1#!/usr/local/bin/python3
2
3print("ping fragment without payload after first fragment")
4
5# |--------|
6# ||
7#          |----|
8
9import os
10from addr import *
11from scapy.all import *
12
13pid=os.getpid()
14eid=pid & 0xffff
15payload=b"ABCDEFGHIJKLMNOP"
16packet=IP(src=LOCAL_ADDR, dst=REMOTE_ADDR)/ \
17    ICMP(type='echo-request', id=eid)/payload
18frag=[]
19fid=pid & 0xffff
20frag.append(IP(src=LOCAL_ADDR, dst=REMOTE_ADDR, proto=1, id=fid,
21    flags='MF')/bytes(packet)[20:36])
22frag.append(IP(src=LOCAL_ADDR, dst=REMOTE_ADDR, proto=1, id=fid,
23    flags='MF'))
24frag.append(IP(src=LOCAL_ADDR, dst=REMOTE_ADDR, proto=1, id=fid,
25    frag=2)/bytes(packet)[36:44])
26eth=[]
27for f in frag:
28	eth.append(Ether(src=LOCAL_MAC, dst=REMOTE_MAC)/f)
29
30if os.fork() == 0:
31	time.sleep(1)
32	sendp(eth, iface=LOCAL_IF)
33	os._exit(0)
34
35ans=sniff(iface=LOCAL_IF, timeout=3, filter=
36    "ip and src "+REMOTE_ADDR+" and dst "+LOCAL_ADDR+" and icmp")
37for a in ans:
38	if a and a.type == ETH_P_IP and \
39	    a.payload.proto == 1 and \
40	    a.payload.frag == 0 and a.payload.flags == 0 and \
41	    icmptypes[a.payload.payload.type] == 'echo-reply':
42		id=a.payload.payload.id
43		print("id=%#x" % (id))
44		if id != eid:
45			print("WRONG ECHO REPLY ID")
46			exit(2)
47		data=a.payload.payload.payload.load
48		print("payload=%s" % (data))
49		if data == payload:
50			exit(0)
51		print("PAYLOAD!=%s" % (payload))
52		exit(1)
53print("NO ECHO REPLY")
54exit(2)
55