| /* |
| * Copyright 2017-present Open Networking Foundation |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.onosproject.routing.bgp; |
| |
| import org.jboss.netty.buffer.ChannelBuffer; |
| import org.jboss.netty.buffer.ChannelBuffers; |
| import org.jboss.netty.channel.Channel; |
| import org.jboss.netty.channel.ChannelHandlerContext; |
| import org.jboss.netty.handler.codec.frame.FrameDecoder; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Class for handling the decoding of the BGP messages. |
| */ |
| class BgpFrameDecoder extends FrameDecoder { |
| private static final Logger log = |
| LoggerFactory.getLogger(BgpFrameDecoder.class); |
| |
| private final BgpSession bgpSession; |
| |
| /** |
| * Constructor for a given BGP Session. |
| * |
| * @param bgpSession the BGP session state to use. |
| */ |
| BgpFrameDecoder(BgpSession bgpSession) { |
| this.bgpSession = bgpSession; |
| } |
| |
| @Override |
| protected Object decode(ChannelHandlerContext ctx, |
| Channel channel, |
| ChannelBuffer buf) throws Exception { |
| // |
| // NOTE: If we close the channel during the decoding, we might still |
| // see some incoming messages while the channel closing is completed. |
| // |
| if (bgpSession.isClosed()) { |
| return null; |
| } |
| |
| log.trace("BGP Peer: decode(): remoteAddr = {} localAddr = {} " + |
| "messageSize = {}", |
| ctx.getChannel().getRemoteAddress(), |
| ctx.getChannel().getLocalAddress(), |
| buf.readableBytes()); |
| |
| // Test for minimum length of the BGP message |
| if (buf.readableBytes() < BgpConstants.BGP_HEADER_LENGTH) { |
| // No enough data received |
| return null; |
| } |
| |
| // |
| // Mark the current buffer position in case we haven't received |
| // the whole message. |
| // |
| buf.markReaderIndex(); |
| |
| // |
| // Read and check the BGP message Marker field: it must be all ones |
| // (See RFC 4271, Section 4.1) |
| // |
| byte[] marker = new byte[BgpConstants.BGP_HEADER_MARKER_LENGTH]; |
| buf.readBytes(marker); |
| for (int i = 0; i < marker.length; i++) { |
| if (marker[i] != (byte) 0xff) { |
| log.debug("BGP RX Error: invalid marker {} at position {}", |
| marker[i], i); |
| // |
| // ERROR: Connection Not Synchronized |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = BgpConstants.Notifications.MessageHeaderError.ERROR_CODE; |
| int errorSubcode = |
| BgpConstants.Notifications.MessageHeaderError.CONNECTION_NOT_SYNCHRONIZED; |
| ChannelBuffer txMessage = |
| BgpNotification.prepareBgpNotification(errorCode, |
| errorSubcode, |
| null); |
| ctx.getChannel().write(txMessage); |
| bgpSession.closeSession(ctx); |
| return null; |
| } |
| } |
| |
| // |
| // Read and check the BGP message Length field |
| // |
| int length = buf.readUnsignedShort(); |
| if ((length < BgpConstants.BGP_HEADER_LENGTH) || |
| (length > BgpConstants.BGP_MESSAGE_MAX_LENGTH)) { |
| log.debug("BGP RX Error: invalid Length field {}. " + |
| "Must be between {} and {}", |
| length, |
| BgpConstants.BGP_HEADER_LENGTH, |
| BgpConstants.BGP_MESSAGE_MAX_LENGTH); |
| // |
| // ERROR: Bad Message Length |
| // |
| // Send NOTIFICATION and close the connection |
| ChannelBuffer txMessage = |
| BgpNotification.prepareBgpNotificationBadMessageLength(length); |
| ctx.getChannel().write(txMessage); |
| bgpSession.closeSession(ctx); |
| return null; |
| } |
| |
| // |
| // Test whether the rest of the message is received: |
| // So far we have read the Marker (16 octets) and the |
| // Length (2 octets) fields. |
| // |
| int remainingMessageLen = |
| length - BgpConstants.BGP_HEADER_MARKER_LENGTH - 2; |
| if (buf.readableBytes() < remainingMessageLen) { |
| // No enough data received |
| buf.resetReaderIndex(); |
| return null; |
| } |
| |
| // |
| // Read the BGP message Type field, and process based on that type |
| // |
| int type = buf.readUnsignedByte(); |
| remainingMessageLen--; // Adjust after reading the type |
| ChannelBuffer message = buf.readBytes(remainingMessageLen); |
| |
| // |
| // Process the remaining of the message based on the message type |
| // |
| switch (type) { |
| case BgpConstants.BGP_TYPE_OPEN: |
| BgpOpen.processBgpOpen(bgpSession, ctx, message); |
| break; |
| case BgpConstants.BGP_TYPE_UPDATE: |
| BgpUpdate.processBgpUpdate(bgpSession, ctx, message); |
| break; |
| case BgpConstants.BGP_TYPE_NOTIFICATION: |
| BgpNotification.processBgpNotification(bgpSession, ctx, message); |
| break; |
| case BgpConstants.BGP_TYPE_KEEPALIVE: |
| BgpKeepalive.processBgpKeepalive(bgpSession, ctx, message); |
| break; |
| default: |
| // |
| // ERROR: Bad Message Type |
| // |
| // Send NOTIFICATION and close the connection |
| int errorCode = BgpConstants.Notifications.MessageHeaderError.ERROR_CODE; |
| int errorSubcode = BgpConstants.Notifications.MessageHeaderError.BAD_MESSAGE_TYPE; |
| ChannelBuffer data = ChannelBuffers.buffer(1); |
| data.writeByte(type); |
| ChannelBuffer txMessage = |
| BgpNotification.prepareBgpNotification(errorCode, errorSubcode, |
| data); |
| ctx.getChannel().write(txMessage); |
| bgpSession.closeSession(ctx); |
| return null; |
| } |
| return null; |
| } |
| } |