#!/bin/sh

if [ -z "$UML" ] ; then UML=linux ; fi
ifconfig tun6to4 > /dev/null 2>&1 || { echo "Please initialize ipv6."; exit 1; }

TAP_DEV=$1
if [ -z "$TAP_DEV" ] ; then TAP_DEV=tap0 ; fi
ifconfig "$TAP_DEV" > /dev/null 2>&1 || { echo "Please initialize $TAP_DEV."; exit 1; }
UML_IPV4_ADDR=$2
UML_IPV4_GW_ADDR=192.168.1.1
if [ -z "$UML_IPV4_ADDR" ] ; then UML_IPV4_ADDR=192.168.1.2 ; fi

fail()
{
    echo "User mode linux startup failed."
    exit 1
}

run()
{
    run_cmd=$1
    shift
    echo "* $run_cmd $@"
    $run_cmd "$@" || fail
}

IPV4_ADDR=`ipv4-addr`
IPV6_ADDR=`ipv6-addr`
IPV6_PREFIX=$(echo $IPV6_ADDR | awk -F: 'BEGIN { OFS=":"; } {print $1,$2,$3; }')
UML_IPV6_NUM=$(echo $UML_IPV4_ADDR | awk -F. '{ print $4; }')
UML_IPV6_ADDR="$IPV6_PREFIX:1::$UML_IPV6_NUM"
UML_IPV6_GW_ADDR="$IPV6_PREFIX:1::1"
ROOT_FS=/usr/imgs/root_fs
COW_FILE=$ROOT_FS.cow_$UML_IPV4_ADDR
echo "IPv4 addr: $IPV4_ADDR"
echo "IPv6 addr: $IPV6_ADDR"
echo "UML IPv4 addr: $UML_IPV4_ADDR"
echo "UML IPv6 addr: $UML_IPV6_ADDR"
echo "UML IPv6 gateway addr: $UML_IPV6_GW_ADDR"
echo "TAP device: $TAP_DEV"
run rm -f $COW_FILE
run ifconfig "$TAP_DEV" "$UML_IPV4_GW_ADDR" up
echo 1 > /proc/sys/net/ipv4/ip_forward
run route add -host "$UML_IPV4_ADDR" dev "$TAP_DEV"
echo 1 > /proc/sys/net/ipv4/conf/$TAP_DEV/proxy_arp
run arp -Ds "$UML_IPV4_ADDR" eth0 pub
run ip -6 addr add $UML_IPV6_GW_ADDR/128 dev "$TAP_DEV"
run ip -6 route add $UML_IPV6_ADDR dev "$TAP_DEV"
echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
# Already set in /etc/rc.d/rc.local
# run iptables -t nat -F POSTROUTING
# run iptables -t nat -s 192.168.1.0/24 -d ! 192.168.1.0/24 -A POSTROUTING -j SNAT --to-source $IPV4_ADDR
xhost +$UML_IPV4_ADDR
$UML root=/dev/ubd0p1 con=port:9000 con0=fd:0,fd:1 ubd0=$COW_FILE,$ROOT_FS eth0=tuntap,$TAP_DEV ip=$UML_IPV4_ADDR ip6=$UML_IPV6_ADDR ip6gw=$UML_IPV6_GW_ADDR

ip -6 route del "$UML_IPV6_ADDR"
ip -6 addr del "$UML_IPV6_GW_ADDR/128" dev "$TAP_DEV"
arp -i eth0 -d "$UML_IPV4_ADDR" pub
route del -host "$UML_IPV4_ADDR"
ifconfig "$TAP_DEV" down