Updated Xexun2 Protocol

5 files changed, 66 insertions, 51 deletions

diff --git a/src/main/java/org/traccar/helper/Checksum.java b/src/main/java/org/traccar/helper/Checksum.java
index e660790ef..db5817275 100644
--- a/src/main/java/org/traccar/helper/Checksum.java
+++ b/src/main/java/org/traccar/helper/Checksum.java
@@ -200,18 +200,14 @@ public final class Checksum {
         return (10 - (checksum % 10)) % 10;
     }
 
-    public static int udp(ByteBuffer data) {
+    public static int ip(ByteBuffer data) {
         int sum = 0;
-        int len = data.capacity();
-        for (int j = 0; len > 1; len--) {
+        while (data.remaining() > 0) {
             sum += data.get() & 0xff;
             if ((sum & 0x80000000) > 0) {
                 sum = (sum & 0xffff) + (sum >> 16);
             }
         }
-        if (len == 1) {
-            sum += data.get() & 0xff;
-        }
         while ((sum >> 16) > 0) {
             sum = (sum & 0xffff) + sum >> 16;
         }
diff --git a/src/main/java/org/traccar/protocol/Xexun2FrameEncoder.java b/src/main/java/org/traccar/protocol/Xexun2FrameEncoder.java
new file mode 100644
index 000000000..52d43c36c
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/Xexun2FrameEncoder.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2022 Stefan Clark (stefan@stefanclark.co.uk)
+ *
+ * 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.ChannelHandlerContext;
+import io.netty.handler.codec.MessageToByteEncoder;
+
+public class Xexun2FrameEncoder extends MessageToByteEncoder<ByteBuf> {
+
+    @Override
+    protected void encode(ChannelHandlerContext ctx, ByteBuf msg, ByteBuf out) {
+        out.writeBytes(msg.readBytes(2));
+
+        while (msg.readableBytes() > 2) {
+            int b = msg.readUnsignedByte();
+            if (b == 0xfa && msg.isReadable() && msg.getUnsignedByte(msg.readerIndex()) == 0xaf) {
+                msg.readUnsignedByte();
+                out.writeByte(0xfb);
+                out.writeByte(0xbf);
+                out.writeByte(0x01);
+            } else if (b == 0xfb && msg.isReadable() && msg.getUnsignedByte(msg.readerIndex()) == 0xbf) {
+                msg.readUnsignedByte();
+                out.writeByte(0xfb);
+                out.writeByte(0xbf);
+                out.writeByte(0x02);
+            } else {
+                out.writeByte(b);
+            }
+        }
+
+        out.writeBytes(msg.readBytes(2));
+
+    }
+}
diff --git a/src/main/java/org/traccar/protocol/Xexun2Protocol.java b/src/main/java/org/traccar/protocol/Xexun2Protocol.java
index 1d5038a22..52cf731f0 100644
--- a/src/main/java/org/traccar/protocol/Xexun2Protocol.java
+++ b/src/main/java/org/traccar/protocol/Xexun2Protocol.java
@@ -35,6 +35,7 @@ public class Xexun2Protocol extends BaseProtocol {
         addServer(new TrackerServer(config, getName(), false) {
             @Override
             protected void addProtocolHandlers(PipelineBuilder pipeline, Config config) {
+                pipeline.addLast(new Xexun2FrameEncoder());
                 pipeline.addLast(new Xexun2FrameDecoder());
                 pipeline.addLast(new Xexun2ProtocolDecoder(Xexun2Protocol.this));
                 pipeline.addLast(new Xexun2ProtocolEncoder(Xexun2Protocol.this));
diff --git a/src/main/java/org/traccar/protocol/Xexun2ProtocolDecoder.java b/src/main/java/org/traccar/protocol/Xexun2ProtocolDecoder.java
index f0158e6ce..913dfaf28 100644
--- a/src/main/java/org/traccar/protocol/Xexun2ProtocolDecoder.java
+++ b/src/main/java/org/traccar/protocol/Xexun2ProtocolDecoder.java
@@ -42,12 +42,14 @@ public class Xexun2ProtocolDecoder extends BaseProtocolDecoder {
         super(protocol);
     }
 
