main.py

#!/usr/bin/env python3
import socket
import sys
import argparse
from datetime import datetime
from scapy.all import IP, TCP, sr1
import random

def scan_syn_port(ip, port, timeout=1):
    """Perform a SYN scan on a single port."""
    src_port = random.randint(1024, 65535)  # Random source port for stealth
    syn_pkt = IP(dst=ip) / TCP(sport=src_port, dport=port, flags="S")
    response = sr1(syn_pkt, timeout=timeout, verbose=0)

    if response is None:
        return False

    if response.haslayer(TCP):
        if response[TCP].flags == 0x12:  # SYN-ACK indicates open port
            # Send RST to close the connection gracefully
            rst_pkt = IP(dst=ip) / TCP(sport=src_port, dport=port, flags="R")
            sr1(rst_pkt, timeout=1, verbose=0)
            return True
        elif response[TCP].flags == 0x14:  # RST-ACK indicates closed port
            return False

    return False

def scan_tcp_connect_port(ip, port):
    """Perform a TCP Connect scan on a single port."""
    try:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(1)  # Set timeout to 1 second
        result = sock.connect_ex((ip, port))
        sock.close()
        return result == 0  # True if port is open
    except socket.error:
        return False

def scan_ports(ip, start_port, end_port, use_syn=False):
    """Scan a range of ports on the target IP."""
    print(f"\nScanning host: {ip}")
    print(f"Scan started at: {datetime.now()}")
    print("-" * 50)

    open_ports = []
    for port in range(start_port, end_port + 1):
        is_open = scan_syn_port(ip, port) if use_syn else scan_tcp_connect_port(ip, port)
        if is_open:
            open_ports.append(port)
            print(f"Port {port}: Open")

    return open_ports

def main():
    """Main function to handle command-line arguments and execute the port scan."""
    parser = argparse.ArgumentParser(description="CLI Port Scanner with TCP Connect and SYN scan options")
    parser.add_argument("host", help="Target IP address or hostname to scan")
    parser.add_argument("start_port", type=int, help="Starting port number")
    parser.add_argument("end_port", type=int, help="Ending port number")
    parser.add_argument("syn_scan", type=str, choices=['yes', 'no'], help="Use SYN scanning (yes/no, requires root privileges for SYN)")

    args = parser.parse_args()

    try:
        # Resolve hostname to IP address
        target_ip = socket.gethostbyname(args.host)
    except socket.gaierror:
        print("Error: Unable to resolve hostname!")
        sys.exit(1)

    # Validate port range
    if args.start_port < 1 or args.end_port > 65535 or args.start_port > args.end_port:
        print("Error: Invalid port range! Ports must be between 1 and 65535.")
        sys.exit(1)

    try:
        use_syn = args.syn_scan == 'yes'
        if use_syn:
            print("Performing SYN scan (requires root privileges)...")
        else:
            print("Performing TCP Connect scan...")

        open_ports = scan_ports(target_ip, args.start_port, args.end_port, use_syn=use_syn)

        print("-" * 50)
        if open_ports:
            print(f"Open ports: {open_ports}")
        else:
            print("No open ports found.")
        print(f"Scan completed at: {datetime.now()}")

    except KeyboardInterrupt:
        print("\nScan interrupted by user.")
        sys.exit(0)
    except socket.error:
        print("Error: Network connectivity issue.")
        sys.exit(1)

if __name__ == "__main__":
    main()