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.Strings;
  11 import com.google.common.util.concurrent.ListenableFuture;
  12 import com.google.common.util.concurrent.SettableFuture;
  13 import io.netty.util.concurrent.Future;
  14 import java.io.EOFException;
  15 import java.util.ArrayDeque;
  16 import java.util.ArrayList;
  17 import java.util.Iterator;
  18 import java.util.List;
  19 import java.util.Optional;
  20 import java.util.Queue;
  21 import java.util.concurrent.Semaphore;
  22 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
  23 import java.util.concurrent.locks.Lock;
  24 import java.util.concurrent.locks.ReentrantLock;
  25 import org.opendaylight.netconf.api.FailedNetconfMessage;
  26 import org.opendaylight.netconf.api.NetconfDocumentedException;
  27 import org.opendaylight.netconf.api.NetconfMessage;
  28 import org.opendaylight.netconf.api.NetconfTerminationReason;
  29 import org.opendaylight.netconf.api.xml.XmlElement;
  30 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  31 import org.opendaylight.netconf.api.xml.XmlUtil;
  32 import org.opendaylight.netconf.client.NetconfClientDispatcher;
  33 import org.opendaylight.netconf.client.NetconfClientSession;
  34 import org.opendaylight.netconf.client.NetconfClientSessionListener;
  35 import org.opendaylight.netconf.client.conf.NetconfClientConfiguration;
  36 import org.opendaylight.netconf.client.conf.NetconfReconnectingClientConfiguration;
  37 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  38 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  39 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  40 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  41 import org.opendaylight.yangtools.util.concurrent.FluentFutures;
  42 import org.opendaylight.yangtools.yang.common.Empty;
  43 import org.opendaylight.yangtools.yang.common.ErrorTag;
  44 import org.opendaylight.yangtools.yang.common.ErrorType;
  45 import org.opendaylight.yangtools.yang.common.QName;
  46 import org.opendaylight.yangtools.yang.common.RpcResult;
  47 import org.opendaylight.yangtools.yang.common.RpcResultBuilder;
  48 import org.slf4j.Logger;
  49 import org.slf4j.LoggerFactory;
  50
  51 public class NetconfDeviceCommunicator implements NetconfClientSessionListener, RemoteDeviceCommunicator {
  52     private static final Logger LOG = LoggerFactory.getLogger(NetconfDeviceCommunicator.class);
  53
  54     protected final RemoteDevice<NetconfDeviceCommunicator> remoteDevice;
  55     private final Optional<UserPreferences> overrideNetconfCapabilities;
  56     protected final RemoteDeviceId id;
  57     private final Lock sessionLock = new ReentrantLock();
  58
  59     private final Semaphore semaphore;
  60     private final int concurentRpcMsgs;
  61
  62     private final Queue<Request> requests = new ArrayDeque<>();
  63     private NetconfClientSession currentSession;
  64
  65     private final SettableFuture<Empty> firstConnectionFuture = SettableFuture.create();
  66     private Future<?> taskFuture;
  67
  68     // isSessionClosing indicates a close operation on the session is issued and
  69     // tearDown will surely be called later to finish the close.
  70     // Used to allow only one thread to enter tearDown and other threads should
  71     // NOT enter it simultaneously and should end its close operation without
  72     // calling tearDown to release the locks they hold to avoid deadlock.
