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