2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
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
9 package org.opendaylight.protocol.bgp.rib.impl;
11 import com.google.common.annotations.VisibleForTesting;
12 import com.google.common.base.Preconditions;
13 import io.netty.channel.Channel;
14 import io.netty.channel.ChannelFuture;
15 import io.netty.channel.ChannelFutureListener;
16 import io.netty.channel.ChannelHandlerContext;
17 import io.netty.channel.ChannelInboundHandlerAdapter;
18 import io.netty.util.concurrent.Promise;
19 import java.util.concurrent.TimeUnit;
20 import javax.annotation.concurrent.GuardedBy;
21 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
22 import org.opendaylight.protocol.bgp.parser.BGPError;
23 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
24 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
25 import org.opendaylight.protocol.bgp.rib.spi.BGPSessionListener;
26 import org.opendaylight.protocol.bgp.rib.spi.SessionNegotiator;
27 import org.opendaylight.protocol.util.Ipv6Util;
28 import org.opendaylight.protocol.util.Values;
29 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
30 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Address;
31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Keepalive;
32 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.KeepaliveBuilder;
33 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Notify;
34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.NotifyBuilder;
35 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.Open;
36 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.OpenBuilder;
37 import org.opendaylight.yangtools.yang.binding.Notification;
38 import org.slf4j.Logger;
39 import org.slf4j.LoggerFactory;
42 * Bgp Session negotiator. Common for local-to-remote and remote-to-local connections.
43 * One difference is session validation performed by injected BGPSessionValidator when OPEN message is received.
45 abstract class AbstractBGPSessionNegotiator extends ChannelInboundHandlerAdapter implements SessionNegotiator {
46 // 4 minutes recommended in http://tools.ietf.org/html/rfc4271#section-8.2.2
47 private static final int INITIAL_HOLDTIMER = 4;
50 * @see <a href="http://tools.ietf.org/html/rfc6793">BGP Support for 4-Octet AS Number Space</a>
52 private static final int AS_TRANS = 23456;
57 * Negotiation has not started yet.
61 * We have sent our Open message, and are waiting for the peer's Open message.
65 * We have received the peer's Open message, which is acceptable, and we're waiting the acknowledgement of our
70 * The negotiation finished.
75 private static final Logger LOG = LoggerFactory.getLogger(AbstractBGPSessionNegotiator.class);
76 private final BGPPeerRegistry registry;
77 private final Promise<BGPSessionImpl> promise;
78 private final Channel channel;
80 private State state = State.IDLE;
82 private BGPSessionImpl session;
84 AbstractBGPSessionNegotiator(final Promise<BGPSessionImpl> promise, final Channel channel,
85 final BGPPeerRegistry registry) {
86 this.promise = Preconditions.checkNotNull(promise);
87 this.channel = Preconditions.checkNotNull(channel);
88 this.registry = registry;
91 private synchronized void startNegotiation() {
92 if (!(this.state == State.IDLE || this.state == State.OPEN_CONFIRM)) {
95 // Open can be sent first either from ODL (IDLE) or from peer (OPEN_CONFIRM)
96 final IpAddress remoteIp = getRemoteIp();
98 // Check if peer is configured in registry before retrieving preferences
99 if (!this.registry.isPeerConfigured(remoteIp)) {
100 final BGPDocumentedException cause = new BGPDocumentedException(
101 String.format("BGP peer with ip: %s not configured, check configured peers in : %s", remoteIp, this.registry), BGPError.CONNECTION_REJECTED);
102 negotiationFailed(cause);
106 final BGPSessionPreferences preferences = this.registry.getPeerPreferences(remoteIp);
108 int as = preferences.getMyAs().getValue().intValue();
109 // Set as AS_TRANS if the value is bigger than 2B
110 if (as > Values.UNSIGNED_SHORT_MAX_VALUE) {
113 sendMessage(new OpenBuilder().setMyAsNumber(as).setHoldTimer(preferences.getHoldTime()).setBgpIdentifier(
114 preferences.getBgpId()).setBgpParameters(preferences.getParams()).build());
115 if (this.state != State.FINISHED) {
116 this.state = State.OPEN_SENT;
117 this.channel.eventLoop().schedule(new Runnable() {
120 synchronized (AbstractBGPSessionNegotiator.this) {
121 if (AbstractBGPSessionNegotiator.this.state != State.FINISHED) {
122 AbstractBGPSessionNegotiator.this
123 .sendMessage(buildErrorNotify(BGPError.HOLD_TIMER_EXPIRED));
124 negotiationFailed(new BGPDocumentedException("HoldTimer expired", BGPError.FSM_ERROR));
125 AbstractBGPSessionNegotiator.this.state = State.FINISHED;
129 }, INITIAL_HOLDTIMER, TimeUnit.MINUTES);
131 } catch (final Exception e) {
132 LOG.warn("Unexpected negotiation failure", e);
133 negotiationFailedCloseChannel(e);
137 private IpAddress getRemoteIp() {
138 final IpAddress remoteIp = StrictBGPPeerRegistry.getIpAddress(this.channel.remoteAddress());
139 if (remoteIp.getIpv6Address() != null) {
140 return new IpAddress(Ipv6Util.getFullForm(remoteIp.getIpv6Address()));
145 protected synchronized void handleMessage(final Notification msg) {
146 LOG.debug("Channel {} handling message in state {}, msg: {}", this.channel, this.state, msg);
