| /* |
| * 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); |
| } |
| } |