diff options
Diffstat (limited to 'src/main/java/org/traccar/protocol/OmnicommFrameDecoder.java')
-rw-r--r-- | src/main/java/org/traccar/protocol/OmnicommFrameDecoder.java | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/OmnicommFrameDecoder.java b/src/main/java/org/traccar/protocol/OmnicommFrameDecoder.java new file mode 100644 index 000000000..1caf6ceb9 --- /dev/null +++ b/src/main/java/org/traccar/protocol/OmnicommFrameDecoder.java @@ -0,0 +1,58 @@ +/* + * Copyright 2019 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 io.netty.channel.ChannelHandlerContext; +import org.traccar.BaseFrameDecoder; + +public class OmnicommFrameDecoder extends BaseFrameDecoder { + + @Override + protected Object decode( + ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception { + + if (buf.readableBytes() < 10) { + return null; + } + + int endIndex = buf.getUnsignedShortLE(2) + buf.readerIndex() + 6; + if (buf.writerIndex() < endIndex) { + return null; + } + + ByteBuf result = Unpooled.buffer(); + result.writeByte(buf.readUnsignedByte()); + while (buf.readerIndex() < endIndex) { + int b = buf.readUnsignedByte(); + if (b == 0xDB) { + int ext = buf.readUnsignedByte(); + if (ext == 0xDC) { + result.writeByte(0xC0); + } else if (ext == 0xDD) { + result.writeByte(0xDB); + } + endIndex += 1; + } else { + result.writeByte(b); + } + } + return result; + } + +} |