netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/listener/NetconfDeviceCommunicator.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 package org.opendaylight.netconf.sal.connect.netconf.listener;
   9
  10 import com.google.common.base.Optional;
  11 import com.google.common.base.Strings;
  12 import com.google.common.collect.Lists;
  13 import com.google.common.util.concurrent.Futures;
  14 import com.google.common.util.concurrent.ListenableFuture;
  15 import com.google.common.util.concurrent.SettableFuture;
  16 import io.netty.util.concurrent.Future;
  17 import java.util.ArrayDeque;
  18 import java.util.Iterator;
  19 import java.util.List;
  20 import java.util.Queue;
  21 import java.util.concurrent.Semaphore;
  22 import java.util.concurrent.atomic.AtomicBoolean;
  23 import java.util.concurrent.locks.Lock;
  24 import java.util.concurrent.locks.ReentrantLock;
  25 import org.opendaylight.controller.config.util.xml.XmlElement;
  26 import org.opendaylight.controller.config.util.xml.XmlUtil;
  27 import org.opendaylight.netconf.api.NetconfDocumentedException;
  28 import org.opendaylight.netconf.api.NetconfMessage;
  29 import org.opendaylight.netconf.api.NetconfTerminationReason;
  30 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  31 import org.opendaylight.netconf.client.NetconfClientDispatcher;
  32 import org.opendaylight.netconf.client.NetconfClientSession;
  33 import org.opendaylight.netconf.client.NetconfClientSessionListener;
  34 import org.opendaylight.netconf.client.conf.NetconfClientConfiguration;
  35 import org.opendaylight.netconf.client.conf.NetconfReconnectingClientConfiguration;
  36 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  37 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  38 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  39 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  40 import org.opendaylight.yangtools.yang.common.QName;
  41 import org.opendaylight.yangtools.yang.common.RpcError;
  42 import org.opendaylight.yangtools.yang.common.RpcResult;
  43 import org.opendaylight.yangtools.yang.common.RpcResultBuilder;
  44 import org.slf4j.Logger;
  45 import org.slf4j.LoggerFactory;
  46
  47 public class NetconfDeviceCommunicator implements NetconfClientSessionListener, RemoteDeviceCommunicator<NetconfMessage> {
  48
  49     private static final Logger LOG = LoggerFactory.getLogger(NetconfDeviceCommunicator.class);
  50
  51     protected final RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> remoteDevice;
  52     private final Optional<UserPreferences> overrideNetconfCapabilities;
  53     protected final RemoteDeviceId id;
  54     private final Lock sessionLock = new ReentrantLock();
  55
  56     private final Semaphore semaphore;
  57     private final int concurentRpcMsgs;
  58
  59     private final Queue<Request> requests = new ArrayDeque<>();
  60     private NetconfClientSession session;
  61
  62     private Future<?> initFuture;
  63     private final SettableFuture<NetconfDeviceCapabilities> firstConnectionFuture;
  64
  65     // isSessionClosing indicates a close operation on the session is issued and
  66     // tearDown will surely be called later to finish the close.
  67     // Used to allow only one thread to enter tearDown and other threads should
  68     // NOT enter it simultaneously and should end its close operation without
  69     // calling tearDown to release the locks they hold to avoid deadlock.
