def connection(self, host, port, iface):
conf.iface = iface
self.state = 'SYN_SENT'
pprint.state(self.state)
# Send SYN
self.packet[IP].dst = host
self.packet[TCP].dport = port
self.packet[TCP].flags = 'S'
res = sr1(self.packet, timeout=10)
if res is None:
# TODO: handle error
pprint.error('Cannot reach host {host} on port {port}'.format(
host=self.packet[IP].dst, port=self.packet[TCP].dport))
elif res[TCP].flags == constant.SYN | constant.ACK:
self.checkAckValue(self.packet[TCP].seq + 1, res[TCP].ack)
# Send ACK
self.packet[TCP].seq = res[TCP].ack
self.packet[TCP].ack = res[TCP].seq + 1
self.packet[TCP].flags = 'A'
send(self.packet)
# Start communication
self.communication()
else:
self.deconnection()
self.state = 'CLOSED'
pprint.state(self.state)
def __init__(self):
self.state = 'CLOSED'
pprint.state(self.state)
os.system('iptables -A OUTPUT -p tcp --tcp-flags RST RST -j DROP')
self.packet = IP() / TCP()
self.packet[TCP].sport = random.randint(1025, 65000)
self.packet[TCP].seq = random.randint(1, 2048) # TODO: Check RFC
def communication(self):
self.state = 'ESTABLISHED'
pprint.state(self.state)
# TODO: Check ack and seq value
# TODO: Connexion established
try:
nb_msg = 0
while True:
data = None
# TODO: Check ack/seq and flags and reply a ACK
data = sniff(filter='tcp and dst port ' + str(self.port), count=1, iface=self.iface)
if data and len(data) <= 0:
# TODO: Handle timeout
print(colors.FAIL + '[!]\tTIMEOUT' + colors.ENDC)
# TODO: Close connexion
break
if self.isFin(data):
self.sendACK(data[0], data[0][TCP].seq + 1)
time.sleep(1)
self.deconnection(data)
break
elif self.containsMessage(data):
nb_msg += 1
print(colors.BOLD + colors.WARNING + '[' + str(nb_msg) + ']: ' + data[0][Raw].load + colors.ENDC)
# Send ACK
ackvalue = data[0][TCP].seq + len(data[0][Raw].load)
self.sendACK(data[0], ackvalue)
except KeyboardInterrupt:
print('Total number of message receive: ' + str(nb_msg))
def __init__(self, port):
self.state = 'CLOSED'
pprint.state(self.state)
self.port = port
self.sniffers = []
self.sessions = []
os.system('iptables -A OUTPUT -p tcp --tcp-flags RST RST -j DROP')
def connection(self, request):
self.state = 'SYN_RCVD'
pprint.state(self.state)
self.packet[TCP].ack = request[0].seq + 1
self.packet[TCP].flags = 'SA'
answer = sr1(self.packet, iface=self.iface, retry=5, timeout = 10)
if answer is None:
# TODO: handle error
pprint.error('Did not receive the ACK for finish the connexion')
elif answer[TCP].flags == constant.ACK:
self.communication()
def deconnection(self):
self.packet[TCP].flags = 'F'
self.state = 'FIN_WAIT_1'
pprint.state(self.state)
fin_ack = sr1(self.packet)
if fin_ack[TCP].flags == constant.ACK:
filter_opt = 'tcp and dst port ' + str(self.packet[TCP].sport)
data = sniff(filter=filter_opt, count=1, timeout=10)
self.packet[TCP].seq = data[0][TCP].ack
self.packet[TCP].ack = data[0][TCP].seq + 1
elif fin_ack[TCP].flags == constant.FIN:
self.packet[TCP].seq = fin_ack[TCP].ack
self.packet[TCP].ack = fin_ack[TCP].seq + 1
self.packet[TCP].flags = 'A'
send(self.packet)
self.state = 'FIN_WAIT_2'
pprint.state(self.state)
self.state = 'TIME_WAIT'
def communication(self):
self.state = 'ESTABLISHED'
pprint.state(self.state)
try:
while True:
message = raw_input('Put the message you want to send: ')
self.packet[TCP].flags = 'PA'
ack = sr1(self.packet / Raw(message), timeout=10)
if ack is None:
# TODO: Handle error
pprint.error('Did not received ack for data')
elif self.checkAck(ack, message):
self.checkAckValue(ack[TCP].ack,
self.packet[TCP].seq + len(message))
self.packet[TCP].seq = ack[TCP].ack
pprint.information('Message received')
except KeyboardInterrupt:
self.deconnection()
self.state = 'CLOSED'
pprint.state(self.state)
def start(self):
self.state = 'LISTEN'
pprint.state(self.state)
try:
filter_options = 'tcp and dst port ' + str(
self.port
) + ' and tcp[tcpflags] & (tcp-syn|tcp-ack) == tcp-syn'
for iface in netifaces.interfaces():
sniffer = AsyncSniffer(filter=filter_options,
prn=self.newSession(iface),
count=1,
iface=iface)
sniffer.start()
self.sniffers.append(sniffer)
pprint.information('sniffing on ' + iface)
while len(self.sessions) <= 0:
time.sleep(1)
while True:
for session in self.sessions:
if session.getState() == 'ESTABLISHED':
session_iface = session.getInterface()
sniffer = AsyncSniffer(
filter=filter_options,
prn=self.newSession(session_iface),
count=1,
iface=session_iface)
sniffer.start()
pprint.information('sniffing on ' + session_iface)
self.sniffers.append(sniffer)
self.sessions.remove(session)
except KeyboardInterrupt:
for sniffer in self.sniffers:
sniffer.stop()
def deconnection(self, data):
self.state = 'CLOSE_WAIT'
pprint.state(self.state)
self.packet[TCP].seq = data[0][TCP].ack
self.packet[TCP].ack = data[0][TCP].seq + 1
self.packet[TCP].flags = 'F'
ackreceived = sr1(self.packet, timeout=10, iface=self.iface)
if self.isAck(ackreceived):
self.checkAckValue(ackreceived[TCP].ack, self.packet[TCP].seq + 1)
self.state = 'LAST_ACK'
pprint.state(self.state)
else:
pprint.error('Did not receive the ACK for finish the deconnection')
self.state = 'CLOSED'
pprint.state(self.state)