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
|
/*
* Copyright 2024 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.Protocol;
import org.traccar.helper.BitUtil;
import org.traccar.session.DeviceSession;
import java.net.SocketAddress;
public class FleetGuideProtocolDecoder extends BaseProtocolDecoder {
public FleetGuideProtocolDecoder(Protocol protocol) {
super(protocol);
}
public static final int MSG_DATA = 0x10;
public static final int MSG_HEARTBEAT = 0x1A;
public static final int MSG_RESPONSE = 0x1C;
@Override
protected Object decode(
Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
ByteBuf buf = (ByteBuf) msg;
buf.readUnsignedByte(); // signature
int options = buf.readUnsignedShortLE();
int length = BitUtil.to(options, 11);
DeviceSession deviceSession;
if (BitUtil.check(options, 11)) {
deviceSession = getDeviceSession(channel, remoteAddress, String.valueOf(buf.readUnsignedIntLE()));
} else {
deviceSession = getDeviceSession(channel, remoteAddress);
}
if (deviceSession == null) {
return null;
}
int type;
if (BitUtil.check(options, 12)) {
type = BitUtil.to(buf.readUnsignedByte(), 4);
} else {
type = 0;
}
if (BitUtil.check(options, 13)) {
buf.readUnsignedShortLE(); // acknowledgement
}
ByteBuf data;
if (BitUtil.check(options, 14)) {
data = decompress(buf.readSlice(length));
} else {
data = buf.readRetainedSlice(length);
}
data.release();
return null;
}
private int readVarSize(ByteBuf buf) {
int b;
int y = 0;
do {
b = buf.readUnsignedByte();
y = (y << 7) | (b & 0x0000007f);
} while ((b & 0x00000080) > 0);
return y;
}
private ByteBuf decompress(ByteBuf in) {
ByteBuf out = Unpooled.buffer();
if (in.readableBytes() < 1) {
return out;
}
int marker = in.readUnsignedByte();
do {
int symbol = in.readUnsignedByte();
if (symbol == marker) {
if (in.getUnsignedByte(in.readerIndex()) == 0) {
out.writeByte(marker);
in.skipBytes(1);
} else {
int length = readVarSize(in);
int offset = readVarSize(in);
for (int i = 0; i < length; i++) {
out.writeByte(out.getUnsignedByte(out.writerIndex() - offset));
}
}
} else {
out.writeByte(symbol);
}
} while (in.isReadable());
return out;
}
}
|
