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.Version;
  13 import be.nikiroo.utils.serial.Importer;
  14
  15 /**
  16  * This class implements a simple server that can bridge two other
  17  * {@link Server}s.
  18  * <p>
  19  * It can, of course, inspect the data that goes through it (by default, it
  20  * prints traces of the data).
  21  * <p>
  22  * Note: this {@link ServerBridge} has to be discarded after use (cannot be
  23  * started twice).
  24  *
  25  * @author niki
  26  */
  27 public class ServerBridge extends Server {
  28         private final String forwardToHost;
  29         private final int forwardToPort;
  30         private final String forwardToKey;
  31
  32         /**
  33          * Create a new server that will start listening on the network when
  34          * {@link ServerBridge#start()} is called.
  35          *
  36          * @param port
  37          *            the port to listen on, or 0 to assign any unallocated port
  38          *            found (which can later on be queried via
  39          *            {@link ServerBridge#getPort()}
  40          * @param key
  41          *            an optional key to encrypt all the communications (if NULL,
  42          *            everything will be sent in clear text)
  43          * @param forwardToHost
  44          *            the host server to forward the calls to
  45          * @param forwardToPort
  46          *            the host port to forward the calls to
  47          * @param forwardToKey
  48          *            an optional key to encrypt all the communications (if NULL,
  49          *            everything will be sent in clear text)
  50          *
  51          * @throws IOException
  52          *             in case of I/O error
  53          * @throws UnknownHostException
  54          *             if the IP address of the host could not be determined
  55          * @throws IllegalArgumentException
  56          *             if the port parameter is outside the specified range of valid
  57          *             port values, which is between 0 and 65535, inclusive
  58          */
  59         public ServerBridge(int port, String key, String forwardToHost,
  60                         int forwardToPort, String forwardToKey) throws IOException {
  61                 super(port, key);
  62                 this.forwardToHost = forwardToHost;
  63                 this.forwardToPort = forwardToPort;
  64                 this.forwardToKey = forwardToKey;
  65         }
  66
  67         /**
  68          * Create a new server that will start listening on the network when
  69          * {@link ServerBridge#start()} is called.
  70          *
  71          * @param name
  72          *            the server name (only used for debug info and traces)
  73          * @param port
  74          *            the port to listen on
  75          * @param key
  76          *            an optional key to encrypt all the communications (if NULL,
  77          *            everything will be sent in clear text)
  78          * @param forwardToHost
  79          *            the host server to forward the calls to
  80          * @param forwardToPort
  81          *            the host port to forward the calls to
  82          * @param forwardToKey
  83          *            an optional key to encrypt all the communications (if NULL,
  84          *            everything will be sent in clear text) use an SSL connection
  85          *            for the forward server or not
  86          *
  87          * @throws IOException
  88          *             in case of I/O error
  89          * @throws UnknownHostException
  90          *             if the IP address of the host could not be determined
  91          * @throws IllegalArgumentException
  92          *             if the port parameter is outside the specified range of valid
  93          *             port values, which is between 0 and 65535, inclusive
  94          */
  95         public ServerBridge(String name, int port, String key,
  96                         String forwardToHost, int forwardToPort, String forwardToKey)
  97                         throws IOException {
  98                 super(name, port, key);
  99                 this.forwardToHost = forwardToHost;
 100                 this.forwardToPort = forwardToPort;
 101                 this.forwardToKey = forwardToKey;
 102         }
 103
 104         /**
 105          * The traces handler for this {@link Server}.
 106          * <p>
 107          * The trace levels are handled as follow:
 108          * <ul>
 109          * <li>1: it will only print basic IN/OUT messages with length</li>
 110          * <li>2: it will try to interpret it as an object (SLOW) and print the
 111          * object class if possible</li>
 112          * <li>3: it will try to print the {@link Object#toString()} value, or the
 113          * data if it is not an object</li>
 114          * <li>4: it will also print the unzipped serialised value if it is an
 115          * object</li>
 116          * </ul>
 117          *
 118          * @param tracer
 119          *            the new traces handler
 120          */
 121         @Override
 122         public void setTraceHandler(TraceHandler tracer) {
 123                 super.setTraceHandler(tracer);
 124         }
 125
 126         @Override
 127         protected ConnectActionServer createConnectActionServer(Socket s) {
 128                 // Bad impl, not up to date (should work, but not efficient)
 129                 return new ConnectActionServerString(s, key) {
 130                         @Override
 131                         public void action(Version clientVersion) throws Exception {
 132                                 onClientContact(clientVersion);
 133                                 final ConnectActionServerString bridge = this;
 134
 135                                 try {
 136                                         new ConnectActionClientString(forwardToHost, forwardToPort,
 137                                                         forwardToKey) {
 138                                                 @Override
 139                                                 public void action(Version serverVersion)
 140                                                                 throws Exception {
 141                                                         onServerContact(serverVersion);
 142
 143                                                         for (String fromClient = bridge.rec(); fromClient != null; fromClient = bridge
 144                                                                         .rec()) {
 145                                                                 onRec(fromClient);
 146                                                                 String fromServer = send(fromClient);
 147                                                                 onSend(fromServer);
 148                                                                 bridge.send(fromServer);
 149                                                         }
 150
 151                                                         getTraceHandler().trace("=== DONE", 1);
 152                                                         getTraceHandler().trace("", 1);
 153                                                 }
 154
 155                                                 @Override
 156                                                 protected void onError(Exception e) {
 157                                                         ServerBridge.this.onError(e);
 158                                                 }
 159                                         }.connect();
 160                                 } catch (Exception e) {
 161                                         ServerBridge.this.onError(e);
 162                                 }
 163                         }
 164                 };
 165         }
 166
 167         /**
 168          * This is the method that is called each time a client contact us.
