| /* |
| * Copyright 2014 Open Networking Laboratory |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.onosproject.sdnip.bgp; |
| |
| import java.net.InetAddress; |
| import java.net.InetSocketAddress; |
| import java.net.SocketAddress; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.TimeUnit; |
| |
| import org.apache.commons.lang3.tuple.Pair; |
| import org.jboss.netty.buffer.ChannelBuffer; |
| import org.jboss.netty.buffer.ChannelBuffers; |
| import org.jboss.netty.channel.ChannelHandlerContext; |
| import org.jboss.netty.channel.ChannelStateEvent; |
| import org.jboss.netty.channel.SimpleChannelHandler; |
| import org.jboss.netty.util.HashedWheelTimer; |
| import org.jboss.netty.util.Timeout; |
| import org.jboss.netty.util.Timer; |
| import org.jboss.netty.util.TimerTask; |
| import org.onosproject.sdnip.bgp.BgpConstants.Notifications; |
| import org.onosproject.sdnip.bgp.BgpConstants.Notifications.HoldTimerExpired; |
| import org.onosproject.sdnip.bgp.BgpConstants.Notifications.MessageHeaderError; |
| import org.onosproject.sdnip.bgp.BgpConstants.Notifications.OpenMessageError; |
| import org.onosproject.sdnip.bgp.BgpConstants.Notifications.UpdateMessageError; |
| import org.onlab.packet.Ip4Address; |
| import org.onlab.packet.Ip4Prefix; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Class for handling the BGP peer sessions. |
| * There is one instance per each BGP peer session. |
| */ |
| public class BgpSession extends SimpleChannelHandler { |
| private static final Logger log = |
| LoggerFactory.getLogger(BgpSession.class); |
| |
| private final BgpSessionManager bgpSessionManager; |
| |
| // Local flag to indicate the session is closed. |
| // It is used to avoid the Netty's asynchronous closing of a channel. |
| private boolean isClosed = false; |
| |
| private SocketAddress remoteAddress; // Peer IP addr/port |
| private Ip4Address remoteIp4Address; // Peer IPv4 address |
| private int remoteBgpVersion; // 1 octet |
| private long remoteAs; // 2 octets |
| private long remoteHoldtime; // 2 octets |
| private Ip4Address remoteBgpId; // 4 octets -> IPv4 address |
| // |
| private SocketAddress localAddress; // Local IP addr/port |
| private Ip4Address localIp4Address; // Local IPv4 address |
| private int localBgpVersion; // 1 octet |
| private long localAs; // 2 octets |
| private long localHoldtime; // 2 octets |
| private Ip4Address localBgpId; // 4 octets -> IPv4 address |
| // |
| private long localKeepaliveInterval; // Keepalive interval |
| |
| // Timers state |
| private Timer timer = new HashedWheelTimer(); |
| private volatile Timeout keepaliveTimeout; // Periodic KEEPALIVE |
| private volatile Timeout sessionTimeout; // Session timeout |
| |
| // BGP RIB-IN routing entries from this peer |
| private ConcurrentMap<Ip4Prefix, BgpRouteEntry> bgpRibIn = |
| new ConcurrentHashMap<>(); |
| |
| /** |
| * Constructor for a given BGP Session Manager. |
| * |
| * @param bgpSessionManager the BGP Session Manager to use |
| */ |
| BgpSession(BgpSessionManager bgpSessionManager) { |
| this.bgpSessionManager = bgpSessionManager; |
| } |
| |
| /** |
| * Gets the BGP RIB-IN routing entries. |
| * |
| * @return the BGP RIB-IN routing entries |
| */ |
| public Collection<BgpRouteEntry> getBgpRibIn() { |
| return bgpRibIn.values(); |
| } |
| |
| /** |
| * Finds a BGP routing entry in the BGP RIB-IN. |
| * |
| * @param prefix the prefix of the route to search for |
| * @return the BGP routing entry if found, otherwise null |
| */ |
| public BgpRouteEntry findBgpRouteEntry(Ip4Prefix prefix) { |
| return bgpRibIn.get(prefix); |
| } |
| |
| /** |
| * Gets the BGP session remote address. |
| * |
| * @return the BGP session remote address |
| */ |
| public SocketAddress getRemoteAddress() { |
| return remoteAddress; |
| } |
| |
| /** |
| * Gets the BGP session remote IPv4 address. |
| * |
| * @return the BGP session remote IPv4 address |
| */ |
| public Ip4Address getRemoteIp4Address() { |
| return remoteIp4Address; |
| } |
| |
| /** |
| * Gets the BGP session remote BGP version. |
| * |
| * @return the BGP session remote BGP version |
| */ |
| public int getRemoteBgpVersion() { |
| return remoteBgpVersion; |
| } |
| |
| /** |
| * Gets the BGP session remote AS number. |
| * |
| * @return the BGP session remote AS number |
| */ |
| public long getRemoteAs() { |
| return remoteAs; |
| } |
| |
| /** |
| * Gets the BGP session remote Holdtime. |
| * |
| * @return the BGP session remote Holdtime |
| */ |
| public long getRemoteHoldtime() { |
| return remoteHoldtime; |
| } |
| |
| /** |
| * Gets the BGP session remote BGP Identifier as an IPv4 address. |
| * |
| * @return the BGP session remote BGP Identifier as an IPv4 address |
| */ |
| public Ip4Address getRemoteBgpId() { |
| return remoteBgpId; |
| } |
| |
| /** |
| * Gets the BGP session local address. |
| * |
| * @return the BGP session local address |
| */ |
| public SocketAddress getLocalAddress() { |
| return localAddress; |
| } |
| |
| /** |
| * Gets the BGP session local BGP version. |
| * |
| * @return the BGP session local BGP version |
| */ |
| public int getLocalBgpVersion() { |
| return localBgpVersion; |
| } |
| |
| /** |
| * Gets the BGP session local AS number. |
| * |
| * @return the BGP session local AS number |
| */ |
| public long getLocalAs() { |
| return localAs; |
| } |
| |
| /** |
| * Gets the BGP session local Holdtime. |
| * |
| * @return the BGP session local Holdtime |
| */ |
| public long getLocalHoldtime() { |
| return localHoldtime; |
| } |
| |
| /** |
| * Gets the BGP session local BGP Identifier as an IPv4 address. |
| * |
| * @return the BGP session local BGP Identifier as an IPv4 address |
| */ |
| public Ip4Address getLocalBgpId() { |
| return localBgpId; |
| } |
| |
| /** |
| * Tests whether the session is closed. |
| * <p> |
| * NOTE: We use this method to avoid the Netty's asynchronous closing |
| * of a channel. |
| * </p> |
| * @return true if the session is closed |
| */ |
| boolean isClosed() { |
| return isClosed; |
| } |
| |
| /** |
| * Closes the session. |
| * |
| * @param ctx the Channel Handler Context |
| */ |
| void closeSession(ChannelHandlerContext ctx) { |
| timer.stop(); |
| closeChannel(ctx); |
| } |
| |
| /** |
| * Closes the netty channel. |
| * |
| * @param ctx the Channel Handler Context |
| */ |
| void closeChannel(ChannelHandlerContext ctx) { |
| isClosed = true; |
| ctx.getChannel().close(); |
| } |
| |
| @Override |
| public void channelOpen(ChannelHandlerContext ctx, |
| ChannelStateEvent channelEvent) { |
| bgpSessionManager.addSessionChannel(channelEvent.getChannel()); |
| } |
| |
| @Override |
| public void channelClosed(ChannelHandlerContext ctx, |
| ChannelStateEvent channelEvent) { |
| bgpSessionManager.removeSessionChannel(channelEvent.getChannel()); |
| } |
| |
| @Override |
| public void channelConnected(ChannelHandlerContext ctx, |
