1#!/usr/local/bin/python3 2 3print("non-overlapping ping fragments with ethernet padding") 4 5# |--------|XX| 6# |----|XX| 7 8import os 9from addr import * 10from scapy.all import * 11 12pid=os.getpid() 13eid=pid & 0xffff 14payload=b"ABCDEFGHIJKLMNOP" 15padding=b"0123" 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 frag=2)/bytes(packet)[36:44]) 24eth=[] 25for f in frag: 26 pkt=bytes(f) + padding 27 eth.append(Ether(src=LOCAL_MAC, dst=REMOTE_MAC, type=0x0800)/pkt) 28 29if os.fork() == 0: 30 time.sleep(1) 31 sendp(eth, iface=LOCAL_IF) 32 os._exit(0) 33 34ans=sniff(iface=LOCAL_IF, timeout=3, filter= 35 "ip and src "+REMOTE_ADDR+" and dst "+LOCAL_ADDR+" and icmp") 36for a in ans: 37 if a and a.type == ETH_P_IP and \ 38 a.payload.proto == 1 and \ 39 a.payload.frag == 0 and a.payload.flags == 0 and \ 40 icmptypes[a.payload.payload.type] == 'echo-reply': 41 id=a.payload.payload.id 42 print("id=%#x" % (id)) 43 if id != eid: 44 print("WRONG ECHO REPLY ID") 45 exit(2) 46 data=a.payload.payload.payload.load 47 print("payload=%s" % (data)) 48 if data == payload: 49 exit(0) 50 print("PAYLOAD!=%s" % (payload)) 51 exit(1) 52print("NO ECHO REPLY") 53exit(2) 54