/*
* Copyright 2017-present 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.routing.bgp;
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.onlab.packet.Ip4Address;
import org.onlab.packet.Ip4Prefix;
import org.onlab.packet.Ip6Address;
import org.onlab.packet.Ip6Prefix;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
/**
* A class for handling BGP UPDATE messages.
*/
final class BgpUpdate {
private static final Logger log = LoggerFactory.getLogger(BgpUpdate.class);
/**
* Default constructor.
* <p>
* The constructor is private to prevent creating an instance of
* this utility class.
*/
private BgpUpdate() {
}
/**
* Processes BGP UPDATE message.
*
* @param bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
* @param message the message to process
*/
static void processBgpUpdate(BgpSession bgpSession,
ChannelHandlerContext ctx,
ChannelBuffer message) {
DecodedBgpRoutes decodedBgpRoutes = new DecodedBgpRoutes();
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 {}",
bgpSession.remoteInfo().address(),
message.readableBytes(), minLength);
//
// ERROR: Bad Message Length
//
// Send NOTIFICATION and close the connection
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotificationBadMessageLength(
message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
return;
}
log.debug("BGP RX UPDATE message from {}",
bgpSession.remoteInfo().address());
//
// Parse the UPDATE message
//
//
// Parse the Withdrawn Routes
//
int withdrawnRoutesLength = message.readUnsignedShort();
if (withdrawnRoutesLength > message.readableBytes()) {
// ERROR: Malformed Attribute List
actionsBgpUpdateMalformedAttributeList(bgpSession, ctx);
return;
}
Collection<Ip4Prefix> withdrawnPrefixes = null;
try {
withdrawnPrefixes = parsePackedIp4Prefixes(withdrawnRoutesLength,
message);
} catch (BgpMessage.BgpParseException e) {
// ERROR: Invalid Network Field
log.debug("Exception parsing Withdrawn Prefixes from BGP peer {}: ",
bgpSession.remoteInfo().bgpId(), e);
actionsBgpUpdateInvalidNetworkField(bgpSession, ctx);
return;
}
for (Ip4Prefix prefix : withdrawnPrefixes) {
log.debug("BGP RX UPDATE message WITHDRAWN from {}: {}",
bgpSession.remoteInfo().address(), prefix);
BgpRouteEntry bgpRouteEntry = bgpSession.findBgpRoute(prefix);
if (bgpRouteEntry != null) {
decodedBgpRoutes.deletedUnicastRoutes4.put(prefix,
bgpRouteEntry);
}
}
//
// Parse the Path Attributes
//
try {
parsePathAttributes(bgpSession, ctx, message, decodedBgpRoutes);
} catch (BgpMessage.BgpParseException e) {
log.debug("Exception parsing Path Attributes from BGP peer {}: ",
bgpSession.remoteInfo().bgpId(), e);
// NOTE: The session was already closed, so nothing else to do
return;
}
//
// Update the BGP RIB-IN
//
for (Ip4Prefix ip4Prefix :
decodedBgpRoutes.deletedUnicastRoutes4.keySet()) {
bgpSession.removeBgpRoute(ip4Prefix);
}
//
for (BgpRouteEntry bgpRouteEntry :
decodedBgpRoutes.addedUnicastRoutes4.values()) {
bgpSession.addBgpRoute(bgpRouteEntry);
}
//
for (Ip6Prefix ip6Prefix :
decodedBgpRoutes.deletedUnicastRoutes6.keySet()) {
bgpSession.removeBgpRoute(ip6Prefix);
}
//
for (BgpRouteEntry bgpRouteEntry :
decodedBgpRoutes.addedUnicastRoutes6.values()) {
bgpSession.addBgpRoute(bgpRouteEntry);
}
//
// Push the updates to the BGP Merged RIB
//
BgpRouteSelector bgpRouteSelector =
bgpSession.getBgpSessionManager().getBgpRouteSelector();
bgpRouteSelector.routeUpdates(
decodedBgpRoutes.addedUnicastRoutes4.values(),
decodedBgpRoutes.deletedUnicastRoutes4.values());
bgpRouteSelector.routeUpdates(
decodedBgpRoutes.addedUnicastRoutes6.values(),
decodedBgpRoutes.deletedUnicastRoutes6.values());
// Start the Session Timeout timer
bgpSession.restartSessionTimeoutTimer(ctx);
}
/**
* Parse BGP Path Attributes from the BGP UPDATE message.
