README for Packet Sniffer

Overview

This repository contains a Python script for a packet sniffer. A packet sniffer is a tool that captures and analyzes packets that are sent over a network. This script captures Ethernet frames and decodes the IPv4 packets within.

Features

• Capture and decode Ethernet frames.
• Extract and display details of IPv4 packets.
• Decode and display ICMP, TCP, and UDP segments.
• Display the raw data of unknown protocols.

Prerequisites

• Python 3.x
• Root/Administrator privileges (required to create raw sockets)

Usage

1. Clone the repository:

git clone https://github.com/yourusername/packet-sniffer.git
cd packet-sniffer

2. Run the script with root/administrator privileges:

sudo python3 packet_sniffer.py

Script Details

packet_sniffer.py

The script consists of the following main parts:

• main(): Sets up a raw socket to capture packets and processes each captured packet.
• ethernet_frame(data): Extracts the Ethernet frame information.
• get_mac_addr(bytes_addr): Converts a MAC address from bytes to a human-readable format.
• ipv4_packet(data): Extracts IPv4 packet information.
• ipv4(addr): Converts an IPv4 address from bytes to a human-readable format.
• icmp_packet(data): Extracts ICMP packet information.
• tcp_segment(data): Extracts TCP segment information.
• udp_segment(data): Extracts UDP segment information.
• format_multiline(prefix, string, size=80): Formats the data for multiline output.
• tab(n, dash=True): Helper function to format tabbed output.

License

This projects is licensed under the MIT License.