  70     private final AtomicBoolean isSessionClosing = new AtomicBoolean(false);
  71
  72     public Boolean isSessionClosing() {
  73         return isSessionClosing.get();
  74     }
  75
  76     public NetconfDeviceCommunicator(final RemoteDeviceId id, final RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> remoteDevice,
  77             final UserPreferences NetconfSessionPreferences, final int rpcMessageLimit) {
  78         this(id, remoteDevice, Optional.of(NetconfSessionPreferences), rpcMessageLimit);
  79     }
  80
  81     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  82                                      final RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> remoteDevice,
  83                                      final int rpcMessageLimit) {
  84         this(id, remoteDevice, Optional.<UserPreferences>absent(), rpcMessageLimit);
  85     }
  86
  87     private NetconfDeviceCommunicator(final RemoteDeviceId id, final RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> remoteDevice,
  88                                       final Optional<UserPreferences> overrideNetconfCapabilities, final int rpcMessageLimit) {
  89         this.concurentRpcMsgs = rpcMessageLimit;
  90         this.id = id;
  91         this.remoteDevice = remoteDevice;
  92         this.overrideNetconfCapabilities = overrideNetconfCapabilities;
  93         this.firstConnectionFuture = SettableFuture.create();
  94         this.semaphore = rpcMessageLimit > 0 ? new Semaphore(rpcMessageLimit) : null;
  95     }
  96
  97     @Override
  98     public void onSessionUp(final NetconfClientSession session) {
  99         sessionLock.lock();
 100         try {
 101             LOG.debug("{}: Session established", id);
 102             this.session = session;
 103
 104             NetconfSessionPreferences netconfSessionPreferences =
 105                                              NetconfSessionPreferences.fromNetconfSession(session);
 106             LOG.trace("{}: Session advertised capabilities: {}", id,
 107                     netconfSessionPreferences);
 108
 109             if (overrideNetconfCapabilities.isPresent()) {
 110                 final NetconfSessionPreferences sessionPreferences = overrideNetconfCapabilities
 111                         .get().getSessionPreferences();
 112                 netconfSessionPreferences = overrideNetconfCapabilities.get().moduleBasedCapsOverrided()
 113                         ? netconfSessionPreferences.replaceModuleCaps(sessionPreferences)
 114                         : netconfSessionPreferences.addModuleCaps(sessionPreferences);
 115
 116                 netconfSessionPreferences = overrideNetconfCapabilities.get().nonModuleBasedCapsOverrided()
 117                         ? netconfSessionPreferences.replaceNonModuleCaps(sessionPreferences)
 118                         : netconfSessionPreferences.addNonModuleCaps(sessionPreferences);
 119                 LOG.debug("{}: Session capabilities overridden, capabilities that will be used: {}", id,
 120                         netconfSessionPreferences);
 121             }
 122
 123             remoteDevice.onRemoteSessionUp(netconfSessionPreferences, this);
 124             if (!firstConnectionFuture.isDone()) {
 125                 firstConnectionFuture.set(netconfSessionPreferences.getNetconfDeviceCapabilities());
 126             }
 127         }
 128         finally {
 129             sessionLock.unlock();
 130         }
 131     }
 132
 133     /**
 134      *
 135      * @param dispatcher
 136      * @param config
 137      * @return future that returns succes on first succesfull connection and failure when the underlying
 138      * reconnecting strategy runs out of reconnection attempts
 139      */
 140     public ListenableFuture<NetconfDeviceCapabilities> initializeRemoteConnection(final NetconfClientDispatcher dispatcher, final NetconfClientConfiguration config) {
 141         if(config instanceof NetconfReconnectingClientConfiguration) {
 142             initFuture = dispatcher.createReconnectingClient((NetconfReconnectingClientConfiguration) config);
 143         } else {
 144             initFuture = dispatcher.createClient(config);
 145         }
 146
 147
 148         initFuture.addListener(future -> {
 149             if (!future.isSuccess() && !future.isCancelled()) {
 150                 LOG.debug("{}: Connection failed", id, future.cause());
 151                 NetconfDeviceCommunicator.this.remoteDevice.onRemoteSessionFailed(future.cause());
 152                 if (firstConnectionFuture.isDone()) {
 153                     firstConnectionFuture.setException(future.cause());
 154                 }
 155             }
 156         });
 157         return firstConnectionFuture;
 158     }
 159
 160     public void disconnect() {
 161         // If session is already in closing, no need to close it again
 162         if(session != null && isSessionClosing.compareAndSet(false, true)) {
 163             session.close();
 164         }
 165     }
 166
 167     private void tearDown(final String reason) {
 168         if (!isSessionClosing()) {
 169             LOG.warn("It's curious that no one to close the session but tearDown is called!");
 170         }
 171         LOG.debug("Tearing down {}", reason);
 172         final List<UncancellableFuture<RpcResult<NetconfMessage>>> futuresToCancel = Lists.newArrayList();
 173         sessionLock.lock();
 174         try {
 175             if( session != null ) {
 176                 session = null;
 177
 178                 /*
 179                  * Walk all requests, check if they have been executing
 180                  * or cancelled and remove them from the queue.
