#!/bin/sh

die() {
    echo "$@" >&2
    exit 1
}

findcmd() {
    type "$1" > /dev/null 2>&1 || \
        die "Couldn't find $1, please install ${2:-it} or fix your path."
}

first() {
    echo "$1"
}

nl='
'

usage="Usage: $0 (start|stop)"
debuglevel=${AHCP_DEBUG_LEVEL:-1}

if [ $debuglevel -ge 2 ]; then
    env | grep ^AHCP
fi

[ $debuglevel -ge 3 ] && set -x

interfaces="$AHCP_INTERFACES"
if [ -z "$interfaces" ]; then die "No interface set"; fi
first_if=$(first $interfaces)

ipv4_address="$AHCP_IPv4_ADDRESS"
ipv6_address="$AHCP_IPv6_ADDRESS"

platform=`uname`

if [ "$platform" = "Linux" ]; then

    findcmd ip iproute

    (ip -6 addr show dev lo | grep -q 'inet6') || \
	die "No IPv6 address on lo, please modprobe ipv6"

    add_ipv6_address() {
	ip -6 addr add "$2/$3" dev "$1"
    }

    del_ipv6_address() {
	ip -6 addr del "$2/$3" dev "$1"
    }

    add_ipv4_address() {
	ip addr add "$2/$3" dev "$1"
    }

    del_ipv4_address() {
	ip addr del "$2/$3" dev "$1"
    }
else

    add_ipv6_address() {
	ifconfig "$1" inet6 "$2/$3"
    }

    del_ipv6_address() {
	ifconfig "$1" inet6 "$2/$3" delete
    }

    add_ipv4_address() {
	ifconfig "$1" inet "$2/$3"
    }

    del_ipv4_address() {
	ifconfig "$1" inet "$2/$3" delete
    }

fi

add_addresses() {
    for i in $interfaces; do
        for a in $ipv6_address; do
            add_ipv6_address $i $a 128
        done
        for a in $ipv4_address; do
            add_ipv4_address $i $a 32
        done
    done
}

del_addresses() {
    for i in $interfaces; do
        for a in $ipv6_address; do
            del_ipv6_address $i $a 128
        done
        for a in $ipv4_address; do
            del_ipv4_address $i $a 32
        done
    done
}

nameserver_start() {
    if [ ! -z "$AHCP_NAMESERVER" ]; then
        info=''
        for n in $AHCP_NAMESERVER; do
            info="${info}nameserver $n$nl"
        done
        if [ -x /sbin/resolvconf ]; then
            echo -n "$info" | /sbin/resolvconf -a "$first_if"
        else
            mv /etc/resolv.conf /etc/resolv.conf.orig
            echo -n "$info" > /etc/resolv.conf
        fi
    fi
}

nameserver_stop() {
    if [ ! -z "$AHCP_NAMESERVER" ]; then
        if [ -x /sbin/resolvconf ]; then
            /sbin/resolvconf -d "$first_if"
        else
            mv /etc/resolv.conf.orig /etc/resolv.conf
        fi
    fi
}

case $1 in
    start)
        add_addresses
        nameserver_start
        ;;
    stop)
        nameserver_stop
        del_addresses
        ;;
    *)
        die "$usage"
        ;;
esac

[ -x /etc/ahcp/ahcp-local.sh ] && /etc/ahcp/ahcp-local.sh $1

exit 0