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Pavlin Radoslavov
80f3e18c 1 parent 2b217144

Refactor the BGP code in the SDN-IP application: 

 * Resolves ONOS-476
 * Moved the BGP message-specific processing from class BgpSession
   to per-message type classes: BgpKeepalive, BgpNotification,
   BgpOpen, BgpUpdate
 * Minor modifications in some of the methods or BGP-specific API
   to accomodate the above change.
   No functional changes.

Change-Id: I95df128fa31c60397a279aaca25a487b7991a6e1
Inline Side-by-side
Showing 9 changed files with 1850 additions and 1495 deletions
......@@ -90,8 +90,9 @@ class BgpFrameDecoder extends FrameDecoder {
int errorSubcode =
MessageHeaderError.CONNECTION_NOT_SYNCHRONIZED;
ChannelBuffer txMessage =
bgpSession.prepareBgpNotification(errorCode, errorSubcode,
null);
BgpNotification.prepareBgpNotification(errorCode,
errorSubcode,
null);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
return null;
......@@ -114,7 +115,7 @@ class BgpFrameDecoder extends FrameDecoder {
//
// Send NOTIFICATION and close the connection
ChannelBuffer txMessage =
bgpSession.prepareBgpNotificationBadMessageLength(length);
BgpNotification.prepareBgpNotificationBadMessageLength(length);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
return null;
......@@ -145,16 +146,16 @@ class BgpFrameDecoder extends FrameDecoder {
//
switch (type) {
case BgpConstants.BGP_TYPE_OPEN:
bgpSession.processBgpOpen(ctx, message);
BgpOpen.processBgpOpen(bgpSession, ctx, message);
break;
case BgpConstants.BGP_TYPE_UPDATE:
bgpSession.processBgpUpdate(ctx, message);
BgpUpdate.processBgpUpdate(bgpSession, ctx, message);
break;
case BgpConstants.BGP_TYPE_NOTIFICATION:
bgpSession.processBgpNotification(ctx, message);
BgpNotification.processBgpNotification(bgpSession, ctx, message);
break;
case BgpConstants.BGP_TYPE_KEEPALIVE:
bgpSession.processBgpKeepalive(ctx, message);
BgpKeepalive.processBgpKeepalive(bgpSession, ctx, message);
break;
default:
//
......@@ -166,8 +167,8 @@ class BgpFrameDecoder extends FrameDecoder {
ChannelBuffer data = ChannelBuffers.buffer(1);
data.writeByte(type);
ChannelBuffer txMessage =
bgpSession.prepareBgpNotification(errorCode, errorSubcode,
data);
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
data);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
return null;
......
/*
* 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 org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A class for handling BGP KEEPALIVE messages.
*/
final class BgpKeepalive {
private static final Logger log =
LoggerFactory.getLogger(BgpKeepalive.class);
/**
* Default constructor.
* <p>
* The constructor is private to prevent creating an instance of
* this utility class.
*/
private BgpKeepalive() {
}
/**
* Processes BGP KEEPALIVE message.
*
* @param bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
* @param message the message to process
*/
static void processBgpKeepalive(BgpSession bgpSession,
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 {}",
bgpSession.getRemoteAddress(),
message.readableBytes() + BgpConstants.BGP_HEADER_LENGTH,
BgpConstants.BGP_KEEPALIVE_EXPECTED_LENGTH);
//
// 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;
}
//
// Parse the KEEPALIVE message: nothing to do
//
log.trace("BGP RX KEEPALIVE message from {}",
bgpSession.getRemoteAddress());
// Start the Session Timeout timer
bgpSession.restartSessionTimeoutTimer(ctx);
}
/**
* Prepares BGP KEEPALIVE message.
*
* @return the message to transmit (BGP header included)
*/
static ChannelBuffer prepareBgpKeepalive() {
ChannelBuffer message =
ChannelBuffers.buffer(BgpConstants.BGP_MESSAGE_MAX_LENGTH);
//
// Prepare the KEEPALIVE message payload: nothing to do
//
return BgpMessage.prepareBgpMessage(BgpConstants.BGP_TYPE_KEEPALIVE,
message);
}
}
/*
* 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 org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A class for preparing BGP messages.