147 switch (this.state) {
149 sendMessage(buildErrorNotify(BGPError.FSM_ERROR));
152 // to avoid race condition when Open message was sent by the peer before startNegotiation could be executed
153 if (msg instanceof Open) {
155 handleOpen((Open) msg);
158 sendMessage(buildErrorNotify(BGPError.FSM_ERROR));
161 if (msg instanceof Keepalive) {
162 negotiationSuccessful(this.session);
163 LOG.info("BGP Session with peer {} established successfully.", this.channel);
164 } else if (msg instanceof Notify) {
165 final Notify ntf = (Notify) msg;
166 negotiationFailed(new BGPDocumentedException("Peer refusal", BGPError.forValue(ntf.getErrorCode(), ntf.getErrorSubcode())));
168 this.state = State.FINISHED;
171 if (msg instanceof Open) {
172 handleOpen((Open) msg);
180 // Catch-all for unexpected message
181 LOG.warn("Channel {} state {} unexpected message {}", this.channel, this.state, msg);
182 sendMessage(buildErrorNotify(BGPError.FSM_ERROR));
183 negotiationFailed(new BGPDocumentedException("Unexpected message channel: " + this.channel + ", state: " + this.state + ", message: " + msg, BGPError.FSM_ERROR));
184 this.state = State.FINISHED;
187 private static Notify buildErrorNotify(final BGPError err) {
188 return buildErrorNotify(err, null);
191 private static Notify buildErrorNotify(final BGPError err, final byte[] data) {
192 final NotifyBuilder builder = new NotifyBuilder().setErrorCode(err.getCode()).setErrorSubcode(err.getSubcode());
193 if (data != null && data.length != 0) {
194 builder.setData(data);
196 return builder.build();
199 private synchronized void handleOpen(final Open openObj) {
200 final IpAddress remoteIp = getRemoteIp();
201 final BGPSessionPreferences preferences = this.registry.getPeerPreferences(remoteIp);
203 final BGPSessionListener peer = this.registry.getPeer(remoteIp, getSourceId(openObj, preferences), getDestinationId(openObj, preferences), openObj);
204 sendMessage(new KeepaliveBuilder().build());
205 this.state = State.OPEN_CONFIRM;
206 this.session = new BGPSessionImpl(peer, this.channel, openObj, preferences, this.registry);
207 this.session.setChannelExtMsgCoder(openObj);
208 LOG.debug("Channel {} moved to OPEN_CONFIRM state with remote proposal {}", this.channel, openObj);
209 } catch (final BGPDocumentedException e) {
210 LOG.warn("Channel {} negotiation failed", this.channel, e);
211 negotiationFailed(e);
215 private synchronized void negotiationFailed(final Throwable e) {
216 LOG.warn("Channel {} negotiation failed: {}", this.channel, e.getMessage());
217 if (e instanceof BGPDocumentedException) {
218 // although sendMessage() can also result in calling this method, it won't create a cycle. In case sendMessage() fails to
219 // deliver the message, this method gets called with different exception (definitely not with BGPDocumentedException).
220 sendMessage(buildErrorNotify(((BGPDocumentedException)e).getError(), ((BGPDocumentedException) e).getData()));
222 if (this.state == State.OPEN_CONFIRM) {
223 this.registry.removePeerSession(getRemoteIp());
225 negotiationFailedCloseChannel(e);
226 this.state = State.FINISHED;
230 * @param openMsg Open message received from remote BGP speaker
231 * @param preferences Local BGP speaker preferences
232 * @return BGP Id of device that accepted the connection
234 protected abstract Ipv4Address getDestinationId(final Open openMsg, final BGPSessionPreferences preferences);
237 * @param openMsg Open message received from remote BGP speaker
238 * @param preferences Local BGP speaker preferences
239 * @return BGP Id of device that accepted the connection
241 protected abstract Ipv4Address getSourceId(final Open openMsg, final BGPSessionPreferences preferences);
243 public synchronized State getState() {
247 private void negotiationSuccessful(final BGPSessionImpl session) {
248 LOG.debug("Negotiation on channel {} successful with session {}", this.channel, session);
249 this.channel.pipeline().replace(this, "session", session);
250 this.promise.setSuccess(session);
253 private void negotiationFailedCloseChannel(final Throwable cause) {
254 LOG.debug("Negotiation on channel {} failed", this.channel, cause);
255 this.channel.close();
256 this.promise.setFailure(cause);
259 private void sendMessage(final Notification msg) {
260 this.channel.writeAndFlush(msg).addListener(new ChannelFutureListener() {
262 public void operationComplete(final ChannelFuture f) {
263 if (!f.isSuccess()) {
264 LOG.warn("Failed to send message {} to channel {}", msg, AbstractBGPSessionNegotiator.this.channel, f.cause());
265 negotiationFailedCloseChannel(f.cause());
267 LOG.trace("Message {} sent to channel {}", msg, AbstractBGPSessionNegotiator.this.channel);
274 public final void channelActive(final ChannelHandlerContext ctx) {
275 LOG.debug("Starting session negotiation on channel {}", this.channel);
280 public final void channelRead(final ChannelHandlerContext ctx, final Object msg) {
281 LOG.debug("Negotiation read invoked on channel {}", this.channel);
283 handleMessage((Notification) msg);
284 } catch (final Exception e) {
285 LOG.debug("Unexpected error while handling negotiation message {}", msg, e);
286 negotiationFailedCloseChannel(e);
292 public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) {
293 LOG.info("Unexpected error during negotiation", cause);
294 negotiationFailedCloseChannel(cause);