1#!/usr/local/bin/python2.7
2# old fragment completely overlaps new one
3
4#      |------------|
5#          |XXXX|
6# |----|
7
8# RFC 5722 drop overlapping fragments
9
10import os
11import threading
12from addr import *
13from scapy.all import *
14
15class Sniff1(threading.Thread):
16	filter = None
17	captured = None
18	packet = None
19	def run(self):
20		self.captured = sniff(iface=SRC_IF, filter=self.filter,
21		    count=1, timeout=3)
22		if self.captured:
23			self.packet = self.captured[0]
24
25dstaddr=sys.argv[1]
26pid=os.getpid() & 0xffff
27payload="ABCDEFGHIJKLOMNOQRSTUVWX"
28dummy="01234567"
29packet=IPv6(src=SRC_OUT6, dst=dstaddr)/ICMPv6EchoRequest(id=pid, data=payload)
30frag0=IPv6ExtHdrFragment(nh=58, id=pid, offset=0, m=1)/str(packet)[40:48]
31frag1=IPv6ExtHdrFragment(nh=58, id=pid, offset=2, m=1)/dummy
32frag2=IPv6ExtHdrFragment(nh=58, id=pid, offset=1)/str(packet)[48:72]
33pkt0=IPv6(src=SRC_OUT6, dst=dstaddr)/frag0
34pkt1=IPv6(src=SRC_OUT6, dst=dstaddr)/frag1
35pkt2=IPv6(src=SRC_OUT6, dst=dstaddr)/frag2
36eth=[]
37eth.append(Ether(src=SRC_MAC, dst=PF_MAC)/pkt2)
38eth.append(Ether(src=SRC_MAC, dst=PF_MAC)/pkt1)
39eth.append(Ether(src=SRC_MAC, dst=PF_MAC)/pkt0)
40
41sniffer = Sniff1();
42sniffer.filter = "ip6 and src %s and dst %s and icmp6" % (dstaddr, SRC_OUT6)
43sniffer.start()
44time.sleep(1)
45sendp(eth, iface=SRC_IF)
46sniffer.join(timeout=5)
47a = sniffer.packet
48
49if a is None:
50	print "no reply"
51	exit(0)
52if a and a.type == ETH_P_IPV6 and \
53    ipv6nh[a.payload.nh] == 'ICMPv6' and \
54    icmp6types[a.payload.payload.type] == 'Echo Reply':
55	id=a.payload.payload.id
56	print "id=%#x" % (id)
57	if id != pid:
58		print "WRONG ECHO REPLY ID"
59		exit(2)
60	data=a.payload.payload.data
61	print "payload=%s" % (data)
62	if data == payload:
63		print "ECHO REPLY"
64		exit(1)
65	print "PAYLOAD!=%s" % (payload)
66	exit(2)
67print "NO ECHO REPLY"
68exit(2)
69