*/
final class BgpMessage {
private static final Logger log =
LoggerFactory.getLogger(BgpMessage.class);
/**
* Default constructor.
* <p>
* The constructor is private to prevent creating an instance of
* this utility class.
*/
private BgpMessage() {
}
/**
* 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)
*/
static 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;
}
}
/*
* 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 org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.onosproject.sdnip.bgp.BgpConstants.Notifications.MessageHeaderError;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A class for handling BGP NOTIFICATION messages.
*/
final class BgpNotification {
private static final Logger log =
LoggerFactory.getLogger(BgpNotification.class);
/**
* Default constructor.
* <p>
* The constructor is private to prevent creating an instance of
* this utility class.
*/
private BgpNotification() {
}
/**
* Processes BGP NOTIFICATION message.
*
* @param bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
* @param message the message to process
*/
static void processBgpNotification(BgpSession bgpSession,
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 {}",
bgpSession.getRemoteAddress(), 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 {}",
bgpSession.getRemoteAddress(), 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
bgpSession.restartSessionTimeoutTimer(ctx);
}
/**
* 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)
*/
static 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 BgpMessage.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)
*/
static 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);
}
}
/*
* 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 org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.onlab.packet.Ip4Address;
import org.onosproject.sdnip.bgp.BgpConstants.Notifications;
import org.onosproject.sdnip.bgp.BgpConstants.Notifications.OpenMessageError;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A class for handling BGP OPEN messages.
*/
final class BgpOpen {
private static final Logger log = LoggerFactory.getLogger(BgpOpen.class);
/**
* Default constructor.
* <p>
* The constructor is private to prevent creating an instance of
* this utility class.
*/
private BgpOpen() {
}
/**
* Processes BGP OPEN message.
*
* @param bgpSession the BGP Session to use
* @param ctx the Channel Handler Context
* @param message the message to process
*/
static void processBgpOpen(BgpSession bgpSession,
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 {}",
bgpSession.getRemoteAddress(), 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;
}
//
// Parse the OPEN message
//
// Remote BGP version
int remoteBgpVersion = message.readUnsignedByte();
if (remoteBgpVersion != BgpConstants.BGP_VERSION) {
log.debug("BGP RX OPEN Error from {}: " +
"Unsupported BGP version {}. Should be {}",
bgpSession.getRemoteAddress(), 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 =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
data);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
return;
}
bgpSession.setRemoteBgpVersion(remoteBgpVersion);
// Remote AS number
long 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 bs : bgpSession.getBgpSessionManager().getBgpSessions()) {
if ((bs.getRemoteAs() != 0) && (remoteAs != bs.getRemoteAs())) {
log.debug("BGP RX OPEN Error from {}: Bad Peer AS {}. " +
"Expected {}",
bgpSession.getRemoteAddress(), remoteAs,
bs.getRemoteAs());
//
// ERROR: Bad Peer AS
//
// Send NOTIFICATION and close the connection
int errorCode = OpenMessageError.ERROR_CODE;
int errorSubcode = OpenMessageError.BAD_PEER_AS;
ChannelBuffer txMessage =
BgpNotification.prepareBgpNotification(errorCode,
errorSubcode, null);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
return;
}
}
bgpSession.setRemoteAs(remoteAs);
// Remote Hold Time
long 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 {}",
bgpSession.getRemoteAddress(), 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 =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
null);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
return;
}
bgpSession.setRemoteHoldtime(remoteHoldtime);
// Remote BGP Identifier
Ip4Address remoteBgpId =
Ip4Address.valueOf((int) message.readUnsignedInt());
bgpSession.setRemoteBgpId(remoteBgpId);
// 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 {}",
bgpSession.getRemoteAddress(), 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 =
BgpNotification.prepareBgpNotification(errorCode, errorSubcode,
null);
ctx.getChannel().write(txMessage);
bgpSession.closeSession(ctx);
return;
}
// NOTE: Parse the optional parameters (if needed)
message.readBytes(optParamLen); // NOTE: data ignored
log.debug("BGP RX OPEN message from {}: " +
"BGPv{} AS {} BGP-ID {} Holdtime {}",
bgpSession.getRemoteAddress(), remoteBgpVersion, remoteAs,
remoteBgpId, remoteHoldtime);
// Send my OPEN followed by KEEPALIVE
ChannelBuffer txMessage = prepareBgpOpen(bgpSession);
ctx.getChannel().write(txMessage);
//
txMessage = BgpKeepalive.prepareBgpKeepalive();
ctx.getChannel().write(txMessage);
// Start the KEEPALIVE timer
bgpSession.restartKeepaliveTimer(ctx);
// Start the Session Timeout timer
bgpSession.restartSessionTimeoutTimer(ctx);
}
/**
* Prepares BGP OPEN message.
