aboutsummaryrefslogtreecommitdiff
path: root/src/main/java/org/traccar/protocol/ObdDongleProtocolDecoder.java
blob: 1c9771ce998fa4d467f35a2ac5e3d7c7522a33e4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/*
 * Copyright 2016 - 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.buffer.Unpooled;
import io.netty.channel.Channel;
import org.traccar.BaseProtocolDecoder;
import org.traccar.DeviceSession;
import org.traccar.NetworkMessage;
import org.traccar.Protocol;
import org.traccar.helper.BitUtil;
import org.traccar.helper.UnitsConverter;
import org.traccar.model.Position;

import java.net.SocketAddress;
import java.nio.charset.StandardCharsets;
import java.util.Date;

public class ObdDongleProtocolDecoder extends BaseProtocolDecoder {

    public ObdDongleProtocolDecoder(Protocol protocol) {
        super(protocol);
    }

    public static final int MSG_TYPE_CONNECT = 0x01;
    public static final int MSG_TYPE_CONNACK = 0x02;
    public static final int MSG_TYPE_PUBLISH = 0x03;
    public static final int MSG_TYPE_PUBACK = 0x04;
    public static final int MSG_TYPE_PINGREQ = 0x0C;
    public static final int MSG_TYPE_PINGRESP = 0x0D;
    public static final int MSG_TYPE_DISCONNECT = 0x0E;

    private static void sendResponse(Channel channel, int type, int index, String imei, ByteBuf content) {
        if (channel != null) {
            ByteBuf response = Unpooled.buffer();
            response.writeShort(0x5555); // header
            response.writeShort(index);
            response.writeBytes(imei.getBytes(StandardCharsets.US_ASCII));
            response.writeByte(type);
            response.writeShort(content.readableBytes());
            response.writeBytes(content);
            content.release();
            response.writeByte(0); // checksum
            response.writeShort(0xAAAA);
            channel.writeAndFlush(new NetworkMessage(response, channel.remoteAddress()));
        }
    }

    @Override
    protected Object decode(
            Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {

        ByteBuf buf = (ByteBuf) msg;

        buf.skipBytes(2); // header
        int index = buf.readUnsignedShort();

        String imei = buf.readSlice(15).toString(StandardCharsets.US_ASCII);
        DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
        if (deviceSession == null) {
            return null;
        }

        int type = buf.readUnsignedByte();

        buf.readUnsignedShort(); // data length

        if (type == MSG_TYPE_CONNECT) {

            ByteBuf response = Unpooled.buffer();
            response.writeByte(1);
            response.writeShort(0);
            response.writeInt(0);
            sendResponse(channel, MSG_TYPE_CONNACK, index, imei, response);

        } else if (type == MSG_TYPE_PUBLISH) {

            int typeMajor = buf.readUnsignedByte();
            int typeMinor = buf.readUnsignedByte();

            buf.readUnsignedByte(); // event id

            Position position = new Position(getProtocolName());
            position.setDeviceId(deviceSession.getDeviceId());

            position.setTime(new Date(buf.readUnsignedInt() * 1000));

            int flags = buf.readUnsignedByte();

            position.setValid(!BitUtil.check(flags, 6));

            position.set(Position.KEY_SATELLITES, BitUtil.to(flags, 4));

            double longitude = ((BitUtil.to(buf.readUnsignedShort(), 1) << 24) + buf.readUnsignedMedium()) * 0.00001;
            position.setLongitude(BitUtil.check(flags, 5) ? longitude : -longitude);

            double latitude = buf.readUnsignedMedium() * 0.00001;
            position.setLatitude(BitUtil.check(flags, 4) ? latitude : -latitude);

            int speedCourse = buf.readUnsignedMedium();
            position.setSpeed(UnitsConverter.knotsFromMph(BitUtil.from(speedCourse, 10) * 0.1));
            position.setCourse(BitUtil.to(speedCourse, 10));

            ByteBuf response = Unpooled.buffer();
            response.writeByte(typeMajor);
            response.writeByte(typeMinor);
            sendResponse(channel, MSG_TYPE_PUBACK, index, imei, response);

            return position;

        }

        return null;
    }

}