Thomas Vachuska | 781d18b | 2014-10-27 10:31:25 -0700 | [diff] [blame] | 1 | /* |
Thomas Vachuska | 4f1a60c | 2014-10-28 13:39:07 -0700 | [diff] [blame] | 2 | * Copyright 2014 Open Networking Laboratory |
Thomas Vachuska | 781d18b | 2014-10-27 10:31:25 -0700 | [diff] [blame] | 3 | * |
Thomas Vachuska | 4f1a60c | 2014-10-28 13:39:07 -0700 | [diff] [blame] | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
Thomas Vachuska | 781d18b | 2014-10-27 10:31:25 -0700 | [diff] [blame] | 7 | * |
Thomas Vachuska | 4f1a60c | 2014-10-28 13:39:07 -0700 | [diff] [blame] | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
Thomas Vachuska | 781d18b | 2014-10-27 10:31:25 -0700 | [diff] [blame] | 15 | */ |
Jonathan Hart | ab63aac | 2014-10-16 08:52:55 -0700 | [diff] [blame] | 16 | package org.onlab.onos.sdnip.bgp; |
| 17 | |
| 18 | import java.net.InetAddress; |
| 19 | import java.net.InetSocketAddress; |
| 20 | import java.net.SocketAddress; |
| 21 | import java.util.ArrayList; |
| 22 | import java.util.Collection; |
| 23 | import java.util.Collections; |
| 24 | import java.util.HashMap; |
| 25 | import java.util.Map; |
| 26 | import java.util.concurrent.ConcurrentHashMap; |
| 27 | import java.util.concurrent.ConcurrentMap; |
| 28 | import java.util.concurrent.TimeUnit; |
| 29 | |
| 30 | import org.apache.commons.lang3.tuple.Pair; |
| 31 | import org.jboss.netty.buffer.ChannelBuffer; |
| 32 | import org.jboss.netty.buffer.ChannelBuffers; |
| 33 | import org.jboss.netty.channel.ChannelHandlerContext; |
| 34 | import org.jboss.netty.channel.ChannelStateEvent; |
| 35 | import org.jboss.netty.channel.SimpleChannelHandler; |
| 36 | import org.jboss.netty.util.HashedWheelTimer; |
| 37 | import org.jboss.netty.util.Timeout; |
| 38 | import org.jboss.netty.util.Timer; |
| 39 | import org.jboss.netty.util.TimerTask; |
| 40 | import org.onlab.onos.sdnip.bgp.BgpConstants.Notifications; |
| 41 | import org.onlab.onos.sdnip.bgp.BgpConstants.Notifications.HoldTimerExpired; |
| 42 | import org.onlab.onos.sdnip.bgp.BgpConstants.Notifications.MessageHeaderError; |
| 43 | import org.onlab.onos.sdnip.bgp.BgpConstants.Notifications.OpenMessageError; |
| 44 | import org.onlab.onos.sdnip.bgp.BgpConstants.Notifications.UpdateMessageError; |
| 45 | import org.onlab.packet.IpAddress; |
| 46 | import org.onlab.packet.IpPrefix; |
| 47 | import org.slf4j.Logger; |
| 48 | import org.slf4j.LoggerFactory; |
| 49 | |
| 50 | /** |
| 51 | * Class for handling the BGP peer sessions. |
| 52 | * There is one instance per each BGP peer session. |
| 53 | */ |
| 54 | public class BgpSession extends SimpleChannelHandler { |
| 55 | private static final Logger log = |
| 56 | LoggerFactory.getLogger(BgpSession.class); |
| 57 | |
| 58 | private final BgpSessionManager bgpSessionManager; |
| 59 | |
| 60 | // Local flag to indicate the session is closed. |
| 61 | // It is used to avoid the Netty's asynchronous closing of a channel. |
| 62 | private boolean isClosed = false; |
| 63 | |
| 64 | private SocketAddress remoteAddress; // Peer IP addr/port |
| 65 | private IpAddress remoteIp4Address; // Peer IPv4 address |
| 66 | private int remoteBgpVersion; // 1 octet |
| 67 | private long remoteAs; // 2 octets |
| 68 | private long remoteHoldtime; // 2 octets |
| 69 | private IpAddress remoteBgpId; // 4 octets -> IPv4 address |
| 70 | // |
| 71 | private SocketAddress localAddress; // Local IP addr/port |
| 72 | private IpAddress localIp4Address; // Local IPv4 address |
| 73 | private int localBgpVersion; // 1 octet |
| 74 | private long localAs; // 2 octets |
| 75 | private long localHoldtime; // 2 octets |
| 76 | private IpAddress localBgpId; // 4 octets -> IPv4 address |
| 77 | // |
| 78 | private long localKeepaliveInterval; // Keepalive interval |
| 79 | |
| 80 | // Timers state |
| 81 | private Timer timer = new HashedWheelTimer(); |
| 82 | private volatile Timeout keepaliveTimeout; // Periodic KEEPALIVE |
| 83 | private volatile Timeout sessionTimeout; // Session timeout |
| 84 | |
| 85 | // BGP RIB-IN routing entries from this peer |
| 86 | private ConcurrentMap<IpPrefix, BgpRouteEntry> bgpRibIn = |
| 87 | new ConcurrentHashMap<>(); |
| 88 | |
| 89 | /** |
| 90 | * Constructor for a given BGP Session Manager. |
| 91 | * |
| 92 | * @param bgpSessionManager the BGP Session Manager to use |
| 93 | */ |
| 94 | BgpSession(BgpSessionManager bgpSessionManager) { |
| 95 | this.bgpSessionManager = bgpSessionManager; |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Gets the BGP RIB-IN routing entries. |
| 100 | * |
| 101 | * @return the BGP RIB-IN routing entries |
| 102 | */ |
| 103 | public Collection<BgpRouteEntry> getBgpRibIn() { |
| 104 | return bgpRibIn.values(); |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * Finds a BGP routing entry in the BGP RIB-IN. |
| 109 | * |
| 110 | * @param prefix the prefix of the route to search for |
| 111 | * @return the BGP routing entry if found, otherwise null |
| 112 | */ |
| 113 | public BgpRouteEntry findBgpRouteEntry(IpPrefix prefix) { |
| 114 | return bgpRibIn.get(prefix); |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * Gets the BGP session remote address. |
| 119 | * |
| 120 | * @return the BGP session remote address |
| 121 | */ |
| 122 | public SocketAddress getRemoteAddress() { |
| 123 | return remoteAddress; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * Gets the BGP session remote IPv4 address. |
| 128 | * |
| 129 | * @return the BGP session remote IPv4 address |
| 130 | */ |
| 131 | public IpAddress getRemoteIp4Address() { |
| 132 | return remoteIp4Address; |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * Gets the BGP session remote BGP version. |
| 137 | * |
| 138 | * @return the BGP session remote BGP version |
| 139 | */ |
| 140 | public int getRemoteBgpVersion() { |
| 141 | return remoteBgpVersion; |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * Gets the BGP session remote AS number. |
| 146 | * |
| 147 | * @return the BGP session remote AS number |
| 148 | */ |
| 149 | public long getRemoteAs() { |
| 150 | return remoteAs; |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * Gets the BGP session remote Holdtime. |
| 155 | * |
| 156 | * @return the BGP session remote Holdtime |
| 157 | */ |
| 158 | public long getRemoteHoldtime() { |
| 159 | return remoteHoldtime; |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * Gets the BGP session remote BGP Identifier as an IPv4 address. |
| 164 | * |
| 165 | * @return the BGP session remote BGP Identifier as an IPv4 address |
| 166 | */ |
| 167 | public IpAddress getRemoteBgpId() { |
| 168 | return remoteBgpId; |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Gets the BGP session local address. |
| 173 | * |
| 174 | * @return the BGP session local address |
| 175 | */ |
| 176 | public SocketAddress getLocalAddress() { |
| 177 | return localAddress; |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * Gets the BGP session local BGP version. |
| 182 | * |
| 183 | * @return the BGP session local BGP version |
| 184 | */ |
| 185 | public int getLocalBgpVersion() { |
| 186 | return localBgpVersion; |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * Gets the BGP session local AS number. |
| 191 | * |
| 192 | * @return the BGP session local AS number |
| 193 | */ |
| 194 | public long getLocalAs() { |
| 195 | return localAs; |
| 196 | } |
| 197 | |
| 198 | /** |
| 199 | * Gets the BGP session local Holdtime. |
| 200 | * |
| 201 | * @return the BGP session local Holdtime |
| 202 | */ |
| 203 | public long getLocalHoldtime() { |
| 204 | return localHoldtime; |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * Gets the BGP session local BGP Identifier as an IPv4 address. |
| 209 | * |
| 210 | * @return the BGP session local BGP Identifier as an IPv4 address |
| 211 | */ |
| 212 | public IpAddress getLocalBgpId() { |
| 213 | return localBgpId; |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * Tests whether the session is closed. |
| 218 | * <p/> |
| 219 | * NOTE: We use this method to avoid the Netty's asynchronous closing |
| 220 | * of a channel. |
| 221 | * |
| 222 | * @param return true if the session is closed |
| 223 | */ |
| 224 | boolean isClosed() { |
| 225 | return isClosed; |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Closes the channel. |
| 230 | * |
| 231 | * @param ctx the Channel Handler Context |
| 232 | */ |
| 233 | void closeChannel(ChannelHandlerContext ctx) { |
| 234 | isClosed = true; |
| 235 | timer.stop(); |
| 236 | ctx.getChannel().close(); |
| 237 | } |
| 238 | |
| 239 | @Override |
| 240 | public void channelConnected(ChannelHandlerContext ctx, |
| 241 | ChannelStateEvent channelEvent) { |
| 242 | localAddress = ctx.getChannel().getLocalAddress(); |
| 243 | remoteAddress = ctx.getChannel().getRemoteAddress(); |
| 244 | |
| 245 | // Assign the local and remote IPv4 addresses |
| 246 | InetAddress inetAddr; |
