Synnefo

#!/bin/bash

# This is an example of a Ganeti kvm ifup script that configures network

# interfaces based on the initial deployment of the Okeanos project

TAP_CONSTANT_MAC=cc:47:52:4e:45:54 # GRNET in hex :-)

MAC2EUI64=/usr/bin/mac2eui64

NFDHCPD_STATE_DIR=/var/lib/nfdhcpd

function routed_setup_ipv4 {

	# get the link's default gateway

	gw=$(ip route list table $LINK | sed -n 's/default via \([^ ]\+\).*/\1/p' | head -1)

	# mangle ARPs to come from the gw's IP

	arptables -D OUTPUT -o $INTERFACE --opcode request -j mangle >/dev/null 2>&1

	arptables -A OUTPUT -o $INTERFACE --opcode request -j mangle --mangle-ip-s "$gw"

	# route interface to the proper routing table

	while ip rule del dev $INTERFACE; do :; done

	ip rule add dev $INTERFACE table $LINK

	# static route mapping IP -> INTERFACE

	ip route replace $IP table $LINK proto static dev $INTERFACE

	# Enable proxy ARP

	echo 1 > /proc/sys/net/ipv4/conf/$INTERFACE/proxy_arp

}

function routed_setup_ipv6 {

	# Add a routing entry for the eui-64

	prefix=$(ip -6 route list table $LINK | awk '/\/64/ {print $1; exit}')

	uplink=$(ip -6 route list table $LINK | sed -n 's/default via .* dev \([^ ]\+\).*/\1/p' | head -1)

	eui64=$($MAC2EUI64 $MAC $prefix)

	while ip -6 rule del dev $INTERFACE; do :; done

	ip -6 rule add dev $INTERFACE table $LINK

	ip -6 ro replace $eui64/128 dev $INTERFACE table $LINK

	ip -6 neigh add proxy $eui64 dev $uplink

	# disable proxy NDP since we're handling this on userspace

	# this should be the default, but better safe than sorry

	echo 0 > /proc/sys/net/ipv6/conf/$INTERFACE/proxy_ndp

}

# pick a firewall profile per NIC, based on tags (and apply it)

function routed_setup_firewall {

	ifprefix="synnefo:network:$INTERFACE_INDEX:"

	for tag in $TAGS; do

		case ${tag#$ifprefix} in

		protected)

			chain=protected

		;;

		unprotected)

			chain=unprotected

		;;

		limited)

			chain=limited

		;;

		esac

	done

	# Flush any old rules. We have to consider all chains, since

	# we are not sure the instance was on the same chain, or had the same

	# tap interface.

	for oldchain in protected unprotected limited; do

		iptables  -D FORWARD -o $INTERFACE -j $oldchain 2>/dev/null

		ip6tables -D FORWARD -o $INTERFACE -j $oldchain 2>/dev/null

	done

	if [ "x$chain" != "x" ]; then

		iptables  -A FORWARD -o $INTERFACE -j $chain

		ip6tables -A FORWARD -o $INTERFACE -j $chain

	fi

}

function routed_setup_nfdhcpd {

	umask 022

	cat >$NFDHCPD_STATE_DIR/$INTERFACE <<EOF

IP=$IP

MAC=$MAC

LINK=$LINK

HOSTNAME=$INSTANCE

TAGS="$TAGS"

EOF

}

if [ "$MODE" = "routed" ]; then

	# special proxy-ARP/NDP routing mode

	# use a constant predefined MAC address for the tap

	ip link set $INTERFACE addr $TAP_CONSTANT_MAC

	# bring the tap up

	ifconfig $INTERFACE 0.0.0.0 up

	# Drop unicast BOOTP/DHCP packets

	iptables -D FORWARD -i $INTERFACE -p udp --dport 67 -j DROP 2>/dev/null

	iptables -A FORWARD -i $INTERFACE -p udp --dport 67 -j DROP

	routed_setup_ipv4

	routed_setup_ipv6

	routed_setup_firewall

	routed_setup_nfdhcpd

elif [ "$MODE" = "bridged" ]; then

	ifconfig $INTERFACE 0.0.0.0 up

	brctl addif $BRIDGE $INTERFACE

	rm -f $NFDHCPD_STATE_DIR/$INTERFACE

fi