netconf/netconf-netty-util/src/main/java/org/opendaylight/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.netconf.nettyutil.handler.ssh.client;
  10
  11 import com.google.common.base.Preconditions;
  12 import io.netty.buffer.ByteBuf;
  13 import io.netty.channel.ChannelHandlerContext;
  14 import io.netty.channel.ChannelOutboundHandlerAdapter;
  15 import io.netty.channel.ChannelPromise;
  16 import io.netty.util.concurrent.Future;
  17 import io.netty.util.concurrent.GenericFutureListener;
  18 import java.io.IOException;
  19 import java.net.SocketAddress;
  20 import org.apache.sshd.client.SshClient;
  21 import org.apache.sshd.client.channel.ClientChannel;
  22 import org.apache.sshd.client.future.AuthFuture;
  23 import org.apache.sshd.client.future.ConnectFuture;
  24 import org.apache.sshd.client.future.OpenFuture;
  25 import org.apache.sshd.client.session.ClientSession;
  26 import org.apache.sshd.client.session.ClientSessionCreator;
  27 import org.apache.sshd.common.future.CloseFuture;
  28 import org.apache.sshd.common.future.SshFutureListener;
  29 import org.opendaylight.netconf.nettyutil.handler.ssh.authentication.AuthenticationHandler;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 /**
  34  * Netty SSH handler class. Acts as interface between Netty and SSH library.
  35  */
  36 public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
  37     private static final Logger LOG = LoggerFactory.getLogger(AsyncSshHandler.class);
  38
  39     public static final String SUBSYSTEM = "netconf";
  40
  41     public static final int SSH_DEFAULT_NIO_WORKERS = 8;
  42     // Disable default timeouts from mina sshd
  43     private static final long DEFAULT_TIMEOUT = -1L;
  44
  45     public static final SshClient DEFAULT_CLIENT;
  46     static {
  47         final SshClient c = SshClient.setUpDefaultClient();
  48         c.getProperties().put(SshClient.AUTH_TIMEOUT, Long.toString(DEFAULT_TIMEOUT));
  49         c.getProperties().put(SshClient.IDLE_TIMEOUT, Long.toString(DEFAULT_TIMEOUT));
  50         // TODO make configurable, or somehow reuse netty threadpool
  51         c.setNioWorkers(SSH_DEFAULT_NIO_WORKERS);
  52         c.start();
  53         DEFAULT_CLIENT = c;
  54     }
  55
  56     private final AuthenticationHandler authenticationHandler;
  57     private final ClientSessionCreator sshClient;
  58     private Future<?> negotiationFuture;
  59
  60     private AsyncSshHandlerReader sshReadAsyncListener;
  61     private AsyncSshHandlerWriter sshWriteAsyncHandler;
  62
  63     private ClientChannel channel;
  64     private ClientSession session;
  65     private ChannelPromise connectPromise;
  66     private GenericFutureListener negotiationFutureListener;
  67
  68     public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final ClientSessionCreator sshClient,
  69             final Future<?> negotiationFuture) {
  70         this(authenticationHandler, sshClient);
  71         this.negotiationFuture = negotiationFuture;
  72     }
  73
  74     /**
  75      *
  76      * @param authenticationHandler
  77      * @param sshClient started SshClient
  78      */
  79     public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final ClientSessionCreator sshClient) {
  80         this.authenticationHandler = Preconditions.checkNotNull(authenticationHandler);
  81         this.sshClient = Preconditions.checkNotNull(sshClient);
  82     }
  83
  84     public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler) {
  85         return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT);
  86     }
  87
  88     /**
  89      *
  90      * Create AsyncSshHandler for netconf subsystem. Negotiation future has to be set to success after successful
  91      * NETCONF negotiation.