| 247 | if (localAddress instanceof InetSocketAddress) { |
| 248 | inetAddr = ((InetSocketAddress) localAddress).getAddress(); |
| 249 | localIp4Address = IpAddress.valueOf(inetAddr.getAddress()); |
| 250 | } |
| 251 | if (remoteAddress instanceof InetSocketAddress) { |
| 252 | inetAddr = ((InetSocketAddress) remoteAddress).getAddress(); |
| 253 | remoteIp4Address = IpAddress.valueOf(inetAddr.getAddress()); |
| 254 | } |
| 255 | |
| 256 | log.debug("BGP Session Connected from {} on {}", |
| 257 | remoteAddress, localAddress); |
| 258 | if (!bgpSessionManager.peerConnected(this)) { |
| 259 | log.debug("Cannot setup BGP Session Connection from {}. Closing...", |
| 260 | remoteAddress); |
| 261 | ctx.getChannel().close(); |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | @Override |
| 266 | public void channelDisconnected(ChannelHandlerContext ctx, |
| 267 | ChannelStateEvent channelEvent) { |
| 268 | log.debug("BGP Session Disconnected from {} on {}", |
| 269 | ctx.getChannel().getRemoteAddress(), |
| 270 | ctx.getChannel().getLocalAddress()); |
| 271 | |
| 272 | // |
| 273 | // Withdraw the routes advertised by this BGP peer |
| 274 | // |
| 275 | // NOTE: We must initialize the RIB-IN before propagating the withdraws |
| 276 | // for further processing. Otherwise, the BGP Decision Process |
| 277 | // will use those routes again. |
| 278 | // |
| 279 | Collection<BgpRouteEntry> deletedRoutes = bgpRibIn.values(); |
| 280 | bgpRibIn = new ConcurrentHashMap<>(); |
| 281 | |
| 282 | // Push the updates to the BGP Merged RIB |
| 283 | BgpSessionManager.BgpRouteSelector bgpRouteSelector = |
| 284 | bgpSessionManager.getBgpRouteSelector(); |
| 285 | Collection<BgpRouteEntry> addedRoutes = Collections.emptyList(); |
| 286 | bgpRouteSelector.routeUpdates(this, addedRoutes, deletedRoutes); |
| 287 | |
| 288 | bgpSessionManager.peerDisconnected(this); |
| 289 | } |
| 290 | |
| 291 | /** |
| 292 | * Processes BGP OPEN message. |
| 293 | * |
| 294 | * @param ctx the Channel Handler Context |
| 295 | * @param message the message to process |
| 296 | */ |
| 297 | void processBgpOpen(ChannelHandlerContext ctx, ChannelBuffer message) { |
| 298 | int minLength = |
| 299 | BgpConstants.BGP_OPEN_MIN_LENGTH - BgpConstants.BGP_HEADER_LENGTH; |
| 300 | if (message.readableBytes() < minLength) { |
| 301 | log.debug("BGP RX OPEN Error from {}: " + |
| 302 | "Message length {} too short. Must be at least {}", |
| 303 | remoteAddress, message.readableBytes(), minLength); |
| 304 | // |
| 305 | // ERROR: Bad Message Length |
| 306 | // |
| 307 | // Send NOTIFICATION and close the connection |
| 308 | ChannelBuffer txMessage = prepareBgpNotificationBadMessageLength( |
| 309 | message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH); |
| 310 | ctx.getChannel().write(txMessage); |
| 311 | closeChannel(ctx); |
| 312 | return; |
| 313 | } |
| 314 | |
| 315 | // |
| 316 | // Parse the OPEN message |
| 317 | // |
| 318 | // Remote BGP version |
| 319 | remoteBgpVersion = message.readUnsignedByte(); |
| 320 | if (remoteBgpVersion != BgpConstants.BGP_VERSION) { |
| 321 | log.debug("BGP RX OPEN Error from {}: " + |
| 322 | "Unsupported BGP version {}. Should be {}", |
| 323 | remoteAddress, remoteBgpVersion, |
| 324 | BgpConstants.BGP_VERSION); |
| 325 | // |
| 326 | // ERROR: Unsupported Version Number |
| 327 | // |
| 328 | // Send NOTIFICATION and close the connection |
| 329 | int errorCode = OpenMessageError.ERROR_CODE; |
| 330 | int errorSubcode = OpenMessageError.UNSUPPORTED_VERSION_NUMBER; |
| 331 | ChannelBuffer data = ChannelBuffers.buffer(2); |
| 332 | data.writeShort(BgpConstants.BGP_VERSION); |
| 333 | ChannelBuffer txMessage = |
| 334 | prepareBgpNotification(errorCode, errorSubcode, data); |
| 335 | ctx.getChannel().write(txMessage); |
| 336 | closeChannel(ctx); |
| 337 | return; |
| 338 | } |
| 339 | |
| 340 | // Remote AS number |
| 341 | remoteAs = message.readUnsignedShort(); |
| 342 | // |
| 343 | // Verify that the AS number is same for all other BGP Sessions |
| 344 | // NOTE: This check applies only for our use-case where all BGP |
| 345 | // sessions are iBGP. |
| 346 | // |
| 347 | for (BgpSession bgpSession : bgpSessionManager.getBgpSessions()) { |
| 348 | if (remoteAs != bgpSession.getRemoteAs()) { |
| 349 | log.debug("BGP RX OPEN Error from {}: Bad Peer AS {}. " + |
| 350 | "Expected {}", |
| 351 | remoteAddress, remoteAs, bgpSession.getRemoteAs()); |
| 352 | // |
| 353 | // ERROR: Bad Peer AS |
| 354 | // |
| 355 | // Send NOTIFICATION and close the connection |
| 356 | int errorCode = OpenMessageError.ERROR_CODE; |
| 357 | int errorSubcode = OpenMessageError.BAD_PEER_AS; |
| 358 | ChannelBuffer txMessage = |
| 359 | prepareBgpNotification(errorCode, errorSubcode, null); |
| 360 | ctx.getChannel().write(txMessage); |
| 361 | closeChannel(ctx); |
| 362 | return; |
| 363 | } |
| 364 | } |
| 365 | |
| 366 | // Remote Hold Time |
| 367 | remoteHoldtime = message.readUnsignedShort(); |
| 368 | if ((remoteHoldtime != 0) && |
| 369 | (remoteHoldtime < BgpConstants.BGP_KEEPALIVE_MIN_HOLDTIME)) { |
| 370 | log.debug("BGP RX OPEN Error from {}: " + |
| 371 | "Unacceptable Hold Time field {}. " + |
| 372 | "Should be 0 or at least {}", |
| 373 | remoteAddress, remoteHoldtime, |
| 374 | BgpConstants.BGP_KEEPALIVE_MIN_HOLDTIME); |
| 375 | // |
| 376 | // ERROR: Unacceptable Hold Time |
| 377 | // |
| 378 | // Send NOTIFICATION and close the connection |
| 379 | int errorCode = OpenMessageError.ERROR_CODE; |
| 380 | int errorSubcode = OpenMessageError.UNACCEPTABLE_HOLD_TIME; |
| 381 | ChannelBuffer txMessage = |
| 382 | prepareBgpNotification(errorCode, errorSubcode, null); |
| 383 | ctx.getChannel().write(txMessage); |
| 384 | closeChannel(ctx); |
| 385 | return; |
| 386 | } |
| 387 | |
| 388 | // Remote BGP Identifier |
| 389 | remoteBgpId = IpAddress.valueOf((int) message.readUnsignedInt()); |
| 390 | |
| 391 | // Optional Parameters |
| 392 | int optParamLen = message.readUnsignedByte(); |
| 393 | if (message.readableBytes() < optParamLen) { |
| 394 | log.debug("BGP RX OPEN Error from {}: " + |
| 395 | "Invalid Optional Parameter Length field {}. " + |
| 396 | "Remaining Optional Parameters {}", |
| 397 | remoteAddress, optParamLen, message.readableBytes()); |
| 398 | // |
| 399 | // ERROR: Invalid Optional Parameter Length field: Unspecific |
| 400 | // |
| 401 | // Send NOTIFICATION and close the connection |
| 402 | int errorCode = OpenMessageError.ERROR_CODE; |
| 403 | int errorSubcode = Notifications.ERROR_SUBCODE_UNSPECIFIC; |
| 404 | ChannelBuffer txMessage = |
| 405 | prepareBgpNotification(errorCode, errorSubcode, null); |
| 406 | ctx.getChannel().write(txMessage); |
| 407 | closeChannel(ctx); |
| 408 | return; |
| 409 | } |
| 410 | // TODO: Parse the optional parameters (if needed) |
| 411 | message.readBytes(optParamLen); // NOTE: data ignored |
| 412 | |
| 413 | // |
| 414 | // Copy some of the remote peer's state/setup to the local setup: |
| 415 | // - BGP version |
| 416 | // - AS number (NOTE: the peer setup is always iBGP) |
| 417 | // - Holdtime |
| 418 | // Also, assign the local BGP ID based on the local setup |
| 419 | // |
| 420 | localBgpVersion = remoteBgpVersion; |
| 421 | localAs = remoteAs; |
| 422 | localHoldtime = remoteHoldtime; |
| 423 | localBgpId = bgpSessionManager.getMyBgpId(); |
| 424 | |
| 425 | // Set the Keepalive interval |
| 426 | if (localHoldtime == 0) { |
| 427 | localKeepaliveInterval = 0; |
| 428 | } else { |
| 429 | localKeepaliveInterval = Math.max(localHoldtime / |
| 430 | BgpConstants.BGP_KEEPALIVE_PER_HOLD_INTERVAL, |
| 431 | BgpConstants.BGP_KEEPALIVE_MIN_INTERVAL); |
| 432 | } |
| 433 | |
| 434 | log.debug("BGP RX OPEN message from {}: " + |
| 435 | "BGPv{} AS {} BGP-ID {} Holdtime {}", |
| 436 | remoteAddress, remoteBgpVersion, remoteAs, |
| 437 | remoteBgpId, remoteHoldtime); |
| 438 | |
| 439 | // Send my OPEN followed by KEEPALIVE |
| 440 | ChannelBuffer txMessage = prepareBgpOpen(); |
| 441 | ctx.getChannel().write(txMessage); |
| 442 | // |
| 443 | txMessage = prepareBgpKeepalive(); |
| 444 | ctx.getChannel().write(txMessage); |
| 445 | |
| 446 | // Start the KEEPALIVE timer |
| 447 | restartKeepaliveTimer(ctx); |
| 448 | |
| 449 | // Start the Session Timeout timer |
| 450 | restartSessionTimeoutTimer(ctx); |
| 451 | } |
| 452 | |
| 453 | /** |
| 454 | * Processes BGP UPDATE message. |
| 455 | * |
| 456 | * @param ctx the Channel Handler Context |
| 457 | * @param message the message to process |
| 458 | */ |
| 459 | void processBgpUpdate(ChannelHandlerContext ctx, ChannelBuffer message) { |
| 460 | Collection<BgpRouteEntry> addedRoutes = null; |
| 461 | Map<IpPrefix, BgpRouteEntry> deletedRoutes = new HashMap<>(); |
| 462 | |
| 463 | int minLength = |
| 464 | BgpConstants.BGP_UPDATE_MIN_LENGTH - BgpConstants.BGP_HEADER_LENGTH; |
| 465 | if (message.readableBytes() < minLength) { |
| 466 | log.debug("BGP RX UPDATE Error from {}: " + |