| ChannelStateEvent channelEvent) { |
| localAddress = ctx.getChannel().getLocalAddress(); |
| remoteAddress = ctx.getChannel().getRemoteAddress(); |
| |
| // Assign the local and remote IPv4 addresses |
| InetAddress inetAddr; |
| if (localAddress instanceof InetSocketAddress) { |
| inetAddr = ((InetSocketAddress) localAddress).getAddress(); |
| localIp4Address = Ip4Address.valueOf(inetAddr.getAddress()); |
| } |
| if (remoteAddress instanceof InetSocketAddress) { |
| inetAddr = ((InetSocketAddress) remoteAddress).getAddress(); |
| remoteIp4Address = Ip4Address.valueOf(inetAddr.getAddress()); |
| } |
| |
| log.debug("BGP Session Connected from {} on {}", |
| remoteAddress, localAddress); |
| if (!bgpSessionManager.peerConnected(this)) { |
| log.debug("Cannot setup BGP Session Connection from {}. Closing...", |
| remoteAddress); |
| ctx.getChannel().close(); |
| } |
| } |
| |
| @Override |
| public void channelDisconnected(ChannelHandlerContext ctx, |
| ChannelStateEvent channelEvent) { |
| log.debug("BGP Session Disconnected from {} on {}", |
| ctx.getChannel().getRemoteAddress(), |
| ctx.getChannel().getLocalAddress()); |
| |
| // |
| // Withdraw the routes advertised by this BGP peer |
| // |
| // NOTE: We must initialize the RIB-IN before propagating the withdraws |
| // for further processing. Otherwise, the BGP Decision Process |
| // will use those routes again. |
| // |
| Collection<BgpRouteEntry> deletedRoutes = bgpRibIn.values(); |
| bgpRibIn = new ConcurrentHashMap<>(); |
| |
| // Push the updates to the BGP Merged RIB |
| BgpSessionManager.BgpRouteSelector bgpRouteSelector = |
| bgpSessionManager.getBgpRouteSelector(); |
| Collection<BgpRouteEntry> addedRoutes = Collections.emptyList(); |
| bgpRouteSelector.routeUpdates(this, addedRoutes, deletedRoutes); |
| |
| bgpSessionManager.peerDisconnected(this); |
| } |
| |
| /** |
| * Processes BGP OPEN message. |
| * |
| * @param ctx the Channel Handler Context |
| * @param message the message to process |
| */ |
| void processBgpOpen(ChannelHandlerContext ctx, ChannelBuffer message) { |
| int minLength = |
| BgpConstants.BGP_OPEN_MIN_LENGTH - BgpConstants.BGP_HEADER_LENGTH; |
| if (message.readableBytes() < minLength) { |
| log.debug("BGP RX OPEN Error from {}: " + |
| "Message length {} too short. Must be at least {}", |
| remoteAddress, message.readableBytes(), minLength); |
| // |
| // ERROR: Bad Message Length |
| // |
| // Send NOTIFICATION and close the connection |
| ChannelBuffer txMessage = prepareBgpNotificationBadMessageLength( |
| message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| return; |
| } |
| |
| // |
| // Parse the OPEN message |
| // |
| // Remote BGP version |
| remoteBgpVersion = message.readUnsignedByte(); |
| if (remoteBgpVersion != BgpConstants.BGP_VERSION) { |
| log.debug("BGP RX OPEN Error from {}: " + |
| "Unsupported BGP version {}. Should be {}", |
| remoteAddress, remoteBgpVersion, |
| BgpConstants.BGP_VERSION); |
| // |
| // ERROR: Unsupported Version Number |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = OpenMessageError.ERROR_CODE; |
| int errorSubcode = OpenMessageError.UNSUPPORTED_VERSION_NUMBER; |
| ChannelBuffer data = ChannelBuffers.buffer(2); |
| data.writeShort(BgpConstants.BGP_VERSION); |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, data); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| return; |
| } |
| |
| // Remote AS number |
| remoteAs = message.readUnsignedShort(); |
| // |
| // Verify that the AS number is same for all other BGP Sessions |
| // NOTE: This check applies only for our use-case where all BGP |
| // sessions are iBGP. |
| // |
| for (BgpSession bgpSession : bgpSessionManager.getBgpSessions()) { |
| if (remoteAs != bgpSession.getRemoteAs()) { |
| log.debug("BGP RX OPEN Error from {}: Bad Peer AS {}. " + |
| "Expected {}", |
| remoteAddress, remoteAs, bgpSession.getRemoteAs()); |
| // |
| // ERROR: Bad Peer AS |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = OpenMessageError.ERROR_CODE; |
| int errorSubcode = OpenMessageError.BAD_PEER_AS; |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, null); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| return; |
| } |
| } |
| |
| // Remote Hold Time |
| remoteHoldtime = message.readUnsignedShort(); |
| if ((remoteHoldtime != 0) && |
| (remoteHoldtime < BgpConstants.BGP_KEEPALIVE_MIN_HOLDTIME)) { |
| log.debug("BGP RX OPEN Error from {}: " + |
| "Unacceptable Hold Time field {}. " + |
| "Should be 0 or at least {}", |
| remoteAddress, remoteHoldtime, |
| BgpConstants.BGP_KEEPALIVE_MIN_HOLDTIME); |
| // |
| // ERROR: Unacceptable Hold Time |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = OpenMessageError.ERROR_CODE; |
| int errorSubcode = OpenMessageError.UNACCEPTABLE_HOLD_TIME; |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, null); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| return; |
| } |
| |
| // Remote BGP Identifier |
| remoteBgpId = Ip4Address.valueOf((int) message.readUnsignedInt()); |
| |
| // Optional Parameters |
| int optParamLen = message.readUnsignedByte(); |
| if (message.readableBytes() < optParamLen) { |
| log.debug("BGP RX OPEN Error from {}: " + |
| "Invalid Optional Parameter Length field {}. " + |
| "Remaining Optional Parameters {}", |
| remoteAddress, optParamLen, message.readableBytes()); |
| // |
| // ERROR: Invalid Optional Parameter Length field: Unspecific |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = OpenMessageError.ERROR_CODE; |
| int errorSubcode = Notifications.ERROR_SUBCODE_UNSPECIFIC; |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, null); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| return; |
| } |
| // TODO: Parse the optional parameters (if needed) |
| message.readBytes(optParamLen); // NOTE: data ignored |
| |
| // |
| // Copy some of the remote peer's state/setup to the local setup: |
| // - BGP version |
| // - AS number (NOTE: the peer setup is always iBGP) |
| // - Holdtime |
| // Also, assign the local BGP ID based on the local setup |
| // |
| localBgpVersion = remoteBgpVersion; |
| localAs = remoteAs; |
| localHoldtime = remoteHoldtime; |
| localBgpId = bgpSessionManager.getMyBgpId(); |
| |
| // Set the Keepalive interval |
| if (localHoldtime == 0) { |
| localKeepaliveInterval = 0; |
| } else { |
| localKeepaliveInterval = Math.max(localHoldtime / |
| BgpConstants.BGP_KEEPALIVE_PER_HOLD_INTERVAL, |
| BgpConstants.BGP_KEEPALIVE_MIN_INTERVAL); |
| } |
| |
| log.debug("BGP RX OPEN message from {}: " + |
| "BGPv{} AS {} BGP-ID {} Holdtime {}", |
| remoteAddress, remoteBgpVersion, remoteAs, |
| remoteBgpId, remoteHoldtime); |
| |
| // Send my OPEN followed by KEEPALIVE |
| ChannelBuffer txMessage = prepareBgpOpen(); |
| ctx.getChannel().write(txMessage); |
| // |
| txMessage = prepareBgpKeepalive(); |
| ctx.getChannel().write(txMessage); |