*
* @param bgpSession the BGP Session to use
* @return the message to transmit (BGP header included)
*/
private static ChannelBuffer prepareBgpOpen(BgpSession bgpSession) {
ChannelBuffer message =
ChannelBuffers.buffer(BgpConstants.BGP_MESSAGE_MAX_LENGTH);
//
// Prepare the OPEN message payload
//
message.writeByte(bgpSession.getLocalBgpVersion());
message.writeShort((int) bgpSession.getLocalAs());
message.writeShort((int) bgpSession.getLocalHoldtime());
message.writeInt(bgpSession.getLocalBgpId().toInt());
message.writeByte(0); // No Optional Parameters
return BgpMessage.prepareBgpMessage(BgpConstants.BGP_TYPE_OPEN,
message);
}
}
......@@ -18,18 +18,14 @@ 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.ExceptionEvent;
......@@ -42,9 +38,6 @@ import org.onlab.packet.Ip4Address;
import org.onlab.packet.Ip4Prefix;
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.slf4j.Logger;
import org.slf4j.LoggerFactory;
......@@ -94,6 +87,18 @@ public class BgpSession extends SimpleChannelHandler {
*/
BgpSession(BgpSessionManager bgpSessionManager) {
this.bgpSessionManager = bgpSessionManager;
// NOTE: We support only BGP4
this.localBgpVersion = BgpConstants.BGP_VERSION;
}
/**
* Gets the BGP Session Manager.
*
* @return the BGP Session Manager
*/
BgpSessionManager getBgpSessionManager() {
return bgpSessionManager;
}
/**
......@@ -101,8 +106,8 @@ public class BgpSession extends SimpleChannelHandler {
*
* @return the BGP RIB-IN routing entries
*/
public Collection<BgpRouteEntry> getBgpRibIn() {
return bgpRibIn.values();
public Map<Ip4Prefix, BgpRouteEntry> bgpRibIn() {
return bgpRibIn;
}
/**
......@@ -143,6 +148,15 @@ public class BgpSession extends SimpleChannelHandler {
}
/**
* Sets the BGP session remote BGP version.
*
* @param remoteBgpVersion the BGP session remote BGP version to set
*/
void setRemoteBgpVersion(int remoteBgpVersion) {
this.remoteBgpVersion = remoteBgpVersion;
}
/**
* Gets the BGP session remote AS number.
*
* @return the BGP session remote AS number
......@@ -152,6 +166,23 @@ public class BgpSession extends SimpleChannelHandler {
}
/**
* Sets the BGP session remote AS number.
*
* @param remoteAs the BGP session remote AS number to set
*/
void setRemoteAs(long remoteAs) {
this.remoteAs = remoteAs;
//
// NOTE: Currently, the local AS number is always set to the remote AS.
// This is done, because the peer setup is always iBGP.
// In the future the local AS number should be configured as part
// of an explicit BGP peering configuration.
//
this.localAs = remoteAs;
}
/**
* Gets the BGP session remote Holdtime.
