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