我如何创建一个框架icmp 我在python上标记malformet数据包
导入socket,struct,uuid,subprocess,fcntl,time,random
列出项目
from binascii import hexlify,unhexlify from datetime import datetime tarRed = raw_input('Ingrese nombre de Tarjeta de Red Utilizada:') subprocess.call(['ifconfig',tarRed,'promisc'])pt = 0x0800 s = socket.socket(socket.AF_PACKET,socket.SOCK_RAW,socket.htons(pt)) s.bind((tarRed,pt)) #GETCheck def getchecksum(ip_header,size):cksum = 0 pointer = 0而size> 1:cksum + = int((str(“%02x”%(ip_header [pointer],)) + str(“%02x”%(ip_header [pointer + 1],))),16)size - = 2指针+ = 2 #if size:#This表示标题为奇数的情况 #cksum + = int(ip_header [pointer])cksum =(cksum>> 16)+ (cksum& 0xffff)cksum + =(cksum>> 16)return(~cksum)& 0xFFFF def _checksum(data):#计算头总和 ip_header_sum = sum(struct.unpack_from(“6H”,data))#add carry ip_header_sum =(ip_header_sum& 0xFFFF)+(ip_header_sum>> 8& 0xFFFF)ip_header_sum = ~ip_header_sum& 0xFFFF返回 ip_header_sum def i_checksum(checksum_packet):total = 0 num_words = len(checksum_packet)/ 2表示struct.unpack中的块(“!%sH”%num_words,checksum_packet [0:num_words * 2]):total + = chunk if len(checksum_packet)%2:total + = ord(checksum_packet [-1])<< 8 总计+ =总计>> 16返回(~total + 0xffff& 0xffff)
def checksum(source_string): sum = 0 countTo =
(len(source_string)/2)*2 count = 0 while count<countTo:
thisVal = ord(source_string[count + 1])*256 + ord(source_string[count]) sum = sum + thisVal sum = sum &
0xffffffff
count = count + 2 if countTo<len(source_string): sum = sum + ord(source_string[len(source_string) - 1]) sum = sum &
0xffffffff sum = (sum >> 16) + (sum & 0xffff) sum = sum + (sum
>> 16) answer = ~sum answer = answer & 0xffff #answer = answer >> 8 | (answer << 8 & 0xff00) return answer def
checksuma(source_string): sum = 0 countTo =
(len(source_string)/2)*2 count = 0 while count<countTo:
thisVal = ord(source_string[count + 1])*256 + ord(source_string[count]) sum = sum + thisVal sum = sum &
0xffffffff
count = count + 2 if countTo<len(source_string): sum = sum + ord(source_string[len(source_string) - 1]) sum = sum &
0xffffffff sum = (sum >> 16) + (sum & 0xffff) sum = sum + (sum
>> 16) answer = ~sum answer = answer & 0xffff answer = answer >> 8 | (answer << 8 & 0xff00) return answer def ultimo(str):
csum = 0
countTo = (len(str) / 2) * 2
count = 0
while count < countTo:
thisVal = ord(str[count+1]) * 256 + ord(str[count])
csum = csum + thisVal
csum = csum & 0xffffffff
count = count + 2
if countTo < len(str):
csum = csum + ord(str[len(str) - 1])
csum = csum & 0xffffffff
csum = (csum >> 16) + (csum & 0xffff)
csum = csum + (csum >> 16)
answer = ~csum
answer = answer & 0xffff
answer = answer >> 8 | (answer << 8 & 0xff00)
return answer
#GETCheck
#MACs adst='ffffffffffff' mac_destino = unhexlify(adst) ma = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) info =
fcntl.ioctl(ma.fileno(), 0x8927, struct.pack('256s', tarRed[:15]))
asrc = ''.join(['%02x:' % ord(char) for char in info[18:24]])[:-1]
sd = asrc.split(':') asrc = sd[0]+sd[1]+sd[2]+sd[3]+sd[4]+sd[5]
mac_origen = unhexlify(asrc)
