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 io.netty.util.concurrent.FutureListener;
  18 import io.netty.util.concurrent.GenericFutureListener;
  19 import java.util.ArrayDeque;
  20 import java.util.Iterator;
  21 import java.util.List;
  22 import java.util.Queue;
  23 import java.util.concurrent.Semaphore;
  24 import java.util.concurrent.atomic.AtomicBoolean;
  25 import java.util.concurrent.locks.Lock;
  26 import java.util.concurrent.locks.ReentrantLock;
  27 import org.opendaylight.controller.config.util.xml.XmlElement;
  28 import org.opendaylight.controller.config.util.xml.XmlUtil;
  29 import org.opendaylight.netconf.api.NetconfDocumentedException;
  30 import org.opendaylight.netconf.api.NetconfMessage;
  31 import org.opendaylight.netconf.api.NetconfTerminationReason;
  32 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  33 import org.opendaylight.netconf.client.NetconfClientDispatcher;
  34 import org.opendaylight.netconf.client.NetconfClientSession;
  35 import org.opendaylight.netconf.client.NetconfClientSessionListener;
  36 import org.opendaylight.netconf.client.conf.NetconfClientConfiguration;
  37 import org.opendaylight.netconf.client.conf.NetconfReconnectingClientConfiguration;
  38 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  39 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  40 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  41 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  42 import org.opendaylight.yangtools.yang.common.QName;
  43 import org.opendaylight.yangtools.yang.common.RpcError;
  44 import org.opendaylight.yangtools.yang.common.RpcResult;
  45 import org.opendaylight.yangtools.yang.common.RpcResultBuilder;
  46 import org.slf4j.Logger;
  47 import org.slf4j.LoggerFactory;
  48
  49 public class NetconfDeviceCommunicator implements NetconfClientSessionListener, RemoteDeviceCommunicator<NetconfMessage> {
  50
  51     private static final Logger LOG = LoggerFactory.getLogger(NetconfDeviceCommunicator.class);
  52
  53     protected final RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> remoteDevice;
  54     private final Optional<UserPreferences> overrideNetconfCapabilities;
  55     protected final RemoteDeviceId id;
  56     private final Lock sessionLock = new ReentrantLock();
  57
  58     private final Semaphore semaphore;
  59     private final int concurentRpcMsgs;
  60
  61     private final Queue<Request> requests = new ArrayDeque<>();
  62     private NetconfClientSession session;
  63
  64     private Future<?> initFuture;
  65     private SettableFuture<NetconfDeviceCapabilities> firstConnectionFuture;
  66
  67     // isSessionClosing indicates a close operation on the session is issued and
  68     // tearDown will surely be called later to finish the close.
  69     // Used to allow only one thread to enter tearDown and other threads should
  70     // NOT enter it simultaneously and should end its close operation without
  71     // calling tearDown to release the locks they hold to avoid deadlock.
  72     private volatile AtomicBoolean isSessionClosing = new AtomicBoolean(false);
  73
  74     public Boolean isSessionClosing() {
  75         return isSessionClosing.get();
  76     }
  77
  78     public NetconfDeviceCommunicator(final RemoteDeviceId id, final RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> remoteDevice,
  79             final UserPreferences NetconfSessionPreferences, final int rpcMessageLimit) {
  80         this(id, remoteDevice, Optional.of(NetconfSessionPreferences), rpcMessageLimit);
  81     }
  82
  83     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  84                                      final RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> remoteDevice,
  85                                      final int rpcMessageLimit) {
  86         this(id, remoteDevice, Optional.<UserPreferences>absent(), rpcMessageLimit);
  87     }
  88
  89     private NetconfDeviceCommunicator(final RemoteDeviceId id, final RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> remoteDevice,
  90                                       final Optional<UserPreferences> overrideNetconfCapabilities, final int rpcMessageLimit) {
  91         this.concurentRpcMsgs = rpcMessageLimit;
  92         this.id = id;
  93         this.remoteDevice = remoteDevice;
  94         this.overrideNetconfCapabilities = overrideNetconfCapabilities;
  95         this.firstConnectionFuture = SettableFuture.create();
  96         this.semaphore = rpcMessageLimit > 0 ? new Semaphore(rpcMessageLimit) : null;
  97     }
  98
  99     @Override
 100     public void onSessionUp(final NetconfClientSession session) {
 101         sessionLock.lock();
 102         try {
 103             LOG.debug("{}: Session established", id);
 104             this.session = session;
 105
 106             NetconfSessionPreferences netconfSessionPreferences =
 107                                              NetconfSessionPreferences.fromNetconfSession(session);
 108             LOG.trace("{}: Session advertised capabilities: {}", id,
 109                     netconfSessionPreferences);
 110
 111             if(overrideNetconfCapabilities.isPresent()) {
 112                 netconfSessionPreferences = overrideNetconfCapabilities.get().isOverride() ?
