123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323 |
- /*
- * Copyright (c) 2006-2014 DMDirc Developers
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
- package com.dmdirc.addons.dcc.io;
-
- import java.io.IOException;
- import java.net.ServerSocket;
- import java.net.Socket;
- import java.util.concurrent.Semaphore;
- import java.util.concurrent.atomic.AtomicBoolean;
-
- /**
- * This class manages the socket and low-level I/O functionality for all types of DCC. Subclasses
- * process the data received by this class.
- */
- public abstract class DCC implements Runnable {
-
- /** Address. */
- protected long address = 0;
- /** Port. */
- protected int port = 0;
- /** Socket used to communicate with. */
- protected Socket socket;
- /** The Thread in use for this. */
- private volatile Thread myThread;
- /** Are we already running? */
- protected final AtomicBoolean running = new AtomicBoolean();
- /** Are we a listen socket? */
- protected boolean listen = false;
- /**
- * The current socket in use if this is a listen socket. This reference may be changed if and
- * only if exactly one permit from the {@link #serverSocketSem} and {@link #serverListeningSem}
- * semaphores is held by the thread doing the modification.
- */
- private ServerSocket serverSocket;
- /**
- * Semaphore to control write access to ServerSocket. If an object acquires a permit from the
- * {@link #serverSocketSem}, then {@link #serverSocket} is <em>guaranteed</em> not to be
- * externally modified until that permit is released, <em>unless</em> the object also acquires a
- * permit from the {@link #serverListeningSem}.
- */
- private final Semaphore serverSocketSem = new Semaphore(1);
- /**
- * Semaphore used when we're blocking waiting for connections. If an object acquires a permit
- * from the {@link #serverListeningSem}, then it is <em>guaranteed</em> that the {@link #run()}
- * method is blocking waiting for incoming connections. In addition, it is <em>guaranteed</em>
- * that the {@link #run()} method is holding the {@link #serverSocketSem} permit, and it will
- * continue holding that permit until it can reacquire the {@link #serverListeningSem} permit.
- */
- private final Semaphore serverListeningSem = new Semaphore(0);
-
- /**
- * Connect this dcc.
- */
- public void connect() {
- try {
- if (listen) {
- address = 0;
- port = serverSocket.getLocalPort();
- } else {
- socket = new Socket(longToIP(address), port);
- socketOpened();
- }
- } catch (IOException ioe) {
- socketClosed();
- return;
- }
-
- myThread = new Thread(this, "DCC-Thread-" + getHost());
- myThread.start();
- }
-
- /**
- * Start a listen socket rather than a connect socket.
- *
- * @throws IOException If the listen socket can't be created
- */
- public void listen() throws IOException {
- serverSocketSem.acquireUninterruptibly();
- serverSocket = new ServerSocket(0, 1);
- serverSocketSem.release();
-
- listen = true;
- connect();
- }
-
- /**
- * Start a listen socket rather than a connect socket, use a port from the given range.
- *
- * @param startPort Port to try first
- * @param endPort Last port to try.
- *
- * @throws IOException If no sockets were available in the given range
- */
- public void listen(final int startPort, final int endPort) throws IOException {
- listen = true;
-
- for (int i = startPort; i <= endPort; ++i) {
- try {
- serverSocketSem.acquireUninterruptibly();
- serverSocket = new ServerSocket(i, 1);
- // Found a socket we can use!
- break;
- } catch (IOException | SecurityException ioe) {
- // Try next socket.
- } finally {
- serverSocketSem.release();
- }
- }
-
- if (serverSocket == null) {
- throw new IOException("No available sockets in range " + startPort + ":" + endPort);
- } else {
- connect();
- }
- }
-
- /**
- * This handles the socket to keep it out of the main thread
- */
- @Override
- public void run() {
- if (running.getAndSet(true)) {
- return;
- }
-
- // handleSocket is implemented by sub classes, and should return false
- // when the socket is closed.
