[ViewVC] Annotation of: cebix/BasiliskII/src/Unix/tunconfig

#!/bin/bash
###########################################################################
# Configuration of the tunN devices for usage with Basilisk II.
# (derived MOL tunconfig script)
#
# This script should be named /usr/share/BasiliskII/tunconfig (unless
# the default name has been changed with the 'etherconfig' keyword).
#
#       Usage:          tunconfig iface up|down
#
# If the linux box is configured as a firewall, the rules below might
# need some adjustments.
#
# The IP Tunnel driver requires IP forwarding to be enabled. Run as root:
#
#       echo 1 >/proc/sys/net/ipv4/ip_forward
#
###########################################################################

SUDO=/usr/bin/sudo
IFCONFIG=/sbin/ifconfig
IPTABLES=/sbin/iptables

#########################################################

[[ "x$1" = "x-n" ]] && {
    DONT_EXECUTE=yes
    shift 1
}

TUN_DEV=$1
ACTION=$2

TUN_NUM=`echo $TUN_DEV | sed s/[^0-9]//g`
NET_NUM=`expr 40 + $TUN_NUM`
TUN_NET=172.20.$NET_NUM.0/24
TUN_HOST=172.20.$NET_NUM.1

#########################################################
# Misc Checks
#########################################################

[[ $# = 2 ]] || {
        echo "Usage: tunconfig [-n] iface up|down"
    exit 2
}

[[ "`id -u`" = "0" ]] && {
    echo "---> $SUDO not necessary." 1>&2
    SUDO=""
}

[[ -x $IPTABLES ]] || {
    echo "---> $IPTABLES not found." 1>&2
    exit 1
}

if [ -n "$SUDO" ]; then
    $SUDO -l | grep -q "NOPASSWD: $IFCONFIG" || {
        echo "---> Missing sudo NOPASSWD: $IFCONFIG." 1>&2
        exit 1
    }
    $SUDO -l | grep -q "NOPASSWD: $IPTABLES" || {
        echo "---> Missing sudo NOPASSWD: $IPTABLES." 1>&2
        exit 1
    }
    IFCONFIG="$SUDO $IFCONFIG"
    IPTABLES="$SUDO $IPTABLES"
fi

[[ "x$DONT_EXECUTE" = "xyes" ]] && exit 0

$IPTABLES -L -n -t nat > /dev/null || exit 1

#########################################################
# Remove old (possibly stale) ruleset
#########################################################

{
    $IPTABLES -t nat -D POSTROUTING -s $TUN_NET -d ! $TUN_NET -j MASQUERADE
} >& /dev/null

#########################################################
# Bring down interface
#########################################################

[[ "$ACTION" = down ]] && {
    $IFCONFIG $TUN_DEV down
}

#########################################################
# Configure interface
#########################################################

[[ "$ACTION" = up ]] && {
    $IFCONFIG $TUN_DEV $TUN_HOST

    # masquerade the tun network
    $IPTABLES -t nat -A POSTROUTING -s $TUN_NET -d ! $TUN_NET -j MASQUERADE
}

exit 0
Revision:	1.2
Committed:	2005-05-14T16:08:17Z (19 years, 6 months ago) by gbeauche
Branch:	MAIN
CVS Tags:	nigel-build-19, nigel-build-17, HEAD
Changes since 1.1:	+32 -9 lines
Log Message:	Try to improve the documentation concerning the "tun" interface. Take note that that kernel module must be loaded and IP forwarding enabled. Also add slight improvements to the "tunconfig" script so that sudo /sbin/ifconfig and sudo /sbin/iptables are really supported for current user if not root.
#	User	Rev	Content
1	gbeauche	1.1	#!/bin/bash
2			###########################################################################
3			# Configuration of the tunN devices for usage with Basilisk II.
4			# (derived MOL tunconfig script)
5			#
6			# This script should be named /usr/share/BasiliskII/tunconfig (unless
7			# the default name has been changed with the 'etherconfig' keyword).
8			#
9			# Usage: tunconfig iface up\|down
10			#
11			# If the linux box is configured as a firewall, the rules below might
12			# need some adjustments.
13			#
14	gbeauche	1.2	# The IP Tunnel driver requires IP forwarding to be enabled. Run as root:
15			#
16			# echo 1 >/proc/sys/net/ipv4/ip_forward
17			#
18	gbeauche	1.1	###########################################################################
19
20			SUDO=/usr/bin/sudo
21	gbeauche	1.2	IFCONFIG=/sbin/ifconfig
22	gbeauche	1.1	IPTABLES=/sbin/iptables
23
24			#########################################################
25
26	gbeauche	1.2	[[ "x$1" = "x-n" ]] && {
27			DONT_EXECUTE=yes
28			shift 1
29			}
30
31	gbeauche	1.1	TUN_DEV=$1
32			ACTION=$2
33
34			TUN_NUM=`echo $TUN_DEV \| sed s/[^0-9]//g`
35			NET_NUM=`expr 40 + $TUN_NUM`
36			TUN_NET=172.20.$NET_NUM.0/24
37			TUN_HOST=172.20.$NET_NUM.1
38
39			#########################################################
40			# Misc Checks
41			#########################################################
42
43			[[ $# = 2 ]] \|\| {
44	gbeauche	1.2	echo "Usage: tunconfig [-n] iface up\|down"
45	gbeauche	1.1	exit 2
46			}
47
48			[[ "`id -u`" = "0" ]] && {
49	gbeauche	1.2	echo "---> $SUDO not necessary." 1>&2
50			SUDO=""
51	gbeauche	1.1	}
52
53	gbeauche	1.2	[[ -x $IPTABLES ]] \|\| {
54	gbeauche	1.1	echo "---> $IPTABLES not found." 1>&2
55	gbeauche	1.2	exit 1
56	gbeauche	1.1	}
57
58	gbeauche	1.2	if [ -n "$SUDO" ]; then
59			$SUDO -l \| grep -q "NOPASSWD: $IFCONFIG" \|\| {
60			echo "---> Missing sudo NOPASSWD: $IFCONFIG." 1>&2
61			exit 1
62			}
63			$SUDO -l \| grep -q "NOPASSWD: $IPTABLES" \|\| {
64			echo "---> Missing sudo NOPASSWD: $IPTABLES." 1>&2
65			exit 1
66			}
67			IFCONFIG="$SUDO $IFCONFIG"
68			IPTABLES="$SUDO $IPTABLES"
69			fi
70
71			[[ "x$DONT_EXECUTE" = "xyes" ]] && exit 0
72
73	gbeauche	1.1	$IPTABLES -L -n -t nat > /dev/null \|\| exit 1
74
75			#########################################################
76			# Remove old (possibly stale) ruleset
77			#########################################################
78
79			{
80			$IPTABLES -t nat -D POSTROUTING -s $TUN_NET -d ! $TUN_NET -j MASQUERADE
81			} >& /dev/null
82
83			#########################################################
84			# Bring down interface
85			#########################################################
86
87			[[ "$ACTION" = down ]] && {
88	gbeauche	1.2	$IFCONFIG $TUN_DEV down
89	gbeauche	1.1	}
90
91			#########################################################
92			# Configure interface
93			#########################################################
94
95			[[ "$ACTION" = up ]] && {
96	gbeauche	1.2	$IFCONFIG $TUN_DEV $TUN_HOST
97	gbeauche	1.1
98			# masquerade the tun network
99			$IPTABLES -t nat -A POSTROUTING -s $TUN_NET -d ! $TUN_NET -j MASQUERADE
100			}
101
102			exit 0