Simple Web Server

Due: 5:00am, Friday, October 11, 2024

Get the Assignment Code

Login to your university Unix account and copy the assignment code to a location under your home directory:

The starter code for this assignment is on the Linux server here:

  /export/home/public/schwesin/cpsc328/assignments/project4

Description

The purpose of this assignment is to create a web server that can respond to simple HTTP GET requests. For example, given a request of:

GET /file.txt HTTP/1.1\r\n
Host: localhost\r\n
Connection: close\r\n
\r\n

Your server must parse the request to get the file path for the request and then construct an appropriate HTTP response. The directory that the server should serve files from is determined by the -d command line argument. Note that your server must ensure that files are only served from the given directory and its subdirectories. It is a security risk if a client can obtain files from arbitrary ancestor directories. If a client requests such a file, then the response code should be “404 Not Found”.

The form of the response will be similar to this:

HTTP/1.1 200 OK\r\n
Content-Type: text/plain\r\n
Content-Length: 5\r\n
Connection: close\r\n
\r\n
Hello

Here is the criteria for the response:

• The response code will either be “200 OK” or “404 Not Found”
• The Content-Type will either be text/html or text/plain; this will be based on the file extension of the requested file.
• The Content-Length is computed from the contents of the file

Here is the general flow of the program:

• Create a socket: this is a combination of getaddrinfo and socket and the value of the -p command line argument.

• Bind the socket with bind.

• Listen on the socket with listen.

• Loop forever:

  • accept new connections with accept.

  • Receive the HTTP response with recv; in this case the client is waiting for a response (the client socket will not be closed), so you need to read until the end of the headers.

  • Create the HTTP response and send it to the client.

  • Close the socket returned from accept with close

Specifications

• The name of the compiled program must be webserver.

• The input to the program must be in the form of command line arguments as follows:

  • -p <string> (required) port
  • -d <string> directory to serve files from (default ./)
  • -v verbose: print the HTTP request that was received

• The following rules must be added to the provided Makefile:

  • Add a rule to build an executable named webserver. This must be the default action of the Makefile.
  • Add a rule called clean to remove any temporary files and the webserver executable.

• If the implementation language is Python, the socket.create_connection and socket.create_server functions are forbidden and the urllib module is forbidden.

• Note: when testing make sure to use 5-digit or greater port numbers.

Turning in the Assignment

To turn in the assignment, execute the submit script by running the command

  make submit

from within the project4 directory.

Grading Criteria

• Consistent coding style
• Modular design
• Correct implementation of the specification
• Correct error checking of library calls

Note: If the submission includes material that was not covered in class and the material is not properly cited, then you will receive a failing grade for this assignment.