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.handler.ssl.SslHandler;
  14 import io.netty.util.concurrent.Promise;
  15 import java.util.concurrent.Future;
  16 import java.util.concurrent.TimeUnit;
  17 import java.util.concurrent.TimeoutException;
  18 import javax.net.ssl.SSLContext;
  19 import javax.net.ssl.SSLEngine;
  20 import org.opendaylight.controller.config.yang.pcep.impl.Tls;
  21 import org.opendaylight.protocol.framework.AbstractSessionNegotiator;
  22 import org.opendaylight.protocol.pcep.impl.spi.Util;
  23 import org.opendaylight.protocol.pcep.impl.tls.SslContextFactory;
  24 import org.opendaylight.protocol.pcep.spi.PCEPErrors;
  25 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.Keepalive;
  26 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.KeepaliveBuilder;
  27 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.OpenBuilder;
  28 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.Pcerr;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.Starttls;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.StarttlsBuilder;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.Message;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.OpenMessage;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.keepalive.message.KeepaliveMessageBuilder;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.open.message.OpenMessageBuilder;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.open.object.Open;
  36 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.pcep.error.object.ErrorObject;
  37 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.pcerr.message.pcerr.message.error.type.SessionCase;
  38 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.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<Message, PCEPSessionImpl> {
  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(new Runnable() {
 151             @Override
 152             public void run() {
 153                 switch (AbstractPCEPSessionNegotiator.this.state) {
 154                 case FINISHED:
 155                 case IDLE:
 156                     break;
 157                 case START_TLS_WAIT:
 158                     sendErrorMessage(PCEPErrors.STARTTLS_TIMER_EXP);
 159                     negotiationFailed(new TimeoutException("StartTLSWait timer expired"));
 160                     AbstractPCEPSessionNegotiator.this.state = State.FINISHED;
 161                 case KEEP_WAIT:
 162                     sendErrorMessage(PCEPErrors.NO_MSG_BEFORE_EXP_KEEPWAIT);
 163                     negotiationFailed(new TimeoutException("KeepWait timer expired"));
 164                     AbstractPCEPSessionNegotiator.this.state = State.FINISHED;
 165                     break;
 166                 case OPEN_WAIT:
 167                     sendErrorMessage(PCEPErrors.NO_OPEN_BEFORE_EXP_OPENWAIT);
 168                     negotiationFailed(new TimeoutException("OpenWait timer expired"));
 169                     AbstractPCEPSessionNegotiator.this.state = State.FINISHED;
 170                     break;
 171                 default:
 172                     break;
 173                 }
 174             }
 175         }, FAIL_TIMER_VALUE, TimeUnit.SECONDS);
 176     }
 177
 178     @Override
 179     protected final void startNegotiation() {
 180         Preconditions.checkState(this.state == State.IDLE);
 181         if (this.tlsConfiguration != null) {
 182             this.sendMessage(new StarttlsBuilder().setStartTlsMessage(new StartTlsMessageBuilder().build()).build());
 183             this.state = State.START_TLS_WAIT;
 184             scheduleFailTimer();
 185             LOG.info("Started TLS connection negotiation with peer {}", this.channel);
 186         } else {
 187             startNegotiationWithOpen();
 188         }
 189     }
 190
 191     private void startNegotiationWithOpen() {
 192         this.localPrefs = getInitialProposal();
 193         final OpenMessage m = new org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.OpenBuilder().setOpenMessage(
 194                 new OpenMessageBuilder().setOpen(this.localPrefs).build()).build();
 195         this.sendMessage(m);
 196         this.state = State.OPEN_WAIT;
 197         scheduleFailTimer();
 198
 199         LOG.info("PCEP session with {} started, sent proposal {}", this.channel, this.localPrefs);
 200     }
 201
 202     private boolean handleMessageKeepWait(final Message msg) {
 203         if (msg instanceof Keepalive) {
 204             this.localOK = true;
 205             if (this.remoteOK) {
 206                 LOG.info("PCEP peer {} completed negotiation", this.channel);
 207                 negotiationSuccessful(createSession(this.channel, this.localPrefs, this.remotePrefs));
 208                 this.state = State.FINISHED;
 209             } else {
 210                 scheduleFailTimer();
 211                 this.state = State.OPEN_WAIT;
 212                 LOG.debug("Channel {} moved to OpenWait state with localOK=1", this.channel);
 213             }
 214             return true;
 215         } else if (msg instanceof Pcerr) {
 216             final org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.pcerr.message.PcerrMessage err = ((Pcerr) msg).getPcerrMessage();
 217             if (err.getErrorType() == null) {
 218                 final ErrorObject obj = err.getErrors().get(0).getErrorObject();
 219                 LOG.warn("Unexpected error received from PCC: type {} value {}", obj.getType(), obj.getValue());
 220                 negotiationFailed(new IllegalStateException("Unexpected error received from PCC."));
 221                 this.state = State.IDLE;
 222                 return true;
 223             }
 224             this.localPrefs = getRevisedProposal(((SessionCase) err.getErrorType()).getSession().getOpen());
