pcep/impl/src/main/java/org/opendaylight/protocol/pcep/impl/AbstractPCEPSessionNegotiator.java

   1 /*
   2  * Copyright (c) 2013 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.protocol.pcep.impl;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import com.google.common.base.Preconditions;
  12 import io.netty.channel.Channel;
  13 import io.netty.channel.ChannelFutureListener;
  14 import io.netty.handler.ssl.SslHandler;
  15 import io.netty.util.concurrent.Promise;
  16 import java.util.concurrent.Future;
  17 import java.util.concurrent.TimeUnit;
  18 import java.util.concurrent.TimeoutException;
  19 import javax.net.ssl.SSLContext;
  20 import javax.net.ssl.SSLEngine;
  21 import org.opendaylight.protocol.pcep.impl.spi.Util;
  22 import org.opendaylight.protocol.pcep.impl.tls.SslContextFactory;
  23 import org.opendaylight.protocol.pcep.spi.PCEPErrors;
  24 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.pcep.app.config.rev160707.pcep.dispatcher.config.Tls;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev181109.Keepalive;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev181109.KeepaliveBuilder;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev181109.OpenBuilder;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev181109.Pcerr;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev181109.Starttls;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev181109.StarttlsBuilder;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.Message;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.OpenMessage;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.keepalive.message.KeepaliveMessageBuilder;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.open.message.OpenMessageBuilder;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.open.object.Open;
  36 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.pcep.error.object.ErrorObject;
  37 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.pcerr.message.pcerr.message.error.type.SessionCase;
  38 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.start.tls.message.StartTlsMessageBuilder;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 /**
  43  * Abstract PCEP session negotiator. Takes care of basic handshake without implementing a specific policy. Policies need
  44  * to be provided by a specific subclass.
  45  */
  46 public abstract class AbstractPCEPSessionNegotiator extends AbstractSessionNegotiator {
  47     /**
  48      * Unified KeepWait and OpenWait timer expiration, in seconds.
  49      */
  50     public static final int FAIL_TIMER_VALUE = 60;
  51
  52     /**
  53      * PCEP session negotiation state transitions are described in RFC5440. Simplification the two timers (KeepWait and
  54      * OpenWait) are merged into a FailTimer, as they are mutually exclusive, have the same timeout value and their
  55      * action is to terminate negotiation. This timer is restarted between state transitions and runs in all states
  56      * except Idle and Finished.
  57      */
  58     @VisibleForTesting
  59     public enum State {
  60         /**
  61          * Negotiation has not begun. It will be activated once we are asked to provide our initial proposal, at which
  62          * point we move into OpenWait state.
  63          */
  64         IDLE,
  65         /**
  66          * Waiting for the peer's StartTLS message
  67          */
  68         START_TLS_WAIT,
  69         /**
  70          * Waiting for the peer's OPEN message.
  71          */
  72         OPEN_WAIT,
  73         /**
  74          * Waiting for the peer's KEEPALIVE message.
  75          */
  76         KEEP_WAIT,
  77         /**
  78          * Negotiation has completed.
  79          */
  80         FINISHED,
  81     }
  82
  83     private static final Logger LOG = LoggerFactory.getLogger(AbstractPCEPSessionNegotiator.class);
  84     private static final Keepalive KEEPALIVE = new KeepaliveBuilder().setKeepaliveMessage(new KeepaliveMessageBuilder().build()).build();
  85
  86     private volatile boolean localOK, openRetry, remoteOK;
  87     private volatile State state = State.IDLE;
  88     private Future<?> failTimer;
  89     private Open localPrefs;
  90     private Open remotePrefs;
  91     private Tls tlsConfiguration;
  92
  93     protected AbstractPCEPSessionNegotiator(final Promise<PCEPSessionImpl> promise, final Channel channel) {
  94         super(promise, channel);
  95     }
  96
  97     /**
  98      * Get the initial session parameters proposal.
  99      *
 100      * @return Session parameters proposal.
