import sys
from scapy.all import sniff, send, IP
from datetime import datetime

modifications = 0

def modify_packet(packet):
    if packet.haslayer(IP):
        if packet[IP].ttl != 65:
            packet[IP].ttl = 65
            modifications += 1
    send(packet)


if __name__ == "__main__":
    if len(sys.argv) != 2:
        print(f"Usage: {sys.argv[0]} <interface>")
        sys.exit(1)

    interface = sys.argv[1]

    start_time = datetime.now()
    print(f"Script started at: {start_time.strftime('%Y-%m-%d %H:%M:%S')}")

    packets = sniff(filter="ip", iface=interface, timeout=30*1, prn=modify_packet)

    end_time = datetime.now()
    print(f"Script ended at: {end_time.strftime('%Y-%m-%d %H:%M:%S')}")
    print(f"{modifications} packets modified")