#MACs cabEther = struct.pack('!6s6sh',mac_destino,mac_origen,pt)
#datosIP
#version = '4'
#IHL = '5' tipoServicio = unhexlify('00') longitudT = struct.pack('!BB',00,24) identificador = struct.pack('!BB',00,01)
flag_Pos = 0x4000 tiempoVida = 05 ptIP = unhexlify('01') SCC = 0
#IPs ip = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) ipO= str( socket.inet_ntoa(fcntl.ioctl(ip.fileno(),0x8915,struct.pack('256s',
tarRed[:15]))[20:24])) ipO1 = ipO.split('.') ipOr =
struct.pack("!BBBB",int(ipO1[0]),int(ipO1[1]),int(ipO1[2]),int(ipO1[3]))
ipD = raw_input('Ingrese la direccion IP destino: ') ipD1 =
ipD.split('.') ipDest =
struct.pack("!BBBB",int(ipD1[0]),int(ipD1[1]),int(ipD1[2]),int(ipD1[3]))
#IPs
#datosIP cabIP = struct.pack('!1s1s2s2shB1sH4s4s',unhexlify('45'),tipoServicio,longitudT,identificador,flag_Pos,tiempoVida,ptIP,SCC,ipOr,ipDest)
SCC = checksum(cabIP) cabIP =
struct.pack('!1s1s2s2shB1sH4s4s',unhexlify('45'),tipoServicio,longitudT,identificador,flag_Pos,tiempoVida,ptIP,socket.htons(SCC),ipOr,ipDest)
#datosIcmp tipo = 8 codigo = 0x00 check = 0x0000 identificador = int((id(1) * random.random()) % 65535) secuencia = 0x0000
#datos = 'qwertyasdfghzxcvbn0102030405060708091011121314151617181920' datos =
1 * 'Q'
#datosIcmp cabIcmp = struct.pack('!bbHHh',tipo,0,0,identificador,1) my_checksum = ultimo(cabIcmp + datos) cabIcmp =
struct.pack('!bbHHh',tipo,0,socket.htons(my_checksum),identificador,1)
cabIcmp = cabIcmp + datos tiempo = datetime.now() print tiempo for i
in range(15): s.send(cabEther + cabIP + cabIcmp,0)
答案 0 :(得分:3)
你的问题几乎无法理解。您似乎在询问如何创建ICMP ECHO数据包,因为您在列出的代码中创建的数据包被系统报告为格式错误。我会尝试回答为什么你的代码不起作用。
首先,您使用的套接字类型不正确。您需要输入类型1,而不是8.这可以通过第三个参数轻松完成:
s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
(请注意,您需要root或管理员权限才能进行此次调用。)
其次,在创建套接字后,您需要创建ICMP标头。 ICMP标头由以下结构组成:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 | Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4 | REST OF HEADER |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
注意第二个四个字节“REST OF HEADER”。第二组四个字节取决于前两个字节中的TYPE / CODE。例如,如果TYPE为0且CODE为0,则表示您正在处理回复应答,因此,后四个字节将变为2字节标识符和2字节<强>序列号字段,从偏移量4开始,到偏移量7结束,如图所示:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 | Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4 | Identifier | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
8 | Data ...
+-+-+-+-+-
要创建此标头,我将使用类型8,即回声请求结构(请注意,此创建中的字节4-5和6-7仅用于说明,通常这将是不同的值其他比零):
icmp = struct.pack(">BBHHH", 8, 0, 0, 0, 0)
在头的初始创建时,校验和为零。我们现在需要的是实际计算校验和(使用此零值),然后使用这个新的校验和值重新创建标头:
icmp = struct.pack(">BBHHH", 8, 0, cksum(icmp), 0, 0)
但这是你的代码再次错误的地方。 i_checksum()
的实施是错误的。为了解决问题,我会留给你解决它。校验和称为1的补码,有很多关于它的在线文章,以及实现它的Linux系统上的C代码。
一旦你有了标题及其正确的校验和(很重要,因为你的系统不会发送数据包,如果不正确),你只需将它发送到某个地方:
s.sendto(icmp, (SOME_REMOTE_HOST, 0))
然后收到回复,如果有的话:
s.recvfrom(1500)
(注意我选择1500字节,因为那是IP帧的MTU,因此答案不可能大于此,尽管它肯定是可能的。)
并且在这一点上,你的代码完全失败 - 仅仅是因为你没有代码执行最后两个步骤,更不用说其他代码来处理如何处理回复和结构解析标题字段。
至于你定义的其他两个功能,它们很奇怪。其中一个似乎暗示它正在处理链接层字段 - 套接字从来就不是这样,因为套接字只处理IP层及以上 - 而另一个似乎是计算校验和的尝试...虽然不正确(再次)。
简而言之,正如 abarnert 所暗示的那样,请澄清(并添加更多)代码和您的问题。