opendaylight/netconf/netconf-netty-util/src/main/java/org/opendaylight/controller/netconf/nettyutil/handler/ssh/client/AsyncSshHandler.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.netconf.nettyutil.handler.ssh.client;
  10
  11 import com.google.common.base.Preconditions;
  12 import io.netty.channel.ChannelHandlerContext;
  13 import io.netty.channel.ChannelOutboundHandlerAdapter;
  14 import io.netty.channel.ChannelPromise;
  15 import java.io.IOException;
  16 import java.net.SocketAddress;
  17 import org.apache.sshd.ClientChannel;
  18 import org.apache.sshd.ClientSession;
  19 import org.apache.sshd.SshClient;
  20 import org.apache.sshd.client.future.AuthFuture;
  21 import org.apache.sshd.client.future.ConnectFuture;
  22 import org.apache.sshd.client.future.OpenFuture;
  23 import org.apache.sshd.common.future.CloseFuture;
  24 import org.apache.sshd.common.future.SshFutureListener;
  25 import org.opendaylight.controller.netconf.nettyutil.handler.ssh.authentication.AuthenticationHandler;
  26 import org.slf4j.Logger;
  27 import org.slf4j.LoggerFactory;
  28
  29 /**
  30  * Netty SSH handler class. Acts as interface between Netty and SSH library.
  31  */
  32 public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
  33
  34     private static final Logger logger = LoggerFactory.getLogger(AsyncSshHandler.class);
  35     public static final String SUBSYSTEM = "netconf";
  36
  37     public static final SshClient DEFAULT_CLIENT = SshClient.setUpDefaultClient();
  38
  39     public static final int SSH_DEFAULT_NIO_WORKERS = 8;
  40
  41     static {
  42         // TODO make configurable, or somehow reuse netty threadpool
  43         DEFAULT_CLIENT.setNioWorkers(SSH_DEFAULT_NIO_WORKERS);
  44         DEFAULT_CLIENT.start();
  45     }
  46
  47     private final AuthenticationHandler authenticationHandler;
  48     private final SshClient sshClient;
  49
  50     private AsyncSshHanderReader sshReadAsyncListener;
  51     private AsyncSshHandlerWriter sshWriteAsyncHandler;
  52
  53     private ClientChannel channel;
  54     private ClientSession session;
  55     private ChannelPromise connectPromise;
  56
  57
  58     public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler) throws IOException {
  59         return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT);
  60     }
  61
  62     /**
  63      *
  64      * @param authenticationHandler
  65      * @param sshClient started SshClient
  66      * @throws IOException
  67      */
  68     public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final SshClient sshClient) throws IOException {
  69         this.authenticationHandler = Preconditions.checkNotNull(authenticationHandler);
  70         this.sshClient = Preconditions.checkNotNull(sshClient);
  71         // Start just in case
  72         sshClient.start();
  73     }
  74
  75     private void startSsh(final ChannelHandlerContext ctx, final SocketAddress address) {
  76         logger.debug("Starting SSH to {} on channel: {}", address, ctx.channel());
  77
  78         final ConnectFuture sshConnectionFuture = sshClient.connect(authenticationHandler.getUsername(), address);
  79         sshConnectionFuture.addListener(new SshFutureListener<ConnectFuture>() {
  80             @Override
  81             public void operationComplete(final ConnectFuture future) {
  82                 if (future.isConnected()) {
  83                     handleSshSessionCreated(future, ctx);
  84                 } else {
  85                     handleSshSetupFailure(ctx, future.getException());
  86                 }
  87             }
  88         });
  89     }
  90
  91     private synchronized void handleSshSessionCreated(final ConnectFuture future, final ChannelHandlerContext ctx) {
  92         try {
  93             logger.trace("SSH session created on channel: {}", ctx.channel());
  94
  95             session = future.getSession();
  96             final AuthFuture authenticateFuture = authenticationHandler.authenticate(session);
  97             authenticateFuture.addListener(new SshFutureListener<AuthFuture>() {
  98                 @Override
  99                 public void operationComplete(final AuthFuture future) {
 100                     if (future.isSuccess()) {
