1#!/usr/local/bin/python2.7 2 3print "udp fragments splitted after udp header" 4 5# |----| 6# |--------| 7 8import os 9from addr import * 10from scapy.all import * 11 12pid=os.getpid() 13uport=pid & 0xffff 14# inetd ignores UDP packets from privileged port or nfs 15if uport < 1024 or uport == 2049: 16 uport+=1024 17payload="ABCDEFGHIJKLMNOP" 18packet=IPv6(src=SRC_OUT6, dst=DST_IN6)/UDP(sport=uport, dport=7)/payload 19frag=[] 20fid=pid & 0xffffffff 21frag.append(IPv6ExtHdrFragment(nh=17, id=fid, m=1)/str(packet)[40:48]) 22frag.append(IPv6ExtHdrFragment(nh=17, id=fid, offset=1)/str(packet)[48:64]) 23eth=[] 24for f in frag: 25 pkt=IPv6(src=SRC_OUT6, dst=DST_IN6)/f 26 eth.append(Ether(src=SRC_MAC, dst=DST_MAC)/pkt) 27 28if os.fork() == 0: 29 time.sleep(1) 30 sendp(eth, iface=SRC_IF) 31 os._exit(0) 32 33ans=sniff(iface=SRC_IF, timeout=3, filter= 34 "ip6 and src "+DST_IN6+" and dst "+SRC_OUT6+" and udp") 35for a in ans: 36 if a and a.type == ETH_P_IPV6 and \ 37 ipv6nh[a.payload.nh] == 'UDP' and \ 38 a.payload.payload.sport == 7: 39 port=a.payload.payload.dport 40 print "port=%d" % (port) 41 if port != uport: 42 print "WRONG UDP ECHO REPLY PORT" 43 exit(2) 44 data=a.payload.payload.load 45 print "payload=%s" % (data) 46 if data == payload: 47 exit(0) 48 print "PAYLOAD!=%s" % (payload) 49 exit(1) 50print "NO UDP ECHO REPLY" 51exit(2) 52