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

   1 package be.nikiroo.utils.serial.server;
   2
   3 import java.io.IOException;
   4 import java.net.ServerSocket;
   5 import java.net.Socket;
   6 import java.net.UnknownHostException;
   7 import java.util.ArrayList;
   8 import java.util.List;
   9
  10 import javax.net.ssl.SSLServerSocket;
  11 import javax.net.ssl.SSLServerSocketFactory;
  12 import javax.net.ssl.SSLSocket;
  13 import javax.net.ssl.SSLSocketFactory;
  14
  15 import be.nikiroo.utils.TraceHandler;
  16
  17 /**
  18  * This class implements a simple server that can listen for connections and
  19  * send/receive objects.
  20  * <p>
  21  * Note: this {@link Server} has to be discarded after use (cannot be started
  22  * twice).
  23  *
  24  * @author niki
  25  */
  26 abstract class Server implements Runnable {
  27         static private final String[] ANON_CIPHERS = getAnonCiphers();
  28
  29         private final String name;
  30         private final boolean ssl;
  31         private final Object lock = new Object();
  32         private final Object counterLock = new Object();
  33
  34         private ServerSocket ss;
  35         private int port;
  36
  37         private boolean started;
  38         private boolean exiting = false;
  39         private int counter;
  40
  41         private long bytesReceived;
  42         private long bytesSent;
  43
  44         private TraceHandler tracer = new TraceHandler();
  45
  46         /**
  47          * Create a new {@link ConnectActionServer} to handle a request.
  48          *
  49          * @param s
  50          *            the socket to service
  51          *
  52          * @return the action
  53          */
  54         abstract ConnectActionServer createConnectActionServer(Socket s);
  55
  56         /**
  57          * Create a new server that will start listening on the network when
  58          * {@link Server#start()} is called.
  59          *
  60          * @param port
  61          *            the port to listen on, or 0 to assign any unallocated port
  62          *            found (which can later on be queried via
  63          *            {@link Server#getPort()}
  64          * @param ssl
  65          *            use a SSL connection (or not)
  66          *
  67          * @throws IOException
  68          *             in case of I/O error
  69          * @throws UnknownHostException
  70          *             if the IP address of the host could not be determined
  71          * @throws IllegalArgumentException
  72          *             if the port parameter is outside the specified range of valid
  73          *             port values, which is between 0 and 65535, inclusive
  74          */
  75         public Server(int port, boolean ssl) throws IOException {
  76                 this((String) null, port, ssl);
  77         }
  78
  79         /**
  80          * Create a new server that will start listening on the network when
  81          * {@link Server#start()} is called.
  82          *
  83          * @param name
  84          *            the server name (only used for debug info and traces)
  85          * @param port
  86          *            the port to listen on
  87          * @param ssl
  88          *            use a SSL connection (or not)
  89          *
  90          * @throws IOException
  91          *             in case of I/O error
  92          * @throws UnknownHostException
  93          *             if the IP address of the host could not be determined
  94          * @throws IllegalArgumentException
  95          *             if the port parameter is outside the specified range of valid
  96          *             port values, which is between 0 and 65535, inclusive
  97          */
  98         public Server(String name, int port, boolean ssl) throws IOException {
  99                 this.name = name;
 100                 this.port = port;
 101                 this.ssl = ssl;
 102                 this.ss = createSocketServer(port, ssl);
 103
 104                 if (this.port == 0) {
 105                         this.port = this.ss.getLocalPort();
 106                 }
 107         }
 108
 109         /**
 110          * The traces handler for this {@link Server}.
 111          *
 112          * @return the traces handler
 113          */
 114         public TraceHandler getTraceHandler() {
 115                 return tracer;
 116         }
 117
 118         /**
 119          * The traces handler for this {@link Server}.
 120          *
 121          * @param tracer
 122          *            the new traces handler
 123          */
 124         public void setTraceHandler(TraceHandler tracer) {
 125                 if (tracer == null) {
 126                         tracer = new TraceHandler(false, false, false);
 127                 }
 128
 129                 this.tracer = tracer;
 130         }
 131
 132         /**
 133          * The name of this {@link Server} if any.
 134          * <p>
 135          * Used for traces and debug purposes only.
 136          *
 137          * @return the name or NULL
 138          */
 139         public String getName() {
 140                 return name;
 141         }
 142
 143         /**
 144          * Return the assigned port.
 145          *
 146          * @return the assigned port
 147          */
 148         public int getPort() {
 149                 return port;
 150         }
 151
 152         /**
 153          * The total amount of bytes received.
