plugins/netconf-client-mdsal/src/main/java/org/opendaylight/netconf/client/mdsal/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.client.mdsal;
   9
  10 import com.google.common.base.Strings;
  11 import com.google.common.collect.ImmutableMap;
  12 import com.google.common.util.concurrent.Futures;
  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.DocumentedException;
  28 import org.opendaylight.netconf.api.NetconfMessage;
  29 import org.opendaylight.netconf.api.NetconfTerminationReason;
  30 import org.opendaylight.netconf.api.xml.XmlElement;
  31 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  32 import org.opendaylight.netconf.api.xml.XmlUtil;
  33 import org.opendaylight.netconf.client.NetconfClientDispatcher;
  34 import org.opendaylight.netconf.client.NetconfClientSession;
  35 import org.opendaylight.netconf.client.NetconfClientSessionListener;
  36 import org.opendaylight.netconf.client.NetconfMessageUtil;
  37 import org.opendaylight.netconf.client.conf.NetconfClientConfiguration;
  38 import org.opendaylight.netconf.client.conf.NetconfReconnectingClientConfiguration;
  39 import org.opendaylight.netconf.client.mdsal.api.NetconfSessionPreferences;
  40 import org.opendaylight.netconf.client.mdsal.api.RemoteDevice;
  41 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceCommunicator;
  42 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceId;
  43 import org.opendaylight.yangtools.yang.common.Empty;
  44 import org.opendaylight.yangtools.yang.common.ErrorSeverity;
  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.RpcError;
  49 import org.opendaylight.yangtools.yang.common.RpcResult;
  50 import org.opendaylight.yangtools.yang.common.RpcResultBuilder;
  51 import org.slf4j.Logger;
  52 import org.slf4j.LoggerFactory;
  53
  54 public class NetconfDeviceCommunicator implements NetconfClientSessionListener, RemoteDeviceCommunicator {
  55     private static final Logger LOG = LoggerFactory.getLogger(NetconfDeviceCommunicator.class);
  56
  57     protected final RemoteDevice<NetconfDeviceCommunicator> remoteDevice;
  58     private final @Nullable UserPreferences overrideNetconfCapabilities;
  59     protected final RemoteDeviceId id;
  60     private final Lock sessionLock = new ReentrantLock();
  61
  62     private final Semaphore semaphore;
  63     private final int concurentRpcMsgs;
  64
  65     private final Queue<Request> requests = new ArrayDeque<>();
  66     private NetconfClientSession currentSession;
  67
  68     private final SettableFuture<Empty> firstConnectionFuture = SettableFuture.create();
  69     private Future<?> taskFuture;
  70
  71     // isSessionClosing indicates a close operation on the session is issued and
  72     // tearDown will surely be called later to finish the close.
  73     // Used to allow only one thread to enter tearDown and other threads should
  74     // NOT enter it simultaneously and should end its close operation without
  75     // calling tearDown to release the locks they hold to avoid deadlock.
