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#! /bin/bash
#*********************************************************************
#
# fai-mk-network -- setup a test network for FAI
#
# This script is part of FAI (Fully Automatic Installation)
# (c) 2015-2022 by Thomas Lange, lange@cs.uni-koeln.de
# Universitaet zu Koeln
#
#*********************************************************************
PATH=/sbin:/bin:/usr/sbin:/usr/bin
tapnum=9 # how many tap devies will be created
brip=192.168.33.250 # IP of bridge device
brname=br0
# default network device used for routing to the outside internet
netdev=$(ip route | awk '/^default/ {print $5}'|head -1)
usage() {
cat <<EOF
fai-mk-network, setup a test network for FAI
Copyright (C) 2015-2022 by Thomas Lange
Usage: fai-mk-network {OPTIONS} USER
-r Remove the network setup.
-P Do not put the bridge into a private network
-i <NIC> Use NIC instead of default network device
DESCRIPTION
fai-mk-network creates $tapnum tap devices which are added to a software bridge.
The tap devices will belong to the user specified. This bridge will be on a
private subnet ($brip/24) unless -P is specified. Also a NATing is enabled for
the private subnet. Using -P the bridge will use the network of $netdev (or -i) instead
of a private subnet. Do not call this command in a network mounted directory
when using -P. You can configure different settings by modifying some variables
in the script itself.
Using fai-kvm(1) you can start virtual machines which are connected
to one of the tap devices.
EOF
exit 0
}
mk_tap_devices() {
for i in $(eval echo {1..$tapnum}); do
[ -f /sys/class/net/tap$i/address ] && continue
ip tuntap add dev tap$i mode tap user $user
done
}
mk_bridge() {
if [ -d /sys/class/net/$brname ]; then
echo "Bridge $brname already exists. Aborting."
exit 4
fi
if [ $private -eq 0 ]; then
dhcpcd -k $netdev
ip addr flush $netdev # remove IP address of real nic
ip link set $netdev down
ip link set $netdev name r$netdev
brname=$netdev # use name of NIC for bridge
fi
ip link add name $brname type bridge
ip link set $brname up
if [ $private -eq 0 ]; then
ip link set r$netdev master $brname
ip link set r$netdev up
dhcpcd $netdev
else
ip addr add $brip/24 brd + dev $brname
fi
for i in $(eval echo {1..$tapnum}); do
[ -f /sys/class/net/tap$i/address ] || continue
ip link set tap$i master $brname # add device to the bridge
ip link set tap$i up
done
}
rm_bridge() {
for i in $(eval echo {1..$tapnum}); do
[ -f /sys/class/net/tap$i/address ] || continue
ip link set tap$i nomaster
ip link set tap$i down
ip tuntap del dev tap$i mode tap
done
if [ $private -eq 0 ]; then
brname=$netdev # use name of NIC for bridge
dhcpcd -k $netdev
ip link set r$netdev nomaster
fi
ip link set $brname down
ip addr flush $brname
ip link delete $brname type bridge
if [ $private -eq 1 ]; then
iptables -t nat -D POSTROUTING -o $netdev -j MASQUERADE
sysctl -w net.ipv4.ip_forward=0
else
ip link set r$netdev down
ip link set r$netdev name $netdev
ip link set $netdev up
dhcpcd $netdev
fi
exit 0
}
remove=0
private=1 # private network by default
while getopts Phri: opt ; do
case "$opt" in
r) remove=1;;
P) private=0 ;;
h) usage ;;
i) netdev=$OPTARG ;;
esac
done
shift $((OPTIND - 1))
if [ $(id -u) != "0" ]; then
echo "ERROR: You must run this program as root."
echo
usage
fi
if [ $remove -eq 1 ]; then
rm_bridge
fi
if [ -z "$1" ]; then
echo "ERROR: Please add a user name which will own the tap devices."
echo ""
usage
fi
user=$1
mk_tap_devices
mk_bridge
# enable forward IP and do NATing
if [ $private -eq 1 ]; then
sysctl -w net.ipv4.ip_forward=1
iptables -t nat -I POSTROUTING -o $netdev -j MASQUERADE
fi
# entry for /etc/network/interfaces:
# auto br0
# iface br0 inet static
# address 192.168.33.1
# netmask 255.255.255.0
# bridge_ports regex (tap).*
|