 154          *
 155          * @return the amount of bytes received
 156          */
 157         public long getBytesReceived() {
 158                 return bytesReceived;
 159         }
 160
 161         /**
 162          * The total amount of bytes sent.
 163          *
 164          * @return the amount of bytes sent
 165          */
 166         public long getBytesSent() {
 167                 return bytesSent;
 168         }
 169
 170         /**
 171          * Start the server (listen on the network for new connections).
 172          * <p>
 173          * Can only be called once.
 174          * <p>
 175          * This call is asynchronous, and will just start a new {@link Thread} on
 176          * itself (see {@link Server#run()}).
 177          */
 178         public void start() {
 179                 new Thread(this).start();
 180         }
 181
 182         /**
 183          * Start the server (listen on the network for new connections).
 184          * <p>
 185          * Can only be called once.
 186          * <p>
 187          * You may call it via {@link Server#start()} for an asynchronous call, too.
 188          */
 189         @Override
 190         public void run() {
 191                 ServerSocket ss = null;
 192                 boolean alreadyStarted = false;
 193                 synchronized (lock) {
 194                         ss = this.ss;
 195                         if (!started && ss != null) {
 196                                 started = true;
 197                         } else {
 198                                 alreadyStarted = started;
 199                         }
 200                 }
 201
 202                 if (alreadyStarted) {
 203                         tracer.error(name + ": cannot start server on port " + port
 204                                         + ", it is already started");
 205                         return;
 206                 }
 207
 208                 if (ss == null) {
 209                         tracer.error(name + ": cannot start server on port " + port
 210                                         + ", it has already been used");
 211                         return;
 212                 }
 213
 214                 try {
 215                         tracer.trace(name + ": server starting on port " + port + " ("
 216                                         + (ssl ? "SSL" : "plain text") + ")");
 217
 218                         while (started && !exiting) {
 219                                 count(1);
 220                                 final Socket s = ss.accept();
 221                                 new Thread(new Runnable() {
 222                                         @Override
 223                                         public void run() {
 224                                                 ConnectActionServer action = null;
 225                                                 try {
 226                                                         action = createConnectActionServer(s);
 227                                                         action.connect();
 228                                                 } finally {
 229                                                         count(-1);
 230                                                         if (action != null) {
 231                                                                 bytesReceived += action.getBytesReceived();
 232                                                                 bytesSent += action.getBytesSent();
 233                                                         }
 234                                                 }
 235                                         }
 236                                 }).start();
 237                         }
 238
 239                         // Will be covered by @link{Server#stop(long)} for timeouts
 240                         while (counter > 0) {
 241                                 Thread.sleep(10);
 242                         }
 243                 } catch (Exception e) {
 244                         if (counter > 0) {
 245                                 onError(e);
 246                         }
 247                 } finally {
 248                         try {
 249                                 ss.close();
 250                         } catch (Exception e) {
 251                                 onError(e);
 252                         }
 253
 254                         this.ss = null;
 255
 256                         started = false;
 257                         exiting = false;
 258                         counter = 0;
 259
 260                         tracer.trace(name + ": client terminated on port " + port);
 261                 }
 262         }
 263
 264         /**
 265          * Will stop the server, synchronously and without a timeout.
 266          */
 267         public void stop() {
 268                 tracer.trace(name + ": stopping server");
 269                 stop(0, true);
 270         }
 271
 272         /**
 273          * Stop the server.
 274          *
 275          * @param timeout
 276          *            the maximum timeout to wait for existing actions to complete,
 277          *            or 0 for "no timeout"
 278          * @param wait
 279          *            wait for the server to be stopped before returning
 280          *            (synchronous) or not (asynchronous)
 281          */
 282         public void stop(final long timeout, final boolean wait) {
 283                 if (wait) {
 284                         stop(timeout);
 285                 } else {
 286                         new Thread(new Runnable() {
 287                                 @Override
 288                                 public void run() {
 289                                         stop(timeout);
 290                                 }
 291                         }).start();
 292                 }
 293         }
 294
 295         /**
 296          * Stop the server (synchronous).
