#!/bin/sh
# 6in4.sh - IPv6-in-IPv4 tunnel backend
# Copyright (c) 2010-2012 OpenWrt.org

[ -n "$INCLUDE_ONLY" ] || {
        . /lib/functions.sh
        . /lib/functions/network.sh
        . ../netifd-proto.sh
        init_proto "$@"
}

proto_6in4_setup() {
        local cfg="$1"
        local iface="$2"
        local link="6in4-$cfg"

        local mtu ttl ipaddr peeraddr ip6addr ip6prefix tunnelid username password updatekey
        json_get_vars mtu ttl ipaddr peeraddr ip6addr ip6prefix tunnelid username password updatekey

        [ -z "$peeraddr" ] && {
                proto_notify_error "$cfg" "MISSING_ADDRESS"
                proto_block_restart "$cfg"
                return
        }

        ( proto_add_host_dependency "$cfg" 0.0.0.0 )

        [ -z "$ipaddr" ] && {
                local wanif
                if ! network_find_wan wanif || ! network_get_ipaddr ipaddr "$wanif"; then
                        proto_notify_error "$cfg" "NO_WAN_LINK"
                        return
                fi
        }

        proto_init_update "$link" 1
        proto_add_ipv6_route "::" 0

        [ -n "$ip6addr" ] && {
                local local6="${ip6addr%%/*}"
                local mask6="${ip6addr##*/}"
                [[ "$local6" = "$mask6" ]] && mask6=
                proto_add_ipv6_address "$local6" "$mask6"
        }

        [ -n "$ip6prefix" ] && proto_add_ipv6_prefix "$ip6prefix"

        proto_add_tunnel
        json_add_string mode sit
        json_add_int mtu "${mtu:-1280}"
        json_add_int ttl "${ttl:-64}"
        json_add_string local "$ipaddr"
        json_add_string remote "$peeraddr"
        proto_close_tunnel

        proto_send_update "$cfg"

        [ -n "$tunnelid" -a -n "$username" -a \( -n "$password" -o -n "$updatekey" \) ] && {
                [ "${#password}" == 32 -a -z "${password//[a-fA-F0-9]/}" ] || {
                        password="$(echo -n "$password" | md5sum)"; password="${password%% *}"
                }

                [ -n "$updatekey" ] && password="$updatekey"

                local url="http://ipv4.tunnelbroker.net/nic/update?username=$username&password=$password&hostname=$tunnelid"
                local try=0
                local max=3

                while [ $((++try)) -le $max ]; do
                        ( exec wget -qO/dev/null "$url" 2>/dev/null ) &
                        local pid=$!
                        ( sleep 5; kill $pid 2>/dev/null ) &
                        wait $pid && break
                done
        }
}

proto_6in4_teardown() {
        local cfg="$1"
}

proto_6in4_init_config() {
        no_device=1             
        available=1

        proto_config_add_string "ipaddr"
        proto_config_add_string "ip6addr"
        proto_config_add_string "ip6prefix"
        proto_config_add_string "peeraddr"
        proto_config_add_string "tunnelid"
        proto_config_add_string "username"
        proto_config_add_string "password"
        proto_config_add_string "updatekey"
        proto_config_add_int "mtu"
        proto_config_add_int "ttl"
}

[ -n "$INCLUDE_ONLY" ] || {
        add_protocol 6in4
}