OpenWrt DHCP Configuration Generator

This Python script automates the generation of static DHCP leases for OpenWrt routers. It fetches an HTML page containing network hardware tables, extracts the required data (MAC addresses, IPv4 addresses, and Hostnames), validates them, and generates a formatted dhcp_hosts.conf file.

✨ Features

• Dynamic HTML Parsing: Utilizes BeautifulSoup to locate and parse specific tables by their headings (e.g., "Static prototype IPs").
• Strict Validation:
  • MAC Addresses: Validates format via Regex and checks the multicast/broadcast bit.
  • IPv4 Addresses: Verifies that the IP belongs to the explicitly allowed subnet.
  • Hostnames: Ensures DNS-compliant naming conventions.
• Cross-Table Collision Protection: Uses global sets to prevent duplicate IP addresses or Hostnames across multiple tables, safely dropping invalid rows to protect network integrity.
• CLI Logging Control: Integrated argparse allows administrators to dynamically change the logging level via the command line.

🛠️ Requirements

The script requires Python 3.10+ and the following external libraries:

pip install requests beautifulsoup4

(Note: re, ipaddress, logging, and argparse are part of the Python Standard Library).

🚀 Usage

You can run the script directly from the terminal. By default, it will only log ERROR level messages to the console.

python main.py

Changing the Log Level

If you need to debug the parsing process or see more detailed warnings, you can override the default logging level using the --loglevel argument:

python main.py --loglevel DEBUG
python main.py --loglevel INFO
python main.py --loglevel WARNING

⚙️ How It Works

1. Fetch: The script downloads the HTML content from the target URL once.
2. Parse: It locates the table under the specified <h2> heading using a custom parsing function.
3. Validate & Filter: Iterates through the rows. If a MAC or IP is invalid, or if an IP/Hostname is already in use (duplicate), the entry is skipped/cleaned.
4. Generate: Outputs a valid OpenWrt configuration file named dhcp_hosts.conf in the root directory.

Output Example (dhcp_hosts.conf)

config host
    option name 'my-prototype-device'
    option ip '192.168.1.50'
    list mac '00:11:22:33:44:55'
    option dns '1'