  73     private static final AtomicIntegerFieldUpdater<NetconfDeviceCommunicator> CLOSING_UPDATER =
  74             AtomicIntegerFieldUpdater.newUpdater(NetconfDeviceCommunicator.class, "closing");
  75     private volatile int closing;
  76
  77     public boolean isSessionClosing() {
  78         return closing != 0;
  79     }
  80
  81     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  82             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice,
  83             final UserPreferences netconfSessionPreferences, final int rpcMessageLimit) {
  84         this(id, remoteDevice, Optional.of(netconfSessionPreferences), rpcMessageLimit);
  85     }
  86
  87     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  88             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice, final int rpcMessageLimit) {
  89         this(id, remoteDevice, Optional.empty(), rpcMessageLimit);
  90     }
  91
  92     private NetconfDeviceCommunicator(final RemoteDeviceId id,
  93             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice,
  94             final Optional<UserPreferences> overrideNetconfCapabilities, final int rpcMessageLimit) {
  95         concurentRpcMsgs = rpcMessageLimit;
  96         this.id = id;
  97         this.remoteDevice = remoteDevice;
  98         this.overrideNetconfCapabilities = overrideNetconfCapabilities;
  99         semaphore = rpcMessageLimit > 0 ? new Semaphore(rpcMessageLimit) : null;
 100     }
 101
 102     @Override
 103     public void onSessionUp(final NetconfClientSession session) {
 104         sessionLock.lock();
 105         try {
 106             LOG.debug("{}: Session established", id);
 107             currentSession = session;
 108
 109             NetconfSessionPreferences netconfSessionPreferences =
 110                                              NetconfSessionPreferences.fromNetconfSession(session);
 111             LOG.trace("{}: Session advertised capabilities: {}", id,
 112                     netconfSessionPreferences);
 113
 114             if (overrideNetconfCapabilities.isPresent()) {
 115                 final NetconfSessionPreferences sessionPreferences = overrideNetconfCapabilities
 116                         .get().getSessionPreferences();
 117                 netconfSessionPreferences = overrideNetconfCapabilities.get().moduleBasedCapsOverrided()
 118                         ? netconfSessionPreferences.replaceModuleCaps(sessionPreferences)
 119                         : netconfSessionPreferences.addModuleCaps(sessionPreferences);
 120
 121                 netconfSessionPreferences = overrideNetconfCapabilities.get().nonModuleBasedCapsOverrided()
 122                         ? netconfSessionPreferences.replaceNonModuleCaps(sessionPreferences)
 123                         : netconfSessionPreferences.addNonModuleCaps(sessionPreferences);
 124                 LOG.debug("{}: Session capabilities overridden, capabilities that will be used: {}", id,
 125                         netconfSessionPreferences);
 126             }
 127
 128             remoteDevice.onRemoteSessionUp(netconfSessionPreferences, this);
 129             if (!firstConnectionFuture.isDone()) {
 130                 // FIXME: right, except ... this does not include the device schema setup, so is it really useful?
 131                 firstConnectionFuture.set(Empty.value());
 132             }
 133         } finally {
 134             sessionLock.unlock();
 135         }
 136     }
 137
 138     /**
 139      * Initialize remote connection.
 140      *
 141      * @param dispatcher {@code NetconfCLientDispatcher}
 142      * @param config     {@code NetconfClientConfiguration}
 143      * @return a ListenableFuture that returns success on first successful connection and failure when the underlying
 144      *         reconnecting strategy runs out of reconnection attempts
 145      */
 146     public ListenableFuture<Empty> initializeRemoteConnection(final NetconfClientDispatcher dispatcher,
 147             final NetconfClientConfiguration config) {
 148
 149         final Future<?> connectFuture;
 150         if (config instanceof NetconfReconnectingClientConfiguration) {
 151             // FIXME: This is weird. If I understand it correctly we want to know about the first connection so as to
 152             //        forward error state. Analyze the call graph to understand what is going on here. We really want
 153             //        to move reconnection away from the socket layer, so that it can properly interface with sessions
 154             //        and generally has some event-driven state (as all good network glue does). There is a second story
 155             //        which is we want to avoid duplicate code, so it depends on other users as well.
 156             final var future = dispatcher.createReconnectingClient((NetconfReconnectingClientConfiguration) config);
 157             taskFuture = future;
 158             connectFuture = future.firstSessionFuture();
 159         } else {
 160             taskFuture = connectFuture = dispatcher.createClient(config);
 161         }
 162
 163         connectFuture.addListener(future -> {
 164             if (!future.isSuccess() && !future.isCancelled()) {
 165                 LOG.debug("{}: Connection failed", id, future.cause());
 166                 remoteDevice.onRemoteSessionFailed(future.cause());
 167                 if (!firstConnectionFuture.isDone()) {
 168                     firstConnectionFuture.setException(future.cause());
 169                 }
 170             }
 171         });
 172         return firstConnectionFuture;
 173     }
 174
 175     public void disconnect() {
 176         // If session is already in closing, no need to close it again
 177         if (currentSession != null && startClosing() && currentSession.isUp()) {
 178             currentSession.close();
 179         }
 180     }
 181
 182     private void tearDown(final String reason) {
 183         if (!isSessionClosing()) {
 184             LOG.warn("It's curious that no one to close the session but tearDown is called!");
 185         }
 186         LOG.debug("Tearing down {}", reason);
 187         final List<UncancellableFuture<RpcResult<NetconfMessage>>> futuresToCancel = new ArrayList<>();
 188         sessionLock.lock();
 189         try {
 190             if (currentSession != null) {
 191                 currentSession = null;
 192                 /*
 193                  * Walk all requests, check if they have been executing
 194                  * or cancelled and remove them from the queue.
