cgivre commented on a change in pull request #1898: DRILL-7443: Enable PCAP Plugin to Reassemble TCP Streams URL: https://github.com/apache/drill/pull/1898#discussion_r349429229
########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/store/pcap/decoder/TcpSession.java ########## @@ -0,0 +1,334 @@ +/* + * 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.drill.exec.store.pcap.decoder; + +import org.joda.time.Instant; +import org.joda.time.Period; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.net.InetAddress; +import java.util.ArrayList; +import java.util.Collections; + +import static org.apache.drill.exec.store.pcap.PcapFormatUtils.parseBytesToASCII; + +/** + * This class is the representation of a TCP session. + */ +public class TcpSession { + + private ArrayList<Packet> packetsFromSender; + private ArrayList<Packet> packetsFromReceiver; + + private long startTime; + private long endTime; + private long sessionLength; + private int packetCount; + private InetAddress srcIP; + private InetAddress dstIP; + private int srcPort; + private int dstPort; + private String srcMac; + private String dstMac; + private long sessionID; + private TcpHandshake handshake; + private long synTime; + private long ackTime; + private long connectTime; + private byte[] sentData; + private byte[] receivedData; + private int sentDataSize; + private int receivedDataSize; + private boolean hasCorruptedData = false; + + + private static final Logger logger = LoggerFactory.getLogger(TcpSession.class); + + public TcpSession (long sessionID) { + packetsFromSender = new ArrayList<>(); + packetsFromReceiver = new ArrayList<>(); + + handshake = new TcpHandshake(); + this.sessionID = sessionID; + } + + /** + * This function adds a packet to the TCP session. + * @param p The Packet to be added to the session + */ + public void addPacket(Packet p) { + + // Only attempt to add TCP packets to session + if (!p.getPacketType().equalsIgnoreCase("TCP")) { + return; + } + + // These variables should be consistent within a TCP session + if (packetCount == 0) { + srcIP = p.getSrc_ip(); + dstIP = p.getDst_ip(); + + srcPort = p.getSrc_port(); + dstPort = p.getDst_port(); + + srcMac = p.getEthernetSource(); + dstMac = p.getEthernetDestination(); + startTime = p.getTimestamp(); + } else if (p.getSessionHash() != sessionID) { + logger.warn("Attempting to add session {} to incorrect TCP session.", sessionID); + return; + } + + // Add packet to appropriate list and increment the data size counter + if (p.getSrc_ip().getHostAddress().equalsIgnoreCase(srcIP.getHostAddress())) { + packetsFromSender.add(p); + // Increment the data size counters + if (p.getData() != null) { + sentDataSize += p.getData().length; + } + + } else { + packetsFromReceiver.add(p); + if (p.getData() != null) { + receivedDataSize += p.getData().length; + } + } + + // Check flags if connection is not established + if (!handshake.isConnected()) { + if (p.getSynFlag() && p.getSrc_ip().getHostAddress().equalsIgnoreCase(srcIP.getHostAddress())) { + // This is part 1 of the TCP session handshake + // The host sends the first SYN packet + handshake.syn = true; + handshake.setSyn(); + synTime = p.getTimestamp(); + } else if (p.getSynFlag() && p.getAckFlag() && p.getSrc_ip().getHostAddress().equalsIgnoreCase(dstIP.getHostAddress())) { + // This condition represents the second part of the TCP Handshake, + // where the receiver sends a frame with the SYN/ACK flags set to the originator + handshake.synAck = true; + handshake.setAck(); + } else if (p.getAckFlag() && p.getSrc_ip().getHostAddress().equalsIgnoreCase(srcIP.getHostAddress())) { + // Finally, this condition represents a successful opening of a TCP session, when the originator sends a frame with only the ACK flag set. + // At this point we finalize the session object and clear out the flags. + handshake.ack = true; + handshake.setAck(); + ackTime = p.getTimestamp(); + connectTime = ackTime - synTime; + //handshake.setConnected(sessionID); + } + } else { + /* Check for flags to close connection. Closing a TCP session is more difficult than opening a session and there are + * a lot of ways that it can go wrong. See https://accedian.com/enterprises/blog/close-tcp-sessions-diagnose-disconnections/ for references on Review comment: Fixed ---------------------------------------------------------------- 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] With regards, Apache Git Services