| 467 | "Message length {} too short. Must be at least {}", |
| 468 | remoteAddress, message.readableBytes(), minLength); |
| 469 | // |
| 470 | // ERROR: Bad Message Length |
| 471 | // |
| 472 | // Send NOTIFICATION and close the connection |
| 473 | ChannelBuffer txMessage = prepareBgpNotificationBadMessageLength( |
| 474 | message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH); |
| 475 | ctx.getChannel().write(txMessage); |
| 476 | closeChannel(ctx); |
| 477 | return; |
| 478 | } |
| 479 | |
| 480 | log.debug("BGP RX UPDATE message from {}", remoteAddress); |
| 481 | |
| 482 | // |
| 483 | // Parse the UPDATE message |
| 484 | // |
| 485 | |
| 486 | // |
| 487 | // Parse the Withdrawn Routes |
| 488 | // |
| 489 | int withdrawnRoutesLength = message.readUnsignedShort(); |
| 490 | if (withdrawnRoutesLength > message.readableBytes()) { |
| 491 | // ERROR: Malformed Attribute List |
| 492 | actionsBgpUpdateMalformedAttributeList(ctx); |
| 493 | return; |
| 494 | } |
| 495 | Collection<IpPrefix> withdrawnPrefixes = null; |
| 496 | try { |
| 497 | withdrawnPrefixes = parsePackedPrefixes(withdrawnRoutesLength, |
| 498 | message); |
| 499 | } catch (BgpParseException e) { |
| 500 | // ERROR: Invalid Network Field |
| 501 | log.debug("Exception parsing Withdrawn Prefixes from BGP peer {}: ", |
| 502 | remoteBgpId, e); |
| 503 | actionsBgpUpdateInvalidNetworkField(ctx); |
| 504 | return; |
| 505 | } |
| 506 | for (IpPrefix prefix : withdrawnPrefixes) { |
| 507 | log.debug("BGP RX UPDATE message WITHDRAWN from {}: {}", |
| 508 | remoteAddress, prefix); |
| 509 | BgpRouteEntry bgpRouteEntry = bgpRibIn.get(prefix); |
| 510 | if (bgpRouteEntry != null) { |
| 511 | deletedRoutes.put(prefix, bgpRouteEntry); |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | // |
| 516 | // Parse the Path Attributes |
| 517 | // |
| 518 | try { |
| 519 | addedRoutes = parsePathAttributes(ctx, message); |
| 520 | } catch (BgpParseException e) { |
| 521 | log.debug("Exception parsing Path Attributes from BGP peer {}: ", |
| 522 | remoteBgpId, e); |
| 523 | // NOTE: The session was already closed, so nothing else to do |
| 524 | return; |
| 525 | } |
| 526 | // Ignore WITHDRAWN routes that are ADDED |
| 527 | for (BgpRouteEntry bgpRouteEntry : addedRoutes) { |
| 528 | deletedRoutes.remove(bgpRouteEntry.prefix()); |
| 529 | } |
| 530 | |
| 531 | // Update the BGP RIB-IN |
| 532 | for (BgpRouteEntry bgpRouteEntry : deletedRoutes.values()) { |
| 533 | bgpRibIn.remove(bgpRouteEntry.prefix()); |
| 534 | } |
| 535 | for (BgpRouteEntry bgpRouteEntry : addedRoutes) { |
| 536 | bgpRibIn.put(bgpRouteEntry.prefix(), bgpRouteEntry); |
| 537 | } |
| 538 | |
| 539 | // Push the updates to the BGP Merged RIB |
| 540 | BgpSessionManager.BgpRouteSelector bgpRouteSelector = |
| 541 | bgpSessionManager.getBgpRouteSelector(); |
| 542 | bgpRouteSelector.routeUpdates(this, addedRoutes, |
| 543 | deletedRoutes.values()); |
| 544 | |
| 545 | // Start the Session Timeout timer |
| 546 | restartSessionTimeoutTimer(ctx); |
| 547 | } |
| 548 | |
| 549 | /** |
| 550 | * Parse BGP Path Attributes from the BGP UPDATE message. |
| 551 | * |
| 552 | * @param ctx the Channel Handler Context |
| 553 | * @param message the message to parse |
| 554 | * @return a collection of the result BGP Route Entries |
| 555 | * @throws BgpParseException |
| 556 | */ |
| 557 | private Collection<BgpRouteEntry> parsePathAttributes( |
| 558 | ChannelHandlerContext ctx, |
| 559 | ChannelBuffer message) |
| 560 | throws BgpParseException { |
| 561 | Map<IpPrefix, BgpRouteEntry> addedRoutes = new HashMap<>(); |
| 562 | |
| 563 | // |
| 564 | // Parsed values |
| 565 | // |
| 566 | Short origin = -1; // Mandatory |
| 567 | BgpRouteEntry.AsPath asPath = null; // Mandatory |
| 568 | IpAddress nextHop = null; // Mandatory |
| 569 | long multiExitDisc = // Optional |
| 570 | BgpConstants.Update.MultiExitDisc.LOWEST_MULTI_EXIT_DISC; |
| 571 | Long localPref = null; // Mandatory |
| 572 | Long aggregatorAsNumber = null; // Optional: unused |
| 573 | IpAddress aggregatorIpAddress = null; // Optional: unused |
| 574 | |
| 575 | // |
| 576 | // Get and verify the Path Attributes Length |
| 577 | // |
| 578 | int pathAttributeLength = message.readUnsignedShort(); |
| 579 | if (pathAttributeLength > message.readableBytes()) { |
| 580 | // ERROR: Malformed Attribute List |
| 581 | actionsBgpUpdateMalformedAttributeList(ctx); |
| 582 | String errorMsg = "Malformed Attribute List"; |
| 583 | throw new BgpParseException(errorMsg); |
| 584 | } |
| 585 | if (pathAttributeLength == 0) { |
| 586 | return addedRoutes.values(); |
| 587 | } |
| 588 | |
| 589 | // |
| 590 | // Parse the Path Attributes |
| 591 | // |
| 592 | int pathAttributeEnd = message.readerIndex() + pathAttributeLength; |
| 593 | while (message.readerIndex() < pathAttributeEnd) { |
| 594 | int attrFlags = message.readUnsignedByte(); |
| 595 | if (message.readerIndex() >= pathAttributeEnd) { |
| 596 | // ERROR: Malformed Attribute List |
| 597 | actionsBgpUpdateMalformedAttributeList(ctx); |
| 598 | String errorMsg = "Malformed Attribute List"; |
| 599 | throw new BgpParseException(errorMsg); |
| 600 | } |
| 601 | int attrTypeCode = message.readUnsignedByte(); |
| 602 | |
| 603 | // The Attribute Flags |
| 604 | boolean optionalBit = ((0x80 & attrFlags) != 0); |
| 605 | boolean transitiveBit = ((0x40 & attrFlags) != 0); |
| 606 | boolean partialBit = ((0x20 & attrFlags) != 0); |
| 607 | boolean extendedLengthBit = ((0x10 & attrFlags) != 0); |
| 608 | |
| 609 | // The Attribute Length |
| 610 | int attrLen = 0; |
| 611 | int attrLenOctets = 1; |
| 612 | if (extendedLengthBit) { |
| 613 | attrLenOctets = 2; |
| 614 | } |
| 615 | if (message.readerIndex() + attrLenOctets > pathAttributeEnd) { |
| 616 | // ERROR: Malformed Attribute List |
| 617 | actionsBgpUpdateMalformedAttributeList(ctx); |
| 618 | String errorMsg = "Malformed Attribute List"; |
| 619 | throw new BgpParseException(errorMsg); |
| 620 | } |
| 621 | if (extendedLengthBit) { |
| 622 | attrLen = message.readUnsignedShort(); |
| 623 | } else { |
| 624 | attrLen = message.readUnsignedByte(); |
| 625 | } |
| 626 | if (message.readerIndex() + attrLen > pathAttributeEnd) { |
| 627 | // ERROR: Malformed Attribute List |
| 628 | actionsBgpUpdateMalformedAttributeList(ctx); |
| 629 | String errorMsg = "Malformed Attribute List"; |
| 630 | throw new BgpParseException(errorMsg); |
| 631 | } |
| 632 | |
| 633 | // |
| 634 | // Verify the Attribute Flags |
| 635 | // |
| 636 | verifyBgpUpdateAttributeFlags(ctx, attrTypeCode, attrLen, |
| 637 | attrFlags, message); |
| 638 | |
| 639 | // |
| 640 | // Extract the Attribute Value based on the Attribute Type Code |
| 641 | // |
| 642 | switch (attrTypeCode) { |
| 643 | |
| 644 | case BgpConstants.Update.Origin.TYPE: |
| 645 | // Attribute Type Code ORIGIN |
| 646 | origin = parseAttributeTypeOrigin(ctx, attrTypeCode, attrLen, |
| 647 | attrFlags, message); |
| 648 | break; |
| 649 | |
| 650 | case BgpConstants.Update.AsPath.TYPE: |
| 651 | // Attribute Type Code AS_PATH |
| 652 | asPath = parseAttributeTypeAsPath(ctx, attrTypeCode, attrLen, |
| 653 | attrFlags, message); |
| 654 | break; |
| 655 | |
| 656 | case BgpConstants.Update.NextHop.TYPE: |
| 657 | // Attribute Type Code NEXT_HOP |
| 658 | nextHop = parseAttributeTypeNextHop(ctx, attrTypeCode, attrLen, |
| 659 | attrFlags, message); |
| 660 | break; |
| 661 | |
| 662 | case BgpConstants.Update.MultiExitDisc.TYPE: |
| 663 | // Attribute Type Code MULTI_EXIT_DISC |
| 664 | multiExitDisc = |
| 665 | parseAttributeTypeMultiExitDisc(ctx, attrTypeCode, attrLen, |
| 666 | attrFlags, message); |
| 667 | break; |
| 668 | |
| 669 | case BgpConstants.Update.LocalPref.TYPE: |
| 670 | // Attribute Type Code LOCAL_PREF |
| 671 | localPref = |
| 672 | parseAttributeTypeLocalPref(ctx, attrTypeCode, attrLen, |
| 673 | attrFlags, message); |
| 674 | break; |
| 675 | |
| 676 | case BgpConstants.Update.AtomicAggregate.TYPE: |
| 677 | // Attribute Type Code ATOMIC_AGGREGATE |
| 678 | parseAttributeTypeAtomicAggregate(ctx, attrTypeCode, attrLen, |
| 679 | attrFlags, message); |
| 680 | // Nothing to do: this attribute is primarily informational |
| 681 | break; |
| 682 | |
| 683 | case BgpConstants.Update.Aggregator.TYPE: |
| 684 | // Attribute Type Code AGGREGATOR |
| 685 | Pair<Long, IpAddress> aggregator = |
| 686 | parseAttributeTypeAggregator(ctx, attrTypeCode, attrLen, |
| 687 | attrFlags, message); |
| 688 | aggregatorAsNumber = aggregator.getLeft(); |
| 689 | aggregatorIpAddress = aggregator.getRight(); |
| 690 | break; |
| 691 | |
| 692 | default: |
| 693 | // TODO: Parse any new Attribute Types if needed |
| 694 | if (!optionalBit) { |
| 695 | // ERROR: Unrecognized Well-known Attribute |
| 696 | actionsBgpUpdateUnrecognizedWellKnownAttribute( |
| 697 | ctx, attrTypeCode, attrLen, attrFlags, message); |
