def callback(self, hdr, data):
# Parse the Ethernet packet
decoder = ImpactDecoder.EthDecoder()
ether = decoder.decode(data)
# Parse the IP packet inside the Ethernet packet, typep
iphdr = ether.child()
udphdr = iphdr.child()
# First check that the packets are not comming from the local host
# Then check that it is a UDP packet (incase you changed the BPF) also
# Check that the destination port for the packet is a closed
port on the host
if (iphdr.get_ip_src() != self.ip):
self.refresh_portlist()
if (iphdr.get_ip_p() == ImpactPacket.UDP.protocol and
udphdr.get_uh_dport() not in self.portlist):
if self.called == 0:
self.callonce()
print "Incoming UDP packet from %s"%iphdr.get_ip_src()
self.dumper.dump(hdr, data)
def refresh_portlist(self):
# bash script to get all the open and listening UDP ports
# used in the callback function as criteria for logging traffic
output = os.popen("./getports.sh")
pl = output.readlines()
self.portlist = []
for p in pl:
self.portlist.append(int(p))