  76     private static final AtomicIntegerFieldUpdater<NetconfDeviceCommunicator> CLOSING_UPDATER =
  77             AtomicIntegerFieldUpdater.newUpdater(NetconfDeviceCommunicator.class, "closing");
  78     private volatile int closing;
  79
  80     public boolean isSessionClosing() {
  81         return closing != 0;
  82     }
  83
  84     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  85             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice, final int rpcMessageLimit) {
  86         this(id, remoteDevice, rpcMessageLimit, null);
  87     }
  88
  89     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  90             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice, final int rpcMessageLimit,
  91             final @Nullable UserPreferences overrideNetconfCapabilities) {
  92         concurentRpcMsgs = rpcMessageLimit;
  93         this.id = id;
  94         this.remoteDevice = remoteDevice;
  95         this.overrideNetconfCapabilities = overrideNetconfCapabilities;
  96         semaphore = rpcMessageLimit > 0 ? new Semaphore(rpcMessageLimit) : null;
  97     }
  98
  99     @Override
 100     public void onSessionUp(final NetconfClientSession session) {
 101         sessionLock.lock();
 102         try {
 103             LOG.debug("{}: Session established", id);
 104             currentSession = session;
 105
 106             var netconfSessionPreferences = NetconfSessionPreferences.fromNetconfSession(session);
 107             LOG.trace("{}: Session advertised capabilities: {}", id, netconfSessionPreferences);
 108
 109             final var localOverride = overrideNetconfCapabilities;
 110             if (localOverride != null) {
 111                 final var sessionPreferences = localOverride.sessionPreferences();
 112                 netconfSessionPreferences = localOverride.overrideModuleCapabilities()
 113                         ? netconfSessionPreferences.replaceModuleCaps(sessionPreferences)
 114                         : netconfSessionPreferences.addModuleCaps(sessionPreferences);
 115
 116                 netconfSessionPreferences = localOverride.overrideNonModuleCapabilities()
 117                         ? netconfSessionPreferences.replaceNonModuleCaps(sessionPreferences)
 118                         : netconfSessionPreferences.addNonModuleCaps(sessionPreferences);
 119                 LOG.debug("{}: Session capabilities overridden, capabilities that will be used: {}", id,
 120                         netconfSessionPreferences);
 121             }
 122
 123             remoteDevice.onRemoteSessionUp(netconfSessionPreferences, this);
 124         } finally {
 125             sessionLock.unlock();
 126         }
 127
 128         // FIXME: right, except ... this does not include the device schema setup, so is it really useful?
 129         if (!firstConnectionFuture.set(Empty.value())) {
 130             LOG.trace("{}: First connection already completed", id);
 131         }
 132     }
 133
 134     /**
 135      * Initialize remote connection.
 136      *
 137      * @param dispatcher {@code NetconfCLientDispatcher}
 138      * @param config     {@code NetconfClientConfiguration}
 139      * @return a ListenableFuture that returns success on first successful connection and failure when the underlying
 140      *         reconnecting strategy runs out of reconnection attempts
 141      */
 142     public ListenableFuture<Empty> initializeRemoteConnection(final NetconfClientDispatcher dispatcher,
 143             final NetconfClientConfiguration config) {
 144
 145         final Future<?> connectFuture;
 146         if (config instanceof NetconfReconnectingClientConfiguration) {
 147             // FIXME: This is weird. If I understand it correctly we want to know about the first connection so as to
 148             //        forward error state. Analyze the call graph to understand what is going on here. We really want
 149             //        to move reconnection away from the socket layer, so that it can properly interface with sessions
 150             //        and generally has some event-driven state (as all good network glue does). There is a second story
 151             //        which is we want to avoid duplicate code, so it depends on other users as well.
 152             final var future = dispatcher.createReconnectingClient((NetconfReconnectingClientConfiguration) config);
 153             taskFuture = future;
 154             connectFuture = future.firstSessionFuture();
 155         } else {
 156             taskFuture = connectFuture = dispatcher.createClient(config);
 157         }
 158
 159         connectFuture.addListener(future -> {
 160             if (!future.isSuccess() && !future.isCancelled()) {
 161                 LOG.debug("{}: Connection failed", id, future.cause());
 162                 remoteDevice.onRemoteSessionFailed(future.cause());
 163                 if (!firstConnectionFuture.isDone()) {
 164                     firstConnectionFuture.setException(future.cause());
 165                 }
 166             }
 167         });
 168         return firstConnectionFuture;
 169     }
 170
 171     public void disconnect() {
 172         // If session is already in closing, no need to close it again
 173         if (currentSession != null && startClosing() && currentSession.isUp()) {
 174             currentSession.close();
 175         }
 176     }
 177
 178     private void tearDown(final String reason) {
 179         if (!isSessionClosing()) {
 180             LOG.warn("It's curious that no one to close the session but tearDown is called!");
 181         }
 182         LOG.debug("Tearing down {}", reason);
 183         final List<UncancellableFuture<RpcResult<NetconfMessage>>> futuresToCancel = new ArrayList<>();
 184         sessionLock.lock();
 185         try {
 186             if (currentSession != null) {
 187                 currentSession = null;
 188                 /*
 189                  * Walk all requests, check if they have been executing
 190                  * or cancelled and remove them from the queue.