| 698 | String errorMsg = "Unrecognized Well-known Attribute: " + |
| 699 | attrTypeCode; |
| 700 | throw new BgpParseException(errorMsg); |
| 701 | } |
| 702 | |
| 703 | // Skip the data from the unrecognized attribute |
| 704 | log.debug("BGP RX UPDATE message from {}: " + |
| 705 | "Unrecognized Attribute Type {}", |
| 706 | remoteAddress, attrTypeCode); |
| 707 | message.skipBytes(attrLen); |
| 708 | break; |
| 709 | } |
| 710 | } |
| 711 | |
| 712 | // |
| 713 | // Verify the Well-known Attributes |
| 714 | // |
| 715 | verifyBgpUpdateWellKnownAttributes(ctx, origin, asPath, nextHop, |
| 716 | localPref); |
| 717 | |
| 718 | // |
| 719 | // Parse the NLRI (Network Layer Reachability Information) |
| 720 | // |
| 721 | Collection<IpPrefix> addedPrefixes = null; |
| 722 | int nlriLength = message.readableBytes(); |
| 723 | try { |
| 724 | addedPrefixes = parsePackedPrefixes(nlriLength, message); |
| 725 | } catch (BgpParseException e) { |
| 726 | // ERROR: Invalid Network Field |
| 727 | log.debug("Exception parsing NLRI from BGP peer {}: ", |
| 728 | remoteBgpId, e); |
| 729 | actionsBgpUpdateInvalidNetworkField(ctx); |
| 730 | // Rethrow the exception |
| 731 | throw e; |
| 732 | } |
| 733 | |
| 734 | // Generate the added routes |
| 735 | for (IpPrefix prefix : addedPrefixes) { |
| 736 | BgpRouteEntry bgpRouteEntry = |
| 737 | new BgpRouteEntry(this, prefix, nextHop, |
| 738 | origin.byteValue(), asPath, localPref); |
| 739 | bgpRouteEntry.setMultiExitDisc(multiExitDisc); |
| 740 | if (bgpRouteEntry.hasAsPathLoop(localAs)) { |
| 741 | log.debug("BGP RX UPDATE message IGNORED from {}: {} " + |
| 742 | "nextHop {}: contains AS Path loop", |
| 743 | remoteAddress, prefix, nextHop); |
| 744 | continue; |
| 745 | } else { |
| 746 | log.debug("BGP RX UPDATE message ADDED from {}: {} nextHop {}", |
| 747 | remoteAddress, prefix, nextHop); |
| 748 | } |
| 749 | addedRoutes.put(prefix, bgpRouteEntry); |
| 750 | } |
| 751 | |
| 752 | return addedRoutes.values(); |
| 753 | } |
| 754 | |
| 755 | /** |
| 756 | * Verifies BGP UPDATE Well-known Attributes. |
| 757 | * |
| 758 | * @param ctx the Channel Handler Context |
| 759 | * @param origin the ORIGIN well-known mandatory attribute |
| 760 | * @param asPath the AS_PATH well-known mandatory attribute |
| 761 | * @param nextHop the NEXT_HOP well-known mandatory attribute |
| 762 | * @param localPref the LOCAL_PREF required attribute |
| 763 | * @throws BgpParseException |
| 764 | */ |
| 765 | private void verifyBgpUpdateWellKnownAttributes( |
| 766 | ChannelHandlerContext ctx, |
| 767 | Short origin, |
| 768 | BgpRouteEntry.AsPath asPath, |
| 769 | IpAddress nextHop, |
| 770 | Long localPref) |
| 771 | throws BgpParseException { |
| 772 | // |
| 773 | // Check for Missing Well-known Attributes |
| 774 | // |
| 775 | if ((origin == null) || (origin == -1)) { |
| 776 | // Missing Attribute Type Code ORIGIN |
| 777 | int type = BgpConstants.Update.Origin.TYPE; |
| 778 | actionsBgpUpdateMissingWellKnownAttribute(ctx, type); |
| 779 | String errorMsg = "Missing Well-known Attribute: ORIGIN"; |
| 780 | throw new BgpParseException(errorMsg); |
| 781 | } |
| 782 | if (asPath == null) { |
| 783 | // Missing Attribute Type Code AS_PATH |
| 784 | int type = BgpConstants.Update.AsPath.TYPE; |
| 785 | actionsBgpUpdateMissingWellKnownAttribute(ctx, type); |
| 786 | String errorMsg = "Missing Well-known Attribute: AS_PATH"; |
| 787 | throw new BgpParseException(errorMsg); |
| 788 | } |
| 789 | if (nextHop == null) { |
| 790 | // Missing Attribute Type Code NEXT_HOP |
| 791 | int type = BgpConstants.Update.NextHop.TYPE; |
| 792 | actionsBgpUpdateMissingWellKnownAttribute(ctx, type); |
| 793 | String errorMsg = "Missing Well-known Attribute: NEXT_HOP"; |
| 794 | throw new BgpParseException(errorMsg); |
| 795 | } |
| 796 | if (localPref == null) { |
| 797 | // Missing Attribute Type Code LOCAL_PREF |
| 798 | // NOTE: Required for iBGP |
| 799 | int type = BgpConstants.Update.LocalPref.TYPE; |
| 800 | actionsBgpUpdateMissingWellKnownAttribute(ctx, type); |
| 801 | String errorMsg = "Missing Well-known Attribute: LOCAL_PREF"; |
| 802 | throw new BgpParseException(errorMsg); |
| 803 | } |
| 804 | } |
| 805 | |
| 806 | /** |
| 807 | * Verifies the BGP UPDATE Attribute Flags. |
| 808 | * |
| 809 | * @param ctx the Channel Handler Context |
| 810 | * @param attrTypeCode the attribute type code |
| 811 | * @param attrLen the attribute length (in octets) |
| 812 | * @param attrFlags the attribute flags |
| 813 | * @param message the message to parse |
| 814 | * @throws BgpParseException |
| 815 | */ |
| 816 | private void verifyBgpUpdateAttributeFlags( |
| 817 | ChannelHandlerContext ctx, |
| 818 | int attrTypeCode, |
| 819 | int attrLen, |
| 820 | int attrFlags, |
| 821 | ChannelBuffer message) |
| 822 | throws BgpParseException { |
| 823 | |
| 824 | // |
| 825 | // Assign the Attribute Type Name and the Well-known flag |
| 826 | // |
| 827 | String typeName = "UNKNOWN"; |
| 828 | boolean isWellKnown = false; |
| 829 | switch (attrTypeCode) { |
| 830 | case BgpConstants.Update.Origin.TYPE: |
| 831 | isWellKnown = true; |
| 832 | typeName = "ORIGIN"; |
| 833 | break; |
| 834 | case BgpConstants.Update.AsPath.TYPE: |
| 835 | isWellKnown = true; |
| 836 | typeName = "AS_PATH"; |
| 837 | break; |
| 838 | case BgpConstants.Update.NextHop.TYPE: |
| 839 | isWellKnown = true; |
| 840 | typeName = "NEXT_HOP"; |
| 841 | break; |
| 842 | case BgpConstants.Update.MultiExitDisc.TYPE: |
| 843 | isWellKnown = false; |
| 844 | typeName = "MULTI_EXIT_DISC"; |
| 845 | break; |
| 846 | case BgpConstants.Update.LocalPref.TYPE: |
| 847 | isWellKnown = true; |
| 848 | typeName = "LOCAL_PREF"; |
| 849 | break; |
| 850 | case BgpConstants.Update.AtomicAggregate.TYPE: |
| 851 | isWellKnown = true; |
| 852 | typeName = "ATOMIC_AGGREGATE"; |
| 853 | break; |
| 854 | case BgpConstants.Update.Aggregator.TYPE: |
| 855 | isWellKnown = false; |
| 856 | typeName = "AGGREGATOR"; |
| 857 | break; |
| 858 | default: |
| 859 | isWellKnown = false; |
| 860 | typeName = "UNKNOWN(" + attrTypeCode + ")"; |
| 861 | break; |
| 862 | } |
| 863 | |
| 864 | // |
| 865 | // Verify the Attribute Flags |
| 866 | // |
| 867 | boolean optionalBit = ((0x80 & attrFlags) != 0); |
| 868 | boolean transitiveBit = ((0x40 & attrFlags) != 0); |
| 869 | boolean partialBit = ((0x20 & attrFlags) != 0); |
| 870 | if ((isWellKnown && optionalBit) || |
| 871 | (isWellKnown && (!transitiveBit)) || |
| 872 | (isWellKnown && partialBit) || |
| 873 | (optionalBit && (!transitiveBit) && partialBit)) { |
| 874 | // |
| 875 | // ERROR: The Optional bit cannot be set for Well-known attributes |
| 876 | // ERROR: The Transtive bit MUST be 1 for well-known attributes |
| 877 | // ERROR: The Partial bit MUST be 0 for well-known attributes |
| 878 | // ERROR: The Partial bit MUST be 0 for optional non-transitive |
| 879 | // attributes |
| 880 | // |
| 881 | actionsBgpUpdateAttributeFlagsError( |
| 882 | ctx, attrTypeCode, attrLen, attrFlags, message); |
| 883 | String errorMsg = "Attribute Flags Error for " + typeName + ": " + |
| 884 | attrFlags; |
| 885 | throw new BgpParseException(errorMsg); |
| 886 | } |
| 887 | } |
| 888 | |
| 889 | /** |
| 890 | * Parses BGP UPDATE Attribute Type ORIGIN. |
| 891 | * |
| 892 | * @param ctx the Channel Handler Context |
| 893 | * @param attrTypeCode the attribute type code |
| 894 | * @param attrLen the attribute length (in octets) |
| 895 | * @param attrFlags the attribute flags |
| 896 | * @param message the message to parse |
| 897 | * @return the parsed ORIGIN value |
| 898 | * @throws BgpParseException |
| 899 | */ |
| 900 | private short parseAttributeTypeOrigin( |
| 901 | ChannelHandlerContext ctx, |
| 902 | int attrTypeCode, |
| 903 | int attrLen, |
| 904 | int attrFlags, |
| 905 | ChannelBuffer message) |
| 906 | throws BgpParseException { |
| 907 | |
| 908 | // Check the Attribute Length |
| 909 | if (attrLen != BgpConstants.Update.Origin.LENGTH) { |
| 910 | // ERROR: Attribute Length Error |
| 911 | actionsBgpUpdateAttributeLengthError( |
| 912 | ctx, attrTypeCode, attrLen, attrFlags, message); |
| 913 | String errorMsg = "Attribute Length Error"; |
| 914 | throw new BgpParseException(errorMsg); |
| 915 | } |
| 916 | |
| 917 | message.markReaderIndex(); |
| 918 | short origin = message.readUnsignedByte(); |
| 919 | switch (origin) { |
| 920 | case BgpConstants.Update.Origin.IGP: |
| 921 | // FALLTHROUGH |
| 922 | case BgpConstants.Update.Origin.EGP: |
| 923 | // FALLTHROUGH |
| 924 | case BgpConstants.Update.Origin.INCOMPLETE: |
| 925 | break; |
| 926 | default: |
| 927 | // ERROR: Invalid ORIGIN Attribute |
| 928 | message.resetReaderIndex(); |
| 929 | actionsBgpUpdateInvalidOriginAttribute( |
| 930 | ctx, attrTypeCode, attrLen, attrFlags, message, origin); |
| 931 | String errorMsg = "Invalid ORIGIN Attribute: " + origin; |
| 932 | throw new BgpParseException(errorMsg); |
| 933 | } |
