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