src/be/nikiroo/utils/serial/server/ServerBridge.java

   1 package be.nikiroo.utils.serial.server;
   2
   3 import java.io.ByteArrayInputStream;
   4 import java.io.IOException;
   5 import java.io.InputStream;
   6 import java.lang.reflect.Array;
   7 import java.net.Socket;
   8 import java.net.UnknownHostException;
   9
  10 import be.nikiroo.utils.StringUtils;
  11 import be.nikiroo.utils.TraceHandler;
  12 import be.nikiroo.utils.serial.Importer;
  13
  14 /**
  15  * This class implements a simple server that can bridge two other
  16  * {@link Server}s.
  17  * <p>
  18  * It can, of course, inspect the data that goes through it (by default, it
  19  * prints traces of the data).
  20  * <p>
  21  * Note: this {@link ServerBridge} has to be discarded after use (cannot be
  22  * started twice).
  23  *
  24  * @author niki
  25  */
  26 public class ServerBridge extends Server {
  27         private final String forwardToHost;
  28         private final int forwardToPort;
  29         private final String forwardToKey;
  30
  31         /**
  32          * Create a new server that will start listening on the network when
  33          * {@link ServerBridge#start()} is called.
  34          *
  35          * @param port
  36          *            the port to listen on, or 0 to assign any unallocated port
  37          *            found (which can later on be queried via
  38          *            {@link ServerBridge#getPort()}
  39          * @param key
  40          *            an optional key to encrypt all the communications (if NULL,
  41          *            everything will be sent in clear text)
  42          * @param forwardToHost
  43          *            the host server to forward the calls to
  44          * @param forwardToPort
  45          *            the host port to forward the calls to
  46          * @param forwardToKey
  47          *            an optional key to encrypt all the communications (if NULL,
  48          *            everything will be sent in clear text)
  49          *
  50          * @throws IOException
  51          *             in case of I/O error
  52          * @throws UnknownHostException
  53          *             if the IP address of the host could not be determined
  54          * @throws IllegalArgumentException
  55          *             if the port parameter is outside the specified range of valid
  56          *             port values, which is between 0 and 65535, inclusive
  57          */
  58         public ServerBridge(int port, String key, String forwardToHost,
  59                         int forwardToPort, String forwardToKey) throws IOException {
  60                 super(port, key);
  61                 this.forwardToHost = forwardToHost;
  62                 this.forwardToPort = forwardToPort;
  63                 this.forwardToKey = forwardToKey;
  64         }
  65
  66         /**
  67          * Create a new server that will start listening on the network when
  68          * {@link ServerBridge#start()} is called.
  69          *
  70          * @param name
  71          *            the server name (only used for debug info and traces)
  72          * @param port
  73          *            the port to listen on
  74          * @param key
  75          *            an optional key to encrypt all the communications (if NULL,
  76          *            everything will be sent in clear text)
  77          * @param forwardToHost
  78          *            the host server to forward the calls to
  79          * @param forwardToPort
  80          *            the host port to forward the calls to
  81          * @param forwardToKey
  82          *            an optional key to encrypt all the communications (if NULL,
  83          *            everything will be sent in clear text) use an SSL connection
  84          *            for the forward server or not
  85          *
  86          * @throws IOException
  87          *             in case of I/O error
  88          * @throws UnknownHostException
  89          *             if the IP address of the host could not be determined
  90          * @throws IllegalArgumentException
  91          *             if the port parameter is outside the specified range of valid
  92          *             port values, which is between 0 and 65535, inclusive
  93          */
  94         public ServerBridge(String name, int port, String key,
  95                         String forwardToHost, int forwardToPort, String forwardToKey)
  96                         throws IOException {
  97                 super(name, port, key);
  98                 this.forwardToHost = forwardToHost;
  99                 this.forwardToPort = forwardToPort;
 100                 this.forwardToKey = forwardToKey;
 101         }
 102
 103         /**
 104          * The traces handler for this {@link Server}.
 105          * <p>
 106          * The trace levels are handled as follow:
 107          * <ul>
 108          * <li>1: it will only print basic IN/OUT messages with length</li>
 109          * <li>2: it will try to interpret it as an object (SLOW) and print the
 110          * object class if possible</li>
 111          * <li>3: it will try to print the {@link Object#toString()} value, or the
 112          * data if it is not an object</li>
 113          * <li>4: it will also print the unzipped serialised value if it is an
 114          * object</li>
 115          * </ul>
 116          *
 117          * @param tracer
 118          *            the new traces handler
 119          */
 120         @Override
 121         public void setTraceHandler(TraceHandler tracer) {
 122                 super.setTraceHandler(tracer);
 123         }
 124
 125         @Override
 126         protected ConnectActionServer createConnectActionServer(Socket s) {
 127                 // Bad impl, not up to date (should work, but not efficient)
 128                 return new ConnectActionServerString(s, key) {
 129                         @Override
 130                         public void action() throws Exception {
 131                                 onClientContact();
 132                                 final ConnectActionServerString bridge = this;
 133
 134                                 try {
 135                                         new ConnectActionClientString(forwardToHost, forwardToPort,
 136                                                         forwardToKey) {
 137                                                 @Override
 138                                                 public void action() throws Exception {
 139                                                         onServerContact();
 140
 141                                                         for (String fromClient = bridge.rec(); fromClient != null; fromClient = bridge
 142                                                                         .rec()) {
 143                                                                 onRec(fromClient);
 144                                                                 String fromServer = send(fromClient);
 145                                                                 onSend(fromServer);
 146                                                                 bridge.send(fromServer);
 147                                                         }
 148
 149                                                         getTraceHandler().trace("=== DONE", 1);
 150                                                         getTraceHandler().trace("", 1);
 151                                                 }
 152
 153                                                 @Override
 154                                                 protected void onError(Exception e) {
 155                                                         ServerBridge.this.onError(e);
 156                                                 }
 157                                         }.connect();
 158                                 } catch (Exception e) {
 159                                         ServerBridge.this.onError(e);
 160                                 }
 161                         }
 162                 };
 163         }
 164
 165         /**
 166          * This is the method that is called each time a client contact us.
