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         } finally {
 130             sessionLock.unlock();
 131         }
 132
 133         // FIXME: right, except ... this does not include the device schema setup, so is it really useful?
 134         if (!firstConnectionFuture.set(Empty.value())) {
 135             LOG.trace("{}: First connection already completed", id);
 136         }
 137     }
 138
 139     /**
 140      * Initialize remote connection.
 141      *
 142      * @param dispatcher {@code NetconfCLientDispatcher}
 143      * @param config     {@code NetconfClientConfiguration}
 144      * @return a ListenableFuture that returns success on first successful connection and failure when the underlying
 145      *         reconnecting strategy runs out of reconnection attempts
 146      */
 147     public ListenableFuture<Empty> initializeRemoteConnection(final NetconfClientDispatcher dispatcher,
 148             final NetconfClientConfiguration config) {
 149
 150         final Future<?> connectFuture;
 151         if (config instanceof NetconfReconnectingClientConfiguration) {
 152             // FIXME: This is weird. If I understand it correctly we want to know about the first connection so as to
 153             //        forward error state. Analyze the call graph to understand what is going on here. We really want
 154             //        to move reconnection away from the socket layer, so that it can properly interface with sessions
 155             //        and generally has some event-driven state (as all good network glue does). There is a second story
 156             //        which is we want to avoid duplicate code, so it depends on other users as well.
 157             final var future = dispatcher.createReconnectingClient((NetconfReconnectingClientConfiguration) config);
 158             taskFuture = future;
 159             connectFuture = future.firstSessionFuture();
 160         } else {
 161             taskFuture = connectFuture = dispatcher.createClient(config);
 162         }
 163
 164         connectFuture.addListener(future -> {
 165             if (!future.isSuccess() && !future.isCancelled()) {
 166                 LOG.debug("{}: Connection failed", id, future.cause());
 167                 remoteDevice.onRemoteSessionFailed(future.cause());
 168                 if (!firstConnectionFuture.isDone()) {
 169                     firstConnectionFuture.setException(future.cause());
 170                 }
 171             }
 172         });
 173         return firstConnectionFuture;
 174     }
 175
 176     public void disconnect() {
 177         // If session is already in closing, no need to close it again
 178         if (currentSession != null && startClosing() && currentSession.isUp()) {
 179             currentSession.close();
 180         }
 181     }
 182
 183     private void tearDown(final String reason) {
 184         if (!isSessionClosing()) {
 185             LOG.warn("It's curious that no one to close the session but tearDown is called!");
 186         }
 187         LOG.debug("Tearing down {}", reason);
 188         final List<UncancellableFuture<RpcResult<NetconfMessage>>> futuresToCancel = new ArrayList<>();
 189         sessionLock.lock();
 190         try {
 191             if (currentSession != null) {
 192                 currentSession = null;
 193                 /*
 194                  * Walk all requests, check if they have been executing
 195                  * or cancelled and remove them from the queue.
 196                  */
 197                 final Iterator<Request> it = requests.iterator();
 198                 while (it.hasNext()) {
 199                     final Request r = it.next();
 200                     if (r.future.isUncancellable()) {
 201                         futuresToCancel.add(r.future);
 202                         it.remove();
 203                     } else if (r.future.isCancelled()) {
 204                         // This just does some house-cleaning
 205                         it.remove();
 206                     }
 207                 }
 208
 209                 remoteDevice.onRemoteSessionDown();
 210             }
 211         } finally {
 212             sessionLock.unlock();
 213         }
 214
 215         // Notify pending request futures outside of the sessionLock to avoid unnecessarily
 216         // blocking the caller.
