Port Scanner

A multithreaded port scanner that checks open ports for multiple IP addresses and saves the results in a JSON file.

Dependencies

• boost/asio.hpp
• nlohmann/json.hpp
• cxxopts.hpp

Usage

The following command-line options are available:

• -f, --file : File to read IPs from (default: "ips.txt")
• -o, --output : Output JSON File (default: "results.json")
• -t, --threads : Number of threads (default: number of available hardware threads)

How it works

The program reads in IP addresses from a text file and divides them into different workloads according to the number of threads specified. Each thread then iterates through each IP address and checks for open ports by attempting a connection on each port number between 1 and 65535. If a connection is successful, the IP address and port number are stored in an unordered_map guarded by a mutex.

When all threads have completed their scans, the program serializes the unordered_map into a JSON object and saves it to a file using the specified filename. The resulting JSON object is structured as follows:

{
    "ip-address-1": {
        "ports": {
            "port-number-1": "open",
            "port-number-2": "open"
        }
    },
    "ip-address-2": {
        "ports": {
            "port-number-3": "open"
        }
    }
}