 113                         netconfSessionPreferences.replaceModuleCaps(overrideNetconfCapabilities.get().getSessionPreferences()) :
 114                         netconfSessionPreferences.addModuleCaps(overrideNetconfCapabilities.get().getSessionPreferences());
 115                 LOG.debug(
 116                         "{}: Session capabilities overridden, capabilities that will be used: {}",
 117                         id, netconfSessionPreferences);
 118             }
 119
 120
 121             remoteDevice.onRemoteSessionUp(netconfSessionPreferences, this);
 122             if (!firstConnectionFuture.isDone()) {
 123                 firstConnectionFuture.set(netconfSessionPreferences.getNetconfDeviceCapabilities());
 124             }
 125         }
 126         finally {
 127             sessionLock.unlock();
 128         }
 129     }
 130
 131     /**
 132      *
 133      * @param dispatcher
 134      * @param config
 135      * @return future that returns succes on first succesfull connection and failure when the underlying
 136      * reconnecting strategy runs out of reconnection attempts
 137      */
 138     public ListenableFuture<NetconfDeviceCapabilities> initializeRemoteConnection(final NetconfClientDispatcher dispatcher, final NetconfClientConfiguration config) {
 139         if(config instanceof NetconfReconnectingClientConfiguration) {
 140             initFuture = dispatcher.createReconnectingClient((NetconfReconnectingClientConfiguration) config);
 141         } else {
 142             initFuture = dispatcher.createClient(config);
 143         }
 144
 145
 146         initFuture.addListener(new GenericFutureListener<Future<Object>>(){
 147
 148             @Override
 149             public void operationComplete(Future<Object> future) throws Exception {
 150                 if (!future.isSuccess() && !future.isCancelled()) {
 151                     LOG.debug("{}: Connection failed", id, future.cause());
 152                     NetconfDeviceCommunicator.this.remoteDevice.onRemoteSessionFailed(future.cause());
 153                     if (firstConnectionFuture.isDone()) {
 154                         firstConnectionFuture.setException(future.cause());
 155                     }
 156                 }
 157             }
 158         });
 159         return firstConnectionFuture;
 160     }
 161
 162     public void disconnect() {
 163         // If session is already in closing, no need to close it again
 164         if(session != null && isSessionClosing.compareAndSet(false, true)) {
 165             session.close();
 166         }
 167     }
 168
 169     private void tearDown( String reason ) {
 170         if (!isSessionClosing()) {
 171             LOG.warn("It's curious that no one to close the session but tearDown is called!");
 172         }
 173         LOG.debug("Tearing down {}", reason);
 174         List<UncancellableFuture<RpcResult<NetconfMessage>>> futuresToCancel = Lists.newArrayList();
 175         sessionLock.lock();
 176         try {
 177             if( session != null ) {
 178                 session = null;
 179
 180                 /*
 181                  * Walk all requests, check if they have been executing
 182                  * or cancelled and remove them from the queue.
 183                  */
 184                 final Iterator<Request> it = requests.iterator();
 185                 while (it.hasNext()) {
 186                     final Request r = it.next();
 187                     if (r.future.isUncancellable()) {
 188                         futuresToCancel.add( r.future );
 189                         it.remove();
 190                     } else if (r.future.isCancelled()) {
 191                         // This just does some house-cleaning
 192                         it.remove();
 193                     }
 194                 }
 195
 196                 remoteDevice.onRemoteSessionDown();
 197             }
 198         }
 199         finally {
 200             sessionLock.unlock();
 201         }
 202
 203         // Notify pending request futures outside of the sessionLock to avoid unnecessarily
 204         // blocking the caller.
