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 java.io.IOException;
  12 import java.net.SocketAddress;
  13
  14 import org.apache.sshd.ClientChannel;
  15 import org.apache.sshd.ClientSession;
  16 import org.apache.sshd.SshClient;
  17 import org.apache.sshd.client.future.AuthFuture;
  18 import org.apache.sshd.client.future.ConnectFuture;
  19 import org.apache.sshd.client.future.OpenFuture;
  20 import org.apache.sshd.common.future.CloseFuture;
  21 import org.apache.sshd.common.future.SshFutureListener;
  22 import org.opendaylight.controller.netconf.nettyutil.handler.ssh.authentication.AuthenticationHandler;
  23 import org.slf4j.Logger;
  24 import org.slf4j.LoggerFactory;
  25
  26 import com.google.common.base.Preconditions;
  27
  28 import io.netty.buffer.ByteBuf;
  29 import io.netty.channel.ChannelHandlerContext;
  30 import io.netty.channel.ChannelOutboundHandlerAdapter;
  31 import io.netty.channel.ChannelPromise;
  32
  33 /**
  34  * Netty SSH handler class. Acts as interface between Netty and SSH library.
  35  */
  36 public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
  37
  38     private static final Logger logger = LoggerFactory.getLogger(AsyncSshHandler.class);
  39     public static final String SUBSYSTEM = "netconf";
  40
  41     public static final SshClient DEFAULT_CLIENT = SshClient.setUpDefaultClient();
  42
  43     public static final int SSH_DEFAULT_NIO_WORKERS = 8;
  44
  45     static {
  46         // TODO make configurable, or somehow reuse netty threadpool
  47         DEFAULT_CLIENT.setNioWorkers(SSH_DEFAULT_NIO_WORKERS);
  48         DEFAULT_CLIENT.start();
  49     }
  50
  51     private final AuthenticationHandler authenticationHandler;
  52     private final SshClient sshClient;
  53
  54     private AsyncSshHandlerReader sshReadAsyncListener;
  55     private AsyncSshHandlerWriter sshWriteAsyncHandler;
  56
  57     private ClientChannel channel;
  58     private ClientSession session;
  59     private ChannelPromise connectPromise;
  60
  61
  62     public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler) throws IOException {
  63         return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT);
  64     }
  65
  66     /**
  67      *
  68      * @param authenticationHandler
  69      * @param sshClient started SshClient
  70      * @throws IOException
  71      */
  72     public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final SshClient sshClient) throws IOException {
  73         this.authenticationHandler = Preconditions.checkNotNull(authenticationHandler);
  74         this.sshClient = Preconditions.checkNotNull(sshClient);
  75         // Start just in case
  76         sshClient.start();
  77     }
  78
  79     private void startSsh(final ChannelHandlerContext ctx, final SocketAddress address) {
  80         logger.debug("Starting SSH to {} on channel: {}", address, ctx.channel());
  81
  82         final ConnectFuture sshConnectionFuture = sshClient.connect(authenticationHandler.getUsername(), address);
  83         sshConnectionFuture.addListener(new SshFutureListener<ConnectFuture>() {
  84             @Override
  85             public void operationComplete(final ConnectFuture future) {
  86                 if (future.isConnected()) {
  87                     handleSshSessionCreated(future, ctx);
  88                 } else {
  89                     handleSshSetupFailure(ctx, future.getException());
  90                 }
  91             }
  92         });
  93     }
  94
  95     private synchronized void handleSshSessionCreated(final ConnectFuture future, final ChannelHandlerContext ctx) {
  96         try {
  97             logger.trace("SSH session created on channel: {}", ctx.channel());
  98
  99             session = future.getSession();
 100             final AuthFuture authenticateFuture = authenticationHandler.authenticate(session);
 101             authenticateFuture.addListener(new SshFutureListener<AuthFuture>() {
 102                 @Override
 103                 public void operationComplete(final AuthFuture future) {
 104                     if (future.isSuccess()) {
 105                         handleSshAuthenticated(session, ctx);
 106                     } else {
 107                         handleSshSetupFailure(ctx, future.getException());
 108                     }
 109                 }
 110             });
 111         } catch (final IOException e) {
 112             handleSshSetupFailure(ctx, e);
