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
9 package org.opendaylight.netconf.nettyutil.handler.ssh.client;
11 import com.google.common.base.Preconditions;
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 org.apache.sshd.client.SshClient;
20 import org.apache.sshd.client.channel.ClientChannel;
21 import org.apache.sshd.client.future.AuthFuture;
22 import org.apache.sshd.client.future.ConnectFuture;
23 import org.apache.sshd.client.session.ClientSession;
24 import org.opendaylight.netconf.nettyutil.handler.ssh.authentication.AuthenticationHandler;
25 import org.slf4j.Logger;
26 import org.slf4j.LoggerFactory;
29 * Netty SSH handler class. Acts as interface between Netty and SSH library.
31 public class AsyncSshHandler extends ChannelOutboundHandlerAdapter {
32 private static final Logger LOG = LoggerFactory.getLogger(AsyncSshHandler.class);
34 public static final String SUBSYSTEM = "netconf";
36 public static final int SSH_DEFAULT_NIO_WORKERS = 8;
37 // Disable default timeouts from mina sshd
38 private static final long DEFAULT_TIMEOUT = -1L;
40 public static final SshClient DEFAULT_CLIENT;
43 final SshClient c = SshClient.setUpDefaultClient();
44 c.getProperties().put(SshClient.AUTH_TIMEOUT, Long.toString(DEFAULT_TIMEOUT));
45 c.getProperties().put(SshClient.IDLE_TIMEOUT, Long.toString(DEFAULT_TIMEOUT));
47 // TODO make configurable, or somehow reuse netty threadpool
48 c.setNioWorkers(SSH_DEFAULT_NIO_WORKERS);
53 private final AuthenticationHandler authenticationHandler;
54 private final SshClient sshClient;
55 private Future<?> negotiationFuture;
57 private AsyncSshHandlerReader sshReadAsyncListener;
58 private AsyncSshHandlerWriter sshWriteAsyncHandler;
60 private ClientChannel channel;
61 private ClientSession session;
62 private ChannelPromise connectPromise;
63 private GenericFutureListener negotiationFutureListener;
65 public AsyncSshHandler(final AuthenticationHandler authenticationHandler, final SshClient sshClient,
66 final Future<?> negotiationFuture) throws IOException {
67 this(authenticationHandler, sshClient);
68 this.negotiationFuture = negotiationFuture;
72 * Constructor of {@code AsyncSshHandler}.
74 * @param authenticationHandler authentication handler
75 * @param sshClient started SshClient
76 * @throws IOException if the I/O operation fails
78 public AsyncSshHandler(final AuthenticationHandler authenticationHandler,
79 final SshClient sshClient) throws IOException {
80 this.authenticationHandler = Preconditions.checkNotNull(authenticationHandler);
81 this.sshClient = Preconditions.checkNotNull(sshClient);
84 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}
96 * @throws IOException if the I/O operation fails
98 public static AsyncSshHandler createForNetconfSubsystem(final AuthenticationHandler authenticationHandler,
99 final Future<?> negotiationFuture) throws IOException {
100 return new AsyncSshHandler(authenticationHandler, DEFAULT_CLIENT, negotiationFuture);
103 private void startSsh(final ChannelHandlerContext ctx, final SocketAddress address) throws IOException {
104 LOG.debug("Starting SSH to {} on channel: {}", address, ctx.channel());
106 final ConnectFuture sshConnectionFuture = sshClient.connect(authenticationHandler.getUsername(), address);
107 sshConnectionFuture.addListener(future -> {
108 if (future.isConnected()) {
109 handleSshSessionCreated(future, ctx);
111 handleSshSetupFailure(ctx, future.getException());
116 private synchronized void handleSshSessionCreated(final ConnectFuture future, final ChannelHandlerContext ctx) {
118 LOG.trace("SSH session created on channel: {}", ctx.channel());
120 session = future.getSession();
121 final AuthFuture authenticateFuture = authenticationHandler.authenticate(session);
122 final ClientSession localSession = session;
123 authenticateFuture.addListener(future1 -> {
124 if (future1.isSuccess()) {
125 handleSshAuthenticated(localSession, ctx);
127 // Exception does not have to be set in the future, add simple exception in such case
128 final Throwable exception = future1.getException() == null
129 ? new IllegalStateException("Authentication failed") : future1.getException();
130 handleSshSetupFailure(ctx, exception);
133 } catch (final IOException e) {
134 handleSshSetupFailure(ctx, e);
138 private synchronized void handleSshAuthenticated(final ClientSession newSession, final ChannelHandlerContext ctx) {
140 LOG.debug("SSH session authenticated on channel: {}, server version: {}", ctx.channel(),
141 newSession.getServerVersion());
