tests/honeynode/2.1/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 java.util.HashMap;
  21 import java.util.Map;
  22 import org.apache.sshd.ClientChannel;
  23 import org.apache.sshd.ClientSession;
  24 import org.apache.sshd.SshClient;
  25 import org.apache.sshd.client.future.AuthFuture;
  26 import org.apache.sshd.client.future.ConnectFuture;
  27 import org.apache.sshd.client.future.OpenFuture;
  28 import org.apache.sshd.common.future.CloseFuture;
  29 import org.apache.sshd.common.future.SshFutureListener;
  30 import org.opendaylight.netconf.nettyutil.handler.ssh.authentication.AuthenticationHandler;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33
  34 /**
  35  * Netty SSH handler class. Acts as interface between Netty and SSH library.
  36  */
  37 public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
  38     private static final Logger LOG = LoggerFactory.getLogger(AsyncSshHandler.class);
  39
  40     public static final String SUBSYSTEM = "netconf";
  41
  42     public static final int SSH_DEFAULT_NIO_WORKERS = 8;
  43     // Disable default timeouts from mina sshd
  44     private static final long DEFAULT_TIMEOUT = -1L;
  45
  46     public static final SshClient DEFAULT_CLIENT;
  47
  48     static {
  49         final Map<String, String> props = new HashMap<>();
  50         props.put(SshClient.AUTH_TIMEOUT, Long.toString(DEFAULT_TIMEOUT));
  51         props.put(SshClient.IDLE_TIMEOUT, Long.toString(DEFAULT_TIMEOUT));
  52
  53         final SshClient c = SshClient.setUpDefaultClient();
  54
  55         c.setProperties(props);
  56         // TODO make configurable, or somehow reuse netty threadpool
  57         c.setNioWorkers(SSH_DEFAULT_NIO_WORKERS);
  58         c.start();
  59         DEFAULT_CLIENT = c;
  60     }
  61
  62     private final AuthenticationHandler authenticationHandler;
  63     private final SshClient sshClient;
  64     private Future<?> negotiationFuture;
  65
  66     private AsyncSshHandlerReader sshReadAsyncListener;
  67     private AsyncSshHandlerWriter sshWriteAsyncHandler;
  68
  69     private ClientChannel channel;
  70     private ClientSession session;
  71     private ChannelPromise connectPromise;
  72     private GenericFutureListener negotiationFutureListener;
  73
  74     public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final SshClient sshClient,
  75             final Future<?> negotiationFuture) throws IOException {
  76         this(authenticationHandler, sshClient);
  77         this.negotiationFuture = negotiationFuture;
  78     }
  79
  80     /**
  81      * Constructor of {@code AsyncSshHandler}.
  82      *
  83      * @param authenticationHandler authentication handler
  84      * @param sshClient             started SshClient
  85      * @throws IOException          if the I/O operation fails
  86      */
  87     public AsyncSshHandler(final AuthenticationHandler authenticationHandler,
  88                            final SshClient sshClient) throws IOException {
  89         this.authenticationHandler = Preconditions.checkNotNull(authenticationHandler);
  90         this.sshClient = Preconditions.checkNotNull(sshClient);
  91     }
  92
  93     public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler)
  94             throws IOException {
  95         return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT);
  96     }
  97
  98     /**
  99      * Create AsyncSshHandler for netconf subsystem. Negotiation future has to be set to success after successful
 100      * netconf negotiation.
