tests/sys/netpfil/pf/frag-overreplace.py

   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
  19 from 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
  31 def 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
  83 if __name__ == '__main__':
  84         main(send)