2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
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
8 package org.opendaylight.netconf.nettyutil.handler.ssh.client;
10 import static java.util.Objects.requireNonNull;
12 import io.netty.channel.ChannelHandlerContext;
13 import io.netty.channel.ChannelOutboundHandlerAdapter;
14 import io.netty.channel.ChannelPromise;
15 import io.netty.util.concurrent.Future;
16 import io.netty.util.concurrent.GenericFutureListener;
17 import java.io.IOException;
18 import java.net.SocketAddress;
19 import java.util.concurrent.atomic.AtomicBoolean;
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.session.ClientSession;
25 import org.opendaylight.netconf.nettyutil.handler.ssh.authentication.AuthenticationHandler;
26 import org.slf4j.Logger;
27 import org.slf4j.LoggerFactory;
30 * Netty SSH handler class. Acts as interface between Netty and SSH library.
32 public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
33 private static final Logger LOG = LoggerFactory.getLogger(AsyncSshHandler.class);
35 public static final String SUBSYSTEM = "netconf";
37 public static final int SSH_DEFAULT_NIO_WORKERS = 8;
38 // Disable default timeouts from mina sshd
39 private static final long DEFAULT_TIMEOUT = -1L;
41 public static final SshClient DEFAULT_CLIENT;
44 final SshClient c = SshClient.setUpDefaultClient();
45 c.getProperties().put(SshClient.AUTH_TIMEOUT, Long.toString(DEFAULT_TIMEOUT));
46 c.getProperties().put(SshClient.IDLE_TIMEOUT, Long.toString(DEFAULT_TIMEOUT));
48 // TODO make configurable, or somehow reuse netty threadpool
49 c.setNioWorkers(SSH_DEFAULT_NIO_WORKERS);
54 private final AuthenticationHandler authenticationHandler;
55 private final SshClient sshClient;
56 private final AtomicBoolean isDisconnected = new AtomicBoolean();
57 private Future<?> negotiationFuture;
59 private AsyncSshHandlerReader sshReadAsyncListener;
60 private AsyncSshHandlerWriter sshWriteAsyncHandler;
62 private ClientChannel channel;
63 private ClientSession session;
64 private ChannelPromise connectPromise;
65 private GenericFutureListener negotiationFutureListener;
67 public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final SshClient sshClient,
68 final Future<?> negotiationFuture) {
69 this(authenticationHandler, sshClient);
70 this.negotiationFuture = negotiationFuture;
74 * Constructor of {@code AsyncSshHandler}.
76 * @param authenticationHandler authentication handler
77 * @param sshClient started SshClient
79 public AsyncSshHandler(final AuthenticationHandler authenticationHandler,
80 final SshClient sshClient) {
81 this.authenticationHandler = requireNonNull(authenticationHandler);
82 this.sshClient = requireNonNull(sshClient);
85 public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler) {
86 return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT);
90 * Create AsyncSshHandler for netconf subsystem. Negotiation future has to be set to success after successful
91 * netconf negotiation.
93 * @param authenticationHandler authentication handler
94 * @param negotiationFuture negotiation future
95 * @return {@code AsyncSshHandler}
97 public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler,
98 final Future<?> negotiationFuture) {
99 return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT, negotiationFuture);
102 private void startSsh(final ChannelHandlerContext ctx, final SocketAddress address) throws IOException {
103 LOG.debug("Starting SSH to {} on channel: {}", address, ctx.channel());
105 final ConnectFuture sshConnectionFuture = sshClient.connect(authenticationHandler.getUsername(), address);
106 sshConnectionFuture.addListener(future -> {
107 if (future.isConnected()) {
108 handleSshSessionCreated(future, ctx);
110 handleSshSetupFailure(ctx, future.getException());
115 private synchronized void handleSshSessionCreated(final ConnectFuture future, final ChannelHandlerContext ctx) {
117 LOG.trace("SSH session created on channel: {}", ctx.channel());
119 session = future.getSession();
120 final AuthFuture authenticateFuture = authenticationHandler.authenticate(session);
121 final ClientSession localSession = session;
122 authenticateFuture.addListener(future1 -> {
123 if (future1.isSuccess()) {
124 handleSshAuthenticated(localSession, ctx);
126 // Exception does not have to be set in the future, add simple exception in such case
127 final Throwable exception = future1.getException() == null
128 ? new IllegalStateException("Authentication failed") : future1.getException();
129 handleSshSetupFailure(ctx, exception);
132 } catch (final IOException e) {
133 handleSshSetupFailure(ctx, e);
137 private synchronized void handleSshAuthenticated(final ClientSession newSession, final ChannelHandlerContext ctx) {