*
* @param bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
* @param message the message to parse
* @param decodedBgpRoutes the container to store the decoded BGP Route
* Entries. It might already contain some route entries such as withdrawn
* IPv4 prefixes
* @throws BgpMessage.BgpParseException
*/
// CHECKSTYLE IGNORE MethodLength FOR NEXT 300 LINES
private static void parsePathAttributes(
BgpSession bgpSession,
ChannelHandlerContext ctx,
ChannelBuffer message,
DecodedBgpRoutes decodedBgpRoutes)
throws BgpMessage.BgpParseException {
//
// Parsed values
//
Short origin = -1; // Mandatory
BgpRouteEntry.AsPath asPath = null; // Mandatory
// Legacy NLRI (RFC 4271). Mandatory NEXT_HOP if legacy NLRI is used
MpNlri legacyNlri = new MpNlri(
BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV4,
BgpConstants.Open.Capabilities.MultiprotocolExtensions.SAFI_UNICAST);
long multiExitDisc = // Optional
BgpConstants.Update.MultiExitDisc.LOWEST_MULTI_EXIT_DISC;
Long localPref = null; // Mandatory
Long aggregatorAsNumber = null; // Optional: unused
Ip4Address aggregatorIpAddress = null; // Optional: unused
Collection<MpNlri> mpNlriReachList = new ArrayList<>(); // Optional
Collection<MpNlri> mpNlriUnreachList = new ArrayList<>(); // Optional
//
// Get and verify the Path Attributes Length
//
int pathAttributeLength = message.readUnsignedShort();
if (pathAttributeLength > message.readableBytes()) {
// ERROR: Malformed Attribute List
actionsBgpUpdateMalformedAttributeList(bgpSession, ctx);
String errorMsg = "Malformed Attribute List";
throw new BgpMessage.BgpParseException(errorMsg);
}
if (pathAttributeLength == 0) {
return;
}
//
// 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(bgpSession, ctx);
String errorMsg = "Malformed Attribute List";
throw new BgpMessage.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(bgpSession, ctx);
String errorMsg = "Malformed Attribute List";
throw new BgpMessage.BgpParseException(errorMsg);
}
if (extendedLengthBit) {
attrLen = message.readUnsignedShort();
} else {
attrLen = message.readUnsignedByte();
}
if (message.readerIndex() + attrLen > pathAttributeEnd) {
// ERROR: Malformed Attribute List
actionsBgpUpdateMalformedAttributeList(bgpSession, ctx);
String errorMsg = "Malformed Attribute List";
throw new BgpMessage.BgpParseException(errorMsg);
}
// Verify the Attribute Flags
verifyBgpUpdateAttributeFlags(bgpSession, 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(bgpSession, ctx,
attrTypeCode, attrLen,
attrFlags, message);
break;
case BgpConstants.Update.AsPath.TYPE:
// Attribute Type Code AS_PATH
asPath = parseAttributeTypeAsPath(bgpSession, ctx,
attrTypeCode, attrLen,
attrFlags, message);
break;
case BgpConstants.Update.NextHop.TYPE:
// Attribute Type Code NEXT_HOP
legacyNlri.nextHop4 =
parseAttributeTypeNextHop(bgpSession, ctx,
attrTypeCode, attrLen,
attrFlags, message);
break;
case BgpConstants.Update.MultiExitDisc.TYPE:
// Attribute Type Code MULTI_EXIT_DISC
multiExitDisc =
parseAttributeTypeMultiExitDisc(bgpSession, ctx,
attrTypeCode, attrLen,
attrFlags, message);
break;
case BgpConstants.Update.LocalPref.TYPE:
// Attribute Type Code LOCAL_PREF
localPref =
parseAttributeTypeLocalPref(bgpSession, ctx,
attrTypeCode, attrLen,
attrFlags, message);
break;
case BgpConstants.Update.AtomicAggregate.TYPE:
// Attribute Type Code ATOMIC_AGGREGATE
parseAttributeTypeAtomicAggregate(bgpSession, 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(bgpSession, ctx,
attrTypeCode, attrLen,
attrFlags, message);
aggregatorAsNumber = aggregator.getLeft();
aggregatorIpAddress = aggregator.getRight();
break;
case BgpConstants.Update.MpReachNlri.TYPE:
// Attribute Type Code MP_REACH_NLRI
MpNlri mpNlriReach =
parseAttributeTypeMpReachNlri(bgpSession, ctx,
attrTypeCode,
attrLen,
attrFlags, message);
if (mpNlriReach != null) {
mpNlriReachList.add(mpNlriReach);
}
break;
case BgpConstants.Update.MpUnreachNlri.TYPE:
// Attribute Type Code MP_UNREACH_NLRI
MpNlri mpNlriUnreach =
parseAttributeTypeMpUnreachNlri(bgpSession, ctx,
