webserv

webserv is a 42 project — a single-threaded, non-blocking HTTP/1.1 web server written in C++98, built on top of Linux's epoll for efficient I/O multiplexing.

⚙️ Features

• HTTP/1.1 request handling (GET, POST, DELETE)
• Custom configuration file syntax for:
  • Multiple server blocks on distinct ports
  • Per-location configuration (root, alias, methods, redirections)
  • Custom error pages per status code
• Static file serving with MIME type detection (mime.types)
• CGI execution with configurable interpreters per file extension (.sh, .py, .php, ...)
• Non-blocking I/O event loop using epoll(2)
• Finite state machine for HTTP request parsing
• Chunked transfer encoding (including trailers)
• Cookie-based session management with timeout
• Request timeout detection (408) and body/header size limits
• Autoindex: directory listing when no index file is found
• File upload via POST with configurable target directory
• Redirections via return STATUS URL directive
• Load testing setup with siege (10 concurrent clients)
• Shell-based test suite for bad request validation (duplicate headers, missing Host, etc.)

🧠 Learning Objectives

• Deep understanding of the HTTP/1.1 protocol: request/response format, status codes, headers
• Socket programming: TCP/IP lifecycle, bind/listen/accept, non-blocking I/O
• Event-driven architecture with epoll: managing clients, CGI pipes, and stdin in a single loop
• Writing a finite state machine for robust incremental HTTP parsing
• Implementing the CGI/1.1 protocol: forking child processes, environment variable passing, pipe communication
• Parsing and validating a custom configuration language (tokenizer + directive parser)
• Session handling and connection lifecycle management (Keep-Alive, timeouts)
• Building a modular C++ codebase under strict C++98 constraints (-Wall -Wextra -Werror)

🚀 Usage

make build
./code/WebServ [config_file]   # defaults to configs/multipleServers.conf

Config files are in configs/. The server can be stopped by pressing Enter on stdin.

📄 Configuration

server {
    listen 8080;

    location / {
        root ./www/default;
        allow_methods GET POST DELETE;
        post_directory ./www/default/post/;
        client_max_body_size 3000000;
        autoindex on;
        index index.html;
        error_page 404 /404.html;
    }

    location /cgi-bin {
        root ./www/default/;
        cgi .sh;
        cgi .py /usr/bin/python3;
    }

    location /old {
        return 301 /new;
    }
}

Directive	Purpose
listen PORT	Port to bind (default 8080)
root PATH	Base directory for serving files
alias PATH	Replace location prefix in resolved path
allow_methods	Whitelist of HTTP methods
client_max_body_size	Max POST body in bytes
client_max_header_size	Max header block in bytes
autoindex on/off	Directory listing
index FILE	Default file for directory requests
post_directory PATH	Where POST uploads are saved
cgi .EXT [/path/bin]	CGI handler for a file extension
return CODE URL	HTTP redirect
error_page CODE /path	Custom error page

🛠️ Makefile targets

Target	Action
make build	Compile the binary (parallel)
make run	Run with configs/default.conf
make run_multiple	Run with configs/multipleServers.conf
make debug	Run under Valgrind
make debugLeaks	Full leak check with Valgrind
make siege_run / make siege_test	Load test (10 clients × 10 s)

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Compiled with c++ -Wall -Wextra -Werror -std=c++98 -g3 on Linux x86_64.