| 934 | |
| 935 | return origin; |
| 936 | } |
| 937 | |
| 938 | /** |
| 939 | * Parses BGP UPDATE Attribute AS Path. |
| 940 | * |
| 941 | * @param ctx the Channel Handler Context |
| 942 | * @param attrTypeCode the attribute type code |
| 943 | * @param attrLen the attribute length (in octets) |
| 944 | * @param attrFlags the attribute flags |
| 945 | * @param message the message to parse |
| 946 | * @return the parsed AS Path |
| 947 | * @throws BgpParseException |
| 948 | */ |
| 949 | private BgpRouteEntry.AsPath parseAttributeTypeAsPath( |
| 950 | ChannelHandlerContext ctx, |
| 951 | int attrTypeCode, |
| 952 | int attrLen, |
| 953 | int attrFlags, |
| 954 | ChannelBuffer message) |
| 955 | throws BgpParseException { |
| 956 | ArrayList<BgpRouteEntry.PathSegment> pathSegments = new ArrayList<>(); |
| 957 | |
| 958 | // |
| 959 | // Parse the message |
| 960 | // |
| 961 | while (attrLen > 0) { |
| 962 | if (attrLen < 2) { |
| 963 | // ERROR: Malformed AS_PATH |
| 964 | actionsBgpUpdateMalformedAsPath(ctx); |
| 965 | String errorMsg = "Malformed AS Path"; |
| 966 | throw new BgpParseException(errorMsg); |
| 967 | } |
| 968 | // Get the Path Segment Type and Length (in number of ASes) |
| 969 | short pathSegmentType = message.readUnsignedByte(); |
| 970 | short pathSegmentLength = message.readUnsignedByte(); |
| 971 | attrLen -= 2; |
| 972 | |
| 973 | // Verify the Path Segment Type |
| 974 | switch (pathSegmentType) { |
| 975 | case BgpConstants.Update.AsPath.AS_SET: |
| 976 | // FALLTHROUGH |
| 977 | case BgpConstants.Update.AsPath.AS_SEQUENCE: |
| 978 | break; |
| 979 | default: |
| 980 | // ERROR: Invalid Path Segment Type |
| 981 | // |
| 982 | // NOTE: The BGP Spec (RFC 4271) doesn't contain Error Subcode |
| 983 | // for "Invalid Path Segment Type", hence we return |
| 984 | // the error as "Malformed AS_PATH". |
| 985 | // |
| 986 | actionsBgpUpdateMalformedAsPath(ctx); |
| 987 | String errorMsg = |
| 988 | "Invalid AS Path Segment Type: " + pathSegmentType; |
| 989 | throw new BgpParseException(errorMsg); |
| 990 | } |
| 991 | |
| 992 | // Parse the AS numbers |
| 993 | if (2 * pathSegmentLength > attrLen) { |
| 994 | // ERROR: Malformed AS_PATH |
| 995 | actionsBgpUpdateMalformedAsPath(ctx); |
| 996 | String errorMsg = "Malformed AS Path"; |
| 997 | throw new BgpParseException(errorMsg); |
| 998 | } |
| 999 | attrLen -= (2 * pathSegmentLength); |
| 1000 | ArrayList<Long> segmentAsNumbers = new ArrayList<>(); |
| 1001 | while (pathSegmentLength-- > 0) { |
| 1002 | long asNumber = message.readUnsignedShort(); |
| 1003 | segmentAsNumbers.add(asNumber); |
| 1004 | } |
| 1005 | |
| 1006 | BgpRouteEntry.PathSegment pathSegment = |
| 1007 | new BgpRouteEntry.PathSegment((byte) pathSegmentType, |
| 1008 | segmentAsNumbers); |
| 1009 | pathSegments.add(pathSegment); |
| 1010 | } |
| 1011 | |
| 1012 | return new BgpRouteEntry.AsPath(pathSegments); |
| 1013 | } |
| 1014 | |
| 1015 | /** |
| 1016 | * Parses BGP UPDATE Attribute Type NEXT_HOP. |
| 1017 | * |
| 1018 | * @param ctx the Channel Handler Context |
| 1019 | * @param attrTypeCode the attribute type code |
| 1020 | * @param attrLen the attribute length (in octets) |
| 1021 | * @param attrFlags the attribute flags |
| 1022 | * @param message the message to parse |
| 1023 | * @return the parsed NEXT_HOP value |
| 1024 | * @throws BgpParseException |
| 1025 | */ |
| 1026 | private IpAddress parseAttributeTypeNextHop( |
| 1027 | ChannelHandlerContext ctx, |
| 1028 | int attrTypeCode, |
| 1029 | int attrLen, |
| 1030 | int attrFlags, |
| 1031 | ChannelBuffer message) |
| 1032 | throws BgpParseException { |
| 1033 | |
| 1034 | // Check the Attribute Length |
| 1035 | if (attrLen != BgpConstants.Update.NextHop.LENGTH) { |
| 1036 | // ERROR: Attribute Length Error |
| 1037 | actionsBgpUpdateAttributeLengthError( |
| 1038 | ctx, attrTypeCode, attrLen, attrFlags, message); |
| 1039 | String errorMsg = "Attribute Length Error"; |
| 1040 | throw new BgpParseException(errorMsg); |
| 1041 | } |
| 1042 | |
| 1043 | message.markReaderIndex(); |
| 1044 | long address = message.readUnsignedInt(); |
| 1045 | IpAddress nextHopAddress = IpAddress.valueOf((int) address); |
| 1046 | // |
| 1047 | // Check whether the NEXT_HOP IP address is semantically correct. |
| 1048 | // As per RFC 4271, Section 6.3: |
| 1049 | // |
| 1050 | // a) It MUST NOT be the IP address of the receiving speaker |
| 1051 | // b) In the case of an EBGP .... |
| 1052 | // |
| 1053 | // Here we check only (a), because (b) doesn't apply for us: all our |
| 1054 | // peers are iBGP. |
| 1055 | // |
| 1056 | if (nextHopAddress.equals(localIp4Address)) { |
| 1057 | // ERROR: Invalid NEXT_HOP Attribute |
| 1058 | message.resetReaderIndex(); |
| 1059 | actionsBgpUpdateInvalidNextHopAttribute( |
| 1060 | ctx, attrTypeCode, attrLen, attrFlags, message, |
| 1061 | nextHopAddress); |
| 1062 | String errorMsg = "Invalid NEXT_HOP Attribute: " + nextHopAddress; |
| 1063 | throw new BgpParseException(errorMsg); |
| 1064 | } |
| 1065 | |
| 1066 | return nextHopAddress; |
| 1067 | } |
| 1068 | |
| 1069 | /** |
| 1070 | * Parses BGP UPDATE Attribute Type MULTI_EXIT_DISC. |
| 1071 | * |
| 1072 | * @param ctx the Channel Handler Context |
| 1073 | * @param attrTypeCode the attribute type code |
| 1074 | * @param attrLen the attribute length (in octets) |
| 1075 | * @param attrFlags the attribute flags |
| 1076 | * @param message the message to parse |
| 1077 | * @return the parsed MULTI_EXIT_DISC value |
| 1078 | * @throws BgpParseException |
| 1079 | */ |
| 1080 | private long parseAttributeTypeMultiExitDisc( |
| 1081 | ChannelHandlerContext ctx, |
| 1082 | int attrTypeCode, |
| 1083 | int attrLen, |
| 1084 | int attrFlags, |
| 1085 | ChannelBuffer message) |
| 1086 | throws BgpParseException { |
| 1087 | |
| 1088 | // Check the Attribute Length |
| 1089 | if (attrLen != BgpConstants.Update.MultiExitDisc.LENGTH) { |
| 1090 | // ERROR: Attribute Length Error |
| 1091 | actionsBgpUpdateAttributeLengthError( |
| 1092 | ctx, attrTypeCode, attrLen, attrFlags, message); |
| 1093 | String errorMsg = "Attribute Length Error"; |
| 1094 | throw new BgpParseException(errorMsg); |
| 1095 | } |
| 1096 | |
| 1097 | long multiExitDisc = message.readUnsignedInt(); |
| 1098 | return multiExitDisc; |
| 1099 | } |
| 1100 | |
| 1101 | /** |
| 1102 | * Parses BGP UPDATE Attribute Type LOCAL_PREF. |
| 1103 | * |
| 1104 | * @param ctx the Channel Handler Context |
| 1105 | * @param attrTypeCode the attribute type code |
| 1106 | * @param attrLen the attribute length (in octets) |
| 1107 | * @param attrFlags the attribute flags |
| 1108 | * @param message the message to parse |
| 1109 | * @return the parsed LOCAL_PREF value |
| 1110 | * @throws BgpParseException |
| 1111 | */ |
| 1112 | private long parseAttributeTypeLocalPref( |
| 1113 | ChannelHandlerContext ctx, |
| 1114 | int attrTypeCode, |
| 1115 | int attrLen, |
| 1116 | int attrFlags, |
| 1117 | ChannelBuffer message) |
| 1118 | throws BgpParseException { |
| 1119 | |
| 1120 | // Check the Attribute Length |
| 1121 | if (attrLen != BgpConstants.Update.LocalPref.LENGTH) { |
| 1122 | // ERROR: Attribute Length Error |
| 1123 | actionsBgpUpdateAttributeLengthError( |
| 1124 | ctx, attrTypeCode, attrLen, attrFlags, message); |
| 1125 | String errorMsg = "Attribute Length Error"; |
| 1126 | throw new BgpParseException(errorMsg); |
| 1127 | } |
| 1128 | |
| 1129 | long localPref = message.readUnsignedInt(); |
| 1130 | return localPref; |
| 1131 | } |
| 1132 | |
| 1133 | /** |
| 1134 | * Parses BGP UPDATE Attribute Type ATOMIC_AGGREGATE. |
| 1135 | * |
| 1136 | * @param ctx the Channel Handler Context |
| 1137 | * @param attrTypeCode the attribute type code |
| 1138 | * @param attrLen the attribute length (in octets) |
| 1139 | * @param attrFlags the attribute flags |
| 1140 | * @param message the message to parse |
| 1141 | * @throws BgpParseException |
| 1142 | */ |
| 1143 | private void parseAttributeTypeAtomicAggregate( |
| 1144 | ChannelHandlerContext ctx, |
| 1145 | int attrTypeCode, |
| 1146 | int attrLen, |
| 1147 | int attrFlags, |
| 1148 | ChannelBuffer message) |
| 1149 | throws BgpParseException { |
| 1150 | |
| 1151 | // Check the Attribute Length |
| 1152 | if (attrLen != BgpConstants.Update.AtomicAggregate.LENGTH) { |
| 1153 | // ERROR: Attribute Length Error |
| 1154 | actionsBgpUpdateAttributeLengthError( |
| 1155 | ctx, attrTypeCode, attrLen, attrFlags, message); |
| 1156 | String errorMsg = "Attribute Length Error"; |
| 1157 | throw new BgpParseException(errorMsg); |
| 1158 | } |
| 1159 | |
| 1160 | // Nothing to do: this attribute is primarily informational |
| 1161 | } |
| 1162 | |
| 1163 | /** |
| 1164 | * Parses BGP UPDATE Attribute Type AGGREGATOR. |
| 1165 | * |
| 1166 | * @param ctx the Channel Handler Context |
| 1167 | * @param attrTypeCode the attribute type code |
| 1168 | * @param attrLen the attribute length (in octets) |
