#!/bin/sh
. /lib/functions/network.sh

dlog() {
    logger -s -p 6 -t "pppoe-check" "$@"
}

ifup_and_logger()
{
    [ -z  $1 ] && return;
    logger -p warn -t "pppoe-check" "wan restart because no response from pppoe server."
    ifup $1;
}

check_ppp_dest_peer()
{
    network_is_autostart vpn || return

    network_is_up vpn || (ifup_and_logger vpn ; return)

    network_is_pending && (ifup_and_logger vpn ; return)

    network_get_device vpn_device vpn

    [ -z $vpn_device ] && return;

    [ $vpn_device != "pptp-vpn" -a $vpn_device != "l2tp-vpn" ] && return;
    
    dest_peer_ip=`ifconfig $vpn_device  2>/dev/null |awk -F ' ' '/P-t-P/ {print substr($3, 7);}'`

    [ -z $dest_peer_ip ] &&  return;

    ping -c 1 -w 3 -q "$dest_peer_ip" 2>&1 >/dev/null && return   
       
    ifup_and_logger vpn
}

check_gateway()
{
    local host_list=
    if [ "$1" == "CN" ]; then
	host_list=$(uci -q get system.netdt.cn_domain)
    else
	host_list=$(uci -q get system.netdt.world_domain)
    fi
    for host in $host_list; do
	ping -c 1 -w 3 -q "$host" &> /dev/null && return 0;
    done
    return 1;
}

check_dns()
{
    local host_list=
    local dns_list=
    if [ "$1" == "CN" ]; then
	host_list=$(uci -q get system.netdt.cn_domain)
	dns_list=$(uci -q get system.netdt.cn_dns)
    else
	host_list=$(uci -q get system.netdt.world_domain)
	dns_list=$(uci -q get system.netdt.world_dns)
    fi
    # then check dns
    for ns in $dns_list; do
	for th in $host_list; do
	    /usr/sbin/nslookupc "$th" "$ns" 5 && return 0
	done
    done
    return 1;
}

LOCKFILE=/var/lock/pppoe-check
trap "lock -u ${LOCKFILE}; exit" INT TERM EXIT
if ! lock -n $LOCKFILE; then
    dlog "pppoe-check already running, skip this sync"
    trap '' EXIT
    exit 0
fi
cc=$(/usr/sbin/bdata get CountryCode)
cc=${cc:-CN}
check_ppp_dest_peer

check_gateway $cc && exit 0

# disable custom dns check since it dose not anyway.
#check_dns $cc && exit 0;

ifup_and_logger wan