 225             if (this.localPrefs == null) {
 226                 sendErrorMessage(PCEPErrors.PCERR_NON_ACC_SESSION_CHAR);
 227                 negotiationFailed(new IllegalStateException("Peer suggested unacceptable retry proposal"));
 228                 this.state = State.FINISHED;
 229                 return true;
 230             }
 231             this.sendMessage(new OpenBuilder().setOpenMessage(new OpenMessageBuilder().setOpen(this.localPrefs).build()).build());
 232             if (!this.remoteOK) {
 233                 this.state = State.OPEN_WAIT;
 234             }
 235             scheduleFailTimer();
 236             return true;
 237         }
 238         return false;
 239     }
 240
 241     private boolean handleMessageOpenWait(final Message msg) {
 242         if (!(msg instanceof org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.Open)) {
 243             return false;
 244         }
 245         final org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.types.rev131005.open.message.OpenMessage o = ((org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.pcep.message.rev131007.Open) msg).getOpenMessage();
 246         final Open open = o.getOpen();
 247         if (isProposalAcceptable(open)) {
 248             this.sendMessage(KEEPALIVE);
 249             this.remotePrefs = open;
 250             this.remoteOK = true;
 251             if (this.localOK) {
 252                 negotiationSuccessful(createSession(this.channel, this.localPrefs, this.remotePrefs));
 253                 LOG.info("PCEP peer {} completed negotiation", this.channel);
 254                 this.state = State.FINISHED;
 255             } else {
 256                 scheduleFailTimer();
 257                 this.state = State.KEEP_WAIT;
 258                 LOG.debug("Channel {} moved to KeepWait state with remoteOK=1", this.channel);
 259             }
 260             return true;
 261         }
 262         if (this.openRetry) {
 263             sendErrorMessage(PCEPErrors.SECOND_OPEN_MSG);
 264             negotiationFailed(new IllegalStateException("OPEN renegotiation failed"));
 265             this.state = State.FINISHED;
 266             return true;
 267         }
 268         final Open newPrefs = getCounterProposal(open);
 269         if (newPrefs == null) {
 270             sendErrorMessage(PCEPErrors.NON_ACC_NON_NEG_SESSION_CHAR);
 271             negotiationFailed(new IllegalStateException("Peer sent unacceptable session parameters"));
 272             this.state = State.FINISHED;
 273             return true;
 274         }
 275         this.sendMessage(Util.createErrorMessage(PCEPErrors.NON_ACC_NEG_SESSION_CHAR, newPrefs));
 276         this.openRetry = true;
 277         this.state = this.localOK ? State.OPEN_WAIT : State.KEEP_WAIT;
 278         scheduleFailTimer();
 279         return true;
 280     }
 281
 282     private boolean handleMessageStartTlsWait(final Message msg) {
 283         if (msg instanceof Starttls) {
 284             final SslContextFactory sslFactory = new SslContextFactory(this.tlsConfiguration);
 285             final SSLContext sslContext = sslFactory.getServerContext();
 286             if (sslContext == null) {
 287                 this.sendErrorMessage(PCEPErrors.NOT_POSSIBLE_WITHOUT_TLS);
 288                 negotiationFailed(new IllegalStateException("Failed to establish a TLS connection."));
 289                 this.state = State.FINISHED;
 290                 return true;
 291             }
 292             final SSLEngine engine = sslContext.createSSLEngine();
 293             engine.setNeedClientAuth(true);
 294             engine.setUseClientMode(false);
 295             this.channel.pipeline().addFirst(new SslHandler(engine));
 296             LOG.info("PCEPS TLS connection with peer: {} established succesfully.", this.channel);
 297             startNegotiationWithOpen();
 298             return true;
 299         } else if (! (msg instanceof Pcerr)) {
 300             this.sendErrorMessage(PCEPErrors.NON_STARTTLS_MSG_RCVD);
 301             negotiationFailed(new IllegalStateException("Unexpected message recieved."));
 302             this.state = State.FINISHED;
 303             return true;
 304         }
 305         return false;
 306     }
 307
 308     @Override
 309     protected final void handleMessage(final Message msg) {
 310         this.failTimer.cancel(false);
 311
 312         LOG.debug("Channel {} handling message {} in state {}", this.channel, msg, this.state);
 313
 314         switch (this.state) {
 315         case FINISHED:
 316         case IDLE:
 317             throw new IllegalStateException("Unexpected handleMessage in state " + this.state);
 318         case START_TLS_WAIT:
 319             if (handleMessageStartTlsWait(msg)) {
 320                 return;
 321             }
 322             break;
 323         case KEEP_WAIT:
 324             if (handleMessageKeepWait(msg)) {
 325                 return;
 326             }
 327             break;
 328         case OPEN_WAIT:
 329             if (handleMessageOpenWait(msg)) {
 330                 return;
 331             }
 332             break;
 333         default:
 334             break;
 335         }
 336         LOG.warn("Channel {} in state {} received unexpected message {}", this.channel, this.state, msg);
 337         sendErrorMessage(PCEPErrors.NON_OR_INVALID_OPEN_MSG);
 338         negotiationFailed(new Exception("Illegal message encountered"));
 339         this.state = State.FINISHED;
 340     }
 341
 342     @VisibleForTesting
 343     State getState() {
 344         return this.state;
 345     }
 346
 347     public void setTlsConfiguration(final Tls tlsConfiguration) {
 348         this.tlsConfiguration = tlsConfiguration;
 349     }
 350 }