1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
#!/usr/bin/env python
from __future__ import print_function
import sys
import socket
# Since pcapy is not a requirement of dpkt, test the import and give message
try:
import pcapy
except ImportError:
print('Could not import pcapy. Please do a $pip install pcapy')
sys.exit(1)
# dpkt imports
from dpkt import dhcp
from dpkt import udp
from dpkt import ip
from dpkt import ethernet
# Grab the default interface and use that for the injection
devices = pcapy.findalldevs()
iface_name = devices[0]
print('Auto Setting Interface to: {:s}'.format(iface_name))
interface = pcapy.open_live(iface_name, 65536, 1, 0)
# Get local ip
src_ip = socket.inet_pton(socket.AF_INET, interface.getnet())
# Generate broadcast ip and eth_addr
broadcast_ip = socket.inet_pton(socket.AF_INET, '255.255.255.255')
broadcast_eth_addr = b'\xFF\xFF\xFF\xFF\xFF\xFF'
# build a dhcp discover packet to request an ip
d = dhcp.DHCP(
xid=1337,
op=dhcp.DHCPDISCOVER,
opts=(
(dhcp.DHCP_OP_REQUEST, b''),
(dhcp.DHCP_OPT_REQ_IP, b''),
(dhcp.DHCP_OPT_ROUTER, b''),
(dhcp.DHCP_OPT_NETMASK, b''),
(dhcp.DHCP_OPT_DNS_SVRS, b'')
)
)
# build udp packet
u = udp.UDP(
dport=67,
sport=68,
data=d
)
u.ulen = len(u)
# build ip packet
i = ip.IP(
dst=broadcast_ip,
src=src_ip,
data=u,
p=ip.IP_PROTO_UDP
)
i.len = len(i)
# build ethernet frame
e = ethernet.Ethernet(
dst=broadcast_eth_addr,
data=i
)
# Inject the packet (send it out)
interface.sendpacket(bytes(e))
print('DHCP request sent!')
|
