Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.pig.shock; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PipedInputStream; import java.io.PipedOutputStream; import java.net.ConnectException; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.Proxy; import java.net.Socket; import java.net.SocketAddress; import java.net.SocketException; import java.net.SocketImpl; import java.net.SocketOptions; import java.net.SocketImplFactory; import java.net.UnknownHostException; import java.net.Proxy.Type; import java.nio.ByteBuffer; import java.nio.channels.SocketChannel; import java.util.HashMap; import java.util.Properties; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import com.jcraft.jsch.ChannelDirectTCPIP; import com.jcraft.jsch.ChannelExec; import com.jcraft.jsch.JSch; import com.jcraft.jsch.JSchException; import com.jcraft.jsch.Logger; import com.jcraft.jsch.Session; import com.jcraft.jsch.SocketFactory; import com.jcraft.jsch.UserInfo; /** * This class replaces the standard SocketImplFactory with a factory * that will use an SSH proxy. Only connect operations are supported. There * are no server operations and nio.channels are not supported. * <p> * This class uses the following system properties: * <ul> * <li>user.home - used to calculate the default .ssh directory * <li>user.name - used for the default ssh user id * <li>ssh.user - will override user.name as the user name to send over ssh * <li>ssh.gateway - sets the ssh host that will proxy connections * <li>ssh.knownhosts - the known hosts file. (We will not add to it) * <li>ssh.identity - the location of the identity file. The default name * is openid in the ssh directory. THIS FILE MUST NOT BE PASSWORD * PROTECTED. * </ul> * @author breed * */ public class SSHSocketImplFactory implements SocketImplFactory, Logger { private static final Log log = LogFactory.getLog(SSHSocketImplFactory.class); Session session; public static SSHSocketImplFactory getFactory() throws JSchException, IOException { return getFactory(System.getProperty("ssh.gateway")); } static HashMap<String, SSHSocketImplFactory> factories = new HashMap<String, SSHSocketImplFactory>(); public synchronized static SSHSocketImplFactory getFactory(String host) throws JSchException, IOException { SSHSocketImplFactory factory = factories.get(host); if (factory == null) { factory = new SSHSocketImplFactory(host); factories.put(host, factory); } return factory; } private SSHSocketImplFactory(String host) throws JSchException, IOException { JSch jsch = new JSch(); jsch.setLogger(this); String passphrase = ""; String defaultSSHDir = System.getProperty("user.home") + "/.ssh"; String identityFile = defaultSSHDir + "/openid"; String user = System.getProperty("user.name"); user = System.getProperty("ssh.user", user); if (host == null) { throw new RuntimeException("ssh.gateway system property must be set"); } String knownHosts = defaultSSHDir + "/known_hosts"; knownHosts = System.getProperty("ssh.knownhosts", knownHosts); jsch.setKnownHosts(knownHosts); identityFile = System.getProperty("ssh.identity", identityFile); jsch.addIdentity(identityFile, passphrase.getBytes()); session = jsch.getSession(user, host); Properties props = new Properties(); props.put("compression.s2c", "none"); props.put("compression.c2s", "none"); props.put("cipher.s2c", "blowfish-cbc,3des-cbc"); props.put("cipher.c2s", "blowfish-cbc,3des-cbc"); if (jsch.getHostKeyRepository().getHostKey(host, null) == null) { // We don't have a way to prompt, so if it isn't there we want // it automatically added. props.put("StrictHostKeyChecking", "no"); } session.setConfig(props); session.setDaemonThread(true); // We have to make sure that SSH uses it's own socket factory so // that we don't get recursion SocketFactory sfactory = new SSHSocketFactory(); session.setSocketFactory(sfactory); UserInfo userinfo = null; session.setUserInfo(userinfo); session.connect(); if (!session.isConnected()) { throw new IOException("Session not connected"); } } public SocketImpl createSocketImpl() { return new SSHSocketImpl(session); } public