1 files changed, 46 insertions, 13 deletions

diff --git a/src/main/java/org/traccar/protocol/DualcamProtocolDecoder.java b/src/main/java/org/traccar/protocol/DualcamProtocolDecoder.java
index d03f7648d..411e2b9d7 100644
--- a/src/main/java/org/traccar/protocol/DualcamProtocolDecoder.java
+++ b/src/main/java/org/traccar/protocol/DualcamProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2021 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2021 - 2023 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.
@@ -42,13 +42,24 @@ public class DualcamProtocolDecoder extends BaseProtocolDecoder {
     public static final int MSG_COMPLETE = 5;
     public static final int MSG_FILE_REQUEST = 8;
     public static final int MSG_INIT_REQUEST = 9;
+    public static final int MSG_PATH_REQUEST = 0x000C;
+    public static final int MSG_PATH_RESPONSE = 0x000D;
 
+    private String model;
     private String uniqueId;
-    private int packetCount;
-    private int currentPacket;
+    private int dataSize;
+    private int dataCurrent;
     private boolean video;
     private ByteBuf media;
 
+    private boolean isPacketData() {
+        if (model == null) {
+            return dataSize < 8192;
+        } else {
+            return !"DSM".equals(model);
+        }
+    }
+
     @Override
     protected Object decode(
             Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
@@ -57,15 +68,21 @@ public class DualcamProtocolDecoder extends BaseProtocolDecoder {
 
         int type = buf.readUnsignedShort();
 
+        DeviceSession deviceSession;
         switch (type) {
             case MSG_INIT:
                 buf.readUnsignedShort(); // protocol id
                 uniqueId = String.valueOf(buf.readLong());
-                DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, uniqueId);
+                deviceSession = getDeviceSession(channel, remoteAddress, uniqueId);
                 long settings = buf.readUnsignedInt();
                 if (channel != null && deviceSession != null) {
+                    model = getDeviceModel(deviceSession);
                     ByteBuf response = Unpooled.buffer();
-                    if (BitUtil.between(settings, 26, 30) > 0) {
+                    if (BitUtil.check(settings, 25)) {
+                        response.writeShort(MSG_PATH_REQUEST);
+                        response.writeShort(2);
+                        response.writeShort(0);
+                    } else if (BitUtil.between(settings, 26, 30) > 0) {
                         response.writeShort(MSG_FILE_REQUEST);
                         String file;
                         if (BitUtil.check(settings, 26)) {
@@ -91,21 +108,29 @@ public class DualcamProtocolDecoder extends BaseProtocolDecoder {
                 break;
             case MSG_START:
                 buf.readUnsignedShort(); // length
-                packetCount = buf.readInt();
-                currentPacket = 1;
+                dataSize = buf.readInt();
+                dataCurrent = isPacketData() ? 1 : 0;
                 media = Unpooled.buffer();
                 if (channel != null) {
                     ByteBuf response = Unpooled.buffer();
                     response.writeShort(MSG_RESUME);
                     response.writeShort(4);
-                    response.writeInt(currentPacket);
+                    response.writeInt(dataCurrent);
                     channel.writeAndFlush(new NetworkMessage(response, remoteAddress));
                 }
                 break;
             case MSG_DATA:
-                buf.readUnsignedShort(); // length
-                media.writeBytes(buf, buf.readableBytes() - 2);
-                if (currentPacket == packetCount) {
+                int length = buf.readUnsignedShort() - 2;
+                media.writeBytes(buf, length);
+                boolean finished;
+                if (isPacketData()) {
+                    finished = dataCurrent == dataSize;
+                    dataCurrent += 1;
+                } else {
+                    finished = dataCurrent + length == dataSize;
+                    dataCurrent += length;
+                }
+                if (finished) {
                     deviceSession = getDeviceSession(channel, remoteAddress);
                     Position position = new Position(getProtocolName());
                     position.setDeviceId(deviceSession.getDeviceId());
@@ -126,8 +151,16 @@ public class DualcamProtocolDecoder extends BaseProtocolDecoder {
                         channel.writeAndFlush(new NetworkMessage(response, remoteAddress));
                     }
                     return position;
-                } else {
-                    currentPacket += 1;
+                }
+                break;
+            case MSG_PATH_RESPONSE:
+                String file = buf.readCharSequence(buf.readUnsignedShort(), StandardCharsets.US_ASCII).toString();
+                if (channel != null) {
+                    ByteBuf response = Unpooled.buffer();
+                    response.writeShort(MSG_FILE_REQUEST);
+                    response.writeShort(file.length());
+                    response.writeCharSequence(file, StandardCharsets.US_ASCII);
+                    channel.writeAndFlush(new NetworkMessage(response, remoteAddress));
                 }
                 break;
             default: