1 files changed, 80 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/AtrackFrameDecoder.java b/src/main/java/org/traccar/protocol/AtrackFrameDecoder.java
new file mode 100644
index 000000000..f071e2d97
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/AtrackFrameDecoder.java
@@ -0,0 +1,80 @@
+/*
+ * 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;
+import org.traccar.helper.BufferUtil;
+
+import java.nio.charset.StandardCharsets;
+
+public class AtrackFrameDecoder extends BaseFrameDecoder {
+
+    private static final int KEEPALIVE_LENGTH = 12;
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
+
+        if (buf.readableBytes() >= 2) {
+
+            if (buf.getUnsignedShort(buf.readerIndex()) == 0xfe02) {
+
+                if (buf.readableBytes() >= KEEPALIVE_LENGTH) {
+                    return buf.readRetainedSlice(KEEPALIVE_LENGTH);
+                }
+
+            } else if (buf.getUnsignedShort(buf.readerIndex()) == 0x4050 && buf.getByte(buf.readerIndex() + 2) != ',') {
+
+                if (buf.readableBytes() > 6) {
+                    int length = buf.getUnsignedShort(buf.readerIndex() + 4) + 4 + 2;
+                    if (buf.readableBytes() >= length) {
+                        return buf.readRetainedSlice(length);
+                    }
+                }
+
+            } else {
+
+                int lengthStart = buf.indexOf(buf.readerIndex() + 3, buf.writerIndex(), (byte) ',') + 1;
+                if (lengthStart > 0) {
+                    int lengthEnd = buf.indexOf(lengthStart, buf.writerIndex(), (byte) ',');
+                    if (lengthEnd > 0) {
+                        int length = lengthEnd + Integer.parseInt(buf.toString(
+                                lengthStart, lengthEnd - lengthStart, StandardCharsets.US_ASCII));
+                        if (buf.readableBytes() > length && buf.getByte(buf.readerIndex() + length) == '\n') {
+                            length += 1;
+                        }
+                        if (buf.readableBytes() >= length) {
+                            return buf.readRetainedSlice(length);
+                        }
+                    }
+                } else {
+                    int endIndex = BufferUtil.indexOf("\r\n", buf);
+                    if (endIndex > 0) {
+                        return buf.readRetainedSlice(endIndex - buf.readerIndex() + 2);
+                    }
+                }
+
+            }
+
+        }
+
+        return null;
+    }
+
+}