 191                  */
 192                 final Iterator<Request> it = requests.iterator();
 193                 while (it.hasNext()) {
 194                     final Request r = it.next();
 195                     if (r.future.isUncancellable()) {
 196                         futuresToCancel.add(r.future);
 197                         it.remove();
 198                     } else if (r.future.isCancelled()) {
 199                         // This just does some house-cleaning
 200                         it.remove();
 201                     }
 202                 }
 203
 204                 remoteDevice.onRemoteSessionDown();
 205             }
 206         } finally {
 207             sessionLock.unlock();
 208         }
 209
 210         // Notify pending request futures outside of the sessionLock to avoid unnecessarily
 211         // blocking the caller.
 212         for (final UncancellableFuture<RpcResult<NetconfMessage>> future : futuresToCancel) {
 213             if (Strings.isNullOrEmpty(reason)) {
 214                 future.set(createSessionDownRpcResult());
 215             } else {
 216                 future.set(createErrorRpcResult(ErrorType.TRANSPORT, reason));
 217             }
 218         }
 219
 220         closing = 0;
 221     }
 222
 223     private RpcResult<NetconfMessage> createSessionDownRpcResult() {
 224         return createErrorRpcResult(ErrorType.TRANSPORT,
 225                 String.format("The netconf session to %1$s is disconnected", id.name()));
 226     }
 227
 228     private static RpcResult<NetconfMessage> createErrorRpcResult(final ErrorType errorType, final String message) {
 229         return RpcResultBuilder.<NetconfMessage>failed()
 230             .withError(errorType, ErrorTag.OPERATION_FAILED, message).build();
 231     }
 232
 233     @Override
 234     public void onSessionDown(final NetconfClientSession session, final Exception exception) {
 235         // If session is already in closing, no need to call tearDown again.
 236         if (startClosing()) {
 237             if (exception instanceof EOFException) {
 238                 LOG.info("{}: Session went down: {}", id, exception.getMessage());
 239             } else {
 240                 LOG.warn("{}: Session went down", id, exception);
 241             }
 242             tearDown(null);
 243         }
 244     }
 245
 246     @Override
 247     public void onSessionTerminated(final NetconfClientSession session, final NetconfTerminationReason reason) {
 248         // onSessionTerminated is called directly by disconnect, no need to compare and set isSessionClosing.
 249         LOG.warn("{}: Session terminated {}", id, reason);
 250         tearDown(reason.getErrorMessage());
 251     }
 252
 253     @Override
 254     public void close() {
 255         // Cancel reconnect if in progress
 256         if (taskFuture != null) {
 257             taskFuture.cancel(false);
 258         }
 259         // Disconnect from device
 260         // tear down not necessary, called indirectly by the close in disconnect()
 261         disconnect();
 262     }
 263
 264     @Override
 265     public void onMessage(final NetconfClientSession session, final NetconfMessage message) {
 266         /*
 267          * Dispatch between notifications and messages. Messages need to be processed
 268          * with lock held, notifications do not.
