分散式網路事件分析記錄系統之 研製 The Design and Implementation of Distributed Network Event Analyzing and Recording System Yi-Lei Chang Advisor: Dr. Kai-Wei Ke 2013/06/17 1

Outline  Introduction  Background  System Design  Compare to simulate system  Demo  Reference 2

Introduction  Network Event  An observable occurrence on network that can be recognize as a specific protocol activity or behavior (e.g., FTP Login, HTTP web browse).  System Goals  Record and analyze network event  FTP  HTTP  VoIP  Abnormal behavior  Distributed system  High flexibility and extensibility 3

Background - Jpcap  Packages  Jpcap  JpcapCaptor  PacketReceiver  Jpcap.packet  ARPPacket  ICMPPacket  IPPacket  TCPPacket  UDPPacket 4

Background - Jpcap 5

System Design 6

Interception System  Capture packets  Track relative connections  Record supported network event 7

Packet Capture  Receive packets from NIC in promiscuous mode  Set basic packet filter  IP  ARP  Not Interception System’s IP  Add packets to PacketPool 8

Packet Pool  Maintain all packets capture by PacketCapture  Each ProtocolParser register to PacketPool have a random integer key to access it’s packet list iterator  Remove useless packets when buffer full  Synchronize needed 9

Protocol Parser  Abstract class ProtocolParser implements Runnable  Define basic steps for a standard protocol parser  Implement Runnable.run() with 4 abstract function called in sequence  isRelative()  processPacket()  isContinue()  endProcess()  The implementation of these abstraction function will change the use of class extends ProtocolParser(e.g., FTPProtocolParser). 10

Protocol Parser 11

Protocol Parser - FTP  Relative: port 21  Process:  Create a connection key “clientIP|clientPort|hostIP|hostPort” for identify every FTP command connection  For every unhandled FTP connection create FTP command Parser  Continue: always  Ending process: unregister with PacketPool 12

Protocol Parser - FTP 13

Protocol Parser – FTP command  Relative: specific connection represent by connection key  Process:  USER/PASS/230 – login event  PORT/227 – tract data connection  STOR/RETR – create FTP recorder to record transmitted file  Continue:  Connection not close  Connection not idle  Ending process:  Unregister with PacketPool  Remove handled state in FTP Parser 14

Protocol Parser – FTP command 15

Protocol Parser – FTP recorder  Relative: specific connection and direction represent IP and Port  Process:  Put data packet to TCPReorderBuffer  Set acknowledge number for TCPReorderBuffer to reference  While buffer full flush data to file  Continue:  Connection not close  Connection not idle  Ending process:  Unregister with PacketPool  Flush all remain data in buffer to file  Log file transmit event into DB 16

Protocol Parser – FTP recorder 17

TCPReordreBuffer  A buffer can store jpcap.packet TCPPacket and reorder packet’s data by sequence  Put:  TCPPacket  ack_number  Get:  in order packet TCP payload in byte array  Missing part info 18

TCPReordreBuffer - put 19

TCPReordreBuffer - get 20

Protocol Parser - HTTP  Relative: port 80  Process:  Create a connection key “clientIP|clientPort|hostIP|hostPort” for identify every HTTP connection  For every unhandled HTTP connection create HTTP recorder  Continue: always  Ending process: unregister with PacketPool 21

Protocol Parser – HTTP recorder  Relative: specific connection specific connection represent by connection key  Process:  Put data packet to TCPReorderBuffer  Set acknowledge number for TCPReorderBuffer to reference  Cut HTTP header, record header information  Log HTTP event into DB  Store HTTP body into DB if its not too big  Continue:  Connection not close  Connection not idle  Ending process:  Unregister with PacketPool  Flush all remain data in buffer to file  Log file transmit event into DB 22

Protocol Parser H.323  Relative: port 1719(H.323RAS), port 1720(Q.931/H.225)  Process:  Maintain device list using gatekeeper RAS message  For every unhandled H245 connection create H245 Parser  Continue: always  Ending process:  Unregister with PacketPool 23

Protocol Parser H.245  Relative: specific connection represent by connection key  Process:  While openlogicchannel message detected, create RTP recorder  Continue:  Disconnect message undetected  Connection not idle  Ending process:  Unregister with PacketPool  Log calling event into DB 24

Protocol Parser RTP  Relative: specific UDP packet with specific source and destination  Process:  Record RTP content  Real-time decode/play if needed  Continue:  Disconnect message undetected  Connection not idle  Ending process:  Unregister with PacketPool 25

Protocol Parser - Abnormal behavior  Relative: ICMP Packet, ARP Packet, TCP SYN packet  Process:  ICMP ping attack  Count ICMP packet for both source and destination  If > 3 ping packet/sec log ping attack event into DB  ARP attack  Record MAC/IP mappings  If MAC/IP mappings changing > 10 times/min log ARP attack event into DB  TCP SYN packet  Record SYN request, remove when 3 way established  If to many SYN request unestablished log SYN attack event into DB  Continue: always  Ending process: Unregister with PacketPool 26

Analyzing and Recording System  HTML page recovery  PCM decode  File storage and presentation 27

Analyzing and Recording System - HTTP Analyzer  Search http response with content-type text/html to get html page file  Search [src=“”] pattern in html file  Search relative http request in DB  Recover/rename relative file and replace links in html file  Cross match DB and html file to recover as much as possible 28

Improvement  FTP active/passive mode, upload, download support  HTTP absolute direct link resolve  H.323 support  Better program structure with higher flexibility and extendibility 29

Compare to other system 本系統 WiresharkClearSight Analyzer 系統特性比較 使用者介面簡易複雜 開放原始碼是是否 擴充性高高低 價格免費 昂貴 系統功能比較 網路協定量統計無有有 分散式架構有無無 儲存側錄檔案 支援檔案及 HTML 頁面還原 只針對封包內容儲存 語音即時監聽有無無 記憶體需求小大大 可分析之協定較少多 多 適合長時間之網路監測是否否 30

Demo 31

Reference  [1] 林佑民 ，「 基於雲端運算之網路通訊監察分析系統之研製 」， 碩士論文 ， 國立 台北科技大學資訊工程系碩士班 ， 2012  [2] 黃威穎 ，「 H.323 網路電話音訊監控與錄製系統之研製 」， 碩士論文國立台北 科技大學資訊工程系碩士班 ，