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 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.DocumentedException;
  26 import org.opendaylight.netconf.api.NetconfTerminationReason;
  27 import org.opendaylight.netconf.api.messages.NetconfMessage;
  28 import org.opendaylight.netconf.api.xml.XmlElement;
  29 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  30 import org.opendaylight.netconf.api.xml.XmlUtil;
  31 import org.opendaylight.netconf.client.NetconfClientSession;
  32 import org.opendaylight.netconf.client.NetconfClientSessionListener;
  33 import org.opendaylight.netconf.client.NetconfMessageUtil;
  34 import org.opendaylight.netconf.client.mdsal.api.NetconfSessionPreferences;
  35 import org.opendaylight.netconf.client.mdsal.api.RemoteDevice;
  36 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceCommunicator;
  37 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceId;
  38 import org.opendaylight.yangtools.yang.common.ErrorSeverity;
  39 import org.opendaylight.yangtools.yang.common.ErrorTag;
  40 import org.opendaylight.yangtools.yang.common.ErrorType;
  41 import org.opendaylight.yangtools.yang.common.QName;
  42 import org.opendaylight.yangtools.yang.common.RpcError;
  43 import org.opendaylight.yangtools.yang.common.RpcResult;
  44 import org.opendaylight.yangtools.yang.common.RpcResultBuilder;
  45 import org.slf4j.Logger;
  46 import org.slf4j.LoggerFactory;
  47
  48 public class NetconfDeviceCommunicator implements NetconfClientSessionListener, RemoteDeviceCommunicator {
  49     private static final Logger LOG = LoggerFactory.getLogger(NetconfDeviceCommunicator.class);
  50
  51     protected final RemoteDevice<NetconfDeviceCommunicator> remoteDevice;
  52     private final @Nullable UserPreferences overrideNetconfCapabilities;
  53     protected final RemoteDeviceId id;
  54     private final Lock sessionLock = new ReentrantLock();
  55
  56     private final Semaphore semaphore;
  57     private final int concurentRpcMsgs;
  58
  59     private final Queue<Request> requests = new ArrayDeque<>();
  60     private NetconfClientSession currentSession;
  61
  62     // isSessionClosing indicates a close operation on the session is issued and
  63     // tearDown will surely be called later to finish the close.
  64     // Used to allow only one thread to enter tearDown and other threads should
  65     // NOT enter it simultaneously and should end its close operation without
  66     // calling tearDown to release the locks they hold to avoid deadlock.
  67     private static final AtomicIntegerFieldUpdater<NetconfDeviceCommunicator> CLOSING_UPDATER =
  68             AtomicIntegerFieldUpdater.newUpdater(NetconfDeviceCommunicator.class, "closing");
  69     private volatile int closing;
  70
  71     public boolean isSessionClosing() {
  72         return closing != 0;
  73     }
  74
  75     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  76             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice, final int rpcMessageLimit) {
  77         this(id, remoteDevice, rpcMessageLimit, null);
  78     }
  79
  80     public NetconfDeviceCommunicator(final RemoteDeviceId id,
  81             final RemoteDevice<NetconfDeviceCommunicator> remoteDevice, final int rpcMessageLimit,
  82             final @Nullable UserPreferences overrideNetconfCapabilities) {
  83         concurentRpcMsgs = rpcMessageLimit;
  84         this.id = id;
  85         this.remoteDevice = remoteDevice;
  86         this.overrideNetconfCapabilities = overrideNetconfCapabilities;
  87         semaphore = rpcMessageLimit > 0 ? new Semaphore(rpcMessageLimit) : null;
  88     }
  89
  90     @Override
  91     public void onSessionUp(final NetconfClientSession session) {
  92         sessionLock.lock();
  93         try {
  94             LOG.debug("{}: Session established", id);
  95             currentSession = session;
  96
  97             var netconfSessionPreferences = NetconfSessionPreferences.fromNetconfSession(session);
  98             LOG.trace("{}: Session advertised capabilities: {}", id, netconfSessionPreferences);
  99
 100             final var localOverride = overrideNetconfCapabilities;
 101             if (localOverride != null) {
 102                 final var sessionPreferences = localOverride.sessionPreferences();
 103                 netconfSessionPreferences = localOverride.overrideModuleCapabilities()
 104                         ? netconfSessionPreferences.replaceModuleCaps(sessionPreferences)
 105                         : netconfSessionPreferences.addModuleCaps(sessionPreferences);
 106
 107                 netconfSessionPreferences = localOverride.overrideNonModuleCapabilities()