 269          */
 270         if (isNotification(message)) {
 271             processNotification(message);
 272         } else {
 273             processMessage(message);
 274         }
 275     }
 276
 277     @Override
 278     public void onError(final NetconfClientSession session, final Exception failure) {
 279         final Request request = pollRequest();
 280         if (request != null) {
 281             request.future.set(RpcResultBuilder.<NetconfMessage>failed()
 282                 .withRpcError(toRpcError(new DocumentedException(failure.getMessage(),
 283                     ErrorType.APPLICATION, ErrorTag.MALFORMED_MESSAGE, ErrorSeverity.ERROR)))
 284                 .build());
 285         } else {
 286             LOG.warn("{}: Ignoring unsolicited failure {}", id, failure.toString());
 287         }
 288     }
 289
 290     private @Nullable Request pollRequest() {
 291         Request request;
 292         sessionLock.lock();
 293
 294         try {
 295             request = requests.peek();
 296             if (request != null && request.future.isUncancellable()) {
 297                 request = requests.poll();
 298                 // we have just removed one request from the queue
 299                 // we can also release one permit
 300                 if (semaphore != null) {
 301                     semaphore.release();
 302                 }
 303             } else {
 304                 request = null;
 305             }
 306         } finally {
 307             sessionLock.unlock();
 308         }
 309         return request;
 310     }
 311
 312     private void processMessage(final NetconfMessage message) {
 313         final Request request = pollRequest();
 314         if (request == null) {
 315             // No matching request, bail out
 316             LOG.warn("{}: Ignoring unsolicited message {}", id, msgToS(message));
 317             return;
 318         }
 319
 320         LOG.debug("{}: Message received {}", id, message);
 321
 322         if (LOG.isTraceEnabled()) {
 323             LOG.trace("{}: Matched request: {} to response: {}", id, msgToS(request.request), msgToS(message));
 324         }
 325
 326         final String inputMsgId = request.request.getDocument().getDocumentElement()
 327             .getAttribute(XmlNetconfConstants.MESSAGE_ID);
 328         final String outputMsgId = message.getDocument().getDocumentElement()
 329             .getAttribute(XmlNetconfConstants.MESSAGE_ID);
 330         if (!inputMsgId.equals(outputMsgId)) {
 331             // FIXME: we should be able to transform directly to RpcError without an intermediate exception
 332             final var ex = new DocumentedException("Response message contained unknown \"message-id\"", null,
 333                 ErrorType.PROTOCOL, ErrorTag.BAD_ATTRIBUTE, ErrorSeverity.ERROR,
 334                 ImmutableMap.of("actual-message-id", outputMsgId, "expected-message-id", inputMsgId));
 335             LOG.warn("{}: Invalid request-reply match, reply message contains different message-id, "
 336                 + "request: {}, response: {}", id, msgToS(request.request), msgToS(message));
 337
 338             request.future.set(RpcResultBuilder.<NetconfMessage>failed().withRpcError(toRpcError(ex)).build());
 339
 340             // recursively processing message to eventually find matching request
 341             processMessage(message);
 342             return;
 343         }
 344
 345         if (NetconfMessageUtil.isErrorMessage(message)) {
 346             // FIXME: we should be able to transform directly to RpcError without an intermediate exception
 347             final var ex = DocumentedException.fromXMLDocument(message.getDocument());
 348             LOG.warn("{}: Error reply from remote device, request: {}, response: {}",
 349                 id, msgToS(request.request), msgToS(message));
 350             request.future.set(RpcResultBuilder.<NetconfMessage>failed().withRpcError(toRpcError(ex)).build());
 351             return;
 352         }
 353
 354         request.future.set(RpcResultBuilder.success(message).build());
 355     }
 356
 357     private static String msgToS(final NetconfMessage msg) {
 358         return XmlUtil.toString(msg.getDocument());
 359     }
 360
 361     private static RpcError toRpcError(final DocumentedException ex) {
 362         final var errorInfo = ex.getErrorInfo();
 363         final String infoString;
 364         if (errorInfo != null) {
 365             final var sb = new StringBuilder();
 366             for (var e : errorInfo.entrySet()) {
 367                 final var tag = e.getKey();
