CSniff

A simple TCP port scanner written in C. (now with multithreading!)

Building

make

The program will be created at ./build/port_sniffer.

You can create an alias in your shell for easier access.

Usage

./build/port_sniffer -t <target_ip> -p <port_or_range> [options]

Scan a single port:

./build/port_sniffer -t 192.168.1.1 -p 80

Scan a range:

./build/port_sniffer -t 192.168.1.1 -p 1-1024

Show only open ports:

./build/port_sniffer -t 192.168.1.1 -p 1-1024 -o

Options

• -t <ip> : Target IPv4 address
• -p <port> : Port or range (e.g. 80 or 1-1024)
• -o : Show open ports only
• -n : Legacy scan mode (single-threaded, no port cap)
• -m : Scan local machine (not yet implemented)
• -h : Help

Notes

• Multithreaded by default using a thread pool (32 workers)
• Ports are corrected automatically if out of range (1-65535)
• Only one scan type flag can be set at a time, conflicts fall back to TCP

Planned

• Run with no args and get an interactive prompt to fill in options
• SYN scan using raw sockets
• UDP scan
• Local machine / default gateway scan with -m
• Actual help output for -h