The aim of this project is to create a simple HTTP server.

Contributors to this project are:

• Nur Almas | nnorazma
• Wong Hong You | hwong
• Yim Jiun Jye | jyim

Technically non-existent. But,

• JJ: Configuration file parsing and CGI
• Hong You: Main server handling.
• Me: Handling requests and responses.

Configuration Taking some referernce from NGINX configuration format, parse information necessary to create a minimum viable webserver. Information here will be required to run the server and send response back to browser.

• Reading from .conf file
• Scan word by word for keywords to be further process
• Keyword/format supported are as follows

server 			//server keyword to parse a server block
{ 				//Start of a server block
	listen 80 81 82 83; 	//listen keyword to parse first non occupied port
	root html;				//root keyword to parse the path to root folder of webserver
	index index.html;		//index keyword to parse the index page of server
	server_name trinity.com;	//server_name keyword to parse the name of website
	
	error_pages 404 html/404.html; //error_page keyword to parse error number and path to error page html
	error_pages 405 html/405.html;

	location /cgi-bin { //location keyword to parse URI of website
		allowedMethods   GET POST; //allowedMethods keyword to parse the permitted method of a request
		index select_cgi.html; //index keyword to parse the index page of location URI, root + URI + index
	}
	
	location /directory {
		allowedMethods   GET;
		autoindex on;
	}
}		//End of a server block
//Any keyword not supported will result in exception being thrown

CGI Execution A simple CGI execution function is also written to run scripts/executable in child process and response will be return.

• https://handoutset.com/wp-content/uploads/2022/05/Web-Server-Programming-Neil-Gray.pdf
• Environtment variable(Env) of webserver and argument(Arg) will be created
• Env and Arg will be passed to execeve() to run scripts or executable

The part I worked on deals with the main handler loop of the server. This covers the following:

Initialisation

• Creating the socket
• Binding the socket to the port
• Listening for incoming connections
• Accepting connections
• Closing connections

Connections

• Reading from the socket(s)
• Writing to the socket(s)
• Closing connections with the socket(s)

I have also helped with the integration of the configuration parser and the request parser into the server.

My job is to handle request parsing, method handling and responses. Here's what I deal with:

• Dividing the request into the header and body
• For all methods I must validate the resource path and validate method permissions.
• GET simply covers locating the required resource, opening and reading the file, and then returning the contents as the response.
• POST:
  • The types of data sent through POST is limited to application/x-www-form-urlencoded and multipart/form-data
  • The data to be stored must be validated; if it exists, send a 409 Conflict.
  • Else, store the data and return a 201 Created.
  • For application/x-www-form-urlencoded:
    • The data sent through will be encoded.
    • Therefore in order to store the data completely, it has to be decoded.
• DELETE:
  • We chose to only test DELETE from command line. (To save time)
  • The data stored is validated, deleted, and return a response 200 OK :thumbs_up:

Web Server Concepts and Examples

C++ Web Server from Scratch

cclaude's 42 Webserv Github Page

Disclaimer: Please don't copy another persons work. Cclaude's page includes a very detailed Readme page with very helpful resources that we used as references.

HTTP related RFCs