Synnefo » snf-network

#!/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 clear_routed_setup_ipv4 {

 arptables -D OUTPUT -o $INTERFACE --opcode request -j mangle

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

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

}

function clear_routed_setup_ipv6 {

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

}

function clear_routed_setup_firewall {

  for oldchain in protected unprotected limited; do

    iptables  -D FORWARD -o $INTERFACE -j $oldchain

    ip6tables -D FORWARD -o $INTERFACE -j $oldchain

  done

}

function clear_ebtables {

  TAP=$INTERFACE

  FROM=FROM${TAP^^}

  TO=TO${TAP^^}

  ebtables -D INPUT -i $TAP -j $FROM

  ebtables -D FORWARD -i $TAP -j $FROM

  ebtables -D FORWARD -o $TAP -j $TO

  ebtables -D OUTPUT -o $TAP -j $TO

  ebtables -X $FROM

  ebtables -X $TO

}

function routed_setup_ipv4 {

	# mangle ARPs to come from the gw's IP

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

	# route interface to the proper routing table

	ip rule add dev $INTERFACE table $TABLE 

	# static route mapping IP -> INTERFACE

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

	# 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=$SUBNET6

	uplink=$PUBLIC_VLAN

	eui64=$($MAC2EUI64 $MAC $prefix)

	ip -6 rule add dev $INTERFACE table $TABLE

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

	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

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

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

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

	fi

}

function setup_ebtables {

  TAP=$INTERFACE

  FROM=FROM${TAP^^}

  TO=TO${TAP^^}

  ebtables -N $FROM

  # do not allow changes in ip-mac pair

  if [ -n "$IP"]; then

    ebtables -A $FROM --ip-source \! $IP -p ipv4 -j DROP

  fi

  ebtables -A $FROM -s \! $MAC -j DROP

  ebtables -A FORWARD -i $TAP -j $FROM

  ebtables -N $TO

  ebtables -A FORWARD -o $TAP -j $TO

  #accept dhcp responses from host (nfdhcpd)

  ebtables -A $TO -p ipv4 --ip-protocol=udp  --ip-destination-port=68 -j ACCEPT

  # allow only packets from the same mac prefix

  ebtables -A $TO -s \! $MAC/$MAC_MASK -j DROP

  if [ $ENABLE_MASQ -a -n "$GATEWAY" ]; then

    # allow packets from/to router (for masquerading)

    ebtables -A $TO -s $PUBLIC_MAC -j ACCEPT

    ebtables -A INPUT -i $TAP -j $FROM

    ebtables -A OUTPUT -o $TAP -j $TO

  fi

}

function setup_nfdhcpd {

	umask 022

  FILE=$NFDHCPD_STATE_DIR/$INTERFACE

  #IFACE is the interface from which the packet seems to arrive

  #needed in bridged mode where the packets seems to arrive from the

  #bridge and not from the tap

	cat >$FILE <<EOF

INDEV=$1

IP=$IP

MAC=$MAC

HOSTNAME=$INSTANCE

TAGS="$TAGS"

GATEWAY=$GATEWAY

SUBNET=$SUBNET 

GATEWAY6=$GATEWAY6 

SUBNET6=$SUBNET6 

EUI64=$($MAC2EUI64 $MAC $SUBNET6 2>/dev/null)

EOF

}

DEFAULT=/etc/default/snf-network

source $DEFAULT

source $CONF

INFRA=$STATE_DIR/infra

source $INFRA

clear_routed_setup_ipv4 > /dev/null 2>&1

clear_routed_setup_ipv6 > /dev/null 2>&1

clear_routed_setup_firewall > /dev/null 2>&1

clear_ebtables > /dev/null 2>&1

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

  TABLE=$LINK

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

	routed_setup_ipv4 > /dev/null 2>&1

	routed_setup_ipv6 > /dev/null 2>&1

	routed_setup_firewall > /dev/null 2>&1

	setup_nfdhcpd $INTERFACE

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

	ifconfig $INTERFACE 0.0.0.0 up

	brctl addif $BRIDGE $INTERFACE

	setup_nfdhcpd $BRIDGE

  if [ $ENABLE_EBTABLES -a "$TYPE" = "private" ]; then

    setup_ebtables > /dev/null 2>&1

  fi

fi