超级网络入门与实践相关的实例

####################################### #sample for icmp traceroute ####################################### from pktbuilder import * import jarray import random import fpformat import time import java.io.IOException def createEchoRequest(srcMac, dstMac, srcIp, dstIp, dataBytes): """ICMP Echo-Request Packet Creation """ #protocol stack is ("Ethernet", "IPv4", "ICMP") packet = Packet(["Ethernet", "IPv4", "ICMP"]) packet.setTextValue("Ethernet", "destination_address", dstMac) packet.setTextValue("Ethernet", "source_address", srcMac) packet.setIntValue("Ethernet", "ether_type", 0x0800) packet.setIntValue("IPv4", "identification", random.randrange(1, 0xFFFF)) packet.setIntValue("IPv4", "protocol", 0x01) packet.setTextValue("IPv4", "source_address", srcIp) packet.setTextValue("IPv4", "destination_address", dstIp) packet.select("ICMP", "icmp_root", "echo_request") data = range(0, dataBytes) packet.setByteArrayValue("ICMP", "data", data) return packet #socket factory creation factory = PcapSocketFactory() #get all device(network adapter) name in sequence devices = factory.getDevices() #print "devices:",devices #local machine address LOCAL_MAC = "00:16:D4:17:25:C4" #local machine IP address LOCAL_IP = "192.168.11.2" #create socket socket = factory.createSocket() #set socket parameter. "devices[1]" is selecting the second device. socket.setPcapSetting(devices[1], PcapSocket.DEFAULT_SNAPLEN, PcapSocket.DEFAULT_PROMISC, 5) #target IP address(www.baidu.com) dstIp = "220.181.38.4" #gateway mac address gatewayMac = "00:16:01:15:a4:88" #data count dataBytes = 10 #maxium passed router maxHops = 40 #buffer creation buffer = jarray.zeros(1600, "b") #Packet Serializer object creation serializer = PacketSerializer() #open the socket socket.open() #receiving filter setting socket.setFilter("ip dst " + LOCAL_IP + " and icmp") #create the ID for ICMP icmpId = random.randrange(1, 0xFFFF) #if reached the destination reachedDst = 0 for i in xrange(1, maxHops) : #sequence NO. of ICMP seqNo = i #field of TTL in IP, increase 1 each time ttl = i #ICMP Echo-Request packet creation packet = createEchoRequest(LOCAL_MAC, gatewayMac, LOCAL_IP, dstIp, dataBytes) #Set the field of id and sequence for protocol of ICMP. packet.setIntValue("ICMP", "identifier", icmpId) packet.setIntValue("ICMP", "sequence_number", seqNo) packet.setIntValue("IPv4", "ttl", ttl) #AutoUtil().printPacket(packet) #Create the raw sending data.With encoding the packet. rawData = serializer.encode(packet) #Sending startTime = time.time() socket.write(rawData, 0, len(rawData)) #Receiving try : rlen = socket.read(buffer, 0, len(buffer)) #ignore the timeout of socket except java.io.IOException : print "Request timeout" continue newPacket = serializer.decodeAuto(buffer, 0, rlen, "Ethernet") # AutoUtil().printPacket(newPacket) if newPacket.contains("ICMP", "echo_reply") : #Check the integration of Packet.The id received must be same as the #ID which sent. recvIcmpId = newPacket.getIntValue("ICMP", "identifier") recvSeqNo = newPacket.getIntValue("ICMP", "sequence_number") if (recvIcmpId != icmpId or recvSeqNo != seqNo): print "Invalid reply with id=", recvIcmpId, " and seq no=", seqNo reachedDst = 1 tempIp = newPacket.getTextValue("IPv4", "source_address") ttl = newPacket.getIntValue("IPv4", "ttl") print i, " from ", tempIp, " time<=", \ fpformat.fix(time.time()-startTime, 4), "(s)", " TTL=", ttl if reachedDst: break #print statistics print "Traceroute complete. " if reachedDst : print dstIp , " is reached." else : print dstIp , " is not reached." #close socket socket.close()