/*

 * Copyright (c) 2010, 2013, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * @test

 * @bug 6370908

 * @summary Add support for HTTP_CONNECT proxy in Socket class

 * @modules java.base/sun.net.www

 */

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.PrintWriter;

import static java.lang.System.out;

import java.net.InetAddress;

import java.net.InetSocketAddress;

import java.net.Proxy;

import java.net.ServerSocket;

import java.net.Socket;

import sun.net.www.MessageHeader;

public class HttpProxy {

    final String proxyHost;

    final int proxyPort;

    static final int SO_TIMEOUT = 15000;

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

        String host;

        int port;

        if (args.length == 0) {

            // Start internal proxy

            ConnectProxyTunnelServer proxy = new ConnectProxyTunnelServer();

            proxy.start();

            host = "localhost";

            port = proxy.getLocalPort();

            out.println("Running with internal proxy: " + host + ":" + port);

        } else if (args.length == 2) {

            host = args[0];

            port = Integer.valueOf(args[1]);

            out.println("Running against specified proxy server: " + host + ":" + port);

        } else {

            System.err.println("Usage: java HttpProxy [<proxy host> <proxy port>]");

            return;

        }

        HttpProxy p = new HttpProxy(host, port);

        p.test();

    }

    public HttpProxy(String proxyHost, int proxyPort) {

        this.proxyHost = proxyHost;

        this.proxyPort = proxyPort;

    }

    void test() throws Exception {

        InetSocketAddress proxyAddress = new InetSocketAddress(proxyHost, proxyPort);

        Proxy httpProxy = new Proxy(Proxy.Type.HTTP, proxyAddress);

        try (ServerSocket ss = new ServerSocket(0);

             Socket sock = new Socket(httpProxy)) {

            sock.setSoTimeout(SO_TIMEOUT);

            sock.setTcpNoDelay(false);

            InetSocketAddress externalAddress =

                new InetSocketAddress(InetAddress.getLocalHost(), ss.getLocalPort());

            out.println("Trying to connect to server socket on " + externalAddress);

            sock.connect(externalAddress);

            try (Socket externalSock = ss.accept()) {

                // perform some simple checks

                check(sock.isBound(), "Socket is not bound");

                check(sock.isConnected(), "Socket is not connected");

                check(!sock.isClosed(), "Socket should not be closed");

                check(sock.getSoTimeout() == SO_TIMEOUT,

                        "Socket should have a previously set timeout");

                check(sock.getTcpNoDelay() ==  false, "NODELAY should be false");

                simpleDataExchange(sock, externalSock);

            }

        }

    }

    static void check(boolean condition, String message) {

        if (!condition) out.println(message);

    }

    static Exception unexpected(Exception e) {

        out.println("Unexcepted Exception: " + e);

        e.printStackTrace();

        return e;

    }

    // performs a simple exchange of data between the two sockets

    // and throws an exception if there is any problem.

    void simpleDataExchange(Socket s1, Socket s2) throws Exception {

        try (final InputStream i1 = s1.getInputStream();

             final InputStream i2 = s2.getInputStream();

             final OutputStream o1 = s1.getOutputStream();

             final OutputStream o2 = s2.getOutputStream()) {

            startSimpleWriter("simpleWriter1", o1, 100);

            startSimpleWriter("simpleWriter2", o2, 200);

            simpleRead(i2, 100);

            simpleRead(i1, 200);

        }

    }

    void startSimpleWriter(String threadName, final OutputStream os, final int start) {

        (new Thread(new Runnable() {

            public void run() {

                try { simpleWrite(os, start); }

                catch (Exception e) {unexpected(e); }

            }}, threadName)).start();

    }

    void simpleWrite(OutputStream os, int start) throws Exception {

        byte b[] = new byte[2];

        for (int i=start; i<start+100; i++) {

            b[0] = (byte) (i / 256);

            b[1] = (byte) (i % 256);

            os.write(b);

