Project #2: Project #2: KENS Tutor utorial ial & Par Partt 1 CS341 Fall 2016 2016. 09. 20
What is KENS? KAIST Educationa Educationall Networkin Networkingg System System A programming environment to build and test network protocols KENSv3 Features: Features: •
•
•
•
•
Discrete event simulator Virtual network devices Virtual system call layer Automated test suite for easy grading Ethernet / IP / TCP
What is KENS? KAIST Educationa Educationall Networkin Networkingg System System A programming environment to build and test network protocols KENSv3 Features: Features: •
•
•
•
•
Discrete event simulator Virtual network devices Virtual system call layer Automated test suite for easy grading Ethernet / IP / TCP
KENS KENSv3 v3 Fr Fram ame ewor ork k
Install KENS Visit and clone (and star!) •
•
https://github.com/ANLAB-KAIST/KENSv3 https://github.com/ANLAB-KAIST/KENSv3 Please DO NOT FORK
Or simply use terminal •
•
$git clone https://github.com/ANLA ht tps://github.com/ANLAB-KAIST/KENSv3 B-KAIST/KENSv3 $tar xzvf kens-v3.skeleton.tar kens-v3.skeleton.tar.gz .gz
Currently supports Cygwin, Linux, OS X We highly recommend recommend Ubuntu 16.04 gcc 5.x is is requi require red d C++ 11+ is required (+gnu extensions)
Install Google Test You need this test to run KENS and evaluate your owncode Gtest •
Google’s framework for C++ tests
https://code.google.com/p/googletest/ http://askubuntu.com/questions/145887/why-no-library-files-installedfor-google-test
Components
Test cases based on GoogleTest (read if you want to)
Components
Your assignment: implement TCP module
Components
Solution that evaluates your implementation
Run test cases $make all •
Then testTCP binary will be generated in build/
$./testTCP •
Will generate test results in gtest format.
Run partial test cases •
•
•
•
$make test_part1 $make test_part2 $make test_part3 $make test_part4
Run reference solution /app/TestTCP/testenv.hpp: line 385 Remove the comment at line 385 •
Run reference solution
Keep the comment at line 385 •
Run your solution
Your task is to implement TCP module TCP module (class TCPAssignment) •
•
•
•
HostModule: interact with other modules like IP NetworkModule: create/delete packets SystemCallInterface: interact with system calls like socket, bind, connect, accept, listen, etc… TimerModule: handle timeouts
You are asked to build TCP stack •
KENS project will be split into 3 parts •
•
•
Connection open/close Reliable data transfer Congestion control
Project #2 Get familiar with KENS Implement open and bind
KENS Projects Your job is to complete TCPAssignment.cpp & TCPAssignment.hpp *** This project is incremental! *** •
Your implementation on part1 will affect implementation of part2, and so on.
Project 2: KENS #1 •
•
Run reference solution Implement socket, bind, getsockname and close
Requirement #1 Run reference solution (refer to slides #10) •
•
•
Open TestCongestion1.pcap with Wireshark Statistic->IO Graph Something like this, but use different colors
Requirement #2 Implement your own socket()/bind()/getsockname()/close() Tests to be completed •
•
•
$make test_part1 (refer to slides #9) For these tests, you should implement socket/bind/getsockname/close functions However, passing test does not guarantee the full score
Team Assignment Make a team of 1 or 2 students Notice about project team will be on KLMS tonight Write your team member information in a reply •
Name, student ID of each member
Later on, we will announce the team ID •
Use the team ID for your submission
Deliverables Report + TCPAssignment.cpp, TCPAssignment.hpp and other source files you implemented. • •
•
File name: {Team_no}_Project2.zip Ex) 03_Project2.zip, 32_Project2.zip, .. 32_Project2/
- report_proj2.pdf - KENS1/ - TCPAssignment.cpp - TCPAssignment.hpp - mycode.cpp <- optional - mycode.hpp <- optional
Content of report • •
Screenshot of the IO Graph Explain your implementation of required functions
Format of report • • •
PDF only, 12pt At most 5 pages ill-formatted submission won’t be accepted
Submission Guideline Team assignment! (or you can choose to work alone) Due: 2:29pm on Tue, 10/4 Late submission is NOT allowed! •
Late submission will get 0 point
Submit on KLMS
Tips for Project 2
KENS You may not be familiar with the framework •
•
Try really, really hard to understand how it works Refer to “KENS internals” in the later section •
Please, read carefully!!