attrTypeCode, attrLen,
attrFlags, message);
if (mpNlriUnreach != null) {
mpNlriUnreachList.add(mpNlriUnreach);
}
break;
default:
// NOTE: Parse any new Attribute Types if needed
if (!optionalBit) {
// ERROR: Unrecognized Well-known Attribute
actionsBgpUpdateUnrecognizedWellKnownAttribute(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags,
message);
String errorMsg = "Unrecognized Well-known Attribute: " +
attrTypeCode;
throw new BgpMessage.BgpParseException(errorMsg);
}
// Skip the data from the unrecognized attribute
log.debug("BGP RX UPDATE message from {}: " +
"Unrecognized Attribute Type {}",
bgpSession.remoteInfo().address(), attrTypeCode);
message.skipBytes(attrLen);
break;
}
}
//
// Parse the NLRI (Network Layer Reachability Information)
//
int nlriLength = message.readableBytes();
try {
Collection<Ip4Prefix> addedPrefixes4 =
parsePackedIp4Prefixes(nlriLength, message);
// Store it inside the legacy NLRI wrapper
legacyNlri.nlri4 = addedPrefixes4;
} catch (BgpMessage.BgpParseException e) {
// ERROR: Invalid Network Field
log.debug("Exception parsing NLRI from BGP peer {}: ",
bgpSession.remoteInfo().bgpId(), e);
actionsBgpUpdateInvalidNetworkField(bgpSession, ctx);
// Rethrow the exception
throw e;
}
// Verify the Well-known Attributes
verifyBgpUpdateWellKnownAttributes(bgpSession, ctx, origin, asPath,
localPref, legacyNlri,
mpNlriReachList);
//
// Generate the deleted routes
//
for (MpNlri mpNlri : mpNlriUnreachList) {
BgpRouteEntry bgpRouteEntry;
// The deleted IPv4 routes
for (Ip4Prefix prefix : mpNlri.nlri4) {
bgpRouteEntry = bgpSession.findBgpRoute(prefix);
if (bgpRouteEntry != null) {
decodedBgpRoutes.deletedUnicastRoutes4.put(prefix,
bgpRouteEntry);
}
}
// The deleted IPv6 routes
for (Ip6Prefix prefix : mpNlri.nlri6) {
bgpRouteEntry = bgpSession.findBgpRoute(prefix);
if (bgpRouteEntry != null) {
decodedBgpRoutes.deletedUnicastRoutes6.put(prefix,
bgpRouteEntry);
}
}
}
//
// Generate the added routes
//
mpNlriReachList.add(legacyNlri);
for (MpNlri mpNlri : mpNlriReachList) {
BgpRouteEntry bgpRouteEntry;
// The added IPv4 routes
for (Ip4Prefix prefix : mpNlri.nlri4) {
bgpRouteEntry =
new BgpRouteEntry(bgpSession, prefix, mpNlri.nextHop4,
origin.byteValue(), asPath, localPref);
bgpRouteEntry.setMultiExitDisc(multiExitDisc);
if (bgpRouteEntry.hasAsPathLoop(bgpSession.localInfo().asNumber())) {
log.debug("BGP RX UPDATE message IGNORED from {}: {} " +
"nextHop {}: contains AS Path loop",
bgpSession.remoteInfo().address(), prefix,
mpNlri.nextHop4);
continue;
} else {
log.debug("BGP RX UPDATE message ADDED from {}: {} nextHop {}",
bgpSession.remoteInfo().address(), prefix,
mpNlri.nextHop4);
}
// Remove from the collection of deleted routes
decodedBgpRoutes.deletedUnicastRoutes4.remove(prefix);
decodedBgpRoutes.addedUnicastRoutes4.put(prefix,
bgpRouteEntry);
}
// The added IPv6 routes
for (Ip6Prefix prefix : mpNlri.nlri6) {
bgpRouteEntry =
new BgpRouteEntry(bgpSession, prefix, mpNlri.nextHop6,
origin.byteValue(), asPath, localPref);
bgpRouteEntry.setMultiExitDisc(multiExitDisc);
if (bgpRouteEntry.hasAsPathLoop(bgpSession.localInfo().asNumber())) {
log.debug("BGP RX UPDATE message IGNORED from {}: {} " +
"nextHop {}: contains AS Path loop",
bgpSession.remoteInfo().address(), prefix,
mpNlri.nextHop6);
continue;
} else {
log.debug("BGP RX UPDATE message ADDED from {}: {} nextHop {}",
bgpSession.remoteInfo().address(), prefix,
mpNlri.nextHop6);
}
// Remove from the collection of deleted routes
decodedBgpRoutes.deletedUnicastRoutes6.remove(prefix);
decodedBgpRoutes.addedUnicastRoutes6.put(prefix,
bgpRouteEntry);
}
}
}
/**
* Verifies BGP UPDATE Well-known Attributes.
*
* @param bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
* @param origin the ORIGIN well-known mandatory attribute
* @param asPath the AS_PATH well-known mandatory attribute
* @param localPref the LOCAL_PREF required attribute
* @param legacyNlri the legacy NLRI. Encapsulates the NEXT_HOP well-known
* mandatory attribute (mandatory if legacy NLRI is used).