 101      */
 102     protected abstract Open getInitialProposal();
 103
 104     /**
 105      * Get the revised session parameters proposal based on the feedback the peer has provided to us.
 106      *
 107      * @param suggestion Peer-provided suggested session parameters
 108      * @return Session parameters proposal, or null if peers session parameters preclude us from suggesting anything
 109      */
 110     protected abstract Open getRevisedProposal(Open suggestion);
 111
 112     /**
 113      * Check whether a peer-provided session parameters proposal is acceptable.
 114      *
 115      * @param proposal peer-proposed session parameters
 116      * @return true if the proposal is acceptable, false otherwise
 117      */
 118     protected abstract boolean isProposalAcceptable(Open proposal);
 119
 120     /**
 121      * Given a peer-provided session parameters proposal which we found unacceptable, provide a counter-proposal. The
 122      * requirement is that the isProposalAcceptable() method has to return true when presented with this proposal.
 123      *
 124      * @param proposal unacceptable peer proposal
 125      * @return our counter-proposal, or null if there is no way to negotiate an acceptable proposal
 126      */
 127     protected abstract Open getCounterProposal(Open proposal);
 128
 129     /**
 130      * Create the protocol session.
 131      *
 132      * @param channel Underlying channel.
 133      * @param localPrefs Session preferences proposed by us and accepted by the peer.
 134      * @param remotePrefs Session preferences proposed by the peer and accepted by us.
 135      * @return New protocol session.
 136      */
 137     protected abstract PCEPSessionImpl createSession(Channel channel, Open localPrefs, Open remotePrefs);
 138
 139     /**
 140      * Sends PCEP Error Message with one PCEPError.
 141      *
 142      * @param value
 143      */
 144     private void sendErrorMessage(final PCEPErrors value) {
 145
 146         this.sendMessage(Util.createErrorMessage(value, null));
 147     }
 148
 149     private void scheduleFailTimer() {
 150         this.failTimer = this.channel.eventLoop().schedule(() -> {
 151             switch (AbstractPCEPSessionNegotiator.this.state) {
 152             case FINISHED:
 153             case IDLE:
 154                 break;
 155             case START_TLS_WAIT:
 156                 sendErrorMessage(PCEPErrors.STARTTLS_TIMER_EXP);
 157                 negotiationFailed(new TimeoutException("StartTLSWait timer expired"));
 158                 AbstractPCEPSessionNegotiator.this.state = State.FINISHED;
 159                 break;
 160             case KEEP_WAIT:
 161                 sendErrorMessage(PCEPErrors.NO_MSG_BEFORE_EXP_KEEPWAIT);
 162                 negotiationFailed(new TimeoutException("KeepWait timer expired"));
 163                 AbstractPCEPSessionNegotiator.this.state = State.FINISHED;
 164                 break;
 165             case OPEN_WAIT:
 166                 sendErrorMessage(PCEPErrors.NO_OPEN_BEFORE_EXP_OPENWAIT);
 167                 negotiationFailed(new TimeoutException("OpenWait timer expired"));
 168                 AbstractPCEPSessionNegotiator.this.state = State.FINISHED;
 169                 break;
 170             default:
 171                 break;
 172             }
 173         }, FAIL_TIMER_VALUE, TimeUnit.SECONDS);
 174     }
 175
 176     @Override
 177     protected final void startNegotiation() {
 178         Preconditions.checkState(this.state == State.IDLE);
 179         if (this.tlsConfiguration != null) {
 180             this.sendMessage(new StarttlsBuilder().setStartTlsMessage(new StartTlsMessageBuilder().build()).build());
 181             this.state = State.START_TLS_WAIT;
 182             scheduleFailTimer();
 183             LOG.info("Started TLS connection negotiation with peer {}", this.channel);
 184         } else {
 185             startNegotiationWithOpen();
 186         }
 187         this.channel.closeFuture().addListener((ChannelFutureListener) f -> cancelTimers());
 188     }
 189
 190     private void cancelTimers() {
