1#!/usr/local/bin/python2.7 2# new fragment completely overlaps old one 3 4# |----| 5# |XXXX| 6# |------------| 7 8# RFC 5722 drop overlapping fragments 9 10import os 11from addr import * 12from scapy.all import * 13 14dstaddr=sys.argv[1] 15pid=os.getpid() 16payload="ABCDEFGHIJKLOMNOQRSTUVWX" 17dummy="01234567" 18packet=IPv6(src=SRC_OUT6, dst=dstaddr)/ICMPv6EchoRequest(id=pid, data=payload) 19frag0=IPv6ExtHdrFragment(nh=58, id=pid, offset=0, m=1)/str(packet)[40:48] 20frag1=IPv6ExtHdrFragment(nh=58, id=pid, offset=2, m=1)/dummy 21frag2=IPv6ExtHdrFragment(nh=58, id=pid, offset=1)/str(packet)[48:72] 22pkt0=IPv6(src=SRC_OUT6, dst=dstaddr)/frag0 23pkt1=IPv6(src=SRC_OUT6, dst=dstaddr)/frag1 24pkt2=IPv6(src=SRC_OUT6, dst=dstaddr)/frag2 25eth=[] 26eth.append(Ether(src=SRC_MAC, dst=PF_MAC)/pkt0) 27eth.append(Ether(src=SRC_MAC, dst=PF_MAC)/pkt1) 28eth.append(Ether(src=SRC_MAC, dst=PF_MAC)/pkt2) 29 30if os.fork() == 0: 31 time.sleep(1) 32 sendp(eth, iface=SRC_IF) 33 os._exit(0) 34 35ans=sniff(iface=SRC_IF, timeout=3, filter= 36 "ip6 and src "+dstaddr+" and dst "+SRC_OUT6+" and icmp6") 37if len(ans) == 0: 38 print "no reply" 39 exit(0) 40a=ans[0] 41if a and a.type == scapy.layers.dot11.ETHER_TYPES.IPv6 and \ 42 ipv6nh[a.payload.nh] == 'ICMPv6' and \ 43 icmp6types[a.payload.payload.type] == 'Echo Reply': 44 id=a.payload.payload.id 45 print "id=%#x" % (id) 46 if id != pid: 47 print "WRONG ECHO REPLY ID" 48 exit(2) 49 data=a.payload.payload.data 50 print "payload=%s" % (data) 51 if data == payload: 52 print "ECHO REPLY" 53 exit(1) 54 print "PAYLOAD!=%s" % (payload) 55 exit(2) 56print "NO ECHO REPLY" 57exit(2) 58