| |
| // Start the KEEPALIVE timer |
| restartKeepaliveTimer(ctx); |
| |
| // Start the Session Timeout timer |
| restartSessionTimeoutTimer(ctx); |
| } |
| |
| /** |
| * Processes BGP UPDATE message. |
| * |
| * @param ctx the Channel Handler Context |
| * @param message the message to process |
| */ |
| void processBgpUpdate(ChannelHandlerContext ctx, ChannelBuffer message) { |
| Collection<BgpRouteEntry> addedRoutes = null; |
| Map<Ip4Prefix, BgpRouteEntry> deletedRoutes = new HashMap<>(); |
| |
| int minLength = |
| BgpConstants.BGP_UPDATE_MIN_LENGTH - BgpConstants.BGP_HEADER_LENGTH; |
| if (message.readableBytes() < minLength) { |
| log.debug("BGP RX UPDATE Error from {}: " + |
| "Message length {} too short. Must be at least {}", |
| remoteAddress, message.readableBytes(), minLength); |
| // |
| // ERROR: Bad Message Length |
| // |
| // Send NOTIFICATION and close the connection |
| ChannelBuffer txMessage = prepareBgpNotificationBadMessageLength( |
| message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| return; |
| } |
| |
| log.debug("BGP RX UPDATE message from {}", remoteAddress); |
| |
| // |
| // Parse the UPDATE message |
| // |
| |
| // |
| // Parse the Withdrawn Routes |
| // |
| int withdrawnRoutesLength = message.readUnsignedShort(); |
| if (withdrawnRoutesLength > message.readableBytes()) { |
| // ERROR: Malformed Attribute List |
| actionsBgpUpdateMalformedAttributeList(ctx); |
| return; |
| } |
| Collection<Ip4Prefix> withdrawnPrefixes = null; |
| try { |
| withdrawnPrefixes = parsePackedPrefixes(withdrawnRoutesLength, |
| message); |
| } catch (BgpParseException e) { |
| // ERROR: Invalid Network Field |
| log.debug("Exception parsing Withdrawn Prefixes from BGP peer {}: ", |
| remoteBgpId, e); |
| actionsBgpUpdateInvalidNetworkField(ctx); |
| return; |
| } |
| for (Ip4Prefix prefix : withdrawnPrefixes) { |
| log.debug("BGP RX UPDATE message WITHDRAWN from {}: {}", |
| remoteAddress, prefix); |
| BgpRouteEntry bgpRouteEntry = bgpRibIn.get(prefix); |
| if (bgpRouteEntry != null) { |
| deletedRoutes.put(prefix, bgpRouteEntry); |
| } |
| } |
| |
| // |
| // Parse the Path Attributes |
| // |
| try { |
| addedRoutes = parsePathAttributes(ctx, message); |
| } catch (BgpParseException e) { |
| log.debug("Exception parsing Path Attributes from BGP peer {}: ", |
| remoteBgpId, e); |
| // NOTE: The session was already closed, so nothing else to do |
| return; |
| } |
| // Ignore WITHDRAWN routes that are ADDED |
| for (BgpRouteEntry bgpRouteEntry : addedRoutes) { |
| deletedRoutes.remove(bgpRouteEntry.prefix()); |
| } |
| |
| // Update the BGP RIB-IN |
| for (BgpRouteEntry bgpRouteEntry : deletedRoutes.values()) { |
| bgpRibIn.remove(bgpRouteEntry.prefix()); |
| } |
| for (BgpRouteEntry bgpRouteEntry : addedRoutes) { |
| bgpRibIn.put(bgpRouteEntry.prefix(), bgpRouteEntry); |
| } |
| |
| // Push the updates to the BGP Merged RIB |
| BgpSessionManager.BgpRouteSelector bgpRouteSelector = |
| bgpSessionManager.getBgpRouteSelector(); |
| bgpRouteSelector.routeUpdates(this, addedRoutes, |
| deletedRoutes.values()); |
| |
| // Start the Session Timeout timer |
| restartSessionTimeoutTimer(ctx); |
| } |
| |
| /** |
| * Parse BGP Path Attributes from the BGP UPDATE message. |
| * |
| * @param ctx the Channel Handler Context |
| * @param message the message to parse |
| * @return a collection of the result BGP Route Entries |
| * @throws BgpParseException |
| */ |
| private Collection<BgpRouteEntry> parsePathAttributes( |
| ChannelHandlerContext ctx, |
| ChannelBuffer message) |
| throws BgpParseException { |
| Map<Ip4Prefix, BgpRouteEntry> addedRoutes = new HashMap<>(); |
| |
| // |
| // Parsed values |
| // |
| Short origin = -1; // Mandatory |
| BgpRouteEntry.AsPath asPath = null; // Mandatory |
| Ip4Address nextHop = null; // Mandatory |
| long multiExitDisc = // Optional |
| BgpConstants.Update.MultiExitDisc.LOWEST_MULTI_EXIT_DISC; |
| Long localPref = null; // Mandatory |
| Long aggregatorAsNumber = null; // Optional: unused |
| Ip4Address aggregatorIpAddress = null; // Optional: unused |
| |
| // |
| // Get and verify the Path Attributes Length |
| // |
| int pathAttributeLength = message.readUnsignedShort(); |
| if (pathAttributeLength > message.readableBytes()) { |
| // ERROR: Malformed Attribute List |
| actionsBgpUpdateMalformedAttributeList(ctx); |
| String errorMsg = "Malformed Attribute List"; |
| throw new BgpParseException(errorMsg); |
| } |
| if (pathAttributeLength == 0) { |
| return addedRoutes.values(); |
| } |
| |
| // |
| // Parse the Path Attributes |
| // |
| int pathAttributeEnd = message.readerIndex() + pathAttributeLength; |
| while (message.readerIndex() < pathAttributeEnd) { |
| int attrFlags = message.readUnsignedByte(); |
| if (message.readerIndex() >= pathAttributeEnd) { |
| // ERROR: Malformed Attribute List |
| actionsBgpUpdateMalformedAttributeList(ctx); |
| String errorMsg = "Malformed Attribute List"; |
| throw new BgpParseException(errorMsg); |
| } |
| int attrTypeCode = message.readUnsignedByte(); |
| |
| // The Attribute Flags |
| boolean optionalBit = ((0x80 & attrFlags) != 0); |
| boolean transitiveBit = ((0x40 & attrFlags) != 0); |
| boolean partialBit = ((0x20 & attrFlags) != 0); |
| boolean extendedLengthBit = ((0x10 & attrFlags) != 0); |
| |
| // The Attribute Length |
| int attrLen = 0; |
| int attrLenOctets = 1; |
| if (extendedLengthBit) { |
| attrLenOctets = 2; |
| } |
| if (message.readerIndex() + attrLenOctets > pathAttributeEnd) { |
| // ERROR: Malformed Attribute List |
| actionsBgpUpdateMalformedAttributeList(ctx); |
| String errorMsg = "Malformed Attribute List"; |
| throw new BgpParseException(errorMsg); |
| } |
| if (extendedLengthBit) { |
| attrLen = message.readUnsignedShort(); |
| } else { |
| attrLen = message.readUnsignedByte(); |
| } |
| if (message.readerIndex() + attrLen > pathAttributeEnd) { |
| // ERROR: Malformed Attribute List |
| actionsBgpUpdateMalformedAttributeList(ctx); |
| String errorMsg = "Malformed Attribute List"; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| // |
| // Verify the Attribute Flags |
| // |
| verifyBgpUpdateAttributeFlags(ctx, attrTypeCode, attrLen, |
| attrFlags, message); |
| |
| // |
| // Extract the Attribute Value based on the Attribute Type Code |
| // |
| switch (attrTypeCode) { |
| |
| case BgpConstants.Update.Origin.TYPE: |
| // Attribute Type Code ORIGIN |
| origin = parseAttributeTypeOrigin(ctx, attrTypeCode, attrLen, |
| attrFlags, message); |
| break; |
| |
| case BgpConstants.Update.AsPath.TYPE: |
| // Attribute Type Code AS_PATH |
| asPath = parseAttributeTypeAsPath(ctx, attrTypeCode, attrLen, |
| attrFlags, message); |
| break; |
| |
| case BgpConstants.Update.NextHop.TYPE: |
| // Attribute Type Code NEXT_HOP |
| nextHop = parseAttributeTypeNextHop(ctx, attrTypeCode, attrLen, |
| attrFlags, message); |
| break; |
