1 files changed, 75 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/Tk103FrameDecoder.java b/src/main/java/org/traccar/protocol/Tk103FrameDecoder.java
new file mode 100644
index 000000000..b61a42563
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/Tk103FrameDecoder.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2017 Valerii Vyshniak (val@val.one)
+ * Copyright 2017 - 2018 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 Tk103FrameDecoder extends BaseFrameDecoder {
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
+
+        if (buf.readableBytes() < 2) {
+            return null;
+        }
+
+        int frameStartIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '(');
+        if (frameStartIndex == -1) {
+            buf.clear();
+            return null;
+        }
+
+        int frameEndIndex, freeTextSymbolCounter;
+        for (frameEndIndex = frameStartIndex, freeTextSymbolCounter = 0;; frameEndIndex++) {
+            int freeTextIndex = frameEndIndex;
+            frameEndIndex = buf.indexOf(frameEndIndex, buf.writerIndex(), (byte) ')');
+            if (frameEndIndex == -1) {
+                break;
+            }
+            for (;; freeTextIndex++, freeTextSymbolCounter++) {
+                freeTextIndex = buf.indexOf(freeTextIndex, frameEndIndex, (byte) '$');
+                if (freeTextIndex == -1 || freeTextIndex >= frameEndIndex) {
+                    break;
+                }
+            }
+            if (freeTextSymbolCounter % 2 == 0) {
+                break;
+            }
+        }
+
+        if (frameEndIndex == -1) {
+            while (buf.readableBytes() > 1024) {
+                int discardUntilIndex = buf.indexOf(buf.readerIndex() + 1, buf.writerIndex(), (byte) '(');
+                if (discardUntilIndex == -1) {
+                    buf.clear();
+                } else {
+                    buf.readerIndex(discardUntilIndex);
+                }
+            }
+            return null;
+        }
+
+        buf.readerIndex(frameStartIndex);
+
+        return buf.readRetainedSlice(frameEndIndex + 1 - frameStartIndex);
+    }
+
+}