1 /*

     2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

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

     4  *

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

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

     7  * published by the Free Software Foundation.

     8  *

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

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

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

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

    13  * accompanied this code).

    14  *

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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

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

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

    21  * questions.

    22  */

    23 

    24 import java.io.IOException;

    25 import java.io.UncheckedIOException;

    26 import java.net.InetSocketAddress;

    27 import java.net.URI;

    28 import java.nio.ByteBuffer;

    29 import java.nio.CharBuffer;

    30 import java.nio.channels.ServerSocketChannel;

    31 import java.nio.channels.SocketChannel;

    32 import java.nio.charset.CharacterCodingException;

    33 import java.nio.charset.StandardCharsets;

    34 import java.security.MessageDigest;

    35 import java.security.NoSuchAlgorithmException;

    36 import java.util.Arrays;

    37 import java.util.Base64;

    38 import java.util.HashMap;

    39 import java.util.Iterator;

    40 import java.util.LinkedList;

    41 import java.util.List;

    42 import java.util.Map;

    43 import java.util.concurrent.CompletableFuture;

    44 import java.util.function.Function;

    45 import java.util.regex.Pattern;

    46 import java.util.stream.Collectors;

    47 

    48 import static java.lang.String.format;

    49 import static java.util.Objects.requireNonNull;

    50 

    51 //

    52 // Performs a simple opening handshake and yields the channel.

    53 //

    54 // Client Request:

    55 //

    56 //    GET /chat HTTP/1.1

    57 //    Host: server.example.com

    58 //    Upgrade: websocket

    59 //    Connection: Upgrade

    60 //    Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==

    61 //    Origin: http://example.com

    62 //    Sec-WebSocket-Protocol: chat, superchat

    63 //    Sec-WebSocket-Version: 13

    64 //

    65 //

    66 // Server Response:

    67 //

    68 //    HTTP/1.1 101 Switching Protocols

    69 //    Upgrade: websocket

    70 //    Connection: Upgrade

    71 //    Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=

    72 //    Sec-WebSocket-Protocol: chat

    73 //

    74 final class HandshakePhase {

    75 

    76     private final ServerSocketChannel ssc;

    77 

    78     HandshakePhase(InetSocketAddress address) {

    79         requireNonNull(address);

    80         try {

    81             ssc = ServerSocketChannel.open();

    82             ssc.bind(address);

    83         } catch (IOException e) {

    84             throw new UncheckedIOException(e);

    85         }

    86     }

    87 

    88     //

    89     // Returned CF completes normally after the handshake has been performed

    90     //

    91     CompletableFuture<SocketChannel> afterHandshake(

    92             Function<List<String>, List<String>> mapping) {

    93         return CompletableFuture.supplyAsync(

    94                 () -> {

    95                     SocketChannel socketChannel = accept();

    96                     try {

    97                         StringBuilder request = new StringBuilder();

    98                         if (!readRequest(socketChannel, request)) {

    99                             throw new IllegalStateException();

   100                         }

   101                         List<String> strings = Arrays.asList(

   102                                 request.toString().split("\r\n")

   103                         );

   104                         List<String> response = mapping.apply(strings);

   105                         writeResponse(socketChannel, response);

   106                         return socketChannel;

   107                     } catch (Throwable t) {

   108                         try {

   109                             socketChannel.close();

   110                         } catch (IOException ignored) { }

   111                         throw t;

   112                     }

   113                 });

   114     }

   115 

   116     CompletableFuture<SocketChannel> afterHandshake() {

   117         return afterHandshake((request) -> {

   118             List<String> response = new LinkedList<>();

   119             Iterator<String> iterator = request.iterator();

   120             if (!iterator.hasNext()) {

   121                 throw new IllegalStateException("The request is empty");

   122             }

   123             if (!"GET / HTTP/1.1".equals(iterator.next())) {

   124                 throw new IllegalStateException

   125                         ("Unexpected status line: " + request.get(0));

   126             }

   127             response.add("HTTP/1.1 101 Switching Protocols");

   128             Map<String, String> requestHeaders = new HashMap<>();

   129             while (iterator.hasNext()) {

   130                 String header = iterator.next();

   131                 String[] split = header.split(": ");

   132                 if (split.length != 2) {

   133                     throw new IllegalStateException

   134                             ("Unexpected header: " + header

   135                                     + ", split=" + Arrays.toString(split));

   136                 }

   137                 if (requestHeaders.put(split[0], split[1]) != null) {

   138                     throw new IllegalStateException

   139                             ("Duplicating headers: " + Arrays.toString(split));