*
* @return the BGP session remote Holdtime
......@@ -161,6 +192,32 @@ public class BgpSession extends SimpleChannelHandler {
}
/**
* Sets the BGP session remote Holdtime.
*
* @param remoteHoldtime the BGP session remote Holdtime to set
*/
void setRemoteHoldtime(long remoteHoldtime) {
this.remoteHoldtime = remoteHoldtime;
//
// NOTE: Currently. the local BGP Holdtime is always set to the remote
// BGP holdtime.
// In the future, the local BGP Holdtime should be configured as part
// of an explicit BGP peering configuration.
//
this.localHoldtime = remoteHoldtime;
// Set the local Keepalive interval
if (localHoldtime == 0) {
localKeepaliveInterval = 0;
} else {
localKeepaliveInterval = Math.max(localHoldtime /
BgpConstants.BGP_KEEPALIVE_PER_HOLD_INTERVAL,
BgpConstants.BGP_KEEPALIVE_MIN_INTERVAL);
}
}
/**
* Gets the BGP session remote BGP Identifier as an IPv4 address.
*
* @return the BGP session remote BGP Identifier as an IPv4 address
......@@ -170,6 +227,15 @@ public class BgpSession extends SimpleChannelHandler {
}
/**
* Sets the BGP session remote BGP Identifier as an IPv4 address.
*
* @param remoteBgpId the BGP session remote BGP Identifier to set
*/
void setRemoteBgpId(Ip4Address remoteBgpId) {
this.remoteBgpId = remoteBgpId;
}
/**
* Gets the BGP session local address.
*
* @return the BGP session local address
......@@ -179,6 +245,15 @@ public class BgpSession extends SimpleChannelHandler {
}
/**
* Gets the BGP session local IPv4 address.
*
* @return the BGP session local IPv4 address
*/
public Ip4Address getLocalIp4Address() {
return localIp4Address;
}
/**
* Gets the BGP session local BGP version.
*
* @return the BGP session local BGP version
......@@ -282,6 +357,12 @@ public class BgpSession extends SimpleChannelHandler {
remoteAddress);
ctx.getChannel().close();
}
//
// Assign the local BGP ID
// NOTE: This should be configuration-based
//
localBgpId = bgpSessionManager.getMyBgpId();
}
@Override
......@@ -326,1458 +407,9 @@ public class BgpSession extends SimpleChannelHandler {
}
/**
* 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;
}
// NOTE: 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:
// NOTE: 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) {
void restartKeepaliveTimer(ChannelHandlerContext ctx) {
if (localKeepaliveInterval == 0) {
return; // Nothing to do
}
......@@ -1811,7 +443,7 @@ public class BgpSession extends SimpleChannelHandler {
}
// Transmit the KEEPALIVE
ChannelBuffer txMessage = prepareBgpKeepalive();
ChannelBuffer txMessage = BgpKeepalive.prepareBgpKeepalive();
ctx.getChannel().write(txMessage);
// Restart the KEEPALIVE timer
......@@ -1822,7 +454,7 @@ public class BgpSession extends SimpleChannelHandler {
/**
* Restarts the BGP Session Timeout Timer.
*/
private void restartSessionTimeoutTimer(ChannelHandlerContext ctx) {
void restartSessionTimeoutTimer(ChannelHandlerContext ctx) {
if (remoteHoldtime == 0) {
return; // Nothing to do
}
......@@ -1866,30 +498,10 @@ public class BgpSession extends SimpleChannelHandler {
int errorCode = HoldTimerExpired.ERROR_CODE;
int errorSubcode = Notifications.ERROR_SUBCODE_UNSPECIFIC;
ChannelBuffer txMessage =
prepareBgpNotification(errorCode, errorSubcode, null);
BgpNotification.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);
}
}
}
......