* @param mpNlriReachList the Multiprotocol NLRI attributes
* @throws BgpMessage.BgpParseException
*/
private static void verifyBgpUpdateWellKnownAttributes(
BgpSession bgpSession,
ChannelHandlerContext ctx,
Short origin,
BgpRouteEntry.AsPath asPath,
Long localPref,
MpNlri legacyNlri,
Collection<MpNlri> mpNlriReachList)
throws BgpMessage.BgpParseException {
boolean hasNlri = false;
boolean hasLegacyNlri = false;
//
// Convenience flags that are used to check for missing attributes.
//
// NOTE: The hasLegacyNlri flag is always set to true if the
// Multiprotocol Extensions are not enabled, even if the UPDATE
// message doesn't contain the legacy NLRI (per RFC 4271).
//
if (!bgpSession.mpExtensions()) {
hasNlri = true;
hasLegacyNlri = true;
} else {
if (!legacyNlri.nlri4.isEmpty()) {
hasNlri = true;
hasLegacyNlri = true;
}
if (!mpNlriReachList.isEmpty()) {
hasNlri = true;
}
}
//
// Check for Missing Well-known Attributes
//
if (hasNlri && ((origin == null) || (origin == -1))) {
// Missing Attribute Type Code ORIGIN
int type = BgpConstants.Update.Origin.TYPE;
actionsBgpUpdateMissingWellKnownAttribute(bgpSession, ctx, type);
String errorMsg = "Missing Well-known Attribute: ORIGIN";
throw new BgpMessage.BgpParseException(errorMsg);
}
if (hasNlri && (asPath == null)) {
// Missing Attribute Type Code AS_PATH
int type = BgpConstants.Update.AsPath.TYPE;
actionsBgpUpdateMissingWellKnownAttribute(bgpSession, ctx, type);
String errorMsg = "Missing Well-known Attribute: AS_PATH";
throw new BgpMessage.BgpParseException(errorMsg);
}
if (hasNlri && (localPref == null)) {
// Missing Attribute Type Code LOCAL_PREF
// NOTE: Required for iBGP
int type = BgpConstants.Update.LocalPref.TYPE;
actionsBgpUpdateMissingWellKnownAttribute(bgpSession, ctx, type);
String errorMsg = "Missing Well-known Attribute: LOCAL_PREF";
throw new BgpMessage.BgpParseException(errorMsg);
}
if (hasLegacyNlri && (legacyNlri.nextHop4 == null)) {
// Missing Attribute Type Code NEXT_HOP
int type = BgpConstants.Update.NextHop.TYPE;
actionsBgpUpdateMissingWellKnownAttribute(bgpSession, ctx, type);
String errorMsg = "Missing Well-known Attribute: NEXT_HOP";
throw new BgpMessage.BgpParseException(errorMsg);
}
}
/**
* Verifies the BGP UPDATE Attribute Flags.
*
* @param bgpSession the BGP Session to use
* @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 BgpMessage.BgpParseException
*/
private static void verifyBgpUpdateAttributeFlags(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.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;
case BgpConstants.Update.MpReachNlri.TYPE:
isWellKnown = false;
typeName = "MP_REACH_NLRI";
break;
case BgpConstants.Update.MpUnreachNlri.TYPE:
isWellKnown = false;
typeName = "MP_UNREACH_NLRI";
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(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Flags Error for " + typeName + ": " +
attrFlags;
throw new BgpMessage.BgpParseException(errorMsg);
}
}
/**
* Parses BGP UPDATE Attribute Type ORIGIN.
*
* @param bgpSession the BGP Session to use
* @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 BgpMessage.BgpParseException
*/
private static short parseAttributeTypeOrigin(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
// Check the Attribute Length
if (attrLen != BgpConstants.Update.Origin.LENGTH) {
// ERROR: Attribute Length Error
actionsBgpUpdateAttributeLengthError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Length Error";
throw new BgpMessage.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(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message,
origin);
String errorMsg = "Invalid ORIGIN Attribute: " + origin;
throw new BgpMessage.BgpParseException(errorMsg);
}
return origin;
}
/**
* Parses BGP UPDATE Attribute AS Path.
*
* @param bgpSession the BGP Session to use
* @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 BgpMessage.BgpParseException
*/
private static BgpRouteEntry.AsPath parseAttributeTypeAsPath(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
ArrayList<BgpRouteEntry.PathSegment> pathSegments = new ArrayList<>();
//
// Parse the message
//
while (attrLen > 0) {
if (attrLen < 2) {
// ERROR: Malformed AS_PATH
actionsBgpUpdateMalformedAsPath(bgpSession, ctx);
String errorMsg = "Malformed AS Path";
throw new BgpMessage.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(bgpSession, ctx);
String errorMsg =
"Invalid AS Path Segment Type: " + pathSegmentType;
throw new BgpMessage.BgpParseException(errorMsg);
}
// 4-octet AS number handling.
