def __init__(self, network):
self.__network = network
self._sn_handler = SequenceHandler()
class TransmitHandler(object):
__network = None
def __init__(self, network):
self.__network = network
self._sn_handler = SequenceHandler()
def reset(self):
self._sn_handler.reset()
def __addEthernetDetails(self):
eth = Ether()
src_mac_padding = '%04x' % self.__port.vl_id
eth.dst = "%s:%s:%s" % (get("MAC_PREFIX_RX"),
src_mac_padding[:2],
src_mac_padding[2:])
eth.src = get("MAC_PREFIX_TX") + ":20"
eth.type = 0x800
self.__packet = eth
def __addIpDetails(self):
port = self.__port
ip_layer = IP()
ip_layer.src = port.ip_src if hasattr(port, 'ip_src') else \
get("TE_IP")
if hasattr(port, 'dest_ip'):
port.ip_dst = port.dest_ip
elif port.ip_dst in ('', None):
port.ip_dst = get("TR_IP")
ip_layer.dst = port.ip_dst
ip_layer.id = self._sn_handler.nextIpId()
ip_layer.ttl = 1
#ip_layer.prot = 0x17
self.__packet = self.__packet/ip_layer
def __addUDPDetails(self):
port = self.__port
udp_layer = UDP()
udp_layer.sport = port.udp_src if hasattr(port, 'udp_src') else \
int(get("TE_UDP"))
udp_layer.dport = port.udp_dst
udp_layer.chksum = 0x00
#udp_layer.len = len(port.payload)
self.__packet = self.__packet/udp_layer
def __addICMP(self):
port = self.__port
icmp = ICMP()
icmp.seq = self._sn_handler.next(port.rx_vl_id)
self.__packet /= icmp
def __addSNMP(self):
oids = self.__port.oids
varbindlist = [SNMPvarbind(oid = \
ASN1_OID(str(oid).replace("enterprises", \
"1.3.6.1.4.1"))) \
for oid in oids]
if 'next' in self.__port.proto:
pdu = SNMPnext(varbindlist = varbindlist)
else:
pdu = SNMPget(varbindlist = varbindlist)
snmp_packet = scapy.SNMP(community = "afdxRead", PDU = pdu, version = 0)
#print "Packet length is ", len(reduce(lambda x,y :
# str(x).replace('.', '') +
# str(y).replace('.', ''), oids))
self.__packet /= snmp_packet
def __addPayload(self):
if 'SNMP' in self.__port.proto:
self.__addSNMP()
else:
self.__packet /= self.__port.payload
def __normalize(self):
port = self.__port
# any payload size greater than 1472 needs to be fragmented
# as the its the ethernet limitation
if (len(port.payload) > 1472 or \
len(port.payload) > int(port.max_frame_size)):
self.__packet = self.fragment(self.__packet)
else:
self.__packet = [self.__packet]
def __addPadding(self, packet):
if packet.haslayer(SNMP):
payload_length = len(packet[SNMP])
else:
payload_length = len(packet[Raw])
padding = ''
# the size index 17 is caculated as 60 - (ethHdr + ipHdr + udpHdr) = 18
# but here we are using the size index as 17 because the last bit will
# be the sequence number which will be added at 'transmit' function
if payload_length < 17:
padding = '\0' * (17 - payload_length)
if (len(packet) + len(padding)) < 59:
padding += '\0' * (59 - (len(packet) + len(padding)))
if hasattr(self.__port, 'sn_func'):
sn = self.__port.sn_func(self.__port.vl_id)
else:
sn = self._sn_handler.next(self.__port.vl_id)
if sn == 0:
padding += '\0'
else:
padding += ('\\x%02X' % sn).decode('string_escape')
packet /= Padding(padding)
return packet
def __createPacket(self):
if self.__port == None:
return
if (not hasattr(self.__port, 'payload')) or self.__port.payload == None:
return
self.__addEthernetDetails()
self.__addIpDetails()
if self.__port.proto in ('UDP', 'SNMP', 'SNMPnext'):
self.__addUDPDetails()
elif self.__port.proto == 'ICMP':
self.__addICMP()
self.__addPayload()
self.__normalize()
def change_sequence_number(self, to_seqno, vlId):
self._sn_handler.change_sn(to_seqno, vlId)
def transmit(self, port, network = None, send = True):
def transmit_low(packet, network):
packet = self.__addPadding(packet)
packets = []
try:
if NETWORK_A in network:
packet[Ether].src = get("MAC_PREFIX_TX") + ":20"
if send:
sendp(packet, iface = get("NETWORK_INTERFACE_A"),
verbose = False)
else:
packets.append(packet)
if NETWORK_B in network:
packet[Ether].src = get("MAC_PREFIX_TX") + ":40"
if send:
sendp(packet, iface = get("NETWORK_INTERFACE_B"),
verbose = False)
else:
packets.append(packet)
except Exception, ex:
general_logger.exception(str(ex))
return packets
self.__port = port
self.__createPacket()
if network == None:
network = self.__network
packets = []
if type(network) == list:
if len(network) == len(self.__packet):
for index in range(0, len(network)):
network_id = network[index]
packet = self.__packet[index]
packets += transmit_low(packet, network_id)
else:
for packet in self.__packet:
packets += transmit_low(packet, network)
if not send:
return packets