1*d39d5ee2SKristof Provost#!/usr/bin/env python3 2*d39d5ee2SKristof Provost# 3*d39d5ee2SKristof Provost# SPDX-License-Identifier: ISC 4*d39d5ee2SKristof Provost# 5*d39d5ee2SKristof Provost# Copyright (c) 2012-2021 Alexander Bluhm <bluhm@openbsd.org> 6*d39d5ee2SKristof Provost# 7*d39d5ee2SKristof Provost# Permission to use, copy, modify, and distribute this software for any 8*d39d5ee2SKristof Provost# purpose with or without fee is hereby granted, provided that the above 9*d39d5ee2SKristof Provost# copyright notice and this permission notice appear in all copies. 10*d39d5ee2SKristof Provost# 11*d39d5ee2SKristof Provost# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12*d39d5ee2SKristof Provost# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13*d39d5ee2SKristof Provost# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14*d39d5ee2SKristof Provost# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15*d39d5ee2SKristof Provost# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16*d39d5ee2SKristof Provost# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17*d39d5ee2SKristof Provost# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18*d39d5ee2SKristof Provost 19*d39d5ee2SKristof Provostfrom fragcommon import * 20*d39d5ee2SKristof Provost 21*d39d5ee2SKristof Provost# index boundary 4096 | 22*d39d5ee2SKristof Provost# |--------------| 23*d39d5ee2SKristof Provost# .... 24*d39d5ee2SKristof Provost# |--------------| 25*d39d5ee2SKristof Provost# |XXXX-----| 26*d39d5ee2SKristof Provost# |--------------| 27*d39d5ee2SKristof Provost# |--------------| 28*d39d5ee2SKristof Provost 29*d39d5ee2SKristof Provost# this should trigger "frag tail overlap %d" and "frag head overlap %d" 30*d39d5ee2SKristof Provost 31*d39d5ee2SKristof Provostdef send(src, dst, send_if, recv_if): 32*d39d5ee2SKristof Provost pid = os.getpid() 33*d39d5ee2SKristof Provost eid = pid & 0xffff 34*d39d5ee2SKristof Provost payload = b"ABCDEFGHIJKLMNOP" 35*d39d5ee2SKristof Provost dummy = b"01234567" 36*d39d5ee2SKristof Provost fragsize = 1024 37*d39d5ee2SKristof Provost boundary = 4096 38*d39d5ee2SKristof Provost fragnum = int(boundary / fragsize) 39*d39d5ee2SKristof Provost packet = sp.IP(src=src, dst=dst)/ \ 40*d39d5ee2SKristof Provost sp.ICMP(type='echo-request', id=eid)/ \ 41*d39d5ee2SKristof Provost (int((boundary + fragsize) / len(payload)) * payload) 42*d39d5ee2SKristof Provost frag = [] 43*d39d5ee2SKristof Provost fid = pid & 0xffff 44*d39d5ee2SKristof Provost 45*d39d5ee2SKristof Provost for i in range(fragnum - 1): 46*d39d5ee2SKristof Provost frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid, 47*d39d5ee2SKristof Provost frag=(i * fragsize) >> 3, flags='MF') / 48*d39d5ee2SKristof Provost bytes(packet)[20 + i * fragsize:20 + (i + 1) * fragsize]) 49*d39d5ee2SKristof Provost frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid, 50*d39d5ee2SKristof Provost frag=(boundary - 8) >> 3, flags='MF') / 51*d39d5ee2SKristof Provost (dummy + bytes(packet)[20 + boundary:20 + boundary + 8])) 52*d39d5ee2SKristof Provost frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid, 53*d39d5ee2SKristof Provost frag=(boundary - fragsize) >> 3, flags='MF') / 54*d39d5ee2SKristof Provost bytes(packet)[20 + boundary - fragsize:20 + boundary]) 55*d39d5ee2SKristof Provost frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid, 56*d39d5ee2SKristof Provost frag=(boundary) >> 3)/bytes(packet)[20 + boundary:]) 57*d39d5ee2SKristof Provost 58*d39d5ee2SKristof Provost eth=[] 59*d39d5ee2SKristof Provost for f in frag: 60*d39d5ee2SKristof Provost eth.append(sp.Ether() / f) 61*d39d5ee2SKristof Provost 62*d39d5ee2SKristof Provost if os.fork() == 0: 63*d39d5ee2SKristof Provost time.sleep(1) 64*d39d5ee2SKristof Provost for e in eth: 65*d39d5ee2SKristof Provost sp.sendp(e, iface=send_if) 66*d39d5ee2SKristof Provost time.sleep(0.001) 67*d39d5ee2SKristof Provost os._exit(0) 68*d39d5ee2SKristof Provost 69*d39d5ee2SKristof Provost ans = sp.sniff(iface=recv_if, timeout=3, filter="") 70*d39d5ee2SKristof Provost for a in ans: 71*d39d5ee2SKristof Provost if a and a.type == sp.ETH_P_IP and \ 72*d39d5ee2SKristof Provost a.payload.proto == 1 and \ 73*d39d5ee2SKristof Provost a.payload.frag == 0 and \ 74*d39d5ee2SKristof Provost sp.icmptypes[a.payload.payload.type] == 'echo-reply': 75*d39d5ee2SKristof Provost id=a.payload.payload.id 76*d39d5ee2SKristof Provost if id != eid: 77*d39d5ee2SKristof Provost print("WRONG ECHO REPLY ID") 78*d39d5ee2SKristof Provost sys.exit(2) 79*d39d5ee2SKristof Provost sys.exit(0) 80*d39d5ee2SKristof Provost print("NO ECHO REPLY") 81*d39d5ee2SKristof Provost sys.exit(1) 82*d39d5ee2SKristof Provost 83*d39d5ee2SKristof Provostif __name__ == '__main__': 84*d39d5ee2SKristof Provost main(send) 85