frag6_udpatomic.py revision 1.9 
1#!/usr/local/bin/python3
2
3print("atomic udp fragment")
4
5# |-------------|
6
7import os
8from addr import *
9from scapy.all import *
10
11pid=os.getpid()
12uport=pid & 0xffff
13# inetd ignores UDP packets from privileged port or nfs
14if uport < 1024 or uport == 2049:
15	uport+=1024
16payload=b"ABCDEFGHIJKLMNOP"
17packet=IPv6(src=LOCAL_ADDR6, dst=REMOTE_ADDR6)/ \
18    UDP(sport=uport, dport=7)/payload
19frag=[]
20fid=pid & 0xffffffff
21frag.append(IPv6ExtHdrFragment(nh=17, id=fid)/bytes(packet)[40:64])
22eth=[]
23for f in frag:
24	pkt=IPv6(src=LOCAL_ADDR6, dst=REMOTE_ADDR6)/f
25	eth.append(Ether(src=LOCAL_MAC, dst=REMOTE_MAC)/pkt)
26
27if os.fork() == 0:
28	time.sleep(1)
29	sendp(eth, iface=LOCAL_IF)
30	os._exit(0)
31
32ans=sniff(iface=LOCAL_IF, timeout=3, filter=
33    "ip6 and src "+REMOTE_ADDR6+" and dst "+LOCAL_ADDR6+" and udp")
34for a in ans:
35	if a and a.type == ETH_P_IPV6 and \
36	    ipv6nh[a.payload.nh] == 'UDP' and \
37	    a.payload.payload.sport == 7:
38		port=a.payload.payload.dport
39		print("port=%d" % (port))
40		if port != uport:
41			print("WRONG UDP ECHO REPLY PORT")
42			exit(2)
43		data=a.payload.payload.load
44		print("payload=%s" % (data))
45		if data == payload:
46			exit(0)
47		print("PAYLOAD!=%s" % (payload))
48		exit(1)
49print("NO UDP ECHO REPLY")
50exit(2)
51