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 static java.util.Objects.requireNonNull;
  11
  12 import com.google.common.base.Strings;
  13 import com.google.common.util.concurrent.ListenableFuture;
  14 import com.google.common.util.concurrent.SettableFuture;
  15 import io.netty.util.concurrent.Future;
  16 import java.io.EOFException;
  17 import java.util.ArrayDeque;
  18 import java.util.ArrayList;
  19 import java.util.Iterator;
  20 import java.util.List;
  21 import java.util.Queue;
  22 import java.util.concurrent.Semaphore;
  23 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
  24 import java.util.concurrent.locks.Lock;
  25 import java.util.concurrent.locks.ReentrantLock;
  26 import org.eclipse.jdt.annotation.Nullable;
  27 import org.opendaylight.netconf.api.FailedNetconfMessage;
  28 import org.opendaylight.netconf.api.NetconfDocumentedException;
  29 import org.opendaylight.netconf.api.NetconfMessage;
  30 import org.opendaylight.netconf.api.NetconfTerminationReason;
  31 import org.opendaylight.netconf.api.xml.XmlElement;
  32 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  33 import org.opendaylight.netconf.api.xml.XmlUtil;
  34 import org.opendaylight.netconf.client.NetconfClientDispatcher;
  35 import org.opendaylight.netconf.client.NetconfClientSession;
  36 import org.opendaylight.netconf.client.NetconfClientSessionListener;
  37 import org.opendaylight.netconf.client.conf.NetconfClientConfiguration;
  38 import org.opendaylight.netconf.client.conf.NetconfReconnectingClientConfiguration;
  39 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  40 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  41 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  42 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  43 import org.opendaylight.yangtools.util.concurrent.FluentFutures;
  44 import org.opendaylight.yangtools.yang.common.Empty;
  45 import org.opendaylight.yangtools.yang.common.ErrorTag;
  46 import org.opendaylight.yangtools.yang.common.ErrorType;
  47 import org.opendaylight.yangtools.yang.common.QName;
  48 import org.opendaylight.yangtools.yang.common.RpcResult;
  49 import org.opendaylight.yangtools.yang.common.RpcResultBuilder;
  50 import org.slf4j.Logger;
  51 import org.slf4j.LoggerFactory;
  52
  53 public class NetconfDeviceCommunicator implements NetconfClientSessionListener, RemoteDeviceCommunicator {
  54     private static final Logger LOG = LoggerFactory.getLogger(NetconfDeviceCommunicator.class);
  55
  56     protected final RemoteDevice<NetconfDeviceCommunicator> remoteDevice;
  57     private final @Nullable UserPreferences overrideNetconfCapabilities;
  58     protected final RemoteDeviceId id;
  59     private final Lock sessionLock = new ReentrantLock();
  60
  61     private final Semaphore semaphore;
  62     private final int concurentRpcMsgs;
  63
  64     private final Queue<Request> requests = new ArrayDeque<>();
  65     private NetconfClientSession currentSession;
  66
  67     private final SettableFuture<Empty> firstConnectionFuture = SettableFuture.create();
  68     private Future<?> taskFuture;
  69
  70     // isSessionClosing indicates a close operation on the session is issued and
  71     // tearDown will surely be called later to finish the close.
  72     // Used to allow only one thread to enter tearDown and other threads should
  73     // NOT enter it simultaneously and should end its close operation without
  74     // calling tearDown to release the locks they hold to avoid deadlock.
