dnsly

README

DNSLY

A high-performance DNS blocker written in Go that blocks DNS requests to selected websites. Perfect for district-wide or network-wide filtering.

Features

• Blocks DNS requests to specified domains (e.g., example.com, blocked.com, etc.)
• Supports DNS over HTTPS (DoH) for DNS resolution
• Logging of blocked requests with source IPs
• Customizable configuration with a simple JSON file

Installation

Prerequisites

• Go 1.18+
• DNS server running on port 53

Clone the repository

git clone https://github.com/vehbiu/dnsly.git
cd dnsly

Build the application

go build -o dnsly main.go

Configuration

Edit the config.json file to customize blocked domains and DNS resolver endpoint. CHANGE THE PASSWORD in the configuration file for security.

{
  "blocked_domains": ["example.com", "blocked.com", "adult-website.com"],
  "search_dns": "1.1.1.1",
  "http_password": "Change-This-Password"
}

Configuration Fields

• blocked_domains: List of domains to block.
• search_dns: The DNS server used for resolving non-blocked domains.
• http_password: Password to see logs.

Usage

Start the DNS Server

./dnsly

The DNS server will start listening on port 53 and block requests to any domains listed in the configuration.

Access Blocked Requests

The server logs all blocked requests, including the domain, blocked IP, and source IP. You can access these logs for monitoring.

How It Works

1. DNS Request Handling: When a DNS request is made, the server checks if the domain is in the blocked_domains list.
2. Blocking Requests: If the domain is blocked, the server responds with an invalid IP (0.0.0.0).
3. DNS Resolution: Non-blocked requests are forwarded to a DNS resolver via DoH (DNS over HTTPS) for resolution.

License

MIT License. See the LICENSE file for details.

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Contributors

• Vehbi Unal - @vehbiu