 297          *
 298          * @param timeout
 299          *            the maximum timeout to wait for existing actions to complete,
 300          *            or 0 for "no timeout"
 301          */
 302         private void stop(long timeout) {
 303                 tracer.trace(name + ": server stopping on port " + port);
 304                 synchronized (lock) {
 305                         if (started && !exiting) {
 306                                 exiting = true;
 307
 308                                 try {
 309                                         new ConnectActionClientObject(createSocket(null, port, ssl))
 310                                                         .connect();
 311                                         long time = 0;
 312                                         while (ss != null && timeout > 0 && timeout > time) {
 313                                                 Thread.sleep(10);
 314                                                 time += 10;
 315                                         }
 316                                 } catch (Exception e) {
 317                                         if (ss != null) {
 318                                                 counter = 0; // will stop the main thread
 319                                                 onError(e);
 320                                         }
 321                                 }
 322                         }
 323                 }
 324
 325                 // return only when stopped
 326                 while (started || exiting) {
 327                         try {
 328                                 Thread.sleep(10);
 329                         } catch (InterruptedException e) {
 330                         }
 331                 }
 332         }
 333
 334         /**
 335          * Change the number of currently serviced actions.
 336          *
 337          * @param change
 338          *            the number to increase or decrease
 339          *
 340          * @return the current number after this operation
 341          */
 342         private int count(int change) {
 343                 synchronized (counterLock) {
 344                         counter += change;
 345                         return counter;
 346                 }
 347         }
 348
 349         /**
 350          * This method will be called on errors.
 351          * <p>
 352          * By default, it will only call the trace handler (so you may want to call
 353          * super {@link Server#onError} if you override it).
 354          *
 355          * @param e
 356          *            the error
 357          */
 358         protected void onError(Exception e) {
 359                 tracer.error(e);
 360         }
 361
 362         /**
 363          * Create a {@link Socket}.
 364          *
 365          * @param host
 366          *            the host to connect to
 367          * @param port
 368          *            the port to connect to
 369          * @param ssl
 370          *            TRUE for SSL mode (or FALSE for plain text mode)
 371          *
 372          * @return the {@link Socket}
 373          *
 374          * @throws IOException
 375          *             in case of I/O error
 376          * @throws UnknownHostException
 377          *             if the host is not known
 378          * @throws IllegalArgumentException
 379          *             if the port parameter is outside the specified range of valid
 380          *             port values, which is between 0 and 65535, inclusive
 381          */
 382         static Socket createSocket(String host, int port, boolean ssl)
 383                         throws IOException {
 384                 Socket s;
 385                 if (ssl) {
 386                         s = SSLSocketFactory.getDefault().createSocket(host, port);
 387                         if (s instanceof SSLSocket) {
 388                                 // Should always be the case
 389                                 ((SSLSocket) s).setEnabledCipherSuites(ANON_CIPHERS);
 390                         }
 391                 } else {
 392                         s = new Socket(host, port);
 393                 }
 394
 395                 return s;
 396         }
 397
 398         /**
 399          * Create a {@link ServerSocket}.
 400          *
 401          * @param port
 402          *            the port to accept connections on
 403          * @param ssl
 404          *            TRUE for SSL mode (or FALSE for plain text mode)
 405          *
 406          * @return the {@link ServerSocket}
 407          *
 408          * @throws IOException
 409          *             in case of I/O error
 410          * @throws UnknownHostException
 411          *             if the IP address of the host could not be determined
 412          * @throws IllegalArgumentException
 413          *             if the port parameter is outside the specified range of valid
 414          *             port values, which is between 0 and 65535, inclusive
 415          */
 416         static ServerSocket createSocketServer(int port, boolean ssl)
 417                         throws IOException {
 418                 ServerSocket ss;
 419                 if (ssl) {
 420                         ss = SSLServerSocketFactory.getDefault().createServerSocket(port);
 421                         if (ss instanceof SSLServerSocket) {
 422                                 // Should always be the case
 423                                 ((SSLServerSocket) ss).setEnabledCipherSuites(ANON_CIPHERS);
 424                         }
 425                 } else {
 426                         ss = new ServerSocket(port);
 427                 }
 428
 429                 return ss;
 430         }
 431
 432         /**
 433          * Return all the supported ciphers that do not use authentication.
 434          *
 435          * @return the list of such supported ciphers
 436          */
 437         public static String[] getAnonCiphers() {
 438                 List<String> anonCiphers = new ArrayList<String>();
 439                 for (String cipher : ((SSLSocketFactory) SSLSocketFactory.getDefault())
 440                                 .getSupportedCipherSuites()) {
 441                         if (cipher.contains("_anon_")) {
 442                                 anonCiphers.add(cipher);
 443                         }
 444                 }
 445
 446                 return anonCiphers.toArray(new String[] {});
 447         }
 448 }