OpenVPNClient.java

import javafx.application.Application;
import javafx.application.Platform;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.file.Paths;
import java.time.LocalDate;
import java.util.Timer;
import java.util.TimerTask;


public class OpenVPNClient extends Application {
	private static final String HOME = System.getenv("HOME");
	private ComboBox<String> configDropDown;
	private TextField usernameField;
	private TextField passwordField;
	private Button connectButton;
	private Button disconnectButton;
	private ClientLogger clientLogger;
	private Label statusLabel;
	private String profilePath;
	private boolean isConnected;

	@Override
	public void start(Stage stage) throws Exception {
		this.clientLogger = new ClientLogger(Paths.get("logs", LocalDate.now().toString().concat(".log")));
		this.configDropDown = new ComboBox<>();
		this.usernameField = new TextField();
		this.passwordField = new PasswordField();
		this.connectButton = new Button("Connect");
		this.disconnectButton = new Button("Disconnect");
		this.disconnectButton.setDisable(true);
		this.isConnected = false;

		this.statusLabel = new Label("Disconnected");
		this.statusLabel.setTextFill(Color.RED);
		loadConfigurations();

		this.connectButton.setOnAction(actionEvent -> {
			this.connectButton.setDisable(true);
			this.statusLabel.setText("Connecting...");
			this.statusLabel.setTextFill(Color.DARKORANGE);
			String username = this.usernameField.getText();

			connectToVpn(username);
			Platform.runLater(() -> pingStatus(5, true));
		});

        this.disconnectButton.setOnAction(actionEvent -> {
            Platform.runLater(() -> {
                this.disconnectButton.setDisable(true);
                this.statusLabel.setText("Disconnecting...");
                this.statusLabel.setTextFill(Color.DARKORANGE);
            });
			disconnectFromVpn();
			Platform.runLater(() -> pingStatus(5, false));
        });

		HBox buttonsBox = new HBox(this.connectButton, this.disconnectButton);
		// Create a layout and add components to it
		VBox root = new VBox();
		root.getChildren().addAll(
				new Label("Select Config:"), configDropDown,
				new Label("Username:"), usernameField,
				new Label("Password:"), passwordField,
				buttonsBox,
				new Label("Status:"), statusLabel
		);

		Scene scene = new Scene(root, 300, 200);
		stage.setTitle("OpenVPN GUI");
		stage.setScene(scene);
		stage.show();
	}

	private void pingStatus(int i, boolean isConnecting) {
		ProcessBuilder pb = new ProcessBuilder("openvpn3", "sessions-list");

		Timer timer = new Timer();
        timer.scheduleAtFixedRate(
			new TimerTask() {
				private int count = 0;

				@Override
				public void run() {
					try {
						Process process = pb.start();
						InputStream inputStream = process.getInputStream();

						BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));

						String line;
						while ((line = reader.readLine()) != null) {
							if (line.contains("connected") && !isConnected) {
								Platform.runLater(() -> {
									disconnectButton.setDisable(false);
									statusLabel.setTextFill(Color.GREEN);
									statusLabel.setText("Connected");
									isConnected = true;
								});
							} else if (line.contains("No sessions available") && isConnected) {
								removeConfig();
								Platform.runLater(() -> {
									connectButton.setDisable(false);
									statusLabel.setTextFill(Color.RED);
									statusLabel.setText("Disconnected");
									isConnected = false;
								});
							}
						}

						process.waitFor();
						reader.close();
					} catch (IOException | InterruptedException e) {
						e.printStackTrace();
					}

					count++;
					if (count >= i) {
						boolean failedConnect = !isConnected && isConnecting;
						boolean failedDisconnect = isConnected && !isConnecting;
						if (failedConnect | failedDisconnect) {
							Platform.runLater(() -> {
								statusLabel.setText("Failed");
								statusLabel.setTextFill(Color.RED);
								connectButton.setDisable(false);
								clientLogger.writeError("Failed operation.");
							});
						}
						if (failedConnect) {
							// Connection may be in pending state. This will remove attempt.
							disconnectFromVpn();
							clientLogger.writeError("Disconnected due to failed connection attempt.");
						}
						timer.cancel();

					}
				}
			},
			0,
			1000
		);
	}

	// reads profile configurations from the output returned from executing the command "openvpn3 configs-list" in a Bash terminal
	private void loadConfigurations() {
		try {
			ProcessBuilder pb = new ProcessBuilder("openvpn3", "configs-list")
					.redirectErrorStream(true);
			Process process = pb.start();
			InputStream is = process.getInputStream();
			BufferedReader reader = new BufferedReader(new InputStreamReader(is));

			String line;
			while ((line = reader.readLine()) != null) {
				if (line.contains("profile")) {
					String profile = line.substring(0, line.indexOf(" "));
					this.profilePath = profile;
				}
			}
			process.waitFor();
			reader.close();
		} catch (IOException | InterruptedException ie) {
			ie.printStackTrace();
		}
	}
	private void disconnectFromVpn() {
		try {
			ProcessBuilder pb = new ProcessBuilder("openvpn3", "session-manage",
					"--disconnect", "--config", this.profilePath);
			Process process = pb.start();

			logStdOut(process);

			process.waitFor();
		} catch (IOException | InterruptedException ie) {
			this.clientLogger.writeError(ie.getMessage());
			throw new RuntimeException("Something went wrong when trying to disconnect.");
		}
	}

	private void connectToVpn(String username) {
		try {
			ProcessBuilder pb = new ProcessBuilder("openvpn3-autoload",
					"--directory", HOME.concat("/.openvpn3/autoload")).redirectErrorStream(true);
			Process process = pb.start();
			logStdOut(process);
			process.waitFor();
		} catch (IOException | InterruptedException ie) {
			this.clientLogger.writeError(ie.getMessage());
		}
	}

	// autoload (i.e. our session starter) adds redundant configs to config-list
	private void removeConfig() {
		try {
			ProcessBuilder pb = new ProcessBuilder("openvpn3", "config-remove",
					"--config", profilePath);
			Process process = pb.start();
			logStdOut(process);
			process.waitFor();
		} catch (IOException | InterruptedException ie) {
			this.clientLogger.writeError(ie.getMessage());
			throw new RuntimeException("Something went wrong when trying to remove config.");
		}
	}

	private void logStdOut(Process process) {
		try (BufferedReader reader =
					 new BufferedReader(new InputStreamReader(process.getInputStream()))){

			String line;
			while ((line = reader.readLine()) != null) {
				this.clientLogger.write(line);
			}

		} catch (IOException ie) {
			ie.printStackTrace();
			throw new RuntimeException("Failed to write STDOUT to log");
		}

	}

}