1#!/usr/local/bin/python3
2
3print("drop too long fragment queue, reassemble less fragments")
4
5# |----|
6#      |----|
7#           |----|
8#                 ...                                           ...
9#                                                                  |----|
10
11import os
12from addr import *
13from scapy.all import *
14
15pid=os.getpid()
16eid=pid & 0xffff
17payload=b"ABCDEFGHIJKLMNOP" * 70
18frag=[]
19fid=pid & 0xffffffff
20# send packets with 65 and 64 fragments
21for max in (64, 63):
22	eid = ~eid & 0xffff
23	packet=IPv6(src=LOCAL_ADDR6, dst=REMOTE_ADDR6)/ \
24	    ICMPv6EchoRequest(id=eid, data=payload)
25	fid = ~fid & 0xffffffff
26	for i in range(max):
27		frag.append(IPv6ExtHdrFragment(nh=58, id=fid, m=1,
28		    offset=i)/bytes(packet)[40+i*8:40+(i+1)*8])
29	frag.append(IPv6ExtHdrFragment(nh=58, id=fid,
30	    offset=max)/bytes(packet)[40+max*8:])
31eth=[]
32for f in frag:
33	pkt=IPv6(src=LOCAL_ADDR6, dst=REMOTE_ADDR6)/f
34	eth.append(Ether(src=LOCAL_MAC, dst=REMOTE_MAC)/pkt)
35
36child = os.fork()
37if child == 0:
38	time.sleep(1)
39	for e in eth:
40		sendp(e, iface=LOCAL_IF)
41		time.sleep(0.001)
42	os._exit(0)
43
44ans=sniff(iface=LOCAL_IF, timeout=6, filter=
45    "ip6 and src "+REMOTE_ADDR6+" and dst "+LOCAL_ADDR6+" and icmp6")
46os.kill(child, 15)
47os.wait()
48
49reply=False
50for a in ans:
51	if a and a.type == ETH_P_IPV6 and \
52	    ipv6nh[a.payload.nh] == 'ICMPv6' and \
53	    icmp6types[a.payload.payload.type] == 'Echo Reply':
54		id=a.payload.payload.id
55		print("id=%#x" % (id))
56		if id == ~eid & 0xffff:
57			print("ECHO REPLY FROM 65 FRAGMENTS")
58			exit(1)
59		if id != eid:
60			print("WRONG ECHO REPLY ID")
61			exit(2)
62		data=a.payload.payload.data
63		print("payload=%s" % (data))
64		if data != payload:
65			print("PAYLOAD!=%s" % (payload))
66			exit(2)
67		reply=True
68if not reply:
69	print("NO ECHO REPLY FROM 64 FRAGMENTS")
70	exit(1)
71print("echo reply from 64 fragments")
72exit(0)
73