1#!/usr/local/bin/python3
2# start of new fragment overlaps old one
3
4# |--------|
5#     |XXXXX----|
6
7# RFC 5722 drop overlapping fragments
8
9import os
10import threading
11from addr import *
12from scapy.all import *
13
14class Sniff1(threading.Thread):
15	filter = None
16	captured = None
17	packet = None
18	def run(self):
19		self.captured = sniff(iface=SRC_IF, filter=self.filter,
20		    count=1, timeout=3)
21		if self.captured:
22			self.packet = self.captured[0]
23
24dstaddr=sys.argv[1]
25pid=os.getpid()
26eid=pid & 0xffff
27payload=b"ABCDEFGHIJKLOMNO"
28dummy=b"01234567"
29packet=IPv6(src=SRC_OUT6, dst=dstaddr)/ICMPv6EchoRequest(id=eid, data=payload)
30fid=pid & 0xffffffff
31frag0=IPv6ExtHdrFragment(nh=58, id=fid, m=1)/bytes(packet)[40:56]
32frag1=IPv6ExtHdrFragment(nh=58, id=fid, offset=1)/(dummy+bytes(packet)[56:64])
33pkt0=IPv6(src=SRC_OUT6, dst=dstaddr)/frag0
34pkt1=IPv6(src=SRC_OUT6, dst=dstaddr)/frag1
35eth=[]
36eth.append(Ether(src=SRC_MAC, dst=PF_MAC)/pkt0)
37eth.append(Ether(src=SRC_MAC, dst=PF_MAC)/pkt1)
38
39sniffer = Sniff1();
40sniffer.filter = "ip6 and src %s and dst %s and icmp6" % (dstaddr, SRC_OUT6)
41sniffer.start()
42time.sleep(1)
43sendp(eth, iface=SRC_IF)
44sniffer.join(timeout=5)
45a = sniffer.packet
46
47if a is None:
48	print("no reply")
49	exit(0)
50if a and a.type == ETH_P_IPV6 and \
51    ipv6nh[a.payload.nh] == 'ICMPv6' and \
52    icmp6types[a.payload.payload.type] == 'Echo Reply':
53	id=a.payload.payload.id
54	print("id=%#x" % (id))
55	if id != eid:
56		print("WRONG ECHO REPLY ID")
57		exit(2)
58	data=a.payload.payload.data
59	print("payload=%s" % (data))
60	if data == payload:
61		print("ECHO REPLY")
62		exit(1)
63	print("PAYLOAD!=%s" % (payload))
64	exit(2)
65print("NO ECHO REPLY")
66exit(2)
67