| 1169 | * @param attrFlags the attribute flags |
| 1170 | * @param message the message to parse |
| 1171 | * @return the parsed AGGREGATOR value: a tuple of <AS-Number, IP-Address> |
| 1172 | * @throws BgpParseException |
| 1173 | */ |
| 1174 | private Pair<Long, IpAddress> parseAttributeTypeAggregator( |
| 1175 | ChannelHandlerContext ctx, |
| 1176 | int attrTypeCode, |
| 1177 | int attrLen, |
| 1178 | int attrFlags, |
| 1179 | ChannelBuffer message) |
| 1180 | throws BgpParseException { |
| 1181 | |
| 1182 | // Check the Attribute Length |
| 1183 | if (attrLen != BgpConstants.Update.Aggregator.LENGTH) { |
| 1184 | // ERROR: Attribute Length Error |
| 1185 | actionsBgpUpdateAttributeLengthError( |
| 1186 | ctx, attrTypeCode, attrLen, attrFlags, message); |
| 1187 | String errorMsg = "Attribute Length Error"; |
| 1188 | throw new BgpParseException(errorMsg); |
| 1189 | } |
| 1190 | |
| 1191 | // The AGGREGATOR AS number |
| 1192 | long aggregatorAsNumber = message.readUnsignedShort(); |
| 1193 | // The AGGREGATOR IP address |
| 1194 | long aggregatorAddress = message.readUnsignedInt(); |
| 1195 | IpAddress aggregatorIpAddress = |
| 1196 | IpAddress.valueOf((int) aggregatorAddress); |
| 1197 | |
| 1198 | Pair<Long, IpAddress> aggregator = Pair.of(aggregatorAsNumber, |
| 1199 | aggregatorIpAddress); |
| 1200 | return aggregator; |
| 1201 | } |
| 1202 | |
| 1203 | /** |
| 1204 | * Parses a message that contains encoded IPv4 network prefixes. |
| 1205 | * <p> |
| 1206 | * The IPv4 prefixes are encoded in the form: |
| 1207 | * <Length, Prefix> where Length is the length in bits of the IPv4 prefix, |
| 1208 | * and Prefix is the IPv4 prefix (padded with trailing bits to the end |
| 1209 | * of an octet). |
| 1210 | * |
| 1211 | * @param totalLength the total length of the data to parse |
| 1212 | * @param message the message with data to parse |
| 1213 | * @return a collection of parsed IPv4 network prefixes |
| 1214 | * @throws BgpParseException |
| 1215 | */ |
| 1216 | private Collection<IpPrefix> parsePackedPrefixes(int totalLength, |
| 1217 | ChannelBuffer message) |
| 1218 | throws BgpParseException { |
| 1219 | Collection<IpPrefix> result = new ArrayList<>(); |
| 1220 | |
| 1221 | if (totalLength == 0) { |
| 1222 | return result; |
| 1223 | } |
| 1224 | |
| 1225 | // Parse the data |
| 1226 | int dataEnd = message.readerIndex() + totalLength; |
| 1227 | while (message.readerIndex() < dataEnd) { |
| 1228 | int prefixBitlen = message.readUnsignedByte(); |
| 1229 | int prefixBytelen = (prefixBitlen + 7) / 8; // Round-up |
| 1230 | if (message.readerIndex() + prefixBytelen > dataEnd) { |
| 1231 | String errorMsg = "Malformed Network Prefixes"; |
| 1232 | throw new BgpParseException(errorMsg); |
| 1233 | } |
| 1234 | |
| 1235 | long address = 0; |
| 1236 | long extraShift = (4 - prefixBytelen) * 8; |
| 1237 | while (prefixBytelen > 0) { |
| 1238 | address <<= 8; |
| 1239 | address |= message.readUnsignedByte(); |
| 1240 | prefixBytelen--; |
| 1241 | } |
| 1242 | address <<= extraShift; |
| 1243 | IpPrefix prefix = |
Jonathan Hart | bcae7bd | 2014-10-16 10:24:41 -0700 | [diff] [blame] | 1244 | IpPrefix.valueOf(IpAddress.valueOf((int) address).toInt(), |
Jonathan Hart | ab63aac | 2014-10-16 08:52:55 -0700 | [diff] [blame] | 1245 | (short) prefixBitlen); |
| 1246 | result.add(prefix); |
| 1247 | } |
| 1248 | |
| 1249 | return result; |
| 1250 | } |
| 1251 | |
| 1252 | /** |
| 1253 | * Applies the appropriate actions after detecting BGP UPDATE |
| 1254 | * Invalid Network Field Error: send NOTIFICATION and close the channel. |
| 1255 | * |
| 1256 | * @param ctx the Channel Handler Context |
| 1257 | */ |
| 1258 | private void actionsBgpUpdateInvalidNetworkField( |
| 1259 | ChannelHandlerContext ctx) { |
| 1260 | log.debug("BGP RX UPDATE Error from {}: Invalid Network Field", |
| 1261 | remoteAddress); |
| 1262 | |
| 1263 | // |
| 1264 | // ERROR: Invalid Network Field |
| 1265 | // |
| 1266 | // Send NOTIFICATION and close the connection |
| 1267 | int errorCode = UpdateMessageError.ERROR_CODE; |
| 1268 | int errorSubcode = UpdateMessageError.INVALID_NETWORK_FIELD; |
| 1269 | ChannelBuffer txMessage = |
| 1270 | prepareBgpNotification(errorCode, errorSubcode, null); |
| 1271 | ctx.getChannel().write(txMessage); |
| 1272 | closeChannel(ctx); |
| 1273 | } |
| 1274 | |
| 1275 | /** |
| 1276 | * Applies the appropriate actions after detecting BGP UPDATE |
| 1277 | * Malformed Attribute List Error: send NOTIFICATION and close the channel. |
| 1278 | * |
| 1279 | * @param ctx the Channel Handler Context |
| 1280 | */ |
| 1281 | private void actionsBgpUpdateMalformedAttributeList( |
| 1282 | ChannelHandlerContext ctx) { |
| 1283 | log.debug("BGP RX UPDATE Error from {}: Malformed Attribute List", |
| 1284 | remoteAddress); |
| 1285 | |
| 1286 | // |
| 1287 | // ERROR: Malformed Attribute List |
| 1288 | // |
| 1289 | // Send NOTIFICATION and close the connection |
| 1290 | int errorCode = UpdateMessageError.ERROR_CODE; |
| 1291 | int errorSubcode = UpdateMessageError.MALFORMED_ATTRIBUTE_LIST; |
| 1292 | ChannelBuffer txMessage = |
| 1293 | prepareBgpNotification(errorCode, errorSubcode, null); |
| 1294 | ctx.getChannel().write(txMessage); |
| 1295 | closeChannel(ctx); |
| 1296 | } |
| 1297 | |
| 1298 | /** |
| 1299 | * Applies the appropriate actions after detecting BGP UPDATE |
| 1300 | * Missing Well-known Attribute Error: send NOTIFICATION and close the |
| 1301 | * channel. |
| 1302 | * |
| 1303 | * @param ctx the Channel Handler Context |
| 1304 | * @param missingAttrTypeCode the missing attribute type code |
| 1305 | */ |
| 1306 | private void actionsBgpUpdateMissingWellKnownAttribute( |
| 1307 | ChannelHandlerContext ctx, |
| 1308 | int missingAttrTypeCode) { |
| 1309 | log.debug("BGP RX UPDATE Error from {}: Missing Well-known Attribute: {}", |
| 1310 | remoteAddress, missingAttrTypeCode); |
| 1311 | |
| 1312 | // |
| 1313 | // ERROR: Missing Well-known Attribute |
| 1314 | // |
| 1315 | // Send NOTIFICATION and close the connection |
| 1316 | int errorCode = UpdateMessageError.ERROR_CODE; |
| 1317 | int errorSubcode = UpdateMessageError.MISSING_WELL_KNOWN_ATTRIBUTE; |
| 1318 | ChannelBuffer data = ChannelBuffers.buffer(1); |
| 1319 | data.writeByte(missingAttrTypeCode); |
| 1320 | ChannelBuffer txMessage = |
| 1321 | prepareBgpNotification(errorCode, errorSubcode, data); |
| 1322 | ctx.getChannel().write(txMessage); |
| 1323 | closeChannel(ctx); |
| 1324 | } |
| 1325 | |
| 1326 | /** |
| 1327 | * Applies the appropriate actions after detecting BGP UPDATE |
| 1328 | * Invalid ORIGIN Attribute Error: send NOTIFICATION and close the channel. |
| 1329 | * |
| 1330 | * @param ctx the Channel Handler Context |
| 1331 | * @param attrTypeCode the attribute type code |
| 1332 | * @param attrLen the attribute length (in octets) |
| 1333 | * @param attrFlags the attribute flags |
| 1334 | * @param message the message with the data |
| 1335 | * @param origin the ORIGIN attribute value |
| 1336 | */ |
| 1337 | private void actionsBgpUpdateInvalidOriginAttribute( |
| 1338 | ChannelHandlerContext ctx, |
| 1339 | int attrTypeCode, |
| 1340 | int attrLen, |
| 1341 | int attrFlags, |
| 1342 | ChannelBuffer message, |
| 1343 | short origin) { |
| 1344 | log.debug("BGP RX UPDATE Error from {}: Invalid ORIGIN Attribute", |
| 1345 | remoteAddress); |
| 1346 | |
| 1347 | // |
| 1348 | // ERROR: Invalid ORIGIN Attribute |
| 1349 | // |
| 1350 | // Send NOTIFICATION and close the connection |
| 1351 | int errorCode = UpdateMessageError.ERROR_CODE; |
| 1352 | int errorSubcode = UpdateMessageError.INVALID_ORIGIN_ATTRIBUTE; |
| 1353 | ChannelBuffer data = |
| 1354 | prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| 1355 | attrFlags, message); |
| 1356 | ChannelBuffer txMessage = |
| 1357 | prepareBgpNotification(errorCode, errorSubcode, data); |
| 1358 | ctx.getChannel().write(txMessage); |
| 1359 | closeChannel(ctx); |
| 1360 | } |
| 1361 | |
| 1362 | /** |
| 1363 | * Applies the appropriate actions after detecting BGP UPDATE |
| 1364 | * Attribute Flags Error: send NOTIFICATION and close the channel. |
| 1365 | * |
| 1366 | * @param ctx the Channel Handler Context |
| 1367 | * @param attrTypeCode the attribute type code |
| 1368 | * @param attrLen the attribute length (in octets) |
| 1369 | * @param attrFlags the attribute flags |
| 1370 | * @param message the message with the data |
| 1371 | */ |
| 1372 | private void actionsBgpUpdateAttributeFlagsError( |
| 1373 | ChannelHandlerContext ctx, |
| 1374 | int attrTypeCode, |
| 1375 | int attrLen, |
| 1376 | int attrFlags, |
| 1377 | ChannelBuffer message) { |
| 1378 | log.debug("BGP RX UPDATE Error from {}: Attribute Flags Error", |
| 1379 | remoteAddress); |
| 1380 | |
| 1381 | // |
| 1382 | // ERROR: Attribute Flags Error |
| 1383 | // |
| 1384 | // Send NOTIFICATION and close the connection |
