robertdavidgraham/masscan
Masscan
Masscan is a command-line network scanner designed for large-scale discovery and infrastructure reconnaissance. It identifies open ports across specific network segments or the entire internet by probing vast address ranges with high efficiency. The tool functions as an asynchronous packet engine, bypassing standard operating system kernel networking stacks to transmit raw packets directly from application memory.
The project distinguishes itself through a specialized architecture that manages millions of concurrent connections by separating packet transmission and reception into independent execution threads. It utilizes a stateless, index-based mathematical algorithm to randomize target selection, ensuring probes are distributed unpredictably across address spaces. To maintain consistent performance and prevent network congestion, the scanner employs a high-precision timer to regulate transmission rates and uses zero-copy buffer management to minimize memory overhead.
The software provides a platform-agnostic interface for raw network access, allowing it to operate consistently across different hardware and operating system environments. It supports the export of collected reconnaissance data into structured formats such as XML, JSON, or plain text for further analysis. The application is distributed as a portable utility, with its core codebase maintained through standardized string handling and automated testing.