3 # SPDX-License-Identifier: BSD-2-Clause
5 # Copyright (c) 2020 Alexander V. Chernikov
7 # Redistribution and use in source and binary forms, with or without
8 # modification, are permitted provided that the following conditions
10 # 1. Redistributions of source code must retain the above copyright
11 # notice, this list of conditions and the following disclaimer.
12 # 2. Redistributions in binary form must reproduce the above copyright
13 # notice, this list of conditions and the following disclaimer in the
14 # documentation and/or other materials provided with the distribution.
16 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 logging.getLogger("scapy").setLevel(logging.CRITICAL)
33 import scapy.all as sc
41 parser = argparse.ArgumentParser(description='ICMP redirect generator')
42 parser.add_argument('--smac', type=str, required=True,
43 help='eth source mac')
44 parser.add_argument('--dmac', type=str, required=True,
46 parser.add_argument('--sip', type=str, required=True,
47 help='remote router source ip')
48 parser.add_argument('--dip', type=str, required=True,
49 help='local router ip')
50 parser.add_argument('--iface', type=str, required=True,
51 help='ifname to send packet to')
52 parser.add_argument('--route', type=str, required=True,
53 help='destination IP to redirect')
54 parser.add_argument('--gw', type=str, required=True,
56 return parser.parse_args()
59 def construct_icmp_redirect(smac, dmac, sip, dip, route_dst, route_gw):
60 e = sc.Ether(src=smac, dst=dmac)
61 l3 = sc.IP(src=sip, dst=dip)
62 icmp = sc.ICMP(type=5, code=1, gw=route_gw)
63 orig_ip = sc.IP(src=sip, dst=route_dst)
64 return e / l3 / icmp / orig_ip / sc.UDP()
67 def send_packet(pkt, iface, feedback=False):
69 # Make kernel receive the packet as well
70 BIOCFEEDBACK = 0x8004427c
71 socket = sc.conf.L2socket(iface=args.iface)
72 fcntl.ioctl(socket.ins, BIOCFEEDBACK, struct.pack('I', 1))
73 sc.sendp(pkt, socket=socket, verbose=True)
75 sc.sendp(pkt, iface=iface, verbose=False)
80 pkt = construct_icmp_redirect(args.smac, args.dmac, args.sip, args.dip,
82 send_packet(pkt, args.iface)
85 if __name__ == '__main__':