  75     private static final AtomicIntegerFieldUpdater<NetconfDeviceCommunicator> CLOSING_UPDATER =
  76             AtomicIntegerFieldUpdater.newUpdater(NetconfDeviceCommunicator.class, "closing");
  77     private volatile int closing;
  78
  79     public boolean isSessionClosing() {
  80         return closing != 0;
  81     }
  82
  83     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  84             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice,
  85             final UserPreferences netconfSessionPreferences, final int rpcMessageLimit) {
  86         this(id, remoteDevice, rpcMessageLimit, requireNonNull(netconfSessionPreferences));
  87     }
  88
  89     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  90             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice, final int rpcMessageLimit) {
  91         this(id, remoteDevice, rpcMessageLimit, null);
  92     }
  93
  94     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  95             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice, final int rpcMessageLimit,
  96             final @Nullable UserPreferences overrideNetconfCapabilities) {
  97         concurentRpcMsgs = rpcMessageLimit;
  98         this.id = id;
  99         this.remoteDevice = remoteDevice;
 100         this.overrideNetconfCapabilities = overrideNetconfCapabilities;
 101         semaphore = rpcMessageLimit > 0 ? new Semaphore(rpcMessageLimit) : null;
 102     }
 103
 104     @Override
 105     public void onSessionUp(final NetconfClientSession session) {
 106         sessionLock.lock();
 107         try {
 108             LOG.debug("{}: Session established", id);
 109             currentSession = session;
 110
 111             NetconfSessionPreferences netconfSessionPreferences =
 112                                              NetconfSessionPreferences.fromNetconfSession(session);
 113             LOG.trace("{}: Session advertised capabilities: {}", id,
 114                     netconfSessionPreferences);
 115
 116             final var localOverride = overrideNetconfCapabilities;
 117             if (localOverride != null) {
 118                 final var sessionPreferences = localOverride.getSessionPreferences();
 119                 netconfSessionPreferences = localOverride.moduleBasedCapsOverrided()
 120                         ? netconfSessionPreferences.replaceModuleCaps(sessionPreferences)
 121                         : netconfSessionPreferences.addModuleCaps(sessionPreferences);
 122
 123                 netconfSessionPreferences = localOverride.nonModuleBasedCapsOverrided()
 124                         ? netconfSessionPreferences.replaceNonModuleCaps(sessionPreferences)
 125                         : netconfSessionPreferences.addNonModuleCaps(sessionPreferences);
 126                 LOG.debug("{}: Session capabilities overridden, capabilities that will be used: {}", id,
 127                         netconfSessionPreferences);
 128             }
 129
 130             remoteDevice.onRemoteSessionUp(netconfSessionPreferences, this);
 131         } finally {
 132             sessionLock.unlock();
 133         }
 134
 135         // FIXME: right, except ... this does not include the device schema setup, so is it really useful?
 136         if (!firstConnectionFuture.set(Empty.value())) {
 137             LOG.trace("{}: First connection already completed", id);
 138         }
 139     }
 140
 141     /**
 142      * Initialize remote connection.
 143      *
 144      * @param dispatcher {@code NetconfCLientDispatcher}
 145      * @param config     {@code NetconfClientConfiguration}
 146      * @return a ListenableFuture that returns success on first successful connection and failure when the underlying
 147      *         reconnecting strategy runs out of reconnection attempts
 148      */
 149     public ListenableFuture<Empty> initializeRemoteConnection(final NetconfClientDispatcher dispatcher,
 150             final NetconfClientConfiguration config) {
 151
 152         final Future<?> connectFuture;
 153         if (config instanceof NetconfReconnectingClientConfiguration) {
 154             // FIXME: This is weird. If I understand it correctly we want to know about the first connection so as to
 155             //        forward error state. Analyze the call graph to understand what is going on here. We really want
 156             //        to move reconnection away from the socket layer, so that it can properly interface with sessions
 157             //        and generally has some event-driven state (as all good network glue does). There is a second story
 158             //        which is we want to avoid duplicate code, so it depends on other users as well.
 159             final var future = dispatcher.createReconnectingClient((NetconfReconnectingClientConfiguration) config);
 160             taskFuture = future;
 161             connectFuture = future.firstSessionFuture();
 162         } else {
 163             taskFuture = connectFuture = dispatcher.createClient(config);
 164         }
 165
 166         connectFuture.addListener(future -> {
 167             if (!future.isSuccess() && !future.isCancelled()) {
 168                 LOG.debug("{}: Connection failed", id, future.cause());
 169                 remoteDevice.onRemoteSessionFailed(future.cause());
 170                 if (!firstConnectionFuture.isDone()) {
 171                     firstConnectionFuture.setException(future.cause());
 172                 }
 173             }
 174         });
 175         return firstConnectionFuture;
 176     }
 177
 178     public void disconnect() {
 179         // If session is already in closing, no need to close it again
 180         if (currentSession != null && startClosing() && currentSession.isUp()) {
 181             currentSession.close();
 182         }
 183     }
 184
 185     private void tearDown(final String reason) {
 186         if (!isSessionClosing()) {
 187             LOG.warn("It's curious that no one to close the session but tearDown is called!");
 188         }
 189         LOG.debug("Tearing down {}", reason);
 190         final List<UncancellableFuture<RpcResult<NetconfMessage>>> futuresToCancel = new ArrayList<>();
 191         sessionLock.lock();
 192         try {
 193             if (currentSession != null) {
 194                 currentSession = null;
 195                 /*
 196                  * Walk all requests, check if they have been executing
 197                  * or cancelled and remove them from the queue.