| 1385 | int errorCode = UpdateMessageError.ERROR_CODE; |
| 1386 | int errorSubcode = UpdateMessageError.ATTRIBUTE_FLAGS_ERROR; |
| 1387 | ChannelBuffer data = |
| 1388 | prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| 1389 | attrFlags, message); |
| 1390 | ChannelBuffer txMessage = |
| 1391 | prepareBgpNotification(errorCode, errorSubcode, data); |
| 1392 | ctx.getChannel().write(txMessage); |
| 1393 | closeChannel(ctx); |
| 1394 | } |
| 1395 | |
| 1396 | /** |
| 1397 | * Applies the appropriate actions after detecting BGP UPDATE |
| 1398 | * Invalid NEXT_HOP Attribute Error: send NOTIFICATION and close the |
| 1399 | * channel. |
| 1400 | * |
| 1401 | * @param ctx the Channel Handler Context |
| 1402 | * @param attrTypeCode the attribute type code |
| 1403 | * @param attrLen the attribute length (in octets) |
| 1404 | * @param attrFlags the attribute flags |
| 1405 | * @param message the message with the data |
| 1406 | * @param nextHop the NEXT_HOP attribute value |
| 1407 | */ |
| 1408 | private void actionsBgpUpdateInvalidNextHopAttribute( |
| 1409 | ChannelHandlerContext ctx, |
| 1410 | int attrTypeCode, |
| 1411 | int attrLen, |
| 1412 | int attrFlags, |
| 1413 | ChannelBuffer message, |
| 1414 | IpAddress nextHop) { |
| 1415 | log.debug("BGP RX UPDATE Error from {}: Invalid NEXT_HOP Attribute {}", |
| 1416 | remoteAddress, nextHop); |
| 1417 | |
| 1418 | // |
| 1419 | // ERROR: Invalid ORIGIN Attribute |
| 1420 | // |
| 1421 | // Send NOTIFICATION and close the connection |
| 1422 | int errorCode = UpdateMessageError.ERROR_CODE; |
| 1423 | int errorSubcode = UpdateMessageError.INVALID_NEXT_HOP_ATTRIBUTE; |
| 1424 | ChannelBuffer data = |
| 1425 | prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| 1426 | attrFlags, message); |
| 1427 | ChannelBuffer txMessage = |
| 1428 | prepareBgpNotification(errorCode, errorSubcode, data); |
| 1429 | ctx.getChannel().write(txMessage); |
| 1430 | closeChannel(ctx); |
| 1431 | } |
| 1432 | |
| 1433 | /** |
| 1434 | * Applies the appropriate actions after detecting BGP UPDATE |
| 1435 | * Unrecognized Well-known Attribute Error: send NOTIFICATION and close |
| 1436 | * the channel. |
| 1437 | * |
| 1438 | * @param ctx the Channel Handler Context |
| 1439 | * @param attrTypeCode the attribute type code |
| 1440 | * @param attrLen the attribute length (in octets) |
| 1441 | * @param attrFlags the attribute flags |
| 1442 | * @param message the message with the data |
| 1443 | */ |
| 1444 | private void actionsBgpUpdateUnrecognizedWellKnownAttribute( |
| 1445 | ChannelHandlerContext ctx, |
| 1446 | int attrTypeCode, |
| 1447 | int attrLen, |
| 1448 | int attrFlags, |
| 1449 | ChannelBuffer message) { |
| 1450 | log.debug("BGP RX UPDATE Error from {}: " + |
| 1451 | "Unrecognized Well-known Attribute Error: {}", |
| 1452 | remoteAddress, attrTypeCode); |
| 1453 | |
| 1454 | // |
| 1455 | // ERROR: Unrecognized Well-known Attribute |
| 1456 | // |
| 1457 | // Send NOTIFICATION and close the connection |
| 1458 | int errorCode = UpdateMessageError.ERROR_CODE; |
| 1459 | int errorSubcode = |
| 1460 | UpdateMessageError.UNRECOGNIZED_WELL_KNOWN_ATTRIBUTE; |
| 1461 | ChannelBuffer data = |
| 1462 | prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| 1463 | attrFlags, message); |
| 1464 | ChannelBuffer txMessage = |
| 1465 | prepareBgpNotification(errorCode, errorSubcode, data); |
| 1466 | ctx.getChannel().write(txMessage); |
| 1467 | closeChannel(ctx); |
| 1468 | } |
| 1469 | |
| 1470 | /** |
| 1471 | * Applies the appropriate actions after detecting BGP UPDATE |
| 1472 | * Attribute Length Error: send NOTIFICATION and close the channel. |
| 1473 | * |
| 1474 | * @param ctx the Channel Handler Context |
| 1475 | * @param attrTypeCode the attribute type code |
| 1476 | * @param attrLen the attribute length (in octets) |
| 1477 | * @param attrFlags the attribute flags |
| 1478 | * @param message the message with the data |
| 1479 | */ |
| 1480 | private void actionsBgpUpdateAttributeLengthError( |
| 1481 | ChannelHandlerContext ctx, |
| 1482 | int attrTypeCode, |
| 1483 | int attrLen, |
| 1484 | int attrFlags, |
| 1485 | ChannelBuffer message) { |
| 1486 | log.debug("BGP RX UPDATE Error from {}: Attribute Length Error", |
| 1487 | remoteAddress); |
| 1488 | |
| 1489 | // |
| 1490 | // ERROR: Attribute Length Error |
| 1491 | // |
| 1492 | // Send NOTIFICATION and close the connection |
| 1493 | int errorCode = UpdateMessageError.ERROR_CODE; |
| 1494 | int errorSubcode = UpdateMessageError.ATTRIBUTE_LENGTH_ERROR; |
| 1495 | ChannelBuffer data = |
| 1496 | prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| 1497 | attrFlags, message); |
| 1498 | ChannelBuffer txMessage = |
| 1499 | prepareBgpNotification(errorCode, errorSubcode, data); |
| 1500 | ctx.getChannel().write(txMessage); |
| 1501 | closeChannel(ctx); |
| 1502 | } |
| 1503 | |
| 1504 | /** |
| 1505 | * Applies the appropriate actions after detecting BGP UPDATE |
| 1506 | * Malformed AS_PATH Error: send NOTIFICATION and close the channel. |
| 1507 | * |
| 1508 | * @param ctx the Channel Handler Context |
| 1509 | */ |
| 1510 | private void actionsBgpUpdateMalformedAsPath( |
| 1511 | ChannelHandlerContext ctx) { |
| 1512 | log.debug("BGP RX UPDATE Error from {}: Malformed AS Path", |
| 1513 | remoteAddress); |
| 1514 | |
| 1515 | // |
| 1516 | // ERROR: Malformed AS_PATH |
| 1517 | // |
| 1518 | // Send NOTIFICATION and close the connection |
| 1519 | int errorCode = UpdateMessageError.ERROR_CODE; |
| 1520 | int errorSubcode = UpdateMessageError.MALFORMED_AS_PATH; |
| 1521 | ChannelBuffer txMessage = |
| 1522 | prepareBgpNotification(errorCode, errorSubcode, null); |
| 1523 | ctx.getChannel().write(txMessage); |
| 1524 | closeChannel(ctx); |
| 1525 | } |
| 1526 | |
| 1527 | /** |
| 1528 | * Processes BGP NOTIFICATION message. |
| 1529 | * |
| 1530 | * @param ctx the Channel Handler Context |
| 1531 | * @param message the message to process |
| 1532 | */ |
| 1533 | void processBgpNotification(ChannelHandlerContext ctx, |
| 1534 | ChannelBuffer message) { |
| 1535 | int minLength = |
| 1536 | BgpConstants.BGP_NOTIFICATION_MIN_LENGTH - BgpConstants.BGP_HEADER_LENGTH; |
| 1537 | if (message.readableBytes() < minLength) { |
| 1538 | log.debug("BGP RX NOTIFICATION Error from {}: " + |
| 1539 | "Message length {} too short. Must be at least {}", |
| 1540 | remoteAddress, message.readableBytes(), minLength); |
| 1541 | // |
| 1542 | // ERROR: Bad Message Length |
| 1543 | // |
| 1544 | // NOTE: We do NOT send NOTIFICATION in response to a notification |
| 1545 | return; |
| 1546 | } |
| 1547 | |
| 1548 | // |
| 1549 | // Parse the NOTIFICATION message |
| 1550 | // |
| 1551 | int errorCode = message.readUnsignedByte(); |
| 1552 | int errorSubcode = message.readUnsignedByte(); |
| 1553 | int dataLength = message.readableBytes(); |
| 1554 | |
| 1555 | log.debug("BGP RX NOTIFICATION message from {}: Error Code {} " + |
| 1556 | "Error Subcode {} Data Length {}", |
| 1557 | remoteAddress, errorCode, errorSubcode, dataLength); |
| 1558 | |
| 1559 | // |
| 1560 | // NOTE: If the peer sent a NOTIFICATION, we leave it to the peer to |
| 1561 | // close the connection. |
| 1562 | // |
| 1563 | |
| 1564 | // Start the Session Timeout timer |
| 1565 | restartSessionTimeoutTimer(ctx); |
| 1566 | } |
| 1567 | |
| 1568 | /** |
| 1569 | * Processes BGP KEEPALIVE message. |
| 1570 | * |
| 1571 | * @param ctx the Channel Handler Context |
| 1572 | * @param message the message to process |
| 1573 | */ |
| 1574 | void processBgpKeepalive(ChannelHandlerContext ctx, |
| 1575 | ChannelBuffer message) { |
| 1576 | if (message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH != |
| 1577 | BgpConstants.BGP_KEEPALIVE_EXPECTED_LENGTH) { |
| 1578 | log.debug("BGP RX KEEPALIVE Error from {}: " + |
| 1579 | "Invalid total message length {}. Expected {}", |
| 1580 | remoteAddress, |
| 1581 | message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH, |
| 1582 | BgpConstants.BGP_KEEPALIVE_EXPECTED_LENGTH); |
| 1583 | // |
| 1584 | // ERROR: Bad Message Length |
| 1585 | // |
| 1586 | // Send NOTIFICATION and close the connection |
| 1587 | ChannelBuffer txMessage = prepareBgpNotificationBadMessageLength( |
| 1588 | message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH); |
| 1589 | ctx.getChannel().write(txMessage); |
| 1590 | closeChannel(ctx); |
| 1591 | return; |
| 1592 | } |
| 1593 | |
| 1594 | // |
| 1595 | // Parse the KEEPALIVE message: nothing to do |
| 1596 | // |
| 1597 | log.debug("BGP RX KEEPALIVE message from {}", remoteAddress); |
| 1598 | |
| 1599 | // Start the Session Timeout timer |
| 1600 | restartSessionTimeoutTimer(ctx); |
| 1601 | } |
| 1602 | |
| 1603 | /** |
| 1604 | * Prepares BGP OPEN message. |
| 1605 | * |
| 1606 | * @return the message to transmit (BGP header included) |
| 1607 | */ |
| 1608 | private ChannelBuffer prepareBgpOpen() { |
| 1609 | ChannelBuffer message = |