| |
| case BgpConstants.Update.MultiExitDisc.TYPE: |
| // Attribute Type Code MULTI_EXIT_DISC |
| multiExitDisc = |
| parseAttributeTypeMultiExitDisc(ctx, attrTypeCode, attrLen, |
| attrFlags, message); |
| break; |
| |
| case BgpConstants.Update.LocalPref.TYPE: |
| // Attribute Type Code LOCAL_PREF |
| localPref = |
| parseAttributeTypeLocalPref(ctx, attrTypeCode, attrLen, |
| attrFlags, message); |
| break; |
| |
| case BgpConstants.Update.AtomicAggregate.TYPE: |
| // Attribute Type Code ATOMIC_AGGREGATE |
| parseAttributeTypeAtomicAggregate(ctx, attrTypeCode, attrLen, |
| attrFlags, message); |
| // Nothing to do: this attribute is primarily informational |
| break; |
| |
| case BgpConstants.Update.Aggregator.TYPE: |
| // Attribute Type Code AGGREGATOR |
| Pair<Long, Ip4Address> aggregator = |
| parseAttributeTypeAggregator(ctx, attrTypeCode, attrLen, |
| attrFlags, message); |
| aggregatorAsNumber = aggregator.getLeft(); |
| aggregatorIpAddress = aggregator.getRight(); |
| break; |
| |
| default: |
| // TODO: Parse any new Attribute Types if needed |
| if (!optionalBit) { |
| // ERROR: Unrecognized Well-known Attribute |
| actionsBgpUpdateUnrecognizedWellKnownAttribute( |
| ctx, attrTypeCode, attrLen, attrFlags, message); |
| String errorMsg = "Unrecognized Well-known Attribute: " + |
| attrTypeCode; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| // Skip the data from the unrecognized attribute |
| log.debug("BGP RX UPDATE message from {}: " + |
| "Unrecognized Attribute Type {}", |
| remoteAddress, attrTypeCode); |
| message.skipBytes(attrLen); |
| break; |
| } |
| } |
| |
| // |
| // Verify the Well-known Attributes |
| // |
| verifyBgpUpdateWellKnownAttributes(ctx, origin, asPath, nextHop, |
| localPref); |
| |
| // |
| // Parse the NLRI (Network Layer Reachability Information) |
| // |
| Collection<Ip4Prefix> addedPrefixes = null; |
| int nlriLength = message.readableBytes(); |
| try { |
| addedPrefixes = parsePackedPrefixes(nlriLength, message); |
| } catch (BgpParseException e) { |
| // ERROR: Invalid Network Field |
| log.debug("Exception parsing NLRI from BGP peer {}: ", |
| remoteBgpId, e); |
| actionsBgpUpdateInvalidNetworkField(ctx); |
| // Rethrow the exception |
| throw e; |
| } |
| |
| // Generate the added routes |
| for (Ip4Prefix prefix : addedPrefixes) { |
| BgpRouteEntry bgpRouteEntry = |
| new BgpRouteEntry(this, prefix, nextHop, |
| origin.byteValue(), asPath, localPref); |
| bgpRouteEntry.setMultiExitDisc(multiExitDisc); |
| if (bgpRouteEntry.hasAsPathLoop(localAs)) { |
| log.debug("BGP RX UPDATE message IGNORED from {}: {} " + |
| "nextHop {}: contains AS Path loop", |
| remoteAddress, prefix, nextHop); |
| continue; |
| } else { |
| log.debug("BGP RX UPDATE message ADDED from {}: {} nextHop {}", |
| remoteAddress, prefix, nextHop); |
| } |
| addedRoutes.put(prefix, bgpRouteEntry); |
| } |
| |
| return addedRoutes.values(); |
| } |
| |
| /** |
| * Verifies BGP UPDATE Well-known Attributes. |
| * |
| * @param ctx the Channel Handler Context |
| * @param origin the ORIGIN well-known mandatory attribute |
| * @param asPath the AS_PATH well-known mandatory attribute |
| * @param nextHop the NEXT_HOP well-known mandatory attribute |
| * @param localPref the LOCAL_PREF required attribute |
| * @throws BgpParseException |
| */ |
| private void verifyBgpUpdateWellKnownAttributes( |
| ChannelHandlerContext ctx, |
| Short origin, |
| BgpRouteEntry.AsPath asPath, |
| Ip4Address nextHop, |
| Long localPref) |
| throws BgpParseException { |
| // |
| // Check for Missing Well-known Attributes |
| // |
| if ((origin == null) || (origin == -1)) { |
| // Missing Attribute Type Code ORIGIN |
| int type = BgpConstants.Update.Origin.TYPE; |
| actionsBgpUpdateMissingWellKnownAttribute(ctx, type); |
| String errorMsg = "Missing Well-known Attribute: ORIGIN"; |
| throw new BgpParseException(errorMsg); |
| } |
| if (asPath == null) { |
| // Missing Attribute Type Code AS_PATH |
| int type = BgpConstants.Update.AsPath.TYPE; |
| actionsBgpUpdateMissingWellKnownAttribute(ctx, type); |
| String errorMsg = "Missing Well-known Attribute: AS_PATH"; |
| throw new BgpParseException(errorMsg); |
| } |
| if (nextHop == null) { |
| // Missing Attribute Type Code NEXT_HOP |
| int type = BgpConstants.Update.NextHop.TYPE; |
| actionsBgpUpdateMissingWellKnownAttribute(ctx, type); |
| String errorMsg = "Missing Well-known Attribute: NEXT_HOP"; |
| throw new BgpParseException(errorMsg); |
| } |
| if (localPref == null) { |
| // Missing Attribute Type Code LOCAL_PREF |
| // NOTE: Required for iBGP |
| int type = BgpConstants.Update.LocalPref.TYPE; |
| actionsBgpUpdateMissingWellKnownAttribute(ctx, type); |
| String errorMsg = "Missing Well-known Attribute: LOCAL_PREF"; |
| throw new BgpParseException(errorMsg); |
| } |
| } |
| |
| /** |
| * Verifies the BGP UPDATE Attribute Flags. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message to parse |
| * @throws BgpParseException |
| */ |
| private void verifyBgpUpdateAttributeFlags( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) |
| throws BgpParseException { |
| |
| // |
| // Assign the Attribute Type Name and the Well-known flag |
| // |
| String typeName = "UNKNOWN"; |
| boolean isWellKnown = false; |
| switch (attrTypeCode) { |
| case BgpConstants.Update.Origin.TYPE: |
| isWellKnown = true; |
| typeName = "ORIGIN"; |
| break; |
| case BgpConstants.Update.AsPath.TYPE: |
| isWellKnown = true; |
| typeName = "AS_PATH"; |
| break; |
| case BgpConstants.Update.NextHop.TYPE: |
| isWellKnown = true; |
| typeName = "NEXT_HOP"; |
| break; |
| case BgpConstants.Update.MultiExitDisc.TYPE: |
| isWellKnown = false; |
| typeName = "MULTI_EXIT_DISC"; |
| break; |
| case BgpConstants.Update.LocalPref.TYPE: |
| isWellKnown = true; |
| typeName = "LOCAL_PREF"; |
| break; |
| case BgpConstants.Update.AtomicAggregate.TYPE: |
| isWellKnown = true; |
| typeName = "ATOMIC_AGGREGATE"; |
| break; |
| case BgpConstants.Update.Aggregator.TYPE: |
| isWellKnown = false; |
| typeName = "AGGREGATOR"; |
| break; |
| default: |
| isWellKnown = false; |
| typeName = "UNKNOWN(" + attrTypeCode + ")"; |
| break; |
| } |
| |
| // |
| // Verify the Attribute Flags |
| // |
| boolean optionalBit = ((0x80 & attrFlags) != 0); |
| boolean transitiveBit = ((0x40 & attrFlags) != 0); |
| boolean partialBit = ((0x20 & attrFlags) != 0); |
| if ((isWellKnown && optionalBit) || |
| (isWellKnown && (!transitiveBit)) || |
| (isWellKnown && partialBit) || |
| (optionalBit && (!transitiveBit) && partialBit)) { |
| // |
| // ERROR: The Optional bit cannot be set for Well-known attributes |
| // ERROR: The Transtive bit MUST be 1 for well-known attributes |
| // ERROR: The Partial bit MUST be 0 for well-known attributes |
| // ERROR: The Partial bit MUST be 0 for optional non-transitive |
| // attributes |
| // |
| actionsBgpUpdateAttributeFlagsError( |
