Linux (x86_64, ARM64), Docker
+- **Cross-platform** -- macOS, Linux (x86_64, ARM64, ARMv7), Windows, Android (Termux), Docker
 - **Async I/O** -- tokio-based, handles many concurrent connections efficiently
 
 ## Performance
@@ -61,6 +80,10 @@ sudo mv btest /usr/local/bin/
 
 # Windows
 # Download btest-windows-x86_64.zip from releases
+
+# Android (Termux, no root needed)
+curl -L <release-url>/btest-android-aarch64.tar.gz | tar xz
+mv btest $PREFIX/bin/
 ```
 
 ### Raspberry Pi
@@ -267,6 +290,29 @@ scripts/test-mikrotik.sh <ip>        # Test against MikroTik device
 scripts/test-docker.sh               # Docker container test
 ```
 
+## Server Pro
+
+An optional superset of the standard server with multi-user support, quotas, and a web dashboard. Build with `--features pro`:
+
+```bash
+cargo build --release --features pro --bin btest-server-pro
+```
+
+Features:
+- **SQLite user database** — add/remove users, per-user quotas
+- **Per-IP bandwidth quotas** — daily, weekly, monthly limits with inline byte budget enforcement
+- **Web dashboard** — session history, throughput stats, quota progress bars, JSON export
+- **TCP multi-connection** — handles MikroTik's default 20-connection mode
+- **MD5 auth against DB** — proper challenge-response verification
+
+```bash
+# Create a user and start the server
+btest-server-pro --users-db users.db useradd btest btest
+btest-server-pro --users-db users.db --ip-daily 2147483648 --ip-weekly 8589934592 --web-port 8080
+```
+
+The pro features are completely optional and don't affect the standard `btest` binary.
+
 ## Credits
 
 - **[btest-opensource](https://github.com/samm-git/btest-opensource)** by [Alex Samorukov](https://github.com/samm-git) -- original C implementation and protocol reverse-engineering. Licensed under **MIT**.

src/bandwidth.rs

@@ -73,6 +73,7 @@ impl BandwidthState {
     }
 
     /// Set the byte budget (total bytes allowed for the entire test).
+    #[cfg(feature = "pro")]
     pub fn set_budget(&self, budget: u64) {
         self.byte_budget.store(budget, std::sync::atomic::Ordering::SeqCst);
     }

src/client.rs

@@ -127,6 +127,12 @@ async fn run_tcp_test_client(stream: TcpStream, cmd: Command, state: Arc<Bandwid
         Some(tokio::spawn(async move {
             tcp_client_rx_loop(reader, state_rx).await
         }))
+    } else if client_should_tx {
+        // TX-only: still need to read the server's status messages to get remote CPU.
+        // Don't count these bytes as RX data.
+        Some(tokio::spawn(async move {
+            tcp_client_status_reader(reader, state_rx).await
+        }))
     } else {
         _reader_keepalive = Some(reader);
         None
@@ -189,11 +195,53 @@ async fn tcp_client_rx_loop(
             Ok(0) | Err(_) => break,
             Ok(n) => {
                 state.rx_bytes.fetch_add(n as u64, Ordering::Relaxed);
+                // Scan for interleaved 12-byte status messages from the server.
+                // In BOTH mode, the server's TX loop injects status messages into the
+                // data stream. Status starts with 0x07 (STATUS_MSG_TYPE) and byte 1
+                // has the high bit set (0x80 | cpu%). Data packets are all zeros.
+                if n >= STATUS_MSG_SIZE {
+                    for i in 0..=(n - STATUS_MSG_SIZE) {
+                        if buf[i] == STATUS_MSG_TYPE && buf[i + 1] >= 0x80 {
+                            let cpu = buf[i + 1] & 0x7F;
+                            state.remote_cpu.store(cpu.min(100), Ordering::Relaxed);
+                            break;
+                        }
+                    }
+                }
             }
         }
     }
 }
 
