kezhenxu94 commented on a change in pull request #6176: URL: https://github.com/apache/skywalking/pull/6176#discussion_r573520188
########## File path: oap-server/server-receiver-plugin/skywalking-zabbix-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zabbix/provider/protocol/ZabbixProtocolDecoder.java ########## @@ -0,0 +1,111 @@ +/* + * 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.skywalking.oap.server.receiver.zabbix.provider.protocol; + +import com.google.common.base.Charsets; +import com.google.gson.Gson; +import com.google.gson.GsonBuilder; +import io.netty.buffer.ByteBuf; +import io.netty.channel.ChannelHandlerContext; +import io.netty.handler.codec.ByteToMessageDecoder; +import lombok.extern.slf4j.Slf4j; +import org.apache.skywalking.oap.server.receiver.zabbix.provider.protocol.bean.ZabbixRequest; +import org.apache.skywalking.oap.server.receiver.zabbix.provider.protocol.bean.ZabbixRequestJsonDeserializer; + +import java.util.List; + +@Slf4j +public class ZabbixProtocolDecoder extends ByteToMessageDecoder { + private static final int HEADER_LEN = 9; + private static final byte[] PROTOCOL = new byte[] {'Z', 'B', 'X', 'D'}; + + private final Gson requestParser = new GsonBuilder() + .registerTypeAdapter(ZabbixRequest.class, new ZabbixRequestJsonDeserializer()).create(); + + @Override + protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception { + try { + // Decode header and get payload + String payload = decodeToPayload(channelHandlerContext, byteBuf); + + // Parse content and add to list + ZabbixRequest request = requestParser.fromJson(payload, ZabbixRequest.class); + list.add(request); + } catch (Exception e) { + errorProtocol(channelHandlerContext, byteBuf, "Parsing zabbix request data error", e); + } + } + + /** + * Decode protocol to payload string + */ + public String decodeToPayload(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf) throws InterruptedException, ZabbixErrorProtocolException { + int readable = byteBuf.readableBytes(); + int baseIndex = byteBuf.readerIndex(); + if (readable < HEADER_LEN) { + throw new ZabbixErrorProtocolException("header length is not enough"); + } + + // Read header + byte[] header = new byte[HEADER_LEN]; + byteBuf.readBytes(header); + if (header[0] != PROTOCOL[0] || header[1] != PROTOCOL[1] || header[2] != PROTOCOL[2] || header[3] != PROTOCOL[3]) { + throw new ZabbixErrorProtocolException("header is not right"); + } + + // Only support communications protocol + if (header[4] != 1) { + throw new ZabbixErrorProtocolException("header flags only support communications protocol"); + } + + // Check payload + int dataLength = header[5] & 0xFF | (header[6] & 0xFF) << 8 | (header[7] & 0xFF) << 16 | (header[8] & 0xFF) << 24; + int totalLength = HEADER_LEN + dataLength + 4; + // If not receive all data, reset buffer and re-decode after content receive finish + if (readable < totalLength) { + byteBuf.readerIndex(baseIndex); + return null; + } + + if (dataLength <= 0) { + throw new ZabbixErrorProtocolException("content could not be empty"); + } + + // Skip protocol extensions + byteBuf.skipBytes(4); + + // Reading content + byte[] payload = new byte[dataLength]; + byteBuf.readBytes(payload); Review comment: ~~This may cause memory leak (as well as line 67), please recheck the JavaDoc of `io.netty.handler.codec.ByteToMessageDecoder`.~~ ``` * Some methods such as {@link ByteBuf#readBytes(int)} will cause a memory leak if the returned buffer * is not released or added to the <tt>out</tt> {@link List}. Use derived buffers like {@link ByteBuf#readSlice(int)} * to avoid leaking memory. ``` EDIT: read the wrong method signature, `io.netty.buffer.ByteBuf#readBytes(byte[])` won't cause leak ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