| ctx, attrTypeCode, attrLen, attrFlags, message); |
| String errorMsg = "Attribute Flags Error for " + typeName + ": " + |
| attrFlags; |
| throw new BgpParseException(errorMsg); |
| } |
| } |
| |
| /** |
| * Parses BGP UPDATE Attribute Type ORIGIN. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message to parse |
| * @return the parsed ORIGIN value |
| * @throws BgpParseException |
| */ |
| private short parseAttributeTypeOrigin( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) |
| throws BgpParseException { |
| |
| // Check the Attribute Length |
| if (attrLen != BgpConstants.Update.Origin.LENGTH) { |
| // ERROR: Attribute Length Error |
| actionsBgpUpdateAttributeLengthError( |
| ctx, attrTypeCode, attrLen, attrFlags, message); |
| String errorMsg = "Attribute Length Error"; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| message.markReaderIndex(); |
| short origin = message.readUnsignedByte(); |
| switch (origin) { |
| case BgpConstants.Update.Origin.IGP: |
| // FALLTHROUGH |
| case BgpConstants.Update.Origin.EGP: |
| // FALLTHROUGH |
| case BgpConstants.Update.Origin.INCOMPLETE: |
| break; |
| default: |
| // ERROR: Invalid ORIGIN Attribute |
| message.resetReaderIndex(); |
| actionsBgpUpdateInvalidOriginAttribute( |
| ctx, attrTypeCode, attrLen, attrFlags, message, origin); |
| String errorMsg = "Invalid ORIGIN Attribute: " + origin; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| return origin; |
| } |
| |
| /** |
| * Parses BGP UPDATE Attribute AS Path. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message to parse |
| * @return the parsed AS Path |
| * @throws BgpParseException |
| */ |
| private BgpRouteEntry.AsPath parseAttributeTypeAsPath( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) |
| throws BgpParseException { |
| ArrayList<BgpRouteEntry.PathSegment> pathSegments = new ArrayList<>(); |
| |
| // |
| // Parse the message |
| // |
| while (attrLen > 0) { |
| if (attrLen < 2) { |
| // ERROR: Malformed AS_PATH |
| actionsBgpUpdateMalformedAsPath(ctx); |
| String errorMsg = "Malformed AS Path"; |
| throw new BgpParseException(errorMsg); |
| } |
| // Get the Path Segment Type and Length (in number of ASes) |
| short pathSegmentType = message.readUnsignedByte(); |
| short pathSegmentLength = message.readUnsignedByte(); |
| attrLen -= 2; |
| |
| // Verify the Path Segment Type |
| switch (pathSegmentType) { |
| case BgpConstants.Update.AsPath.AS_SET: |
| // FALLTHROUGH |
| case BgpConstants.Update.AsPath.AS_SEQUENCE: |
| // FALLTHROUGH |
| case BgpConstants.Update.AsPath.AS_CONFED_SEQUENCE: |
| // FALLTHROUGH |
| case BgpConstants.Update.AsPath.AS_CONFED_SET: |
| break; |
| default: |
| // ERROR: Invalid Path Segment Type |
| // |
| // NOTE: The BGP Spec (RFC 4271) doesn't contain Error Subcode |
| // for "Invalid Path Segment Type", hence we return |
| // the error as "Malformed AS_PATH". |
| // |
| actionsBgpUpdateMalformedAsPath(ctx); |
| String errorMsg = |
| "Invalid AS Path Segment Type: " + pathSegmentType; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| // Parse the AS numbers |
| if (2 * pathSegmentLength > attrLen) { |
| // ERROR: Malformed AS_PATH |
| actionsBgpUpdateMalformedAsPath(ctx); |
| String errorMsg = "Malformed AS Path"; |
| throw new BgpParseException(errorMsg); |
| } |
| attrLen -= (2 * pathSegmentLength); |
| ArrayList<Long> segmentAsNumbers = new ArrayList<>(); |
| while (pathSegmentLength-- > 0) { |
| long asNumber = message.readUnsignedShort(); |
| segmentAsNumbers.add(asNumber); |
| } |
| |
| BgpRouteEntry.PathSegment pathSegment = |
| new BgpRouteEntry.PathSegment((byte) pathSegmentType, |
| segmentAsNumbers); |
| pathSegments.add(pathSegment); |
| } |
| |
| return new BgpRouteEntry.AsPath(pathSegments); |
| } |
| |
| /** |
| * Parses BGP UPDATE Attribute Type NEXT_HOP. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message to parse |
| * @return the parsed NEXT_HOP value |
| * @throws BgpParseException |
| */ |
| private Ip4Address parseAttributeTypeNextHop( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) |
| throws BgpParseException { |
| |
| // Check the Attribute Length |
| if (attrLen != BgpConstants.Update.NextHop.LENGTH) { |
| // ERROR: Attribute Length Error |
| actionsBgpUpdateAttributeLengthError( |
| ctx, attrTypeCode, attrLen, attrFlags, message); |
| String errorMsg = "Attribute Length Error"; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| message.markReaderIndex(); |
| Ip4Address nextHopAddress = |
| Ip4Address.valueOf((int) message.readUnsignedInt()); |
| // |
| // Check whether the NEXT_HOP IP address is semantically correct. |
| // As per RFC 4271, Section 6.3: |
| // |
| // a) It MUST NOT be the IP address of the receiving speaker |
| // b) In the case of an EBGP .... |
| // |
| // Here we check only (a), because (b) doesn't apply for us: all our |
| // peers are iBGP. |
| // |
| if (nextHopAddress.equals(localIp4Address)) { |
| // ERROR: Invalid NEXT_HOP Attribute |
| message.resetReaderIndex(); |
| actionsBgpUpdateInvalidNextHopAttribute( |
| ctx, attrTypeCode, attrLen, attrFlags, message, |
| nextHopAddress); |
| String errorMsg = "Invalid NEXT_HOP Attribute: " + nextHopAddress; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| return nextHopAddress; |
| } |
| |
| /** |
| * Parses BGP UPDATE Attribute Type MULTI_EXIT_DISC. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message to parse |
| * @return the parsed MULTI_EXIT_DISC value |
| * @throws BgpParseException |
| */ |
| private long parseAttributeTypeMultiExitDisc( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) |
| throws BgpParseException { |
| |
| // Check the Attribute Length |
| if (attrLen != BgpConstants.Update.MultiExitDisc.LENGTH) { |
| // ERROR: Attribute Length Error |
| actionsBgpUpdateAttributeLengthError( |
| ctx, attrTypeCode, attrLen, attrFlags, message); |
| String errorMsg = "Attribute Length Error"; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| long multiExitDisc = message.readUnsignedInt(); |
| return multiExitDisc; |
| } |
| |
| /** |
| * Parses BGP UPDATE Attribute Type LOCAL_PREF. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message to parse |
| * @return the parsed LOCAL_PREF value |
| * @throws BgpParseException |
| */ |
| private long parseAttributeTypeLocalPref( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) |
| throws BgpParseException { |
| |
| // Check the Attribute Length |
| if (attrLen != BgpConstants.Update.LocalPref.LENGTH) { |
| // ERROR: Attribute Length Error |
| actionsBgpUpdateAttributeLengthError( |
| ctx, attrTypeCode, attrLen, attrFlags, message); |
| String errorMsg = "Attribute Length Error"; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| long localPref = message.readUnsignedInt(); |
| return localPref; |
| } |
| |
| /** |
