Work toward IPv6 support in BGP: implement decoding of the

BGP UPDATE attributes: MP_REACH_NLRI and MP_UNREACH_NLRI (RFC 4760).

Note: currently, the IPv6 NLRI is decoded, but it not used.

This work is in the context of ONOS-422.

Change-Id: Ia61b94dedfe0b1a7d7f563e805a3086f56d4da03

@@ -376,6 +376,46 @@ public final class BgpConstants {
             /** BGP UPDATE Attributes Type Code AGGREGATOR length. */
             public static final int LENGTH = 6;
         }
+
+        /**
+         * BGP UPDATE: MP_REACH_NLRI related constants.
+         */
+        public static final class MpReachNlri {
+            /**
+             * Default constructor.
+             * <p>
+             * The constructor is private to prevent creating an instance of
+             * this utility class.
+             */
+            private MpReachNlri() {
+            }
+
+            /** BGP UPDATE Attributes Type Code MP_REACH_NLRI. */
+            public static final int TYPE = 14;
+
+            /** BGP UPDATE Attributes Type Code MP_REACH_NLRI min length. */
+            public static final int MIN_LENGTH = 5;
+        }
+
+        /**
+         * BGP UPDATE: MP_UNREACH_NLRI related constants.
+         */
+        public static final class MpUnreachNlri {
+            /**
+             * Default constructor.
+             * <p>
+             * The constructor is private to prevent creating an instance of
+             * this utility class.
+             */
+            private MpUnreachNlri() {
+            }
+
+            /** BGP UPDATE Attributes Type Code MP_UNREACH_NLRI. */
+            public static final int TYPE = 15;
+
+            /** BGP UPDATE Attributes Type Code MP_UNREACH_NLRI min length. */
+            public static final int MIN_LENGTH = 3;
+        }
     }
 
     /**

@@ -36,6 +36,7 @@ import org.jboss.netty.util.Timer;
 import org.jboss.netty.util.TimerTask;
 import org.onlab.packet.Ip4Address;
 import org.onlab.packet.Ip4Prefix;
+import org.onlab.packet.Ip6Prefix;
 import org.onosproject.sdnip.bgp.BgpConstants.Notifications;
 import org.onosproject.sdnip.bgp.BgpConstants.Notifications.HoldTimerExpired;
 import org.slf4j.Logger;
@@ -62,6 +63,8 @@ public class BgpSession extends SimpleChannelHandler {
     private long remoteAs4Octet;                // 4 octets
     private long remoteHoldtime;                // 2 octets
     private Ip4Address remoteBgpId;             // 4 octets -> IPv4 address
+    private boolean remoteMpExtensions;         // Peer Multiprotocol
+                                                // Extensions enabled: RFC 4760
     private boolean remoteIpv4Unicast;          // Peer IPv4/UNICAST AFI/SAFI
     private boolean remoteIpv4Multicast;        // Peer IPv4/MULTICAST AFI/SAFI
     private boolean remoteIpv6Unicast;          // Peer IPv6/UNICAST AFI/SAFI
@@ -74,6 +77,8 @@ public class BgpSession extends SimpleChannelHandler {
     private long localAs;                       // 2 octets
     private long localHoldtime;                 // 2 octets
     private Ip4Address localBgpId;              // 4 octets -> IPv4 address
+    private boolean localMpExtensions;          // Local Multiprotocol
+                                                // Extensions enabled: RFC 4760
     private boolean localIpv4Unicast;        // Local IPv4/UNICAST AFI/SAFI
     private boolean localIpv4Multicast;      // Local IPv4/MULTICAST AFI/SAFI
     private boolean localIpv6Unicast;        // Local IPv6/UNICAST AFI/SAFI
@@ -88,7 +93,9 @@ public class BgpSession extends SimpleChannelHandler {
     private volatile Timeout sessionTimeout;    // Session timeout
 
     // BGP RIB-IN routing entries from this peer
-    private ConcurrentMap<Ip4Prefix, BgpRouteEntry> bgpRibIn =
+    private ConcurrentMap<Ip4Prefix, BgpRouteEntry> bgpRibIn4 =
+        new ConcurrentHashMap<>();
+    private ConcurrentMap<Ip6Prefix, BgpRouteEntry> bgpRibIn6 =
         new ConcurrentHashMap<>();
 
     /**
@@ -113,22 +120,41 @@ public class BgpSession extends SimpleChannelHandler {
     }
 
     /**
-     * Gets the BGP RIB-IN routing entries.
+     * Gets the BGP RIB-IN IPv4 routing entries.
+     *
+     * @return the BGP RIB-IN IPv4 routing entries
+     */
+    public Map<Ip4Prefix, BgpRouteEntry> bgpRibIn4() {
+        return bgpRibIn4;
+    }
+
+    /**
+     * Gets the BGP RIB-IN IPv6 routing entries.
      *
-     * @return the BGP RIB-IN routing entries
+     * @return the BGP RIB-IN IPv6 routing entries
      */
-    public Map<Ip4Prefix, BgpRouteEntry> bgpRibIn() {
-        return bgpRibIn;
+    public Map<Ip6Prefix, BgpRouteEntry> bgpRibIn6() {
+        return bgpRibIn6;
     }
 
