DNS Resolver in Rust

A comprehensive recursive DNS resolver written in Rust that provides both a library interface and an HTTP REST API server for DNS resolution.

Live Demo

Try the DNS resolver online:

• Primary: https://dns.gauravkumarsingh.live/
• Mirror: https://dns-resolver.onrender.com/

Features

• Recursive DNS Resolution: Starts from root DNS servers and follows the delegation chain to resolve domain names
• Forward DNS Lookup: Resolve domain names to IPv4 addresses
• Reverse DNS Lookup: Resolve IPv4 addresses back to domain names (PTR records)
• Web Interface: Modern, responsive UI for easy DNS resolution
• HTTP REST API: Web server with endpoints for DNS resolution
• Caching: Built-in memory cache with 1-hour TTL to improve performance
• Multiple Record Types: Supports A, NS, CNAME, PTR, and other DNS record types
• Timeout Handling: 5-second timeout for DNS queries to prevent hanging

Installation

Clone the repository and build:

git clone https://github.com/gausk/dns-resolver.git
cd dns-resolver
cargo build --release

Usage

HTTP Server

Start the DNS resolver HTTP server locally:

cargo run --release

The server runs on http://localhost:3000 and provides:

• Web Interface: UI at http://localhost:3000/
• REST API: Programmatic access via endpoints below

API Endpoints

Forward DNS Resolution

curl "http://localhost:3000/resolve?domain=google.com"
# Response: {"ip":"172.217.14.110"}

Reverse DNS Resolution

curl "http://localhost:3000/reverse_resolve?ip=8.8.8.8"
# Response: {"domain":"dns.google"}

Command Line Example

Run the example with default domains:

cargo run --example resolve

Or specify custom domains:

cargo run --example resolve -- google.com github.com rust-lang.org

Testing

Run the test suite:

cargo test