#!/bin/sh
# 2020-06-13, Nico Schottelius
# See https://ungleich.ch/u/products/viirb-ipv6-box/

if [ $# -ne 2 ]; then
    echo "$0 viirb-ip-address viirb-id"
    echo "    viirb-ip-address: where to find the viirb"
    echo "    viirb-id: number in decimal format"
    exit 1
fi


set -x
viirb_ip=$1; shift
id=$1; shift
hex_id=$(printf "%0.2x\n" "$id")
viirb_hostname=viirb${id}

prefix_base=2a0a:e5c1:3
my_prefix=${prefix_base}${hex_id}
my_network=${my_prefix}::/48

my_wireguard_ip=${my_prefix}::42
my_lan_ip=${my_prefix}:cafe::42
my_wifi_ip=${my_prefix}:7ea::42

# wireguard
private_key=$(wg genkey)
public_key=$(echo $private_key | wg pubkey)

vpn_endpoint_host=vpn-2a0ae5c1300.ungleich.ch
vpn_endpoint_pubkey=ft68G2RID7gZ6PXjFCSCOdJ9yspRg+tUw0YrNK9cTxE=

ping -c3 ${viirb_ip}
if [ $? -ne 0 ]; then
    echo "Cannot reach ${viirb_ip}, aborting"
    exit 1
fi

cat <<EOF | ssh -t "root@${viirb_ip}"
set -x
# Setup lan to also retrieve an ip address via dhcp

# This stays in the final setup
uci set network.lan.proto='dhcp'
uci delete network.lan.ipaddr
uci delete network.lan.netmask

# The IPv6 lan configuration
uci set network.lanv6=interface
uci set network.lanv6.proto='static'
uci set network.lanv6.ip6addr='${my_lan_ip}/64'
uci set network.lanv6.ifname='br-lan'

# LAN / Router advertisements / DHCP
# DHCP: we are not authoratative
uci delete dhcp.@dnsmasq[0].authoritative
uci delete dhcp.lan.dhcpv6
uci delete dhcp.lan.start
uci delete dhcp.lan.limit
uci delete dhcp.lan.leasetime

# Do not announce ULA - we have GUA
uci delete network.globals.ula_prefix

# This is configuring the dhcp IPv4 client
uci set dhcp.lan=dhcp

# Setup Router Advertisements
uci set dhcp.lan.interface='lanv6'
uci set dhcp.lan.ra='server'
uci set dhcp.lan.dynamicdhcp='0'

# Fix DNS: make dnsmasq NOT use a resolv.conf
# so that it only reads from our servers with DNS64 enabled
uci set dhcp.@dnsmasq[0].noresolv='1'

# Fix DNS: make the OS use the locally provided DNS servers
# otherwise the VPN tunnel cannot be established
dhcp.@dnsmasq[0].localuse='0'

# DNS upstream over VPN gives DNS64
uci delete dhcp.@dnsmasq[0].server
uci add_list dhcp.@dnsmasq[0].server='2a0a:e5c0:0:a::a'
uci add_list dhcp.@dnsmasq[0].server='2a0a:e5c0:2:a::a'

# wifi ip address
uci set network.wifi=interface
uci set network.wifi.proto='static'
uci set network.wifi.ip6addr='${my_wifi_ip}/64'

# Wifi configuration
uci set wireless.radio0=wifi-device
uci set wireless.radio0.type='mac80211'
uci set wireless.radio0.hwmode='11g'
uci set wireless.radio0.path='platform/10300000.wmac'
uci set wireless.radio0.htmode='HT40'
uci set wireless.radio0.country='CH'
uci set wireless.radio0.channel='6'

uci set wireless.default_radio0=wifi-iface
uci set wireless.default_radio0.device='radio0'
uci set wireless.default_radio0.mode='ap'
uci set wireless.default_radio0.encryption='psk2'
uci set wireless.default_radio0.key='iloveipv6'
uci set wireless.default_radio0.ssid='IPv6 everywhere ${viirb_hostname}'
uci set wireless.default_radio0.network='wifi'

