1 files changed, 49 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/G1rusFrameDecoder.java b/src/main/java/org/traccar/protocol/G1rusFrameDecoder.java
new file mode 100644
index 000000000..8c67207ad
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/G1rusFrameDecoder.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2022 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 G1rusFrameDecoder extends BaseFrameDecoder {
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
+
+        ByteBuf result = Unpooled.buffer();
+
+        while (buf.isReadable()) {
+            int b = buf.readUnsignedByte();
+            if (b == 0x1B) {
+                int ext = buf.readUnsignedByte();
+                if (ext == 0x00) {
+                    result.writeByte(0x1B);
+                } else {
+                    result.writeByte(0xF8);
+                }
+            } else {
+                result.writeByte(b);
+            }
+        }
+
+        return result;
+    }
+
+}