 191         this.failTimer.cancel(false);
 192     }
 193
 194     private void startNegotiationWithOpen() {
 195         this.localPrefs = getInitialProposal();
 196         final OpenMessage m = new org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev181109.OpenBuilder().setOpenMessage(
 197                 new OpenMessageBuilder().setOpen(this.localPrefs).build()).build();
 198         this.sendMessage(m);
 199         this.state = State.OPEN_WAIT;
 200         scheduleFailTimer();
 201
 202         LOG.info("PCEP session with {} started, sent proposal {}", this.channel, this.localPrefs);
 203     }
 204
 205     private boolean handleMessageKeepWait(final Message msg) {
 206         if (msg instanceof Keepalive) {
 207             return handleMessageKeepAlive();
 208         } else if (msg instanceof Pcerr) {
 209             return handleMessagePcerr(msg);
 210         }
 211         return false;
 212     }
 213
 214     private boolean handleMessageKeepAlive() {
 215         this.localOK = true;
 216         if (this.remoteOK) {
 217             LOG.info("PCEP peer {} completed negotiation", this.channel);
 218             negotiationSuccessful(createSession(this.channel, this.localPrefs, this.remotePrefs));
 219             this.state = State.FINISHED;
 220         } else {
 221             scheduleFailTimer();
 222             this.state = State.OPEN_WAIT;
 223             LOG.debug("Channel {} moved to OpenWait state with localOK=1", this.channel);
 224         }
 225         return true;
 226     }
 227
 228     private boolean handleMessagePcerr(final Message msg) {
 229         final org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.pcerr.message.PcerrMessage err = ((Pcerr) msg).getPcerrMessage();
 230         if (err.getErrorType() == null) {
 231             final ErrorObject obj = err.getErrors().get(0).getErrorObject();
 232             LOG.warn("Unexpected error received from PCC: type {} value {}", obj.getType(), obj.getValue());
 233             negotiationFailed(new IllegalStateException("Unexpected error received from PCC."));
 234             this.state = State.IDLE;
 235             return true;
 236         }
 237         this.localPrefs = getRevisedProposal(((SessionCase) err.getErrorType()).getSession().getOpen());
 238         if (this.localPrefs == null) {
 239             sendErrorMessage(PCEPErrors.PCERR_NON_ACC_SESSION_CHAR);
 240             negotiationFailed(new IllegalStateException("Peer suggested unacceptable retry proposal"));
 241             this.state = State.FINISHED;
 242             return true;
 243         }
 244         this.sendMessage(new OpenBuilder().setOpenMessage(new OpenMessageBuilder().setOpen(this.localPrefs).build()).build());
 245         if (!this.remoteOK) {
 246             this.state = State.OPEN_WAIT;
 247         }
 248         scheduleFailTimer();
 249         return true;
 250     }
 251
 252     private boolean handleMessageOpenWait(final Message msg) {
 253         if (!(msg instanceof org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev181109.Open)) {
 254             return false;
 255         }
 256         final org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev181109.open.message.OpenMessage o = ((org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev181109.Open) msg).getOpenMessage();
 257         final Open open = o.getOpen();
 258         if (isProposalAcceptable(open)) {
 259             this.sendMessage(KEEPALIVE);
 260             this.remotePrefs = open;
 261             this.remoteOK = true;
 262             if (this.localOK) {
 263                 negotiationSuccessful(createSession(this.channel, this.localPrefs, this.remotePrefs));
 264                 LOG.info("PCEP peer {} completed negotiation", this.channel);
 265                 this.state = State.FINISHED;
 266             } else {
 267                 scheduleFailTimer();
 268                 this.state = State.KEEP_WAIT;
 269                 LOG.debug("Channel {} moved to KeepWait state with remoteOK=1", this.channel);
 270             }
 271             return true;
