🔴 Blocker - DNS Blocker Server

Overview

Blocker is a Python-based DNS server designed to block specific domains (e.g., ads, malware, adult content) by redirecting them to a local address (127.0.0.1). The program provides:

• Custom Blocklist Management: Easily add or update blocked domains.
• Platform Support: Works on Linux and Windows.
• DNS Fallback: Forwards unresolved domains to upstream DNS servers like Google DNS (8.8.8.8).
• Network Packet Sniffer: Monitors DNS queries for improved diagnostics.

Features

• Customizable Blocklists
• Logs for Debugging
• Platform-Specific DNS Setup
• Configurable via GUI

Prerequisites

Ensure your system meets the following requirements:

• Python: Version 3.x.
• Privileges: Administrative/root access for DNS configuration.
• Npcap: latest version(for Windows only)

Installation and Setup

1. Clone the Repository

git clone https://github.com/Fyroo/Blocker.git
cd Blocker

2. Start the Program

Linux:

bash run_linux.sh

Windows:

run_windows.bat

If setup hasn’t been completed, the run scripts will automatically invoke the appropriate setup script.

Configuration

Blocklist Management

The blocklist files are located in the data/ directory:

• nsfw_domains.txt: Block adult content.
• ads_domains.txt: Block ads and trackers.

To add a domain, simply append it to the relevant file, one domain per line.

Logs

Logs are stored in the logs/ directory. These can be reviewed to troubleshoot issues or monitor activity.

GUI Configuration

The GUI provides options to:

• View and update blocklists.
• view live dns traffic on disered interface
• Adjust auto-update settings for blocklists.
• Monitor DNS query activity.

How It Works

1. DNS Query Interception: Captures incoming DNS queries.
2. Domain Filtering: Checks the queried domain against the blocklist.
3. Blocking: Returns 127.0.0.1 for blocked domains.
4. Forwarding: Unblocked domains are forwarded to the upstream DNS server (8.8.8.8 by default).

DNS Configuration

Linux

The script modifies /etc/resolv.conf to use 127.0.0.1 as the primary DNS server:

nameserver 127.0.0.1

Note: If NetworkManager or systemd-resolved overwrites this file, you may need to disable automatic DNS updates.

Windows

The script uses the netsh command to set 127.0.0.1 as the DNS server:

netsh interface ip set dns "Local Area Connection" static 127.0.0.1

Troubleshooting

Chrome Secure DNS Issue

Chrome’s Secure DNS feature may bypass the local DNS server. To fix this:

1. Go to Chrome settings: chrome://settings/
2. Navigate to Privacy and security.
3. Disable Use secure DNS under Security.

Permission Errors

If you encounter permission errors, ensure you run the setup or run scripts with elevated privileges:

• Linux: Use sudo.
• Windows: Run the batch files as an administrator.

Project Structure

. 📂 Blocker
├── 📄 README.md
├── 📂 data/
│   ├── ads_domains.txt
│   ├── config.json
│   ├── nsfw_domains.txt
├── 📂 logs/
├── 📄 requirements.txt
├── 📄 run_linux.sh
├── 📄 run_windows.bat
├── 📄 setup_linux.sh
├── 📄 setup_windows.bat
├── 📂 src/
│   ├── __main__.py
│   ├── configuration_interface.py
│   ├── configuration_module.py
│   ├── dashboard_interface.py
│   ├── dns_resolver_interface.py
│   ├── dns_resolver_module.py
│   ├── domain_fetch_module.py
│   ├── interface_list_module.py
│   ├── logger_module.py
│   ├── setdns_module.py
│   ├── sniffer_interface.py
│   ├── sniffer_module.py
└── 📂 venv/

Contributing

Feel free to submit issues or pull requests to improve this project. Contributions are welcome!