 205         for( UncancellableFuture<RpcResult<NetconfMessage>> future: futuresToCancel ) {
 206             if( Strings.isNullOrEmpty( reason ) ) {
 207                 future.set( createSessionDownRpcResult() );
 208             } else {
 209                 future.set( createErrorRpcResult( RpcError.ErrorType.TRANSPORT, reason ) );
 210             }
 211         }
 212
 213         isSessionClosing.set(false);
 214     }
 215
 216     private RpcResult<NetconfMessage> createSessionDownRpcResult() {
 217         return createErrorRpcResult( RpcError.ErrorType.TRANSPORT,
 218                              String.format( "The netconf session to %1$s is disconnected", id.getName() ) );
 219     }
 220
 221     private RpcResult<NetconfMessage> createErrorRpcResult( RpcError.ErrorType errorType, String message ) {
 222         return RpcResultBuilder.<NetconfMessage>failed()
 223                 .withError(errorType, NetconfDocumentedException.ErrorTag.operation_failed.getTagValue(), message).build();
 224     }
 225
 226     @Override
 227     public void onSessionDown(final NetconfClientSession session, final Exception e) {
 228         // If session is already in closing, no need to call tearDown again.
 229         if (isSessionClosing.compareAndSet(false, true)) {
 230             LOG.warn("{}: Session went down", id, e);
 231             tearDown( null );
 232         }
 233     }
 234
 235     @Override
 236     public void onSessionTerminated(final NetconfClientSession session, final NetconfTerminationReason reason) {
 237         // onSessionTerminated is called directly by disconnect, no need to compare and set isSessionClosing.
 238         LOG.warn("{}: Session terminated {}", id, reason);
 239         tearDown( reason.getErrorMessage() );
 240     }
 241
 242     @Override
 243     public void close() {
 244         // Cancel reconnect if in progress
 245         if(initFuture != null) {
 246             initFuture.cancel(false);
 247         }
 248         // Disconnect from device
 249         // tear down not necessary, called indirectly by the close in disconnect()
 250         disconnect();
 251     }
 252
 253     @Override
 254     public void onMessage(final NetconfClientSession session, final NetconfMessage message) {
 255         /*
 256          * Dispatch between notifications and messages. Messages need to be processed
 257          * with lock held, notifications do not.
 258          */
 259         if (isNotification(message)) {
 260             processNotification(message);
 261         } else {
 262             processMessage(message);
 263         }
 264     }
 265
 266     private void processMessage(final NetconfMessage message) {
 267         Request request = null;
 268         sessionLock.lock();
 269
 270         try {
 271             request = requests.peek();
 272             if (request != null && request.future.isUncancellable()) {
 273                 requests.poll();
 274                 // we have just removed one request from the queue
 275                 // we can also release one permit
 276                 if(semaphore != null) {
 277                     semaphore.release();
 278                 }
 279             } else {
 280                 request = null;
 281                 LOG.warn("{}: Ignoring unsolicited message {}", id,
 282                         msgToS(message));
 283             }
 284         }
 285         finally {
 286             sessionLock.unlock();
 287         }
 288
 289         if( request != null ) {
 290
 291             LOG.debug("{}: Message received {}", id, message);
 292
 293             if(LOG.isTraceEnabled()) {
 294                 LOG.trace( "{}: Matched request: {} to response: {}", id, msgToS( request.request ), msgToS( message ) );
 295             }
 296
 297             try {
 298                 NetconfMessageTransformUtil.checkValidReply( request.request, message );
 299             } catch (final NetconfDocumentedException e) {
 300                 LOG.warn(
 301                         "{}: Invalid request-reply match, reply message contains different message-id, request: {}, response: {}",
 302                         id, msgToS(request.request), msgToS(message), e);
 303
 304                 request.future.set( RpcResultBuilder.<NetconfMessage>failed()
 305                         .withRpcError( NetconfMessageTransformUtil.toRpcError( e ) ).build() );
 306
 307                 //recursively processing message to eventually find matching request
 308                 processMessage(message);
 309
 310                 return;
 311             }
 312
 313             try {
 314                 NetconfMessageTransformUtil.checkSuccessReply(message);
