| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.dubbo.qos.pu; |
| |
| import org.apache.dubbo.qos.command.BaseCommand; |
| import org.apache.dubbo.qos.command.CommandContext; |
| import org.apache.dubbo.qos.command.decoder.TelnetCommandDecoder; |
| import org.apache.dubbo.remoting.api.ProtocolDetector; |
| import org.apache.dubbo.remoting.buffer.ChannelBuffer; |
| import org.apache.dubbo.remoting.buffer.ChannelBuffers; |
| import org.apache.dubbo.remoting.buffer.HeapChannelBuffer; |
| import org.apache.dubbo.rpc.model.FrameworkModel; |
| |
| import io.netty.util.CharsetUtil; |
| |
| import static java.lang.Math.min; |
| |
| |
| public class TelnetDetector implements ProtocolDetector { |
| |
| private FrameworkModel frameworkModel; |
| private final int MaxSize = 2048; |
| private final ChannelBuffer AytPreface = new HeapChannelBuffer(new byte[]{(byte) 0xff, (byte) 0xf6}); |
| |
| public TelnetDetector(FrameworkModel frameworkModel) { |
| this.frameworkModel = frameworkModel; |
| } |
| |
| @Override |
| public Result detect(ChannelBuffer in) { |
| if (in.readableBytes() >= MaxSize) { |
| return Result.UNRECOGNIZED; |
| } |
| Result resCommand = commandDetect(in); |
| if (resCommand.equals(Result.RECOGNIZED)){ |
| return resCommand; |
| } |
| Result resAyt = telnetAytDetect(in); |
| if (resAyt.equals(Result.RECOGNIZED)) { |
| return resAyt; |
| } |
| if (resAyt.equals(Result.UNRECOGNIZED) && resCommand.equals(Result.UNRECOGNIZED)) { |
| return Result.UNRECOGNIZED; |
| } |
| return Result.NEED_MORE_DATA; |
| } |
| |
| private Result commandDetect(ChannelBuffer in) { |
| // detect if remote channel send a qos command to server |
| ChannelBuffer back = in.copy(); |
| byte[] backBytes = new byte[back.readableBytes()]; |
| back.getBytes(back.readerIndex(), backBytes); |
| |
| String s = new String(backBytes, CharsetUtil.UTF_8); |
| // trim /r/n to let parser work for input |
| s = s.trim(); |
| CommandContext commandContext = TelnetCommandDecoder.decode(s); |
| if(frameworkModel.getExtensionLoader(BaseCommand.class).hasExtension(commandContext.getCommandName())){ |
| return Result.RECOGNIZED; |
| } |
| return Result.UNRECOGNIZED; |
| } |
| |
| private Result telnetAytDetect(ChannelBuffer in) { |
| // detect if remote channel send a telnet ayt command to server |
| int prefaceLen = AytPreface.readableBytes(); |
| int bytesRead = min(in.readableBytes(), prefaceLen); |
| if(bytesRead == 0 || !ChannelBuffers.prefixEquals(in, AytPreface, bytesRead)) { |
| return Result.UNRECOGNIZED; |
| } |
| if(bytesRead == prefaceLen) { |
| // we need to consume preface because it's not a qos command |
| // consume and remember to mark, pu server handler reset reader index |
| in.readBytes(AytPreface.readableBytes()); |
| in.markReaderIndex(); |
| return Result.RECOGNIZED; |
| } |
| return Result.NEED_MORE_DATA; |
| } |
| |
| } |