Recommendations: •
•
See how test cases work Understand how socket APIs work •
•
Refer to Project #1 slides’ supplementary material
Read the document at http://anlab-kaist.github.io/KENSv3/doxygen/
testopen.cpp
testopen.cpp
socket()/bind()/getsockname()/close() Does not actually generate network packets Internal file descriptor/context management Internal address management logic Be familiar with KENS
Bind rule Passive socket (server socket): need explicit bind Active socket (client socket): need implicit bind Address is consist of ip_address and port_number (sockaddr_in) 143.248.234.2:5555 and 10.0.0.2:5555 do not overlap 143.248.234.2:5555 and 0.0.0.0:5555 overlap (INADDR_ANY) 143.248.234.2:5555 and 143.248.234.3:5555 do not overlap 0.0.0.0:5555 and 0.0.0.0:5556 do not overlap (different port) Closed sockets do not overlap with any socket
Context management Implement bind rule for your bind Will pass $make test_part1 Suggestion: •
•
•
Make a global bound contexts list Save whether a context is bound Save the bounded address and port
Recommended books TCP/IP Illrustrated,Vol 2, Stevens •
Book about the ‘actual’ implementation of TCP
KENS Internals – Supplementary Material
What is KENS? KAIST Educational Networking System A programming environment to build and test network protocols KENSv3 Features: •
•
•
•
•
Discrete Event simulator Virtual network devices Virtual system call layer Automated test suite for easy grading Ethernet / IP / TCP
KENSv3 Framework
KENSv3 Dataflow
Components
E: Event-based simulation framework (do not have to read)
Components
Test cases based on GoogleTest (read if you want to)
Components
Your assignment: implement TCP module
Components
Solution that evaluates your implementation
Convention Packet : •
If you have a packet (either received or allocated), you have to free it, or pass it to other network module
Message: •
•
•
If you allocated a message, you have to free it by yourselves i.e. if you received a message, do not free it If message is passed to the receiver, messageFinished callback or messageCanceled are called to notify that the message is to be freed.
Detailed documentation at http://anlab-kaist.github.io/KENSv3/doxygen/
HostModule HostModule(std::string name, Host* host); •
host: Host to insert this module name: this module’s name
Have to implement: •
packetArrived(from_where, packet) •
If “IP” layer passed the packet, from_where = “IP”
Optional implementation: •
•
initialize(): automatically before host starts finalize(): automatically when TCP have to clean up
HostModule Provided utilities (you can use them after you inherit this class) (however, you cannot override them) •
•
sendPacket(“module_name”, packet) ex) sendPacket(“IP”, packet) name is defined via HostModule(name, host) getHost() •
•
Current time (getCurrentTime) Routing information
NetworkModule You can allocate/deallocate packets Provided utilities
You cannot directly allocate Packet (via new Packet)
System Call Interface Multiple protocols are distinguished by “address family”, and “protocol” Manages file descriptors and their domain You have to implement: •
•
•
systemCallback(UUID syscallUUID, int pid, const SystemCallParameter& param) Automatically called if system calls are raised System calls are automatically blocks the application, you have to unblock manually
System Call Interface Provided utilities: •
•
•
createFileDescriptor: allocate a new file descriptor KENS framework handles fd number mapping to applications removeFileDescriptor: deallocate fd returnSystemCall(syscall_id, ret) unblocks the system call with the return value
TimerModule timerCallback(void* payload) •
Automatically called with given paramter
addTimer(void* payload, Time timeAfter) •
•
•
Create a timer with given parameter timerCallback is automatically called after timeAfter Returns a unique identifier of created timer
cancelTimer(UUID key) •
Cancel the timer with the identifier