int asPathLen;
if (bgpSession.isAs4OctetCapable()) {
asPathLen = BgpConstants.Update.AS_4OCTET_LENGTH;
} else {
asPathLen = BgpConstants.Update.AS_LENGTH;
}
// Parse the AS numbers
if (asPathLen * pathSegmentLength > attrLen) {
// ERROR: Malformed AS_PATH
actionsBgpUpdateMalformedAsPath(bgpSession, ctx);
String errorMsg = "Malformed AS Path";
throw new BgpMessage.BgpParseException(errorMsg);
}
attrLen -= (asPathLen * pathSegmentLength);
ArrayList<Long> segmentAsNumbers = new ArrayList<>();
while (pathSegmentLength-- > 0) {
long asNumber;
if (asPathLen == BgpConstants.Update.AS_4OCTET_LENGTH) {
asNumber = message.readUnsignedInt();
} else {
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 bgpSession the BGP Session to use
* @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 BgpMessage.BgpParseException
*/
private static Ip4Address parseAttributeTypeNextHop(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
// Check the Attribute Length
if (attrLen != BgpConstants.Update.NextHop.LENGTH) {
// ERROR: Attribute Length Error
actionsBgpUpdateAttributeLengthError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Length Error";
throw new BgpMessage.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(bgpSession.localInfo().ip4Address())) {
// ERROR: Invalid NEXT_HOP Attribute
message.resetReaderIndex();
actionsBgpUpdateInvalidNextHopAttribute(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message,
nextHopAddress);
String errorMsg = "Invalid NEXT_HOP Attribute: " + nextHopAddress;
throw new BgpMessage.BgpParseException(errorMsg);
}
return nextHopAddress;
}
/**
* Parses BGP UPDATE Attribute Type MULTI_EXIT_DISC.
*
* @param bgpSession the BGP Session to use
* @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 BgpMessage.BgpParseException
*/
private static long parseAttributeTypeMultiExitDisc(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
// Check the Attribute Length
if (attrLen != BgpConstants.Update.MultiExitDisc.LENGTH) {
// ERROR: Attribute Length Error
actionsBgpUpdateAttributeLengthError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Length Error";
throw new BgpMessage.BgpParseException(errorMsg);
}
long multiExitDisc = message.readUnsignedInt();
return multiExitDisc;
}
/**
* Parses BGP UPDATE Attribute Type LOCAL_PREF.
*
* @param bgpSession the BGP Session to use
* @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 BgpMessage.BgpParseException
*/
private static long parseAttributeTypeLocalPref(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
// Check the Attribute Length
if (attrLen != BgpConstants.Update.LocalPref.LENGTH) {
// ERROR: Attribute Length Error
actionsBgpUpdateAttributeLengthError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Length Error";
throw new BgpMessage.BgpParseException(errorMsg);
}
long localPref = message.readUnsignedInt();
return localPref;
}
/**
* Parses BGP UPDATE Attribute Type ATOMIC_AGGREGATE.
*
* @param bgpSession the BGP Session to use
* @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 BgpMessage.BgpParseException
*/
private static void parseAttributeTypeAtomicAggregate(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
// Check the Attribute Length
if (attrLen != BgpConstants.Update.AtomicAggregate.LENGTH) {
// ERROR: Attribute Length Error
actionsBgpUpdateAttributeLengthError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Length Error";
throw new BgpMessage.BgpParseException(errorMsg);
}
// Nothing to do: this attribute is primarily informational
}
/**
* Parses BGP UPDATE Attribute Type AGGREGATOR.
*
* @param bgpSession the BGP Session to use
* @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 BgpMessage.BgpParseException
*/
private static Pair<Long, Ip4Address> parseAttributeTypeAggregator(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
int expectedAttrLen;
if (bgpSession.isAs4OctetCapable()) {
expectedAttrLen = BgpConstants.Update.Aggregator.AS4_LENGTH;
} else {
expectedAttrLen = BgpConstants.Update.Aggregator.AS2_LENGTH;
}
// Check the Attribute Length
if (attrLen != expectedAttrLen) {
// ERROR: Attribute Length Error
actionsBgpUpdateAttributeLengthError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Length Error";
throw new BgpMessage.BgpParseException(errorMsg);
}
// The AGGREGATOR AS number
long aggregatorAsNumber;
if (bgpSession.isAs4OctetCapable()) {
aggregatorAsNumber = message.readUnsignedInt();
} else {
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 BGP UPDATE Attribute Type MP_REACH_NLRI.
*
* @param bgpSession the BGP Session to use
* @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 MP_REACH_NLRI information if recognized, otherwise
* null
* @throws BgpMessage.BgpParseException
*/
private static MpNlri parseAttributeTypeMpReachNlri(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
int attributeEnd = message.readerIndex() + attrLen;
// Check the Attribute Length
if (attrLen < BgpConstants.Update.MpReachNlri.MIN_LENGTH) {
// ERROR: Attribute Length Error
actionsBgpUpdateAttributeLengthError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Length Error";
throw new BgpMessage.BgpParseException(errorMsg);
}
message.markReaderIndex();
int afi = message.readUnsignedShort();
int safi = message.readUnsignedByte();
int nextHopLen = message.readUnsignedByte();
//
// Verify the AFI/SAFI, and skip the attribute if not recognized.
