Scripts to support IPv6 networking in Debian pre-boot (initramfs) environment

debian-initramfs-ipv6-hook-script

#!/bin/sh
# Script to be placed in /etc/initramfs-tools/hooks/ipv6

PREREQ=""

prereqs()
{
    echo "$PREREQ"
}

case $1 in
prereqs)
    prereqs
    exit 0
    ;;
esac

if [ ! -x /bin/ip ]; then
    exit 0
fi

. /usr/share/initramfs-tools/hook-functions

copy_exec /bin/ip

debian-initramfs-ipv6-premount-script

#!/bin/sh
# Script to be placed in /etc/initramfs-tools/scripts/init-premount/ipv6

PREREQ=""
prereqs()
{
	echo "$PREREQ"
}

parse_options()
{
        local v6opts
        v6opts="$1"
	echo "v6opts='$v6opts'"

	addr=""
	gw=""
	iface=""
	accept_ra=0
	forwarding=0

        local IFS=","
        for x in $v6opts; do
                case $x in
                addr=*)
                        addr=${x#addr=}
                        ;;
                gw=*)
                        gw=${x#gw=}
                        ;;
                iface=*)
                        iface=${x#iface=}
                        ;;
                accept_ra=*)
                        iface=${x#accept_ra=}
                        ;;
                ll=*)
                        ll=${x#ll=}
                        ;;
                forwarding=*)
                        forwarding=${x#forwarding=}
                        ;;
		esac
        done
	if [ ! -d /proc/sys/net/ipv6/conf/${iface} ]; then
	    echo "IPv6: Interface ${iface} not found, sorry."
	    return 0
	fi
	echo -ne "IPv6 address: ${addr}\t"
	echo "IPv6 gateway: ${gw}"
	echo -ne "IPv6 iface: ${iface}\t"
        echo "IPv6 link-local address: ${ll}"
	echo ${accept_ra} > /proc/sys/net/ipv6/conf/${iface}/accept_ra
	echo ${forwarding} > /proc/sys/net/ipv6/conf/${iface}/forwarding
	if [ "x${ll}" != "" ]; then
	    /bin/ip -6 address flush dev ${iface}
	    /bin/ip -6 address add ${ll} scope link dev ${iface}
	fi
	/bin/ip link set ${iface} up
	/bin/ip -6 address add ${addr} dev ${iface}
	if [ "x${gw}" != "" ]; then
	    /bin/ip -6 route del default
	    /bin/ip -6 route add default via ${gw}
	fi
#	/bin/ip -6 addr show dev ${iface}
        return 0
}

case $1 in
# get pre-requisites
prereqs)
	prereqs
	exit 0
	;;
esac

for x in $(cat /proc/cmdline); do
	case ${x} in
	ipv6=*)
		opt="${x#ipv6=}"
		modprobe ipv6
		# syntax: ipv6=addr=<address>/<netmask>,gw=<gateway>,iface=<interface>,forwarding=<0/1>,accept_ra=<0/1/2>
		# colons are not used as delimiters due to them being in use in ipv6 addrs
		parse_options ${opt}
		;;
	esac
done