 108                         ? netconfSessionPreferences.replaceNonModuleCaps(sessionPreferences)
 109                         : netconfSessionPreferences.addNonModuleCaps(sessionPreferences);
 110                 LOG.debug("{}: Session capabilities overridden, capabilities that will be used: {}", id,
 111                         netconfSessionPreferences);
 112             }
 113
 114             remoteDevice.onRemoteSessionUp(netconfSessionPreferences, this);
 115         } finally {
 116             sessionLock.unlock();
 117         }
 118     }
 119
 120     public void disconnect() {
 121         // If session is already in closing, no need to close it again
 122         if (currentSession != null && startClosing() && currentSession.isUp()) {
 123             currentSession.close();
 124         }
 125     }
 126
 127     private void tearDown(final String reason) {
 128         if (!isSessionClosing()) {
 129             LOG.warn("It's curious that no one to close the session but tearDown is called!");
 130         }
 131         LOG.debug("Tearing down {}", reason);
 132         final List<UncancellableFuture<RpcResult<NetconfMessage>>> futuresToCancel = new ArrayList<>();
 133         sessionLock.lock();
 134         try {
 135             if (currentSession != null) {
 136                 currentSession = null;
 137                 /*
 138                  * Walk all requests, check if they have been executing
 139                  * or cancelled and remove them from the queue.
 140                  */
 141                 final Iterator<Request> it = requests.iterator();
 142                 while (it.hasNext()) {
 143                     final Request r = it.next();
 144                     if (r.future.isUncancellable()) {
 145                         futuresToCancel.add(r.future);
 146                         it.remove();
 147                     } else if (r.future.isCancelled()) {
 148                         // This just does some house-cleaning
 149                         it.remove();
 150                     }
 151                 }
 152
 153                 remoteDevice.onRemoteSessionDown();
 154             }
 155         } finally {
 156             sessionLock.unlock();
 157         }
 158
 159         // Notify pending request futures outside of the sessionLock to avoid unnecessarily
 160         // blocking the caller.
 161         for (final UncancellableFuture<RpcResult<NetconfMessage>> future : futuresToCancel) {
 162             if (Strings.isNullOrEmpty(reason)) {
 163                 future.set(createSessionDownRpcResult());
 164             } else {
 165                 future.set(createErrorRpcResult(ErrorType.TRANSPORT, reason));
 166             }
 167         }
 168
 169         closing = 0;
 170     }
 171
 172     private RpcResult<NetconfMessage> createSessionDownRpcResult() {
 173         return createErrorRpcResult(ErrorType.TRANSPORT,
 174                 String.format("The netconf session to %1$s is disconnected", id.name()));
 175     }
 176
 177     private static RpcResult<NetconfMessage> createErrorRpcResult(final ErrorType errorType, final String message) {
 178         return RpcResultBuilder.<NetconfMessage>failed()
 179             .withError(errorType, ErrorTag.OPERATION_FAILED, message).build();
 180     }
 181
 182     @Override
 183     public void onSessionDown(final NetconfClientSession session, final Exception exception) {
 184         // If session is already in closing, no need to call tearDown again.
 185         if (startClosing()) {
 186             if (exception instanceof EOFException) {
 187                 LOG.info("{}: Session went down: {}", id, exception.getMessage());
 188             } else {
 189                 LOG.warn("{}: Session went down", id, exception);
 190             }
 191             tearDown(null);
 192         }
 193     }
 194
 195     @Override
 196     public void onSessionTerminated(final NetconfClientSession session, final NetconfTerminationReason reason) {
 197         // onSessionTerminated is called directly by disconnect, no need to compare and set isSessionClosing.
 198         LOG.warn("{}: Session terminated {}", id, reason);
 199         tearDown(reason.getErrorMessage());
 200     }
 201
 202     @Override
 203     public void close() {
 204         // Disconnect from device
 205         // tear down not necessary, called indirectly by the close in disconnect()
 206         disconnect();
 207     }
 208
 209     @Override
 210     public void onMessage(final NetconfClientSession session, final NetconfMessage message) {
 211         /*
 212          * Dispatch between notifications and messages. Messages need to be processed
 213          * with lock held, notifications do not.
