ft_nmap

This is our ft_nmap program from 42 (https://42.fr/) a low-level networking project, the goal is to re-code a part of the nmap utility with some extra features.

Summary

• Introduction
• Demo
• Constraints
• Features
• Scans
• Installation
• Usage
• Examples
• Compatibility
• Authors

Introduction

Nmap is a free ports scanner created by Fyodor and distributed by Insecure.org. It is conceived to detect open ports, identify hosted services and obtain information on the operating system of a distant computer. This software has become a reference for network admin because the audit of Nmap reports give indications on the network security. It is available for Windows, Mac OS X, Linux, BSD and Solaris. The goal of this project is to code the main features, i.e different types of scans and decent performances.

Demo

Constraints

The program had to be coded in C. We were supposed to use the libpcap library, but since we are a bit stubborn, we made it from scratch with raw C sockets.

Features

• Multithreading
• Host discovery (multithreaded as well)
• Masks support, scan an entire network
• Multiple scantypes in one command
• Dynamic timeout
• Supports IP files (.ip)
• Progress bar
• Non root connect scan
• Tester (ft_server)
• Advanced services recognition
• Different verbose levels
• Custom payloads for a better response rate

Scans

• TCP SYN (Stealth) Scan
• UDP Scan
• TCP FIN, NULL, and Xmas Scans
• TCP Connect Scan

Installation

Run make to compile the project, make will install the required databases and compile the binary ft_nmap as well as ft_server.

Usage

Getting started with ft_nmap is easy, simply run ./ft_nmap scanme.org to scan scanme.org. Since ft_nmap has a lot of options, run ./ft_nmap -h to display the help menu. By default, ft_nmap will perform a connect/SYN scan (depending if run with sudo or not) on the first 1024 ports of the target.

Examples

Here are some more advanced usages for ft_nmap

• sudo ./ft_nmap localhost --scan=FIN,SYN
• sudo ./ft_nmap scanme.org localhost --verbose=INFO -t 50 2>log.txt
• sudo ./ft_nmap --file=list.ip -s SYN,FIN,NULL,UDP -t 250
• sudo ./ft_nmap 10.0.2.1/24 -t 20 -v

Compatibility

This project is only compatible with Linux.

Authors

Lucas Nicosia (https://github.com/lnicosia)
Ludovic Menthiller (https://github.com/lumenthi)