 315             } catch(final NetconfDocumentedException e) {
 316                 LOG.warn(
 317                         "{}: Error reply from remote device, request: {}, response: {}",
 318                         id, msgToS(request.request), msgToS(message), e);
 319
 320                 request.future.set( RpcResultBuilder.<NetconfMessage>failed()
 321                         .withRpcError( NetconfMessageTransformUtil.toRpcError( e ) ).build() );
 322                 return;
 323             }
 324
 325             request.future.set( RpcResultBuilder.success( message ).build() );
 326         }
 327     }
 328
 329     private static String msgToS(final NetconfMessage msg) {
 330         return XmlUtil.toString(msg.getDocument());
 331     }
 332
 333     @Override
 334     public ListenableFuture<RpcResult<NetconfMessage>> sendRequest(final NetconfMessage message, final QName rpc) {
 335         sessionLock.lock();
 336
 337         if (semaphore != null && !semaphore.tryAcquire()) {
 338             LOG.warn("Limit of concurrent rpc messages was reached (limit :" +
 339                     concurentRpcMsgs + "). Rpc reply message is needed. Discarding request of Netconf device with id" + id.getName());
 340             sessionLock.unlock();
 341             return Futures.immediateFailedFuture(new NetconfDocumentedException("Limit of rpc messages was reached (Limit :" +
 342                     concurentRpcMsgs + ") waiting for emptying the queue of Netconf device with id" + id.getName()));
 343         }
 344
 345         try {
 346             return sendRequestWithLock(message, rpc);
 347         } finally {
 348             sessionLock.unlock();
 349         }
 350     }
 351
 352     private ListenableFuture<RpcResult<NetconfMessage>> sendRequestWithLock(
 353                                                final NetconfMessage message, final QName rpc) {
 354         if(LOG.isTraceEnabled()) {
 355             LOG.trace("{}: Sending message {}", id, msgToS(message));
 356         }
 357
 358         if (session == null) {
 359             LOG.warn("{}: Session is disconnected, failing RPC request {}",
 360                     id, message);
 361             return Futures.immediateFuture( createSessionDownRpcResult() );
 362         }
 363
 364         final Request req = new Request( new UncancellableFuture<RpcResult<NetconfMessage>>(true),
 365                                          message );
 366         requests.add(req);
 367
 368         session.sendMessage(req.request).addListener(new FutureListener<Void>() {
 369             @Override
 370             public void operationComplete(final Future<Void> future) throws Exception {
 371                 if( !future.isSuccess() ) {
 372                     // We expect that a session down will occur at this point
 373                     LOG.debug("{}: Failed to send request {}", id,
 374                             XmlUtil.toString(req.request.getDocument()),
 375                             future.cause());
 376
 377                     if( future.cause() != null ) {
 378                         req.future.set( createErrorRpcResult( RpcError.ErrorType.TRANSPORT,
 379                                                               future.cause().getLocalizedMessage() ) );
 380                     } else {
 381                         req.future.set( createSessionDownRpcResult() ); // assume session is down
 382                     }
 383                     req.future.setException( future.cause() );
 384                 }
 385                 else {
 386                     LOG.trace("Finished sending request {}", req.request);
 387                 }
 388             }
 389         });
 390
 391         return req.future;
 392     }
 393
 394     private void processNotification(final NetconfMessage notification) {
 395         if(LOG.isTraceEnabled()) {
 396             LOG.trace("{}: Notification received: {}", id, notification);
 397         }
 398
 399         remoteDevice.onNotification(notification);
 400     }
 401
 402     private static boolean isNotification(final NetconfMessage message) {
 403         final XmlElement xmle = XmlElement.fromDomDocument(message.getDocument());
 404         return XmlNetconfConstants.NOTIFICATION_ELEMENT_NAME.equals(xmle.getName()) ;
 405     }
 406
 407     private static final class Request {
 408         final UncancellableFuture<RpcResult<NetconfMessage>> future;
 409         final NetconfMessage request;
 410
 411         private Request(final UncancellableFuture<RpcResult<NetconfMessage>> future,
 412                         final NetconfMessage request) {
 413             this.future = future;
 414             this.request = request;
 415         }
 416     }
 417 }