 214          */
 215         if (isNotification(message)) {
 216             processNotification(message);
 217         } else {
 218             processMessage(message);
 219         }
 220     }
 221
 222     @Override
 223     public void onError(final NetconfClientSession session, final Exception failure) {
 224         final Request request = pollRequest();
 225         if (request != null) {
 226             request.future.set(RpcResultBuilder.<NetconfMessage>failed()
 227                 .withRpcError(toRpcError(new DocumentedException(failure.getMessage(),
 228                     ErrorType.APPLICATION, ErrorTag.MALFORMED_MESSAGE, ErrorSeverity.ERROR)))
 229                 .build());
 230         } else {
 231             LOG.warn("{}: Ignoring unsolicited failure {}", id, failure.toString());
 232         }
 233     }
 234
 235     private @Nullable Request pollRequest() {
 236         Request request;
 237         sessionLock.lock();
 238
 239         try {
 240             request = requests.peek();
 241             if (request != null && request.future.isUncancellable()) {
 242                 request = requests.poll();
 243                 // we have just removed one request from the queue
 244                 // we can also release one permit
 245                 if (semaphore != null) {
 246                     semaphore.release();
 247                 }
 248             } else {
 249                 request = null;
 250             }
 251         } finally {
 252             sessionLock.unlock();
 253         }
 254         return request;
 255     }
 256
 257     private void processMessage(final NetconfMessage message) {
 258         final Request request = pollRequest();
 259         if (request == null) {
 260             // No matching request, bail out
 261             LOG.warn("{}: Ignoring unsolicited message {}", id, msgToS(message));
 262             return;
 263         }
 264
 265         LOG.debug("{}: Message received {}", id, message);
 266
 267         if (LOG.isTraceEnabled()) {
 268             LOG.trace("{}: Matched request: {} to response: {}", id, msgToS(request.request), msgToS(message));
 269         }
 270
 271         final String inputMsgId = request.request.getDocument().getDocumentElement()
 272             .getAttribute(XmlNetconfConstants.MESSAGE_ID);
 273         final String outputMsgId = message.getDocument().getDocumentElement()
 274             .getAttribute(XmlNetconfConstants.MESSAGE_ID);
 275         if (!inputMsgId.equals(outputMsgId)) {
 276             // FIXME: we should be able to transform directly to RpcError without an intermediate exception
 277             final var ex = new DocumentedException("Response message contained unknown \"message-id\"", null,
 278                 ErrorType.PROTOCOL, ErrorTag.BAD_ATTRIBUTE, ErrorSeverity.ERROR,
 279                 ImmutableMap.of("actual-message-id", outputMsgId, "expected-message-id", inputMsgId));
 280             LOG.warn("{}: Invalid request-reply match, reply message contains different message-id, "
 281                 + "request: {}, response: {}", id, msgToS(request.request), msgToS(message));
 282
 283             request.future.set(RpcResultBuilder.<NetconfMessage>failed().withRpcError(toRpcError(ex)).build());
 284
 285             // recursively processing message to eventually find matching request
 286             processMessage(message);
 287             return;
 288         }
 289
 290         if (NetconfMessageUtil.isErrorMessage(message)) {
 291             // FIXME: we should be able to transform directly to RpcError without an intermediate exception
 292             final var ex = DocumentedException.fromXMLDocument(message.getDocument());
 293             LOG.warn("{}: Error reply from remote device, request: {}, response: {}",
 294                 id, msgToS(request.request), msgToS(message));
 295             request.future.set(RpcResultBuilder.<NetconfMessage>failed().withRpcError(toRpcError(ex)).build());
 296             return;
 297         }
 298
 299         request.future.set(RpcResultBuilder.success(message).build());
 300     }
 301
 302     private static String msgToS(final NetconfMessage msg) {
 303         return XmlUtil.toString(msg.getDocument());
 304     }
 305
 306     private static RpcError toRpcError(final DocumentedException ex) {
 307         final var errorInfo = ex.getErrorInfo();
 308         final String infoString;
 309         if (errorInfo != null) {
 310             final var sb = new StringBuilder();
 311             for (var e : errorInfo.entrySet()) {
 312                 final var tag = e.getKey();
