HCF

+import os
+
+class HCF():
+    def __init__(self, ipaddr) :
+        self.IPaddresses = ipaddr
+        self.IPaddressdict = {}
+        self.InitialTTL = [2, 10, 30, 32, 60, 64, 128, 255]
+
+        self.DoTraceroute(self.IPaddresses)
+
+
+    # Traceroute 
+    def DoTraceroute(self, IPaddress) :
+        traceroute = []
+        for ip in IPaddress :
+            traceroute.append(os.popen("traceroute " + ip).read())
+
+        # parsing
+        for trace, ip in zip(traceroute, IPaddress) :
+            splitline = trace.split('\n')
+            lastline = splitline[len(splitline)-2]
+
+            if len(splitline) < 2 : # no result
+                lastline = splitline[len(splitline)-2]
+            
+            hc = lastline.split(' ')[0] 
+            try:
+                int(hc)
+            except:
+                hc = lastline.split(" ")[1]
+
+            self.IPaddressdict[ip] = str(int(hc)-1)
+        print(self.IPaddressdict)
+
+    def CheckHopCount(self, IP, HopCount):
+        if str(self.IPaddressdict[IP]) != str(HopCount) :
+            return True
+        else :
+            return False
+    
+
+    def IsSpoofed(self, packet):
+        TTL = packet['ttl']
+        src = packet['src']
+
+        initialTTL = 2
+
+        for e in self.InitialTTL :
+            if TTL < e :
+                initialTTL = e
+                break
+        hc = initialTTL - TTL
+
+        flag = self.CheckHopCount(src, hc)
+
+        print("IP Spoofing " + str(flag))
+
+        return flag
\ No newline at end of file

+#from hopCountFiltering import HCFStateManager
+from HCF import *
+from struct import *
+import sys
+import socket
+
+def PacketMonitoring():
+    IP = []
+    for i in range(1, 10):
+        ip = '10.0.'+str(i+1)+'.100'
+        IP.append(ip)
+    packetManager = HCF(IP)
+
+    # set up the socket
+    try:
+        sock = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.ntohs(0x0003))
+        
+    except socket.error as e:
+        err = e.args[0]
+        print ("Error setting up socket: ", e)
+        sys.exit()
+
+    while True:
+        packet = sock.recvfrom(65535)
+        packet = packet[0]
+        eth_length = 14
+
+        eth_header = packet[:eth_length]
+        eth = unpack('!6s6sH', eth_header)
+        eth_protocol = socket.ntohs(eth[2])
+
+        if eth_protocol == 8 : # IP protocol
+            ip_header = packet[eth_length:20+eth_length]
+            iphead = unpack("!BBHHHBBH4s4s", ip_header)
+            version_ihl = iphead[0]
+            version = version_ihl >> 4
+            ihl = version_ihl & 0xF
+            iph_length = ihl * 4
+            ttl = iphead[5]
+            source_addr = socket.inet_ntoa(iphead[8])
+            dest_addr = socket.inet_ntoa(iphead[9])
+
+            print("\nSource IP address: ", source_addr)
+            print("TTL: ", ttl)
+
+            try :
+                packetTest = packetManager.IsSpoofed({'ttl':ttl, 'src':source_addr})
+            except Exception as e :
+                print(e)
+                continue
+
+if __name__ == "__main__":
+    PacketMonitoring()

+#!/usr/bin/python
+from mininet.topo import Topo
+from mininet.net import Mininet
+from mininet.node import Node
+from mininet.log import setLogLevel, info
+from mininet.cli import CLI
+
+class LinuxRouter( Node ):
+    "A Node with IP forwarding enabled."
+
+    def config( self, **params ):
+        super( LinuxRouter, self).config( **params )
+        # Enable forwarding on the router
+        self.cmd( 'sysctl net.ipv4.ip_forward=1' )
+
+    def terminate( self ):
+        self.cmd( 'sysctl net.ipv4.ip_forward=0' )
+        super( LinuxRouter, self ).terminate()
+
+
+class NetworkTopo(Topo) :
+    def __init__(self) :
+        self.routerIPlist = ['10.0.1.1/24', '10.0.2.1/24', '10.0.3.1/24']
+        self.n = 10 # n > 3
+        self.routerlist = [0] * self.n
+        self.switchlist = [0] * self.n
+        self.hostlist = [0] * self.n
+        Topo.__init__(self)
+
+    def CreateRouterIP(self) :
+        default = '10.0.'
+        for i in range(3, self.n) :
+            router_ip = default + str(i+1) + '.1/24'
+            self.routerIPlist.append(router_ip)
+        
+    def CreateRouter(self):
+        for i in range(0, self.n):
+            name = 'r' + str(i)
+            self.routerlist[i] = self.addNode(name, cls=LinuxRouter, ip=self.routerIPlist[i])
+
+    def CreateSwitch(self) :
+        for i in range(0, self.n):
+            name = 's'+str(i)
+            self.switchlist[i] = self.addSwitch(name)
+
+    def Createlink(self):
+        # router <-> switch
+        for i in range(0, self.n):
+            name2 = 'r'+str(i)+'-eth1'
+            self.addLink(self.switchlist[i], self.routerlist[i], intfName2=name2 , params2={'ip':self.routerIPlist[i]})
+
+        # router <-> router
+        self.addLink(self.routerlist[0], self.routerlist[1], intfName1='r0-eth0', intfName2='r1-eth0', params1={'ip':'10.100.0.1/24'}, params2={'ip':'10.100.0.2/24'})
+
+        cnt = 1
+        for i in range(2, self.n):
+            name1 = 'r'+str(i-1)+'-eth2'
+            name2 = 'r'+str(i)+'-eth0'
+            ip1 = '10.10'+str(cnt)+'.0.1/24'
+            ip2 = '10.10'+str(cnt)+'.0.2/24'
+            cnt += 1
+            self.addLink(self.routerlist[i-1], self.routerlist[i], intfName1=name1, intfName2=name2, params1={'ip':ip1}, params2={'ip':ip2})
+
+    def CreateHost(self) :
+        for i in range(0, self.n) :
+            name = 'h'+str(i)
+            ip = '10.0.'+str(i+1)+'.100/24'
+            defaultroute = 'via 10.0.'+str(i+1)+'.1'
+            self.hostlist[i] = self.addHost(name, ip=ip, defaultRoute=defaultroute)
+
+    def build(self, **_opts) :
+        self.CreateRouterIP()
+        self.CreateRouter()
+        self.CreateSwitch()
+        self.Createlink()
+        self.CreateHost()
+
+        # switch <-> host
+        for h, s in zip(self.hostlist, self.switchlist):
+            self.addLink(h, s)
+
+
+def run() :
+    topo = NetworkTopo()
+    net = Mininet(topo=topo)
+    net.start()
+    n = 10 # n > 3
+    router = [0] * n
+
+    for i in range(0, n):
+        name = 'r'+str(i)
+        router[i] = net.get(name)
+        router[i].cmd('python3 RIP.py&')
+
+        info(net[name].cmd('route'))
+
+    CLI(net)
+    net.stop()
+
+if __name__ == '__main__' :
+    setLogLevel('info')
+    run()