 167          */
 168         protected void onClientContact() {
 169                 getTraceHandler().trace(">>> CLIENT ");
 170         }
 171
 172         /**
 173          * This is the method that is called each time a client contact us.
 174          */
 175         protected void onServerContact() {
 176                 getTraceHandler().trace("<<< SERVER");
 177                 getTraceHandler().trace("");
 178         }
 179
 180         /**
 181          * This is the method that is called each time a client contact us.
 182          *
 183          * @param data
 184          *            the data sent by the client
 185          */
 186         protected void onRec(String data) {
 187                 trace(">>> CLIENT", data);
 188         }
 189
 190         /**
 191          * This is the method that is called each time the forwarded server contact
 192          * us.
 193          *
 194          * @param data
 195          *            the data sent by the client
 196          */
 197         protected void onSend(String data) {
 198                 trace("<<< SERVER", data);
 199         }
 200
 201         @Override
 202         public void run() {
 203                 getTraceHandler().trace(
 204                                 getName() + ": will forward to " + forwardToHost + ":"
 205                                                 + forwardToPort + " ("
 206                                                 + (forwardToKey != null ? "encrypted" : "plain text")
 207                                                 + ")");
 208                 super.run();
 209         }
 210
 211         /**
 212          * Trace the data with the given prefix.
 213          *
 214          * @param prefix
 215          *            the prefix (client, server, version...)
 216          * @param data
 217          *            the data to trace
 218          */
 219         private void trace(String prefix, String data) {
 220                 // TODO: we convert to string and back
 221                 int size = data == null ? 0 : data.length();
 222                 String ssize = StringUtils.formatNumber(size) + "bytes";
 223
 224                 getTraceHandler().trace(prefix + ": " + ssize, 1);
 225
 226                 if (getTraceHandler().getTraceLevel() >= 2) {
 227                         try {
 228                                 while (data.startsWith("ZIP:") || data.startsWith("B64:")) {
 229                                         if (data.startsWith("ZIP:")) {
 230                                                 data = StringUtils.unbase64s(data.substring(4), true);
 231                                         } else if (data.startsWith("B64:")) {
 232                                                 data = StringUtils.unbase64s(data.substring(4), false);
 233                                         }
 234                                 }
 235
 236                                 InputStream stream = new ByteArrayInputStream(
 237                                                 data.getBytes("UTF-8"));
 238                                 try {
 239                                         Object obj = new Importer().read(stream).getValue();
 240                                         if (obj == null) {
 241                                                 getTraceHandler().trace("NULL", 2);
 242                                                 getTraceHandler().trace("NULL", 3);
 243                                                 getTraceHandler().trace("NULL", 4);
 244                                         } else {
 245                                                 if (obj.getClass().isArray()) {
 246                                                         getTraceHandler().trace(
 247                                                                         "(" + obj.getClass() + ") with "
 248                                                                                         + Array.getLength(obj)
 249                                                                                         + "element(s)", 3);
 250                                                 } else {
 251                                                         getTraceHandler().trace("(" + obj.getClass() + ")",
 252                                                                         2);
 253                                                 }
 254                                                 getTraceHandler().trace("" + obj.toString(), 3);
 255                                                 getTraceHandler().trace(data, 4);
 256                                         }
 257                                 } finally {
 258                                         stream.close();
 259                                 }
 260                         } catch (NoSuchMethodException e) {
 261                                 getTraceHandler().trace("(not an object)", 2);
 262                                 getTraceHandler().trace(data, 3);
 263                                 getTraceHandler().trace("", 4);
 264                         } catch (NoSuchFieldException e) {
 265                                 getTraceHandler().trace(
 266                                                 "(incompatible: " + e.getMessage() + ")", 2);
 267                                 getTraceHandler().trace(data, 3);
 268                                 getTraceHandler().trace("", 4);
 269                         } catch (ClassNotFoundException e) {
 270                                 getTraceHandler().trace(
 271                                                 "(unknown object: " + e.getMessage() + ")", 2);
 272                                 getTraceHandler().trace(data, 3);
 273                                 getTraceHandler().trace("", 4);
 274                         } catch (Exception e) {
 275                                 getTraceHandler().trace(
 276                                                 "(decode error: " + e.getMessage() + ")", 2);
 277                                 getTraceHandler().trace(data, 3);
 278                                 getTraceHandler().trace("", 4);
 279                         }
 280
 281                         getTraceHandler().trace("", 2);
 282                 }
 283         }
 284 }