 313                 sb.append('<').append(tag).append('>').append(e.getValue()).append("</").append(tag).append('>');
 314             }
 315             infoString = sb.toString();
 316         } else {
 317             infoString = "";
 318         }
 319
 320         return ex.getErrorSeverity() == ErrorSeverity.ERROR
 321             ? RpcResultBuilder.newError(ex.getErrorType(), ex.getErrorTag(), ex.getLocalizedMessage(), null,
 322                 infoString, ex.getCause())
 323             : RpcResultBuilder.newWarning(ex.getErrorType(), ex.getErrorTag(), ex.getLocalizedMessage(), null,
 324                 infoString, ex.getCause());
 325     }
 326
 327     @Override
 328     public ListenableFuture<RpcResult<NetconfMessage>> sendRequest(final NetconfMessage message, final QName rpc) {
 329         sessionLock.lock();
 330         try {
 331             if (semaphore != null && !semaphore.tryAcquire()) {
 332                 LOG.warn("Limit of concurrent rpc messages was reached (limit: {}). Rpc reply message is needed. "
 333                     + "Discarding request of Netconf device with id: {}", concurentRpcMsgs, id.name());
 334                 return Futures.immediateFailedFuture(new DocumentedException(
 335                         "Limit of rpc messages was reached (Limit :" + concurentRpcMsgs
 336                         + ") waiting for emptying the queue of Netconf device with id: " + id.name()));
 337             }
 338
 339             return sendRequestWithLock(message, rpc);
 340         } finally {
 341             sessionLock.unlock();
 342         }
 343     }
 344
 345     private ListenableFuture<RpcResult<NetconfMessage>> sendRequestWithLock(final NetconfMessage message,
 346                                                                             final QName rpc) {
 347         if (LOG.isTraceEnabled()) {
 348             LOG.trace("{}: Sending message {}", id, msgToS(message));
 349         }
 350
 351         if (currentSession == null) {
 352             LOG.warn("{}: Session is disconnected, failing RPC request {}",
 353                     id, message);
 354             return Futures.immediateFuture(createSessionDownRpcResult());
 355         }
 356
 357         final Request req = new Request(new UncancellableFuture<>(true), message);
 358         requests.add(req);
 359
 360         currentSession.sendMessage(req.request).addListener(future -> {
 361             if (!future.isSuccess()) {
 362                 // We expect that a session down will occur at this point
 363                 LOG.debug("{}: Failed to send request {}", id,
 364                         XmlUtil.toString(req.request.getDocument()),
 365                         future.cause());
 366
 367                 if (future.cause() != null) {
 368                     req.future.set(createErrorRpcResult(ErrorType.TRANSPORT, future.cause().getLocalizedMessage()));
 369                 } else {
 370                     req.future.set(createSessionDownRpcResult()); // assume session is down
 371                 }
 372                 req.future.setException(future.cause());
 373             } else {
 374                 LOG.trace("Finished sending request {}", req.request);
 375             }
 376         });
 377
 378         return req.future;
 379     }
 380
 381     private void processNotification(final NetconfMessage notification) {
 382         if (LOG.isTraceEnabled()) {
 383             LOG.trace("{}: Notification received: {}", id, notification);
 384         }
 385
 386         remoteDevice.onNotification(notification);
 387     }
 388
 389     private static boolean isNotification(final NetconfMessage message) {
 390         if (message.getDocument() == null) {
 391             // We have no message, which mean we have a FailedNetconfMessage
 392             return false;
 393         }
 394         final XmlElement xmle = XmlElement.fromDomDocument(message.getDocument());
 395         return XmlNetconfConstants.NOTIFICATION_ELEMENT_NAME.equals(xmle.getName()) ;
 396     }
 397
 398     private static final class Request {
 399         final UncancellableFuture<RpcResult<NetconfMessage>> future;
 400         final NetconfMessage request;
 401
 402         private Request(final UncancellableFuture<RpcResult<NetconfMessage>> future,
 403                         final NetconfMessage request) {
 404             this.future = future;
 405             this.request = request;
 406         }
 407     }
 408
 409     private boolean startClosing() {
 410         return CLOSING_UPDATER.compareAndSet(this, 0, 1);
 411     }
 412 }