- * It represents a single action: a client is expected to only execute one - * action, while a server is expected to execute one action for each client - * action. - * - * @author niki - */ -abstract class ConnectAction { - // We separate each "packet" we send with this character and make sure it - // does not occurs in the message itself. - static private char STREAM_SEP = '\b'; - static private String[] STREAM_RAW = new String[] { "\\", "\b" }; - static private String[] STREAM_CODED = new String[] { "\\\\", "\\b" }; - - private Socket s; - private boolean server; - - private Version clientVersion; - private Version serverVersion; - - private CryptUtils crypt; - - private Object lock = new Object(); - private NextableInputStream in; - private BufferedOutputStream out; - private boolean contentToSend; - - /** - * Method that will be called when an action is performed on either the - * client or server this {@link ConnectAction} represent. - * - * @param version - * the version on the other side of the communication (client or - * server) - * - * @throws Exception - * in case of I/O error - */ - abstract protected void action(Version version) throws Exception; - - /** - * Method called when we negotiate the version with the client. - *
- * Thus, it is only called on the server. - *
- * Will return the actual server version by default. - * - * @param clientVersion - * the client version - * - * @return the version to send to the client - */ - abstract protected Version negotiateVersion(Version clientVersion); - - /** - * Handler called when an unexpected error occurs in the code. - * - * @param e - * the exception that occurred, SSLException usually denotes a - * crypt error - */ - abstract protected void onError(Exception e); - - /** - * Create a new {@link ConnectAction}. - * - * @param s - * the socket to bind to - * @param server - * TRUE for a server action, FALSE for a client action (will - * impact the process) - * @param key - * an optional key to encrypt all the communications (if NULL, - * everything will be sent in clear text) - * @param version - * the client-or-server version (depending upon the boolean - * parameter server) - */ - protected ConnectAction(Socket s, boolean server, String key, - Version version) { - this.s = s; - this.server = server; - if (key != null) { - crypt = new CryptUtils(key); - } - - if (version == null) { - version = new Version(); - } - - if (server) { - serverVersion = version; - } else { - clientVersion = version; - } - } - - /** - * The version of this client-or-server. - * - * @return the version - */ - public Version getVersion() { - if (server) { - return serverVersion; - } - - return clientVersion; - } - - /** - * The total amount of bytes received. - * - * @return the amount of bytes received - */ - public long getBytesReceived() { - return in.getBytesRead(); - } - - /** - * The total amount of bytes sent. - * - * @return the amount of bytes sent - */ - public long getBytesWritten() { - return out.getBytesWritten(); - } - - /** - * Actually start the process (this is synchronous). - */ - public void connect() { - try { - in = new NextableInputStream(s.getInputStream(), - new NextableInputStreamStep(STREAM_SEP)); - try { - out = new BufferedOutputStream(s.getOutputStream()); - try { - // Negotiate version - Version version; - if (server) { - String HELLO = recString(); - if (HELLO == null || !HELLO.startsWith("VERSION ")) { - throw new SSLException( - "Client used bad encryption key"); - } - version = negotiateVersion(new Version( - HELLO.substring("VERSION ".length()))); - sendString("VERSION " + version); - } else { - String HELLO = sendString("VERSION " + clientVersion); - if (HELLO == null || !HELLO.startsWith("VERSION ")) { - throw new SSLException( - "Server did not accept the encryption key"); - } - version = new Version(HELLO.substring("VERSION " - .length())); - } - - // Actual code - action(version); - } finally { - out.close(); - } - } finally { - in.close(); - } - } catch (Exception e) { - onError(e); - } finally { - try { - s.close(); - } catch (Exception e) { - onError(e); - } - } - } - - /** - * Serialise and send the given object to the counter part (and, only for - * client, return the deserialised answer -- the server will always receive - * NULL). - * - * @param data - * the data to send - * - * @return the answer (which can be NULL if no answer, or NULL for an answer - * which is NULL) if this action is a client, always NULL if it is a - * server - * - * @throws IOException - * in case of I/O error - * @throws NoSuchFieldException - * if the serialised data contains information about a field - * which does actually not exist in the class we know of - * @throws NoSuchMethodException - * if a class described in the serialised data cannot be created - * because it is not compatible with this code - * @throws ClassNotFoundException - * if a class described in the serialised data cannot be found - */ - protected Object sendObject(Object data) throws IOException, - NoSuchFieldException, NoSuchMethodException, ClassNotFoundException { - return send(out, data, false); - } - - /** - * Reserved for the server: flush the data to the client and retrieve its - * answer. - *