 198                  */
 199                 final Iterator<Request> it = requests.iterator();
 200                 while (it.hasNext()) {
 201                     final Request r = it.next();
 202                     if (r.future.isUncancellable()) {
 203                         futuresToCancel.add(r.future);
 204                         it.remove();
 205                     } else if (r.future.isCancelled()) {
 206                         // This just does some house-cleaning
 207                         it.remove();
 208                     }
 209                 }
 210
 211                 remoteDevice.onRemoteSessionDown();
 212             }
 213         } finally {
 214             sessionLock.unlock();
 215         }
 216
 217         // Notify pending request futures outside of the sessionLock to avoid unnecessarily
 218         // blocking the caller.
 219         for (final UncancellableFuture<RpcResult<NetconfMessage>> future : futuresToCancel) {
 220             if (Strings.isNullOrEmpty(reason)) {
 221                 future.set(createSessionDownRpcResult());
 222             } else {
 223                 future.set(createErrorRpcResult(ErrorType.TRANSPORT, reason));
 224             }
 225         }
 226
 227         closing = 0;
 228     }
 229
 230     private RpcResult<NetconfMessage> createSessionDownRpcResult() {
 231         return createErrorRpcResult(ErrorType.TRANSPORT,
 232                 String.format("The netconf session to %1$s is disconnected", id.getName()));
 233     }
 234
 235     private static RpcResult<NetconfMessage> createErrorRpcResult(final ErrorType errorType, final String message) {
 236         return RpcResultBuilder.<NetconfMessage>failed()
 237             .withError(errorType, ErrorTag.OPERATION_FAILED, message).build();
 238     }
 239
 240     @Override
 241     public void onSessionDown(final NetconfClientSession session, final Exception exception) {
 242         // If session is already in closing, no need to call tearDown again.
 243         if (startClosing()) {
 244             if (exception instanceof EOFException) {
 245                 LOG.info("{}: Session went down: {}", id, exception.getMessage());
 246             } else {
 247                 LOG.warn("{}: Session went down", id, exception);
 248             }
 249             tearDown(null);
 250         }
 251     }
 252
 253     @Override
 254     public void onSessionTerminated(final NetconfClientSession session, final NetconfTerminationReason reason) {
 255         // onSessionTerminated is called directly by disconnect, no need to compare and set isSessionClosing.
 256         LOG.warn("{}: Session terminated {}", id, reason);
 257         tearDown(reason.getErrorMessage());
 258     }
 259
 260     @Override
 261     public void close() {
 262         // Cancel reconnect if in progress
 263         if (taskFuture != null) {
 264             taskFuture.cancel(false);
 265         }
 266         // Disconnect from device
 267         // tear down not necessary, called indirectly by the close in disconnect()
 268         disconnect();
 269     }
 270
 271     @Override
 272     public void onMessage(final NetconfClientSession session, final NetconfMessage message) {
 273         /*
 274          * Dispatch between notifications and messages. Messages need to be processed
 275          * with lock held, notifications do not.
 276          */
 277         if (isNotification(message)) {
 278             processNotification(message);
 279         } else {
 280             processMessage(message);
 281         }
 282     }
 283
 284     private void processMessage(final NetconfMessage message) {
 285         Request request = null;
 286         sessionLock.lock();
 287
 288         try {
 289             request = requests.peek();
 290             if (request != null && request.future.isUncancellable()) {
 291                 request = requests.poll();
 292                 // we have just removed one request from the queue
 293                 // we can also release one permit
 294                 if (semaphore != null) {
 295                     semaphore.release();
 296                 }
 297             } else {
 298                 request = null;
 299                 LOG.warn("{}: Ignoring unsolicited message {}", id,
 300                         msgToS(message));
 301             }
 302         } finally {
 303             sessionLock.unlock();
 304         }
 305
 306         if (request == null) {
 307             // No matching request, bail out
 308             return;
 309         }
 310
 311
 312         if (message instanceof FailedNetconfMessage) {
 313             request.future.set(NetconfMessageTransformUtil.toRpcResult((FailedNetconfMessage) message));
 314             return;
 315         }
 316
 317         LOG.debug("{}: Message received {}", id, message);
 318
 319         if (LOG.isTraceEnabled()) {
 320             LOG.trace("{}: Matched request: {} to response: {}", id, msgToS(request.request), msgToS(message));
 321         }
 322
 323         try {
 324             NetconfMessageTransformUtil.checkValidReply(request.request, message);
 325         } catch (final NetconfDocumentedException e) {
 326             LOG.warn("{}: Invalid request-reply match, reply message contains different message-id, "