139 LOG.debug("SSH session authenticated on channel: {}, server version: {}", ctx.channel(),
140 newSession.getServerVersion());
142 channel = newSession.createSubsystemChannel(SUBSYSTEM);
143 channel.setStreaming(ClientChannel.Streaming.Async);
144 channel.open().addListener(future -> {
145 if (future.isOpened()) {
146 handleSshChanelOpened(ctx);
148 handleSshSetupFailure(ctx, future.getException());
153 } catch (final IOException e) {
154 handleSshSetupFailure(ctx, e);
158 private synchronized void handleSshChanelOpened(final ChannelHandlerContext ctx) {
159 LOG.trace("SSH subsystem channel opened successfully on channel: {}", ctx.channel());
161 if (negotiationFuture == null) {
162 connectPromise.setSuccess();
165 // TODO we should also read from error stream and at least log from that
167 ClientChannel localChannel = channel;
168 sshReadAsyncListener = new AsyncSshHandlerReader(() -> AsyncSshHandler.this.disconnect(ctx, ctx.newPromise()),
169 ctx::fireChannelRead, localChannel.toString(), localChannel.getAsyncOut());
171 // if readAsyncListener receives immediate close,
172 // it will close this handler and closing this handler sets channel variable to null
173 if (channel != null) {
174 sshWriteAsyncHandler = new AsyncSshHandlerWriter(channel.getAsyncIn());
175 ctx.fireChannelActive();
179 private synchronized void handleSshSetupFailure(final ChannelHandlerContext ctx, final Throwable error) {
180 LOG.warn("Unable to setup SSH connection on channel: {}", ctx.channel(), error);
182 // If the promise is not yet done, we have failed with initial connect and set connectPromise to failure
183 if (!connectPromise.isDone()) {
184 connectPromise.setFailure(error);
187 disconnect(ctx, ctx.newPromise());
191 public synchronized void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise) {
192 sshWriteAsyncHandler.write(ctx, msg, promise);
196 public synchronized void connect(final ChannelHandlerContext ctx, final SocketAddress remoteAddress,
197 final SocketAddress localAddress, final ChannelPromise promise) throws Exception {
198 LOG.debug("SSH session connecting on channel {}. promise: {} ", ctx.channel(), connectPromise);
199 this.connectPromise = promise;
201 if (negotiationFuture != null) {
202 negotiationFutureListener = future -> {
203 if (future.isSuccess()) {
204 promise.setSuccess();
207 //complete connection promise with netconf negotiation future
208 negotiationFuture.addListener(negotiationFutureListener);
210 startSsh(ctx, remoteAddress);
214 public void close(final ChannelHandlerContext ctx, final ChannelPromise promise) {
215 disconnect(ctx, promise);
219 public void disconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
220 if (isDisconnected.compareAndSet(false, true)) {
221 safelyDisconnect(ctx, promise);
225 @SuppressWarnings("checkstyle:IllegalCatch")
226 private synchronized void safelyDisconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
227 LOG.trace("Closing SSH session on channel: {} with connect promise in state: {}",
228 ctx.channel(), connectPromise);
230 // If we have already succeeded and the session was dropped after,
231 // we need to fire inactive to notify reconnect logic
232 if (connectPromise.isSuccess()) {
233 ctx.fireChannelInactive();
236 if (sshWriteAsyncHandler != null) {
237 sshWriteAsyncHandler.close();
240 if (sshReadAsyncListener != null) {
241 sshReadAsyncListener.close();
244 //If connection promise is not already set, it means negotiation failed
245 //we must set connection promise to failure
246 if (!connectPromise.isDone()) {
247 connectPromise.setFailure(new IllegalStateException("Negotiation failed"));
250 //Remove listener from negotiation future, we don't want notifications
251 //from negotiation anymore
252 if (negotiationFuture != null) {
253 negotiationFuture.removeListener(negotiationFutureListener);
256 if (session != null && !session.isClosed() && !session.isClosing()) {
257 session.close(false).addListener(future -> {
258 synchronized (this) {
259 if (!future.isClosed()) {
267 // Super disconnect is necessary in this case since we are using NioSocketChannel and it needs
268 // to cleanup its resources e.g. Socket that it tries to open in its constructor
269 // (https://bugs.opendaylight.org/show_bug.cgi?id=2430)
270 // TODO better solution would be to implement custom ChannelFactory + Channel
271 // that will use mina SSH lib internally: port this to custom channel implementation
273 // Disconnect has to be closed after inactive channel event was fired, because it interferes with it
274 super.disconnect(ctx, ctx.newPromise());
275 } catch (final Exception e) {
276 LOG.warn("Unable to cleanup all resources for channel: {}. Ignoring.", ctx.channel(), e);
280 promise.setSuccess();
281 LOG.debug("SSH session closed on channel: {}", ctx.channel());