boolean isEnabled(int arg0) { // Default to not logging anything return false; } public void log(int arg0, String arg1) { log.error(arg0 + ": " + arg1); } static class SSHProcess extends Process { ChannelExec channel; InputStream is; InputStream es; OutputStream os; SSHProcess(ChannelExec channel) throws IOException { this.channel = channel; is = channel.getInputStream(); es = channel.getErrStream(); os = channel.getOutputStream(); } /* (non-Javadoc) * @see java.lang.Process#destroy() */ @Override public void destroy() { channel.disconnect(); } /* (non-Javadoc) * @see java.lang.Process#exitValue() */ @Override public int exitValue() { return channel.getExitStatus(); } /* (non-Javadoc) * @see java.lang.Process#getErrorStream() */ @Override public InputStream getErrorStream() { return es; } /* (non-Javadoc) * @see java.lang.Process#getInputStream() */ @Override public InputStream getInputStream() { return is; } /* (non-Javadoc) * @see java.lang.Process#getOutputStream() */ @Override public OutputStream getOutputStream() { return os; } /* (non-Javadoc) * @see java.lang.Process#waitFor() */ @Override public int waitFor() throws InterruptedException { while (channel.isConnected()) { Thread.sleep(1000); } return channel.getExitStatus(); } } public Process ssh(String cmd) throws JSchException, IOException { ChannelExec channel = (ChannelExec) session.openChannel("exec"); channel.setCommand(cmd); channel.setPty(true); channel.connect(); return new SSHProcess(channel); } } /** * This socket factory is only used by SSH. We implement it using nio.channels * since those classes do not use the SocketImplFactory. * * @author breed * */ class SSHSocketFactory implements SocketFactory { private final static Log log = LogFactory.getLog(SSHSocketFactory.class); public Socket createSocket(String host, int port) throws IOException, UnknownHostException { String socksHost = System.getProperty("socksProxyHost"); Socket s; InetSocketAddress addr = new InetSocketAddress(host, port); if (socksHost != null) { Proxy proxy = new Proxy(Type.SOCKS, new InetSocketAddress(socksHost, 1080)); s = new Socket(proxy); s.connect(addr); } else { log.error(addr); SocketChannel sc = SocketChannel.open(addr); s = sc.socket(); } s.setTcpNoDelay(true); return s; } public InputStream getInputStream(Socket socket) throws IOException { return new ChannelInputStream(socket.getChannel()); } public OutputStream getOutputStream(Socket socket) throws IOException { return new ChannelOutputStream(socket.getChannel()); } } class ChannelOutputStream extends OutputStream { SocketChannel sc; public ChannelOutputStream(SocketChannel sc) { this.sc = sc; } @Override public void write(int b) throws IOException { byte bs[] = new byte[1]; bs[0] = (byte) b; write(bs); } @Override public void write(byte b[], int off, int len) throws IOException { sc.write(ByteBuffer.wrap(b, off, len)); } } class ChannelInputStream extends InputStream { SocketChannel sc; public ChannelInputStream(SocketChannel sc) { this.sc = sc; } @Override public int read() throws IOException { byte b[] = new byte[1]; if (read(b) != 1) { return -1; } return b[0] & 0xff; } @Override public int read(byte b[], int off, int len) throws IOException { return sc.read(ByteBuffer.wrap(b, off, len)); } } /** * We aren't going to actually create any new connection, we will forward * things to SSH. */ class SSHSocketImpl extends SocketImpl { private static final Log log = LogFactory.getLog(SSHSocketImpl.class); Session session; ChannelDirectTCPIP channel; InputStream is; OutputStream os; SSHSocketImpl(Session session) { this.session = session; } @Override protected void accept(SocketImpl s) throws IOException { throw new IOException("SSHSocketImpl does not implement accept"); } @Override protected int available() throws IOException { if (is == null) { throw new ConnectException("Not connected"); } return is.available(); } @Override protected void bind(InetAddress host, int port) throws IOException { if ((host != null && !host.isAnyLocalAddress()) || port != 0) { throw new IOException("SSHSocketImpl