 272         }
 273         if (this.openRetry) {
 274             sendErrorMessage(PCEPErrors.SECOND_OPEN_MSG);
 275             negotiationFailed(new IllegalStateException("OPEN renegotiation failed"));
 276             this.state = State.FINISHED;
 277             return true;
 278         }
 279         final Open newPrefs = getCounterProposal(open);
 280         if (newPrefs == null) {
 281             sendErrorMessage(PCEPErrors.NON_ACC_NON_NEG_SESSION_CHAR);
 282             negotiationFailed(new IllegalStateException("Peer sent unacceptable session parameters"));
 283             this.state = State.FINISHED;
 284             return true;
 285         }
 286         this.sendMessage(Util.createErrorMessage(PCEPErrors.NON_ACC_NEG_SESSION_CHAR, newPrefs));
 287         this.openRetry = true;
 288         this.state = this.localOK ? State.OPEN_WAIT : State.KEEP_WAIT;
 289         scheduleFailTimer();
 290         return true;
 291     }
 292
 293     private boolean handleMessageStartTlsWait(final Message msg) {
 294         if (msg instanceof Starttls) {
 295             final SslContextFactory sslFactory = new SslContextFactory(this.tlsConfiguration);
 296             final SSLContext sslContext = sslFactory.getServerContext();
 297             if (sslContext == null) {
 298                 this.sendErrorMessage(PCEPErrors.NOT_POSSIBLE_WITHOUT_TLS);
 299                 negotiationFailed(new IllegalStateException("Failed to establish a TLS connection."));
 300                 this.state = State.FINISHED;
 301                 return true;
 302             }
 303             final SSLEngine engine = sslContext.createSSLEngine();
 304             engine.setNeedClientAuth(true);
 305             engine.setUseClientMode(false);
 306             this.channel.pipeline().addFirst(new SslHandler(engine));
 307             LOG.info("PCEPS TLS connection with peer: {} established succesfully.", this.channel);
 308             startNegotiationWithOpen();
 309             return true;
 310         } else if (!(msg instanceof Pcerr)) {
 311             this.sendErrorMessage(PCEPErrors.NON_STARTTLS_MSG_RCVD);
 312             negotiationFailed(new IllegalStateException("Unexpected message recieved."));
 313             this.state = State.FINISHED;
 314             return true;
 315         }
 316         return false;
 317     }
 318
 319     @Override
 320     protected final void handleMessage(final Message msg) {
 321         cancelTimers();
 322
 323         LOG.debug("Channel {} handling message {} in state {}", this.channel, msg, this.state);
 324
 325         switch (this.state) {
 326         case FINISHED:
 327         case IDLE:
 328             throw new IllegalStateException("Unexpected handleMessage in state " + this.state);
 329         case START_TLS_WAIT:
 330             if (handleMessageStartTlsWait(msg)) {
 331                 return;
 332             }
 333             break;
 334         case KEEP_WAIT:
 335             if (handleMessageKeepWait(msg)) {
 336                 return;
 337             }
 338             break;
 339         case OPEN_WAIT:
 340             if (handleMessageOpenWait(msg)) {
 341                 return;
 342             }
 343             break;
 344         default:
 345             break;
 346         }
 347         LOG.warn("Channel {} in state {} received unexpected message {}", this.channel, this.state, msg);
 348         sendErrorMessage(PCEPErrors.NON_OR_INVALID_OPEN_MSG);
 349         negotiationFailed(new Exception("Illegal message encountered"));
 350         this.state = State.FINISHED;
 351     }
 352
 353     @VisibleForTesting
 354     State getState() {
 355         return this.state;
 356     }
 357
 358     public void setTlsConfiguration(final Tls tlsConfiguration) {
 359         this.tlsConfiguration = tlsConfiguration;
 360     }
 361
 362     @Override
 363     protected void negotiationFailed(final Throwable cause) {
 364         LOG.debug("Negotiation on channel {} failed", this.channel, cause);
 365         this.channel.close();
 366         this.promise.setFailure(cause);
 367     }
 368 }