| * Parses BGP UPDATE Attribute Type ATOMIC_AGGREGATE. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message to parse |
| * @throws BgpParseException |
| */ |
| private void parseAttributeTypeAtomicAggregate( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) |
| throws BgpParseException { |
| |
| // Check the Attribute Length |
| if (attrLen != BgpConstants.Update.AtomicAggregate.LENGTH) { |
| // ERROR: Attribute Length Error |
| actionsBgpUpdateAttributeLengthError( |
| ctx, attrTypeCode, attrLen, attrFlags, message); |
| String errorMsg = "Attribute Length Error"; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| // Nothing to do: this attribute is primarily informational |
| } |
| |
| /** |
| * Parses BGP UPDATE Attribute Type AGGREGATOR. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message to parse |
| * @return the parsed AGGREGATOR value: a tuple of <AS-Number, IP-Address> |
| * @throws BgpParseException |
| */ |
| private Pair<Long, Ip4Address> parseAttributeTypeAggregator( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) |
| throws BgpParseException { |
| |
| // Check the Attribute Length |
| if (attrLen != BgpConstants.Update.Aggregator.LENGTH) { |
| // ERROR: Attribute Length Error |
| actionsBgpUpdateAttributeLengthError( |
| ctx, attrTypeCode, attrLen, attrFlags, message); |
| String errorMsg = "Attribute Length Error"; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| // The AGGREGATOR AS number |
| long aggregatorAsNumber = message.readUnsignedShort(); |
| // The AGGREGATOR IP address |
| Ip4Address aggregatorIpAddress = |
| Ip4Address.valueOf((int) message.readUnsignedInt()); |
| |
| Pair<Long, Ip4Address> aggregator = Pair.of(aggregatorAsNumber, |
| aggregatorIpAddress); |
| return aggregator; |
| } |
| |
| /** |
| * Parses a message that contains encoded IPv4 network prefixes. |
| * <p> |
| * The IPv4 prefixes are encoded in the form: |
| * <Length, Prefix> where Length is the length in bits of the IPv4 prefix, |
| * and Prefix is the IPv4 prefix (padded with trailing bits to the end |
| * of an octet). |
| * |
| * @param totalLength the total length of the data to parse |
| * @param message the message with data to parse |
| * @return a collection of parsed IPv4 network prefixes |
| * @throws BgpParseException |
| */ |
| private Collection<Ip4Prefix> parsePackedPrefixes(int totalLength, |
| ChannelBuffer message) |
| throws BgpParseException { |
| Collection<Ip4Prefix> result = new ArrayList<>(); |
| |
| if (totalLength == 0) { |
| return result; |
| } |
| |
| // Parse the data |
| int dataEnd = message.readerIndex() + totalLength; |
| while (message.readerIndex() < dataEnd) { |
| int prefixBitlen = message.readUnsignedByte(); |
| int prefixBytelen = (prefixBitlen + 7) / 8; // Round-up |
| if (message.readerIndex() + prefixBytelen > dataEnd) { |
| String errorMsg = "Malformed Network Prefixes"; |
| throw new BgpParseException(errorMsg); |
| } |
| |
| long address = 0; |
| long extraShift = (4 - prefixBytelen) * 8; |
| while (prefixBytelen > 0) { |
| address <<= 8; |
| address |= message.readUnsignedByte(); |
| prefixBytelen--; |
| } |
| address <<= extraShift; |
| Ip4Prefix prefix = |
| Ip4Prefix.valueOf(Ip4Address.valueOf((int) address), |
| prefixBitlen); |
| result.add(prefix); |
| } |
| |
| return result; |
| } |
| |
| /** |
| * Applies the appropriate actions after detecting BGP UPDATE |
| * Invalid Network Field Error: send NOTIFICATION and close the channel. |
| * |
| * @param ctx the Channel Handler Context |
| */ |
| private void actionsBgpUpdateInvalidNetworkField( |
| ChannelHandlerContext ctx) { |
| log.debug("BGP RX UPDATE Error from {}: Invalid Network Field", |
| remoteAddress); |
| |
| // |
| // ERROR: Invalid Network Field |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = UpdateMessageError.ERROR_CODE; |
| int errorSubcode = UpdateMessageError.INVALID_NETWORK_FIELD; |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, null); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| } |
| |
| /** |
| * Applies the appropriate actions after detecting BGP UPDATE |
| * Malformed Attribute List Error: send NOTIFICATION and close the channel. |
| * |
| * @param ctx the Channel Handler Context |
| */ |
| private void actionsBgpUpdateMalformedAttributeList( |
| ChannelHandlerContext ctx) { |
| log.debug("BGP RX UPDATE Error from {}: Malformed Attribute List", |
| remoteAddress); |
| |
| // |
| // ERROR: Malformed Attribute List |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = UpdateMessageError.ERROR_CODE; |
| int errorSubcode = UpdateMessageError.MALFORMED_ATTRIBUTE_LIST; |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, null); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| } |
| |
| /** |
| * Applies the appropriate actions after detecting BGP UPDATE |
| * Missing Well-known Attribute Error: send NOTIFICATION and close the |
| * channel. |
| * |
| * @param ctx the Channel Handler Context |
| * @param missingAttrTypeCode the missing attribute type code |
| */ |
| private void actionsBgpUpdateMissingWellKnownAttribute( |
| ChannelHandlerContext ctx, |
| int missingAttrTypeCode) { |
| log.debug("BGP RX UPDATE Error from {}: Missing Well-known Attribute: {}", |
| remoteAddress, missingAttrTypeCode); |
| |
| // |
| // ERROR: Missing Well-known Attribute |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = UpdateMessageError.ERROR_CODE; |
| int errorSubcode = UpdateMessageError.MISSING_WELL_KNOWN_ATTRIBUTE; |
| ChannelBuffer data = ChannelBuffers.buffer(1); |
| data.writeByte(missingAttrTypeCode); |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, data); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| } |
| |
| /** |
| * Applies the appropriate actions after detecting BGP UPDATE |
| * Invalid ORIGIN Attribute Error: send NOTIFICATION and close the channel. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message with the data |
| * @param origin the ORIGIN attribute value |
| */ |
| private void actionsBgpUpdateInvalidOriginAttribute( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message, |
| short origin) { |
| log.debug("BGP RX UPDATE Error from {}: Invalid ORIGIN Attribute", |
| remoteAddress); |
| |
| // |
| // ERROR: Invalid ORIGIN Attribute |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = UpdateMessageError.ERROR_CODE; |
| int errorSubcode = UpdateMessageError.INVALID_ORIGIN_ATTRIBUTE; |
| ChannelBuffer data = |
| prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| attrFlags, message); |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, data); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| } |
| |
| /** |
| * Applies the appropriate actions after detecting BGP UPDATE |
| * Attribute Flags Error: send NOTIFICATION and close the channel. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message with the data |
| */ |
| private void actionsBgpUpdateAttributeFlagsError( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) { |
