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.buffer.ByteBuf;
  13 import io.netty.channel.ChannelHandlerContext;
  14 import io.netty.channel.ChannelOutboundHandlerAdapter;
  15 import io.netty.channel.ChannelPromise;
  16 import java.io.IOException;
  17 import java.net.SocketAddress;
  18 import org.apache.sshd.ClientChannel;
  19 import org.apache.sshd.ClientSession;
  20 import org.apache.sshd.SshClient;
  21 import org.apache.sshd.client.future.AuthFuture;
  22 import org.apache.sshd.client.future.ConnectFuture;
  23 import org.apache.sshd.client.future.OpenFuture;
  24 import org.apache.sshd.common.future.CloseFuture;
  25 import org.apache.sshd.common.future.SshFutureListener;
  26 import org.opendaylight.controller.netconf.nettyutil.handler.ssh.authentication.AuthenticationHandler;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29
  30 /**
  31  * Netty SSH handler class. Acts as interface between Netty and SSH library.
  32  */
  33 public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
  34
  35     private static final Logger LOG = LoggerFactory.getLogger(AsyncSshHandler.class);
  36     public static final String SUBSYSTEM = "netconf";
  37
  38     public static final SshClient DEFAULT_CLIENT = SshClient.setUpDefaultClient();
  39
  40     public static final int SSH_DEFAULT_NIO_WORKERS = 8;
  41
  42     static {
  43         // TODO make configurable, or somehow reuse netty threadpool
  44         DEFAULT_CLIENT.setNioWorkers(SSH_DEFAULT_NIO_WORKERS);
  45         DEFAULT_CLIENT.start();
  46     }
  47
  48     private final AuthenticationHandler authenticationHandler;
  49     private final SshClient sshClient;
  50
  51     private AsyncSshHandlerReader sshReadAsyncListener;
  52     private AsyncSshHandlerWriter sshWriteAsyncHandler;
  53
  54     private ClientChannel channel;
  55     private ClientSession session;
  56     private ChannelPromise connectPromise;
  57
  58
  59     public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler) throws IOException {
  60         return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT);
  61     }
  62
  63     /**
  64      *
  65      * @param authenticationHandler
  66      * @param sshClient started SshClient
  67      * @throws IOException
  68      */
  69     public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final SshClient sshClient) throws IOException {
  70         this.authenticationHandler = Preconditions.checkNotNull(authenticationHandler);
  71         this.sshClient = Preconditions.checkNotNull(sshClient);
  72         // Start just in case
  73         sshClient.start();
  74     }
  75
  76     private void startSsh(final ChannelHandlerContext ctx, final SocketAddress address) {
  77         LOG.debug("Starting SSH to {} on channel: {}", address, ctx.channel());
  78
  79         final ConnectFuture sshConnectionFuture = sshClient.connect(authenticationHandler.getUsername(), address);
  80         sshConnectionFuture.addListener(new SshFutureListener<ConnectFuture>() {
  81             @Override
  82             public void operationComplete(final ConnectFuture future) {
  83                 if (future.isConnected()) {
  84                     handleSshSessionCreated(future, ctx);
  85                 } else {
  86                     handleSshSetupFailure(ctx, future.getException());
  87                 }
  88             }
  89         });
  90     }
  91
  92     private synchronized void handleSshSessionCreated(final ConnectFuture future, final ChannelHandlerContext ctx) {
  93         try {
  94             LOG.trace("SSH session created on channel: {}", ctx.channel());
  95
  96             session = future.getSession();
  97             final AuthFuture authenticateFuture = authenticationHandler.authenticate(session);
  98             authenticateFuture.addListener(new SshFutureListener<AuthFuture>() {
  99                 @Override
 100                 public void operationComplete(final AuthFuture future) {
 101                     if (future.isSuccess()) {
 102                         handleSshAuthenticated(session, ctx);
 103                     } else {
 104                         handleSshSetupFailure(ctx, future.getException());
 105                     }
 106                 }
 107             });
 108         } catch (final IOException e) {
 109             handleSshSetupFailure(ctx, e);
 110         }
 111     }
 112
 113     private synchronized void handleSshAuthenticated(final ClientSession session, final ChannelHandlerContext ctx) {
 114         try {
 115             LOG.debug("SSH session authenticated on channel: {}, server version: {}", ctx.channel(), session.getServerVersion());
 116
 117             channel = session.createSubsystemChannel(SUBSYSTEM);
 118             channel.setStreaming(ClientChannel.Streaming.Async);
 119             channel.open().addListener(new SshFutureListener<OpenFuture>() {