// NOTE: Currently, we support only IPv4/IPv6 UNICAST
//
if (((afi != BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV4) &&
(afi != BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV6)) ||
(safi != BgpConstants.Open.Capabilities.MultiprotocolExtensions.SAFI_UNICAST)) {
// Skip the attribute
message.resetReaderIndex();
message.skipBytes(attrLen);
return null;
}
//
// Verify the next-hop length
//
int expectedNextHopLen = 0;
switch (afi) {
case BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV4:
expectedNextHopLen = Ip4Address.BYTE_LENGTH;
break;
case BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV6:
expectedNextHopLen = Ip6Address.BYTE_LENGTH;
break;
default:
// UNREACHABLE
break;
}
if (nextHopLen != expectedNextHopLen) {
// ERROR: Optional Attribute Error
message.resetReaderIndex();
actionsBgpUpdateOptionalAttributeError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Invalid next-hop network address length. " +
"Received " + nextHopLen + " expected " + expectedNextHopLen;
throw new BgpMessage.BgpParseException(errorMsg);
}
// NOTE: We use "+ 1" to take into account the Reserved field (1 octet)
if (message.readerIndex() + nextHopLen + 1 >= attributeEnd) {
// ERROR: Optional Attribute Error
message.resetReaderIndex();
actionsBgpUpdateOptionalAttributeError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Malformed next-hop network address";
throw new BgpMessage.BgpParseException(errorMsg);
}
//
// Get the Next-hop address, skip the Reserved field, and get the NLRI
//
byte[] nextHopBuffer = new byte[nextHopLen];
message.readBytes(nextHopBuffer, 0, nextHopLen);
int reserved = message.readUnsignedByte();
MpNlri mpNlri = new MpNlri(afi, safi);
try {
switch (afi) {
case BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV4:
// The next-hop address
mpNlri.nextHop4 = Ip4Address.valueOf(nextHopBuffer);
// The NLRI
mpNlri.nlri4 = parsePackedIp4Prefixes(
attributeEnd - message.readerIndex(),
message);
break;
case BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV6:
// The next-hop address
mpNlri.nextHop6 = Ip6Address.valueOf(nextHopBuffer);
// The NLRI
mpNlri.nlri6 = parsePackedIp6Prefixes(
attributeEnd - message.readerIndex(),
message);
break;
default:
// UNREACHABLE
break;
}
} catch (BgpMessage.BgpParseException e) {
// ERROR: Optional Attribute Error
message.resetReaderIndex();
actionsBgpUpdateOptionalAttributeError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Malformed network layer reachability information";
throw new BgpMessage.BgpParseException(errorMsg);
}
return mpNlri;
}
/**
* Parses BGP UPDATE Attribute Type MP_UNREACH_NLRI.
*
* @param bgpSession the BGP Session to use
* @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 MP_UNREACH_NLRI information if recognized, otherwise
* null
* @throws BgpMessage.BgpParseException
*/
private static MpNlri parseAttributeTypeMpUnreachNlri(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
int attributeEnd = message.readerIndex() + attrLen;
// Check the Attribute Length
if (attrLen < BgpConstants.Update.MpUnreachNlri.MIN_LENGTH) {
// ERROR: Attribute Length Error
actionsBgpUpdateAttributeLengthError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Length Error";
throw new BgpMessage.BgpParseException(errorMsg);
}
message.markReaderIndex();
int afi = message.readUnsignedShort();
int safi = message.readUnsignedByte();
//
// Verify the AFI/SAFI, and skip the attribute if not recognized.
// NOTE: Currently, we support only IPv4/IPv6 UNICAST
//
if (((afi != BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV4) &&
(afi != BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV6)) ||
(safi != BgpConstants.Open.Capabilities.MultiprotocolExtensions.SAFI_UNICAST)) {
// Skip the attribute
message.resetReaderIndex();
message.skipBytes(attrLen);
return null;
}
//
// Get the Withdrawn Routes
//
MpNlri mpNlri = new MpNlri(afi, safi);
try {
switch (afi) {
case BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV4:
// The Withdrawn Routes
mpNlri.nlri4 = parsePackedIp4Prefixes(
attributeEnd - message.readerIndex(),
message);
break;
case BgpConstants.Open.Capabilities.MultiprotocolExtensions.AFI_IPV6:
// The Withdrawn Routes
mpNlri.nlri6 = parsePackedIp6Prefixes(
attributeEnd - message.readerIndex(),
message);
break;
default:
// UNREACHABLE
break;
}
} catch (BgpMessage.BgpParseException e) {
// ERROR: Optional Attribute Error
message.resetReaderIndex();
actionsBgpUpdateOptionalAttributeError(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Malformed withdrawn routes";
throw new BgpMessage.BgpParseException(errorMsg);
}
return mpNlri;
}
/**
* 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 BgpMessage.BgpParseException
*/
private static Collection<Ip4Prefix> parsePackedIp4Prefixes(
int totalLength,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
Collection<Ip4Prefix> result = new ArrayList<>();
if (totalLength == 0) {
return result;
}
// Parse the data
byte[] buffer = new byte[Ip4Address.BYTE_LENGTH];
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 BgpMessage.BgpParseException(errorMsg);
}
message.readBytes(buffer, 0, prefixBytelen);
Ip4Prefix prefix = Ip4Prefix.valueOf(Ip4Address.valueOf(buffer),
prefixBitlen);
result.add(prefix);
}
return result;
}
/**
* Parses a message that contains encoded IPv6 network prefixes.
