dpkt/examples/dhcprequest.py

54 lines
909 B
Python

#!/usr/bin/env python
import dnet
from dpkt import dhcp
from dpkt import udp
from dpkt import ip
from dpkt import ethernet
sysintf = 'eth0'
hw = dnet.eth(sysintf)
intf = dnet.intf()
# build a dhcp discover packet to request an ip
d = dhcp.DHCP(
chaddr=hw.get(),
xid=1337,
op=dhcp.DHCPDISCOVER,
opts=(
(dhcp.DHCP_OP_REQUEST, ''),
(dhcp.DHCP_OPT_REQ_IP, ''),
(dhcp.DHCP_OPT_ROUTER, ''),
(dhcp.DHCP_OPT_NETMASK, ''),
(dhcp.DHCP_OPT_DNS_SVRS, '')
)
)
# build udp packet
u = udp.UDP(
dport=67,
sport=68,
data=d
)
u.ulen = len(u)
# build ip packet
i = ip.IP(
dst=dnet.ip_aton('255.255.255.255'),
src=intf.get(sysintf)['addr'].ip,
data=u,
p=ip.IP_PROTO_UDP
)
i.len = len(i)
# build ethernet frame
e = ethernet.Ethernet(
dst=dnet.ETH_ADDR_BROADCAST,
src=hw.get(),
data=i
)
# send the data out
hw.send(str(e))