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