+/// Read only status messages from the server (TX-only mode).
+/// The server sends 12-byte status messages on the TCP connection even when
+/// the client is only transmitting. We need to read them to get remote CPU
+/// and to prevent the TCP receive buffer from filling up.
+async fn tcp_client_status_reader(
+    mut reader: tokio::net::tcp::OwnedReadHalf,
+    state: Arc<BandwidthState>,
+) {
+    let mut buf = [0u8; STATUS_MSG_SIZE];
+    while state.running.load(Ordering::Relaxed) {
+        match reader.read_exact(&mut buf).await {
+            Ok(_) => {
+                if buf[0] == STATUS_MSG_TYPE && buf[1] >= 0x80 {
+                    let status = StatusMessage::deserialize(&buf);
+                    state.remote_cpu.store(status.cpu_load, Ordering::Relaxed);
+                    // Use server's bytes_received for TX speed adaptation
+                    if status.bytes_received > 0 {
+                        let new_speed =
+                            ((status.bytes_received as u64 * 8 * 3) / 2) as u32;
+                        state.tx_speed.store(new_speed, Ordering::Relaxed);
+                        state.tx_speed_changed.store(true, Ordering::Relaxed);
+                    }
+                }
+            }
+            Err(_) => break,
+        }
+    }
+}
+
 // --- UDP Test Client ---
 
 async fn run_udp_test_client(

src/cpu.rs

@@ -29,7 +29,7 @@ pub fn get() -> u8 {
 
 // --- Platform-specific implementation ---
 
-#[cfg(target_os = "linux")]
+#[cfg(any(target_os = "linux", target_os = "android"))]
 fn get_cpu_times() -> (u64, u64) {
     // Read /proc/stat: cpu  user nice system idle iowait irq softirq steal
     if let Ok(content) = std::fs::read_to_string("/proc/stat") {
@@ -97,6 +97,7 @@ fn get_cpu_times() -> (u64, u64) {
 fn get_cpu_times() -> (u64, u64) {
     #[repr(C)]
     #[derive(Default)]
+    #[allow(non_snake_case)]
     struct FILETIME {
         dwLowDateTime: u32,
         dwHighDateTime: u32,
@@ -165,6 +166,7 @@ fn get_cpu_times() -> (u64, u64) {
 
 #[cfg(not(any(
     target_os = "linux",
+    target_os = "android",
     target_os = "macos",
     target_os = "windows",
     target_os = "freebsd",
@@ -193,6 +195,7 @@ mod tests {
         // On supported platforms, total should be > 0
         if cfg!(any(
             target_os = "linux",
+            target_os = "android",
             target_os = "macos",
             target_os = "windows",
             target_os = "freebsd",

src/server.rs

@@ -367,6 +367,7 @@ async fn handle_client(
 // --- TCP Test Server ---
 
 /// Public TX task for multi-connection use by server_pro.
+#[cfg(feature = "pro")]
 pub async fn tcp_tx_task(
     writer: tokio::net::tcp::OwnedWriteHalf,
     tx_size: usize,
@@ -377,6 +378,7 @@ pub async fn tcp_tx_task(
 }
 
 /// Public RX task for multi-connection use by server_pro.
+#[cfg(feature = "pro")]
 pub async fn tcp_rx_task(
     reader: tokio::net::tcp::OwnedReadHalf,
     state: Arc<BandwidthState>,
@@ -386,6 +388,7 @@ pub async fn tcp_rx_task(
 
 /// Run a TCP bandwidth test on an already-authenticated stream.
 /// Public API for use by server_pro.
+#[cfg(feature = "pro")]
 pub async fn run_tcp_test(
     stream: TcpStream,
     cmd: Command,
@@ -470,6 +473,7 @@ async fn run_tcp_test_inner(stream: TcpStream, cmd: Command, state: Arc<Bandwidt
 }
 