        }

    }

    void simpleRead(InputStream is, int start) throws Exception {

        byte b[] = new byte [2];

        for (int i=start; i<start+100; i++) {

            int x = is.read(b);

            if (x == 1)

                x += is.read(b,1,1);

            if (x!=2)

                throw new Exception("read error");

            int r = bytes(b[0], b[1]);

            if (r != i)

                throw new Exception("read " + r + " expected " +i);

        }

    }

    int bytes(byte b1, byte b2) {

        int i1 = (int)b1 & 0xFF;

        int i2 = (int)b2 & 0xFF;

        return i1 * 256 + i2;

    }

    static class ConnectProxyTunnelServer extends Thread {

        private final ServerSocket ss;

        public ConnectProxyTunnelServer() throws IOException {

            ss = new ServerSocket(0);

        }

        @Override

        public void run() {

            try (Socket clientSocket = ss.accept()) {

                processRequest(clientSocket);

            } catch (Exception e) {

                out.println("Proxy Failed: " + e);

                e.printStackTrace();

            } finally {

                try { ss.close(); } catch (IOException x) { unexpected(x); }

            }

        }

        /**

         * Returns the port on which the proxy is accepting connections.

         */

        public int getLocalPort() {

            return ss.getLocalPort();

        }

        /*

         * Processes the CONNECT request

         */

        private void processRequest(Socket clientSocket) throws Exception {

            MessageHeader mheader = new MessageHeader(clientSocket.getInputStream());

            String statusLine = mheader.getValue(0);

            if (!statusLine.startsWith("CONNECT")) {

                out.println("proxy server: processes only "

                                  + "CONNECT method requests, recieved: "

                                  + statusLine);

                return;

            }

            // retrieve the host and port info from the status-line

            InetSocketAddress serverAddr = getConnectInfo(statusLine);

            //open socket to the server

            try (Socket serverSocket = new Socket(serverAddr.getAddress(),

                                                  serverAddr.getPort())) {

                Forwarder clientFW = new Forwarder(clientSocket.getInputStream(),

                                                   serverSocket.getOutputStream());

                Thread clientForwarderThread = new Thread(clientFW, "ClientForwarder");

                clientForwarderThread.start();

                send200(clientSocket);

                Forwarder serverFW = new Forwarder(serverSocket.getInputStream(),

                                                   clientSocket.getOutputStream());

                serverFW.run();

                clientForwarderThread.join();

            }

        }

        private void send200(Socket clientSocket) throws IOException {

            OutputStream out = clientSocket.getOutputStream();

            PrintWriter pout = new PrintWriter(out);

            pout.println("HTTP/1.1 200 OK");

            pout.println();

            pout.flush();

        }

        /*

         * This method retrieves the hostname and port of the tunnel destination

         * from the request line.

         * @param connectStr

         *        of the form: <i>CONNECT server-name:server-port HTTP/1.x</i>

         */

        static InetSocketAddress getConnectInfo(String connectStr)

            throws Exception

        {

            try {

                int starti = connectStr.indexOf(' ');

                int endi = connectStr.lastIndexOf(' ');

                String connectInfo = connectStr.substring(starti+1, endi).trim();

                // retrieve server name and port

                endi = connectInfo.indexOf(':');

                String name = connectInfo.substring(0, endi);

                int port = Integer.parseInt(connectInfo.substring(endi+1));

                return new InetSocketAddress(name, port);

            } catch (Exception e) {

                out.println("Proxy recieved a request: " + connectStr);

                throw unexpected(e);

            }

        }

    }

    /* Reads from the given InputStream and writes to the given OutputStream */

    static class Forwarder implements Runnable

    {

        private final InputStream in;

        private final OutputStream os;

        Forwarder(InputStream in, OutputStream os) {

            this.in = in;

            this.os = os;

        }

        @Override

        public void run() {

            try {

                byte[] ba = new byte[1024];

                int count;

                while ((count = in.read(ba)) != -1) {

                    os.write(ba, 0, count);

                }

            } catch (IOException e) {

                unexpected(e);

            }

        }

    }

}