 101                         handleSshAuthenticated(session, ctx);
 102                     } else {
 103                         handleSshSetupFailure(ctx, future.getException());
 104                     }
 105                 }
 106             });
 107         } catch (final IOException e) {
 108             handleSshSetupFailure(ctx, e);
 109         }
 110     }
 111
 112     private synchronized void handleSshAuthenticated(final ClientSession session, final ChannelHandlerContext ctx) {
 113         try {
 114             logger.debug("SSH session authenticated on channel: {}, server version: {}", ctx.channel(), session.getServerVersion());
 115
 116             channel = session.createSubsystemChannel(SUBSYSTEM);
 117             channel.setStreaming(ClientChannel.Streaming.Async);
 118             channel.open().addListener(new SshFutureListener<OpenFuture>() {
 119                 @Override
 120                 public void operationComplete(final OpenFuture future) {
 121                     if(future.isOpened()) {
 122                         handleSshChanelOpened(ctx);
 123                     } else {
 124                         handleSshSetupFailure(ctx, future.getException());
 125                     }
 126                 }
 127             });
 128
 129
 130         } catch (final IOException e) {
 131             handleSshSetupFailure(ctx, e);
 132         }
 133     }
 134
 135     private synchronized void handleSshChanelOpened(final ChannelHandlerContext ctx) {
 136         logger.trace("SSH subsystem channel opened successfully on channel: {}", ctx.channel());
 137
 138         connectPromise.setSuccess();
 139         connectPromise = null;
 140
 141         sshReadAsyncListener = new AsyncSshHanderReader(this, ctx, channel.getAsyncOut());
 142         // if readAsyncListener receives immediate close, it will close this handler and closing this handler sets channel variable to null
 143         if(channel != null) {
 144             sshWriteAsyncHandler = new AsyncSshHandlerWriter(channel.getAsyncIn());
 145             ctx.fireChannelActive();
 146         }
 147     }
 148
 149     private synchronized void handleSshSetupFailure(final ChannelHandlerContext ctx, final Throwable e) {
 150         logger.warn("Unable to setup SSH connection on channel: {}", ctx.channel(), e);
 151         connectPromise.setFailure(e);
 152         connectPromise = null;
 153         throw new IllegalStateException("Unable to setup SSH connection on channel: " + ctx.channel(), e);
 154     }
 155
 156     @Override
 157     public synchronized void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise) {
 158         sshWriteAsyncHandler.write(ctx, msg, promise);
 159     }
 160
 161     @Override
 162     public synchronized void connect(final ChannelHandlerContext ctx, final SocketAddress remoteAddress, final SocketAddress localAddress, final ChannelPromise promise) throws Exception {
 163         this.connectPromise = promise;
 164         startSsh(ctx, remoteAddress);
 165     }
 166
 167     @Override
 168     public void close(final ChannelHandlerContext ctx, final ChannelPromise promise) throws Exception {
 169         disconnect(ctx, promise);
 170     }
 171
 172     @Override
 173     public synchronized void disconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
 174         if(sshReadAsyncListener != null) {
 175             sshReadAsyncListener.close();
 176         }
 177
 178         if(sshWriteAsyncHandler != null) {
 179             sshWriteAsyncHandler.close();
 180         }
 181
 182         if(session!= null && !session.isClosed() && !session.isClosing()) {
 183             session.close(false).addListener(new SshFutureListener<CloseFuture>() {
 184                 @Override
 185                 public void operationComplete(final CloseFuture future) {
 186                     if (future.isClosed() == false) {
 187                         session.close(true);
 188                     }
 189                     session = null;
 190                 }
 191             });
 192         }
 193
 194         channel = null;
 195         promise.setSuccess();
 196
 197         logger.debug("SSH session closed on channel: {}", ctx.channel());
 198         ctx.fireChannelInactive();
 199     }
 200
 201 }