From 99f09134fb9c710114296d603c97a76f5cfb0d2a Mon Sep 17 00:00:00 2001 From: Anton Tananaev Date: Sun, 18 Dec 2016 23:33:42 +1300 Subject: Implement AIS protocol decoder --- src/org/traccar/helper/BitBuffer.java | 93 +++++++++++++++ src/org/traccar/protocol/AisProtocol.java | 43 +++++++ src/org/traccar/protocol/AisProtocolDecoder.java | 139 +++++++++++++++++++++++ 3 files changed, 275 insertions(+) create mode 100644 src/org/traccar/helper/BitBuffer.java create mode 100644 src/org/traccar/protocol/AisProtocol.java create mode 100644 src/org/traccar/protocol/AisProtocolDecoder.java (limited to 'src/org/traccar') diff --git a/src/org/traccar/helper/BitBuffer.java b/src/org/traccar/helper/BitBuffer.java new file mode 100644 index 000000000..7626988cc --- /dev/null +++ b/src/org/traccar/helper/BitBuffer.java @@ -0,0 +1,93 @@ +/* + * Copyright 2016 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.helper; + +import org.jboss.netty.buffer.ChannelBuffer; +import org.jboss.netty.buffer.ChannelBuffers; + +public class BitBuffer { + + private ChannelBuffer buffer = ChannelBuffers.dynamicBuffer(); + + private int writeByte; + private int writeCount; + + private int readByte; + private int readCount; + + public void writeEncoded(byte[] bytes) { + for (byte b : bytes) { + b -= 48; + if (b > 40) { + b -= 8; + } + write(b); + } + } + + public void write(int b) { + if (writeCount == 0) { + writeByte |= b; + writeCount = 6; + } else { + int remaining = 8 - writeCount; + writeByte <<= remaining; + writeByte |= b >> (6 - remaining); + buffer.writeByte(writeByte); + writeByte = b & ((1 << (6 - remaining)) - 1); + writeCount = 6 - remaining; + } + } + + public int readUnsigned(int length) { + int result = 0; + + while (length > 0) { + if (readCount == 0) { + readByte = buffer.readUnsignedByte(); + readCount = 8; + } + if (readCount >= length) { + result <<= length; + result |= readByte >> (readCount - length); + readByte &= (1 << (readCount - length)) - 1; + readCount -= length; + length = 0; + } else { + result <<= readCount; + result |= readByte; + length -= readCount; + readByte = 0; + readCount = 0; + } + } + + return result; + } + + public int readSigned(int length) { + int result = readUnsigned(length); + int signBit = 1 << (length - 1); + if ((result & signBit) == 0) { + return result; + } else { + result &= signBit - 1; + result += ~(signBit - 1); + return result; + } + } + +} diff --git a/src/org/traccar/protocol/AisProtocol.java b/src/org/traccar/protocol/AisProtocol.java new file mode 100644 index 000000000..4b2e1719e --- /dev/null +++ b/src/org/traccar/protocol/AisProtocol.java @@ -0,0 +1,43 @@ +/* + * Copyright 2016 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 org.jboss.netty.bootstrap.ConnectionlessBootstrap; +import org.jboss.netty.channel.ChannelPipeline; +import org.jboss.netty.handler.codec.string.StringDecoder; +import org.traccar.BaseProtocol; +import org.traccar.TrackerServer; + +import java.util.List; + +public class AisProtocol extends BaseProtocol { + + public AisProtocol() { + super("ais"); + } + + @Override + public void initTrackerServers(List serverList) { + serverList.add(new TrackerServer(new ConnectionlessBootstrap(), getName()) { + @Override + protected void addSpecificHandlers(ChannelPipeline pipeline) { + pipeline.addLast("stringDecoder", new StringDecoder()); + pipeline.addLast("objectDecoder", new AisProtocolDecoder(AisProtocol.this)); + } + }); + } + +} diff --git a/src/org/traccar/protocol/AisProtocolDecoder.java b/src/org/traccar/protocol/AisProtocolDecoder.java new file mode 100644 index 000000000..3ccca6dd3 --- /dev/null +++ b/src/org/traccar/protocol/AisProtocolDecoder.java @@ -0,0 +1,139 @@ +/* + * Copyright 2016 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 org.jboss.netty.channel.Channel; +import org.traccar.BaseProtocolDecoder; +import org.traccar.DeviceSession; +import org.traccar.helper.BitBuffer; +import org.traccar.helper.Parser; +import org.traccar.helper.PatternBuilder; +import org.traccar.model.Position; + +import java.net.SocketAddress; +import java.util.ArrayList; +import java.util.Date; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.regex.Pattern; + +public class AisProtocolDecoder extends BaseProtocolDecoder { + + public AisProtocolDecoder(AisProtocol protocol) { + super(protocol); + } + + private static final Pattern PATTERN = new PatternBuilder() + .text("!AIVDM,") + .number("(d+),") // count + .number("(d+),") // index + .number("(d+)?,") // id + .expression(".,") // radio channel + .expression("([^,]+),") // payload + .any() + .compile(); + + private Position decodePayload(Channel channel, SocketAddress remoteAddress, BitBuffer buf) { + + int type = buf.readUnsigned(6); + if (type == 1 || type == 2 || type == 3 || type == 18) { + + buf.readUnsigned(2); + int mmsi = buf.readUnsigned(30); + + DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, String.valueOf(mmsi)); + if (deviceSession == null) { + return null; + } + + Position position = new Position(); + position.setProtocol(getProtocolName()); + position.setDeviceId(deviceSession.getDeviceId()); + + position.setTime(new Date()); + + if (type == 18) { + buf.readUnsigned(8); // reserved + } else { + position.set(Position.KEY_STATUS, buf.readUnsigned(4)); + position.set("turn", buf.readSigned(8)); + } + + position.setSpeed(buf.readUnsigned(10) * 0.1); + position.setValid(buf.readUnsigned(1) != 0); + position.setLongitude(buf.readSigned(28) * 0.0001 / 60.0); + position.setLatitude(buf.readSigned(27) * 0.0001 / 60.0); + position.setCourse(buf.readUnsigned(12) * 0.1); + + position.set("heading", buf.readUnsigned(9)); + + return position; + + } + + return null; + } + + @Override + protected Object decode( + Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { + + String[] sentences = ((String) msg).split("\\r\\n"); + + List positions = new ArrayList<>(); + Map buffers = new HashMap<>(); + + for (String sentence : sentences) { + if (!sentence.isEmpty()) { + Parser parser = new Parser(PATTERN, sentence); + if (parser.matches()) { + + int count = parser.nextInt(); + int index = parser.nextInt(); + int id = parser.nextInt(); + + Position position = null; + + if (count == 1) { + BitBuffer bits = new BitBuffer(); + bits.writeEncoded(parser.next().getBytes()); + position = decodePayload(channel, remoteAddress, bits); + } else { + BitBuffer bits = buffers.get(id); + if (bits == null) { + bits = new BitBuffer(); + buffers.put(id, bits); + } + bits.writeEncoded(parser.next().getBytes()); + if (count == index) { + position = decodePayload(channel, remoteAddress, bits); + buffers.remove(id); + } + } + + if (position != null) { + positions.add(position); + } + + } + } + } + + return positions; + } + +} -- cgit v1.2.3