 327                 + "request: {}, response: {}", id, msgToS(request.request), msgToS(message), e);
 328
 329             request.future.set(RpcResultBuilder.<NetconfMessage>failed()
 330                 .withRpcError(NetconfMessageTransformUtil.toRpcError(e))
 331                 .build());
 332
 333             //recursively processing message to eventually find matching request
 334             processMessage(message);
 335             return;
 336         }
 337
 338         try {
 339             NetconfMessageTransformUtil.checkSuccessReply(message);
 340         } catch (final NetconfDocumentedException e) {
 341             LOG.warn("{}: Error reply from remote device, request: {}, response: {}",
 342                 id, msgToS(request.request), msgToS(message), e);
 343
 344             request.future.set(RpcResultBuilder.<NetconfMessage>failed()
 345                 .withRpcError(NetconfMessageTransformUtil.toRpcError(e))
 346                 .build());
 347             return;
 348         }
 349
 350         request.future.set(RpcResultBuilder.success(message).build());
 351     }
 352
 353     private static String msgToS(final NetconfMessage msg) {
 354         return XmlUtil.toString(msg.getDocument());
 355     }
 356
 357     @Override
 358     public ListenableFuture<RpcResult<NetconfMessage>> sendRequest(final NetconfMessage message, final QName rpc) {
 359         sessionLock.lock();
 360         try {
 361             if (semaphore != null && !semaphore.tryAcquire()) {
 362                 LOG.warn("Limit of concurrent rpc messages was reached (limit: {}). Rpc reply message is needed. "
 363                     + "Discarding request of Netconf device with id: {}", concurentRpcMsgs, id.getName());
 364                 return FluentFutures.immediateFailedFluentFuture(new NetconfDocumentedException(
 365                         "Limit of rpc messages was reached (Limit :" + concurentRpcMsgs
 366                         + ") waiting for emptying the queue of Netconf device with id: " + id.getName()));
 367             }
 368
 369             return sendRequestWithLock(message, rpc);
 370         } finally {
 371             sessionLock.unlock();
 372         }
 373     }
 374
 375     private ListenableFuture<RpcResult<NetconfMessage>> sendRequestWithLock(final NetconfMessage message,
 376                                                                             final QName rpc) {
 377         if (LOG.isTraceEnabled()) {
 378             LOG.trace("{}: Sending message {}", id, msgToS(message));
 379         }
 380
 381         if (currentSession == null) {
 382             LOG.warn("{}: Session is disconnected, failing RPC request {}",
 383                     id, message);
 384             return FluentFutures.immediateFluentFuture(createSessionDownRpcResult());
 385         }
 386
 387         final Request req = new Request(new UncancellableFuture<>(true), message);
 388         requests.add(req);
 389
 390         currentSession.sendMessage(req.request).addListener(future -> {
 391             if (!future.isSuccess()) {
 392                 // We expect that a session down will occur at this point
 393                 LOG.debug("{}: Failed to send request {}", id,
 394                         XmlUtil.toString(req.request.getDocument()),
 395                         future.cause());
 396
 397                 if (future.cause() != null) {
 398                     req.future.set(createErrorRpcResult(ErrorType.TRANSPORT, future.cause().getLocalizedMessage()));
 399                 } else {
 400                     req.future.set(createSessionDownRpcResult()); // assume session is down
 401                 }
 402                 req.future.setException(future.cause());
 403             } else {
 404                 LOG.trace("Finished sending request {}", req.request);
 405             }
 406         });
 407
 408         return req.future;
 409     }
 410
 411     private void processNotification(final NetconfMessage notification) {
 412         if (LOG.isTraceEnabled()) {
 413             LOG.trace("{}: Notification received: {}", id, notification);
 414         }
 415
 416         remoteDevice.onNotification(notification);
 417     }
 418
 419     private static boolean isNotification(final NetconfMessage message) {
 420         if (message.getDocument() == null) {
 421             // We have no message, which mean we have a FailedNetconfMessage
 422             return false;
 423         }
 424         final XmlElement xmle = XmlElement.fromDomDocument(message.getDocument());
 425         return XmlNetconfConstants.NOTIFICATION_ELEMENT_NAME.equals(xmle.getName()) ;
 426     }
 427
 428     private static final class Request {
 429         final UncancellableFuture<RpcResult<NetconfMessage>> future;
 430         final NetconfMessage request;
 431
 432         private Request(final UncancellableFuture<RpcResult<NetconfMessage>> future,
 433                         final NetconfMessage request) {
 434             this.future = future;
 435             this.request = request;
 436         }
 437     }
 438
 439     private boolean startClosing() {
 440         return CLOSING_UPDATER.compareAndSet(this, 0, 1);
 441     }
 442 }