* <p>
* The IPv6 prefixes are encoded in the form:
* <Length, Prefix> where Length is the length in bits of the IPv6 prefix,
* and Prefix is the IPv6 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 IPv6 network prefixes
* @throws BgpMessage.BgpParseException
*/
private static Collection<Ip6Prefix> parsePackedIp6Prefixes(
int totalLength,
ChannelBuffer message)
throws BgpMessage.BgpParseException {
Collection<Ip6Prefix> result = new ArrayList<>();
if (totalLength == 0) {
return result;
}
// Parse the data
byte[] buffer = new byte[Ip6Address.BYTE_LENGTH];
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 BgpMessage.BgpParseException(errorMsg);
}
message.readBytes(buffer, 0, prefixBytelen);
Ip6Prefix prefix = Ip6Prefix.valueOf(Ip6Address.valueOf(buffer),
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 bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
*/
private static void actionsBgpUpdateInvalidNetworkField(
BgpSession bgpSession,
ChannelHandlerContext ctx) {
log.debug("BGP RX UPDATE Error from {}: Invalid Network Field",
bgpSession.remoteInfo().address());
//
// ERROR: Invalid Network Field
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode = BgpConstants.Notifications.UpdateMessageError.INVALID_NETWORK_FIELD;
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
null);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* Applies the appropriate actions after detecting BGP UPDATE
* Malformed Attribute List Error: send NOTIFICATION and close the channel.
*
* @param bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
*/
private static void actionsBgpUpdateMalformedAttributeList(
BgpSession bgpSession,
ChannelHandlerContext ctx) {
log.debug("BGP RX UPDATE Error from {}: Malformed Attribute List",
bgpSession.remoteInfo().address());
//
// ERROR: Malformed Attribute List
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode = BgpConstants.Notifications.UpdateMessageError.MALFORMED_ATTRIBUTE_LIST;
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
null);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* Applies the appropriate actions after detecting BGP UPDATE
* Missing Well-known Attribute Error: send NOTIFICATION and close the
* channel.
*
* @param bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
* @param missingAttrTypeCode the missing attribute type code
*/
private static void actionsBgpUpdateMissingWellKnownAttribute(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int missingAttrTypeCode) {
log.debug("BGP RX UPDATE Error from {}: Missing Well-known Attribute: {}",
bgpSession.remoteInfo().address(), missingAttrTypeCode);
//
// ERROR: Missing Well-known Attribute
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode = BgpConstants.Notifications.UpdateMessageError.MISSING_WELL_KNOWN_ATTRIBUTE;
ChannelBuffer data = ChannelBuffers.buffer(1);
data.writeByte(missingAttrTypeCode);
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
data);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* Applies the appropriate actions after detecting BGP UPDATE
* Invalid ORIGIN Attribute Error: send NOTIFICATION and close the channel.
*
* @param bgpSession the BGP Session to use
* @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 static void actionsBgpUpdateInvalidOriginAttribute(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message,
short origin) {
log.debug("BGP RX UPDATE Error from {}: Invalid ORIGIN Attribute",
bgpSession.remoteInfo().address());
//
// ERROR: Invalid ORIGIN Attribute
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode = BgpConstants.Notifications.UpdateMessageError.INVALID_ORIGIN_ATTRIBUTE;
ChannelBuffer data =
prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen,
attrFlags, message);
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
data);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* Applies the appropriate actions after detecting BGP UPDATE
* Attribute Flags Error: send NOTIFICATION and close the channel.
*
* @param bgpSession the BGP Session to use
* @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 static void actionsBgpUpdateAttributeFlagsError(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message) {
log.debug("BGP RX UPDATE Error from {}: Attribute Flags Error",
bgpSession.remoteInfo().address());
//
// ERROR: Attribute Flags Error
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode = BgpConstants.Notifications.UpdateMessageError.ATTRIBUTE_FLAGS_ERROR;
ChannelBuffer data =
prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen,
attrFlags, message);
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
data);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* Applies the appropriate actions after detecting BGP UPDATE
* Invalid NEXT_HOP Attribute Error: send NOTIFICATION and close the
* channel.
