Add Digital Systems DSF22 protocol

1 files changed, 44 insertions, 0 deletions

diff --git a/src/main/java/org/traccar/protocol/Dsf22FrameDecoder.java b/src/main/java/org/traccar/protocol/Dsf22FrameDecoder.java
new file mode 100644
index 000000000..388c97f85
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/Dsf22FrameDecoder.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2021 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.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import org.traccar.BaseFrameDecoder;
+
+public class Dsf22FrameDecoder extends BaseFrameDecoder {
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
+
+        if (buf.readableBytes() < 21) {
+            return null;
+        }
+
+        int count = buf.getUnsignedByte(buf.readerIndex() + 4);
+
+        int length = 2 + 2 + 1 + count * (4 + 4 + 4 + 1 + 2 + 1);
+
+        if (buf.readableBytes() >= length) {
+            return buf.readRetainedSlice(length);
+        } else {
+            return null;
+        }
+    }
+
+}