+    public static final int FLAG = 0xfaaf;
+    public static final int MSG_COMMAND = 0x07;
     public static final int MSG_POSITION = 0x14;
 
     private void sendResponse(Channel channel, int type, int index, ByteBuf imei) {
         if (channel != null) {
             ByteBuf response = Unpooled.buffer();
-            response.writeShort(Xexun2ProtocolEncoder.FLAG);
+            response.writeShort(FLAG);
 
             response.writeShort(type);
             response.writeShort(index);
@@ -56,7 +58,7 @@ public class Xexun2ProtocolDecoder extends BaseProtocolDecoder {
             response.writeShort(0xfffe); // checksum
             response.writeByte(1); // response
 
-            response.writeShort(Xexun2ProtocolEncoder.FLAG);
+            response.writeShort(FLAG);
 
             channel.writeAndFlush(new NetworkMessage(response, channel.remoteAddress()));
         }
@@ -99,13 +101,13 @@ public class Xexun2ProtocolDecoder extends BaseProtocolDecoder {
         }
 
         int payloadSize = buf.readUnsignedShort() & 0x03ff;
-        int checksum = buf.readUnsignedShort(); // checksum
+        int checksum = buf.readUnsignedShort();
 
-        if (checksum != Checksum.udp(buf.nioBuffer(buf.readerIndex(), payloadSize))) {
+        if (checksum != Checksum.ip(buf.nioBuffer(buf.readerIndex(), payloadSize))) {
             return null;
         }
 
-        if (type != Xexun2ProtocolEncoder.MSG_COMMAND) {
+        if (type != MSG_COMMAND) {
             sendResponse(channel, type, index, imei);
         }
 
diff --git a/src/main/java/org/traccar/protocol/Xexun2ProtocolEncoder.java b/src/main/java/org/traccar/protocol/Xexun2ProtocolEncoder.java
index 6e1e1d68d..c315cab30 100644
--- a/src/main/java/org/traccar/protocol/Xexun2ProtocolEncoder.java
+++ b/src/main/java/org/traccar/protocol/Xexun2ProtocolEncoder.java
@@ -23,61 +23,29 @@ import org.traccar.helper.DataConverter;
 import org.traccar.model.Command;
 import org.traccar.Protocol;
 
+import java.nio.charset.StandardCharsets;
+
 public class Xexun2ProtocolEncoder extends BaseProtocolEncoder {
 
     public Xexun2ProtocolEncoder(Protocol protocol) {
         super(protocol);
     }
 
-    public static final int FLAG = 0xfaaf;
-    public static final int MSG_COMMAND = 0x07;
-
-    private static ByteBuf encodeFrame(ByteBuf buf) {
-        int bufLength = buf.readableBytes();
-        if (bufLength < 5) {
-            return null;
-        }
-
-        ByteBuf result = Unpooled.buffer();
-
-        result.writeBytes(buf.readBytes(2));
-
-        while (buf.readerIndex() < bufLength - 2) {
-            int b = buf.readUnsignedByte();
-            if (b == 0xfa && buf.isReadable() && buf.getUnsignedByte(buf.readerIndex()) == 0xaf) {
-                buf.readUnsignedByte();
-                result.writeByte(0xfb);
-                result.writeByte(0xbf);
-                result.writeByte(0x01);
-            } else if (b == 0xfb && buf.isReadable() && buf.getUnsignedByte(buf.readerIndex()) == 0xbf) {
-                buf.readUnsignedByte();
-                result.writeByte(0xfb);
-                result.writeByte(0xbf);
-                result.writeByte(0x02);
-            } else {
-                result.writeByte(b);
-            }
-        }
-        result.writeBytes(buf.readBytes(2));
-
-        return result;
-    }
-
     private static ByteBuf encodeContent(String uniqueId, String content) {
         ByteBuf buf = Unpooled.buffer();
 
-        ByteBuf message = Unpooled.copiedBuffer(content.getBytes());
+        ByteBuf message = Unpooled.copiedBuffer(content.getBytes(StandardCharsets.US_ASCII));
 
-        buf.writeShort(FLAG);
-        buf.writeShort(MSG_COMMAND);
+        buf.writeShort(Xexun2ProtocolDecoder.FLAG);
+        buf.writeShort(Xexun2ProtocolDecoder.MSG_COMMAND);
         buf.writeShort(1); // index
         buf.writeBytes(DataConverter.parseHex(uniqueId + "0"));
         buf.writeShort(message.capacity());
-        buf.writeShort(Checksum.udp(message.nioBuffer()));
+        buf.writeShort(Checksum.ip(message.nioBuffer()));
         buf.writeBytes(message);
-        buf.writeShort(FLAG);
+        buf.writeShort(Xexun2ProtocolDecoder.FLAG);
 
-        return encodeFrame(buf);
+        return buf;
     }
 
     @Override