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Diffstat (limited to 'framework/src/onos/apps/routing/src/main/java/org/onosproject/routing/bgp/BgpFrameDecoder.java')
| -rw-r--r-- | framework/src/onos/apps/routing/src/main/java/org/onosproject/routing/bgp/BgpFrameDecoder.java | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/framework/src/onos/apps/routing/src/main/java/org/onosproject/routing/bgp/BgpFrameDecoder.java b/framework/src/onos/apps/routing/src/main/java/org/onosproject/routing/bgp/BgpFrameDecoder.java new file mode 100644 index 00000000..98ec4a45 --- /dev/null +++ b/framework/src/onos/apps/routing/src/main/java/org/onosproject/routing/bgp/BgpFrameDecoder.java @@ -0,0 +1,177 @@ +/* + * Copyright 2014-2015 Open Networking Laboratory + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.onosproject.routing.bgp; + +import org.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; + } +} |