- * Also used internally for the client (only do something if there is - * contentToSend). - *
- * Will only flush the data if there is contentToSend. - * - * @return the deserialised answer (which can actually be NULL) - * - * @throws IOException - * in case of I/O error - * @throws NoSuchFieldException - * if the serialised data contains information about a field - * which does actually not exist in the class we know of - * @throws NoSuchMethodException - * if a class described in the serialised data cannot be created - * because it is not compatible with this code - * @throws ClassNotFoundException - * if a class described in the serialised data cannot be found - * @throws java.lang.NullPointerException - * if the counter part has no data to send - */ - protected Object recObject() throws IOException, NoSuchFieldException, - NoSuchMethodException, ClassNotFoundException, - java.lang.NullPointerException { - return rec(false); - } - - /** - * Send the given string to the counter part (and, only for client, return - * the answer -- the server will always receive NULL). - * - * @param line - * the data to send (we will add a line feed) - * - * @return the answer if this action is a client (without the added line - * feed), NULL if it is a server - * - * @throws IOException - * in case of I/O error - * @throws SSLException - * in case of crypt error - */ - protected String sendString(String line) throws IOException { - try { - return (String) send(out, line, true); - } catch (NoSuchFieldException e) { - // Cannot happen - e.printStackTrace(); - } catch (NoSuchMethodException e) { - // Cannot happen - e.printStackTrace(); - } catch (ClassNotFoundException e) { - // Cannot happen - e.printStackTrace(); - } - - return null; - } - - /** - * Reserved for the server (externally): flush the data to the client and - * retrieve its answer. - *
- * Also used internally for the client (only do something if there is - * contentToSend). - *
- * Will only flush the data if there is contentToSend. - * - * @return the answer (which can be NULL if no more content) - * - * @throws IOException - * in case of I/O error - * @throws SSLException - * in case of crypt error - */ - protected String recString() throws IOException { - try { - return (String) rec(true); - } catch (NoSuchFieldException e) { - // Cannot happen - e.printStackTrace(); - } catch (NoSuchMethodException e) { - // Cannot happen - e.printStackTrace(); - } catch (ClassNotFoundException e) { - // Cannot happen - e.printStackTrace(); - } catch (NullPointerException e) { - // Should happen - e.printStackTrace(); - } - - return null; - } - - /** - * Serialise and send the given object to the counter part (and, only for - * client, return the deserialised answer -- the server will always receive - * NULL). - * - * @param out - * the stream to write to - * @param data - * the data to write - * @param asString - * TRUE to write it as a String, FALSE to write it as an Object - * - * @return the answer (which can be NULL if no answer, or NULL for an answer - * which is NULL) if this action is a client, always NULL if it is a - * server - * - * @throws IOException - * in case of I/O error - * @throws SSLException - * in case of crypt error - * @throws IOException - * in case of I/O error - * @throws NoSuchFieldException - * if the serialised data contains information about a field - * which does actually not exist in the class we know of - * @throws NoSuchMethodException - * if a class described in the serialised data cannot be created - * because it is not compatible with this code - * @throws ClassNotFoundException - * if a class described in the serialised data cannot be found - */ - private Object send(BufferedOutputStream out, Object data, boolean asString) - throws IOException, NoSuchFieldException, NoSuchMethodException, - ClassNotFoundException, java.lang.NullPointerException { - - synchronized (lock) { - OutputStream sub; - if (crypt != null) { - sub = crypt.encrypt64(out.open()); - } else { - sub = out.open(); - } - - sub = new ReplaceOutputStream(sub, STREAM_RAW, STREAM_CODED); - try { - if (asString) { - sub.write(StringUtils.getBytes(data.toString())); - } else { - new Exporter(sub).append(data); - } - } finally { - sub.close(); - } - - out.write(STREAM_SEP); - - if (server) { - out.flush(); - return null; - } - - contentToSend = true; - try { - return rec(asString); - } catch (NullPointerException e) { - // We accept no data here for Objects - } - - return null; - } - } - - /** - * Reserved for the server: flush the data to the client and retrieve its - * answer. - *
- * Also used internally for the client (only do something if there is - * contentToSend). - *
- * Will only flush the data if there is contentToSend. - *
- * Note that the behaviour is slightly different for String and Object - * reading regarding exceptions: - *