/*

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

/*

 * @test

 * @bug 4742177

 * @library /test/lib

 * @summary Re-test IPv6 (and specifically MulticastSocket) with latest Linux & USAGI code

 */

import java.util.*;

import java.net.*;

import jdk.test.lib.NetworkConfiguration;

import jdk.test.lib.net.IPSupport;

public class NoLoopbackPackets {

    private static String osname;

    static boolean isWindows() {

        if (osname == null)

            osname = System.getProperty("os.name");

        return osname.contains("Windows");

    }

    private static final String MESSAGE = "hello world (" + System.nanoTime() + ")";

    public static void main(String[] args) throws Exception {

        if (isWindows()) {

            System.out.println("The test only run on non-Windows OS. Bye.");

            return;

        }

        MulticastSocket msock = null;

        List<SocketAddress> failedGroups = new ArrayList<SocketAddress>();

        Sender sender = null;

        Thread senderThread = null;

        try {

            msock = new MulticastSocket();

            int port = msock.getLocalPort();

            // we will send packets to three multicast groups :-

            // 224.1.1.1, ::ffff:224.1.1.2, and ff02::1:1

            //

            List<SocketAddress> groups = new ArrayList<SocketAddress>();

            if (IPSupport.hasIPv4()) {

                groups.add(new InetSocketAddress(InetAddress.getByName("224.1.1.1"), port));

            }

            NetworkConfiguration nc = NetworkConfiguration.probe();

            if (IPSupport.hasIPv6() && nc.hasTestableIPv6Address()) {

                groups.add(new InetSocketAddress(InetAddress.getByName("::ffff:224.1.1.2"), port));

                groups.add(new InetSocketAddress(InetAddress.getByName("ff02::1:1"), port));

            }

            if (groups.isEmpty()) {

                System.err.println("Nothing to test: there are no network interfaces");

            }

            sender = new Sender(groups);

            senderThread = new Thread(sender);

            senderThread.start();

            // Now try to receive multicast packets. we should not see any of them

            // since we disable loopback mode.

            //

            msock.setSoTimeout(5000);       // 5 seconds

            byte[] buf = new byte[1024];

            for (int i = 0; i < buf.length; i++) {

                buf[i] = (byte) 'z';

            }

            DatagramPacket packet = new DatagramPacket(buf, 0, buf.length);

            byte[] expected = MESSAGE.getBytes();

            assert expected.length <= buf.length;

            for (SocketAddress group : groups) {

                System.out.println("joining group: " + group);

                msock.joinGroup(group, null);

                try {

                    do {

                        for (int i = 0; i < buf.length; i++) {

                            buf[i] = (byte) 'a';

                        }

                        msock.receive(packet);

                        byte[] data = packet.getData();

                        int len = packet.getLength();

                        if (expected(data, len, expected)) {

                            failedGroups.add(group);

                            break;

                        } else {

                            System.err.println("WARNING: Unexpected packet received from "

                                               + group + ": "

                                               + len + " bytes");

                            System.err.println("\t as text: " + new String(data, 0, len));

                        }

                    } while (true);

                } catch (SocketTimeoutException e) {

                    // we expect this

                    System.out.println("Received expected exception from " + group + ": " + e);

                } finally {

                    msock.leaveGroup(group, null);

                }

            }

        } finally {

            if (msock != null) try { msock.close(); } catch (Exception e) {}

            if (sender != null) {

                sender.stop();

            }

        }

        try {

            if (failedGroups.size() > 0) {

                System.out.println("We should not receive anything from following groups, but we did:");

                for (SocketAddress group : failedGroups)

                    System.out.println(group);

                throw new RuntimeException("test failed.");

            }

        } finally {

            if (senderThread != null) {

                senderThread.join();

            }

        }

    }

    static boolean expected(byte[] data, int len, byte[] expected) {

        if (len != expected.length) return false;

        for (int i = 0; i < len; i++) {

            if (data[i] != expected[i]) return false;

        }

        return true;

    }

    static class Sender implements Runnable {

        private List<SocketAddress> sendToGroups;

        private volatile boolean stop;

        public Sender(List<SocketAddress> groups) {

            sendToGroups = groups;

        }

        public void run() {

            byte[] buf = MESSAGE.getBytes();

            List<DatagramPacket> packets = new ArrayList<DatagramPacket>();

            try (MulticastSocket msock = new MulticastSocket()) {

                for (SocketAddress group : sendToGroups) {

                    DatagramPacket packet = new DatagramPacket(buf, buf.length, group);

                    packets.add(packet);

                }

                msock.setLoopbackMode(true);    // disable loopback mode

                while (!stop) {

                    for (DatagramPacket packet : packets) {

                        msock.send(packet);

                    }

                    Thread.sleep(1000);     // 1 second

                }

            } catch (Exception e) {

                throw new RuntimeException(e);

            }

        }

        void stop() {

            stop = true;

        }

    }

}