Tinkernet

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Tinkernet

• Students
• Dan Turner, Mark Kegel, Erik Shimshock and
• Ryan Ausanka-Crues
• Faculty
• Titus Winters, Mike Erlinger

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Project Overview

• Who we are
• Harvey Mudd College University California
  Riverside
• What is Tinkernet?
• System to allow students to write the networking
  code of an OS
• Why would you want it?
• Provides a convenient and controlled environment
  to write and test networking code

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Who we are

• Harvey Mudd College - small Science and Engr
  College - 700 students 100 Computer Science
  Majors
• University California Riverside - large state
  university - 15000 students, 1000 Computer
  Science and Computer Engr majors

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What is Tinkernet?

• Stand alone environment to provide a laboratory
  for computer networking experiments.
• Cheap and Easy to build and to maintain

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Tinkernet Operational Overview

• Students work on a Server where they develop
  networking code that is then linked into a OS
  kernel. This kernel is then download to a
  machine and executed. Students can then exercise
  their code and evaluate the performance of their
  networking code.

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Tinkernet Hardware
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(No Transcript)
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SoftwareBeginning
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Behind the ScenesCompiling the Kernel

• OSKit
• provides a fully operable kernel
• we strip out the networking module
• student code gets compiled in as the new
  networking module
• then you have your kernel...

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Behind the ScenesBooting the Kernel

• tinkercontroller
• is a daemon that manages the nodes
• a free node is chosen, and the kernel is sent to
  it
• if all has gone well, you have a running kernel

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Behind the Scenes
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Student Assignments

• Writing modules to handle the protocol stack
• ethernet, IP, UDP, ARP
• TCP - could do but is a lot of work
• Scaled down version of TCP
• Study created protocols discovery
• ?

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How it works...
Students
Nodes
Tinkerbell
SSH
TFTP
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The Student Perspective

• (1) Student writes code
• (2) Student compiles code into kernel
• (3) Student uses tinkerboot to load kernel
  Tinkerboot
• (4) Student tests kernel netprintf
• (5) Kernel dies, and student repeats the first
  four steps

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SoftwareStudent Boots Kernel
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The Student Perspective
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SoftwareStudent Tests Kernel
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The Running Kernel

• Kernels are expected to respond to
• ARP requests
• IP broadcast
• Handle IP packets
• Also UDP
• Also need to be able to generate their own packets

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Controlling the Kernel

• Each node has two network cards
• Is hooked in to two separate networks warzone
  and admin
• Student packets are sent over warzone
• Admin network handles management of each node -
  booting, restarting, debug

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Software Interaction
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Why this approach?

• Mini Emulab - but we wanted control, I.e. 24 hour
  availability
• Tinkernet development is a good learning
  environment for OS/Systems
• Oskit - probably a bad choicefuture Linux
• Need to add more labs

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Tinkernet in the classroom

• Lectures discuss the back material of the various
  protocols (Computer Networks by Peterson Davie
• Each Lab has a write-up of background, tasks and
  questions
• Students work together for 2 hours in a dedicate
  terminal room - uncover issues in lab
  description, etc. Thereafter they are on their
  own

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Tinkernet in the classroom, cont.

• Students create a web page (restricted login)
  that includes
• Discussion of lab - issues uncover, things not
  understood, time taken, etc.
• Source code (in C)
• Exchange of network messages (Ethereal)
• Answers to questions

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Tinkernet in the classroom, cont.

• Assessment
• Plan to ask questions before the course and
  before and after each lab.
• Still to be done

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Things left to do...

• DocumentationTwiki is up. We will make changes
  in the Spring http//tinkernet.cs.hmc.edu8080/wik
  i/index.php/Main_page
• Currently Package for Distribution. Looking for
  others interested in using
  
• Develop assessment materials

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Questions ?