     /**
-     * Finds a BGP routing entry in the BGP RIB-IN.
+     * Finds a BGP IPv4 routing entry in the BGP RIB-IN.
      *
-     * @param prefix the prefix of the route to search for
-     * @return the BGP routing entry if found, otherwise null
+     * @param prefix the IPv4 prefix of the route to search for
+     * @return the IPv4 BGP routing entry if found, otherwise null
      */
     public BgpRouteEntry findBgpRouteEntry(Ip4Prefix prefix) {
-        return bgpRibIn.get(prefix);
+        return bgpRibIn4.get(prefix);
+    }
+
+    /**
+     * Finds a BGP IPv6 routing entry in the BGP RIB-IN.
+     *
+     * @param prefix the IPv6 prefix of the route to search for
+     * @return the IPv6 BGP routing entry if found, otherwise null
+     */
+    public BgpRouteEntry findBgpRouteEntry(Ip6Prefix prefix) {
+        return bgpRibIn6.get(prefix);
     }
 
     /**
@@ -256,6 +282,16 @@ public class BgpSession extends SimpleChannelHandler {
     }
 
     /**
+     * Gets the BGP Multiprotocol Extensions for the session.
+     *
+     * @return true if the BGP Multiprotocol Extensions are enabled for the
+     * session, otherwise false
+     */
+     public boolean getMpExtensions() {
+        return remoteMpExtensions && localMpExtensions;
+    }
+
+    /**
      * Gets the BGP session remote AFI/SAFI configuration for IPv4 unicast.
      *
      * @return the BGP session remote AFI/SAFI configuration for IPv4 unicast
@@ -268,10 +304,11 @@ public class BgpSession extends SimpleChannelHandler {
      * Sets the BGP session remote AFI/SAFI configuration for IPv4 unicast.
      */
     void setRemoteIpv4Unicast() {
+        this.remoteMpExtensions = true;
         this.remoteIpv4Unicast = true;
         // Copy the remote AFI/SAFI setting to the local configuration
-        // NOTE: Uncomment the line below if the AFI/SAFI is supported locally
-        // this.localIpv4Unicast = true;
+        this.localMpExtensions = true;
+        this.localIpv4Unicast = true;
     }
 
     /**
@@ -287,10 +324,11 @@ public class BgpSession extends SimpleChannelHandler {
      * Sets the BGP session remote AFI/SAFI configuration for IPv4 multicast.
      */
     void setRemoteIpv4Multicast() {
+        this.remoteMpExtensions = true;
         this.remoteIpv4Multicast = true;
         // Copy the remote AFI/SAFI setting to the local configuration
-        // NOTE: Uncomment the line below if the AFI/SAFI is supported locally
-        // this.localIpv4Multicast = true;
+        this.localMpExtensions = true;
+        this.localIpv4Multicast = true;
     }
 
     /**
@@ -306,10 +344,11 @@ public class BgpSession extends SimpleChannelHandler {
      * Sets the BGP session remote AFI/SAFI configuration for IPv6 unicast.
      */
     void setRemoteIpv6Unicast() {
+        this.remoteMpExtensions = true;
         this.remoteIpv6Unicast = true;
         // Copy the remote AFI/SAFI setting to the local configuration
-        // NOTE: Uncomment the line below if the AFI/SAFI is supported locally
-        // this.localIpv6Unicast = true;
+        this.localMpExtensions = true;
+        this.localIpv6Unicast = true;
     }
 
     /**
@@ -325,10 +364,11 @@ public class BgpSession extends SimpleChannelHandler {
      * Sets the BGP session remote AFI/SAFI configuration for IPv6 multicast.
      */
     void setRemoteIpv6Multicast() {
+        this.remoteMpExtensions = true;
         this.remoteIpv6Multicast = true;
         // Copy the remote AFI/SAFI setting to the local configuration
-        // NOTE: Uncomment the line below if the AFI/SAFI is supported locally
-        // this.localIpv6Multicast = true;
+        this.localMpExtensions = true;
+        this.localIpv6Multicast = true;
     }
 
     /**
@@ -576,14 +616,17 @@ public class BgpSession extends SimpleChannelHandler {
         // for further processing. Otherwise, the BGP Decision Process
         // will use those routes again.
         //
-        Collection<BgpRouteEntry> deletedRoutes = bgpRibIn.values();
-        bgpRibIn = new ConcurrentHashMap<>();
+        Collection<BgpRouteEntry> deletedRoutes4 = bgpRibIn4.values();
+        Collection<BgpRouteEntry> deletedRoutes6 = bgpRibIn6.values();
+        bgpRibIn4 = new ConcurrentHashMap<>();
+        bgpRibIn6 = new ConcurrentHashMap<>();
 
         // Push the updates to the BGP Merged RIB
         BgpSessionManager.BgpRouteSelector bgpRouteSelector =
             bgpSessionManager.getBgpRouteSelector();
         Collection<BgpRouteEntry> addedRoutes = Collections.emptyList();
-        bgpRouteSelector.routeUpdates(this, addedRoutes, deletedRoutes);
+        bgpRouteSelector.routeUpdates(this, addedRoutes, deletedRoutes4);
+        bgpRouteSelector.routeUpdates(this, addedRoutes, deletedRoutes6);
 
         bgpSessionManager.peerDisconnected(this);
     }

@@ -81,7 +81,8 @@ public class BgpRoutesListCommand extends AbstractShellCommand {
 
         // Print the routes
         if (foundBgpSession != null) {
-            printRoutes(foundBgpSession.bgpRibIn().values());
+            printRoutes(foundBgpSession.bgpRibIn4().values());
+            printRoutes(foundBgpSession.bgpRibIn6().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.bgpRibIn().values();
+        Collection<BgpRouteEntry> bgpRibIn = bgpSession.bgpRibIn4().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.bgpRibIn().values();
+            bgpRibIn = bgpSession.bgpRibIn4().values();
         }
 
         return bgpRibIn;