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 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

 * 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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 */

/**

 * @test

 * @requires os.family != "solaris"

 * @run testng ConnectionReset

 * @run testng/othervm -Djdk.net.usePlainSocketImpl ConnectionReset

 * @summary Test behavior of read and available when a connection is reset

 */

import java.io.IOException;

import java.io.InputStream;

import java.net.InetAddress;

import java.net.InetSocketAddress;

import java.net.ServerSocket;

import java.net.Socket;

import org.testng.annotations.Test;

import static org.testng.Assert.*;

@Test

public class ConnectionReset {

    static final int REPEAT_COUNT = 5;

    /**

     * Tests available before read when there are no bytes to read

     */

    public void testAvailableBeforeRead1() throws IOException {

        System.out.println("testAvailableBeforeRead1");

        withResetConnection(null, s -> {

            InputStream in = s.getInputStream();

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

                int bytesAvailable = in.available();

                System.out.format("available => %d%n", bytesAvailable);

                assertTrue(bytesAvailable == 0);

                try {

                    int bytesRead = in.read();

                    if (bytesRead == -1) {

                        System.out.println("read => EOF");

                    } else {

                        System.out.println("read => 1 byte");

                    }

                    assertTrue(false);

                } catch (IOException ioe) {

                    System.out.format("read => %s (expected)%n", ioe);

                }

            }

        });

    }

    /**

     * Tests available before read when there are bytes to read

     */

    public void testAvailableBeforeRead2() throws IOException {

        System.out.println("testAvailableBeforeRead2");

        byte[] data = { 1, 2, 3 };

        withResetConnection(data, s -> {

            InputStream in = s.getInputStream();

            int remaining = data.length;

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

                int bytesAvailable = in.available();

                System.out.format("available => %d%n", bytesAvailable);

                assertTrue(bytesAvailable <= remaining);

                try {

                    int bytesRead = in.read();

                    if (bytesRead == -1) {

                        System.out.println("read => EOF");

                        assertTrue(false);

                    } else {

                        System.out.println("read => 1 byte");

                        assertTrue(remaining > 0);

                        remaining--;

                    }

                } catch (IOException ioe) {

                    System.out.format("read => %s%n", ioe);

                    remaining = 0;

                }

            }

        });

    }

    /**

     * Tests read before available when there are no bytes to read

     */

    public void testReadBeforeAvailable1() throws IOException {

        System.out.println("testReadBeforeAvailable1");

        withResetConnection(null, s -> {

            InputStream in = s.getInputStream();

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

                try {

                    int bytesRead = in.read();

                    if (bytesRead == -1) {

                        System.out.println("read => EOF");

                    } else {

                        System.out.println("read => 1 byte");

                    }

                    assertTrue(false);

                } catch (IOException ioe) {

                    System.out.format("read => %s (expected)%n", ioe);

                }

                int bytesAvailable = in.available();

                System.out.format("available => %d%n", bytesAvailable);

                assertTrue(bytesAvailable == 0);

            }

        });

    }

    /**

     * Tests read before available when there are bytes to read

     */

    public void testReadBeforeAvailable2() throws IOException {

        System.out.println("testReadBeforeAvailable2");

        byte[] data = { 1, 2, 3 };

        withResetConnection(data, s -> {

            InputStream in = s.getInputStream();

            int remaining = data.length;

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

                try {

                    int bytesRead = in.read();

                    if (bytesRead == -1) {

                        System.out.println("read => EOF");

                        assertTrue(false);

                    } else {

                        System.out.println("read => 1 byte");

                        assertTrue(remaining > 0);

                        remaining--;

                    }

                } catch (IOException ioe) {

                    System.out.format("read => %s%n", ioe);

                    remaining = 0;

                }

                int bytesAvailable = in.available();

                System.out.format("available => %d%n", bytesAvailable);

                assertTrue(bytesAvailable <= remaining);

            }

        });

    }

    /**

     * Tests available and read on a socket closed after connection reset

     */

    public void testAfterClose() throws IOException {

        System.out.println("testAfterClose");

        withResetConnection(null, s -> {

            InputStream in = s.getInputStream();

            try {

                in.read();

                assertTrue(false);

            } catch (IOException ioe) {

                // expected

            }

            s.close();

            try {

                int bytesAvailable = in.available();

                System.out.format("available => %d%n", bytesAvailable);

                assertTrue(false);

            } catch (IOException ioe) {

                System.out.format("available => %s (expected)%n", ioe);

            }

            try {

                int n = in.read();

                System.out.format("read => %d%n", n);

                assertTrue(false);

            } catch (IOException ioe) {

                System.out.format("read => %s (expected)%n", ioe);

            }

        });

    }

    interface ThrowingConsumer<T> {

        void accept(T t) throws IOException;

    }

    /**

     * Invokes a consumer with a Socket connected to a peer that has closed the

     * connection with a "connection reset". The peer sends the given data bytes

     * before closing (when data is not null).

     */

    static void withResetConnection(byte[] data, ThrowingConsumer<Socket> consumer)

        throws IOException

    {

        var loopback = InetAddress.getLoopbackAddress();

        try (var listener = new ServerSocket()) {

            listener.bind(new InetSocketAddress(loopback, 0));

            try (var socket = new Socket()) {

                socket.connect(listener.getLocalSocketAddress());

                try (Socket peer = listener.accept()) {

                    if (data != null) {

                        peer.getOutputStream().write(data);

                    }

                    peer.setSoLinger(true, 0);

                }

                consumer.accept(socket);

            }

        }

    }

}