 181                  */
 182                 final Iterator<Request> it = requests.iterator();
 183                 while (it.hasNext()) {
 184                     final Request r = it.next();
 185                     if (r.future.isUncancellable()) {
 186                         futuresToCancel.add( r.future );
 187                         it.remove();
 188                     } else if (r.future.isCancelled()) {
 189                         // This just does some house-cleaning
 190                         it.remove();
 191                     }
 192                 }
 193
 194                 remoteDevice.onRemoteSessionDown();
 195             }
 196         }
 197         finally {
 198             sessionLock.unlock();
 199         }
 200
 201         // Notify pending request futures outside of the sessionLock to avoid unnecessarily
 202         // blocking the caller.
 203         for (final UncancellableFuture<RpcResult<NetconfMessage>> future : futuresToCancel) {
 204             if( Strings.isNullOrEmpty( reason ) ) {
 205                 future.set( createSessionDownRpcResult() );
 206             } else {
 207                 future.set( createErrorRpcResult( RpcError.ErrorType.TRANSPORT, reason ) );
 208             }
 209         }
 210
 211         isSessionClosing.set(false);
 212     }
 213
 214     private RpcResult<NetconfMessage> createSessionDownRpcResult() {
 215         return createErrorRpcResult( RpcError.ErrorType.TRANSPORT,
 216                              String.format( "The netconf session to %1$s is disconnected", id.getName() ) );
 217     }
 218
 219     private static RpcResult<NetconfMessage> createErrorRpcResult(final RpcError.ErrorType errorType,
 220             final String message) {
 221         return RpcResultBuilder.<NetconfMessage>failed()
 222                 .withError(errorType, NetconfDocumentedException.ErrorTag.OPERATION_FAILED.getTagValue(), message).build();
 223     }
 224
 225     @Override
 226     public void onSessionDown(final NetconfClientSession session, final Exception e) {
 227         // If session is already in closing, no need to call tearDown again.
 228         if (isSessionClosing.compareAndSet(false, true)) {
 229             LOG.warn("{}: Session went down", id, e);
 230             tearDown( null );
 231         }
 232     }
 233
 234     @Override
 235     public void onSessionTerminated(final NetconfClientSession session, final NetconfTerminationReason reason) {
 236         // onSessionTerminated is called directly by disconnect, no need to compare and set isSessionClosing.
 237         LOG.warn("{}: Session terminated {}", id, reason);
 238         tearDown( reason.getErrorMessage() );
 239     }
 240
 241     @Override
 242     public void close() {
 243         // Cancel reconnect if in progress
 244         if(initFuture != null) {
 245             initFuture.cancel(false);
 246         }
 247         // Disconnect from device
 248         // tear down not necessary, called indirectly by the close in disconnect()
 249         disconnect();
 250     }
 251
 252     @Override
 253     public void onMessage(final NetconfClientSession session, final NetconfMessage message) {
 254         /*
 255          * Dispatch between notifications and messages. Messages need to be processed
 256          * with lock held, notifications do not.
 257          */
 258         if (isNotification(message)) {
 259             processNotification(message);
 260         } else {
 261             processMessage(message);
 262         }
 263     }
 264
 265     private void processMessage(final NetconfMessage message) {
 266         Request request = null;
 267         sessionLock.lock();
 268
 269         try {
 270             request = requests.peek();
 271             if (request != null && request.future.isUncancellable()) {
 272                 requests.poll();
 273                 // we have just removed one request from the queue
 274                 // we can also release one permit
 275                 if(semaphore != null) {
 276                     semaphore.release();
 277                 }
 278             } else {
 279                 request = null;
 280                 LOG.warn("{}: Ignoring unsolicited message {}", id,
 281                         msgToS(message));
 282             }
 283         }
 284         finally {
 285             sessionLock.unlock();
 286         }
 287
 288         if( request != null ) {
 289
 290             LOG.debug("{}: Message received {}", id, message);
 291
 292             if(LOG.isTraceEnabled()) {
 293                 LOG.trace( "{}: Matched request: {} to response: {}", id, msgToS( request.request ), msgToS( message ) );
 294             }
 295
 296             try {
 297                 NetconfMessageTransformUtil.checkValidReply( request.request, message );
 298             } catch (final NetconfDocumentedException e) {
 299                 LOG.warn(
 300                         "{}: Invalid request-reply match, reply message contains different message-id, request: {}, response: {}",
