# iperf3-gui

A Flutter-based Android GUI wrapper for iperf3, the popular network performance
measurement tool.

## Features

- Client-mode network throughput testing
- Configurable server, port, duration and parallel streams
- Live iperf3 output, streamed line by line while the test runs
- Stop a running test early
- Copy the transcript to the clipboard
- iperf3 3.19 compiled into the app as a native library — no external binary

## Architecture

```
lib/
├── domain/
│   ├── models/          # TestConfiguration, Iperf3Result
├── data/
│   └── services/        # Iperf3Service (MethodChannel → JNI)
├── ui/
│   └── features/
│       └── test_run/    # TestRunScreen, TestRunViewModel
└── main.dart            # App entry point

android/app/src/main/
├── kotlin/…/IperfRunner.kt   # MethodChannel handler, runs tests off the platform thread
└── cpp/iperf_jni.c           # JNI bridge into the iperf3 API
```

See [docs/README.md](docs/README.md) for the data flow, the native API surface
and the design decisions behind them.

## Why JNI instead of executing a binary

Android SELinux in Enforcing mode blocks `execve()` from the `untrusted_app`
domain, so shipping an iperf3 ELF in assets and running it via `Process.start()`
fails with "Permission denied". iperf3 is therefore compiled as a shared library
(`libiperf3jni.so`) and called in-process over JNI.

`assets/iperf3/` still holds the pre-compiled binaries from that earlier
approach. They are not declared in `pubspec.yaml`, so they are not packaged into
the APK, and nothing in the app reads them.

## Building

Prerequisites:
- Flutter 3.47+
- Android SDK with platform android-36
- JDK 17
- NDK r28+ and CMake 3.22.1 (for the native build)

```bash
flutter pub get
flutter analyze
flutter test
flutter build apk --debug
adb install -r build/app/outputs/flutter-apk/app-debug.apk
```

## Testing against a local server

```bash
iperf3 -s -p 5201                 # on a machine on the same network
ip -4 addr show                   # note its address
```

Enter that address in the app, then press GO.

## Dependencies

- Dart: `provider`
- Native: iperf3 3.19 + cJSON, built by CMake for `armeabi-v7a` and `arm64-v8a`

## License

MIT — bundled iperf3 3.19 is BSD-3-Clause licensed.