 195                  */
 196                 final Iterator<Request> it = requests.iterator();
 197                 while (it.hasNext()) {
 198                     final Request r = it.next();
 199                     if (r.future.isUncancellable()) {
 200                         futuresToCancel.add(r.future);
 201                         it.remove();
 202                     } else if (r.future.isCancelled()) {
 203                         // This just does some house-cleaning
 204                         it.remove();
 205                     }
 206                 }
 207
 208                 remoteDevice.onRemoteSessionDown();
 209             }
 210         } finally {
 211             sessionLock.unlock();
 212         }
 213
 214         // Notify pending request futures outside of the sessionLock to avoid unnecessarily
 215         // blocking the caller.
 216         for (final UncancellableFuture<RpcResult<NetconfMessage>> future : futuresToCancel) {
 217             if (Strings.isNullOrEmpty(reason)) {
 218                 future.set(createSessionDownRpcResult());
 219             } else {
 220                 future.set(createErrorRpcResult(ErrorType.TRANSPORT, reason));
 221             }
 222         }
 223
 224         closing = 0;
 225     }
 226
 227     private RpcResult<NetconfMessage> createSessionDownRpcResult() {
 228         return createErrorRpcResult(ErrorType.TRANSPORT,
 229                 String.format("The netconf session to %1$s is disconnected", id.getName()));
 230     }
 231
 232     private static RpcResult<NetconfMessage> createErrorRpcResult(final ErrorType errorType, final String message) {
 233         return RpcResultBuilder.<NetconfMessage>failed()
 234             .withError(errorType, ErrorTag.OPERATION_FAILED, message).build();
 235     }
 236
 237     @Override
 238     public void onSessionDown(final NetconfClientSession session, final Exception exception) {
 239         // If session is already in closing, no need to call tearDown again.
 240         if (startClosing()) {
 241             if (exception instanceof EOFException) {
 242                 LOG.info("{}: Session went down: {}", id, exception.getMessage());
 243             } else {
 244                 LOG.warn("{}: Session went down", id, exception);
 245             }
 246             tearDown(null);
 247         }
 248     }
 249
 250     @Override
 251     public void onSessionTerminated(final NetconfClientSession session, final NetconfTerminationReason reason) {
 252         // onSessionTerminated is called directly by disconnect, no need to compare and set isSessionClosing.
 253         LOG.warn("{}: Session terminated {}", id, reason);
 254         tearDown(reason.getErrorMessage());
 255     }
 256
 257     @Override
 258     public void close() {
 259         // Cancel reconnect if in progress
 260         if (taskFuture != null) {
 261             taskFuture.cancel(false);
 262         }
 263         // Disconnect from device
 264         // tear down not necessary, called indirectly by the close in disconnect()
 265         disconnect();
 266     }
 267
 268     @Override
 269     public void onMessage(final NetconfClientSession session, final NetconfMessage message) {
 270         /*
 271          * Dispatch between notifications and messages. Messages need to be processed
 272          * with lock held, notifications do not.
 273          */
 274         if (isNotification(message)) {
 275             processNotification(message);
 276         } else {
 277             processMessage(message);
 278         }
 279     }
 280
 281     private void processMessage(final NetconfMessage message) {
 282         Request request = null;
 283         sessionLock.lock();
 284
 285         try {
 286             request = requests.peek();
 287             if (request != null && request.future.isUncancellable()) {
 288                 request = requests.poll();
 289                 // we have just removed one request from the queue
 290                 // we can also release one permit
 291                 if (semaphore != null) {
 292                     semaphore.release();
 293                 }
 294             } else {
 295                 request = null;
 296                 LOG.warn("{}: Ignoring unsolicited message {}", id,
 297                         msgToS(message));
 298             }
 299         } finally {
 300             sessionLock.unlock();
 301         }
 302
 303         if (request == null) {
 304             // No matching request, bail out
 305             return;
 306         }
 307
 308
 309         if (message instanceof FailedNetconfMessage) {
 310             request.future.set(NetconfMessageTransformUtil.toRpcResult((FailedNetconfMessage) message));
 311             return;
 312         }
 313
 314         LOG.debug("{}: Message received {}", id, message);
 315
 316         if (LOG.isTraceEnabled()) {
 317             LOG.trace("{}: Matched request: {} to response: {}", id, msgToS(request.request), msgToS(message));
 318         }
 319
 320         try {
 321             NetconfMessageTransformUtil.checkValidReply(request.request, message);
 322         } catch (final NetconfDocumentedException e) {
 323             LOG.warn("{}: Invalid request-reply match, reply message contains different message-id, "