/*
* 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.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
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.onosproject.sdnip.bgp.BgpConstants.Notifications.UpdateMessageError;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 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) {
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 {}",
bgpSession.getRemoteAddress(), 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.getRemoteAddress());
//
// 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 = parsePackedPrefixes(withdrawnRoutesLength,
message);
} catch (BgpParseException e) {
// ERROR: Invalid Network Field
log.debug("Exception parsing Withdrawn Prefixes from BGP peer {}: ",
bgpSession.getRemoteBgpId(), e);
actionsBgpUpdateInvalidNetworkField(bgpSession, ctx);
return;
}
for (Ip4Prefix prefix : withdrawnPrefixes) {
log.debug("BGP RX UPDATE message WITHDRAWN from {}: {}",
bgpSession.getRemoteAddress(), prefix);
BgpRouteEntry bgpRouteEntry = bgpSession.bgpRibIn().get(prefix);
if (bgpRouteEntry != null) {
deletedRoutes.put(prefix, bgpRouteEntry);
}
}
//
// Parse the Path Attributes
//
try {
addedRoutes = parsePathAttributes(bgpSession, ctx, message);
} catch (BgpParseException e) {
log.debug("Exception parsing Path Attributes from BGP peer {}: ",
bgpSession.getRemoteBgpId(), 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()) {
bgpSession.bgpRibIn().remove(bgpRouteEntry.prefix());
}
for (BgpRouteEntry bgpRouteEntry : addedRoutes) {
bgpSession.bgpRibIn().put(bgpRouteEntry.prefix(), bgpRouteEntry);
}
// Push the updates to the BGP Merged RIB
BgpSessionManager.BgpRouteSelector bgpRouteSelector =
bgpSession.getBgpSessionManager().getBgpRouteSelector();
bgpRouteSelector.routeUpdates(bgpSession, addedRoutes,
deletedRoutes.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
* @return a collection of the result BGP Route Entries
* @throws BgpParseException
*/
private static Collection<BgpRouteEntry> parsePathAttributes(
BgpSession bgpSession,
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(bgpSession, 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(bgpSession, 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(bgpSession, 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(bgpSession, ctx);
String errorMsg = "Malformed Attribute List";
throw new 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
nextHop = 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;
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 BgpParseException(errorMsg);
}
// Skip the data from the unrecognized attribute
log.debug("BGP RX UPDATE message from {}: " +
"Unrecognized Attribute Type {}",
bgpSession.getRemoteAddress(), attrTypeCode);
message.skipBytes(attrLen);
break;
}
}
// Verify the Well-known Attributes
verifyBgpUpdateWellKnownAttributes(bgpSession, 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 {}: ",
bgpSession.getRemoteBgpId(), e);
actionsBgpUpdateInvalidNetworkField(bgpSession, ctx);
// Rethrow the exception
throw e;
}
// Generate the added routes
for (Ip4Prefix prefix : addedPrefixes) {
BgpRouteEntry bgpRouteEntry =
new BgpRouteEntry(bgpSession, prefix, nextHop,
origin.byteValue(), asPath, localPref);
bgpRouteEntry.setMultiExitDisc(multiExitDisc);
if (bgpRouteEntry.hasAsPathLoop(bgpSession.getLocalAs())) {
log.debug("BGP RX UPDATE message IGNORED from {}: {} " +
"nextHop {}: contains AS Path loop",
bgpSession.getRemoteAddress(), prefix, nextHop);
continue;
} else {
log.debug("BGP RX UPDATE message ADDED from {}: {} nextHop {}",
bgpSession.getRemoteAddress(), prefix, nextHop);
}
addedRoutes.put(prefix, bgpRouteEntry);
}
return addedRoutes.values();
}
/**
* 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 nextHop the NEXT_HOP well-known mandatory attribute
* @param localPref the LOCAL_PREF required attribute
* @throws BgpParseException
*/
private static void verifyBgpUpdateWellKnownAttributes(
BgpSession bgpSession,
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(bgpSession, 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(bgpSession, 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(bgpSession, 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(bgpSession, ctx, type);
String errorMsg = "Missing Well-known Attribute: LOCAL_PREF";
throw new 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 BgpParseException
*/
private static void verifyBgpUpdateAttributeFlags(
BgpSession bgpSession,
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(
bgpSession, ctx, attrTypeCode, attrLen, attrFlags, message);
String errorMsg = "Attribute Flags Error for " + typeName + ": " +
attrFlags;
throw new 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 BgpParseException
*/
private static short parseAttributeTypeOrigin(
BgpSession bgpSession,
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(
bgpSession, 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(
