85 lines
2.8 KiB
Python
85 lines
2.8 KiB
Python
#!/usr/bin/env python3
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#
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# SPDX-License-Identifier: ISC
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#
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# Copyright (c) 2012-2021 Alexander Bluhm <bluhm@openbsd.org>
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#
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# Permission to use, copy, modify, and distribute this software for any
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# purpose with or without fee is hereby granted, provided that the above
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# copyright notice and this permission notice appear in all copies.
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#
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# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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from fragcommon import *
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# index boundary 4096 |
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# |--------------|
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# ....
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# |--------------|
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# |XXXX-----|
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# |--------------|
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# |--------------|
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# this should trigger "frag tail overlap %d" and "frag head overlap %d"
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def send(src, dst, send_if, recv_if):
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pid = os.getpid()
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eid = pid & 0xffff
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payload = b"ABCDEFGHIJKLMNOP"
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dummy = b"01234567"
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fragsize = 1024
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boundary = 4096
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fragnum = int(boundary / fragsize)
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packet = sp.IP(src=src, dst=dst)/ \
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sp.ICMP(type='echo-request', id=eid)/ \
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(int((boundary + fragsize) / len(payload)) * payload)
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frag = []
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fid = pid & 0xffff
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for i in range(fragnum - 1):
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frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid,
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frag=(i * fragsize) >> 3, flags='MF') /
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bytes(packet)[20 + i * fragsize:20 + (i + 1) * fragsize])
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frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid,
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frag=(boundary - 8) >> 3, flags='MF') /
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(dummy + bytes(packet)[20 + boundary:20 + boundary + 8]))
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frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid,
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frag=(boundary - fragsize) >> 3, flags='MF') /
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bytes(packet)[20 + boundary - fragsize:20 + boundary])
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frag.append(sp.IP(src=src, dst=dst, proto=1, id=fid,
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frag=(boundary) >> 3)/bytes(packet)[20 + boundary:])
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eth=[]
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for f in frag:
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eth.append(sp.Ether() / f)
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if os.fork() == 0:
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time.sleep(1)
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for e in eth:
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sp.sendp(e, iface=send_if)
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time.sleep(0.001)
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os._exit(0)
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ans = sp.sniff(iface=recv_if, timeout=3, filter="")
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for a in ans:
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if a and a.type == sp.ETH_P_IP and \
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a.payload.proto == 1 and \
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a.payload.frag == 0 and \
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sp.icmptypes[a.payload.payload.type] == 'echo-reply':
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id=a.payload.payload.id
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if id != eid:
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print("WRONG ECHO REPLY ID")
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sys.exit(2)
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sys.exit(0)
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print("NO ECHO REPLY")
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sys.exit(1)
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if __name__ == '__main__':
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main(send)
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