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

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 * 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,

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 */

/* @test

 * @bug 4527345 7026376

 * @summary Unit test for DatagramChannel's multicast support

 * @build MulticastSendReceiveTests NetworkConfiguration

 * @run main MulticastSendReceiveTests

 */

import java.nio.ByteBuffer;

import java.nio.channels.*;

import java.net.*;

import static java.net.StandardProtocolFamily.*;

import java.util.*;

import java.io.IOException;

public class MulticastSendReceiveTests {

    static final Random rand = new Random();

    static final ProtocolFamily UNSPEC = new ProtocolFamily() {

        public String name() {

            return "UNSPEC";

        }

    };

    /**

     * Send datagram from given local address to given multicast

     * group.

     */

    static int sendDatagram(InetAddress local,

                            NetworkInterface nif,

                            InetAddress group,

                            int port)

        throws IOException

    {

        ProtocolFamily family = (group instanceof Inet6Address) ?

            StandardProtocolFamily.INET6 : StandardProtocolFamily.INET;

        DatagramChannel dc = DatagramChannel.open(family)

            .bind(new InetSocketAddress(local, 0))

            .setOption(StandardSocketOption.IP_MULTICAST_IF, nif);

        int id = rand.nextInt();

        byte[] msg = Integer.toString(id).getBytes("UTF-8");

        ByteBuffer buf = ByteBuffer.wrap(msg);

        System.out.format("Send message from %s -> group %s (id=0x%x)\n",

            local.getHostAddress(), group.getHostAddress(), id);

        dc.send(buf, new InetSocketAddress(group, port));

        dc.close();

        return id;

    }

    /**

     * Wait (with timeout) for datagram.

     *

     * @param   expectedSender - expected sender address, or

     *                           null if no datagram expected

     * @param   id - expected id of datagram

     */

    static void receiveDatagram(DatagramChannel dc,

                                InetAddress expectedSender,

                                int id)

        throws IOException

    {

        Selector sel = Selector.open();

        dc.configureBlocking(false);

        dc.register(sel, SelectionKey.OP_READ);

        ByteBuffer buf = ByteBuffer.allocateDirect(100);

        try {

            for (;;) {

                System.out.println("Waiting to receive message");

                sel.select(5*1000);

                SocketAddress sa = dc.receive(buf);

                // no datagram received

                if (sa == null) {

                    if (expectedSender != null) {

                        throw new RuntimeException("Expected message not recieved");

                    }

                    System.out.println("No message received (correct)");

                    return;

                }

                // datagram received

                InetAddress sender = ((InetSocketAddress)sa).getAddress();

                buf.flip();

                byte[] bytes = new byte[buf.remaining()];

                buf.get(bytes);

                int receivedId = Integer.parseInt(new String(bytes));

                System.out.format("Received message from %s (id=0x%x)\n",

                    sender, receivedId);

                if (expectedSender == null) {

                    if (receivedId == id)

                        throw new RuntimeException("Message not expected");

                    System.out.println("Message ignored (has wrong id)");

                } else {

                    if (sender.equals(expectedSender)) {

                        System.out.println("Message expected");

                        return;

                    }

                    System.out.println("Message ignored (wrong sender)");

                }

                sel.selectedKeys().clear();

                buf.rewind();

            }

        } finally {

            sel.close();

        }

    }

    /**

     * Exercise multicast send/receive on given group/interface

     */

    static void test(ProtocolFamily family,

                     NetworkInterface nif,

                     InetAddress group,

                     InetAddress source)

        throws IOException

    {

        System.out.format("\nTest DatagramChannel to %s socket\n", family.name());

        try (DatagramChannel dc = (family == UNSPEC) ?

                DatagramChannel.open() : DatagramChannel.open(family)) {

            dc.setOption(StandardSocketOption.SO_REUSEADDR, true)

              .bind(new InetSocketAddress(0));

            // join group

            System.out.format("join %s @ %s\n", group.getHostAddress(),

                nif.getName());

            MembershipKey key;

            try {

                key = dc.join(group, nif);

            } catch (IllegalArgumentException iae) {

                if (family == UNSPEC) {

                    System.out.println("Not supported");

                    return;

                }

                throw iae;

            }

            // send message to group

            int port = ((InetSocketAddress)dc.getLocalAddress()).getPort();

            int id = sendDatagram(source, nif, group, port);

            // receive message and check id matches

            receiveDatagram(dc, source, id);

            // exclude-mode filtering

            try {

                System.out.format("block %s\n", source.getHostAddress());

                // may throw UOE

                key.block(source);

                id = sendDatagram(source, nif, group, port);

                receiveDatagram(dc, null, id);

                // unblock source, send message, message should be received

                System.out.format("unblock %s\n", source.getHostAddress());

                key.unblock(source);

                id = sendDatagram(source, nif, group, port);

                receiveDatagram(dc, source, id);

            } catch (UnsupportedOperationException x) {

                System.out.println("Exclude-mode filtering not supported!");

            }

            key.drop();

            // include-mode filtering

            InetAddress bogus = (group instanceof Inet6Address) ?

                InetAddress.getByName("fe80::1234") :

                InetAddress.getByName("1.2.3.4");

            System.out.format("join %s @ %s only-source %s\n", group.getHostAddress(),

                nif.getName(), bogus.getHostAddress());

            try {

                // may throw UOE

                key = dc.join(group, nif, bogus);

                id = sendDatagram(source, nif, group, port);

                receiveDatagram(dc, null, id);

                System.out.format("join %s @ %s only-source %s\n", group.getHostAddress(),

                    nif.getName(), source.getHostAddress());

                key = dc.join(group, nif, source);

                id = sendDatagram(source, nif, group, port);

                receiveDatagram(dc, source, id);

            } catch (UnsupportedOperationException x) {

                System.out.println("Include-mode filtering not supported!");

            }

        }

    }

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

        NetworkConfiguration config = NetworkConfiguration.probe();

        // multicast groups used for the test

        InetAddress ip4Group = InetAddress.getByName("225.4.5.6");

        InetAddress ip6Group = InetAddress.getByName("ff02::a");

        for (NetworkInterface nif: config.ip4Interfaces()) {

            InetAddress source = config.ip4Addresses(nif).iterator().next();

            test(INET,   nif, ip4Group, source);

            test(UNSPEC, nif, ip4Group, source);

        }

        for (NetworkInterface nif: config.ip6Interfaces()) {

            InetAddress source = config.ip6Addresses(nif).iterator().next();

            test(INET6,  nif, ip6Group, source);

            test(UNSPEC, nif, ip6Group, source);

        }

    }

}