def foo(in_filename, out_filename):
# open the input file for reading
f = PcapReader(in_filename)
# open the output file for writing
o = PcapWriter(out_filename)
# read the first packet from the input file
p = f.read_packet()
# while we haven't processed the last packet
while p:
layer = p.firstlayer()
while not isinstance(layer, NoPayload):
if (type(layer) is IPv6):
new_layer = IP()
del new_layer.ihl
new_layer.ttl = layer.hlim
new_layer.proto = layer.nh
new_layer.src = ".".join(map(str, six2four(layer.src)))
new_layer.dst = ".".join(map(str, six2four(layer.dst)))
new_layer.add_payload(layer.payload)
prev_layer = layer.underlayer
del layer
prev_layer.remove_payload()
prev_layer.add_payload(new_layer)
if type(prev_layer) is Ether:
prev_layer.type = ETH_P_IP
layer = new_layer
if layer.default_fields.has_key('chksum'):
del layer.chksum
if layer.default_fields.has_key('len'):
del layer.len
# advance to the next layer
layer = layer.payload
# write the packet we just dissected into the output file
o.write(p)
# read the next packet
p = f.read_packet()
# close the input file
f.close()
# close the output file
o.close()
# Construct UDP header
udp = UDP(sport=7070, dport=9090, chksum=0)
udp.len = 200 # This should be the combined length of all fragments
# Construct payload
payload = "A" * 72 # Put 80 bytes in the first fragment (72 byte from payload + 8byte udp header)
# Construct the entire packet and send it out
pkt = ip / udp / payload # For other fragments, we should use ip/payload
send(pkt, verbose=0)
pkt.show()
#----------------------second fragment---------------------
print(
"----------------------------------second fragment---------------------------------"
)
ip.proto = 17
payload2 = "B" * 80 # 80 / 8
ip.frag = 10
pkt2 = ip / payload2
send(pkt2, verbose=0)
pkt2.show()
#----------------------third fragment---------------------
print(
"----------------------------------Third fragment---------------------------------"
)
payload3 = "C" * 40
ip.frag = 20
ip.flags = 0
pkt3 = ip / payload3
send(pkt3, verbose=0)
pkt3.show()
if j != 0:
packet_ihl = IP(dst=list_of_network_addresses[j]) / TCP(dport=22)
packet_tos = IP(dst=list_of_network_addresses[j]) / TCP(dport=22)
packet_len = IP(dst=list_of_network_addresses[j]) / TCP(dport=22)
packet_id = IP(dst=list_of_network_addresses[j]) / TCP(dport=22)
packet_frag = IP(dst=list_of_network_addresses[j]) / TCP(dport=22)
packet_ttl = IP(dst=list_of_network_addresses[j]) / TCP(dport=22)
packet_proto = IP(dst=list_of_network_addresses[j]) / TCP(dport=22)
packet_ihl.ihl = 18
packet_tos.tos = 18
packet_len.len = 18
packet_id.id = 18
packet_frag.frag = 18
packet_ttl.ttl = 18
packet_proto.proto = 18
answer_ihl = sr(packet_ihl, timeout=4)
answer_tos = sr(packet_tos, timeout=4)
answer_len = sr(packet_len, timeout=4)
answer_id = sr(packet_id, timeout=4)
answer_frag = sr(packet_frag, timeout=4)
answer_ttl = sr(packet_ttl, timeout=4)
answer_proto = sr(packet_proto, timeout=4)
if len(answer_ihl[0]) != 0:
if len(
nx.dijkstra_path(graph_ihl, list_of_network_addresses[0],
list_of_network_addresses[j])) == 2:
graph_ihl.add_edge(str(list_of_network_addresses[0]),
str(list_of_network_addresses[j]),
def getIPPacket(self):
"""
构造IP数据包
:return:
"""
# chksum = self.entries[9].get()
try:
eth = Ether()
eth.src = self.entries[0].get()
eth.dst = self.entries[1].get()
eth.type = int(self.entries[2].get())
ip_packet = IP()
ip_packet.versionion = int(self.entries[3].get())
ip_packet.ihl = int(self.entries[4].get())
ip_packet.tos = int(self.entries[5].get())
ip_packet.len = int(self.entries[6].get())
ip_packet.id = int(self.entries[7].get())
ip_packet.flags = int(self.entries[8].get())
ip_packet.frag = int(self.entries[9].get())
ip_packet.ttl = int(self.entries[10].get())
ip_packet.proto = int(self.entries[11].get())
payload = self.entries[16].get()
ip_packet.src = self.entries[13].get()
ip_packet.dst = self.entries[14].get()
# 不含payload计算首部校验和
if payload == '':
print("无payload的IP报文")
ip_packet.show()
checksum_scapy = IP(raw(ip_packet)).chksum
# 自主计算验证IP首部检验和并进行填充
print("scapy自动计算的IP首部检验和是：%04x (%s)" %
(checksum_scapy, str(checksum_scapy)))
# 1.将IP首部和自动设置为0
ip_packet.chksum = 0
# 2.生成ip首部的数据字符串
x = raw(ip_packet)
ipString = "".join("%02x" % orb(x) for x in x)
# 3.将ip首部的数据字符串转换成字节数组
ipbytes = bytearray.fromhex(ipString)
# 4.调用校验和计算函数计算校验和
checksum_self = self.IP_headchecksum(ipbytes)
# 5.进行校验和验证
print("验证计算IP首部的检验和是：%04x (%s)" %
(checksum_self, str(checksum_self)))
# 含payload计算首部校验和
else:
print("含有payload的IP报文")
ip_packet = ip_packet / payload
ip_packet.show()
ip_packet.len = 20 + len(payload)
checksum_scapy = IP(raw(ip_packet)).chksum
print("scapy自动计算的IP首部检验和是：%04x (%s)" %
(checksum_scapy, str(checksum_scapy)))
ip_packet.chksum = 0
ip_packet.ihl = 5
print('\n 报文长度是：%s' % str(ip_packet.len))
x = raw(ip_packet)
ipString = "".join("%02x" % orb(x) for x in x)
ipbytes = bytearray.fromhex(ipString)
checksum_self = self.IP_headchecksum(ipbytes[0:ip_packet.ihl *
4])
print("验证计算IP首部的检验和是：%04x (%s)" %
(checksum_self, str(checksum_self)))
if checksum_self == checksum_scapy:
print("检验和正确")
else:
print("检验和不正确")
ip_packet.chksum = checksum_self
self.entries[12].delete(0, END)
self.entries[12].insert(0, hex(ip_packet.chksum))
ip_packet.show()
self.resultText.insert('end', ip_packet.summary() + '\n')
self.resultText.insert('end', str(ip_packet) + '\n')
return eth / ip_packet
except Exception as e:
print(e.with_traceback())
finally:
pass