does not implement bind"); } } @Override protected void close() throws IOException { if (channel != null) { // channel.disconnect(); is = null; os = null; } } public final static String defaultDomain = ".inktomisearch.com"; @Override protected void connect(String host, int port) throws IOException { InetAddress addr = null; try { addr = InetAddress.getByName(host); } catch (UnknownHostException e) { host += defaultDomain; addr = InetAddress.getByName(host); } connect(addr, port); } @Override protected void connect(InetAddress address, int port) throws IOException { connect(new InetSocketAddress(address, port), 300000); } @Override protected void connect(SocketAddress address, int timeout) throws IOException { try { if (!session.isConnected()) { session.connect(); } channel = (ChannelDirectTCPIP) session.openChannel("direct-tcpip"); //is = channel.getInputStream(); //os = channel.getOutputStream(); channel.setHost(((InetSocketAddress) address).getHostName()); channel.setPort(((InetSocketAddress) address).getPort()); channel.setOrgPort(22); is = new PipedInputStream(); os = new PipedOutputStream(); channel.setInputStream(new PipedInputStream((PipedOutputStream) os)); channel.setOutputStream(new PipedOutputStream((PipedInputStream) is)); channel.connect(); if (!channel.isConnected()) { log.error("Not connected"); } if (channel.isEOF()) { log.error("EOF"); } } catch (JSchException e) { log.error(e); IOException newE = new IOException(e.getMessage()); newE.setStackTrace(e.getStackTrace()); throw newE; } } @Override protected void create(boolean stream) throws IOException { if (stream == false) { throw new IOException("Cannot handle UDP streams"); } } @Override protected InputStream getInputStream() throws IOException { return is; } @Override protected OutputStream getOutputStream() throws IOException { return os; } @Override protected void listen(int backlog) throws IOException { throw new IOException("SSHSocketImpl does not implement listen"); } @Override protected void sendUrgentData(int data) throws IOException { throw new IOException("SSHSocketImpl does not implement sendUrgentData"); } public Object getOption(int optID) throws SocketException { if (optID == SocketOptions.SO_SNDBUF) return Integer.valueOf(1024); else throw new SocketException("SSHSocketImpl does not implement getOption for " + optID); } /** * We silently ignore setOptions because they do happen, but there is * nothing that we can do about it. */ public void setOption(int optID, Object value) throws SocketException { } static public void main(String args[]) { try { System.setProperty("ssh.gateway", "ucdev2"); final SSHSocketImplFactory fac = SSHSocketImplFactory.getFactory(); Socket.setSocketImplFactory(fac); for (int i = 0; i < 10; i++) { new Thread() { @Override public void run() { try { log.error("Starting " + this); connectTest("www.yahoo.com"); log.error("Finished " + this); } catch (Exception e) { log.error(e); } } }.start(); } Thread.sleep(1000000); connectTest("www.news.com"); log.info("******** Starting PART II"); for (int i = 0; i < 10; i++) { new Thread() { @Override public void run() { try { log.error("Starting " + this); connectTest("www.flickr.com"); log.error("Finished " + this); } catch (Exception e) { log.error(e); } } }.start(); } } catch (Exception e) { log.error(e); } } private static void connectTest(String host) throws JSchException, IOException { Socket s = new Socket(host, 80); s.getOutputStream().write("GET / HTTP/1.0\r\n\r\n".getBytes()); byte b[] = new byte[80]; int rc = s.getInputStream().read(b); System.out.write(b, 0, rc); s.close(); } private static void lsTest(SSHSocketImplFactory fac) throws JSchException, IOException { Process p = fac.ssh("ls"); byte b[] = new byte[1024]; final InputStream es = p.getErrorStream(); new Thread() { @Override public void run() { try { while (es.available() > 0) { es.read(); } } catch (Exception e) { } } }.start(); p.getOutputStream().close(); InputStream is = p.getInputStream(); int rc; while ((rc = is.read(b)) > 0) { System.out.write(b, 0, rc); } } }