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