 120                 @Override
 121                 public void operationComplete(final OpenFuture future) {
 122                     if(future.isOpened()) {
 123                         handleSshChanelOpened(ctx);
 124                     } else {
 125                         handleSshSetupFailure(ctx, future.getException());
 126                     }
 127                 }
 128             });
 129
 130
 131         } catch (final IOException e) {
 132             handleSshSetupFailure(ctx, e);
 133         }
 134     }
 135
 136     private synchronized void handleSshChanelOpened(final ChannelHandlerContext ctx) {
 137         LOG.trace("SSH subsystem channel opened successfully on channel: {}", ctx.channel());
 138
 139         connectPromise.setSuccess();
 140
 141         // TODO we should also read from error stream and at least log from that
 142
 143         sshReadAsyncListener = new AsyncSshHandlerReader(new AutoCloseable() {
 144             @Override
 145             public void close() throws Exception {
 146                 AsyncSshHandler.this.disconnect(ctx, ctx.newPromise());
 147             }
 148         }, new AsyncSshHandlerReader.ReadMsgHandler() {
 149             @Override
 150             public void onMessageRead(final ByteBuf msg) {
 151                 ctx.fireChannelRead(msg);
 152             }
 153         }, channel.toString(), channel.getAsyncOut());
 154
 155         // if readAsyncListener receives immediate close, it will close this handler and closing this handler sets channel variable to null
 156         if(channel != null) {
 157             sshWriteAsyncHandler = new AsyncSshHandlerWriter(channel.getAsyncIn());
 158             ctx.fireChannelActive();
 159         }
 160     }
 161
 162     private synchronized void handleSshSetupFailure(final ChannelHandlerContext ctx, final Throwable e) {
 163         LOG.warn("Unable to setup SSH connection on channel: {}", ctx.channel(), e);
 164         disconnect(ctx, ctx.newPromise());
 165
 166         // If the promise is not yet done, we have failed with initial connect and set connectPromise to failure
 167         if(!connectPromise.isDone()) {
 168             connectPromise.setFailure(e);
 169         }
 170     }
 171
 172     @Override
 173     public synchronized void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise) {
 174         sshWriteAsyncHandler.write(ctx, msg, promise);
 175     }
 176
 177     @Override
 178     public synchronized void connect(final ChannelHandlerContext ctx, final SocketAddress remoteAddress, final SocketAddress localAddress, final ChannelPromise promise) throws Exception {
 179         this.connectPromise = promise;
 180         startSsh(ctx, remoteAddress);
 181     }
 182
 183     @Override
 184     public void close(final ChannelHandlerContext ctx, final ChannelPromise promise) throws Exception {
 185         disconnect(ctx, promise);
 186     }
 187
 188     @Override
 189     public synchronized void disconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
 190         // Super disconnect is necessary in this case since we are using NioSocketChannel and it needs to cleanup its resources
 191         // e.g. Socket that it tries to open in its constructor (https://bugs.opendaylight.org/show_bug.cgi?id=2430)
 192         // TODO better solution would be to implement custom ChannelFactory + Channel that will use mina SSH lib internally: port this to custom channel implementation
 193         try {
 194             super.disconnect(ctx, ctx.newPromise());
 195         } catch (final Exception e) {
 196             LOG.warn("Unable to cleanup all resources for channel: {}. Ignoring.", ctx.channel(), e);
 197         }
 198
 199         if(sshReadAsyncListener != null) {
 200             sshReadAsyncListener.close();
 201         }
 202
 203         if(sshWriteAsyncHandler != null) {
 204             sshWriteAsyncHandler.close();
 205         }
 206
 207         if(session!= null && !session.isClosed() && !session.isClosing()) {
 208             session.close(false).addListener(new SshFutureListener<CloseFuture>() {
 209                 @Override
 210                 public void operationComplete(final CloseFuture future) {
 211                     if (future.isClosed() == false) {
 212                         session.close(true);
 213                     }
 214                     session = null;
 215                 }
 216             });
 217         }
 218
 219         // If we have already succeeded and the session was dropped after, we need to fire inactive to notify reconnect logic
 220         if(connectPromise.isSuccess()) {
 221             ctx.fireChannelInactive();
 222         }
 223
 224         channel = null;
 225
 226         promise.setSuccess();
 227         LOG.debug("SSH session closed on channel: {}", ctx.channel());
 228     }
 229
 230 }