113 lines
4.2 KiB
Python
113 lines
4.2 KiB
Python
#!/usr/bin/env python3
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#
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# SPDX-License-Identifier: BSD-2-Clause
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#
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# Copyright (c) 2021 Kristof Provost <kp@FreeBSD.org>
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions
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# are met:
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# 1. Redistributions of source code must retain the above copyright
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# notice, this list of conditions and the following disclaimer.
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# 2. Redistributions in binary form must reproduce the above copyright
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# notice, this list of conditions and the following disclaimer in the
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# documentation and/or other materials provided with the distribution.
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#
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# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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# SUCH DAMAGE.
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#
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import argparse
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import scapy.all as sp
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import sys
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import os
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curdir = os.path.dirname(os.path.realpath(__file__))
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netpfil_common = curdir + "/../netpfil/common"
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sys.path.append(netpfil_common)
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from sniffer import Sniffer
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def check_stp(args, packet):
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stp = packet.getlayer(sp.STP)
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if stp is None:
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return False
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if stp.rootmac != "00:0c:29:01:01:01":
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return False
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# Ensure we don't get confused by valid STP packets generated by if_bridge
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if (stp.maxage >= 6 and stp.maxage <= 40) and \
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(stp.hellotime >= 1 and stp.hellotime <= 2) and \
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(stp.fwddelay >= 4 and stp.fwddelay <= 30):
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return False
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print("This packet should have been dropped")
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print(packet.show())
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return True
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def invalid_stp(send_if):
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llc = sp.Ether(src="00:0c:29:0b:91:0a", dst="01:80:C2:00:00:00") \
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/ sp.LLC()
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# Bad maxage
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stp = llc / sp.STP(proto=0, rootid=32768, rootmac="00:0c:29:01:01:01", \
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bridgeid=32768, bridgemac="00:0c:29:01:01:01", \
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portid=0x8007, maxage=41, hellotime=2, fwddelay=30)
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sp.sendp(stp, iface=send_if, verbose=False)
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stp = llc / sp.STP(proto=0, rootid=32768, rootmac="00:0c:29:01:01:01", \
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bridgeid=32768, bridgemac="00:0c:29:01:01:01", \
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portid=0x8007, maxage=5, hellotime=2, fwddelay=30)
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sp.sendp(stp, iface=send_if, verbose=False)
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# Bad hellotime
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stp = llc / sp.STP(proto=0, rootid=32768, rootmac="00:0c:29:01:01:01", \
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bridgeid=32768, bridgemac="00:0c:29:01:01:01", \
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portid=0x8007, maxage=40, hellotime=3, fwddelay=30)
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sp.sendp(stp, iface=send_if, verbose=False)
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stp = llc / sp.STP(proto=0, rootid=32768, rootmac="00:0c:29:01:01:01", \
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bridgeid=32768, bridgemac="00:0c:29:01:01:01", \
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portid=0x8007, maxage=40, hellotime=1, fwddelay=30)
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sp.sendp(stp, iface=send_if, verbose=False)
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# Bad fwddelay
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stp = llc / sp.STP(proto=0, rootid=32768, rootmac="00:0c:29:01:01:01", \
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bridgeid=32768, bridgemac="00:0c:29:01:01:01", \
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portid=0x8007, maxage=40, hellotime=2, fwddelay=31)
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sp.sendp(stp, iface=send_if, verbose=False)
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stp = llc / sp.STP(proto=0, rootid=32768, rootmac="00:0c:29:01:01:01", \
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bridgeid=32768, bridgemac="00:0c:29:01:01:01", \
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portid=0x8007, maxage=40, hellotime=2, fwddelay=3)
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sp.sendp(stp, iface=send_if, verbose=False)
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def main():
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parser = argparse.ArgumentParser("stp.py",
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description="STP test tool")
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parser.add_argument('--sendif', nargs=1,
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required=True,
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help='The interface through which the packet(s) will be sent')
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parser.add_argument('--recvif', nargs=1,
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help='The interface on which to expect the ICMP echo request')
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args = parser.parse_args()
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sniffer = Sniffer(args, check_stp)
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invalid_stp(args.sendif[0])
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sniffer.join()
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# The 'correct' packet is a corrupt STP packet, so it shouldn't turn up.
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if sniffer.foundCorrectPacket:
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sys.exit(1)
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if __name__ == '__main__':
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main()
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