  92      *
  93      * @param authenticationHandler
  94      * @param negotiationFuture
  95      * @return
  96      */
  97     public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler,
  98             final Future<?> negotiationFuture) {
  99         return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT, negotiationFuture);
 100     }
 101
 102     private void startSsh(final ChannelHandlerContext ctx, final SocketAddress address) throws IOException {
 103         LOG.debug("Starting SSH to {} on channel: {}", address, ctx.channel());
 104
 105         final ConnectFuture sshConnectionFuture = sshClient.connect(authenticationHandler.getUsername(), address);
 106         sshConnectionFuture.addListener(new SshFutureListener<ConnectFuture>() {
 107             @Override
 108             public void operationComplete(final ConnectFuture future) {
 109                 if (future.isConnected()) {
 110                     handleSshSessionCreated(future, ctx);
 111                 } else {
 112                     handleSshSetupFailure(ctx, future.getException());
 113                 }
 114             }
 115         });
 116     }
 117
 118     private synchronized void handleSshSessionCreated(final ConnectFuture future, final ChannelHandlerContext ctx) {
 119         try {
 120             LOG.trace("SSH session created on channel: {}", ctx.channel());
 121
 122             session = future.getSession();
 123             final AuthFuture authenticateFuture = authenticationHandler.authenticate(session);
 124             authenticateFuture.addListener(new SshFutureListener<AuthFuture>() {
 125                 @Override
 126                 public void operationComplete(final AuthFuture future) {
 127                     if (future.isSuccess()) {
 128                         handleSshAuthenticated(session, ctx);
 129                     } else {
 130                         // Exception does not have to be set in the future, add simple exception in such case
 131                         final Throwable exception = future.getException() == null ?
 132                                 new IllegalStateException("Authentication failed") :
 133                                 future.getException();
 134                         handleSshSetupFailure(ctx, exception);
 135                     }
 136                 }
 137             });
 138         } catch (final IOException e) {
 139             handleSshSetupFailure(ctx, e);
 140         }
 141     }
 142
 143     private synchronized void handleSshAuthenticated(final ClientSession session, final ChannelHandlerContext ctx) {
 144         try {
 145             LOG.debug("SSH session authenticated on channel: {}, server version: {}", ctx.channel(), session.getServerVersion());
 146
 147             channel = session.createSubsystemChannel(SUBSYSTEM);
 148             channel.setStreaming(ClientChannel.Streaming.Async);
 149             channel.open().addListener(new SshFutureListener<OpenFuture>() {
 150                 @Override
 151                 public void operationComplete(final OpenFuture future) {
 152                     if(future.isOpened()) {
 153                         handleSshChanelOpened(ctx);
 154                     } else {
 155                         handleSshSetupFailure(ctx, future.getException());
 156                     }
 157                 }
 158             });
 159
 160
 161         } catch (final IOException e) {
 162             handleSshSetupFailure(ctx, e);
 163         }
 164     }
 165
 166     private synchronized void handleSshChanelOpened(final ChannelHandlerContext ctx) {
 167         LOG.trace("SSH subsystem channel opened successfully on channel: {}", ctx.channel());
 168
 169         if(negotiationFuture == null) {
 170             connectPromise.setSuccess();
 171         }
 172
 173         // TODO we should also read from error stream and at least log from that
 174
 175         sshReadAsyncListener = new AsyncSshHandlerReader(new AutoCloseable() {
 176             @Override
 177             public void close() throws Exception {
 178                 AsyncSshHandler.this.disconnect(ctx, ctx.newPromise());
 179             }
 180         }, new AsyncSshHandlerReader.ReadMsgHandler() {
 181             @Override
 182             public void onMessageRead(final ByteBuf msg) {
 183                 ctx.fireChannelRead(msg);
 184             }
 185         }, channel.toString(), channel.getAsyncOut());
 186
 187         // if readAsyncListener receives immediate close, it will close this handler and closing this handler sets channel variable to null
 188         if(channel != null) {
 189             sshWriteAsyncHandler = new AsyncSshHandlerWriter(channel.getAsyncIn());