# Wifi / Router advertisements
uci set dhcp.wifi=dhcp
uci set dhcp.wifi.interface='wifi'
uci set dhcp.wifi.ra='server'
uci set dhcp.wifi.dynamicdhcp='0'

# Ensure it is not disabled
uci delete wireless.radio0.disabled

# This is temporary - keeping it until the config process is through
# Probably not needet - we can connect to the final IPv6 address!
# This code commented out == The address vanishes due to above reconfiguration
# uci set network.lanv4temp=interface
# uci set network.lanv4temp.proto='static'
# uci set network.lanv4temp.ifname='br-lan'
# uci set network.lanv4temp.ipaddr='192.168.61.1'
# uci set network.lanv4temp.netmask='255.255.255.0'

uci commit

# Need to reboot to restore /etc/resolv.conf
reboot

#/etc/init.d/network restart
EOF

# ensure viirb is back
# ensure viirb network is up and running - bridge takes a bit of time
# ensure viirb gives out ipv6 address
# Found: 30s is not enough for full reconfiguration
echo "Public VPN key: ${id} ${public_key}"
sleep 60

# change to ipv6
viirb_ip=${my_lan_ip}

ping -c5 ${viirb_ip}

cat <<EOF | ssh -t "root@${viirb_ip}"
ping -c5 ungleich.ch || exit 1

# update the sources
opkg update

# install wireguard + gui
opkg install wireguard
opkg install luci-app-wireguard

# VPN / Wireguard
uci set network.wg0=interface
uci set network.wg0.proto='wireguard'
uci set network.wg0.private_key='${private_key}'
uci set network.wg0.listen_port='51820'
uci set network.wg0.addresses='${my_wireguard_ip}/64'

if ! uci get network.@wireguard_wg0[0]; then
   uci add network wireguard_wg0
fi

uci set network.@wireguard_wg0[0]=wireguard_wg0
uci set network.@wireguard_wg0[0].persistent_keepalive='25'
uci set network.@wireguard_wg0[0].public_key='${vpn_endpoint_pubkey}'
uci set network.@wireguard_wg0[0].description='IPv6VPN.ch by ungleich'
uci set network.@wireguard_wg0[0].allowed_ips='::/0'
uci set network.@wireguard_wg0[0].endpoint_host='${vpn_endpoint_host}'
uci set network.@wireguard_wg0[0].endpoint_port='51820'
uci set network.@wireguard_wg0[0].route_allowed_ips='1'

uci set system.@system[0].hostname="${viirb_hostname}"

# Firewall configuration
if ! uci show firewall | grep "name='Allow-SSH'"; then
uci add firewall rule
uci set firewall.@rule[-1].name='Allow-SSH'
uci set firewall.@rule[-1].src='wan'
uci set firewall.@rule[-1].dest='lan'
uci set firewall.@rule[-1].proto='tcp'
uci set firewall.@rule[-1].dest_port='22'
uci set firewall.@rule[-1].target='ACCEPT'
fi

if ! uci show firewall | grep "name='Allow-HTTPS'"; then
uci add firewall rule
uci set firewall.@rule[-1].name='Allow-HTTPS'
uci set firewall.@rule[-1].src='wan'
uci set firewall.@rule[-1].dest='lan'
uci set firewall.@rule[-1].proto='tcp'
uci set firewall.@rule[-1].dest_port='443'
uci set firewall.@rule[-1].target='ACCEPT'
fi

if ! uci show firewall | grep "name='Allow-HTTP'"; then
uci add firewall rule
uci set firewall.@rule[-1].name='Allow-HTTP'
uci set firewall.@rule[-1].src='wan'
uci set firewall.@rule[-1].dest='lan'
uci set firewall.@rule[-1].proto='tcp'
uci set firewall.@rule[-1].dest_port='80'
uci set firewall.@rule[-1].target='ACCEPT'
fi

# Add interfaces to the right network zone
uci set firewall.@zone[0].network='lan lanv6 wifi'
uci set firewall.@zone[1].network='wg0'

uci commit

reboot
EOF

echo "Wireguard public key and id: ${id} ${public_key}"
echo ${public_key} > ${viirb_hostname}.public_key