| log.debug("BGP RX UPDATE Error from {}: Attribute Flags Error", |
| remoteAddress); |
| |
| // |
| // ERROR: Attribute Flags Error |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = UpdateMessageError.ERROR_CODE; |
| int errorSubcode = UpdateMessageError.ATTRIBUTE_FLAGS_ERROR; |
| ChannelBuffer data = |
| prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| attrFlags, message); |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, data); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| } |
| |
| /** |
| * Applies the appropriate actions after detecting BGP UPDATE |
| * Invalid NEXT_HOP Attribute Error: send NOTIFICATION and close the |
| * channel. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message with the data |
| * @param nextHop the NEXT_HOP attribute value |
| */ |
| private void actionsBgpUpdateInvalidNextHopAttribute( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message, |
| Ip4Address nextHop) { |
| log.debug("BGP RX UPDATE Error from {}: Invalid NEXT_HOP Attribute {}", |
| remoteAddress, nextHop); |
| |
| // |
| // ERROR: Invalid ORIGIN Attribute |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = UpdateMessageError.ERROR_CODE; |
| int errorSubcode = UpdateMessageError.INVALID_NEXT_HOP_ATTRIBUTE; |
| ChannelBuffer data = |
| prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| attrFlags, message); |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, data); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| } |
| |
| /** |
| * Applies the appropriate actions after detecting BGP UPDATE |
| * Unrecognized Well-known Attribute Error: send NOTIFICATION and close |
| * the channel. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message with the data |
| */ |
| private void actionsBgpUpdateUnrecognizedWellKnownAttribute( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) { |
| log.debug("BGP RX UPDATE Error from {}: " + |
| "Unrecognized Well-known Attribute Error: {}", |
| remoteAddress, attrTypeCode); |
| |
| // |
| // ERROR: Unrecognized Well-known Attribute |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = UpdateMessageError.ERROR_CODE; |
| int errorSubcode = |
| UpdateMessageError.UNRECOGNIZED_WELL_KNOWN_ATTRIBUTE; |
| ChannelBuffer data = |
| prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| attrFlags, message); |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, data); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| } |
| |
| /** |
| * Applies the appropriate actions after detecting BGP UPDATE |
| * Attribute Length Error: send NOTIFICATION and close the channel. |
| * |
| * @param ctx the Channel Handler Context |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message with the data |
| */ |
| private void actionsBgpUpdateAttributeLengthError( |
| ChannelHandlerContext ctx, |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) { |
| log.debug("BGP RX UPDATE Error from {}: Attribute Length Error", |
| remoteAddress); |
| |
| // |
| // ERROR: Attribute Length Error |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = UpdateMessageError.ERROR_CODE; |
| int errorSubcode = UpdateMessageError.ATTRIBUTE_LENGTH_ERROR; |
| ChannelBuffer data = |
| prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen, |
| attrFlags, message); |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, data); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| } |
| |
| /** |
| * Applies the appropriate actions after detecting BGP UPDATE |
| * Malformed AS_PATH Error: send NOTIFICATION and close the channel. |
| * |
| * @param ctx the Channel Handler Context |
| */ |
| private void actionsBgpUpdateMalformedAsPath( |
| ChannelHandlerContext ctx) { |
| log.debug("BGP RX UPDATE Error from {}: Malformed AS Path", |
| remoteAddress); |
| |
| // |
| // ERROR: Malformed AS_PATH |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = UpdateMessageError.ERROR_CODE; |
| int errorSubcode = UpdateMessageError.MALFORMED_AS_PATH; |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, null); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| } |
| |
| /** |
| * Processes BGP NOTIFICATION message. |
| * |
| * @param ctx the Channel Handler Context |
| * @param message the message to process |
| */ |
| void processBgpNotification(ChannelHandlerContext ctx, |
| ChannelBuffer message) { |
| int minLength = |
| BgpConstants.BGP_NOTIFICATION_MIN_LENGTH - BgpConstants.BGP_HEADER_LENGTH; |
| if (message.readableBytes() < minLength) { |
| log.debug("BGP RX NOTIFICATION Error from {}: " + |
| "Message length {} too short. Must be at least {}", |
| remoteAddress, message.readableBytes(), minLength); |
| // |
| // ERROR: Bad Message Length |
| // |
| // NOTE: We do NOT send NOTIFICATION in response to a notification |
| return; |
| } |
| |
| // |
| // Parse the NOTIFICATION message |
| // |
| int errorCode = message.readUnsignedByte(); |
| int errorSubcode = message.readUnsignedByte(); |
| int dataLength = message.readableBytes(); |
| |
| log.debug("BGP RX NOTIFICATION message from {}: Error Code {} " + |
| "Error Subcode {} Data Length {}", |
| remoteAddress, errorCode, errorSubcode, dataLength); |
| |
| // |
| // NOTE: If the peer sent a NOTIFICATION, we leave it to the peer to |
| // close the connection. |
| // |
| |
| // Start the Session Timeout timer |
| restartSessionTimeoutTimer(ctx); |
| } |
| |
| /** |
| * Processes BGP KEEPALIVE message. |
| * |
| * @param ctx the Channel Handler Context |
| * @param message the message to process |
| */ |
| void processBgpKeepalive(ChannelHandlerContext ctx, |
| ChannelBuffer message) { |
| if (message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH != |
| BgpConstants.BGP_KEEPALIVE_EXPECTED_LENGTH) { |
| log.debug("BGP RX KEEPALIVE Error from {}: " + |
| "Invalid total message length {}. Expected {}", |
| remoteAddress, |
| message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH, |
| BgpConstants.BGP_KEEPALIVE_EXPECTED_LENGTH); |
| // |
| // ERROR: Bad Message Length |
| // |
| // Send NOTIFICATION and close the connection |
| ChannelBuffer txMessage = prepareBgpNotificationBadMessageLength( |
| message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH); |
| ctx.getChannel().write(txMessage); |
| closeSession(ctx); |
| return; |
| } |
| |
| // |
| // Parse the KEEPALIVE message: nothing to do |
| // |
| log.trace("BGP RX KEEPALIVE message from {}", remoteAddress); |
| |
| // Start the Session Timeout timer |
| restartSessionTimeoutTimer(ctx); |
| } |
| |
| /** |
| * Prepares BGP OPEN message. |
| * |
| * @return the message to transmit (BGP header included) |
| */ |
| private ChannelBuffer prepareBgpOpen() { |
| ChannelBuffer message = |
| ChannelBuffers.buffer(BgpConstants.BGP_MESSAGE_MAX_LENGTH); |
| |
| // |
| // Prepare the OPEN message payload |
| // |
| message.writeByte(localBgpVersion); |
