def wrong_checksum_a(testname): hs = TESTS[testname].host_s hr = TESTS[testname].host_r r_mac = info.get("router_mac", hs) target_ip = info.get("host_ip", hr) i = IP(dst=target_ip) chk = checksum(bytes(i)) chk = (chk + 1) % (2**16) i.chksum = chk return Ether(dst=r_mac) / i
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