 169          */
 170         protected void onClientContact(Version clientVersion) {
 171                 getTraceHandler().trace(">>> CLIENT " + clientVersion);
 172         }
 173
 174         /**
 175          * This is the method that is called each time a client contact us.
 176          */
 177         protected void onServerContact(Version serverVersion) {
 178                 getTraceHandler().trace("<<< SERVER " + serverVersion);
 179                 getTraceHandler().trace("");
 180         }
 181
 182         /**
 183          * This is the method that is called each time a client contact us.
 184          *
 185          * @param data
 186          *            the data sent by the client
 187          */
 188         protected void onRec(String data) {
 189                 trace(">>> CLIENT", data);
 190         }
 191
 192         /**
 193          * This is the method that is called each time the forwarded server contact
 194          * us.
 195          *
 196          * @param data
 197          *            the data sent by the client
 198          */
 199         protected void onSend(String data) {
 200                 trace("<<< SERVER", data);
 201         }
 202
 203         @Override
 204         protected ConnectActionClient getConnectionToMe()
 205                         throws UnknownHostException, IOException {
 206                 return new ConnectActionClientString(new Socket((String) null,
 207                                 getPort()), key);
 208         }
 209
 210         @Override
 211         public void run() {
 212                 getTraceHandler().trace(
 213                                 getName() + ": will forward to " + forwardToHost + ":"
 214                                                 + forwardToPort + " ("
 215                                                 + (forwardToKey != null ? "encrypted" : "plain text")
 216                                                 + ")");
 217                 super.run();
 218         }
 219
 220         /**
 221          * Trace the data with the given prefix.
 222          *
 223          * @param prefix
 224          *            the prefix (client, server, version...)
 225          * @param data
 226          *            the data to trace
 227          */
 228         private void trace(String prefix, String data) {
 229                 // TODO: we convert to string and back
 230                 int size = data == null ? 0 : data.length();
 231                 String ssize = StringUtils.formatNumber(size) + "bytes";
 232
 233                 getTraceHandler().trace(prefix + ": " + ssize, 1);
 234
 235                 if (getTraceHandler().getTraceLevel() >= 2) {
 236                         try {
 237                                 while (data.startsWith("ZIP:") || data.startsWith("B64:")) {
 238                                         if (data.startsWith("ZIP:")) {
 239                                                 data = StringUtils.unzip64s(data.substring(4));
 240                                         } else if (data.startsWith("B64:")) {
 241                                                 data = StringUtils.unzip64s(data.substring(4));
 242                                         }
 243                                 }
 244
 245                                 InputStream stream = new ByteArrayInputStream(
 246                                                 StringUtils.getBytes(data));
 247                                 try {
 248                                         Object obj = new Importer().read(stream).getValue();
 249                                         if (obj == null) {
 250                                                 getTraceHandler().trace("NULL", 2);
 251                                                 getTraceHandler().trace("NULL", 3);
 252                                                 getTraceHandler().trace("NULL", 4);
 253                                         } else {
 254                                                 if (obj.getClass().isArray()) {
 255                                                         getTraceHandler().trace(
 256                                                                         "(" + obj.getClass() + ") with "
 257                                                                                         + Array.getLength(obj)
 258                                                                                         + "element(s)", 3);
 259                                                 } else {
 260                                                         getTraceHandler().trace("(" + obj.getClass() + ")",
 261                                                                         2);
 262                                                 }
 263                                                 getTraceHandler().trace("" + obj.toString(), 3);
 264                                                 getTraceHandler().trace(data, 4);
 265                                         }
 266                                 } finally {
 267                                         stream.close();
 268                                 }
 269                         } catch (NoSuchMethodException e) {
 270                                 getTraceHandler().trace("(not an object)", 2);
 271                                 getTraceHandler().trace(data, 3);
 272                                 getTraceHandler().trace("", 4);
 273                         } catch (NoSuchFieldException e) {
 274                                 getTraceHandler().trace(
 275                                                 "(incompatible: " + e.getMessage() + ")", 2);
 276                                 getTraceHandler().trace(data, 3);
 277                                 getTraceHandler().trace("", 4);
 278                         } catch (ClassNotFoundException e) {
 279                                 getTraceHandler().trace(
 280                                                 "(unknown object: " + e.getMessage() + ")", 2);
 281                                 getTraceHandler().trace(data, 3);
 282                                 getTraceHandler().trace("", 4);
 283                         } catch (Exception e) {
 284                                 getTraceHandler().trace(
 285                                                 "(decode error: " + e.getMessage() + ")", 2);
 286                                 getTraceHandler().trace(data, 3);
 287                                 getTraceHandler().trace("", 4);
 288                         }
 289
 290                         getTraceHandler().trace("", 2);
 291                 }
 292         }
 293 }