86 lines
3.2 KiB
Python
86 lines
3.2 KiB
Python
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#!/usr/bin/env python
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# -
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# SPDX-License-Identifier: BSD-2-Clause
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#
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# Copyright (c) 2020 Alexander V. Chernikov
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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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# $FreeBSD$
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#
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import argparse
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import scapy.all as sc
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import socket
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import sys
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import fcntl
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import struct
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def parse_args():
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parser = argparse.ArgumentParser(description='ICMP redirect generator')
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parser.add_argument('--smac', type=str, required=True,
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help='eth source mac')
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parser.add_argument('--dmac', type=str, required=True,
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help='eth dest mac')
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parser.add_argument('--sip', type=str, required=True,
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help='remote router source ip')
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parser.add_argument('--dip', type=str, required=True,
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help='local router ip')
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parser.add_argument('--iface', type=str, required=True,
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help='ifname to send packet to')
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parser.add_argument('--route', type=str, required=True,
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help='destination IP to redirect')
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parser.add_argument('--gw', type=str, required=True,
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help='redirect GW')
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return parser.parse_args()
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def construct_icmp_redirect(smac, dmac, sip, dip, route_dst, route_gw):
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e = sc.Ether(src=smac, dst=dmac)
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l3 = sc.IP(src=sip, dst=dip)
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icmp = sc.ICMP(type=5, code=1, gw=route_gw)
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orig_ip = sc.IP(src=sip, dst=route_dst)
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return e / l3 / icmp / orig_ip / sc.UDP()
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def send_packet(pkt, iface, feedback=False):
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if feedback:
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# Make kernel receive the packet as well
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BIOCFEEDBACK = 0x8004427c
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socket = sc.conf.L2socket(iface=args.iface)
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fcntl.ioctl(socket.ins, BIOCFEEDBACK, struct.pack('I', 1))
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sc.sendp(pkt, socket=socket, verbose=True)
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else:
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sc.sendp(pkt, iface=iface, verbose=False)
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def main():
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args = parse_args()
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pkt = construct_icmp_redirect(args.smac, args.dmac, args.sip, args.dip,
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args.route, args.gw)
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send_packet(pkt, args.iface)
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if __name__ == '__main__':
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main()
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