Packet Sniffer

This is a packet sniffing script written in Python using the Scapy library. It allows you to capture and analyze network packets on a specified interface. The script provides options to filter packets based on a filter expression and keyword, and it saves the captured packets to a log file.

Features

• Capture network packets on a specified interface.
• Filter packets based on a filter expression in BPF syntax.
• Filter packets based on a keyword in the payload.
• Limit the number of packets captured.
• Save captured packets and relevant information to a log file.

Requirements

• Python 3.x
• Scapy library (pip install scapy)

Note:

• When running the script, you might need to use sudo or run the script as an administrator, depending on your operating system and network interface permissions. This is required to have the necessary permissions for capturing network packets.

Usage

python sniff.py [-h] [-i INTERFACE] [-e EXPRESSION] [-f FILTER] [-l LOG] [-c COUNT]

Options

• -h, --help: Show the help message and usage information.
• -i INTERFACE, --interface INTERFACE: Specify the interface to sniff on. Default: eth0.
• -e EXPRESSION, --expression EXPRESSION: Specify the filter expression in BPF syntax (optional).
• -f FILTER, --filter FILTER: Filter keyword to limit the sniffing (optional).
• -l LOG, --log LOG: Specify the log file to save the captured packets. Default: sniff_log.txt.
• -c COUNT, --count COUNT: Specify the maximum number of packets to capture (optional).

Examples

1. Capture packets on the default interface (eth0) and save to the default log file (sniff_log.txt):

python sniff.py

2. Capture packets on a specific interface (e.g., wlan0) and save to a specific log file (capture.log):

python sniff.py -i wlan0 -l capture.log

3. Capture HTTP packets with a filter expression and filter for a specific keyword:

python sniff.py -e "tcp port 80" -f password

Notes

• Make sure to have the necessary permissions and comply with legal and ethical considerations when capturing and analyzing network traffic.
• Depending on your operating system and network interface permissions, you might need to run the script with sudo or as an administrator to have the necessary permissions for capturing network packets.