xref: /freebsd/share/examples/netgraph/udp.tunnel (revision 641a6cfb86023499caafe26a4d821a0b885cf00b)
1#!/bin/sh
2# $FreeBSD$
3
4# This script sets up a virtual point-to-point WAN link between
5# two subnets, using UDP packets as the ``WAN connection.''
6# The two subnets might be non-routable addresses behind a
7# firewall.
8#
9
10# Here define the local and remote inside networks as well
11# as the local and remote outside IP addresses and UDP port
12# number that will be used for the tunnel.
13#
14LOC_INTERIOR_IP=192.168.1.1
15LOC_EXTERIOR_IP=1.1.1.1
16REM_INTERIOR_IP=192.168.2.1
17REM_EXTERIOR_IP=2.2.2.2
18REM_INSIDE_NET=192.168.2.0
19UDP_TUNNEL_PORT=4028
20
21# Create the interface node ``ng0'' if it doesn't exist already,
22# otherwise just make sure it's not connected to anything.
23# In FreeBSD, interfaces cannot be removed so it might already
24# be there from before.
25#
26if ifconfig ng0 >/dev/null 2>&1; then
27	ifconfig ng0 inet down delete >/dev/null 2>&1
28	ngctl shutdown ng0:
29else
30	ngctl mkpeer iface dummy inet
31fi
32
33# Attach a UDP socket to the ``inet'' hook of the interface node
34# using the ng_ksocket(4) node type.
35#
36ngctl mkpeer ng0: ksocket inet inet/dgram/udp
37
38# Bind the UDP socket to the local external IP address and port
39#
40ngctl msg ng0:inet bind inet/${LOC_EXTERIOR_IP}:${UDP_TUNNEL_PORT}
41
42# Connect the UDP socket to the peer's external IP address and port
43#
44ngctl msg ng0:inet connect inet/${REM_EXTERIOR_IP}:${UDP_TUNNEL_PORT}
45
46# Configure the point-to-point interface
47#
48ifconfig ng0 ${LOC_INTERIOR_IP} ${REM_INTERIOR_IP}
49
50# Add a route to the peer's interior network via the tunnel
51#
52route add ${REM_INSIDE_NET} ${REM_INTERIOR_IP}
53
54