 368                 sb.append('<').append(tag).append('>').append(e.getValue()).append("</").append(tag).append('>');
 369             }
 370             infoString = sb.toString();
 371         } else {
 372             infoString = "";
 373         }
 374
 375         return ex.getErrorSeverity() == ErrorSeverity.ERROR
 376             ? RpcResultBuilder.newError(ex.getErrorType(), ex.getErrorTag(), ex.getLocalizedMessage(), null,
 377                 infoString, ex.getCause())
 378             : RpcResultBuilder.newWarning(ex.getErrorType(), ex.getErrorTag(), ex.getLocalizedMessage(), null,
 379                 infoString, ex.getCause());
 380     }
 381
 382     @Override
 383     public ListenableFuture<RpcResult<NetconfMessage>> sendRequest(final NetconfMessage message, final QName rpc) {
 384         sessionLock.lock();
 385         try {
 386             if (semaphore != null && !semaphore.tryAcquire()) {
 387                 LOG.warn("Limit of concurrent rpc messages was reached (limit: {}). Rpc reply message is needed. "
 388                     + "Discarding request of Netconf device with id: {}", concurentRpcMsgs, id.name());
 389                 return Futures.immediateFailedFuture(new DocumentedException(
 390                         "Limit of rpc messages was reached (Limit :" + concurentRpcMsgs
 391                         + ") waiting for emptying the queue of Netconf device with id: " + id.name()));
 392             }
 393
 394             return sendRequestWithLock(message, rpc);
 395         } finally {
 396             sessionLock.unlock();
 397         }
 398     }
 399
 400     private ListenableFuture<RpcResult<NetconfMessage>> sendRequestWithLock(final NetconfMessage message,
 401                                                                             final QName rpc) {
 402         if (LOG.isTraceEnabled()) {
 403             LOG.trace("{}: Sending message {}", id, msgToS(message));
 404         }
 405
 406         if (currentSession == null) {
 407             LOG.warn("{}: Session is disconnected, failing RPC request {}",
 408                     id, message);
 409             return Futures.immediateFuture(createSessionDownRpcResult());
 410         }
 411
 412         final Request req = new Request(new UncancellableFuture<>(true), message);
 413         requests.add(req);
 414
 415         currentSession.sendMessage(req.request).addListener(future -> {
 416             if (!future.isSuccess()) {
 417                 // We expect that a session down will occur at this point
 418                 LOG.debug("{}: Failed to send request {}", id,
 419                         XmlUtil.toString(req.request.getDocument()),
 420                         future.cause());
 421
 422                 if (future.cause() != null) {
 423                     req.future.set(createErrorRpcResult(ErrorType.TRANSPORT, future.cause().getLocalizedMessage()));
 424                 } else {
 425                     req.future.set(createSessionDownRpcResult()); // assume session is down
 426                 }
 427                 req.future.setException(future.cause());
 428             } else {
 429                 LOG.trace("Finished sending request {}", req.request);
 430             }
 431         });
 432
 433         return req.future;
 434     }
 435
 436     private void processNotification(final NetconfMessage notification) {
 437         if (LOG.isTraceEnabled()) {
 438             LOG.trace("{}: Notification received: {}", id, notification);
 439         }
 440
 441         remoteDevice.onNotification(notification);
 442     }
 443
 444     private static boolean isNotification(final NetconfMessage message) {
 445         if (message.getDocument() == null) {
 446             // We have no message, which mean we have a FailedNetconfMessage
 447             return false;
 448         }
 449         final XmlElement xmle = XmlElement.fromDomDocument(message.getDocument());
 450         return XmlNetconfConstants.NOTIFICATION_ELEMENT_NAME.equals(xmle.getName()) ;
 451     }
 452
 453     private static final class Request {
 454         final UncancellableFuture<RpcResult<NetconfMessage>> future;
 455         final NetconfMessage request;
 456
 457         private Request(final UncancellableFuture<RpcResult<NetconfMessage>> future,
 458                         final NetconfMessage request) {
 459             this.future = future;
 460             this.request = request;
 461         }
 462     }
 463
 464     private boolean startClosing() {
 465         return CLOSING_UPDATER.compareAndSet(this, 0, 1);
 466     }
 467 }