bgpSession, 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 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 BgpParseException
*/
private static BgpRouteEntry.AsPath parseAttributeTypeAsPath(
BgpSession bgpSession,
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(bgpSession, 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(bgpSession, 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(bgpSession, 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 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 BgpParseException
*/
private static Ip4Address parseAttributeTypeNextHop(
BgpSession bgpSession,
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(
bgpSession, 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(bgpSession.getLocalIp4Address())) {
// ERROR: Invalid NEXT_HOP Attribute
message.resetReaderIndex();
actionsBgpUpdateInvalidNextHopAttribute(
bgpSession, 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 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 BgpParseException
*/
private static long parseAttributeTypeMultiExitDisc(
BgpSession bgpSession,
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(
bgpSession, 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 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 BgpParseException
*/
private static long parseAttributeTypeLocalPref(
BgpSession bgpSession,
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(
bgpSession, 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 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 BgpParseException
*/
private static void parseAttributeTypeAtomicAggregate(
BgpSession bgpSession,
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(
bgpSession, 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 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 BgpParseException
*/
private static Pair<Long, Ip4Address> parseAttributeTypeAggregator(
BgpSession bgpSession,
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(
bgpSession, 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 static 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 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.getRemoteAddress());
//
// ERROR: Invalid Network Field
//
// Send NOTIFICATION and close the connection
int errorCode = UpdateMessageError.ERROR_CODE;
int errorSubcode = 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.getRemoteAddress());
//
// ERROR: Malformed Attribute List
//
// Send NOTIFICATION and close the connection
int errorCode = UpdateMessageError.ERROR_CODE;
int errorSubcode = 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.getRemoteAddress(), 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 =
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.getRemoteAddress());
//
// 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 =
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.getRemoteAddress());
//
// 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 =
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.getRemoteAddress(), 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 =
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.getRemoteAddress(), 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 =
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.getRemoteAddress());
//
// 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 =
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.getRemoteAddress());
//
// ERROR: Malformed AS_PATH
//
// Send NOTIFICATION and close the connection
int errorCode = UpdateMessageError.ERROR_CODE;
int errorSubcode = 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;
}
/**
* An exception indicating a parsing error of the BGP message.
*/
private static final class BgpParseException extends Exception {
/**
* Default constructor.
*/
private BgpParseException() {
super();
}
/**
* Constructor for a specific exception details message.
*
* @param message the message with the exception details
*/
private BgpParseException(String message) {
super(message);
}
}
}
......@@ -81,7 +81,7 @@ public class BgpRoutesListCommand extends AbstractShellCommand {
// Print the routes
if (foundBgpSession != null) {
printRoutes(foundBgpSession.getBgpRibIn());
printRoutes(foundBgpSession.bgpRibIn().values());
} else {
printRoutes(service.getBgpRoutes());
}
......
......@@ -303,7 +303,7 @@ public class BgpSessionManagerTest {
private Collection<BgpRouteEntry> waitForBgpRibIn(BgpSession bgpSession,
long expectedRoutes)
throws InterruptedException {
Collection<BgpRouteEntry> bgpRibIn = bgpSession.getBgpRibIn();
Collection<BgpRouteEntry> bgpRibIn = bgpSession.bgpRibIn().values();
final int maxChecks = 500; // Max wait of 5 seconds
for (int i = 0; i < maxChecks; i++) {
......@@ -311,7 +311,7 @@ public class BgpSessionManagerTest {
break;
}
Thread.sleep(10);
bgpRibIn = bgpSession.getBgpRibIn();
bgpRibIn = bgpSession.bgpRibIn().values();
}
return bgpRibIn;
......