Initial FleetGuide implementation

1 files changed, 98 insertions, 0 deletions

diff --git a/src/main/java/org/traccar/protocol/FleetGuideProtocolDecoder.java b/src/main/java/org/traccar/protocol/FleetGuideProtocolDecoder.java
new file mode 100644
index 000000000..d63187921
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/FleetGuideProtocolDecoder.java
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2024 Anton Tananaev (anton@traccar.org)
+ *
+ * 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.traccar.protocol;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import org.traccar.BaseProtocolDecoder;
+import org.traccar.Protocol;
+import org.traccar.helper.BitUtil;
+import org.traccar.session.DeviceSession;
+
+import java.lang.reflect.Method;
+import java.net.SocketAddress;
+
+public class FleetGuideProtocolDecoder extends BaseProtocolDecoder {
+
+    public FleetGuideProtocolDecoder(Protocol protocol) {
+        super(protocol);
+    }
+
+    public static final int MSG_DATA = 0x10;
+    public static final int MSG_HEARTBEAT = 0x1A;
+    public static final int MSG_RESPONSE = 0x1C;
+
+    @Override
+    protected Object decode(
+            Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
+
+        ByteBuf buf = (ByteBuf) msg;
+
+        buf.readUnsignedByte(); // signature
+        int options = buf.readUnsignedShort();
+        int length = BitUtil.to(options, 11);
+
+        DeviceSession deviceSession;
+        if (BitUtil.check(options, 11)) {
+            deviceSession = getDeviceSession(channel, remoteAddress, String.valueOf(buf.readUnsignedInt()));
+        } else {
+            deviceSession = getDeviceSession(channel, remoteAddress);
+        }
+        if (deviceSession == null) {
+            return null;
+        }
+
+        int type;
+        if (BitUtil.check(options, 12)) {
+            type = BitUtil.to(buf.readUnsignedByte(), 4);
+        } else {
+            type = 0;
+        }
+
+        if (BitUtil.check(options, 13)) {
+            buf.readUnsignedShort(); // acknowledgement
+        }
+
+        ByteBuf data;
+        if (BitUtil.check(options, 14)) {
+            data = decompress(buf.readSlice(length));
+        } else {
+            data = buf.readRetainedSlice(length);
+        }
+
+        data.release();
+
+        return null;
+    }
+
+    private ByteBuf decompress(ByteBuf input) throws ReflectiveOperationException {
+
+        Class<?> clazz = Class.forName("io.netty.handler.codec.compression.FastLz");
+        Method method = clazz.getDeclaredMethod(
+                "decompress", ByteBuf.class, int.class, int.class, ByteBuf.class, int.class, int.class);
+
+        ByteBuf output = Unpooled.buffer();
+        int result = (Integer) method.invoke(
+                null, input, input.readerIndex(), input.readableBytes(), output, 0, Integer.MAX_VALUE);
+        if (result <= 0) {
+            throw new IllegalArgumentException("FastLz decompression failed");
+        }
+
+        return output;
+    }
+
+}