 190             ctx.fireChannelActive();
 191         }
 192     }
 193
 194     private synchronized void handleSshSetupFailure(final ChannelHandlerContext ctx, final Throwable e) {
 195         LOG.warn("Unable to setup SSH connection on channel: {}", ctx.channel(), e);
 196
 197         // If the promise is not yet done, we have failed with initial connect and set connectPromise to failure
 198         if(!connectPromise.isDone()) {
 199             connectPromise.setFailure(e);
 200         }
 201
 202         disconnect(ctx, ctx.newPromise());
 203     }
 204
 205     @Override
 206     public synchronized void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise) {
 207         sshWriteAsyncHandler.write(ctx, msg, promise);
 208     }
 209
 210     @Override
 211     public synchronized void connect(final ChannelHandlerContext ctx, final SocketAddress remoteAddress, final SocketAddress localAddress, final ChannelPromise promise) throws Exception {
 212         LOG.debug("SSH session connecting on channel {}. promise: {} ", ctx.channel(), connectPromise);
 213         this.connectPromise = promise;
 214
 215         if(negotiationFuture != null) {
 216
 217             negotiationFutureListener = new GenericFutureListener<Future<?>>() {
 218                 @Override
 219                 public void operationComplete(final Future<?> future) {
 220                     if (future.isSuccess()) {
 221                         connectPromise.setSuccess();
 222                     }
 223                 }
 224             };
 225             //complete connection promise with netconf negotiation future
 226             negotiationFuture.addListener(negotiationFutureListener);
 227         }
 228         startSsh(ctx, remoteAddress);
 229     }
 230
 231     @Override
 232     public void close(final ChannelHandlerContext ctx, final ChannelPromise promise) throws Exception {
 233         disconnect(ctx, promise);
 234     }
 235
 236     @Override
 237     public synchronized void disconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
 238         LOG.trace("Closing SSH session on channel: {} with connect promise in state: {}", ctx.channel(), connectPromise);
 239
 240         // If we have already succeeded and the session was dropped after, we need to fire inactive to notify reconnect logic
 241         if(connectPromise.isSuccess()) {
 242             ctx.fireChannelInactive();
 243         }
 244
 245         if(sshWriteAsyncHandler != null) {
 246             sshWriteAsyncHandler.close();
 247         }
 248
 249         if(sshReadAsyncListener != null) {
 250             sshReadAsyncListener.close();
 251         }
 252
 253         //If connection promise is not already set, it means negotiation failed
 254         //we must set connection promise to failure
 255         if(!connectPromise.isDone()) {
 256             connectPromise.setFailure(new IllegalStateException("Negotiation failed"));
 257         }
 258
 259         //Remove listener from negotiation future, we don't want notifications
 260         //from negotiation anymore
 261         if(negotiationFuture != null) {
 262             negotiationFuture.removeListener(negotiationFutureListener);
 263         }
 264
 265         if(session!= null && !session.isClosed() && !session.isClosing()) {
 266             session.close(false).addListener(new SshFutureListener<CloseFuture>() {
 267                 @Override
 268                 public void operationComplete(final CloseFuture future) {
 269                     if (future.isClosed() == false) {
 270                         session.close(true);
 271                     }
 272                     session = null;
 273                 }
 274             });
 275         }
 276
 277         // Super disconnect is necessary in this case since we are using NioSocketChannel and it needs to cleanup its resources
 278         // e.g. Socket that it tries to open in its constructor (https://bugs.opendaylight.org/show_bug.cgi?id=2430)
 279         // TODO better solution would be to implement custom ChannelFactory + Channel that will use mina SSH lib internally: port this to custom channel implementation
 280         try {
 281             // Disconnect has to be closed after inactive channel event was fired, because it interferes with it
 282             super.disconnect(ctx, ctx.newPromise());
 283         } catch (final Exception e) {
 284             LOG.warn("Unable to cleanup all resources for channel: {}. Ignoring.", ctx.channel(), e);
 285         }
 286
 287         channel = null;
 288         promise.setSuccess();
 289         LOG.debug("SSH session closed on channel: {}", ctx.channel());
 290     }
 291
 292 }