| 1610 | ChannelBuffers.buffer(BgpConstants.BGP_MESSAGE_MAX_LENGTH); |
| 1611 | |
| 1612 | // |
| 1613 | // Prepare the OPEN message payload |
| 1614 | // |
| 1615 | message.writeByte(localBgpVersion); |
| 1616 | message.writeShort((int) localAs); |
| 1617 | message.writeShort((int) localHoldtime); |
Jonathan Hart | bcae7bd | 2014-10-16 10:24:41 -0700 | [diff] [blame] | 1618 | message.writeInt(bgpSessionManager.getMyBgpId().toInt()); |
Jonathan Hart | ab63aac | 2014-10-16 08:52:55 -0700 | [diff] [blame] | 1619 | message.writeByte(0); // No Optional Parameters |
| 1620 | return prepareBgpMessage(BgpConstants.BGP_TYPE_OPEN, message); |
| 1621 | } |
| 1622 | |
| 1623 | /** |
| 1624 | * Prepares BGP KEEPALIVE message. |
| 1625 | * |
| 1626 | * @return the message to transmit (BGP header included) |
| 1627 | */ |
| 1628 | private ChannelBuffer prepareBgpKeepalive() { |
| 1629 | ChannelBuffer message = |
| 1630 | ChannelBuffers.buffer(BgpConstants.BGP_MESSAGE_MAX_LENGTH); |
| 1631 | |
| 1632 | // |
| 1633 | // Prepare the KEEPALIVE message payload: nothing to do |
| 1634 | // |
| 1635 | return prepareBgpMessage(BgpConstants.BGP_TYPE_KEEPALIVE, message); |
| 1636 | } |
| 1637 | |
| 1638 | /** |
| 1639 | * Prepares BGP NOTIFICATION message. |
| 1640 | * |
| 1641 | * @param errorCode the BGP NOTIFICATION Error Code |
| 1642 | * @param errorSubcode the BGP NOTIFICATION Error Subcode if applicable, |
| 1643 | * otherwise BgpConstants.Notifications.ERROR_SUBCODE_UNSPECIFIC |
| 1644 | * @param payload the BGP NOTIFICATION Data if applicable, otherwise null |
| 1645 | * @return the message to transmit (BGP header included) |
| 1646 | */ |
| 1647 | ChannelBuffer prepareBgpNotification(int errorCode, int errorSubcode, |
| 1648 | ChannelBuffer data) { |
| 1649 | ChannelBuffer message = |
| 1650 | ChannelBuffers.buffer(BgpConstants.BGP_MESSAGE_MAX_LENGTH); |
| 1651 | |
| 1652 | // |
| 1653 | // Prepare the NOTIFICATION message payload |
| 1654 | // |
| 1655 | message.writeByte(errorCode); |
| 1656 | message.writeByte(errorSubcode); |
| 1657 | if (data != null) { |
| 1658 | message.writeBytes(data); |
| 1659 | } |
| 1660 | return prepareBgpMessage(BgpConstants.BGP_TYPE_NOTIFICATION, message); |
| 1661 | } |
| 1662 | |
| 1663 | /** |
| 1664 | * Prepares BGP NOTIFICATION message: Bad Message Length. |
| 1665 | * |
| 1666 | * @param length the erroneous Length field |
| 1667 | * @return the message to transmit (BGP header included) |
| 1668 | */ |
| 1669 | ChannelBuffer prepareBgpNotificationBadMessageLength(int length) { |
| 1670 | int errorCode = MessageHeaderError.ERROR_CODE; |
| 1671 | int errorSubcode = MessageHeaderError.BAD_MESSAGE_LENGTH; |
| 1672 | ChannelBuffer data = ChannelBuffers.buffer(2); |
| 1673 | data.writeShort(length); |
| 1674 | |
| 1675 | return prepareBgpNotification(errorCode, errorSubcode, data); |
| 1676 | } |
| 1677 | |
| 1678 | /** |
| 1679 | * Prepares BGP UPDATE Notification data payload. |
| 1680 | * |
| 1681 | * @param attrTypeCode the attribute type code |
| 1682 | * @param attrLen the attribute length (in octets) |
| 1683 | * @param attrFlags the attribute flags |
| 1684 | * @param message the message with the data |
| 1685 | * @return the buffer with the data payload for the BGP UPDATE Notification |
| 1686 | */ |
| 1687 | private ChannelBuffer prepareBgpUpdateNotificationDataPayload( |
| 1688 | int attrTypeCode, |
| 1689 | int attrLen, |
| 1690 | int attrFlags, |
| 1691 | ChannelBuffer message) { |
| 1692 | // Compute the attribute length field octets |
| 1693 | boolean extendedLengthBit = ((0x10 & attrFlags) != 0); |
| 1694 | int attrLenOctets = 1; |
| 1695 | if (extendedLengthBit) { |
| 1696 | attrLenOctets = 2; |
| 1697 | } |
| 1698 | ChannelBuffer data = |
| 1699 | ChannelBuffers.buffer(attrLen + attrLenOctets + 1); |
| 1700 | data.writeByte(attrTypeCode); |
| 1701 | if (extendedLengthBit) { |
| 1702 | data.writeShort(attrLen); |
| 1703 | } else { |
| 1704 | data.writeByte(attrLen); |
| 1705 | } |
| 1706 | data.writeBytes(message, attrLen); |
| 1707 | return data; |
| 1708 | } |
| 1709 | |
| 1710 | /** |
| 1711 | * Prepares BGP message. |
| 1712 | * |
| 1713 | * @param type the BGP message type |
| 1714 | * @param payload the message payload to transmit (BGP header excluded) |
| 1715 | * @return the message to transmit (BGP header included) |
| 1716 | */ |
| 1717 | private ChannelBuffer prepareBgpMessage(int type, ChannelBuffer payload) { |
| 1718 | ChannelBuffer message = |
| 1719 | ChannelBuffers.buffer(BgpConstants.BGP_HEADER_LENGTH + |
| 1720 | payload.readableBytes()); |
| 1721 | |
| 1722 | // Write the marker |
| 1723 | for (int i = 0; i < BgpConstants.BGP_HEADER_MARKER_LENGTH; i++) { |
| 1724 | message.writeByte(0xff); |
| 1725 | } |
| 1726 | |
| 1727 | // Write the rest of the BGP header |
| 1728 | message.writeShort(BgpConstants.BGP_HEADER_LENGTH + |
| 1729 | payload.readableBytes()); |
| 1730 | message.writeByte(type); |
| 1731 | |
| 1732 | // Write the payload |
| 1733 | message.writeBytes(payload); |
| 1734 | return message; |
| 1735 | } |
| 1736 | |
| 1737 | /** |
| 1738 | * Restarts the BGP KeepaliveTimer. |
| 1739 | */ |
| 1740 | private void restartKeepaliveTimer(ChannelHandlerContext ctx) { |
| 1741 | if (localKeepaliveInterval == 0) { |
| 1742 | return; // Nothing to do |
| 1743 | } |
| 1744 | keepaliveTimeout = timer.newTimeout(new TransmitKeepaliveTask(ctx), |
| 1745 | localKeepaliveInterval, |
| 1746 | TimeUnit.SECONDS); |
| 1747 | } |
| 1748 | |
| 1749 | /** |
| 1750 | * Task class for transmitting KEEPALIVE messages. |
| 1751 | */ |
| 1752 | private final class TransmitKeepaliveTask implements TimerTask { |
| 1753 | private final ChannelHandlerContext ctx; |
| 1754 | |
| 1755 | /** |
| 1756 | * Constructor for given Channel Handler Context. |
| 1757 | * |
| 1758 | * @param ctx the Channel Handler Context to use |
| 1759 | */ |
| 1760 | TransmitKeepaliveTask(ChannelHandlerContext ctx) { |
| 1761 | this.ctx = ctx; |
| 1762 | } |
| 1763 | |
| 1764 | @Override |
| 1765 | public void run(Timeout timeout) throws Exception { |
| 1766 | if (timeout.isCancelled()) { |
| 1767 | return; |
| 1768 | } |
| 1769 | if (!ctx.getChannel().isOpen()) { |
| 1770 | return; |
| 1771 | } |
| 1772 | |
| 1773 | // Transmit the KEEPALIVE |
| 1774 | ChannelBuffer txMessage = prepareBgpKeepalive(); |
| 1775 | ctx.getChannel().write(txMessage); |
| 1776 | |
| 1777 | // Restart the KEEPALIVE timer |
| 1778 | restartKeepaliveTimer(ctx); |
| 1779 | } |
| 1780 | } |
| 1781 | |
| 1782 | /** |
| 1783 | * Restarts the BGP Session Timeout Timer. |
| 1784 | */ |
| 1785 | private void restartSessionTimeoutTimer(ChannelHandlerContext ctx) { |
| 1786 | if (remoteHoldtime == 0) { |
| 1787 | return; // Nothing to do |
| 1788 | } |
| 1789 | if (sessionTimeout != null) { |
| 1790 | sessionTimeout.cancel(); |
| 1791 | } |
| 1792 | sessionTimeout = timer.newTimeout(new SessionTimeoutTask(ctx), |
| 1793 | remoteHoldtime, |
| 1794 | TimeUnit.SECONDS); |
| 1795 | } |
| 1796 | |
| 1797 | /** |
| 1798 | * Task class for BGP Session timeout. |
| 1799 | */ |
| 1800 | private final class SessionTimeoutTask implements TimerTask { |
| 1801 | private final ChannelHandlerContext ctx; |
| 1802 | |
| 1803 | /** |
| 1804 | * Constructor for given Channel Handler Context. |
| 1805 | * |
| 1806 | * @param ctx the Channel Handler Context to use |
| 1807 | */ |
| 1808 | SessionTimeoutTask(ChannelHandlerContext ctx) { |
| 1809 | this.ctx = ctx; |
| 1810 | } |
| 1811 | |
| 1812 | @Override |
| 1813 | public void run(Timeout timeout) throws Exception { |
| 1814 | if (timeout.isCancelled()) { |
| 1815 | return; |
| 1816 | } |
| 1817 | if (!ctx.getChannel().isOpen()) { |
| 1818 | return; |
| 1819 | } |
| 1820 | |
| 1821 | log.debug("BGP Session Timeout: peer {}", remoteAddress); |
| 1822 | // |
| 1823 | // ERROR: Invalid Optional Parameter Length field: Unspecific |
| 1824 | // |
| 1825 | // Send NOTIFICATION and close the connection |
| 1826 | int errorCode = HoldTimerExpired.ERROR_CODE; |
| 1827 | int errorSubcode = Notifications.ERROR_SUBCODE_UNSPECIFIC; |
| 1828 | ChannelBuffer txMessage = |
| 1829 | prepareBgpNotification(errorCode, errorSubcode, null); |
| 1830 | ctx.getChannel().write(txMessage); |
| 1831 | closeChannel(ctx); |
| 1832 | } |
| 1833 | } |
| 1834 | |
| 1835 | /** |
| 1836 | * An exception indicating a parsing error of the BGP message. |
| 1837 | */ |
| 1838 | private static class BgpParseException extends Exception { |
| 1839 | /** |
| 1840 | * Default constructor. |
| 1841 | */ |
| 1842 | public BgpParseException() { |
| 1843 | super(); |
| 1844 | } |
| 1845 | |
| 1846 | /** |
| 1847 | * Constructor for a specific exception details message. |
| 1848 | * |
| 1849 | * @param message the message with the exception details |
| 1850 | */ |
| 1851 | public BgpParseException(String message) { |
| 1852 | super(message); |
| 1853 | } |
| 1854 | } |
| 1855 | } |