*
* @param bgpSession the BGP Session to use
* @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 static void actionsBgpUpdateInvalidNextHopAttribute(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message,
Ip4Address nextHop) {
log.debug("BGP RX UPDATE Error from {}: Invalid NEXT_HOP Attribute {}",
bgpSession.remoteInfo().address(), nextHop);
//
// ERROR: Invalid NEXT_HOP Attribute
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode = BgpConstants.Notifications.UpdateMessageError.INVALID_NEXT_HOP_ATTRIBUTE;
ChannelBuffer data =
prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen,
attrFlags, message);
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
data);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* Applies the appropriate actions after detecting BGP UPDATE
* Unrecognized Well-known Attribute Error: send NOTIFICATION and close
* the channel.
*
* @param bgpSession the BGP Session to use
* @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 static void actionsBgpUpdateUnrecognizedWellKnownAttribute(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message) {
log.debug("BGP RX UPDATE Error from {}: " +
"Unrecognized Well-known Attribute Error: {}",
bgpSession.remoteInfo().address(), attrTypeCode);
//
// ERROR: Unrecognized Well-known Attribute
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode =
BgpConstants.Notifications.UpdateMessageError.UNRECOGNIZED_WELL_KNOWN_ATTRIBUTE;
ChannelBuffer data =
prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen,
attrFlags, message);
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
data);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* Applies the appropriate actions after detecting BGP UPDATE
* Optional Attribute Error: send NOTIFICATION and close
* the channel.
*
* @param bgpSession the BGP Session to use
* @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 static void actionsBgpUpdateOptionalAttributeError(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message) {
log.debug("BGP RX UPDATE Error from {}: Optional Attribute Error: {}",
bgpSession.remoteInfo().address(), attrTypeCode);
//
// ERROR: Optional Attribute Error
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode =
BgpConstants.Notifications.UpdateMessageError.OPTIONAL_ATTRIBUTE_ERROR;
ChannelBuffer data =
prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen,
attrFlags, message);
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
data);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* Applies the appropriate actions after detecting BGP UPDATE
* Attribute Length Error: send NOTIFICATION and close the channel.
*
* @param bgpSession the BGP Session to use
* @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 static void actionsBgpUpdateAttributeLengthError(
BgpSession bgpSession,
ChannelHandlerContext ctx,
int attrTypeCode,
int attrLen,
int attrFlags,
ChannelBuffer message) {
log.debug("BGP RX UPDATE Error from {}: Attribute Length Error",
bgpSession.remoteInfo().address());
//
// ERROR: Attribute Length Error
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode = BgpConstants.Notifications.UpdateMessageError.ATTRIBUTE_LENGTH_ERROR;
ChannelBuffer data =
prepareBgpUpdateNotificationDataPayload(attrTypeCode, attrLen,
attrFlags, message);
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
data);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* Applies the appropriate actions after detecting BGP UPDATE
* Malformed AS_PATH Error: send NOTIFICATION and close the channel.
*
* @param bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
*/
private static void actionsBgpUpdateMalformedAsPath(
BgpSession bgpSession,
ChannelHandlerContext ctx) {
log.debug("BGP RX UPDATE Error from {}: Malformed AS Path",
bgpSession.remoteInfo().address());
//
// ERROR: Malformed AS_PATH
//
// Send NOTIFICATION and close the connection
int errorCode = BgpConstants.Notifications.UpdateMessageError.ERROR_CODE;
int errorSubcode = BgpConstants.Notifications.UpdateMessageError.MALFORMED_AS_PATH;
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
null);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
}
/**
* 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 static 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;
}
/**
* Helper class for storing Multiprotocol Network Layer Reachability
* information.
*/
private static final class MpNlri {
private final int afi;
private final int safi;
private Ip4Address nextHop4;
private Ip6Address nextHop6;
private Collection<Ip4Prefix> nlri4 = new ArrayList<>();
private Collection<Ip6Prefix> nlri6 = new ArrayList<>();
/**
* Constructor.
*
* @param afi the Address Family Identifier
* @param safi the Subsequent Address Family Identifier
*/
private MpNlri(int afi, int safi) {
this.afi = afi;
this.safi = safi;
}
}
/**
* Helper class for storing decoded BGP routing information.
*/
private static final class DecodedBgpRoutes {
private final Map<Ip4Prefix, BgpRouteEntry> addedUnicastRoutes4 =
new HashMap<>();
private final Map<Ip6Prefix, BgpRouteEntry> addedUnicastRoutes6 =
new HashMap<>();
private final Map<Ip4Prefix, BgpRouteEntry> deletedUnicastRoutes4 =
new HashMap<>();
private final Map<Ip6Prefix, BgpRouteEntry> deletedUnicastRoutes6 =
new HashMap<>();
}
}