BMP route monitoring message decoder

Receive BPG update message

Change-Id: I681a85b0a16d833bbacf465b9835f32478c2ddd6
diff --git a/apps/bgpmonitoring/app/src/main/java/org/onosproject/bgpmonitoring/type/BmpRouteMonitoringMessage.java b/apps/bgpmonitoring/app/src/main/java/org/onosproject/bgpmonitoring/type/BmpRouteMonitoringMessage.java
new file mode 100644
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+++ b/apps/bgpmonitoring/app/src/main/java/org/onosproject/bgpmonitoring/type/BmpRouteMonitoringMessage.java
@@ -0,0 +1,204 @@
+/*
+ * Copyright 2024-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.bgpmonitoring.type;
+
+import com.google.common.base.MoreObjects;
+import org.jboss.netty.buffer.ChannelBuffers;
+
+import org.onosproject.bgpio.exceptions.BgpParseException;
+import org.onosproject.bgpio.protocol.BgpMessage;
+import org.onosproject.bgpio.protocol.ver4.BgpMessageVer4;
+import org.onosproject.bgpio.types.BgpHeader;
+import org.onosproject.bgpmonitoring.RouteMonitoringMessage;
+import org.onosproject.bgpmonitoring.BmpParseException;
+import org.onosproject.bgpmonitoring.PerPeer;
+import org.onlab.packet.Deserializer;
+import java.util.Objects;
+import java.util.function.BiPredicate;
+import java.nio.ByteBuffer;
+
+import static com.google.common.base.Preconditions.checkState;
+
+/**
+ * Used to provide an initial dump of all routes received from a peer.
+ * As well as an ongoing mechanism that sends the incremental routes
+ * advertised and withdrawn by a peer to the monitoring station.
+ * <p>
+ * Route Monitoring messages are used for initial synchronization of the
+ * ADJ-RIBs-In.  They are also used for ongoing monitoring of the
+ * ADJ-RIB-In state.  Route monitoring messages are state-compressed.
+ * <p>
+ * Route Mirroring messages are used for verbatim duplication of
+ * messages as received.  A possible use for mirroring is exact
+ * mirroring of one or more monitored BGP sessions, without state
+ * compression.  Another possible use is the mirroring of messages that
+ * have been treated-as-withdraw [RFC7606], for debugging purposes.
+ * Mirrored messages may be sampled, or may be lossless.  The Messages
+ * Lost Information code is provided to allow losses to be indicated.
+ * Following the common BMP header and per-peer header is a set of TLVs
+ * that contain information about a message or set of messages.  Each
+ * TLV comprises a 2-byte type code, a 2-byte length field, and a
+ * variable-length value.  Inclusion of any given TLV is OPTIONAL;
+ * however, at least one TLV SHOULD be included, otherwise there's no
+ * point in sending the message.
+ */
+public final class BmpRouteMonitoringMessage extends RouteMonitoringMessage {
+
+
+    private PerPeer perPeer;
+
+    private BgpMessage bgpMessage;
+
+    private BmpRouteMonitoringMessage(Builder builder) {
+        this.perPeer = builder.perPeer;
+        this.bgpMessage = builder.bgpMessage;
+    }
+
+    /**
+     * Returns Bgp message.
+     *
+     * @return Bgp message
+     */
+    @Override
+    public BgpMessage getBgpMessage() {
+        return bgpMessage;
+    }
+
+    /**
+     * Returns BMP Header of BMP Message.
+     *
+     * @return BMP Header of BMP Message
+     */
+    @Override
+    public PerPeer getPerPeer() {
+        return perPeer;
+    }
+
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        BmpRouteMonitoringMessage that = (BmpRouteMonitoringMessage) o;
+        return Objects.equals(perPeer, that.perPeer) &&
+                Objects.equals(bgpMessage, that.bgpMessage);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(perPeer, bgpMessage);
+    }
+
+    /**
+     * Data deserializer function for BMP route monitoring.
+     *
+     * @return data deserializer function
+     */
+    public static Deserializer<BmpRouteMonitoringMessage> deserializer() {
+        return (data, offset, length) -> {
+            BiPredicate<ByteBuffer, Integer> isValidBuffer = (b, l)
+                    -> b.hasRemaining() && b.remaining() >= l;
+
+            ByteBuffer bb = ByteBuffer.wrap(data, offset, length);
+            if (!isValidBuffer.test(bb, ROUTE_MONITORING_HEADER_MIN_LENGTH +
+                    PerPeerPacket.PEER_HEADER_MIN_LENGTH)) {
+                throw new BmpParseException("Invalid bmp route monitoring message buffer size.");
+            }
+
+            byte[] perPeerBytes = new byte[PerPeerPacket.PEER_HEADER_MIN_LENGTH];
+            bb.get(perPeerBytes);
+
+            byte[] routeBytes = new byte[bb.remaining()];
+            bb.get(routeBytes);
+            Builder builder = new Builder()
+                    .perPeer(PerPeerPacket.deserializer().deserialize(perPeerBytes,
+                            0, PerPeerPacket.PEER_HEADER_MIN_LENGTH));
+            try {
+                builder.bgpMessage(BgpMessageVer4.READER.readFrom(ChannelBuffers.wrappedBuffer(routeBytes),
+                        new BgpHeader()));
+            } catch (BgpParseException ex) {
+                throw new BmpParseException(ex);
+            }
+            return builder.build();
+
+        };
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("perPeer", perPeer)
+                .add("bgpMessage", bgpMessage)
+                .toString();
+    }
+
+    /**
+     * Builder for BMP route monitoring message.
+     */
+    private static class Builder {
+
+        private PerPeer perPeer;
+
+        private BgpMessage bgpMessage;
+
+        /**
+         * Setter bmp per peer header.
+         *
+         * @param perPeer bmp per peer header.
+         * @return this class builder.
+         */
+        public Builder perPeer(PerPeer perPeer) {
+            this.perPeer = perPeer;
+            return this;
+        }
+
+        /**
+         * Setter bpg message.
+         *
+         * @param bgpMessage bpg message.
+         * @return this class builder.
+         */
+        public Builder bgpMessage(BgpMessage bgpMessage) {
+            this.bgpMessage = bgpMessage;
+            return this;
+        }
+
+        /**
+         * Checks arguments for bgp route monitoring message.
+         */
+        private void checkArguments() {
+            checkState(perPeer != null, "Invalid bmp statistics per peer buffer.");
+            checkState(bgpMessage != null, "Invalid bgp message.");
+        }
+
+        /**
+         * Builds BMP route monitoring message.
+         *
+         * @return BMP route monitoring message.
+         */
+        public BmpRouteMonitoringMessage build() {
+            checkArguments();
+            return new BmpRouteMonitoringMessage(this);
+        }
+
+    }
+
+}