- final Thread thisThread = Thread.currentThread();
-
- while (myThread == thisThread) {
- serverSocketSem.acquireUninterruptibly();
-
- if (serverSocket == null) {
- serverSocketSem.release();
-
- if (!handleSocket()) {
- close();
- break;
- }
- } else {
- try {
- serverListeningSem.release();
- socket = serverSocket.accept();
- serverSocket.close();
- socketOpened();
- } catch (IOException ioe) {
- socketClosed();
- break;
- } finally {
- serverListeningSem.acquireUninterruptibly();
- serverSocket = null;
- serverSocketSem.release();
- }
- }
-
- // Yield to reduce CPU usage.
- Thread.yield();
- }
- // Socket closed
-
- running.set(false);
- }
-
- /**
- * Called to close the socket
- */
- public void close() {
- boolean haveSLS = false;
-
- while (!serverSocketSem.tryAcquire() && !(haveSLS = serverListeningSem.tryAcquire())) {
- Thread.yield();
- }
-
- if (serverSocket != null) {
- try {
- if (!serverSocket.isClosed()) {
- serverSocket.close();
- }
- } catch (IOException ioe) {
- }
- serverSocket = null;
- }
-
- if (haveSLS) {
- serverListeningSem.release();
- } else {
- serverSocketSem.release();
- }
-
- if (socket != null) {
- try {
- if (!socket.isClosed()) {
- socket.close();
- }
- } catch (IOException ioe) {
- }
- socketClosed();
- socket = null;
- }
- }
-
- /**
- * Called when the socket is first opened, before any data is handled.
- */
- protected void socketOpened() {
- }
-
- /**
- * Called when the socket is closed, before the thread terminates.
- */
- protected void socketClosed() {
- }
-
- /**
- * Check if this socket can be written to.
- *
- * @return True if the socket is writable, false otherwise
- */
- public boolean isWriteable() {
- return false;
- }
-
- /**
- * Called periodically to read or write data to this DCC's socket. Implementations should
- * attempt to send or receive one unit of data (for example one block of binary data, or one
- * line of ASCII data) each time this method is called.
- * <p>
- * The return value of this method is used to determine whether the DCC has been completed. If
- * the method returns <code>false</code>, the DCC is assumed to have finished (i.e., the socket
- * has closed), and the method will not be called again. A return value of <code>true</code>
- * will cause the method to be recalled.
- *
- * @return false when socket is closed, true will cause the method to be called again.
- */
- protected abstract boolean handleSocket();
-
- /**
- * Set the address to connect to for this DCC
- *
- * @param address Address as an int (Network Byte Order, as specified in the DCC CTCP)
- * @param port Port to connect to
- */
- public void setAddress(final long address, final int port) {
- this.address = address;
- this.port = port;
- }
-
- /**
- * Is this a listening socket
- *
- * @return True if this is a listening socket
- */
- public boolean isListenSocket() {
- return listen;
- }
-
- /**
- * Get the host this socket is listening on/connecting to
- *
- * @return The IP that this socket is listening on/connecting to.
- */
- public String getHost() {
- return longToIP(address);
- }
-
- /**
- * Get the port this socket is listening on/connecting to
- *
- * @return The port that this socket is listening on/connecting to.
- */
- public int getPort() {
- return port;
- }
-
- /**
- * Convert the given IP Address to a long
- *
- * @param ip Input IP Address
- *
- * @return ip as a long
- */
- public static long ipToLong(final String ip) {
- final String[] bits = ip.split("\\.");
- if (bits.length > 3) {
- return (Long.parseLong(bits[0]) << 24) + (Long.parseLong(bits[1]) << 16)
- + (Long.parseLong(bits[2]) << 8) + Long.parseLong(bits[3]);
- }
- return 0;
- }
-
- /**
- * Convert the given long to an IP Address
- *
- * @param in Input long
- *
- * @return long as an IP
- */
- public static String longToIP(final long in) {
- return ((in & 0xff000000) >> 24) + "." + ((in & 0x00ff0000) >> 16) + "."
- + ((in & 0x0000ff00) >> 8) + "." + (in & 0x000000ff);
- }
-
- }
|