poky/scripts/runqemu-ifup

#!/bin/bash

QEMU network interface configuration script. This utility needs to

be run as root, and will use the tunctl binary from a native sysroot.

Note: many Linux distros these days still use an older version of

tunctl which does not support the group permissions option, hence

the need to use build system's version.

If you find yourself calling this script a lot, you can add the

the following to your /etc/sudoers file to be able to run this

command without entering your password each time:

ALL=NOPASSWD: /path/to/runqemu-ifup

ALL=NOPASSWD: /path/to/runqemu-ifdown

If you'd like to create a bank of tap devices at once, you should use

the runqemu-gen-tapdevs script instead. If tap devices are set up using

that script, the runqemu script will never end up calling this

script.

Copyright (c) 2006-2011 Linux Foundation

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License version 2 as

published by the Free Software Foundation.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License along

with this program; if not, write to the Free Software Foundation, Inc.,

51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

usage() { echo "sudo $(basename $0) " }

if [ $EUID -ne 0 ]; then echo "Error: This script (runqemu-ifup) must be run with root privileges" exit 1 fi

if [ $# -ne 3 ]; then usage exit 1 fi

USERID="-u $1" GROUP="-g $2" NATIVE_SYSROOT_DIR=$3

TUNCTL=$NATIVE_SYSROOT_DIR/usr/bin/tunctl if [ ! -x "$TUNCTL" ]; then echo "Error: Unable to find tunctl binary in '$NATIVE_SYSROOT_DIR/usr/bin'" exit 1 fi

TAP=$TUNCTL -b $GROUP 2>&1 STATUS=$? if [ $STATUS -ne 0 ]; then

If tunctl -g fails, try using tunctl -u, for older host kernels

which do not support the TUNSETGROUP ioctl

TAP=`$TUNCTL -b $USERID 2>&1`
STATUS=$?
if [ $STATUS -ne 0 ]; then
	echo "tunctl failed:"
	exit 1
fi

fi

IFCONFIG=which ifconfig 2> /dev/null if [ "x$IFCONFIG" = "x" ]; then # better than nothing... IFCONFIG=/sbin/ifconfig fi if [ ! -x "$IFCONFIG" ]; then echo "$IFCONFIG cannot be executed" exit 1 fi

ROUTE=which route if [ "x$ROUTE" = "x" ]; then # better than nothing... ROUTE=/sbin/route fi if [ ! -x "$ROUTE" ]; then echo "$ROUTE cannot be executed" exit 1 fi

IPTABLES=which iptables 2> /dev/null if [ "x$IPTABLES" = "x" ]; then IPTABLES=/sbin/iptables fi if [ ! -x "$IPTABLES" ]; then echo "$IPTABLES cannot be executed" exit 1 fi

n=$[ (echo $TAP | sed 's/tap//' * 2) + 1 ] $IFCONFIG $TAP 192.168.7.$n netmask 255.255.255.255

dest=$[ (echo $TAP | sed 's/tap//' * 2) + 2 ] $ROUTE add -host 192.168.7.$dest $TAP

setup NAT for tap0 interface to have internet access in QEMU

$IPTABLES -A POSTROUTING -t nat -j MASQUERADE -s 192.168.7.$n/32 $IPTABLES -A POSTROUTING -t nat -j MASQUERADE -s 192.168.7.$dest/32 echo 1 > /proc/sys/net/ipv4/ip_forward echo 1 > /proc/sys/net/ipv4/conf/$TAP/proxy_arp $IPTABLES -P FORWARD ACCEPT

echo $TAP