 301                         id, msgToS(request.request), msgToS(message), e);
 302
 303                 request.future.set( RpcResultBuilder.<NetconfMessage>failed()
 304                         .withRpcError( NetconfMessageTransformUtil.toRpcError( e ) ).build() );
 305
 306                 //recursively processing message to eventually find matching request
 307                 processMessage(message);
 308
 309                 return;
 310             }
 311
 312             try {
 313                 NetconfMessageTransformUtil.checkSuccessReply(message);
 314             } catch(final NetconfDocumentedException e) {
 315                 LOG.warn(
 316                         "{}: Error reply from remote device, request: {}, response: {}",
 317                         id, msgToS(request.request), msgToS(message), e);
 318
 319                 request.future.set( RpcResultBuilder.<NetconfMessage>failed()
 320                         .withRpcError( NetconfMessageTransformUtil.toRpcError( e ) ).build() );
 321                 return;
 322             }
 323
 324             request.future.set( RpcResultBuilder.success( message ).build() );
 325         }
 326     }
 327
 328     private static String msgToS(final NetconfMessage msg) {
 329         return XmlUtil.toString(msg.getDocument());
 330     }
 331
 332     @Override
 333     public ListenableFuture<RpcResult<NetconfMessage>> sendRequest(final NetconfMessage message, final QName rpc) {
 334         sessionLock.lock();
 335
 336         if (semaphore != null && !semaphore.tryAcquire()) {
 337             LOG.warn("Limit of concurrent rpc messages was reached (limit :" +
 338                     concurentRpcMsgs + "). Rpc reply message is needed. Discarding request of Netconf device with id" + id.getName());
 339             sessionLock.unlock();
 340             return Futures.immediateFailedFuture(new NetconfDocumentedException("Limit of rpc messages was reached (Limit :" +
 341                     concurentRpcMsgs + ") waiting for emptying the queue of Netconf device with id" + id.getName()));
 342         }
 343
 344         try {
 345             return sendRequestWithLock(message, rpc);
 346         } finally {
 347             sessionLock.unlock();
 348         }
 349     }
 350
 351     private ListenableFuture<RpcResult<NetconfMessage>> sendRequestWithLock(
 352                                                final NetconfMessage message, final QName rpc) {
 353         if(LOG.isTraceEnabled()) {
 354             LOG.trace("{}: Sending message {}", id, msgToS(message));
 355         }
 356
 357         if (session == null) {
 358             LOG.warn("{}: Session is disconnected, failing RPC request {}",
 359                     id, message);
 360             return Futures.immediateFuture( createSessionDownRpcResult() );
 361         }
 362
 363         final Request req = new Request(new UncancellableFuture<>(true), message);
 364         requests.add(req);
 365
 366         session.sendMessage(req.request).addListener(future -> {
 367             if( !future.isSuccess() ) {
 368                 // We expect that a session down will occur at this point
 369                 LOG.debug("{}: Failed to send request {}", id,
 370                         XmlUtil.toString(req.request.getDocument()),
 371                         future.cause());
 372
 373                 if( future.cause() != null ) {
 374                     req.future.set( createErrorRpcResult( RpcError.ErrorType.TRANSPORT,
 375                                                           future.cause().getLocalizedMessage() ) );
 376                 } else {
 377                     req.future.set( createSessionDownRpcResult() ); // assume session is down
 378                 }
 379                 req.future.setException( future.cause() );
 380             }
 381             else {
 382                 LOG.trace("Finished sending request {}", req.request);
 383             }
 384         });
 385
 386         return req.future;
 387     }
 388
 389     private void processNotification(final NetconfMessage notification) {
 390         if(LOG.isTraceEnabled()) {
 391             LOG.trace("{}: Notification received: {}", id, notification);
 392         }
 393
 394         remoteDevice.onNotification(notification);
 395     }
 396
 397     private static boolean isNotification(final NetconfMessage message) {
 398         final XmlElement xmle = XmlElement.fromDomDocument(message.getDocument());
 399         return XmlNetconfConstants.NOTIFICATION_ELEMENT_NAME.equals(xmle.getName()) ;
 400     }
 401
 402     private static final class Request {
 403         final UncancellableFuture<RpcResult<NetconfMessage>> future;
 404         final NetconfMessage request;
 405
 406         private Request(final UncancellableFuture<RpcResult<NetconfMessage>> future,
 407                         final NetconfMessage request) {
 408             this.future = future;
 409             this.request = request;
 410         }
 411     }
 412 }