143 channel = newSession.createSubsystemChannel(SUBSYSTEM);
144 channel.setStreaming(ClientChannel.Streaming.Async);
145 channel.open().addListener(future -> {
146 if (future.isOpened()) {
147 handleSshChanelOpened(ctx);
149 handleSshSetupFailure(ctx, future.getException());
154 } catch (final IOException e) {
155 handleSshSetupFailure(ctx, e);
159 private synchronized void handleSshChanelOpened(final ChannelHandlerContext ctx) {
160 LOG.trace("SSH subsystem channel opened successfully on channel: {}", ctx.channel());
162 if (negotiationFuture == null) {
163 connectPromise.setSuccess();
166 // TODO we should also read from error stream and at least log from that
168 ClientChannel localChannel = channel;
169 sshReadAsyncListener = new AsyncSshHandlerReader(() -> AsyncSshHandler.this.disconnect(ctx, ctx.newPromise()),
170 msg -> ctx.fireChannelRead(msg), localChannel.toString(), localChannel.getAsyncOut());
172 // if readAsyncListener receives immediate close,
173 // it will close this handler and closing this handler sets channel variable to null
174 if (channel != null) {
175 sshWriteAsyncHandler = new AsyncSshHandlerWriter(channel.getAsyncIn());
176 ctx.fireChannelActive();
180 private synchronized void handleSshSetupFailure(final ChannelHandlerContext ctx, final Throwable error) {
181 LOG.warn("Unable to setup SSH connection on channel: {}", ctx.channel(), error);
183 // If the promise is not yet done, we have failed with initial connect and set connectPromise to failure
184 if (!connectPromise.isDone()) {
185 connectPromise.setFailure(error);
188 disconnect(ctx, ctx.newPromise());
192 public synchronized void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise) {
193 sshWriteAsyncHandler.write(ctx, msg, promise);
197 public synchronized void connect(final ChannelHandlerContext ctx, final SocketAddress remoteAddress,
198 final SocketAddress localAddress, final ChannelPromise promise) throws Exception {
199 LOG.debug("SSH session connecting on channel {}. promise: {} ", ctx.channel(), connectPromise);
200 this.connectPromise = promise;
202 if (negotiationFuture != null) {
203 negotiationFutureListener = future -> {
204 if (future.isSuccess()) {
205 promise.setSuccess();
208 //complete connection promise with netconf negotiation future
209 negotiationFuture.addListener(negotiationFutureListener);
211 startSsh(ctx, remoteAddress);
215 public void close(final ChannelHandlerContext ctx, final ChannelPromise promise) throws Exception {
216 disconnect(ctx, promise);
219 @SuppressWarnings("checkstyle:IllegalCatch")
221 public synchronized void disconnect(final ChannelHandlerContext ctx, final ChannelPromise promise) {
222 LOG.trace("Closing SSH session on channel: {} with connect promise in state: {}",
223 ctx.channel(),connectPromise);
225 // If we have already succeeded and the session was dropped after,
226 // we need to fire inactive to notify reconnect logic
227 if (connectPromise.isSuccess()) {
228 ctx.fireChannelInactive();
231 if (sshWriteAsyncHandler != null) {
232 sshWriteAsyncHandler.close();
235 if (sshReadAsyncListener != null) {
236 sshReadAsyncListener.close();
239 //If connection promise is not already set, it means negotiation failed
240 //we must set connection promise to failure
241 if (!connectPromise.isDone()) {
242 connectPromise.setFailure(new IllegalStateException("Negotiation failed"));
245 //Remove listener from negotiation future, we don't want notifications
246 //from negotiation anymore
247 if (negotiationFuture != null) {
248 negotiationFuture.removeListener(negotiationFutureListener);
251 if (session != null && !session.isClosed() && !session.isClosing()) {
252 session.close(false).addListener(future -> {
253 synchronized (this) {
254 if (!future.isClosed()) {
262 // Super disconnect is necessary in this case since we are using NioSocketChannel and it needs
263 // to cleanup its resources e.g. Socket that it tries to open in its constructor
264 // (https://bugs.opendaylight.org/show_bug.cgi?id=2430)
265 // TODO better solution would be to implement custom ChannelFactory + Channel
266 // that will use mina SSH lib internally: port this to custom channel implementation
268 // Disconnect has to be closed after inactive channel event was fired, because it interferes with it
269 super.disconnect(ctx, ctx.newPromise());
270 } catch (final Exception e) {
271 LOG.warn("Unable to cleanup all resources for channel: {}. Ignoring.", ctx.channel(), e);
275 promise.setSuccess();
276 LOG.debug("SSH session closed on channel: {}", ctx.channel());