 324                 + "request: {}, response: {}", id, msgToS(request.request), msgToS(message), e);
 325
 326             request.future.set(RpcResultBuilder.<NetconfMessage>failed()
 327                 .withRpcError(NetconfMessageTransformUtil.toRpcError(e))
 328                 .build());
 329
 330             //recursively processing message to eventually find matching request
 331             processMessage(message);
 332             return;
 333         }
 334
 335         try {
 336             NetconfMessageTransformUtil.checkSuccessReply(message);
 337         } catch (final NetconfDocumentedException e) {
 338             LOG.warn("{}: Error reply from remote device, request: {}, response: {}",
 339                 id, msgToS(request.request), msgToS(message), e);
 340
 341             request.future.set(RpcResultBuilder.<NetconfMessage>failed()
 342                 .withRpcError(NetconfMessageTransformUtil.toRpcError(e))
 343                 .build());
 344             return;
 345         }
 346
 347         request.future.set(RpcResultBuilder.success(message).build());
 348     }
 349
 350     private static String msgToS(final NetconfMessage msg) {
 351         return XmlUtil.toString(msg.getDocument());
 352     }
 353
 354     @Override
 355     public ListenableFuture<RpcResult<NetconfMessage>> sendRequest(final NetconfMessage message, final QName rpc) {
 356         sessionLock.lock();
 357         try {
 358             if (semaphore != null && !semaphore.tryAcquire()) {
 359                 LOG.warn("Limit of concurrent rpc messages was reached (limit: {}). Rpc reply message is needed. "
 360                     + "Discarding request of Netconf device with id: {}", concurentRpcMsgs, id.getName());
 361                 return FluentFutures.immediateFailedFluentFuture(new NetconfDocumentedException(
 362                         "Limit of rpc messages was reached (Limit :" + concurentRpcMsgs
 363                         + ") waiting for emptying the queue of Netconf device with id: " + id.getName()));
 364             }
 365
 366             return sendRequestWithLock(message, rpc);
 367         } finally {
 368             sessionLock.unlock();
 369         }
 370     }
 371
 372     private ListenableFuture<RpcResult<NetconfMessage>> sendRequestWithLock(final NetconfMessage message,
 373                                                                             final QName rpc) {
 374         if (LOG.isTraceEnabled()) {
 375             LOG.trace("{}: Sending message {}", id, msgToS(message));
 376         }
 377
 378         if (currentSession == null) {
 379             LOG.warn("{}: Session is disconnected, failing RPC request {}",
 380                     id, message);
 381             return FluentFutures.immediateFluentFuture(createSessionDownRpcResult());
 382         }
 383
 384         final Request req = new Request(new UncancellableFuture<>(true), message);
 385         requests.add(req);
 386
 387         currentSession.sendMessage(req.request).addListener(future -> {
 388             if (!future.isSuccess()) {
 389                 // We expect that a session down will occur at this point
 390                 LOG.debug("{}: Failed to send request {}", id,
 391                         XmlUtil.toString(req.request.getDocument()),
 392                         future.cause());
 393
 394                 if (future.cause() != null) {
 395                     req.future.set(createErrorRpcResult(ErrorType.TRANSPORT, future.cause().getLocalizedMessage()));
 396                 } else {
 397                     req.future.set(createSessionDownRpcResult()); // assume session is down
 398                 }
 399                 req.future.setException(future.cause());
 400             } else {
 401                 LOG.trace("Finished sending request {}", req.request);
 402             }
 403         });
 404
 405         return req.future;
 406     }
 407
 408     private void processNotification(final NetconfMessage notification) {
 409         if (LOG.isTraceEnabled()) {
 410             LOG.trace("{}: Notification received: {}", id, notification);
 411         }
 412
 413         remoteDevice.onNotification(notification);
 414     }
 415
 416     private static boolean isNotification(final NetconfMessage message) {
 417         if (message.getDocument() == null) {
 418             // We have no message, which mean we have a FailedNetconfMessage
 419             return false;
 420         }
 421         final XmlElement xmle = XmlElement.fromDomDocument(message.getDocument());
 422         return XmlNetconfConstants.NOTIFICATION_ELEMENT_NAME.equals(xmle.getName()) ;
 423     }
 424
 425     private static final class Request {
 426         final UncancellableFuture<RpcResult<NetconfMessage>> future;
 427         final NetconfMessage request;
 428
 429         private Request(final UncancellableFuture<RpcResult<NetconfMessage>> future,
 430                         final NetconfMessage request) {
 431             this.future = future;
 432             this.request = request;
 433         }
 434     }
 435
 436     private boolean startClosing() {
 437         return CLOSING_UPDATER.compareAndSet(this, 0, 1);
 438     }
 439 }