This project has been created as part of the 42 curriculum by Ayman Elasefar (ayelasef), Abderrahmane Habibi Ihlane (ahabibi-), Ayoub Laaoufi (aylaaouf).

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Webserv

Description

Webserv is a fully functional HTTP/1.1 web server written from scratch in C++98, inspired by the architecture and configuration style of nginx. It is a core milestone of the 42 school curriculum, designed to give students a deep understanding of how web servers work under the hood.

The server handles real-world HTTP communication in a single-threaded, non-blocking event loop powered by poll(). It supports multiple virtual hosts, location-based routing, CGI script execution, file uploads, static file serving, and persistent connections — all without relying on threads or blocking I/O on the main loop.

Key Features

• Non-blocking I/O via poll() — single event loop, no threads, no blocking syscalls
• HTTP/1.1 compliance: persistent connections (keep-alive), correct status codes, headers
• Multiple virtual servers with independent listen, server_name, host, and error_page directives
• Location blocks with per-route method restrictions, autoindex, index, and return (redirect)
• CGI support (Python) — fully asynchronous, pipe fds registered in the poll loop
• CGI timeout — unresponsive child processes are killed and reaped after a timeout; a 504 Gateway Timeout is returned
• File uploads via POST with client_max_body_size enforcement
• Static file serving with auto-generated directory listings (autoindex on)
• HTTP Range requests — 206 Partial Content for video streaming
• Session & cookie management — cookie-based session tracking with eviction of idle sessions
• Custom error pages per server block
• Graceful shutdown with SIGINT handling

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Instructions

Requirements

• A C++98-compatible compiler (c++ or g++)
• GNU make
• A POSIX-compliant OS (Linux or macOS)

Compilation

git clone https://github.com/aelasefa/Webserv.git
cd Webserv
make

This produces a webserv binary in the project root. The build uses -Wall -Wextra -Werror flags throughout.

Running the Server

./webserv [config_file]

If no config file is provided, the server falls back to conf/Default.conf.

Example:

./webserv conf/Default.conf

Then open your browser at http://localhost:8080/ or test with curl:

curl -v --http1.1 http://localhost:8080/

Configuration File Format

The configuration syntax follows an nginx-inspired block structure:

server {
    listen       8080;
    server_name  localhost;
    host         127.0.0.1;
    root         www/;
    client_max_body_size 1000000;
    index        index.html;
    error_page   404 error_pages/404.html;

    location / {
        allow_methods  GET POST;
        autoindex      off;
    }

    location /uploads {
        allow_methods  GET POST DELETE;
        autoindex      on;
        upload_store   www/uploads/;
    }

    location /cgi-bin {
        allow_methods  GET POST;
        cgi_extension  .py;
    }
}

Supported directives:

Directive	Scope	Description
listen	server	Port to bind
server_name	server	Virtual host name
host	server	IP address to bind
root	server / location	Document root
index	server / location	Default index file
client_max_body_size	server	Maximum request body size (bytes)
error_page	server	Custom error page per status code
allow_methods	location	Allowed HTTP methods (GET, POST, DELETE)
autoindex	location	Directory listing (on / off)
upload_store	location	Target storage path for uploaded files
cgi_extension	location	File extensions handled by CGI
return	location	HTTP redirect to another path

Stress Testing

# Install siege
apt-get install siege   # Debian/Ubuntu
brew install siege      # macOS

# Run a load test (255 concurrent users for 30 seconds)
siege -c255 -t30S http://localhost:8080/

Target: Target 100% availability with no leaks or hung connections.

Cleanup

make clean    # remove object files
make fclean   # remove object files and binary
make re       # full rebuild

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Resources

HTTP & Networking

• RFC 7230 — HTTP/1.1: Message Syntax and Routing
• RFC 7231 — HTTP/1.1: Semantics and Content
• RFC 7233 — HTTP/1.1: Range Requests
• Beej's Guide to Network Programming
• MDN Web Docs — HTTP
• nginx documentation
• RFC 6265 — cookies and HTTP State Management

System Calls & I/O Multiplexing

• man poll, man socket, man accept, man recv, man send
• man fork, man execve, man waitpid, man pipe
• The C10K Problem — Dan Kegel
• IBM — Non-blocking I/O and select()

CGI

• CGI implementation guide
• RFC 3875 — The Common Gateway Interface (CGI/1.1)

Tutorials & Articles

• How to build a simple HTTP server
• Writing a Web Server from Scratch (series)