| message.writeShort((int) localAs); |
| message.writeShort((int) localHoldtime); |
| message.writeInt(bgpSessionManager.getMyBgpId().toInt()); |
| message.writeByte(0); // No Optional Parameters |
| return prepareBgpMessage(BgpConstants.BGP_TYPE_OPEN, message); |
| } |
| |
| /** |
| * Prepares BGP KEEPALIVE message. |
| * |
| * @return the message to transmit (BGP header included) |
| */ |
| private ChannelBuffer prepareBgpKeepalive() { |
| ChannelBuffer message = |
| ChannelBuffers.buffer(BgpConstants.BGP_MESSAGE_MAX_LENGTH); |
| |
| // |
| // Prepare the KEEPALIVE message payload: nothing to do |
| // |
| return prepareBgpMessage(BgpConstants.BGP_TYPE_KEEPALIVE, message); |
| } |
| |
| /** |
| * Prepares BGP NOTIFICATION message. |
| * |
| * @param errorCode the BGP NOTIFICATION Error Code |
| * @param errorSubcode the BGP NOTIFICATION Error Subcode if applicable, |
| * otherwise BgpConstants.Notifications.ERROR_SUBCODE_UNSPECIFIC |
| * @param data the BGP NOTIFICATION Data if applicable, otherwise null |
| * @return the message to transmit (BGP header included) |
| */ |
| ChannelBuffer prepareBgpNotification(int errorCode, int errorSubcode, |
| ChannelBuffer data) { |
| ChannelBuffer message = |
| ChannelBuffers.buffer(BgpConstants.BGP_MESSAGE_MAX_LENGTH); |
| |
| // |
| // Prepare the NOTIFICATION message payload |
| // |
| message.writeByte(errorCode); |
| message.writeByte(errorSubcode); |
| if (data != null) { |
| message.writeBytes(data); |
| } |
| return prepareBgpMessage(BgpConstants.BGP_TYPE_NOTIFICATION, message); |
| } |
| |
| /** |
| * Prepares BGP NOTIFICATION message: Bad Message Length. |
| * |
| * @param length the erroneous Length field |
| * @return the message to transmit (BGP header included) |
| */ |
| ChannelBuffer prepareBgpNotificationBadMessageLength(int length) { |
| int errorCode = MessageHeaderError.ERROR_CODE; |
| int errorSubcode = MessageHeaderError.BAD_MESSAGE_LENGTH; |
| ChannelBuffer data = ChannelBuffers.buffer(2); |
| data.writeShort(length); |
| |
| return prepareBgpNotification(errorCode, errorSubcode, data); |
| } |
| |
| /** |
| * Prepares BGP UPDATE Notification data payload. |
| * |
| * @param attrTypeCode the attribute type code |
| * @param attrLen the attribute length (in octets) |
| * @param attrFlags the attribute flags |
| * @param message the message with the data |
| * @return the buffer with the data payload for the BGP UPDATE Notification |
| */ |
| private ChannelBuffer prepareBgpUpdateNotificationDataPayload( |
| int attrTypeCode, |
| int attrLen, |
| int attrFlags, |
| ChannelBuffer message) { |
| // Compute the attribute length field octets |
| boolean extendedLengthBit = ((0x10 & attrFlags) != 0); |
| int attrLenOctets = 1; |
| if (extendedLengthBit) { |
| attrLenOctets = 2; |
| } |
| ChannelBuffer data = |
| ChannelBuffers.buffer(attrLen + attrLenOctets + 1); |
| data.writeByte(attrTypeCode); |
| if (extendedLengthBit) { |
| data.writeShort(attrLen); |
| } else { |
| data.writeByte(attrLen); |
| } |
| data.writeBytes(message, attrLen); |
| return data; |
| } |
| |
| /** |
| * Prepares BGP message. |
| * |
| * @param type the BGP message type |
| * @param payload the message payload to transmit (BGP header excluded) |
| * @return the message to transmit (BGP header included) |
| */ |
| private ChannelBuffer prepareBgpMessage(int type, ChannelBuffer payload) { |
| ChannelBuffer message = |
| ChannelBuffers.buffer(BgpConstants.BGP_HEADER_LENGTH + |
| payload.readableBytes()); |
| |
| // Write the marker |
| for (int i = 0; i < BgpConstants.BGP_HEADER_MARKER_LENGTH; i++) { |
| message.writeByte(0xff); |
| } |
| |
| // Write the rest of the BGP header |
| message.writeShort(BgpConstants.BGP_HEADER_LENGTH + |
| payload.readableBytes()); |
| message.writeByte(type); |
| |
| // Write the payload |
| message.writeBytes(payload); |
| return message; |
| } |
| |
| /** |
| * Restarts the BGP KeepaliveTimer. |
| */ |
| private void restartKeepaliveTimer(ChannelHandlerContext ctx) { |
| if (localKeepaliveInterval == 0) { |
| return; // Nothing to do |
| } |
| keepaliveTimeout = timer.newTimeout(new TransmitKeepaliveTask(ctx), |
| localKeepaliveInterval, |
| TimeUnit.SECONDS); |
| } |
| |
| /** |
| * Task class for transmitting KEEPALIVE messages. |
| */ |
| private final class TransmitKeepaliveTask implements TimerTask { |
| private final ChannelHandlerContext ctx; |
| |
| /** |
| * Constructor for given Channel Handler Context. |
| * |
| * @param ctx the Channel Handler Context to use |
| */ |
| TransmitKeepaliveTask(ChannelHandlerContext ctx) { |
| this.ctx = ctx; |
| } |
| |
| @Override |
| public void run(Timeout timeout) throws Exception { |
| if (timeout.isCancelled()) { |
| return; |
| } |
| if (!ctx.getChannel().isOpen()) { |
| return; |
| } |
| |
| // Transmit the KEEPALIVE |
| ChannelBuffer txMessage = prepareBgpKeepalive(); |
| ctx.getChannel().write(txMessage); |
| |
| // Restart the KEEPALIVE timer |
| restartKeepaliveTimer(ctx); |
| } |
| } |
| |
| /** |
| * Restarts the BGP Session Timeout Timer. |
| */ |
| private void restartSessionTimeoutTimer(ChannelHandlerContext ctx) { |
| if (remoteHoldtime == 0) { |
| return; // Nothing to do |
| } |
| if (sessionTimeout != null) { |
| sessionTimeout.cancel(); |
| } |
| sessionTimeout = timer.newTimeout(new SessionTimeoutTask(ctx), |
| remoteHoldtime, |
| TimeUnit.SECONDS); |
| } |
| |
| /** |
| * Task class for BGP Session timeout. |
| */ |
| private final class SessionTimeoutTask implements TimerTask { |
| private final ChannelHandlerContext ctx; |
| |
| /** |
| * Constructor for given Channel Handler Context. |
| * |
| * @param ctx the Channel Handler Context to use |
| */ |
| SessionTimeoutTask(ChannelHandlerContext ctx) { |
| this.ctx = ctx; |
| } |
| |
| @Override |
| public void run(Timeout timeout) throws Exception { |
| if (timeout.isCancelled()) { |
| return; |
| } |
| if (!ctx.getChannel().isOpen()) { |
| return; |
| } |
| |
| log.debug("BGP Session Timeout: peer {}", remoteAddress); |
| // |
| // ERROR: Invalid Optional Parameter Length field: Unspecific |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = HoldTimerExpired.ERROR_CODE; |
| int errorSubcode = Notifications.ERROR_SUBCODE_UNSPECIFIC; |
| ChannelBuffer txMessage = |
| prepareBgpNotification(errorCode, errorSubcode, null); |
| ctx.getChannel().write(txMessage); |
| closeChannel(ctx); |
| } |
| } |
| |
| /** |
| * An exception indicating a parsing error of the BGP message. |
| */ |
| private static class BgpParseException extends Exception { |
| /** |
| * Default constructor. |
| */ |
| public BgpParseException() { |
| super(); |
| } |
| |
| /** |
| * Constructor for a specific exception details message. |
| * |
| * @param message the message with the exception details |
| */ |
| public BgpParseException(String message) { |
| super(message); |
| } |
| } |
| } |