   140                 }

   141             }

   142             if (requestHeaders.containsKey("Sec-WebSocket-Protocol")) {

   143                 throw new IllegalStateException("Subprotocols are not expected");

   144             }

   145             if (requestHeaders.containsKey("Sec-WebSocket-Extensions")) {

   146                 throw new IllegalStateException("Extensions are not expected");

   147             }

   148             expectHeader(requestHeaders, "Connection", "Upgrade");

   149             response.add("Connection: Upgrade");

   150             expectHeader(requestHeaders, "Upgrade", "websocket");

   151             response.add("Upgrade: websocket");

   152             expectHeader(requestHeaders, "Sec-WebSocket-Version", "13");

   153             String key = requestHeaders.get("Sec-WebSocket-Key");

   154             if (key == null) {

   155                 throw new IllegalStateException("Sec-WebSocket-Key is missing");

   156             }

   157             MessageDigest sha1 = null;

   158             try {

   159                 sha1 = MessageDigest.getInstance("SHA-1");

   160             } catch (NoSuchAlgorithmException e) {

   161                 throw new InternalError(e);

   162             }

   163             String x = key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

   164             sha1.update(x.getBytes(StandardCharsets.ISO_8859_1));

   165             String v = Base64.getEncoder().encodeToString(sha1.digest());

   166             response.add("Sec-WebSocket-Accept: " + v);

   167             return response;

   168         });

   169     }

   170 

   171     private String expectHeader(Map<String, String> headers,

   172                                 String name,

   173                                 String value) {

   174         String v = headers.get(name);

   175         if (!value.equals(v)) {

   176             throw new IllegalStateException(

   177                     format("Expected '%s: %s', actual: '%s: %s'",

   178                             name, value, name, v)

   179             );

   180         }

   181         return v;

   182     }

   183 

   184     URI getURI() {

   185         InetSocketAddress a;

   186         try {

   187             a = (InetSocketAddress) ssc.getLocalAddress();

   188         } catch (IOException e) {

   189             throw new UncheckedIOException(e);

   190         }

   191         return URI.create("ws://" + a.getHostName() + ":" + a.getPort());

   192     }

   193 

   194     private int read(SocketChannel socketChannel, ByteBuffer buffer) {

   195         try {

   196             int num = socketChannel.read(buffer);

   197             if (num == -1) {

   198                 throw new IllegalStateException("Unexpected EOF");

   199             }

   200             assert socketChannel.isBlocking() && num > 0;

   201             return num;

   202         } catch (IOException e) {

   203             throw new UncheckedIOException(e);

   204         }

   205     }

   206 

   207     private SocketChannel accept() {

   208         SocketChannel socketChannel = null;

   209         try {

   210             socketChannel = ssc.accept();

   211             socketChannel.configureBlocking(true);

   212         } catch (IOException e) {

   213             if (socketChannel != null) {

   214                 try {

   215                     socketChannel.close();

   216                 } catch (IOException ignored) { }

   217             }

   218             throw new UncheckedIOException(e);

   219         }

   220         return socketChannel;

   221     }

   222 

   223     private boolean readRequest(SocketChannel socketChannel,

   224                                 StringBuilder request) {

   225         ByteBuffer buffer = ByteBuffer.allocateDirect(512);

   226         read(socketChannel, buffer);

   227         CharBuffer decoded;

   228         buffer.flip();

   229         try {

   230             decoded =

   231                     StandardCharsets.ISO_8859_1.newDecoder().decode(buffer);

   232         } catch (CharacterCodingException e) {

   233             throw new UncheckedIOException(e);

   234         }

   235         request.append(decoded);

   236         return Pattern.compile("\r\n\r\n").matcher(request).find();

   237     }

   238 

   239     private void writeResponse(SocketChannel socketChannel,

   240                                List<String> response) {

   241         String s = response.stream().collect(Collectors.joining("\r\n"))

   242                 + "\r\n\r\n";

   243         ByteBuffer encoded;

   244         try {

   245             encoded =

   246                     StandardCharsets.ISO_8859_1.newEncoder().encode(CharBuffer.wrap(s));

   247         } catch (CharacterCodingException e) {

   248             throw new UncheckedIOException(e);

   249         }

   250         write(socketChannel, encoded);

   251     }

   252 

   253     private void write(SocketChannel socketChannel, ByteBuffer buffer) {

   254         try {

   255             while (buffer.hasRemaining()) {

   256                 socketChannel.write(buffer);

   257             }

   258         } catch (IOException e) {

   259             try {

   260                 socketChannel.close();

   261             } catch (IOException ignored) { }

   262             throw new UncheckedIOException(e);

   263         }

   264     }

   265 }