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
diff --git a/apps/sdnip/src/main/java/org/onosproject/sdnip/bgp/BgpOpen.java b/apps/sdnip/src/main/java/org/onosproject/sdnip/bgp/BgpOpen.java
new file mode 100644
index 0000000..92086f3
--- /dev/null
+++ b/apps/sdnip/src/main/java/org/onosproject/sdnip/bgp/BgpOpen.java
@@ -0,0 +1,220 @@
+/*
+ * 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);
+ }
+}