 113         }
 114     }
 115
 116     private synchronized void handleSshAuthenticated(final ClientSession session, final ChannelHandlerContext ctx) {
 117         try {
 118             logger.debug("SSH session authenticated on channel: {}, server version: {}", ctx.channel(), session.getServerVersion());
 119
 120             channel = session.createSubsystemChannel(SUBSYSTEM);
 121             channel.setStreaming(ClientChannel.Streaming.Async);
 122             channel.open().addListener(new SshFutureListener<OpenFuture>() {
 123                 @Override
 124                 public void operationComplete(final OpenFuture future) {
 125                     if(future.isOpened()) {
 126                         handleSshChanelOpened(ctx);
 127                     } else {
 128                         handleSshSetupFailure(ctx, future.getException());
 129                     }
 130                 }
 131             });
 132
 133
 134         } catch (final IOException e) {
 135             handleSshSetupFailure(ctx, e);
 136         }
 137     }
 138
 139     private synchronized void handleSshChanelOpened(final ChannelHandlerContext ctx) {
 140         logger.trace("SSH subsystem channel opened successfully on channel: {}", ctx.channel());
 141
 142         connectPromise.setSuccess();
 143         connectPromise = null;
 144
 145         // TODO we should also read from error stream and at least log from that
 146
 147         sshReadAsyncListener = new AsyncSshHandlerReader(new AutoCloseable() {
 148             @Override
 149             public void close() throws Exception {
 150                 AsyncSshHandler.this.disconnect(ctx, ctx.newPromise());
 151             }
 152         }, new AsyncSshHandlerReader.ReadMsgHandler() {
 153             @Override
 154             public void onMessageRead(final ByteBuf msg) {
 155                 ctx.fireChannelRead(msg);
 156             }
 157         }, channel.toString(), channel.getAsyncOut());
 158
 159         // if readAsyncListener receives immediate close, it will close this handler and closing this handler sets channel variable to null
 160         if(channel != null) {
 161             sshWriteAsyncHandler = new AsyncSshHandlerWriter(channel.getAsyncIn());
 162             ctx.fireChannelActive();
 163         }
 164     }
 165
 166     private synchronized void handleSshSetupFailure(final ChannelHandlerContext ctx, final Throwable e) {
 167         logger.warn("Unable to setup SSH connection on channel: {}", ctx.channel(), e);
 168         connectPromise.setFailure(e);
 169         connectPromise = null;
 170         throw new IllegalStateException("Unable to setup SSH connection on channel: " + ctx.channel(), e);
 171     }
 172
 173     @Override
 174     public synchronized void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise) {
 175         sshWriteAsyncHandler.write(ctx, msg, promise);
 176     }
 177
 178     @Override
 179     public synchronized void connect(final ChannelHandlerContext ctx, final SocketAddress remoteAddress, final SocketAddress localAddress, final ChannelPromise promise) throws Exception {
 180         this.connectPromise = promise;
 181         startSsh(ctx, remoteAddress);
 182     }
 183
 184     @Override
 185     public void close(final ChannelHandlerContext ctx, final ChannelPromise promise) throws Exception {
 186         disconnect(ctx, promise);
 187     }
 188
 189     @Override
 190     public synchronized void disconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
 191         if(sshReadAsyncListener != null) {
 192             sshReadAsyncListener.close();
 193         }
 194
 195         if(sshWriteAsyncHandler != null) {
 196             sshWriteAsyncHandler.close();
 197         }
 198
 199         if(session!= null && !session.isClosed() && !session.isClosing()) {
 200             session.close(false).addListener(new SshFutureListener<CloseFuture>() {
 201                 @Override
 202                 public void operationComplete(final CloseFuture future) {
 203                     if (future.isClosed() == false) {
 204                         session.close(true);
 205                     }
 206                     session = null;
 207                 }
 208             });
 209         }
 210
 211         channel = null;
 212         promise.setSuccess();
 213
 214         logger.debug("SSH session closed on channel: {}", ctx.channel());
 215         ctx.fireChannelInactive();
 216     }
 217
 218 }