EECS 3214 : Programming Assignment 2

Submit this assignment using the submit command (see the instructions below). The deadline is March 21, 10 am.

Simple peer-to-peer application programming

Objective:

The objective of this lab is to build a very simple distributed messaging system. The previous assignment built a directory server to allow clients to log on to a server and view other people logged on to the same server.

The application you will write for this assignment implements interaction between hosts (peers).

For this assignment, you should write an application that does the following.

The concurrent directory server program runs waiting for a connection from a client.
The clients and the server should (in general) run on different machines.
Each client can send three different messages to the directory server -- JOIN, LEAVE and LIST. The first two are for joining and leaving the list of peers who are online and are willing to chat. The last is to retrieve the list of online peers. The server responds to these messages with the appropriate actions. Note that the server needs to be concurrent because multiple clients should be able to talk to it simultaneously.
The LIST message should return all the information (IP address, listening port number of the peer etc) so that a peer can be contacted directly.
A client should be able to invite the peer for a chat by opening a TCP connection directly.
You can design the protocol for the chat. A peer should be able to initiate a chat connection, exchange chat messages and either peer should be able to close the connection. The peers need not be concurrent.
This is meant to be a skeletal program, and you probably will need to impose some limitations; that is fine, just state them clearly.
You will lose points if your peer programs do not close the sockets when the program quits.
In order to prevent two students from using the same socket number on the same machine, you should use the socket number that is 20000 + x, where x is the last 4 digits of your student number.
You may use C/C++ or Java.
Check the class page for clarifications etc.
You can download the basic client server code in the language of your choice from any site, but please cite that source in your report and code. Not doing so is a breach of academic honesty. For your convenience, here are very short barebones java code for a seqential server and client. Some host names in one of the undergrad labs (LAS 1004) are ptl10,....,ptl23.

Compiling the server and client programs (C language only)

Compile the programs with gcc instead of cc.
For the server program, you need the -lsocket flag
For the client program, you need the flags -lsocket -lnsl

Instructions for submitting assignment 1 Submit the programs using the following command:

submit 3214 a2 <filename>.
Read the manpages ("man submit") for more details on the submit command. You can also use the web interface to the submit command.
It may not be possible to submit the files after the deadline.

The programs you submit should work and be documented.
Your assignment should include a separate (typed) document containing the results (You can hand this in the class). This document should contains details of

the overall program design, a textual description of "how it works", and design decisions made.
possible improvements and extensions to your program that you would do if you had more time.
situations (if any) when your program may not work correctly.
how the grader can compile and run your program.

Demonstration The TA may ask you to demonstrate to her that your program works on the departmental Linux machines. You will run the server, and 4 clients and show that the program implements the specifications described above.

Grading

Program works correctly : 40%
quality of code and in-line documentation : 25%
report : 35%

NOTE: Late submissions get no credit.

Copying, teamwork

Modifying the skeleton programs for client server programs is permitted. Otherwise, copying of programs (also written homeworks and exams) or teamwork on an assignment (written or programming) is not permitted. No form of copying is tolerated in this (or any) course, in accordance with departmental policy.