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# this should trigger "frag index %d, new %d" log in kernel 29 30def send(src, dst, send_if, recv_if): 31 pid = os.getpid() 32 eid = pid & 0xffff 33 payload = b"ABCDEFGHIJKLMNOP" 34 dummy = b"01234567" 35 fragsize = 64 36 boundary = 4096 37 fragnum = int(boundary / fragsize) 38 packet = sp.IP(src=src, dst=dst)/ \ 39 sp.ICMP(type='echo-request', id=eid)/ \ 40 (int((boundary + 8) / len(payload)) * payload) 41 frag = [] 42 fid = pid & 0xffff 43 for i in range(fragnum - 1): 44 frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid, 45 frag=(i * fragsize) >> 3, flags='MF') / 46 bytes(packet)[20 + i * fragsize:20 + (i + 1) * fragsize]) 47 frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid, 48 frag=(boundary - 8) >> 3) / 49 (dummy + bytes(packet)[20 + boundary:20 + boundary + 8])) 50 frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid, 51 frag=(boundary - fragsize) >> 3, flags='MF') / 52 bytes(packet)[20 + boundary - fragsize:20 + boundary]) 53 eth = [] 54 for f in frag: 55 eth.append(sp.Ether() / f) 56 57 if os.fork() == 0: 58 time.sleep(1) 59 for e in eth: 60 sp.sendp(e, iface=send_if) 61 time.sleep(0.001) 62 os._exit(0) 63 64 ans = sp.sniff(iface=recv_if, timeout=5) 65 print(ans) 66 for a in ans: 67 a.show() 68 if a and a.type == sp.ETH_P_IP and \ 69 a.payload.proto == 1 and \ 70 a.payload.frag == 0 and \ 71 sp.icmptypes[a.payload.payload.type] == 'echo-reply': 72 id = a.payload.payload.id 73 print("id=%#x" % (id)) 74 if id != eid: 75 print("WRONG ECHO REPLY ID") 76 sys.exit(2) 77 sys.exit(0) 78 print("NO ECHO REPLY") 79 exit(1) 80 81if __name__ == '__main__': 82 main(send) 83