 217         for (final UncancellableFuture<RpcResult<NetconfMessage>> future : futuresToCancel) {
 218             if (Strings.isNullOrEmpty(reason)) {
 219                 future.set(createSessionDownRpcResult());
 220             } else {
 221                 future.set(createErrorRpcResult(ErrorType.TRANSPORT, reason));
 222             }
 223         }
 224
 225         closing = 0;
 226     }
 227
 228     private RpcResult<NetconfMessage> createSessionDownRpcResult() {
 229         return createErrorRpcResult(ErrorType.TRANSPORT,
 230                 String.format("The netconf session to %1$s is disconnected", id.getName()));
 231     }
 232
 233     private static RpcResult<NetconfMessage> createErrorRpcResult(final ErrorType errorType, final String message) {
 234         return RpcResultBuilder.<NetconfMessage>failed()
 235             .withError(errorType, ErrorTag.OPERATION_FAILED, message).build();
 236     }
 237
 238     @Override
 239     public void onSessionDown(final NetconfClientSession session, final Exception exception) {
 240         // If session is already in closing, no need to call tearDown again.
 241         if (startClosing()) {
 242             if (exception instanceof EOFException) {
 243                 LOG.info("{}: Session went down: {}", id, exception.getMessage());
 244             } else {
 245                 LOG.warn("{}: Session went down", id, exception);
 246             }
 247             tearDown(null);
 248         }
 249     }
 250
 251     @Override
 252     public void onSessionTerminated(final NetconfClientSession session, final NetconfTerminationReason reason) {
 253         // onSessionTerminated is called directly by disconnect, no need to compare and set isSessionClosing.
 254         LOG.warn("{}: Session terminated {}", id, reason);
 255         tearDown(reason.getErrorMessage());
 256     }
 257
 258     @Override
 259     public void close() {
 260         // Cancel reconnect if in progress
 261         if (taskFuture != null) {
 262             taskFuture.cancel(false);
 263         }
 264         // Disconnect from device
 265         // tear down not necessary, called indirectly by the close in disconnect()
 266         disconnect();
 267     }
 268
 269     @Override
 270     public void onMessage(final NetconfClientSession session, final NetconfMessage message) {
 271         /*
 272          * Dispatch between notifications and messages. Messages need to be processed
 273          * with lock held, notifications do not.
 274          */
 275         if (isNotification(message)) {
 276             processNotification(message);
 277         } else {
 278             processMessage(message);
 279         }
 280     }
 281
 282     private void processMessage(final NetconfMessage message) {
 283         Request request = null;
 284         sessionLock.lock();
 285
 286         try {
 287             request = requests.peek();
 288             if (request != null && request.future.isUncancellable()) {
 289                 request = requests.poll();
 290                 // we have just removed one request from the queue
 291                 // we can also release one permit
 292                 if (semaphore != null) {
 293                     semaphore.release();
 294                 }
 295             } else {
 296                 request = null;
 297                 LOG.warn("{}: Ignoring unsolicited message {}", id,
 298                         msgToS(message));
 299             }
 300         } finally {
 301             sessionLock.unlock();
 302         }
 303
 304         if (request == null) {
 305             // No matching request, bail out
 306             return;
 307         }
 308
 309
 310         if (message instanceof FailedNetconfMessage) {
 311             request.future.set(NetconfMessageTransformUtil.toRpcResult((FailedNetconfMessage) message));
 312             return;
 313         }
 314
 315         LOG.debug("{}: Message received {}", id, message);
 316
 317         if (LOG.isTraceEnabled()) {
 318             LOG.trace("{}: Matched request: {} to response: {}", id, msgToS(request.request), msgToS(message));
 319         }
 320
 321         try {
 322             NetconfMessageTransformUtil.checkValidReply(request.request, message);
 323         } catch (final NetconfDocumentedException e) {
 324             LOG.warn("{}: Invalid request-reply match, reply message contains different message-id, "
 325                 + "request: {}, response: {}", id, msgToS(request.request), msgToS(message), e);
 326
 327             request.future.set(RpcResultBuilder.<NetconfMessage>failed()
 328                 .withRpcError(NetconfMessageTransformUtil.toRpcError(e))
 329                 .build());
 330
 331             //recursively processing message to eventually find matching request