 101      *
 102      * @param authenticationHandler authentication handler
 103      * @param negotiationFuture     negotiation future
 104      * @return                      {@code AsyncSshHandler}
 105      * @throws IOException          if the I/O operation fails
 106      */
 107     public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler,
 108             final Future<?> negotiationFuture) throws IOException {
 109         return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT, negotiationFuture);
 110     }
 111
 112     private void startSsh(final ChannelHandlerContext ctx, final SocketAddress address) {
 113         LOG.debug("Starting SSH to {} on channel: {}", address, ctx.channel());
 114
 115         final ConnectFuture sshConnectionFuture = sshClient.connect(authenticationHandler.getUsername(), address);
 116         sshConnectionFuture.addListener(new SshFutureListener<ConnectFuture>() {
 117             @Override
 118             public void operationComplete(final ConnectFuture future) {
 119                 if (future.isConnected()) {
 120                     handleSshSessionCreated(future, ctx);
 121                 } else {
 122                     handleSshSetupFailure(ctx, future.getException());
 123                 }
 124             }
 125         });
 126     }
 127
 128     private synchronized void handleSshSessionCreated(final ConnectFuture future, final ChannelHandlerContext ctx) {
 129         try {
 130             LOG.trace("SSH session created on channel: {}", ctx.channel());
 131
 132             session = future.getSession();
 133             final AuthFuture authenticateFuture = authenticationHandler.authenticate(session);
 134             authenticateFuture.addListener(new SshFutureListener<AuthFuture>() {
 135                 @Override
 136                 public void operationComplete(final AuthFuture future) {
 137                     if (future.isSuccess()) {
 138                         handleSshAuthenticated(session, ctx);
 139                     } else {
 140                         // Exception does not have to be set in the future, add simple exception in such case
 141                         final Throwable exception = future.getException() == null
 142                                 ? new IllegalStateException("Authentication failed") : future.getException();
 143                         handleSshSetupFailure(ctx, exception);
 144                     }
 145                 }
 146             });
 147         } catch (final IOException e) {
 148             handleSshSetupFailure(ctx, e);
 149         }
 150     }
 151
 152     private synchronized void handleSshAuthenticated(final ClientSession session, final ChannelHandlerContext ctx) {
 153         try {
 154             LOG.debug("SSH session authenticated on channel: {}, server version: {}", ctx.channel(),
 155                     session.getServerVersion());
 156
 157             channel = session.createSubsystemChannel(SUBSYSTEM);
 158             channel.setStreaming(ClientChannel.Streaming.Async);
 159             channel.open().addListener(new SshFutureListener<OpenFuture>() {
 160                 @Override
 161                 public void operationComplete(final OpenFuture future) {
 162                     if (future.isOpened()) {
 163                         handleSshChanelOpened(ctx);
 164                     } else {
 165                         handleSshSetupFailure(ctx, future.getException());
 166                     }
 167                 }
 168             });
 169
 170
 171         } catch (final IOException e) {
 172             handleSshSetupFailure(ctx, e);
 173         }
 174     }
 175
 176     private synchronized void handleSshChanelOpened(final ChannelHandlerContext ctx) {
 177         LOG.trace("SSH subsystem channel opened successfully on channel: {}", ctx.channel());
 178
 179         if (negotiationFuture == null) {
 180             connectPromise.setSuccess();
 181         }
 182
 183         // TODO we should also read from error stream and at least log from that
 184
 185         sshReadAsyncListener = new AsyncSshHandlerReader(new AutoCloseable() {
 186             @Override
 187             public void close() throws Exception {
 188                 AsyncSshHandler.this.disconnect(ctx, ctx.newPromise());
 189             }
 190         }, new AsyncSshHandlerReader.ReadMsgHandler() {
 191             @Override
 192             public void onMessageRead(final ByteBuf msg) {
 193                 ctx.fireChannelRead(msg);
 194             }
 195         }, channel.toString(), channel.getAsyncOut());
 196
 197         // if readAsyncListener receives immediate close,
 198         // it will close this handler and closing this handler sets channel variable to null
 199         if (channel != null) {
 200             sshWriteAsyncHandler = new AsyncSshHandlerWriter(channel.getAsyncIn());
