1 files changed, 60 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/WliFrameDecoder.java b/src/main/java/org/traccar/protocol/WliFrameDecoder.java
new file mode 100644
index 000000000..d918be1c3
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/WliFrameDecoder.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2020 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 io.netty.channel.ChannelHandlerContext;
+import org.traccar.BaseFrameDecoder;
+
+public class WliFrameDecoder extends BaseFrameDecoder {
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
+
+        if (buf.readableBytes() < 2) {
+            return null;
+        }
+
+        int index = buf.indexOf(buf.readerIndex() + 1, buf.writerIndex(), (byte) 0x03);
+        if (index != -1) {
+            ByteBuf result = Unpooled.buffer(index + 1 - buf.readerIndex());
+
+            while (buf.readerIndex() <= index) {
+                int b = buf.readUnsignedByte();
+                if (b == 0xDB) {
+                    int ext = buf.readUnsignedByte();
+                    if (ext == 0xD2) {
+                        result.writeByte(0x02);
+                    } else if (ext == 0xD3) {
+                        result.writeByte(0x03);
+                    } else if (ext == 0xDD) {
+                        result.writeByte(0xDB);
+                    }
+                } else {
+                    result.writeByte(b);
+                }
+            }
+
+            return result;
+        }
+
+        return null;
+    }
+
+}