CS33300 - Assignment 1

Handed out: Tuesday, March 30, 2004
Due: Tuesday, April 6, 2004. 11:59 p.m.

Web Server

Your task is to write a simple web server capable of delivering both files and running CGI programs. Your web server must be compiled into a file called 'webserve' and run as follows:

% webserve 12345
Yourname web server. 
Listening on port 12345

The argument to the web server is the TCP port number on which connections are to be received. This can be any number in the range 1024-65535.

Once the web server is running, users should be able to connect to it using any browser. Simply enter a URL such as:

http://somemachine.cs.uchicago.edu:12345/index.html

Requirements

The server must be written in C.
The server is only allowed to deliver files from the same directory in which it is started. Accessing subdirectories is okay as long as the subdirectories are below the starting directory.
If a file has UNIX execute permissions, your web server should treat it as a CGI program and run it.
Your server should minimally recognize the following file types---to be determined solely by file suffix (.html, .jpg, .gif, .png, .txt). All other files should be sent back as raw data of unknown type.
Your server only needs to support the HTTP/1.0 protocol and only needs to implement the HTTP "GET" operation.

Implementation Hints

Read the "Unix Network Programming" book and learn about programming with sockets.
Web servers operate using something known as the HTTP protocol. Find out details of the protocol by searching on the web or consulting a book.
Search the web for details of how CGI programs work.

Testing

To test your web-server, we will run it from the following directory:

/stage/classes/current/33000-1/test/assign1

We will then connect your web server and attempt to load a file called "index.html."

Handin

Your assignment should consist of three files:

Makefile          -  Makefile for the project
webserver.c       -  Source code for the server
README            -  README file with your name and details

You are free to implement the web server in any manner that you see fit.

To hand in your assignment:

Put all of your files in a directory called 'assign1'
Make a tar-ball
```
% tar -cf yourname_assign1.tar assign1
```

Verify contents

% tar -tf yourname_assign1.tar
assign1/Makefile
assign1/README
assign1/webserver.c

Hand it in

% cp yourname_assign1.tar /stage/classes/current/33300-1/handin/assign1