 201             ctx.fireChannelActive();
 202         }
 203     }
 204
 205     private synchronized void handleSshSetupFailure(final ChannelHandlerContext ctx, final Throwable error) {
 206         LOG.warn("Unable to setup SSH connection on channel: {}", ctx.channel(), error);
 207
 208         // If the promise is not yet done, we have failed with initial connect and set connectPromise to failure
 209         if (!connectPromise.isDone()) {
 210             connectPromise.setFailure(error);
 211         }
 212
 213         disconnect(ctx, ctx.newPromise());
 214     }
 215
 216     @Override
 217     public synchronized void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise) {
 218         sshWriteAsyncHandler.write(ctx, msg, promise);
 219     }
 220
 221     @Override
 222     public synchronized void connect(final ChannelHandlerContext ctx, final SocketAddress remoteAddress,
 223                                      final SocketAddress localAddress, final ChannelPromise promise) throws Exception {
 224         LOG.debug("SSH session connecting on channel {}. promise: {} ", ctx.channel(), connectPromise);
 225         this.connectPromise = promise;
 226
 227         if (negotiationFuture != null) {
 228
 229             negotiationFutureListener = new GenericFutureListener<Future<?>>() {
 230                 @Override
 231                 public void operationComplete(final Future<?> future) {
 232                     if (future.isSuccess()) {
 233                         connectPromise.setSuccess();
 234                     }
 235                 }
 236             };
 237             //complete connection promise with netconf negotiation future
 238             negotiationFuture.addListener(negotiationFutureListener);
 239         }
 240         startSsh(ctx, remoteAddress);
 241     }
 242
 243     @Override
 244     public void close(final ChannelHandlerContext ctx, final ChannelPromise promise) throws Exception {
 245         disconnect(ctx, promise);
 246     }
 247
 248     @SuppressWarnings("checkstyle:IllegalCatch")
 249     @Override
 250     public synchronized void disconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
 251         LOG.trace("Closing SSH session on channel: {} with connect promise in state: {}",
 252                 ctx.channel(),connectPromise);
 253
 254         // If we have already succeeded and the session was dropped after,
 255         // we need to fire inactive to notify reconnect logic
 256         if (connectPromise.isSuccess()) {
 257             ctx.fireChannelInactive();
 258         }
 259
 260         if (sshWriteAsyncHandler != null) {
 261             sshWriteAsyncHandler.close();
 262         }
 263
 264         if (sshReadAsyncListener != null) {
 265             sshReadAsyncListener.close();
 266         }
 267
 268         //If connection promise is not already set, it means negotiation failed
 269         //we must set connection promise to failure
 270         if (!connectPromise.isDone()) {
 271             connectPromise.setFailure(new IllegalStateException("Negotiation failed"));
 272         }
 273
 274         //Remove listener from negotiation future, we don't want notifications
 275         //from negotiation anymore
 276         if (negotiationFuture != null) {
 277             negotiationFuture.removeListener(negotiationFutureListener);
 278         }
 279
 280         if (session != null && !session.isClosed() && !session.isClosing()) {
 281             session.close(false).addListener(new SshFutureListener<CloseFuture>() {
 282                 @Override
 283                 public void operationComplete(final CloseFuture future) {
 284                     if (future.isClosed() == false) {
 285                         session.close(true);
 286                     }
 287                     session = null;
 288                 }
 289             });
 290         }
 291
 292         // Super disconnect is necessary in this case since we are using NioSocketChannel and it needs
 293         // to cleanup its resources e.g. Socket that it tries to open in its constructor
 294         // (https://bugs.opendaylight.org/show_bug.cgi?id=2430)
 295         // TODO better solution would be to implement custom ChannelFactory + Channel
 296         // that will use mina SSH lib internally: port this to custom channel implementation
 297         try {
 298             // Disconnect has to be closed after inactive channel event was fired, because it interferes with it
 299             super.disconnect(ctx, ctx.newPromise());
 300         } catch (final Exception e) {
 301             LOG.warn("Unable to cleanup all resources for channel: {}. Ignoring.", ctx.channel(), e);
 302         }
 303
 304         channel = null;
 305         promise.setSuccess();
 306         LOG.debug("SSH session closed on channel: {}", ctx.channel());
 307     }
 308
 309 }