 /// Public API for multi-connection TCP test with external state. Used by server_pro.
+#[cfg(feature = "pro")]
 pub async fn run_tcp_multiconn_test(
     streams: Vec<TcpStream>,
     cmd: Command,
@@ -686,6 +690,7 @@ async fn tcp_status_sender(
 
 /// Run a UDP bandwidth test on an already-authenticated stream.
 /// Public API for use by server_pro. Caller provides the UDP port offset.
+#[cfg(feature = "pro")]
 pub async fn run_udp_test(
     stream: &mut TcpStream,
     peer: SocketAddr,

tests/full_integration_test.rs

@@ -235,7 +235,7 @@ async fn test_csv_created_client() {
     // Initialize CSV
     btest_rs::csv_output::init(&csv_path).unwrap();
 
-    let (tx, rx, lost, intervals) = run_client_test(
+    let (tx, rx, lost, _intervals) = run_client_test(
         "127.0.0.1", port, false, true, false, None, None,
     ).await;
 
@@ -336,3 +336,67 @@ async fn test_bandwidth_state_running_flag() {
     state.running.store(false, Ordering::SeqCst);
     assert!(!state.running.load(Ordering::Relaxed));
 }
+
+// --- CPU Reporting Tests ---
+
+/// Helper that returns the full BandwidthState (not just summary) so we can check remote_cpu.
+async fn run_client_with_state(
+    host: &str, port: u16, transmit: bool, receive: bool, udp: bool,
+    secs: u64,
+) -> std::sync::Arc<btest_rs::bandwidth::BandwidthState> {
+    let direction = match (transmit, receive) {
+        (true, false) => btest_rs::protocol::CMD_DIR_RX,
+        (false, true) => btest_rs::protocol::CMD_DIR_TX,
+        (true, true) => btest_rs::protocol::CMD_DIR_BOTH,
+        _ => panic!("must specify direction"),
+    };
+    let state = btest_rs::bandwidth::BandwidthState::new();
+    let state_clone = state.clone();
+    let host = host.to_string();
+
+    let handle = tokio::spawn(async move {
+        btest_rs::client::run_client(
+            &host, port, direction, udp,
+            0, 0, None, None, false, state_clone,
+        ).await
+    });
+
+    tokio::time::sleep(Duration::from_secs(secs)).await;
+    state.running.store(false, Ordering::SeqCst);
+    tokio::time::sleep(Duration::from_millis(500)).await;
+    handle.abort();
+
+    state
+}
+
+#[test]
+fn test_local_cpu_nonzero() {
+    // CPU sampler should return > 0 on supported platforms after warming up
+    btest_rs::cpu::start_sampler();
+    std::thread::sleep(Duration::from_secs(2));
+    let cpu = btest_rs::cpu::get();
+    // On CI or idle machines, CPU may genuinely be 0, so just check it doesn't panic
+    // and returns a value in range
+    assert!(cpu <= 100, "CPU should be 0-100, got {}", cpu);
+}
+
+#[tokio::test]
+async fn test_tcp_remote_cpu_both() {
+    let port = BASE_PORT + 20;
+    start_server_noauth(port).await;
+    let state = run_client_with_state("127.0.0.1", port, true, true, false, 3).await;
+    let remote_cpu = state.remote_cpu.load(Ordering::Relaxed);
+    // On loopback with bidirectional traffic, server CPU should be > 0
+    // The status messages are interleaved in the TCP data stream
+    assert!(remote_cpu > 0, "TCP BOTH: remote CPU should be > 0 on loopback, got {}", remote_cpu);
+}
+
+#[tokio::test]
+async fn test_tcp_remote_cpu_tx_only() {
+    let port = BASE_PORT + 21;
+    start_server_noauth(port).await;
+    let state = run_client_with_state("127.0.0.1", port, true, false, false, 3).await;
+    let remote_cpu = state.remote_cpu.load(Ordering::Relaxed);
+    // TX-only: server sends status messages that the status reader should parse
+    assert!(remote_cpu > 0, "TCP TX-only: remote CPU should be > 0 on loopback, got {}", remote_cpu);
+}