 332             processMessage(message);
 333             return;
 334         }
 335
 336         try {
 337             NetconfMessageTransformUtil.checkSuccessReply(message);
 338         } catch (final NetconfDocumentedException e) {
 339             LOG.warn("{}: Error reply from remote device, request: {}, response: {}",
 340                 id, msgToS(request.request), msgToS(message), e);
 341
 342             request.future.set(RpcResultBuilder.<NetconfMessage>failed()
 343                 .withRpcError(NetconfMessageTransformUtil.toRpcError(e))
 344                 .build());
 345             return;
 346         }
 347
 348         request.future.set(RpcResultBuilder.success(message).build());
 349     }
 350
 351     private static String msgToS(final NetconfMessage msg) {
 352         return XmlUtil.toString(msg.getDocument());
 353     }
 354
 355     @Override
 356     public ListenableFuture<RpcResult<NetconfMessage>> sendRequest(final NetconfMessage message, final QName rpc) {
 357         sessionLock.lock();
 358         try {
 359             if (semaphore != null && !semaphore.tryAcquire()) {
 360                 LOG.warn("Limit of concurrent rpc messages was reached (limit: {}). Rpc reply message is needed. "
 361                     + "Discarding request of Netconf device with id: {}", concurentRpcMsgs, id.getName());
 362                 return FluentFutures.immediateFailedFluentFuture(new NetconfDocumentedException(
 363                         "Limit of rpc messages was reached (Limit :" + concurentRpcMsgs
 364                         + ") waiting for emptying the queue of Netconf device with id: " + id.getName()));
 365             }
 366
 367             return sendRequestWithLock(message, rpc);
 368         } finally {
 369             sessionLock.unlock();
 370         }
 371     }
 372
 373     private ListenableFuture<RpcResult<NetconfMessage>> sendRequestWithLock(final NetconfMessage message,
 374                                                                             final QName rpc) {
 375         if (LOG.isTraceEnabled()) {
 376             LOG.trace("{}: Sending message {}", id, msgToS(message));
 377         }
 378
 379         if (currentSession == null) {
 380             LOG.warn("{}: Session is disconnected, failing RPC request {}",
 381                     id, message);
 382             return FluentFutures.immediateFluentFuture(createSessionDownRpcResult());
 383         }
 384
 385         final Request req = new Request(new UncancellableFuture<>(true), message);
 386         requests.add(req);
 387
 388         currentSession.sendMessage(req.request).addListener(future -> {
 389             if (!future.isSuccess()) {
 390                 // We expect that a session down will occur at this point
 391                 LOG.debug("{}: Failed to send request {}", id,
 392                         XmlUtil.toString(req.request.getDocument()),
 393                         future.cause());
 394
 395                 if (future.cause() != null) {
 396                     req.future.set(createErrorRpcResult(ErrorType.TRANSPORT, future.cause().getLocalizedMessage()));
 397                 } else {
 398                     req.future.set(createSessionDownRpcResult()); // assume session is down
 399                 }
 400                 req.future.setException(future.cause());
 401             } else {
 402                 LOG.trace("Finished sending request {}", req.request);
 403             }
 404         });
 405
 406         return req.future;
 407     }
 408
 409     private void processNotification(final NetconfMessage notification) {
 410         if (LOG.isTraceEnabled()) {
 411             LOG.trace("{}: Notification received: {}", id, notification);
 412         }
 413
 414         remoteDevice.onNotification(notification);
 415     }
 416
 417     private static boolean isNotification(final NetconfMessage message) {
 418         if (message.getDocument() == null) {
 419             // We have no message, which mean we have a FailedNetconfMessage
 420             return false;
 421         }
 422         final XmlElement xmle = XmlElement.fromDomDocument(message.getDocument());
 423         return XmlNetconfConstants.NOTIFICATION_ELEMENT_NAME.equals(xmle.getName()) ;
 424     }
 425
 426     private static final class Request {
 427         final UncancellableFuture<RpcResult<NetconfMessage>> future;
 428         final NetconfMessage request;
 429
 430         private Request(final UncancellableFuture<RpcResult<NetconfMessage>> future,
 431                         final NetconfMessage request) {
 432             this.future = future;
 433             this.request = request;
 434         }
 435     }
 436
 437     private boolean startClosing() {
 438         return CLOSING_UPDATER.compareAndSet(this, 0, 1);
 439     }
 440 }